High Levels Of Arsenic Research Articles

Predictions of Arsenic in Domestic Well Water Sourced from Alluvial Aquifers of the Western Great Basin, USA.

Chronic exposure to high levels of arsenic in drinking water can have wide-ranging health effects and is a global health concern. The domestic well population of the western Great Basin (WGB) is at increased risk of exposure to arsenic due to the hydrologic, geologic, and climatic setting of the region. A logistic regression (LR) model was developed to predict the probability of elevated arsenic (≥5 μg/L) in alluvial aquifers and assess the potential geologic hazard level posed to domestic well populations. Alluvial aquifers are susceptible to arsenic contamination, which is a concern because they are the primary source of water for domestic well users of the WGB. The probability of elevated arsenic at a domestic well is strongly influenced by tectonic and geothermal variables, including the total Quaternary fault length in the hydrographic basin and the distance between the sampled well and a geothermal system. The model had an overall accuracy of 81%, sensitivity of 92%, and specificity of 55%. Results show a >50% probability of elevated arsenic in untreated well water for approximately 49 thousand (64%) alluvial-aquifer domestic well users in northern Nevada, northeastern California, and western Utah.

Association of antibiotics and heavy metal arsenic to horizontal gene transfer from multidrug-resistant clinical strains to antibiotic-sensitive environmental strains.

The emergence of multidrug-resistant bacteria is currently posing a significant threat to global public health. By testing for resistance to different antibiotic classes, we discovered that the majority of clinical bacteria are multidrug-resistant. These clinical multidrug-resistant species have antibiotic resistance genes on their plasmids that can be horizontally transferred to various antibiotic susceptible environmental bacterial species, resulting in antibiotic-resistant transconjugates. Furthermore, we discovered that the presence of an optimal concentration of antibiotics or heavy metal (arsenic) facilitates horizontal gene transfer through the formation of transconjugants. Notably, the addition of a conjugation inhibitor (2-hexadecynoic acid, a synthetic fatty acid) completely blocked the formation of antibiotic or arsenic-induced transconjugants. We discovered a high level of arsenic in water from the Shukratal region, Uttarakhand, India, which corresponded to a high serum level of arsenic in clinically infected individuals from the Shukratal region compared to other locations in Uttarakhand. Importantly, bacterial strains isolated from infected people who drink water from the Shukratal region with high arsenic levels were found to be more antibiotic-resistant than strains isolated from other sites. We discovered that bacterial strains isolated from individuals with high serum arsenic levels are significantly more resistant to antibiotics than individuals with low serum arsenic levels within the Shurkratal. This research sheds light on imminent threats to global health in which improper clinical, industrial, and other waste disposal, increased antibiotic concentrations in the environment, and increased human interference can easily transform commensal and pathogenic bacteria found in environmental niches into life-threatening multidrug-resistant superbugs.

Hydrogeochemical Characteristics and Groundwater Quality Assessment of a Relatively- Pristine Agricultural Basin (Palas Basin)

This study investigates the spatial and temporal changes in groundwater levels and quality in the Palas Basin, a relatively-pristine semi-arid agricultural basin in T . Although groundwater is solely used as irrigation and drinking potable water resource throughout the basin, measurements regarding the dynamics and quality of groundwater were quite rare. The analyses were based on data collected from 12 water quality monitoring wells and 15 groundwater level monitoring wells during June 2019-May 2020. Water samples were analyzed for pH, electrical conductivity, temperature, nitrate, nitrite, ammonium, total nitrogen, total hardness, alkalinity, chloride,sulfate, phosphate, total organic carbon, calcium, magnesium, sodium, potassium, and arsenic. Data analyses included hydrogeochemical analysis and multivariate statistical analysis such as principal component analysis and cluster analyses. Results showed that water quality in the basin is mostly controlled by natural factors, however, anthropogenic impacts from agriculture activities were apparent in some regions. The basin shows significant changes in water levels throughout the year due to irrigation activities. The groundwater quality was classified as either Ca-Mg-HCO3and Ca-Mg-SO4 type. In the majority of the basin, water quality was suitable for irrigation and drinking water uses, however, a few sampling sites had very high electrical conductivity, sulfate, nitrate, and arsenic levels. The high levels of nitrates were detected in areas, where agriculture is intense, indicating that agricultural activities might be affecting water quality. High sulfate, electrical conductivity, and arsenic levels could be related to the hydrogeological setting of the basin. This study showed that agricultural activities and natural factors were effective on the hydrogeochemical characteristics of the Palas Basin.

