Meta-Analysis on the associations between Prenatal Perfluoroalkyl Substances Exposure and Adverse Birth Outcomes

The epidemiological associations between the prenatal perfluoroalkyl substances(PFASs)exposure and the reproductive outcomes remain controversial.A continuous evaluation is needed to combine the inconsistent results.In this study,we explored the associations between PFASs exposure and the low birth weight(LBW),preterm birth and small for gestational age(SGA).The quality of selected literature,quantitative estimates,publication bias and subgroup analysis were performed on the basis of 17 retrieved articles published before December 2020.The results showed a significant positive association between the perfluorooctane sulfonate(PFOS)exposure and the risk of LBW[Odds ratio(OR)=1.17;95%confidence interval(CI):1.01,1.36;heterogeneity:P=0.30,I2=17%].The positive association was also observed between the PFOS and the risk of preterm birth(OR=1.19;95%CI:1.01,1.39,P=0.007;I2=62%).There was a paucity of evidence regarding the negative effects of perfluorooctanoic acid(PFOA),perfluorohexanesulfonic acid(PFHxS)and perfluorononanoic acid(PFNA)on the pregnancy outcomes.The findings from the subgroup analysis(the sampling period,the birth gender and biologic specimens)did not substantially altered the results of the overall pooled estimate ORs.The increased prevalence of negative birth outcomes with gestational PFASs exposure warrants further explorations from biological process perspective.

Occurrence of perfluoroalkyl substances in matched human serum,urine,hair and nail

The purpose of this study was to determine perfluoroalkyl substances（PFASs） in human serum, urine, hair and nail from general populations, and to investigate the possibility for human urine, hair and nail used as the biomonitoring sample for PFASs exposure. We detected the concentrations of PFHx A, PFOA, PFNA, PFDA, PFUn DA, PFDo A, PFHx S and PFOS in 39 matched human serum, urine, hair and nail samples from Shenzhen in China. The detection frequency and the median level of PFOS were all higher than that of the other PFASs in four matrices. The median concentration of PFOS in serum, urine, hair, and nail were 9.24 ng/mL, 13.96 ng/L, 0.58 ng/g and 0.63 ng/g, respectively. The results of spearman correlation test indicated that nail was an ideal matrix for biomonitoring PFOS rather than human urine and hair in general populations for the non-invasive sampling.

Spatial and vertical variations of perfluoroalkyl substances in sediments of the Haihe River,China

The levels of six perfluoroalkyl substances（PFASs） in surface sediment and their vertical variations in dated sediment cores from the Haihe River were investigated; studied substances included perfluorooctanoic acid（PFOA）,perfluorononanoic acid（PFNA）,perfluorooctane sulfonate（PFOS）,perfluorodecanoic acid（PFDA）,perfluoroundecanoic acid（PFUnA）,and perfluorododecanoic acid（PFDoA）. Results showed that the total PFAS concentration in surface sediment ranged between 0.52 and 16.33 ng/g dry weight（dw） with an average of3.47 ng/g dw,with PFOS and PFOA as the dominant PFASs. In general,the PFAS concentrations in the mainstream increased from the upper to the lower reaches,except that a drop occurred downstream of the Erdao dam. Although the PFASs in the sediment cores did not show a clear decreasing or increasing trend with depth,the three cores had a similar vertical variation.The PFAS levels were relatively low in the surface sediment,and reached the first high point at8–20 cm as a result of the wide use of PFASs from 1990 to 2000. After that the PFAS levels decreased,and then increased to a second high point at about 40–48 cm,which might be caused by the leaching of PFASs in sediment. Because PFASs have hydrophilic groups and relatively high solubility,the PFASs will transfer from the upper to lower layers of sediment when water infiltration occurs,leading to the fluctuation of PFAS levels in sediment cores. This study suggests that both the temporal variation of sources and transfer processes of PFASs in sediments are important factors influencing the vertical variation of PFASs in sediment cores.

Association of serum levels of perfluoroalkyl substances with gestational diabetes mellitus and postpartum blood glucose

