Throwing the Baby Out with the Drinking Water: Unintended Consequences of Arsenic Mitigation Efforts in Bangladesh

The 1994 discovery of arsenic in ground water in Bangladesh prompted a massive public health effort to test all tubewells in the country and convince nearly one-quarter of the population to switch to arsenic-free drinking water sources. According to numerous sources, the campaign was effective in leading the majority of households at risk of arsenic poisoning to abandon backyard wells in favor of more remote tubewells or surface water sources, a switch widely believed to have saved numerous lives. We investigate the possibility of unintended health consequences of the wide-scale abandonment of shallow tubewells due to higher exposure to fecal-oral pathogens in water from arsenic-free sources. Significant small-scale variability of arsenic concentrations in ground water allows us to compare trends in infant and child mortality between otherwise similar households in the same village who did and did not have an incentive to abandon shallow tubewells. While child mortality rates were similar among households with arsenic-contaminated and arsenic-free wells prior to public knowledge of the arsenic problem, post-2000 households living on arsenic-contaminated land have 27% higher rates of infant and child mortality than those not encouraged to switch sources, implying that the campaign doubled mortality from diarrheal disease. These findings provide novel evidence of a strong association between drinking water contamination and child mortality, a question of current scientific debate in settings with high levels of exposure to microbial pathogens through other channels.