Perfluoroalkyl Substances Levels Research Articles

Early life poly- and perfluoroalkyl substance levels and adiposity in the first 2 years of life.

Poly- and perfluoroalkyl substances (PFASs) are nondegradable, man-made chemicals. They accumulate in humans with potential harmful effects, especially in susceptible periods of human development, such as the first months of life. We found that, in our cohort, exclusively breastfed (EBF) infants had 3 times higher PFAS plasma levels compared with exclusively formula-fed (EFF) infants at the age of 3 months. Thus, PFASs could potentially reduce the health benefits of breastfeeding. We investigated the associations between PFAS levels at the age of 3 months and accelerated gain in fat mass during the first 6 months of life, body composition at 2 years, and whether these associations differ between EBF and EFF infants. In 372 healthy term-born infants, we longitudinally assessed anthropometrics, body composition (by air-displacement plethysmography and dual-energy X-ray absorptiometry), and visceral and subcutaneous fat (by abdominal ultrasound) until the age of 2 years. The plasma levels of 5 individual PFASs were determined by liquid chromatography-electrospray ionization-tandem mass spectrometry at the age of 3 months. We studied associations between PFAS levels and outcomes using multiple regression analyses. Higher early life plasma perfluorooctanoic acid and total PFAS levels were associated with an accelerated gain in fat mass percentage [FM%; >0.67 SD score (SDS)] during the first 6 months of life. Higher early life PFAS levels were associated with lower fat-free mass (FFM) SDS at the age of 2 years, but not with total FM% SDS at 2 years. Furthermore, we found opposite effects of PFAS levels (negative) and exclusive breastfeeding (positive) at the age of 3 months on FFM SDS at 2 years. Higher PFAS levels in early life are associated with accelerated gains in FM% during the first 6 months of life and with lower FFM SDS at the age of 2 years, which have been associated with an unfavorable body composition and metabolic profile later in life. Our findings warrant further research with longer follow-up times.

Assessment of legacy and emerging PFAS in the Oder River: Occurrence, distribution, and sources

The purpose of the study was to evaluate the occurrence and distribution of emerging contaminants, poly- and perfluoroalkyl substances (PFAS), in the Polish Oder River, aiming to uncover new insights into their environmental impact. The research aimed to identify potential sources of PFAS, assess water quality levels, and verify compliance with European Union environmental quality standards. The concentrations of 25 PFAS (20 legacy and 5 emerging) in 20 samples from intakes upstream and downstream of urban areas were analyzed using novel, developed in these studies, environmental analytical procedures involving solid phase extraction and liquid chromatography–tandem mass spectrometry. The presence of 14 PFAS was confirmed, and the concentration of Σ14PFAS ranged from 7.6 to 68.0 ng/L. The main components were short-chain analogs. PFBA was the most abundant, accounting for about one-third of all PFAS detected. An exception was observed in the waters of the Gliwice Canal, where ADONA represented half of the detected Σ14PFAS. Alternative PFOS replacements were found in all samples. In 11 of 20 water samples, environmental quality standards for PFOS exceeded the limit of 0.65 ng/L. In 5 of 9 cases, the ability of urban areas to increase PFAS levels in the river was determined. 9.5%–54.4% share of alternative PFAS in relation to the sum of the targeted PFAS showing their increasing use as substitutes for phased-out PFOS. Hierarchical cluster analysis was used to identify potential sources of PFAS. Analysis revealed that PFAS in the Oder River most likely originated from domestic and agricultural wastewater, as well as chemical industry discharges. However, the occurrence of PFAS in the Oder River is low and comparable to other recent European studies. These findings provide valuable insights for environmental management to mitigate the risks associated with PFAS pollution in Polish rivers. Moreover, the developed analytical procedure provides a valuable tool that can be successfully applied by other researchers to monitor PFAS in rivers around the world.

