Abstract  In 2013 a contamination of drinking water by perfluoroalkylated substances (PFASs) was discovered in areas of the Veneto Region (northern Italy). In this study the exposure to PFASs of people living in the aforesaid areas was characterized: contaminant serum concentrations were measured and compared with those of a control population group living in neighboring areas at background exposure (based on available drinking water data). The enrolled population was also genotyped for the OATP1A2*3 allelic variant, possibly affecting PFAS excretion and hence the internal dose. The difference in PFAS concentrations between exposed and not exposed subjects was significantly larger for nine of the 12 substances analyzed, and confirmed that water contamination had resulted in an appreciable high exposure of the residing population over time. Within the group of exposed subjects, subgroups at different exposure levels were identified. The contamination of drinking water of the residence area was found to be the main factor influencing PFAS serum levels; in addition to water contamination, other relevant influencing factors were sex, the years of residence and raising own livestock. No relationship with the genetic trait for the studied renal transporter was evidenced. These results provide a baseline characterization of PFAS exposure of the monitored population groups for further studies, planned to be carried out in the near future.

Abstract  Effects of perfluorobutanesulfonic acid (PFBS), perfluorohexanesulfonic acid (PFHxS), perfluorononanoic acid (PFNA), and perfluoroheptanoic acid (PFHpA) on earthworms (Eisenia fetida) in soils contaminated with these compounds at 0.1, 1, 10, 1,000, and 100,000 μg kg-1dry weight, covering concentration levels found in background, biosolid-amended, and facility-surrounding soils, were investigated. Earthworms were exposed to spiked soil for 21 days. Concentrations of these compounds in earthworms after 21-d exposure ranged from below detection to 127 mg kg-1wet weight with the rank order of PFNA > PFHxS > PFHpA > PFBS; no mortality of earthworms was observed in all treatments including controls, except PFBS at 1,000 μg kg-1and all PFASs at 100,000 μg kg-1. The highest weight loss (29%) was observed for earthworms exposed to PFNA at 100,000 μg kg-1, which was significantly different from all other treatments except PFHpA at 100,000 μg kg-1. These results are expected to fill some data gaps in toxicity of PFASs in terrestrial environments and provide helpful information on the potential for trophic transport of PFASs from soil to higher organisms.

Abstract  Perfluorooctane sulfonamide (PFOSA) is a precursor of perfluorooctane sulfonic acid (PFOS) and can be broken down to PFOS in environment and biota. In the present work, PFOSA was spiked in soil and its biodegradation in soil, uptake and metabolism in wheat (Triticum aestivum L.) and earthworms (Eisenia fetida) were investigated. The results indicated that PFOSA could be biodegraded to highly stable PFOS, which has the same perfluorinated carbon chain length as PFOSA, by microbes in soil. PFOSA could be taken up by wheat root and earthworm from soil with higher bioaccumulation ability than PFOS. In both wheat and earthworms, PFOSA also degraded to PFOS. However, other shorter-chain perfluoroalkane sulfonates (PFSAs), including perfluorohexane sulfonate (PFHxS) and perfluorobutane sulfonate (PFBS), were observed in wheat, but not in soil and earthworms, suggesting that wheat displayed distinctly different degradation mechanisms to PFOSA from soil microbes and earthworms.

