ARSENIC POLLUTION AND REMEDIAL MEASURES IN WEST BENGAL: AN OVERVIEW

Abstract

During the past twenty years, Arsenic (As) contamination via groundwater has become a significant issue worldwide and is now a serious concern within the Indo-Bangladesh Gangetic delta. Arsenic enters physical body through contaminated groundwater consumed as beverage. Food safety in this region is facing severe consequences as bio-accumulation of Arsenic is happening through food crops irrigated with As-contaminated water. Chronic exposure to Arsenic may cause not only cancerous and non-cancer health effects. Reports suggest that about 20% population in West Bengal is very affected. Various techniques are being introduced to supply arsenic-free beverage at a reasonable cost. But a rigorous change in habit and state of mind for procuring safe beverage in those surviving in As-contaminated zones is that the most essential step towards curbing the fatal consequences of arsenic exposure. Harvesting rain water and utilization of proper purification techniques are often considered a possible alternative of safe beverage. Arsenic in groundwater above the WHO maximum permissible limit of 0.01 mg l−1 has been found in six districts of West Bengal covering a neighborhood of 34 000 km2 with a population of 30 million. at the present, 37 administrative blocks by the side of the River Ganga and adjoining areas are affected. Areas suffering from arsenic contamination in groundwater are all located within the upper delta plain, and are mostly within the abandoned meander belt. Quite 8,00,000 people from 312 villages/wards are affected with arsenic contaminated beverage and amongst them a minimum of 175 000 people show arsenical skin lesions. Thousands of tube-well waters in these six districts are analyzed for arsenic species. Hair, nails, scales, urine, liver tissue analyses show elevated concentrations of arsenic in people drinking arsenic-contaminated water for an extended period. The source of the arsenic is geological. Bore-hole sediment analyses show high arsenic concentrations in just few soil layers which is found to be related to iron-pyrites. Various social problems arise thanks to arsenical skin lesions in these districts. Poor socio-economic conditions, malnutrition, illiteracy, food habits and intake of arsenic-contaminated water for several years have aggravated the arsenic toxicity. altogether these districts, major water demands are met from groundwater and therefore the geochemical reaction, caused by high withdrawal of water could also be the explanation for arsenic leaching from the source. If alternative water resources aren't utilised, an honest percentage of the 30 million people of those six districts may suffer from arsenic toxicity within the near future.