It's the dead of winter, so what's up with the summer-like surge in gasoline prices?
Local fuel costs have jumped to their highest levels in more than a year, despite stable national demand for gasoline.
Despite the run-up, few analysts foresee a return to the record fuel and oil prices of 2008, and a key federal energy-forecasting agency predicted that average gasoline prices would stay under $3 a gallon nationwide in 2010.
That mid-range forecast might be of little comfort to consumers facing higher fuel budgets today. Since Dec. 14, fuel prices have gained 12 cents per gallon on average in Nevada, going from $2.73 to $2.85 on Thursday, according to travel club AAA. The last time you paid $2.85 for a gallon of unleaded gasoline was in October 2008. Back then, that price felt like a bargain, given that fuel prices had hit a record $4.28 a gallon in Las Vegas just four months earlier. Through late 2008 and into early 2009, gasoline prices continued to fall; a gallon of fuel averaged $2.35 nationwide in 2009, according to numbers from the U.S. Energy Information Administration.
Knowing what's behind the recent increase requires figuring out what's happening with crude oil, because petroleum makes up more than half a gallon of gasoline. Oil prices rose from just below $70 a barrel in mid-December to more than $83 a barrel in early January, and that's why you're paying more for fuel these days.
Credit a weak dollar and investor exuberance for January's higher oil prices. Crude is traded globally in U.S. dollars, so a softer dollar means buyers need more cash to purchase a barrel of petroleum. As for investors, they're snapping up oil futures on a bet that an improving economy will goose energy consumption by the end of the year and into 2011.
The jump in fuel prices has real implications for economic vitality: Every 10-cent move upward in gasoline prices costs consumers almost $14 billion more in annual fuel expenses, wrote Peter Boockvar, an analyst with New York trading firm Miller Tabak & Co., last week.
Higher fuel prices also affect local tourists.
Visitors chartering limousines and buses already pay a $3-per-hour fuel surcharge set by the Nevada Taxicab Authority. Alan Waxler, president and chief executive officer of local charter-transportation company Alan Waxler Group, said he fears the authority could bump that surcharge to $4 if fuel prices keep rising. The company has begun replacing its fleet with hybrids and vehicles that run on biodiesel fuel to cushion the blow of higher gasoline prices.
"We try to be as thrifty and efficient as we can with the fuel we utilize. That's really the only thing we can do," Waxler said.
Businesses and consumers might not see much price relief in the first half of 2010. Gasoline prices traditionally surge in the spring, as oil refineries shut down to switch from winter fuel blends to summer recipes, and travelers hit the road for warm-weather vacations. Denton Cinquegrana, West Coast markets editor with the Oil Price Information Service in New Jersey, said he wouldn't be surprised to see the national average, currently at $2.75, hover near $3 per gallon in the spring. Nevada's average typically runs 10 cents to 12 cents above national levels.
AAA doesn't project price trends, but Michael Geeser, a spokesman for AAA Nevada, said history shows that motorists should count on an uptick in fuel prices from spring to mid-summer.
"I don't think anybody's predicting records will be broken this year, but given that we're starting a dollar ahead of where we were last year, prices could get steep toward summer," Geeser said.
The Energy Information Administration predicts that oil prices will average $80 a barrel in 2010, with an average of $2.84 for a gallon of gasoline.
Few observers expect oil prices to jump substantially from their current levels by the end of 2010. Analysts say crude remains overpriced when weighed against going rates for other commodities, and today's supply-demand balance just doesn't warrant much-higher oil prices.
Cinquegrana said he believes oil should be trading in the mid-$60s, where it was last year. That cost would translate into gasoline prices ranging from 35 cents to 60 cents below today's rates, he said.
"Demand, for lack of a better term, is in the toilet," Cinquegrana said. "I don't think the economy has gotten that much better. There are still a lot of people out of work, and demand has been in the tank for much of the last year." The fleet of cars on the road today is also more fuel-efficient than it was a few years ago, and that curbs demand for fuel. Plus, oil refiners are operating their plants at just 80 percent of production capacity, so there's plenty of room to expand output if demand rises, Cinquegrana added.
Phil Flynn, an energy analyst with PFGBest, wrote in a Wednesday report that over the long range, oil prices should drop to around $44 a barrel.
But John Felmy, chief economist with the American Petroleum Institute, said he believes oil is priced right for now, mostly because worldwide inventories of crude remain steady. For oil to be overvalued, you'd need to see big stockpiles of crude build up globally, and that just hasn't happened, he said. Also, the International Energy Agency predicts that, as economies around the world continue to recover from the recession, global demand for crude will rise in coming years to a level greater than consumption before the downturn, so it's not unreasonable to anticipate higher crude prices.
Still, petroleum costs have eased off their winter run-up in the last few days. They closed Thursday at $79.39, down 26 cents from Wednesday and noticeably below the $83.18 they reached on Jan. 6.
Flynn's explanation for the price decline starts with China, the growth machine that's supposed to absorb every spare drop of global crude to power its hungry economy. The Chinese government said earlier last week that the country's banks must boost their cash-reserve requirements, which could mean less money for economic expansion there. With China "ready to let some air out of its expanding bubble," oil supplies might not be as tight as analysts expected, so investors have tweaked their oil bets downward, Flynn said.
What's more, a larger meltdown in the prices of commodities ranging from precious metals to corn also affected oil prices, Flynn said. And U.S. supplies of refined petroleum products such as heating oil and diesel fuel rose 3.6 million barrels from Jan. 1 to Jan. 8, while gasoline inventory jumped 6.8 million barrels in the same week. Crude-oil stores increase 1.2 million barrels. The result? "A total bearish smackdown," Flynn said.
In addition to the strength of the dollar and the health of the economy, expect geopolitical issues to affect gasoline prices in 2010. Possible sanctions against Iran for its efforts to go nuclear and civil unrest in Nigeria could pinch oil supplies. The hurricane season, which runs from May to November, could disrupt refining and importing activity along the U.S. Gulf Coast; early estimates from Colorado State University's hurricane-forecast team call for an above-average year for storm activity.
Even the upcoming Winter Olympics could affect fuel prices. Geeser said consumers tend to stay in and cluster around the television during the games, and that cocooning could mean a drop in demand that brings lower oil and fuel prices in a month or so.
Contact reporter Jennifer Robison at jrobison @reviewjournal.com or 702-380-4512.
Thursday, May 13, 2010
Increase in gas, CNG prices resented
Showing great resentment against the government announcement of an increase in prices of natural gas and CNG, people from cross section of life demanded of the federal government to withdraw its decision, which would add to the miseries of the already inflation-hit people.
The government ‘as a New Year gift’, announced an increase in price of CNG in terms of kilogram by Rs5.57 to Rs55.30 from Rs49.73 per kg in Potohar region (Rawalpindi, Islamabad and Gujar Khan). On the other hand for domestic consumers the tariff of gas for those who consume 50 M3 per month has been increased to Rs95.01 per MMBTU per month from Rs80.65 per MMBTU per month; for those who consume 50 to 100 M3 per month the tariff has been increased to Rs99.48 per MMBTU per month from Rs84.45 per MMBTU. Likewise the consumers who fall under second slab of over 200 M3 to 300 M3 per month the tariff would now be Rs383.42 per MMBTU as against Rs325.48 per MMBTU, and so on. Similarly the rate of other slabs has also been increased not only for domestic gas consumers, but also for commercial consumers as well as CNG stations, fertilisers factories, independent power producers and captive powers, cement factories.
Talking to ‘The News’ a number of people including Abid Hussain Shah, who works in a private company said that with each passing day the government is burdening people with raising prices of daily use commodities. “First it was ‘atta’ followed by sugar and now the price of gas has been increased for general public. “We can’t understand what is this government trying to do? With the new increase in Sui gas bills people like me will not be able to pay their gas bills. I can’t understand how will we survive in this country,” he bemoaned.
On the other hand, Punjab Urban Transport Owners Association General Secretary Muhammad Arshad Niazi announced an increase of Rs5 in stop-to-stop fares of local transport from Rs10 to Rs15. Talking to ‘The News’ he said that they cannot run the transport on existing fares and they were compelled to increase the fares.
Rawalpindi-Islamabad Transport Union President Malik Muhammad Sultan also supported the views of Punjab Urban Transport Owners Association saying the transporters throughout Punjab have started charging Rs15 as stop-to-stop fare against Rs10, therefore they would also charge the same fare. He said that 100% Suzuki pickups and around 50% wagons run on CNG and they cannot afford to run their vehicles by charging existing fares.
However, District Regional Transport Authority (DRTA) Secretary Muhammad Asif Chaudhry made it clear that the transporters cannot increase the public transport fares on their own. “The government will take strict action against the transporters, if they will increase the fares on their own,” he added.
Dr. Uzma Irfan, a resident of B-block, Satellite Town, said that the government is not thinking about the plight of a common man and is testing their patience. People are already facing high prices of daily use commodities and now the hike in price of gas and CNG will also increase their woes.
Rahat Abbasi, a cart pusher in Raja Bazaar said that he earns around Rs300 per day and lives in a rented room along with his family and was paying a monthly rent of Rs2,000 rent per month. “Two of my kids go to school and in prevailing circumstances when the prices of each and every commodity are touching the sky, the new price of gas will be too much for people like me, I am worried as how will I be able to pay my monthly gas bill?,” he added.
Salma Usman, a housewife, said the government was creating difficulties for them but they were not coming on roads. “If public will not come on roads to mark their protest against the present situation, the government will continue creating more and more troubles for them.
Talking to ‘The News’ Tasleem Abbasi said that despite increasing gas prices, the government has failed to improve gas pressure.
The government ‘as a New Year gift’, announced an increase in price of CNG in terms of kilogram by Rs5.57 to Rs55.30 from Rs49.73 per kg in Potohar region (Rawalpindi, Islamabad and Gujar Khan). On the other hand for domestic consumers the tariff of gas for those who consume 50 M3 per month has been increased to Rs95.01 per MMBTU per month from Rs80.65 per MMBTU per month; for those who consume 50 to 100 M3 per month the tariff has been increased to Rs99.48 per MMBTU per month from Rs84.45 per MMBTU. Likewise the consumers who fall under second slab of over 200 M3 to 300 M3 per month the tariff would now be Rs383.42 per MMBTU as against Rs325.48 per MMBTU, and so on. Similarly the rate of other slabs has also been increased not only for domestic gas consumers, but also for commercial consumers as well as CNG stations, fertilisers factories, independent power producers and captive powers, cement factories.
Talking to ‘The News’ a number of people including Abid Hussain Shah, who works in a private company said that with each passing day the government is burdening people with raising prices of daily use commodities. “First it was ‘atta’ followed by sugar and now the price of gas has been increased for general public. “We can’t understand what is this government trying to do? With the new increase in Sui gas bills people like me will not be able to pay their gas bills. I can’t understand how will we survive in this country,” he bemoaned.
On the other hand, Punjab Urban Transport Owners Association General Secretary Muhammad Arshad Niazi announced an increase of Rs5 in stop-to-stop fares of local transport from Rs10 to Rs15. Talking to ‘The News’ he said that they cannot run the transport on existing fares and they were compelled to increase the fares.
Rawalpindi-Islamabad Transport Union President Malik Muhammad Sultan also supported the views of Punjab Urban Transport Owners Association saying the transporters throughout Punjab have started charging Rs15 as stop-to-stop fare against Rs10, therefore they would also charge the same fare. He said that 100% Suzuki pickups and around 50% wagons run on CNG and they cannot afford to run their vehicles by charging existing fares.
However, District Regional Transport Authority (DRTA) Secretary Muhammad Asif Chaudhry made it clear that the transporters cannot increase the public transport fares on their own. “The government will take strict action against the transporters, if they will increase the fares on their own,” he added.
Dr. Uzma Irfan, a resident of B-block, Satellite Town, said that the government is not thinking about the plight of a common man and is testing their patience. People are already facing high prices of daily use commodities and now the hike in price of gas and CNG will also increase their woes.
Rahat Abbasi, a cart pusher in Raja Bazaar said that he earns around Rs300 per day and lives in a rented room along with his family and was paying a monthly rent of Rs2,000 rent per month. “Two of my kids go to school and in prevailing circumstances when the prices of each and every commodity are touching the sky, the new price of gas will be too much for people like me, I am worried as how will I be able to pay my monthly gas bill?,” he added.
Salma Usman, a housewife, said the government was creating difficulties for them but they were not coming on roads. “If public will not come on roads to mark their protest against the present situation, the government will continue creating more and more troubles for them.
Talking to ‘The News’ Tasleem Abbasi said that despite increasing gas prices, the government has failed to improve gas pressure.
Summer Gas Prices to Spike but Not to Record Highs
Global crude oil prices hit an 18-month high as the average price of a gallon of regular gasoline reached $2.85, the highest it's been since October 2008. This is both good news and bad news. The bad news is that the economic recovery could slow if gas prices rise too fast. The good news, though, is that the United States is almost certainly not headed toward another summer of $4-a-gallon gas .
Powerful Trading Strategies
Powerful trading strategies are investment trading plans designed to maximize risk/reward ratios. This is because the strategies are both profitable and can be replicated over and over again in a risk-averse way. Powerful trading strategies can be short, intermediate or long term in nature. The point is that powerful trading strategies consist of low cost, low risk, robust solutions to investing..Risk and Reward
Most trading failures are the result of a trader never understanding that his expectations of return resulted in the implicit acknowledgment of more risk than the trader intended. Risk should be measured by back-testing under all market conditions under a variety of time periods using real data. Traders should consider that the greatest risk in a trade occurs at the beginning of a trade. Even if the chance of a stock rise or fall is a 50/50 wager once a protective stop is added, the chance of success necessarily falls because risk is no longer unlimited. That is fine as long as the trader goes on to understand that he or she can now absorb more losses than the trader who wants more wins, but will eventually fall prey to a single devastating loss. Thus, traders who make money are traders who can extract a maximum amount of gain from a winning trade adjusted for risk.
Earnings Growth, Technical Analysis
Find companies that have at least three quarters of increasing growth, increasing earnings and increased ownership by mutual funds. Buy the stock of these companies when the 50-day moving average crosses above the 200-day moving average. Sell the stock when the stock drops below the 200-day moving average. This is called a dual moving average trading strategy. Moving average is the closing price of the stock averaged each day for the number of days in the moving average. Earnings are what drives stock prices for intermediate and long term trades. Back-test moving averages to explore different levels of success. Some traders employ a triple moving average strategy with the third moving average being a very long term measure.
Use Volume Explosions
Choose stocks with a history of increasing earnings. Note if the stock is near or above the 50-day moving average. If trading volume increases by 300 percent, and the price increases, buy the stock. The volume increase indicates that a large institution has completed its buying program, and there is now less stock available for purchase. Volume and price gains will continue for a few days. Do not chase the stock as it will probably trade back down for a few days in reaction to the swift price move. Buy when the stock moves out of its price retrenchment. Sell when the stock falls below its 200-day moving average
Natural Gas Trading Strategies
Natural gas trading strategies are determined by two forces: the securities used to trade natural gas and the seasonal and long-term trends that create varying prices in the marketplace. Natural gas strategies trade with regard to the value of other energy products as well. Each strategy offers profit opportunities as long as proper risk management and protective stops are employed.
Natural Gas Trading Opportunities
Natural gas can be traded in the futures market as a commodity. Using the futures markets provides great leverage, especially when used to trade major trends. Natural gas can also be traded as an exchange-traded fund, which is a stock that owns only natural gas companies. Individual companies can also be purchased both as a long-term provider of natural gas and for the transmission of natural gas through a pipeline strategy. These stocks often pay handsome dividends and are an income play.
Investors can also invest in the exploration of natural gas. Stocks are valued according to the expected sales of the inventory of natural gas they control. All of these possibilities are found in the investment arena. Natural gas is usually traded using one of three strategies: the relative value of natural gas to oil and other energy products; the seasonal demand for natural gas in the winter months; and the long term price of energy stocks--especially the strategic value of natural gas, which is clean and abundant in the United States
Seasonal Strategies
Natural gas strategies for seasonal products is a standard futures and options trade. Traders anticipate, from weather reports and climatologists, the expected weather patterns, especially during the high demand winter months. Because the trade is seasonal, traders tend to use futures, options on futures and options on stocks to leverage the value of the trade. As a result, option premiums tend to move to extreme values and then rapidly decline as the market anticipates warming trends. Traders also trade natural gas depending on the level of economic activity. Demand slumps during economic downturns, dropping prices but with the anticipation of economic recovery. For these trades, investors usually buy stocks of natural gas transmission entities and exploration companies because the demand and value of their inventories are worth more.
Long-Term Strategies
In recent years, natural gas traded in line with the large run-up in crude oil. These are profitable strategies because at certain prices large institutional clients, such as businesses and energy producers, move energy production from oil to gas. The measure of energy, British thermal units, or BTUs, are different for every energy source. Consumers use the lowest price of energy available. This substitution effect keeps the relative value of oil, gas, nuclear and alternative energies in a narrow grid of price relationships. Given the important strategic availability of natural gas, particularly in the United States, natural gas may well become the beneficiary of tax and legislative action, thus effectively raising its value.
Natural Gas-Leveraged Trading Strategies
Natural gas futures and options are often traded like other commodities with respect to price discrepancies involving the near and longer term expiration dates. Option strategies involving covered calls can be used to produce income with minimal risk. Natural gas is also traded in a variety of strategies to produce gains if price rises, falls and trends in a narrow range.
Natural Gas Trading Opportunities
Natural gas can be traded in the futures market as a commodity. Using the futures markets provides great leverage, especially when used to trade major trends. Natural gas can also be traded as an exchange-traded fund, which is a stock that owns only natural gas companies. Individual companies can also be purchased both as a long-term provider of natural gas and for the transmission of natural gas through a pipeline strategy. These stocks often pay handsome dividends and are an income play.
Investors can also invest in the exploration of natural gas. Stocks are valued according to the expected sales of the inventory of natural gas they control. All of these possibilities are found in the investment arena. Natural gas is usually traded using one of three strategies: the relative value of natural gas to oil and other energy products; the seasonal demand for natural gas in the winter months; and the long term price of energy stocks--especially the strategic value of natural gas, which is clean and abundant in the United States
Seasonal Strategies
Natural gas strategies for seasonal products is a standard futures and options trade. Traders anticipate, from weather reports and climatologists, the expected weather patterns, especially during the high demand winter months. Because the trade is seasonal, traders tend to use futures, options on futures and options on stocks to leverage the value of the trade. As a result, option premiums tend to move to extreme values and then rapidly decline as the market anticipates warming trends. Traders also trade natural gas depending on the level of economic activity. Demand slumps during economic downturns, dropping prices but with the anticipation of economic recovery. For these trades, investors usually buy stocks of natural gas transmission entities and exploration companies because the demand and value of their inventories are worth more.
Long-Term Strategies
In recent years, natural gas traded in line with the large run-up in crude oil. These are profitable strategies because at certain prices large institutional clients, such as businesses and energy producers, move energy production from oil to gas. The measure of energy, British thermal units, or BTUs, are different for every energy source. Consumers use the lowest price of energy available. This substitution effect keeps the relative value of oil, gas, nuclear and alternative energies in a narrow grid of price relationships. Given the important strategic availability of natural gas, particularly in the United States, natural gas may well become the beneficiary of tax and legislative action, thus effectively raising its value.
Natural Gas-Leveraged Trading Strategies
Natural gas futures and options are often traded like other commodities with respect to price discrepancies involving the near and longer term expiration dates. Option strategies involving covered calls can be used to produce income with minimal risk. Natural gas is also traded in a variety of strategies to produce gains if price rises, falls and trends in a narrow range.
Conclusion
North American LNG capacity is expected to grow dramatically by 2010. This capacity growth could help offset the decline of existing North American gas fields, and could help moderate price growth. However, the proposed LNG projects will face a variety of legal, engineering, and environmental challenges which could delay or cancel some of the projects. In addition, a variety of supply-side bottlenecks will reduce the average sendout of the proposed terminals. Finally, global competition for LNG supplies may result in continued upward pressure on U.S. gas prices.
For reference, the entire global supply of LNG averaged less than 18 bcfd for 2004 [11]. Even if global LNG shipments increased dramatically by 2010, much of that capacity will likely be locked-in by Japan, South Korea, and other major LNG importers. Thus, it is unlikely that the projected 51 bcfd of North American capacity could be fully utilized by 2010.
Therefore, the proposed LNG terminals will not be a panacea for curing North America’s natural gas shortfall.
For reference, the entire global supply of LNG averaged less than 18 bcfd for 2004 [11]. Even if global LNG shipments increased dramatically by 2010, much of that capacity will likely be locked-in by Japan, South Korea, and other major LNG importers. Thus, it is unlikely that the projected 51 bcfd of North American capacity could be fully utilized by 2010.
Therefore, the proposed LNG terminals will not be a panacea for curing North America’s natural gas shortfall.
Challenges for LNG Expansion
The top five LNG importing countries are shown in Table 1 below, with other countries grouped by region for comparison. Table 1 indicates that the U.S. has a significant foothold in the global LNG market, and is currently importing about 10% of global supply. However, unlike the U.S., most of the other importing countries have government-owned or -subsidized utilities and manufacturing industries, which affects long-term LNG purchasing strategies.
Table 1. Top LNG Importing Countries, 2004
Country
2004 Imports (BCF)
% of World Total
Japan
2,873
44.5%
South Korea
1,048
16.2%
United States
652
10.1%
Spain
618
9.6%
Taiwan
332
5.2%
Other European Countries
805
12.5%
Other Asian Countries
93
1.4%
Other Caribbean/Central American Countries
31
0.5%
World Total, 2004 (NOTE 1)
6,453
100%
NOTE 1: Totals may not add due to rounding.
Many of the major LNG importers outside of the U.S. have locked-in long-term supply contracts with the support of their respective governments, and 20-year contracts are not uncommon [12]. These long-term contracts imply dedicated LNG tankers traveling dedicated supply routes. However, the U.S. government does not currently negotiate long-term supply contracts for the U.S. gas market, since this is handled by the private sector. Therefore, it is possible that the U.S. will continue to obtain a higher proportion of imported LNG through spot markets, as compared with other countries with socialized energy sectors and locked-in LNG supply. This could have the effect of maintaining upward pressure on U.S. gas prices despite increased LNG imports.
Table 1. Top LNG Importing Countries, 2004
Country
2004 Imports (BCF)
% of World Total
Japan
2,873
44.5%
South Korea
1,048
16.2%
United States
652
10.1%
Spain
618
9.6%
Taiwan
332
5.2%
Other European Countries
805
12.5%
Other Asian Countries
93
1.4%
Other Caribbean/Central American Countries
31
0.5%
World Total, 2004 (NOTE 1)
6,453
100%
NOTE 1: Totals may not add due to rounding.
Many of the major LNG importers outside of the U.S. have locked-in long-term supply contracts with the support of their respective governments, and 20-year contracts are not uncommon [12]. These long-term contracts imply dedicated LNG tankers traveling dedicated supply routes. However, the U.S. government does not currently negotiate long-term supply contracts for the U.S. gas market, since this is handled by the private sector. Therefore, it is possible that the U.S. will continue to obtain a higher proportion of imported LNG through spot markets, as compared with other countries with socialized energy sectors and locked-in LNG supply. This could have the effect of maintaining upward pressure on U.S. gas prices despite increased LNG imports.
Challenges for LNG Expansion
The projections listed in Figures 1 and 2 above show a dramatic increase in LNG capacity, especially between 2008 and 2010. However, the proposed LNG projects will face a variety of legal, economic, and engineering challenges prior to and during construction. These challenges could potentially delay the startup date for some projects, and may lead to cancellation of others.
Legal and Jurisdiction Issues
Some LNG projects are being challenged despite FERC approval. For example, the proposed Weaver’s Cove LNG project in Fall River, Massachusetts was approved by the FERC in June 2005, over vigorous objection by many State and Local officials and by citizens’ groups. Opponents claimed that the densely-populated Fall River area is not safe for an LNG terminal, and that the project could disrupt tourism and sea life. Opponents have plans to petition the FERC for a re-evaluation of the project, and may eventually file lawsuits with the U.S. Court of Appeals to challenge FERC’s authority in this matter. [3, 4]
In addition, the California Public Utilities Commission (CPUC) is challenging FERC’s jurisdiction over approving on-shore LNG projects. CPUC’s case regarding Sound Energy Solutions Long Beach project is currently pending in the U.S. Court of Appeals. Contention over such projects is challenging the very basis for federal approval of LNG projects, which could impact the approval of LNG projects across the country. [5, 6]
Engineering and Environmental Issues
Some projects are facing opposition or cost overruns due to engineering and environmental issues. For example, ExxonMobil recently withdrew the Maritime Administration (MARAD) application for their proposed Pearl Crossing deepwater LNG port (originally number 37 on the project list in Appendix B). This facility was planned with baseload capacity of 2.8 bcfd, and was among the larger LNG facilities originally planned. Like many offshore LNG ports, Pearl Crossing was designed to use sea water to regasify LNG in an open loop process. However, a coalition of environmental groups, sport-fishing groups, and commercial fishing industry groups claimed that the open-loop water intake would kill large quantities of fish eggs and sea life. Public pressure from these groups likely contributed to ExxonMobil’s decision to withdraw their MARAD application on October 19, 2005. [7, 8]
Supply-Side Bottlenecks
Once the feasible projects are ultimately built, their average sendout will likely be much less than 100% of capacity. For one thing, LNG terminals are batch processes, and can only deliver gas as ships are unloaded, or out of on-site storage from previous shipments. Thus, the ultimate sendout from each terminal is dependent on how many (and how often) LNG tankers can be docked. In this respect, the number of tankers available at any given time is a key variable. In addition, the proposed terminals will tie-in to existing pipeline networks. Some observers point to additional bottlenecks in the existing U.S. pipeline system which could further limit the average sendout of these terminals [9]. For reference, the existing U.S. LNG terminals imported about 652 BCF in 2004, averaging about 1.78 BCF/day. The nominal capacity for these terminals is about 4.22 BCF/day, for an average usage factor of 42% of capacity.
