Metabolic Perturbations Associated with an Exposure Mixture of Per- and Polyfluoroalkyl Substances in the Atlanta African American Maternal-Child Cohort

Effect of PFAS serum exposure pattern on the lipid metabolism: Time to step-forward in causal inference in epidemiology

Associations of per- and polyfluoroalkyl substances (PFAS) on lipid metabolism have been documented but research remains scarce regarding effect of PFAS on lipid variability. To deeply understand their relationship, a step-forward in causal inference is expected. To address these, we conducted a longitudinal study with three repeated measurements involving 201 participants in Beijing, among which 100 eligible participants were included for the present study. Twenty-three PFAS and four lipid indicators were assessed at each visit. We used linear mixed models and quantile g-computation models to investigate associations between PFAS and blood lipid levels. A latent class growth model described PFAS serum exposure patterns, and a generalized linear model demonstrated associations between these patterns and lipid variability. Our study found that PFDA was associated with increased TC (β = 0.083, 95% CI: 0.011, 0.155) and HDL-C (β = 0.106, 95% CI: 0.034, 0.178). The PFAS mixture also showed a positive relationship with TC (β = 0.06, 95% CI: 0.02, 0.10), with PFDA contributing most positively. Compared to the low trajectory group, the middle trajectory group for PFDA was associated with VIM of TC (β = 0.756, 95% CI: 0.153, 1.359). Furthermore, PFDA showed biological gradients with lipid metabolism. This is the first repeated-measures study to identify the impact of PFAS serum exposure pattern on the lipid metabolism and the first to estimate the association between PFAS and blood lipid levels in middle-aged and elderly Chinese and reinforce the evidence of their causal relationship through epidemiological studies.

Assessment of human exposure to uncommon industrial toxicants in Glynn County, Georgia

Coastal Glynn County, Georgia, is home to four hazardous sites on the United States EPA's National Priorities List. Toxicants of concern include mercury, the pesticide toxaphene, and Aroclor 1268, a mixture of highly chlorinated polychlorinated biphenyls (PCBs); these toxicants are known to persist in the local environment and/or regional aquatic life, including local seafood. At the invitation of, and in partnership with, local community leaders and environmental groups, we conducted a human exposure study in Glynn County. The average age of the study participants was 61 years, 66 % were female, and 46 % were Black. Mercury levels in study participants were comparable to the general US population. Levels of less chlorinated PCBs (PCB 118, 138, 153 and 180) were lower in participants compared to the general population, but the highly chlorinated PCBs associated with Aroclor 1268 were elevated; 19.3 %, 25.0 % and 39.8 % of participants were above the estimated 95th percentile reference values for PCBs 196 + 203, 199, and 206, respectively. About 20 % of participants were above the 95th percentile reference level for both toxaphene Parlars tested (Parlars 26 and 50). We also report on several other toxicants including other metals (lead and cadmium), p,p'-DDE, and poly- and per-fluorinated alkyl substances (PFAS). This study provides evidence that toxicants associated with local hazardous sites have contributed to exposures in Glynn County residents, and that some residents have exposures far exceeding what is common in the general population.

Prenatal PFAS exposure and outcomes related to maternal gut microbiome composition in later pregnancy

The composition of the gut microbiome is dependent on factors including diet, lifestyle, and exposure to environmental chemicals, and has implications for human health. Per- and polyfluoroalkyl substances (PFAS), a class of man-made chemicals that have nonstick and flame-retardant properties may impact on gut microbiome composition. Our objective was to elucidate links between PFAS and maternal gut microbiome composition in two geographically diverse sites of the Environmental Influences on Child Health Outcomes program. The present analysis includes participants in the Atlanta African American Maternal Child Cohort; ATL AA and a predominately non-Hispanic White subsample of the Michigan Archive for Research on Child Health Cohort; MARCH with serum or plasma PFAS concentrations measured in early or late pregnancy and 16s rRNA sequencing from maternal gut microbiome samples available primarily in later pregnancy (2nd-3rd trimester). Linear regression models tested associations between prenatal PFAS levels (separately for the 1st/3rd trimesters) and measures of alpha diversity, bacterial composition differences, and differential taxonomic abundance. Bayesian Kernel Machine Regression and Elastic net regression mixture modeling were also incorporated. In both cohorts, multiple PFAS were significantly associated with the relative abundance of specific microbiome taxa even after adjustment for covariates including maternal diet, age, race, BMI, and smoking; A total of 16 significant family-level associations were identified for ATL AA (e.g., PFOA with Clostridiaceae; natural log fold change = 0.94) and 13 significant family-level associations identified for MARCH e.g., PFOS with Desulfovibrionaceae; natural log fold change = -1.53 (pFDR<0.05), but similarities between cohorts were lacking. Mixture analyses did not identify interactive or combined effects but did provide modest evidence of inclusion of individual PFAS in beta diversity models in both cohorts. In 2 distinct cohorts, there were significant associations between prenatal PFAS and the relative abundance of several bacterial taxa, but these differences were cohort-specific. This work suggests that PFAS may modulate the gut microbiome during pregnancy.

