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Every breath you take Sharon Beder There are many good reasons to reduce our dependence on fossil fuels, apart from the much publicised problem of global warming. One is the generation of fine particulate matter that arises from burning fossil fuels. New research has revealed that these fine particles are particularly hazardous to health.
Particles less than ten thousandths of a millimetre (10 microns) in diameter can penetrate deep into the lungs and then into the blood stream. By comparison a human hair is about a 100 thousandth of a millimetre in diameter. The fine particles are produced by burning fossil fuels and biomass and by various industrial processes, for example power plants, petrol and diesel exhaust, wood fires, land clearing, ore processing and refining.
Researchers at Johns Hopkins School of Public Health in the US have found that an average increase of just 0.01 milligrams per cubic metre (mg/m3) of these particles over 24 hours will increase the overall death rate by half a percentage. So if 100 people die each day in a large city, then an increase of 0.02mg/m3 averaged over a day will mean an extra death that day.
Standards in the US restrict the daily average of these particles to 0.15 mg/m3. However the researchers, who studied 20 major US cities over a number of years, found that though all the cities were well within that standard, extra deaths were being caused. This was after taking account of other differences between cities such as socioeconomic status, access to health care, weather and temperature, other pollutants in the air and influenza outbreaks.
The researchers estimated that between 20 and 200 early deaths are being caused each day in the US by these tiny dust and soot particles; that is between 7300 and 73,000 deaths per year. These deaths are mainly from respiratory illnesses, but also heart attacks, with elderly people being the most vulnerable. The American Lung Association estimates that these particles together with urban smog also cause 400,000 asthma attacks each year and respiratory problems for a million people in the US.
A Sydney study done by NSW Department of Health researchers found an increase of 0.025 mg/m3 of these particles resulted in a 2.6% increase in deaths each day, double the increase found in the US study. The researchers estimated that in Sydney there were an additional 397 deaths each year due to exposure to these particles.
The goal in Australia, set by the National Environmental Protection Council, is that by 2008 an average of 0.05 mg/m3 over 24 hours would only be exceeded 5 days per year. The Council estimated the health benefit of meeting this goal would be worth some $4 billion. The Council is currently reviewing whether there should also be a separate standard for the finer and more dangerous 2.5 micron particles.
Efforts in the US (since 1997) to regulate 2.5 micron particles have been obstructed by court challenges from industry groups which argue that the cost of meeting such standards is too high. Compliance is estimated by the Environmental Protection Agency (EPA) to require a $10 billion investment and by industry to require a $60 billion investment. But the health benefits are estimated by the EPA to be $20-100 billion every year, clearly much higher.
In February this year, in the case of EPA v. American Trucking Association, the Supreme Court ruled that the EPA did not have to consider costs in setting air quality standards and confirmed the legitimacy of its regulation of 2.5 micron particles.
Elements of the fossil fuel industry have already shown themselves to be opposed to the establishment of the 0.05mg/m3 Australian goal. Significant reductions in fine particulate matter and associated deaths will not be achieved without strong political will, and what we have seen recently in Australia and the US with regard to reducing fossil fuel dependence to avert global warming is not very encouraging.
G. Morgan et al. 1998, 'Air Pollution and Daily Mortality in Sydney, Australia, 1989 to 1993', American Journal of Public Health 88(5).
NEPC, 2001, 'The Need for a PM2.5 Standard in Australia', Issues Paper, May, http://www.nepc.gov.au/pdf/issues_paper.pdf
J. Samet et al, 2000, 'Fine Particulate Air Pollution and Mortality in 20 U.S. Cites, 1987-1994', New England Journal of Medicine 343(24).