An assessment of the exposure of Americans to perfluorooctane sulfonate: a comparison of estimated intake with values inferred from NHANES data.
To better understand human exposure to perfluorinated compounds (PFCs), a model that assesses exposure to perfluorooctane sulfonate (PFOS) and its precursors from both an intake and a body burden perspective and combines the two with a simple pharmacokinetic (PK) model is demonstrated. Exposure pathways were modeled under "typical" and "contaminated" scenarios, for young children and adults. A range of intakes was also estimated from serum concentrations of PFOS reported in the National Health and Nutrition Examination Survey (NHANES) using a first-order 1-compartment PK model. Total PFOS intakes (medians summed over all pathways) were estimated as: 160 and 2200 ng/day for adults and 50 and 640 ng/day for children under typical and contaminated scenarios, respectively. Food ingestion appears to be the primary route of exposure in the general population. For children, the contribution from dust ingestion is nearly as great as from food ingestion. Pathway-specific contributions span several orders of magnitude and exhibit considerable overlap. PK modeling suggests central tendency PFOS intakes for adults range between 1.6 and 24.2 ng/kg-bw/day, and the forward-based intake estimates are within this range. The favorable comparison reported between the forward-modeled and the back-calculated range of intake predictions lends validity to the proposed framework.
Office of Research and Development, U.S. Environmental Protection Agency, National Exposure Research Laboratory, 109 TW Alexander Dr. (MD E205-04), Research Triangle Park, North Carolina 27711, USA. geghy.peter@epa.gov
Peter P
PP
Egeghy
Matthew
M
Lorber
D000328:Adult; D017738:Alkanesulfonic Acids / Q000097:blood* / Q000493:pharmacokinetics / Q000633:toxicity; D001822:Body Burden; D001835:Body Weight; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure / Q000032:analysis*; D004785:Environmental Pollutants / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D005260:Female; D005466:Fluorocarbons / Q000097:blood* / Q000493:pharmacokinetics / Q000633:toxicity; D006801:Humans; D008297:Male; D008954:Models, Biological; D009749:Nutrition Surveys / Q000379:methods*; D018570:Risk Assessment / Q000379:methods; D013997:Time Factors
D017738:Alkanesulfonic Acids; D004785:Environmental Pollutants; D005466:Fluorocarbons; C076994:perfluorooctane sulfonic acid