SUBSURFACE ARSENIC OCCURRENCE AND DEPTH OF CONTAMINATION IN BANGLADESH

Md. Masud Karim, Yasukazu Komori
Dainichi Consultant Incorporated, 3-1-21 Yabuta Minami, Gifu 500, Japan.
Tel: (058) 271 2501 Fax: (058) 276 6418
and
Monira Alam
Research Student, Faculty of Agriculture, Gifu University, 1-1 Yanagido, Gifu 501-11, Japan.
Tel. & Fax: (058) 293 2927


SUMMARY

Both soil and underground water of the southwestern Bangladesh has already been threatened with arsenic contamination affecting health of millions of people. An estimated 44% of total  area of Bangladesh (34 districts) and 53 million rural people are at risk of arsenic poisoning. In the southwestern and some parts of eastern Bangladesh, arsenic content in soil and underground water has identified higher contamination. The experts at Bangladesh Council for Scientific and Industrial Research (BCSIR) found the highest contamination, 14 mg/l of shallow tube well water in Pabna, a northern district and 220 mg/kg of soil in Sylhet area of Bangladesh.1) The World Health Organization (WHO) standard for arsenic in drinking water is 0.01 mg/l. However, the maximum permissible limit of arsenic in drinking water of Bangladesh is 0.05 mg/l. Worsening contamination  of groundwater aquifer and sufferings of the millions of people demands extensive research in this field.

This study is a preliminary evaluation of our ongoing research on current state of the subsurface contamination of arsenic in Bangladesh. Last decade water resources management has been analyzed to cope with the problem in the source level. Possible geo-hydrological and geo-chemical occurrences of arsenic in subsurface are discussed. The concentration 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. And the concentration of arsenic in tubewell water decreases with the depth of subsurface.

Key words: Subsurface arsenic contamination, arsenic in groundwater of Bangladesh, Geo-hydrological & Geo-chemical occurrences of arsenic.