Child and Adolescent Manganese Biomarkers and Adolescent Postural Balance in Marietta CARES Cohort Participants

BACKGROUND

Manganese (Mn) plays a significant role in both human health and global industries. Epidemiological studies of exposed populations demonstrate a dose-dependent association between Mn and neuromotor effects ranging from subclinical effects to a clinically defined syndrome. However, little is known about the relationship between early life Mn biomarkers and adolescent postural balance.

OBJECTIVES

This study investigated the associations between childhood and adolescent Mn biomarkers and adolescent postural balance in participants from the longitudinal Marietta Communities Actively Researching Exposures Study (CARES) cohort.

METHODS

Participants were recruited into CARES when they were 7-9 y old, and reenrolled at 13-18 years of age. At both time points, participants provided samples of blood, hair, and toenails that were analyzed for blood Mn and lead (Pb), serum cotinine, hair Mn, and toenail Mn. In adolescence, participants completed a postural balance assessment. Greater sway indicates postural instability (harmful effect), whereas lesser sway indicates postural stability (beneficial effect). Multivariable linear regression models were conducted to investigate the associations between childhood and adolescent Mn biomarkers and adolescent postural balance adjusted for age, sex, height-weight ratio, parent/caregiver intelligence quotient, socioeconomic status, blood Pb, and serum cotinine.

RESULTS

CARES participants who completed the adolescent postural balance assessment (n = 123 ) were 98% White and 54% female and had a mean age of 16 y (range: 13-18 y). In both childhood and adolescence, higher Mn biomarker concentrations were significantly associated with greater adolescent sway measures. Supplemental analyses revealed sex-specific associations; higher childhood Mn biomarker concentrations were significantly associated with greater sway in females compared with males.

DISCUSSION

This study found childhood and adolescent Mn biomarkers were associated with subclinical neuromotor effects in adolescence. This study demonstrates postural balance as a sensitive measure to assess the association between Mn biomarkers and neuromotor function. https://doi.org/10.1289/EHP13381.

Associations between follicular fluid trace elements and ovarian response during in vitro fertilization

INTRODUCTION

Exposure to trace elements has been associated with ovarian response in experimental studies. We conducted a hypothesis-generating study of associations between ovarian follicular fluid (FF) trace elements and measures of ovarian response among women using in vitro fertilization (IVF).

METHODS

We collected ovarian FF specimens from 56 women. We determined concentrations (μg/L) of 11 trace elements using inductively coupled plasma-tandem mass spectrometry. We estimated associations between women's FF trace elements per interquartile range difference, and measures of ovarian response using linear (peak estradiol (E2), baseline anti-mullerian hormone (AMH), and follicle stimulating hormone (FSH)) and negative binomial (baseline antral follicle count (AFC) and oocyte count) regression, adjusting for confounding factors. We used principal component analysis (PCA) to estimate the associations of the FF trace elements mixture. We also explored FF oxidative stress enzymes as causal mediators of the associations.

RESULTS

Higher FF cobalt was associated with greater peak E2 (mean difference = 351.48 pg/mL; 95%CI: 21.76, 724.71) and AFC (rate ratio = 1.14; 95%CI: 1.01, 1.28), and higher FF copper was associated with greater peak E2 (mean difference = 335.66 pg/mL; 95%CI: 81.77, 753.08) and oocyte count (rate ratio = 1.19; 95%CI: 1.02, 1.43). Higher FF mercury was also associated with greater peak E2 (mean difference = 410.70 pg/mL; 95%CI: 61.90, 883.39). Higher FF lead was associated with lesser AFC (rate ratio = 0.85; 95%CI: 0.73, 0.98). Using PCA, the mixture of Sr, Hg, and As was associated with higher peak estradiol, AFC, and oocyte count. FF glutathione peroxidase, paraoxonase, and arylesterase activities were inconsistent mediators of the associations, but the effect estimates were imprecise.

CONCLUSION

Our results suggest that essential and non-essential trace elements in FF were associated with ovarian response during IVF.

Early childhood exposure to environmental phenols and parabens, phthalates, organophosphate pesticides, and trace elements in association with attention deficit hyperactivity disorder (ADHD) symptoms in the CHARGE study

BACKGROUND

A growing body of literature investigated childhood exposure to environmental chemicals in association with attention-deficit/hyperactivity disorder (ADHD) symptoms, but limited studies considered urinary mixtures of multiple chemical classes. This study examined associations of concurrent exposure to non-persistent chemicals with ADHD symptoms in children diagnosed with autism spectrum disorder (ASD), developmental delay (DD), and typical development (TD).

METHODS

A total of 549 children aged 2-5 years from the Childhood Autism Risks from Genetics and Environment (CHARGE) case-control study were administered the Aberrant Behavior Checklist (ABC). This study focused on the ADHD/noncompliance subscale and its two subdomains (hyperactivity/impulsivity, inattention). Sixty-two chemicals from four classes (phenols/parabens, phthalates, organophosphate pesticides, trace elements) were quantified in child urine samples, and 43 chemicals detected in > 70% samples were used to investigate their associations with ADHD symptoms. Negative binomial regression was used for single-chemical analysis, and weighted quantile sum regression with repeated holdout validation was applied for mixture analysis for each chemical class and all chemicals. The mixture analyses were further stratified by diagnostic group.

RESULTS

A phthalate metabolite mixture was associated with higher ADHD/noncompliance scores (median count ratio [CR] = 1.10; 2.5th, 97.5th percentile: 1.00, 1.21), especially hyperactivity/impulsivity (median CR = 1.09; 2.5th, 97.5th percentile: 1.00, 1.25). The possible contributors to these mixture effects were di-2-ethylhexyl phthalate (DEHP) metabolites and mono-2-heptyl phthalate (MHPP). These associations were likely driven by children with ASD as these were observed among children with ASD, but not among TD or those with DD. Additionally, among children with ASD, a mixture of all chemicals was associated with ADHD/noncompliance and hyperactivity/impulsivity, and possible contributors were 3,4-dihydroxy benzoic acid, DEHP metabolites, MHPP, mono-n-butyl phthalate, and cadmium.

CONCLUSIONS

Early childhood exposure to a phthalate mixture was associated with ADHD symptoms, particularly among children with ASD. While the diverse diagnostic profiles limited generalizability, our findings suggest a potential link between phthalate exposure and the comorbidity of ASD and ADHD.

Placental cellular composition and umbilical cord tissue metal(loid) concentrations: A descriptive molecular epidemiology study leveraging DNA methylation

The placenta is a mixture of cell types, which may regulate maternal-fetal transfer of exogenous chemicals or become altered in response to exposures. We leveraged placental DNA methylation to characterize major constituent cell types and applied compositional data analysis to test associations with non-essential metal(loid)s measured in paired umbilical cord tissue (N = 158). Higher proportions of syncytiotrophoblasts were associated with lower arsenic, whereas higher proportions of Hofbauer cells were associated with higher cadmium concentrations in umbilical cords. These findings suggest that placental cellular composition influences amounts of metal(loid)s transferred to the fetus or that prenatal exposures alter the placental cellular makeup.

Perfluoroalkyl substances (PFAS) and lead (Pb) as "cardiovascular disruptors" in 9-11-year-old children living in Syracuse, New York, United States

OBJECTIVE

Per- and polyfluoro-alkyl substances (PFAS) and lead (Pb) are ubiquitous environmental toxicants with apparent impact on cardiovascular disease (CVD) risk. As one possible mechanism for this increased risk, we have previously demonstrated an association between Pb exposure and heightened cardiovascular reactivity to acute psychological stress, a CVD risk factor. The present study expands this approach and considers both PFAS and Pb exposures (and the possible interaction).

METHODS

We assessed 14 serum PFAS and whole blood Pb concentrations in a sample of 9-11 year-old children (N = 291; 43.2% White, 56.8% Black; 53.5% female). We measured cardiovascular functioning at rest and during psychological stress as well as multiple indicators of subclinical CVD including resting blood pressure (BP), carotid-femoral pulse wave velocity (cfPWV), carotid intima-media thickness (cIMT), and left ventricular mass (LVM). Data analysis included general linear modeling as well as a non-parametric approach to study metal mixtures, specifically Bayesian Kernel Machine Regression (BKMR).

RESULTS

Significant interactions between different PFAS and with Pb suggest the importance of considering toxicant mixtures when assessing potential disruption of the cardiovascular system. The pattern of findings suggests that greater "vascular reactivity" (elevated BP and vascular resistance during acute psychological stress) was associated with higher concentrations of perfluorononanoic acid (PFNA), perfluorohexane sulfonate (PFHxS), and Pb, but only when perfluorooctanoic acid (PFOA) was concurrently elevated. With respect to subclinical outcomes, increasing perfluorodecanoic acid (PFDA) was associated with greater cIMT (β = 0.21, p = 0.010).

CONCLUSION

To our knowledge this is the first study to consider how PFAS exposures might affect cardiovascular functioning and subclinical disease. Although a complex pattern of associations emerged, it does appear that PFAS and Pb can be classified as "cardiovascular disruptors" in children. Further research is needed to replicate these novel findings and determine whether these disruptions produce future cardiovascular disease.

Prenatal Metal Exposure Alters the Placental Proteome in a Sex-Dependent Manner in Extremely Low Gestational Age Newborns: Links to Gestational Age

Prenatal exposure to toxic metals is associated with altered placental function and adverse infant and child health outcomes. Adverse outcomes include those that are observed at the time of birth, such as low birthweight, as well as those that arise later in life, such as neurological impairment. It is often the case that these adverse outcomes show sex-specific responses in relation to toxicant exposures. While the precise molecular mechanisms linking in utero toxic metal exposures with later-in-life health are unknown, placental inflammation is posited to play a critical role. Here, we sought to understand whether in utero metal exposure is associated with alterations in the expression of the placental proteome by identifying metal associated proteins (MAPs). Within the Extremely Low Gestational Age Newborns (ELGAN) cohort (n = 230), placental and umbilical cord tissue samples were collected at birth. Arsenic (As), cadmium (Cd), lead (Pb), selenium (Se), and manganese (Mn) concentrations were measured in umbilical cord tissue samples via ICP-MS/MS. Protein expression was examined in placental samples using an LC-MS/MS-based, global, untargeted proteomics analysis measuring more than 3400 proteins. MAPs were then evaluated for associations with pregnancy and neonatal outcomes, including placental weight and gestational age. We hypothesized that metal levels would be positively associated with the altered expression of inflammation/immune-associated pathways and that sex-specific patterns of metal-associated placental protein expression would be observed. Sex-specific analyses identified 89 unique MAPs expressed in female placentas and 41 unique MAPs expressed in male placentas. Notably, many of the female-associated MAPs are known to be involved in immune-related processes, while the male-associated MAPs are associated with intracellular transport and cell localization. Further, several MAPs were significantly associated with gestational age in males and females and placental weight in males. These data highlight the linkage between prenatal metal exposure and an altered placental proteome, with implications for altering the trajectory of fetal development.

