Debendra Nath Guha Mazumder

Bio: Debendra Nath Guha Mazumder is an academic researcher from Bose Corporation. The author has contributed to research in topics: Population & Arsenic contamination of groundwater. The author has an hindex of 13, co-authored 19 publications receiving 1271 citations.

Arsenic in drinking water and the prevalence of respiratory effects in West Bengal, India

Abstract: Background A large population in West Bengal, India has been exposed to naturally occurring inorganic arsenic through their drinking water. A cross-sectional survey involving 7683 participants of all ages was conducted in an arsenic-affected region between April 1995 and March 1996. The main focus of the study was skin keratoses and pigmentation alterations, two characteristic signs of ingested inorganic arsenic. Strong exposure-response gradients were found for these skin lesions. The study also collected limited information concerning respiratory system signs and symptoms, which we report here because increasing evidence suggests that arsenic ingestion also causes pulmonary effects. Methods Participants were clinically examined and interviewed, and the arsenic content in their current primary drinking water source was measured. There were few smokers and analyses were confined to non-smokers (N = 6864 participants). Results Among both males and females, the prevalence of cough, shortness of breath, and chest sounds (crepitations and/or rhonchi) in the lungs rose with increasing arsenic concentrations in drinking water. These respiratory effects were most pronounced in individuals with high arsenic water concentrations who also had skin lesions. Prevalence odds ratio (POR) estimates were markedly increased for participants with arsenic-induced skin lesions who also had high levels of arsenic in their current drinking water source (>500 μg/l) compared with individuals who had normal skin and were exposed to low levels of arsenic (,50 μg/l). In participants with skin lesions, the age-adjusted POR estimates for cough were 7.8 for females (95% CI : 3.1‐19.5) and 5.0 for males (95% CI : 2.6‐9.9); for chest sounds POR for females was 9.6 (95% CI : 4.0‐22.9) and for males 6.9 (95% CI : 3.1‐15.0). The POR for shortness of breath in females was 23.2 (95% CI : 5.8‐92.8) and in males 3.7 (95% CI : 1.3‐10.6). Conclusion These results add to evidence that long-term ingestion of inorganic arsenic can cause respiratory effects.

Children's intellectual function in relation to arsenic exposure.

Abstract: Background: Very little evidence exists concerning the possible impairment of children’s intellectual function in relation to arsenic exposure in utero and during childhood. Methods: We conducted a cross-sectional study among 351 children age 5 to 15 years who were selected from a source population of 7683 people in West Bengal, India, in 2001–2003. Intellectual function was assessed with 6 subtests from the Wechsler Intelligence Scale for Children as well as with the Total Sentence Recall test, the Colored Progressive Matrices test, and a pegboard test. Arsenic in urine and lifetime water sources (including during the pregnancy period) were assessed using measurements of samples from 409 wells. The test scores were analyzed with linear regression analyses based on the method of generalized estimating equations incorporating relevant covariates. Results: Stratifying urinary arsenic concentrations into tertiles, we found associations between arsenic and reductions in the adjusted scores of the vocabulary test (0, 0.14, 0.28; P for trend 0.02), the object assembly test (0, 0.16, 0.24; P for trend 0.03), and the picture completion test (0, 0.15, 0.26; P for trend 0.02). These findings correspond to relative declines of 12% (95% confidence interval 0.4% to 24%) in the vocabulary test, 21% (0.8% to 42%) in the object assembly test, and of 13% (0.3% to 24%) in the picture completion test in the upper urinary arsenic tertile. However, we did not find evidence of an association between test results and arsenic water concentrations during pregnancy or childhood. Conclusions: Current arsenic concentrations in urine, which reflect all sources of recent exposure, including water and food, were associated with small decrements in intellectual testing in schoolaged children in West Bengal. We did not see associations between long-term water arsenic concentrations and intellectual function. (Epidemiology 2007;18: 44 –51)

Hepatic damage caused by chronic arsenic toxicity in experimental animals.

Abstract: Objective: Noncirrhotic fibrosis of the liver is common in subjects chronically consuming ground water geologically contaminated with arsenic, but the mechanism of the hepatic fibrosis is not known. Because lipid peroxidation has been implicated in the development of several other forms of hepatic fibrosis, including iron and copper overload, we have explored the roles of oxidative stress and lipid peroxidation in the causation of hepatic fibrosis in a murine model of chronic arsenic toxicity. Methods: Male BALB/c mice were given drinking water contaminated with arsenic (3.2 mg/L) or arsenic-free (<0.01 mg/L, control) ad libitum. Mice were sacrificed at 3, 6, 9, 12, and 15 months for examination of hepatic histology and assays of hepatic reduced glutathione content, lipid peroxidation, enzymes of the antioxidant defense system, and membrane-bound sodium/potassium ATPase (Na+/K+ ATPase). Results: After 12 months of arsenic feeding, the liver weights increased significantly as did serum aspartate aminotrans...

