Groundwater arsenic contamination in India: a review of its magnitude, health, social, socio-economic effects and approaches for arsenic mitigation.

摘要

During our last 25 years' field survey in India, we have registered groundwater arsenic contamination and its health effects from the states of West-Bengal, Jharkhand, Bihar, Uttar Pradesh in the flood plain of Ganga River; Assam and Manipur in the flood plain of Brahamaputra and Imphal Rivers. Groundwater of Rajnandgaon village in Chhattisgarh state is also arsenic contaminated and some people had arsenical skin lesions although the source of arsenic in Chhattisgarh is not from flood plains of Newer Alluvium (Holocene) as in Ganga, Brahmaputra, and Imphal rivers. The magnitude of arsenic contamination in Chhattisgarh state is negligible compared to flood plain contamination. The total area and population of these states are 529,674 km 2 & approx. 359 million respectively. So far we have analyzed 171,387 hand tube-well water samples from all these states and have found about 50% of hand tube-wells in affected districts of these states is arsenic affected above WHO guideline value of arsenic in drinking water (10 g/L). In our preliminary survey screening 100,731 people from arsenic affected villages of West Bengal, Jharkhand, Bihar, Uttar Pradesh and Chhattisgarh, 10,113 patients were registered with different kinds of arsenical skin lesions. Arsenic neuropathy as well as adverse pregnancy outcomes such as spontaneous abortion, still-birth, preterm birth and low birth weight were recorded. We have found arsenic related cancer in many patients suffering from arsenic related skin lesions in the affected districts. Infants and children drinking arsenic contaminated water are at high risk. Analyses of 42,000 biological samples from arsenic affected areas showed elevated level of arsenic in both patients and non-patients indicating that many are sub-clinically affected. Groundwater arsenic contamination and its health effects from West-Bengal surfaced in 1982. Even, after thirty years, with our every new survey, we are finding new arsenic affected villages and people suffering from arsenic related diseases from West-Bengal. People in newly arsenic identified states are in more danger, as many are not aware of their arsenic contamination in hand tube-wells and unknowingly drinking arsenic contaminated groundwater. Even after spending millions dollars for arsenic testing in groundwater and for providing arsenic safe water to the villagers from contaminated hand tube-wells, the overall result has not been satisfactory. So far little attempts have been made for treating the patients suffering from arsenic toxicity and to reduce their arsenic related social and socio-economic problems. Proper watershed management and economical utilization of all available alternative safe sources of water has not been tried. From our last 25 years field experience we have realized that to combat the arsenic crises we need to educate and create awareness among the villagers about the dangers of arsenic toxicity and the importance of using arsenic safe water. This can only be achieved by active community participation and whole-hearted support from the government and the arsenic researchers.