Abstract  Landfill leachate is often an important source of emerging organic contaminants including perfluoroalkyl and polyfluoroalkyl substances (PFASs) requiring proper treatment to protect surface water and groundwater resources. This study investigated the occurrence of PFASs in the leachate of a capped landfill site in Singapore and the efficacy of PFASs removal during flow through a constructed wetland (CW) treatment system. The CW treatment system consists of equalization tank, aeration lagoons, sedimentation tank, reed beds and polishing ponds. Target compounds included 11 perfluoroalkyl acids (PFAAs) (7 perfluoroalkyl carboxylic acids (PFCAs) and 4 perfluoroalkane sulfonates (PFSAs)) and 7 PFAA precursors. Although total PFASs concentrations in the leachate varied widely (1269 to 7661 ng/L) over the one-year sampling period, the PFASs composition remained relatively stable with PFCAs consistently being predominant (64.0 ± 3.8%). Perfluorobutane sulfonate (PFBS) concentrations were highly correlated with total PFASs concentrations and could be an indicator for the release of PFASs from this landfill. The release of short-chain PFAAs strongly depended on precipitation whereas concentrations of the other PFASs appeared to be controlled by partitioning. Overall, the CW treatment system removed 61% of total PFASs and 50-96% of individual PFASs. PFAAs were removed most efficiently in the reed bed (42-49%), likely due to the combination of sorption to soils and sediments and plant uptake, whereas most of the PFAA precursors (i.e. 5:3 fluorotelomer carboxylate (5:3 acid), N-substituted perfluorooctane sulfonamides (N-MeFOSAA and N-EtFOSAA)) were removed in the aeration lagoon (>55%) by biodegradation. The sedimentation tank and polishing ponds were relatively inefficient, with only 7% PFASs removal.

Abstract  A series of perfluorobutane sulfonate (PFBS)-related substances are produced as the alternatives to corresponding perfluorooctane sulfonate (PFOS). However, there is little reliable information about PFBS available for the whole ecotoxicology compartments. At present, its ecotoxicity of perfluorobutane sulfonate potassium (PFBSK) was selected as a typical PFBS chemical to investigate and evaluate its aquatic, terrestrial, microorganism and sediment toxicity according to the Organization for Economic Cooperation and Development (OECD) guideline under the framework of the REACH regulation. Meanwhile, the ecotoxicology hazard and risk for PFBSK and PFOS were compared comprehensively.

PFBSK did not show acute and chronic aquatic, microorganisms and terrestrial animal toxicity, while exhibited some terrestrial plants toxicity. The ecotoxicology of PFBSK decreased sharply except for terrestrial plants compared with PFOS. Especially, for acute and chronic aquatic ecotoxicity, PFBSK is lower than 100 times those of PFOS.

Although the similar terrestrial plants toxicity level was observed for PFBSK and PFOS, the lower risk of PFBSK was deduced for the reason that there was far less chances to be exposed and retained in the soil and sediment for its high water solubility and low adsorption.

In conclusion, PFBSK showed lower ecotoxicity hazard and risk than those of PFOS. PFBSK could be an environmental friendly alternative to PFOS.

Abstract  BACKGROUND: Multiple Northeast U.S. communities have discovered per- and polyfluoroalkyl substances (PFASs) in drinking water aquifers in excess of health-based regulatory levels or advisories. Regional stakeholders (consultants, regulators, and others) need technical background and tools to mitigate risks associated with exposure to PFAS-affected groundwater.

OBJECTIVES: The aim was to identify challenges faced by stakeholders to extend best practices to other regions experiencing PFAS releases and to establish a framework for research strategies and best management practices.

METHODS AND APPROACH: Management challenges were identified during stakeholder engagement events connecting attendees with PFAS experts in focus areas, including fate/transport, toxicology, and regulation. Review of the literature provided perspective on challenges in all focus areas. Publicly available data were used to characterize sources of PFAS impacts in groundwater and conduct a geospatial case study of potential source locations relative to drinking water aquifers in Rhode Island.

DISCUSSION: Challenges in managing PFAS impacts in drinking water arise from the large number of relevant PFASs, unconsolidated information regarding sources, and limited studies on some PFASs. In particular, there is still considerable uncertainty regarding human health impacts of PFASs. Frameworks sequentially evaluating exposure, persistence, and treatability can prioritize PFASs for evaluation of potential human health impacts. A regional case study illustrates how risk-based, geospatial methods can help address knowledge gaps regarding potential sources of PFASs in drinking water aquifers and evaluate risk of exposure.

