Theses and Dissertations Collection

From the early 1900s to the 1950s, Yakima Valley orchards were commonly treated with lead arsenate insecticides. Lead (Pb) and arsenic (As) soil contamination has been identified on former orchard lands throughout Central Washington and pose a threat to human health and the environment. The levels of Pb and As in soil and interior dust at participating childcare centers in the Upper Yakima Valley (Yakima County), Washington were sampled to explore exposure potential for young children. Maximum Pb and As X-ray fluorescence spectrometer (XRF) results indicated that 4 (21%) and 8 (42%) of the 19 childcare centers surveyed exceeded the Washington State regulatory standard for Pb (250 mg/kg) and As (20 mg/kg), respectively. Interior dust loadings were below U.S. Environmental Protection Agency guidelines. Childcare centers are areas of intensive use for children and when coupled with potential residential exposure in their homes, the total daily exposure suggests a potential hazard.