standOff, and the article is at its publisher via the link below. When we have changed our mind. Some entries in the table begin with a word in capitals and the reason for it. EVIDENCE CORRECTED — the finding still stands, but we had quoted the wrong sentence from the paper, and the quotation has been replaced with the right one. RETRACTED — the entry itself was wrong; it stays on the page, marked, with the reason, rather than being deleted. WITHDRAWN AND REPLACED — the entry was wrong, and a corrected version of it appears in the entries below. Each mark carries its own reason, in brackets, because the reasons differ from one entry to the next. An entry we have WITHDRAWN is removed from this page and kept in the record, with its reason. A line reading Audit and a date is a later re-reading of the entry against its whole sentence: DOUBTFUL means it was kept, and the reason says what is loose about it. Quotation marks inside the tagger's sentence. Where a tag is the tagger's own sentence, a phrase in quotation marks inside it is borrowed from the paper — the tagger's wording around it is not. The paper's own sentence is the evidence quote for that row; on this page it is withheld with the article, and the article is at its publisher. Nothing inside quotation marks anywhere on this page is ours: if it is quoted, it is the paper's. Whose words a concept carries. A concept entry records a term the paper itself uses, so the term, the sense given for it, and its evidence are the paper's own words, quoted where the paper fixes them. This is the opposite of a sense entry in the tag table, which is the tagger's sentence about how the paper uses a term. Where a concept entry could not be grounded in the paper's words, the entry says so on its own row.| relation to other work | claim_relations | how this paper stands to another: agrees, contradicts, extends, qualifies |
| claim type | claim_type | the shape of the claim: existence, mechanism, method, critique, prediction, null |
| concept edge | concept_edges | an asserted relation between two concepts, with the sentence asserting it |
| concept | concepts | an idea the paper works with, quoted where the paper uses it |
| content tag | content_tags | a finding, definition, quantity, statistic or variable named in the paper |
| contribution | contribution | what the paper claims to add |
| control | controls | an experiment run to eliminate a rival explanation |
| limitation | limitations | what the paper says its evidence cannot support |
| mechanism | mechanisms | how the reported effect is said to come about |
| method | method | how the paper produced its evidence |
| object of study | object_of_study | what the paper is about — the thing it investigates |
| phenomenon | phenomenon | the effect or regularity under study |
| research question | research_question | the question the paper sets itself |
| sense | senses | a distinct use of a term, quoted where the paper fixes it |
| transfer | transfers | a method or concept carried in from another field |
Relations on this page carry a quotation for the claim. Where a relation was separately evidenced — and so tested against the vocabulary for its type — the row says so; 4 of 4 relations here carry that mark. The rest are the tagger’s reading of the sentence quoted beside them.
| facet | tag | field | conf. | whose words |
|---|---|---|---|---|
| object_of_study | the rate at which three perfluoroalkyl acids leave human serum, measured in people whose exposure has stopped Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | object_of_study | the paper's words | |
| research_question | how long PFOS, PFHS and PFOA persist in human serum once occupational exposure ends, a number previously available only by extrapolation from monkeys and rodents Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | research_question | the paper's words | |
| contribution | the first direct human serum elimination half-lives for PFOS, PFHS and PFOA, from 26 retired fluorochemical workers followed for five years Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | contribution | the paper's words | |
| claim_type | existence Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | claim_type | the paper's words | |
| phenomenon | serum elimination of perfluoroalkyl acids that is slow enough in humans, and fast enough in every other species measured, that the interspecies gap is itself the finding Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | phenomenon | the paper's words | |
| method | observational-study Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: observational-study | method | the paper's words | |
| mechanisms | a high-affinity transporter returns filtered perfluoroalkyl acid from the renal tubule to the blood; because it saturates, the elimination rate depends on concentration and on how much transporter a species expresses Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: saturable renal resorption | mechanisms[0] | 0.95 | the tagger's words |
| mechanisms | species and sexes differ in which proximal-tubule anion transporters they express, so the same molecule is returned to the blood at different rates - offered as the reason the human half-life is years and the rat's is days Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | mechanisms[1] | 0.95 | the tagger's words |
| mechanisms | the C-F bond's stability and the high electronegativity of perfluorinated alkyl acids make metabolism unfavourable, so elimination is the only route of loss and half-life is set entirely by excretion Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | mechanisms[2] | 0.95 | the tagger's words |