International Competition for Available Supplies
Even though LNG has played a minor role in North American energy markets, the global LNG market is mature. Significant quantities of LNG have been shipped for about forty years, with most of the LNG shipped to Asia, and almost half of current global supply being shipped to Japan [10]. See Figure 3 below showing 2004 LNG imports by region [11].
The projections listed in Figures 1 and 2 above show a dramatic increase in LNG capacity, especially between 2008 and 2010. However, the proposed LNG projects will face a variety of legal, economic, and engineering challenges prior to and during construction. These challenges could potentially delay the startup date for some projects, and may lead to cancellation of others.
Legal and Jurisdiction Issues
Some LNG projects are being challenged despite FERC approval. For example, the proposed Weaver’s Cove LNG project in Fall River, Massachusetts was approved by the FERC in June 2005, over vigorous objection by many State and Local officials and by citizens’ groups. Opponents claimed that the densely-populated Fall River area is not safe for an LNG terminal, and that the project could disrupt tourism and sea life. Opponents have plans to petition the FERC for a re-evaluation of the project, and may eventually file lawsuits with the U.S. Court of Appeals to challenge FERC’s authority in this matter. [3, 4]
In addition, the California Public Utilities Commission (CPUC) is challenging FERC’s jurisdiction over approving on-shore LNG projects. CPUC’s case regarding Sound Energy Solutions Long Beach project is currently pending in the U.S. Court of Appeals. Contention over such projects is challenging the very basis for federal approval of LNG projects, which could impact the approval of LNG projects across the country. [5, 6]
Engineering and Environmental Issues
Some projects are facing opposition or cost overruns due to engineering and environmental issues. For example, ExxonMobil recently withdrew the Maritime Administration (MARAD) application for their proposed Pearl Crossing deepwater LNG port (originally number 37 on the project list in Appendix B). This facility was planned with baseload capacity of 2.8 bcfd, and was among the larger LNG facilities originally planned. Like many offshore LNG ports, Pearl Crossing was designed to use sea water to regasify LNG in an open loop process. However, a coalition of environmental groups, sport-fishing groups, and commercial fishing industry groups claimed that the open-loop water intake would kill large quantities of fish eggs and sea life. Public pressure from these groups likely contributed to ExxonMobil’s decision to withdraw their MARAD application on October 19, 2005. [7, 8]
Supply-Side Bottlenecks
Once the feasible projects are ultimately built, their average sendout will likely be much less than 100% of capacity. For one thing, LNG terminals are batch processes, and can only deliver gas as ships are unloaded, or out of on-site storage from previous shipments. Thus, the ultimate sendout from each terminal is dependent on how many (and how often) LNG tankers can be docked. In this respect, the number of tankers available at any given time is a key variable. In addition, the proposed terminals will tie-in to existing pipeline networks. Some observers point to additional bottlenecks in the existing U.S. pipeline system which could further limit the average sendout of these terminals [9]. For reference, the existing U.S. LNG terminals imported about 652 BCF in 2004, averaging about 1.78 BCF/day. The nominal capacity for these terminals is about 4.22 BCF/day, for an average usage factor of 42% of capacity.
International Competition for Available Supplies
Even though LNG has played a minor role in North American energy markets, the global LNG market is mature. Significant quantities of LNG have been shipped for about forty years, with most of the LNG shipped to Asia, and almost half of current global supply being shipped to Japan [10]. See Figure 3 below showing 2004 LNG imports by region [11].
North American LNG Outlook: Liquefied natural gas (LNG) capacity expected to surge by 2010, but LNG will not be a panacea for North American natural g
Cumulative LNG capacity is shown below in Figure 2. The chart indicates that by 2008, the total North American LNG capacity is projected to be about 33 bcfd, or about 54% of U.S. average daily natural gas demand over the period 2001-2004. By 2010, the total LNG capacity is projected to be over 51 bcfd, which is equal to about 83% of current U.S. average daily demand. Therefore, the proposed capacity represents a significant expansion of natural gas supply for the North American market, which could eventually create downward pressure on natural gas prices.
North American LNG Outlook: Liquefied natural gas (LNG) capacity expected to surge by 2010, but LNG will not be a panacea for North American natural g
Executive Summary
Recent hurricanes and energy price volatility have focused the nation’s attention on natural gas markets. However, North American natural gas production faced challenges, even prior to the hurricanes. In order to meet projected North American natural gas demand, energy companies are increasingly looking to import liquefied natural gas (LNG) as an alternative to domestic and Canadian natural gas. There are currently five terminals where LNG can be offloaded from tankers and shipped to North American customers via pipelines and trucks, with a total existing capacity of over 4 billion cubic feet per day (bcfd). Energy companies have proposed 41 LNG projects (both new construction and expansions), totaling over 47 bcfd of capacity. If the new projects are built according to schedule, they will bring the ultimate total North American LNG capacity to just over 51 bcfd by 2010, which is equivalent to 83% of the U.S. average daily natural gas demand for the period 2001 – 2004.
Such LNG capacity, if fully utilized, has the potential to flood the North American market with natural gas and drive prices down substantially. However, the global LNG supply averaged less than 18 bcfd in 2004, which is considerably less than the proposed 51 bcfd mentioned above. There are also questions about the viability of some projects due to legal, environmental, and engineering issues. In addition, the ultimate capacity will not be fully utilized 100% of the time, since the number of available tankers and the quantity of available supply will likely be limiting factors. Finally, the U.S. will be increasingly dependent on a highly competitive global marketplace for LNG, with established consumers such as Japan competing for available supplies, which may tend to keep U.S. natural gas prices elevated.
Motivation for LNG Imports
n flat or declining since the early 1970s, Canadian production has flatlined since about 2001, and hurricanes have recently taken a bite out of Gulf of Mexico production capacity. Conversely, some overseas suppliers produce more natural gas than can be used locally. In order to export this natural gas, the gas is liquefied at temperatures around -260ºF, which greatly reduces its volume, and is then loaded on cryogenic tankers and shipped overseas. At the destination, the LNG can be trans-shipped via rail or truck, or can be regasified and fed into existing pipeline networks.
Background on North American LNG Imports
To offset increasing demand and decreasing North American supplies, energy companies are proposing a wave of LNG terminal projects [1]. Although the U.S. already imports LNG at 5 existing locations, 41 proposed North American projects and expansions will permit an increase in imports of LNG from overseas suppliers. Much of this imported LNG will be sourced from existing suppliers, such as Algeria, Trinidad and Tobago, Indonesia, Qatar and other Persian Gulf nations. In addition, increasing supplies are being shipped (or soon will be) from Nigeria, Russia, and the Caspian region in central Asia.
LNG Capacity Projections
We obtained information on 41 new projects and expansions from the Federal Energy Regulatory Commission (FERC) website [2] and a variety of commercial and government websites. For a map showing locations of these projects, see Appendix A. For a detailed list of all existing and proposed LNG projects, project information, and references, see Appendix B.
We obtained estimated startup dates on most projects from both corporate and government sources. Estimated startup dates could not be found for a few projects, so we extrapolated startup date estimates based on the status of their FERC/EPA proposals (see Appendix B for more information).
Projections of year-by-year capacity additions are shown below in Figure 1. As shown in the chart, 2008 appears to be a significant year for LNG capacity, with about 20 bcfd of capacity scheduled to come on-line in that year alone.
Natural gas is a key component of the U.S. economy: it heats our homes and businesses, supplies key industries with heat and power, and powers an increasing share of our electrical capacity. Unfortunately, supply shortfalls have contributed to large price increases in recent years. Domestic natural gas production has bee
Recent hurricanes and energy price volatility have focused the nation’s attention on natural gas markets. However, North American natural gas production faced challenges, even prior to the hurricanes. In order to meet projected North American natural gas demand, energy companies are increasingly looking to import liquefied natural gas (LNG) as an alternative to domestic and Canadian natural gas. There are currently five terminals where LNG can be offloaded from tankers and shipped to North American customers via pipelines and trucks, with a total existing capacity of over 4 billion cubic feet per day (bcfd). Energy companies have proposed 41 LNG projects (both new construction and expansions), totaling over 47 bcfd of capacity. If the new projects are built according to schedule, they will bring the ultimate total North American LNG capacity to just over 51 bcfd by 2010, which is equivalent to 83% of the U.S. average daily natural gas demand for the period 2001 – 2004.
Such LNG capacity, if fully utilized, has the potential to flood the North American market with natural gas and drive prices down substantially. However, the global LNG supply averaged less than 18 bcfd in 2004, which is considerably less than the proposed 51 bcfd mentioned above. There are also questions about the viability of some projects due to legal, environmental, and engineering issues. In addition, the ultimate capacity will not be fully utilized 100% of the time, since the number of available tankers and the quantity of available supply will likely be limiting factors. Finally, the U.S. will be increasingly dependent on a highly competitive global marketplace for LNG, with established consumers such as Japan competing for available supplies, which may tend to keep U.S. natural gas prices elevated.
Motivation for LNG Imports
n flat or declining since the early 1970s, Canadian production has flatlined since about 2001, and hurricanes have recently taken a bite out of Gulf of Mexico production capacity. Conversely, some overseas suppliers produce more natural gas than can be used locally. In order to export this natural gas, the gas is liquefied at temperatures around -260ºF, which greatly reduces its volume, and is then loaded on cryogenic tankers and shipped overseas. At the destination, the LNG can be trans-shipped via rail or truck, or can be regasified and fed into existing pipeline networks.
Background on North American LNG Imports
To offset increasing demand and decreasing North American supplies, energy companies are proposing a wave of LNG terminal projects [1]. Although the U.S. already imports LNG at 5 existing locations, 41 proposed North American projects and expansions will permit an increase in imports of LNG from overseas suppliers. Much of this imported LNG will be sourced from existing suppliers, such as Algeria, Trinidad and Tobago, Indonesia, Qatar and other Persian Gulf nations. In addition, increasing supplies are being shipped (or soon will be) from Nigeria, Russia, and the Caspian region in central Asia.
LNG Capacity Projections
We obtained information on 41 new projects and expansions from the Federal Energy Regulatory Commission (FERC) website [2] and a variety of commercial and government websites. For a map showing locations of these projects, see Appendix A. For a detailed list of all existing and proposed LNG projects, project information, and references, see Appendix B.
We obtained estimated startup dates on most projects from both corporate and government sources. Estimated startup dates could not be found for a few projects, so we extrapolated startup date estimates based on the status of their FERC/EPA proposals (see Appendix B for more information).
Projections of year-by-year capacity additions are shown below in Figure 1. As shown in the chart, 2008 appears to be a significant year for LNG capacity, with about 20 bcfd of capacity scheduled to come on-line in that year alone.
Natural gas is a key component of the U.S. economy: it heats our homes and businesses, supplies key industries with heat and power, and powers an increasing share of our electrical capacity. Unfortunately, supply shortfalls have contributed to large price increases in recent years. Domestic natural gas production has bee
Why LNG Now?
2002 US Natural Gas consumption = 22.6 Tcf
• 12 Tcf increase over next 10 years
! More electricity from natural gas
• Supply and Demand Issues
! Domestic production shortfall expected
! Canadian pipeline imports not adequate
enough to meet needs
! Supply/demand imbalance = higher prices
Supply and Demand Realities
• Higher natural gas prices drive greater LNG expansion, which serves to lower LNG production
costs
• Lower LNG production entices gas producers to monetize gas reserves, especially when import demand is rising and can’t keep up (applies mostly to North America)
• 12 Tcf increase over next 10 years
! More electricity from natural gas
• Supply and Demand Issues
! Domestic production shortfall expected
! Canadian pipeline imports not adequate
enough to meet needs
! Supply/demand imbalance = higher prices
Supply and Demand Realities
• Higher natural gas prices drive greater LNG expansion, which serves to lower LNG production
costs
• Lower LNG production entices gas producers to monetize gas reserves, especially when import demand is rising and can’t keep up (applies mostly to North America)
What is LNG?
LNG Composition
Nitrogen N 0.0% 1.3%
Butane C4 0.0% 2.5%
Propane C3 0.0% 4.0%
Ethane C2 0.0% 14.0%
Methane C1 83.0% 99.8%
Low High
Composition Range
Volume Reduction: 1/600
Pressure: 1 atmosphere
Temperature: -259 degrees F -161degrees C
LNG is Not…
• Compressed Natural Gas (CNG)
• Natural Gas Liquids (NGL)
• Liquefied Petroleum Gas (LPG)
• Gas to Liquids (GTL)
LNG Markets
• Preferred option for long distance natural gas
transportation
• Supply peak shaving
• Natural gas distribution system flexibility
• Seasonal gas storage
• Alternative motor fuel to diesel
• Natural gas service to remote areas
LNG vs. Natural Gas
• LNG Competes with:
! Pipeline Delivered Natural Gas
! Diesel
! Heating Oil
! Electricity
! Coal
• In a regulated market LNG should be at price parity with
other commodities
• In an unregulated market, LNG must compete on its own
merit, notably cost
• Dependant Factor
! LNG growth tied to natural gas demand
• Independent Factor
! LNG must be cost competitive to natural gas
LNG Value Chain
• Exploration and Production
• Liquefaction
• Shipping
• Storage and Re-gasification
Nitrogen N 0.0% 1.3%
Butane C4 0.0% 2.5%
Propane C3 0.0% 4.0%
Ethane C2 0.0% 14.0%
Methane C1 83.0% 99.8%
Low High
Composition Range
Volume Reduction: 1/600
Pressure: 1 atmosphere
Temperature: -259 degrees F -161degrees C
LNG is Not…
• Compressed Natural Gas (CNG)
• Natural Gas Liquids (NGL)
• Liquefied Petroleum Gas (LPG)
• Gas to Liquids (GTL)
LNG Markets
• Preferred option for long distance natural gas
transportation
• Supply peak shaving
• Natural gas distribution system flexibility
• Seasonal gas storage
• Alternative motor fuel to diesel
• Natural gas service to remote areas
LNG vs. Natural Gas
• LNG Competes with:
! Pipeline Delivered Natural Gas
! Diesel
! Heating Oil
! Electricity
! Coal
• In a regulated market LNG should be at price parity with
other commodities
• In an unregulated market, LNG must compete on its own
merit, notably cost
• Dependant Factor
! LNG growth tied to natural gas demand
• Independent Factor
! LNG must be cost competitive to natural gas
LNG Value Chain
• Exploration and Production
• Liquefaction
• Shipping
• Storage and Re-gasification
Wednesday, May 12, 2010
Energy Access
While the focus in developed countries is increasingly directed towards employing clean or renewable energies to limit the emission of greenhouse gases, the use of alternative energy sources in developing countries is first and foremost about access to safer, cleaner, cheaper and more reliable energy. Microfinance has been identified as one of the key facilitators towards economic development in the developing world.What is Microfinance?
Microfinance is a financial tool that is used to promote entrepreneurship in developing nations. This opens doors towards economic prosperity for millions of people. Microfinance loans for energy services or “Energy Lending” are also used to provide people access to high quality modern energy services. These are offered and serviced by Microfinance Institutions (MFI’s) to people interested in moving away from traditional fuels (wood, biomass etc.). These loans can offset the initial investment associated with cleaner technologies such as LP Gas which provides higher quality and greater safety. Microfinance can provide clients with access to high quality modern energy services. In doing so, such loans can offset the high upfront cost associated with cleaner technologies such as LP Gas which provides higher quality, greater safety and often leads to increased income.
Microfinance in Morocco
The WLPGA believes that the portable nature of bottled LP Gas, combined with its clean burning characteristics, presents an immediate, ‘win-win’ solution to rapidly expand the availability of modern energy to those that have been without it. In May 2004, a workshop was held in Morocco which led to the launching of the microfinance scheme stemming from the LP Gas Rural Energy Challenge.The initiative is still going strong.
Morocco has a robust and extensive infrastructure of professional, credible MFI network that works in the country’s poorer communities. This microfinance pilot project was initiated in partnership with WLPGA members Afriquia Gaz, Shell du Maroc, Total Maroc, as well as with the well-established Moroccan MFI, Zakoura Foundation.
World LP Gas Association and the United Nations Development Programme (UNDP)
Another initiative within the Rural Energy Challenge with UNDP was a microfinance pilot project to support entrepreneurial use of LP Gas in various parts of the world.
Please click here for more information on WLPGA and UNDP projects.
Energy Access in South Africa
South Africa’s national electricity utility Eskom recently launched a demand-side management (DSM) initiative in the Western Cape region in response to a shortfall in electrical supply capacity. The programme included replacing of electric cooking stoves and heaters with LP Gas equivalents. With access to LP Gas, programme participants were able to reduce their electricity consumption, while increasing the efficiency of their energy use. This was a consequence of the rural energy challenge
Asian Development Bank
Working together with the Asian Development BankWLPGA kicked off an initiative entitled “The Asia-Pacific Regional Initiative - Access to Energy for the Poor” with the Asian Development Bank (ADB) designed to bring clean modern energy to millions of villagers in the Asia-Pacific region. This programme was launched at the ADB headquarters in Manila in April. The project seeks to address the growing awareness of the potential for cleaner and more modern energy to provide an environmentally sustainable and relatively cheap means of supplying off-grid access to energy for the poor, particularly in developing countries. An estimated 1.6 billion people in developing countries, 1 billion of whom are in the Asia-Pacific region, do not have access to modern energy services for basic cooking, heating and lighting.
Access to Energy for the Poor will focus on a village level, demand-driven approach to improving the standard of living, quality of life, general health and health services of the people in poor communities in both off-grid rural villages and under-served urban settlements. It will also seek to create sustainable grass roots markets in these communities through creative financing schemes such as microfinance initiatives. WLPGA is a founding partner of this initiative and expects to be involved in its work over the next two years.
To learn more about this initiative from the Asia Development Bank, please click
http://www.adb.org/Documents/Papers/Access-Energy-Poor/Access-Energy-Poor.pdf
http://www.fdc.org.au/energy-initiative.html
To read about WLPGA participation in the new Asian Development Bank Energy Partnership that aims to reach 100 million people by 2015, please click
http://www.worldlpgas.com/news-and-events/news/wlpga-participating-in-new-asian-development-bank-energy-partnership
Rural Use Of LP Gas
For decades rural communities have benefited from LP Gas, which has enabled access to modern conveniences, especially where costly grid-based energy services are unavailable. LP Gas can be stored and easily transported and because it is also clean and efficient, it can be used anywhere to deliver excellent energy service options. LP Gas can have profound and beneficial effects on the economy, environment and the quality of rural life.
In developing rural communities, LP Gas can provide a first modern alternative to traditional cooking fuels (e.g. firewood, charcoal, dung), contributing to a better quality of life and importantly, liberating women and children from time spent collecting fuel, thus enabling them to pursue education or value-added economic activities within the community.
The LP Gas Rural Energy Challenge
The LP Gas Rural Energy Challenge is a public-private partnership initiative between the United Nations Development Programme (UNDP) and the WLPGA. It was designed to create viable and sustainable markets for LP Gas delivery and consumption as a means to generate a wide range of productive services contributing to sustainable energy solutions to improve people’s lives. The Rural LP Gas Challenge has held country workshops in Honduras, Turkey, South Africa, Ghana, Vietnam, Morocco, and China.
The rural areas of the developed world can also greatly benefit from the use of LP Gas in agriculture and recreational applications. LP Gas provides an efficient solution to agricultural activities such as crop drying, weed control, sterilization as well as fuel for farm equipment. The developing world can also benefit from the portability and reliability of LP Gas in recreational uses such as cooking fuel for recreational vehicles, portable camping stoves and in the warding off of mosquitoes.
In developing rural communities, LP Gas can provide a first modern alternative to traditional cooking fuels (e.g. firewood, charcoal, dung), contributing to a better quality of life and importantly, liberating women and children from time spent collecting fuel, thus enabling them to pursue education or value-added economic activities within the community.
The LP Gas Rural Energy Challenge
The LP Gas Rural Energy Challenge is a public-private partnership initiative between the United Nations Development Programme (UNDP) and the WLPGA. It was designed to create viable and sustainable markets for LP Gas delivery and consumption as a means to generate a wide range of productive services contributing to sustainable energy solutions to improve people’s lives. The Rural LP Gas Challenge has held country workshops in Honduras, Turkey, South Africa, Ghana, Vietnam, Morocco, and China.
The rural areas of the developed world can also greatly benefit from the use of LP Gas in agriculture and recreational applications. LP Gas provides an efficient solution to agricultural activities such as crop drying, weed control, sterilization as well as fuel for farm equipment. The developing world can also benefit from the portability and reliability of LP Gas in recreational uses such as cooking fuel for recreational vehicles, portable camping stoves and in the warding off of mosquitoes.
Sustainable Development
WLPGA contributes to sustainable development through its activities in:
RURAL USE OF LP GAS
LP Gas can have profound and beneficial effects on the economy, environment and the quality of rural life.
ASIAN DEVELOPMENT BANK
WLPGA kicked off an initiative entitled “The Asia-Pacific Regional Initiative - Access to Energy for the Poor” with the Asian Development Bank (ADB) designed to bring clean modern energy to millions of villagers in the Asia-Pacific region.
ENERGY ACCESS
The WLPGA believes that the portable nature of bottled LP Gas, combined with its clean burning characteristics, presents an immediate, ‘win-win’ solution to rapidly expand the availability of modern energy to those that have been without it.
RURAL USE OF LP GAS
LP Gas can have profound and beneficial effects on the economy, environment and the quality of rural life.
ASIAN DEVELOPMENT BANK
WLPGA kicked off an initiative entitled “The Asia-Pacific Regional Initiative - Access to Energy for the Poor” with the Asian Development Bank (ADB) designed to bring clean modern energy to millions of villagers in the Asia-Pacific region.
ENERGY ACCESS
The WLPGA believes that the portable nature of bottled LP Gas, combined with its clean burning characteristics, presents an immediate, ‘win-win’ solution to rapidly expand the availability of modern energy to those that have been without it.
Motor vehicle pollution
Motor vehicle pollution has severe adverse health impacts on the community, especially for people living in urban areas or in locations close to busy roads. LP Gas as an automotive fuel (Autogas) emits significantly fewer harmful gasses such as CO2, NOx, and particulate matters (PM)*. The use of Autogas is a solution to health impacts related to vehicle emissions.
*Source: The European Emissions Test Programme, 2003
For more information on LP Gas as an Automotive fuel please visit: GAIN (Global Autgas Industry Network)
WLPG Publications:
Ten Good Reasons for Making the Autogas Choice -
Health Effects and Costs of Vehcile Emissions -
For more information on vehicle emissions please refer to the following:
United States (U.S.)
• Environmental Protection Agency (E.P.A)
European Union (EU)
• European Commission on Environment
United Nations (U.N.)
• United Nations Environment Programme (UNEP)
Australia
• Department of Environment, Water, Heritage and the Arts
*Source: The European Emissions Test Programme, 2003
For more information on LP Gas as an Automotive fuel please visit: GAIN (Global Autgas Industry Network)
WLPG Publications:
Ten Good Reasons for Making the Autogas Choice -
Health Effects and Costs of Vehcile Emissions -
For more information on vehicle emissions please refer to the following:
United States (U.S.)
• Environmental Protection Agency (E.P.A)
European Union (EU)
• European Commission on Environment
United Nations (U.N.)
• United Nations Environment Programme (UNEP)
Australia
• Department of Environment, Water, Heritage and the Arts
Indoor Air Pollution
LP Gas is being increasingly recognized as a solution to indoor air pollution caused by the use of traditional cooking and heating fuels in multiple applications.
Fact … smoke from indoor cooking fires kills 1.6 million every year, much more people than malaria, and almost as many as unsafe water and sanitation
… smoke in the home is the fourth greatest cause of death and disease in the world’s poorest countries WHO has highlighted LP Gas as the cost effective solution for reducing pollution from cooking fuel “… investing US$ 13 billion per year to halve, by 2015, the number of people worldwide cooking with solid fuels by supplying them with LP Gas shows a payback of US$ 91 billion per year”
Source: ‘Fuel for Life Household Energy and Health’, WHO, September 2006
Indoor Air Pollution
Indoor air pollution is one of the biggest health problems afflicting poor communities in developing countries. The use of cleaner and more efficient LP Gas is increasingly recognized as an ideal solution to the problem of indoor air pollution caused by the use of traditional cooking and heating fuels such as firewood or coal.
