Persistent organic pollutants in Greenlandic pregnant women and indices of foetal growth: The ACCEPT study

Multiple-component covalent organic frameworks for simultaneous extraction and determination of multitarget pollutants in sea foods

Persistent organic pollutants (POPs), such as perfluoroalkyl and polyfluoroalkyl substances (PFASs), polychlorinated biphenyls (PCBs), and bisphenols (BPs), have been raising global concerns due to their toxic effects on environment and human health. The monitoring of residues of POPs in seafood is crucial for assessing the accumulation of these contaminants in the study area and mitigating potential risks to human health. However, the diversity and complexity of POPs in seafood present significant challenges for their simultaneous detection. Here, a novel multi-component fluoro-functionalized covalent organic framework (OH-F-COF) was designed as SPE adsorbent for simultaneous extraction POPs. On this basis, the recognition and adsorption mechanisms were investigated by molecular simulation. Due to multiple interactions and large specific surface area, OH-F-COF displayed satisfactory coextraction performance for PFASs, PCBs, and BPs. Under optimized conditions, the OH-F-COF sorbent was employed in a strategy of simultaneous extraction and stepwise elution (SESE), in combination with HPLC-MS/MS and GC-MS method, to effectively determined POPs in seafood collected from coastal areas of China. The method obtained low detection limits for BPs (0.0037 -0.0089 ng/g), PFASs (0.0038 -0.0207 ng/g), and PCBs (0.2308 -0.2499 ng/g), respectively. This approach provided new research ideas for analyzing and controlling multitarget POPs in seafood. ENVIRONMENTAL IMPLICATIONS: Persistent organic pollutants (POPs), such as perfluoroalkyl and polyfluoroalkyl substances (PFASs), polychlorinated biphenyls (PCBs), and bisphenols (BPs), have caused serious hazards to human health and ecosystems. Hence, there is a need to develop a quantitative method that can rapidly detect POPs in environmental and food samples. Herein, a novel multi-component fluorine-functionalized covalent organic skeletons (OH-F-COF) were prepared at room temperature, and served as adsorbent for POPs. The SESE-SPE strategy combined with chromatographic techniques was used to achieve a rapid detection of POPs in sea foods from the coastal provinces of China. This method provides a valuable tool for analyzing POPs in environmental and food samples.

Environmental contaminants in Arctic human populations: Trends over 30 years

INTRODUCTION

Arctic Monitoring and Assessment Programme (AMAP) monitors persistent organic pollutant (POP) levels in the Arctic populations and assesses health effects related to exposure to them. Many internationally regulated POPs persist in humans and biota, while new Emerging Contaminants of Arctic Concern (ECAC), many of which are unregulated, present additional challenges. Biomonitoring offers valuable insights into temporal trends within human matrices, revealing critical information not only about the efficacy of international regulations but also serving as an early warning system for exposure and risks for human health.

METHODS

Data analyzed in this study is aggregated data presented in the AMAP Human Health in the Arctic assessments, which provide data on contaminant concentrations measured in human matrices from adults, and children across various population studies conducted in the Arctic since the 1980 s. Linear regression analyses were used to assess trends of various POPs including organochlorine (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and per- and polyfluoroalkyl substances (PFAS), measured over time from the Arctic populations in Finland, Norway, Sweden, Denmark, Iceland, Canada and Alaska (USA).

RESULTS

Overall, decreasing trends were observed for PCBs and OCPs. Regulated PFAS showed decreasing trends, but increasing trends were observed for unregulated PFAS in certain populations. PBDEs showed decreasing or inconsistent trends in certain Arctic populations.

CONCLUSIONS

Decreasing trends are observed for legacy POPs, but the trends for new emerging contaminants are inconsistent. More focus is needed on biomonitoring the new emerging contaminants of concern in the Arctic and their implications on human health.

Systematic review and meta-analysis of birth weight and perfluorohexane sulfonate exposures: examination of sample timing and study confidence

We examined the association between mean birth weight (BW) differences and perfluorohexane sulfonate (PFHxS) exposure biomarkers.We fit a random effects model to estimate the overall pooled effect and for different strata based on biomarker sample timing and overall study confidence. We also conducted an analysis to examine the impact of a continuous measure of gestational age sample timing on the overall pooled effect.We detected a -7.9 g (95% CI -15.0 to -0.7; pQ=0.85; I2=0%) BW decrease per ln ng/mL PFHxS increase based on 27 studies. The 11 medium confidence studies (β=-10.0 g; 95% CI -21.1 to 1.1) showed larger deficits than 12 high (β=-6.8 g; 95% CI -16.3 to 2.8) and 4 low confidence studies (β=-1.5 g; 95% CI -51.6 to 48.7). 10 studies with mid-pregnancy to late-pregnancy sampling periods showed smaller deficits (β=-3.9 g; 95% CI -17.7 to 9.9) than 5 post-partum studies (β=-28.3 g; 95% CI -69.3 to 12.7) and 12 early sampling studies (β=-7.6 g; 95% CI -16.2 to 1.1). 6 of 12 studies with the earliest sampling timing showed results closer to the null.Overall, we detected a small but statistically significant BW deficit across 27 studies. We saw comparable BW deficit magnitudes in both the medium and high confidence studies as well as the early pregnancy group. Despite no definitive pattern by sample timing, larger deficits were seen in postpartum studies. We also saw results closer to the null for a subset of studies restricted to the earliest biomarker collection times. Serial pregnancy sampling, improved precision in gestational age estimates and more standardised reporting of sample variation and exposure units in future epidemiologic research may offer a greater understanding of the relationship between PFHxS on BW and any potential impact of pregnancy haemodynamics.

The associations between maternal and fetal exposure to endocrine-disrupting chemicals and asymmetric fetal growth restriction: a prospective cohort study

Recent evidence has revealed associations between endocrine-disrupting chemicals (EDCs) and placental insufficiency due to altered placental growth, syncytialization, and trophoblast invasion. However, no epidemiologic study has reported associations between exposure to EDCs and asymmetric fetal growth restriction (FGR) caused by placenta insufficiency. The aim of this study was to evaluate the association between EDC exposure and asymmetric FGR. This was a prospective cohort study including women admitted for delivery to the Maternal Fetal Center at Seoul St. Mary's Hospital between October 2021 and October 2022. Maternal urine and cord blood samples were collected, and the levels of bisphenol-A (BPA), monoethyl phthalates, and perfluorooctanoic acid in each specimen were analyzed. We investigated linear and non-linear associations between the levels of EDCs and fetal growth parameters, including the head circumference (HC)/abdominal circumference (AC) ratio as an asymmetric parameter. The levels of EDCs were compared between fetuses with and without asymmetric FGR. Of the EDCs, only the fetal levels of BPA showed a linear association with the HC/AC ratio after adjusting for confounding variables (β = 0.003, p < 0.05). When comparing the normal growth and asymmetric FGR groups, the asymmetric FGR group showed significantly higher maternal and fetal BPA levels compared to the normal growth group (maternal urine BPA, 3.99 μg/g creatinine vs. 1.71 μg/g creatinine [p < 0.05]; cord blood BPA, 1.96 μg/L vs. -0.86 μg/L [p < 0.05]). In conclusion, fetal exposure levels of BPA show linear associations with asymmetric fetal growth patterns. High maternal and fetal exposure to BPA might be associated with asymmetric FGR.

