Sequencing-based fine-mapping and in silico functional characterization of the 10q24.32 arsenic metabolism efficiency locus across multiple arsenic-exposed populations.

Inorganic arsenic is highly toxic and carcinogenic to humans. Exposed individuals vary in their ability to metabolize arsenic, and variability in arsenic metabolism efficiency (AME) is associated with risks of arsenic-related toxicities. Inherited genetic variation in the 10q24.32 region, near the arsenic methyltransferase (AS3MT) gene, is associated with urine-based measures of AME in multiple arsenic-exposed populations. To identify potential causal variants in this region, we applied fine mapping approaches to targeted sequencing data generated for exposed individuals from Bangladeshi, American Indian, and European American populations (n = 2,357, 557, and 648 respectively). We identified three independent association signals for Bangladeshis, two for American Indians, and one for European Americans. The size of the confidence sets for each signal varied from 4 to 85 variants. There was one signal shared across all three populations, represented by the same SNP in American Indians and European Americans (rs191177668) and in strong linkage disequilibrium (LD) with a lead SNP in Bangladesh (rs145537350). Beyond this shared signal, differences in LD patterns, minor allele frequency (MAF) (e.g., rs12573221 ~13% in Bangladesh ~0.2% among American Indians), and/or heterogeneity in effect sizes across populations likely contributed to the apparent population specificity of the additional identified signals. One of our potential causal variants influences AS3MT expression and nearby DNA methylation in numerous GTEx tissue types (with rs4919690 as a likely causal variant). Several SNPs in our confidence sets overlap transcription factor binding sites and cis-regulatory elements (from ENCODE). Taken together, our analyses reveal multiple potential causal variants in the 10q24.32 region influencing AME, including a variant shared across populations, and elucidate potential biological mechanisms underlying the impact of genetic variation on AME.

Association of Urinary Metals With Cardiovascular Disease Incidence and All-Cause Mortality in the Multi-Ethnic Study of Atherosclerosis (MESA).

BACKGROUND: Exposure to metals has been associated with cardiovascular disease (CVD) end points and mortality, yet prospective evidence is limited beyond arsenic, cadmium, and lead. In this study, we assessed the prospective association of urinary metals with incident CVD and all-cause mortality in a racially diverse population of US adults from MESA (Multi-Ethnic Study of Atherosclerosis). METHODS: We included 6599 participants (mean [SD] age, 62.1 [10.2] years; 53% female) with urinary metals available at baseline (2000 to 2001) and followed through December 2019. We used Cox proportional hazards models to estimate the adjusted hazard ratio and 95% CI of CVD and all-cause mortality by baseline urinary levels of cadmium, tungsten, and uranium (nonessential metals), and cobalt, copper, and zinc (essential metals). The joint association of the 6 metals as mixture and the corresponding 10-year survival probability was calculated using Cox Elastic-Net. RESULTS: During follow-up, 1162 participants developed CVD, and 1844 participants died. In models adjusted by behavioral and clinical indicators, the HR (95% CI) for incident CVD and all-cause mortality comparing the highest with the lowest quartile were, respectively: 1.25 (1.03, 1.53) and 1.68 (1.43, 1.96) for cadmium; 1.20 (1.01, 1.42) and 1.16 (1.01, 1.33) for tungsten; 1.32 (1.08, 1.62) and 1.32 (1.12, 1.56) for uranium; 1.24 (1.03, 1.48) and 1.37 (1.19, 1.58) for cobalt; 1.42 (1.18, 1.70) and 1.50 (1.29, 1.74) for copper; and 1.21 (1.01, 1.45) and 1.38 (1.20, 1.59) for zinc. A positive linear dose-response was identified for cadmium and copper with both end points. The adjusted HRs (95% CI) for an interquartile range (IQR) increase in the mixture of these 6 urinary metals and the corresponding 10-year survival probability difference (95% CI) were 1.29 (1.11, 1.56) and -1.1% (-2.0, -0.05) for incident CVD and 1.66 (1.47, 1.91) and -2.0% (-2.6, -1.5) for all-cause mortality. CONCLUSIONS: This epidemiological study in US adults indicates that urinary metal levels are associated with increased CVD risk and mortality. These findings can inform the development of novel preventive strategies to improve cardiovascular health.

Cardiovascular Disease Risk Factors in Women: The Impact of Race and Ethnicity: A Scientific Statement From the American Heart Association.

