Polyfluoroalkyl Chemicals in the U.S. Population: Data from the National Health and Nutrition Examination Survey (NHANES) 2003–2004 and Comparisons with NHANES 1999

Polyfluoroalkyl Chemicals in the U.S. Population: Data from the National Health and Nutrition Examination Survey (NHANES) 2003–2004 and Comparisons with NHANES 1999–2000 Antonia M. Calafat Lee-Yang Wong Zsuzsanna Kuklenyik John A. Reidy Larry L. Needham

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Polyfluoroalkyl Chemicals in the U.S. Population: Data from the National Health and Nutrition Examination Survey (NHANES) 2003–2004 and Comparisons with NHANES 1999–2000 2007 Environmental Health Perspectives 10.1289/ehp.10598 calafat2007-polyfluoroalkyl-chemicals-in-the-u calafat2007-polyfluoroalkyl-chemicals-in-the-u.txt, the project's staged copy 35fc08d2cfbb17b92e8db3229936a1576304cb3f cc-by environmental-science

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0 spans located by searching the stored text for the quote's exact words, allowing any whitespace between them serum concentrations of twelve polyfluoroalkyl chemicals in a representative sample of the U.S. population aged 12 and over Quotation withheld because this record is not cleared for redistribution. whether U.S. population exposure to PFCs changed after the 2002 discontinuation of PFOS production Quotation withheld because this record is not cleared for redistribution. the first nationally representative PFC serum estimates after the manufacturing change, with a method-equivalence check spanning the two survey waves Quotation withheld because this record is not cleared for redistribution. existence Quotation withheld because this record is not cleared for redistribution. population-wide, measurable exposure to persistent fluorinated chemicals, declining for three compounds and rising for one Quotation withheld because this record is not cleared for redistribution. observational-study observational-study Quotation withheld because this record is not cleared for redistribution. electrochemical fluorination of PFOS and related compounds stopped in 2002, and three of the four common PFCs show lower geometric means four years later production phase-out reaching human serum Quotation withheld because this record is not cleared for redistribution. PFHxS declines least because it clears slowest - 7.3 years against 4.8 for PFOS and 3.5 for PFOA - so the same phase-out shows up later in it differential elimination half-life Quotation withheld because this record is not cleared for redistribution. PFOS and PFOA correlate more strongly with each other than either does with PFHxS, which the authors read as a shared source that PFHxS does not have separate formation pathways Quotation withheld because this record is not cleared for redistribution. PFHxS is higher in adolescents than adults, and the proposed reason is contact with carpets treated with it - a route specific to one compound childhood carpet contact Quotation withheld because this record is not cleared for redistribution. PFNA doubled, and the authors say human exposure data for it are too limited to interpret the rise confidently Quotation withheld because this record is not cleared for redistribution. for the two rarest analytes no 95th percentile could be calculated at all Quotation withheld because this record is not cleared for redistribution. no definite association between PFOS or PFOA exposure and adverse health effects has been established in humans Quotation withheld because this record is not cleared for redistribution. the animal effects that motivate concern occur at serum concentrations orders of magnitude above those measured here Quotation withheld because this record is not cleared for redistribution. the persistent-organic-pollutant framework, carried from chlorinated chemicals to fluorinated ones, including the expectation that concentrations rise with age - which fails here Quotation withheld because this record is not cleared for redistribution. 124 split samples run through BOTH analytical methods, to test whether the method change between survey waves produced the trend eliminates: a fall in serum concentrations that is a change of analytical method between survey waves - the split samples make the two methods comparable on the same serum · outcome: held Quotation withheld because this record is not cleared for redistribution. the explicit question of whether the decline is an artefact of changed methodology eliminates: the same artefact, asked as a question of the result rather than of the instrument · outcome: held Quotation withheld because this record is not cleared for redistribution. calibration standards spiked into calf serum to account for matrix effects and the absence of labelled internal standards for most analytes eliminates: a systematic bias from the serum matrix, or from the absence of an isotope-labelled internal standard for most analytes, being read as a concentration difference · outcome: held Quotation withheld because this record is not cleared for redistribution. low- and high-concentration quality-control pools run alongside reagent blank, serum blank and the samples eliminates: analytical drift across a run being reported as variation between people · outcome: held Quotation withheld because this record is not cleared for redistribution. agreement of the declines with independent series - Red Cross blood donors and Arctic ringed seals eliminates: a decline confined to this survey's sampling frame - the seals and the blood donors share no methodology and no population with NHANES · outcome: held Quotation withheld because this record is not cleared for redistribution. confounding, tested by re-adding each excluded variable and watching the beta coefficients eliminates: a coefficient that survives only under the authors' final choice of covariates · outcome: held Quotation withheld because this record is not cleared for redistribution. the split-sample comparison for analytes other than PFOA eliminates: that the change in concentrations between survey rounds is a change in analytical method - answered for PFOA and left unshown for the other analytes · outcome: partial Quotation withheld because this record is not cleared for redistribution. emission-reduction efforts for PFNA, the one compound that rose eliminates: an emissions