Assessing Exposure to Chloroform in Swimming Pools Using Physiologically Based Toxicokinetic Modeling

This work examines the use of physiologically based toxicokinetic (PBTK) modeling to assess exposure to the most abundant disinfection by-product (DBP), chloroform (TCM), to be found in indoor swimming pools. Real exposure scenarios including environmental (water and air levels) and biological (alveolar air or blood levels) data extracted from the literature were simulated. Predicted biological data matched up well with the reported actual levels, thereby confirming the reliability of this approach. Relative contributions of inhalation and dermal absorption to the total body burden were estimated and compared to the inconsistent results of reported studies. The PBTK simulations served to explain this inconsistency, suggesting that the prevalence of each pathway depends on environmental concentrations and on the ratio between air and water levels in particular. Likewise, comparisons between 24-h typical household and typical 1- or 2-h swimming pool exposure scenarios point to the preponderance of the latter.