Exposure to Arsenic and Subclinical Cardiovascular Disease in 9- to 11-Year-Old Children, Syracuse, New York

Importance

Studies in adults have demonstrated associations between arsenic exposure and clinical and subclinical cardiovascular disease (CVD). No studies to date have considered potential associations in children.

Objective

To examine the association between total urinary arsenic levels in children and subclinical indicators of CVD.

Design, Setting, and Participants

This cross-sectional study considered 245 children, a subset from the Environmental Exposures and Child Health Outcomes (EECHO) cohort. Children from the Syracuse, New York, metropolitan area were recruited from August 1, 2013, until November 30, 2017, with enrollment throughout the year. Statistical analysis was performed from January 1, 2022, to February 28, 2023.

Exposures

Total urinary arsenic was measured using inductively coupled plasma mass spectrometry. Creatinine concentration was used to adjust for urinary dilution. In addition, potential exposure routes (eg, diet) were measured.

Main Outcomes and Measures

Three indicators of subclinical CVD were assessed: carotid-femoral pulse wave velocity, carotid intima media thickness, and echocardiographic measures of cardiac remodeling.

Results

The study sample included 245 children aged 9 to 11 years (mean [SD] age, 10.52 [0.93] years; 133 [54.3%] female). The geometric mean of the creatinine-adjusted total arsenic level in the population was 7.76 μg/g creatinine. After adjustment for covariates, elevated total arsenic levels were associated with significantly greater carotid intima media thickness (β = 0.21; 95% CI, 0.08-0.33; P = .001). In addition, echocardiography revealed that elevated total arsenic was significantly higher for children with concentric hypertrophy (indicated by greater left ventricular mass and greater relative wall thickness; geometric mean, 16.77 μg/g creatinine; 95% CI, 9.87-28.79 μg/g) relative to the reference group (geometric mean, 7.39 μg/g creatinine; 95% CI, 6.36-8.58 μg/g). With respect to exposure source, significant geographic clustering of total arsenic was found in 1 urban area of Syracuse, New York.

Conclusions and Relevance

These findings suggest a significant association between arsenic exposure and subclinical CVD in children. Elevated total arsenic levels were found in an area of Syracuse with known elevations of toxic metals from industrial waste, suggesting historical pollution as a possible source. Given the novelty and potential importance of this association, further research is needed to confirm our findings. Any potential effect of urinary arsenic exposure in childhood on actual clinical CVD outcomes in adulthood remains to be determined.

Airborne levels of cadmium are correlated with urinary cadmium concentrations among young children living in the New York state city of Syracuse, USA

Air pollution is a serious public health issue with early childhood exposure being of high concern because of the greater risk that children might experience negative health outcomes. Industrial sources in and near communities are one potential path of exposure that children might face with greater levels of air pollution correlating with higher levels of toxicants detected in children. We compare estimated ambient air concentrations of Cadmium (Cd) to a cohort (n = 281) of 9 to 11-year old children during their early childhood years (0-5 years of age) in a mid-size city in Upstate New York. Levels of Cd air pollution are compared to children's urine-Cd levels. Urine has been shown to be a superior biomarker to blood for Cd exposure particularly for longer-term exposures. We find that participants who reside in households that faced greater Cd air pollution during the child's early years have higher urine-Cd levels. This association is stable and stronger than previously presented associations for blood-Cd. Findings support expanded use of air modelling data for risk screening to reduce the potential health burden that industrial pollution can have.

Early childhood exposure to environmental phenols and parabens, phthalates, organophosphate pesticides, and trace elements in association with attention deficit hyperactivity disorder (ADHD) symptoms in the CHARGE study

Background

Agrowing body of literature investigated childhood exposure to environmental chemicals in association with attention deficit hyperactivity disorder (ADHD) symptoms, but limited studies considered urinary mixtures of multiple chemical classes. This study examined associations of concurrent exposure to non-persistent chemicals with ADHD symptoms in children diagnosed with autism spectrum disorder (ASD), developmental delay, and typical development.

Methods

A total of 574 children aged 2-5 years from the Childhood Autism Risks from Genetics and Environment (CHARGE) case-control study was administered the Aberrant Behavior Checklist (ABC). This study focused on the Hyperactivity subscale and its two subdomains (hyperactivity/impulsivity, inattention). Sixty-two chemicals from four classes (phenols/parabens, phthalates, organophosphate pesticides, trace elements) were quantified in child urine samples, and 43 chemicals detected in >70% samples were used in statistical analyses. Weighted quantile sum regression for negative binomial outcomes with repeated holdout validation was performed to investigate covariate-adjusted associations between mixtures and ABC scores in 574 children. The mixture analyses were further restricted to 232 children with ASD.

Results

Phthalate metabolite mixtures, weighted for mono-n-butylphthalate (MNBP), mono-2-heptyl phthalate, and mono-carboxy isononyl phthalate, were associated with the Hyperactivity subscale (mean incidence rate ratio [mIRR] = 1.11; 2.5th, 97.5th percentile: 1.00, 1.23), especially the hyperactivity/impulsivity subdomain (mIRR = 1.14; 2.5th, 97.5th percentile: 1.06, 1.26). These associations remained similar after restricting to children with ASD. The inattention subdomain was associated with a phenols/parabens mixture, weighted for several parabens and bisphenols (mIRR = 1.13; 2.5th, 97.5th percentile: 1.00, 1.28) and a total mixture, weighted for 3,4-dihydroxy benzoic acid, MNBR and mono-(2-ethyl-5-carboxypentyl) phthalate (mIRR = 1.11; 2.5th, 97.5th percentile: 1.01,1.25) only among children with ASD.

Conclusions

Concurrent exposure to phthalate mixtures was associated with hyperactivity in early childhood. Though causal inference cannot be made based on our cross-sectional findings, this study warrants further research on mixtures of larger number of chemicals from multiple classes in association with ADHD-related behaviors in young children.

Metal mixtures modeling identifies birth weight-associated gene networks in the placentas of children born extremely preterm

Prenatal exposure to toxic metals is linked to numerous adverse birth and later-in-life outcomes. These outcomes are tied to disrupted biological processes in fetal-derived tissues including the placenta and umbilical cord yet the precise pathways are understudied in these target tissues. We set out to examine the relationship between metal concentrations in umbilical cord and altered gene expression networks in placental tissue. These novel relationships were investigated in a subset of the Extremely Low Gestational Age Newborn (ELGAN) cohort (n = 226). Prenatal exposure to 11 metals/metalloids was measured using inductively coupled plasma tandem-mass spectrometry (ICP-MS/MS) in cord tissue, ensuring passage through the placental barrier. RNA-sequencing was used to quantify >37,000 mRNA transcripts. Differentially expressed genes (DEGs) were identified with respect to each metal. Weighted gene co-expression analysis identified gene networks modulated by metals. Two innovative mixtures modeling techniques, namely principal components analysis and quantile-based g-computation, were employed to identify genes/gene networks associated with multi-metal exposure. Individually, lead was associated with the strongest genomic response of 191 DEGs. Joint lead and cadmium exposure was related to 657 DEGs, including DNA Methyl Transferase 1 (DNMT1). These genes were enriched for the Eukaryotic Initiation Factor 2 (EIF2) pathway. Four gene networks, each containing genes within a Nuclear Factor kappa-light-chain-enhancer of Activated B Cells (NF-kB)-mediated network, were significantly increased in average expression level in relation to increases in all metal concentrations. All four of these metal mixture-associated gene networks were negatively correlated with important predictors of neonatal health including birth weight, placenta weight, and fetal growth. Bringing together novel methodologies from epidemiological mixtures analyses and toxicogenomics, applied to a unique cohort of extremely preterm children, the present study highlighted critical genes and pathways in the placenta dysregulated by prenatal metal mixtures. These represent potential mechanisms underlying the developmental origins of metal-induced disease.

The Inflammation Biomarker GlycA Reflects Plasma N-Glycan Branching

BACKGROUND

GlycA is a nuclear magnetic resonance (NMR) signal in plasma that correlates with inflammation and cardiovascular outcomes in large data sets. The signal is thought to originate from N-acetylglucosamine (GlcNAc) residues of branched plasma N-glycans, though direct experimental evidence is limited. Trace element concentrations affect plasma glycosylation patterns and may thereby also influence GlycA.

METHODS

NMR GlycA signal was measured in plasma samples from 87 individuals and correlated with MALDI-MS N-glycomics and trace element analysis. We further evaluated the genetic association with GlycA at rs13107325, a single nucleotide polymorphism resulting in a missense variant within SLC39A8, a manganese transporter that influences N-glycan branching, both in our samples and existing genome-wide association studies data from 22 835 participants in the Women's Health Study (WHS).

RESULTS

GlycA signal was correlated with both N-glycan branching (r2 ranging from 0.125-0.265; all P < 0.001) and copper concentration (r2 = 0.348, P < 0.0001). In addition, GlycA levels were associated with rs13107325 genotype in the WHS (β [standard error of the mean] = -4.66 [1.2674], P = 0.0002).

CONCLUSIONS

These results provide the first direct experimental evidence linking the GlycA NMR signal to N-glycan branching commonly associated with acute phase reactive proteins involved in inflammation.

Prenatal exposure to multiple metallic and metalloid trace elements and the risk of bacterial sepsis in extremely low gestational age newborns: A prospective cohort study

BACKGROUND

Prenatal exposures to metallic and metalloid trace elements have been linked to altered immune function in animal studies, but few epidemiologic studies have investigated immunological effects in humans. We evaluated the risk of bacterial sepsis (an extreme immune response to bacterial infection) in relation to prenatal metal/metalloid exposures, individually and jointly, within a US-based cohort of infants born extremely preterm.

METHODS

We analyzed data from 269 participants in the US-based ELGAN cohort, which enrolled infants delivered at <28 weeks' gestation (2002-2004). Concentrations of 8 trace elements-including 4 non-essential and 4 essential-were measured using inductively coupled plasma tandem mass spectrometry in umbilical cord tissue, reflecting in utero fetal exposures. The infants were followed from birth to postnatal day 28 with bacterial blood culture results reported weekly to detect sepsis. Discrete-time hazard and quantile g-computation models were fit to estimate associations for individual trace elements and their mixtures with sepsis incidence.

