Running the gauntlet; flyway-wide patterns of pollutant exposure in blood of migratory shorebirds

BackgroundPer- and polyflouralkyl substances (PFAS) are a group of persistent chemicals used extensively in industries and consumer products due to their water-repellent properties. Studies have linked PFAS exposure to adverse health effects, and human exposure to PFAS, especially during pregnancy, is of great concern. In this study, we report how serum PFAS concentrations during pregnancy correlated with serum PFAS of partners from the same household. Further, we report how serum PFAS concentrations change during the course of pregnancy and associations between PFAS and blood lipid concentrations as well as exploratory analyses of associations between physical activity and PFAS concentrations.MethodsIn this secondary analysis of data from the FitMum study conducted from 2018 to 2021, 216 healthy, pregnant women, and 110 of their partners were included. Non-fasting venous blood samples were collected from the mothers at three test visits during pregnancy and at delivery, where blood from partners were also collected. Serum samples from all timepoints were analyzed for 15 short- and long-chained PFAS using liquid chromatography triple quadrupole linear ion trap mass spectrometry. Total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglyceride blood concentrations were measured at three test visits during pregnancy and at delivery. Physical activity was measured with a wrist-worn activity tracker 24/7 from inclusion before gestational age week 15 + 0 and throughout pregnancy.ResultsIn serum samples we detected the following PFAS: PFOS, PFOA, PFHxS, PFNA, PFDA, and PFUnDA. The maternal median concentrations at baseline were: PFOS: 4.09 ng/mL, PFOA: 0.81 ng/mL, PFHxS: 0.29 ng/mL, PFNA: 0.42 ng/mL, PFDA: 0.25 ng/mL, and PFUnDA: 0.19 ng/mL. Partner serum PFAS concentrations were 3–145% higher than maternal concentration (except for PFUnDA). PFAS concentrations correlated within couples. All PFAS decreased significantly during pregnancy (PFOS -23.1 percent 95%-CI [-31.9;-13.2] from baseline to delivery). All PFAS concentrations were associated with increased HDL-C concentrations. No associations between physical activity and maternal PFAS concentrations were found.ConclusionsOverall, serum PFAS concentrations decreased during pregnancy. PFAS concentrations within households were strongly correlated. PFAS and HDL-C concentrations were positively associated. We found no associations between physical activity and serum PFAS concentrations.Trial registrationThe study was registered at ClinicalTrials.gov; NCT03679130; 20/09/2018.

PFAS levels and exposure determinants in sensitive population groups

Occurrence and infant exposure assessment of per and polyfluoroalkyl substances in breast milk from South Africa

PFAS concentrations in the blood of Danish surfers.

Per- and polyfluoroalkyl substances (PFAS) are extensively used in urban environments and are, thus, found in urban stormwater. However, the relevance of stormwater as a pathway for PFAS to urban streams is largely unknown. This study evaluated the impact of urban stormwater runoff on PFAS concentrations and spatial distribution in three urban streams affected by stormwater discharges from separate sewer systems. River water was sampled during dry (DW) and wet weather (WW) upstream, immediately downstream, and further downstream of three urbanized areas with separate sewer systems and with and without point sources (i.e. waste water treatment plant, airports). Water samples were analyzed for 34 targeted PFAS compounds and sediment samples for 35 targeted PFAS and 30 PFAS compounds using a total oxidizable precursor assay. The sum of the quantified PFAS concentrations ranged from the reporting limit (RL) to 84.7 ng/L during DW and increased as the streams were affected by WW discharges (0.87 to 102.3 ng/L). The highest PFAS concentrations were found downstream of urban areas and/or point sources (i.e. airports) during WW, indicating a clear contribution from stormwater discharges. A consistent PFAS contribution from the WWTP was observed under both DW and WW conditions. During WW events, concentrations of perfluorooctanesulfonic acid (PFOS) and total PFAS (PFOA equivalents) exceeded the annual average environmental quality standards, which are an established limit of 0.65 ng/L for PFOS and a proposed limit of 4.4 ng/L for total PFAS. Notably, except for the legacy PFAS, PFOS and perfluorooctanoic acid (PFOA), the most frequently quantified PFAS during DW were short-chain. For WW, long-chain perfluorocarboxylic acids (PFCAs) and a precursor, 6:2 Fluorotelomer sulfonic acid (6:2 FTS), were more frequently quantified, suggesting stormwater is a source of these longer-chain and particle-associated PFAS. The detection of unregulated fluorotelomer sulfonates (FTSs) such as 6:2 and 8:2 FTS during WW suggests a need for regulatory action, as these compounds can degrade into more stable PFAS. In sediment, higher concentrations, and a greater variety of PFAS were found at sites with known point sources i.e. airports. Long-chain PFCAs (C7-C13), perfluoroalkyl sulfonates (PFSAs) (C6), and precursors (i.e. N-Ethyl perfluorooctane sulfonamidoacetic acid), were more prevalent in sediments than in the water. Notably, PFOS concentrations in sediment exceeded the lowest Predicted No-Effect Concentration (PNEC) across sites, posing a potential long-term environmental risk, though current PNECs for other PFAS may underestimate such risks. The findings of the study highlight urban stormwater as a source of PFAS to urban streams indicating the need to minimize PFAS sources in the urban environment and to effectively treat stormwater to protect receiving water bodies.