Occurrence, mass loading, and post-control temporal trend of legacy perfluoroalkyl substances (PFASs) in the middle and lower Yangtze River

Present study focused on per- and polyfluoroalkyl substances (PFASs) occurrence in dry and wet seasons in the middle and lower Yangtze River (YZR) and changing temporal trends after years of control. Results revealed that perfluorooctanoic acid (PFOA) was 75 % of total PFAS concentrations (∑11PFASs). ∑11PFASs were ranged 0.20–28.49 ng/L and 1.17–112.84 μg/kg in water and sediment. The logKoc of perfluoroalkyl carboxylic acids was positive with the carbon chain length (p < 0.05, r2 = 0.78). A meta-analysis of results from 16 peer-reviewed publications about PFASs in the YZR showed that fluorochemical industries strongly influenced the high PFAS levels in the detected scenes. PFOA was still the primary pollutant. Individual PFAS in the lower reach was higher than those in the middle reach. The mass loading of PFASs imported into the sea was 10.80 t/y. This study will help develop effective approaches for controlling emerging pollutants in the YZR.

Spatial distribution, isomer signature and air-soil exchange of legacy and emerging poly- and perfluoroalkyl substances

Widespread occurrences of various poly- and perfluoroalkyl substances (PFAS) in terrestrial environment calls for the growing interest in their transport behaviors. However, limited studies detected PFAS with structural diversity in tree barks, which reflect the long-term contamination in atmosphere and play a vital role in air-soil exchange behaviors. In this study, 26 PFAS congeners and typical branched isomers were investigated in surface soils and tree barks at 28 sites along the Taihu Lake, Taipu River, and Huangpu River. Concentrations of total PFAS in soils and tree barks were 0.991–29.4 and 7.99–188 ng/g dw, with PFPeA and PFDoA were the largest contributors in the two matrices. The highest PFAS levels were found in the Taihu Lake watershed, where textile manufacturing and metal plating activities highly prosper. With regard to the congener and isomer signatures, short-chain homologs dominated in soils (65.5%), whereas long-chain PFAS showed a major proportion in barks (41.9%). The composition of linear isomers of PFOS, PFOA and PFHxS implied that precursor degradation might be an important source of PFAS in addition to the 3M electrochemical fluorination (ECF). Additionally, the distance from the emission source, total organic carbon (TOC), logKOA and logKOW were considered potential influencing factors in PFAS distributions. Based on the multi-media fugacity model, about 71% of the fugacity fraction (ffs) values of the PFAS were below 0.3, indicating the dominant deposition from the atmosphere to the soil. The average fluxes of air-soil exchange for PFAS were −0.700 ± 11.0 ng/(m2·h). Notably, the estimated daily exposure to PFAS ranged from 9.57 × 10−2 to 8.59 × 10−1 ng/kg·bw/day for children and 3.31 × 10−2 to 3.09 × 10−1 ng/kg·bw/day for adults, suggesting low risks from outdoor inhalation and dermal uptake. Overall, results from distribution with structural diversity, air-soil exchange and preliminary risk assessment. This study provided in-depth insight of PFAS in multi-medium environment and bridged gaps between field data and policy-making for pollution control.

Assessment of perfluoroalkyl substances concentration levels in wild bat guano samples

Perfluoroalkyl substances (PFASs) are substances commonly used in the production of various everyday objects, including among others kitchen dishes, cosmetics, or clothes. They penetrate to the environment and living organisms causing disturbances in the functioning of many internal organs and systems. Due to environmental pollution, wildlife is also exposed to PFASs, but the knowledge about this issue is rather limited. The aim of this study was to evaluate the exposure of wild greater mouse-eared bats (Myotis myotis), living in Poland, to six selected PFASs: five perfluoroalkyl carboxylic acids (perfluorobutanoic acid—PFBuA, perfluoropentanoic acid—PFPeA, perfluorohexanoic acid—PFHxA, perfluoroheptanoic acid—PFHpA, perfluorooctanoic acid—PFOA) and perfluorooctane sulfonic acid (PFOS) through the analysis of guano samples with liquid chromatography with tandem mass spectrometry (LC–MS–MS) method. To our knowledge this is the first study concerning the PFASs levels in bats, as well as using guano samples to evaluate the exposure of wild mammals to these substances. A total of 40 guano samples were collected from 4 bats summer (nursery) colonies located in various parts of Poland. The presence of PFASs mentioned were detected in all colonies studied, and concentration levels of these substances were sampling dependent. The highest concentration levels were observed in the case of PFPeA [1.34 and 3060 ng/g dry weight (dw)] and PFHxA (8.30–314 ng/g dw). This study confirms the exposure of wild bats to PFASs.

