The Application of Physiologically Based Pharmacokinetic Modeling to Determine Route-Specific Contributions to Tissue Dosimetry of Trihalomethanes in Drinking Water

Finished drinking water contains numerous contaminants, including drinking water disinfection byproducts (DBPs). Animal studies are often conducted via the oral route, and the understanding of their relevance to humans is complicated because of the uncertainties in human exposure assessments for DBPs. Volatile contaminants, including some DBPs, in drinking water may enter the human body across the skin, through the lungs and through oral consumption. This study was undertaken to estimate the total exposure of humans to the trihalomethane DBPs through the dermal, inhalation and oral routes. The results for volatile compounds demonstrate that additional exposure through inhalation may represent a quantitatively important exposure route.

Several manuscripts describing these findings in the EPA’s 2006 report will be prepared and published in the open, peer-reviewed literature.