Cardiovascular disease is the leading cause of death in women, yet differences exist among certain racial and ethnic groups. Aside from traditional risk factors, behavioral and environmental factors and social determinants of health affect cardiovascular health and risk in women. Language barriers, discrimination, acculturation, and health care access disproportionately affect women of underrepresented races and ethnicities. These factors result in a higher prevalence of cardiovascular disease and significant challenges in the diagnosis and treatment of cardiovascular conditions. Culturally sensitive, peer-led community and health care professional education is a necessary step in the prevention of cardiovascular disease. Equitable access to evidence-based cardiovascular preventive health care should be available for all women regardless of race and ethnicity; however, these guidelines are not equally incorporated into clinical practice. This scientific statement reviews the current evidence on racial and ethnic differences in cardiovascular risk factors and current cardiovascular preventive therapies for women in the United States.

Omics feature selection with the extended SIS R package: identification of a body mass index epigenetic multimarker in the Strong Heart Study.

The statistical analysis of omics data poses a great computational challenge given their ultra-high-dimensional nature and frequent between-features correlation. In this work, we extended the iterative sure independence screening (ISIS) algorithm by pairing ISIS with elastic-net (Enet) and 2 versions of adaptive elastic-net (adaptive elastic-net (AEnet) and multistep adaptive elastic-net (MSAEnet)) to efficiently improve feature selection and effect estimation in omics research. We subsequently used genome-wide human blood DNA methylation data from American Indian participants in the Strong Heart Study (n = 2235 participants; measured in 1989-1991) to compare the performance (predictive accuracy, coefficient estimation, and computational efficiency) of ISIS-paired regularization methods with that of a bayesian shrinkage and traditional linear regression to identify an epigenomic multimarker of body mass index (BMI). ISIS-AEnet outperformed the other methods in prediction. In biological pathway enrichment analysis of genes annotated to BMI-related differentially methylated positions, ISIS-AEnet captured most of the enriched pathways in common for at least 2 of all the evaluated methods. ISIS-AEnet can favor biological discovery because it identifies the most robust biological pathways while achieving an optimal balance between bias and efficient feature selection. In the extended SIS R package, we also implemented ISIS paired with Cox and logistic regression for time-to-event and binary endpoints, respectively, and a bootstrap approach for the estimation of regression coefficients.

Baseline characteristics including blood and urine metal levels in the Trial to Assess Chelation Therapy 2 (TACT2).

BACKGROUND: The reduction in cardiovascular disease (CVD) events with edetate disodium (EDTA) in the Trial to Assess Chelation Therapy (TACT) suggested that chelation of toxic metals might provide novel opportunities to reduce CVD in patients with diabetes. Lead and cadmium are vasculotoxic metals chelated by EDTA. We present baseline characteristics for participants in TACT2, a randomized, double-masked, placebo-controlled trial designed as a replication of the TACT trial limited to patients with diabetes. METHODS: TACT2 enrolled 1,000 participants with diabetes and prior myocardial infarction, age 50 years or older between September 2016 and December 2020. Among 959 participants with at least one infusion, 933 had blood and/or urine metals measured at the Centers for Diseases Control and Prevention using the same methodology as in the National Health and Nutrition Examination Survey (NHANES). We compared metal levels in TACT2 to a contemporaneous subset of NHANES participants with CVD, diabetes and other inclusion criteria similar to TACT2's participants. RESULTS: At baseline, the median (interquartile range, IQR) age was 67 (60, 72) years, 27% were women, 78% reported white race, mean (SD) BMI was 32.7 (6.6) kg/m2, 4% reported type 1 diabetes, 46.8% were treated with insulin, 22.3% with GLP1-receptor agonists or SGLT-2 inhibitors, 90.2% with aspirin, warfarin or P2Y12 inhibitors, and 86.5% with statins. Blood lead was detectable in all participants; median (IQR) was 9.19 (6.30, 13.9) µg/L. Blood and urine cadmium were detectable in 97% and median (IQR) levels were 0.28 (0.18, 0.43) µg/L and 0.30 (0.18, 0.51) µg/g creatinine, respectively. Metal levels were largely similar to those in the contemporaneous NHANES subset. CONCLUSIONS: TACT2 participants were characterized by high use of medication to treat CVD and diabetes and similar baseline metal levels as in the general US population. TACT2 will determine whether chelation therapy reduces the occurrence of subsequent CVD events in this high-risk population. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov. Identifier: NCT02733185. https://clinicaltrials.gov/study/NCT02733185.

Blood DNA methylation and liver cancer in American Indians: evidence from the Strong Heart Study.