Chronic Kidney Disease: Combined Effects of Gene Polymorphisms of Tissue Inhibitors of Metalloproteinase 3, Total Urinary Arsenic, and Blood Lead Concentration.

The tissue inhibitor of metalloproteinase 3 (TIMP3) is known to be an anti-fibrotic factor. Arsenic, lead, and cadmium exposure and selenium intake may affect TIMP3 expression. The downregulation of TIMP3 expression is related to kidney fibrosis. Genotypes of TIMP3 are related to hypertension and cardiovascular diseases. Therefore, this study explored whether TIMP3 polymorphism is associated with hypertension-related chronic kidney disease (CKD). In addition, the combined effects of TIMP3 polymorphism and total urinary arsenic, blood lead and cadmium, and plasma selenium concentrations on CKD, were investigated. This was a case-control study, with 213 CKD patients and 423 age- and sex-matched controls recruited. Polymerase chain reaction-restriction fragment length polymorphism was used to determine TIMP3 gene polymorphisms. The concentrations of urinary arsenic species, plasma selenium, and blood lead and cadmium were measured. The odds ratio (OR) of CKD in the TIMP3rs9609643 GA/AA genotype was higher than that of the GG genotype at high levels of total urinary arsenic and blood lead; the OR and 95% confidence interval (CI) were 0.57 (0.31-1.05) and 0.52 (0.30-0.93), respectively, after multivariate adjustment. High blood lead levels tended to interact with the TIMP3rs9609643 GG genotype to increase the OR of CKD, and gave the highest OR (95% CI) for CKD of 5.97 (2.60-13.67). Our study supports a possible role for the TIMP3rs9609643 risk genotype combined with high total urinary arsenic or with high blood lead concentration to increase the OR of CKD.

Spatial structure and composition of invertebrates in high altitude rivers of the central Andes (Olaroz Salar, Argentina).

This study aimed to examine the spatial variation in sets of micro and macroinvertebrates and to detect how physicochemical and environmental variables affect community structures in high Andean rivers. Six sites were sampled in three rivers of the Argentinian plateau, in altitudes between 3900-4400 masl during the dry season (May-October 2017). The variables that affected the structure of the micro and macroinvertebrate communities were: altitude, conductivity, turbidity, water temperature, hardness, oxygen, and lead. Sites with high levels of arsenic, lead and boron were identified. Assemblages of species common to high Andean courses were recorded on a north-south axis. The registered community structure has similarities with High Andean streams of Bolivia and rivers of the Catamarca plateau, increasing the differences in composition and assemblages towards the south (Mendoza and Patagonian Andes). Diptera was the best represented with Orthocladiinae and Podonominae, reaching better representativeness at higher altitudes. Together with them, Austrelmis, Hydracarina, Hirudinea, Nais, Hyalella constitute the dominant group. There is a trend towards a decrease in the richness of species with respect to altitude, related to the proximity of the Salar and the increase in conductivity, carbonates and hardness.