Perfluoroalkyl substances in umbilical cord blood and blood pressure in offspring: a prospective cohort study

BackgroundHumans are widely exposed to perfluoroalkyl substances (PFAS), which have been found to be associated with various adverse birth outcomes. As blood pressure (BP) is an important parameter reflecting cardiovascular health in early life, it is necessary to investigate the association of PFAS exposure during early lifetime and BP in childhood. Therefore, we investigated the potential association between PFAS levels in umbilical cord blood and BP of the offspring at 4 years of age in a prospective cohort study.MethodsPFAS in umbilical cord blood samples after birth were measured with high-performance liquid chromatography/tandem mass spectrometry in the Shanghai Birth Cohort. BP was measured at 4 years of age in the offspring. Multiple linear regression model was used to investigate the association between individual PFAS level and BP of the offspring. Bayesian kernel machine regression (BKMR) was used to analyze the relationship between the PFAS mixture and BP of the offspring, while weighted quantile sum (WQS) regression was utilized for sensitivity analysis.ResultsA total of 129 mother-child pairs were included in our analysis. In multiple linear regressions, we observed that long-chain PFAS, mainly including perfluorooctane sulfonate (PFOS), perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFUA), was negatively associated with systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial blood pressure (MAP). BKMR showed that an increase in umbilical cord blood PFAS mixture levels was significantly associated with a decrease in SBP, DBP and MAP [Estimated differences (SD): -0.433 (0.161); -0.437 (0.176); -0.382 (0.179), respectively]. The most important component in the association with SBP, DBP, and MAP was PFUA. PFDoA was found to be positively associated with SBP, DBP and MAP in both models. Sensitivity analysis with WQS regression showed consistent results.ConclusionOur findings suggested that umbilical blood PFAS exposure was negatively associated with BP in offspring at 4 years of age, including SBP, DBP, and MAP.

SAT441 Association Of PFOS Exposure And The Risk Of Coronary Artery Disease In Postmenopausal Women

Abstract Disclosure: A. Arredondo Eve: None. E. Tunc: None. D. Mehta: None. H. Erbak-Yilmaz: None. S. Volkan Emren: None. F. Akyildiz-Akcay: None. Z. Madak Erdogan: None. Cardiovascular diseases (CVD) are the number one cause of death globally. In addition to traditional risk factors such as unhealthy lifestyles (smoking, obesity, sedentary) and genetics, common environmental exposures, including persistent environmental contaminants, may also influence cardiovascular disease risk. Perfluoroalkyl substances (PFAS) are a class of highly fluorinated chemicals used in our daily household necessities and industrial products known to persist in our environment for years, causing health concerns that are now linked to endocrine disruptions and related outcomes in women, including interference of the cardiovascular and reproductive systems. In postmenopausal women, higher levels of PFAS are observed than in premenopausal women due to the cessation of menstruation, which is crucial for PFAS excretion. Because of these findings, we explored the association between Perfluorooctanoic acid (PFOA), Perfluorooctane sulfonate (PFOS), Perfluorobutanesulfonic acid (PFBS) in postmenopausal women from our previously established CVD cohort using liquid chromatography with tandem mass spectrometry (LC-MS-MS) analysis and supported by machine learning approaches. Here we show that PFOS levels were significantly higher in postmenopausal women with coronary cardiovascular disease (CAD) when compared to control and coronary microvascular disease (CMD) group. We also found that specific metabolite concentrations (alanine, isoleucine, proline, and tyrosine) were negatively associated with serum PFOS levels. A significant correlation with changes in the expression of proteins such as growth hormone (GH), tyrosine-protein kinase Mer (MERTK), metalloproteinase inhibitor 4 (TIMP4), transferrin receptor protein 1 (TFRC), thrombospondin-2 (THBS2) and PFOS was observed. Our findings may provide new insight into the potential mechanism underlying the increased risk of cardiovascular events in postmenopausal women and the emerging evidence on PFAS-induced risk of cardiovascular diseases in this vulnerable population. Presentation: Saturday, June 17, 2023

Relationship between the Consumption of Fermented Red Beetroot Juice and Levels of Perfluoroalkyl Substances in the Human Body's Fluids and Blood Parameters.