Maternal per- and polyfluoroalkyl substances exposure, cord blood lipidomics and infant anthropometry: A mediation analysis

Maternal exposure to per- and polyfluoroalkyl substances (PFAS) has been associated with offspring adiposity; however, underlying mechanisms remain unclear. In this study, we quantified 11 PFAS in maternal plasma collected between 12 and 16 gestational weeks and 104 lipid metabolites in the cord blood of 525 mother-infant pairs. Principal components of multiple PFAS compounds, extracted by principal component analysis, were employed to investigate the effect of the PFAS mixture. Infant anthropometric indicators included weight, length, waist/arm circumference, and abdominal/triceps/subscapular skinfold thickness at birth and 6 and 12 months old. Multiple linear regression showed that maternal PFAS exposure was primarily associated with increased glycerophospholipids and decreased fatty acyls and bile acids in cord blood. Four glycerophospholipids (16:0 PI, 16:0-18:1 PI, 18:0-20:4 PI, and 18:0-18:1 PS), fatty acyls (5(S)-HETE, 15(S)-HETE, 13-HDoHE, and dhkPGF2), and bile acids (GCA, TCA, TCDA, and TDCA) partially mediated the positive associations of the first principle component of PFAS compounds (with positive loadings for all PFAS compounds), PFNA, and PFUdA with infant skinfold thickness with mediating proportions ranging from 15.24% to 33.39%. Our findings provide novel insights into mechanisms underlying the effects of maternal PFAS exposure on infant growth.

Impact of prenatal phthalate exposure on newborn metabolome and infant neurodevelopment

We evaluated associations among exposure to prenatal phthalate metabolites, perturbations of the newborn metabolome, and infant neurobehavioral functioning in mother-newborn pairs enrolled in the Atlanta African American Maternal-Child Cohort during 2016-2018. We quantified eight phthalate metabolites in prenatal urine samples collected between 8- and 14-weeks' (visit 1; n = 216) and 24- and 30-weeks' gestation (visit 2; n = 145) and metabolite features in newborn dried-blood spot samples collected at delivery. Associations between phthalate metabolite concentrations and metabolic feature intensities at both visits were examined using adjusted generalized linear models (MWAS). Then, an exploratory meet-in-the-middle (MITM) analysis was conducted in a subset with NICU Neonatal Neurobehavioral Scale (NNNS) scores (visit 1 n = 81; visit 2 n = 71). In both the MWAS and MITM, many of the confirmed metabolites are involved in tyrosine and tryptophan metabolism, including tryptophan, tyrosine, thyroxine, and serine. This analysis elucidates how prenatal phthalate exposure disrupts the newborn metabolome and infant neurobehavioral outcomes.