RESULTS

Approximately 30% of the extremely preterm infants developed sepsis during the follow-up period (median follow-up: 2 weeks). After adjustment for potential confounders, no trace element was individually associated with sepsis risk. However, there was some evidence of a non-monotonic relationship for cadmium, with hazard ratios (HRs) for the second, third, and fourth (highest) quartiles being 1.13 (95% CI: 0.51-2.54), 1.94 (95% CI: 0.87-4.32), and 1.88 (95% CI: 0.90-3.93), respectively. The HRs for a quartile increase in concentrations of all 8 elements, all 4 non-essential elements, and all 4 essential elements were 0.92 (95% CI: 0.68-1.25), 1.19 (95% CI: 0.92-1.55), and 0.77 (95% CI: 0.57-1.06). Cadmium had the greatest positive contribution whereas arsenic, copper, and selenium had the greatest negative contributions to the mixture associations.

CONCLUSIONS

We found some evidence that greater prenatal exposure to cadmium was associated with an increased the risk of bacterial sepsis in extremely preterm infants. However, this risk was counteracted by a combination of arsenic, copper, and selenium. Future studies are needed to confirm these findings and to evaluate the potential for nutritional interventions to prevent sepsis in high-risk infants.

Environmental exposures to pesticides, phthalates, phenols and trace elements are associated with neurodevelopment in the CHARGE study

OBJECTIVE

To determine if higher exposures measured in early childhood to environmental phenols, phthalates, pesticides, and/or trace elements, are associated with increased odds of having a diagnosis of Autism Spectrum Disorder (ASD), Developmental Delay (DD), or Other Early Concerns (OEC) compared to typically developing children (TD).

METHODS

This study included 627 children between the ages of 2-5 who participated in the Childhood Autism Risks from Genetics and Environment (CHARGE) study. Urine samples were collected at the same study visit where diagnostic assessments to confirm diagnosis indicated during the recruitment process were performed. Adjusted multinomial regression models of each chemical with diagnosis as the outcome were conducted. Additionally, two methods were used to analyze mixtures: repeated holdout multinomial weighted quantile sum (WQS) regression for each chemical class; and a total urinary mixture effect was assessed with repeated holdout random subset WQS.

RESULTS

Many urinary chemicals were associated with increased odds of ASD, DD or OEC compared to TD; however, most did not remain significant after false discovery rate adjustment. Repeated holdout WQS indices provided evidence for associations of both a phenol/paraben mixture effect and a trace element mixture effect on DD independently. In analyses adjusted for confounders and other exposures, results suggested an association of a pesticide mixture effect with increased risk for ASD. Results also suggested associations of a total urinary mixture with greater odds of both ASD and DD separately.

CONCLUSION

Higher concentrations of urinary biomarkers were associated with ASD, DD, and OEC compared to TD, with consistency of the results comparing single chemical analyses and mixture analyses. Given that the biospecimens used for chemical analysis were generally collected many months after diagnoses were made, the direction of any causal association is unknown. Hence findings may reflect higher exposures among children with non-typical development than TD children due to differences in behaviors, metabolism, or toxicokinetics.

Biomonitoring of exposure to Great Lakes contaminants among licensed anglers and Burmese refugees in Western New York: Toxic metals and persistent organic pollutants, 2010-2015

Between 2010 and 2015, the New York State Department of Health (NYSDOH) conducted a biomonitoring program to gather exposure data on Great Lakes contaminants among licensed anglers and Burmese refugees living in western New York who ate locally caught fish. Four hundred and nine adult licensed anglers and 206 adult Burmese refugees participated in this program. Participants provided blood and urine samples and completed a detailed questionnaire. Herein, we present blood metal levels (cadmium, lead, and total mercury) and serum persistent organic pollutant concentrations [polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), dichlorodiphenyldichloroethylene (DDE), and trans-nonachlor]. Multiple linear regression was applied to investigate the associations between analyte concentrations and indicators of fish consumption (locally caught fish meals, store-bought fish meals, and consuming fish/shellfish in the past week). Licensed anglers consumed a median of 16 locally caught fish meals and 22 store-bought fish meals while Burmese refugees consumed a median of 106 locally caught fish meals and 104 store-bought fish/shellfish meals in the past year. Compared to the general U.S. adult population, licensed anglers had higher blood lead and mercury levels; and Burmese refuges had higher blood cadmium, lead, and mercury, and higher serum DDE levels. Eating more locally caught fish was associated with higher blood lead, blood mercury, and serum ∑PCBs concentrations among licensed anglers. Licensed anglers and Burmese refugees who reported fish/shellfish consumption in the past week had elevated blood mercury levels compared with those who reported no consumption. Among licensed anglers, eating more store-bought fish meals was also associated with higher blood mercury levels. As part of the program, NYSDOH staff provided fish advisory outreach and education to all participants on ways to reduce their exposures, make healthier choices of fish to eat, and waters to fish from. Overall, our findings on exposure levels and fish consumption provide information to support the development and implementation of exposure reduction public health actions.

High Lead Exposure Associated With Higher Blood Pressure in Haiti: a Warning Sign for Low-Income Countries

Cardiovascular disease is the leading cause of death in lower-income countries including Haiti. Environmental lead exposure is associated with high blood pressure and cardiovascular mortality in high-income countries but has not been systematically measured and evaluated as a potential modifiable cardiovascular risk factor in lower-income countries where 6.5 billion people reside. We hypothesized lead exposure is high in urban Haiti and associated with higher blood pressure levels. Blood lead levels were measured in 2504 participants ≥18 years enrolled in a longitudinal population-based cohort study in Port-au-Prince. Lead screening was conducted using LeadCare II (detection limit ≥3.3 µg/dL). Levels below detection were imputed by dividing the level of detection by √2. Associations between lead (quartiles) and systolic blood pressure and diastolic blood pressure were assessed, adjusting for age, sex, obesity, smoking, alcohol, physical activity, income, and antihypertensive medication use. The median age of participants was 40 years and 60.1% were female. The geometric mean blood lead level was 4.73µg/dL, 71.1% had a detectable lead level and 42.3% had a blood lead level ≥5 µg/dL. After multivariable adjustment, lead levels in quartile four (≥6.5 µg/dL) compared with quartile 1 (<3.4 µg/dL) were associated with 2.42 mm Hg (95% CI, 0.36-4.49) higher systolic blood pressure and 1.96 mm Hg (95% CI, 0.56-3.37) higher diastolic blood pressure. In conclusion, widespread environmental lead exposure is evident in urban Haiti, with higher lead levels associated with higher systolic and diastolic blood pressure. Lead is a current and potentially modifiable pollutant in lower-income countries that warrants urgent public health remediation. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03892265.

Co-exposure to manganese and lead and pediatric neurocognition in East Liverpool, Ohio

Exposure to metal mixtures may lead to health impacts greater than the effects associated with singular exposures. Two common childhood environmental exposures, manganese (Mn) and lead (Pb), are associated with similar adverse neurodevelopmental effects; however, the effects surrounding concurrent exposure to both metals remain unclear. We study the impact of joint exposure to Mn and Pb on cognitive performance in school-aged children participating in the Communities Actively Researching Exposure Study (CARES) based in East Liverpool, Ohio. Blood Pb levels were measured for each child (geometric mean (GM) = 1.13 μg/dL, range 0.30 μg/dL - 6.64 μg/dL). Mn was measured in participant blood, hair, and toenails with GMs of 10.1 μg/L, 360 ng/g, 0.974 μg/g, respectively. Trained team members administered the Wechsler Intelligence Scale for Children-IV (WISC-IV) to assess intelligence quotient (IQ). The WISC-IV provides scores for Full Scale IQ, Perceptual Reasoning, Processing Speed, Working Memory, and Verbal Comprehension. Interactions between blood Pb and all Mn biomarkers were tested in linear models adjusted for child sex, household income, and serum cotinine. Separate regression models were run for each of the Mn biomarkers. The cohort was comprised of 106 children with a mean age of 8.4 years. Interactions between blood Pb and hair Mn were significant (p < 0.05) for four out of the five IQ domains. The effect of blood Pb on IQ was more pronounced at higher levels of hair and toenail Mn. No significant associations were observed when characterizing the main effect of Mn using blood. Uncovering the health impacts associated with exposure mixtures is critical to understanding the impact of real-life conditions. Our findings suggest that joint exposure to Mn and Pb may produce heightened neurocognitive impacts even at blood Pb levels below the CDC reference concentration of 5 μg/dL.

Lead uptake into calcified and keratinized compartments of horns from a convenience sample of lead-dosed goats

Hair and/or nail analyses are sometimes used in biomonitoring studies due to the convenience of sample collection, storage, and transport, as well as the potential to assess past exposures to toxic metals, such as lead (Pb). However, the validity of Pb measurements in these keratinized matrices as biomarkers of absorbed dose remains unclear. The aim of this study was to examine the uptake of Pb into horns harvested postmortem from 11 goats that received a cumulative oral dose of up to 151 g Pb acetate over a period of 1-11 years as part of a long-term blood Pb proficiency testing program. Uptake of Pb into keratinized horn was compared to the corresponding underlying bony horn core, which, as part of the bone compartment, provided a measure of absorbed Pb dose. Two complementary analytical techniques were used to assess Pb: X-Ray Fluorescence (XRF) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Detectable amounts of Pb were found in all keratinized horn samples (0.45-6.6 µg/g) and in all but one bony core sample (1.4-68 µg/g). In both bony core and keratinized horn samples, Pb accumulation increased with dose over a low-to-moderate cumulative-dose interval, consistent with previous observations, but plateaued at higher doses. Significant associations were observed between Pb in keratinized horn and bony core samples particularly with XRF measurements, which represent the surface bone compartment. These findings provide evidence that Pb is excreted in keratinized tissues but reflects only a small fraction of the absorbed Pb dose, likely transferred from underlying bone tissue.

Toxic elements in follicular fluid adversely influence the likelihood of pregnancy and live birth in women undergoing IVF

STUDY QUESTION

Are follicular fluid (FF), arsenic (As), mercury (Hg), cadmium (Cd) and lead (Pb) concentrations associated with IVF outcomes among women undergoing IVF?

SUMMARY ANSWER

There was a non-linear association between higher FF Hg concentration and a lower likelihood of biochemical pregnancy and live birth. Higher FF Pb concentration was also associated with a lower probability of live birth.

WHAT IS KNOWN ALREADY

Previous research suggests that toxic elements may affect fertility among couples conceiving with and without assistance. However, the results have been inconsistent, possibly related in part to exposure misclassification. Very few studies have used ovarian FF to measure toxic elements, as it requires an invasive collection procedure, yet it may offer a more accurate estimate of a biologically effective dose than blood or urine.