PURPOSE: Liver cancer incidence among American Indians/Alaska Natives has risen over the past 20 years. Peripheral blood DNA methylation may be associated with liver cancer and could be used as a biomarker for cancer risk. We evaluated the association of blood DNA methylation with risk of liver cancer. METHODS: We conducted a prospective cohort study in 2324 American Indians, between age 45 and 75 years, from Arizona, Oklahoma, North Dakota and South Dakota who participated in the Strong Heart Study between 1989 and 1991. Liver cancer deaths (n = 21) were ascertained using death certificates obtained through 2017. The mean follow-up duration (SD) for non-cases was 25.1 (5.6) years and for cases, 11.0 (8.8) years. DNA methylation was assessed from blood samples collected at baseline using MethylationEPIC BeadChip 850 K arrays. We used Cox regression models adjusted for age, sex, center, body mass index, low-density lipoprotein cholesterol, smoking, alcohol consumption, and immune cell proportions to examine the associations. RESULTS: We identified 9 CpG sites associated with liver cancer. cg16057201 annotated to MRFAP1) was hypermethylated among cases vs. non-cases (hazard ratio (HR) for one standard deviation increase in methylation was 1.25 (95% CI 1.14, 1.37). The other eight CpGs were hypomethylated and the corresponding HRs (95% CI) ranged from 0.58 (0.44, 0.75) for cg04967787 (annotated to PPRC1) to 0.77 (0.67, 0.88) for cg08550308. We also assessed 7 differentially methylated CpG sites associated with liver cancer in previous studies. The adjusted HR for cg15079934 (annotated to LPS1) was 1.93 (95% CI 1.10, 3.39). CONCLUSIONS: Blood DNA methylation may be associated with liver cancer mortality and may be altered during the development of liver cancer.

Arsenic Exposure, Blood DNA Methylation, and Cardiovascular Disease.

BACKGROUND: Epigenetic dysregulation has been proposed as a key mechanism for arsenic-related cardiovascular disease (CVD). We evaluated differentially methylated positions (DMPs) as potential mediators on the association between arsenic and CVD. METHODS: Blood DNA methylation was measured in 2321 participants (mean age 56.2, 58.6% women) of the Strong Heart Study, a prospective cohort of American Indians. Urinary arsenic species were measured using high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry. We identified DMPs that are potential mediators between arsenic and CVD. In a cross-species analysis, we compared those DMPs with differential liver DNA methylation following early-life arsenic exposure in the apoE knockout (apoE-/-) mouse model of atherosclerosis. RESULTS: A total of 20 and 13 DMPs were potential mediators for CVD incidence and mortality, respectively, several of them annotated to genes related to diabetes. Eleven of these DMPs were similarly associated with incident CVD in 3 diverse prospective cohorts (Framingham Heart Study, Women's Health Initiative, and Multi-Ethnic Study of Atherosclerosis). In the mouse model, differentially methylated regions in 20 of those genes and DMPs in 10 genes were associated with arsenic. CONCLUSIONS: Differential DNA methylation might be part of the biological link between arsenic and CVD. The gene functions suggest that diabetes might represent a relevant mechanism for arsenic-related cardiovascular risk in populations with a high burden of diabetes.

Edetate Disodium-Based Chelation for Patients With a Previous Myocardial Infarction and Diabetes: TACT2 Randomized Clinical Trial.

Importance: In 2013, the Trial to Assess Chelation Therapy (TACT) reported that edetate disodium (EDTA)-based chelation significantly reduced cardiovascular disease (CVD) events by 18% in 1708 patients with a prior myocardial infarction (MI). Objective: To replicate the finding of TACT in individuals with diabetes and previous MI. Design, Setting, and Participants: A 2 × 2 factorial, double-masked, placebo-controlled, multicenter trial at 88 sites in the US and Canada, involving participants who were 50 years or older, had diabetes, and had experienced an MI at least 6 weeks before recruitment compared the effect of EDTA-based chelation vs placebo infusions on CVD events and compared the effect of high doses of oral multivitamins and minerals with oral placebo. This article reports on the chelation vs placebo infusion comparisons. Interventions: Eligible participants were randomly assigned to 40 weekly infusions of an EDTA-based chelation solution or matching placebo and to twice daily oral, high-dose multivitamin and mineral supplements or matching placebo for 60 months. This article addresses the chelation study. Main Outcomes and Measures: The primary end point was the composite of all-cause mortality, MI, stroke, coronary revascularization, or hospitalization for unstable angina. Median follow-up was 48 months. Primary comparisons were made from patients who received at least 1 assigned infusion. Results: Of the 959 participants (median age, 67 years [IQR, 60-72 years]; 27% females; 78% White, 10% Black, and 20% Hispanic), 483 received at least 1 chelation infusion and 476 at least 1 placebo infusion. A primary end point event occurred in 172 participants (35.6%) in the chelation group and in 170 (35.7%) in the placebo group (adjusted hazard ratio [HR], 0.93; 95% CI, 0.76-1.16; P = .53). The 5-year primary event cumulative incidence rates were 45.8% for the chelation group and 46.5% for the placebo group. CV death, MI, or stroke events occurred in 89 participants (18.4%) in the chelation group and in 94 (19.7%) in the placebo group (adjusted HR, 0.89; 95% CI, 0.66-1.19). Death from any cause occurred in 84 participants (17.4%) in the chelation group and in 84 (17.6%) in the placebo group (adjusted HR, 0.96; 95% CI, 0.71-1.30). Chelation reduced median blood lead levels from 9.03 µg/L at baseline to 3.46 µg/L at infusion 40 (P < .001). Corresponding levels in the placebo group were 9.3 µg/L and 8.7 µg/L, respectively. Conclusions and Relevance: Despite effectively reducing blood lead levels, EDTA chelation was not effective in reducing cardiovascular events in stable patients with coronary artery disease who have diabetes and a history of MI. Trial Registration: ClinicalTrials.gov Identifier: NCT02733185.

