Abstract
Ingestion of soils and house dusts is an important pathway for children's exposure to sorbed organic pollutants such as polychlorinated biphenyls (PCBs). To reduce the uncertainty of the exposure estimates, it is important to understand the extent to which chemicals desorb and become bioaccessible following ingestion. In this study we use a three compartment in vitro digestive system to model the role of soil and house dust physicochemical properties on the post ingestion bioaccessibility of PCBs. Matched pairs (n = 37) of soil and dust were characterized for percent carbon and nitrogen, pH, moisture content, and particle size distribution. They were then fortified with a mixture of 18 PCBs and processed through the assay. The percent bioaccessibility of each PCB was calculated, then modeled using individual PCB log K(ow) values and the soil and dust properties. The bioaccessibility of the PCBs in soil (x̄ = 65 ± 16%) was greater (p < 0.001) than that of the PCBs in house dust (x̄ = 36 ± 14%). In the soil model, carbon was the sole statistically significant predictive (p ≤ 0.05) variable, while in house dust, both carbon and clay content were statistically significant (p ≤ 0.05) predictors.