Chronic arsenic toxicity & human health Guha Mazumder, D N
Indian journal of medical research (New Delhi, India : 1994),
10/2008, Letnik:
128, Številka:
4
Journal Article
Recenzirano
Chronic arsenic toxicity (arsenicosis) due to drinking of arsenic contaminated ground water is a major environmental health hazard throughout the world including India. A lot of new information is ...emerging from extensive research on health effects of chronic arsenic toxicity (CAT) in humans during the last two decades. Available literature has been reviewed to highlight the problem including its malignancies. Pigmentation and keratosis are the specific skin lesions characteristics of CAT. CAT also produces various systemic manifestations over and above skin lesions, important ones being chronic lung disease like chronic bronchitis, chronic obstructive pulmonary disease and bronchiectasis, liver disease like non-cirrhotic portal fibrosis and other diseases like polyneuropathy, peripheral vascular disease, hypertension and ischeamic heart disease, diabetes mellitus, non-pitting oedema of feet/hands, weakness and anaemia. Cancer of skin, lung and urinary bladder are important cancers associated with chronic arsenic toxicity. Stoppage of drinking of arsenic contaminated water is the main stay in the management of arsenicosis as specific chelation therapy has limited value. Early skin cancer, detectable by regular active surveillance, is curable. In addition to dermatological features, CAT produces protean clinical manifestations. Treatment of arsenicosis is unsatisfactory and is mostly symtomatic.
The increasing demand and use of plastics in our daily lives have caused an increase in microplastics (MPs) concentration in water bodies. Increasing MP in water affects aquatic life and is ...associated with several health issues. All sources of water whether fresh, marine, or sewage have reported the presence of various MPs. It is clear from relevant literature that the presence of MP with a particular chemical composition could be indicative of its source and could contribute to its removal. Increasing population density, plastic litters, fishing activities, and industrial wastes are major contributors of MP in water. This review is systematically undertaken where Raman spectroscopy (RS) is used as an indispensable tool to identify the chemical composition of the MP in various water sources (fresh/ground/drinking; ocean/sea; waste/sewage) between 2015 and 2021. Based on the Raman spectra, polystyrene (PS), polyethylene terephthalate (PET), polyethylene (PE), and polypropylene (PP) are some of the common MP identified in the water sources.
Background: Ingested inorganic arsenic (InAs) is methylated to monomethylated (MMA) and dimethylated metabolites (DMA). Methylation may have an important role in arsenic toxicity, because the ...monomethylated trivaient metabolite MMA(III) is highly toxic. Objectives: We assessed the relationship of creatinine and nutrition—using dietary intake and blood concentrations of micronutrients—with arsenic metabolism, as reflected in the proportions of InAS, MMA, and DMA in urine, in the first study that incorporated both dietary and micronutrient data. Methods: We studied methylation patterns and nutritional factors in 405 persons who were selected from a cross-sectional survey of 7,638 people in an arsenic-exposed population in West Bengal, India. We assessed associations of urine creatinine and nutritional factors (19 dietary intake variables and 16 blood micronutrients) with arsenic metabolites in urine. Results: Urinary creatinine had the strongest relationship with overall arsenic methylation to DMA. Those with the highest urinary creatinine concentrations had 7.2% more arsenic as DMA compared with those with low creatinine (p < 0.001). Animal fat intake had the strongest relationship with MMA% (highest tertile animal fat intake had 2.3% more arsenic as MMA, p < 0.001). Low serum selenium and low folate were also associated with increased MMA%. Conclusions: Urine creatinine concentration was the strongest biological marker of arsenic methylation efficiency, and therefore should not be used to adjust for urine concentration in arsenic studies. The new finding that animal fat intake has a positive relationship with MMA% warrants further assessment in other studies. Increased MMA% was also associated, to a lesser extent, with low serum selenium and folate.
Safe limit of arsenic in soil in relation to dietary exposure of arsenicosis patients was established in Malda district of West Bengal. Out of 182 participants examined, 80 (43.9%) participants ...showed clinical features of arsenicosis, characterized by arsenical skin lesion (pigmentation and keratosis), while 102 participants did not have any such lesion (control). Experimental results of the twenty eight soils (own field) of the participants showed the mean Olsen extractable and total arsenic concentration of 0.206 and 6.70mgkg−1, respectively. Arsenic concentration in rice grain ranged from 2.00 to 1260μgkg−1 with the mean value of 146μgkg−1. The hazard quotient (HQ) for intake of As by human through consumption of rice varied from 0.03 to 3.52. HQ exceeds 1.0 for drinking water and rice grain grown in the study area in many cases. As high as 77.6% variation in As content in rice grain could be explained by the solubility-free ion activity model. Toxic limit of extractable As in soil for rice in relation to soil properties and human health hazard, associated with consumption of rice grain by human, was established. For example, the permissible limit of Olsen extractable As in soil would be 0.43mgkg−1 for rice cultivation, if soil pH and organic carbon content were 7.5% and 0.50%, respectively. However, the critical limit of Olsen extractable As in soil would be 0.54mgkg−1, if soil pH and organic carbon were 8.5% and 0.75%, respectively. The conceptual framework of fixing the toxic limit of arsenic in soils with respect to soil properties and human health under modeling-framework was established.
