Health effects of diesel exhaust emissions--a mixture of air pollutants of worldwide concern.

Diesel exhaust is a mixture of particles and gases. It contains more than several hundred different organic and inorganic components, including many chemicals that have been designated as toxic air pollutants. Because mutagens and carcinogens are present in both the gaseous and particulate components, lung cancer has been the focus of attention as a health risk in animal and human research. Moreover, since the epidemiologic data suggest carcinogenicity in humans, and the diesel exhaust exposure data in evaluations in rats by NIOSH, IARC, WHO, and the California EPA, are said to demonstrate or support carcinogenicity, agencies have designated them as latent occupational carcinogens (NIOSH) or toxic air pollutants (California EPA). In regard to their non-carcinogenic effects, a contribution to airway inflammation and allergies, and in relation to disease, the possibility of contracting asthma and chronic bronchitis, have been investigated both experimentally and epidemiologically, and concern has increased about their health effects, particularly in children.