Half-lives of PFOA, PFPeS, PFHxS, PFHpS and PFOS after end of exposure to contaminated drinking water

By Y. Li, Y. Xu, K. Scott, C. Lindh, K. Jakobsson, and T. Fletcher
Environ. Epi.
November 11, 2019
DOI: 10.1097/01.EE9.0000608476.06577.16

Background/Aim: Per- and polyfluoroalkyl substances (PFAS) comprise a group of many different substance that been produced and widely used. They have been reported in humans and wildlife. The purpose of this observational study was to estimate the elimination half-life PFAS from human serum after end of exposure to contaminated drinking water.

Method: Municipal drinking water contaminated with PFAS had been distributed to one third of households in Ronneby, Sweden. The source was firefighting foam used in a nearby airfield since the mid-1980s. Clean water was provided from December 16, 2013. Up to ten blood samples were collected between June 2014 and May 2019 from 108 participants with a large age span (4-84 years) and balanced gender (53% female). Several PFAS were analyzed. In the present study, we reported the dominant ones: perfluorooctanoic acid (PFOA), perfluoropentane sulfonate (PFPeS), perfluorohexane sulfonate (PFHxS), perfluoroheptane sulfonate (PFHpS) and linear perfluorooctane sulfonate (PFOS).

Results: Median initial serum concentrations were: PFOA 16 ng/ml (range 2-78), PFPeS 5.9 ng/ml (range 1-49), PFHxS 257 ng/ml (range 15-1304), PFHpS 12 ng/ml (1-70) and PFOS 169 ng/ml (12-682). The observed data are consistent with a first-order elimination model. The mean estimated half-lives were 3.0 years (95% CI 2.8-3.2) for PFOA, 1.0 years (95% CI 0.9-1) for PFPeS, 4.7 years (95% CI 4.3-5.2) for PFHxS, 4.7 years (95% CI 4.3-5.3) for PFHpS and 2.9 years (95% CI 2.7-3.1) for PFOS. There was a marked age and BMI effect on half-life with more rapid elimination in younger ages and lower BMI for all PFAS studied.

Conclusion: These are the first half-life data on elimination of new PFAS compounds in a community and they are marked variation with carbon chain length.

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