Изучение влияния загрязнения кормов ртутью и мышьяком на безопасность продукции животноводства

A review of some aspects obtaining environmentally friendly livestock products studies under the conditions of agricultural territories technogenic pollution of for the case of high levels of mercury and arsenic in the agrosphere is presented. The mercury and arsenic toxic effects of on the farm animals physiological state and productivity when taken with the diet, even in small quantities, have been confirmed. The simultaneous analysis of wool, blood and urine animals samples expediency for the presence of mercury and arsenic in order to predict the possible consequences of exposure to these toxicants on the animal organism and determine the environmental safety level of the products obtained is noted. The importance of the public health risk assessing from present in food toxicants impact is emphasized. The conclusion about the predicting the possible mercury and arsenic content of in food raw materials of animal origin problem relevance and the need to ration their intake with the diet in order to obtain animal products that meet sanitary and hygienic requirements is made.

Abstract P033: Characterizing the relationship between arsenic exposure and breast cancer risk in Canada

Abstract Background: Although an established carcinogen for cancers of the skin, bladder and lungs, the relationship between arsenic exposure and breast cancer risk is not known. Studies to date have been conducted in populations with endemically high levels of arsenic, have been limited by small sample sizes and methodological concerns. The impact of chronic exposure to low levels of arsenic remains unclear. This project aims to: 1) describe arsenic exposure in Canada and 2) to evaluate the association between urinary arsenic levels and breast cancer risk among Canadian women. Methods: The Canadian Health Measures Survey (CHMS) is a nationally representative cross-sectional survey that collects self-reported and objective health measures, including biomonitoring data, from participants in biennial cycles. To date, CHMS has collected data from approximately 25,000 participants between the ages of 3 – 80 years. This analysis utilized demographic, lifestyle and reproductive data collected from Cycles 1-5 (2007-2017). Urinary arsenic levels (µg/L) were quantified using high-performance liquid chromatography (HPLC) with inductively coupled plasma mass spectrometry (ICP-MS). Incident breast cancers were ascertained through linkage to the Canadian Cancer Registry and the Discharge Abstract Database. Participants were eligible for inclusion if they were female, older than 18 at the time of urine sample collection, had no personal history of any cancer, and had quantified urinary arsenic and creatinine levels. Arsenic exposure was described using weighted percentiles and then categorized by tertiles. Cox proportional hazards regression was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) of arsenic exposure and breast cancer risk. Multivariate models adjusted for relevant confounders. Quantile g-computation will be used to estimate the joint association between multiple metals and breast cancer risk. Results: This analysis included 5,100 women with a mean age of 44.6 years and an average follow-up of 6.6 years. The median total urinary arsenic level was 7.8 µg/g of creatinine (2.70 µg/g – 84.83 µg/g). Approximately 5% of women had elevated urinary arsenic levels above the clinically relevant threshold of 50 ug/L. Women in the highest tertile of urinary arsenic levels (> 13.0 µg/L) had a significant two-fold increased risk of developing breast cancer compared to women in the referent group in age-adjusted models (HR = 2.10; 95%CI 1.06-3.96, P-trend = 0.03). Similar trends were observed in the fully adjusted models (HR= 2.05; 95%CI 1.05-3.94, P-trend = 0.035). Metal mixture analyses are ongoing, and results will be presented. Significance: To our knowledge, this represents the first analysis of arsenic levels and breast cancer risk in a nationally representative, Canadian cohort. Our findings suggest that exposure to arsenic, even at low levels, is associated with an increased risk of breast cancer and are important for informing population-level interventions to reduce the burden of breast cancer in Canada and around the globe. Citation Format: Katherine Pullella, Vicky Chang, Anthony Hanley, Shelley Harris, Jan Lubiński, Steven Narod, Joanne Kotsopoulos. Characterizing the relationship between arsenic exposure and breast cancer risk in Canada. [abstract]. In: Proceedings of the AACR Special Conference: Precision Prevention, Early Detection, and Interception of Cancer; 2022 Nov 17-19; Austin, TX. Philadelphia (PA): AACR; Can Prev Res 2023;16(1 Suppl): Abstract nr P033.

