A frantic search for oil, to keep the global car fleet running, touches the world s most fragile environments. Oil companies are now clamouring to drill in the Arctic National Wildlife Refuge where estimated reserves would fuel American autos for a mere 200 days. The main chemical emissions are carbon monoxide and dioxide, oxides of nitrogen and sulfur as well as particulates like lead. Carbon monoxide slows the rate at which oxygen is absorbed into the bloodstream. Small exposures cause shortness of breath and decreased alertness.
Large amounts can kill.
Motor vehicles produce an estimated 67 per cent of the carbon monoxide in the atmosphere. Smog , the dirty brown air which envelopes many cities, is a mixture of hydrocarbons and nitrogen oxides chemically altered by sunlight. Concentrations of less than one part per million of nitrogen oxides are enough to disable persons with chronic respiratory diseases. Hydrocarbons such as benzene are proven carcinogens. And diesel engines also produce large quantities of particulates which are known to produce cancer.