Prenatal exposure to poly- and perfluoroalkyl substances and postpartum depression in women with twin pregnancies

BACKGROUND

Women with multiple pregnancies are vulnerable to experience postpartum depression (PPD). Emerging evidence indicates an association between poly- and perfluoroalkyl substances (PFAS) exposure and PPD in women delivering singletons. The health risks of PFAS may also be present in women delivering twins.

OBJECTIVE

To estimate the impacts of prenatal PFAS exposure on the risk of PPD in women with twin pregnancies.

METHODS

Our study included 150 mothers who gave birth to twins and were enrolled in the Wuhan Twin Birth Cohort. The concentrations of maternal plasma PFAS were measured in each trimester and averaged. Eight individual PFAS were included in analyses. We used Edinburgh Postnatal Depression Scale to evaluate maternal depression at early pregnancy and 1 and 6 months after childbirth. The outcome was dichotomized using a cutoff value of ≥10 for main analyses. Associations were examined using multiple informant models and modified Poisson regressions. PFAS mixture effects were estimated using quantile g-computation.

RESULTS

Using quantile g-computation models, a quartile increase in the PFAS mixture during the first, second, third, and average pregnancy was significantly associated with a relative risk (RR) of 1.73 (95% CI: 1.42, 2.12), 1.54 (95% CI: 1.27, 1.84), 1.75 (95% CI: 1.49, 2.08), and 1.63 (95% CI: 1.35, 1.97) for PPD at 6 months after childbirth, respectively. The results of the single-PFAS models also indicated significant positive associations between individual PFAS and PPD at both 1 and 6 months.

CONCLUSIONS

The first study of women with twin pregnancies suggests that prenatal exposure to PFAS increases PPD risk up to 6 months postpartum. Twin pregnant women should receive long-term follow-up after delivery and extensive social support.

Polybrominated diphenyl ether (PBDE) exposure and adverse maternal and infant health outcomes: Systematic review

Polybrominated diphenyl ethers (PBDEs) are flame retardants found in ambient environment and are measured in humans. There are reports on general PBDE toxicity, including endocrine disrupting properties. Studies on adverse maternal and infant outcomes and underlying toxicity mechanisms needs to be understood. The objective of this study was to conduct a systematic review to examine the state of science on the relationship between PBDE and adverse maternal/infant health outcomes and related maternal biomarker changes. This literature review was conducted using PubMed, Scopus, Embase and Web of Science for published articles from January 2005-February 2022. Article quality was assessed using Newcastle-Ottawa Scale. Of the 1518 articles, only 54 human observational studies were screened in for this review. A second reviewer examined the validity of these articles. Reports on associations between PBDE and maternal health outcomes included gestational hypertension/preeclampsia (N = 2) and gestational diabetes mellitus/glycemic index (N = 6). Meanwhile, reports on PBDE and infant outcomes (N=32) included effects on infant birth weight, birth length and cephalic perimeter, preterm birth, fetal growth restriction and APGAR scores. Although findings on PBDE exposure and adverse infant outcomes showed inconsistencies across studies, in general, negative correlations between maternal PBDEs and infant birth weight, birth length and cephalic perimeter were seen, in few cases, after stratification by sex. Association between maternal PBDE and maternal biomarkers (N=18) suggested negative impact of PBDE exposure on markers relevant to neuro-endocrine system and inflammatory processes. The review findings identified potential associations between maternal PBDE and adverse maternal/infant health outcomes. Furthermore, PBDE-related biomarker changes suggest disturbances in maternal mechanisms relevant to endocrine disrupting properties of PBDEs. The observed study heterogeneity can be attributed to factors namely, sample size, study design and statistical analysis. Overall review findings imply the necessity for further research to validate PBDE exposure-related adverse maternal/infant health effects and to validate underlying toxicity mechanisms.

Update of the risk assessment of polybrominated diphenyl ethers (PBDEs) in food

The European Commission asked EFSA to update its 2011 risk assessment on polybrominated diphenyl ethers (PBDEs) in food, focusing on 10 congeners: BDE-28, -47, -49, -99, -100, -138, -153, -154, -183 and ‑209. The CONTAM Panel concluded that the neurodevelopmental effects on behaviour and reproductive/developmental effects are the critical effects in rodent studies. For four congeners (BDE-47, -99, -153, -209) the Panel derived Reference Points, i.e. benchmark doses and corresponding lower 95% confidence limits (BMDLs), for endpoint-specific benchmark responses. Since repeated exposure to PBDEs results in accumulation of these chemicals in the body, the Panel estimated the body burden at the BMDL in rodents, and the chronic intake that would lead to the same body burden in humans. For the remaining six congeners no studies were available to identify Reference Points. The Panel concluded that there is scientific basis for inclusion of all 10 congeners in a common assessment group and performed a combined risk assessment. The Panel concluded that the combined margin of exposure (MOET) approach was the most appropriate risk metric and applied a tiered approach to the risk characterisation. Over 84,000 analytical results for the 10 congeners in food were used to estimate the exposure across dietary surveys and age groups of the European population. The most important contributors to the chronic dietary Lower Bound exposure to PBDEs were meat and meat products and fish and seafood. Taking into account the uncertainties affecting the assessment, the Panel concluded that it is likely that current dietary exposure to PBDEs in the European population raises a health concern.

Associations of cord plasma per- and polyfluoroakyl substances (PFAS) with neonatal and child body composition and adiposity: The GUSTO study

BACKGROUND

The influence of prenatal exposure to per- and poly- fluoroalkyl substances (PFAS) on birth size and offspring adiposity is unclear, especially for the newer, shorter-chained replacement PFAS.

METHODS

In the GUSTO multi-ethnic Singaporean mother-offspring cohort, 12 PFAS were measured in 783 cord plasma samples using ultra-performance-liquid chromatography-tandem-mass-spectrometer (UPLC-MS/MS). Outcomes included offspring anthropometry, other indicators of body composition/metabolic health, and MRI-derived abdominal adiposity (subset) at birth and 6 years of age. PFAS were modeled individually, in categories of long-chain and short-chain PFAS, and as scores of three principal components (PC) derived using PC analysis (PC1, PC2, and PC3 reflect predominant exposure patterns to "very-long-PFAS", "long-PFAS", and "short-PFAS", respectively). Associations with outcomes were assessed using multivariable linear regressions, adjusted for important covariates such as maternal sociodemographic and lifestyle factors.

RESULTS

Overall, cord PFAS levels showed either no or positive associations (mostly for long-chain PFAS) with birth weight, length and head circumference. In general, PFAS were associated with higher neonatal abdominal adiposity, driven by shorter-chain PFAS. Perfluoroheptanoic acid (PFHpA) was associated with higher volumes of superficial subcutaneous adipose tissue (sSAT) (3.75 [1.13, 6.37] mL per SD increase in PFAS) and internal adipose tissue (IAT) (1.39 [0.41, 2.38] mL). Higher levels of perfluorobutanesulfonic acid (PFBS), short-chain PFAS, and PC3 were associated with higher IAT volume (β range 1.22-1.41 mL/SD, all P < 0.02), especially in girls. Higher PC3 score was additionally associated with higher sSAT (3.12 [0.45, 5.80] mL) volume. At age 6 years, most observed associations did not persist. No consistent associations were observed between PFAS and whole-body adiposity measures.

CONCLUSIONS

Fetal exposure to emerging short-chain PFAS was associated with higher abdominal adiposity at birth but not at age 6 years. Further research is needed to replicate the findings and to determine if these effects may reappear beyond early childhood. Population exposure to newer PFAS and consequent health impact must be monitored.

