ASSESSMENT OF CARCINOGENIC RISK FROM PERSONAL EXPOSURE TO BENZO(A)PYRENE IN THE TOTAL HUMAN ENVIRONMENTAL EXPOSURE STUDY (THEES)

The Total Human Environmental Exposure Study (THEES) was an investigat ion of multimedia exposure to the ubiquitous environmental carcinogen, benzo(a)pyrene (BaP). The three-phase study was conducted in Phillips burg, New Jersey and involved the participation of 14-15 individuals ( 8-10 homes) during each 14-day monitoring period. Microenvironmental s ampling of air, food, water and soil indicated that environmental expo sure to BaP was primarily through air and food. Exposure and risk esti mates were, therefore, based on the results of personal monitoring of breathing zone air and prepared food samples. Based on a comparison of the range and magnitude of inhalation and dietary BaP exposures, food ingestion was clearly the predominant exposure pathway. The relative contributions of other potential sources of community exposure to BaP (e.g., soil and drinking water ingestion) were also assessed. The exce ss cancer risk estimates for food ingestion were consistently greater than those for personal air, reflecting both the predominantly higher BaP exposures through the diet and the higher carcinogenic potency val ue for oral exposure. Overall, the total lifetime risk from personal e xposure to BaP for nonsmokers in the community was estimated at 10(-5) . In identifying risk reduction options, it is important to account fo r the observation that personal activities, lifestyle, and diet strong ly influenced individual exposures to BaP.