| limitations | the authors state that human pharmacokinetics is not likely to be one-compartment, in the same discussion that reports half-lives fitted with a one-compartment first-order model - the model is disclaimed and its output is the paper's headline number Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | limitations[0] | 0.95 | the tagger's words |
| limitations | continuing non-occupational exposure could flatten the observed decline, so the half-lives may be biased long; the paper raises this and does not quantify it Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | limitations[1] | 0.95 | the tagger's words |
| limitations | the model was selected by looking at a semi-log plot, not by comparing candidate models - linearity by eye is the entire justification for first-order kinetics Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | limitations[2] | 0.85 | the tagger's words |
| limitations | 26 subjects, 24 of them male, all retired from two plants of one company; the two women are the whole basis for the sex comparison Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | limitations[3] | 0.95 | the tagger's words |
| limitations | three of the original participants had post-baseline occupational exposure: one was dropped entirely, one truncated, one's start point moved for a single analyte - principled and disclosed, but the cohort is not the cohort recruited Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | limitations[4] | 0.95 | the tagger's words |
| transfers | first-order elimination kinetics and the half-life construct, carried from single-dose animal pharmacokinetics onto an observational human cohort with no known dose and no defined time zero Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | transfers[0] | 0.95 | the tagger's words |
| transfers | the renal transporter explanation, carried from rodent sex-difference studies to account for a between-species difference in humans Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | transfers[1] | 0.95 | the tagger's words |
| controls | split analyses of the same blood collection, to separate assay variability from real decline Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. eliminates: assay variability being read as a fall in serum concentration, since both halves of the split come from one blood collection · outcome: held | controls[0] | 0.95 | the tagger's words |
| controls | spiked recovery and precision at three PFOA concentrations spanning the assay range Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. eliminates: a half-life derived from an assay that is accurate at one concentration and not across the decline it is measuring · outcome: held | controls[1] | 0.95 | the tagger's words |
| controls | spiked recovery and precision for PFHS, the analyte with the longest and most variable half-life Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. eliminates: the same, for the analyte whose half-life is longest and most variable and therefore rests on the most measurements · outcome: partial | controls[2] | 0.95 | the tagger's words |
| controls | blank rabbit or calf serum run with each batch, to detect contamination in a laboratory that also handled these compounds Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. eliminates: contamination of the samples in a laboratory that also handled these compounds - a blank that comes back clean on each run is what separates measured serum from carry-over · outcome (stated by the tagger, no quotation): held | controls[3] | 0.95 | the tagger's words |
| controls | end-of-study concentrations checked against general-population reference values, to show the decline was not floored by background exposure Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. eliminates: an elimination rate flattened by continuing background exposure, which would lengthen every half-life in the study · outcome: held | controls[4] | 0.95 | the tagger's words |
| controls | the same check applied per subject rather than to the median, which is where it stops holding for four of the 26 Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. eliminates: a median that holds while individuals do not - the per-subject form is where the check stops holding, for four of twenty-six · outcome: partial | controls[5] | 0.95 | the tagger's words |
| controls | regression of half-life on age, years worked, job and time since retirement, to test whether the estimate tracks anything about the person rather than the chemistry Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. eliminates: a half-life that tracks age, tenure, job or time since retirement rather than the chemistry of the compound · outcome: held | controls[6] | 0.95 | the tagger's words |
| controls | self-reported disease and medication review, for renal or hepatic conditions that would alter clearance Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. eliminates: altered renal or hepatic clearance in a subject being reported as the elimination rate of the compound · outcome: held | controls[7] | 0.95 | the tagger's words |
| concepts | half-life of serum elimination Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: half-life of serum elimination | concepts[0] | 0.95 | the paper's words |
| concepts | first-order model Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: first-order model | concepts[1] | 0.95 | the paper's words |
| concepts | semi-log plot Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: semi-log plot | concepts[2] | 0.95 | the paper's words |
| concepts | PFOS Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: PFOS | concepts[3] | 0.95 | the paper's words |
| concepts | PFHS Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: PFHS | concepts[4] | 0.95 | the paper's words |
