Dietary exposures to food contaminants across the United States

Food consumption is an important route of human exposure to pesticides and industrial pollutants. Average dietary exposures to 37 pollutants were calc ulated for the whole United States population and for children under age 12 years by combining contaminant data with food consumption data and summing across food types. Pollutant exposures were compared to benchmark concentr ations, which are based on standard toxicological references, for cancer an d noncancer health effects. Average food ingestion exposures for the whole population exceeded benchmark concentrations for arsenic, chlordane, DDT, d ieldrin, dioxins, and polychlorinated biphenyls, when nondetects were assum ed to be equal to zero. For each of these pollutants, exposure through fish consumption accounts for a large percentage of food exposures. Exposure da ta for childhood age groups indicated that benchmark concentrations for the six identified pollutants are exceeded by the time age 12 years is reached . The methods used in this analysis could underestimate risks from childhoo d exposure, as children have a longer time to develop tumors and they may b e more susceptible to carcinogens; therefore, there may be several addition al contaminants of concern. In addition, several additional pollutants exce eded benchmark levels when nondetects were assumed to be equal to one half the detection limit. Uncertainties in exposure levels may be large, primari ly because of numerous samples with contaminant levels below detection limi ts. (C) 2000 Academic Press.