Retrospective Exposure Estimation and Predicted versus Observed Serum Perfluorooctanoic Acid Concentrations for Participants in the C8 Health Project

Abstract

Background: People living or working in eastern Ohio and western West Virginia have been exposed to perfluorooctanoic acid (PFOA) released by DuPont Washington Works facilities.Objectives: Our objective was to estimate historical PFOA exposures and serum concentrations experienced by 45,276 non-occupationally exposed participants in the C8 Health Project who consented to share their residential histories and a 2005–2006 serum PFOA measurement.Methods: We estimated annual PFOA exposure rates for each individual based on predicted calibrated water concentrations and predicted air concentrations using an environmental fate and transport model, individual residential histories, and maps of public water supply networks. We coupled individual exposure estimates with a one-compartment absorption, distribution, metabolism, and excretion (ADME) model to estimate time-dependent serum concentrations.Results: For all participants (n = 45,276), predicted and observed median serum concentrations in 2005–2006 are 14.2 and 24.3 ppb, respectively [Spearman’s rank correlation coefficient (rs) = 0.67]. For participants who provided daily public well water consumption rate and who had the same residence and workplace in one of six municipal water districts for 5 years before the serum sample (n = 1,074), predicted and observed median serum concentrations in 2005–2006 are 32.2 and 40.0 ppb, respectively (rs = 0.82).Conclusions: Serum PFOA concentrations predicted by linked exposure and ADME models correlated well with observed 2005–2006 human serum concentrations for C8 Health Project participants. These individualized retrospective exposure and serum estimates are being used in a variety of epidemiologic studies being conducted in this region.

Perfluorooctanoic Acid Exposure and Thyroid Disease in Community and Worker Cohorts

“…retrospective serum PFOa concentration estimates were from a multistage modeling procedure described in detail elsewhere 23,25,26 and briefly summarized here. Yearly air and drinking water PFOa concentrations were estimated using an environmental fate and transport model.…”

“…Yearly intake rates were used in an absorption/distribution/metabolism/excretion model to generate yearly serum PFOa concentration estimates. 26 For plant workers, an occupational exposure model (using work history information along with modeled job-and departmentspecific serum concentration estimates) was used to generate yearly serum PFOa concentration estimates for years when they worked at the plant. 27 For years after workers stopped working at the plant, serum estimates were decayed at an annual rate of 18% until reaching the community exposure model estimates.…”

A cohort incidence study of workers exposed to perfluorooctanoic acid (PFOA)

“…We estimated PFOA serum levels over time for these workers by considering occupational5 and residential exposures (the latter from contaminated drinking water) 6. In the mortality study, we found positive dose–response trends for kidney cancer and kidney disease, based on small numbers of deaths 16…”

“…Human exposure to PFOA can occur through occupational exposure5 or through food (contamination during preparation and from packaging), drinking water,6 house dust7 and air 8. PFOA was found in the serum of more than 99% of the general USA population in the 2005–2006 National Health and Nutrition Examination Survey (NHANES), with a median concentration of 4 ng/mL 9.…”

Reverse phase high performance liquid chromatographic method development based on ultravioletvisible detector for the analysis of 1-hydroxypyrene (PAH biomarker) in human urine

“…Exposure to environmental contaminants is often evaluated using tools known as biomarkers of exposure [1,2]. The urinary 1-hydroxypyrene (1-OHPyr) is a reliable and sensitive biomarker of exposure to the low-level occupational and environmental exposure to polycyclic aromatic hydrocarbons (PAHs).…”