Inclusion of Drinking Water Source and Testing Questions into Electronic Medical Records: Advancing Environmental Medicine and Public Health Outreach in New Jersey.

Chronic arsenic exposure is associated with adverse health outcomes, and early life exposure is particularly damaging. Households with pregnant people and young children drinking from unregulated wells in arsenic-prevalent regions are therefore a public health priority for outreach and intervention. A partnership between Columbia University, New Jersey government partners, and Hunterdon Healthcare has informed Hunterdon County residents of the risks faced from drinking arsenic-contaminated water and offered free well testing through a practice-based water test kit distribution and an online patient portal outreach. Encouraged by those successes, Hunterdon Healthcare incorporated questions about drinking water source and arsenic testing history into the electronic medical record (EMR) template used by most primary care practices in Hunterdon County. The new EMR fields allow for additional targeting of risk-based outreach and water test kit distribution, offering promising new opportunities for public health and environmental medicine outreach, surveillance, and research.

Toxic Metals and Subclinical Atherosclerosis in Carotid, Femoral, and Coronary Vascular Territories: The Aragon Workers Health Study.

OBJECTIVE: Studies evaluating the association of metals with subclinical atherosclerosis are mostly limited to carotid arteries. We assessed individual and joint associations of nonessential metals exposure with subclinical atherosclerosis in 3 vascular territories. Approach and Results: One thousand eight hundred seventy-three Aragon Workers Health Study participants had urinary determinations of inorganic arsenic species, barium, cadmium, chromium, antimony, titanium, uranium, vanadium, and tungsten. Plaque presence in carotid and femoral arteries was determined by ultrasound. Coronary Agatston calcium score ≥1 was determined by computed tomography scan. Median arsenic, barium, cadmium, chromium, antimony, titanium, uranium, vanadium, and tungsten levels were 1.83, 1.98, 0.27, 1.18, 0.05, 9.8, 0.03, 0.66, and 0.23 µg/g creatinine, respectively. The adjusted odds ratio (95% CI) for subclinical atherosclerosis presence in at least one territory was 1.25 (1.03-1.51) for arsenic, 1.67 (1.22-2.29) for cadmium, and 1.26 (1.04-1.52) for titanium. These associations were driven by arsenic and cadmium in carotid, cadmium and titanium in femoral, and titanium in coronary territories and mostly remained after additional adjustment for the other relevant metals. Titanium, cadmium, and antimony also showed positive associations with alternative definitions of increased coronary calcium. Bayesian Kernel Machine Regression analysis simultaneously evaluating metal associations suggested an interaction between arsenic and the joint cadmium-titanium exposure. CONCLUSIONS: Our results support arsenic and cadmium and identify titanium and potentially antimony as atherosclerosis risk factors. Exposure reduction and mitigation interventions of these metals may decrease cardiovascular risk in individuals without clinical disease.

The Pregnancy, Arsenic, and Immune Response (PAIR) Study in rural northern Bangladesh.

