What air toxics are included in the 2002 national-scale assessment?
The 2002 national-scale assessment is a national-level risk assessment based on the emissions of air toxics and produces census-tract level estimates of ambient and exposure concentrations for 181 air toxics, including diesel PM, which we assessed for noncancer effects only. The following individual listed HAPs were not included in this assessment: chloramben, 2,3,7,8-tetrachlorodibenzo-p-dioxin, N-nitroso-N-methylurea, asbestos, fine mineral fibers, radionuclides, and 2-acetylaminofluorene. The individual cresols (o,m,p-cresols) and individual xylenes (o,m,p- xylenes) were included in the modeling, but the results were combined into the mixture category for both. Therefore, only the results for the mixtures (identified as the mixed isomers) may be found in the results section. Using the concentration estimates for the 181 air toxics, NATA estimates cancer risk and noncancer hazard (only the respiratory and neurologic endpoints) for 124 of these. For 57 air toxics, we have concentratio
