Air and asthma

Sir: Your article "Pollution not to blame for childhood asthma" (9 January) implies that air pollution is only a problem in urban areas. Unfortunately for those living in rural areas, this is not the case.

Levels of ozone (summertime smog) are higher in the countryside than in towns and cities. The pollutants which react to form ozone are pumped out in towns and cities, mainly from road traffic. However, chemical and meteorological factors such as wind direction mean that smog levels reach their peak in rural areas, many miles away from where the pollution is emitted.

Thus the pollution monitoring sites with the most breaches of government health standards for summertime smog in 1997 were at Lullington Heath in Sussex, Somerton in Somerset and Harwell in Oxfordshire.

The report suggests that although air pollution does not cause asthma, it does aggravate the problem. This only strengthens the case for tough action to cut vehicle emissions, the main source of the problem.

The Government has the perfect opportunity to do just this by supporting the Road Traffic Reduction Bill when it is debated in Parliament at the end of the month.

TONY BOSWORTH

Air Pollution Campaigner

Friends of the Earth

London N1