The catastrophic health crisis caused by drinking metal-contaminated groundwater in Bangladesh affects tens of millions of people and requires urgent attention. Our study suggests that 49% of Bangladesh’s area has As concentrations above WHO guidelines. Similarly, 50%, 3%, < 1%, and < 1% of Bangladesh’s area exceeds WHO guidelines for Mn, Pb, Ni, and Cr, respectively. Our estimate that 60 million Bangladeshis are drinking water with As concentrations above the WHO health-based guideline agrees with the BGS/DPHE’s 57 million-person estimate. In addition, our estimate that 50% of Bangladesh’s area exceeds the WHO health-based guideline for Mn is comparable with the BGS/DPHE’s estimate. Similarly, B, Ba, Cr, Mo, Ni, Pb, and U were discovered at concentrations above WHO health-based guidelines in relatively small areas of Bangladesh by our team, the BGS/DPHE team, or both teams (28). Considering the population of this country and that 97% of its people drink from wells (2,4), these data suggest that tens of millions of Bangladeshis are drinking water with unsafe levels of As, Mn, B, Ba, Cr, Mo, Ni, Pb, or U. Arsenic in Bangladesh’s tubewell water was found to be the most significant health risk. Drinking water with safe levels of As could be supplied to tens of millions by the integrated use of groundwater monitoring, drilling deeper tubewells, and appropriate treatment systems (10,11,39). However, mitigation efforts should not be limited to As; the health risks from other toxins in this region’s drinking water must also be addressed. Figures 2-6 will allow scientists, policy makers, and aid workers to initiate a rapid action program to focus in more detail on the areas with the highest concentrations of As, Mn, Pb, Ni, and Cr as we have documented in these maps. Strategies to supply this region with drinking water that has safe levels of As, Mn, Pb, Ni, Cr, other toxic elements, and agents that magnify chronic As poisoning must be studied, developed, and quickly implemented.
