Population-based dietary intakes and tap water concentrations for selectedelements in the EPA Region V National Human Exposure Assessment Survey (NHEXAS)

A National Human Exposure Assessment Survey (NHEXAS) field study was perfor med in U.S. Environmental Protection Agency (EPA) Region V, providing popul ation-based exposure distribution data for selected elements in several per sonal, environmental, and biological media. Population distributions are re ported for the 11 elements that were measured in water and dietary samples. Dietary intakes and home tap water concentrations of lead, arsenic, and ca dmium were further examined for intermedia associations, for differences be tween dietary exposure for adults and children, and to estimate the proport ion of the population above health-based reference values (dietary) or regu latory action levels or maximum contaminant levels (water). Water lead and arsenic concentrations were significantly associated with dietary intake. I ntake of all elements was higher From solid foods than From liquid foods (i ncluding drinking water). Dietary intakes of Pb, As, and Cd were greater th an those calculated for intake from home tap water or inhalation on a mu g/ day basis. Median dietary intakes for the Region V population for Pb, As, a nd Cd were 0.10, 0,13, and 0.19 mu g/kg bw/day, respectively. While Pb, As, and Cd concentrations in the foods consumed by 0 to 6-year-old children we re similar to or lower than those for adults, dietary intakes calculated on a body weight basis were 1.5 to 2.5 times higher for young children. Intra personal intake differences accounted for most of the variance in short-ter m (daily) dietary intakes for Pb and As, while interpersonal differences ac counted for more of the intake variance for Cd. Only small percentages of t he population exceeded health-based intake reference values or concentratio ns equal to regulatory levels in water for Pb, As, and Cd.