CONCLUSION: Lessons learned from stakeholder engagement can assist in developing strategies for management of PFASs in other regions. However, current management practices primarily target a subset of PFASs for which in-depth studies are available. Exposure to less-studied, co-occurring PFASs remains largely unaddressed. Frameworks leveraging the current state of science can be applied toward accelerating this process and reducing exposure to total PFASs in drinking water, even as research regarding health effects continues. https://doi.org/10.1289/EHP2727.

Abstract  A method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with QuEChERS (quick, easy, cheap, effective, rugged, and safe) sample preparation was developed for the simultaneous determination of 12 perfluorocarboxylic acids (PFCAs) and 7 perfluorosulfonic acids (PFSAs) in the muscle of shrimp, shellfish, and fish. A modified QuEChERS procedure was applied to the extraction and concentration of perfluorinated compounds (PFCs) as well as for removal of interferences. The determination of the 19 PFCs was performed by LC-MS/MS in negative-ion detection mode. 13C-labeled PFCs, as a stable isotopic internal standard (except for L-PFBS, L-PFPeS, ipPFNS, and L-PFNS, for which no labeled analogs were available), was used for calibration. The limits of detection ranged from 0.01–1.0 μg/kg. The recoveries of spiked sample at 0.02–8.0 μg/kg ranged from 61 to 117% with relative standard deviations of less than 14%. The developed method was successfully utilized to monitor real samples, which demonstrated that it is a simple, fast, and robust method and could be used to monitor PFCAs and PFSAs in aquatic products. Most of the samples tested positive, mainly for perfluorooctane sulfonate acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorobutanoic acid (PFBA), but other samples of the 14 studied PFCs were also present. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.

Abstract  Identification and characterization of environmental hazards that impact human health must rely on the best possible science to inform and inspire appropriate public health intervention. The perfluorinated alkylate substances (PFASs) are persistent emerging pollutants that are now being recognized as important human health hazards. Although the PFASs have been produced for over 60 years, academic research on environmental health aspects has appeared only in the most recent 10 years or so. In the meantime, these persistent chemicals accumulated in the global environment. Some early studies e.g., on population exposures and toxicity, were not released to the public until after year 2000. Still, the first PFAS risk assessments ignored these reports and relied on scant journal publications. The first guidelines and legal limits for PFAS exposure, e.g., from drinking water, were proposed 10 years ago. They have decreased substantially since then, but remain higher than suggested by data on human adverse effects, especially on the immune system, that occur at background exposure levels. By now, the best-known PFASs are being phased out, and related PFASs are being introduced as substitutes. Given the substantial delays in discovery of PFAS toxicity, in dissemination of findings, and in regulatory decisions, PFAS substitutes and other persistent industrial chemicals should be subjected to prior scrutiny before widespread usage.

Abstract  Perfluoroalkyl and polyfluoroalkyl substances (PFASs) can be transferred from a mother to her fetus during pregnancy and adversely affect fetal development. However, the efficiency and influencing factors of PFASs maternal-fetal transfer remain unclear. We measured the levels of six perfluoroalkylcarboxylates, three perfluoroalkylsulfonates, and one sulfonamide in 369 pairs of maternal and umbilical cord serum and examined the transplacental transfer efficiency (TTE) of PFASs by the functional group and carbon chain length in a prospective birth cohort in Shandong, China. All ten PFASs were detected in both maternal and umbilical cord serum in nearly all samples. Maternal and cord levels were closely correlated (the correlation coefficient [r] ranging from 0.485 to 0.908) in most PFASs except perfluorobutane sulfonic acid (PFBS) (r = 0.159). TTE was significantly affected by the functional group and carbon chain length. Compared to perfluoroalkylcarboxylates, perfluoroalkylsulfonates had a lower ratio of maternal to fetal transfer. A U-shaped relationship between carbon chain length and TTE was observed for perfluoroalkylcarboxylates while a monotonic descending trend was identified between TTE and the increasing carbon chain length for perfluoroalkylsulfonates. PFASs can readily pass through the placenta. The functional group and carbon chain length are important determinants for the TTE of PFASs.

