GIVEN A CHOICE between using a nearby water well known to be contaminated with arsenic or a more distant one not known to be poisoned, every sane person would opt for the latter. In Bangladesh in the early 2000s, however, that appears to have been the wrong decision. In 1999 the government began a massive campaign to convince households drawing water from shallow backyard wells with high concentrations of arsenic to switch to deeper wells or streams that were free of the toxic metal. Arsenic is present naturally in groundwater across the globe, but is especially prevalent in Bangladesh. Prior to the campaign, roughly 65% of Bangladeshis in the authors’ sample were drinking water with unsafe levels of arsenic, high exposure to which could lead to increased rates of cancer and infant mortality as well as decreased intelligence quotient for affected children. However, alternative sources were typically farther away from people’s homes, increasing the likelihood that users would make fewer trips and store their water for longer periods of time. And improperly stored water is often mishandled, increasing the rates of cholera, dysentery and other water-borne diseases. As a result, by asking people not to use wells polluted with arsenic, the government unintentionally caused the number of deaths resulting from ingesting water contaminated by faecal matter to rise.
In a new working paper published by the National Bureau of Economic Research, Nina Buchmann, an economist at Stanford, and her co-authors collected data from 3,138 Bangladeshi households in 2007. Their data included a sample of more than 12,000 children born between 1980 and 2007, which allowed them to evaluate the mortality rate among households that were and were not encouraged to switch water sources during the government’s campaign. According to their study, post-campaign, households encouraged to switch water sources had 48% higher rates of child mortality than those not encouraged to switch. They found that the increase in deaths was higher in households that were farther away from a deep well, which increases the storage time.