Human biomonitoring (HBM) complements air and surface measurements by integrating exposure from all routes and sources, strengthening occupational exposure assessment and control. In occupational settings, HBM can quantify exposure during routine work and nonroutine activities, evaluate controls, investigate incidents (potential overexposures), and support medical surveillance. To use HBM to its full potential, occupational health and safety professionals (OHPs) should adopt harmonized biomonitoring approaches reflecting best practice. This short communication presents the BASIC Guide series (Human Biomonitoring and Surveillance of Chemical Exposure in Occupational Settings), initiated by the International Society of Exposure Science Human Biomonitoring working group (ISES Europe HBM WG) as an integral part of the HBM Global Network. These chemical-specific practical documents operationalize the OECD (Organisation for Economic Co-operation and Development) occupational biomonitoring guidance, supporting the consistent implementation of exposure biomonitoring programs. Each BASIC Guide provides clear instructions on biomarker selection, sample handling, analytical methods, quality assurance, and result interpretation and communication. By translating international frameworks into actionable protocols, the BASIC Guides improve reproducibility and regulatory alignment in occupational HBM and enable more defensible exposure assessments worldwide.

Uterine fibroids are the most common benign smooth muscle neoplasm of the uterine wall and are a major indication for hysterectomy. Although common risk factors include African Ancestry, family history, obesity, and early menarche, exposure to non-essential metals is an emerging risk factor that has not been previously examined in Caribbean populations. In this cross-sectional study, a sample of the prospective Tobago Health Study, we assessed associations between individual urinary concentrations of metals and metal mixtures with self-reported uterine fibroid prevalence among 441 women (40–87 years old). We used logistic regression to estimate associations between concentrations of six metals (non-essential metals—arsenic, cadmium, and lead; essential metals—copper, manganese, and zinc) individually and as a mixture with the odds of uterine fibroids. Models were adjusted for urinary creatinine, age, body mass index, education, and number of live childbirths. We assessed the effects of metal mixtures using weighted quantile sum regression. The rate of prevalence of uterine fibroids was 48.3%. In adjusted models, each 10-fold increase in µg/L urinary concentrations of total arsenic, dimethylarsinic acid, and arsenobetaine was associated with 61%, 84%, and 38% higher odds of uterine fibroids, respectively (β: 1.61; 95% CI: 1.04, 2.53); (β: 1.84; 95% CI: 1.11, 3.09); and (β: 1.38; 95% CI: 1.05, 1.82). Other metals were not associated with the odds of uterine fibroids. We observed no significant associations between metal mixtures and the odds of uterine fibroids. Urinary arsenic and arsenical metabolites were associated with higher odds of uterine fibroids in a cohort of African Caribbean women. Raising awareness about arsenic and metal exposure is prudent, and further research in longitudinal studies is needed to replicate the findings of this study and inform policies for public health protection of women's health.

Our study examined the association between blood As and total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), non-HDLC, and triglyceride (TGL) levels among Uruguayan adolescents and assessed the role of body mass index (BMI) and sex as potential effect modifiers. Adolescents, 9-20-year-old (n = 327 in complete-case and 337 in imputed dataset) in Uruguay had blood As measured two times (T1 and T2), a year apart, during 2021–2023. Serum lipid markers were measured at T2. Blood As was averaged and log transformed. Separate linear regressions were built for each lipid marker. Analyses were stratified by sex and at 85th percentile of BMI to assess effect modification. Median (range) blood As at T1 and T2 were 0.38 (0.18, 4.01) µg/L and 0.36 (0.14, 4.81) µg/L, respectively. 8

