Arsenic, a potent carcinogen, can cause malignant arsenical skin lesions may be Bowen's disease, basal cell carcinoma, or squamous cell carcinoma. Apart from carcinoma and melanoma, chronic arsenic exposure can cause respiratory disease, gastrointestinal disorder, liver malfunction, nervous system disorder, haematological diseases like anaemia, leucopaenia and thrombocytopaenia, diabetes and severe cardiovascular malfunction. Vegetables and crops grown in arsenic contaminated groundwater can add many fold daily arsenic intake through human food apart from drinking water. The main economy of highly arsenic affected areas of West Bengal depends on agriculture, so uncontrolled uplifting of groundwater for irrigation is being practised over past few decades. Our research group studied on various aspects of arsenic entry into human foodchain and its health effects. By studying arsenic accumulation in different vegetables, we found that tuberous vegetables accumulated higher amount of arsenic than leafy vegetables and leafy vegetables followed by fruity vegetable. The highest arsenic accumulation was observed in potato, brinjal, arum, amaranth, radish, lady's finger, cauliflower whereas lower level of arsenic accumulation was observed in beans, green chilli, tomato, bitter guard, lemon, turmeric. The major oil seed of this region is mustard and was found to accumulate arsenic in the range 0.339-0.373 mg/kg. In pulses group, pea showed the highest arsenic content of 1.30 mg/kg whereas moong (Mung bean) found the lowest value (0.314 mg/kg). Rice, the principal crop of this region, accumulated arsenic irrespective to its varieties. The arsenic accumulation was found to be more in Boro rice than in Aman, while high yielding rice varieties were found to accumulate more arsenic than local. From dietary study we found that a total daily intake of 560 μg and 393 μg of arsenic for adult and children respectively. The people having poor nutrition were found to be affected more from arsenic toxicity than the people having adequate nutrition. The present review represents the current scenario of arsenic contamination and suggests probable sustainable mitigation strategies to battle against the curse of arsenic contamination.

Arsenic in foodchain and community health risk: a study in Gangetic West Bengal

Globally alarming ten heavy metal (Zn, Al, Cd, Pb, Cu, Ni, Fe, Mn, Cr, Co) concentrations were estimated in surface water and sediment of the Meghna River in Bangladesh from September 2015 to March 2016. Heavy metals were analyzed by Atomic Absorption Spectrophotometer (AAS). Results indicated that, all the metals in water were found below the safe limit of drinking water standard of WHO (1993) and EU (1998) with the exclusion of Fe, Ni and Al. In sediment, all the trace metals were recorded below the limit compared to other scientific results. For three seasons at two sampling points no significant difference in heavy metals was founded at the significance level (p > 0.05). Multivariate statistical analyses such as principal component analysis and correlation matrix disclosed prevalent anthropogenic interferences of Zn, Al, Cd, Pb, Cu, Ni, Fe, Mn, Cr, Co in water and sediment. The very strong positive correlation was recorded between Fe vs Al (0.992), Mn v’s Cu (0.948), Fe vs Mn (0.939), Zn vs Al (0.929), Fe vs Zn (0.920) in water. In sediment, very strong linear relationships were found in Cd vs Zn (0.999), Cd vs Cu (0.998), Zn vs Cu (0.996), Cd vs Ni (0.995), Ni vs Cu (0.994), Ni vs Zn (0.993) etc. at the 0.05 significance level which direct their common origin exclusively from industrial effluents, municipal wastes and agricultural inputs. Necessary steps should be taken to protect this River from pollution and also to reduce the environmental risk.

