Environmental Exposure to Arsenic, Lead, and Cadmium in People Living near Janghang Copper Smelter in Korea

Environmental risk score of multiple pollutants for kidney damage among residents in vulnerable areas by occupational chemical exposure in Korea

This study aimed to develop an environmental risk score (ERS) of multiple pollutants (MP) causing kidney damage (KD) in Korean residents near abandoned metal mines or smelters and evaluate the association between ERS and KD by a history of occupational chemical exposure (OCE). Exposure to MP, consisting of nine metals, four polycyclic aromatic hydrocarbons, and four volatile organic compounds, was measured as urinary metabolites. The study participants were recruited from the Forensic Research via Omics Markers (FROM) study (n = 256). Beta-2-microglobulin (β2-MG), N-acetyl-β-D-glucosaminidase (NAG), and estimated glomerular filtration rate (eGFR) were used as biomarkers of KD. Bayesian kernel machine regression (BKMR) was selected as the optimal ERS model with the best performance and stability of the predicted effect size among the elastic net, adaptive elastic net, weighted quantile sum regression, BKMR, Bayesian additive regression tree, and super learner model. Variable importance was estimated to evaluate the effects of metabolites on KD. When stratified with the history of OCE after adjusting for several confounding factors, the risks for KD were higher in the OCE group than those in the non-OCE group; the odds ratio (OR; 95% CI) for ERS in non-OCE and OCE groups were 2.97 (2.19, 4.02) and 6.43 (2.85, 14.5) for β2-MG, 1.37 (1.01, 1.86) and 4.16 (1.85, 9.39) for NAG, and 4.57 (3.37, 6.19) and 6.44 (2.85, 14.5) for eGFR, respectively. We found that the ERS stratified history of OCE was the most suitable for evaluating the association between MP and KD, and the risks were higher in the OCE group than those in the non-OCE group.

Associations between plasma metabolites and heavy metal exposure in residents of environmentally polluted areas

Heavy metals are commonly released into the environment through industrial processes such as mining and refining. The rapid industrialization that occurred in South Korea during the 1960s and 1970s contributed significantly to the economy of the country; however, the associated mining and refining led to considerable environmental pollution, and although mining is now in decline in South Korea, the detrimental effects on residents inhabiting the surrounding areas remain. The bioaccumulation of toxic heavy metals leads to metabolic alterations in human homeostasis, with disruptions in this balance leading to various health issues. This study used metabolomics to explore metabolomic alterations in the plasma samples of residents living in mining and refining areas. The results showed significant increases in metabolites involved in glycolysis and the surrounding metabolic pathways, such as glucose-6-phosphate, phosphoenolpyruvate, lactate, and inosine monophosphate, in those inhabiting polluted areas. An investigation of the associations between metabolites and blood clinical parameters through meet-in-the-middle analysis indicated that female residents were more affected by heavy metal exposure, resulting in more metabolomic alterations. For women, inhabiting the abandoned mine area, metabolites in the glycolysis and pentose phosphate pathways, such as ribose-5-phosphate and 3-phosphoglycerate, have shown a negative correlation with albumin and calcium. Finally, Mendelian randomization(MR) was used to determine the causal effects of these heavy metal exposure-related metabolites on heavy metal exposure-related clinical parameters. Metabolite biomarkers could provide insights into altered metabolic pathways related to exposure to toxic heavy metals and improve our understanding of the molecular mechanisms underlying the health effects of toxic heavy metal exposure.

Association Between Multiple Heavy Metal Exposures and Cholesterol Levels in Residents Living Near a Smelter Plant in Korea

BACKGROUND

Considering the interactions between heavy metals, a comprehensive evaluation of the effects of exposure to various types of co-interacting heavy metals on health is required. This study assessed the association between dyslipidemia markers and blood mercury, lead, cadmium, iron, zinc, and nickel levels in residents of an abandoned refinery plant.

METHODS

A total of 972 individuals (exposed group: 567, control group: 405) living near the Janghang refinery plant in the Republic of Korea were included. Blood mercury, lead, cadmium, iron, zinc, nickel, cholesterol, and triglyceride levels were measured. The combined effect of the six heavy metals on dyslipidemia markers was evaluated using a Bayesian kernel machine regression (BKMR) model and compared with the results of a linear regression analysis. The BKMR model results were compared using a stratified analysis of the exposed and control groups.

RESULTS

In the BKMR model, the combined effect of the six heavy metals was significantly associated with total cholesterol (TC) levels both below the 45th percentile and above the 55th percentile in the total population. The combined effect range between the 25th and 75th percentiles of the six metals on TC levels was larger in the exposed group than that in the total population. In the control group, the combined effects of the changes in concentration of the six heavy metals on the TC concentration were not statistically significant.

CONCLUSION

These results suggest that the cholesterol levels of residents around the Janghang refinery plant may be elevated owing to exposure to multiple heavy metals.