Background: Metal exposures are increasingly recognized as a major risk factor for chronic diseases, yet very few prior studies have comprehensively characterized metal concentrations in the Caribbean. Objective: This study characterized urinary metal concentrations and their associations with demographic characteristics and other lifestyle factors among middle-aged and older Tobagonian adults. Methods: We quantified urinary concentrations of 18 metals and metalloids (referred to here as "metals") in 896 adults from a subsample of the Tobago Health Study, including 466 men and 430 women. Morning spot urine samples were collected from men in 2014-2016, and from women in 2019-2020. Metal concentrations were compared to studies of adults from other populations. Metal exposure risk factors included demographics, body composition, and lifestyle, including diet. We used sex-stratified partial least squares (PLS) regression to identify risk factors associated with metal concentrations. Results: Twelve metals including arsenic (As), barium (Ba), cadmium (Cd), cobalt (Co), cesium (Cs), copper (Cu), molybdenum (Mo), lead (Pb), tin (Sn), thallium (Tl), uranium (U) and zinc (Zn) were detected in >87% of participants in both men and women. Compared to other populations, Zn and Tl concentrations were higher among Tobagonian men and women. We observed distinct urinary metal concentration patterns among men and women that varied by age, education, body composition and lifestyle factors. SIGNIFICANCE: A mix of non-modifiable and modifiable risk factors associated with urinary metal concentrations were identified. These findings can inform future studies to identify vulnerable populations and tailor public health messaging to reduce exposure risk. Future research is needed to understand sex differences and how these exposures may contribute to adverse health outcomes. Impact: This study provides the first comprehensive characterization of urinary metal concentrations among middle-aged and older adults in Tobago, identifying both modifiable and non-modifiable factors associated with exposure. Twelve metals, including arsenic, cadmium, lead, and thallium, were detected in most participants, with some concentrations exceeding those reported in other populations. Distinct urinary metal concentration patterns that varied by demographics and lifestyle factors were observed among men and women. The exposure profiles of adults from Tobago can inform targeted public health strategies and lay the groundwork for future research on the health impacts of metal exposures in this understudied population.

Studies of non-occupational exposure to trace elements (TE) and semen quality have had inconsistent results, and few studies have accounted for temporal variability or TE mixtures. To help address the data gap, we quantified associations between seminal plasma (SP) trace element concentrations and sperm quality measures among male partners of in vitro fertilization patients. We collected semen samples from 27 male partners an average of 8.6 days prior to the day of oocyte retrieval (time 1), and from 35 male partners on the day of oocyte retrieval (time 2). We determined concentrations of 14 TEs in SP using inductively coupled plasma-tandem mass spectrometry. We used linear mixed-effects regression to estimate associations between individual TEs, expressed as the change in sperm quality between the 25th and 75th percentiles of trace element distributions, adjusted for age, days between specimen collections, racial identity, recent seafood consumption, and cigarette smoking. We used principal component analysis (PCA) to estimate associations with TE mixtures at time 2. We found positive associations between SP Se and sperm concentration (%change = 47.75%; 95% CI: 4.20, 85.65) and motile sperm concentration (%change = 44.30%; 95% CI: 5.10, 88.75), and similar associations for SP As (%change = 30.50%; 95% CI: 6.85, 54.15 and %change = 25.15%, 95% CI: 12.55, 30.35, respectively). The PCA mixture of higher SP Cd, As, and Mo and lower Cu and Se suggests a pattern of poor sperm quality, though the associations were not statistically significant. Our findings underscore the importance of considering temporal variability of seminal plasma TE concentrations and suggest potentially important associations between exposure to essential TEs and semen quality which should be targeted for further investigation, including Se and As.

Arsenic is among the most important environmental toxicants contributing to the global prevalence of hypertension. Multiple studies have reported a greater burden of hypertension among people of African ancestry, yet the contribution of environmental factors to this burden is unclear. Therefore, we investigated the association of arsenic exposure with increased risk of hypertension and high blood pressure in 965 Afro-Caribbean adults in the Tobago Health Study. Linear and logistic regression analyses were conducted for the total cohort and stratified by sex and age separately. We also examined potential effect modification by sex. Each unit (μg/L) increase in ΣAs was associated with 2% higher odds of hypertension in the total cohort and 4% higher odds among women. Higher ΣAs was associated with higher diastolic blood pressure and mean arterial pressure (MAP) among men. The associations of higher ΣAs with hypertension among women and with higher MAP among men were significant only in mid-life but not in older age. The data suggest effect modification by sex for the relationship between ΣAs and MAP in men. The findings suggest that exposure to inorganic arsenic contributes to age- and sex-specific patterns for greater risks of hypertension and high blood pressure among Afro-Caribbean adults.

