Residential arsenic and lead levels in an agricultural community with a history of lead arsenate use

Lead arsenate (PbHAsO4) was used as an insecticide in Washington fruit orchards from 1905 to 1947. We examined exposure potential for children living in an agricultural community with historic PbHAsO4 use. Soil and housedust samples were collected from 58 residences. Families were asked about land use history, age of home, and remodeling activities. Median concentrations of arsenic were higher in housedust than in soil (9.0 and 4.2 μg/g, respectively; P=0.05), as were lead concentrations (129 and 46 μg/g, respectively; P=0.0001). Significant associations were observed between indoor and outdoor levels of each metal, indicating track-in as an important exposure pathway. Homes on or near land use for pear or apple production between 1905 and 1947 had significantly higher soil (P=0.005) and housedust (P=0.004) lead, and soil arsenic (P=0.04) than did the other homes. Homes more than 30 years old had significantly higher soil and housedust lead than did newer homes (P=0.01). Homes remodeled within the past two years had significantly higher soil (P=0.01) and housedust (P=0.04) lead. Child doses extrapolated from these data indicate that 36% of homes had soil or dust arsenic levels above the minimum risk level estimated by the Agency for Toxic Substances and Disease Registry. None of the measured lead levels exceeded current US Environmental Protection Agency guidelines. Public health education programs focused on residential hygiene would be of value in areas of historic PbHAsO4 use.