It's not all about PFAS: Metal(loid)s are associated with physiological and metabolic changes in a native frog from conservation wetlands.

Polyfluoroalkyl and perfluoroalkyl substances (PFAS) are persistent organic pollutants and exposure have been suggested with the risk of developing preeclampsia. Yet, evidence on the associations of PFAS with preeclampsia is still conflicting. Thus, the current study conducted a systematic review and meta-analysis of the epidemiological evidence linking maternal PFAS exposure to preeclampsia. This research methodology involved searching three electronic databases for epidemiological studies, and then conducting a meta-analysis using a random-effects model to analyse the heterogeneity between the studies. The quality and strength of evidence for each exposure-outcome pair was also evaluated, as well as the risk of bias. The search identified 10 potentially eligible studies related to maternal PFAS blood level with preeclampsia, which 7 were ultimately selected. Meta-analysis demonstrated evidence of association between combined PFAS compounds in pregnant mother with preeclampsia with zero heterogeneity (I2=0.0%, Q= 3.09, df= 6, p=0.798). Preeclampsia was found to have moderate association with maternal perfluorooctanoic acid (PFOA) exposure (Test for overall effect: z=2.2, p=0.03; Test for heterogeneity: I2=0.0%, Q= 3.49, df= 6, p=0.745) as well as maternal perfluorooctane sulfonate (PFOS) exposure (Test for overall effect: z=2.5, p=0.01; Test for heterogeneity: I2=0.0%, Q= 3.70, df= 6, p=0.718). This study showed significant associations between PFOA and PFOS exposure with the risk of preeclampsia. However, in-depth investigation is imperative to elucidate the impact of the different concentration and types of PFAS on preeclampsia risk.

Per- and poly-fluoroalkyl substances (PFAS) do not accumulate with age or affect population survival in ruddy turnstone (Arenaria interpres)

BackgroundPediatric thyroid diseases have been increasing in recent years. Environmental risk factors such as exposures to chemical contaminants may play a role but are largely unexplored. Archived neonatal dried blood spots (DBS) offer an innovative approach to investigate environmental exposures and effects.ObjectiveIn this pilot study, we applied a new method for quantifying per- and polyfluoroalkyl substances (PFAS) to 18 archived DBS from babies born in California from 1985–2018 and acquired thyroid hormone measurements from newborn screening tests. Leveraging these novel data, we evaluated (1) changes in the concentrations of eight PFAS over time and (2) the relationship between PFAS concentrations, thyroid hormone concentrations, and neonatal characteristics to inform future research.MethodsPFAS concentrations in DBS were measured using ultra-high-performance liquid chromatography-mass spectrometry. Summary statistics and non-parametric Wilcoxon rank-sum and Kruskal–Wallis tests were used to evaluate temporal changes in PFAS concentrations and relationships between PFAS concentrations, thyroid hormone concentrations, and neonatal characteristics.ResultsThe concentration and detection frequencies of several PFAS (PFOA, PFOS, and PFOSA) declined over the assessment period. We observed that the timing of specimen collection in hours after birth was related to thyroid hormone but not PFAS concentrations, and that thyroid hormones were related to some PFAS concentrations (PFOA and PFOS).Impact statementThis pilot study examines the relationship between concentrations of eight per- and polyfluoroalkyl substances (PFAS), thyroid hormone levels, and neonatal characteristics in newborn dried blood spots (DBS) collected over a period of 33 years. To our knowledge, 6 of the 22 PFAS we attempted to measure have not been quantified previously in neonatal DBS, and this is the first study to examine both PFAS and thyroid hormone concentrations using DBS. This research demonstrates the feasibility of using newborn DBS for quantifying PFAS exposures in population-based studies, highlights methodological considerations in the use of thyroid hormone data for future studies using newborn DBS, and indicates potential relationships between PFAS concentrations and thyroid hormones for follow-up in future research.