Impact of PFOS Exposure on Murine Fetal Hematopoietic Stem Cells, Associated with Intrauterine Metabolic Perturbation

This study hypothesized that perfluorooctanesulfonate (PFOS) exposure disrupts maternal-fetal metabolism, affecting fetal liver hematopoietic stem cell (FL-HSC) development. Pregnant mice received PFOS (0.3 and 3 μg/g bw) and were sacrificed on gestation day 14.5. Metabolomic analysis of maternal plasma revealed disruptions in steroid hormone, purine, carbohydrate, and amino acid metabolism, which aligned with the enriched pathways in amniotic fluid (AF). FL analysis indicated increased purine metabolism and disrupted glucose and amino acid metabolism. FL exhibited higher levels of polyunsaturated fatty acids, glycolytic and TCA metabolites, and pro-inflammatory cytokine IL-23, crucial for hematopoiesis regulation. Transcriptomic analysis of FL-HSCs revealed disturbances in the PPAR signaling pathway, pyruvate metabolism, oxidative phosphorylation, and amino acid metabolism, correlating with FL metabolic changes. Metabolomic analysis indicated significant rises in glycerophospholipid and vitamin B6 metabolism related to HSC expansion and differentiation. Flow cytometric analysis confirmed increased HSC populations and progenitor activation for megakaryocyte, erythrocyte, and lymphocyte lineages. The CFU assay showed a significant increase in BFU-E and CFU-G, but a decrease in CFU-GM in FL-HSCs from the H-PFOS group, indicating altered differentiation potential. These findings provide for the first time insights into the effects of PFOS on maternal-fetal metabolism and fetal hematopoiesis, highlighting implications for pollution-affected immune functions.

Prostaglandins: Biological Action, Therapeutic Aspects, and Pathophysiology of Autism Spectrum Disorders

Esterified ARA on the inner surface of the cell membrane is hydrolyzed to its free form by phospholipase A2 (PLA2), which is further metabolized by COXs and lipoxygenases (LOXs) and cytochrome P450 (CYP) enzymes. PGs produce detrimental effects due to their proinflammatory properties. The generation of prostaglandin (PG)G2 and PGH2 is triggered by cyclooxygenase (COX) isozymes such as COX-1 and COX-2. Prostaglandin E2 (PGE2) is significantly elevated in ASD. Considerable data indicate that COX enzymes and their metabolites of ARA play important roles in the initiation and development of human neurodevelopmental diseases. The involvement of disrupted COX2/PGE2 signaling in ASD pathology in changing neuronal cell behavior and the expression of ASD-related genes and proteins is due to disrupted COX2/PGE2 signaling. Prostacyclin (PGI2) is synthesized from arachidonic acid by metabolic-pathway-dependent cyclooxygenase (COX) and synthesized in a primary step of ARA transformation (PGG2, PGH2), by degradation of the abovementioned prostaglandins.

Metabolomics Signatures of Exposure to Ambient Air Pollution: A Large-Scale Metabolome-Wide Association Study in the Cancer Prevention Study-II Nutrition Cohort

Existing air pollution metabolomics studies showed inconsistent results, often limited by small sample size and individual air pollutants effects. We conducted a metabolome-wide association study among 1096 women (68.2 ± 5.7 years) who provided blood samples (1998-2001) within the Cancer Prevention Study-II Nutrition Cohort. Annual average individual exposures to particulate matter, nitrogen dioxide, ozone, sulfur dioxide, and carbon monoxide in the year of blood draw were used. Metabolomics profiling was conducted on serum samples by Metabolon. We evaluated the individual air pollutants effects using multiple linear regression and the mixture effect using quantile g-computation, adjusting for confounders and false discovery rate (FDR). Ninety-five metabolites were significantly associated with at least one air pollutant or mixture (FDR < 0.05). These metabolites were enriched in pathways related to oxidative stress, systemic inflammation, energy metabolism, signals transduction, nucleic acid damage and repair, and xenobiotics. Sixty metabolites were confirmed with level 1 or 2 evidence, among which 21 have been previously linked to air pollution exposure, including taurine, creatinine, and sebacate. Overall, our results replicate prior findings in a large sample and provide novel insights into biological responses to long-term air pollution exposure using mixture analysis.

Sex specificity in associations between exposure to a mixture of per and poly-fluoroalkyl substances and anxiety among US adults

BACKGROUND

Exposure to per and poly-fluoroalkyl substances (PFAS) is suggested to interfere with the central nervous system that may affect mental health. Studies on the relationships between exposure to PFAS mixtures and anxiety in humans are rare. This study aimed to evaluate the associations between single and combined exposure to PFAS and anxiety among adults.