Per- and polyfluoroalkyl substances (PFASs) are a group of fluorinated, organic, man-made chemicals; they do not occur naturally in the environment. This study aimed to determine the profile and content of PFASs in the volunteers' blood plasma and urine after the consumption of fermented red beetroot juice and then correlated it with the blood parameters. Over 42 days, 24 healthy volunteers ingested 200 mL/60 kg of body weight of fermented red beetroot juice. PFASs were analyzed using the micro-HPLC-MS/MS method. Five perfluoroalkyl substances were found in the volunteers' body fluids. After consuming the juice, it was discovered that regarding the perfluorocarboxylic acids, a downward trend was observed, while regarding the perfluoroalkane sulfonates, and their plasma content showed a statistically significant upward trend. Analysis of the hematology parameters indicated that the intake of fermented red beetroot juice showed a significant decrease in mean corpuscular volume (MCV), platelets concentration, mean platelet volume (MPV), platelet large cell ratio (P-LCR) at the significance level p < 0.01, and hematocrit (p < 0.05). On the other hand, the dietary intervention also indicated a significant (p < 0.01) increase in corpuscular/cellular hemoglobin concentration (MCHC). In the case of blood biochemistry, no significant change was observed in the blood samples after the intake of the fermented beetroot juice. However, a decreasing tendency of total cholesterol and low-density lipoprotein concentration (LDL-C) was observed. Based on the presented results, there is a need to analyze and monitor health-promoting food regarding undesirable substances and their impact on consumer health.

Occurrence and risk assessments of per- and polyfluoroalkyl substances in tea bags from India

The presence of perfluoroalkyl substances (PFAS) in the environment continues to raise safety concerns due to their widespread presence, durability, ability to accumulate in the body, and potential health effects at low concentrations. Given the widespread consumption of tea, it is important to understand if it could be a source of PFAS exposure. In this study, 108 tea bag samples were collected from the Indian market and analyzed for the presence of 12 PFAS using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results showed that 90% of the samples contained detectable levels of PFAS, with concentrations ranging from <LOD to 109.02 ng/g. The most commonly found PFAS were PFOS, PFHxS, and PFuNA. The estimated daily intake of PFAS based on these concentrations was calculated to be between 0.003 ng kg−1 d−1 and 1.40 ng kg−1 d−1. As tea is consumed daily, there is a probability that a considerable amount of PFOS, PFHxS, and PFuNA could be absorbed into the body. This study is crucial as it provides valuable insights into the potential health hazards associated with long-term exposure to PFOS, PFHxS, and PFuNA in India. Furthermore, the study highlights the need for continued monitoring and assessment of PFAS levels in commonly consumed products to ensure the population's safety.

Perfluoroalkyl substances (PFASs) in aquatic products from the Yellow-Bohai Sea coasts, China: Concentrations and profiles across species and regions

Perfluoroalkyl substances (PFASs) are emerging contaminants capable of harming human health, primarily via ingesting aquatic products. The current study monitored a survey of 23 PFASs in 1049 aquatic products from the coasts of the Yellow-Bohai Sea in China to comprehensively investigate the concentrations and distributions of PFASs. PFOA, PFOS, PFNA, PFOSA, and PFUdA were more predominantly and frequently detected than other PFASs in all samples, dominating PFAS patterns in aquatic products. The mean levels of ∑PFASs in different species followed the order: marine shellfish > marine crustaceans > fish > cephalopods > sea cucumber. Profiles of PFASs differ between species, suggesting species-specific accumulation plays a role. Various aquatic species are potential environmental bioindicators that signal individual PFAS contamination. For instance, clams can act as a potential PFOA bioindicator. High ∑PFAS levels in some sites (such as Binzhou, Dongying, Cangzhou, and Weifang) could be attributed to industrial activities involving fluoropolymer manufacture. The differences between PFAS concentrations and profiles in aquatic products across the study regions have been proposed as PFAS fingerprints of the Yellow-Bohai Sea coasts. Analyses of principal components and Spearman correlations indicated that the precursor biodegradation possibly contribute to C8–C10 PFCAs in the study samples. This study reported a wide presence of PFASs in different species of aquatic products across the Yellow-Bohai Sea coasts. The potential health risks that PFASs pose in certain species (such as marine shellfish and marine crustaceans) should not be neglected.

Perfluoroalkyl substance exposure is associated with asthma and innate immune cell count in US adolescents stratified by sex.