| concepts | PFOA Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: PFOA | concepts[5] | 0.95 | the paper's words |
| concepts | retired fluorochemical production workers Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | concepts[6] | 0.95 | the paper's words |
| concepts | saturable renal resorption Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: saturable renal resorption | concepts[7] | 0.95 | the paper's words |
| concepts | organic anion transporters Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: organic anion transporters | concepts[8] | 0.95 | the paper's words |
| concepts | tubular resorption Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: tubular resorption | concepts[9] | 0.95 | the paper's words |
| concepts | internal standard Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: internal standard | concepts[10] | 0.95 | the paper's words |
| concepts | lower limit of quantitation Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: lower limit of quantitation | concepts[11] | 0.95 | the paper's words |
| concepts | split analyses Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: split analyses | concepts[12] | 0.95 | the paper's words |
| concepts | linear isomer Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: linear isomer | concepts[13] | 0.95 | the paper's words |
| concepts | branched chain isomers Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: branched chain isomers | concepts[14] | 0.95 | the paper's words |
| concepts | cynomolgus monkeys Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: cynomolgus monkeys | concepts[15] | 0.95 | the paper's words |
| concepts | ion ratios Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: ion ratios | concepts[16] | 0.95 | the paper's words |
| concepts | environmental exposure Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: environmental exposure | concepts[17] | 0.95 | the paper's words |
| concepts | rate of elimination Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: rate of elimination | concepts[18] | 0.95 | the paper's words |
| concepts | right skewness Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: right skewness | concepts[19] | 0.95 | the paper's words |
| senses | half-life of serum elimination - the ARITHMETIC mean over the 26 subjects: 5.4 y for PFOS, 8.5 y for PFHS, 3.8 y for PFOA Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | senses[0] | 0.95 | the tagger's words |
| senses | half-life of serum elimination - the GEOMETRIC mean over the same 26 subjects: 4.8 y for PFOS, 7.3 y for PFHS, 3.5 y for PFOA. These are the three numbers later papers quote as the half-life, without naming the statistic Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | senses[1] | 0.95 | the tagger's words |
| senses | half-life of serum elimination - the arithmetic mean after removing the two longest-eliminating subjects, which collapses onto the geometric mean and shows the gap between the first two senses is two people Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | senses[2] | 0.95 | the tagger's words |
| claim_relations | builds-on → Calafat et al.'s NHANES estimates of general-population serum concentrations, used here as the background floor the retirees had to stay above Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | claim_relations[0] | 0.95 | the tagger's words |
| claim_relations | extends → intravenous and repeated-oral-dose pharmacokinetic studies in cynomolgus monkeys, from which human persistence had previously been extrapolated Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | claim_relations[1] | 0.95 | the tagger's words |
| claim_relations | qualifies → one-compartment first-order pharmacokinetic modelling of perfluoroalkyl acids in humans Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | claim_relations[2] | 0.95 | the tagger's words |
| concept_edges | PFHS —contrasted-with→ PFOS Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. differs in: human serum elimination half-life and its dispersion · the relation itself is separately evidenced · strength of the relation: 0.9 · differs in (stated by the tagger, no quotation): human serum elimination half-life and its dispersion · the relation stated: eliminates more slowly and more variably | concept_edges[0] | 0.95 | the tagger's words |
| concept_edges | retired fluorochemical production workers —contrasted-with→ cynomolgus monkeys Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. differs in: serum elimination half-life of PFOA · the relation itself is separately evidenced · strength of the relation: 0.9 · differs in (stated by the tagger, no quotation): serum elimination half-life of PFOA · the relation stated: eliminate PFOA on a scale of years rather than weeks | concept_edges[1] | 0.95 | the tagger's words |
| concept_edges | PFOS —operationalised-as→ ion ratios Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. the relation itself is separately evidenced · strength of the relation: 0.9 · the relation stated: serum concentration is quantified as an ion ratio against a labelled internal standard
Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but the span says quantification of PFOS was based on ion ratios; operationalised-as is loose. also in: PFOS · ion ratios | concept_edges[2] | 0.95 | the tagger's words |
| concept_edges | environmental exposure —causes→ rate of elimination Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. direction on the measure: reduces · the relation itself is separately evidenced · strength of the relation: 0.45 — the record marks this weak · direction on the measure (stated by the tagger, no quotation): reduces · the relation stated: continuing background intake would flatten the observed decline, biasing the estimated half-life long
Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but the span says it is POSSIBLE that environmental exposure produced shallower slopes; hedged. also in: environmental exposure · rate of elimination | concept_edges[3] | 0.85 | the tagger's words |
| content_tags | The human PFOA half-life is considerably longer than in cynomolgus monkeys (about 14-40 days). Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | content_tags.findings[0] | 0.95 | the tagger's words |
| content_tags | Excluding the two subjects with the highest half-lives brought the arithmetic means close to the geometric means and medians. Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | content_tags.findings[1] | 0.95 | the tagger's words |
| content_tags | The human PFHS half-life may be longer and more variable than that of PFOS. Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | content_tags.findings[2] | 0.95 | the tagger's words |
| content_tags | no subject characteristic - age, years worked, job, time since retirement - predicts the half-life Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | content_tags.findings[3] | 0.95 | the tagger's words |
| content_tags | the two female subjects' half-lives are statistically indistinguishable from the men's, on n=2 Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | content_tags.findings[4] | 0.85 | the tagger's words |
| content_tags | the time for serum concentration to halve, estimated per subject from the slope of log concentration against time under an assumed first-order model Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: half-life of serum elimination | content_tags.definitions[0] | 0.95 | the tagger's words |
| content_tags | the lowest acceptable standard value fitted on the standard curves used; 10.0 ng/mL for all analyses regardless of instrument Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: lower limit of quantitation | content_tags.definitions[1] | 0.95 | the tagger's words |
| content_tags | arithmetic mean serum elimination half-life of PFOS Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | content_tags.quantities[0] | 0.95 | the tagger's words |
| content_tags | geometric mean serum elimination half-life of PFOS - the value cited downstream Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | content_tags.quantities[1] | 0.95 | the tagger's words |
| content_tags | arithmetic mean serum elimination half-life of PFHS, the longest of the three Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | content_tags.quantities[2] | 0.95 | the tagger's words |
| content_tags | geometric mean serum elimination half-life of PFHS Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | content_tags.quantities[3] | 0.95 | the tagger's words |
| content_tags | arithmetic mean serum elimination half-life of PFOA Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | content_tags.quantities[4] | 0.95 | the tagger's words |
| content_tags | geometric mean serum elimination half-life of PFOA Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | content_tags.quantities[5] | 0.95 | the tagger's words |
| content_tags | lower limit of quantitation for every analyte and instrument Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | content_tags.quantities[6] | 0.95 | the tagger's words |
| content_tags | mean length of follow-up, 5.0 years Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | content_tags.quantities[7] | 0.95 | the tagger's words |
| content_tags | arithmetic mean Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: arithmetic mean | content_tags.statistics[0] | 0.95 | the tagger's words |
| content_tags | geometric mean Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: geometric mean | content_tags.statistics[1] | 0.95 | the tagger's words |
| content_tags | 95% CI Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: 95% CI | content_tags.statistics[2] | 0.95 | the tagger's words |
| content_tags | Pearson correlation coefficients Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: Pearson correlation coefficients | content_tags.statistics[3] | 0.95 | the tagger's words |
| content_tags | Spearman Rho correlations Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: Spearman Rho correlations | content_tags.statistics[4] | 0.95 | the tagger's words |
| content_tags | multiple regression Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: multiple regression | content_tags.statistics[5] | 0.95 | the tagger's words |
| content_tags | log-normal distribution Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: log-normal distribution | content_tags.statistics[6] | 0.95 | the tagger's words |
| content_tags | CVs Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: CVs | content_tags.statistics[7] | 0.95 | the tagger's words |
| content_tags | initial and end-of-study perfluorochemical concentration Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. | content_tags.variables[0] | 0.95 | the tagger's words |
| content_tags | age at study onset Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: age at study onset | content_tags.variables[1] | 0.95 | the tagger's words |
| content_tags | years worked Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: years worked | content_tags.variables[2] | 0.95 | the tagger's words |
| content_tags | years since retirement Quotation withheld — this record is not cleared for redistribution. The sentence is in the paper at the link above. also in: years since retirement | content_tags.variables[3] | 0.95 | the tagger's words |
Tags that could not be placed in the text:
What was deliberately not tagged, and why, is recorded per paper by the tagger. Where a paper has no such record, this page says so rather than implying that nothing was declined.