METHODS

Data were extracted from the National Health and Nutrition Examination Survey (NHANES, 2007-2012). Six serum PFAS concentrations were accessed including perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), PFOS (perfluorooctanesulfonic acid), PFHxS (perfluorohexane sulfonate), PFDA (perfluorodecanoic acid), Me-PFOSA-AcOH (2-(N-methylperfluorooctanesulfonamide) acetic acid). The anxiety state was defined through the questionnaire responses of the participants. Weighted logistics regression was used to calculate their odds ratio (OR) and corresponding confidence interval (95% CI) that assessed the relationship between PFAS exposure and anxiety. Moreover, Two different statistical methods including quantile-based g-computation (Qgcomp), and Bayesian kernel machine regression (BKMR) were employed to investigate the overall effects of PFAS mixtures on anxiety.

RESULTS

The effects of specific PFAS exposure on anxiety varied by sex. In male participants, one-unit increase in PFDA (OR = 0.62; 95%CI: 0.44, 0.88), PFOA (OR = 0.60; 95%CI: 0.41, 0.87), PFNA (OR = 0.68; 95%CI: 0.46, 0.96) concentrations were inversely linked to anxiety. In female participants, a one-unit increase in PFOA (OR = 1.50; 95%CI: 1.05, 2.14) concentration was associated with anxiety. Analysis of Qgcomp demonstrated that PFAS mixtures were negatively associated with anxiety in males (OR = 0.85; 95%CI: 0.74, 0.99), and were positively associated with anxiety in females(OR = 1.16; 95%CI: 1.01, 1.33). Analysis of BKMR suggested that PFAS mixtures were negatively associated with anxiety in the males, while its associations with anxiety were positive in the females.

IMPACT

Although a growing number of studies have focused on the relationship between PFAS and anxiety, most have been performed based on animal observations rather than human populations, and the combined effects of PFAS mixtures on anxiety have not been evaluated. To address these gaps, this study first explored the associations between individual PFAS and PFAS mixture exposures and anxiety among US adults. Using data from the National Health and Nutrition Examination Survey, we demonstrated that co-exposure to a mixture of PFAS was negatively associated with anxiety in males, and its association was contrary in females.

Contaminant Exposure Profiles Demonstrate Similar Physiological Effects Across Environments Despite Unique Profile Composition in Formosa, Argentina, and Connecticut, USA

OBJECTIVE

Exposure to environmental contaminants is globally universal. However, communities vary in the specific combination of contaminants to which they are exposed, potentially contributing to variation in human health and creating "locally situated biologies." We investigated how environmental exposures differ across environments by comparing exposure profiles between two contexts that differ markedly across political, economic, and sociocultural factors-Namqom, Formosa, Argentina, and New Haven, Connecticut, United States.

METHODS

We collected infant urine, maternal urine, and human milk samples from mother-infant dyads in Formosa (n = 13) and New Haven (n = 21). We used untargeted liquid chromatography with high-resolution mass spectrometry (LC-HRMS) to annotate environmental contaminants and endogenous metabolites in these samples, and we analyzed the data using exposome-wide association studies (EWAS) followed by pathway enrichment.

RESULTS

We found statistically significant differences between the chemical exposure profiles of the Argentinian and US mothers, mostly involving pesticides; however, we observed similarities in the infant urine and human milk environmental contaminant profiles, suggesting that the maternal body may buffer infant exposure through human milk. We also found that infants and mothers were exposed to contaminants that were associated with alterations in amino acid and carbohydrate metabolism. Infants additionally showed alterations in vitamin metabolism, including vitamins B1, B3, and B6.

CONCLUSIONS

Differences in chemical exposure profiles may be related to structural factors. Despite variation in the composition of exposure profiles between the two study sites, environmental contaminant exposure was associated with similar patterns in human physiology when we considered contaminants comprehensively rather than individually, with implications for metabolic and cardiovascular disease risk as well as infant cognitive development.

