Associations of estimated residential soil arsenic and lead concentrations and community-level environmental measures with mother-child health conditions in South Carolina

Association between blood lead, cadmium, selenium levels and hyperlipidemia: A population-based study

BACKGROUND

There are limited epidemiological investigations of blood metal levels related to hyperlipidemia, and results indicating the association between blood lead (Pb), cadmium (Cd) and selenium (Se), and lipid biomarkers have been conflicting.

METHODS

We included populations for which NHANES collected complete data. Multivariate logistic regression and subgroup analyses were conducted to ascertain the relationship between blood Pb, Cd, and Se levels and hyperlipidemia. Nonlinear relationships were characterized by smoothed curve fitting and threshold effect analysis.

RESULTS

5429 participants in all, with a mean age of 53.70 ± 16.63 years, were included; 47.1% of the subjects were male, and 3683 (67.8%) of them had hyperlipidemia. After modifying for variables with confounders in a multivariate logistic regression model, we discovered a positive correlation between blood Pb and Se levels and hyperlipidemia (Pb: OR:2.12, 95% CI:1.56-2.88; Se: OR:1.84, 95% CI:1.38-2.45). Gender, age, smoking status, alcohol use status, hypertension, diabetes, and body mass index were not significantly linked with this positive correlation, according to subgroup analysis and interaction test (P for interaction>0.05). Positive correlations between blood Pb, Cd, and Se levels and the risk of hyperlipidemia have been found using smooth curve fitting.

CONCLUSIONS

This study demonstrates that higher blood levels of Pb, Cd, and selenium are linked to an increased risk of hyperlipidemia.

Urinary Arsenic Concentration and Its Relationship with Bronchial Asthma in Children from Arica, Chile

In the city of Arica, northern Chile, the population has been involuntarily exposed to arsenic of natural and anthropogenic origin. This study aims to evaluate the association between urinary arsenic concentration and bronchial asthma diagnosis in the children of Arica. A cross-sectional analysis of a database of 1892 subjects under 18 years of age enrolled in the Environmental Health Centre between 2009 and 2021 was carried out. Arsenic exposure was obtained from a urine sample and bronchial asthma diagnosis from the database of the system for the management of explicit health guarantees. Logistic regression models were used to assess the association between inorganic arsenic and asthma. The median inorganic arsenic was 15 μg/L, and the prevalence of asthma was 7.4%. After adjusting for sex, age, ethnicity, and urinary creatinine, children with the highest tertile of urinary arsenic concentration (≥21.4 μg/L) had a greater chance of developing asthma (odds ratio (OR) 1.90; 95% confidence interval (CI) [1.13-3.18]). When exploring the modifying effect of ethnicity, the association increased among children belonging to any ethnic group (OR 3.51, 95%CI [1.43-8.65]). These findings suggest a relationship between arsenic exposure and bronchial asthma in children. While further studies are needed to assess the impact of arsenic on respiratory health, mitigation efforts to reduce arsenic exposure should be maintained.

The Effect of Mixture of Heavy Metals on Obesity in Individuals ≥50 Years of Age

Little is known about the association between a mixture of heavy metals and obesity among individuals ≥50 years of age with comorbidities. Thus, we identified the associations of serum cadmium (Cd), lead (Pb), and mercury (Hg) with obesity using linear regression models; weighted quantile sum (WQS) regression, quantile g-computation (qgcomp), and Bayesian kernel machine regression (BKMR) were conducted as secondary analyses. Of the 6434 subjects included in the analysis, 13.8% had obesity and 44.6% had abdominal obesity. In the logistic regression model, serum Hg was associated with obesity and abdominal obesity, and significant trends were observed for these heavy metal tertiles (p < 0.001). Serum Hg levels were also associated with body mass index (BMI) and waist circumference (WC). The WQS index was significantly associated with both obesity (OR = 1.43, 95% CI: 1.40-1.46) and abdominal obesity (β = 1.51, 95% CI: 1.48-1.54). The qgcomp index also found a significant association between heavy metals and both obesity (OR = 1.35, 95% CI: 1.12-1.63) and abdominal obesity (OR = 1.34, 95% CI: 1.12-1.60). Serum Hg was the most heavily weighed heavy metal in these models. In BKMR analysis, the overall effect of the mixture was significantly associated with obesity, BMI, and WC. Serum Hg showed positive trends and was observed as the most important factor associated with obesity, BMI, and WC. Our findings were largely robust to secondary analyses that used three novel mixture modeling approaches: WQS, qpcomp, and BKMR. Given increasing exposure to heavy metals, well-characterized cohorts of individuals aged ≥50 years are required to determine the mixed effects of heavy metals on obesity and related diseases.