BACKGROUND: Arsenic exposure and micronutrient deficiencies may alter immune reactivity to influenza vaccination in pregnant women, transplacental transfer of maternal antibodies to the foetus, and maternal and infant acute morbidity. OBJECTIVES: The Pregnancy, Arsenic, and Immune Response (PAIR) Study was designed to assess whether arsenic exposure and micronutrient deficiencies alter maternal and newborn immunity and acute morbidity following maternal seasonal influenza vaccination during pregnancy. POPULATION: The PAIR Study recruited pregnant women across a large rural study area in Gaibandha District, northern Bangladesh, 2018-2019. DESIGN: Prospective, longitudinal pregnancy and birth cohort. METHODS: We conducted home visits to enrol pregnant women in the late first or early second trimester (11-17 weeks of gestational age). Women received a quadrivalent seasonal inactivated influenza vaccine at enrolment. Follow-up included up to 13 visits between enrolment and 3 months postpartum. Arsenic was measured in drinking water and maternal urine. Micronutrient deficiencies were assessed using plasma biomarkers. Vaccine-specific antibody titres were measured in maternal and infant serum. Weekly telephone surveillance ascertained acute morbidity symptoms in women and infants. PRELIMINARY RESULTS: We enrolled 784 pregnant women between October 2018 and March 2019. Of 784 women who enrolled, 736 (93.9%) delivered live births and 551 (70.3%) completed follow-up visits to 3 months postpartum. Arsenic was detected (≥0.02 µg/L) in 99.7% of water specimens collected from participants at enrolment. The medians (interquartile ranges) of water and urinary arsenic at enrolment were 5.1 (0.5, 25.1) µg/L and 33.1 (19.6, 56.5) µg/L, respectively. Water and urinary arsenic were strongly correlated (Spearman's ⍴ = 0.72) among women with water arsenic ≥ median but weakly correlated (⍴ = 0.17) among women with water arsenic < median. CONCLUSIONS: The PAIR Study is well positioned to examine the effects of low-moderate arsenic exposure and micronutrient deficiencies on immune outcomes in women and infants. REGISTRATION: NCT03930017.

Cohort Network: A Knowledge Graph toward Data Dissemination and Knowledge-Driven Discovery for Cohort Studies.

Contemporary environmental health sciences draw on large-scale longitudinal studies to understand the impact of environmental exposures and behavior factors on the risk of disease and identify potential underlying mechanisms. In such studies, cohorts of individuals are assembled and followed up over time. Each cohort generates hundreds of publications, which are typically neither coherently organized nor summarized, hence limiting knowledge-driven dissemination. Hence, we propose a Cohort Network, a multilayer knowledge graph approach to extract exposures, outcomes, and their connections. We applied the Cohort Network on 121 peer-reviewed papers published over the past 10 years from the Veterans Affairs (VA) Normative Aging Study (NAS). The Cohort Network visualized connections between exposures and outcomes across different publications and identified key exposures and outcomes, such as air pollution, DNA methylation, and lung function. We demonstrated the utility of the Cohort Network for new hypothesis generation, e.g., identification of potential mediators of exposure-outcome associations. The Cohort Network can be used by investigators to summarize the cohort's research and facilitate knowledge-driven discovery and dissemination.

Exposure to metals among Electronic Nicotine Delivery System (ENDS) users in the PATH study: A longitudinal analysis.

BACKGROUND: Few studies have evaluated Electronic Nicotine Delivery Systems (ENDS) in longitudinal studies, as a potential source of metals which may have carcinogenic, neurotoxic, and cardiotoxic effects. We evaluated metal body burden by ENDS use status in a longitudinal population-based national survey. METHODS: We used the Population Assessment of Tobacco and Health (PATH) Study wave 1 (2013-2014), wave 2 (2014-2015), and wave 3 (2015-2016) adult data to assess urinary concentrations of seven metals among (1) ENDS only users who never used any nonelectronic tobacco products (n = 50), (2) ENDS only users who were former users of any nonelectronic tobacco products (n = 123) and (3) Never users (n = 1501) of any tobacco product. RESULTS: Among ENDS only users who never used any nonelectronic tobacco products (n = 50), the geometric mean ratios (GMRs) of Cd and Pb were 1.25 (95%CI: 1.09-1.42) and 1.19 (95%CI: 1.05-1.34), respectively, compared to never users after adjustment for PATH Study wave, age, sex, race/ethnicity, education, region, secondhand smoke at home and work, and cannabis and other substance use. After the same adjustment, the corresponding GMRs were 1.48 (95%CI: 1.32-1.67) and 1.43 (95%CI: 1.28-1.60) for ENDS only users who were former users of any nonelectronic tobacco products (n = 123). No difference was observed in urinary concentrations of other metals comparing ENDS users to never users of any tobacco product. DISCUSSION: ENDS users show higher urinary levels of Cd and Pb, including lifetime exclusive ENDS users compared to never users of any tobacco product. These findings are limited by the small sample size and could be related to underreporting of past combustible tobacco use or other factors. Metals typical of ENDS such as nickel and chromium unfortunately are not available in PATH. Studies assessing metal exposure associated with long term lifetime exclusive ENDS use (≥5 years) with larger sample size are needed.

