气候变化领域集成服务门户

Relationships between total soil or bioaccessible lead (Pb), measured using an in vitro bioaccessibility assay, and childrens blood lead levels (BLL) were investigated in an urban neighborhood in Philadelphia, PA, with a history of soil Pb contamination. Soil samples from 38 homes were analyzed to determine whether accounting for the bioaccessible Pb fraction improves statistical relationships with childrens BLLs. Total soil Pb concentration ranged from 58 to 2821 mg/kg; the bioaccessible Pb concentration ranged from 47 to 2567 mg/kg. Childrens BLLs ranged from 0.3 to 9.8 mu g/dL. Hierarchical models were used to compare relationships between total or bioaccessible Pb in soil and childrens BLLs. Total soil Pb concentration as the predictor accounted for 23% of the variability in child BLL; bioaccessible soil Pb concentration as the predictor accounted for 26% of BLL variability. A bootstrapping analysis confirmed a significant increase in R2 for the model using bioaccessible soil Pb concentration as the predictor with 99.0% of bootstraps showing a positive increase. Estimated increases of 1.3 mu g/dL and 1.5 mu g/dL in BLL per 1000 mg/kg Pb in soil were observed for this study area using total and bioaccessible Pb concentrations, respectively. Childrens age did not contribute significantly to the prediction of BLLs.