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SOURCE OF GENOTOXICITY AND CANCER RISK IN AMBIENT AIR
Citation:
Lewtas, J., C. Lewis, R. Zweidinger, R. Stevens, AND L. Cupitt. SOURCE OF GENOTOXICITY AND CANCER RISK IN AMBIENT AIR. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-95/297.
Description:
Products of incomplete combustion are identified as a major source of carcinogenic risk in urban areas, especially those from small non-industrial sources. he major ubiquitous emission i sources outdoors in populated areas are residential home heating and motor vehicles. olycyclic organic matter adsorbed to the particles emitted from incomplete combustion are estimated to make the largest contribution to human genotoxic and cancer risk. utagenic emission factors combined with dispersion modeling estimated that automobiles and heating sources were major sources of mutagens. mbient air studies to apportion the sources of mutagens in nonindustrial areas confirmed this prediction. o apportion and estimate the cancer risk of ambient, organic matter from particles, in vivo animal tumor data, receptor modeling and human exposure data were combined. umorigenicity studies of the source apportioned ambient organic matter provided the relative tumor potencies of two ambient samples of different source, composition. he human cancer unit risks were developed based on the comparative potency method using tumor data from these ambient samples. esidential wood combustion accounted for 75% of the exposure to particle associated organics, but only 20% of the estimated cancer risk. he remaining 80% of the risk appears to be associated with the mobile source component and atmospheric transformation products from these source emissions.