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1.
On the Use of Hair Analysis for Assessing Arsenic Intoxication.
Katz, SA
International journal of environmental research and public health. 2019;(6)
Abstract
Correlations between the concentrations of arsenic in scalp hair and in drinking water as well as in blood and/or urine have been reported. These correlations clearly show exposure⁻absorption⁻excretion relationships. In addition, arsenic metabolites such as monomethylarsonic acid and dimethylarsinic acid have been identified and quantified in these tissues and fluids, leaving little doubt that elevated levels of arsenic in the hair can reflect systemic arsenic intoxication. Consequently, hair analysis has potential merit as a screening procedure for poisoning by arsenic. However, questions regarding the exogenous versus the endogenous deposition of arsenic in the hair, and uncertainties about the normal level of arsenic in the hair remain unresolved. Pending their resolution, the determination of arsenic in hair should remain a screening tool, and clinical signs and symptoms should be employed to complete the diagnosis of arsenic poisoning.
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2.
Heavy metals in food crops: Health risks, fate, mechanisms, and management.
Rai, PK, Lee, SS, Zhang, M, Tsang, YF, Kim, KH
Environment international. 2019;:365-385
Abstract
Food security is a high-priority issue for sustainable global development both quantitatively and qualitatively. In recent decades, adverse effects of unexpected contaminants on crop quality have threatened both food security and human health. Heavy metals and metalloids (e.g., Hg, As, Pb, Cd, and Cr) can disturb human metabolomics, contributing to morbidity and even mortality. Therefore, this review focuses on and describes heavy metal contamination in soil-food crop subsystems with respect to human health risks. It also explores the possible geographical pathways of heavy metals in such subsystems. In-depth discussion is further offered on physiological/molecular translocation mechanisms involved in the uptake of metallic contaminants inside food crops. Finally, management strategies are proposed to regain sustainability in soil-food subsystems.
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3.
Effects of arsenic toxicity beyond epigenetic modifications.
Bjørklund, G, Aaseth, J, Chirumbolo, S, Urbina, MA, Uddin, R
Environmental geochemistry and health. 2018;(3):955-965
Abstract
Worldwide chronic arsenic (As) poisoning by arsenic-contaminated groundwater is one of the most threatening public health problems. Chronic inorganic As (inAs) exposure has been associated with various forms of cancers and numerous other pathological effects in humans, collectively known as arsenicosis. Over the past decade, evidence indicated that As-induced epigenetic modifications have a role in the adverse effects on human health. The main objective of this article is to review the evidence on epigenetic modifications induced by arsenicals. The epigenetic components play a crucial role in the regulation of gene expression, at both transcriptional and posttranscriptional levels. We synthesized the large body of existing research on arsenic exposure and epigenetic mechanisms of health outcomes with an emphasis on recent publications. Changes in patterns of DNA methylation, histone posttranslational modifications, and microRNAs have been repeatedly observed after inAs exposure in laboratory studies and in studies of human populations. Such alterations have the potential to disturb cellular homeostasis, resulting in the modulation of key pathways in the As-induced carcinogenesis. The present article reviews recent data on As-induced epigenetic effects and concludes that it is time for heightened awareness of pathogenic arsenic exposure, particularly for pregnant women and children, given the potential for a long-lasting disturbed cellular homeostasis.
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4.
Prospects of genetic engineering utilizing potential genes for regulating arsenic accumulation in plants.
Kumari, P, Rastogi, A, Shukla, A, Srivastava, S, Yadav, S
Chemosphere. 2018;:397-406
Abstract
The rapid pace of industrial, agricultural and anthropogenic activities in the 20th century has resulted in contamination of heavy metals across the globe. Arsenic (As) is a ubiquitous, naturally occurring toxic metalloid, contaminating the soil and water and affecting human health in several countries. Several physicochemical methods exist for the cleanup of As contamination but these are expensive and disastrous to microbes and soil. Plant based remediation approaches are low cost and environmentally safe. Hence, extensive biochemical, molecular and genetic experiments have been conducted to understand plants' responses to As stress and have led to the identification of potential genes. The available knowledge needs to be utilized to either reduce As accumulation in crop plants (rice) or to enhance As levels in shoots of hyperaccumulators (Pteris vittata). Gene manipulation using biotechnological tools can be an effective approach to exploit the potential genes (plasmamembrane and vacuolar transporters, glutathione and phytochelatin biosynthetic enzymes, etc.) playing pivotal roles in uptake, translocation, transformation, complexation, and compartmentalization of As in plants. The transgenic plants with increased tolerance to As and altered (increased/decreased) As accumulation have been developed. The need, however, exists to design plants with altered expression of two or more genes for harmonizing various events (like arsenate reduction, arsenite complexation, sequestration and translocation) so as to achieve desirable reduction (crop plants) or increase (phytoremediator plants) in As content. This review sheds light on transgenic approaches adopted to modulate As levels in plants and proposes future directions to achieve desirable results.