Cross-sectional associations between drinking water arsenic and urinary inorganic arsenic in the United States: NHANES 2003-2014.

BACKGROUND: Inorganic arsenic is a potent carcinogen and toxicant associated with numerous adverse health outcomes. The contribution of drinking water from private wells and regulated community water systems (CWSs) to total inorganic arsenic exposure is not clear. OBJECTIVES: To determine the association between drinking water arsenic estimates and urinary arsenic concentrations in the 2003-2014 National Health and Nutrition Examination Survey (NHANES). METHODS: We evaluated 11,088 participants from the 2003-2014 NHANES cycles. For each participant, we assigned private well and CWS arsenic levels according to county of residence using estimates previously derived by the U.S. Environmental Protection Agency and U.S. Geological Survey. We used recalibrated urinary dimethylarsinate (rDMA) to reflect the internal dose of estimated water arsenic by applying a previously validated, residual-based method that removes the contribution of dietary arsenic sources. We compared the adjusted geometric mean ratios and corresponding percent change of urinary rDMA across tertiles of private well and CWS arsenic levels, with the lowest tertile as the reference. Comparisons were made overall and stratified by census region and race/ethnicity. RESULTS: Overall, the geometric mean of urinary rDMA was 2.52 (2.30, 2.77) µg/L among private well users and 2.64 (2.57, 2.72) µg/L among CWS users. Urinary rDMA was highest among participants in the West and South, and among Mexican American, Other Hispanic, and Non-Hispanic Other participants. Urinary rDMA levels were 25% (95% confidence interval (CI): 17-34%) and 20% (95% CI: 12-29%) higher comparing the highest to the lowest tertile of CWS and private well arsenic, respectively. The strongest associations between water arsenic and urinary rDMA were observed among participants in the South, West, and among Mexican American and Non-Hispanic White and Black participants. DISCUSSION: Both private wells and regulated CWSs are associated with inorganic arsenic internal dose as reflected in urine in the general U.S.

Exposure to secondhand and thirdhand smoke in private vehicles: Measurements in air and dust samples.

BACKGROUND: This study aimed to estimate airborne nicotine concentrations and nicotine, cotinine, and tobacco-specific nitrosamines (TSNAs) in settled dust from private cars in Spain and the UK. METHODS: We measured vapor-phase nicotine concentrations in a convenience sample of 45 private cars from Spain (N = 30) and the UK (N = 15) in 2017-2018. We recruited non-smoking drivers (n = 20), smoking drivers who do not smoke inside the car (n = 15), and smoking drivers who smoke inside (n = 10). Nicotine, cotinine, and three TSNAs (NNK, NNN, NNA) were also measured in settled dust in a random subsample (n = 20). We computed medians and interquartile ranges (IQR) of secondhand smoke (SHS) and thirdhand smoke (THS) compounds according to the drivers' profile. RESULTS: 24-h samples yielded median airborne nicotine concentrations below the limit of quantification (LOQ) (IQR:

Fine particulate matter composition in American Indian vs. Non-American Indian communities.

BACKGROUND: Fine particulate matter (PM2.5) exposure is a known risk factor for numerous adverse health outcomes, with varying estimates of component-specific effects. Populations with compromised health conditions such as diabetes can be more sensitive to the health impacts of air pollution exposure. Recent trends in PM2.5 in primarily American Indian- (AI-) populated areas examined in previous work declined more gradually compared to the declines observed in the rest of the US. To further investigate components contributing to these findings, we compared trends in concentrations of six PM2.5 components in AI- vs. non-AI-populated counties over time (2000-2017) in the contiguous US. METHODS: We implemented component-specific linear mixed models to estimate differences in annual county-level concentrations of sulfate, nitrate, ammonium, organic matter, black carbon, and mineral dust from well-validated surface PM2.5 models in AI- vs. non-AI-populated counties, using a multi-criteria approach to classify counties as AI- or non-AI-populated. Models adjusted for population density and median household income. We included interaction terms with calendar year to estimate whether concentration differences in AI- vs. non-AI-populated counties varied over time. RESULTS: Our final analysis included 3108 counties, with 199 (6.4%) classified as AI-populated. On average across the study period, adjusted concentrations of all six PM2.5 components in AI-populated counties were significantly lower than in non-AI-populated counties. However, component-specific levels in AI- vs. non-AI-populated counties varied over time: sulfate and ammonium levels were significantly lower in AI- vs. non-AI-populated counties before 2011 but higher after 2011 and nitrate levels were consistently lower in AI-populated counties. CONCLUSIONS: This study indicates time trend differences of specific components by AI-populated county type. Notably, decreases in sulfate and ammonium may contribute to steeper declines in total PM2.5 in non-AI vs. AI-populated counties. These findings provide potential directives for additional monitoring and regulations of key emissions sources impacting tribal lands.