The occurrence and distributions of per- and polyfluoroalkyl substances (PFAS) in groundwater after a PFAS leakage incident in 2018.

BACKGROUND AND AIM: Certain fruit juices, such as apple juice (AJ), contain bioactive molecules that can impair intestinal drug absorption through inhibition of transporter Organic Anion Transporting Polypeptide 2B1 (OATP2B1). Because some PFAS have been shown to be OATP2B1 substrates, we used a translational research paradigm to explore our hypothesis that higher fruit juice intake is associated with lower PFAS concentrations. METHODS: Female C57Bl/6 mice were administered perfluorooctane sulfonic acid (PFOS, 5 mg/kg) in buffer or in 4x AJ concentrate, with blood and tissues collected 5 hours after administration. Tissue PFOS was extracted and quantified by LC-MS. Epidemiologic analysis was conducted on 345 adolescents aged 12-19 years and 1,458 adults aged 20-80 years using the National Health and Nutrition Examination Study (NHANES), 2013 - 2014 cycle. Pure (100%) fruit juice intake was assessed by 24h dietary recall. Log-2 transformed serum concentrations of PFOS, perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS) were evaluated. Multivariable regression models were used to assess changes in PFAS concentrations in relation to dietary intake of juice, adjusting for covariates. RESULTS:In mice, 4x AJ co-administration decreased PFOS concentrations in blood, liver, kidney, and brain 5 hours after administration, indicating that 4x AJ can inhibit or delay PFOS absorption. Intake of pure fruit juice more than 1 time in the previous 24h was associated with a 15% (95%CI: -28%, -1%) reduction in serum PFOA concentration compared with no intake of juice among adolescents. No associations were observed between fruit juice intake and PFAS concentrations in adults. CONCLUSIONS:Combining experimental and epidemiological data, fruit juice consumption might lower PFAS burden. More research is needed to elucidate the effect of fruit juice consumption on PFAS concentrations in humans across age groups. KEYWORDS: PFAS, juice, translational, exposure reduction

Amphibians serve a central role in food webs and provide a link between aquatic and terrestrial habitats. Because of their dependence on water, amphibians are susceptible to legacy and emerging contaminants. We investigated mercury (Hg) and per- and polyfluoroalkyl substances (PFAS) concentrations in wild populations of two amphibian species-the green frog (Lithobates clamitans) and the American toad (Anaxyrus americanus)-which exhibit different life histories. We evaluated if proximity to PFAS point source (State Superfund site) impacted PFAS exposures in amphibians and assessed length, mass, sex, diet, and trophic position as predictors of contaminant concentrations. We found higher Hg concentrations in the more aquatic species (ie, green frog), but higher PFAS concentrations (summed PFAS, perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnA), perfluorododecanoic acid (PFDoA), perfluorotridecanoic acid (PFTrDA), and perfluorotetradecanoic acid (PFTeDA)) in the more terrestrial species (ie, American toad). Proximity to the PFAS State Superfund site did not strongly affect PFAS exposures in amphibians. Of the biological predictors tested, diet best explained PFAS concentrations, but other factors (e.g., physiological differences) are likely contributing to the difference in PFAS bioaccumulation between aquatic and terrestrial species. Only three reports on PFAS concentrations in wild amphibians exist, all from contaminated sites in China, reporting much higher concentrations than found here. Additionally, experimental exposure studies have only investigated the effects of exposure to a few PFAS compounds, of which long-chain perfluoroalkyl carboxylic acids (PFCAs) detected here (PFDA, PDUnA, PFDoA, PFTrDA, and PFTeDA) are not represented in the literature. To truly understand the effects that detectable PFAS impose on wild amphibians, research is needed on the effects of more PFAS compounds, bioaccumulation in larval and terrestrial amphibians, and the elimination of PFAS via their skin to different media.

