HBM-II-Werte für Perfluoroctansäure (PFOA) und Perfluoroctansulfonsäure (PFOS) in Blutplasma – Stellungnahme der Kommission Human-Biomonitoring des Umweltbundesamtes

Monitoring of per- and polyfluoroalkyl substances (PFAS) in human blood samples collected in three regions with known PFAS releases in the environment and three control regions in South Germany

Per- and polyfluoroalkyl substances (PFAS) are known as persistent and bioaccumulative chemicals. The present paper describes the analysis of 969 human blood samples collected in South Germany aiming to determine whether there are statistic significant differences in internal PFAS burden between three regions with known PFAS releases in the environment (study regions) and three regions without known PFAS releases in the environment (control regions). Nine environmental relevant PFAS were analyzed, including the perfluorooctanoic acid (PFOA) substitute 3H-perfluoro-3-[(3-methoxy-propoxy)propanoic acid] ammonium salt (ADONA). We found that concentrations of PFOA and perfluorooctane sulfonate (PFOS) were higher than for all other PFAS in all of the six regions, but all medians of PFOA (between 0.8 and 0.9 ng/ml for the study and control regions) and PFOS (between 1.3 and 1.5 ng/ml for the study regions and between 1.4 and 1.5 ng/ml for the control regions) were below the human biomonitoring values (HBM) I for PFOA (2 ng/ml) und for PFOS (5 ng/ml) derived by the German HBM Commission. Concentrations of ADONA were below the limit of quantification in all samples. Minor differences were observed in PFAS blood levels between study and control regions. Especially for PFOS and PFOA the medians for women are slightly lower compared to men. In summary, individuals living in regions with known environmental PFAS contaminations show no higher internal PFAS exposure to controls and in comparison to other studies in the literature.

Immunomodulation and exposure to per- and polyfluoroalkyl substances: an overview of the current evidence from animal and human studies

Per- and polyfluoroalkyl substances (PFAS) have been widely used and represent a class of environmental persistent chemicals. An association of a reduction of vaccination efficacy with PFAS serum levels in humans was used by the European Food Safety Authority as a key effect for PFAS risk assessment. The data support for using this association is reviewed by a critical analysis of the respective human epidemiology and the available animal studies on the immunomodulation of PFAS. Based on an analysis of the available human epidemiology, the overall level of evidence regarding associations between PFAS serum levels and reduced antibody response remains weak. Absence of an association between an increase in clinical infections and PFAS serum levels and the limited understanding of the importance of antibody levels as an isolated data point further support this conclusion. Animal toxicity studies with PFAS focusing on immunomodulation also provide only limited support for immunomodulation as an important endpoint in PFAS toxicity. While immunomodulation is observed after PFAS administration, generally at blood concentrations several orders of magnitude above those seen in environmentally exposed humans, the relevance of these observation is hampered by the high doses required to influence immune endpoints, the limited number of endpoints assessed, and inconsistent results. The limitations of the current database on associations of human PFAS exposures outlined here indicate that more evidence is required to select immunomodulation as a critical endpoint for human PFAS risk assessment.

Human biomonitoring of per- and polyfluoroalkyl substances in German blood plasma samples from 1982 to 2019

The findings of per- and polyfluoroalkyl substances (PFAS) in humans and the environment all over the world have raised concerns and public awareness for this group of man-made chemicals. In the last three decades, this led to different regulatory restrictions for specific PFAS as well as shifts in the production and usage of these substances. In this study, we analyzed the PFAS levels of 100 human blood plasma samples collected from 2009 to 2019 for the German Environmental Specimen Bank (ESB) to further elucidate the time course of exposure towards this substance group as shown by Schröter-Kermani et al., (2013) with samples from 1982 to 2010. A spectrum of 37 PFAS, including perfluorocarboxylic (PFCA) and -sulfonic acids (PFSA) as well as potential precursors and substitutes like ADONA, GenX or F-53B was analyzed by UHPLC coupled with high-resolution mass spectrometry. Validation was successful for 33 of the substances. The two legacy substances perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) were detected in every sample of the 2009-2019 dataset and showed the highest concentrations with ranges of 0.27-14.0 ng/mL and 1.21-14.1 ng/mL, respectively. A significant portion of total PFOS analytes was present as branched isomers (mean: 34 ± 7%). High detection frequencies of 95% and 82% were also found for perfluorohexane sulfonic acid (PFHxS) and perfluorononanoic acid (PFNA), respectively, but in lower concentrations (PFHxS: <LOQ - 4.62 ng/mL; PFNA: <LOQ - 3.66 ng/mL) than PFOA and PFOS. Besides other PFCA and PFSA only 8:2 fluorotelomer sulfonic acid (8:2 FtS) and N-methyl perfluorooctane sulfonamidoacetic acid were detected in very few samples. In combination with the previous results from 1982 to 2010, declining temporal trends were observed for all PFAS (PFOA, PFNA, PFHxS, and PFOS) frequently detected in the ESB samples. The results of this study indicate a decrease in human exposure to known PFAS in Germany over the last three decades and emphasize the importance of long-term human biomonitoring studies for investigating the effects of chemical regulation.

Per- and polyfluoroalkyl substances in blood plasma - Results of the German Environmental Survey for children and adolescents 2014-2017 (GerES V)

The 5th cycle of the German Environmental Survey (GerES V) investigated the internal human exposure of children and adolescents aged 3-17 years in Germany to per- and polyfluoroalkyl substances (PFAS). The fieldwork of the population-representative GerES V was performed from 2014 to 2017. In total, 1109 blood plasma samples were analysed for 12 PFAS including perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorohexane sulfonic acid (PFHxS). PFOS was quantified in all and PFOA in almost all samples, demonstrating ubiquitous exposure. The highest geometric mean concentrations measured were 2.49 ng/mL for PFOS, followed by PFOA (1.12 ng/mL) and PFHxS (0.36 ng/mL), while concentrations of other PFAS were found in much lower concentrations. The 95th percentile levels of PFOS and PFOA were 6.00 and 3.24 ng/mL, respectively. The results document a still considerable exposure of the young generation to the phased out chemicals PFOS and PFOA. The observed exposure levels vary substantially between individuals and might be due to different multiple sources. The relative contribution of various exposure parameters such as diet or the specific use of consumer products need to be further explored. Although additional investigations on the time trend of human exposure are warranted, GerES V underlines the need for an effective and sustainable regulation of PFAS as a whole.