Association of Metals and Metalloids With Urinary Albumin/Creatinine Ratio: Evidence From a Cross-Sectional Study Among Elderly in Beijing

Background

Environmental exposure to toxic elements contributes to the pathogenesis of chronic kidney disease (CKD). Few studies focus on the association of urinary metals and metalloids concentrations with the urinary albumin/creatinine ratio (UACR) among elderly, especially in areas and seasons with severe air pollution.

Objective

We aimed to evaluate the associations of urinary metals and metalloids concentration with UACR, which is an early and sensitive indicator of CKD.

Method

We conducted a cross-sectional study among 275 elderly people in Beijing from November to December 2016, which has experienced the most severe air pollution in China. We measured 15 urinary metals and metalloids concentration and estimated their association with UACR using a generalized linear model (GLM). Bayesian kernel machine regression (BKMR) and quantile g-computation (qgcomp) models were also conducted to evaluate the combined effect of metal and metalloid mixtures concentration.

Results

Of the 275 elderly people included in the analysis, we found that higher urinary Cu concentration was positively associated with UACR using GLM (β = 0.36, 95% CI: 0.25, 0.46). Using the BKMR model, we found that the change in UACR was positively associated with a change in urinary Cu concentration from its 25th to 75th percentile value with all other metals and metalloids concentration fixed at their 25th, 50th, or 75th percentile levels. Urinary Cu concentration had the most significant positive contribution (59.15%) in the qgcomp model. Our finding was largely robust in three mixture modeling approaches: GLM, qgcomp, and BKMR.

Conclusion

This finding suggests that urinary Cu concentration was strongly positively associated with UACR. Further analyses in cohort studies are required to corroborate this finding.

Environmental science and pollution research role of heavy metal concentrations and vitamin intake from food in depression: a national cross-sectional study (2009-2017)

Little is known about associations between depression and serum heavy metal levels, dietary vitamin intakes. Thus, we sought to determine the nature of these associations and to predict risks of depression using marginal effects. A data set of 16,371 individuals aged ≥10 years that participated in Korea National Health and Nutrition Examination Surveys (KNHANES) conducted from 2009 to 2017 (excluding 2014 and 2015) was used to obtain information on sociodemographics, family histories, lifestyles, serum heavy metal levels, food intakes, and depression. Serum cadmium (Cd) and lead (Pb) levels were analyzed by graphite furnace atomic absorption spectrometry and mercury (Hg) levels using a mercury analyzer. Daily vitamin intakes were calculated by 24-h dietary recall. The results obtained showed that females are at higher risk of depression than males. A doubling of serum Cd was associated with a 21% increase in depression (AOR 1.21, 95% CI: 1.07-1.37, p = 0.002), whereas twofold increases in daily vitamin B1, B3 and vitamin A intakes reduced the risk of depression by 17% (0.83, 95% CI: 0.73-0.95, p = 0.005), 20% (0.80, 95% CI: 0.70-0.91, p = 0.001), and 8% (0.92, 95% CI: 0.85-0.99, p = 0.020), respectively. Interactions between heavy metals, vitamin intakes, and sex did not influence the risk of depression. The result shows that increased daily dietary vitamin intake might protect the public against depression. Further studies are needed to reduce the risks posed by heavy metals and to determine more comprehensively the effects of daily dietary vitamin intake on depression.