Abstract  An effective, specific and accurate method is presented for the quantification of 13 markers of anthropogenic contaminants in water using solid phase extraction (SPE) followed by high performance liquid chromatography (HPLC) tandem mass spectrometry (MS/MS). Validation was conducted according to the International Conference on Harmonisation (ICH) guidelines. Method recoveries ranged from 77 to 114% and limits of quantification between 0.75 and 4.91 ng/L. A study was undertaken to quantify the concentrations and loadings of the selected contaminants in 6 sewage treatment works (STW) effluent discharges as well as concentrations in 5 rain-driven street runoffs and field drainages. Detection frequencies in STW effluent ranged from 25% (ethinylestradiol) to 100% (benzoylecgonine, bisphenol-A (BPA), bisphenol-S (BPS) and diclofenac). Average concentrations of detected compounds in STW effluents ranged from 3.62 ng/L (ethinylestradiol) to 210 ng/L (BPA). Levels of perfluorinated compounds (PFCs) perfluorooctanoic acid (PFOA) and perfluorononanoic acid (PFNA) as well as the plasticiser BPA were found in street runoff at maximum levels of 1160 ng/L, 647 ng/L and 2405 ng/L respectively (8.52, 3.09 and 2.7 times more concentrated than maximum levels in STW effluents respectively). Rain-driven street runoff may have an effect on levels of PFCs and plasticisers in receiving rivers and should be further investigated. Together, this method with the 13 selected contaminants enables the quantification of various markers of anthropogenic pollutants: inter alia pharmaceuticals, illicit drugs and their metabolites from humans and improper disposal of drugs, while the plasticisers and perfluorinated compounds may also indicate contamination from industrial and transport activity (street runoff).

Abstract  Perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) are the main representatives of an rising class of persistent organic pollutants (POPs), perfluorochemicals (PFCs). In this study, determination of selected PFCs concentration in liver, brain, tail, adipose and peritoneum tissues of free-living European beaver (Castor fiber L.) was addressed. Tissue samples, collected from beavers living in Masurian Lakeland (NE Poland), were analyzed by dispersive Solid Phase Extraction (d-SPE) with micro-UHPLC-MS/MS system. In a group of ten selected pefrluorinated compounds only two perfluorinated acids (PFOA and PFNA) and one perfluorinated sulfonate (PFOS) were quantified. PFOA was detected in all analysed tissue samples in both female and male beavers in a range from 0.55 to 0.98ngg(-1) ww whereas PFOS was identified in all analyzed female beaver tissues and only in liver, subcutaneous adipose and peritoneum tissues of male beavers at the concentration level from 0.86 to 5.08ngg(-1) ww. PFNA was only identified in female beaver tissues (liver, subcutaneous adipose and peritoneum) in a range from 1.50 to 6.61ngg(-1) ww. This study demonstrated the bioaccumulation of PFCs in tissue samples collected from beavers living in area known as green lungs of Poland. The results provided in this study indicate for the increasing risk of PFCs occurrence in the environment and the level of PFCs in tissue of free-living European beavers may serve as bioindicator of environmental pollution by these compounds.

Abstract  Perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA), which are classified as perfluoroalkyl and polyfluoroalkyl substances (PFASs), have been widely used in industrial applications as a surface protectant. PFASs have been detected in wildlife and in humans around the globe. The purposes of this study are to develop and validate a physiologically based pharmacokinetic (PBPK) model for detecting PFNA and PFDA in male and female rats, and to apply the model to a human health risk assessment regarding the sex difference. A PBPK model of PFNA and PFDA was established based on an in vivo study in male and female rats. Analytes in biological samples (plasma, nine tissues, urine, and feces) were determined by ultra-liquid chromatography coupled tandem mass spectrometry (UPLC-MS/MS) method. PFNA and PFDA showed a gender differences in the elimination half-life and volume of distribution. The tissue-plasma partition coefficients were the highest in the liver in both male and female rats. The predicted rat plasma and urine concentrations simulated and fitted were in good agreement with the observed values. The PBPK models of PFNA and PFDA in male and female rats were then extrapolated to a human PBPK model based on human physiological parameters. The external doses were calculated at 3.35 ng/kg/day (male) and 17.0 ng/kg/day (female) for PFNA and 0.530 ng/kg/day (male) and 0.661 ng/kg/day (female) for PFDA. Human risk assessment was estimated using Korean biomonitoring values considering the gender differences. This study provides valuable insight into human health risk assessment regarding PFNA and PFDA exposure.

