Analysis of Air Toxics Emissions, Exposures, Cancer Risks and Controllability in Five Urban Areas. Volume 1. Base Year Analysis and Results

摘要

The report is the first phase of a study to define the multiple source, multiple pollutant nature of the urban air toxics problem (also known as 'urban soup') and to discern what control measures (or combinations of measures) can best be employed to mitigate the urban air toxics problem. The report documents the base year analysis, involving dispersion modeling of emissions data for 25 carcinogenic air toxics in five U.S. urban areas and a subsequent exposure/risk assessment to estimate aggregate cancer incidence. Aggregate (multi-source, multi-pollutant) cancer incidence (or population risk) across the 5 cities in this study averaged about 6 excess cases per million persons, ranging from about 2 to 10 in individual cities. The most important pollutants contributing to aggregate incidence are polycyclic organic matter, 1,3-butadiene, formaldehyde and hexavalent chromium. The most important sources are road vehicles, comfort and industrial cooling towers, chrome platers, solvent use and fuel combustion, including woodstoves.