Comparative Biomonitoring of Arsenic Exposure in Mothers and Their Neonates in Comarca Lagunera, Mexico

Multiple comorbidities related to arsenic exposure through drinking water continue to be public problems worldwide, principally in chronically exposed populations, such as those in the Comarca Lagunera (CL), Mexico. In addition, this relationship could be exacerbated by an early life exposure through the placenta and later through breast milk. This study conducted a comparative analysis of arsenic levels in multiple biological samples from pregnant women and their neonates in the CL and the comparison region, Saltillo. Total arsenic levels in placenta, breast milk, blood, and urine were measured in pregnant women and their neonates from rural areas of seven municipalities of the CL using atomic absorption spectrophotometry with hydride generation methodology. The average concentrations of tAs in drinking water were 47.7 µg/L and 0.05 µg/L in the exposed and non-exposed areas, respectively. Mean levels of tAs were 7.80 µg/kg, 77.04 µg/g-Cr, and 4.30 µg/L in placenta, blood, urine, and breast milk, respectively, in mothers, and 107.92 µg/g-Cr in neonates in the exposed group, which were significantly higher than those in the non-exposed area. High levels of urinary arsenic in neonates were maintained 4 days after birth, demonstrating an early arsenic exposure route through the placenta and breast milk. In addition, our study suggested that breastfeeding may reduce arsenic exposure in infants in arsenic-contaminated areas. Further studies are necessary to follow up on comorbidities later in life in neonates and to provide interventions in this region.

TIMP3 Gene Polymorphisms of -1296 T > C and -915 A > G Increase the Susceptibility to Arsenic-Induced Skin Cancer: A Cohort Study and In Silico Analysis of Mutation Impacts

Long-term exposure to arsenic may induce several human cancers, including non-melanoma skin cancer. The tissue inhibitor of metalloproteinase (TIMP)-3, encoded by the TIMP3 gene, may inhibit tumor growth, invasion, and metastasis of several cancer types. In this study, we aimed to investigate effects of the TIMP3 -1296 T > C (rs9619311) and -915 A > G (rs2234921) single-nucleotide polymorphisms (SNPs) on skin cancer risk in an arsenic-exposed population, and to evaluate the influence of allele-specific changes by an in silico analysis. In total, 1078 study participants were followed up for a median of 15 years for newly diagnosed skin cancer. New cases were identified through linkage to the National Cancer Registry of Taiwan. A Cox regression analysis was used to evaluate the effects of TIMP3 variants. Transcription factor (TF) profiling of binding sites of allele-specific changes in SNPs was conducted using the JASPAR scan tool. We observed borderline associations between TIMP3 genotypes and skin cancer risk. However, when combined with high arsenic exposure levels, the rs9619311 C allele, rs2234921 G allele, or C-G haplotype groups exhibited a greater risk of developing skin cancer compared to the respective common homozygous genotype group. The in silico analysis revealed several TF motifs located at or flanking the two SNP sites. We validated that the C allele of rs9619311 attenuated the binding affinity of BACH2, MEIS2, NFE2L2, and PBX2 to the TIMP3 promoter, and that the G allele of rs2234921 reduced the affinity of E2F8 and RUNX1 to bind to the promoter. Our findings suggest significant modifications of the effect of the association between arsenic exposure and skin cancer risk by the TIMP3 rs9619311 and rs2234921 variants. The predicted TFs and their differential binding affinities to the TIMP3 promoter provide insights into how TIMP3 interacts with arsenic through TFs in skin cancer formation.