Diet, lifestyle and contaminants in three east Greenland Inuit municipalities

Persistent organic pollutants (POP) are environmental contaminants transported over long distances to the Arctic where they biomagnify in marine mammals subsistence hunted by Inuit and may therefore affect human health. Marine mammals in east Greenland are known to have the highest POP concentrations in the circumpolar Arctic area. Due to high intake of marine mammals, east Greenlandic Inuit likewise have the highest POP body burdens across the Arctic. This cross-sectional study aims to investigate the levels of POP and metals in Inuit with a high intake of top predatory species including killer whales and polar bears. Study participants include 37 men and 21 women from Kulusuk, Tasiilaq and Ittoqqortoormiit during year 2013-2015. Lipophilic POP (11 organochlorine-pesticides, 14 polychlorinated-biphenyls (PCB), 10 polybrominated diphenyl ethers), polyunsaturated fatty acids (PFUA) and cotinine were determined in plasma. Fifteen perfluoroalkylated substances (PFAS) were measured in serum and urine and the renal clearance was estimated. Finally the concentration of 10 metals were measured in whole blood. The median age was 38 years, Ittoqqortoormiit Inuit being the oldest. The smoking rate was around 70%, and Kulusuk participants had the lowest PFUA concentrations. Significant municipality differences were observed for lipophilic POP, serum PFAS, mercury, arsenic and selenium with highest concentrations in Ittoqqortoormiit Inuit. Males had higher blood concentrations of PFAS and lead. The estimated PFAS renal clearance and ratio of urine to serum were significantly higher for females, suggesting a sex difference in excretion via the kidney, maybe partly because men had higher serum PFAS concentrations. We observed that Inuit with intake of >200 g polar bear per week had significantly higher levels of PCB, PFAS, arsenic and selenium. In summary, the level of blood POP and heavy metals seems to relate to sex and the frequency intake of meat from marine mammals.

Prenatal per- and polyfluoroalkyl substances (PFAS) exposure in relation to preterm birth subtypes and size-for-gestational age in the LIFECODES cohort 2006-2008

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals widely used in consumer and industrial products. Numerous studies have linked prenatal PFAS exposures to increased risks of adverse pregnancy outcomes such as preterm birth (PTB) and small-for-gestational age (SGA).However, limited evidence is available for the effects of PFAS on PTB subtypes and large-for-gestational age (LGA).

OBJECTIVE

To examine the associations of PFAS with PTB [overall, placental (pPTB), spontaneous (sPTB)], BW Z-score, and size-for-gestational age (SGA, LGA).

METHODS

Our nested case-control study included 128 preterm cases and 373 term controls from the LIFECODES cohort between 2006 and 2008 (n = 501). Plasma concentrations of nine PFAS were measured in early pregnancy samples. Logistic regression was used to assess individual PFAS-birth outcome associations, while Bayesian Kernel Machine Regression (BKMR) was used to evaluate the joint effects of all PFAS. Effect modification by fetal sex was examined, and stratified analyses were conducted to obtain fetal sex-specific estimates.

RESULTS

Compared to term births, the odds of pPTB were higher from an interquartile range increase in perfluorodecanoic acid (PFDA) (OR = 1.60, 95% CI: 1.00-2.56), perfluorononanoic acid (PFNA) (OR = 1.67, 95% CI: 1.06-2.61), and perfluoroundecanoic acid (PFUA) (OR = 1.77, 95% CI: 1.00-3.12), with stronger associations observed in women who delivered males. BKMR analysis identified PFNA as the most important PFAS responsible for pPTB (conditional PIP = 0.78), with increasing ORs at higher percentiles of PFAS mixture. For LGA, positive associations were observed with PFDA and perfluorooctanoic acid in females only, and with PFUA in males only. BKMR analysis showed increasing, but null effects of PFAS mixture on LGA.

CONCLUSIONS

The effect of prenatal exposure to single and multiple PFAS on PTB and LGA depended on fetal sex. Future studies should strongly consider examining PTB subtypes and sex-specific effects of PFAS on pregnancy outcomes.

Prenatal Exposure to PFAS, Associations with Preterm Birth and Modification by Maternal Estrogen Levels: The Maoming Birth Study

BACKGROUND

Estrogens play a critical role in parturition, and poly- and perfluoroalkyl substances (PFAS), which have estrogenic effects, have been associated with preterm birth. However, the impact of estrogens on the association between PFAS and preterm birth is unknown.

OBJECTIVE

The objective of this study is to investigate if estrogens modified the association between PFAS and preterm birth, using a nested case-control study design.

METHODS

A total of 371 preterm births and 508 controls were selected from a birth cohort study in China between 2016 and 2018. Perfluorobutanoic acid (PFBA), perfluorohexanesulfonic acid (PFHxS) and its branched isomer, perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS) and its branched isomer, and perfluorononanoic acid (PFNA) were quantified in maternal serum (mean gestational age of 32 wk). Estradiol and estriol were quantified in cord serum. Preterm birth was defined as live delivery at < 37 gestational weeks. Causal mediation analysis was used to estimate the mediation and interaction effects of estrogen on the association between PFAS and preterm birth. Latent profile analysis was used to identify important estrogen profiles. Multiple linear regression was used to estimate associations between PFAS and preterm birth and interactions between PFAS and estrogens on preterm birth.

RESULTS

Overall, higher odds ratios (ORs) of preterm birth were associated with each 1 ln-unit PFAS increase: PFBA [1.20, 95% confidence interval (CI): 1.14, 1.26], PFNA (1.30, 95% CI: 1.21, 1.39), PFOA (1.98, 95% CI: 1.54, 2.55), and PFOS (1.91, 95% CI: 1.76, 2.07) and its branched isomer (1.91, 95% CI: 1.90, 1.92). We detected statistically significant interactions between cord estradiol and PFAS on preterm birth, while no mediation effects of cord estrogen were observed. The ORs of PFOS (4.29, 95% CI: 1.31, 8.25), its branched isomer (6.71, 95% CI: 1.06, 11.91), and preterm birth were greater for participants with high cord estrogen levels than for participants with low cord estrogen levels.

DISCUSSION

Our findings suggest that estrogen modified the association between maternal PFAS exposure and preterm birth. Further studies on maternal PFAS exposure and preterm birth, taking interaction effects of cord estrogens into account, are warranted. https://doi.org/10.1289/EHP11377.

Associations between maternal exposure to perfluoroalkylated substances (PFASs) and infant birth weight: a meta-analysis

The objective of this study was to determine the associations between maternal exposure to PFASs and infant birth weight and to explore evidence for a possible dose-response relationship. Four databases including PubMed, Embase, Web of Science, and Medline before 20 September 2022 were systematically searched. A fixed-effect model was used to estimate the change in infant birth weight (g) associated with PFAS concentrations increasing by 10-fold. Dose-response meta-analyses were also conducted when possible. The study follows the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A total of 21 studies were included. Among these studies, 18 studies examined the associations between PFOA and birth weight, 17 studies reported PFOS, and 11 studies discussed PFHxS. Associations between PFHxS (ES = -5.67, 95% CI: -33.92 to 22.59, P = 0.694) were weaker than those for PFOA and PFOS (ES = -58.62, 95% CI: -85.23 to -32.01, P < 0.001 for PFOA; ES = -54.75, 95% CI: -84.48 to -25.02, P < 0.001 for PFOS). The association was significantly stronger in the high median PFOS concentration group (ES = -107.23, 95% CI: -171.07 to -43.39, P < 0.001) than the lower one (ES = -29.15, 95% CI: -63.60 to -5.30, P = 0.097; meta-regression, P = 0.045). Limited evidence of a dose-response relationship was found. This study showed negative associations between maternal exposure to PFASs and infant birth weight. Limited evidence of a dose-response relationship between exposure to PFOS and infant birth weight was found. Further studies are needed to find more evidence.