Cord plasma metabolomic signatures of prenatal per- and polyfluoroalkyl substance (PFAS) exposures in the Boston Birth Cohort

BACKGROUND

Prenatal per- and polyfluoroalkyl substance (PFAS) exposures are associated with adverse offspring health outcomes, yet the underlying pathological mechanisms are unclear. Cord blood metabolomics can identify potentially important pathways associated with prenatal PFAS exposures, providing mechanistic insights that may help explain PFAS' long-term health effects.

METHODS

The study included 590 mother-infant dyads from the Boston Birth Cohort. We measured PFAS in maternal plasma samples collected 24-72 h after delivery and metabolites in cord plasma samples. We used metabolome-wide association studies and pathway enrichment analyses to identify metabolites and pathways associated with individual PFAS, and quantile-based g-computation models to examine associations of metabolites with the PFAS mixture. We used False Discovery Rate to account for multiple comparisons.

RESULTS

We found that 331 metabolites and 18 pathways were associated with ≥ 1 PFAS, and 38 metabolites were associated with the PFAS mixture, predominantly amino acids and lipids. Amino acids such as alanine and lysine and their pathways, crucial to energy generation, biosynthesis, and bone health, were associated with PFAS and may explain PFAS' effects on fetal growth restriction. Carnitines and carnitine shuttle pathway, associated with 7 PFAS and the PFAS mixture, are involved in mitochondrial fatty acid β-oxidation, which may predispose higher risks of fetal and child growth restriction and cardiovascular diseases. Lipids, such as glycerophospholipids and their related pathway, can contribute to insulin resistance and diabetes by modulating transporters on cell membranes, participating in β-cell signaling pathways, and inducing oxidative damage. Neurotransmission-related metabolites and pathways associated with PFAS, including cofactors, precursors, and neurotransmitters, may explain the PFAS' effects on child neurodevelopment. We observed stronger associations between prenatal PFAS exposures and metabolites in males.

CONCLUSIONS

This prospective birth cohort study contributes to the limited literature on potential metabolomic perturbations for prenatal PFAS exposures. Future studies are needed to replicate our findings and link prenatal PFAS associated metabolomic perturbations to long-term child health outcomes.

Prenatal exposure to per- and polyfluoroalkyl substances and sex-specific associations with offspring adiposity at 10 years of age: Metabolic perturbation plays a role

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) have been suspected as potential environmental obesogens, with several mechanisms being proposed, including the role of metabolomics. However, current epidemiological studies have yielded inconclusive findings.

OBJECTIVES

We aimed to estimate the associations of prenatal exposure to PFAS with offspring adiposity measures, and to explore the potential metabolic pathways underlying these associations.

METHODS

A total of 464 mother-child pairs from the Sheyang Mini Birth Cohort Study (SMBCS) were included in this study. Cord serum concentrations of 12 PFAS and urine metabolite profiles at age 10 were obtained from the SMBCS database. Adiposity-related anthropometric measurements and body composition estimates of children aged 10 were used to assess offspring obesity. Multiple linear regression models and quantile g-computation were conducted to estimate the associations of prenatal exposure to individual and multiple PFAS with obesity at 10 years old. Metabolomics analysis was performed to characterize the biological pathways associated with PFAS exposure or obesity, subsequently identifying the overlapping metabolic pathways underlying the PFAS-obesity relationship.

RESULTS

Prenatal exposure to several PFAS was significantly associated with elevated obesity-related markers in 10-year-old children. After stratification by sex, the effects were more pronounced in girls. Quantile g-computation results indicated that exposure to higher levels of PFAS mixtures during pregnancy was associated with increased odds of obesity in girls, with PFNA emerging as the predominant driving compound. Untargeted metabolomics results showed that several amino acid metabolic pathways were characterized as the overlapping pathways underlying the above associations.

CONCLUSIONS

Taken together, our findings suggested the potential obesogenic effects of prenatal exposure to PFAS and offered insight into the possible metabolic mechanisms underlying PFAS-related offspring obesity.

Association of per- and polyfluoroalkyl substances with the antioxidant bilirubin across pregnancy

BACKGROUND

In mechanistic and preliminary human studies, prenatal exposure to per- and polyfluoroalkyl substances (PFAS) is associated with oxidative stress, a potential contributor to maternal liver disease. Bilirubin is an endogenous antioxidant abundant in the liver that may serve as a physiological modulator of oxidative stress in pregnant people. Hence, our objective was to estimate the association between repeated measures of PFAS and bilirubin during pregnancy.