Associations of multiple plasma metals with osteoporosis: findings from the Dongfeng-Tongji cohort

With the aging population, osteoporosis has become a more prevalent public health issue. Existing researches have indicated significant relations of single metal exposure with osteoporosis (e.g., lead, copper, and zinc), whereas the evidence regarding the joint association of metal mixtures with osteoporosis remain limited and inconclusive. A total of 4924 participants from the Dongfeng-Tongji cohort were included in the present study. Plasma levels of 23 metals were determined by inductively coupled plasma mass spectrometry, and the presence of osteoporosis was defined as a bone mineral density T-score ≤  - 2.5. We applied stepwise regression, plasma metal score, and quantile g-computation model to evaluate the association between plasma metal mixtures and osteoporosis risk. Of the 4924 participants, the prevalence of osteoporosis was 10.9% (N = 265) in males and 27.5% (N = 684) in females. In the multiple-metals model, arsenic was positively associated with osteoporosis in males, while zinc was positively associated with osteoporosis in females. Comparing extreme quartiles, the multivariate-adjusted ORs of osteoporosis were 2.20 (95% CI, 1.29, 3.79; P-trend = 0.006) for arsenic in males and 2.16 (95% CI, 1.44, 3.23; P-trend < 0.001) for zinc in females. The plasma metal score was significantly and positively associated with a higher risk of osteoporosis, with ORs (95% CI) comparing extreme quartiles were 5.00 (95% CI, 3.36, 7.65; P-trend < 0.001) in males and 1.76 (95% CI, 1.35, 2.29; P-trend < 0.001) in females. Furthermore, the results of quantile g-computation revealed a consistent positive trend of metal mixtures with risk of osteoporosis and suggested the dominant role of arsenic in males and zinc in females, respectively. Our findings highlighted the importance of controlling metal mixtures exposure for the prevention of osteoporosis in the middle-aged and elder population. Further prospective studies in larger populations are warranted to confirm our findings.

A comprehensive review on environmental pollutants and osteoporosis: Insights into molecular pathways

A significant problem that has an impact on community wellbeing is environmental pollution. Environmental pollution due to air, water, or soil pollutants might pose a severe risk to global health, necessitating intense scientific effort. Osteoporosis is a common chronic condition with substantial clinical implications on mortality, morbidity, and quality of life. It is closely linked to bone fractures. Worldwide, osteoporosis affects around 200 million people, and every year, there are almost 9 million fractures. There is evidence that certain environmental factors may increase the risk of osteoporosis in addition to traditional risk factors. It is crucial to understand the molecular mechanisms at play because there is a connection between osteoporosis and exposure to environmental pollutants such as heavy metals, air pollutants, endocrine disruptors, metal ions and trace elements. Hence, in this scoping review, we explore potential explanations for the link between pollutants and bone deterioration through deep insights into molecular pathways. Understanding and recognizing these pollutants as modifiable risk factors for osteoporosis would possibly help to enhance environmental policy thereby aiding in the improvement of bone health and improving patient quality of life.

Impact of multi-heavy metal exposure on renal damage indicators in Korea: An analysis using Bayesian Kernel Machine Regression

Exposure to cadmium (Cd), arsenic (As), and mercury (Hg) is associated with renal tubular damage. People living near refineries are often exposed to multiple heavy metals at high concentrations. This cross-sectional study investigated the association between combined urinary Cd, As, and Hg levels and renal damage markers in 871 residents living near the Janghang refinery plant and in a control area. Urinary Cd, As, Hg, N-acetyl-β-D-glucosaminidase (NAG), and β2-microglobulin (β2-MG) levels were measured. The combined effects of Cd, As, and Hg on renal tubular damage markers were assessed using linear regression and a Bayesian Kernel Machine Regression (BKMR) model. The results of the BKMR model were compared using a stratified analysis of the exposure and control groups. While the linear regression showed that only Cd concentration was significantly associated with urinary NAG levels (β = 0.447, P value < .05), the BKMR model showed that Cd and Hg levels were also significantly associated with urinary NAG levels. The combined effect of the 3 heavy metals on urinary NAG levels was significant and stronger in the exposure group than in the control group. However, no relationship was observed between the exposure concentrations of the 3 heavy metals and urinary β2-MG levels. The results suggest that the BKMR model can be used to assess the health effects of heavy-metal exposure on vulnerable residents.

Exposure to Hazardous Substances and Their Health Effects Among Residents Living Near Three Industrial Waste Incinerators in Korea

BACKGROUND

This study aimed to evaluate exposure to various hazardous substances emitted by incineration facilities and their likely effect on the health for residents of Bugi-myeon, Cheongju, Korea, which has three incineration facilities.

METHODS

Heavy metals, polycyclic aromatic hydrocarbons (PAHs), and dioxin concentrations in the air and soil of exposed and control areas were measured. Moreover, the exposure levels to harmful substances and its effects on health were investigated in 1,124 exposed and 232 control adults.

RESULTS

PAHs and dioxin concentrations in the air in the exposed area were significantly higher than in the control area. Urinary cadmium and PAHs metabolite concentrations were significantly higher in the exposed group than in the control group. The exposure group also had a higher prevalence of depression and self-reported allergic symptoms than the control group.