This study was conducted to examine the association of perfluoroalkyl substance（PFAS）exposure with gestational diabetes mellitus（GDM） risk and postpartum fasting blood glucose.We used a 1：2 matched case–control study with 84 GDM subjects and 168 healthy pregnant women from Beijing, China. The maternal blood was collected at 1–2 days before delivery, and eight linear isomers and fourteen branched isomers were determined in maternal serum.Logistic regression analyses were performed to evaluate the associations after adjusting for potential confounders. The median of the sum of levels of total PFASs was 4.24 ng/m L with a interquartile range（IQR） of 2.82–6.54 ng/m L. Although maternal PFAS exposure was not associated with risk of GDM, significant positive associations were observed between evaluated exposure to specific PFAS congeners and increasing blood glucose. The odds ratio（ORs） of the highest category of postpartum fasting blood glucose for perfluoro-1-metylheptylsulfonat（1 m-PFOS）, perfluoro-3/4-metylheptylsulfonat（3 m＋4 m-PFOS）, perfluoro-5-metylheptylsulfonat（5 m-PFOS）, and perfluorohexane sulfonate（PFHx S） were 2.03（95% CI： 1.09–3.77）, 1.93（95% CI：1.04–3.58）, 2.48（95% CI： 1.33–4.65）, and 2.26（95% CI： 1.21–4.21）, respectively, suggesting negative effects of maternal exposure to specific PFAS compounds on glucose metabolism.

Source apportionment of perfluoroalkyl substances in surface sediments from lakes in Jiangsu Province,China:Comparison of three receptor models

Receptor models have been proved as useful tools to identify source categories and quantitatively calculate the contributions of extracted sources.In this study,sixty surface sediment samples were collected from fourteen lakes in Jiangsu Province,China.The total concentrations of C_4–C_（14）-perfluoroalkyl carboxylic acids and perfluorooctane sulfonic acid（∑_（12）PFASs） in sediments ranged from 0.264 to 4.44 ng/g dw（dry weight）,with an average of 1.76 ng/g dw.Three commonly-applied receptor models,namely principal component analysis-multiple linear regression（PCA-MLR）,positive matrix factorization（PMF） and Unmix models,were employed to apportion PFAS sources in sediments.Overall,these three models all could well track the ∑_（12） PFASs concentrations as well as the concentrations explained in sediments.These three models identified consistently four PFAS sources：the textile treatment sources,the fluoropolymer processing aid/fluororesin coating sources,the textile treatment/metal plating sources and the precious metal sources,contributing 28.1%,37.0%,29.7% and 5.3% by PCA-MLR model,30.60%,39.3%,22.4% and 7.7% by PMF model,and 20.6%,52.4%,20.2% and 6.8% by Unmix model to the ∑_（12） PFASs,respectively.Comparative statistics of multiple analytical methods could minimize individual-method weaknesses and provide convergent results to enhance the persuasiveness of the conclusions.The findings could give us a better knowledge of PFAS sources in aquatic environments.

Levels and trends of poly-and perfluoroalkyl substances in the Arctic environment-An update

Poly-and perfluoroalkyl substances(PFASs)are important environmental contaminants globally and in the early 2000s they were shown to be ubiquitous contaminants in Arctic wildlife.Previous reviews by Butt et al.and Letcher et al.have covered studies on levels and trends of PFASs in the Arctic that were available to 2009.The purpose of this review is to focus on more recent work,generally published between 2009 and 2018,with emphasis on PFASs of emerging concern such as perfluoroalkyl carboxylates(PFCAs)and short-chain perfluoroalkyl sulfonates(PFSAs)and their precursors.Atmospheric measurements over the period 2006e2014 have shown that fluorotelomer alcohols(FTOHs)as well as perfluorobutanoic acid(PFBA)and perfluoroctanoic acid(PFOA)are the most prominent PFASs in the arctic atmosphere,all with increasing concentrations at Alert although PFOA concentrations declined at the Zeppelin Station(Svalbard).Results from ice cores show generally increasing deposition of PFCAs on the Devon Ice cap in the Canadian arctic while declining fluxes were found in a glacier on Svalbard.An extensive dataset exists for long-term trends of long-chain PFCAs that have been reported in Arctic biota with some datasets including archived samples from the 1970s and 1980s.Trends in PFCAs over time vary among the same species across the North American Arctic,East and West Greenland,and Svalbard.Most long term time series show a decline from higher concentrations in the early 2000s.However there have been recent(post 2010)increasing trends of PFCAs in ringed seals in the Canadian Arctic,East Greenland polar bears and in arctic foxes in Svalbard.Annual biological sampling is helping to determine these relatively short term changes.Rising levels of some PFCAs have been explained by continued emissions of long-chain PFCAs and/or their precursors and inflows to the Arctic Ocean,especially from the North Atlantic.While the effectiveness of biological sampling for temporal trends in long-chain PFCAs and PFSAs has been demonstrated,this does not apply to the C4eC8ePFCAs,perfluorobutane sulfonamide(FBSA),or perfluorobutane sulfonate(PFBS)which are generally present at low concentrations in biota.In addition to air sampling,sampling abiotic media such as glacial cores,and annual sampling of lake waters and seawater would appear to be the best approaches for investigating trends in the less bioaccumulative PFASs.