Abstract  The historical use of aqueous film forming foams (AFFF) containing perfluoroalkyl substances (PFASs) for firefighting and training activities has resulted in groundwater contamination. The competitive adsorption of PFASs and the effect of co-existing compounds on the removal of PFASs by anion-exchange resins were studied in this study. Perfluorohexane sulfonate (PFHxS) was selected as the representative PFAS, and resin IRA910 was found to be effective for PFHxS removal. When PFHxS was co-removed with other PFASs in bisolute system, it replaced the adsorbed PFASs with shorter C-F chains on the IRA910, while perfluorooctanesulfonate (PFOS) was not replaced by PFHxS. The competitive adsorption among PFASs decreased in the order of PFOS?>?PFHxS?>?PFOA?>?PFBS>PFHxA?>?PFBA, closely related to the hydrophobicity and functional groups of PFASs. The nonionic organic compounds could not interfere with the PFHxS removal, while ionic ones can reduce the sorption amount and their influence to the sorption of PFHxS was concentration dependent. The presence of inorganic anions slightly decreased the removal efficiency of PFHxS and the influence of different inorganic anions was similar due to multiple effects including competitive anion, screening effect, and salting-out effect in the adsorption process.

Abstract  Perfluorobutane sulfonate (PFBS) is considered a less-toxic replacement for perfluorooctane sulfonate (PFOS), with multiple applications in industrial and consumer products. Previous studies comparing their toxicity generally used similar exposure levels, without taking internal concentrations into account. The current study compared the reproductive toxicity of PFOS and PFBS, at similar internal concentrations, to Caenorhabditis elegans (C. elegans). PFBS was much less bioaccumulative than PFOS. The 48-h median lethal concentrations (LC50) for PFOS and PFBS were 1.4 μM (95% confidence interval [CI]: 1.1-1.6) and 794 μM (95% CI: 624-1009), respectively. Egg production and brood number of C. elegans decreased markedly following exposure to 0.1 μM PFOS or 1000 or 1500 μM PFBS. Germ-cell apoptosis and production of reactive oxygen species increased significantly following exposure to 2 μM PFOS or 500 or 1000 μM PFBS. Expression of the antioxidant genes sod-3, ctl-2, and gst-4 and the pro-apoptotic genes egl-1 and ced-13 was altered significantly following PFOS and PFBS exposure. These findings indicate that both chemicals exert reproductive toxicity in C. elegans, probably owing to germ-cell apoptosis resulting from elevated levels of reactive oxygen species. The vastly different exposure concentrations of PFBS and PFOS used in this study produced similar internal concentrations, leading to the reproductive toxicities observed.

Abstract  This study investigated perfluoroalkyl substances (PFASs) in multimedia environments to confirm the effects of emission sources of PFASs and to elucidate their spatial distribution. The highest PFAS levels were detected from the samples of air (272.30 pg/m3) and surface water (36.54 ng/L) in an industrial complex area, meanwhile high PFAS levels were found from the samples of soil (8.80 ng/g) and sediment (84.98 ng/g) in urban areas and near wastewater treatment plants (WWTPs). Perfluorobutane sulfonate (PFBS) was primarily detected in water, influent and effluent, whereas long chain perfluorocarboxylic acids (PFCAs) and perfluorooctane sulfonate (PFOS) were dominant in dust, soil, sediment and sludge. While PFBS and neutral PFASs were dominant in air, PFCAs were primarily detected in plant and fish. The specific distribution patterns of PFASs in each matrix showed the influences of surrounding environments and different physicochemical characteristics of each congener. These findings suggest that the industrial complex and WWTP might be major emission sources to air and aquatic environments, respectively. This is the first study in which 6 neutral and 13 ionic PFASs were investigated simultaneously for nine different matrices in multimedia environments, and also it would be a good model study for future assessment of PFASs.

