What About Diesel PM?
In this assessment, the potential risk from diesel exhaust emissions is not addressed in the same fashion that other pollutants are. This is because data are not sufficient to develop a numerical estimate of carcinogenic potency for this pollutant. However, EPA has concluded that diesel exhaust ranks with the other substances that the national-scale assessment suggests pose the greatest relative risk. First, a large number of human epidemiology studies show increased lung cancer associated with diesel exhaust. Furthermore, exposures in these epidemiology studies are in the same range as ambient exposures throughout the United States. In addition to the potential for lung cancer risk, there is a significant potential for non-cancer health effects as well, based on the contribution of diesel particulate matter to ambient levels of fine particles. Exposure to fine particles contributes to harmful respiratory and cardiovascular effects, and to premature mortality. More information on health effects associated with diesel exhaust can be found in the Health Assessment Document for Diesel Exhaust