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DETERMINANTS OF HUMAN EXPOSURES TO AIR TOXICS AND ASSOCIATED HEALTH EFFECTS
Citation:
OZKAYNAK, H. A. DETERMINANTS OF HUMAN EXPOSURES TO AIR TOXICS AND ASSOCIATED HEALTH EFFECTS. Presented at 17th Annual Conference of the International Society of Exposure Analysis, Durham, NC, October 14 - 18, 2007.
Impact/Purpose:
The overall objective of this research is to develop, apply, and evaluate a human exposure model for predicting population exposures to the components of particulate matter (PM) identified as potential toxic agents contributing to adverse health effects.
Description:
Individuals are exposed to wide variety of air toxics in various indoor and outdoor microenvironments during the course of their daily activities. Sources of emissions include a wide variety of indoor and outdoor sources, including stationary and mobile sources, building materials and consumer products. Contributions to personal exposures from sources that have indoor or outdoor components may be estimated using information from available monitoring studies and predictions from human exposure models (e.g., SHEDS, HAPEM, APEX). A number of recent field studies (e.g., RIOPA, TEACH studies) have shown the importance of residential, near-roadway and commuting environments on personal exposures to air toxics. Results from a modeling-based analysis conducted as part of USEPA's recent NATA study, also showed the distribution of some of the ratios of personal to ambient air toxics concentrations to be skewed, indicating the importance of both microenvironmental and personal mobility factors. However, the variation in exposures to different outdoor air toxics has been found to be pollutant, site and activity dependent, and influenced by major or roadway emission sources. Thus, the complexity in the spatial and microenvironmental variation of exposures among the different population subgroups, especially in the context inter- and intra-urban analysis of air toxics health effects, could pose several challenges. However, recent advances in exposure modeling tools and better information on time-activity, commuting and exposure factors data provide unique opportunities for improving the assignment of exposures during the course of future community air toxics studies. This presentation will review the relevant findings from recent air toxics exposure and health studies, and discuss the limitations of existing measurement and modeling data that may hamper the investigation of health effects of exposures to air toxics.