Abstract  The extent of per- and polyfluoroalkyl substances (PFAS) in groundwater surrounding legacy landfills is currently poorly constrained. Seventeen PFAS were analysed in groundwater surrounding legacy landfills in a major Australian urban re-development precinct. Sampling locations (n = 13) included sites installed directly in waste material and down-gradient from landfills, some of which exhibited evidence of leachate contamination including elevated concentrations of ammonia-N (≤106 mg/L), bicarbonate (≤1,740 mg/L) and dissolved methane (≤10.4 mg/L). Between one and fourteen PFAS were detected at all sites and PFOS, PFHxS, PFOA and PFBS were detected in all samples. The sum of detected PFAS (∑14PFAS) varied from 26 ng/L at an ambient background site to 5,200 ng/L near a potential industrial point-source. PFHxS had the highest median concentration (34 ng/L; range: 2.6-280 ng/L) followed by PFOS (26 ng/L; range: 1.3-4,800 ng/L), PFHxA (19 ng/L; range:

Abstract  High-level contaminations of perfluoroalkyl substances (PFASs) were determined in both surface water and groundwater around a fluorochemical industrial park (FIP) in Fuxin, China, over the past few years. Yet little is known about whether groundwater PFAS contaminations in Fuxin could be introduced into home-produced vegetables and eggs in local residences via the application of groundwater for the irrigation or feeding purposes. In the present study, ten PFAS analytes were analyzed via high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to investigate the extent of PFAS contaminations in the groundwater, soil, and home-produced vegetable and egg samples derived from Fuxin. As the predominant PFAS contaminants, perfluorobutane sulfonate (PFBS) and perfluorooctanoic acid (PFOA) were observed in groundwater beneath the Fuxin FIP with the maximum concentrations of 21.2 and 2.51 µg/L, respectively, which were 24-fold and 5-fold higher individually compared to those reported previously. Both of them were also higher than the updated health advisories for PFBS and PFOA in drinking water issued by the Minnesota Department of Health and the US Environmental Protection Agency. In addition, short-chain PFASs involving perfluorobutanoic acid (PFBA) and PFBS were found to be the major contaminants in both home-produced vegetables and eggs from the residential gardens around the FIP. Statistically significant relationships were determined between the levels of PFBA, PFOA, and PFBS in local groundwater and those observed in home-produced vegetables (p = 0.003, p = 0.025, and p < 0.001), suggesting potential entry of those PFAS contaminants into home-produced vegetables via irrigation with groundwater beneath the FIP.

Abstract  Organic compounds could be taken up by plants via different pathways, depending on chemical properties and biological species, which is important for the risk assessment and risk control. To investigate the transport pathways of perfluoroalkyl acids (PFAAs) by wheat (Triticum acstivnm L.), the uptake of five perfluoroalkyl carboxylic acids (PFCAs): TFA (C2), PFPrA (C3), PFBA (C4), PFHxA (C6), PFOA (C8), and a perfluoroalkyl sulfonic acid: PFOS (C8)) were studied using hydroponic experiments. Various inhibitors including a metabolic inhibitor (Na3VO4), two anion channel blockers (9-AC, DIDS), and two aquaporin inhibitors (AgNO3, glycerol) were examined. The wheat root and shoot showed different concentration trends with the carbon chain length of PFAAs. The uptake of TFA was inhibited by Na3VO4 and 9-AC whereas PFPrA was inhibited by Na3VO4, AgNO3 and 9-AC. For the other four PFAAs, only Na3VO4 was effective. These results together with the result of concentration-dependent uptake, which followed the Michaelis-Menten model, indicate that the uptake of PFAAs by wheat is mainly an energy-dependent active process mediated by carriers. For the ultra-short chain PFCAs (C2 and C3), aquaporins and anion channels may also be involved. A competition between TFA and PFPrA was determined during the plant uptake but no competition was observed between these two shorter chain analogues with other analogues, neither between PFBA and PFHxA, PFBA and PFBS, PFOA and PFOS.