Anthropometric measures and arsenic methylation among pregnant women in rural northern Bangladesh.

INTRODUCTION: Arsenic methylation converts inorganic arsenic (iAs) to monomethyl (MMA) and dimethyl (DMA) arsenic compounds. Body mass index (BMI) has been positively associated with arsenic methylation efficiency (higher DMA%) in adults, but evidence in pregnancy is inconsistent. We estimated associations between anthropometric measures and arsenic methylation among pregnant women in rural northern Bangladesh. METHODS: We enrolled pregnant women (n = 784) (median [IQR] gestational week: 14 [13, 15]) in Gaibandha District, Bangladesh from 2018 to 2019. Anthropometric measures were BMI, subscapular and triceps skinfold thicknesses, and mid-upper arm circumference (MUAC), fat area (MUAFA), and muscle area (MUAMA). Arsenic methylation measures were urinary iAs, MMA, and DMA divided by their sum and multiplied by 100 (iAs%, MMA%, and DMA%), primary methylation index (MMA/iAs; PMI), and secondary methylation index (DMA/MMA; SMI). In complete cases (n = 765 [97.6%]), we fitted linear, beta, and Dirichlet regression models to estimate cross-sectional differences in iAs%, MMA%, DMA%, PMI, and SMI per IQR-unit difference in each anthropometric measure, adjusting for drinking water arsenic, age, gestational age, education, living standards index, and plasma folate, vitamin B12, and homocysteine. RESULTS: Median (IQR) BMI, subscapular skinfold thickness, triceps skinfold thickness, MUAC, MUAFA, and MUAMA were 21.5 (19.4, 23.8) kg/m2, 17.9 (13.2, 24.2) mm, 14.2 (10.2, 18.7) mm, 25.9 (23.8, 28.0) cm, 15.3 (10.5, 20.3) cm2, and 29.9 (25.6, 34.2) cm2, respectively. Median (IQR) iAs%, MMA%, DMA%, PMI, and SMI were 12.0 (9.3, 15.2)%, 6.6 (5.3, 8.3)%, 81.0 (77.1, 84.6)%, 0.6 (0.4, 0.7), and 12.2 (9.3, 15.7), respectively. In both unadjusted and adjusted linear models, all anthropometric measures were negatively associated with iAs%, MMA%, and PMI and positively associated with DMA% and SMI. For example, fully adjusted mean differences (95% CI) in DMA% per IQR-unit difference in BMI, subscapular skinfolds thickness, triceps skinfold thickness, MUAC, MUAFA, and MUAMA were 1.72 (1.16, 2.28), 1.58 (0.95, 2.21), 1.74 (1.11, 2.37), 1.45 (0.85, 2.06), 1.70 (1.08, 2.31), and 0.70 (0.13, 1.27) pp, respectively. CONCLUSIONS: Anthropometric measures were positively associated with arsenic methylation efficiency among pregnant women in the early second trimester.

Behavioral determinants of arsenic-safe water use among Great Plains Indian Nation private well users: results from the Community-Led Strong Heart Water Study Arsenic Mitigation Program.