CONCLUSION

The possibility of residents in Bugi-myeon being exposed to hazardous substances at incineration facilities cannot be ruled out. To prevent them from further exposure to hazardous substances, it is necessary to prohibit the expansion of additional incineration facilities in this area and to implement continuous monitoring projects for residents.

Built and social indices for hazards in Children's environments

Leveraging the capabilities of the Historical Spatial Data Infrastructure (HSDI) and composite indices we explore the importance of children's built and social environments on health. We apply contemporary GIS methods to a set of 2000 historical school records contextualized within an existing HSDI to establish seven variables measuring the relative quality of each child's built and social environments. We then combined these variables to create a composite index that assesses acute (short-term) health risks generated by their environments. Our results show that higher acute index values significantly correlated with higher presence of disease in the home. Further, higher income significantly correlated with lower acute index values, indicating that the relative quality of children's environments in our study area were constrained by familial wealth. This work demonstrates the importance of analyzing multiple activity spaces when assessing built and social environments, as well as the importance of spatial microdata.

Lead intoxication-induced exosomes promote autophagy and apoptosis in renal proximal tubule cells by activating the adenosine 5'-monophosphate-activated protein kinase signaling

Lead (Pb) intoxication is known to damage the proximal tubules of kidney. Autophagy and apoptosis have been shown to be involved in a variety of renal injuries, but the underlying mechanisms remain largely unknown. In this study, we constructed a mice model of Pb intoxication and validated it against lead concentrations in blood and urine. Electron microscopy revealed that Pb promoted the accumulation of autophagosomes. Subsequent immunofluorescence and western blotting revealed that Pb intoxication suppressed the autophagic flux. Next, exosomes were isolated and extracted through ultracentrifugation, and were further identified by diameter analysis and marker detection. We also demonstrated that autophagy and apoptosis were enhanced in renal cells with exosomes of Pb expose. Furthermore, the specific mechanisms were explored by RNA sequencing and it was found that several targeted genes regulated by differential exosomal miRNAs and lncRNAs. Target genes accumulated in several signaling pathways, especially the adenosine 5'-monophosphate-activated protein kinase (AMPK) signaling. We found that Pb intoxication-induced exosomes activated the AMPK signaling in renal proximal tubule cells. Furthermore, autophagy and apoptosis assays showed that GSK-690693, an AMPK inhibitor, significantly alleviated exosome-induced renal injuries by Pb intoxication. In conclusion, Pb-mediated exosome-induced autophagy and apoptosis via activating the AMPK signaling contributing to Pb-induced nephrotoxicity in renal cells.

Association between levels of exposure to heavy metals and renal function indicators of residents in environmentally vulnerable areas

Abandoned metal mines and refineries are considered environmentally vulnerable areas owing to high levels of exposure to heavy metals. This study examined the association between heavy metal exposure and renal function indicators. We studied a total of 298 participants, of which 74 and 68 resided in low- and high-exposure abandoned metal mine areas, respectively, with 121 in the refinery area and 35 in the control area. Blood and urine samples were collected from the participants to analyze the levels of blood lead, cadmium, and creatinine and urinary cadmium, NAG, and β2-MG. The estimated glomerular filtration rate, which is calculated using the Chronic Kidney Disease Epidemiology Collaboration equation, was used for assessments. The study participants comprised more females than males, and their mean age was 70.3 years. The blood lead and cadmium as well as urinary cadmium levels were 2.12 μg/dL, 1.89 μg/L, and 2.11 μg/L, respectively, in the heavy metal-exposure areas, and 1.18 μg/dL, 0.89 μg/L, and 1.11 μg/L, respectively, in the control area. The odds ratio (OR) for exceeding the reference value showed that blood cadmium in the refinery area was 38 times higher than that in the control area. Urinary cadmium was seven times higher in the low-exposure abandoned metal mine area than in the control area. NAG showed a positive correlation with urinary cadmium in all areas. In the refinery area, correlations were observed between β2-MG and urinary cadmium levels and the eGFR and blood cadmium level; in the high-exposure abandoned metal mine area, correlations were observed between NAG, β2-MG, and the eGFR and blood cadmium. In this study, the association between Cd exposure and some renal function indicators was observed. This study's findings and the obtained biological samples can serve as a basis for future molecular biological research.

Health Status and Quality of Life in the Population near Zhezkazgan Copper Smelter, Kazakhstan

Background

The industrial city of Zhezkazgan is one of the most important cities in the industrial sector and the most polluted city in the Republic of Kazakhstan. There is placed Kazakhstan's largest copper smelter. The entire technological process (extraction, crushing, grinding, purification, and smelting of pure ingots) of the production of the copper smelter releases into the environment mainly various kinds of solid particles, sulfur oxides (SOx), and various carcinogenic elements. Emissions from the industrial facilities extend to a significant area around the city, combined with other sources of environmental pollution (motor transport, thermal power plant, individual heating systems, and others).

Objective

This study assessed the health status of residents of villages near Zhezkazgan by screening, quality of life studies, and official medical statistics.