A Review on Per- and Polyfluoroalkyl Substances in Pregnant Women: Maternal Exposure, Placental Transfer, and Relevant Model Simulation

Per- and polyfluoroalkyl substances (PFASs) are important and ubiquitous environmental contaminants worldwide. These novel contaminants can enter human bodies via various pathways, subsequently posing risks to the ecosystem and human health. The exposure of pregnant women to PFASs might pose risks to the health of mothers and the growth and development of fetuses. However, little information is available about the placental transfer of PFASs from mothers to fetuses and the related mechanisms through model simulation. In the present study, based upon a review of previously published literature, we initially summarized the exposure pathways of PFASs in pregnant women, factors affecting the efficiency of placental transfer, and mechanisms associated with placental transfer; outlined simulation analysis approaches using molecular docking and machine learning to reveal the mechanisms of placental transfer; and finally highlighted future research emphases that need to be focused on. Consequently, it was notable that the binding of PFASs to proteins during placental transfer could be simulated by molecular docking and that the placental transfer efficiency of PFASs could also be predicted by machine learning. Therefore, future research on the maternal-fetal transfer mechanisms of PFASs with the benefit of simulation analysis approaches is warranted to provide a scientific basis for the health effects of PFASs on newborns.

Systematic review and meta-analysis of birth weight and PFNA exposures

We used a systematic review that included risk of bias and study sensitivity analysis to identify 34 studies examining changes in birth weight (BWT) in relation to PFNA biomarker measures (e.g., maternal serum/plasma or umbilical cord samples). We fit a random effects model of the overall pooled estimate and stratified estimates based on sample timing and overall study confidence. We conducted a meta-regression to further examine the impact of gestational age at biomarker sample timing. We detected a -32.9 g (95%CI: -47.0, -18.7) mean BWT deficit per each ln PFNA increase from 27 included studies. We did not detect evidence of publication bias (p_E = 0.30) or between-study heterogeneity in the summary estimate (p_Q = 0.05; I² = 36%). The twelve high confidence studies yielded a smaller pooled effect estimate (β = -28.0 g; 95%CI: -49.0, -6.9) than the ten medium (β = -39.0 g; 95%CI: -61.8, -16.3) or four low (β = -36.9 g; 95%CI: -82.9, 9.1) confidence studies. The stratum-specific results based on earlier pregnancy sampling periods in 11 studies showed smaller deficits (β = -22.0 g; 95%CI: -40.1, -4.0) compared to 10 mid- and late-pregnancy (β = -44.2 g; 95%CI: -64.8, -23.5) studies and six post-partum studies (β = -42.9 g; 95%CI: -88.0, 2.2). Using estimates of the specific gestational week of sampling, the meta-regression showed results consistent with the categorical sample analysis, in that as gestational age at sampling time increases across these studies, the summary effect estimate of a mean BWT deficit got larger. Overall, we detected mean BWT deficits for PFNA that were larger and more consistent across studies than previous PFAS meta-analyses. Compared to studies with later sampling, BWT deficits were smaller but remained sizeable for even the earliest sampling periods. Contrary to earlier meta-analyses for PFOA and PFOS, BWT deficits that were detected across all strata did not appear to be fully explained by potential bias due to pregnancy hemodynamics from sampling timing differences.

Evaluation of Per- and Polyfluoroalkyl Substances (PFAS) In Vitro Toxicity Testing for Developmental Neurotoxicity

Per- and polyfluoroalkyl substances (PFAS) are a diverse set of commercial chemicals widely detected in humans and the environment. However, only a limited number of PFAS are associated with epidemiological or experimental data for hazard identification. To provide developmental neurotoxicity (DNT) hazard information, the work herein employed DNT new approach methods (NAMs) to generate in vitro screening data for a set of 160 PFAS. The DNT NAMs battery was comprised of the microelectrode array neuronal network formation assay (NFA) and high-content imaging (HCI) assays to evaluate proliferation, apoptosis, and neurite outgrowth. The majority of PFAS (118/160) were inactive or equivocal in the DNT NAMs, leaving 42 active PFAS that decreased measures of neural network connectivity and neurite length. Analytical quality control indicated 43/118 inactive PFAS samples and 10/42 active PFAS samples were degraded; as such, careful interpretation is required as some negatives may have been due to loss of the parent PFAS, and some actives may have resulted from a mixture of parent and/or degradants of PFAS. PFAS containing a perfluorinated carbon (C) chain length ≥8, a high C:fluorine ratio, or a carboxylic acid moiety were more likely to be bioactive in the DNT NAMs. Of the PFAS positives in DNT NAMs, 85% were also active in other EPA ToxCast assays, whereas 79% of PFAS inactives in the DNT NAMs were active in other assays. These data demonstrate that a subset of PFAS perturb neurodevelopmental processes in vitro and suggest focusing future studies of DNT on PFAS with certain structural feature descriptors.

Legacy Chemical Pollutants in House Dust of Homes of Pregnant African Americans in Atlanta

We developed and applied a method for measuring selected persistent organic pollutants (POPs) (i.e., polybrominated diphenyl ethers (PBDEs), organochlorine pesticides, and polychlorinated biphenyls (PCBs)) in dust collected from pregnant African Americans (AAs) in Atlanta using isotope dilution gas chromatography-tandem mass spectrometry. Limits of quantification were ranged from 0.10 to 2.50 ng/g dust. NIST standard reference material measurements demonstrated the robustness of our method. Our accuracies ranged from 82 to 108%, relative standard deviations ranged from 2 to 16%, and extraction recoveries ranged from 76 to 102%. We measured POPs in dust collected from 34 homes of pregnant AAs participating in the Atlanta AA birth cohort study who were enrolled from 2016 to 2019. Concentrations of POPs were detected in all samples with the frequencies of detection ranging from 8 to 100%. Concentrations of PBDE congeners 99 and 47, p,p'-DDT, and PCB153 were detected at some of the highest concentrations with geometric means of 1270, 730, 63.4 and 240 ng/g, respectively. The ratio of DDT/DDE was quite large (~2.7) indicating that p,p'-DDT remains intact in homes for long periods of time. These data demonstrate that care should be taken to remediate POPs in indoor dust, especially in vulnerable, disparate segments of the population.

Association of single and multiple prefluoroalkyl substances exposure with preterm birth: Results from a Chinese birth cohort study

BACKGROUND

Perfluoroalkyl substances (PFASs) are persistent organic pollutants that may lead the adverse birth outcomes, including preterm birth (PTB). However, previous studies have reported inconsistent results on the association between PFASs and PTB, and lack of the epidemiological evidence regarding the effect of PFASs mixture on PTB. This study aimed to explore association of individual and multiple exposure to PFASs with PTB.

METHODS

The study subjects were consisted of 1341 pregnant women from Guangxi Zhuang Birth Cohort in Guangxi, China, from June 2015 to April 2019. Nine PFASs concentrations in the maternal serum were examined by ultrahigh liquid performance chromatography-tandem mass spectrometry, and the gestational weeks were obtained from medical records. We applied binary logistics regression model to explore correlation between individual PFAS and PTB and inspected the combined effect of PFASs mixture on PTB by applying Bayesian kernel machine regression (BKMR) and weighted quantile sum (WQS) regression models.