Perand polyfluoroalkyl substances (PFAS) may affect adolescent health, yet factors related to PFAS concentrations in serum are poorly understood. We studied demographic, life-style and physiological determinants of serum PFAS concentrations in Swedish adolescents from a nation-wide survey, Riksmaten Adolescents 2016–17 (RMA, age 10–21 years, n = 1098). Serum samples were analyzed for 42 PFAS, using liquid chromatography-tandem mass spectrometry. The cumulative probability model was used to estimate associations between serum PFAS and determinants, using ordinal logistic regression. Legacy linear (lin-) perfluorooctanoic acid (PFOA), perfluorononaoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), lin-perfluorohexanesulfonic acid (PFHxS) and lin-/branched (br-) perfluorooctanesulfonic acid (PFOS) were quantifiable in ≥70% of the samples. The emerging PFAS 9-chlorohexanedecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS) was quantified in 5.4% of the samples, suggesting initiation of long-range transport far from production sites. Median concentrations of all legacy PFAS were <2 ng/g serum, with a few participants having very high (>100 ng/g serum) lin-PFHxS and lin-/br-PFOS concentrations due to previous high exposure from PFAS-contaminated drinking water. Legacy PFAS exposure was strongly associated with birth country of the participants and their mothers. 2-fold higher estimated adjusted mean (EAM) concentrations were seen among high income country participants with mothers from high income countries than among low/lower-middle income country participants with mothers from the same category. Menstruating females had lower br-PFOS EAM concentrations than those who were not. Iron status (plasma ferritin) among females may be a marker of intensity of menstrual bleeding, but it was not significantly associated with legacy PFAS concentrations among females. Further studies are needed to determine how physiological changes occurring around menstruation affect the toxicokinetics of PFAS in females. In conclusion, PFAS are pollutants of the industrialized world and some of the identified determinants may be overlooked confounders/effect modifiers that should be included in future PFAS/health studies among adolescents.