BACKGROUND:Our goal was to evaluate the relationship between prenatal fluoride exposure and pregnancy outcomes. METHODS:We measured urinary fluoride collected during the second trimester among pregnant people recruited from California and Illinois from 2014 to 2020 (N = 949). We evaluated risk differences (RDs) of preterm birth (PTB), small-for-gestational age (SGA), large-for-gestational age (LGA), gestational diabetes, and differences in birthweight, birthweight-for-gestational age z-scores, and gestational age associated with a 0.1 mg/l increase in fluoride using linear regression to estimate effects on the additive scale. We also used modified treatment policies with machine learning to estimate the effects of hypothetical interventions to reduce urinary fluoride by 0.1 and 0.5 mg/l on pregnancy outcomes. In the Illinois cohort, we estimated effects by trimester. RESULTS:In our main analyses, we found no associations between urinary fluoride levels and pregnancy outcomes. For instance, for a 0.1 mg/l increase in fluoride, we saw no change in the risk of PTB, SGA, or gestational diabetes. We also found no differences associated with hypothetical reductions of prenatal fluoride by 0.1 mg/l or 0.5 mg/l for any outcomes. In the trimester-specific analyses for Illinois participants, we found increased LGA risk during the first (RD = 0.004, 95% CI -0.001, 0.009) and third trimesters (RD = 0.007, 95% CI 0.001, 0.012), and reduced LGA risk during the second trimester (RD = -0.006, 95% CI -0.011, 0.000), associated with 0.1 mg/l higher urinary fluoride. CONCLUSIONS:Prenatal fluoride exposure does not appear to affect pregnancy outcomes, but preliminary evidence suggests that higher fluoride levels may affect the risk of LGA depending on timing of exposure during pregnancy.

While essential trace minerals are known to influence DNA methylation (DNAm), molybdenum's (Mo) role in epigenetic regulation remains largely unexplored. This study examined associations between Mo status and DNAm of the brain-derived neurotrophic factor (BDNF) gene, a critical regulator of neurogenesis, in children aged 9-11 years, focusing on 107 CpG sites across BDNF and its antisense transcript (BDNF-AS).BDNF and BDNF-AS methylation was analyzed in blood samples from 72 children randomly selected from a cohort of 292 participants. Dietary Mo intake was estimated from food records, and creatinine-adjusted urinary Mo levels were quantified. Higher urinary molybdenum was significantly associated with decreased methylation at five BDNF 5'UTR sites (p<.05) and increased methylation of BDNF-AS (p =  .0001), consistent with enhanced BDNF transcriptional activity. African American children exhibited lower urinary Mo excretion than European American children, suggesting greater retention, and showed cortisol-associated increases in BDNF methylation not observed in European American children.These findings demonstrate associations between molybdenum status and DNA methylation patterns at the BDNF locus in children. While functional validation through BDNF protein measurement is needed, results suggest molybdenum may influence neurotrophin gene regulation through epigenetic mechanisms, highlighting the importance of trace mineral nutrition during neurodevelopment.