RESULTS

In adjusted logistics regression model, perfluorooctane sulfonate (PFOS), perfluoroheptanoic acid (PFHpA), perfluorobutanesulfonic acid (PFBS), ∑perfluorinated sulfonic acids (PFSA), and ∑PFASs were positively associated with the risk of PTB. In contrast, perfluoroundecanoic acid (PFUnA), perfluorohexane sulfonate (PFHxS), and perfluorooctanoic acid (PFOA) were negatively associated with the risk of PTB. These associations of n PFOS and PFHpA with PTB were found to be more pronounced in male infants. Restricted cubic splines (RCSs) showed an inverse U-shaped relationship between PFBS and PTB. Analysis from BKMR model showed a positive association between PFASs mixture and PTB, and no evidence of interactions among the nine PFASs were detected. Additionally, PFHpA, PFOS, and PFBS were identified as the main contributors for the effect of PFASs mixture on increasing the risk of PTB by BKMR and WQS models.

CONCLUSION

Prenatal exposure to higher levels of PFASs mixture was associated with higher risk of PTB.

Associations of prenatal exposure to perfluoroalkyl substances with preterm birth: A family-based birth cohort study

Studies have investigated associations between maternal exposure to PFAS and preterm birth, but the impact of paternal and overall family exposure to PFAS mixtures on preterm birth remains unknown. To address this knowledge gap, a total of 355 preterm births and 481 controls were selected for a family-based birth cohort study in a coastal area of China, between 2016 and 2018. Seven PFAS, including perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA), perfluorohexanesulfonic acid (PFHxS), perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA), were quantified in maternal, paternal and neonatal sera. Preterm birth was defined as live delivery at <37 completed gestational weeks. Bayesian kernel machine regression (BKMR) model was used to inspect the combined effect of family PFAS mixtures. Latent class analysis was used to identify family-level PFAS exposure profiles. Multiple linear regression analysis showed higher odds of preterm birth in association with higher maternal PFBA (OR = 1.16, 95%CI:1.09, 1.25), PFOA (OR = 1.51, 95%CI:1.27, 1.80), PFOS (OR = 2.07, 95%CI:1.70, 2.52) and PFNA (OR = 1.36, 95%CI: 1.01, 1.83), and neonatal PFBA (OR = 1.16, 95%CI:1.05,1.29), PFHxA (OR = 1.46, 95%CI:1.32, 1.62), PFHxS (OR = 1.15, 95%CI:1.05, 1.26) and PFNA (OR = 1.30, 95%CI:1.09,1.56). The associations were reversed between individual paternal PFAS exposures and preterm birth. At the family level, higher PFAS mixture concentration was associated with higher odds of preterm birth. In particular, higher PFNA and PFDA exposure was associated with greater preterm birth risk (OR = 2.55, 95%CI:1.45, 4.50). The PFAS-preterm association was modified by family-level seafood consumption. Our results suggest that higher family-level PFNA and PFDA exposure was associated with greater preterm birth risk, although the results for individual paternal, maternal and neonatal PFAS exposures were contradictory. If replicated in other coastal areas, these findings highlight a need to focus on the family triad and to consider seafood consumption when assessing the reproductive toxicity of PFAS exposure.

Per- and polyfluoroalkyl substances (PFAS) exposure in women seeking in vitro fertilization-embryo transfer treatment (IVF-ET) in China: Blood-follicular transfer and associations with IVF-ET outcomes

As follicular fluid constitutes a critical microenvironment for the development of oocytes, investigation of environmental contaminants in follicular fluid may facilitate a better understanding of the influence of environmental exposure on reproductive health. In the present study, we aimed to investigate per- and polyfluoroalkyl substances (PFAS) exposure in women receiving in vitro fertilization-embryo transfer (IVF-ET) treatment, determine the blood-follicle transfer efficiencies (BFTE) of PFAS, and explore potential associations between PFAS exposure and selected IVF-ET outcomes. Our results revealed that n-PFOA was the most abundant PFAS in both serum and follicular fluid (FF) (median = 5.85 and 5.56 ng/mL, respectively), followed by n-PFOS (4.95 and 4.28 ng/mL), 6:2 Cl-PFESA (2.18 and 2.10 ng/mL), PFNA (1.37 and 1.37 ng/mL), PFUdA (0.33 and 0.97 ng/mL), PFDA (0.37 and 0.66 ng/mL), PFHxS (0.42 and 0.39 ng/mL), and PFHpS (0.11 and 0.10 ng/mL). The median BFTE ranged from 0.65 to 0.92 for individual PFAS, indicating a relatively high tendency of PFAS to cross the blood-follicle barrier (BFB). An inverted V-shaped trend was observed between the median BFTE and the number of fluorinated carbon atoms or the log K_ow (octanol-water partition coefficient) for individual PFAS, suggesting the influence by physicochemical properties and molecular structures. Although our data did not find any clear pattern in the link between blood or follicular fluid concentrations of PFAS and selected IVF-ET outcomes, our study raises the need for better characterization of exposure to environmental chemicals in follicular fluid together with its potential influence on reproductive health.

Association Between Exposure to Per- and Polyfluoroalkyl Substances and Birth Outcomes: A Systematic Review and Meta-Analysis

Background

A large body of emerging evidence suggests that per- and polyfluoroalkyl substances (PFAS) affect birth outcomes in various pathways, but the evidence is inconsistent. Therefore, this study aimed to systematically review the epidemiological evidence on PFAS exposure and birth outcomes.

Methods

Three electronic databases were searched for epidemiological studies through February 13, 2021. We used random-effects meta-analysis for eight birth outcome indicators to calculate summary effect estimates for various exposure types. The risk of bias and the overall quality and level of evidence for each exposure-outcome pair were assessed.

Results

The initial search identified 58 potentially eligible studies, of which 46 were ultimately included. Many PFAS were found to have previously unrecognized statistically significant associations with birth outcomes. Specifically, birth weight (BW) was associated with PFAS, with effect sizes ranging from −181.209 g (95% confidence interval (CI) = −360.620 to −1.798) per 1 ng/ml increase in perfluoroheptanesulfonate (PFHpS) to −24.252 g (95% CI = −38.574 to −9.930) per 1 ln (ng/ml) increase in perfluorodecaoic acid (PFDA). Similar patterns were observed between other PFAS and birth outcomes: perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) with birth length (BL) and ponderal index (PI), PFOS and perfluorododecanoic acid (PFDoDA) with head circumference (HC), PFHpS with gestational age (GA), and perfluorononanoic acid (PFNA) and PFHpS with preterm birth (PTB). Additionally, PFDA showed a statistically significant association with small for gestational age (SGA). The level of the combined evidence for each exposure-outcome pair was considered to be “moderate”.

Conclusion

This study showed that PFAS exposure was significantly associated with increased risks of various adverse birth outcomes and that different birth outcome indicators had different degrees of sensitivity to PFAS. Further studies are needed to confirm our results by expanding the sample size, clarifying the effects of different types or doses of PFAS and the time of blood collection on birth outcomes, and fully considering the possible confounders.