WLPGA has established a relationship with the World Health Organization (WHO) and has appointed Industry Council member, Kimball Chen, Chairman and CEO, Energy Transportation Group as WLPGA’s “Special Envoy on Health” with the specific role of supporting the WLPGA in contacts with health ministries and health-focused organisations such as WHO. A joint study released Fuel For Life, Household Energy and Health highlights LP Gas as the cost effective solution for reducing pollution from cooking fuel in the developing world. It recommends that $13 billion be invested annually in providing LP Gas access to deliver health benefits to the poor and contribute to sustainable development.
Source: ‘Fuel For Life, Household Energy and Health’, WHO September 2006
Click here to download related WLPGA Publication:
Household Fuels & Ill Health in Developing Countries: What Improvements can be brought by LP Gas? - 4.5mb
Fact … smoke from indoor cooking fires kills 1.6 million every year, much more people than malaria, and almost as many as unsafe water and sanitation
… smoke in the home is the fourth greatest cause of death and disease in the world’s poorest countries WHO has highlighted LP Gas as the cost effective solution for reducing pollution from cooking fuel “… investing US$ 13 billion per year to halve, by 2015, the number of people worldwide cooking with solid fuels by supplying them with LP Gas shows a payback of US$ 91 billion per year”
Source: ‘Fuel for Life Household Energy and Health’, WHO, September 2006
Indoor Air Pollution
Indoor air pollution is one of the biggest health problems afflicting poor communities in developing countries. The use of cleaner and more efficient LP Gas is increasingly recognized as an ideal solution to the problem of indoor air pollution caused by the use of traditional cooking and heating fuels such as firewood or coal.
WLPGA has established a relationship with the World Health Organization (WHO) and has appointed Industry Council member, Kimball Chen, Chairman and CEO, Energy Transportation Group as WLPGA’s “Special Envoy on Health” with the specific role of supporting the WLPGA in contacts with health ministries and health-focused organisations such as WHO. A joint study released Fuel For Life, Household Energy and Health highlights LP Gas as the cost effective solution for reducing pollution from cooking fuel in the developing world. It recommends that $13 billion be invested annually in providing LP Gas access to deliver health benefits to the poor and contribute to sustainable development.
Source: ‘Fuel For Life, Household Energy and Health’, WHO September 2006
Click here to download related WLPGA Publication:
Household Fuels & Ill Health in Developing Countries: What Improvements can be brought by LP Gas? - 4.5mb
Annex A3 –Particle Emissions from Current Technology Engines
above very conveniently compresses a very large body of PM test data into two highly
informative charts. It can be readily seen that the relative emission rates of particles for each fuel type are similar in both the idle testing and the 50 km/h tests, even though the absolute values differed quite substantially.
Conventional diesels (those without any exhaust after-treatment to reduce particle levels) clearly have the highest emission levels while conventional multipoint injected gasoline and LP Gas fuelled vehicles are substantially lower. Readers should note that the vertical scale is logarithmic so each vertical division represents a ten-fold increase in particle concentration.
In both the idle and the 50 km/h tests, the conventional diesel engines have particle concentrations between 100 and 1000 times higher than most of the gasoline and LP Gas vehicles.
But it is interesting to note that direct injection gasoline (DIG) engines also have extremely high PM emissions – typically between 10 and 100 times higher than the current mainstream LP Gas and gasoline engines. The use of gasoline DI technology is likely to increase, as vehicle manufacturers strive to further improve fuel economy. But the charts tell us that this strategy has potentially serious environmental downside, given that gasoline PM emissions have not previously been considered sufficiently high to warrant regulation. The Ricardo results are consistent with the results of other studies into particle emissions from DIG engines.
Responding to the results of this research, the 2009 Euro 5 emission regulations introduce, for the first time, gasoline PM emission limits. This extension to the scope of Euro regulations specifically addressed gasoline DIG engines only – PM from gasoline engines with non-DI fuel delivery systems will not be regulated.
On a more general front, in the US there is a growing concern that particle emissions from gasoline vehicles may represent a larger health threat than previously understood. In 2006 the US Environmental Protection Agency (US EPA) released the results of a large scale testing program in Kansas City to measure particle emissions from gasoline fuelled cars and light trucks in various age groups. The results of these tests are summarised in Figure 9.2 below.
By way of comparison, the PM emission limit for diesel cars and light commercial vehicles in the Euro 4 standard (in force since 2005 in Europe and progressively adopted in many other economies) is 25 mg per kilometre (equivalent to 40 mg per mile). The 2009 (Euro 5) regulation reduces the limit to 5mg/km (8mg/mile).
From the above chart it can be inferred that many in-use gasoline vehicles are emitting significantly higher PM emissions than current technology diesels.
The high volatility of LP Gas results in almost instant transformation into the gaseous phase when injected directly into the cylinder. This greatly reduces the likelihood of direct injection LP Gas engines producing the high PM levels generated by their gasoline counterparts.
informative charts. It can be readily seen that the relative emission rates of particles for each fuel type are similar in both the idle testing and the 50 km/h tests, even though the absolute values differed quite substantially.
Conventional diesels (those without any exhaust after-treatment to reduce particle levels) clearly have the highest emission levels while conventional multipoint injected gasoline and LP Gas fuelled vehicles are substantially lower. Readers should note that the vertical scale is logarithmic so each vertical division represents a ten-fold increase in particle concentration.
In both the idle and the 50 km/h tests, the conventional diesel engines have particle concentrations between 100 and 1000 times higher than most of the gasoline and LP Gas vehicles.
But it is interesting to note that direct injection gasoline (DIG) engines also have extremely high PM emissions – typically between 10 and 100 times higher than the current mainstream LP Gas and gasoline engines. The use of gasoline DI technology is likely to increase, as vehicle manufacturers strive to further improve fuel economy. But the charts tell us that this strategy has potentially serious environmental downside, given that gasoline PM emissions have not previously been considered sufficiently high to warrant regulation. The Ricardo results are consistent with the results of other studies into particle emissions from DIG engines.
Responding to the results of this research, the 2009 Euro 5 emission regulations introduce, for the first time, gasoline PM emission limits. This extension to the scope of Euro regulations specifically addressed gasoline DIG engines only – PM from gasoline engines with non-DI fuel delivery systems will not be regulated.
On a more general front, in the US there is a growing concern that particle emissions from gasoline vehicles may represent a larger health threat than previously understood. In 2006 the US Environmental Protection Agency (US EPA) released the results of a large scale testing program in Kansas City to measure particle emissions from gasoline fuelled cars and light trucks in various age groups. The results of these tests are summarised in Figure 9.2 below.
By way of comparison, the PM emission limit for diesel cars and light commercial vehicles in the Euro 4 standard (in force since 2005 in Europe and progressively adopted in many other economies) is 25 mg per kilometre (equivalent to 40 mg per mile). The 2009 (Euro 5) regulation reduces the limit to 5mg/km (8mg/mile).
From the above chart it can be inferred that many in-use gasoline vehicles are emitting significantly higher PM emissions than current technology diesels.
The high volatility of LP Gas results in almost instant transformation into the gaseous phase when injected directly into the cylinder. This greatly reduces the likelihood of direct injection LP Gas engines producing the high PM levels generated by their gasoline counterparts.
Annex A2 - Ambient Air Quality Standards
8.1 Background
The huge social and economic costs associated with human exposure to air pollution are now widely recognised. As a consequence, most developed (and many developing) economies now have introduced maximum exposure levels, either a goals or, in some cases, mandatory limits.
A 2005 World Health Organisation (WHO) study confirmed that the developed world is not immune from the consequences of air pollution. The research concluded that exposure to current PM levels reduces the life expectancy of every person in the EU by an average of nine months, and has a direct economic impact of up to €161 billion (US$220 billion) every year. (WHO, 2005-1) Although not mandated in law, the World Health Organisation (WHO) has published guidelines for a range of pollutants (WHO, 2005-2), including recommended maximum exposure levels. In common with the other regulated and recommended limits discussed in this Section, the WHO recommendations are framed as average pollutant concentration over a specified time period (for example micrograms per cubic metre <μg/m3> over a 24-hour period).
In the USA, for instance, standards for ambient air pollution levels are set through the Clean Air Act. The Act is a federal law covering the entire country, but regional governments at both the state and local level required to implement many of the act's requirements. Under the Clean Air Act the US Environmental Protection Agency (EPA) sets limits on a range of air pollutants to help ensure a degree of health and environmental protection to the population.
The Act also gives the EPA powers to intervene at a local level in cases where individual pollution sources such as chemical plants or other industrial activities create an excessively high source of pollution. Although state and local authorities are responsible for implementing much of the activities required under the Act, the EPA may nevertheless intervene and issue sanctions against the state or local agencies, and if necessary can take over enforcement actions in that area.
A set of European Union exposure limits are being phased in over the period 2010 to 2015. They are generally consistent with the approaches taken in other jurisdictions, and also with the WHO
recommendations discussed below.
Actual recommended and mandated exposure limits for each of the above examples are tabulated in Section 8.2 below.
Pollutants tabulated in Section 8.2 are of particular significance because whole populations are
exposed to them in the air we breathe, but it should be noted that many other pollutants are
extremely hazardous and, in circumstances where higher local concentrations occur, can also
represent a severe health risk.
8.2 Air Quality Standards and Regulations
Four pollutants have been identified by the WHO as having the greatest net impact on human health.
These are tabulated below (Table 8.1), together with the recommended guideline limits.
Pollutant Exposure limit Averaging period
Particulate matter (PM10) * 50 μg/m3 24-hour mean
Particulate matter (PM10) 20 μg/m3 annual mean
Particulate matter (PM2.5) ** 25 μg/m3 24-hour mean
Particulate matter (PM2.5) 10 μg/m3 annual mean
Ozone (O3) 100 μg/m3 8-hour mean
Nitrogen Dioxide (NO2) 40 μg/m3 annual mean
Nitrogen Dioxide (NO2) 500 μg/m3 1-hour mean
Sulphur Dioxide (SO2) 20 μg/m3 24-hour mean
Sulphur Dioxide (SO2) 500 μg/m3 10-minute mean
* PM10 means particles with an aerodynamic diameter smaller than 10 microns (μm)
** PM2.5 means particles with an aerodynamic diameter smaller than 2.5 μm
Table 8.1: WHO Exposure Guidelines for Key Pollutants
These guidelines represent recommended exposure limits, but many cities have ambient air PM2.5
levels that exceed the maximum recommended levels by a factor of five or more. Even worse,
measurements taken where wood fires are used for indoor cooking (Park, 2003) found PM2.5
concentrations that sometimes exceeded 8,000μg/m3 – over 300 times higher than the WHO 24-hour
limit. This situation is probably repeated in many regions around the world.
Recognising the damage created by air pollution, in addition to its 2005 legislation the European
Union is now phasing in a new set of legislated exposure limits. Table 8.2 summarises the coverage of some of these Directives, most of which become mandatory over the period 2010 to 2015. (In some instances member states can apply for extensions of up to five years).
More information on the implementation of these regulations can be found at
http://ec.europa.eu/environment/air/quality/standards.htm Pollutant Exposure Limit Averaging period Fine particles (PM2.5) 25 μg/m3 1 year Sulphur dioxide (SO2) 350 μg/m3 1 hour Sulphur dioxide
(SO2) 125 μg/m3 24 hours
Nitrogen dioxide (NO2) 200 μg/m3 1 hour
Nitrogen dioxide (NO2) 40 μg/m3 1 year
PM10 50 μg/m3 24 hours
PM10 40 μg/m3 1 year
Lead (Pb) 0.5 μg/m3 1 year
Carbon monoxide (CO) 10 mg/m3 Max daily 8 hr mean
Benzene 5 μg/m3 1 year
Ozone 120 μg/m3 Max daily 8 hr mean
Polycyclic Aromatic Hydrocarbons 1 ng/m3 1 year
Table 8.2: European Union Air Quality Standards The ambitious targets now being set generate many challenges, as they not only take effect over relatively short lead times, but they also include a broader range of pollutants. Fortunately, many industries now accept that accelerated development of more efficient and lower polluting vehicles,
machinery and industrial processes, using cleaner fuels, is now a business imperative.
The following table summarises the US EPA’s ambient pollution limits established under the Clean Air Act (http://www.epa.gov/air/criteria.html). The limits are generally in line with those promulgated by the European Union (Table 8.2), and those recommended by the WHO (Table 8.1).
Pollutant Level Averaging Time
Carbon Monoxide 9 ppm (10 mg/m3) 8-hour
Carbon Monoxide 35 ppm (40 mg/m3) 1-hour
Lead 0.15 μg/m3 Rolling 3-Month Average
Nitrogen Dioxide 0.053 ppm (100 μg/m3) Annual (Arithmetic Mean)
Particulate Matter (PM10) 150 μg/m3 24-hour
Particulate Matter PM2.5) 15.0 μg/m3 Annual (Arithmetic Mean)
Particulate Matter (PM2.5)[24
hr]
35 μg/m3 24-hour
Ozone [8hr] 0.075 ppm (2008 std) 8-hour
Ozone [1hr] 0.12 ppm 1-hour
Sulphur Dioxide 0.03 ppm Annual (Arithmetic Mean)
Sulphur Dioxide 0.14 ppm 24-hour
Table 8.3: USA Clean Air Act - Ambient Pollutant Limits
Many other countries have similar limits or targets, some of which are based on either the WHO or the US limits.
China, for instance, has air quality standards which generally fall between the WHO and the US
levels. However, the Chinese standards do not include PM2.5, which is one of the most critical
pollutants from a health perspective.
Australia's ambient air quality standards, which were promulgated in June 1998 are legally binding on each level of government, and were required to be met by the year 2008. The latest State compliance reports, tabled in 2006, show generally good progress has been achieved, but many States still reported at least several non-compliance areas. Ozone and PM10 appear to be the pollutants where the greatest level of non-compliance exists.
The huge social and economic costs associated with human exposure to air pollution are now widely recognised. As a consequence, most developed (and many developing) economies now have introduced maximum exposure levels, either a goals or, in some cases, mandatory limits.
A 2005 World Health Organisation (WHO) study confirmed that the developed world is not immune from the consequences of air pollution. The research concluded that exposure to current PM levels reduces the life expectancy of every person in the EU by an average of nine months, and has a direct economic impact of up to €161 billion (US$220 billion) every year. (WHO, 2005-1) Although not mandated in law, the World Health Organisation (WHO) has published guidelines for a range of pollutants (WHO, 2005-2), including recommended maximum exposure levels. In common with the other regulated and recommended limits discussed in this Section, the WHO recommendations are framed as average pollutant concentration over a specified time period (for example micrograms per cubic metre <μg/m3> over a 24-hour period).
In the USA, for instance, standards for ambient air pollution levels are set through the Clean Air Act. The Act is a federal law covering the entire country, but regional governments at both the state and local level required to implement many of the act's requirements. Under the Clean Air Act the US Environmental Protection Agency (EPA) sets limits on a range of air pollutants to help ensure a degree of health and environmental protection to the population.
The Act also gives the EPA powers to intervene at a local level in cases where individual pollution sources such as chemical plants or other industrial activities create an excessively high source of pollution. Although state and local authorities are responsible for implementing much of the activities required under the Act, the EPA may nevertheless intervene and issue sanctions against the state or local agencies, and if necessary can take over enforcement actions in that area.
A set of European Union exposure limits are being phased in over the period 2010 to 2015. They are generally consistent with the approaches taken in other jurisdictions, and also with the WHO
recommendations discussed below.
Actual recommended and mandated exposure limits for each of the above examples are tabulated in Section 8.2 below.
Pollutants tabulated in Section 8.2 are of particular significance because whole populations are
exposed to them in the air we breathe, but it should be noted that many other pollutants are
extremely hazardous and, in circumstances where higher local concentrations occur, can also
represent a severe health risk.
8.2 Air Quality Standards and Regulations
Four pollutants have been identified by the WHO as having the greatest net impact on human health.
These are tabulated below (Table 8.1), together with the recommended guideline limits.
Pollutant Exposure limit Averaging period
Particulate matter (PM10) * 50 μg/m3 24-hour mean
Particulate matter (PM10) 20 μg/m3 annual mean
Particulate matter (PM2.5) ** 25 μg/m3 24-hour mean
Particulate matter (PM2.5) 10 μg/m3 annual mean
Ozone (O3) 100 μg/m3 8-hour mean
Nitrogen Dioxide (NO2) 40 μg/m3 annual mean
Nitrogen Dioxide (NO2) 500 μg/m3 1-hour mean
Sulphur Dioxide (SO2) 20 μg/m3 24-hour mean
Sulphur Dioxide (SO2) 500 μg/m3 10-minute mean
* PM10 means particles with an aerodynamic diameter smaller than 10 microns (μm)
** PM2.5 means particles with an aerodynamic diameter smaller than 2.5 μm
Table 8.1: WHO Exposure Guidelines for Key Pollutants
These guidelines represent recommended exposure limits, but many cities have ambient air PM2.5
levels that exceed the maximum recommended levels by a factor of five or more. Even worse,
measurements taken where wood fires are used for indoor cooking (Park, 2003) found PM2.5
concentrations that sometimes exceeded 8,000μg/m3 – over 300 times higher than the WHO 24-hour
limit. This situation is probably repeated in many regions around the world.
Recognising the damage created by air pollution, in addition to its 2005 legislation the European
Union is now phasing in a new set of legislated exposure limits. Table 8.2 summarises the coverage of some of these Directives, most of which become mandatory over the period 2010 to 2015. (In some instances member states can apply for extensions of up to five years).
More information on the implementation of these regulations can be found at
http://ec.europa.eu/environment/air/quality/standards.htm Pollutant Exposure Limit Averaging period Fine particles (PM2.5) 25 μg/m3 1 year Sulphur dioxide (SO2) 350 μg/m3 1 hour Sulphur dioxide
(SO2) 125 μg/m3 24 hours
Nitrogen dioxide (NO2) 200 μg/m3 1 hour
Nitrogen dioxide (NO2) 40 μg/m3 1 year
PM10 50 μg/m3 24 hours
PM10 40 μg/m3 1 year
Lead (Pb) 0.5 μg/m3 1 year
Carbon monoxide (CO) 10 mg/m3 Max daily 8 hr mean
Benzene 5 μg/m3 1 year
Ozone 120 μg/m3 Max daily 8 hr mean
Polycyclic Aromatic Hydrocarbons 1 ng/m3 1 year
Table 8.2: European Union Air Quality Standards The ambitious targets now being set generate many challenges, as they not only take effect over relatively short lead times, but they also include a broader range of pollutants. Fortunately, many industries now accept that accelerated development of more efficient and lower polluting vehicles,
machinery and industrial processes, using cleaner fuels, is now a business imperative.
The following table summarises the US EPA’s ambient pollution limits established under the Clean Air Act (http://www.epa.gov/air/criteria.html). The limits are generally in line with those promulgated by the European Union (Table 8.2), and those recommended by the WHO (Table 8.1).
Pollutant Level Averaging Time
Carbon Monoxide 9 ppm (10 mg/m3) 8-hour
Carbon Monoxide 35 ppm (40 mg/m3) 1-hour
Lead 0.15 μg/m3 Rolling 3-Month Average
Nitrogen Dioxide 0.053 ppm (100 μg/m3) Annual (Arithmetic Mean)
Particulate Matter (PM10) 150 μg/m3 24-hour
Particulate Matter PM2.5) 15.0 μg/m3 Annual (Arithmetic Mean)
Particulate Matter (PM2.5)[24
hr]
35 μg/m3 24-hour
Ozone [8hr] 0.075 ppm (2008 std) 8-hour
Ozone [1hr] 0.12 ppm 1-hour
Sulphur Dioxide 0.03 ppm Annual (Arithmetic Mean)
Sulphur Dioxide 0.14 ppm 24-hour
Table 8.3: USA Clean Air Act - Ambient Pollutant Limits
Many other countries have similar limits or targets, some of which are based on either the WHO or the US limits.
China, for instance, has air quality standards which generally fall between the WHO and the US
levels. However, the Chinese standards do not include PM2.5, which is one of the most critical
pollutants from a health perspective.
Australia's ambient air quality standards, which were promulgated in June 1998 are legally binding on each level of government, and were required to be met by the year 2008. The latest State compliance reports, tabled in 2006, show generally good progress has been achieved, but many States still reported at least several non-compliance areas. Ozone and PM10 appear to be the pollutants where the greatest level of non-compliance exists.
Annex A1 - Pollutants and their Health Effects
This section reviews linkages between pollutants and human health in a little more detail. It will beuseful to have an understanding of these linkages when, later in the document, we examinepollutant emission levels from a range of fuels in the most significant energy-intensive applications.
Table 7.1, from a 2009 report published by the Victoria Transport Policy Institute, Canada (VPI 2009)summarises the key health effects of some common pollutants.
7.1 Regulated (Criteria) Pollutants
7.1.1 Particulates (PM)
"Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets. Particle pollution is made up of a number of components, including acids (such as nitrates and sulphates), organic chemicals, metals, and soil or dust particles.
he size of particles is directly linked to their potential for causing health problems. The main health concerns relate to particles that are 10 micrometers in diameter or smaller because those are the particles that generally pass through the throat and nose and enter the lungs. Once inhaled, these particles can affect the heart and lungs and cause serious health effects. EPA groups particle pollution into two categories: "Inhalable coarse particles," such as those found near roadways and dusty industries, are larger than 2.5 micrometers and smaller than 10 micrometers in diameter. "Fine particles," such as those found in smoke and haze, are 2.5 micrometers in diameter and smaller. These particles can be directly emitted from sources such as forest fires, or they can form when gases emitted from power plants, industries and automobiles react in the air.
7.1.2 Oxides of Nitrogen (NOx)
The term "Oxides of Nitrogen" covers several gaseous compounds, the most significant of which are nitric oxide (NO), nitrogen dioxide (NO2) and nitrous oxide (N2O).
These compounds are formed by a reaction between oxygen and nitrogen during high-temperature combustion, such as in an internal combustion engine or a high-temperature flame. Although these compounds are chemically different, they are often referred to collectively as NOx. NOx affects human health in two ways. Firstly, in their own right they irritate the eyes and the lungs and are believed to lower the body's resistance to infection. These symptoms are most severely experienced by those people who already have asthma. Nitrogen dioxide has also been proved to also adversely affect plant life.
Clinical studies have shown a relationship between hospital admissions and ambient NOx levels for respiratory problems experienced by otherwise healthy people. But the strongest reactions are encountered by patients who have pre-existing respiratory illnesses. Table 7.2 below provides some
examples.
Table 7.2: Examples of Dose Response to Excess Levels of Nitrous Oxide (NAS 1997)
52
In a second health-related environmental impact, NOx reacts with volatile organic compounds (VOCs)
in the presence of sunlight to form ozone (O3). Ozone is a precursor of photochemical smog, and is discussed separately in this section.
The temperatures and pressures found in the combustion of internal combustion engines are ideal for the formation of NOx, and in some American cities over 60% of all ambient NOx is attributed to motor vehicle sources.
But motor vehicles are not the only source. Industrial engines, furnaces and many industrial
processes also generate these compounds. Even nature is a source, with lightning strikes and even the decomposition of micro-bacteria in the soil making a contribution. From a climate change perspective nitrous oxide is of some significance. Although it is generally emitted in relatively low amounts, it is an extremely powerful greenhouse gas with a CO2 equivalence
of around 410. This number means that one tonne of nitrous oxide has the same impact on climate
change as 410 tonnes of CO2.
7.1.3 Volatile Organic Compounds (VOCs), including Hydrocarbons (HC)
Volatile Organic Compounds (VOCs) are compounds containing at least one carbon atom, excluding carbon monoxide and carbon dioxide, which evaporate readily to the atmosphere. VOCs include a wide range of individual substances from many substance classes such as hydrocarbons, halocarbons and oxygenates.
Major VOC emission sources are the organic solvents used in many consumer and commercial
products such as cleaning products, paints, commercial printing inks; transportation sector activities such as the exhaust emissions from cars and trucks; various industrial processes such as chemical manufacturing; and combustion of fossil and biomass fuels. Not all VOCs originate from man-made sources, however, in more populated and industrial areas man made emissions predominate. When VOCs are released to the atmosphere, they can react with other chemicals, notably oxides of nitrogen, in photochemical reactions to form ground-level ozone and particulate matter. These two air pollutants are the main ingredients of smog and cause serious health effects for humans, including many thousands of premature deaths, hospital admissions and emergency room visits every year.
