Arsenic contamination along the Ganges Basin: A multi-disciplinary approach toward sustainable mitigation strategy

Research Project , Research Report 2003

Ryutaro OHTSUKA Dept. of Human Ecology, Univ. of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
Kazuo YAMAMOTO Environmental Science Center, U Tokyo
Chiho WATANABE Department of Urban Environmental Engineering, U of Toyo
Kensuke FUKUSHI Engineering Research Institute, U Tokyo
Makhan Maharjan Dept. of Regional Development Studies, Toyo University
Aktah Ahmed National Institute of Preventive and Social Medicine, Dhaka, Bangladesh(Research Partners)
M.M. RAHMAN Bangladesh University of Engineering and Technology, Dhaka, Bangladesh
M.H. RAHMAN Massachusetts Institute of Technology, USA
Charles HARVEY EAWAG, Zurich, Switzerland
Stephan HUG University of Rajshahi,, Bangladesh
M.H. RAHMAN Bengal Engineering College, India
P.Bandyopadhyay National Institute of Preventive and Social Medicine, Dhaka, Bangladesh

Abstract

Chronic exposure to arsenic through “naturally-“contaminated groundwater can found in many developing countries. We have extended our survey conducted in Bangladesh to Nepal, another country along the Ganges basin. Although the first report regarding arsenic contamination in Terai region, the lowland Nepal, was put out in 1999, community-based survey has not been conducted. We chose three communities in a “hot spot” district of Terai and conducted two surveys in December 2002 to February 2003and in August 2003. Among the water samples from 146 tubewells in use, 98% and 88% exceeded arsenic concentration of 10 (Bangladesh provisional standard) and 50 ppm (WHO recommendation) , respectively. Among 1,343 villagers including children, 6.9% was identified as exhibiting positive dermatological signs (keratosis and/or melanosis), with the younger subjects showing much less prevalence (only 0.6%). Excluding those under 15 years, males (15.4%) exhibited much higher prevalence than females (6.6%), confirming our observation in rural Bangladesh. Water consumption was unlikely to explain this sex-related difference. In addition, mutual relationship between nutritional status and arsenic exposure was recognized. That is, 1) the higher the exposure level, the lower the BMI, an index for nutritional status, and 2) the prevalence was higher among those having low BMIs than those with higher BMIs. Regarding the removal technology of arsenic, focus has been on two systems including AIRP and IARP. With a sand-filer system constructed in UT campus, several factors affecting the removal efficacy have been identified.

Keywords:

water quality, arsenic, drinking water, health effects, exposure evaluation, arsenic removal, chemical speciation, nutritional status, Nepal