Effects of prenatal exposure to persistent organic pollutants on neonatal Outcomes:A mother-child cohort (Shanghai, China)

Persistent organic pollutants (POPs), known as common environmental pollutants, which have adverse effects on neurobehavioral development, are widely applied in industry and agriculture. However, evidence about neurodevelopmental toxicity of POPs in humans is limited. This study aimed to explore the relationship between prenatal exposure to POPs and birth outcome of the newborn including birth length, weight, and head circumference. In this study, 1522 mother-child pairs were included in this study and cord blood samples were collected, which were detected to determine exposure level of 37 POPs in total. After delivery, the neonatal anthropometric indices detection (birth length, weight, and head circumference) was performed. According to the multivariate linear regression, the newborn with high detection rates (≥75 percentile) of hexachlorobenzene (HCB), beta-hexachlorocyclohexane (β-HCH), p,p'-dichlorodiphenyl dichloroethylene (p,p'-DDE) in the umbilical cord blood were demonstrated negative relationship with birth head circumference after adjusting for confounding factors, but not related with birth length and weight. After confirming that there was a nonlinear relationship between HCB and birth head circumference based on sex stratification through the generalized additive model (GAM), further two-piecewise linear regression model was conducted to explore the saturation threshold effect between HCB and birth head circumference, which showed cord serum HCB concentration greater than 0.5 μg/L was negatively associated with birth head circumference in girls. Our study provided evidence for the adverse influence of HCB, β-HCH and p,p'-DDE exposure during pregnancy on the birth head circumference of offspring. Although HCB induced reduction of birth head circumference was found in girls, the mechanism of gender difference remained unclear. Further studies are needed to explore the effect of POPs on the growth and development of offspring based on in vivo or in vitro experimental models.

Prenatal exposure to persistent organic pollutants and metals and problematic child behavior at 3-5 years of age: a Greenlandic cohort study

High levels of persistent organic pollutants (POPs) and heavy metals are found in Arctic populations. POP and heavy metals are linked to impaired cognitive development. This study examined associations between prenatal POP and metals exposure and problematic child behavior using the Strength and Difficulties Questionnaire (SDQ). POPs and metals were measured in 102 pregnant Greenlandic women. During follow-up at 3–5 years, parents answered an assisted questionnaire including children’s SDQ scores. Associations were analyzed using linear and logistic regression analyses and adjusted for maternal plasma cotinine, educational level and age at delivery. In the adjusted analyses, the medium tertile of hexachlorobenzene (β = 3.06, p = 0.010), β-hexachlorocyclohexane (β = 3.58, p = 0.004) and trans-nonachlor (β = 2.06, p = 0.082) were positively associated with SDQ scores. The continuous cis-nonachlor (OR = 1.09, p = 0.079), dichloro-diphenyl-dichloroethylene (OR = 1.01, p = 0.077), trans-nonachlor (OR = 1.01, p = 0.091), and sum Organochlorine-Pesticides (OR = 1.00, p = 0.094) were positively associated with abnormal SDQ score and the continuous mirex (OR = 1.28, p = 0.096), oxychlordane (OR = 1.04, p = 0.066), and trans-nonachlor (OR = 1.02, p = 0.071) with abnormal hyperactivity score. We found no consistent evidence of associations between polychlorinated biphenyls, perfluoroalkylated substances and heavy metals and problematic behavior. Prenatal organochlorine pesticide exposure associated significantly with problematic behavior in 3–5 year old children.

Dietary habits among men and women in West Greenland: follow-up on the ACCEPT birth cohort

BACKGROUND

In the past decades, the diet in Greenland has been in transition resulting in a lower intake of traditional food and a higher intake of imported western food. This diet transition can affect public health negatively, and thus, continued monitoring of dietary habits is important. The present study aimed to follow up on the dietary habits of pregnant women included in the Greenlandic ACCEPT birth cohort (2013-2015) and the children's father.

METHODS

The follow-up food intake was assessed in 2019-2020 using food frequency questionnaires for 101 mothers and 76 fathers aged 24-55 years living in Nuuk, Sisimiut, and Ilulissat. Non-parametric statistical methods were used (Mann-Whitney U test/Spearman correlation) to assess the dietary pattern and influencing factors.

RESULTS

The proportion of traditional and imported food was 14 and 86%, respectively. Intake frequency differed by gender (vegetables, fruits, fast food), the living town (terrestrial animals, vegetables, fruits), and age (fish, meat products, fruits, fast food). Socioeconomic and lifestyle factors significantly correlated with the intake frequency of several traditional and imported foods. Few changes in the mother's dietary habits from inclusion (during pregnancy) to follow-up (3-5 years later) were found, showing less frequent intake of seabirds and fruits and more frequent meat intake.

CONCLUSION

We identified several factors that could affect dietary habits, and the results may be used to target future food recommendation for relevant population groups.

Umbilical cord serum perfluoroalkyl substance mixtures in relation to thyroid function of newborns: Findings from Sheyang Mini Birth Cohort Study

BACKGROUND

The epidemiological evidence on the associations between prenatal exposure to perfluoroalkyl substances (PFAS) and thyroid hormones in newborns was inconclusive.

OBJECTIVES

We aimed to estimate associations of fetal exposure to PFAS individually and in mixtures with thyroid function of newborns.

METHODS

A total of 490 mother-newborn pairs were included from Sheyang Mini Birth Cohort Study (SMBCS), a prospective cohort that recruited between June 2009 and January 2010. 12 PFAS and 7 thyroid function indicators were quantified in umbilical cord serum. We examined associations of prenatal exposure to individual and a mixture of PFAS with thyroid function indicators using multivariable linear regression and weighted quantile sum (WQS) regression models with adjustment for potential confounders, respectively.

RESULTS

Higher cord serum concentrations of PFAS mixtures were related to increases in TT4 and FT4 levels, and reductions in TSH concentrations of newborns. Combining single-chemical models with multiple-chemical models, PFOS, PFNA and PFUnDA were associated with increased TT4 levels with contributing to the mixture effects of 46.4%, 22.8%, and 16.7%, respectively. PFOS exposure was in positive association with cord serum FT4 concentrations and contributed 28.9% to the joint effects of mixtures. PFNA and PFHpA were the most important contributors to the decreases of TSH levels of newborns with 46.3% and 45.0% among the mixtures, respectively.

CONCLUSIONS

The current findings indicated the thyroid disruption of individual PFAS and their mixtures in cord serum. Additional studies are warranted to explore the underlying biological mechanisms, particularly for PFAS mixtures.

Time Trend of Persistent Organic Pollutants and Metals in Greenlandic Inuit during 1994-2015

Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs), organchlorine pesticides and perfluoroalkylated substances (PFASs) and heavy metals bioaccumulate in the marine food chain in the Arctic regions, and thus, the Greenlandic population has a higher body burden due to relatively high intake of marine mammals. We assessed the temporal trend for POPs, including PCB 153; 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE); oxychlordane; six PFASs; mercury; lead and selenium in Inuit from Ilulissat, Nuuk, and across Greenland (including thirteen towns/districts), from 1994 to 2015. Data showed a significant annual decrease of 6.85-8.61% for PCB153, 6.67-8.61% for p,p'-DDE, 6.11-9.52% for oxychlordane, 5.92-6.76% for mercury and 6.48-9.43% for lead in Inuit women from Nuuk, Ilulissat, and across thirteen Greenlandic districts. The blood selenium level of all Greenlandic women increased 1.01% annually, while the trend direction was negative for Nuuk women. A similar pattern was seen for men across Greenland, with a yearly decrease of 11.3% for PCB 153, 8.61% for p,p'-DDE, 15.6% for oxychlordane, 13.1% for mercury and 12.2% for lead. Perfluorooctane sulfonate, perfluorohexane sulfonate and perfluorooctanoic acid significantly decreased 5.82-11.7% annually for both women and men across Greenland. For perfluorononanoic acid, perfluorodecanoic acid and perfluoroundecanoic acid, we observed an increasing trend for women across Greenland. In conclusion, there was a decreasing trend of the regulated POPs and metals but a potential increasing trend of the nonregulated PFASs in the Greenlandic population between 1994 and 2015. The continuing biomonitoring of contaminants of concern is important to protect the Arctic population heath.