BACKGROUND:Prenatal exposure to chemical mixtures may have greater fetal health impacts than single chemicals due to complex, interacting biological mechanisms. Hydroxylated polycyclic aromatic hydrocarbon metabolites (OH-PAHs) and metals/metalloids share exposure sources, yet evidence of their combined effects on perinatal outcomes is limited. OBJECTIVE:To examine associations between individual cotinine, OH-PAHs, and metals/metalloids and birth weight, and to investigate their overall and interactive effects. METHODS:We included 1120 mothers from the Maternal and Infant Environmental Health Riskscape (MIEHR) study in Houston, Texas. A large suite of chemical constituents, including cotinine, six OH-PAHs, and 18 metals/metalloids, was measured in spot urine samples collected at delivery. Birth weight, abstracted from medical records, was converted into z-scores standardized by gestational age and sex. Linear regression was employed to examine associations between each constituent and birth weight, adjusted for covariates. Bayesian kernel machine regression (BKMR) was used to evaluate individual, joint, and interactive effects of multiclass chemical mixture on birth weight. RESULTS:Based on the BMKR analysis, no overall mixture effect on birth weight was observed. The exposure-response functions showed no clear patterns between OH-PAHs and birth weight. After accounting for the other constituents in the mixture, molybdenum, thallium, and strontium were negatively associated with birth weight, whereas barium and tungsten were positively associated. In comparing the 75th versus 25th percentiles of the distribution with other constituents fixed at their median levels, the strongest associations were observed for molybdenum and barium with a change in birth weight z-scores of -0.12 (95% credible interval: -0.23, -0.01) and 0.14 (0.02, 0.27), respectively. No interactions between individual mixture constituents were identified. SIGNIFICANCE:In the MIEHR study, with relatively lower urinary OH-PAH and metals/metalloids concentrations compared with women from other U.S. pregnancy cohorts, molybdenum was associated with decreased birth weight, and barium with increased birth weight. Given that both metals are relatively understudied, additional investigation is warranted. IMPACT:Few studies have examined associations between prenatal exposure to mixtures of PAH metabolites and birth weight, particularly in combination with metals/metalloids, despite shared exposure sources and potential biological mechanisms. We found heterogeneous associations for specific PAH metabolites and metals, most notably molybdenum and barium, revealing complex environmental chemical effects on birth weight within a mixture framework. Given pregnant women's simultaneous exposure to sources from industry and traffic and beneficial trace elements, our findings underscore the need to consider co-exposure effects to better integrate the effects of constituents on infant health and inform public health surveillance.

Exposure to elements such as arsenic, cadmium, lead, and mercury, which are associated with cancer, cardiovascular disease, and kidney disease, are not well-studied in Central American populations. We evaluated differences in urine metal(loid) concentrations by dietary/behavioral, occupational, and geographic factors within a cohort of adult male workers in El Salvador in the MesoAmerican Nephropathy Occupational Study (MANOS). We measured spot urinary concentrations of 14 metal(loid)s and speciated arsenic in 194 participants in 2021. We compared concentrations in our study to the US National Health and Nutrition Examination Survey (NHANES) data. We used multiple linear regression to examine known metal(loid) exposure sources (e.g. smoking and seafood consumption) and the role of occupational and geographic-related predictors (e.g. industry and region) in association with urinary metal(loid) concentrations. We detected 13 of 14 metal(loid)s and all targeted biomarkers of arsenic species in participants' urine samples, with detection frequencies ranging from 4-100%. Compared to NHANES data, MANOS participants had significantly higher (p<0.05) median concentrations (& micro;g/L) of all arsenic species (sum of inorganic arsenic species 10 vs. 54), cobalt (0.39 vs. 0.030), and thallium (0.27 vs. 0.20), while molybdenum and uranium were significantly lower in MANOS (35 vs. 49 and 0.0035 vs. 0.75, respectively). Arsenobetaine concentrations were 140% higher (95% CI: 58, 260%) in recent seafood consumers. Among smokers, cadmium and lead were 57% (95% CI: 21, 102) and 38% higher (95% CI: 3, 85), respectively. The sum of inorganic arsenic species was 48% higher (95% CI: 24, 77), while mercury and lead were-30% (95% CI:-48,-6.4) and-43% (95% CI:-59,-22) lower in sugarcane workers compared to corn workers. Compared to participants with normal kidney function, indicated by estimated glomerular filtration rate (eGFR) >90 ml/min/1.73m(2), participants with higher Ba, Cs, Pb, and Tl concentrations had lower kidney function, while those with higher Mn and U had higher kidney function. Findings suggest dietary, renal, and workplace factors influence some metal(loid) exposures in El Salvador. Understanding sources of metal(loid) concentrations may help identify strategies to reduce exposures and accompanying health risks.

In this work, a proof of concept is provided that shows the potential for automating total mercury and mercury speciation analysis in whole blood.