Rapid gold cyanidation from a sulfur-high and arsenic-high micro-fine concentrate via facile two-stage roasting pre-treatment

This study was conducted on a micro-fine refractory gold concentrate with high levels of arsenic and sulfur, and main focus on being the roasting pre-treatment conditions and leaching conditions of the gold concentrate. Additionally, the potential reason and reaction mechanism of the roasting process were discussed, utilizing scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS), X-ray powder diffraction (XRD), and X-ray fluorescence spectrometry (XRF). Satisfactory results were obtained when the gold concentrate was roasted for 2 h at 500 °C followed by 3 h at 650 °C. The reason responsible for rapid gold leaching from this type of ore lied in that the coating containing sulfur and arsenic around micro-fine gold particles was largely removed via roasting. Relatively lower cyanide consumption resulted from that (a) sulfur and arsenic in the ore were effectively removed with two-stage roasting and (b) the leach time required was extremely short. Notably, the good gold extraction of over 80 % and lower cyanide consumption of 0.82 kg/t were attained within only 0.5 h, and short leach time produced less inevitable ions content in the slurry, which is of great significance for subsequent purification processes and saving energy.

Hair manifestations in factory workers with arsenic exposure in Hayatabad industrial estate Peshawar, Pakistan

BACKGROUND & OBJECTIVE: Arsenic is present both naturally and from manmade sources like factory effluents. Contamination by arsenic of the groundwater is a major source of health detriment in south-east Asian countries. The aim of this study was to identify levels of arsenic in drinking water sources and factory effluents and to analyse arsenic levels in hair samples from factory workers and their families, along with morphological changes in hair in industrial workers in Peshawar.
 METHODOLOGY: Water and hair samples were collected by random sampling from a labor colony of 81 factory and non-factory household members living and working in the same industrial estate and analyzed for arsenic. Hair morphology was carried out in histomorphology laboratory at Khyber Medical University, Peshawar. The results obtained from both groups were compared with normal hair histomorphology. The data was analyzed by using SPSS version 20.
 RESULTS: The arsenic level in drinking water, colony tube wells and households was not within the permissible level of WHO (10µg/L). The arsenic level in factory effluent was 68µg/l (Pakistan Government's acceptable level is 50µg/L). The difference was statistically significant p≤0.001 between the two groups, the factory workers had a relatively higher level of arsenic, ~34ppb, in their scalp hair. Hair arsenic level also came out to be <1.00µg/g. There was a wide variation in the histomorphology of the hair samples in both groups.
 CONCLUSION: Elevated levels of arsenic in factory effluent demonstrate improper decontamination. The arsenic levels were within permissible levels, long term effects cannot be ruled out.

Oxidative stress responses as a marker of toxicity in mice exposed to polluted groundwater from an automobile junk market in South-Western Nigeria.

The global trade in used vehicles and their components generates huge financial benefits but leads to detrimental environmental consequences including groundwater pollution and potential adverse health effects mediated by free-radical processes such as lipid peroxidation. We investigated oxidative stress responses in thirty-six, female mice orally exposed (via drinking) to graded concentrations (0%, 50%, and 100%) of groundwater from a well located within a major automobile junk market in SW-Nigeria containing extremely high levels of arsenic (0.332 ± 0.089mg/l) and seventeen PAHs, which serves as domestic water supply. Blood samples from the mice were assayed for selected biochemical parameters at intervals of 7, 14, and 28days. A significant dose- and duration-dependent increase in malondialdehyde (MDA) and Myeloperoxidase (MPO) confirmed oxidative stress onset due to exposure to the polluted well-water, while a significant decline in nitric oxide (NO-) levels may suggest impaired endothelial smooth-muscle relaxation which may lead to the development of metabolic diseases over time. Superoxide dismutase (SOD) and reduced glutathione (GSH) showed a contrasting trend with Glutathione peroxidase (GPx), while Glutathione-S-Transferase (GST) declined significantly by the 28th day. Two clusters were identified by principal component analysis-one involving MDA, SOD, and GSH suggesting that antioxidant responses driven mainly by SOD and GSH proved insufficient in scavenging the free radicals generated by lipid peroxidation. NO- and total protein clustered together possibly due to the significant declines in both over the study period. Histological examination of liver tissue of exposed mice corroborated the above findings and highlights the need for urgent remedial action.