STUDY DESIGN SIZE DURATION

This is a prospective study of 56 women undergoing IVF, from October 2015 to June 2017. FF was collected for analysis on the day of oocyte retrieval.

PARTICIPANTS/MATERIALS SETTING METHODS

As, Cd, Hg and Pb were determined in 197 FF specimens, using inductively coupled plasma tandem mass spectrometry. FF glutathione peroxidase, glutathione reductase, total glutathione-S-transferase, superoxide dismutase, arylesterase and paraoxonase (PON1p) activities were measured using kinetic enzyme assays.

MAIN RESULTS AND THE ROLE OF CHANCE

Non-linear associations were detected, in which the probabilities of biochemical pregnancy (P = 0.05) and live birth (P = 0.05) were lower in association with FF Hg greater than ∼0.51 µg/l Hg, adjusted for age, race, cigarette smoking and recent seafood consumption. Higher FF Pb was also associated with a lower likelihood of live birth (relative risk (RR) = 0.68, 95% CI: 0.46, 1.00; P = 0.05). We also found a suggestive, although imprecise, antagonizing mediating effect of PON1p activity on the association between FF Pb and live birth (-28.3%; 95% CI: -358%, 270%).

LIMITATIONS REASONS FOR CAUTION

The results should be interpreted judiciously given the limited sample size and difficulty accounting for correlated data in generalized additive models and mediation analyses. Additionally, women undergoing IVF are highly selected with respect to age and socioeconomic status, and so the generalizability of the results may be limited.

WIDER IMPLICATIONS OF THE FINDINGS

Overall, the results suggest that FF Hg was associated with a lower likelihood of biochemical pregnancy and live birth, with a potential threshold effect, and that higher FF Pb was associated with a lower probability of live birth. These results may help to guide clinical recommendations for limiting the exposure of patients to Hg and Pb and ultimately improve IVF success rates.

STUDY FUNDING/COMPETING INTERESTS

This work was funded in part by the National Institute of Environmental Health Sciences (NIEHS), grant number 1R56ES023886-01, to the University at Albany (M.S.B.), and in part by the National Institute of Environmental Health Sciences (NIEHS), grant number 1U2CES026542-01, to the Wadsworth Center (P.J.P.). The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Identifying sensitive windows of airborne lead exposure associated with behavioral outcomes at age 12

Despite the precipitous decline of airborne lead concentrations following the removal of lead in gasoline, lead is still detectable in ambient air in most urban areas. Few studies, however, have examined the health effects of contemporary airborne lead concentrations in children.

METHODS

We estimated monthly air lead exposure among 263 children (Cincinnati Childhood Allergy and Air Pollution Study; Cincinnati, OH; 2001-2005) using temporally scaled predictions from a validated land use model and assessed neurobehavioral outcomes at age 12 years using the parent-completed Behavioral Assessment System for Children, 2nd edition. We used distributed lag models to estimate the effect of airborne lead exposure on behavioral outcomes while adjusting for potential confounding by maternal education, community-level deprivation, blood lead concentrations, greenspace, and traffic related air pollution.

RESULTS

We identified sensitive windows during mid- and late childhood for increased anxiety and atypicality scores, whereas sensitive windows for increased aggression and attention problems were identified immediately following birth. The strongest effect was at age 12, where a 1 ng/m3 increase in airborne lead exposure was associated with a 3.1-point (95% confidence interval: 0.4, 5.7) increase in anxiety scores. No sensitive windows were identified for depression, somatization, conduct problems, hyperactivity, or withdrawal behaviors.

CONCLUSIONS

We observed associations between exposure to airborne lead concentrations and poor behavioral outcomes at concentrations 10 times lower than the National Ambient Air Quality Standards set by the US Environmental Protection Agency.

Quality assurance and harmonization for targeted biomonitoring measurements of environmental organic chemicals across the Children's Health Exposure Analysis Resource laboratory network

A consortium of laboratories established under the Children's Health Exposure Analysis Resource (CHEAR) used a multifaceted quality assurance program to promote measurement harmonization for trace organics analyses of human biospecimens that included: (1) participation in external quality assurance (EQA)/proficiency testing (PT) programs; (2) analyses of a urine-based CHEAR common quality control (QC) pool with each analytical batch across all participating laboratories; (3) method validation against NIST Standard Reference Materials® (SRMs); and (4) analyses of blinded duplicates and other project-specific QC samples. The capability of five CHEAR laboratories in organic chemical analysis increased across the 4-year period, and performance in the external PT program improved over time - recent challenges reporting >90% analytes with satisfactory performance. The CHEAR QC pools were analyzed for several classes of organic chemicals including phthalate metabolites and environmental phenols by the participating laboratories with every batch of project samples, which provided a rich source of measurement data for the assessment of intra- and inter-laboratory variance. Within-laboratory and overall variabilities in measurements across laboratories were calculated for target chemicals in urine QC pools; the coefficient of variation (CV) was generally below 25% across batches, studies and laboratories and indicated acceptable analytical imprecision. The suite of organic chemicals analyzed in the CHEAR QC pool was broader than those reported for commercially available reference materials. The accuracy of each of the laboratories' methods was verified through the analysis of several NIST SRMs and was, for example, 97 ± 5.2% for environmental phenols and 95 ± 11% for phthalates. Analysis of blinded duplicate samples showed excellent agreement and reliability of measurements. The intra-class correlation coefficients (ICC) for phthalate metabolites analyzed in various batches across three CHEAR laboratories showed excellent reliability (typically >0.90). Overall, the multifaceted quality assurance protocols followed among the CHEAR laboratories ensured reliable and reproducible data quality for several classes of organic chemicals. Increased participation in external PT programs through inclusion of additional target analytes will further enhance the confidence in data quality.

Variability of essential and non-essential trace elements in the follicular fluid of women undergoing in vitro fertilization (IVF)

Both essential and non-essential elements have been associated with female reproductive function in epidemiologic investigations, including among IVF populations. To date, most investigators have used blood or urine to assess biomarkers of exposure, with few employing ovarian follicular fluid (FF). FF may offer a more direct "snapshot" of the oocyte microenvironment than blood or urine, however previous studies report follicle-to-follicle variability in FF constituents that may contribute to exposure misclassification. Our objectives were to investigate sources of trace element variability, to estimate FF biomarker reliability among women undergoing IVF (n = 34), and to determine the minimum number of follicles required to estimate subject-specific mean concentrations. We measured As, Hg, Cd, Pb, Cu, Mn, Se, and Zn in FF samples using inductively coupled plasma tandem mass spectrometry. Inter-subject (between-women) variability contributed most of the variability in FF element concentrations, with ovarian, follicular, and analytical as smaller sources of variability. The proportion of variability attributable to sources between-follicles differed by age, body mass index (BMI), race, and cigarette smoking for Cu, Se, and Zn, by BMI and cigarette smoking for As, by primary infertility diagnosis for Hg, Cu, Se, and Zn, and by ovarian stimulation protocol for Mn and Se. Four to five individual follicles were sufficient to estimate subject-specific mean Cu, Se, and Zn concentrations, while >14 were necessary for As, Hg, Cd, Pb, and Mn. Overall, our results suggest that FF is a suitable source of biomarkers of As and Hg exposure in ovarian follicles. Although limited in size, our study offers the most comprehensive exploration of biological variation in FF trace elements to date and may provide guidance for future studies of ovarian trace element exposures.

Linking metal (Pb, Hg, Cd) industrial air pollution risk to blood metal levels and cardiovascular functioning and structure among children in Syracuse, NY

BACKGROUND

Exposure to air pollution has been linked to individual health effects in occupational environments and communities proximate to air pollution sources. Use of estimated chemical concentrations from the Risk Screening Environmental Indicators (RSEI) model, derived from the Toxics Release Inventory, can help approximate some contributions to individual lifetime exposure to risk from air pollution and holds potential for linkages with specific health outcome data.

OBJECTIVES

Our objectives were: (1) use regression modeling to test for associations between observed blood metal concentrations in children and RSEI total air concentrations of the same metals released from proximate manufacturing facilities; (2) determine the relative contribution of RSEI air pollution to blood metal concentrations; and (3) examine associations between chronic metal exposure and cardiovascular functioning and structure in study participants.

METHODS

Using data synthesis methods and regression modeling we linked individual blood-based levels of lead, mercury, and cadmium(Pb, Hg, Cd) and cardiovascular functioning and structure to proximate industrial releases of the same metals captured by the Environmental Protection Agency's (EPA) RSEI geographic microdata.

RESULTS

We found that RSEI-derived ground-level ambient air concentrations of Hg and Cd were a significant predictor of blood metal levels, when controlling for covariates and other exposure variables. In addition to associations with blood metal findings, RSEI concentrations also predicted cardiovascular dysfunction and risk including changes in left-ventricular mass, blood pressure, and heart rate.

DISCUSSION

Right-to-know data, such as EPA's RSEI, can be linked to objective health outcomes, rather than simply serving as a non-specific risk estimate. These data can serve as a proxy for hazard exposure and should be used more widely to understand the dynamics of environmental exposure. Furthermore, since these data are both a product of and contribute to regulatory decision making, they could serve as an important link between disease risk and translation-orientated national environmental health policy.

Measurement harmonization and traceability for trace element analyses across the Children's Health Exposure Analysis Resource laboratory network

Harmonization and traceability are related metrological principles that are indispensable to assuring measurement comparability across different biomonitoring studies. The Children's Health Exposure Analysis Resource (CHEAR) was established in 2015 with six laboratories providing environmental exposure measurements on biospecimens. To ensure harmonization across studies for trace elements, CHEAR used a multi-faceted approach that included: 1) an initial interlaboratory validation exercise based on the analysis of certified blood and urine reference materials; 2) frequent participation in an established interlaboratory proficiency program for trace elements; and 3) analysis of a common pool of well-characterized biological reference materials with each analytical batch. Method accuracy and precision were established for each laboratory via analysis of NIST SRM 955c Toxic Elements in Caprine Blood, SRM 2668 Toxic Elements in Frozen Human Urine and SRM 3668 Mercury, Perchlorate, and Iodide in Frozen Human Urine. The differences among the six laboratories for As, Cd, Hg, and Mn in urine and Cd, Hg, and Pb in whole blood were judged to be fit-for-purpose. Interlaboratory performance over a 5-year period demonstrated an improvement in performance, such that for 2018-2019, >99% of challenges for urine As, Cd, Hg, and Mn, and 95% for whole blood Cd, Hg, Pb, and Mn, were found to be satisfactory. The CHEAR common reference materials were analyzed by at least 5 laboratories for 22 elements in urine and 13-14 elements in whole blood, thus providing a rich source of data to assess intra- and inter-run performance. The suite of trace elements with assigned values in both blood and urine matrices are more comprehensive than similar reference materials from other sources, and is reflective of the concentrations necessary to support biomonitoring studies. While some areas for future improvement were identified, significant progress was made to improve harmonization of trace element measurements in biological matrices among the CHEAR network labs.

