Government sets tougher air pollution targets
Scotland has been set the toughest targets in the UK for the reduction of air pollution levels over the next decade, while London’s are the most lenient.
The new standards, which should see an overall reduction in air pollution of more than 50% by 2010, were announced by the Department of the Environment, Food and Rural Affairs on 17 September, acting on recommendations by the Department of Health’s Committee on the Medical Effects of Air Pollution (COMEAP). COMEAP considers that the long-term effects of particle air pollution on health are at least ten times greater than the short-term effects on which present policies are based.
As a result of COMEAP’s recommendations the new targets set are:
- for Scotland, a 24-hour mean of 50 microgrammes per cubic metre (mg/m3), not to be exceeded more than 7 times a year, and an annual mean of 18 mg/m3 to be met by the end of 2010;
- for the UK, except Scotland and London, a 24-hour mean of 50 mg/m3, not to be exceeded more than 7 times a year, and an annual mean of 20 mg/m3 to be met by end 2010; and
- for London, a 24-hour mean of 50 mg/m3, not to be exceeded more than 10 – 14 times a year, and an annual mean of 23-25 mg/m3 to be met by 2010, although a provisional annual mean of 20 mg/m3 by 2015 was also set.
There are also tougher targets for benzene and carbon monoxide and, for the first time, a target for polycyclic aromatic hydrocarbons (PAH). The targets proposed for benzene, of 3.25 mg/m3, down from 16 mg/m3, and for PAH, 0.25 nanograms per cubic metre (ng/m3) as an annual average by 2010, both reflect latest health advice. For carbon monoxide, the Government suggests a limit of 10 mg/m3 set in an EU air quality directive, to be achieved by 2004 instead of by the legal deadline of 2005, and 1.6 mg/m3 less than current maximum levels.
The reason for the tougher targets proposed by the Government and the Scottish Executive is the latest advice from COMEAP about the health effects from long-term exposure to particle air pollution. In its recently published report published on 1 May 2001, the Committee suggests that emerging evidence points to the chronic health effects of particle air pollution being substantially more significant than previously thought, particularly from heart disease. The Committee considers that on the basis of studies carried out in the United States, an estimated 200,000 to 500,000 life years might be gained in this country per 1mg/m3 drop in concentrations of particle air pollution, representing a reduction of about 5% on present levels, and an average gain of 1.5 to 3.5 days per person. However, although everyone is exposed, it is likely that only some of the population is susceptible to the adverse effects of long term exposure to air pollution. For example, if only one million people living in the most polluted areas, rather than the entire population were affected, the gain would be around 3 to 6.5 months per person.
The Committee’s report explains that the number of people affected is unknown, and so an accurate calculation of the gain in the susceptible population is not possible, but is at least 10 times greater than the short-term health effects of day to day changes in particle air pollution suggested by the Committee in a 1998 report, which led to the adoption of the current standards.
Different standards were adopted for London and for Scotland as “development, industrial activity and transport levels differ markedly”, and because the capital would not have been realistically able to achieve the UK standard. However, nationwide, the trend in urban air quality is continuing to improve. Last year in urban areas there were 16 days of moderate or higher air pollution on average per site, the lowest figure recorded since the series began in 1993 (see related story).
“In recent years we have seen the levels of particle air pollution fall significantly as new policy measures to cut emissions from industry and traffic take effect,” Environment Minister Michael Meacher said, announcing the new targets. “But the latest advice from health experts shows that particle air pollution is still having a significant impact on health. The proposals published today involve a significant strengthening of our air quality targets for particles and other important air pollutants. They confirm the Government’s commitment to respond promptly to the latest advice from health experts.”
However, Conservatives in the Greater London Assembly have questioned why the new targets are so much weaker in the capital. “I am pleased that the Government have pledged to reduce pollution in the capital -however, the particles target is much weaker than the targets Labour inherited in 1997,” commented Roger Evans, the Conservatives Environment Spokesman in the GLA. “The Government has said that Ken Livingstone has his own air quality strategy for the capital (see following story). Does such a weak target condemn that strategy as one that will simply not work?”