Association between heavy metals, high-sensitivity C-reaction protein and 10-year risk of cardiovascular diseases among adult Korean population

The prevalence of cardiovascular diseases (CVDs) in Korea tends to be increasing. It has worsened during the COVID-19 pandemic. Increasing evidence shows heavy metals are associated with increased CVD risk. We aimed to determine the association between the serum heavy metal levels and 10-year risk of CVDs and to predict risks of CVDs based on marginal effects. Heavy metals were measured by a graphite furnace atomic absorption spectrometry and direct mercury analyzer. The results show a significant relationship between the increase in cadmium, lead, mercury, hs-CRP levels and the 10-year risk of CVD after adjustment for serum cotinine, age group, sex, body mass index, a family history of CVDs, diabetes or hyperlipidemia, high-risk drinking, physical activity, and diabetes. A doubling of serum cadmium, lead, mercury, and hs-CRP was associated with the increase in the 10-year risk of CVD by 0.14%, 0.10%, 0.11% and 0.22%, respectively. Therefore, a special concern should be given to the harmful impacts of heavy metals on the 10-year risk of CVD. It is important to develop a prevention strategy targeting the high-risk population to slow down this progression to risk factors related to heavy metals and reduce prevalence. Remarkedly, hs-CRP is the most validated and widely used inflammatory marker, and could be a potential clinical value in predicting and monitoring CVDs.

Environmental Justice in the American Public Health Context: Trends in the Scientific Literature at the Intersection Between Health, Environment, and Social Status

Although various governmental entities in the USA are required to consider environmental justice (EJ) impacts of their actions during decision-making, socially vulnerable groups continue to be disproportionately exposed to environmental hazards. Tools and programs to quantify and mitigate environmental injustices are limited by existing data, which may not capture the full range of health disparities exacerbated by the complex interactions between environmental exposures and social stressors. In this study, we analyzed how the scientific literature approaches EJ issues in the USA. We searched PubMed for journal articles discussing at least one sociodemographic or environmental variable in the context of cumulative impacts and analyzed the relative frequency with which various EJ topics were studied. Our findings indicate that demographic variables are commonly used in epidemiologic studies, though some areas (e.g., age) are better studied than others. Similarly, occupational exposure and ambient air pollution were more studied than other types of exposures. Word frequency analyses revealed which toxicants and health outcomes are the most frequently studied. In addition, temporality analyses showed that the rate of occupational publications rose rapidly in the 1970-1980s and has since plateaued, while other publication rates increased two decades later and are still on the rise. Cumulative impacts are considered in a relatively small portion of journal articles across all topics; nevertheless, they have seen an exponential climb in the last decade. A more equitable distribution of scientific efforts might be needed for a better distribution of funding, policy-making efforts, and other resources to socially and environmentally vulnerable communities.

A new screening index to better target low-level lead exposure in Atlanta, Georgia

Lead poisoning is often seen as a problem of the past. While acute cases are now rare, there is no known safe level of lead for children and blood lead levels at and below 5 μg/dL are associated with neurological deficits. Previous work has established that risk factors for lead exposure include race/ethnicity, poverty, Medicaid enrollment, housing built before 1950, and age. Efficient blood lead screening is crucial in the greater Atlanta area as pockets of poverty and old housing put some children at particularly high risk for chronic exposure to low levels of lead. Here, 20 years of data on children’s blood lead levels in Georgia were used to create maps to assess the spatial distribution of blood lead screening and blood lead levels in the Atlanta area. ZIP code tabulation area (ZCTA)-level screening rates continue to be associated with relative poverty but not with housing age, a well-established risk factor for lead exposure. Building on previous research, a priority screening index based on poverty and housing age was also created to identify specific high-risk census tracts for screening within Atlanta ZCTAs. This index shows a total of 18 highest-priority census tracts in the greater Atlanta area. Together, these 18 tracts contain 2715 children under six years old, 1.7% of all children under six years old in the entire greater Atlanta area.

Blood lead levels in children in urban and rural areas: Using multilevel modeling to investigate impacts of gender, race, poverty, and the environment

Many studies of children's exposure to lead (Pb) are carried out in urban and industrialized environments. This study analyzed blood lead level (BLL) data collected from 2011 to 2016 from approximately 140,000 children ages <1 to 6 years across South Carolina (SC), including urban and rural areas. Individual-level characteristics included children's age, and race/ethnicity. Block group variables examined included population by race and ethnicity, households below the poverty level, median year homes built, urban/rural classification, and percent road coverage. BLL were higher in urban compared to rural children but increased to a greater extent in rural children from age < 1 year to 2 years. Road coverage was strongly associated with higher BLL in urban areas, and with home age more weakly, but neither road coverage nor home age was associated with BLL in rural areas. Young urban children may receive greater exposure to Pb from house dust and outdoor legacy Pb contamination, and young rural children through diet and drinking water. Black children had higher BLL in urban areas than white children, and the converse was true in rural areas. Population data indicated that rural areas had more poverty than urban areas, but strong associations between increased children's BLL and either ethnicity or socio-economic status (SES) at the block group level was not observed, likely due to distinct characteristics of poverty and geographic distribution by ethnicity in urban as compared to rural areas of SC. Individual demographics and environmental characteristics may be more closely associated with BLL than geographically aggregated SES and race/ethnicity characteristics. Interventions to reduce children's exposure to Pb should occur at as early an age as possible, and differences between rural and urban areas should be considered as interventions are developed to reduce children's BLL.