Bioarchaeology of Arsenic, an Invisible Natural Pollutant, and Its Effect on the Mitimaes of Camarones Cove, Arica, during Inca Times

During the expansion of Tawantinsuyo, the Inca Empire sustained its hegemony by using multiple strategies, including moving specialized groups called mitimaes to their conquered territories. This study examines bioarchaeological evidence from the Camarones 9 (CAM-9) Inca period cemetery at the mouth of the Camarones Valley in northern Chile. The waters in this valley contain concentrations of arsenic that are 100 times above the norm (10 μg/L) for human ingestion, causing serious health consequences. We study the environmental health effects on this population, using atomic absorption spectrometry and hydride generation to investigate arsenic concentration in the bone tissues of 16 individuals sampled from this burial site. Three of four individuals presented arsenic levels in their bones that were beyond the standard 1 μg/g, with a median of 3.6 μg/g; in some, the levels were nine times higher than those currently recommended by the World Health Organization. Considering previous and current bioarchaeological evidence, especially the high arsenic levels found in these individuals, we postulate that the CAM-9 site population corresponds to mitimaes who settled on the Camarones coast. This study is relevant to all regions of the world that present ecotoxic loads.

FLUORIDE AND CHILDREN’S HEALTH IN INDIA: DISTRICT LEVEL ANALYSIS

Quality issues in water such as presence of high levels of arsenic, nitrates, iron, salinity and fluoride has been witnessed in various parts in India. Presence of fluoride at alarming levels has led to severe threat to human survival. Prolong consumption of contaminated water with an unsafe fluoride level can lead to many diseases. Therefore, using the exogenous variation in fluoride across districts, we try to assess the impact of fluoride contaminated water on health outcomes particularly for children; dental and skeletal diseases. Usingnationally representative dataset for India, greater exposure to fluoride contamination is associated with adverse health outcomes amongst school going children. Our findings suggest that an additional increase in fluoride contamination leads to higher risk of dental (odds ratio-1.196) and skeletal diseases (odds ratio-1.206). Moreover, the intensity and incidence of such diseases (dental-1.398 and skeletal diseases-1.494) has increased drastically over time. Our estimates are also robust to district and time fixed effects. Our findings also suggestchildren who belong to the age group of 7-14 years of age experience such adverse health outcomes relatively more than those who belongs to 0-6 years of age, owing to visibility of fluoride related symptoms at later stages in life. Uniformity of our results holds even after using an alternative measure of estimation, Propensity Score Matching.

Membrane technology as an emergency response against drinking water shortage in scenarios of dam failure

With dam failure events, there can be changes in water quality and difficulties in the operation of water treatment plants (WTPs) since they were not designed for water treatment under severe pollution conditions. To avoid that, it was investigated two strategies based on pre-oxidation, ultrafiltration (UF) and reverse osmosis (RO) integrated into a conventional treatment process (coagulation, flocculation, and sand filtration) or with each other, with the potential to reduce the risks of drinking water shortage and guarantee a safe drinking water supply. The study considered the context of the Velhas river basin (Brazil), where water quality is compromised by high turbidities (500–3000 NTU) and excessive arsenic (∼0.4 mg/L), iron (∼50 mg/L), and manganese (∼3 mg/L) levels. They were only partially removed by conventional treatments (removals: 74 ± 21%) and potability standards were only achieved after the membrane separation processes were considered (As: <0.01 mg/L, Mn: <0.1 mg/L, and Fe: <0.3 mg/L). The high water quality after RO enables its blend with the stream obtained after sand filters and would allow for greater flexibility during the operation of WTPs operation. Despite the susceptibility to fouling and most frequent maintenance, the pre-oxidation-UF-RO system would also guarantee a safe drinking water supply. The decision for the most adequate strategy was then based on a multicriteria analysis. A retrofit of conventional WTPs by their integration with UF-RO was classified as the best strategy for centralized facilities, whereas pre-oxidation-UF-RO better fits the reality of decentralized treatments given the lower costs and deployment time. The methodology based on multicriteria analysis and water treatment technologies, exemplified by membranes in this study, presented satisfactory results for different scenarios of critical treatment.

