SUBSURFACE OCCURRENCE AND CONTAMINATION OF ARSENIC IN GROUNDWATER OF BANGLADESH

Subsurface contamination of arsenic in the southwestern Bangladesh has threatened severely, which affects health of millions of people. A preliminary estimation reported that 44% of total area of Bangladesh (34 districts) and 53 million people are great risk of this disaster. Experts at Bangladesh Council for Scientific and Industrial Research (BCSIR) found the highest contamination of 14mg/l in a shallow tube well water of Pabna district and 220mg/kg of soil in Sylhet district. This paper is a preliminary investigation of the recent arsenic calamity in Bangladesh. In organizing the paper, water resources management and geo-hydrological occurrences have been discussed to figure out the reason of contamination. The concentration distribution of arsenic and the stratigraphic occurrence are presented. It is observed that arsenic concentration in tubewell water of 31 districts of Bangladesh contain above the maximum permissible limit (0.05mg/l). And the concentration of arsenic in tubewell water decreases with the depth of subsurface.