Almost all ground-level ozone and in the order of two-thirds of particulate matter are formed in the atmosphere through the reactions of precursor substances, with VOCs being one of the most
significant. Consequently, reduction of atmospheric levels of particulate matter and ozone must be accomplished through reductions of precursors, such as VOCs. A number of hydrocarbon compounds, classified as “air toxics” are extremely hazardous to humans,
but many are only generated in very small quantities. Some air toxics are known to be carcinogenic and this group of chemicals is also suspected to play a role in the rapid growth of a number of “20th century” illnesses, including asthma. However, because their ambient concentrations are extremely low, it has not yet been possible to reliably establish dose response characteristics, nor to place a direct monetary cost on their exposure effects. Air toxics are discussed in some detail in Section 7.2.
7.1.4 Ozone (O3) Ozone is a gas simply composed of three oxygen atoms.
It is not usually emitted directly into the air, but at ground-level is created by a chemical reaction between oxides of nitrogen (NOx) and volatile organic compounds
(VOCs) in the presence of sunlight. Ozone has the same (Picture courtesy of US EPA)
53 chemical structure whether it occurs high above the earth or at ground-level, and can be "good" or "bad," depending on its location in the atmosphere. In the earth's lower atmosphere, ground-level ozone is considered "bad."
Motor vehicle exhaust and industrial emissions, gasoline vapours, and chemical solvents as well as natural sources emit NOx and VOCs that help form ozone, which is the primary constituent of
photochemical smog.
Many urban areas tend to have high levels of ground level ozone and its attendant smog haze, but even rural areas are also subject to increased levels when wind carries ozone and pollutants that form it long distances from their original sources.
Health Effects
People with lung disease, children, older adults, and people who are active can be affected when
ozone levels are unhealthy. Numerous scientific studies have linked ground-level ozone exposure to a variety of problems, including:
• airway irritation, coughing, and pain when taking a deep breath;
• wheezing and breathing difficulties during exercise or outdoor activities;
• inflammation, which is much like a sunburn on the skin;
• aggravation of asthma and increased susceptibility to respiratory illnesses like pneumonia
and bronchitis; and,
• permanent lung damage with repeated exposures.
Environmental Effects
Ground-level ozone can have detrimental effects on plants and ecosystems. These effects include:
• interfering with the ability of sensitive plants to produce and store food, making them more
susceptible to certain diseases, insects, other pollutants, competition and harsh weather;
• damaging the leaves of trees and other plants, negatively impacting the appearance of
urban vegetation, as well as vegetation in national parks and recreation areas; and
• reducing forest growth and crop yields, potentially impacting species diversity in
ecosystems.
Ozone also damages vegetation and ecosystems. In the United States alone, it is responsible for an estimated US$500 million in reduced crop production each year.
7.1.5 Carbon Monoxide (CO)
Carbon Monoxide (CO) is a colourless, odourless, poisonous gas composed of one atom each of
carbon and oxygen. It is formed when carbon-based fuel is not burned completely.
Motor vehicle exhaust is the most significant source of carbon monoxide in most developed
countries, and in highly urbanised areas, motor vehicles can account for up to 95% of the total.
Other non-road engines and vehicles (such as construction equipment) can account for the remaining engine-generated carbon monoxide emissions. Other sources include industrial processes (such as metals processing and chemical manufacturing), residential wood burning, and natural sources such as forest fires.
Exposure to indoor carbon monoxide can often be more dangerous than breathing outdoor
concentrations. Woodstoves, solid fuel heaters and hearths, cigarette smoke, gas and kerosene
space heaters are sources of carbon monoxide indoors and concentrations can rise to dangerous
levels if there is insufficient ventilation. Most LP Gas heaters are equipped with an oxygen depletion sensor which automatically turns off the heater if there is insufficient ventilation to sustain complete combustion.
54 Carbon monoxide can cause harmful health effects by reducing oxygen delivery to the body's organs (like the heart and brain) and tissues. Oxygen is transported around the body via the red blood cells by binding to a substance within the red blood cells called haemoglobin, which is also responsible for their red colour.
Haemoglobin takes up oxygen as blood passes through the lungs, and at the same time carbon
dioxide, produced by the body's metabolism, is released from the blood into the exhaled breath. The combination of oxygen with haemoglobin is called oxyhaemoglobin and this 'oxygenated' blood is carried away from the lungs through the bloodstream to all the tissues of the body.
Carbon monoxide can also bind to haemoglobin but does so about 240 times more tightly than
oxygen, forming a compound called carboxyhaemoglobin. This means that if both carbon monoxide and oxygen are inhaled, carbon monoxide will preferentially bind to haemoglobin. This reduces the amount of haemoglobin available to bind to oxygen, so the body and tissues become starved of oxygen.
Carboxyhaemoglobin also has direct effects on the blood vessels of the body - causing them to
become 'leaky'. This is seen especially in the brain, causing the brain to swell, leading to
unconsciousness and neurological damage.
The health threat from lower levels of carbon monoxide is most serious for those who suffer from heart disease, like angina, clogged arteries, or congestive heart failure. For a person with heart disease, a single exposure to carbon monoxide at low levels may cause chest pain and reduce that person's ability to exercise; repeated exposures may contribute to other cardiovascular effects.
But even healthy people can be affected by high levels of CO. People who breathe high levels of
carbon monoxide can develop vision problems, reduced ability to work or learn, reduced manual
dexterity, and difficulty performing complex tasks. At extremely high levels, carbon monoxide is poisonous and can cause death.
Carbon monoxide also contributes to the formation of ground level ozone, which can trigger serious
respiratory problems (see Section 7.1.4).
7.1.6 Fuel Sulphur Content and Sulphur Dioxide (SO2)
Sulphur dioxide causes a wide variety of health and environmental impacts because of the way it
reacts with other substances in the air. Particularly sensitive groups include people with asthma who are active outdoors and children, the elderly, and people with heart or lung disease. Peak levels of sulphur dioxide can cause temporary breathing difficulty for people with asthma who are active outdoors. Longer-term exposures to high levels of sulphur dioxide gas and particles cause respiratory illness and aggravate existing heart disease.
Sulphur dioxide also reacts with other chemicals in the air to form tiny sulphate particles. When
these are inhaled, they gather in the lungs and are associated with increased respiratory symptoms and disease, difficulty in breathing, and even premature death.
When sulphur dioxide and nitrogen oxides react with other substances in the air they can form acids, which fall to earth as rain, fog, snow, or dry particles – this phenomenon is commonly described as “acid rain”, which may be carried by the wind for hundreds of kilometres.
Acid rain damages forests and crops, changes the makeup of soil, and makes lakes and streams acidic and unsuitable for fish. Continued exposure over a long time changes the natural variety of plants and animals in an ecosystem.
Sulphur dioxide is generated in huge quantities, as Figure 7.3 below illustrates. (US EPA 2002)
55
Figure 7.3: Annual Sulphur Dioxide Emissions in the USA (2002), note logarithmic scale
Given the extensive human health impacts and acid rain damage to crops, ecology, buildings and
infrastructure, there is clearly a strong imperative to minimise emissions of this pollutant.
Although considerable progress has already been made through the mandating of low sulphur
gasoline and diesel fuels, and the introduction of emission reduction measures for power stations,
the chart shows that there is considerable scope for further reductions in other areas.
Particle emission rates from diesel engines have a linear relationship with sulphur content in the fuel.
The following chart illustrates this relationship.
Figure 7.4: Diesel Fuel Sulphur Content Versus Particle Emissions
Testing commissioned by the Australian Government (EA, 2003), summarised in Figure 7.4, utilised six fuels, with sulphur content ranging from 24ppm to 1700ppm. Testing was performed in an independent heavy-duty emission testing facility (Parsons Australia), using the transient “real world” composite urban emissions drive cycle (CUEDC). Two medium-duty diesel vehicles were tested, and the chart represents the averaged emission rates on each fuel. The high sulphur fuel effectively increased PM emissions by 300mg/km, to double the “base” emissions for these vehicles (no particle filter installed).
Relationship between Sulfur Content and Particle Emissions (Australian Testing)
0
100
200
300
400
500
600
700
0 500 1000 1500 2000
Sulfur (ppm)
PM (mg/km)
56
High sulphur fuels also inhibit the use of modern pollution control technologies, including exhaust
catalyst systems and diesel particle filters. Sulphur “poisons” the active surfaces of these devices and can seriously degrade their effectiveness.
LP Gas contains only very small concentrations of sulphur, and consequently emits little or no sulphur dioxide. It is the ideal energy source to replace many of the sulphur-bearing fuels still in use, particularly coal heaters and many industrial process heat sources.
7.1.7 Lead (Pb)
Lead is a widely used metal that, once released to the environment, can contaminate air, food,
water, or soil. Exposures to even small amounts of lead over a long time can accumulate to reach
harmful levels. Short-term exposure to high levels of lead may also cause harm. Lead can adversely affect the nervous, reproductive, digestive, cardiovascular blood-forming systems, and the kidney. In men, adverse reproductive effects include reduced sperm count and abnormal sperm. In women, adverse reproductive effects include reduced fertility, still-birth, or miscarriage. Children are a sensitive population as they absorb lead more readily and their developing nervous system puts them at increased risk for lead-related harm, including learning disabilities.
Lead additives were frequently used to raise the octane rating of gasoline and were a major source of airborne lead pollution. Most developed countries now ban the use of these additives. LP Gas contains no lead.
7.2 Air Toxic Compounds
Toxic air pollutants, also known as hazardous air pollutants (HAP), are those pollutants that are
known or suspected to cause cancer or other serious health effects, such as reproductive effects or
birth defects, or adverse environmental effects.
The US EPA is lists 187 pollutants as “Air Toxics”.
Although these chemicals are known to be
extremely hazardous to humans, many of them
exist in only extremely low concentrations in
ambient air, making it extremely difficult to
characterise their toxicity with any degree of
certainty. Figure 7.5 compares typical motor
vehicle engine-out emissions of some key air
toxics for the most widely available commercial
fuels (Anyon, 2002), based on data from an
Argonne National Laboratory report (Winebrake
J., 2000).
Note: CURE = Cancer Unit Risk Estimate, defined
as “the upper-bound excess lifetime cancer risk
estimated to result from continuous exposure to
and agent (e.g. chemical) at a concentration of 1 microgram per cubic metre in air or 1 microgram
per litre in water”. Hence the higher the CURE number, the higher the human cancer risk.
This document reviews the health effects of five air toxics - benzene, 1,3-butadiene, toluene, xylenes
and Polycyclic Aromatic Hydrocarbons (PAH). These five air toxics are ranked by the WHO as having
the greatest health damaging potential, based on a combination of their inherent toxicity and typical
human exposure levels.
Table 7.6, based on Australian Government data (NPI 2000) also highlights the extremely low air toxic
emission levels from LP Gas fuelled vehicles, compared with gasoline and diesel equivalents.
Figure 7.5: Comparison of Transport Sector Air
Toxic Emissions by Fuel Type
57
Air Toxic Emissions, Passenger Car Exhaust (g/km)
By Road Type
Road Type: Arterial Freeway Residential
Benzene
Gasoline 0.08291 0.08817 0.09541
Diesel 0.00334 0.00313 0.00518
LP Gas 0.00001 0.00001 0.00002
1,3-butadiene
Gasoline 0.01064 0.00993 0.01642
Diesel 0.00064 0.00059 0.00099
LP Gas 0.00010 0.00009 0.00015
PAHs
Gasoline 0.00668 0.00625 0.01035
Diesel 0.00674 0.00628 0.01041
LP Gas 0.00000 0.00000 0.00000
Toluene
Gasoline 0.05618 0.02531 0.05618
Diesel 0.01573 0.00710 0.01573
LP Gas 0.00000 0.00000 0.00000
Xylenes
Gasoline 0.08880 0.04175 0.08880
Diesel 0.03405 0.02516 0.03405
LP Gas 0.00000 0.00000 0.00000
Table 7.6: Passenger Car Air Toxic Emissions by Fuel and Road Type (NPI 2000)
People exposed to toxic air pollutants at sufficient concentrations and durations may have an
increased chance of getting cancer or experiencing other serious health effects. These health effects
can include damage to the immune system, as well as neurological, reproductive (e.g., reduced
fertility), developmental, respiratory and other health problems.
In addition to exposure from breathing air toxics, some toxic air pollutants such as mercury can
deposit onto soils or surface waters, where they are taken up by plants and ingested by animals and
are eventually magnified up through the food chain. Like humans, animals may experience health
problems if exposed to sufficient quantities of air toxics over time.
Once toxic air pollutants enter the body, some persistent toxic air pollutants accumulate in body
tissues. Predators typically accumulate even greater pollutant concentrations than their
contaminated prey. As a result, people and other animals at the top of the food chain that eat
contaminated fish or meat are exposed to concentrations that are much higher than the
concentrations in the water, air, or soil.
Humans are exposed to toxic air pollutants in many ways that can pose health risks, such as by:
• Breathing contaminated air.
• Eating contaminated food products, such as fish from contaminated waters; meat, milk, or
eggs from animals that fed on contaminated plants; and fruits and vegetables grown in
contaminated soil on which air toxics have been deposited.
• Drinking water contaminated by toxic air pollutants.
• Ingesting contaminated soil. Young children are especially vulnerable because they often
ingest soil from their hands or from objects they place in their mouths.
58
• Touching (making skin contact with) contaminated soil, dust, or water (for example, during
recreational use of contaminated water bodies).
PAHs are compounds that contain only hydrocarbon and carbon and are a group of over several
hundred organic chemicals with two or more fused aromatic rings. Two ring PAHs are found in the
vapour phase, two to five ring PAHs can be found in both the vapour and particulate phases and
PAHs consisting of five or more rings tend to be solids adsorbed onto other particles in the
atmosphere. Benzo-a-pyrene (B[a]P) is a five-ring compound and probably the most well known
PAH. B[a]P is often used a marker for PAHs.
PAHs are formed mainly as a result of incomplete combustion of organic materials during industrial
and other human activities, such as processing of coal and crude oil, combustion of natural gas,
combustion of refuse, wood burning stoves, motor vehicle exhaust, cooking, tobacco smoke, and
natural processes such as carbonisation.
7.2.1 Benzene
Benzene is a natural component of crude oil. Almost all benzene found at ground level comes from
human activities. It is emitted from industrial sources and a range of combustion sources including
motor vehicle exhaust and solid fuel combustion. Benzene is also emitted from tobacco smoke. The
major outdoor source is evaporative emissions and evaporation losses from motor vehicles, and
evaporation losses during the handling, distribution and storage of gasoline. Workers in industries
exposed to motor vehicle exhaust are at risk of exposure.
Benzene is naturally broken down by chemical reactions within the atmosphere. The length of time
that benzene vapour remains in the air varies between a few hours and a few days depending on
environmental factors, climate and the concentration of other chemicals in the air, such as nitrogen
and sulphur dioxide. It does not bio-accumulate in aquatic or terrestrial systems.
Inhalation is the dominant pathway for benzene exposure in humans. Smoking is an important
source of personal exposure. Extended travel in motorcars also produces exposures that are second
only to smoking as contributors to the intensity of overall exposure.
Current understanding of health effects of benzene are mainly derived from animal studies and
human health studies in the occupational setting.
Acute effects of benzene include skin and eye irritations, drowsiness, dizziness, headaches, and
vomiting. The most significant adverse effects of chronic benzene exposure are haematotoxicity,
genotoxicity, carcinogenicity and can also lead to birth defects in humans and animals. There
appears to be a dose-response relationship without any threshold effect. The mechanisms of
benzene toxicity are not well understood.
Benzene is carcinogenic and long term exposure can affect normal blood production and can be
harmful to the immune system. It can cause cancers and leukaemia (cancer of the tissues that form
white blood cells) in laboratory animals and human populations exposed for long periods, and has
been linked with birth defects in animals and humans.
Both the International Agency for Research and Cancer (IARC) and the US EPA have classified
benzene as known human carcinogens.
Although all in the population are susceptible to the adverse health effects of benzene, it is thought
that at levels occurring in the ambient atmosphere, benzene does not have short-term or acute
effects.
Even though adverse health effects have been documented with both acute and chronic exposures
to benzene, for the purposes of the derivation of exposure-response functions, the main health
endpoint that has been utilized is leukaemia.
59
7.2.2 1,3-Butadiene
1,3-butadiene is emitted from oil refineries and chemical manufacturing plants. The major source of
1,3-butadiene is incomplete combustion of gasoline and diesel fuel. 1,3-Butadiene is highly reactive
and can oxidise to form formaldehyde and acrolin, two toxic substances in their own right. 1,3-
Butadiene is emitted from industrial facilities, tobacco smoke and motor vehicle emissions. Workers
in industries that use or produce 1,3-butadiene or are exposed to motor vehicle exhaust are at risk of
exposure. The probable route of human exposure to 1,3-butadiene is through inhalation.
Exposure to 1,3-butadiene can irritate the eyes, nose and throat. Acute exposure to 1,3-butadiene
can cause central nervous system damage, blurred vision, nausea, fatigue, headache, decreased
pulse rate and pressure, and unconsciousness. Long term exposure to lower levels has shown
increases in heart and lung damage. There are inadequate human data (based on only a few
occupational studies) but sufficient animal data to suggest that 1,3-butadiene is a human carcinogen.
Chemical compounds closely related to 1,3-butadiene are known human carcinogens.
The US EPA classified 1,3-butadiene in Group B2: probable human carcinogen. IARC classifies 1,3
Butadiene as a probable human carcinogen. The recent WHO revision of air quality guidelines
concluded that 1,3-butadiene is probably carcinogenic to humans (Group 2A).
7.2.3 Polycyclic Aromatic Hydrocarbons
PAHs contain only hydrocarbon and carbon and are a group of over several hundred organic
chemicals with two or more fused aromatic rings. Benzo-a-Pyrene (B[a]P) is probably the most well
known PAH carcinogen and is found in the exhaust of engines (especially diesels) as well as being one
of many carcinogens found in cigarette smoke.
PAHs are formed mainly as a result of pyrolitic processes, especially the incomplete combustion of
organic materials during industrial and other human activities, such as processing of coal and crude
oil, combustion of natural gas, combustion of refuse, vehicle traffic, cooking, tobacco smoke, and
natural processes such as carbonisation.
Occupational PAH exposure can occur in petroleum manufacture and use, or where coal, wood or
other plant materials are burned. Most PAHs in air they are generally found attached to particulate
matter. Occupational exposure to PAH may occur in coal production plants, coking plants and coalgasification
sites.
Data from animal studies indicate that several PAH may induce a number of adverse effects including
carcinogenicity and reproductive toxicity. B[a]P is by far the most intensively studied PAH in
animals. The lung carcinogenicity of B[a]P is enhanced by co-exposure to other substances such as
cigarette smoke and probably airborne particulates. Results from epidemiological studies indicate an
increase in lung cancer occurs in humans exposed to coke oven emissions, roofing tar emissions, and
cigarette smoke. Each of these contains a number of PAH.
7.2.4 Toluene
Toluene is widespread in the environment due to its use in a variety of commercial and household
products and it is found in tobacco smoke. Indoor toluene levels can be higher than outdoor levels
during non-occupational exposure to paints and thinners, and also where tobacco smoke is present.
Sniffing glue or paint can lead to high exposures. Air pollution from vehicles is a major source of
exposure. Toluene is emitted during crude petroleum and natural gas extraction, and petroleum
refining. Workers in industries exposed to motor vehicle exhaust are at risk of exposure.
The central nervous system (CNS) is the primary target organ for toluene toxicity in both animals and
humans for acute and chronic exposure. CNS dysfunction (often reversible) and narcosis are
observed in humans exposed to low or moderate levels. Short term exposure to high levels of
60
toluene can result in light-headedness and euphoria. CNS depression occurs in chronic abusers
exposed to high levels.
Symptoms include cerebral atrophy, and impaired speech hearing and vision. Irritation of the upper
respiratory tract is associated with chronic inhalation. Toluene does not appear to be carcinogenic.
The US EPA has classified toluene in Group D, not classifiable as carcinogenic to human.
7.2.5 Xylenes
Xylenes are emitted during petroleum refining, solid fuel combustion, and are a component of
vehicle exhaust. They are also embodied in numerous domestic products.
Acute exposure to xylenes results in irritation of the respiratory tract, transient eye irritation and
neurological effects. Chronic inhalation exposure results in Central Nervous System (CNS) effects
such as headaches, dizziness, fatigue, tremors and un-coordination. Other effects of chronic
exposure include impaired pulmonary function, and possible affects on the blood and kidneys.
The evidence of developmental or reproductive effects on humans in inconclusive. Xylenes do not
appear to be carcinogenic.
Table 7.1, from a 2009 report published by the Victoria Transport Policy Institute, Canada (VPI 2009)summarises the key health effects of some common pollutants.
7.1 Regulated (Criteria) Pollutants
7.1.1 Particulates (PM)
"Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets. Particle pollution is made up of a number of components, including acids (such as nitrates and sulphates), organic chemicals, metals, and soil or dust particles.
he size of particles is directly linked to their potential for causing health problems. The main health concerns relate to particles that are 10 micrometers in diameter or smaller because those are the particles that generally pass through the throat and nose and enter the lungs. Once inhaled, these particles can affect the heart and lungs and cause serious health effects. EPA groups particle pollution into two categories: "Inhalable coarse particles," such as those found near roadways and dusty industries, are larger than 2.5 micrometers and smaller than 10 micrometers in diameter. "Fine particles," such as those found in smoke and haze, are 2.5 micrometers in diameter and smaller. These particles can be directly emitted from sources such as forest fires, or they can form when gases emitted from power plants, industries and automobiles react in the air.
7.1.2 Oxides of Nitrogen (NOx)
The term "Oxides of Nitrogen" covers several gaseous compounds, the most significant of which are nitric oxide (NO), nitrogen dioxide (NO2) and nitrous oxide (N2O).
These compounds are formed by a reaction between oxygen and nitrogen during high-temperature combustion, such as in an internal combustion engine or a high-temperature flame. Although these compounds are chemically different, they are often referred to collectively as NOx. NOx affects human health in two ways. Firstly, in their own right they irritate the eyes and the lungs and are believed to lower the body's resistance to infection. These symptoms are most severely experienced by those people who already have asthma. Nitrogen dioxide has also been proved to also adversely affect plant life.
Clinical studies have shown a relationship between hospital admissions and ambient NOx levels for respiratory problems experienced by otherwise healthy people. But the strongest reactions are encountered by patients who have pre-existing respiratory illnesses. Table 7.2 below provides some
examples.
Table 7.2: Examples of Dose Response to Excess Levels of Nitrous Oxide (NAS 1997)
52
In a second health-related environmental impact, NOx reacts with volatile organic compounds (VOCs)
in the presence of sunlight to form ozone (O3). Ozone is a precursor of photochemical smog, and is discussed separately in this section.
The temperatures and pressures found in the combustion of internal combustion engines are ideal for the formation of NOx, and in some American cities over 60% of all ambient NOx is attributed to motor vehicle sources.
But motor vehicles are not the only source. Industrial engines, furnaces and many industrial
processes also generate these compounds. Even nature is a source, with lightning strikes and even the decomposition of micro-bacteria in the soil making a contribution. From a climate change perspective nitrous oxide is of some significance. Although it is generally emitted in relatively low amounts, it is an extremely powerful greenhouse gas with a CO2 equivalence
of around 410. This number means that one tonne of nitrous oxide has the same impact on climate
change as 410 tonnes of CO2.
7.1.3 Volatile Organic Compounds (VOCs), including Hydrocarbons (HC)
Volatile Organic Compounds (VOCs) are compounds containing at least one carbon atom, excluding carbon monoxide and carbon dioxide, which evaporate readily to the atmosphere. VOCs include a wide range of individual substances from many substance classes such as hydrocarbons, halocarbons and oxygenates.
Major VOC emission sources are the organic solvents used in many consumer and commercial
products such as cleaning products, paints, commercial printing inks; transportation sector activities such as the exhaust emissions from cars and trucks; various industrial processes such as chemical manufacturing; and combustion of fossil and biomass fuels. Not all VOCs originate from man-made sources, however, in more populated and industrial areas man made emissions predominate. When VOCs are released to the atmosphere, they can react with other chemicals, notably oxides of nitrogen, in photochemical reactions to form ground-level ozone and particulate matter. These two air pollutants are the main ingredients of smog and cause serious health effects for humans, including many thousands of premature deaths, hospital admissions and emergency room visits every year.
Almost all ground-level ozone and in the order of two-thirds of particulate matter are formed in the atmosphere through the reactions of precursor substances, with VOCs being one of the most
significant. Consequently, reduction of atmospheric levels of particulate matter and ozone must be accomplished through reductions of precursors, such as VOCs. A number of hydrocarbon compounds, classified as “air toxics” are extremely hazardous to humans,
but many are only generated in very small quantities. Some air toxics are known to be carcinogenic and this group of chemicals is also suspected to play a role in the rapid growth of a number of “20th century” illnesses, including asthma. However, because their ambient concentrations are extremely low, it has not yet been possible to reliably establish dose response characteristics, nor to place a direct monetary cost on their exposure effects. Air toxics are discussed in some detail in Section 7.2.
