Half-life of serum elimination of perfluorooctanesulfonate,perfluorohexanesulfonate, and perfluorooctanoate in retired fluorochemical production workers.
Level 4 - case-series / case-control
Single-cohort prospective follow-up study (case series / uncontrolled longitudinal cohort)
PubMed 17805419 · doi:10.1289/ehp.10009
What was done
An observational study evaluated the serum elimination half-lives of perfluorooctanesulfonate (PFOS), perfluorohexanesulfonate (PFHS), and perfluorooctanoate (PFOA). Periodic blood samples were collected over 5 years from 26 retired fluorochemical production workers (24 male, 2 female) without further occupational exposure. Serum was stored at -80 degrees C and analyzed by HPLC-mass spectrometry using isotope-labeled internal standards. Elimination rates were estimated using a first-order kinetic model.
What was found
Initial arithmetic mean serum concentrations were 799 ng/mL (range, 145-3,490) for PFOS, 290 ng/mL (range, 16-1,295) for PFHS, and 691 ng/mL (range, 72-5,100) for PFOA. Arithmetic and geometric mean serum elimination half-lives were: - PFOS: arithmetic mean 5.4 years (95% CI, 3.9-6.9); geometric mean 4.8 years (95% CI, 4.0-5.8) - PFHS: arithmetic mean 8.5 years (95% CI, 6.4-10.6); geometric mean 7.3 years (95% CI, 5.8-9.2) - PFOA: arithmetic mean 3.8 years (95% CI, 3.1-4.4); geometric mean 3.5 years (95% CI, 3.0-4.1)
Why it matters
This study provides empirical human clearance data showing that PFOS, PFHS, and PFOA persist in human serum for multiple years, far longer than in common laboratory animal models.
Limits
The cohort was small (n = 26) and predominantly male (24/26). The study examined occupationally exposed workers, which may not directly reflect pharmacokinetics under general population background exposure levels, and did not account for ongoing non-occupational background intake during the 5-year follow-up.
Cited by
- supports PFAS chemicals have a half-life of 2 to 5 years in the human body.
- supports PFAS chemicals have an elimination half-life in the human body of 2 to 5 years.