High prevalence of elevated blood lead levels in both rural and urban Iowa newborns: Spatial patterns and area-level covariates

Lead in maternal blood can cross the placenta and result in elevated blood lead levels in newborns, potentially producing negative effects on neurocognitive function, particularly if combined with childhood lead exposure. Little research exists, however, into the burden of elevated blood lead levels in newborns, or the places and populations in which elevated lead levels are observed in newborns, particularly in rural settings. Using ~2300 dried bloods spots collected within 1-3 days of birth among Iowa newborns, linked with the area of mother's residence at the time of birth, we examine the spatial patterns of elevated (>5 μg/dL) blood lead levels and the ecological-level predictors of elevated blood lead levels. We find that one in five newborns exceed the 5 μg/dL action level set by the US Centers for Disease Control & Prevention (CDC). Bayesian spatial zero inflated regression indicates that elevated blood lead in newborns is associated with areas of increased pre-1940s housing and childbearing-age women with low educational status in both rural and urban settings. No differences in blood lead levels or the proportion of children exceeding 5 μg/dL are observed between urban and rural maternal residence, though a spatial cluster of elevated blood lead is observed in rural counties. These characteristics can guide the recommendation for testing of infants at well-baby appointments in places where risk factors are present, potentially leading to earlier initiation of case management. The findings also suggest that rural populations are at as great of risk of elevated blood lead levels as are urban populations. Analysis of newborn dried blood spots is an important tool for lead poisoning surveillance in newborns and can direct public health efforts towards specific places and populations where lead testing and case management will have the greatest impact.

Potential sources and racial disparities in the residential distribution of soil arsenic and lead among pregnant women

Exposure to arsenic (As) or lead (Pb) has been associated with adverse health outcomes, and high-risk populations can be disproportionately exposed to these metals in soils. The objectives of this study were: to examine if predicted soil As and Pb concentrations at maternal residences of South Carolina (SC) low-income mothers differed based on maternal race (non-Hispanic black versus white), to examine whether differences in predicted residential soil As and Pb concentrations among black and white mothers differed by socioeconomic status (SES), and to examine whether such disparities persisted after controlling for anthropogenic sources of these metals, including direction from, and distance to industrial facilities. Kriged soil As and Pb concentrations were estimated at maternal residences in 11 locations in SC, and models with maternal race and individual and US Census block group level SES measures were examined. US Environmental Protection Agency Toxics Release Inventory (TRI) facility As and Pb releases categorized by distance and direction to block groups in which mothers resided were also identified, as were proxy measures for historic use of leaded gasoline (road density) and Pb-based paint (categories of median year home built by US Census block group). Consistent racial disparities were observed for predicted residential soil As and Pb concentrations, and the disparity was stronger for Pb than As (betas from adjusted models for black mothers were 0.12 and 2.2 for As and Pb, respectively, all p<0.006). Higher road density and older homes in block groups were more closely associated with higher predicted soil As and Pb concentrations than on-site releases of As and Pb categorized by facility location. These findings suggest that non-Hispanic black mothers in this study population had elevated residential As and Pb soil concentrations, after adjusting for SES, and that soil As and Pb concentrations were not associated with recent industrial releases.