Exposure to perfluoroalkyl substances (PFAS) may be harmful to humans; however, previous studies have been inconsistent regarding the potential for PFAS-induced immunosuppresion. This study explored the relationship between PFAS exposure and risks of asthma, wheezing, and immunosuppression in 12-19year-olds using the National Health and Nutrition Examination Survey (NHANES) data. Logistic regression models were used to reveal associations between serum PFAS levels and risks of asthma, wheezing, asthma attack, and emergency department visits. Pearson's correlation was used to determine the relationship between serum PFAS levels and leukocyte count. Data were also stratified by sex. We found that medium-low levels of serum perfluorooctane sulfonate (PFOS) (6.90-12.40ng/mL) and serum perfluorooctanoic acid (PFOA) (2.43-3.60ng/mL) were negatively related, respectively, to current asthma and wheezing in boys, and to wheezing in girls. Meanwhile, boys with medium-high levels (1.50-3.00ng/mL) of serum perfluorohexanesulfonate (PFHxS) had a high risk of wheezing. Among asthmatic participants, both medium-high levels (3.75-5.07ng/mL) of serum PFOA and high levels (> 3.92ng/mL) of PFHxS correlated with asthma attacks in boys; likewise, medium-low levels (0.70-0.99ng/mL) of serum PFNA correlated with asthma attacks in girls. Also, PFOA and PFNA levels were weakly positively correlated with basophil count, whereas PFOS levels were weakly negatively correlated with eosinophils in asthmatic boys, indicating that basophils may be important in the immune response to PFAS exposure among asthmatics.

Perfluoroalkyl Substances in the Circumpolar Arctic and Northern Populations

Persistent organic pollutants including perfluoroalkyl substances (PFAS) are globally ubiquitous contaminants transported with sea currents and atmospheric movements, accumulating in the environment, food-chain, animals and humans and possess a potential health risk including the immune-, neurobehavioral-, and reproductive systems. The profile and concentrations found in humans elicit regional differences that might be related to the countries PFAS use, production, lifestyle, and diet. In the Arctic, the PFAS compounds were never produced or used, however, the Arctic Indigenous and northern populations consuming traditional diet including marine mammals at the top of the food-chain (e.g., whales, seals, polar bears) are particularly exposed to PFAS. This mini review gives a short overview on health effects in the circumpolar Arctic populations and aims to compare the PFAS levels in the Arctic with primary focus on the period 2010-20 and relate the levels with the general national country populations. As expected, regional concentration and profile differences were found over the circumpolar Arctic with the highest level found in Greenland. Moreover, in general the regulated PFAS (perfluorooctane sulfonate, perfluoro-octanoate, perfluorohexane sulfonate) tend to decrease and the unregulated PFAS (e.g., perfluorononanoic acid, perfluorodecanoic acid, perfluoroundecanoic acid) increases in concentration during this period. Generally, the PFAS levels were higher in men than women increasing with age. For most Arctic regions, the PFAS levels were higher compared to the general national country populations.

PFAS levels and determinants of variability in exposure in European teenagers - Results from the HBM4EU aligned studies (2014-2021).

Perfluoroalkyl substances (PFAS) are man-made fluorinated chemicals, widely used in various types of consumer products, resulting in their omnipresence in human populations. The aim of this study was to describe current PFAS levels in European teenagers and to investigate the determinants of serum/plasma concentrations in this specific age group. PFAS concentrations were determined in serum or plasma samples from 1957 teenagers (12-18 years) from 9 European countries as part of the HBM4EU aligned studies (2014-2021). Questionnaire data were post-harmonized by each study and quality checked centrally. Only PFAS with an overall quantification frequency of at least 60% (PFOS, PFOA, PFHxS and PFNA) were included in the analyses. Sociodemographic and lifestyle factors were analysed together with food consumption frequencies to identify determinants of PFAS exposure. The variables study, sex and the highest educational level of household were included as fixed factors in the multivariable linear regression models for all PFAS and each dietary variable was added to the fixed model one by one and for each PFAS separately. The European exposure values for PFAS were reported as geometric means with 95% confidence intervals (CI): PFOS [2.13μg/L (1.63-2.78)], PFOA ([0.97μg/L (0.75-1.26)]), PFNA [0.30μg/L (0.19-0.45)] and PFHxS [0.41μg/L (0.33-0.52)]. The estimated geometric mean exposure levels were significantly higher in the North and West versus the South and East of Europe. Boys had significantly higher concentrations of the four PFAS compared to girls and significantly higher PFASs concentrations were found in teenagers from households with a higher education level. Consumption of seafood and fish at least 2 times per week was significantly associated with 21% (95% CI: 12-31%) increase in PFOS concentrations and 20% (95% CI: 10-31%) increase in PFNA concentrations as compared to less frequent consumption of seafood and fish. The same trend was observed for PFOA and PFHxS but not statistically significant. Consumption of eggs at least 2 times per week was associated with 11% (95% CI: 2-22%) and 14% (95% CI: 2-27%) increase in PFOS and PFNA concentrations, respectively, as compared to less frequent consumption of eggs. Significantly higher PFOS concentrations were observed for participants consuming offal (14% (95% CI: 3-26%)), the same trend was observed for the other PFAS but not statistically significant. Local food consumption at least 2 times per week was associated with 40% (95% CI: 19-64%) increase in PFOS levels as compared to those consuming local food less frequently. This work provides information about current levels of PFAS in European teenagers and potential dietary sources of exposure to PFAS in European teenagers. These results can be of use for targeted monitoring of PFAS in food.