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5.
Nutritional management can assist a significant role in alleviation of arsenicosis.
Sharma, A, Flora, SJS
Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS). 2018;:11-20
Abstract
Consumption of arsenic contaminated water causes serious skin disease and cancer in a significant number of exposed people. Chelating agents, consider an expensive therapy, are employed in the treatment of arsenic intoxication. There are reports which suggest that the poorest suffer the most from arsenicosis. This may be due to improper diet intake, consist of low protein and micronutrients which increase the vulnerability to arsenic-related disorders. Several human studies demonstrated the associations between malnourishment and the development of arsenic-caused skin lesions, skin cancer and cardiovascular effects. Thus, there is an urgent need of implementation of mitigation strategies for improving the health of exposed populations. Nutrition enhances the detoxification process so food rich in vitamins, protein, antioxidants help in its detoxification process. Methylation is the detoxification process which takes place via S-adenosylmethionine (SAM). It is a methyl group donor and it derived its methyl group from diet. Nutritional intervention thus may appear as a practical and inexpensive approach. Nutrition provides protection from toxic effect of arsenic by two ways (i) methylation of As (ii) antioxidants which provides protection against free radical species. The governments and NGOs may run awareness programmes in arsenic affected area regarding prevention and alternate therapy which can decrease the susceptibility of the exposed population. They could also help in distributing cheaper, high protein diets particularly to the masses who cannot afford such foods. Thus, to prevent arsenicosis alternate therapy and proper nutrition could be the important strategy for alleviating its toxic effects. This mini review provides an insight on the importance of nutrition in preventing adverse effect cause by arsenic to suffer population.
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6.
Concentrations of arsenic and lead in rice (Oryza sativa L.) in Iran: A systematic review and carcinogenic risk assessment.
Fakhri, Y, Bjørklund, G, Bandpei, AM, Chirumbolo, S, Keramati, H, Hosseini Pouya, R, Asadi, A, Amanidaz, N, Sarafraz, M, Sheikhmohammad, A, et al
Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association. 2018;:267-277
Abstract
Exposure to heavy metals such as arsenic (As), lead (Pb), and cadmium (Cd) in either the short or the long term can cause cancers in humans. Dietary intake and consumption of rice (Oryza sativa L.) is increasing in Iran, and several studies on the concentration of heavy metals in rice have been carried out in this country in recent years. In this perspective, the main objective of the present study was to investigate, even via a meta-analysis of the existing literature, the presence of As and Pb in rice from many geographical areas in Iran, as well as to estimate the carcinogenic risk of these heavy metals in rice consumers. The results of the present ten years-spanning systematic review indicate that 21 reports, collecting a total of 2088 samples, were performed between 2008 and October 2017. The minimum and maximum concentration of As was observed in the Golestan area (0.01 ± 0.01 mg/kg d.w) and the Gillan region (3 mg/kg d.w); and Pb in the Shahrekord (0.07 ± 0.02 mg/kg d.w) and Mazandaran (35 mg/kg d.w). The meta-analysis of data showed that pooled concentration of As in the rice was 0.04 (95%CI: 0.02-0.06 mg/kg d.w), which resulted lower than the National Standard (NS) limits. However, the pooled concentration of Pb in the rice was 0.38 (95%CI: 0.25-0.5 mg/kg d.w), i.e., higher than NS limits. The heterogeneity was significant between As (I2 = 63%, P value = .003) and Pb (I2 = 96%, P value < .001) studies. The carcinogenic risk assessment showed that minimum and maximum incremental lifetime cancer risk (ILCR) of As was in the 45-54 (4.53 × 10-2) and 15-24 (5.50 × 10-2) year age groups consumers; and Pb, 45-54 (2.442 × 10-3) and 15-24 (2.96 × 10-3), respectively. The overall carcinogenesis risk of As (4.864 × 10-2) was 18.5 times higher than Pb (2.623 × 10-3). All age groups consumers of rice content of As and Pb are at considerable carcinogenesis risk (ILCR > 10-3). Therefore a decreased level of heavy metals in rice cultivation should be encouraged and performed in next planning.
