Application of Hazard Information to Individual and Multiple Air Toxics. J. C. Caldwell, U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards (MD-15), Research Triangle Park, NC 27711; and T. J. Woodruff and D. A. Axelrad, U.S. Environmental Protection Agency, Office of Policy, Planning and Evaluation, 401 M St. SW (2123), Washington, DC 20460
EPA’s Cumulative Exposure Project has modeled outdoor concentrations of approximately 150 hazardous air pollutants (HAPs). This presentation focuses on application of currently available hazard characterization information to these pollutants (or pollutant classes) with an emphasis on the inhalation route of exposure. Presumptive health protective values for both cancer and noncancer endpoints are drawn from USEPA, California EPA and ATSDR sources for each pollutant. Using such values, two types of analysis are presented. First, a screening methodology is presented which can be used to compare modeled ambient concentrations for individual HAPs with health protective values for a variety of health endpoints. Second, a methodology is presented which investigates the hazard that a combination of HAPs may present. Although application of such information does not constitute a rigorous risk assessment, it can be used to identify pollutants and combinations of pollutants which may occur in sufficient concentration to be of concern, and to provide a first step in identification of communities which may merit further study.
The views expressed in this presentation are those of the authors, and do not necessarily represent those of the U.S. Environmental Protection Agency.