7.1.4 Ozone (O3) Ozone is a gas simply composed of three oxygen atoms.
It is not usually emitted directly into the air, but at ground-level is created by a chemical reaction between oxides of nitrogen (NOx) and volatile organic compounds
(VOCs) in the presence of sunlight. Ozone has the same (Picture courtesy of US EPA)
53 chemical structure whether it occurs high above the earth or at ground-level, and can be "good" or "bad," depending on its location in the atmosphere. In the earth's lower atmosphere, ground-level ozone is considered "bad."
Motor vehicle exhaust and industrial emissions, gasoline vapours, and chemical solvents as well as natural sources emit NOx and VOCs that help form ozone, which is the primary constituent of
photochemical smog.
Many urban areas tend to have high levels of ground level ozone and its attendant smog haze, but even rural areas are also subject to increased levels when wind carries ozone and pollutants that form it long distances from their original sources.
Health Effects
People with lung disease, children, older adults, and people who are active can be affected when
ozone levels are unhealthy. Numerous scientific studies have linked ground-level ozone exposure to a variety of problems, including:
• airway irritation, coughing, and pain when taking a deep breath;
• wheezing and breathing difficulties during exercise or outdoor activities;
• inflammation, which is much like a sunburn on the skin;
• aggravation of asthma and increased susceptibility to respiratory illnesses like pneumonia
and bronchitis; and,
• permanent lung damage with repeated exposures.
Environmental Effects
Ground-level ozone can have detrimental effects on plants and ecosystems. These effects include:
• interfering with the ability of sensitive plants to produce and store food, making them more
susceptible to certain diseases, insects, other pollutants, competition and harsh weather;
• damaging the leaves of trees and other plants, negatively impacting the appearance of
urban vegetation, as well as vegetation in national parks and recreation areas; and
• reducing forest growth and crop yields, potentially impacting species diversity in
ecosystems.
Ozone also damages vegetation and ecosystems. In the United States alone, it is responsible for an estimated US$500 million in reduced crop production each year.
7.1.5 Carbon Monoxide (CO)
Carbon Monoxide (CO) is a colourless, odourless, poisonous gas composed of one atom each of
carbon and oxygen. It is formed when carbon-based fuel is not burned completely.
Motor vehicle exhaust is the most significant source of carbon monoxide in most developed
countries, and in highly urbanised areas, motor vehicles can account for up to 95% of the total.
Other non-road engines and vehicles (such as construction equipment) can account for the remaining engine-generated carbon monoxide emissions. Other sources include industrial processes (such as metals processing and chemical manufacturing), residential wood burning, and natural sources such as forest fires.
Exposure to indoor carbon monoxide can often be more dangerous than breathing outdoor
concentrations. Woodstoves, solid fuel heaters and hearths, cigarette smoke, gas and kerosene
space heaters are sources of carbon monoxide indoors and concentrations can rise to dangerous
levels if there is insufficient ventilation. Most LP Gas heaters are equipped with an oxygen depletion sensor which automatically turns off the heater if there is insufficient ventilation to sustain complete combustion.
54 Carbon monoxide can cause harmful health effects by reducing oxygen delivery to the body's organs (like the heart and brain) and tissues. Oxygen is transported around the body via the red blood cells by binding to a substance within the red blood cells called haemoglobin, which is also responsible for their red colour.
Haemoglobin takes up oxygen as blood passes through the lungs, and at the same time carbon
dioxide, produced by the body's metabolism, is released from the blood into the exhaled breath. The combination of oxygen with haemoglobin is called oxyhaemoglobin and this 'oxygenated' blood is carried away from the lungs through the bloodstream to all the tissues of the body.
Carbon monoxide can also bind to haemoglobin but does so about 240 times more tightly than
oxygen, forming a compound called carboxyhaemoglobin. This means that if both carbon monoxide and oxygen are inhaled, carbon monoxide will preferentially bind to haemoglobin. This reduces the amount of haemoglobin available to bind to oxygen, so the body and tissues become starved of oxygen.
Carboxyhaemoglobin also has direct effects on the blood vessels of the body - causing them to
become 'leaky'. This is seen especially in the brain, causing the brain to swell, leading to
unconsciousness and neurological damage.
The health threat from lower levels of carbon monoxide is most serious for those who suffer from heart disease, like angina, clogged arteries, or congestive heart failure. For a person with heart disease, a single exposure to carbon monoxide at low levels may cause chest pain and reduce that person's ability to exercise; repeated exposures may contribute to other cardiovascular effects.
But even healthy people can be affected by high levels of CO. People who breathe high levels of
carbon monoxide can develop vision problems, reduced ability to work or learn, reduced manual
dexterity, and difficulty performing complex tasks. At extremely high levels, carbon monoxide is poisonous and can cause death.
Carbon monoxide also contributes to the formation of ground level ozone, which can trigger serious
respiratory problems (see Section 7.1.4).
7.1.6 Fuel Sulphur Content and Sulphur Dioxide (SO2)
Sulphur dioxide causes a wide variety of health and environmental impacts because of the way it
reacts with other substances in the air. Particularly sensitive groups include people with asthma who are active outdoors and children, the elderly, and people with heart or lung disease. Peak levels of sulphur dioxide can cause temporary breathing difficulty for people with asthma who are active outdoors. Longer-term exposures to high levels of sulphur dioxide gas and particles cause respiratory illness and aggravate existing heart disease.
Sulphur dioxide also reacts with other chemicals in the air to form tiny sulphate particles. When
these are inhaled, they gather in the lungs and are associated with increased respiratory symptoms and disease, difficulty in breathing, and even premature death.
When sulphur dioxide and nitrogen oxides react with other substances in the air they can form acids, which fall to earth as rain, fog, snow, or dry particles – this phenomenon is commonly described as “acid rain”, which may be carried by the wind for hundreds of kilometres.
Acid rain damages forests and crops, changes the makeup of soil, and makes lakes and streams acidic and unsuitable for fish. Continued exposure over a long time changes the natural variety of plants and animals in an ecosystem.
Sulphur dioxide is generated in huge quantities, as Figure 7.3 below illustrates. (US EPA 2002)
55
Figure 7.3: Annual Sulphur Dioxide Emissions in the USA (2002), note logarithmic scale
Given the extensive human health impacts and acid rain damage to crops, ecology, buildings and
infrastructure, there is clearly a strong imperative to minimise emissions of this pollutant.
Although considerable progress has already been made through the mandating of low sulphur
gasoline and diesel fuels, and the introduction of emission reduction measures for power stations,
the chart shows that there is considerable scope for further reductions in other areas.
Particle emission rates from diesel engines have a linear relationship with sulphur content in the fuel.
The following chart illustrates this relationship.
Figure 7.4: Diesel Fuel Sulphur Content Versus Particle Emissions
Testing commissioned by the Australian Government (EA, 2003), summarised in Figure 7.4, utilised six fuels, with sulphur content ranging from 24ppm to 1700ppm. Testing was performed in an independent heavy-duty emission testing facility (Parsons Australia), using the transient “real world” composite urban emissions drive cycle (CUEDC). Two medium-duty diesel vehicles were tested, and the chart represents the averaged emission rates on each fuel. The high sulphur fuel effectively increased PM emissions by 300mg/km, to double the “base” emissions for these vehicles (no particle filter installed).
Relationship between Sulfur Content and Particle Emissions (Australian Testing)
0
100
200
300
400
500
600
700
0 500 1000 1500 2000
Sulfur (ppm)
PM (mg/km)
56
High sulphur fuels also inhibit the use of modern pollution control technologies, including exhaust
catalyst systems and diesel particle filters. Sulphur “poisons” the active surfaces of these devices and can seriously degrade their effectiveness.
LP Gas contains only very small concentrations of sulphur, and consequently emits little or no sulphur dioxide. It is the ideal energy source to replace many of the sulphur-bearing fuels still in use, particularly coal heaters and many industrial process heat sources.
7.1.7 Lead (Pb)
Lead is a widely used metal that, once released to the environment, can contaminate air, food,
water, or soil. Exposures to even small amounts of lead over a long time can accumulate to reach
harmful levels. Short-term exposure to high levels of lead may also cause harm. Lead can adversely affect the nervous, reproductive, digestive, cardiovascular blood-forming systems, and the kidney. In men, adverse reproductive effects include reduced sperm count and abnormal sperm. In women, adverse reproductive effects include reduced fertility, still-birth, or miscarriage. Children are a sensitive population as they absorb lead more readily and their developing nervous system puts them at increased risk for lead-related harm, including learning disabilities.
Lead additives were frequently used to raise the octane rating of gasoline and were a major source of airborne lead pollution. Most developed countries now ban the use of these additives. LP Gas contains no lead.
7.2 Air Toxic Compounds
Toxic air pollutants, also known as hazardous air pollutants (HAP), are those pollutants that are
known or suspected to cause cancer or other serious health effects, such as reproductive effects or
birth defects, or adverse environmental effects.
The US EPA is lists 187 pollutants as “Air Toxics”.
Although these chemicals are known to be
extremely hazardous to humans, many of them
exist in only extremely low concentrations in
ambient air, making it extremely difficult to
characterise their toxicity with any degree of
certainty. Figure 7.5 compares typical motor
vehicle engine-out emissions of some key air
toxics for the most widely available commercial
fuels (Anyon, 2002), based on data from an
Argonne National Laboratory report (Winebrake
J., 2000).
Note: CURE = Cancer Unit Risk Estimate, defined
as “the upper-bound excess lifetime cancer risk
estimated to result from continuous exposure to
and agent (e.g. chemical) at a concentration of 1 microgram per cubic metre in air or 1 microgram
per litre in water”. Hence the higher the CURE number, the higher the human cancer risk.
This document reviews the health effects of five air toxics - benzene, 1,3-butadiene, toluene, xylenes
and Polycyclic Aromatic Hydrocarbons (PAH). These five air toxics are ranked by the WHO as having
the greatest health damaging potential, based on a combination of their inherent toxicity and typical
human exposure levels.
Table 7.6, based on Australian Government data (NPI 2000) also highlights the extremely low air toxic
emission levels from LP Gas fuelled vehicles, compared with gasoline and diesel equivalents.
Figure 7.5: Comparison of Transport Sector Air
Toxic Emissions by Fuel Type
57
Air Toxic Emissions, Passenger Car Exhaust (g/km)
By Road Type
Road Type: Arterial Freeway Residential
Benzene
Gasoline 0.08291 0.08817 0.09541
Diesel 0.00334 0.00313 0.00518
LP Gas 0.00001 0.00001 0.00002
1,3-butadiene
Gasoline 0.01064 0.00993 0.01642
Diesel 0.00064 0.00059 0.00099
LP Gas 0.00010 0.00009 0.00015
PAHs
Gasoline 0.00668 0.00625 0.01035
Diesel 0.00674 0.00628 0.01041
LP Gas 0.00000 0.00000 0.00000
Toluene
Gasoline 0.05618 0.02531 0.05618
Diesel 0.01573 0.00710 0.01573
LP Gas 0.00000 0.00000 0.00000
Xylenes
Gasoline 0.08880 0.04175 0.08880
Diesel 0.03405 0.02516 0.03405
LP Gas 0.00000 0.00000 0.00000
Table 7.6: Passenger Car Air Toxic Emissions by Fuel and Road Type (NPI 2000)
People exposed to toxic air pollutants at sufficient concentrations and durations may have an
increased chance of getting cancer or experiencing other serious health effects. These health effects
can include damage to the immune system, as well as neurological, reproductive (e.g., reduced
fertility), developmental, respiratory and other health problems.
In addition to exposure from breathing air toxics, some toxic air pollutants such as mercury can
deposit onto soils or surface waters, where they are taken up by plants and ingested by animals and
are eventually magnified up through the food chain. Like humans, animals may experience health
problems if exposed to sufficient quantities of air toxics over time.
Once toxic air pollutants enter the body, some persistent toxic air pollutants accumulate in body
tissues. Predators typically accumulate even greater pollutant concentrations than their
contaminated prey. As a result, people and other animals at the top of the food chain that eat
contaminated fish or meat are exposed to concentrations that are much higher than the
concentrations in the water, air, or soil.
Humans are exposed to toxic air pollutants in many ways that can pose health risks, such as by:
• Breathing contaminated air.
• Eating contaminated food products, such as fish from contaminated waters; meat, milk, or
eggs from animals that fed on contaminated plants; and fruits and vegetables grown in
contaminated soil on which air toxics have been deposited.
• Drinking water contaminated by toxic air pollutants.
• Ingesting contaminated soil. Young children are especially vulnerable because they often
ingest soil from their hands or from objects they place in their mouths.
58
• Touching (making skin contact with) contaminated soil, dust, or water (for example, during
recreational use of contaminated water bodies).
PAHs are compounds that contain only hydrocarbon and carbon and are a group of over several
hundred organic chemicals with two or more fused aromatic rings. Two ring PAHs are found in the
vapour phase, two to five ring PAHs can be found in both the vapour and particulate phases and
PAHs consisting of five or more rings tend to be solids adsorbed onto other particles in the
atmosphere. Benzo-a-pyrene (B[a]P) is a five-ring compound and probably the most well known
PAH. B[a]P is often used a marker for PAHs.
PAHs are formed mainly as a result of incomplete combustion of organic materials during industrial
and other human activities, such as processing of coal and crude oil, combustion of natural gas,
combustion of refuse, wood burning stoves, motor vehicle exhaust, cooking, tobacco smoke, and
natural processes such as carbonisation.
7.2.1 Benzene
Benzene is a natural component of crude oil. Almost all benzene found at ground level comes from
human activities. It is emitted from industrial sources and a range of combustion sources including
motor vehicle exhaust and solid fuel combustion. Benzene is also emitted from tobacco smoke. The
major outdoor source is evaporative emissions and evaporation losses from motor vehicles, and
evaporation losses during the handling, distribution and storage of gasoline. Workers in industries
exposed to motor vehicle exhaust are at risk of exposure.
Benzene is naturally broken down by chemical reactions within the atmosphere. The length of time
that benzene vapour remains in the air varies between a few hours and a few days depending on
environmental factors, climate and the concentration of other chemicals in the air, such as nitrogen
and sulphur dioxide. It does not bio-accumulate in aquatic or terrestrial systems.
Inhalation is the dominant pathway for benzene exposure in humans. Smoking is an important
source of personal exposure. Extended travel in motorcars also produces exposures that are second
only to smoking as contributors to the intensity of overall exposure.
Current understanding of health effects of benzene are mainly derived from animal studies and
human health studies in the occupational setting.
Acute effects of benzene include skin and eye irritations, drowsiness, dizziness, headaches, and
vomiting. The most significant adverse effects of chronic benzene exposure are haematotoxicity,
genotoxicity, carcinogenicity and can also lead to birth defects in humans and animals. There
appears to be a dose-response relationship without any threshold effect. The mechanisms of
benzene toxicity are not well understood.
Benzene is carcinogenic and long term exposure can affect normal blood production and can be
harmful to the immune system. It can cause cancers and leukaemia (cancer of the tissues that form
white blood cells) in laboratory animals and human populations exposed for long periods, and has
been linked with birth defects in animals and humans.
Both the International Agency for Research and Cancer (IARC) and the US EPA have classified
benzene as known human carcinogens.
Although all in the population are susceptible to the adverse health effects of benzene, it is thought
that at levels occurring in the ambient atmosphere, benzene does not have short-term or acute
effects.
Even though adverse health effects have been documented with both acute and chronic exposures
to benzene, for the purposes of the derivation of exposure-response functions, the main health
endpoint that has been utilized is leukaemia.
59
7.2.2 1,3-Butadiene
1,3-butadiene is emitted from oil refineries and chemical manufacturing plants. The major source of
1,3-butadiene is incomplete combustion of gasoline and diesel fuel. 1,3-Butadiene is highly reactive
and can oxidise to form formaldehyde and acrolin, two toxic substances in their own right. 1,3-
Butadiene is emitted from industrial facilities, tobacco smoke and motor vehicle emissions. Workers
in industries that use or produce 1,3-butadiene or are exposed to motor vehicle exhaust are at risk of
exposure. The probable route of human exposure to 1,3-butadiene is through inhalation.
Exposure to 1,3-butadiene can irritate the eyes, nose and throat. Acute exposure to 1,3-butadiene
can cause central nervous system damage, blurred vision, nausea, fatigue, headache, decreased
pulse rate and pressure, and unconsciousness. Long term exposure to lower levels has shown
increases in heart and lung damage. There are inadequate human data (based on only a few
occupational studies) but sufficient animal data to suggest that 1,3-butadiene is a human carcinogen.
Chemical compounds closely related to 1,3-butadiene are known human carcinogens.
The US EPA classified 1,3-butadiene in Group B2: probable human carcinogen. IARC classifies 1,3
Butadiene as a probable human carcinogen. The recent WHO revision of air quality guidelines
concluded that 1,3-butadiene is probably carcinogenic to humans (Group 2A).
7.2.3 Polycyclic Aromatic Hydrocarbons
PAHs contain only hydrocarbon and carbon and are a group of over several hundred organic
chemicals with two or more fused aromatic rings. Benzo-a-Pyrene (B[a]P) is probably the most well
known PAH carcinogen and is found in the exhaust of engines (especially diesels) as well as being one
of many carcinogens found in cigarette smoke.
PAHs are formed mainly as a result of pyrolitic processes, especially the incomplete combustion of
organic materials during industrial and other human activities, such as processing of coal and crude
oil, combustion of natural gas, combustion of refuse, vehicle traffic, cooking, tobacco smoke, and
natural processes such as carbonisation.
Occupational PAH exposure can occur in petroleum manufacture and use, or where coal, wood or
other plant materials are burned. Most PAHs in air they are generally found attached to particulate
matter. Occupational exposure to PAH may occur in coal production plants, coking plants and coalgasification
sites.
Data from animal studies indicate that several PAH may induce a number of adverse effects including
carcinogenicity and reproductive toxicity. B[a]P is by far the most intensively studied PAH in
animals. The lung carcinogenicity of B[a]P is enhanced by co-exposure to other substances such as
cigarette smoke and probably airborne particulates. Results from epidemiological studies indicate an
increase in lung cancer occurs in humans exposed to coke oven emissions, roofing tar emissions, and
cigarette smoke. Each of these contains a number of PAH.
7.2.4 Toluene
Toluene is widespread in the environment due to its use in a variety of commercial and household
products and it is found in tobacco smoke. Indoor toluene levels can be higher than outdoor levels
during non-occupational exposure to paints and thinners, and also where tobacco smoke is present.
Sniffing glue or paint can lead to high exposures. Air pollution from vehicles is a major source of
exposure. Toluene is emitted during crude petroleum and natural gas extraction, and petroleum
refining. Workers in industries exposed to motor vehicle exhaust are at risk of exposure.
The central nervous system (CNS) is the primary target organ for toluene toxicity in both animals and
humans for acute and chronic exposure. CNS dysfunction (often reversible) and narcosis are
observed in humans exposed to low or moderate levels. Short term exposure to high levels of
60
toluene can result in light-headedness and euphoria. CNS depression occurs in chronic abusers
exposed to high levels.
Symptoms include cerebral atrophy, and impaired speech hearing and vision. Irritation of the upper
respiratory tract is associated with chronic inhalation. Toluene does not appear to be carcinogenic.
The US EPA has classified toluene in Group D, not classifiable as carcinogenic to human.
7.2.5 Xylenes
Xylenes are emitted during petroleum refining, solid fuel combustion, and are a component of
vehicle exhaust. They are also embodied in numerous domestic products.
Acute exposure to xylenes results in irritation of the respiratory tract, transient eye irritation and
neurological effects. Chronic inhalation exposure results in Central Nervous System (CNS) effects
such as headaches, dizziness, fatigue, tremors and un-coordination. Other effects of chronic
exposure include impaired pulmonary function, and possible affects on the blood and kidneys.
The evidence of developmental or reproductive effects on humans in inconclusive. Xylenes do not
appear to be carcinogenic.
Conclusions
Life on this planet depends on energy for its very existence. We need controllable energy to feed
and nurture our families, provide heat and light, and transport goods and people to their
destinations. Industry and businesses need energy to produce the goods and services we
demand.
But there can be a downside. Every year countless numbers of the earth's population have their
lives cut short, or suffer serious illness through exposure to combustion pollutants. The social and economic consequences are enormous, but can be minimized by using cleaner fuels.
Making “clean fuel” choices can directly help to improve the wellbeing of whole communities.
Improvements in public health flowing from the use of cleaner fuels not only reduces the cost of
providing health care and social services, but also contributes to the broader economy by helping to avoid the impacts of diminished productivity. Solid fuels, ranging from coal, through to wood, crop waste and even animal dung can, when used for cooking and heating, expose families to dangerous levels of pollution – often 20 or even 100 times higher than recommended maximum limits. The use of wood as a combustion fuel represents not only a highly visible consumption of our limited forest resources, but also has a very high impact on the environment and consequently on our health. Unfortunately the communities most affected by the use of these fuels are often also the poorest, so reliance must be placed on governments and aid agencies to direct more emphasis and resources towards programs to alleviate the intense suffering that results from the use of these dangerous energy sources.
Even the commonplace and convenient liquid fuels, such as diesel and gasoline, continue to
create serious levels of pollution in most developed countries, despite ever-tighter regulation of
the appliances and vehicles using these fuels. To illustrate this, the table below summarises and compares the pollutant and greenhouse emission characteristics of the principal transport fuels, relative to gasoline as a baseline (Anyon,
2002).
Gasoline Diesel CNG LP GAS
Gaseous Pollutants O O √ √
Particulates O X √ √
GHG Emissions O √ √ √
Air Toxics O X √ √
(Legend: √=better, O=neutral, X=worse, ?=Uncertain
Overall, LP Gas rates very highly and gives little or no ground to any others in the table, across all of the features considered to be of greatest importance in a general-purpose fuel. With its
intrinsically clean burning characteristics, LP Gas offers a practical avenue towards cleaning up the air we breathe.
As well as outperforming most traditional fuels, from a health perspective, LP Gas is readily
available, convenient and is frequently a lower cost alternative to other energy sources.
and nurture our families, provide heat and light, and transport goods and people to their
destinations. Industry and businesses need energy to produce the goods and services we
demand.
But there can be a downside. Every year countless numbers of the earth's population have their
lives cut short, or suffer serious illness through exposure to combustion pollutants. The social and economic consequences are enormous, but can be minimized by using cleaner fuels.
Making “clean fuel” choices can directly help to improve the wellbeing of whole communities.
Improvements in public health flowing from the use of cleaner fuels not only reduces the cost of
providing health care and social services, but also contributes to the broader economy by helping to avoid the impacts of diminished productivity. Solid fuels, ranging from coal, through to wood, crop waste and even animal dung can, when used for cooking and heating, expose families to dangerous levels of pollution – often 20 or even 100 times higher than recommended maximum limits. The use of wood as a combustion fuel represents not only a highly visible consumption of our limited forest resources, but also has a very high impact on the environment and consequently on our health. Unfortunately the communities most affected by the use of these fuels are often also the poorest, so reliance must be placed on governments and aid agencies to direct more emphasis and resources towards programs to alleviate the intense suffering that results from the use of these dangerous energy sources.
Even the commonplace and convenient liquid fuels, such as diesel and gasoline, continue to
create serious levels of pollution in most developed countries, despite ever-tighter regulation of
the appliances and vehicles using these fuels. To illustrate this, the table below summarises and compares the pollutant and greenhouse emission characteristics of the principal transport fuels, relative to gasoline as a baseline (Anyon,
2002).
Gasoline Diesel CNG LP GAS
Gaseous Pollutants O O √ √
Particulates O X √ √
GHG Emissions O √ √ √
Air Toxics O X √ √
(Legend: √=better, O=neutral, X=worse, ?=Uncertain
Overall, LP Gas rates very highly and gives little or no ground to any others in the table, across all of the features considered to be of greatest importance in a general-purpose fuel. With its
intrinsically clean burning characteristics, LP Gas offers a practical avenue towards cleaning up the air we breathe.
As well as outperforming most traditional fuels, from a health perspective, LP Gas is readily
available, convenient and is frequently a lower cost alternative to other energy sources.
LP Gas in Key Applications
The value of switching to LP Gas as an energy source can be demonstrated by examining some
practical applications. Using independent research and practical test data to evaluate and
compare a range of commercially available liquid and gaseous fuels, together with some
“harvested” solid fuels, the health and economic benefits of using LP Gas become self-evident.
The applications discussed include:
• Road transport
• Cooking (focusing principally on developing regions)
• Residential space and water heating
• Electrical power generation
• Other Applications
Annexes to this report provide more in-depth coverage of several topics for readers who may
wish to explore specific technical issues in more detail.
Based on their relative emission rates in each application, each fuel is assessed in relation to its
impact on human health and, where feasible, estimates are made of the consequential economic
impacts of human exposure to each fuel, in each of the applications discussed.
