Water on already slightly acid rocks and sands becomes more acid with pollution, releasing toxic metals such as cadmium, lead, mercury and aluminium. Vehicle exhausts spew out oxides of nitrogen and hydrocarbons which include cancer-inducing chemicals. Diesel is particularly rich in such pollution. Together in the air, these chemicals react in sunlight to form ozone, a substance which is essential outside the atmosphere where it protects the earth from harmful ultra-violet rays. Inside the atmosphere, however, it is a pollutant which eats through leaf-cell walls, making them permeable to acidic rainfall, and leaching out key nutrients.
Ozone also attacks the lungs of mammals and birds.
The American bald eagle used as a mascot at the Los Angeles Olympics died from lung disease caused by air pollution. Parents campaigning organizations in Austria and West Germany have long believed that cot-deaths could be associated with industrial air pollution, just as people who died in the London smogs are now known to have suffered severe lung irritation from sulphuric acid particles. Similarly the US Clean Air Scientific Advisory Committee concludes that current air quality standards do not protect asthmatics. This finding may lead to amendment of the Clean Air Act, requiring substantial extra amounts of sulphur to be cleaned from power station gases. The issue of air pollution and health is one which should concern us all.