Background:Non-Hispanic Black women have almost double the risk of preterm birth compared with non-Hispanic White women in the United States, and the disparity is not fully explained by sociodemographic factors, health behaviors, or medical factors. Thus, it is critical to look beyond these "traditional" risk factors and evaluate contributions from psychosocial stressors, chemical exposures, and features of residential environments where pregnant women live. Methods:This study was conducted among 1,847 Black and White women recruited at the time of delivery between 2021 and 2023 in greater Houston, Texas to examine the contribution of individual- and neighborhood-level factors to the Black/White disparity in preterm birth using two-fold Blinder-Oaxaca decomposition. We evaluated the contribution from variables within the following domains: sociodemographics; perinatal history; comorbidities and health behaviors; chemical exposures; social factors; and neighborhood characteristics. We present the results as percent contributions to the disparity for each covariate and by domain. Results:With a 6.6% higher prevalence of preterm birth among Black mothers compared with White mothers, variables included in our decomposition analysis explained 63.0% of the preterm birth disparity, with perinatal history explaining the highest proportion (36.3%), followed by neighborhood characteristics (32.8%). Individual variables with the highest contributions included residing in a more racially minoritized and economically disadvantaged neighborhood (19.2%) and having a previous pregnancy complication (18.5%), a hypertensive disorder in the index pregnancy (16.7%), or chronic hypertension before pregnancy (16.8%). Conclusion:Our study underscores the importance of perinatal history and neighborhood factors in explaining disparities in preterm birth, which should be further explored in other populations.

BACKGROUND:Chronic kidney disease of unknown etiology (CKDu) is a major health concern among outdoor manual workers in rural Central America and South Asia. The CURE study is a prospective longitudinal cohort designed to investigate CKDu's environmental risk factors through standardized exposure assessments, questionnaires, and biological and environmental sample collection. METHODS:This manuscript details the development of a standardized exposure assessment protocol within the CKDu CURE Consortium. The study recruits adults (18-45 years) from CKDu hotspots across five countries, ensuring proportional representation across three eGFR categories (20-59, 60-89, ≥90 mL/min/1.73m2) and excluding participants with diabetes or other known CKD causes. The CURE study is committed to promptly returning clinically and environmentally relevant test results to participants after analysis. RESULTS:Exposure assessment includes demographics, healthcare access, nephrotoxic medications, infectious pathogens, and agricultural work conditions (e.g., heat stress, hydration, diet, agrochemicals, toxicants). Biological and environmental samples (water, dust, soil, wristbands) are collected considering seasonal variations. Omics analyses, including metabolomics, will investigate environmental and biological interactions. Statistical analyses will assess relationships between exposures and CKDu onset or progression, incorporating environmental mixture analyses. CONCLUSION:CURE will provide critical insights into CKDu risk factors, supporting future research and prevention strategies. A comprehensive exposure assessment will enhance understanding of environmental contributors, guiding interventions at individual, workplace, and community levels to mitigate CKDu's impact.

Human biomonitoring (HBM) provides an integrated chemical exposures assessment considering all routes and sources of exposure. The accurate interpretation and comparability of biomarkers of exposure and effect depend on harmonized, quality-assured sampling, processing, and analysis. Currently, the lack of broadly accepted guidance on minimum information required for collecting and reporting HBM data, hinders comparability between studies. Furthermore, it prevents HBM from reaching its full potential as a reliable approach for assessing and managing the risks of human exposure to chemicals.The European Chapter of the International Society of Exposure Science HBM Working Group (ISES Europe HBM working group) has established a global human biomonitoring community network (HBM Global Network) to develop a guidance to define the minimum information to be collected and reported in HBM, called the “Minimum Information Requirements for Human Biomonitoring (MIR-HBM)”. This work builds on previous efforts to harmonize HBM worldwide.The MIR-HBM guidance covers all phases of HBM from the design phase to the effective communication of results. By carefully defining MIR for all phases, researchers and health professionals can make their HBM studies and programs are robust, reproducible, and meaningful. Acceptance and implementation of MIR-HBM Guidelines in both the general population and occupational fields would improve the interpretability and regulatory utility of HBM data. While implementation challenges remain—such as varying local capacities, and ethical and legal differences at the national levels, this initiative represents an important step toward harmonizing HBM practice and supports an ongoing dialogue among policymakers, legal experts, and scientists to effectively address these challenges. Leveraging the data and insights from HBM, policymakers can develop more effective strategies to protect public health and ensure safer working environments.