METHODS

The study population included 332 participants in the Atlanta African American Maternal-Child Cohort between 2014 and 2020. Serum samples were collected up to two times (early pregnancy: 6-18 gestational weeks; late pregnancy: 21-36 gestational weeks) for the measurement of perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and total bilirubin. We analyzed single PFAS with linear mixed effect regression and a mixture of the four PFAS with quantile g-computation. Models were repeated with a multiplicative interaction term to explore effect modification by study visit.

RESULTS

Overall, PFHxS was positively associated with bilirubin (β = 0.08, 95 % CI = 0.01, 0.15). We also found during late pregnancy, there was a positive association of PFHxS and the PFAS mixture with bilirubin (β = 0.12, 95 % CI = 0.02, 0.22; ψ = 0.19, 95 % CI = 0.03, 0.34, respectively). Finally, study visit modified the PFOA-bilirubin association (interaction p-value = 0.09), which was greater during early pregnancy (β = 0.08, 95 % CI = 0.01, 0.15).

CONCLUSION

In a prospective cohort of pregnant African Americans, an increase in PFOA, PFHxS, and the PFAS mixture was associated with an increase in bilirubin. Our results suggest that, depending on pregnancy stage, prenatal PFAS exposure disrupts the maternal liver antioxidant capacity.

Metabolic Perturbations Associated with both PFAS Exposure and Perinatal/Antenatal Depression in Pregnant Individuals: A Meet-in-the-Middle Scoping Review

PURPOSE OF REVIEW

Depression during the perinatal or antenatal period affects at least 1 in 10 women worldwide, with long term health implications for the mother and child. Concurrently, there is increasing evidence associating maternal exposure to per- and poly-fluoroalkyl substances (PFAS) to adverse pregnancy outcomes. We reviewed the body of evidence examining both the associations between PFAS exposure and perturbations in the maternal metabolome, and the associations between the maternal metabolome and perinatal/antenatal depression. Through this, we sought to explore existing evidence of the perinatal metabolome as a potential mediation pathway linking PFAS exposure and perinatal/antenatal depression.

RECENT FINDINGS

There are few studies examining the metabolomics of PFAS exposure-specifically in pregnant women-and the metabolomics of perinatal/antenatal depression, let alone studies examining both simultaneously. Of the studies reviewed (N = 11), the majority were cross sectional, based outside of the US, and conducted on largely homogenous populations. Our review identified 23 metabolic pathways in the perinatal metabolome common to both PFAS exposure and perinatal/antenatal depression. Future studies may consider findings from our review to conduct literature-derived hypothesis testing focusing on fatty acid metabolism, alanine metabolism, glutamate metabolism, and tyrosine metabolism when exploring the biochemical mechanisms conferring the risk of perinatal/antenatal depression due to PFAS exposure. We recommend that researchers also utilize heterogenous populations, longitudinal study designs, and mediation approaches to elucidate key pathways linking PFAS exposures to perinatal/antenatal depression.

Advancing Understanding of Chemical Exposures and Maternal-child Health Through the U.S. Environmental Influences on Child Health Outcomes (ECHO) Program: A Scoping Review

PURPOSE OF REVIEW

Environmental chemical exposures may disrupt child development, with long-lasting health impacts. To date, U.S. studies of early environmental exposures have been limited in size and diversity, hindering power and generalizability. With harmonized data from over 60,000 participants representing 69 pregnancy cohorts, the National Institutes of Health's Environmental influences on Child Health Outcomes (ECHO) Program is the largest study of U.S. children's health. Here, we: (1) review ECHO-wide studies of chemical exposures and maternal-child health; and (2) outline opportunities for future research using ECHO data.