explanation for the one compound that ROSE - the reduction efforts that would provide it were looked for and not found, which the paper says · outcome: absent-declared-unreported Quotation withheld because this record is not cleared for redistribution. limits of detection limits of detection Quotation withheld because this record is not cleared for redistribution. geometric mean geometric mean Quotation withheld because this record is not cleared for redistribution. Biomonitoring Biomonitoring Quotation withheld because this record is not cleared for redistribution. serum cotinine serum cotinine Quotation withheld because this record is not cleared for redistribution. split samples split samples Quotation withheld because this record is not cleared for redistribution. PFBuS PFBuS Quotation withheld because this record is not cleared for redistribution. lipophilic POPs lipophilic POPs Quotation withheld because this record is not cleared for redistribution. half-life half-life Quotation withheld because this record is not cleared for redistribution. a NON-DETECT is entered as LOD divided by the square root of 2 - imputed, not measured Quotation withheld because this record is not cleared for redistribution. a mean is REPORTABLE only where the analyte was detected in at least 60% of samples Quotation withheld because this record is not cleared for redistribution. a SMOKER is anyone with serum cotinine above 10 ug/L - a biomarker threshold, not self-report Quotation withheld because this record is not cleared for redistribution. RACE/ETHNICITY is three self-reported categories, and everyone else is counted in the total but excluded from every subgroup comparison Quotation withheld because this record is not cleared for redistribution. a CONFOUNDER is a variable whose re-addition moves a beta coefficient by 10% or more Quotation withheld because this record is not cleared for redistribution. a RETAINED model term is one surviving backward elimination at p < 0.05 Quotation withheld because this record is not cleared for redistribution. extends → the NHANES 1999-2000 PFC serum concentrations reported by the same group note: the same survey, the same laboratory, four years later, and the comparison is the paper's point Quotation withheld because this record is not cleared for redistribution. confirms → reported reductions in PFOS and PFOA in Red Cross blood donors and in Arctic ringed seals note: independent populations and an independent species moving the same way over the same interval Quotation withheld because this record is not cleared for redistribution. Apparent reductions in PFOS, PFOA and PFHxS most likely relate to the 2002 end of electrochemical-fluorination production. Quotation withheld because this record is not cleared for redistribution. unlike lipophilic persistent organic pollutants, these PFCs do not accumulate with age Quotation withheld because this record is not cleared for redistribution. PFBuS was detected less often than PFOS, PFOA and PFHxS. Quotation withheld because this record is not cleared for redistribution. the two analytical methods agreed on 124 split samples, so the trend is not a method artefact Quotation withheld because this record is not cleared for redistribution. limits of detection limits of detection Quotation withheld because this record is not cleared for redistribution. smokers smokers Quotation withheld because this record is not cleared for redistribution. Race/ethnicity Race/ethnicity Quotation withheld because this record is not cleared for redistribution. PFOS, PFOA, PFHxS and PFNA detected in over 98% of 2,094 samples — None value source note: THE VALUE DRAWS ON THE PAPER BEYOND THIS QUOTE: part of it is printed elsewhere in the paper, not in this quote ('of 12 PFCs, including PFOS and PFOA, in 2,094 participants…'). Quotation withheld because this record is not cleared for redistribution. limits of detection 0.1 to 1.0 ug/L; accuracy 84 to 135%; precision about 10 to 26% — None Quotation withheld because this record is not cleared for redistribution. EVIDENCE CORRECTED (RE-GROUNDED - THE POINTER WAS WRONG, NOT THE CLAIM) · geometric means down about 32% for PFOS, 25% for PFOA, 10% for PFHxS; PFNA up 100% — None EVIDENCE CORRECTED: RE-GROUNDED - THE POINTER WAS WRONG, NOT THE CLAIM. The old evidence was verbatim, anchored and correctly cut, and it contained NONE of this claim's numbers (10, 100, 25, 32). The paper states the claim in one sentence elsewhere and the tagger did not use it. the project, 2026-08-23: 'WE HAVE SPENT THE DAY VERIFYING THAT QUOTES ARE REAL AND NONE OF IT ASKS WHETHER THEY ARE RELEVANT.' Confirmed by reading the claim, the old span and the candidate together; the candidate carries every number AND the claim's own content words. Quotation withheld because this record is not cleared for redistribution. serum elimination half-lives: PFHxS 7.3 years, PFOA 3.5, PFOS 4.8 — None Quotation withheld because this record is not cleared for redistribution. PFNA ammonium salt production 15-75 tonnes in 2004; PFOA emissions about 15 tonnes, down from 45 in 1999 — None Quotation withheld because this record is not cleared for redistribution. smoking threshold: serum cotinine above 10 ug/L — None Quotation withheld because this record is not cleared for redistribution. geometric mean of a log-transformed, survey-weighted distribution geometric mean of a log-transformed, survey-weighted distribution Quotation withheld because this record is not cleared for redistribution. backward elimination at p < 0.05 with Satterwaite adjusted F statistics backward elimination at p < 0.05 with Satterwaite adjusted F statistics Quotation withheld because this record is not cleared for redistribution. detection frequency threshold of 60% for parametric statistics detection frequency threshold of 60% for parametric statistics Quotation withheld because this record is not cleared for redistribution. serum cotinine serum cotinine Quotation withheld because this record is not cleared for redistribution. geometric mean geometric mean Quotation withheld because this record is not cleared for redistribution.

The full text of this article is not redistributable, so it is not included here. The evidence sentences are withheld with it; the tag layer and its grounding status remain. The article itself is at https://doi.org/10.1289/ehp.10598.