Where it is practical to do so, data is presented graphically, using consistent charting formats. For instance, pollutant emissions relevant to each fuel are displayed on a horizontally oriented bar chart similar to that shown opposite, together with numerical values. Units of measurement are those most appropriate to the application (for instance grams per kilometre for road
transport or grams per megajoule for heating). Pollutant emission rates are based on independent test reports from recognised testing or research organisations. Given the inherent variability of emission test results, even from appliances or vehicles of nominally the same type and technology level, data from multiple tests have been aggregated to generate a representative average value, wherever possible. Where adequate data is available, typical health costs for each pollutant, in the context of each specific application, will also be
displayed in a vertically oriented chart style, for each fuel type (see opposite). Again, health costs are reported in units appropriate to the application. Where it is not feasible to quantify health impacts in monetary terms, the differences are expressed as ratios or as qualitative discussion.
Calculated health costs can vary greatly according to a number of local and regional factors. These include: population density, income levels, health care costs and the extent to which social services are available. (For a more detailed discussion of the health and economic impacts of different pollutants, please refer to Section 4.1. Moreover, pollutant emission rates vary considerably (both in absolute terms and relative to one another) in response to a number of factors, including: the type of appliance, its operating principles, technology levels, the presence or otherwise of post-combustion pollution reduction systems and typical duty cycles. For these reasons, although they have been accounted for wherever it has been feasible to do so, estimates of overall pollutant emissions may not be as precise as those for, say, CO2. For any given fuel CO2 is accurately calculated by simply multiplying the mass of fuel consumed by a single constant number, regardless of the application for which
the fuel is used or the technologies employed.
5.1 Road Transport
Gasoline and diesel have been the principal fuels used in mainstream road transport for over a
century. But concerns over unhealthy air, climate change and dwindling reserves, coupled with
the potential for disruptions to supply, have led to greatly increased availability of alternative,
lower polluting energy sources for motor vehicles. Since the middle of the 20th century, motor vehicle use has been closely associated with public health. This issue was brought to the forefront in California, where a rapidly growing and highly motorised population was subjected to severe photochemical smog episodes caused mainly by emissions of hydrocarbon products and oxides of nitrogen which reacted in the presence of California's strong sunlight. The severe incidence of respiratory and heart related illnesses attributable to the smog, coupled with the loss of visual amenity, led to the introduction of regulated limits for pollutant emissions from new cars and periodic checks on in used cars to ensure that they were being properly maintained.
The rapid increase in popularity of diesel powered vehicles, particularly in Europe and Asia, has
focused a great deal of attention on the adverse health impacts of fine particulate matter (PM),
which is emitted from diesel engines at much higher rates than from gasoline or gaseous fuelled
engines.
The particles generated by internal combustion engines are especially dangerous because of their
extremely small size, with most particles less than one micron (1/1000 mm) diameter. These tiny
particles can penetrate into the deepest and most sensitive parts of the lung, even passing
through the lung tissue directly into the bloodstream. Fine particles have been designated by the
US EPA as a cancer causing pollutant, and are also directly the cause of serious respiratory and
cardiac diseases and possibly brain damage.
For these reasons, the monetary health impact attached to PM is typically around 20 to 30 times
higher per kilogram than for VOCs or NOx, and over 100 times higher than for CO.
Over recent years, controlling PM emissions has been the highest priority for regulators, and the
maximum permitted emission levels have been reduced by a factor of 28 over the past decade or
so. Many new technologies to reduce particle production inside the engine, and to filter particles
out of the exhaust, have been developed to meet these more stringent regulations. NOx
emissions, because of their influence on ozone as well as particles, are also a high priority.
Tables 5.1(a) and (b), below, summarise the progression of European regulation for passenger
cars and heavy-duty trucks and buses since their inception in 1992 (Source:
http://www.dieselnet.com).Over the past half century, every developed country and most developing countries have
progressively introduced similar controls on emission levels from new vehicles. The international
nature of motor vehicle manufacturing and trade has also prompted an increasing level of
harmonisation in emission standards and regulations. The most broadly implemented standards
(generally referred to as the Euro regulations) are those developed through the United Nations
Economic Commission for Europe (UNECE), which are uniformly applied across the whole of the European Union and have also been adopted in many other regions. The European Commission
proposes and adopts first the Euro regulations in the European Union, and then those regulations
are translated into UNECE regulations. The USA still retains its own set of emission regulations,
but work is proceeding to unify the two systems.
LP Gas (often called Autogas when used as an automotive fuel) is the
most widely available and accepted alternative fuel for road transport.
Over 13 million LP Gas fuelled vehicles are now in use around the world,
consuming over 20 million tonnes of fuel annually. As well as being
practical and clean, the attractiveness of LP Gas in many countries is
enhanced through fuel taxation policies which make it a much lower cost
alternative to gasoline or diesel for both light and heavy duty vehicles.
In many instances, LP Gas fuel systems are fitted to vehicles as an
aftermarket conversion, though in some markets, particularly in the
Asian region, factory-built LP Gas vehicles represent a large and growing
proportion of new vehicles.
Heavy-duty LP Gas engines have been in existence for almost 100 years in the USA, but for many
decades their use outside the USA was extremely limited. A number of heavy duty LP Gas engines
(mostly adaptations of their diesel counterparts) are now available from several of the larger
engine manufacturers. These engines are being used in buses and mid-size trucks, mainly in the
USA and South Korea, but increasingly in other regions around the world.
The very low gaseous and particulate emissions from LP Gas engines make them ideally suited for
buses and delivery vehicles operating in urban areas. To address this specific issue in monetary
terms, in 2001 Australia's Bus Industry Council engaged Mr Paul Watkiss, one of Europe’s
foremost experts in transport externality pricing, to translate the outcomes of European
externality studies into an Australian context (BIC, 2001).
Focusing on the pollution damage created by buses, on a cents per kilometre basis, his work takes
account of Australia’s human and vehicle population densities, city size and morbidity/mortality
values, as well as local vehicle emissions performance. The results of his analysis are summarised
in the chart below.
Figure 5.2 is particularly valuable because, even though the work was completed in 2001, it
includes engine and exhaust after treatment technologies which match those required to meet
current regulations (i.e. diesels operating on ultra-low sulphur diesel (ULSD) and fitted with
exhaust particle filters, now more generally referred to as continuously regenerating traps – CRT).
The chart clearly shows how policies which encourage the uptake of LP Gas fuelled buses and
trucks in urban areas have potential to deliver even better outcomes than current diesel
technology, in the areas where it is vitally important to have the cleanest possible vehicles.
The lower emissions from purpose built LP Gas buses have enabled operators to deliver Euro III
and Euro IV emissions performance well ahead of regulatory schedules.
For more detailed information on particle emissions from gasoline, diesel and LP Gas motor
vehicles, please refer to Annex A3 – Particle Emissions from Current Technology Vehicles.
Each of the following four sets of charts and accompanying notes summarises (for different
vehicle categories) emissions of the transport vehicle pollutants which are of most concern from a
health perspective (PM, NOx, HC, CO).
Health cost impacts for individual pollutants use French values calculated by Rabl and Sparado
(Rabl and Spadaro, 2000). The numerical values are in Table 4.4 of this document.
(a)
The two passenger car sets each present data for vehicles operating on gasoline, diesel and LP
Gas. One set relates to pre-2005 cars (Euro 3 compliant) where no particle filter is fitted to the
diesel powered vehicles. The second covers current technology (Euro 5) cars, the diesel versions
of which are almost universally equipped with a diesel particle filter which reduces tailpipe PM
emissions sufficiently to meet the stringent Euro 5 limits.
Passenger Cars
Data for these charts was drawn principally from a comparative emissions project performed
jointly by three independent European emission testing laboratories (EETP, 2004). The data from his project is particularly relevant because it tested the diesel, gasoline and LP Gas variants of
seven different Euro 3 certified cars, enabling direct comparisons to be made of their emissions
performance on each fuel. Looking ahead to future regulations, the program also included testing
of a diesel fuelled variant equipped with a diesel particle filter (DPF).
For the Euro 5 charts, the DPF equipped vehicle results are used for the diesel PM emissions, and
NOx emissions are factored to reflect the lower emissions of this pollutant for current technology
vehicles. Average emissions of the other pollutants were already sufficiently low in the Euro 3
vehicles to meet current Euro 5 limits, so were not factored.
(b) Heavy Duty Trucks and Buses
Although a considerable body of test data exists for heavy-duty vehicle engines, most results are
expressed in grams per kilowatt.-hour (g/kWh), which is not directly convertible to the required
grams per kilometre (g/km) units. Of the available g/km data, many different test cycles have
been used, with different speed profiles and energy content, which make comparisons extremely
difficult.
Fortunately, the Australian Government commissioned a comprehensive series of test programs
over the period 2000-2005, involving transient drive cycle chassis dynamometer testing of almost
900 vehicles, including a number of alternative (CNG and LP Gas) fuelled heavy duty vehicles.
Data from this testing, together with data from other sources, has been distilled into a
comprehensive set of speed-related on-road emission factors (in g/km) by the Queensland State
Government for all regulated pollutants, greenhouse gases and a wide range of “air toxic”
pollutants.
Based on the anticipated increased stringency of progressively introduced Euro regulations, the
data has also been factored to provide emission factors for future years through to Euro 5. Given
the high degree of consistency and coherency in the underlying database, these emission factors
have been used as the basis for heavy duty and bus emission rates.
Only two fuels are included for heavy duty vehicles: Diesel and LP Gas. Gasoline fuelled heavy
vehicles are available, but represent only a tiny proportion of the total population, so have been
omitted. CNG, although not explicitly included, is taken to have similar emission characteristics to
LP Gas for the pollutants under consideration.
PASSENGER CARS AND DERIVATIVES
Euro 3 (no particle filter on diesels)
Diesel vehicles manufactured
prior to 2005 in Europe, and
even today in many countries,
diesel vehicles represent by
far the greatest health hazard
of all fuel types.
This set of charts highlights
the difference in health
impacts of vehicles powered
by diesel, and those powered
by other liquid and gaseous
fuels (principally gasoline
(petrol) and LP Gas).
Diesel, because of its
intrinsically high emission
levels of damaging particulate
matter (PM) and oxides of
nitrogen (NOx) has much
more severe health impacts
than the other commercially
available fuels.
Other regulated pollutants:
volatile organic compounds
(VOCs) and carbon monoxide
(CO) have lower health cost
values. They are inherently
emitted at low levels from
diesels and, since the mid-
1980’s have been tightly
controlled in many sparkignition
vehicles through the
installation of catalytic
converters.
LP Gas has the lowest health
cost impacts of all
commercially available fuels.
Pollutant Emissions (g/km)
Health Cost
(€ per 1000km)
0.035
0.004
0.003
Diesel
Petrol
LPG
g/km
PM
5.6
2.4
0.02 0.00
PM NOx HC CO
Health Cost €/1000km
Diesel
0.6 0.8
0.06 0.02
PM NOx HC CO
Health Cost €/1000km
Petrol
0.5 0.3 0.05 0.02
PM NOx HC CO
Health Cost€/1000km
LP Gas
0.150
0.050
0.020
Diesel
Petrol
LPG
g/km
NOx
0.030
0.090
0.070
Diesel
Petrol
LPG
g/km HC (VOC)
0.240
0.855
1.070
Diesel
Petrol
LPG
g/km
CO
NOTES:
For these older technology engines (which
continue to be installed in new vehicles sold in
many countries), the health cost impacts are
much higher for diesels because of their high
emission rates of particles (PM) and NOx.
8.0
1.5
0.9
Diesel Petrol LP Gas
Health Cost €/1000km
Health Cost
Totals
Application:
PASSENGER CARS AND DERIVATIVES
Euro 5 (with particle filter on diesels)
Until recently, there was a very
distinct difference in the health
impacts of vehicles powered by
diesel, and those powered by
other liquid and gaseous fuels
(principally gasoline (petrol)
and LP Gas).
Diesel, because of its
intrinsically high emission levels
of damaging particulate matter
(PM) and oxides of nitrogen
(NOx) had much more severe
health impacts than the other
commercially available fuels.
Other regulated pollutants:
volatile organic compounds
(VOCs) and carbon monoxide
(CO) have lower health cost
values. They are inherently
emitted at low levels from
diesels and, since the mid-
1980’s have been tightly
controlled in many sparkignition
vehicles through the
installation of catalytic
converters.
However, since 2004 in Europe,
and at later varying times in
some other countries, a high
proportion of new diesel
vehicles have been fitted with
particle filters, which typically
reduce PM emissions by over
90%.
Despite the very significant
health risk reductions for
diesels, LP Gas remains the
cleanest fuel by a wide margin.
Pollutant Emissions (g/km)
Health Cost
(€ per 1000km)
0.0035
0.0040
0.0030
Diesel
Petrol
LPG
g/km
PM
0.6
6.1
0.02 0.00
PM NOx HC CO
Health Cost €/1000km
Diesel
0.6 0.8
0.06 0.02
PM NOx HC CO
Health Cost €/1000km
Petrol
0.5 0.3 0.05 0.02
PM NOx HC CO
NOTES:
For this class of vehicles, overall health impacts are
relatively low for all fuels.
The principal differential is high NOx emissions from
diesels.
6.7
1.5
0.9
Diesel Petrol LP Gas
Health Cost €/1000km
Health Cost
Totals
Application:
HEAVY DUTY TRUCKS & BUSES
Euro 3 (no particle filter on diesels)
This set of charts highlights the
difference in health impacts of
vehicles powered by diesel, and
those powered by gaseous
fuels.
Spark-ignition gas-fuelled
vehicles are starting to be used
more widely in heavy-duty
applications, mainly for urban
buses and delivery trucks, but
are still very much in the
minority.
Gasoline (petrol) fuelled HD
vehicles are rare, though some
continue to be used in the USA
and some developing countries.
Diesel, because of its
intrinsically high emission levels
of damaging particulate matter
(PM) and oxides of nitrogen
(NOx) has much more severe
health impacts than the other
commercially available fuels.
For these vehicles categories,
LP Gas and NG have the lowest
health cost impacts.
Pollutant Emissions (g/km)
Health Cost
(€ per 1000km)
72.0
111.6
0.37 0.04
PM NOx HC CO
Health Cost €/1000km
Diesel
8.6
88.2
1.63 0.03
PM NOx HC CO
Health Cost€/1000km LP Gas
NOTES:
For this class of vehicles, overall health
impacts are significantly higher for diesels due
to high PM and NOx levels.
184.0
98.5
Diesel LP Gas
Health Cost €/1000km
Health Cost
Totals
35
Application:
HEAVY DUTY TRUCKS & BUSES
Euro 4/5 (with particle filter on diesels)
Diesel, because of its
intrinsically high emission
levels of damaging particulate
matter (PM) and oxides of
nitrogen (NOx) had much more
severe health impacts than the
other commercially available
fuels.
However, since 2004 in Europe,
and at later varying times in
some other countries, new
diesel vehicles have been fitted
with particle filters, which
reduce PM emissions by over
90%, in some cases by up to
99%.
Other regulated pollutants:
volatile organic compounds
(VOCs) and carbon monoxide
(CO) have lower health cost
values.
Spark-ignition gas-fuelled
vehicles are starting to be used
more widely in heavy-duty
applications, mainly for urban
buses and delivery trucks, but
are still very much in the
minority.
Gasoline (petrol) fuelled HD
vehicles are rare, though some
continue to be used in the USA
and some developing
countries.
For this group of vehicles, the
new diesel technologies greatly
reduce fuel-specific differences
in health cost impacts.
Pollutant Emissions (g/km)
Health Cost
(€ per 1000km)
NOTES:
The chart opposite highlights the very significant
health benefits flowing from new PM reduction
technologies on modern diesel engines. The health
cost impacts of all fuels are now at similar levels,
It is important to note the health impact of noise are
not monetarized
36
5.2 Cooking
The cooking appliances used by most people in the developed world operate at the flick of a
switch or the twist of a knob. Electricity or a reticulated gas supply provides instant, clean energy
for preparing their food. For hundreds of millions of the world's population, the luxury of choice
does not exist - everything is dictated simply by the need to survive from one day to the next.
The World Health Organisation estimates that more than
half of the world's population rely on dung, wood, crop
waste or coal to meet their most basic energy needs.
Energy from these fuels is thought to account for nearly
one-tenth of all human energy demand today - more than
hydro and nuclear power together. Cooking and heating
with these fuels in confined spaces, often without any flue,
results in exposure to extremely high levels of toxic
pollutants. At times, pollutant concentrations can rise to
levels 100 times higher than the maximum recommended
exposure limits (WHO, 2005-3).
A consequence of this continued exposure, indoor air pollution is estimated to be responsible for
the deaths of more than 1.6 million people every year.
As we have seen in other situations, the most dangerous pollutant is very fine particulate matter
(PM). A large proportion of these particles are less than 1 micron (1/1000 mm) diameter, with
some being even 100 times smaller again. Because of their extremely small size the particles can
be inhaled into the deepest and most sensitive parts of the lung. The smallest can pass through
the lung tissue and directly into the bloodstream, where they can also lead to heart disease and
possibly brain damage.
Respiratory diseases and cancers resulting from exposure to PM are extremely common, and it is
the very young and the elderly who suffer the greatest.
The following chart (Figure 5.3) is indicative of the extremely high incidence of respiratory
problems for women, very young children and the elderly, who often spend most of their time in
the home, in some remote areas in developing nations. The source of pollution causing most of
this illness is smoke from fires used for cooking or other domestic activities.
Figure 5.3: Respiratory Infections by Gender and Age Group – Central Kenya
(Ezzati, 2000)
37
A number of studies have been performed to measure concentrations of particulate matter
adjacent to areas where indoor cooking is performed using a range of fuel sources. Universally,
when the fuel being used is wood, dung, harvest waste or other biomass material, the PM
concentration is many times the WHO recommended exposure limits for humans.
For example, an extensive year 2000 research program (Ezzati M et al 2000) in Kenya measured
indoor PM levels for 14 hours a day over 137 days, in 38 households. The average PM exposure
level was measured to be around 3500 μg per cubic metre during the active learning periods,
rising to 4500 μg per cubic metre when the fires were smouldering. These alarming figures are in
stark contrast to the World Health Organisation's recommended average exposure limit of 20 μg
per cubic metre. The household members were therefore continuously exposed to particle
concentrations 200 times higher than the recommended exposure limit.
A 2005 study (Smith KR 2005) compared the relative amounts of pollution generated cooking a
single meal using a range of six fuels typically available to households in developing countries,
plus biogas. This study also included LP Gas, which was used as the reference against which
emissions from all the other fuels were compared on a ratiometric basis. (See figure 5.4)
1.0
3.1
19
22
60
64
1.0
4.2
17
18
32
115
1.0
1.3
26
30
124
63
1.0 10.0 100.0 1000.0
LP Gas
Kerosene
Wood
Roots
Crop Residues
Dung
Relative Pollutant Levels
PM
VOC
CO
Figure 5.4: Pollutants Emitted Per Meal Relative to LP Gas
The WHO has produced an assessment of a range of risk factors and their contribution to disease.
Indoor air pollution was identified as the eighth most important risk factor and is estimated to be
responsible for 2.7% of the total global burden of disease. This finding ranks indoor air pollution
as exceeding outdoor air pollution by a factor of five, measured by combining the estimated years
of life lost due to disability and premature death.
Note Logarithmic Scale
38
In developing countries with high mortality rates, the ranking increases to an estimated 3.7% of
the total impact of disease, making it the highest cause of premature death after malnutrition,
unsafe sex and lack of safe water and sanitation.
For many people, especially in rural areas, the choices of fuel for cooking are either solid fuel or LP
Gas. As we have seen under the previous two headings, solid fuel is neither an environmentally
sound nor a healthy option and its use should be discouraged. In some countries and Germany is
an example, emissions from domestic solid fuel appliances are monitored and sanctions can be
applied if they are found to have excessive levels of emissions.
But for around half of the world's population the penalties are much greater than a simple fine.
In many poorer countries, cooking over an open fire using wood, charcoal, crop waste or even
animal dung is the only option available. Exposure to the extremely high levels of pollutants
emitted by these fires, particularly in a confined space, is reliably reported by the World Health
Organisation and other independent researchers to result in premature deaths of more than 1.5
million people every year. Women and young children are those most greatly affected.
Providing these families with access to simple LP Gas burners to replace the wood burning
fireplace can dramatically reduce exposure to these harmful pollutants and the tragic
consequences. There are other social benefits. It is often the role of one of the female members
of these families to gather the wood required for the days cooking. This duty, which can involve
several hours of hard work a day, can be replaced by more meaningful tasks.
5.3 Residential Space and Water Heating
5.3.1 Indoor Air Quality
Air pollution is generally associated with the air outside, but under many circumstances higher
levels of pollution can exist indoors. Moreover, since most people spend most (typically around
90 per cent) of their time indoors at home, school or work rather than outdoors, the exposure
time is generally much longer, increasing the risk of adverse health outcomes.
If ventilation of rooms is poor, or if heating appliances and associated flues or chimneys are faulty,
the concentration of some pollutants can build up to levels which may be harmful to human
health. But it should be noted that heaters are not the only cause of high indoor pollutant
concentrations –- other sources can include chemicals in paints, adhesives and furnishing
materials.
Symptoms can range from being quite mild, such as headaches,
tiredness or lethargy; or more severe such as aggravation of
asthma or allergic responses. All indoor combustion appliances,
regardless of the fuel used, need to have an adequate supply of
air to ensure proper combustion and to avoid any build-up of
fumes in the room. Although unflued gas heaters emit
extremely low levels of undesirable substances, compared with
wood and other solid fuels, they too must have adequate fresh
air ventilation to ensure proper operation.
The most significant emissions associated with unflued gas
heaters are nitrogen dioxide (NO2) and carbon monoxide (CO).
Both pollutants are odourless and hence difficult to detect, but CO is of particular concern, since
exposure to high levels can have serious consequences. To avoid risks associated with exposure
to excessive CO levels, most LP Gas heaters are equipped with an oxygen depletion sensor which
automatically turns off the heater if there is insufficient ventilation to sustain complete
combustion.
39
In good condition and properly used, unflued gas heaters only release small amounts of these
pollutants, which have not been found to affect human health. But levels can build up with
insufficient ventilation or if the heater is faulty, or inappropriately installed.
In contrast, solid fuel heaters produce very high levels of respirable particles which, as we have
seen in previous sections of this document can cause ill health or, in extreme cases, death.
Although solid fuel heaters in developed countries invariably have a chimney or flue to carry the
combustion products outside, leakage through cracked or faulty flues, or the occurrence of
chimney “back-draughts” can lead to persistent high levels of particles inside the building.
Open fires, in particular, also require good ventilation to maintain efficient combustion and to
generate sufficiently high chimney flows for effectively entraining the smoke and other
combustion products. As well as producing high levels of carbon monoxide (CO) and fine
particulate matter (PM), solid fuel coal fires also generate a range of acidic sulphur oxides (SOx).
Kerosene heaters emit much lower levels of particle emissions than solid fuel, but the same
precautions regarding adequate ventilation must be observed to avoid excessive CO levels.
Unvented kerosene heaters may also generate acid aerosols (US EPA 1993).
The large number of variables influencing indoor air pollution levels for any given fuel (ventilation
rate, burner design, heat output, flue efficiency, etc) and the disparity between test methods
make it difficult to assemble reliable data to compare pollutant exposure levels associated with a
range of available fuels.
But it is possible to infer potential impacts by comparing the total pollutant emissions from the
combustion of different fuels. Data from the European Environmental Agency (EEA, 2007) allows
such a comparison to be made. Because this data impacts primarily on outdoor air quality, the
tabulated emissions data is located in Section 5.3.2 – Impacts on Outdoor Air.
A number of studies have been performed to explore possible health effects associated with
unflued gas heaters. Most are based on natural gas appliances but, given that the difference in
emissions between these fuels is generally quite small, the results of these studies can also be
applied in relation to LP Gas with a high degree of reliability. Although the results of some studies
show a small effect, others do not, and meta-analyses show no overall effect (Basu and Samet
1999).
In Japan, Shima and Adachi (2000) studied 842 children aged 9–10 years, from 9 elementary
schools and found no statistically significant association between the prevalence of respiratory
symptoms (measured over three consecutive years) and the presence of unflued gas appliances in
the home.
It is therefore reasonable to conclude that, given the general availability of heaters incorporating
automatic safety controls, there is little risk of negative health impacts from the use of LP Gas
heaters, and the use of these appliances certainly minimizes exposure to other hazardous particle
pollutants including sulphur dioxide (SO2) and fine particulate matter (PM).
Even though these findings confirm the low-polluting characteristics of LP Gas heaters for
domestic heating it is worth re-stating that, like all indoor combustion heaters regardless of fuel
type, they must receive adequate ventilation for proper operation.
5.3.2 Outdoor Air Quality.
In many locations solid fuel heaters produce enough pollution to directly affect the health of
people in the community. The impacts are intensified when temperature inversions, commonly
occurring on colder windless evenings, trap the flue gases in layers close to the ground, producing
high concentrations of particles and other unhealthy products of combustion. Visual amenity can
also be degraded significantly by the smoky haze created by these heaters.