Association of serum lead and mercury level with cardiometabolic risk factors and liver enzymes in a nationally representative sample of adolescents: the CASPIAN-III study

This study aims to determine the difference of serum Pb and Hg levels in adolescents with or without metabolic syndrome (MetS) and the association of serum levels of these heavy metals with cardiometabolic risk factors and liver enzymes in Iranian adolescents. The study population consisted of 320 adolescents (160 with MetS and 160 healthy controls). The relationship between serum heavy metals and cardiometabolic risk factors was assessed by linear regression. The odds ratios (OR) of having metabolic syndrome across Pb and Hg quartiles were determined by multiple logistic regression analysis. The mean (SD) of Pb and Hg concentrations were higher in adolescents with MetS than in those without it (0.83 (0.27) and 0.17 (0.01) vs. 0.65 (0.15) and 0.10 (0.08) μg/L, P = 0.01 and 0.0001, respectively). Increase in serum Pb and Hg was associated with increase in some cardiometabolic risk factors. Among boys and girls, diastolic blood pressure (DBP), fasting blood glucose, total cholesterol (TC), triglycerides (TG), and alanine aminotransaminase increased significantly across quartiles of serum Pb. Among girls, SBP, DBP, TC, and TG had a significant increase across Hg quartiles. The corresponding figure among boys was significant for SBP, DBP, and TG. Higher quartiles of Pb increased the risk of having MetS (OR 95 % CI 3.10, 2.25-4.27), the corresponding figure was 2.03, 1.75-3.16, across Hg quartiles. Our study showed significant associations between serum Pb and Hg levels with cardiometabolic risk factors in adolescents. In future surveys, the role of potential confounders should be considered more extensively. The clinical significance of these findings needs to be confirmed in longitudinal studies. By considering the origins of chronic diseases from early life, controlling environmental pollutants should be considered as a health priority for primordial or primary prevention of noncommunicable diseases.

Associations between land cover categories, soil concentrations of arsenic, lead and barium, and population race/ethnicity and socioeconomic status

The potential of using land cover/use categories as a proxy for soil metal concentrations was examined by measuring associations between Anderson land cover category percentages and soil concentrations of As, Pb, and Ba in ten sampling areas. Land cover category and metal associations with ethnicity and socioeconomic status at the United States Census 2000 block and block group levels also were investigated. Arsenic and Pb were highest in urban locations; Ba was a function of geology. Consistent associations were observed between urban/built up land cover, and Pb and poverty. Land cover can be used as proxy for metal concentrations, although associations are metal-dependent.

Association between risk of birth defects occurring level and arsenic concentrations in soils of Lvliang, Shanxi province of China

The risk of birth defects is generally accredited with genetic factors, environmental causes, but the contribution of environmental factors to birth defects is still inconclusive. With the hypothesis of associations of geochemical features distribution and birth defects risk, we collected birth records and measured the chemical components in soil samples from a high prevalence area of birth defects in Shanxi province, China. The relative risk levels among villages were estimated with conditional spatial autoregressive model and the relationships between the risk levels of the villages and the 15 types of chemical elements concentration in the cropland and woodland soils were explored. The results revealed that the arsenic levels in cropland soil showed a significant association with birth defects occurring risk in this area, which is consistent with existing evidences of arsenic as a teratogen and warrants further investigation on arsenic exposure routine to birth defect occurring risk.

Temporal and spatial variation in residential soil metal concentrations: implications for exposure assessments

Understanding temporal and spatial variation in soil chemicals is critical in exposure assessments. We measured eight metals in subsamples, duplicates (~0.3 m), and repeat soil samples taken 1-6 years after initial sampling (~5 m). We estimated variance components (VCs) of metal concentrations using nested analyses accounting for sampling area, land use and soil type, and calculated coefficients of variation (CVs) for repeat sample pairs. Total variance for all metals was similar, but VCs were proportioned differently by metal and sample type. Spatial variation explained the majority of variance in duplicate samples. CVs of metal concentrations were not significantly different over the long time interval, but repeat samples had larger VCs for unexplained error. Sampling area and land use were important for Ba and Mn, and Pb and Hg, respectively. Results suggest metals are stable over long times and suitable for exposure assessments, but that individual metal behavior should be considered.