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7.
Groundwater Arsenic Contamination in the Ganga River Basin: A Future Health Danger.
Chakraborti, D, Singh, SK, Rahman, MM, Dutta, RN, Mukherjee, SC, Pati, S, Kar, PB
International journal of environmental research and public health. 2018;(2)
Abstract
This study highlights the severity of arsenic contamination in the Ganga River basin (GRB), which encompasses significant geographic portions of India, Bangladesh, Nepal, and Tibet. The entire GRB experiences elevated levels of arsenic in the groundwater (up to 4730 µg/L), irrigation water (~1000 µg/L), and in food materials (up to 3947 µg/kg), all exceeding the World Health Organization's standards for drinking water, the United Nations Food and Agricultural Organization's standard for irrigation water (100 µg/L), and the Chinese Ministry of Health's standard for food in South Asia (0.15 mg/kg), respectively. Several individuals demonstrated dermal, neurological, reproductive, cognitive, and cancerous effects; many children have been diagnosed with a range of arsenicosis symptoms, and numerous arsenic-induced deaths of youthful victims are reported in the GRB. Victims of arsenic exposure face critical social challenges in the form of social isolation and hatred by their respective communities. Reluctance to establish arsenic standards and unsustainable arsenic mitigation programs have aggravated the arsenic calamity in the GRB and put millions of lives in danger. This alarming situation resembles a ticking time bomb. We feel that after 29 years of arsenic research in the GRB, we have seen the tip of the iceberg with respect to the actual magnitude of the catastrophe; thus, a reduced arsenic standard for drinking water, testing all available drinking water sources, and sustainable and cost-effective arsenic mitigation programs that include the participation of the people are urgently needed.
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8.
Current and future microbiological strategies to remove As and Cd from drinking water.
Byrne, JM, Kappler, A
Microbial biotechnology. 2017;(5):1098-1101
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9.
Autotrophic microbial arsenotrophy in arsenic-rich soda lakes.
Oremland, RS, Saltikov, CW, Stolz, JF, Hollibaugh, JT
FEMS microbiology letters. 2017;(15)
Abstract
A number of prokaryotes are capable of employing arsenic oxy-anions as either electron acceptors [arsenate; As(V)] or electron donors [arsenite; As(III)] to sustain arsenic-dependent growth ('arsenotrophy'). A subset of these microorganisms function as either chemoautotrophs or photoautotrophs, whereby they gain sufficient energy from their redox metabolism of arsenic to completely satisfy their carbon needs for growth by autotrophy, that is the fixation of inorganic carbon (e.g. HCO3-) into their biomass. Here we review what has been learned of these processes by investigations we have undertaken in three soda lakes of the western USA and from the physiological characterizations of the relevant bacteria, which include the critical genes involved, such as respiratory arsenate reductase (arrA) and the discovery of its arsenite-oxidizing counterpart (arxA). When possible, we refer to instances of similar process occurring in other, less extreme ecosystems and by microbes other than haloalkaliphiles.
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10.
Assessment of human dietary exposure to arsenic through rice.
Davis, MA, Signes-Pastor, AJ, Argos, M, Slaughter, F, Pendergrast, C, Punshon, T, Gossai, A, Ahsan, H, Karagas, MR
The Science of the total environment. 2017;:1237-1244
Abstract
Rice accumulates 10-fold higher inorganic arsenic (i-As), an established human carcinogen, than other grains. This review summarizes epidemiologic studies that examined the association between rice consumption and biomarkers of arsenic exposure. After reviewing the literature we identified 20 studies, among them included 18 observational and 2 human experimental studies that reported on associations between rice consumption and an arsenic biomarker. Among individuals not exposed to contaminated water, rice is a source of i-As exposure - rice consumption has been consistently related to arsenic biomarkers, and the relationship has been clearly demonstrated in experimental studies. Early-life i-As exposure is of particular concern due to its association with lifelong adverse health outcomes. Maternal rice consumption during pregnancy also has been associated with infant toenail total arsenic concentrations indicating that dietary exposure during pregnancy results in fetal exposure. Thus, the collective evidence indicates that rice is an independent source of arsenic exposure in populations around the world and highlights the importance of investigating its affect on health.