ABSTRACT
Perhaps the leading reason for continued exposure is that shallow wells continue to be installed by individual households throughout Bangladesh, either as additional wells or to replace failed wells, and that these wells remain largely untested (Fig. 1). Most rural households in Bangladesh have nowhere to turn if they install a new well
1 TIMELINE
It is disturbing to enter almost any village of the Bengal basin today and find that groundwater drawn from untested shallow wells continues to be used routinely for drinking and cooking, given that the arsenic problem was already recognized in the mid-1980s in West Bengal and the mid-1990s in Bangladesh. Naturally elevated arsenic levels have since been documented in groundwater across the world, but Bangladesh remains the most affected single country (Ravenscroft et al., 2009). A first national survey completed in 2000showed that a population close to 57 million was exposed to arsenic levels exceeding the WHO guideline for drinking water of 10 μg/L by up to two orders of magnitude. Two representative drinking-water surveys conducted since have indicated a decline in the exposed population to 52 million in 2009 and 40 million in 2013, which is still an enormous number (BBS/UNICEF, 2015). Relative to the Bangladesh standard of 50 μg/L, the corresponding decline in the exposed population over the same period has been from an initial 35 to 22 and 20 million, respectively. After some initial successes, arsenic mitigation has clearly stagnated.