•A case study was conducted in Malda district (West Bengal) where arsenicosis is a severe problem.•An integrated approach by physicians and soil scientists was adopted to assess the As hazard.•We established a link of arsenicosis in human with arsenic content in water, soil and plant.•Novelty lies in prescription of toxic limit of metal in soil in relation to human health.•Modeling of As in soil plant system opens up a research avenue of remediation.
The hepatotoxic effect of arsenic when used in therapeutic dose has long been recognized. We described the nature and degree of liver involvement and its pathogenesis due to prolonged drinking of ...arsenic-contaminated water in West Bengal, India. From hospital-based studies on 248 cases of arsenicosis, hepatomegaly was found in 190 patients (76.6%). Non cirrhotic portal fibrosis was the predominant lesions in 63 out of 69 cases who underwent liver biopsy. The portal fibrosis was characterized by expansion of portal zones with streaky fibrosis, a few of which contained leash of vessels. However, portal hypertension was found in smaller number of cases.
A cross-sectional epidemiological study was carried out on 7683 people residing in arsenic-affected districts of West Bengal. Out of these, 3467 and 4216 people consumed water-containing arsenic below and above 0.05 mg/l, respectively. Prevalence of hepatomegaly was significantly higher in arsenic-exposed people (10.2%) compared to controls (2.99%,
P < 0.001). The incidence of hepatomegaly was found to have a linear relationship proportionate to increasing exposure of arsenic in drinking water in both sexes (
P < 0.001).
In an experimental study, BALB/C mice were given water contaminated with arsenic (3.2 mg/l) ad libitum for 15 months, the animals being sacrificed at 3-month intervals. We observed progressive reduction of hepatic glutathione and enzymes of anti-oxidative defense system associated with lipid peroxidation. Liver histology showed fatty infiltration at 12 months and hepatic fibrosis at 15 months.
Our studies show that prolong drinking of arsenic-contaminated water is associated with hepatomegaly. Predominant lesion of hepatic fibrosis appears to be caused by arsenic induced oxystress.
There has been widespread speculation about whether nutritional deficiencies increase the susceptibility to arsenic health effects. This is the first study to investigate whether dietary ...micronutrient and macronutrient intake modulates the well-established human risk of arsenic-induced skin lesions, including alterations in skin pigmentation and keratoses. The study was conducted in West Bengal, India, which along with Bangladesh constitutes the largest population in the world exposed to arsenic from drinking water. In this case-control study design, cases were patients with arsenic-induced skin lesions and had < 500 µg/L arsenic in their drinking water. For each case, an age- and sex-matched control was selected from participants of a 1995-1996 cross-sectional survey, whose drinking water at that time also contained < 500 µg/L arsenic. Nutritional assessment was based on a 24-hr recall for major dietary constituents and a 1-week recall for less common constituents. Modest increases in risk were related to being in the lowest quintiles of intake of animal protein odds ratio (OR) = 1.94; 95% confidence interval (CI), 1.05-3.59, calcium (OR = 1.89; 95% CI, 1.04-3.43), fiber (OR = 2.20; 95% CI, 1.15-4.21), and folate (OR = 1.67; 95% CI, 0.87-3.2). Conditional logistic regression suggested that the strongest associations were with low calcium, low animal protein, low folate, and low fiber intake. Nutrient intake was not related to arsenic exposure. We conclude that low intake of calcium, animal protein, folate, and fiber may increase susceptibility to arsenic-caused skin lesions. However, in light of the small magnitude of increased risks related to these dietary deficiencies, prevention should focus on reducing exposure to arsenic.