40
Research in Australia (Ayers et al 1999) clearly shows that cities where wood burning heaters are
prevalent have much higher ambient particle levels than other cities. For instance, the four major
cities, Sydney, Brisbane, Melbourne and Adelaide yielded average PM10 concentrations in the
range 20-25 μg/m3, whereas Canberra and Launceston (where wood heaters are popular) yielded
averages 2-3 times higher at 43and 65μg/m3 (see Figure 5.5).
0
10
20
30
40
50
60
70
Launceston Canberra Major
Capitals
WHO Limit
65
43
23 25
PM2.5 Concentration (μg/m3)
Influence of Wood Fired Heaters on Ambient PM
Levels in Australian Cities
Figure 5.5: Influence of Wood Fired Heaters on Ambient PM Levels in Australian Cities
Both of the wood-burning cities have low housing density, with relatively fewer industrial and
transport sources, so without the influence of wood heaters it could be expected that particle
levels would actually be lower than the larger cities. The fact that PM levels are significantly
higher underlines the impact on local air quality from wood burning, even in modern developed
cities.
Table 5.6, below, uses data from the European Environmental Agency, published in a 2009 Swiss
report by Atlantic Consulting (Atlantic, 2009) to summarise emission rates in grams per gigajoule
(g/GJ) of energy for both combustion heaters and water boilers operating on gaseous and liquid
fuels, wood and coal/briquettes. This table highlights the very significant benefits of using
gaseous fuels for domestic space and water heating.
Emissions, g/GJ
Fuel NO2 VOC PM10 PM2.5 CO
Residential Combustion Heater
Gaseous 57.0 10.5 0.5 0.5 31.0
Liquid 68.0 15.5 3.7 3.7 46.0
Wood 74.5 925 695 694 5,300
Coal 109 484 404 397 4,602
<50 kW Household Boiler
Gaseous 70.0 10.0 0.5 0.5 30.0
Liquid 70.0 15.0 3.0 3.0 40.0
41
Wood 120.0 400 475 475 4,000
Coal 130.0 300 38 360 4,000
Briquettes 200.0 200 100 100 3,000
Table 5.6: Emissions from Residential Combustion Appliances for Five Fuels (Atlantic, 2009)
Also, from a practical perspective, switching to an LP Gas heater is not only beneficial to the
environment and to community health, but is also much more convenient, more controllable, and
avoids dust and grime build-up in the house interior and areas around chimneys or flues.
5.4 Electrical Power Generation
As well as providing motive power for on road vehicles, internal combustion engines are used in
numerous other applications. The diversity of these applications makes it impractical to cover
them all separately in this report. Additionally, many of the non-road applications utilise only a
very limited range of fuel types. For instance virtually all construction, excavation, mining and
equivalent heavy duty plant and equipment use diesel fuel. Consequently there is an almost
complete lack of data comparing emissions and exposure levels for different fuel types for these
applications.
Nevertheless, some important categories of equipment are available to operate on a range of
different fuels. The most significant of these is local electricity generation, with numerous
examples of generators operating on diesel, gasoline, LP Gas and natural gas. Some other types
of equipment, such as pumps, pressure washers and compressors are also available, to a limited
extent, for operation using several fuel types. All these applications have one important feature
in common, in that they generally operate mostly in constant load, constant speed mode.
Portable and transportable electricity generating plant can therefore be used to characterise
emissions and health impacts associated with this class of equipment. Two types of generator will
be considered in this section; medium power (typically around 100 kW) and low power domestic
or trade type generators, which usually have a rated power less than 15 kW.
42
5.4.1 Medium Capacity Generator Sets
Many rural and isolated communities in both developed and less wealthy developing regions do
not have access to centralised electricity grids as a source of power for lighting, communications
and entertainment.
By necessity electrical power must be produced locally, usually by
way of a diesel powered generator. Unless the generator’s
engine is very modern and equipped with the latest emission
reduction technologies, people living in the vicinity of the
generator plant can be exposed to noise and high levels of
ultrafine particles in the diesel exhaust.
These soot particles, and highly toxic chemicals adhering to the
soot, are linked to the incidence of cancers, are damaging to the
lungs and can also affect the heart and human neurological systems. Compared with a traditional
diesel appliance (not fitted with a particle filter), an LP Gas powered generator will typically have
90 to 98% lower particle emission levels, as well as greatly reducing the potential for exposure to
other toxic substances.
In more developed areas, this class of generator is generally used
either as a standby power source in case of failure of the mains
supply, or as a continuous power source on sites where mains
power is not readily available, such as on construction sites or
where there is a need to drive relatively high powered mobile
equipment.
The example used to illustrate the relative emissions and health
cost impacts for this category of plant is a generator set operating for a continuous 12 hours every
day with a load of 80 kW, powered by a 6.8 litre engine. The fuel types compared are diesel,
natural gas and LP Gas.
Table 5.7 summarises the emission rates of each regulated pollutant in grams per kilowatt-hour,
together with a health cost value (expressed as Euros per tonne of pollutant emitted) for each
pollutant. The health cost values used in the table are representative of mid-level values for road
vehicles operating in a typical developed region. Note: In this example the diesel PM emissions
are quite low relative to the gaseous fuels, probably reflecting the constant load-speed nature of
generator operation, which avoids the very high PM peaks typically observed during acceleration
phases of diesel road vehicles. Conversely, NOx levels are quite high, which is consistent with
continuous high load, high temperature combustion.
Fuel Type
Pollutant Emissions Rates (g/kWh)
HC NOx CO PM
LP Gas 0.14 0.11 4.61 0.03
Natural Gas 0.09 0.62 3.49 0.03
Diesel 0.40 6.43 1.21 0.28
Health Impact Cost (€/kg) 0.7 15.7 0.02 120
Table 5.7: Pollutant Emission Rates for Typical 80kW Generators on Diesel, NG and LP Gas
43
The chart below (Figure 5.8) presents the data in Table 5.7 as a graphic representation of the
relative emission levels (in grams per kilowatt-hour) for each pollutant and fuel type, while
operating at a constant 80 kW load. Emissions data is drawn from the US EPA non-road engine
certification database www.epa.gov/OMS/certdata.htm#largeng
LP Gas
NG
Diesel
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
HC
NOx
CO
PM
0.14 0.11
4.61
0.03
0.09 0.62
3.49
0.03
0.40
6.43
1.21
0.28
Emissions (g/kW-h)
Medium Duty Engine Emissions for Three Fuels
Figure 5.8: Pollutant Emission Rates for Typical 80kW Generators on Diesel, NG and LP Gas
Applying the health cost values in Table 5.7, factored by the annual duty cycle, Figure 5.9 below
illustrates the relative health costs for each pollutant/fuel type combination, together with the
net total health cost for each fuel.
LP Gas
NG
Diesel
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
HC
NOx
CO
PM
34
612
32 1,184
22 3,385
24 1,184
99
35,397
8
11,837
Health Cost (€/yr)
Medium Non-Road Engine Annual Health Costs Based on 80kW
Average Power, 12 hrs/day
TOTALS:
LP Gas........€1,862/yr
NG.............€4,615/yr
Diesel........€47,341/yr
Figure 5.9: Annual Health Impact Costs for Typical 80kW Generators on Diesel, NG and LP Gas
The health impact cost figures clearly indicate the value of using a gaseous fuel, in particular LP
Gas, wherever the choice is available.
44
5.4.2 Small Generator Sets
Generators in this category tend to be constructed for intermittent
rather than continuous power generation and are primarily used for
recreation or trade-related activities. In areas where the mains power
may be unreliable, they are also frequently used for domestic power
backup, enabling lighting, refrigeration and other low-power services to
be maintained. Their power output ranges typically from around 15
kW for the larger models, down to less than 1.0 kW for the smallest
examples.
Fuel choices for these appliances are generally gasoline, LP Gas or diesel. Both two-stroke and
four-engines are available, particularly for the gasoline fuelled versions. In many countries the
emissions from small engine-powered equipment is not regulated. This can result in very high
levels of CO, HC and PM being emitted from some engines,
especially if manufactured in one of the countries which currently
do not have domestic emission standards for this type of
equipment.
Taking data from a US EPA report summarising non-road engine
emissions (US EPA 1991) the following table (Table 5.10) compares
emissions of CO, HC, NOx and PM from older generators using
1990’s technology levels, when this type of equipment was not required to comply with any
emission regulations. In the absence of reliable test data from that era comparing like-for-like
gasoline and LP Gas engines, the LP Gas emission figures have been calculated by multiplying the
gasoline emission factor by the ratio of LP Gas/gasoline emissions in Figure 5.7, for each pollutant.
Emissions (g/kW-h)
HC CO NOx PM
2-Stroke Gasoline 279 651 0.39 10.32
4-Stroke Gasoline 12.73 473 2.72 0.07
4-Stroke Diesel 1.74 6.70 8.04 1.34
4-Stroke LP Gas 10.59 473 1.03 0.05
Table 5.10: Pollutant Emission Rates for Unregulated Small Generators on Diesel, Gasoline and LP Gas
Many developed countries have now introduced progressively more stringent regulations for nonroad
engines, but the limits tend to be quite lax compared with those for on-road vehicles. This is
illustrated by the following chart (Figure 5.11), which is directly based on analysis of all relevant
certification test data contained in the US EPA’s 2008 small engine certification database
(http://www.epa.gov/OMS/certdata.htm#smallsi)
45
Figure 5.11: Pollutant Emissions of Small Generators Operating on Gasoline and LP Gas
Using the same pollutant health cost impact values that have been used in earlier sections of this
report, the following chart (Figure 5.12) translates the emission rates into monetary healthrelated
costs, further emphasising the adverse implications of choosing the wrong fuel for this
type of equipment.
Figure 5.12: Health Cost Impacts of Emissions from Small Generators Operating on Gasoline and LP Gas
5.5 Other LP Gas Applications
In every neighbourhood hundreds, if not thousands of engine powered appliances are owned and
used by residents, including lawnmowers, brush cutters, pressure washers, chain saws - the list is
very long. Together, the use of this equipment on a typical workday or week end amounts to a
considerable energy load, with the pollutants spread across the community.
Using the same methodology as that used in the previous section for small generators, once again
the US EPA database has been analysed on a broader front to include all currently certified small
46
spark ignition engines operating on gasoline or LP Gas (dual fuel and mixed fuel engines were
excluded from this analysis).
The following two charts (Figures 5.13 and 5.14) tell the same story as their counterparts in the
previous Section, but in this case are based on analysis of test data for a total of almost 2700
engines in the database.
Figure 5.13: Pollutant Emissions of Small Generators Operating on Gasoline and LP Gas
In this analysis we see similar trends to those for small generators, though, surprisingly, carbon
monoxide emissions from the smallest two-stroke engines (on a grams per kilowatt-hour basis)
are actually lower than for the four stroke group, despite the four strokes being generally
recognised as having much more efficient combustion than the two strokes.
Figure 5.14 provides a perspective on the relative emissions from current model two and fourstroke
small gasoline engines compared with equivalent LP Gas fuelled units.
The health cost analysis follows the same format, though from the cost data we can infer that,
overall, the broader spectrum of equipment in the full database tends to have higher emission
levels than the generator category discussed in the previous Section. Health impact values (in
€/tonne) are the same as those used for motor vehicles and the medium/heavy non-road engine
applications analysed in earlier sections.
47
Figure 5.14: Health Cost Impacts of Emissions from Small Engines Operating on Gasoline and LP Gas
Thermal desiccation (also commonly referred to as “flame weeding”), heats plant tissues rapidly
to rupture cells but not so extensively as to burn them. It is used widely in Western Europe and
the USA to halt the growth of weeds above slow-emerging root crops, such as carrots and
potatoes, as well as for killing weed growth around the stems of some above-ground crops such
as maize.
LP Gas has proved to be an ideal fuel for this application and is now almost universally used,
having supplanted earlier technologies based on kerosene and oil burning. Because it does not
introduce any chemicals into the soil, LP Gas fuelled thermal desiccation completely avoids any
danger of soil contamination, and is widely used for the farming of organic crops.
So we can see there are many wide-ranging applications for LP Gas as a source of heat energy forindustry, the home and for recreation: from metal cutting to grilling a steak to gliding around in a hot air balloon. In all cases, LP Gas provides a convenient, safe, controllable and low polluting
energy source, with minimal adverse impacts on public health
practical applications. Using independent research and practical test data to evaluate and
compare a range of commercially available liquid and gaseous fuels, together with some
“harvested” solid fuels, the health and economic benefits of using LP Gas become self-evident.
The applications discussed include:
• Road transport
• Cooking (focusing principally on developing regions)
• Residential space and water heating
• Electrical power generation
• Other Applications
Annexes to this report provide more in-depth coverage of several topics for readers who may
wish to explore specific technical issues in more detail.
Based on their relative emission rates in each application, each fuel is assessed in relation to its
impact on human health and, where feasible, estimates are made of the consequential economic
impacts of human exposure to each fuel, in each of the applications discussed.
Where it is practical to do so, data is presented graphically, using consistent charting formats. For instance, pollutant emissions relevant to each fuel are displayed on a horizontally oriented bar chart similar to that shown opposite, together with numerical values. Units of measurement are those most appropriate to the application (for instance grams per kilometre for road
transport or grams per megajoule for heating). Pollutant emission rates are based on independent test reports from recognised testing or research organisations. Given the inherent variability of emission test results, even from appliances or vehicles of nominally the same type and technology level, data from multiple tests have been aggregated to generate a representative average value, wherever possible. Where adequate data is available, typical health costs for each pollutant, in the context of each specific application, will also be
displayed in a vertically oriented chart style, for each fuel type (see opposite). Again, health costs are reported in units appropriate to the application. Where it is not feasible to quantify health impacts in monetary terms, the differences are expressed as ratios or as qualitative discussion.
Calculated health costs can vary greatly according to a number of local and regional factors. These include: population density, income levels, health care costs and the extent to which social services are available. (For a more detailed discussion of the health and economic impacts of different pollutants, please refer to Section 4.1. Moreover, pollutant emission rates vary considerably (both in absolute terms and relative to one another) in response to a number of factors, including: the type of appliance, its operating principles, technology levels, the presence or otherwise of post-combustion pollution reduction systems and typical duty cycles. For these reasons, although they have been accounted for wherever it has been feasible to do so, estimates of overall pollutant emissions may not be as precise as those for, say, CO2. For any given fuel CO2 is accurately calculated by simply multiplying the mass of fuel consumed by a single constant number, regardless of the application for which
the fuel is used or the technologies employed.
5.1 Road Transport
Gasoline and diesel have been the principal fuels used in mainstream road transport for over a
century. But concerns over unhealthy air, climate change and dwindling reserves, coupled with
the potential for disruptions to supply, have led to greatly increased availability of alternative,
lower polluting energy sources for motor vehicles. Since the middle of the 20th century, motor vehicle use has been closely associated with public health. This issue was brought to the forefront in California, where a rapidly growing and highly motorised population was subjected to severe photochemical smog episodes caused mainly by emissions of hydrocarbon products and oxides of nitrogen which reacted in the presence of California's strong sunlight. The severe incidence of respiratory and heart related illnesses attributable to the smog, coupled with the loss of visual amenity, led to the introduction of regulated limits for pollutant emissions from new cars and periodic checks on in used cars to ensure that they were being properly maintained.
The rapid increase in popularity of diesel powered vehicles, particularly in Europe and Asia, has
focused a great deal of attention on the adverse health impacts of fine particulate matter (PM),
which is emitted from diesel engines at much higher rates than from gasoline or gaseous fuelled
engines.
The particles generated by internal combustion engines are especially dangerous because of their
extremely small size, with most particles less than one micron (1/1000 mm) diameter. These tiny
particles can penetrate into the deepest and most sensitive parts of the lung, even passing
through the lung tissue directly into the bloodstream. Fine particles have been designated by the
US EPA as a cancer causing pollutant, and are also directly the cause of serious respiratory and
cardiac diseases and possibly brain damage.
For these reasons, the monetary health impact attached to PM is typically around 20 to 30 times
higher per kilogram than for VOCs or NOx, and over 100 times higher than for CO.
Over recent years, controlling PM emissions has been the highest priority for regulators, and the
maximum permitted emission levels have been reduced by a factor of 28 over the past decade or
so. Many new technologies to reduce particle production inside the engine, and to filter particles
out of the exhaust, have been developed to meet these more stringent regulations. NOx
emissions, because of their influence on ozone as well as particles, are also a high priority.
Tables 5.1(a) and (b), below, summarise the progression of European regulation for passenger
cars and heavy-duty trucks and buses since their inception in 1992 (Source:
http://www.dieselnet.com).Over the past half century, every developed country and most developing countries have
progressively introduced similar controls on emission levels from new vehicles. The international
nature of motor vehicle manufacturing and trade has also prompted an increasing level of
harmonisation in emission standards and regulations. The most broadly implemented standards
(generally referred to as the Euro regulations) are those developed through the United Nations
Economic Commission for Europe (UNECE), which are uniformly applied across the whole of the European Union and have also been adopted in many other regions. The European Commission
proposes and adopts first the Euro regulations in the European Union, and then those regulations
are translated into UNECE regulations. The USA still retains its own set of emission regulations,
but work is proceeding to unify the two systems.
LP Gas (often called Autogas when used as an automotive fuel) is the
most widely available and accepted alternative fuel for road transport.
Over 13 million LP Gas fuelled vehicles are now in use around the world,
consuming over 20 million tonnes of fuel annually. As well as being
practical and clean, the attractiveness of LP Gas in many countries is
enhanced through fuel taxation policies which make it a much lower cost
alternative to gasoline or diesel for both light and heavy duty vehicles.
In many instances, LP Gas fuel systems are fitted to vehicles as an
aftermarket conversion, though in some markets, particularly in the
Asian region, factory-built LP Gas vehicles represent a large and growing
proportion of new vehicles.
Heavy-duty LP Gas engines have been in existence for almost 100 years in the USA, but for many
decades their use outside the USA was extremely limited. A number of heavy duty LP Gas engines
(mostly adaptations of their diesel counterparts) are now available from several of the larger
engine manufacturers. These engines are being used in buses and mid-size trucks, mainly in the
USA and South Korea, but increasingly in other regions around the world.
The very low gaseous and particulate emissions from LP Gas engines make them ideally suited for
buses and delivery vehicles operating in urban areas. To address this specific issue in monetary
terms, in 2001 Australia's Bus Industry Council engaged Mr Paul Watkiss, one of Europe’s
foremost experts in transport externality pricing, to translate the outcomes of European
externality studies into an Australian context (BIC, 2001).
Focusing on the pollution damage created by buses, on a cents per kilometre basis, his work takes
account of Australia’s human and vehicle population densities, city size and morbidity/mortality
values, as well as local vehicle emissions performance. The results of his analysis are summarised
in the chart below.
Figure 5.2 is particularly valuable because, even though the work was completed in 2001, it
includes engine and exhaust after treatment technologies which match those required to meet
current regulations (i.e. diesels operating on ultra-low sulphur diesel (ULSD) and fitted with
exhaust particle filters, now more generally referred to as continuously regenerating traps – CRT).
The chart clearly shows how policies which encourage the uptake of LP Gas fuelled buses and
trucks in urban areas have potential to deliver even better outcomes than current diesel
technology, in the areas where it is vitally important to have the cleanest possible vehicles.
The lower emissions from purpose built LP Gas buses have enabled operators to deliver Euro III
and Euro IV emissions performance well ahead of regulatory schedules.
For more detailed information on particle emissions from gasoline, diesel and LP Gas motor
vehicles, please refer to Annex A3 – Particle Emissions from Current Technology Vehicles.
Each of the following four sets of charts and accompanying notes summarises (for different
vehicle categories) emissions of the transport vehicle pollutants which are of most concern from a
health perspective (PM, NOx, HC, CO).
Health cost impacts for individual pollutants use French values calculated by Rabl and Sparado
(Rabl and Spadaro, 2000). The numerical values are in Table 4.4 of this document.
(a)
The two passenger car sets each present data for vehicles operating on gasoline, diesel and LP
Gas. One set relates to pre-2005 cars (Euro 3 compliant) where no particle filter is fitted to the
diesel powered vehicles. The second covers current technology (Euro 5) cars, the diesel versions
of which are almost universally equipped with a diesel particle filter which reduces tailpipe PM
emissions sufficiently to meet the stringent Euro 5 limits.
Passenger Cars
Data for these charts was drawn principally from a comparative emissions project performed
jointly by three independent European emission testing laboratories (EETP, 2004). The data from his project is particularly relevant because it tested the diesel, gasoline and LP Gas variants of
seven different Euro 3 certified cars, enabling direct comparisons to be made of their emissions
performance on each fuel. Looking ahead to future regulations, the program also included testing
of a diesel fuelled variant equipped with a diesel particle filter (DPF).
For the Euro 5 charts, the DPF equipped vehicle results are used for the diesel PM emissions, and
NOx emissions are factored to reflect the lower emissions of this pollutant for current technology
vehicles. Average emissions of the other pollutants were already sufficiently low in the Euro 3
vehicles to meet current Euro 5 limits, so were not factored.
(b) Heavy Duty Trucks and Buses
Although a considerable body of test data exists for heavy-duty vehicle engines, most results are
expressed in grams per kilowatt.-hour (g/kWh), which is not directly convertible to the required
grams per kilometre (g/km) units. Of the available g/km data, many different test cycles have
been used, with different speed profiles and energy content, which make comparisons extremely
difficult.
Fortunately, the Australian Government commissioned a comprehensive series of test programs
over the period 2000-2005, involving transient drive cycle chassis dynamometer testing of almost
900 vehicles, including a number of alternative (CNG and LP Gas) fuelled heavy duty vehicles.
Data from this testing, together with data from other sources, has been distilled into a
comprehensive set of speed-related on-road emission factors (in g/km) by the Queensland State
Government for all regulated pollutants, greenhouse gases and a wide range of “air toxic”
pollutants.
Based on the anticipated increased stringency of progressively introduced Euro regulations, the
data has also been factored to provide emission factors for future years through to Euro 5. Given
the high degree of consistency and coherency in the underlying database, these emission factors
have been used as the basis for heavy duty and bus emission rates.
Only two fuels are included for heavy duty vehicles: Diesel and LP Gas. Gasoline fuelled heavy
vehicles are available, but represent only a tiny proportion of the total population, so have been
omitted. CNG, although not explicitly included, is taken to have similar emission characteristics to
LP Gas for the pollutants under consideration.
PASSENGER CARS AND DERIVATIVES
Euro 3 (no particle filter on diesels)
Diesel vehicles manufactured
prior to 2005 in Europe, and
even today in many countries,
diesel vehicles represent by
far the greatest health hazard
of all fuel types.
This set of charts highlights
the difference in health
impacts of vehicles powered
by diesel, and those powered
by other liquid and gaseous
fuels (principally gasoline
(petrol) and LP Gas).
Diesel, because of its
intrinsically high emission
levels of damaging particulate
matter (PM) and oxides of
nitrogen (NOx) has much
more severe health impacts
than the other commercially
available fuels.
Other regulated pollutants:
volatile organic compounds
(VOCs) and carbon monoxide
(CO) have lower health cost
values. They are inherently
emitted at low levels from
diesels and, since the mid-
1980’s have been tightly
controlled in many sparkignition
vehicles through the
installation of catalytic
converters.
LP Gas has the lowest health
cost impacts of all
commercially available fuels.
Pollutant Emissions (g/km)
Health Cost
(€ per 1000km)
0.035
0.004
0.003
Diesel
Petrol
LPG
g/km
PM
5.6
2.4
0.02 0.00
PM NOx HC CO
Health Cost €/1000km
Diesel
0.6 0.8
0.06 0.02
PM NOx HC CO
Health Cost €/1000km
Petrol
0.5 0.3 0.05 0.02
PM NOx HC CO
Health Cost€/1000km
LP Gas
0.150
0.050
0.020
Diesel
Petrol
LPG
g/km
NOx
0.030
0.090
0.070
Diesel
Petrol
LPG
g/km HC (VOC)
0.240
0.855
1.070
Diesel
Petrol
LPG
g/km
CO
NOTES:
For these older technology engines (which
continue to be installed in new vehicles sold in
many countries), the health cost impacts are
much higher for diesels because of their high
emission rates of particles (PM) and NOx.
8.0
1.5
0.9
Diesel Petrol LP Gas
Health Cost €/1000km
Health Cost
Totals
Application:
PASSENGER CARS AND DERIVATIVES
Euro 5 (with particle filter on diesels)
Until recently, there was a very
distinct difference in the health
impacts of vehicles powered by
diesel, and those powered by
other liquid and gaseous fuels
(principally gasoline (petrol)
and LP Gas).
Diesel, because of its
intrinsically high emission levels
of damaging particulate matter
(PM) and oxides of nitrogen
(NOx) had much more severe
health impacts than the other
commercially available fuels.
Other regulated pollutants:
volatile organic compounds
(VOCs) and carbon monoxide
(CO) have lower health cost
values. They are inherently
emitted at low levels from
diesels and, since the mid-
1980’s have been tightly
controlled in many sparkignition
vehicles through the
installation of catalytic
converters.
However, since 2004 in Europe,
and at later varying times in
some other countries, a high
proportion of new diesel
vehicles have been fitted with
particle filters, which typically
reduce PM emissions by over
90%.