An on-line solid phase extraction-liquid chromatography tandem mass spectrometry method for the determination of perfluoroalkyl substances in the Antarctic ice core samples

An on-line solid phase extraction-high performance liquid chromatography-tandem mass spectrometry method for the analysis of perfluoroalkyl substances（PFASs） in water samples was developed.The optimal analytical conditions were obtained through the optimization of the extraction efficiency of online solid phase extraction column,sample loading rate and loading volume,and the concentration of ammonium acetate in mobile phase.Under the optimal condition,the analytical method displayed good linearity（r^2〉0.99） for 12 PFASs（C5-C14 perfluoroalkyl carboxylic acids and C6/C8 perfluoroalkyl sulfonic acids） over a concentration range of 0.5-100 ng/L.The limits of quantitation for samples were between 0.025 ng/L and 0.5 ng/L and the relative standard deviations（RSD） of five consecutive analyses were less than 10%for 1 ng/L standard solution.Satisfactory results were obtained using this analytical method for the analysis of perfluoroalkyl substances in Antarctic ice core samples.The recoveries of all perfluoroalkyl substances were in a range of 73%-117%when the samples were spiked with standards at the concentrations of 2.5 ng/L and 25 ng/L.

Occurrence,profiles,and ecotoxicity of poly-and perfluoroalkyl substances and their alternatives in global apex predators:A critical review

Certain poly-and perfluoroalkyl substances(PFASs)exhibit significant bioaccumulation/biomagnification behaviors in ecosystems.PFASs,such as perfluorooctane sulfonate(PFOS),perfluorooctanoic acid(PFOA),perfluorohexanesulfonic acid(PFHxS)and related precursors,have elicited attention from both public and national regulatory agencies,which has resulted in worldwide restrictions on their production and use.Apex predators occupy the top trophic positions in ecosystems and are most affected by the biomagnification behavior of PFASs.Meanwhile,the long lifespans of apex predators also lead to the high body burden of PFASs.The high body burden of PFASs might be linked to adverse health effects and even pose a potential threat to their reproduction.As seen in previous reviews of PFASs,knowledge is lacking between the current stage of the PFAS body burden and related effects in apex predators.This review summarized PFAS occurrence in global apex predators,including information on the geographic distribution,levels,profiles,and tissue distribution,and discussed the trophic transfer and ecotoxicity of PFASs.In the case where legacy PFASs were restricted under international convention,the occurrence of novel PFASs,such as 6:2 chlorinated polyfluorinated ether sulfonate(6:2 Cl-PFESA)and perfluoroethylcyclohexane sulfonate(PFECHS),in apex predators arose as an emerging issue.Future studies should develop an effective analytical method and focus on the toxicity and trophic transfer behavior of novel PFASs.

Analysis of PFAS Levels and Associations with Adolescent Anthropometric Outcomes in NHANES

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are found in some consumer products due to their heat resistance and durability. However, there is potential for these substances to bioaccumulate in humans. It is relevant to investigate biological effects of these chemicals, as studies have suggested early life exposure may impact human developmental outcomes such as infant birth weight and youth adiposity. The objective of the current study was to determine if a relationship exists between increasing levels of certain PFAS and anthropometrics in adolescents ages 12 - 18. The three PFAS examined were: perfluorodecanoic acid (PFDeA), 2-(N-methyl-perfluoroctane sulfonamido) acetic acid (Me-PFOSA-AcOH), and perfluoroundecanoic acid (PFUA). The data was obtained from the National Health and Nutrition Examination Survey (NHANES) from the years 2011-2012 (N = 287) and 2013-2014 (N = 344). An additional analysis combined data from 3 NHANES survey cycles using sampling weights for the years 2011-2016 (N = 875) to generate a larger sample size of detectable PFAS. PFAS concentrations were classified as above or below the lower limit of detection (LLOD) to evaluate differences in weight, waist circumference, BMI (body mass index), and height using Student’s t-tests. These same anthropometric outcomes were examined as continuous variables in linear regression models and were stratified by sex. In the 2013-2014 dataset, there were significant inverse associations between female concentrations of PFUA and PFDeA with waist circumference (PFUA β = −0.056;95% CI, −0.106, −0.005;PFDeA β = −0.06;95% CI, −0.10, −0.02), weight-for-age z-score (PFUA β = −0.40;95% CI, −0.74, −0.05;PFDeA β = −0.38;95% CI, −0.64, −0.12), and BMI-for-age z-score (PFUA β = −0.48;95% CI, −0.86, −0.10;PFDeA β = −0.45;95% CI, −0.73, −0.16). In the 2011-2012 dataset, males displayed a significant inverse relationship between PFDeA and waist circumference (β = −0.08;95% CI, −0.14, −0.02), weight-for-age z-score (β = −0.49;95% CI, −0.88, −0.11), and BMI-for-age z-score (β = −0.44;95% CI, −0.84, −0.05). In the combined analysis of NHANES years 2011-2016, there were significant inverse associations with PFUA and PFDeA and weight-for-age z-score, waist circumference, and BMI-for-age z-score. In the given sample years, there was no compelling evidence for a relationship between any of the perfluoroalkyl chemicals and height, nor between Me-PFOSA-AcOH and any of the body measures after adjusting for age, sex, and race/ethnicity. This suggests that PFUA and PFDeA exposure in adolescents may be related to smaller waist circumference, weight, and BMI, but longitudinal studies are recommended to confirm these findings.

