Linking biomarker data to pharmacokinetic (PK) models permits comparison of absorbed dose with a toxicological benchmark, which is an important step to understanding the health implications of pesticide exposure. The purpose of this analysis was to evaluate the feasibility of reconstructing the absorbed dose of two pesticides using PK models developed from biomarker data in a study of occupational application of these compounds. Twenty-four-hour urine samples were collected from farmers 24 h before through 96 h after a typical application of chlorpyrifos or 2,4-D. PK models were used to link the amounts found in urine samples to absorbed dose. Modeled total body dose estimates (in micrograms) were compared to measured dose from time 0-96 h. Despite the complexities surrounding the interpretation of biomonitoring data from a field setting, the models developed as part of this analysis accurately estimated the absorbed dose of 2,4-D and chlorpyrifos when collection of urine samples was largely complete. Over half of the farmers were excluded from modeling due to suspected noncompliance with urine collection or confounding exposure events, which highlights the importance of these issues for designing and interpreting biomonitoring data in future studies. Further evaluation of PK models in scenarios using single void samples is warranted for improving field-based dose assessments.
|Original language||English (US)|
|Number of pages||11|
|Journal||Journal of Toxicology and Environmental Health - Part A: Current Issues|
|State||Published - Jan 2008|
Bibliographical noteFunding Information:
This work was supported by grant 5 T32 ES010956 from the National Institute of Environmental Health Sciences (NIEHS), NIH. The contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIEHS, NIH. This work was also supported by the University of Minnesota Doctoral Dissertation Fellowship. The Farm Family Exposure Study was funded through a grant to the University of Minnesota by Bayer, Dow, Dupont, FMC, Monsanto, Syngenta, and the American Chemistry Council.