Abstract  Perfluoroalkyl acids (PFAAs) are a group of emerging persistent organic pollutants (POPs), which have been ubiquitously detected in the environmental media. However, national scale investigations on their occurrence and distribution in drinking water are still insufficient. In this study, we detected the 17 priority PFAAs in drinking water from 79 cities of 31 provincial-level administrative regions throughout China, and investigated their occurrence and distribution. Additionally, we also analyzed the influencing factors on their profiles, such as the existence of industrial sources, socioeconomic factors (population density and GDP), and assessed levels of risk associated with contaminated drinking water. On the national scale, the sum concentrations of the 17 PFAAs (∑17PFAAs) in drinking water was in a range of 4.49-174.93 ng/L with a mean value of 35.13 ng/L. Among the 17 individual PFAAs, perfluorobutanoic acids (PFBA) was the most abundant individual PFAAs with the median concentration of 17.87 ng/L, followed by perfluorooctanoic acid (PFOA, 0.74 ng/L), perfluorononanoic acid (PFNA, 0.40 ng/L) and perfluorooctane sulfonic acid (PFOS, 0.25 ng/L). The geographic distribution characteristic of ∑17PFAAs in drinking water was in a descending order of Southwestern China (57.67 ng/L) > Eastern coastal China (32.85 ng/L) > Middle China (29.89 ng/L) > Northwestern China (28.49 ng/L) > Northeastern China (22.03 ng/L), and in general, the existence of the industrial sources could positively affect the contamination levels of PFAAs in drinking water. The pollution level of PFAAs in drinking water also varied among the three different city levels (medium-sized city > big city > town). In towns, the positive correlations were observed between the population density and the ∑17PFAAs (R2 = 0.45, p < 0.01), and the individual concentration of PFHxA, PFBS, and PFOA (p < 0.01). Moreover, besides PFAAs in Yunnan, Jiangsu, and Jiangxi, concentrations of related PFAAs in drinking water from 28 provinces were less than the suggested drinking water advisories. The relatively higher concentrations of PFAAs in Yunnan, Jiangsu, and Jiangxi suggest that further studies focusing on their sources and potential health risk to humans are needed.

Abstract  Context: Abnormal maternal thyroid function in pregnancy may impair fetal brain development, but more evidence is needed to refine and corroborate the hypothesis.

Objective: To estimate the association between maternal thyroid function in early pregnancy and neuropsychological performance of the child at 5 years of age.

Design: Follow-up study.

Participants: A cohort of 1153 women and their children sampled from the Danish National Birth Cohort. Maternal thyroid-stimulating hormone (TSH) and free thyroxine (fT4) were measured in stored biobank sera from early pregnancy.

Main outcomes measures: Child neuropsychological test results (Wechsler Intelligence Scale/Test of Everyday Attention), test of motor function (Movement Assessment Battery), and results of parent and teacher reports (Behavior Rating Inventory of Executive Function/Strengths and Difficulties Questionnaire).

Results: Altogether 145 children (12.6%) were born to mothers with abnormal thyroid function in the early pregnancy. High maternal TSH and low fT4 were associated with lower child verbal intelligence quotient (adjusted mean difference TSH ≥ 10 mIU/L vs 0.1 to 2.49 mIU/L, -8.9 [95% confidence interval (CI), -15 to -2.4]; fT4 < 10 pmol/l vs 12.0 to 18.99 pmol/l, -13 [95% CI, -19 to -7.3]). Abnormal maternal thyroid function was also associated with adverse motor function and teacher-reported problems of executive function and behavior, and these associations were dominated by exposure to maternal hypothyroxinemia.

