Figure 1

Map of the entire Bengal Basin showing the general distribution of As in tubewells on the basis of data collected by Dr. Chakraborti's laboratory at the School of Environmental Studies, Jadavpur University, Kolkata, India. Most tubewells contain >50 μg L-1 arsenic in red areas and <50 μg L-1 in green areas. Orange areas indicate a mixed distribution high- and low-As well. Also shown are the location of the two study sites and the two largest cities in the region. Adapted from [9].