Two common mercury species (inorganic mercury and methylmercury) found in blood can be separated in under 5 mins on a C8 column and detected at levels below 1 μg L −1 by vapor generation coupled to ICP-MS/MS.

Monochromatic excitation (M-) based on a low-power X-ray (20-50W) source with doubly curved crystal (DCC) optics has been used successfully for X-ray fluorescence (XRF) analysis of many different sample matrices. Previously, a "first-generation" M-XRF analyzer, the HD Mobile (R) (X-ray Optical Systems, (XOS) East Greenbush NY), was used in a field-based public health study. The HD Mobile (R) was optimized to detect Pb, Cd, Hg and As in consumer products, food, and cultural medications, with limits of detection (LOD) on the order of a single digit mu g/g (ppm) mass fraction. In this current study, two "second generation" DCC-enabled XRF analyzers were evaluated for detecting key toxic elements in food matrices. The two instruments evaluated included: the ZmaxTM XRF Analyzer and the EmaxTM Analyzer, which are both manufactured by Z-Spec (East Greenbush, NY, US). The ZmaxTM uses an X-ray tube operated at 35W with a single DCC optic for a 17.5-keV excitation beam optimized to detect Pb, As, Hg, Ni and Cr. A fast silicon drift detector (SDD) is used to detect fluorescence x-rays. The EmaxTM uses an X-ray tube operated at 40 W with DCC optics for a 30-keV excitation beam, and a thicker 1-mm SDD optimized to detect Cd, Mo, Sb, and Sn, along with many other elements. While the primary focus of the current study was the EmaxTM and ZmaxTM, several other XRF analyzers were available and were included for comparison purposes. They included the HD Mobile (R) (XOS), and two 'conventional' portable XRF analyzers: the NitonTM XL3t GOLDD XRF, and the NitonTM XL5 Plus, both manufactured by ThermoFisher Scientific (Tewksbury, MA). Z-Spec used certified reference materials (CRMs) to optimize the Fundamental Parameters algorithm for the ZmaxTM and EmaxTM analyzers to achieve acceptable performance for key toxic elements in biological matrices. For the ZmaxTM, difference plots show good agreement between found values and CRM assigned values for the elements studied (Pb, As, Cu, Mn, Ni, Hg and Zn). For the EmaxTM, there was good agreement for values obtained for Cd in CRMs. Archived food-based proficiency test (PT) samples were analyzed to assess the performance of the ZmaxTM and EmaxTM as screening tools to detect key elements. Some of the PT samples were also analyzed using the two NitonTM XRF instruments as well as the HD Mobile (R) for comparison purposes. These PT samples were spiked with toxic elements and circulated by the FDA to US-based public health laboratories funded under the Food Emergency Response Network (FERN), with target values assigned based on consensus data obtained from analyses based on Inductively Coupled Plasma Mass Spectrometry (ICP-MS). For the FERN 2022 PT samples (sausage meat), which were spiked with Tl, Cd and Pb, ZmaxTM values were within the tolerance range required for ICP-MS analysis. Estimated LODs in mu g/g (ppm) were: Pb, 0.06; Tl, 0.06; Hg, 0.06; Cd, 0.04; and Sn, 0.11. Several 'real-world' samples were analyzed using the ZmaxTM and EmaxTM devices, including medicinal herbs such as moringa and pot marigold, as well as various spices like cloves, coriander, and curry.