Conclusions: Maternal thyroid hormone abnormalities were associated with adverse neuropsychological function of the child at 5 years of age. For intelligence, marked hypothyroidism was important, whereas for motor function and executive and behavior problems, maternal hypothyroxinemia was predominant.

Abstract  Epidemiologic evidence regarding the effects of in utero exposure to per- and polyfluoroalkyl substances (PFAS), particularly short-chain PFAS, on fetal reproductive hormones is limited and inconsistent. This study aimed to assess the relationship between maternal PFAS exposure and fetal reproductive hormones. A total of 752 mother-infant pairs who were recruited in the Shanghai Birth Cohort Study between 2013 and 2016 were selected. We quantified 10 PFAS, including two short-chain PFAS congeners (perfluorobutanesulfonate, PFBS and perfluoroheptanoic acid, PFHpA), in maternal blood plasma in early pregnancy. Dehydroepiandrosterone sulfate (DHEA-S), sex hormone-binding globulin (SHBG), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and total testosterone (TT) were measured in the umbilical cord blood using chemiluminescence kits. Free androgen index (FM) was calculated by TT divided by SHBG. Multiple linear regression found that one In-unit increase in maternal PFBS was associated with decreases in FSH (-0.159; 95% CI: -0.290, -0.029), LH (-0.113; 95% CI: -0.221, -0.004), and FM (-0.009; 95% CI: -0.017, -0.001). In addition, PFHpA showed negative associations with LH (-0.154; 95% CI: -0.297, -0.011) and FM (-0.008; 95% CI: -0.014, -0.002). When PFAS were analyzed in quartiles, significant negative associations were observed between PFBS and FSH, and between PFHpA and FAL Overall, prenatal exposure to PFBS and PFHpA was associated with the disturbance of fetal gonadotropins as well as free androgen level in this prospective cohort, suggesting that the reproductive toxicity of short-chain PFAS may not be neglected.

Abstract  Background Residents of a large area of the Veneto Region (North-Eastern Italy) were exposed for decades to drinking water contaminated by perfluoroalkyl substances (PFAS). PFAS have been consistently associated with raised serum lipids, mainly in cross-sectional studies and in background exposure contexts, but the shape of the dose-response relationships has been poorly investigated. The objectives of our study were to evaluate the association between serum PFAS and serum lipids and their dose-response patterns in a large exposed population. Methods A cross-sectional study was conducted in 16,224 individuals aged 20–39 years recruited in the regional health surveillance program. 15,720 subjects were analysed after excluding pregnant women (n = 327), participants reporting use of cholesterol lowering medications (n = 67) or with missing information on the selected covariates (n = 110). Twelve PFAS were measured by HPLC-MS in serum; three (PFOA, PFOS and PFHxS) were quantifiable in at least 50% of samples. Non-fasting serum total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and triglycerides were measured by enzymatic assays in automated analysers and low-density lipoprotein cholesterol (LDL-C), non-HDL cholesterol and total/HDL cholesterol ratio were calculated. The associations between natural log (ln) transformed PFAS and lipids were assessed through generalized additive models using linear regression and smoothing thin plate splines, adjusted for potential confounders. Results There were strong positive associations between the ln-transformed PFOA, PFOS, and PFHxS and TC, HDL-C, and LDL-C, and between ln PFOA and PFHxS and triglycerides. Each ln-increase in PFOA was associated with an increase of 1.94 mg/dL (95% CI 1.48–2.41) in TC, with 4.99 mg/dL (CI 4.12–5.86) for PFOS and 2.02 mg/dL (CI 1.45–2.58) for PFHxS. Conclusions Investigation of the shape of exposure-response associations using splines showed a positive association with the largest increases per unit of PFAS in cholesterol levels occurring at the lower range of PFAS concentrations for each compound. Previous article in issueNext article in issue