RECENT FINDINGS

As of early 2024, in addition to over 200 single-cohort (or award) papers on chemical exposures supported by ECHO, ten collaborative multi-cohort papers have been made possible by ECHO data harmonization and new data collection. Multi-cohort papers have examined prenatal exposure to per- and polyfluoroalkyl substances (PFAS), phthalates, phenols and parabens, organophosphate esters (OPEs), metals, melamine and aromatic amines, and emerging contaminants. They have primarily focused on describing patterns of maternal exposure or examining associations with maternal and infant outcomes; fewer studies have examined later child outcomes (e.g., autism) although follow up of enrolled ECHO children continues. The NICHD's Data and Specimen Hub (DASH) database houses extensive ECHO data including over 470,000 chemical assay results and complementary data on priority outcome areas (pre, peri-, and postnatal, airway, obesity, neurodevelopment, and positive health), making it a rich resource for future analyses. ECHO's extensive data repository, including biomarkers of chemical exposures, can be used to advance our understanding of environmental influences on children's health. Although few published studies have capitalized on these unique harmonized data to date, many analyses are underway with data now widely available.

Impact of perfluorooctanoic acid (PFOA) and perfluorobutanoic acid (PFBA) on oxidative stress and metabolic biomarkers in human neuronal cells (SH-SY5Y)

Perfluorinated alkyl substances (PFAS) are pervasive environmental contaminants that have attracted considerable attention due to their widespread utilization, resilient characteristics, adverse health implications, and regulatory scrutiny. Despite documented toxicity in living organisms, the precise molecular mechanisms governing the induced adverse effects remain unclear. This study aims to elucidate mechanisms of toxic action by collecting empirical data sets along oxidative stress and metabolic disruption pathways. We investigated the impact of long-chain PFAS (perfluorooctanoic acid (PFOA)) and its short-chain analog (perfluorobutanoic acid (PFBA)) on human neuronal cells (SH-SY5Y). The functionalities of enzymes associated with oxidative stress (catalase and glutathione reductase) and cellular metabolism (lactate dehydrogenase and pyruvate dehydrogenase) were also characterized. Our results reveal that a 24-hour exposure to PFOA and PFBA generated significant levels of reactive oxygen species. Correspondingly, there was a notable decline in catalase and glutathione reductase activities, with PFBA demonstrating a more pronounced effect. High concentrations of PFOA and PFBA reduced metabolic activity. Lactate dehydrogenase activity was only impacted by a high concentration of PFBA, while pyruvate dehydrogenase activity was decreased with PFBA exposure and increased with PFOA exposure. The findings from this study contribute to the knowledge of PFAS and cell interactions and reveal the potential underlying mechanisms of PFAS-induced toxicity.

Per- and polyfluoroalkyl substances (PFAS) in senior care facilities and older adult residents

Per- and polyfluoroalkyl substances (PFAS) are fluorinated organic compounds used in a variety of consumer products and industrial applications that persist in the environment, bioaccumulate in biological tissues, and can have adverse effects on human health, especially in vulnerable populations. In this study, we focused on PFAS exposures in residents of senior care facilities. To investigate relationships between indoor, personal, and internal PFAS exposures, we analyzed 19 PFAS in matched samples of dust collected from the residents' bedrooms, and wristbands and serum collected from the residents. The median ∑PFAS concentrations (the sum of all PFAS detected in the samples) measured in dust, wristbands, and serum were 120 ng/g, 0.05 ng/g, and 4.0 ng/mL, respectively. The most abundant compounds in serum were linear- and branched-perfluorooctane sulfonic acid (L-PFOS and B-PFOS, respectively) at medians of 1.7 ng/mL and 0.83 ng/mL, respectively, followed by the linear perfluorooctanoic acid (L-PFOA) found at a median concentration of 0.59 ng/mL. Overall, these three PFAS comprised 80 % of the serum ∑PFAS concentrations. A similar pattern was observed in dust with L-PFOS and L-PFOA found as the most abundant PFAS (median concentrations of 13 and 7.8 ng/g, respectively), with the overall contribution of 50 % to the ∑PFAS concentration. Only L-PFOA was found in wristbands at a median concentration of 0.02 ng/g. Significant correlations were found between the concentrations of several PFAS in dust and serum, and in dust and wristbands, suggesting that the indoor environment could be a significant contributor to the personal and internal PFAS exposures in seniors. Our findings demonstrate that residents of assisted living facilities are widely exposed to PFAS, with several PFAS found in blood of each study participant and in the assisted living environment.