Methods

This study assessed the health status and quality of life of residents near Zhezkazgan city. The cohort included residents from Talap village (main group) and Malshybai village (comparison group) from the Ulytau district in the Karaganda region. The sampling for the health check and quality of life survey covered 260 adult residents of Talap village and 146 adult residents of Malshybai village. Univariate analysis was used to calculate the odds ratio (OR) with a 95% confidence interval (95% CI).

Results

In the city district of Zhezkazgan, the overall mortality rate and mortality from diseases of the circulatory system, neoplasms, and respiratory diseases were much higher than in the Karaganda region and the Republic of Kazakhstan from 2015-2020. Residents of the Talap settlement had higher rates of coronary heart disease (CHD) (OR 1.30; 95% CI: 0.70-2.39; and p < 0.05), arterial hypertension (AH) (OR 1.84; 95% CI: 1.11-3.03; and p < 0.05), decreased hemoglobin (OR 1.89; 95% CI: 1.17-3.07; and p < 0.05), and endocrine diseases (diabetes mellitus, obesity, and thyrotoxicosis) (OR 1.76; 95% CI: 1.12-2.79; and p < 0.05) at registration than residents of the Malshybai settlement. Residents of both settlements expressed dissatisfaction with the quality of drinking water and the presence of the area where launch vehicles fell.

Conclusion

Indicators of pollution in the city, statistics of official mortality, and differences in morbidity indicated the negative impact of hazardous emissions from industrial facilities of the copper smelter on public health.

Validity of Geolocation and Distance to Exposure Sources from Geographical Information Systems for Environmental Monitoring of Toxic Metal Exposures Based on Correlation with Biological Samples: a Systematic Review

PURPOSE OF REVIEW

In epidemiologic studies, biomarkers are the best possible choice to assess individual exposure to toxic metals since they integrate all exposure sources. However, measuring biomarkers is not always feasible, given potential budgetary and time constraints or limited availability of samples. Alternatively, approximations to individual metal exposure obtained from geographic information systems (GIS) have become popular to evaluate diverse metal-related health outcomes. Our objective was to conduct a systematic review of epidemiological studies that evaluated the validity of GIS-based geolocation and distance to pollutant sources as an approximation of individual metal exposure based on correlation with biological samples.

RECENT FINDINGS

We considered 11 toxic metals: lead (Pb), cadmium (Cd), antimony (Sb), aluminum (Al), arsenic (As), chromium (Cr), nickel (Ni), mercury (Hg), tungsten (W), uranium (U), and vanadium (V). The final review included 12 manuscripts which included seven metals (Pb, Cd, Al, As, Cr, Hg, and Ni). Many studies used geolocation of the individuals to compare exposed (industrial, urban, agricultural, or landfill sources) and unexposed areas and not so many studies used distance to a source. For all metals, except lead, there was more animal than human biosampling to conduct biological validation. We observed a trend towards higher levels of Cd, Cr, Hg, and Pb in biosamples collected closer to exposure sources, supporting that GIS-based proxies for these metals might approximate individual exposure. However, given the low number and heterogeneity of the retrieved studies, the accumulated evidence is, overall, not sufficient. Given the practical benefits and potential of modern GIS technologies, which allow environmental monitoring at a reasonable cost, additional validation studies that include human biosampling are needed to support the use of GIS-based individual exposure measures in epidemiologic studies.

Exploring the Link Between the Serum/Blood Levels of Heavy Metals (Pb, As, Cd, and Cu) and 2 Novel Biomarkers of Cardiovascular Stress (Growth Differentiation Factor 15 and Soluble Suppression of Tumorigenicity 2) in Copper Smelter Workers

OBJECTIVE

Studying the association between the occupational exposure to Pb, As, Cd, and Cu with the serum levels of 2 novel biomarkers of cardiovascular stress; growth differentiation factor 15 and soluble suppression of tumorigenicity 2, in some Egyptian Cu smelter workers.

METHODS

Forty-one exposed workers and 41 administrative controls were clinically evaluated. Serum/blood levels of heavy metals and biomarkers were measured for both groups.

RESULTS

The smelter workers showed significantly elevated levels of heavy metals and biomarkers compared with controls. The elevated serum levels of both biomarkers were significantly and positively correlated with each other, the levels of heavy metals, and the duration of employment of the exposed workers.

CONCLUSIONS

There was a significant association between the levels of heavy metals and both biomarkers among the smelter workers. Further prospective studies should be performed.