Concentrations of Persistent Organic Pollutants in Women's Serum in the European Arctic Russia

Persistent organic pollutants (POPs) are heterogeneous carbon-based compounds that can seriously affect human health. The aim of this study was to measure serum concentrations of POPs in women residing in the Euro-Arctic Region of Russia. A total of 204 women from seven rural settlements of the Nenets Autonomous Okrug (NAO) took part in the study. We measured serum concentrations of 11 polychlorinated biphenyls (PCBs) and 17 organochlorine pesticides (OCPs) across the study sites and among Nenets and non-Nenets residents. Measurement of POPs was performed using an Agilent 7890A gas chromatograph equipped with an Agilent 7000 series MS/MS triple quadrupole system. The concentrations of all POPs were low and similar to findings from other Arctic countries. However, significant geographic differences between the settlements were observed with exceptionally high concentrations of PCBs in Varnek located on Vaygach Island. Both ΣDDT (p = 0.011) and ΣPCB (p = 0.038) concentrations were significantly lower in Nenets. Our main findings suggest that the serum concentrations of the legacy POPs in women in the Euro-Arctic Region of Russia are low and similar to those in other Arctic countries. Significant variations between settlements, and between Nenets and non-Nenets residents, were found. Arctic biomonitoring research in Russia should include studies on the associations between nutrition and concentrations of POPs.

Early-Life Exposure to Per- and Poly-Fluorinated Alkyl Substances and Growth, Adiposity, and Puberty in Children: A Systematic Review

Per- or polyfluoroalkyl substances (PFAS), a family of synthetic polyfluorinated compounds, are widely used in consumer products. Ubiquitous exposures to PFAS, in consideration of their persistence, bioaccumulation potential, and toxicities have led to concerns regarding possible harmful effects during critical periods of development in early-life and long-term consequences on health. The potential effects of PFAS depend on various factors including the type of PFAS and the timing and level of exposure. We performed a systematic review of the epidemiologic literature to assess the effects of early-life PFAS exposure on prenatal and postnatal growth, adiposity, and puberty in children and adolescents. For birth size, most studies indicated that prenatal PFAS exposure, in particular long-chain PFAS, may impair fetal growth, albeit some reports of null associations with maternal PFAS. For growth within 2 years of age, prenatal PFAS exposure showed no associations with height and either null or negative associations with weight. However, postnatal PFAS exposures were inversely related to height and weight at 2 years in a cross-sectional study. For postnatal adiposity, prenatal PFAS may mostly have negative associations with body mass index in the first 2 years of life, but positive relationships with adiposity in childhood and adolescence, although some studies showed null associations. For puberty, the evidence for associations between early-life PFAS exposure and pubertal development or sex hormone levels were limited and inconclusive. From experimental studies, plausible mechanisms through which PFAS may affect early-life growth and puberty include PFAS-induced activation of peroxisome proliferator-activated receptor, alterations of thyroid or steroid hormone synthesis and metabolism, and their weak estrogenic or anti-androgenic properties. Although the published literature suggests possible effects of PFAS exposures on early-life growth, adiposity, and puberty, current human evidence is limited in establishing PFAS-induced effects on early-life physical development. Further investigation is warranted to clarify PFAS-induced effects on growth and physical development in consideration of the critical time-window of exposure, concomitant exposure to chemical mixtures including various PFAS types, and possible non-monotonic dose-response relationship for growth and adiposity trajectories.

Perfluoroalkyl acids in pregnant women from Nunavik (Quebec, Canada): Trends in exposure and associations with country foods consumption

BACKGROUND

Perfluoroalkyl acids (PFAAs) are persistent and ubiquitous environmental contaminants that potentially disrupt endocrine system functions. While some PFAAs (perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA)) are regulated, currently used fluorotelomer alcohols (FTOHs) can be transported to the Arctic and are degraded in a number of PFAAs which biomagnify in Arctic wildlife (e.g. perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUdA)).

OBJECTIVES

From 2004 to 2017, 279 pregnant Inuit women were recruited as part of biomonitoring projects in Nunavik. Our goal was to evaluate: (i) time-trends in plasma/serum PFAAs levels in pregnant Nunavimmiut women between 2004 and 2017; (ii) compare plasma/serum PFAAs levels in Nunavimmiut women in 2016-2017 to those measured in women of childbearing age in the Canadian Health Measure Survey (CHMS); and (iii) evaluate the associations of PFAAs levels with the consumption of country foods and pregnancy and maternal characteristics during pregnancy in the 97 participants recruited in 2016-2017.

METHODS

Individual blood sample were collected for serum or plasma PFAAs (PFOS, PFOA, pentafluorobenzoic acid (PFBA), perfluorohexanoic acid (PFHxA), perfluorobutanesulfonic acid (PFBS), perfluorohexane-1-sulfonic acid (PFHxS), PFNA, PFDA, PFUdA) analyses. Socio-demographic data, pregnancy and maternal characteristics and country foods consumption were documented using a questionnaire. Omega-3 and -6 polyunsaturated fatty acids (PUFA) were measured in red blood cell membranes and their ratio used as a biomarker of marine country foods consumption. Time-trends in PFAAs levels were evaluated using ANCOVA models adjusted for relevant co-variables. Serum/plasma levels of PFAAs in the 97 pregnant women aged 16 to 40 years old and recruited in 2016-2017 were compared to those measured in women aged 18 to 40 years old from the CHMS cycle 5 (2016-2017) using the geometric means (GM) and 95% confidence intervals (95% CI). Multivariate regression analyses were performed to examine associations between concentrations of PFAAs and country foods consumption data.

RESULTS

Statistically-significant downward time trends were noted for concentrations of PFOS, PFOA and PFHxS in pregnant Nunavik women between 2004 and 2017. Conversely, between 2011 and 2016-2017, PFNA, PFDA and PFUdA maternal serum levels increased by 19, 13 and 21% respectively. Among participants in 2016-2017, mean concentrations for PFNA (GM: 2.4 μg/L), PFDA (0.53 μg/L) and PFUdA (0.61 μg/L) were higher than those measured in women aged 18-40 years old in the Cycle 5 (2016-2017) of the CHMS. PFOA (0.53 μg/L) and PFHxS (0.26 μg/L) were lower than in CHMS, whereas PFBA, PFHxA and PFBS were not detected in 2016-2017. Ratios of serum/plasma levels of PFNA/PFOA, PFNA/PFOS, PFNA/PFHxS and PFUdA/PFDA were significantly higher in the 97 pregnant women from Nunavik recruited in 2016-2017 compared to CHMS, highlighting their distinct exposure profile. In multivariate models, PFHxS, PFOS, PFNA, PFDA and PFUdA levels in 2016-2017 were strongly associated with the omega-3/omega-6 PUFA ratio, indicating a positive association between marine country foods consumption and higher exposure to PFAAs.