Early life blood lead levels and asthma diagnosis at age 4-6 years

The USA has a high burden of childhood asthma. Previous studies have observed associations between higher blood lead levels and greater hypersensitivity in children. The objective of the present study was to estimate the association between blood lead concentrations during early childhood and an asthma diagnosis between 48 and 72 months of age amongst a cohort with well-characterized blood lead concentrations. Blood lead concentrations were measured at 6, 12, 18, 24, 36, and 48 months of age in 222 children. The presence of an asthma diagnosis between 48 and 72 months was assessed using a questionnaire which asked parents or guardians whether they had been told by a physician, in the past 12 months, that their child had asthma. Crude and adjusted risk ratios (RR) of an asthma diagnosis were estimated for several parameterizations of blood lead exposure including lifetime average (6 to 48 months) and infancy average (6 to 24 months) concentrations. After adjustment for child sex, birthweight, daycare attendance, maternal race, education, parity, breastfeeding, income, and household smoking, age-specific or composite measures of blood lead were not associated with asthma diagnosis by 72 months of age in this cohort.

Seafood consumption is associated with higher follicular fluid arsenic (As) and mercury (Hg) concentrations in women undergoing in vitro fertilization (IVF)

Human exposure to non-essential toxic metals such as cadmium (Cd), mercury (Hg), and lead (Pb), and metalloids such as arsenic (As) commonly occurs through diet. Toxic trace element exposures have been reported in association with fertility and fecundity in epidemiologic studies even at low to moderate levels. While most previous studies employed blood and urine biomarkers of exposure, few have assessed toxic trace elements in ovarian follicular fluid (FF), which surrounds the developing oocyte and hence may better reflect concentrations potentially affecting reproductive outcomes. Our objective was to identify dietary predictors of FF toxic trace elements in n = 56 women (mean age: 38.3 years) undergoing in vitro fertilization (IVF) at the University of California at San Francisco. We determined As, Hg, Cd, and Pb in 197 FF specimens, collected on the day of oocyte retrieval, using inductively coupled plasma tandem mass spectrometry. A comprehensive food frequency questionnaire was used to assess the weekly and annual dietary "patterns" of participants. Consumption of specific seafood items and turkey were correlated with individual FF toxic trace elements. We also found that each unit higher seafood consumption in the past week dominated by mollusks, shrimp, and bass was associated with 60% higher FF As (95% confidence interval (CI): 25%, 105%) and FF Hg (95%CI: 7%, 136%) concentrations. Higher annual seafood consumption dominated by urchin, crab, and trout was associated with 16% higher FF As (95%CI: -2%, 38%) and 31% higher FF Hg (95%CI: 7%, 60%) concentrations per unit intake. No associations were noted between diet and Cd and Pb levels in FF. Overall, our results suggest that higher seafood consumption contributes to elevated levels of As and Hg in FF. These findings are consistent with previous IVF studies that assessed toxic trace element exposures in blood and urine. To our knowledge, this is the first study to report that diet might be a source of As, Hg, Cd, and Pb in FF.

The schizophrenia risk locus in SLC39A8 alters brain metal transport and plasma glycosylation

A common missense variant in SLC39A8 is convincingly associated with schizophrenia and several additional phenotypes. Homozygous loss-of-function mutations in SLC39A8 result in undetectable serum manganese (Mn) and a Congenital Disorder of Glycosylation (CDG) due to the exquisite sensitivity of glycosyltransferases to Mn concentration. Here, we identified several Mn-related changes in human carriers of the common SLC39A8 missense allele. Analysis of structural brain MRI scans showed a dose-dependent change in the ratio of T2w to T1w signal in several regions. Comprehensive trace element analysis confirmed a specific reduction of only serum Mn, and plasma protein N-glycome profiling revealed reduced complexity and branching. N-glycome profiling from two individuals with SLC39A8-CDG showed similar but more severe alterations in branching that improved with Mn supplementation, suggesting that the common variant exists on a spectrum of hypofunction with potential for reversibility. Characterizing the functional impact of this variant will enhance our understanding of schizophrenia pathogenesis and identify novel therapeutic targets and biomarkers.

Dietary contributions to increased background lead, mercury, and cadmium in 9-11 Year old children: Accounting for racial differences

BACKGROUND

Initial interest in the adverse consequences of exposure to lead (Pb), mercury (Hg), and cadmium (Cd) focused on relatively high exposures through environmental or occupational sources; however, recent evidence suggests even low-level background exposure to non-essential metals might be detrimental, particularly for children's health and development. One potentially important source of increased background levels of non-essential toxic metals is diet.

OBJECTIVES

We considered whether differences in diet are associated with levels of non-essential metals in blood and whether racial differences in metals are mediated by dietary differences.

METHODS

We assessed blood levels of Pb, Hg, and Cd in a sample of 9-11 year-old children (N = 295) comprised of 42% European Americans (EAs), 58% African American (AAs), and 47% female. Diet was assessed using 24-h dietary recalls during phone interviews administered to parents on two consecutive days (Friday and Saturday). The Healthy Eating Index-2105 (HEI-2015) was calculated to assess diet quality.

RESULTS

The current study identified significant dietary sources of non-essential metal exposure - namely total fruit for Pb, total protein for Hg, and greens and beans for Cd. Moreover, AAs were found to have significantly higher blood levels of Pb and Hg than EAs and these racial differences were significantly mediated by these dietary differences.

DISCUSSION

This study is one of very few to consider total diet in children and exposure to the non-essential metals Pb, Hg, and Cd, and the first to demonstrate that racial differences in increased background blood levels of non-essential toxic metals can be accounted for by racial differences in diet. Given regional differences in food consumption patterns and specific farm and store sources for the foods, the generalizability of the current findings has yet to be determined; however, commonly consumed foods appear to be a significant source of low-level non-essential metals.

Opportunities for evaluating chemical exposures and child health in the United States: the Environmental influences on Child Health Outcomes (ECHO) Program

The Environmental Influences on Child Health Outcomes (ECHO) Program will evaluate environmental factors affecting children's health (perinatal, neurodevelopmental, obesity, respiratory, and positive health outcomes) by pooling cohorts composed of >50,000 children in the largest US study of its kind. Our objective was to identify opportunities for studying chemicals and child health using existing or future ECHO chemical exposure data. We described chemical-related information collected by ECHO cohorts and reviewed ECHO-relevant literature on exposure routes, sources, and environmental and human monitoring. Fifty-six ECHO cohorts have existing or planned chemical biomonitoring data for mothers or children. Environmental phenols/parabens, phthalates, metals/metalloids, and tobacco biomarkers are each being measured by ≥15 cohorts, predominantly during pregnancy and childhood, indicating ample opportunities to study child health outcomes. Cohorts are collecting questionnaire data on multiple exposure sources and conducting environmental monitoring including air, dust, and water sample collection that could be used for exposure assessment studies. To supplement existing chemical data, we recommend biomonitoring of emerging chemicals, nontargeted analysis to identify novel chemicals, and expanded measurement of chemicals in alternative biological matrices and dust samples. ECHO's rich data and samples represent an unprecedented opportunity to accelerate environmental chemical research to improve the health of US children.

Arsenic Exposure Decreases Adiposity During High-Fat Feeding

OBJECTIVE

Arsenic is an endocrine-disrupting chemical associated with diabetes risk. Increased adiposity is a significant risk factor for diabetes and its comorbidities. Here, the impact of chronic arsenic exposure on adiposity and metabolic health was assessed in mice.

METHODS

Male C57BL/6J mice were provided ad libitum access to a normal or high-fat diet and water +/- 50 mg/L of sodium arsenite. Changes in body weight, body composition, insulin sensitivity, energy expenditure, and locomotor activity were measured. Measures of adiposity were compared with accumulated arsenic in the liver.

RESULTS

Despite uniform arsenic exposure, internal arsenic levels varied significantly among arsenic-exposed mice. Hepatic arsenic levels in exposed mice negatively correlated with overall weight gain, individual adipose depot masses, and hepatic triglyceride accumulation. No effects were observed in mice on a normal diet. For mice on a high-fat diet, arsenic exposure reduced fasting insulin levels, homeostatic model assessment of insulin resistance and β-cell function, and systemic insulin resistance. Arsenic exposure did not alter energy expenditure or activity.

CONCLUSIONS

Collectively, these data indicate that arsenic is antiobesogenic and that concentration at the source poorly predicts arsenic accumulation and phenotypic outcomes. In future studies, investigators should consider internal accumulation of arsenic rather than source concentration when assessing the outcomes of arsenic exposure.

Bone Mineral Composition Among Long-Term Parenteral Nutrition Patients: Postmortem Assessment of Calcium, Phosphorus, Magnesium, and Select Trace Elements

BACKGROUND

Patients receiving long-term parenteral nutrition (PN) treatment are at risk of developing metabolic bone diseases (MBDs). The bone compartment serves as a repository for a range of metal(loid)s that are administered intravenously to patients via PN solutions. Thus, the mineral composition of patient bones may be linked to the development of MBDs in this group.

METHODS

We measured 12 elements in bone samples obtained post mortem from 7 long-term (2-21 years) PN patients and 18 control bones obtained from hip/knee replacement surgery. The samples were cleaned, digested, and subsequently analyzed using a method based on inductively coupled plasma tandem mass spectrometry.

RESULTS

Compared with the control group, bones obtained from PN patients were significantly (P < 0.05) depleted in calcium (Ca), phosphorus (P), magnesium (Mg), chromium, and strontium and enriched in manganese (Mn), zinc, barium, cadmium (Cd), and uranium (U). No differences were observed for cobalt or lead.

CONCLUSIONS

Depletion of major components of bone mineral (Ca, P, and Mg) and enrichment in known toxicants (Cd, Mn, U) are concerns for PN patients.

Evaluating associations between early pregnancy trace elements mixture and 2nd trimester gestational glucose levels: A comparison of three statistical approaches

OBJECTIVE

Studies have shown that individual trace element levels might be associated with abnormal glycemic status, with implications for diabetes. Few studies have considered these trace elements as a mixture and their impact on gestational glucose levels. Comparing three statistical approaches, we assessed the associations between essential trace elements mixture and gestational glucose levels.