Children's intellectual function in relation to arsenic exposure. Commentary

Abstract: Background: Very little evidence exists concerning the possible impairment of children's intellectual function in relation to arsenic exposure in utero and during childhood. Methods: We conducted a cross-sectional study among 351 children age 5 to 15 years who were selected from a source population of 7683 people in West Bengal, India, in 2001-2003. Intellectual function was assessed with 6 subtests from the Wechsler Intelligence Scale for Children as well as with the Total Sentence Recall test, the Colored Progressive Matrices test, and a pegboard test. Arsenic in urine and lifetime water sources (including during the pregnancy period) were assessed using measurements of samples from 409 wells. The test scores were analyzed with linear regression analyses based on the method of generalized estimating equations incorporating relevant covariates. Results: Stratifying urinary arsenic concentrations into tertiles, we found associations between arsenic and reductions in the adjusted scores of the vocabulary test (0, -0.14, -0.28; P for trend = 0.02), the object assembly test (0, -0.16, -0.24; P for trend = 0.03), and the picture completion test (0, -0.15, -0.26; P for trend = 0.02). These findings correspond to relative declines of 12% (95% confidence interval =0.4% to 24%) in the vocabulary test, 21% (-0.8% to 42%) in the object assembly test, and of 13% (0.3% to 24%) in the picture completion test in the upper urinary arsenic tertile. However, we did not find evidence of an association between test results and arsenic water concentrations during pregnancy or childhood. Conclusions: Current arsenic concentrations in urine, which reflect all sources of recent exposure, including water and food, were associated with small decrements in intellectual testing in schoolaged children in West Bengal. We did not see associations between long-term water arsenic concentrations and intellectual function.

Arsenic-induced skin lesions among Atacameño people in Northern Chile despite good nutrition and centuries of exposure.

Abstract: It has been suggested that the indigenous Atacameno people in Northern Chile might be protected from the health effects of arsenic in drinking water because of many centuries of exposure. Here we report on the first intensive investigation of arsenic-induced skin lesions in this population. We selected 11 families (44 participants) from the village of Chiu Chiu, which is supplied with water containing between 750 and 800 microg/L inorganic arsenic. For comparison, 8 families (31 participants) were also selected from a village where the water contains approximately 10 microg/L inorganic arsenic. After being transported to the nearest city for blind assessment, participants were examined by four physicians with experience in studying arsenic-induced lesions. Four of the six men from the exposed village, who had been drinking the contaminated water for more than 20 years, were diagnosed with skin lesions due to arsenic, but none of the women had definite lesions. A 13-year-old girl had definite skin pigmentation changes due to arsenic, and a 19-year-old boy had both pigmentation changes and keratoses on the palms of his hands and the soles of his feet. Family interviews identified a wide range of fruits and vegetables consumed daily by the affected participants, as well as the weekly intake of red meat and chicken. However, the prevalence of skin lesions among men and children in the small population studied was similar to that reported with corresponding arsenic drinking water concentrations in both Taiwan and West Bengal, India--populations in which extensive malnutrition has been thought to increase susceptibility.

Contamination of drinking-water by arsenic in Bangladesh: a public health emergency

Abstract: The contamination of groundwater by arsenic in Bangladesh is the largest poisoning of a population in history, with millions of people exposed. This paper describes the history of the discovery of arsenic in drinking-water in Bangladesh and recommends intervention strategies. Tube-wells were installed to provide ‘‘pure water’’ to prevent morbidity and mortality from gastrointestinal disease. The water from the millions of tube-wells that were installed was not tested for arsenic contamination. Studies in other countries where the population has had long-term exposure to arsenic in groundwater indicate that 1 in 10 people who drink water containing 500mg of arsenic per litre may ultimately die from cancers caused by arsenic, including lung, bladder and skin cancers. The rapid allocation of funding and prompt expansion of current interventions to address this contamination should be facilitated. The fundamental intervention is the identification and provision of arsenic-free drinking water. Arsenic is rapidly excreted in urine, and for early or mild cases, no specific treatment is required. Community education and participation are essential to ensure that interventions are successful; these should be coupled with follow-up monitoring to confirm that exposure has ended. Taken together with the discovery of arsenic in groundwater in other countries, the experience in Bangladesh shows that groundwater sources throughout the world that are used for drinking-water should be tested for arsenic.

The Broad Scope of Health Effects from Chronic Arsenic Exposure: Update on a Worldwide Public Health Problem

Abstract: Background: Concerns for arsenic exposure are not limited to toxic waste sites and massive poisoning events. Chronic exposure continues to be a major public health problem worldwide, affecting hundreds of millions of persons. Objectives: We reviewed recent information on worldwide concerns for arsenic exposures and public health to heighten awareness of the current scope of arsenic exposure and health outcomes and the importance of reducing exposure, particularly during pregnancy and early life. Methods: We synthesized the large body of current research pertaining to arsenic exposure and health outcomes with an emphasis on recent publications. Discussion: Locations of high arsenic exposure via drinking water span from Bangladesh, Chile, and Taiwan to the United States. The U.S. Environmental Protection Agency maximum contaminant level (MCL) in drinking water is 10 µg/L; however, concentrations of > 3,000 µg/L have been found in wells in the United States. In addition, exposure through diet is of growing concern. Knowledge of the scope of arsenic-associated health effects has broadened; arsenic leaves essentially no bodily system untouched. Arsenic is a known carcinogen associated with skin, lung, bladder, kidney, and liver cancer. Dermatological, developmental, neurological, respiratory, cardiovascular, immunological, and endocrine effects are also evident. Most remarkably, early-life exposure may be related to increased risks for several types of cancer and other diseases during adulthood. Conclusions: These data call for heightened awareness of arsenic-related pathologies in broader contexts than previously perceived. Testing foods and drinking water for arsenic, including individual private wells, should be a top priority to reduce exposure, particularly for pregnant women and children, given the potential for life-long effects of developmental exposure.