Nephrotoxic Biomarkers with Specific Indications for Metallic Pollutants: Implications for Environmental Health

Environmental and occupational exposure to heavy metals and metalloids is a major global health risk. The kidney is often a site of early damage. Nephrotoxicity is both a major consequence of heavy metal exposure and potentially an early warning of greater damage. A paradigm shift occurred at the beginning of the 21st century in the field of renal medicine. The medical model of kidney failure and treatment began to give way to a social model of risk factors and prevention with important implications for environmental health. This development threw into focus the need for better biomarkers: markers of exposure to known nephrotoxins; markers of early damage for diagnosis and prevention; markers of disease development for intervention and choice of therapy. Constituents of electronic waste, e-waste or e-pollution, such as cadmium (Cd), lead (Pb), mercury (HG), arsenic (As) and silica (SiO₂) are all potential nephrotoxins; they target the renal proximal tubules through distinct pathways. Different nephrotoxic biomarkers offer the possibility of identifying exposure to individual pollutants. In this review, a selection of prominent urinary markers of tubule damage is considered as potential tools for identifying environmental exposure to some key metallic pollutants.

Serum heavy metals of passive smoker females and its correlation to bone biomarkers and risk of osteoporosis

Serum total and free calcium reflect the status of the body health and disease. Smoking is risk factor for many diseases as cardiovascular, lung, and cancers. The goal of this work is to evaluate the correlation between serum lead, cadmium arsenate resulting from passive smoking, and bone status in females. This study was conducted on two hundred women (age 30-50 years) divided into four groups (each 50). Group I, control, included non-smoking healthy women. Group II included heavy smoker (>20 cigarettes/day). Group III, nonsmoker women with osteoporosis, have many fractures. Group IV, smoking women with osteoporosis, included heavy smokers (>20 cigarettes/day) with osteoporotic women and have many fractures. Data obtained showed that T-score of osteoporotic smokers was -3.5 that indicated reduced bone mineral density (BMD) while serum total and ionized calcium were statistically significant decreased in smokers with or without osteoporosis compared with nonsmokers (p < 0.001). A negative correlation between total and free calcium and cadmium levels in smokers was compared with nonsmokers (r =-0.65). The levels of C-terminal pro-peptide of pro-collagen type I (PICP) and N-terminal pro-peptide of procollagen type I (PINP) were higher in smoker osteoporotic women than nonsmokers. It was concluded that cadmium resulting from smoking may compete with absorption of calcium and reduced its level and BMD and increased incidence of osteoporosis. The elevated PICP and PINP indicated decreased rate of proto collagen I turnover in bone tissue and increased incidence of osteoporosis.

Assessment of the hyperlipidemia risk for residents exposed to potential emitted metals in the vicinity of a petrochemical complex

Hyperlipidemia, which is associated with certain environmental factors, is a risk factor for cardiovascular disease. Heavy metals are important pollutants from industrial emissions. However, the relationship between the exposure to heavy metals and the occurrence of hyperlipidemia is limited. This study aimed to investigate the association between serum metal levels and the risk of hyperlipidemia in adults living near a petrochemical complex. Our study subjects were 959 residents aged above 35 years in 11 townships near the largest petrochemical complex in central Taiwan. The serum levels of chromium, arsenic, and mercury in the study subjects were measured. The basic characteristics of the study subjects were collected via a questionnaire survey, and the levels of blood lipid biomarkers were analyzed by health examination. The definition of hyperlipidemia was defined in the provided guidelines. Adjusted generalized linear and logistic regression models were applied to evaluate the associations between petrochemical-related metal exposure and hyperlipidemia. The study subjects had chromium, arsenic, and mercury serum levels of 3.24±3.45, 3.45±4.66, and 1.24±1.08 (μg/L), respectively, and close proximity of the study subjects to the petrochemical complex was significantly associated with increased serum metal levels. The results showed that the total cholesterol levels were significantly associated with the increased serum chromium, arsenic, and mercury levels. And, the LDL-C levels were significantly associated with the increased serum mercury levels. In addition, the increased serum arsenic and mercury levels of the study subjects were significantly associated with higher odds ratios for abnormal total cholesterol levels and the risk of hyperlipidemia. Residing in close proximity to a petrochemical complex and high arsenic and mercury exposure were associated with elevated blood lipid levels and an increased risk of hyperlipidemia among the residential population in the vicinity of the petrochemical industry.

Chronic Exposure to Lead and Cadmium in Residents Living Near a Zinc Smelter

This study aimed to measure lead (Pb) and cadmium (Cd) exposure levels in residents living near a zinc (Zn) smelter in Seokpo-myeon, Bonghwa-gun, South Korea, and identify factors affecting exposure. Residents aged ≥20 years living within 3 km and ≥30 km away from the smelter were classified as the exposure group (n = 549), and the control group (n = 265), respectively. Data were obtained through a questionnaire survey. Blood Pb levels in the exposure group (4.19 µg/dL) were higher than in the control group (2.70 µg/dL). The exposure group (1.32 µg/L) also had higher urinary Cd concentrations than the control group (0.80 µg/L). Male sex, older age, previous work at the smelter, smoking, and proximity to the smelter were associated with higher blood Pb levels on multivariate analysis; urinary Cd concentration was significantly higher in women, those who were older, those with experience of working in a Zn smelter or mine, those with proximity to the Zn smelter, and those who consumed locally grown vegetables. In conclusion, Zn smelters are major source of Pb and Cd pollution and require ongoing public health management to prevent potential adverse health effects.