METHODS

We used data from 1720 women enrolled in the Eunice Kennedy Shriver National Institute of Child Health and Human Development's Fetal Growth Study, for whom trace element concentrations (zinc, selenium, copper, molybdenum) were measured by inductively coupled plasma mass spectrometry (ICP-MS) using plasma collected during the 1st trimester. Non-fasting glucose levels were measured during the gestational diabetes mellitus (GDM) screening test in the 2nd trimester. We applied (1) Bayesian Kernel Machine Regression (BKMR); (2) adaptive Least Absolute Shrinkage and Selection Operator (LASSO) in a mutually adjusted linear regression model; and (3) generalized additive models (GAMs) to evaluate the joint associations between trace elements mixture and glucose levels adjusting for potential confounders.

RESULTS

Using BKMR, we observed a mean 2.7 mg/dL higher glucose level for each interquartile increase of plasma copper (95% credible interval: 0.9, 4.5). The positive association between plasma copper and glucose levels was more pronounced at higher quartiles of zinc. Similar associations were detected using adaptive LASSO and GAM. In addition, results from adaptive LASSO and GAM suggested a super-additive interaction between molybdenum and selenium (both p-values = 0.04).

CONCLUSION

Employing different statistical methods, we found consistent evidence of higher gestational glucose levels associated with higher copper and potential synergism between zinc and copper on glucose levels.

Development and characterization of reference materials for trace element analysis of keratinized matrices

Biomonitoring for human exposure to lead, arsenic, mercury, and other toxic metal(loid)s often relies on analyzing traditional biospecimens such as blood and urine. While biomonitoring based on blood and urine is well-established, non-traditional biospecimens such as hair and nails can offer the potential to explore past exposures as well as the advantages of non-invasive collection and ease of storage. The present study describes the production of four reference materials (NYS RMs 18-01 through 18-04) based on caprine horn, a keratinized tissue similar to human hair and nails, intended to serve as a resource for calibration, quality control, and method validation purposes. The elemental content and homogeneity of these candidate reference materials were characterized for 17 elements using inductively coupled plasma mass spectrometry (ICP-MS). Commutability between two or more of the NYS caprine horn RMs and human nails was established for 8 elements (Ba, Ca, Cr, Cu, Mn, Pb, Sr, and Zn) based on analysis by ICP-MS/MS and ICP-optical emission spectrometry. The development and optimization of an ICP-MS/MS instrumental method for the determination of 17 elements in keratinized tissues is described. The method was validated against three certified reference materials based on human hair showing good accuracy and method repeatability better than 25% for all analytes. This study also describes sample preparation issues and addresses common challenges including surface contamination, microwave digestion, matrix effects, and spectral interferences in inorganic mass spectrometry. New York State Department of Health Keratin Matrix Reference Materials. Graphical abstract.

A comparison of blood and toenails as biomarkers of children's exposure to lead and their correlation with cognitive function

This study sought to compare lead (Pb) concentrations in toenails and blood and to investigate the association of each biomarker with children's cognitive function. Toenails and whole blood samples were collected from 224 twelve-year-old children, and their full-scale intelligence quotient (FSIQ) was assessed using the Wechsler Intelligence Scale for Children-4th edition. Inductively coupled plasma-mass spectrometry was used to determine blood (BPb) and toenail (TPb) Pb concentrations. Log BPb and Log TPb were significantly correlated (r² = 0.49, p < 0.001). In unadjusted analyses, both log-transformed BPb and TPb were significantly associated with decreased FSIQ, but BPb accounted for approximately quadruple the FSIQ scores' variability than log-transformed TPb (model R² = 0.12 and R² = 0.03, respectively). After adjusting for neighborhood deprivation, caregiver intelligence (assessed with the Wechsler Abbreviated Scale of Intelligence-2nd edition), and child BMI, BPb remained significantly associated with decreased FSIQ, while TPb did not (p = 0.16). These results suggest that while concentrations of Pb in blood and toenails are correlated, TPb does not predict cognitive outcomes at these exposure levels. With caution and in conjunction with BPb, TPb may be used as a population-based biomarker of Pb exposure.

Coal smoke, gestational cadmium exposure, and fetal growth

BACKGROUND

Gestational cadmium exposure may impair fetal growth. Coal smoke has largely been unexplored as a source of cadmium exposure. We investigated the relationship between gestational cadmium exposure and fetal growth, and assessed coal smoke as a potential source of airborne cadmium, among non-smoking pregnant women in Ulaanbaatar, Mongolia, where coal combustion in home heating stoves is a major source of outdoor and indoor air pollution.

METHODS

This observational study was nested within the Ulaanbaatar Gestation and Air Pollution Research (UGAAR) study, a randomized controlled trial of portable high efficiency particulate air (HEPA) filter air cleaner use during pregnancy, fetal growth, and early childhood development. We measured third trimester blood cadmium concentrations in 374 out of 465 participants who had a live birth. We used multiple linear and logistic regression to assess the relationships between log₂-transformed maternal blood cadmium concentrations and birth weight, length, head circumference, ponderal index, low birth weight, small for gestational age, and preterm birth in crude and adjusted models. We also evaluated the relationships between log₂-transformed blood cadmium concentrations and the density of coal-burning stoves within 5000 m of each participant's apartment as a proxy of coal smoke emissions from home heating stoves.

RESULTS

The median (25th,75th percentile) blood cadmium concentration was 0.20 (0.15, 0.29) μg/L. A doubling of blood cadmium was associated with a 95 g (95% CI: 34, 155 g) reduction in birth weight in adjusted models. An interquartile range increase in coal stove density (from 3.4 to 4.9 gers/hectare) surrounding participants' apartments was associated with a 12.2% (95% CI: 0.3, 25.6%) increase in blood cadmium concentrations.

CONCLUSIONS

Gestational cadmium exposure was associated with reduced birth weight. In settings where coal is a widely used fuel, cadmium may play a role in the putative association between air pollution and impaired fetal growth.

Biomonitoring of populations in Western New York at risk for exposure to Great Lakes contaminants

The New York State Department of Health conducted the Healthy Fishing Communities Program in collaboration with the Agency for Toxic Substances and Disease Registry to assess human exposure to contaminants common to Lake Ontario, Lake Erie and surrounding rivers and waterways among populations in western New York State who eat locally caught fish. The program enrolled licensed anglers and Burmese refugees and immigrants, living near four designated Great Lakes Areas of Concern: Buffalo River, Niagara River, Eighteenmile Creek, and the Rochester Embayment. These target populations were sampled and enrolled independently into the program between February and October of 2013. A core set of contaminants were measured in blood and urine of 409 licensed anglers and 206 Burmese refugees and immigrants which included lead, cadmium, mercury, PCBs, PBDEs, organochlorine pesticides (hexachlorobenzene, mirex, DDT, DDE, and chlordane and its metabolites oxychlordane and trans-Nonachlor), and PFOS and PFOA. Biomonitoring results showed that both groups had higher geometric means for blood lead, total blood mercury, and serum PFOS compared to the 2013-2014 NHANES reference levels. The Burmese refugee group also showed higher geometric means for creatinine-adjusted urine mercury and lipid-adjusted serum DDE compared to national levels. Licensed angler participants reported eating a median of 16 locally caught fish meals in the past year. Burmese participants consumed local fish throughout the year, and most frequently in the summer (median 39 fish meals or 3 times a week). The study results provide valuable information on populations at high risk of exposure to contaminants in the Great Lakes Basin of western New York. The results provide the foundation for developing and implementing public health actions to reduce potential exposures to Great Lakes pollutants.

A Prospective Study of Early Pregnancy Essential Metal(loid)s and Glucose Levels Late in the Second Trimester

CONTEXT

Studies suggest many essential trace metal(loid)s are involved in glucose metabolism, but the associations among pregnant women are unclear.

OBJECTIVE

To assess associations between early pregnancy plasma zinc, selenium, copper, and molybdenum levels and blood glucose levels later in the second trimester.

DESIGN

The Eunice Kennedy Shriver National Institute of Child Health and Human Development Fetal Growth Studies‒Singleton Cohort is a prospective cohort study conducted between July 2009 and January 2013.

SETTING

Twelve academic research hospitals in the United States.

PATIENTS

A total of 1857 multiracial, nonobese, healthy women.

MAIN OUTCOME MEASURE

Blood glucose levels from 1-hour 50-g gestational load test (GLT) at 24 to 28 weeks of gestation.

RESULTS

Higher concentrations of first-trimester copper were associated with higher glucose levels from the GLT (i.e., every 50% increase in copper concentration was related to 4.9 mg/dL higher glucose level; 95% CI: 2.2, 7.5 mg/dL) adjusted for maternal sociodemographic characteristics and reproductive history. In contrast, every 50% increase in molybdenum concentration was associated with 1.2 mg/dL lower mean glucose level (95% CI: -2.3, -0.1 mg/dL). The magnitude of these associations was greater at the upper tails of glucose level distribution based on quantile regressions of the 10th, 50th, and 90th percentiles.

CONCLUSIONS

Higher copper and lower molybdenum concentrations could increase the risk of glucose dysregulation during pregnancy, with women at higher risk of gestational diabetes mellitus potentially affected to a greater extent. Further work is needed to understand the mechanisms involved with early pregnancy essential metal(loid)s to inform clinical diagnosis and prevention of glucose intolerance during pregnancy.

A study of lead uptake and distribution in horns from lead-dosed goats using synchrotron radiation-induced micro X-ray fluorescence elemental imaging

OBJECTIVE

The principal goal of this study was to investigate the uptake and distribution of lead (Pb) in the horns of Pb-dosed goats, and to explore possible links to their historical Pb dosing records. Horn is a keratinized material that grows in discrete increments with the potential to preserve the historical record of past environmental exposures. While previous studies have leveraged this potential to examine environmental and biological phenomena in horns, Pb uptake has never been explored.

METHODS

Horns were collected post-mortem from three goats that had been previously used to produce blood lead reference materials for the New York State proficiency testing program. The animals were periodically dosed with lead acetate, administered orally in a capsule, over a 5 to 8-year period. Horn cross sections were taken from each animal and analyzed using synchrotron radiation-induced micro X-ray fluorescence spectrometry (SR-μXRF) at the Cornell High Energy Synchrotron Source (CHESS).

RESULTS

Elemental distribution maps were obtained by SR-μXRF for Pb, Ca, S, Se, and three other elements (Br, Zn and Cu), with values reported quantitatively as a mass fraction (μg/g for trace elements and mg/g for Ca and S). Accumulations of Pb were clearly visible as a series of narrow "rings" in each of the horn samples analyzed. The elements Ca, S, Br, Zn, and Cu were also detected as discrete rings within each cross-section, with Br strongly correlated with S in the samples examined. A marginal increase in Se may coincide with Pb accumulation in horn cross-sections. Annual mineralization estimates based on the relative distribution of Ca and S were used to establish a tentative timeline for horn growth, with each timeline linked to the pattern of Pb accumulation in the corresponding horn cross-section sample.

