Arsenic is a metalloid element, belongs to V group in periodic table, found in the natural environment in some abundance in the Earth’s crust and in small quantities in rock, soil, water and air. About one third of the arsenic in the atmosphere comes from natural sources, such as volcanoes, and the rest comes from man-made sources. The mineral (inorganic) forms of arsenic (iAs) are generally more toxic than its more complex organic compounds found naturally in plant and animal tissues.
Countries where As levels in drinking water have been found to exceed the World Health Organization Standard of 10 µg/l include Argentina, Australia, Bangladesh, chile, China, Hungary, India, Mexico, Peru, Taiwan, United States of America. The National Academy of Sciences estimates that about 75,000 to 100,000 tons of arsenic is produced annually on a global scale. About 80% of arsenic compounds are used to manufacture products with agricultural applications such as insecticides, herbicides, fungicides, algaecides, sheep dips, wood preservatives, dyestuffs and for the eradication of tapeworms in sheep and cattle. In addition, the use of arsenic in microelectronics is increasing. Thus, in addition to water contamination by this metal, anthropogenic activity is also important. Arsenic exposure causes diabetes mellitus besides other toxic effects like Cancerous diseases such as: Skin cancer, bladder cancer, liver, lung and stomach cancer.
Non-cancerous diseases such as: Peripheral vascular disease, cardiovascular and cerbrovascular diseases, hypertension, goitre, hepatomegaly, respiratory system dysfunction, nervous system dysfunction and diabetes mellitus.
Arsenic have been recently proposed as additional risk factors for type 2 diabetes. Hydroarsenicism is a major public health problem since millions of people worldwide are exposed to arsenic by the drinking of contaminated water. An increased prevalalence of diabetes has been consistently observed among residents of high arsenic exposure areas, whereas inconsistent findings have been reported from occupational and community-based studies in low arsenic exposure areas. Peoples are exposed to arsenic through many foods containing small amounts of arsenic and water, eating or breathing soil or dust particles contaminated with arsenic, drinking groundwater from natural deposits containing arsenic, breathing sawdust or burning smoke from wood treated with arsenic, working in a job that involves arsenic production or use, such as copper or lead smelting, wood treating, or pesticide application, touching arsenic-containing materials
Chronic exposure to inorganic arsenic represents a risk factor for diabetes mellitus in both environmental and occupational. The researchers reportedly concluded: “Given widespread exposure to inorganic arsenic from drinking water worldwide, elucidating the contribution of arsenic to the diabetes epidemic is a public health research priority with potential implications for the prevention and control of diabetes .
Arsenic induced type 2 diabetes depends on concentration of arsenic, arsenic compound, time of exposure, biological model. Arsenic induced diabetes also depends on individual susceptibility which includes: genetic factors, nutritional status, health status, detoxification capability, interactions with other trace elements, and presence of other risk factors for diabetes mellitus.
The pandemic of arsenic poisoning due to contaminated groundwater in West Bengal, India, and all of Bangladesh has been thought to be limited to the Ganges Delta (the Lower Ganga Plain), despite early survey reports of arsenic contamination in groundwater in the Union Territory of Chandigarh and its surroundings in the northwestern Upper Ganga Plain and recent findings in the Terai area of Nepal.
High levels of arsenic above the permissible levels of 50 parts per billion (ppb) are found in the alluvial plains of Ganges covering six districts of West Bengal. Presence of heavy metals in groundwater is found in 40 districts from 13 states, viz., Andhra Pradesh, Assam, Bihar, Haryana, Himachal Pradesh, Karnataka, Madhya Pradesh, Orissa, Punjab, Rajasthan, Tamil Nadu, Uttar Pradesh, West Bengal, and five blocks of Delhi. There is increase in the prevalence of diabetes mellitus among residents of arseniasis-endemic areas as compared to residents in non-endemic areas. The spread of arsenic contamination in groundwater seems to be assuming gargantuan proportions. What is worse is that inhabitants of the affected areas are unaware and the local authorities totally oblivious to this grave problem. It was known that West Bengal (WB) and Bangladesh had high levels of arsenic in the groundwater, but slowly the problem is spreading to other states like Uttar Pradesh. This is confirmed by the reports of All India Institute of Medical Sciences, New Delhi that people living in the Ballia district of UP also have high levels of arsenic in their blood, hair, nails, etc.
People should be made aware that their arsenic-related diseases are due to the arsenic-contaminated groundwater they are using for drinking and cooking. Lowering of the ingested inorganic arsenic level and introduction of newer treatment options (implementation of laterite, the natural material) to ensure safe water supply (arsenic free and/or low arsenic within permissible limit) are the urgent needs to safeguard against mass arsenic poisoning and internal arsenic-related health problems.
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