Arsenic, cadmium, and selenium exposures and bone mineral density-related endpoints: The HORTEGA study

BACKGROUND AND OBJECTIVES

Experimental data suggest that trace elements, such as arsenic (As), cadmium (Cd), and selenium (Se) can influence the bone remodeling process. We evaluated the cross-sectional association between As, Cd, and Se biomarkers with bone mineral density (BMD) measured at the calcaneus, in a representative sample of a general population from Spain. As secondary analyses we evaluated the associations of interest in subgroups defined by well-established BMD determinants, and also conducted prospective analysis of osteoporosis-related incident bone fractures restricted to participants older than 50 years-old.

METHODS

In N = 1365 Hortega Study participants >20 years-old, urine As and Cd were measured by inductively coupled-plasma mass spectrometry (ICPMS); plasma Se was measured by atomic absorption spectrometry (AAS) with graphite furnace; and BMD at the calcaneus was measured using the Peripheral Instaneuous X-ray Imaging system (PIXI). As levels were corrected for arsenobetaine (Asb) to account for inorganic As exposure.

RESULTS

The median of total urine As, Asb-corrected urine As, urine Cd, and plasma Se was 61.3, 6.53 and 0.39 μg/g creatinine, and 84.9 μg/L, respectively. In cross-sectional analysis, urine As and Cd were not associated with reduced BMD (T-score < -1 SD). We observed a non-linear dose-response of Se and reduced BMD, showing an inverse association below ~105 μg/L, which became increasingly positive above ~105 μg/L. The evaluated subgroups did not show differential associations. In prospective analysis, while we also observed a U-shape dose-response of Se with the incidence of osteoporosis-related bone fractures, the positive association above ~105 μg/L was markedly stronger, compared to the cross-sectional analysis.

CONCLUSIONS

Our results support that Se, but not As and Cd, was associated to BMD-related disease. The association of Se and BMD-related disease was non-linear, including a strong positive association with osteoporosis-related bone fractures risk at the higher Se exposure range. Considering the substantial burden of bone loss in elderly populations, additional large prospective studies are needed to confirm the relevance of our findings to bone loss prevention in the population depending on Se exposure levels.

Exposure to heavy metals and the risk of osteopenia or osteoporosis: a systematic review and meta-analysis

The relationship between heavy metal exposure and risk of osteopenia or osteoporosis has biological plausibility, yet it remains inconclusive; therefore, we conducted a systematic review and meta-analysis to evaluate the associations between exposure to heavy metals (i.e., cadmium, lead, and mercury) and the risk of osteopenia or osteoporosis. Databases of MEDLINE, Embase, Scopus, and Web of Science were searched through November 2019, to identify studies that evaluated the relationship between exposure to cadmium, lead, and mercury and risk of osteopenia or osteoporosis in adults. Fourteen eligible studies were included. Effect sizes expressed as pooled odds ratios (OR) and 95% confidence intervals (CI) were estimated using weighted random-effect models. Exposure to cadmium (OR = 1.35; 95% CI: 1.17 to 1.56; P ≤ 0.001) and lead (OR = 1.15; 95% CI: 1.00 to 1.32; P = 0.05) was associated with an increased risk of osteopenia or osteoporosis, unlike mercury. Subgroup analyses showed cadmium exposure increased the risk of osteopenia or osteoporosis in older (> 65 yrs.; OR = 1.43; 95%CI: 1.08 to 1.88, P = 0.01) compared with younger (18-65 yrs.; OR = 1.24; 95% CI: 1.02 to 1.52, P = 0.03) adults. Also, lead exposure increased the risk in men (OR = 1.55; 95% CI: 1.15 to 2.09, P = 0.007) unlike in women. By contrast to urinary levels, blood (OR = 1.26; 95% CI: 1.08 to 1.47, P = 0.003) and dietary (OR = 1.46; 95% CI: 1.28 to 1.67, P < 0.001) levels of cadmium were associated with an increased risk of osteopenia or osteoporosis. Exposure to cadmium and lead may be associated with an increased risk of osteopenia or osteoporosis, although high heterogeneity was detected.

The Immunotoxicity of Chronic Exposure to High Levels of Lead: An Ex Vivo Investigation

Lead (Pb) is a toxic metal known for its wide-ranging adverse health effects. However, a compound of Pb is still used in the caulking process to repair wooden fishing boats. The present study aimed to measure Pb exposure and its immunologic effects in boatyard workers in Nakhon Si Thammarat province, Thailand, in comparison with an age-matched control group of farmers. The age, body mass index, and smoking history in workers (n = 14) and controls (n = 16) did not differ. The median blood Pb concentration was 8.7-fold higher in workers than controls (37.1 versus 4.3 µg/dL, p < 0.001). Workers had 8.4% lower phagocytic active cells than controls (89.9% versus 98.1%, p = 0.019). In response to a mitogen stimulation, the peripheral blood mononuclear cells (PBMCs) from workers produced 2-fold higher ratios of interleukin-4 (IL-4) to interferon-γ than the PBMCs from controls (p = 0.026). Furthermore, Pb-exposed workers had 33.9% lower cytotoxic T (Tc) cells than controls (24.3% versus 36.8%, p = 0.004). In stark contrast, the percentage of regulatory T (Treg) cells in workers was 2.7-fold higher than controls (6.1% versus 2.3%, p < 0.001). In all subjects, blood Pb showed positive correlations with the percentages of Treg cells (r = 0.843, p < 0.001) and IL-4 (r = 0.473, p = 0.041) while showing an inverse correlation with the percentages of Tc cells (r = −0.563, p = 0.015). These findings indicate that chronic high Pb exposure may cause a shift towards humoral immune response, together with a suppression of cellular immunity, thereby suggesting an elevation in cancer risk in Pb-exposed workers.

