AN INTEGRATED FRAMEWORK TO IDENTIFY SIGNIFICANT HUMAN EXPOSURES (SHELE)

Typically, health risk assessment methodologies have been designed to assess risks associated with exposure to individual chemicals through one specific medium, such as air, water, or food. This is partly becau se classical experimental methodology is used to study pure chemicals, and partly because a majority of early promulgated environmental laws (e.g., Clean Air Act, Clean Water Act) regulated chemicals in a given matrix via a specific route. Often, however, exposures in the ambient environment are through multiple routes, multiple media and to multip le chemicals. Presented here is a multimedia framework that health ris k assessors can use to identify significant human exposure levels (SHE Ls) on a site-specific basis. This framework is presented in the conte xt of a decision tree that links health guidance values such as minima l risk levels (MRLs) with site-specific data, using a range of decisio n-support models. It includes a provision to estimate a level of conce rn by comparing the estimated total dose (exposures) with guidance val ues established by the Agency, by other federal organizations, and by basket-survey results. If a SHEL has been identified, a range of follo w-up public health actions may be indicated (i.e., surveillance, healt h education, or other preventive interventions). This framework serves to (1) integrate the overall health assessment process, (2) evaluate the need for public health interventions, (3) incorporate innovative d ecision-support methods/models, and (4) demonstrate utility of such me thods in public health practice and the pursuit of the Agency's missio n.