Heavy metal contamination in surface water and sediment of the Meghna River, Bangladesh

Arsenic is a natural drinking water contaminant affecting 26 million people in West Bengal, India. Chronic arsenic exposure causes cancer, cardiovascular disease, liver disease, neuropathies and ocular diseases. The aims of the present study were to assess bioindicators of hepatocellular injury as indicated by the levels of liver enzymes, to determine the auto immune status, as indicated by the amounts of anti-nuclear antibodies (ANA) and anti-dsDNA antibodies in their serum, and to predict cardiovascular risk in the arsenic exposed population. Effect of chronic arsenic exposure on liver was determined by liver function tests. Autoimmune status was measured by measuring ANA and anti-dsDNA in serum. Inflammatory cytokines associated with increased cardiovascular disease risk, IL6, IL8 and MCP-1 were determined. Our results indicated that serum levels of bilirubin, alanine transaminase, aspartate transaminase, alkaline phosphatase and ANA were increased in the arsenic exposed population. Serum levels of IL6 and IL8 also increased in the arsenic exposed group. Chronic arsenic exposure causes liver injury, increases the serum levels of autoimmune markers and imparts increased cardiovascular risk.

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Arsenic exposure through drinking water increases the risk of liver and cardiovascular diseases in the population of West Bengal, India.

Concentrations of six heavy metals (chromium, nickel, copper, arsenic, cadmium, and lead) in fish and vegetables were estimated to evaluate contamination levels and health risks for Bangladeshi adults. The analyzed metals varied between different species of fish and vegetables. Metals like Ni, Cd, and Pb in fish species were higher than the respective maximum allowable concentrations (MAC), whereas As, Cd, and Pb in some species of vegetables exceeded the MAC. Health risks associated with these metal intakes were evaluated in terms of dietary intake and target hazard quotients (THQs). The THQ values for individual metals were below 1 (except As for some species), suggesting that people would not experience significant health hazards if they ingest a single metal from one species of fish and/or vegetable. However, total metal THQ (TTHQ) signifies the potential non-carcinogenic health hazard to the highly exposed consumers in Bangladesh. Also, the estimation showed that the carcinogenic risk (TR) of...

Determination of Heavy Metals in Fish and Vegetables in Bangladesh and Health Implications

Integrated phytobial remediation for sustainable management of arsenic in soil and water.

Polymorphisms in the TNF-α and IL10 Gene Promoters and Risk of Arsenic-Induced Skin Lesions and Other Nondermatological Health Effects

The synthesis of poly(hydridocarbyne), one of a class of carbon-based random network polymers and a structural isomer of polyacetlyene, is reported. The network backbone of this polymer is primarily composed of tetrahedrally hybridized carbon atoms, each bearing one hydride substituent and linked via three carbon-carbon single bonds into a three-dimensional random network of fused rings. This atomic-level carbon network backbone confers unusual properties on the polymer, including facile thermal decomposition to form diamond or diamond-like carbon high-quality films at atmospheric pressure, by direct deposition or by chemical vapor deposition (CVD), without the use of hydrogen or any other reagent.

Diamond and diamond-like carbon from a preceramic polymer

Two procedures to improve the performance of the Hach EZ test kit for quantifying inorganic arsenic concentrations in drinking water have been investigated. In the first, a digital image of the colored spot formed on the test strip, obtained with a flat-bed scanner was analyzed, by the computer program Colors, for the R, G, and B values. Calibrations were constructed by plotting the B values as a function of concentration. Agreement between the experimentally determined B-values and those of the printed chart was only obtained by either increasing the reaction time (to 40 min) or increasing the reaction temperature. The precision as a function of concentration was quantified. A comparison with previously estimated values for visual comparison of the colours, showed that the improved precision of the digital analysis would produce fewer false positive and fewer false negative results at the important threshold values of 10 and 50 μg L−1. By running the test for 24 h, improved performance at the low concentration (around 10 μg L−1) end of the response scale was obtained.

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James K. Kearns

Papers

Polymorphisms in the TNF-α and IL10 Gene Promoters and Risk of Arsenic-Induced Skin Lesions and Other Nondermatological Health Effects

Diamond and diamond-like carbon from a preceramic polymer

Improving the accuracy and precision of an arsenic field test kit: increased reaction time and digital image analysis