Inorganic arsenic in drinking water and breast cancer risk: a case-control study in Northern Chile

BACKGROUND AND AIM: Exposure to arsenic in drinking water is a well-established cause of lung, bladder and skin cancer, however the relation between arsenic and breast cancer is less clear. Between 2014-2018, we conducted a breast cancer incident case-control study in Northern Chile, where from 1950-1970 the population was exposed to high levels of arsenic in drinking water (up to 900 &amp;#x3bc;g/l). METHODS: We analyzed 703 breast cancer cases and 491 population-based female controls with data collected on lifetime exposure to As and potential confounders. Using logistic regression, we tested whether exposure to higher levels of arsenic in drinking water related to differential risk of breast cancer. Initial causal models adjusted for age and education. Additional models included other known risk factors for breast cancer and several sensitivity analyses evaluated different exposure windows. RESULTS: Both cases and controls were around 58 years of age and about half had finished high school or had additional studies. Cases, compared to controls, were exposed to lower median concentrations of arsenic (&amp;#x3bc;g/L): 60 [interquartile range (IQR), 11-636] versus 70 (40-299). Adjusted odds ratios for category of highest single-year arsenic concentrations in water (&amp;#x3c;49, 50-199, 200-799, and &amp;#x2265; 800 &amp;#x3bc;g/L) were 1.00, 0.70 [95% confidence interval (CI), 0.52-0.94], 0.71 (0.51-1.01), and 1.02 (0.72-1.44), respectively. Results were similar after various adjustments, using different metrics of arsenic exposure, and windows of exposure. CONCLUSIONS: Compared with women with the lowest levels of exposure to arsenic in drinking water, those with higher (up to 799 &amp;#x3bc;g/L) arsenic exposure, had lower odds of breast cancer, in accordance with evidence implying a potentially therapeutic effect of arsenic exposure. Differential arsenic sensitivity of breast cancer cell types may explain differences in the direction of the effect and lack of precision for some exposure groups. KEYWORDS: arsenic, breast cancer, drinking water

As3MT-mediated SAM consumption, which inhibits the methylation of histones and LINE1, is involved in arsenic-induced male reproductive damage

Studies have demonstrated that arsenic (As) induces male reproductive injury, however, the mechanism remains unknown. The high levels of arsenic (3) methyltransferase (As3MT) promote As-induced male reproductive toxicity. For As-exposed mice, the germ cells in seminiferous tubules and sperm quality were reduced. Exposure to As caused lower S-adenosylmethionine (SAM) and 5-methylcytosine (5 mC) levels, histone and DNA hypomethylation, upregulation of long interspersed element class 1 (LINE1, or L1), defective repair of double-strand breaks (DSBs), and the arrest of meiosis, resulting in apoptosis of germ cells and lower litter size. For GC-2spd (GC-2) cells, As induced apoptosis, which was prevented by adding SAM or by reducing the expression of As3MT. The levels of LINE1, affected by SAM content, were involved in As-induced apoptosis. Furthermore, folic acid (FA) and vitamin B12 (VB12) supplements restored SAM, 5 mC, and LINE1 levels and blocked impairment of spermatogenesis and testes and lower litter size. Exposed to As, mice with As3MT knockdown showed less impairment of spermatogenesis and testes and greater litter size compared to As-exposed wild-type (WT) mice. Thus, the high As3MT levels induced by As consume SAM and block histone and LINE1 DNA methylation, elevating LINE1 expression and evoking impairment of spermatogenesis, which causes male reproductive damage. Overall, we have found a mechanism for As-induced male reproductive damage, which provides biological insights into the alleviation of reproductive injury induced by environmental factors.

Health Remedies as a Source of Lead, Mercury, and Arsenic Exposure, New York City, 2010-2019.