Estimated Transfer of Perfluoroalkyl Substances (PFAS) from Maternal Serum to Breast Milk in Women Highly Exposed from Contaminated Drinking Water: A Study in the Ronneby Mother–Child Cohort

Infancy perfluoroalkyl substances (PFAS) exposure from breastfeeding is partially determined by the transfer efficiencies (TEs) of PFAS from maternal serum into breast milk. However, to our knowledge there are no studies of such TEs in highly exposed populations. We estimated the TEs of PFAS from maternal serum into colostrum and breast milk in a cohort of women with a wide range of PFAS exposures. The Ronneby Mother-Child Cohort was established in 2015 after PFAS contamination was discovered in the public drinking water of Ronneby, Sweden. We measured seven PFAS in matched samples of maternal serum at delivery and colostrum and breast milk. We calculated the TE (in percentage) as the ratio of PFAS in colostrum or breast milk to serum multiplied by 100 and evaluated whether TEs varied by PFAS, lactation stage, or exposure level using a series of linear mixed-effects models with a random intercept for each woman. This study included 126 mothers. PFAS associated with firefighting foams [i.e., perfluorohexane sulfonic acid (PFHxS) and perfluorooctane sulfonic acid (PFOS)] were substantially elevated in the serum, colostrum, and breast milk samples of highly exposed women in the cohort and showed strong correlation. PFHxS and PFOS also contributed the largest fraction of total PFAS on average in colostrum and breast milk. Median TEs varied from 0.9% to 4.3% and were higher for perfluoroalkyl carboxylic acids, including perfluorooctanoic acid, than perfluoroalkane sulfonic acids, including PFHxS and PFOS. TEs varied by exposure level, but there was not a consistent pattern in this variation. PFAS concentrations in the colostrum and breast milk of highly exposed women were higher than the concentrations in low-exposed women, and TEs were of a similar magnitude across exposure categories. This implies that breastfeeding may be an important route of PFAS exposure for breastfeeding infants with highly exposed mothers, although the relative contribution of breastfeeding vs. prenatal transplacental transfer remains to be clarified. https://doi.org/10.1289/EHP11292.

Detected prenatal perfluorooctanoic acid (PFOA) exposure is associated with decreased fetal head biometric parameters in participants experiencing higher perceived stress during pregnancy in the MADRES cohort.