CONCLUSIONS

Following ingestion, absorbed Pb is eventually deposited into caprine horns, resulting in discrete accumulations or "rings." Elemental mapping by SR-μXRF clearly show Ca-rich layers that vary with annual periodicity, consistent with previous reports of horn mineralization. Localized enrichment of Cu, Zn, Br and S appear to coincide with the keratinized regions related to the annual growth ring pattern in horns. Spatial analysis of horns for Pb accumulation may be useful as a qualitative marker of time-resolved exposures that may reflect specific periods of acute Pb absorption.

Ultra-trace element analysis of human follicular fluid by ICP-MS/MS: pre-analytical challenges, contamination control, and matrix effects

Follicular fluid (FF), which is the fluid that envelops the developing oocyte (egg cell) in the ovary, can be analyzed to assess trace element content as well as to determine potential exposure to toxic elements in women seeking in vitro fertilization (IVF) treatment. Such measurements may be useful in establishing associations with potential adverse effects on oocyte viability and subsequent pregnancy outcomes. The principal goal of this study was to leverage the next generation of inorganic mass spectrometry based on ICP-MS/MS to address the numerous analytical challenges of (ultra-)trace element analysis of human FF specimens. Ultra-trace element measurements are defined by the Clinical Laboratory Standards Institute as fluid concentrations below 10 μg L^-1 or tissue mass fractions below 1 μg g^-1. Stringent pre-analytical procedures were developed to minimize exogenous contamination during FF specimen collection and storage in a prospective study of 56 women seeking IVF treatment. ICP-MS/MS instrumental parameters were carefully optimized, and the method validated for 11 biologically important elements that included 4 at trace levels (Cu, Se, Sr, and Zn) and 7 at ultra-trace levels (As, Cd, Co, Mo, Mn, Hg, and Pb). Method limits of detection (LODs) for ultra-trace elements varied from 5.6 ng L^-1 for Cd to 0.11 μg L^-1 for Mo. A total of 197 human FF specimens were analyzed using the proposed ICP-MS/MS method with 84% of specimens detectable for Pb and 100% detectable for Co, Cu, Mn, Mo, Sr, and Zn. The method based on ICP-MS/MS was compared to a previous method developed for FF using SF-ICP-MS.

Variability in the spatial density of vacant properties contributes to background lead (Pb) exposure in children

BACKGROUND

Heightened blood lead levels (BLL) are associated with cognitive deficiencies and adverse behavioral outcomes. Lead-contaminated house dust is the primary source of exposure in U.S. children, and evidence suggests that even background (low-level) exposure has negative consequences. Identifying sources of background exposure is of great public health significance because of the larger number of children that can be affected.

METHODS

Blood lead was assessed in a bi-racial sample of children from Syracuse, NY, aged 9-11, using established biomonitoring methods. The spatial density of vacant properties was modelled from publicly available georeferenced datasets. Further, regression models were used to measure the impact of this spatial density variable on children's BLL.

RESULTS

In a sample of 221 children, with a mean BLL of 1.06 µg/dL (SD = 0.68), results showed increases in spatial density of vacant properties predict increases in median blood-PB levels, b = 0.14 (0.06-0.21), p < .001. This association held true even after accounting for demographic covariates, and age of individual housing. Further analysis showed spatial autocorrelation of the residuals changed from a clustered pattern to a random pattern once the spatial density variable was introduced to the model.

DISCUSSION

This study is the first to identify a background-lead exposure source using spatial density modelling. As vacant properties deteriorate, lead-contaminated dust likely disperses into the surrounding environment. High-density areas have an accumulation of lead hazards in environmental media, namely soil and dust, putting more children at risk of exposure.

Lead poisoning risk assessment of radiology workers using lead shields

Purpose: Lead containing dust may be present on the exterior surfaces of shields used to prevent radiation exposure. We determined whether use of lead shields poses an exposure risk for radiology personnel.Methods: We collected hand dustwipe and blood samples from 58 Radiology Department employees of an academic hospital. Samples were analyzed for lead content by atomic absorption spectroscopy. Results were compared between lead apron users (46) and nonusers (12).Results: Hand dustwipe lead was undetectable (<3 µg/sample) in all cases. Blood lead levels ranged from 0-3 µg/dL.Conclusions: In this study of Radiology Department workers, we did not find an increased risk of lead contamination on their hands or in their blood. Although our sample size is small, we conclude that lead poisoning is unlikely to occur with high frequency in lead shield users.

Tracking Declines in Mercury Exposure in the New York City Adult Population, 2004-2014

Mercury is a toxic metal that can be measured in human blood and urine. Population-based biomonitoring from 2004 guided New York City (NYC) Department of Health and Mental Hygiene (DOHMH) efforts to reduce exposures by educating the public about risks and benefits of fish consumption-a predominant source of exposure in the general population-and removing mercury-containing skin-lightening creams and other consumer products from the marketplace. We describe changes in exposures over the past decade in relation to these local public health actions and in the context of national changes by comparing mercury concentrations measured in blood (1201 specimens) and urine (1408 specimens) from the NYC Health and Nutrition Examination Survey (NYC HANES) 2013-2014 with measurements from NYC HANES 2004 and National Health and Nutrition Examination Surveys (NHANES) 2003-2004 and 2013-2014. We found that NYC adult blood and urine geometric mean mercury concentrations decreased 46% and 45%, respectively. Adult New Yorkers with blood mercury concentration ≥ 5 μg/L (the New York State reportable level) declined from 24.8% (95% CL = 22.2%, 27.7%) to 12.0% (95% CL = 10.1%, 14.3%). The decline in blood mercury in NYC was greater than the national decline, while the decline in urine mercury was similar. As in 2004, Asian New Yorkers had higher blood mercury concentrations than other racial/ethnic groups. Foreign-born adults of East or Southeast Asian origin had the highest prevalence of reportable levels (29.7%; 95% CL = 21.0%, 40.1%) across sociodemographic groups, and Asians generally were the most frequent fish consumers, eating on average 11 fish meals in the past month compared with 7 among other groups (p < 0.001). Fish consumption patterns were similar over time, and fish continues to be consumed more frequently in NYC than nationwide (24.7% of NYC adults ate fish ten or more times in the past 30 days vs. 14.7% nationally, p < 0.001). The findings are consistent with the hypothesis that blood mercury levels have declined in part because of local and national efforts to promote consumption of lower mercury fish. Local NYC efforts may have accelerated the reduction in exposure. Having "silver-colored fillings" on five or more teeth was associated with the highest 95th percentile for urine mercury (4.06 μg/L; 95% CL = 3.1, 5.9). An estimated 5.5% of the adult population (95% CL = 4.3%, 7.0%) reported using a skin-lightening cream in the past 30 days, but there was little evidence that use was associated with elevated urine mercury in 2013-14.

Characterization of Arsenic in dried baby shrimp (Acetes sp.) using synchrotron-based X-Ray Spectrometry and LC coupled to ICP-MS/MS

The arsenic content of dried baby shrimp (Acetes sp.) was investigated as part of an independent field study of human exposure to toxic metals/metalloids among the ethnic Chinese community located in Upstate New York. The dried baby shrimp were analyzed in a home environment using a portable X-ray Fluorescence (XRF) instrument based on monochromatic excitation. Study participants had obtained their dried baby shrimp either from a local Chinese market or prepared them at home. The shrimp are typically between 10-20 mm in size and are consumed whole, without separating the tail from the head. Elevated levels of As were detected using portable XRF, ranging between 5-30 μg/g. Shrimp samples were taken to the Cornell High Energy Synchrotron Source (CHESS) for Synchrotron Radiation μXRF (SR-μXRF) elemental mapping using a 384-pixel Maia detector system. The Maia detector provided high resolution trace element images for As, Ca, and Br, (among others) and showed localized accumulation of As within the shrimp's cephalothorax (head), and various abdominal segments. As quantification by SR-μXRF was performed using a Lobster hepatopancreas reference material pellet (NRC-CNRC TORT-2), with results in good agreement with both portable XRF and ICP-MS. Additional As characterization using μX-ray Absorption Near Edge Spectroscopy (μXANES) with the Maia XRF detector at CHESS identified arsenobetaine and/or arsenocholine as the possible As species present. Further arsenic speciation analysis by LC-ICP-MS/MS confirmed that the majority of As (>95%) is present as the largely non-toxic arsenobetaine species with trace amounts of arsenocholine, methylated As and inorganic As species detected.

Declines in adult blood lead levels in New York City compared with the United States, 2004-2014

OBJECTIVES

To assess changes in lead exposure in the New York City (NYC) adult population over a 10-year period and to contrast changes with national estimates, overall, and by socio-demographics and smoking status.

METHODS

We used measurements of blood lead levels (BLLs) from NYC resident adults who participated in the NYC Health and Nutrition Examination Surveys (HANES) in 2004 and 2013-2014. We compared estimates of geometric means (GM), 95th percentiles, and prevalence of BLL ≥ 5 µg/dL overall and by subgroups over time, with adults who participated in the National HANES (NHANES) 2001-2004 and 2011-2014.

RESULTS

The GM BLLs among NYC adults declined from 1.79 µg/dL in 2004 to 1.13 µg/dL in 2013-2014 (P < .0001). The declines over this period ranged from 30.1% to 43.2% across socio-demographic groups and smoking status (P < .0001 for all comparisons), and were slightly greater than declines observed nationally. The drop in prevalence of elevated BLLs (≥ 5 µg/dL) was also greater in NYC (4.8-0.5%), compared with NHANES (3.8-2.0%). By 2013-2014, NYC adults with lower annual family income (< $20,000) no longer had higher GM BLLs relative to those with higher incomes (≥ $75,000), a disparity improvement not observed nationally. Likewise, GM BLLs and 95th percentiles for non-Hispanic black adults in NYC were lower than GM BLLs for non-Hispanic white adults. Non-Hispanic Asian adults had the highest GM BLLs compared with other racial/ethnic groups, both in NYC in 2013-14 and nationally in 2011-2014 (1.37 µg/dL, P = .1048 and 1.22 µg/dL, P = .0004, respectively).

CONCLUSION

The lessening of disparity in lead exposure across income groups and decreasing exposure at the high end of the distribution among non-Hispanic black and Asian adults in NYC suggest that regulatory and outreach efforts have effectively targeted these higher exposure risk groups. However, Asian adults still had the highest average BLL, suggesting a need for enhanced outreach to this group. Local surveillance remains an important tool to monitor BLLs of local populations and to inform initiatives to reduce exposures in those at highest risk.