INTRODUCTION:Low-level arsenic (As) exposure is linked to cognitive deficits, but its impact on specific executive functions (EF) in adolescents is not well understood. Additionally, neighborhood socioeconomic context may interact with As exposure to influence cognitive outcomes. This study examines associations between blood As levels, neighborhood disadvantage, and EF performance in adolescents from Montevideo, Uruguay. METHODS:We analyzed data from 344 adolescents in the Salud Ambiental Montevideo (SAM) cohort, where blood As levels were measured at two time points, with values averaged and log2-transformed for analysis. EFs, including working memory, inhibitory control, cognitive flexibility, and fluid cognition, were assessed using the NIH Cognitive Toolbox. Neighborhood disadvantage (ND) was represented as a factor encompassing sociodemographic indicators. Multiple imputation was used to handle missing data, and linear regression models tested associations between As exposure, EFs, and potential interactions with ND. Furthermore, we explored effect modification by age (young adolescents <11.6 years, older adolescents ≥11.6 years). RESULTS:Based on multivariable models, there was no evidence for an association between blood As and EFs or fluid cognition or of interactions with neighborhood disadvantage. Exploratory analyses revealed evidence of effect modification by age, with inverse associations between As exposure and inhibitory control and working memory at younger ages. CONCLUSION:There was no evidence for an association between low-level blood As and EFs in adolescents overall, but age-related susceptibility to As was suggested for younger ages. Further research on low-level As exposure in adolescents is needed to better understand critical windows of susceptibility and socioeconomic contexts for neurotoxic effects of As.

BACKGROUND:Manganese (Mn) is essential in growth and development, yet higher levels of Mn are associated with deficits in neurodevelopment. Elevated air Mn was identified near Mn alloy processing facilities in Southeast Side Chicago resulting in community concern about child exposure and health. METHODS:Blood, hair, and soil samples were collected and analyzed for multiple metals for children ages 7-17 years and a parent/primary caregiver completed surveys. We used generalized estimating equations to assess associations between metals and the Adaptive Behavior Assessment System 3rd Edition (ABAS-3) scores. Sensitivity analyses were conducted to determine effect modification by child sex on associations between metals and ABAS-3 scores. Bayesian kernel machine regression was used as our principal analytic framework to assess the associations between metal mixtures and adaptive behaviors. RESULTS:The analyses included 108 children. Residential distance from the nearest Mn industrial source was inversely correlated with soil Mn levels and some were above the federal screening level. A significant association was found between soil Mn and lower ABAS-3 score (β: 3.78, 95 % CI: 7.31, -0.25), and between blood Mn and lower scores in females (β: 11.8, 95 % CI: 21.7, -1.87). ABAS-3 scores were negatively associated with the blood metals mixture, primarily driven by Mn. CONCLUSION:Children in Southeast Side Chicago have elevated levels of soil Mn and soil Mn was associated with poorer ABAS-3 scores. Sex-specific differences were found between metal levels and ABAS-3 scores. After considering multiple metals in mixture, Mn was the primary driver of poorer adaptive behavior.

Exposure to trace elements and per- and polyfluoroalkyl substances (PFAS) during pregnancy is linked to adverse reproductive and developmental outcomes. High smoking rates in western Pennsylvania may influence exposure to these chemicals. We characterized PFAS, trace element, and smoking exposure in the second trimester of pregnancy among women in western Pennsylvania. We measured 38 urine trace elements and 11 serum PFAS in 46 pregnant women in 2017–2021 as part of a nested pilot study from the Magee Obstetric Maternal and Infant (MOMI) biobank and database. We statistically compared environmental chemical concentrations between smoking and non-smoking participants in the MOMI pilot study. Additionally, we descriptively compared MOMI concentrations to a nationally representative sample of US women of reproductive age from the National Health and Nutrition Examination Survey (NHANES) and to published studies characterizing exposures among international populations. Two PFAS (PFOA and PFOS) and 16 trace elements were highly detected in the MOMI pilot study sample. Smoking participants had distributions of 10 trace element concentrations that tended to be significantly higher compared to non-smoking participants, but no significant differences in the distributions of serum PFAS concentrations. All participants had summed PFAS concentrations > 2 μg/L—the National Academies of Sciences Engineering and Medicine threshold for recommending additional health screening. MOMI non-smoking participants had higher concentrations of seven trace elements and lower concentrations of both PFAS compared with NHANES non-smoking participants, while MOMI smoking participants had higher concentrations of 12 trace elements and lower concentrations of both PFAS compared with NHANES smoking participants. Further research is necessary to identify the sources of exposure, potential health effects, and effective strategies to reduce exposure to these environmental chemicals.