Despite the very significant
health risk reductions for
diesels, LP Gas remains the
cleanest fuel by a wide margin.
Pollutant Emissions (g/km)
Health Cost
(€ per 1000km)
0.0035
0.0040
0.0030
Diesel
Petrol
LPG
g/km
PM
0.6
6.1
0.02 0.00
PM NOx HC CO
Health Cost €/1000km
Diesel
0.6 0.8
0.06 0.02
PM NOx HC CO
Health Cost €/1000km
Petrol
0.5 0.3 0.05 0.02
PM NOx HC CO
NOTES:
For this class of vehicles, overall health impacts are
relatively low for all fuels.
The principal differential is high NOx emissions from
diesels.
6.7
1.5
0.9
Diesel Petrol LP Gas
Health Cost €/1000km
Health Cost
Totals
Application:
HEAVY DUTY TRUCKS & BUSES
Euro 3 (no particle filter on diesels)
This set of charts highlights the
difference in health impacts of
vehicles powered by diesel, and
those powered by gaseous
fuels.
Spark-ignition gas-fuelled
vehicles are starting to be used
more widely in heavy-duty
applications, mainly for urban
buses and delivery trucks, but
are still very much in the
minority.
Gasoline (petrol) fuelled HD
vehicles are rare, though some
continue to be used in the USA
and some developing countries.
Diesel, because of its
intrinsically high emission levels
of damaging particulate matter
(PM) and oxides of nitrogen
(NOx) has much more severe
health impacts than the other
commercially available fuels.
For these vehicles categories,
LP Gas and NG have the lowest
health cost impacts.
Pollutant Emissions (g/km)
Health Cost
(€ per 1000km)
72.0
111.6
0.37 0.04
PM NOx HC CO
Health Cost €/1000km
Diesel
8.6
88.2
1.63 0.03
PM NOx HC CO
Health Cost€/1000km LP Gas
NOTES:
For this class of vehicles, overall health
impacts are significantly higher for diesels due
to high PM and NOx levels.
184.0
98.5
Diesel LP Gas
Health Cost €/1000km
Health Cost
Totals
35
Application:
HEAVY DUTY TRUCKS & BUSES
Euro 4/5 (with particle filter on diesels)
Diesel, because of its
intrinsically high emission
levels of damaging particulate
matter (PM) and oxides of
nitrogen (NOx) had much more
severe health impacts than the
other commercially available
fuels.
However, since 2004 in Europe,
and at later varying times in
some other countries, new
diesel vehicles have been fitted
with particle filters, which
reduce PM emissions by over
90%, in some cases by up to
99%.
Other regulated pollutants:
volatile organic compounds
(VOCs) and carbon monoxide
(CO) have lower health cost
values.
Spark-ignition gas-fuelled
vehicles are starting to be used
more widely in heavy-duty
applications, mainly for urban
buses and delivery trucks, but
are still very much in the
minority.
Gasoline (petrol) fuelled HD
vehicles are rare, though some
continue to be used in the USA
and some developing
countries.
For this group of vehicles, the
new diesel technologies greatly
reduce fuel-specific differences
in health cost impacts.
Pollutant Emissions (g/km)
Health Cost
(€ per 1000km)
NOTES:
The chart opposite highlights the very significant
health benefits flowing from new PM reduction
technologies on modern diesel engines. The health
cost impacts of all fuels are now at similar levels,
It is important to note the health impact of noise are
not monetarized
36
5.2 Cooking
The cooking appliances used by most people in the developed world operate at the flick of a
switch or the twist of a knob. Electricity or a reticulated gas supply provides instant, clean energy
for preparing their food. For hundreds of millions of the world's population, the luxury of choice
does not exist - everything is dictated simply by the need to survive from one day to the next.
The World Health Organisation estimates that more than
half of the world's population rely on dung, wood, crop
waste or coal to meet their most basic energy needs.
Energy from these fuels is thought to account for nearly
one-tenth of all human energy demand today - more than
hydro and nuclear power together. Cooking and heating
with these fuels in confined spaces, often without any flue,
results in exposure to extremely high levels of toxic
pollutants. At times, pollutant concentrations can rise to
levels 100 times higher than the maximum recommended
exposure limits (WHO, 2005-3).
A consequence of this continued exposure, indoor air pollution is estimated to be responsible for
the deaths of more than 1.6 million people every year.
As we have seen in other situations, the most dangerous pollutant is very fine particulate matter
(PM). A large proportion of these particles are less than 1 micron (1/1000 mm) diameter, with
some being even 100 times smaller again. Because of their extremely small size the particles can
be inhaled into the deepest and most sensitive parts of the lung. The smallest can pass through
the lung tissue and directly into the bloodstream, where they can also lead to heart disease and
possibly brain damage.
Respiratory diseases and cancers resulting from exposure to PM are extremely common, and it is
the very young and the elderly who suffer the greatest.
The following chart (Figure 5.3) is indicative of the extremely high incidence of respiratory
problems for women, very young children and the elderly, who often spend most of their time in
the home, in some remote areas in developing nations. The source of pollution causing most of
this illness is smoke from fires used for cooking or other domestic activities.
Figure 5.3: Respiratory Infections by Gender and Age Group – Central Kenya
(Ezzati, 2000)
37
A number of studies have been performed to measure concentrations of particulate matter
adjacent to areas where indoor cooking is performed using a range of fuel sources. Universally,
when the fuel being used is wood, dung, harvest waste or other biomass material, the PM
concentration is many times the WHO recommended exposure limits for humans.
For example, an extensive year 2000 research program (Ezzati M et al 2000) in Kenya measured
indoor PM levels for 14 hours a day over 137 days, in 38 households. The average PM exposure
level was measured to be around 3500 μg per cubic metre during the active learning periods,
rising to 4500 μg per cubic metre when the fires were smouldering. These alarming figures are in
stark contrast to the World Health Organisation's recommended average exposure limit of 20 μg
per cubic metre. The household members were therefore continuously exposed to particle
concentrations 200 times higher than the recommended exposure limit.
A 2005 study (Smith KR 2005) compared the relative amounts of pollution generated cooking a
single meal using a range of six fuels typically available to households in developing countries,
plus biogas. This study also included LP Gas, which was used as the reference against which
emissions from all the other fuels were compared on a ratiometric basis. (See figure 5.4)
1.0
3.1
19
22
60
64
1.0
4.2
17
18
32
115
1.0
1.3
26
30
124
63
1.0 10.0 100.0 1000.0
LP Gas
Kerosene
Wood
Roots
Crop Residues
Dung
Relative Pollutant Levels
PM
VOC
CO
Figure 5.4: Pollutants Emitted Per Meal Relative to LP Gas
The WHO has produced an assessment of a range of risk factors and their contribution to disease.
Indoor air pollution was identified as the eighth most important risk factor and is estimated to be
responsible for 2.7% of the total global burden of disease. This finding ranks indoor air pollution
as exceeding outdoor air pollution by a factor of five, measured by combining the estimated years
of life lost due to disability and premature death.
Note Logarithmic Scale
38
In developing countries with high mortality rates, the ranking increases to an estimated 3.7% of
the total impact of disease, making it the highest cause of premature death after malnutrition,
unsafe sex and lack of safe water and sanitation.
For many people, especially in rural areas, the choices of fuel for cooking are either solid fuel or LP
Gas. As we have seen under the previous two headings, solid fuel is neither an environmentally
sound nor a healthy option and its use should be discouraged. In some countries and Germany is
an example, emissions from domestic solid fuel appliances are monitored and sanctions can be
applied if they are found to have excessive levels of emissions.
But for around half of the world's population the penalties are much greater than a simple fine.
In many poorer countries, cooking over an open fire using wood, charcoal, crop waste or even
animal dung is the only option available. Exposure to the extremely high levels of pollutants
emitted by these fires, particularly in a confined space, is reliably reported by the World Health
Organisation and other independent researchers to result in premature deaths of more than 1.5
million people every year. Women and young children are those most greatly affected.
Providing these families with access to simple LP Gas burners to replace the wood burning
fireplace can dramatically reduce exposure to these harmful pollutants and the tragic
consequences. There are other social benefits. It is often the role of one of the female members
of these families to gather the wood required for the days cooking. This duty, which can involve
several hours of hard work a day, can be replaced by more meaningful tasks.
5.3 Residential Space and Water Heating
5.3.1 Indoor Air Quality
Air pollution is generally associated with the air outside, but under many circumstances higher
levels of pollution can exist indoors. Moreover, since most people spend most (typically around
90 per cent) of their time indoors at home, school or work rather than outdoors, the exposure
time is generally much longer, increasing the risk of adverse health outcomes.
If ventilation of rooms is poor, or if heating appliances and associated flues or chimneys are faulty,
the concentration of some pollutants can build up to levels which may be harmful to human
health. But it should be noted that heaters are not the only cause of high indoor pollutant
concentrations –- other sources can include chemicals in paints, adhesives and furnishing
materials.
Symptoms can range from being quite mild, such as headaches,
tiredness or lethargy; or more severe such as aggravation of
asthma or allergic responses. All indoor combustion appliances,
regardless of the fuel used, need to have an adequate supply of
air to ensure proper combustion and to avoid any build-up of
fumes in the room. Although unflued gas heaters emit
extremely low levels of undesirable substances, compared with
wood and other solid fuels, they too must have adequate fresh
air ventilation to ensure proper operation.
The most significant emissions associated with unflued gas
heaters are nitrogen dioxide (NO2) and carbon monoxide (CO).
Both pollutants are odourless and hence difficult to detect, but CO is of particular concern, since
exposure to high levels can have serious consequences. To avoid risks associated with exposure
to excessive CO levels, most LP Gas heaters are equipped with an oxygen depletion sensor which
automatically turns off the heater if there is insufficient ventilation to sustain complete
combustion.
39
In good condition and properly used, unflued gas heaters only release small amounts of these
pollutants, which have not been found to affect human health. But levels can build up with
insufficient ventilation or if the heater is faulty, or inappropriately installed.
In contrast, solid fuel heaters produce very high levels of respirable particles which, as we have
seen in previous sections of this document can cause ill health or, in extreme cases, death.
Although solid fuel heaters in developed countries invariably have a chimney or flue to carry the
combustion products outside, leakage through cracked or faulty flues, or the occurrence of
chimney “back-draughts” can lead to persistent high levels of particles inside the building.
Open fires, in particular, also require good ventilation to maintain efficient combustion and to
generate sufficiently high chimney flows for effectively entraining the smoke and other
combustion products. As well as producing high levels of carbon monoxide (CO) and fine
particulate matter (PM), solid fuel coal fires also generate a range of acidic sulphur oxides (SOx).
Kerosene heaters emit much lower levels of particle emissions than solid fuel, but the same
precautions regarding adequate ventilation must be observed to avoid excessive CO levels.
Unvented kerosene heaters may also generate acid aerosols (US EPA 1993).
The large number of variables influencing indoor air pollution levels for any given fuel (ventilation
rate, burner design, heat output, flue efficiency, etc) and the disparity between test methods
make it difficult to assemble reliable data to compare pollutant exposure levels associated with a
range of available fuels.
But it is possible to infer potential impacts by comparing the total pollutant emissions from the
combustion of different fuels. Data from the European Environmental Agency (EEA, 2007) allows
such a comparison to be made. Because this data impacts primarily on outdoor air quality, the
tabulated emissions data is located in Section 5.3.2 – Impacts on Outdoor Air.
A number of studies have been performed to explore possible health effects associated with
unflued gas heaters. Most are based on natural gas appliances but, given that the difference in
emissions between these fuels is generally quite small, the results of these studies can also be
applied in relation to LP Gas with a high degree of reliability. Although the results of some studies
show a small effect, others do not, and meta-analyses show no overall effect (Basu and Samet
1999).
In Japan, Shima and Adachi (2000) studied 842 children aged 9–10 years, from 9 elementary
schools and found no statistically significant association between the prevalence of respiratory
symptoms (measured over three consecutive years) and the presence of unflued gas appliances in
the home.
It is therefore reasonable to conclude that, given the general availability of heaters incorporating
automatic safety controls, there is little risk of negative health impacts from the use of LP Gas
heaters, and the use of these appliances certainly minimizes exposure to other hazardous particle
pollutants including sulphur dioxide (SO2) and fine particulate matter (PM).
Even though these findings confirm the low-polluting characteristics of LP Gas heaters for
domestic heating it is worth re-stating that, like all indoor combustion heaters regardless of fuel
type, they must receive adequate ventilation for proper operation.
5.3.2 Outdoor Air Quality.
In many locations solid fuel heaters produce enough pollution to directly affect the health of
people in the community. The impacts are intensified when temperature inversions, commonly
occurring on colder windless evenings, trap the flue gases in layers close to the ground, producing
high concentrations of particles and other unhealthy products of combustion. Visual amenity can
also be degraded significantly by the smoky haze created by these heaters.
40
Research in Australia (Ayers et al 1999) clearly shows that cities where wood burning heaters are
prevalent have much higher ambient particle levels than other cities. For instance, the four major
cities, Sydney, Brisbane, Melbourne and Adelaide yielded average PM10 concentrations in the
range 20-25 μg/m3, whereas Canberra and Launceston (where wood heaters are popular) yielded
averages 2-3 times higher at 43and 65μg/m3 (see Figure 5.5).
0
10
20
30
40
50
60
70
Launceston Canberra Major
Capitals
WHO Limit
65
43
23 25
PM2.5 Concentration (μg/m3)
Influence of Wood Fired Heaters on Ambient PM
Levels in Australian Cities
Figure 5.5: Influence of Wood Fired Heaters on Ambient PM Levels in Australian Cities
Both of the wood-burning cities have low housing density, with relatively fewer industrial and
transport sources, so without the influence of wood heaters it could be expected that particle
levels would actually be lower than the larger cities. The fact that PM levels are significantly
higher underlines the impact on local air quality from wood burning, even in modern developed
cities.
Table 5.6, below, uses data from the European Environmental Agency, published in a 2009 Swiss
report by Atlantic Consulting (Atlantic, 2009) to summarise emission rates in grams per gigajoule
(g/GJ) of energy for both combustion heaters and water boilers operating on gaseous and liquid
fuels, wood and coal/briquettes. This table highlights the very significant benefits of using
gaseous fuels for domestic space and water heating.
Emissions, g/GJ
Fuel NO2 VOC PM10 PM2.5 CO
Residential Combustion Heater
Gaseous 57.0 10.5 0.5 0.5 31.0
Liquid 68.0 15.5 3.7 3.7 46.0
Wood 74.5 925 695 694 5,300
Coal 109 484 404 397 4,602
<50 kW Household Boiler
Gaseous 70.0 10.0 0.5 0.5 30.0
Liquid 70.0 15.0 3.0 3.0 40.0
41
Wood 120.0 400 475 475 4,000
Coal 130.0 300 38 360 4,000
Briquettes 200.0 200 100 100 3,000
Table 5.6: Emissions from Residential Combustion Appliances for Five Fuels (Atlantic, 2009)
Also, from a practical perspective, switching to an LP Gas heater is not only beneficial to the
environment and to community health, but is also much more convenient, more controllable, and
avoids dust and grime build-up in the house interior and areas around chimneys or flues.
5.4 Electrical Power Generation
As well as providing motive power for on road vehicles, internal combustion engines are used in
numerous other applications. The diversity of these applications makes it impractical to cover
them all separately in this report. Additionally, many of the non-road applications utilise only a
very limited range of fuel types. For instance virtually all construction, excavation, mining and
equivalent heavy duty plant and equipment use diesel fuel. Consequently there is an almost
complete lack of data comparing emissions and exposure levels for different fuel types for these
applications.
Nevertheless, some important categories of equipment are available to operate on a range of
different fuels. The most significant of these is local electricity generation, with numerous
examples of generators operating on diesel, gasoline, LP Gas and natural gas. Some other types
of equipment, such as pumps, pressure washers and compressors are also available, to a limited
extent, for operation using several fuel types. All these applications have one important feature
in common, in that they generally operate mostly in constant load, constant speed mode.
Portable and transportable electricity generating plant can therefore be used to characterise
emissions and health impacts associated with this class of equipment. Two types of generator will
be considered in this section; medium power (typically around 100 kW) and low power domestic
or trade type generators, which usually have a rated power less than 15 kW.
42
5.4.1 Medium Capacity Generator Sets
Many rural and isolated communities in both developed and less wealthy developing regions do
not have access to centralised electricity grids as a source of power for lighting, communications
and entertainment.
By necessity electrical power must be produced locally, usually by
way of a diesel powered generator. Unless the generator’s
engine is very modern and equipped with the latest emission
reduction technologies, people living in the vicinity of the
generator plant can be exposed to noise and high levels of
ultrafine particles in the diesel exhaust.
These soot particles, and highly toxic chemicals adhering to the
soot, are linked to the incidence of cancers, are damaging to the
lungs and can also affect the heart and human neurological systems. Compared with a traditional
diesel appliance (not fitted with a particle filter), an LP Gas powered generator will typically have
90 to 98% lower particle emission levels, as well as greatly reducing the potential for exposure to
other toxic substances.
In more developed areas, this class of generator is generally used
either as a standby power source in case of failure of the mains
supply, or as a continuous power source on sites where mains
power is not readily available, such as on construction sites or
where there is a need to drive relatively high powered mobile
equipment.
The example used to illustrate the relative emissions and health
cost impacts for this category of plant is a generator set operating for a continuous 12 hours every
day with a load of 80 kW, powered by a 6.8 litre engine. The fuel types compared are diesel,
natural gas and LP Gas.
Table 5.7 summarises the emission rates of each regulated pollutant in grams per kilowatt-hour,
together with a health cost value (expressed as Euros per tonne of pollutant emitted) for each
pollutant. The health cost values used in the table are representative of mid-level values for road
vehicles operating in a typical developed region. Note: In this example the diesel PM emissions
are quite low relative to the gaseous fuels, probably reflecting the constant load-speed nature of
generator operation, which avoids the very high PM peaks typically observed during acceleration
phases of diesel road vehicles. Conversely, NOx levels are quite high, which is consistent with
continuous high load, high temperature combustion.
Fuel Type
Pollutant Emissions Rates (g/kWh)
HC NOx CO PM
LP Gas 0.14 0.11 4.61 0.03
Natural Gas 0.09 0.62 3.49 0.03
Diesel 0.40 6.43 1.21 0.28
Health Impact Cost (€/kg) 0.7 15.7 0.02 120
Table 5.7: Pollutant Emission Rates for Typical 80kW Generators on Diesel, NG and LP Gas
43
The chart below (Figure 5.8) presents the data in Table 5.7 as a graphic representation of the
relative emission levels (in grams per kilowatt-hour) for each pollutant and fuel type, while
operating at a constant 80 kW load. Emissions data is drawn from the US EPA non-road engine
certification database www.epa.gov/OMS/certdata.htm#largeng
LP Gas
NG
Diesel
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
HC
NOx
CO
PM
0.14 0.11
4.61
0.03
0.09 0.62
3.49
0.03
0.40
6.43
1.21
0.28
Emissions (g/kW-h)
Medium Duty Engine Emissions for Three Fuels
Figure 5.8: Pollutant Emission Rates for Typical 80kW Generators on Diesel, NG and LP Gas
Applying the health cost values in Table 5.7, factored by the annual duty cycle, Figure 5.9 below
illustrates the relative health costs for each pollutant/fuel type combination, together with the
net total health cost for each fuel.
LP Gas
NG
Diesel
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
HC
NOx
CO
PM
34
612
32 1,184
22 3,385
24 1,184
99
35,397
8
11,837
Health Cost (€/yr)
Medium Non-Road Engine Annual Health Costs Based on 80kW
Average Power, 12 hrs/day
TOTALS:
LP Gas........€1,862/yr
NG.............€4,615/yr
Diesel........€47,341/yr
Figure 5.9: Annual Health Impact Costs for Typical 80kW Generators on Diesel, NG and LP Gas
The health impact cost figures clearly indicate the value of using a gaseous fuel, in particular LP
Gas, wherever the choice is available.
44
5.4.2 Small Generator Sets
Generators in this category tend to be constructed for intermittent
rather than continuous power generation and are primarily used for
recreation or trade-related activities. In areas where the mains power
may be unreliable, they are also frequently used for domestic power
backup, enabling lighting, refrigeration and other low-power services to
be maintained. Their power output ranges typically from around 15
kW for the larger models, down to less than 1.0 kW for the smallest
examples.
Fuel choices for these appliances are generally gasoline, LP Gas or diesel. Both two-stroke and
four-engines are available, particularly for the gasoline fuelled versions. In many countries the
emissions from small engine-powered equipment is not regulated. This can result in very high
levels of CO, HC and PM being emitted from some engines,
especially if manufactured in one of the countries which currently
do not have domestic emission standards for this type of
equipment.
Taking data from a US EPA report summarising non-road engine
emissions (US EPA 1991) the following table (Table 5.10) compares
emissions of CO, HC, NOx and PM from older generators using
1990’s technology levels, when this type of equipment was not required to comply with any
emission regulations. In the absence of reliable test data from that era comparing like-for-like
gasoline and LP Gas engines, the LP Gas emission figures have been calculated by multiplying the
gasoline emission factor by the ratio of LP Gas/gasoline emissions in Figure 5.7, for each pollutant.
Emissions (g/kW-h)
HC CO NOx PM
2-Stroke Gasoline 279 651 0.39 10.32
4-Stroke Gasoline 12.73 473 2.72 0.07
4-Stroke Diesel 1.74 6.70 8.04 1.34
4-Stroke LP Gas 10.59 473 1.03 0.05
Table 5.10: Pollutant Emission Rates for Unregulated Small Generators on Diesel, Gasoline and LP Gas
Many developed countries have now introduced progressively more stringent regulations for nonroad
engines, but the limits tend to be quite lax compared with those for on-road vehicles. This is
illustrated by the following chart (Figure 5.11), which is directly based on analysis of all relevant
certification test data contained in the US EPA’s 2008 small engine certification database
(http://www.epa.gov/OMS/certdata.htm#smallsi)
45
Figure 5.11: Pollutant Emissions of Small Generators Operating on Gasoline and LP Gas
Using the same pollutant health cost impact values that have been used in earlier sections of this
report, the following chart (Figure 5.12) translates the emission rates into monetary healthrelated
costs, further emphasising the adverse implications of choosing the wrong fuel for this
type of equipment.
Figure 5.12: Health Cost Impacts of Emissions from Small Generators Operating on Gasoline and LP Gas
5.5 Other LP Gas Applications
In every neighbourhood hundreds, if not thousands of engine powered appliances are owned and
used by residents, including lawnmowers, brush cutters, pressure washers, chain saws - the list is
very long. Together, the use of this equipment on a typical workday or week end amounts to a
considerable energy load, with the pollutants spread across the community.
Using the same methodology as that used in the previous section for small generators, once again
the US EPA database has been analysed on a broader front to include all currently certified small
46
spark ignition engines operating on gasoline or LP Gas (dual fuel and mixed fuel engines were
excluded from this analysis).
The following two charts (Figures 5.13 and 5.14) tell the same story as their counterparts in the
previous Section, but in this case are based on analysis of test data for a total of almost 2700
engines in the database.
Figure 5.13: Pollutant Emissions of Small Generators Operating on Gasoline and LP Gas
In this analysis we see similar trends to those for small generators, though, surprisingly, carbon
monoxide emissions from the smallest two-stroke engines (on a grams per kilowatt-hour basis)
are actually lower than for the four stroke group, despite the four strokes being generally
recognised as having much more efficient combustion than the two strokes.
Figure 5.14 provides a perspective on the relative emissions from current model two and fourstroke
small gasoline engines compared with equivalent LP Gas fuelled units.
The health cost analysis follows the same format, though from the cost data we can infer that,
overall, the broader spectrum of equipment in the full database tends to have higher emission
levels than the generator category discussed in the previous Section. Health impact values (in
€/tonne) are the same as those used for motor vehicles and the medium/heavy non-road engine
applications analysed in earlier sections.
47
Figure 5.14: Health Cost Impacts of Emissions from Small Engines Operating on Gasoline and LP Gas
Thermal desiccation (also commonly referred to as “flame weeding”), heats plant tissues rapidly
to rupture cells but not so extensively as to burn them. It is used widely in Western Europe and
the USA to halt the growth of weeds above slow-emerging root crops, such as carrots and
potatoes, as well as for killing weed growth around the stems of some above-ground crops such
as maize.
LP Gas has proved to be an ideal fuel for this application and is now almost universally used,
having supplanted earlier technologies based on kerosene and oil burning. Because it does not
introduce any chemicals into the soil, LP Gas fuelled thermal desiccation completely avoids any
danger of soil contamination, and is widely used for the farming of organic crops.
So we can see there are many wide-ranging applications for LP Gas as a source of heat energy forindustry, the home and for recreation: from metal cutting to grilling a steak to gliding around in a hot air balloon. In all cases, LP Gas provides a convenient, safe, controllable and low polluting
energy source, with minimal adverse impacts on public health
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