An assessment of exposure to rare earth elements among patients receiving long-term parenteral nutrition

Patients receiving long-term parenteral nutrition (PN) are exposed to potentially toxic elements, which may accumulate in bone. Bone samples collected from seven PN patients (average = 14 years) and eighteen hip/knee samples were analyzed for Al as part of a previous investigation. Yttrium was serendipitously detected in the PN bone samples, leading to the present investigation of rare earth elements (REEs). A method for quantitating fifteen REEs in digested bone was developed based on tandem ICP-MS (ICP-MS/MS) to resolve spectral interferences. The method was validated against nine biological reference materials (RMs) for which assigned values were available for most REEs. Values found in two NIST bone SRMs (1400 Bone Ash and 1486 Bone Meal) compared favorably to those reported elsewhere. Method detection limits ranged from 0.9 ng g^-1 (Tm) to 5.8 ng g^-1 (Y). Median REE values in the PN patient group were at least fifteen times higher than the "control" group, and exceeded all previously reported data for eleven REEs in human bones. REE content in PN bones normalized to the Earth's upper crust revealed anomalies for Gd in two patients, likely from exposure to Gd-containing contrast agents used in MRI studies. A retrospective review of the medical record for one patient revealed an almost certain case of nephrogenic systemic fibrosis, associated with Gd exposure. Analysis of two current PN formulations showed traces of REEs with relative abundances similar to those found in the PN bones, providing convincing evidence that PN solutions were the primary source of REEs in this population.

The effect of portable HEPA filter air cleaners on indoor PM2.5 concentrations and second hand tobacco smoke exposure among pregnant women in Ulaanbaatar, Mongolia: The UGAAR randomized controlled trial

BACKGROUND

Portable HEPA filter air cleaners can reduce indoor fine particulate matter (PM_2.5), but their use has not been adequately evaluated in high pollution settings. We assessed air cleaner effectiveness in reducing indoor residential PM_2.5 and second hand smoke (SHS) exposures among non-smoking pregnant women in Ulaanbaatar, Mongolia.

METHODS

We randomized 540 participants to an intervention group receiving 1 or 2 HEPA filter air cleaners or a control group receiving no air cleaners. We followed 259 intervention and 253 control participants to the end of pregnancy. We measured one-week indoor residential PM_2.5 concentrations in early (~11weeks gestation) and late (~31weeks gestation) pregnancy and collected outdoor PM_2.5 data from centrally-located government monitors. We assessed blood cadmium in late pregnancy. Hair nicotine was quantified in a subset (n=125) to evaluate blood cadmium as a biomarker of SHS exposure. We evaluated air cleaner effectiveness using mixed effects and multiple linear regression models and used stratified models and interaction terms to evaluate potential modifiers of effectiveness.

RESULTS

The overall geometric mean (GM) one-week outdoor PM_2.5 concentration was 47.9μg/m³ (95% CI: 44.6, 51.6μg/m³), with highest concentrations in winter (118.0μg/m³; 110.4, 126.2μg/m³). One-week indoor and outdoor PM_2.5 concentrations were correlated (r=0.69). Indoor PM_2.5 concentrations were 29% (21, 37%) lower in intervention versus control apartments, with GMs of 17.3μg/m³ (15.8, 18.8μg/m³) and 24.5μg/m³ (22.2, 27.0μg/m³), respectively. Air cleaner effectiveness was greater when air cleaners were first deployed (40%; 31, 48%) than after approximately five months of use (15%; 0, 27%). Blood cadmium concentrations were 14% (4, 23%) lower among intervention participants, likely due to reduced SHS exposure.

CONCLUSIONS

Portable HEPA filter air cleaners can lower indoor PM_2.5 concentrations and SHS exposures in highly polluted settings.

Arsenic exposure induces glucose intolerance and alters global energy metabolism

Environmental pollutants acting as endocrine-disrupting chemicals (EDCs) are recognized as potential contributors to metabolic disease pathogenesis. One such pollutant, arsenic, contaminates the drinking water of ~100 million people globally and has been associated with insulin resistance and diabetes in epidemiological studies. Despite these observations, the precise metabolic derangements induced by arsenic remain incompletely characterized. In the present study, the impact of arsenic on in vivo metabolic physiology was examined in 8-wk-old male C57BL/6J mice exposed to 50 mg/l inorganic arsenite in their drinking water for 8 wk. Glucose metabolism was assessed via in vivo metabolic testing, and feeding behavior was analyzed using indirect calorimetry in metabolic cages. Pancreatic islet composition was assessed via immunofluorescence microscopy. Arsenic-exposed mice exhibited impaired glucose tolerance compared with controls; however, no difference in peripheral insulin resistance was noted between groups. Instead, early insulin release during glucose challenge was attenuated relative to the rise in glycemia. Despite decreased insulin secretion, pancreatic β-cell mass was not altered, suggesting that arsenic primarily disrupts β-cell function. Finally, metabolic cage analyses revealed that arsenic exposure induced novel alterations in the diurnal rhythm of food intake and energy metabolism. Taken together, these data suggest that arsenic exposure impairs glucose tolerance through functional impairments in insulin secretion from β-cells rather than by augmenting peripheral insulin resistance. Further elucidation of the mechanisms underlying arsenic-induced behavioral and β-cell-specific metabolic disruptions will inform future intervention strategies to address this ubiquitous environmental contaminant and novel diabetes risk factor.

Background lead and mercury exposures: Psychological and behavioral problems in children

BACKGROUND

The potential harm from exposure to nonessential metals, particularly mercury (Hg) and lead (Pb), has been the focus of research for years. Initial interest focused on relatively high exposures; however, recent evidence suggests that even background exposures might have adverse consequences for child development. Identifying the extent of these consequences is now a priority.

METHODS

We assessed blood Pb and Hg levels in a biracial sample of 9-11 year-old children (N = 203). Neurodevelopment and psychological functioning assessments included hostility, disruptive behaviors, emotion regulation, and autism spectrum disorder behaviors. Parasympathetic (vagal) responses to acute stress were indexed by heart rate variability (HRV) at rest and during stress.

RESULTS

With increasing Pb levels, children exhibit higher levels of hostile distrust and oppositional defiant behaviors, were more dissatisfied and uncertain about their emotions, and had difficulties with communication. These significant associations were found within a range of blood Pb levels from 0.19 to 3.25μg/dL, well below the "reference value" for children of >5μg/dL. Vagal reactivity interacted with Hg such that increasing Hg was associated with increasing autism spectrum behaviors for those children with sustained vagal tone during acute stress.

CONCLUSIONS

This study is the first to demonstrate an association between very low-level Pb exposure and fundamental psychological mechanisms that might explain prior associations with more complex outcomes such as delinquency. Analyses of vagal reactivity yielded entirely novel associations suggesting that Hg may increase autism spectrum behaviors in children with sustained vagal tone during acute stress. The novelty of these later findings requires additional research for confirmation and the cross-sectional nature of the data caution against assumptions of causality without further research.

Impact of air manganese on child neurodevelopment in East Liverpool, Ohio

BACKGROUND

East Liverpool, Ohio, the site of a hazardous waste incinerator and a manganese (Mn) processor, has had air Mn concentrations exceeding United States Environmental Protection Agency reference levels for over a decade. Save Our County, Inc., a community organization, was formed to address community environmental health concerns related to local industry. Researchers from the University of Cincinnati partnered with Save Our County to determine if air Mn had an impact on the neurocognitive function of children in the community.

METHODS

Children 7-9 years of age from East Liverpool and its surrounding communities, were enrolled (N=106) in the Communities Actively Researching Exposure Study from between March 2013-June 2014. Blood and hair were analyzed for Mn and lead, and serum was analyzed for cotinine. We used linear regression to assess associations between biological measures and IQ subscale scores.

RESULTS

Geometric mean blood lead (n=67), blood Mn (n=66), hair Mn (n=98), and serum cotinine (n=69) concentrations were 1.13±1.96μg/dL, 10.06±1.30μg/L, and 360.22±2.17ng/g, 0.76±6.12μg/L respectively. After adjusting for potential confounders, hair Mn was negatively associated with Full Scale IQ.

CONCLUSIONS

Hair Mn was negatively associated with child IQ scores. Community partners were instrumental in the conception and implementation of this study.

Low-level environmental metals and metalloids and incident pregnancy loss

Environmental exposure to metals and metalloids is associated with pregnancy loss in some but not all studies. We assessed arsenic, cadmium, mercury, and lead concentrations in 501 couples upon trying for pregnancy and followed them throughout pregnancy to estimate the risk of incident pregnancy loss. Using Cox proportional hazard models, we estimated hazard ratios (HR) and 95% confidence intervals (CIs) for pregnancy loss after covariate adjustment for each partner modeled individually then we jointly modeled both partners' concentrations. Incidence of pregnancy loss was 28%. In individual partner models, the highest adjusted HRs were observed for female and male blood cadmium (HR=1.08; CI 0.81, 1.44; HR=1.09; 95% CI 0.84, 1.41, respectively). In couple based models, neither partner's blood cadmium concentrations were associated with loss (HR=1.01; 95% CI 0.75, 1.37; HR=0.92; CI 0.68, 1.25, respectively). We observed no evidence of a significant relation between metal(loids) at these environmentally relevant concentrations and pregnancy loss.

Lead Aprons Are a Lead Exposure Hazard

PURPOSE

To determine whether lead-containing shields have lead dust on the external surface.

METHODS

Institutional review board approval was obtained for this descriptive study of a convenience sample of 172 shields. Each shield was tested for external lead dust via a qualitative rapid on-site test and a laboratory-based quantitative dust wipe analysis, flame atomic absorption spectrometry (FAAS). The χ² test was used to test the association with age, type of shield, lead sheet thickness, storage method, and visual and radiographic appearance.

RESULTS

Sixty-three percent (95% confidence interval [CI]: 56%-70%) of the shields had detectable surface lead by FAAS and 50% (95% CI: 43%-57%) by the qualitative method. Lead dust by FAAS ranged from undetectable to 998 μg/ft². The quantitative detection of lead was significantly associated with the following: (1) visual appearance of the shield (1 = best, 3 = worst): 88% of shields that scored 3 had detectable dust lead; (2) type of shield: a greater proportion of the pediatric patient, full-body, and thyroid shields were positive than vests and skirts; (3) use of a hanger for storage: 27% of shields on a hanger were positive versus 67% not on hangers. Radiographic determination of shield intactness, thickness of interior lead sheets, and age of shield were unrelated to presence of surface dust lead.

CONCLUSIONS

Sixty-three percent of shields had detectable surface lead that was associated with visual appearance, type of shield, and storage method. Lead-containing shields are a newly identified, potentially widespread source of lead exposure in the health industry.