The pollution indices of trace elements in soils and plants close to the copper and zinc smelting works in Poland's Lower Silesia

The quality of soils polluted by trace elements around the facilities with the Cu and Zn smelting activities and the post-flotation tailings pond from copper industry were assessed. The level of the contamination of soils was determined on the basis of the contamination factor and the geoaccumulation index. The geoaccumulation index allows to distinguish more degrees of soil contamination and simplifies the assessment of the useable value of soil. The degrees of soil contamination and the pollution load index were shown. It has been shown that the pollution indices are a useful tool in describing the soil quality and planning corrective actions in the areas contaminated as a result of industrial activity. Histograms of pollution indices were used in order to detect the distribution of trace elements in soils. The content of metals in biomass was assessed using bioaccumulation indices. Triticum L. and Brassica napus L. show low bioaccumulation of studied metals in cereal plants. The correlations were used in order to detect the relationship among trace elements in soil as well as the relationship of metal (soil)-metal (plant) and metal bioaccumulation (plant)-metal (soil). The highest values of indices were recorded for the Oława smelter, presumably due to the long operation period before technological changes limiting the emission of pollutants were introduced. This research area was classified as very highly contaminated with all trace elements. Soils around other facilities are at least moderately contaminated.

Copper-zinc imbalance induces kidney tubule damage and oxidative stress in a population exposed to chronic environmental cadmium

PURPOSE

This cross-sectional study aimed to assess the effect of environmental cadmium (Cd) exposure and essential metal imbalance on renal tubular damage and oxidative stress in 979 adults living in a Cd-polluted area near an abandoned copper (Cu) refinery.

METHODS

We analyzed urinary Cd concentrations, renal tubular damage and oxidative stress markers, such as beta-2 microglobulin (β2-MG) and N-acetyl-β-D-glucosaminidase (NAG) activity and urine malondialdehyde (MDA) levels. The serum copper-to-zinc ratio (CZR) was used as an essential metal imbalance indicator. We divided the subjects into two Cd exposure groups based on the reference level of urinary Cd for renal dysfunction (2 μg/g creatinine).

RESULTS

The geometric mean concentration of urinary Cd in all subjects was 2.25 μg/g creatinine. In both low and high Cd exposure groups, urinary Cd levels were positively correlated with urinary NAG activity, but not with serum CZR. After multivariate adjustment, serum CZR was strongly associated with urinary β2-MG levels in the low Cd exposure group (β = 1.360, P = 0.019) and was significantly associated with urinary MDA levels, regardless of Cd exposure level. In addition, the risk of renal tubular damage was significantly associated with urinary Cd level, particularly in the lowest or highest CZR tertile groups.

CONCLUSIONS

Essential metal imbalance may be a determinant of oxidative stress and renal tubular damage in a chronically Cd-exposed population, and proper zinc supplementation will be effective in preventing adverse health effects due to Cd exposure.

Changes in rat myocardium contractility under subchronic intoxication with lead and cadmium salts administered alone or in combination

Subchronic intoxications induced in male rats by repeated intraperitoneal injections of lead acetate and cadmium chloride, administered either alone or in combination, are shown to affect the biochemical, cytological and morphometric parameters of blood, liver, heart and kidneys. The single twitch parameters of myocardial trabecular and papillary muscle preparations were measured in the isometric regime to identify changes in the heterometric (length-force) and chronoinotropic (frequency-force) contractility regulation systems. Differences in the responses of these systems in trabecules and papillary muscles to the above intoxications are shown. A number of myocardium mechanical characteristics changing in rats under the effect of a combined lead-cadmium intoxication and increased proportion of α-myosin heavy chains were observed to normalize fully or partially if such intoxication was induced against background administration of a proposed bioprotective complex. Based on the experimental results and literature data, some assumptions are suggested concerning the mechanisms of the cardiotoxic effects produced by lead and cadmium.

Trace element biomonitoring in hair and blood of occupationally unexposed population residing in polluted areas of East Kazakhstan and Pavlodar regions

INTRODUCTION

Eastern and North-Eastern regions of Kazakhstan are considered to be environmentally disadvantaged due to industrial pollution and activity of the former Semipalatinsk Nuclear Test Site. Ferrous metallurgy is represented by the world's largest ferroalloy plant located in Aksu. In addition to a ferroalloy plant, Aksu is the home for the largest thermal power plant in Kazakhstan.