Perfluoroalkyl substances (PFAS) are ubiquitous synthetic chemicals with long half-lives and are known to cross the placenta during pregnancy. We examined the influence of maternal PFAS levels on in utero fetal growth trajectories and assessed whether maternal stress modified these associations. Blood serum concentrations of five PFAS (PFOS, PFHxS, PFNA, PFOA, PFDA) were measured in 335 prenatal specimens (mean gestational age (GA): 21±9 weeks) in the MADRES cohort. Fetal growth outcomes (head circumference (HC), abdominal circumference (AC), biparietal diameter (BPD), femur length (FL), and estimated fetal weight (EFW)) were abstracted from ultrasound medical records and measured at the 3rd trimester study visit (N = 833 scans, GA range 10-42 weeks, mean 2.4 scans/participant). Adjusted linear mixed models with a GA quadratic growth curve were used for each PFAS exposure and growth outcome. PFOS and PFHxS were modeled continuously (100% sample detection), while PFOA, PFNA, and PFDA were modeled categorically (57-70% sample detection). Scores on the Perceived Stress Scale (PSS) measured in pregnancy were dichotomized at the median (<13 vs. ≥ 13) in stratified models. Participants were on average 29±6 years old and predominately Hispanic (76%). Median serum concentrations of PFOS, PFHxS, PFNA, PFOA and PFDA were 1.34, 1.10, 0.07, 0.12, and 0.04 ng/mL, respectively. Participants with detected PFOA concentrations had fetuses with -2.5 mm (95% CI -4.2, -0.8) smaller HC and-0.7 mm (95% CI -1.3, -0.2) smaller BPD on average for a fixed GA than those without detected PFOA concentrations. In models stratified by PSS level, the effects of PFOA on fetal growth parameters were stronger and only significant in participants with higher stress levels (HC: β= -3.5, 95% CI -5.8, -1.4; BPD: β = -0.8, 95% CI -1.6, -1.1). Prenatal PFOA exposure adversely impacted fetal head biometric parameters in participants experiencing higher stress during pregnancy.

Determinants of polyfluoroalkyl substances and perfluoroalkyl substances (PFAS) biomarkers in First Nations Communities of the Northwest Territories and Yukon

Background and Aim: Polyfluoroalkyl substances and perfluoroalkyl substances (PFAS) include numerous anthropogenic chemicals used in firefighting foams, non-stick cookware, food packaging, and waterproof clothing. Research has shown some PFAS exposures appear to be decreasing in the general population of Canada. In contrast, prior to a human biomonitoring research completed in Old Crow, Yukon and the Mackenzie Valley, Northwest Territories, much less was known on exposure patterns for Dene and Gwich’in populations. This research aims to describe exposure patterns among these populations by identifying determinants and potential sources of PFAS exposure for participants. Method: Nine PFAS (including: perfluorooctanoic acid (PFOA), perfluorooctane sulphonic acid (PFOS), perfluorohexane sulphonic acid (PFHxS), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUdA), perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA), and perfluorobutane sulphonic acid (PFBS)) were quantified using liquid chromatography mass spectrometry in blood samples collected in Old Crow (n=54) and the Dehcho Region, Northwest Territories (n=125). Results: This research showed that, for most PFAS, levels in Old Crow and the Dehcho Region, Northwest Territories were similar or lower to those observed in the Canadian Health Measures Survey. The key exception to this was perfluorononanoic acid (PFNA) which, relative to the CHMS (0.51 &amp;#x3bc;g/L), was approximately 1.8 times higher in Old Crow (0.94 &amp;#x3bc;g/L) and 2.8 times higher in Dehcho (1.42 &amp;#x3bc;g/L) than observed in the general Canadian population. This presentation will report results describing the associations, using multivariable logistic regression, between PFAS levels and consumption of traditional food, lifestyle factors, and demographics. Conclusions: The results highlight the importance of expanding PFAS analytical suites beyond PFOS and PFOA for both human biomonitoring as well as environmental sampling in northern environments. Keywords: Biomonitoring; Contaminants; Indigenous; Traditional Foods; PFAS; PFNA

Exposure to perfluoroalkyl substances and cardiovascular disease: Experimental and epidemiological evidence in India

Background and Aims : Polyfluoro- and perfluoroalkyl substances (PFAS) are organic chemicals extensively used worldwide for industrial and consumer products. Due to their chemical stability, PFAS represent a major cause of environmental pollution. PFAS accumulate in animal and human blood and tissues exerting their toxicity. Our aim is to establish the relationship between PFAS levels in the blood and its association with cardiovascular disorders.

Interlaboratory Comparison Investigations (ICIs) and External Quality Assurance Schemes (EQUASs) for human biomonitoring of perfluoroalkyl substances (PFASs) in serum as part of the quality assurance programme under HBM4EU