Between 2001 and 2003, the authors studied pregnancy outcomes and infant mortality among 202 married women in West Bengal, India. Reproductive histories were ascertained using structured interviews. ...Arsenic exposure during each pregnancy, including all water sources used, was assessed; this involved measurements from 409 wells. Odds ratios for spontaneous abortion, stillbirth, neonatal mortality, and infant mortality were estimated with logistic regression based on the method of generalized estimating equations. Exposure to high concentrations of arsenic (≥200 μg/liter) during pregnancy was associated with a sixfold increased risk of stillbirth after adjustment for potential confounders (odds ratio (OR) = 6.07, 95% confidence interval (CI): 1.54, 24.0; p = 0.01). Arsenic-related skin lesions were found in 12 women who had a substantially increased risk of stillbirth (OR = 13.1, 95% CI: 3.17, 54.0; p = 0.002). The odds ratio for neonatal death was 2.81 (95% CI: 0.73, 10.8). No association was found between arsenic exposure and spontaneous abortion (OR = 1.01, 95% CI: 0.38, 2.70) or overall infant mortality (OR = 1.33, 95% CI: 0.43, 4.04). This study adds to the limited evidence that exposure to high concentrations of arsenic during pregnancy increases the risk of stillbirth. However, there was no indication of the increased rates of spontaneous abortion and overall infant mortality that have been reported in some studies.
Background & objectives: Hepatitis B virus (HBV) and HIV co-infection has variable prevalence worldwide. In comparison to HBV mono-infection, the course of chronic HBV infection is accelerated in ...HIV/HBV co-infected patients. the present study was carried out to analyse the baseline characteristics (clinical, biochemical, serological and virological) of treatment naïve HIV/HBV co-infected and HIV mono-infected patients.
Methods: Between July 2011 and January 2013, a total number of 1331 HIV-seropositive treatment naïve individuals, enrolled in the ART Centre of Calcutta School of Tropical Medicine, Kolkata, India, were screened for hepatitis B surface antigen (HBsAg). A total of 1253 HIV mono-infected and 78 HIV/HBV co-infected patients were characterized. The co-infected patients were evaluated for HBeAg and anti-HBe antibody by ELISA. HIV RNA was quantified for all co-infected patients. HBV DNA was detected and quantified by real time-PCR amplification followed by HBV genotype determination.
Results: HIV/HBV co-infected patients had proportionately more advanced HIV disease (WHO clinical stage 3 and 4) than HIV mono-infected individuals (37.1 vs. 19.9%). The co-infected patients had significantly higher serum bilirubin, alanine aminotransferase (ALT), alkaline phosphatase and ALT/platelet ratio index (APRI). CD4 count was non-significantly lower in co-infected patients. Majority (61.5%) were HBeAg positive with higher HIV RNA (P<0.05), HBV DNA (p<0.001) and APRI (p<0.05) compared to those who were HBeAg negative. HBV/D was the predominant genotype (73.2%) and D2 (43.7%) was the commonest subgenotype.
Interpretation & conclusions: HIV/HBV co-infected patients had significantly higher serum bilirubin, ALT, alkaline phosphatase and lower platelet count. HBeAg positive co-infected patients had higher HIV RNA and HBV DNA compared to HBeAg negative co-infected patients. Prior to initiation of antiretroviral treatment (ART) all patients should be screened for HBsAg to initiate appropriate ART regimen.
To assess whether nutritional deficiency increases susceptibility to arsenic-related health effects.
Assessment of nutrition was based on a 24 h recall method of all dietary constituents.
...Epidemiological cross-sectional study was conducted in an arsenic endemic area of West Bengal with groundwater arsenic contamination.
The study was composed of two groups – Group 1 (cases, n 108) exhibiting skin lesions and Group 2 (exposed controls, n 100) not exhibiting skin lesions – age- and sex-matched and having similar arsenic exposure through drinking water and arsenic levels in urine and hair.
Both groups belonged to low socio-economic strata (Group 1 significantly poorer, P<0·01) and had low BMI (prevalence of BMI<18·5 kg/m2: in 38% in Group 1 and 27% in Group 2). Energy intake was below the Recommended Daily Allowance (set by the Indian Council of Medical Research) in males and females in both groups. Increased risk of arsenical skin lesions was found for those in the lowest quintile of protein intake (v. highest quintile: OR=4·60, 95% CI 1·36, 15·50 in males; OR=5·62, 95% CI 1·19, 34·57 in females). Significantly lower intakes of energy, protein, thiamin, niacin, Mg, Zn and choline were observed in both males and females of Group 1 compared with Group 2. Significantly lower intakes of carbohydrate, riboflavin, niacin and Cu were also observed in female cases with skin lesions compared with non-cases.
Deficiencies of Zn, Mg and Cu, in addition to protein, B vitamins and choline, are found to be associated with arsenical skin lesions in West Bengal.
Gene-specific hypermethylation has previously been detected in Arsenic exposed persons. To monitor the level of whole genome methylation in persons exposed to different levels of Arsenic via drinking ...water, DNA was extracted from peripheral blood mononuclear cells of 64 persons. Uptake of methyl group from ³H labeled S-Adenosyl Methionine after incubation of DNA with SssI methylase was measured. Results showed statistically significant (P = 0.0004) decrease in uptake of ³H methyl group in the persons exposed to 250-500 μg/L arsenic, indicating genomic hypermethylation.
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