Environmental arsenic contamination and its health effects in a historic gold mining area of the Mangalur greenstone belt of Northeastern Karnataka, India

This report summarizes recent findings of environmental arsenic (As) contamination and the consequent health effects in a community located near historic gold mining activities in the Mangalur greenstone belt of Karnataka, India. Arsenic contents in water, hair, nail, soil and food were measured by FI-HG-AAS. Elemental analyses of soils were determined by ICP-MS (inductively coupled plasma-mass spectrometry). Of 59 tube-well water samples, 79% had As above 10 μg L(-1) (maximum 303 μg L(-1)). Of 12 topsoil samples, six were found to contain As greater than 2000 mg kg(-1) possibly indicating the impact of mine tailings on the area. All hair and nail samples collected from 171 residents contained elevated As. Arsenical skin lesions were observed among 58.6% of a total 181 screened individuals. Histopathological analysis of puncture biopsies of suspected arsenical dermatological symptoms confirmed the diagnosis in three out of four patients. Based on the time-course of As-like symptoms reported by the community as well as the presence of overt arsenicosis, it is hypothesized that the primary route of exposure in the study area was via contaminated groundwater; however, the identified high As content in residential soil could also be a significant source of As exposure via ingestion. Additional studies are required to determine the extent as well as the relative contribution of geologic and anthropogenic factors in environmental As contamination in the region. This study report is to our knowledge one of the first to describe overt arsenicosis in this region of Karnataka, India as well as more broadly an area with underlying greenstone geology and historic mining activity.

Tanshinone I activates the Nrf2-dependent antioxidant response and protects against As(III)-induced lung inflammation in vitro and in vivo

AIMS

The NF-E2 p45-related factor 2 (Nrf2) signaling pathway regulates the cellular antioxidant response and activation of Nrf2 has recently been shown to limit tissue damage from exposure to environmental toxicants, including As(III). In an attempt to identify improved molecular agents for systemic protection against environmental insults, we have focused on the identification of novel medicinal plant-derived Nrf2 activators.

RESULTS

Tanshinones [tanshinone I (T-I), tanshinone IIA, dihydrotanshinone, cryptotanshinone], phenanthrenequinone-based redox therapeutics derived from the medicinal herb Salvia miltiorrhiza, have been tested as experimental therapeutics for Nrf2-dependent cytoprotection. Using a dual luciferase reporter assay overexpressing wild-type or mutant Kelch-like ECH-associated protein-1 (Keap1), we demonstrate that T-I is a potent Keap1-C151-dependent Nrf2 activator that stabilizes Nrf2 by hindering its ubiquitination. In human bronchial epithelial cells exposed to As(III), T-I displays pronounced cytoprotective activity with upregulation of Nrf2-orchestrated gene expression. In Nrf2 wild-type mice, systemic administration of T-I attenuates As(III) induced inflammatory lung damage, a protective effect not observed in Nrf2 knockout mice.

INNOVATION

Tanshinones have been identified as a novel class of Nrf2-inducers for antioxidant tissue protection in an in vivo As(III) inhalation model, that is relevant to low doses of environmental exposure.

CONCLUSION

T-I represents a prototype Nrf2-activator that displays cytoprotective activity upon systemic administration targeting lung damage originating from environmental insults. T-I based Nrf2-directed systemic intervention may provide therapeutic benefit in protecting other organs against environmental insults.

Associations between soil lead concentrations and populations by race/ethnicity and income-to-poverty ratio in urban and rural areas

Lead (Pb) is a well-studied environmental contaminant that has many negative health effects, especially for children. Both racial/ethnic and income disparities have been documented with respect to exposure to Pb in soils. The objectives of this study were to assess whether soil Pb concentrations in rural and urban areas of South Carolina USA, previously identified as having clusters of intellectual disabilities (ID) in children, were positively associated with populations of minority and low-income individuals and children (≤ 6 years of age). Surface soils from two rural and two urban areas with identified clusters of ID were analyzed for Pb and concentrations were spatially interpolated using inverse distance weighted analysis. Population race/ethnicity and income-to-poverty ratio (ITPR) from United States Census 2000 block group data were aerially interpolated by block group within each area. Urban areas had significantly higher concentrations of Pb than rural areas. Significant positive associations between black, non-Hispanic Latino, individuals and children ≤ 6 years of age and mean estimated Pb concentrations were observed in both urban (r = 0.38, p = 0.0007) and rural (r = 0.53, p = 0.04) areas. Significant positive associations also were observed between individuals and children with an ITPR < 1.00 and Pb concentrations, though primarily in urban areas. Racial/ethnic minorities and low ITPR individuals, including children, may be at elevated risk for exposure to Pb in soils.