Is phytoremediation the solution for arsenic contamination of groundwater in India and Bangladesh?

摘要

Groundwater which is not present in abundance in nature is one of the most important sources of drinking water. The contamination of groundwater with arsenic is a serious problem encountered in northern India and Bangladesh. To understand the magnitude of the arsenic calamity in West Bengal, a detailed study spanning seven years was made in North 24-Parganas, one of the nine arsenic-affected districts. Area and population of North 24-Parganas district are 4093.82 km super(2) and 7.3 million, respectively. Nearly forty eight thousand water samples were analysed from hand tube wells of North 24-Parganas which are in use for drinking. 29.2% of the tube wells were found to have arsenic above 50 mu g/l, which is beyond the maximum permissible limit of World Health Organization (WHO) while 52.8% had arsenic above 10 mu g/l, which is slightly above the WHO recommended value of arsenic in drinking water. Out of the 22 blocks of North 24-Parganas, arsenic has been found in 20 blocks above the maximum permissible limit and so far in 16 blocks people have been identified as suffering from arsenical skin lesions. From the data, it is estimated that about 2.0 million and 1.0 million people are drinking arsenic contaminated water above 10 mu g/l and 50 mu g/l level, respectively in North 24-Parganas alone. Extrapolation of the data indicated that about 0.1 million people may be suffering from arsenical skin lesions in North 24-Parganas alone. Studies conducted by UNICEF and Jadavpur University showed that 14 districts in Bihar, 11 districts in Uttar Pradesh, two each in Assam and Chattisgarh and one in Jharkhand display large-scale arsenic contamination.