BACKGROUND: The objective of this study was to evaluate the behavioral determinants associated with exclusive use of arsenic-safe water in the community-led Strong Heart Water Study (SHWS) arsenic mitigation program. METHODS: The SHWS is a randomized controlled trial of a community-led arsenic mitigation program designed to reduce arsenic exposure among private well users in American Indian Great Plains communities. All households received point-of-use (POU) arsenic filters installed at baseline and were followed for 2 years. Behavioral determinants selected were those targeted during the development of the SHWS program, and were assessed at baseline and follow-up. RESULTS: Among participants, exclusive use of arsenic-safe water for drinking and cooking at follow-up was associated with higher self-efficacy for accessing local resources to learn about arsenic (OR: 5.19, 95% CI: 1.48-18.21) and higher self-efficacy to resolve challenges related to arsenic in water using local resources (OR: 3.11, 95% CI: 1.11-8.71). Higher commitment to use the POU arsenic filter faucet at baseline was also a significant predictor of exclusive arsenic-safe water use for drinking (OR: 32.57, 95% CI: 1.42-746.70) and cooking (OR: 15.90, 95% CI: 1.33-189.52) at follow-up. From baseline to follow-up, the SHWS program significantly increased perceived vulnerability to arsenic exposure, self-efficacy, descriptive norms, and injunctive norms. Changing one's arsenic filter cartridge after installation was associated with higher self-efficacy to obtain arsenic-safe water for drinking (OR: 6.22, 95% CI: 1.33-29.07) and cooking (OR: 10.65, 95% CI: 2.48-45.68) and higher perceived vulnerability of personal health effects (OR: 7.79, 95% CI: 1.17-51.98) from drinking arsenic-unsafe water. CONCLUSIONS: The community-led SHWS program conducted a theory-driven approach for intervention development and evaluation that allowed for behavioral determinants to be identified that were associated with the use of arsenic safe water and changing one's arsenic filter cartridge. These results demonstrate that theory-driven, context-specific formative research can influence behavior change interventions to reduce water arsenic exposure. The SHWS can serve as a model for the design of theory-driven intervention approaches that engage communities to reduce arsenic exposure. TRIAL REGISTRATION: The SHWS is registered with ClinicalTrials.gov (Identifier: NCT03725592).

The trial to assess chelation therapy 2 (TACT2): Rationale and design.

BACKGROUND: Intravenous edetate disodium-based infusions reduced cardiovascular events in a prior clinical trial. The Trial to Assess Chelation Therapy 2 (TACT2) will replicate the initial study design. METHODS: TACT2 is an NIH-sponsored, randomized, 2x2 factorial, double masked, placebo-controlled, multicenter clinical trial testing 40 weekly infusions of a multi-component edetate disodium (disodium ethylenediamine tetra-acetic acid, or Na2EDTA)-based chelation solution and twice daily oral, high-dose multivitamin and mineral supplements in patients with diabetes and a prior myocardial infarction (MI). TACT2 completed enrollment of 1000 subjects in December 2020, and infusions in December 2021. Subjects are followed for 2.5 to 5 years. The primary endpoint is time to first occurrence of all-cause mortality, MI, stroke, coronary revascularization, or hospitalization for unstable angina. The trial has >;85% power to detect a 30% relative reduction in the primary endpoint. TACT2 also includes a Trace Metals and Biorepository Core Lab, to test whether benefits of treatment, if present, are due to chelation of lead and cadmium from patients. Design features of TACT2 were chosen to replicate selected features of the first TACT, which demonstrated a significant reduction in cardiovascular outcomes in the EDTA chelation arm compared with placebo among patients with a prior MI, with the largest effect in patients with diabetes. RESULTS: Results are expected in 2024. CONCLUSION: TACT2 may provide definitive evidence of the benefit of edetate disodiumbased chelation on cardiovascular outcomes, as well as the clinical importance of longitudinal changes in toxic metal levels of participants.

Air Pollution in American Indian Versus Non-American Indian Communities, 2000-2018.

Objectives. To compare fine particulate matter (PM2.5) concentrations in American Indian (AI)-populated with those in non-AI-populated counties over time (2000-2018) in the contiguous United States. Methods. We used a multicriteria approach to classify counties as AI- or non--AI-populated. We ran linear mixed effects models to estimate the difference in countywide annual PM2.5 concentrations from well-validated prediction models and monitoring sites (modeled and measured PM2.5, respectively) in AI- versus non-AI-populated counties. Results. On average, adjusted modeled PM2.5 concentrations in AI-populated counties were 0.38 micrograms per cubic meter (95% confidence interval [CI] = 0.23, 0.54) lower than in non-AI-populated counties. However, this difference was not constant over time: in 2000, modeled concentrations in AI-populated counties were 1.46 micrograms per cubic meter (95% CI = 1.25, 1.68) lower, and by 2018, they were 0.66 micrograms per cubic meter (95% CI = 0.45, 0.87) higher. Over the study period, adjusted modeled PM2.5 mean concentrations decreased by 2.13 micrograms per cubic meter in AI-populated counties versus 4.26 micrograms per cubic meter in non-AI-populated counties. Results were similar for measured PM2.5. Conclusions. This study highlights disparities in PM2.5 trends between AI- and non-AI-populated counties over time, underscoring the need to strengthen air pollution regulations and prevention implementation in tribal territories and areas where AI populations live. (Am J Public Health. 2022;112(4): 615-623. https://doi.org/10.2105/AJPH.2021.306650).