CONCLUSIONS

The exposure of pregnant women to long-chain PFAAs (PFNA, PFDA and PFUdA) increased from 2004 to 2017 in Nunavik. Associations noted between PFAAs levels and the omega-3/omega-6 ratio highlights the importance of implementing additional strict regulations on PFAAs and their precursors to protect the high nutritional quality and cultural importance of country foods in Nunavik.

Exposure characteristics for congeners, isomers, and enantiomers of perfluoroalkyl substances in mothers and infants

Per- and polyfluoroalkyl substances (PFASs) are ubiquitous in the environment, making it inevitable for humans to be exposed to these pollutants. The exposure begins while in utero and continues in infancy, during the potentially most sensitive early stages of life. This review summarizes the current knowledge on pre- and neo-natal exposures based on more than 200 articles published from 2000 to date. All relevant biological matrices used in the cited studies were included, such as maternal blood, umbilical cord blood, breast milk, placenta, amniotic fluid, fetal organs, newborns' dried blood spots, and infant serum. We show that such exposures are geographically global with significant discrepancies among countries and continents, and that while the levels of major legacy PFASs (PFOS and PFOA) have declined since 2000, those of others may have not. We also show that levels of PFOS and PFOA exceed those of some major environmental toxins, such as p,p'-DDE, BDE-47, PCB-153, PBB-153, and OH-PBDEs in maternal blood. Given that the behavior and potential effects have an origin in molecular structure, biomonitoring and research at the levels of isomers and enantiomers are critically important. Through critical analysis of these works, we summarize the major achievements, consensus, and the deficiencies of existing research. To our knowledge, this is the first review on the overall internal exposure status of mothers and infants to PFASs during pregnancy and lactation.

A polyphenol-rich cranberry extract protects against endogenous exposure to persistent organic pollutants during weight loss in mice

The dramatic rise in the global occurrence of obesity and associated diseases calls for new strategies to promote weight loss. However, while the beneficial effects of weight loss are well known, rapid loss of fat mass can also lead to the endogenous release of liposoluble molecules with potential harmful effects, such as persistent organic pollutants (POP). The aim of this study was to evaluate the impact of a polyphenol-rich cranberry extract (CE) on POP release and their potential deleterious effects during weight loss of obese mice. C57BL/6 J mice were fed an obesogenic diet with or without a mixture of POP for 12 weeks and then changed to a low-fat diet to induce weight loss and endogenous POP release. The POP-exposed mice were then separated in two groups during weight loss, receiving either CE or the vehicle. Unexpectedly, despite the higher fat loss in the CE-treated group, the circulating levels of POP were not enhanced in these mice. Moreover, glucose homeostasis was further improved during CE-induced weight loss, as revealed by lower fasting glycemia and improved glucose tolerance as compared to vehicle-treated mice. Interestingly, the CE extract also induced changes in the gut microbiota after weight loss in POP-exposed mice, including blooming of Parvibacter, a member of the Coriobacteriaceae family which has been predicted to play a role in xenobiotic metabolism. Our data thus suggests that the gut microbiota can be targeted by polyphenol-rich extracts to protect from increased POP exposure and their detrimental metabolic effects during rapid weight loss.

Exposure to per- and polyfluorinated alkyl substances in pregnant Brazilian women and its association with fetal growth

Research pertaining to exposure of humans to per- and polyfluorinated alkyl substances (PFASs) has received considerable public and regulatory attention in recent years. Although several studies have reported exposure to PFASs by populations in North America and western Europe, such information is still scarce in Latin America, including Brazil. In this study, concentrations of thirteen PFASs were determined in whole blood collected during the second trimester from 252 pregnant Brazilian women. This is a nested case-control study within the Brazilian Ribeirao Preto and Sao Luiz Birth Cohort Study (BRISA) with selected birth outcomes cases (n = 63) and matched controls (n = 189). PFASs concentrations were associated with conditions including preeclampsia, birth weight (BW), preterm birth, and intrauterine growth restriction (IUGR). Among PFASs measured, perfluorooctane sulfonate (PFOS) was found at the highest concentration (range: 1.06-106 ng mL^-1 with a median value of 3.41 ng mL^-1) which was followed by perfluorooctanoic acid (PFOA, range: 0.11-2.77 ng mL^-1 with a median value of 0.20 ng mL^-1). A significant positive association of PFOS and PFOA concentrations with fetal growth restriction (p < 0.05) was found. This is the first study to assess whole blood concentrations of PFASs and their effect on fetal growth in pregnant Brazilian women.

Placental transfer of pesticides studied in human placental perfusion

To investigate the transplacental transport of pesticides, the pyrethroid cypermethrin and the fungicide azoles, propiconazole and bitertanol were tested in the placental perfusion model. Cypermethrin, propiconazole and bitertanol were also tested in the BeWo cell transfer model. The pesticides were chosen with the selection criteria: use in Denmark, significant treated areas and knowledge on hormone-disrupting effects. Propiconazole and bitertanol showed rapid transfer and adsorbance to the system in both placental perfusion and BeWo cell system, whereas cypermethrin had a slower transport across the placental cell layers in the two models. There was no difference between data of the single pesticides and their mixture in either placental perfusion or BeWo cell transfer model. Both the placental perfusion model and the BeWo cell model metabolized the pesticides and released metabolites into both foetal and maternal circulation. Using human exposure models, this study shows the potential exposure of the human foetus to pesticides cypermethrin, propiconazole and bitertanol and their metabolites.

High trans-placental transfer of perfluoroalkyl substances alternatives in the matched maternal-cord blood serum: Evidence from a birth cohort study

BACKGROUND

Recent studies suggest that perfluoroalkyl substances (PFAS) and PFAS alternatives can cross the placental barrier. However, little is known on the differential patterns of trans-placental transfer (TPT) among conventional PFAS and PFAS alternatives in epidemiological study.

OBJECTIVES

We aimed to characterize comprehensive TPT patterns in conventional PFAS and PFAS alternatives using matched maternal-cord blood serum from a birth cohort.

METHODS

A total of 424 mother-fetus pairs were recruited from the Maoming Birth Cohort during 2015-2018. We detected 20 PFAS in cord and maternal serum using an ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). TPT of PFAS was calculated via cord to maternal serum concentration ratios.

RESULTS

Both of PFOS alternatives (chlorinated polyfluorinated ether sulfonates, Cl-PFESAs) and PFOA short-chain alternative (perfluorobutanoic acid, PFBA) were widely detected in the cord and maternal serum. In cord serum, the predominant PFAS was PFOS (1.93 ng/mL), followed by PFBA (1.45 ng/mL), PFOA (0.75 ng/mL) and 6:2 Cl-PFESA (0.32 ng/mL). We found that the PFAS alternatives had higher TPT than PFOS and PFOA, such as PFBA vs. PFOA (median: 1.41 vs. 0.73, P < 0.001) and 8:2 Cl-PFESA vs. PFOS (median: 0.98 vs. 0.42, P < 0.001). Moreover, the TPT of 8:2 Cl-PFESA was higher than the precursor, linear and isomeric PFOS, respectively (P < 0.01). Furthermore, we found a U-shaped pattern for TPT in perfluorocarboxylic acid compounds (PFCAs) across different length of carbon chain.

CONCLUSION

Our findings suggest that PFAS alternatives may be more easily across the placenta than conventional PFAS. Given the widespread usage of PFAS alternatives, our results indicate that more research is needed to assess the potential health risks of prenatal exposure to PFAS alternatives in children.