Are there any risks from air toxics that are not covered by the national-scale assessment?
As mentioned above, the assessment only addresses the risks from 32 air toxics and diesel particulate matter. While these pollutants are expected to dominate the inhalation risks from outdoor sources of air toxics, the remaining 156 toxic air pollutants can also contribute to risks, especially in localized areas around individual sources. Non-inhalation exposures, such as ingestion and dermal exposures, are not included. Evaluation of these additional pathways for exposure is especially important for pollutants that persist in the environment and bioaccumulate, such as mercury and PCBs. The highest localized inhalation exposures and risks are not captured by the national-scale approach. It is important to use local-scale assessments to characterize exposures and risks very close to specific sources. Predicted inhalation exposures associated with indoor sources of air toxics are not included in the current assessment due to lack of emissions data. For certain air toxics, total long-term