Objectives. To describe the types of health remedies collected during poisoning investigations in New York City over a 10-year period that were found to contain high levels of lead, mercury, or arsenic. Methods. Between 2010 and 2019, the New York City Department of Health and Mental Hygiene collected 584 samples of health remedies during poisoning investigations and store surveys for lead, mercury, or arsenic analysis. Results. There was a significant association between blood lead levels and estimated cumulative daily lead exposures among adult users of rasa shastra Ayurvedic medications. Also, average blood lead levels among adult rasa shastra users were significantly higher than levels among those using other types of non-Ayurvedic health remedies. Conclusions. Rasa shastra Ayurvedic medications can contain very high levels of lead, mercury, and arsenic. This underscores the importance of screening for lead, mercury, and arsenic exposures within at-risk populations. Public Health Implications. The general ease of accessibility to rasa shastra medications raises concerns. There is a need for systemic change that results in primary prevention, that is, removal of the source through policy development and regulatory enforcement in the country of origin. (Am J Public Health. 2022;112(S7):S730-S740. https://doi.org/10.2105/AJPH.2022.306906).

Влияние генетического полиморфизма генов GSTM1, GSTT1 и GSTP1 на содержание металлов в крови у плавильщиков производства сплавов цветных металлов

Heavy metal ions are known to induce generation of a large number of reactive oxygen species (ROS). Glutathione S-transferases (GSTs) play an important role in adaptation and response to oxidative stress. GSTM1, GSTT1, and GSTP1 genes have numerous described polymorphisms, the most significant being GSTM1, GSTT1, and GSTP1 Ile105Val deletion ones. Our objective was to study the relationship between the genetic polymorphism of GSTM1, GSTT1, GSTP1 genes and blood levels of metals in smelter operators engaged in crude lead refining. We examined 55 male lead-refining furnace operators working at a non-ferrous metal alloy plant. Blood metal concentrations were measured by inductively coupled plasma mass spectrometry. GSTM1 and GSTT1 deletion polymorphisms were determined using real-time SYBR Green qPCR and that of GSTP1 Ile105Val – using a commercial SNP Screening Kit. Statistical data processing was carried out using the Mann – Whitney U-test. Blood levels of industry-specific metals were not statistically different between the workers with GSTT1 and GSTP1 genotypes. We established, however, that men with the null genotype of GSTM1 had significantly higher blood arsenic levels. Our findings indicate that a high blood arsenic level associated with occupational exposure may be attributed to the GSTM1 null genotype. This observation can be used to identify the most vulnerable groups of individuals at risk of overexposure to arsenic.

Effects of genetic polymorphisms of GSTM1, GSTT1, and GSTP1 genes on blood metal levels in non-ferrous metal alloy smelter operators

Heavy metal ions are known to induce generation of a large number of reactive oxygen species (ROS). Glutathione S-transferases (GSTs) play an important role in adaptation and response to oxidative stress. GSTM1, GSTT1, and GSTP1 genes have numerous described polymorphisms, the most significant being GSTM1, GSTT1, and GSTP1 Ile105Val deletion ones. Our objective was to study the relationship between the genetic polymorphism of GSTM1, GSTT1, GSTP1 genes and blood levels of metals in smelter operators engaged in crude lead refining. We examined 55 male lead-refining furnace operators working at a non-ferrous metal alloy plant. Blood metal concentrations were measured by inductively coupled plasma mass spectrometry. GSTM1 and GSTT1 deletion polymorphisms were determined using real-time SYBR Green qPCR and that of GSTP1 Ile105Val – using a commercial SNP Screening Kit. Statistical data processing was carried out using the Mann – Whitney U-test. Blood levels of industry-specific metals were not statistically different between the workers with GSTT1 and GSTP1 genotypes. We established, however, that men with the null genotype of GSTM1 had significantly higher blood arsenic levels. Our findings indicate that a high blood arsenic level associated with occupational exposure may be attributed to the GSTM1 null genotype. This observation can be used to identify the most vulnerable groups of individuals at risk of overexposure to arsenic.