Are maternal plasma concentrations of perfluoroalkyl and polyfluoroalkyl substances (PFASs) during pregnancy associated with anogenital distance (AGD) in male infants at birth, 6, and 12 months of age? Higher maternal plasma concentrations of some PFASs were associated with shorter AGD in male infants at birth and 6months of age. Two animal studies have found that exposure to PFASs was associated with shorter AGD in male rat fetuses and wild male minks. There is only one human study on the topic that did not identify consistent patterns between maternal serum concentrations of PFASs during pregnancy and AGD in male infants. In the prospective cohort study, a total of 1292 eligible pregnant women were recruited at 12-16weeks of gestation between April and December 2012 at the Maternal and Child Health Hospital of Minhang district in Shanghai, China. At delivery, 667 male singletons were born. They were then followed up at birth (n = 439) and at 6 (n = 411) and 12months (n = 376) of age when anopenile distance (AGDAP) and anoscrotal distance (AGDAS) were measured. A total of 500 male infants who had both maternal plasma concentrations of PFASs and at least one AGD measurement of at three time points were included in the present study. Multiple linear regression models were used to evaluate the potential linear associations between maternal concentrations of PFASs and AGD. Maternal plasma concentrations (ln-transformed) of perfluorooctane sulfonate (PFOS), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUdA) were inversely associated with AGDAS or AGDAP at birth (AGDAS: per ln unit increase in PFAS concentrations: β (95% CI): -0.65 (-1.27 to -0.02)mm for PFOS; -0.58 (-1.11 to -0.06)mm for PFDA; and -0.57 (-1.09 to -0.06)mm for PFUdA; AGDAP: per ln unit increase in PFAS concentrations: β (95% CI): -0.63 (-1.24 to -0.01)mm for PFDA and - 0.76 (-1.36 to -0.16)mm for PFUdA). At 6months of age, per unit increase in maternal ln concentrations of PFOS and perfluorotridecanoic acid (PFTrDA), AGDAS decreased on average by -2.21 (95% CI: -4.28 to -0.14) and -1.11 (95% CI: -2.17 to -0.06)mm, respectively. Additionally, ln-transformed perfluorooctanoic acid (PFOA) showed nonsignificant but inverse associations with both AGDAS and AGDAP at 6months of age. We found no significant associations between ln-transformed maternal concentrations of PFASs and either AGDAS or AGDAP at 12months of age. However, significantly inverse association of ln-transformed PFOA with AGDAP was observed in male infants who never or shortly breastfed (<3months) at 12months of age. AGD measurements were performed by different examiners at each follow-up visit, and the intra-examiner variation was not assessed, which might cause intra-rater and inter-rater measurement errors. Additionally, our study may have selection bias since a considerable number of participants withdrew from the cohort although the differences in demographic characteristics were not statistically significant between included mother-infant pairs and those excluded. No statistical correction was made for multiple comparisons. Our findings may have important implications for the early development of genital health in male infants since PFASs can be detected in almost all pregnant women and infants worldwide. This study was supported by grants from the National Key Research and Development program of China (2018YFC1002801 and 2016YFC1000505), the Science and Technology Commission of Shanghai Municipality (16ZR1430100), the National Natural Science Foundation of China (81428011), and the Innovation-Oriented Science and Technology Grant from National Health Commission Key Laboratory of Reproduction Regulation (CX2017-06). The authors have no conflicts of interest to declare. N/A.

Longitudinal trends in per- and polyfluoroalkyl substances (PFAS) serum concentrations across pregnancy have not been thoroughly examined, despite evidence linking prenatal PFAS exposures with adverse birth outcomes. We sought to characterize longitudinal PFAS concentrations across pregnancy and to examine the maternal-fetal transfer ratio among participants in a study of risk and protective factors for adverse birth outcomes among African Americans. In the Atlanta African American Maternal-Child cohort (2014-2020), we quantified serum concentrations of four PFAS in 376 participants and an additional eight PFAS in a subset of 301 participants during early (8-14 weeks gestation) and late pregnancy (24-30 weeks gestation). Among these, PFAS concentrations were also measured among 199 newborns with available dried blood spot (DBS) samples. We characterized the patterns, variability, and associations in PFAS concentrations at different time points across pregnancy using intraclass correlation coefficients (ICCs), maternal-newborn pairs transfer ratios, linear mixed effect models, and multivariable linear regression, adjusting for socioeconomic and prenatal predictors. Perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) were detected in of maternal samples, with PFHxS and PFOS having the highest median concentrations. We observed high variability in PFAS concentrations across pregnancy time points (). All median PFAS concentrations increased from early to late pregnancy, except for PFOA and N-methyl perfluorooctane sulfonamido acetic acid (NMFOSAA), which decreased [paired -test for all PFAS except for PFOA and perfluorobutane sulfonic acid (PFBS)]. Prenatal serum PFAS were weakly to moderately correlated with newborn DBS PFAS ( ). The median maternal-fetal PFAS transfer ratio was lower for PFAS with longer carbon chains. After adjusting for socioeconomic and prenatal predictors, in linear mixed effect models, the adjusted mean PFAS concentrations significantly increased during pregnancy, except for PFOA. In multivariable linear regression, PFAS concentrations in early pregnancy significantly predicted the PFAS concentrations in late pregnancy and in newborns. We found that the concentrations of most PFAS increased during pregnancy, and the magnitude of variability differed by individual PFAS. Future studies are needed to understand the influence of within-person PFAS variability during and after pregnancy on birth outcomes. https://doi.org/10.1289/EHP14334.