OBJECTIVE

Biomonitoring of 31 hair and blood trace elements (Ag, Ba, Be, Bi, Cs, Co, Ce, Cr, Cu, Eu, Gd, Hf, In, La, Li, Mn, Mo, Nb, Nd, Pb, Sc, Sn, Tl, Th, U, V, W, Y, Yb, Zn, and Zr) in non-occupationally exposed population residing in polluted areas of East Kazakhstan and Pavlodar regions.

METHODS

Five case groups, residing in the vicinity to the former Semipalatinsk Nuclear Test Site (Akzhar, Borodulikha, and Karaul) or in proximity to industrial plants (Aksu and Ust-Kamenogorsk) have been assessed vs. controls from a rural settlement in Kurchum. In total, 204 hair and blood samples were analyzed by inductively coupled plasma mass spectrometry.

RESULTS

The observed blood concentrations of trace elements were in agreement with earlier studies on residents of industrially polluted areas. Elevated levels of blood Ba, Mn, Pb, V, and Zn were detected in residents of Aksu and Ust-Kamenogorsk. The elemental composition of head hair was characterized by greater stability between the study sites.

CONCLUSION

Residency near the former Semipalatinsk Test Site could be considered as safe, while the environmental status of industrial settlements appears to be rather adverse.

Collaborative response to arsenic-contaminated soil in an Appalachian Kentucky neighborhood

The aim of this study was to identify factors associated with an increased exposure to arsenic-contaminated soil in a Kentucky neighborhood as part of collaborative public health response. An exposure assessment survey was administered to residents and toenail clippings and soil samples analyzed for arsenic concentration. The associations between exposure variables and arsenic concentrations were evaluated using a multivariate-generalized estimating equation. An ecological assessment of cancer incidence in the community was also conducted using standardized incidence ratio maps. Median toenail arsenic was 0.48 micrograms/gram (µg/g), twice the expected regional level of 0.2 µg/g. Mean residence surface soil arsenic level was 64.8 ppm. An increase of 1 ppm of residence concentration was significantly associated with a 0.003 µg/g rise in toenail levels. Concentrations for respondents who engaged in digging were 0.68 µg/g significantly higher compared to individuals who did not. No significantly elevated rates of lung or bladder cancer were observed in the affected ZIP codes. Living in areas with high soil arsenic contamination might lead to (1) increased exposure; (2) elevated residence soil arsenic concentrations and (3) the action of digging in the soil was associated with elevated toenail arsenic levels. Based upon elevated soil levels identified, residents were recommended to move from the contaminated environment until remediation was complete. Additional recommendations included regular health-care follow-up.

Toxic Metals and Chronic Kidney Disease: a Systematic Review of Recent Literature

PURPOSE OF REVIEW

Arsenic (As), cadmium (Cd), and lead (Pb) are ubiquitous toxicants with evidence of adverse kidney impacts at high exposure levels. There is less evidence whether environmental exposure to As, Cd, or Pb plays a role in development of chronic kidney disease (CKD). We conducted a systematic review to summarize the recent epidemiologic literature examining the relationship between As, Cd, or Pb with CKD.

RECENT FINDINGS

We included peer-reviewed studies published in English between January 2013 and April 2018 for As and Cd, and all dates prior to April 2018 for Pb. We imposed temporality requirements for both the definition of CKD (as per NKF-KDOQI guidelines) and environmental exposures prior to disease diagnosis. Our assessment included cohort, case-control or cross-sectional study designs that satisfied 5 inclusion criteria. We included a total of eight articles of which three, two, and four studies examined the effects of As, Cd, or Pb, respectively. Studies of As exposure consistently reported positive association with CKD incidence; studies of Pb exposure were mixed. We found little evidence of association between Cd exposure and CKD. Additional well-designed prospective cohort studies are needed and we present recommendations for future studies.

Relationship between Heavy Metal Exposure and Bone Mineral Density in Korean Adult

Background

Exposure to heavy metals from environmental and industrial sources remains a concern of serious public health risk. This study was conducted to analysis the relationship between heavy metal concentrations and bone density.

Methods

This study used data from a nation-based sample of Koreans (n=2,429) from 2008 to 2011 Korea National Health and Nutrition Examination Survey. We were obtained heavy metals (lead, mercury and cadmium), socioeconomic and demographic factors and bone mineral density (BMD) measured by T-score.

Results

Menopausal women, current smoker or the frequent alcohol drinking, low educational level and low family income were greater in the osteopenia or osteoporosis groups than normal group, and were associated with an increased blood heavy metal concentration levels. The highest quartile group in blood lead had a 1.47 times (95% confidence interval [CI] 1.16-1.87) risk of osteopenia or osteoporosis. In case of blood cadmium, the risk for osteopenia or osteoporosis increased 2.1 times (95% CI 1.64-2.68).

Conclusions

We observed a significant association between blood heavy metals (lead and cadmium) levels and low BMD. Our findings suggest that heavy metal exposure may be a risk factor for osteoporosis.