And part of the reason lies beyond its control. Although moves to cut dangerous pollutants are on track, car emissions are not coming down much. The overall aim of the National Air Quality Strategy is to cut pollutants from industry, power stations and traffic. The Deputy Prime Minister, John Prescott, launching a review of the strategy, said improving air quality would be put on the fast track. They are benzene, 1,3-butadiene, and carbon monoxide.
Carbon monoxide reduces the blood's capacity to carry oxygen.
The other two pollutants are known to cause cancer. For lead, which damages brain development in children, the target date comes forward one year to 2004. Nitrogen dioxide, linked to breathing problems, will have to meet new limits on hourly emission rates. Worldwide asthma increase The targets for ozone and sulphur dioxide, also linked with respiratory problems, remain unchanged. The greatest concern for ministers is the eighth of the main pollutants, particulate matter.