Perfluoroalkyl substances (PFASs) are of very high concern due to their persistence and accumulative behaviour as well as their manifold adverse health effects. Human biomonitoring (HBM) based on the determination of PFASs in serum samples is an adequate and established strategy for exposure and risk assessment of the population. The suspected health risks associated with exposure levels in the general population call for reliable HBM data verified by Quality Assurance and Quality Control (QA/QC) measures. PFASs were among the chemicals selected as priority substances in HBM4EU, a pan-European project to harmonize and advance HBM within 30 European countries. For this purpose, the analytical comparability and accuracy of PFASs-analysing laboratories was assessed in a QA/QC programme comprising Interlaboratory Comparison Investigations (ICIs) and External Quality Assurance Schemes (EQUASs). This paper presents the evaluation process and discusses the results of four ICI/EQUAS rounds for the determination of eight perfluoroalkyl carboxylic acids and four perfluoroalkyl sulfonic acids (PFBS, PFHxS, PFHpS, PFOS) in serum. All 21 participating laboratories achieved satisfactory results for at least six of these biomarkers, although low limits of quantification (of about 0.1 μg/L) were required to quantify serum PFAS levels at general population exposure levels. The mean relative standard deviation of the participants' results (study RSDR) significantly improved from 22 % to 13 % over all PFAS biomarkers in the course of the four rounds. This QA/QC programme succeeded in establishing a network of laboratories with high analytical comparability and accuracy for the analysis of PFASs across 12 European countries.

Optimizing the fugacity model to select appropriate remediation pathways for perfluoroalkyl substances (PFASs) in a lake

Increased anthropogenic activities have caused contamination of perfluoroalkyl substances (PFASs) in lakes worldwide. However, how to remediate their contamination remains unclear. In this study, a heavily polluted lake, Baiyangdian Lake in China, was selected to investigate current PFASs levels in multimedia, stimulate their transport fate based upon an optimized fugacity model, and finally identify appropriate remediation pathways. From 2008–2019, the average concentrations of PFASs in the lake increased approximately 7–40 times in the environment and biota. Spatially, with continuous import of perfluorohexane sulfonate (PFHxS) and perfluorooctanoic acid (PFOA), barring fish, a noticeable north-south difference was distinguished in the PFASs composition in multimedia from the lake. Based on the optimized fugacity model simulation, the water phase was the primary transport path (~76.5%) for PFASs, with a total flux of 333 kg y-1. Compared with bioaccumulation fluxes in submerged plants (6.2 kg y-1), emerged plants (2.6 kg y-1), and fish (1.1 kg y-1), the exchange flux of PFASs between water and sediment remained high (~94 kg y-1). Considering remediation cost, sediment cleaning is currently the most cost-effective pathway, while harvesting submerged plant could be a promising pathway in the future. This study provides a basis for remediating PFASs-polluted lakes on a global scale.

Poly- and perfluoroalkyl substances (PFAS) exposure through infant feeding in early life.

Per- and polyfluoroalkyl substances (PFAS) are non-degradable, man-made-chemicals with an elimination half-life of multiple years, causing accumulation in the environment and humans with potential harmful effects. However, longitudinal PFAS levels in human milk, daily PFAS intake and the association with infant plasma PFAS levels have never been reported. We investigated longitudinal PFOA and PFOS levels in human milk and the daily PFAS intake through infant feeding in the first 3months of life, the most important determinants and the correlation with PFAS plasma levels at age 3months and 2years. In 372 healthy term-born Dutch infants, we determined PFOA and PFOS levels in human milk given at age 1 and 3months, in 6 infant formula brands and in infant plasma at 3months and 2years, using liquid-chromatography-electrospray-ionization-tandem-mass-spectrometry(LC-ESI-MS/MS). We studied the associations between daily PFAS intake and predictive characteristics by multiple regression models. PFOA and PFOS levels in human milk decreased between 1 and 3months after delivery, regardless whether breastfeeding was given exclusively(EBF) or in combination with formula feeding. PFOA and PFOS could not be detected in any formula feeding. Daily PFAS intake(ng/kg) was highest in EBF-infants. Higher amount of human milk, older maternal age, lower parity and first-time breastfeeding were associated with higher daily intake. Daily PFAS intake in early life was strongly correlated with PFAS plasma levels at age 3months and 2years(R=0.642-0.875, p<0.001). Human milk contains PFOA and PFOS, in contrast to formula feeding. Daily PFOA and PFOS intake in early life is highest in exclusively breastfed infants and it is highly correlated with infant's plasma levels throughout infancy. Our findings show that breastfeeding is an important PFAS exposure pathway in the first months of life, with unknown but potential adverse effects. Knowing the important health benefits of breastfeeding, our findings warrant more research about the health outcomes in later life.