Predicting human exposure from multiple pathways: An integrated approach.

摘要

Human populations are in continuous contact with varying amounts of environmental pollutants in food, water, and air. Managing the health and environmental risks related to environmental pollutants requires an integrated model for estimating environmental transport and human exposure. We developed methods and supporting data for deriving pathway-exposure factors (PEFs) that link chemical concentrations in multiple environmental media to human exposure. Each PEF numerically translates a chemical concentration in each of the primary environmental media (air, water, and soil) into population exposure rates (in mg/kg-d) for specific routes of exposure. Incorporated into each PEF is information on human physiology and life style, as well as data describing pollutant behavior in food chains or in microenvironments, such as indoor air. We developed PEFs for nine exposure pathways (inhalation; water intake; fruit and vegetable, and grain ingestion; meat, milk, and fish consumption; soil ingestion; and dermal absorption) associated with five environmental media(endash)atmospheric gases and particles; soil; and ground and surface water. We discuss here the matrix of PEFs that link these exposure pathways and environmental media and describe the human, animal, and environmental data needed to derive the respective PEFs. Using examples for exposure to contaminants in potable water and to contaminants transferred from air to food, we consider the completeness of current exposure models and the treatment of uncertainty in exposure estimates. Results indicate that risk managers should consider the potential for multiple results indicate that risk managers should consider the potential for multiple pathways, avoid risk assessments derived from single value estimates, be aware of the uncertainty in risk estimates, and include this awareness in their decisions. 18 refs., 3 figs.