Migration mechanism and risk assessment of perand polyfluoroalkyl substances in the Ya'Er Lake oxidation pond area,China

The migration mechanisms,sources,and environmental risks of 29 legacy and emerging perfluorinated and polyfluoroalkyl species present in an oxidation pond(Ya'Er Lake)were investigated for treating sewage based on the analysis of their occurrence and distribution.The concentration of per-and polyfluoroalkyl substances(PFAS)in pond area was between0.30 and 63.2 ng/g dw(dry weight),with the overall average concentration of 8.00 ng/g dw.Notably,the PFAS concentrations in the surface sediments near the sewage outlet in Pond-1(50.2 ng/g dw)and Pond-5(average 15.1 ng/g dw)were 1–2 orders of magnitude higher than those in other areas.In general,the legacy PFAS,i.e.,perfluorooctane sulfonic acid was considered to be the major pollutant in the polluted area,on average,accounting for 73.0%of the total concentration of PFAS pollutants.By evaluating the regional distribution of different PFAS homologs,the short-chain PFAS pollutants with lower K_(ow)were found to migrate farther in both horizontal and vertical directions.The sewage outlets in Pond-1 and Pond-5are the main pollution sources in polluted area and the emerging PFAS pollutants in Pond-5have replaced the legacy PFAS pollutants as the main pollutants.Based on positive matrix factorization analysis,three main industrial sources of PFAS pollutants in the study area were identified:protective coating,fire-fighting,and food packaging sources.Moreover,the environmental risk assessment results showed that most study areas exhibited medium environmental risk(0.01≤Risk quotient(RQ)<1),indicating that the ecological environment risks in this area need further attention.

Degradation of perfluorooctanoic acid by inductively heated Fenton-like process over the Fe_(3)O_(4)/MIL-101 composite

To efficiently remove perfluorooctanoic acid(PFOA),we developed a composite of magnetic Fe_(3)O_(4)nanocrystals and MIL-101(an iron-based metal organic framework).Because of its high surface area,porous structure,and complexation between PFOA as confirmed by experimental results and density functional theory simulation,the magnetic composite showed a Langmuir adsorption capacity of 415 mg/g in the presence of various groundwater components,and thus adsorbed PFOA at environment-relevant concentration within 20 min.The catalyst loaded with PFOA can then be magnetically separated from the synthetic groundwater.This adsorption step concentrated PFOA near MIL-101 and resulted in a fast decomposition rate in the decomposition step,where MIL-101 served as an efficient Fenton agent due to its abundant Fe^(3+)/Fe^(2+)sites.Meanwhile,the alternative magnetic field was introduced to change the production pathway of reactive oxygen species and superoxide radical anions were produced,which was critical for PFOA degradation.In addition,the inductive heating effect heat the magnetic particles to445 K through an in-situ approach,which thus further accelerated Fenton reactions rate.In addition,and achieved a complete degradation of PFOA within 30 min.This newly developed Fenton catalyst demonstrates advantages over conventionally heterogeneous and homogeneous catalysts,and thus is promising for practical applications.

PFAS in the GCC:Towards environmental sustainability and public health protection

Per-and polyfluoroalkyl substances(PFAS)present a growing environmental and health concern glob-ally.This study examines the state of PFAS research and management in the Gulf Cooperation Council(GCC)countries,including the United Arab Emirates,Kingdom of Saudi Arabia,Kuwait,Qatar,Bahrain,and Sultanate of Oman.A comprehensive search was conducted in the PubMed,Web of Science,and Scopus databases,including English-language literature without temporal constraints up until November 2023.The search specifically targeted primary research studies employing descriptive or observational methodologies that were published in peer-reviewed journals.The review focused on studies investi-gating PFAS in both human and environmental contexts within the GCC region.The NIH Quality Assessment Tools and PRISMA guidelines were employed to evaluate the quality of the included studies and report the results.Despite some progress in understanding PFAS,considerable knowledge gaps exist,particularly in wastewater treatment processes and environmental monitoring.The study underscores the need for enhanced research,monitoring,and regulatory strategies to address the environmental sustainability challenges posed by PFAS,ensuring the protection of public health and ecosystems in the GCC region.