PARTICULATE AIR-POLLUTION - POSSIBLE RELEVANCE IN ASTHMA

The relative importance of air pollution in the pathogenesis of bronch ial asthma has been of interest for several decades. Numerous studies on the role of gaseous air pollution containing ozone, nitrogen dioxid e, sulfur dioxide, and carbon monoxide have been published. Very littl e attention has been focused on the role of respirable particles in th e causation of asthma. In this article we summarize some of our ongoin g investigations into the sources and composition of airborne particle s in the Los Angeles and Pasadena atmosphere, including the search for biologically active particles that may induce asthma attacks. It is f ound that the urban atmosphere contains not only combustion-derived pa rticles from diesel engine exhaust and gasoline-powered motor vehicle exhaust, bur also particles formed from biological starting materials including plant debris, cigarette smoke, wood smoke, and meat smoke as well as tire debris containing some natural rubber and paved road dus t. Paved road dust is a very complex mixture of particles including ga rden soil, tire dust, plant fragments, redeposited atmospheric particl es of all types, and pollen fragments presumably ground up by passing traffic. We have shown previously that latex allergen can be extracted from tire dust, from roadside dust, and front respirable air samples taken at Los Angeles and Long Beach. At present, work is underway to i dentify the larger range of allergens that may be contributed by the e ntrainment of paved road dust into the atmosphere. The possible import ance of pollen fragments present in paved rand dust in very small part icle sizes is discussed as well as their potential relevance in asthma .