Encouraging residents of Bangladesh to switch to safe wells could save millions of lives by preventing the cancer and cardiovascular disease caused by long-term exposure to arsenic, a new study says. About 33 million inhabitants are currently exposed to high levels of naturally occurring arsenic in what the World Health Organization calls the “largest mass poisoning of a population in history” (CMAJ 2002;166[12]:1578). The exposure is occurring through 9 million shallow tube wells that were dug to prevent water-borne diseases caused by contaminated surface water.
A recent study involving 4997 of these wells in the Araihazar district (population 55 000) found that 48% of them were safe (Bull World Health Organ 2002;80[9]:732-7). Although only half of these residents had access to safe water from their own well, 88% lived within 100 m of a safe one, and 95% within 200 m. “Well-switching should be more systematically encouraged,” conclude US researcher Alexander van Geen and colleagues.
But switching wells may not be as simple as it sounds, because most wells are privately owned and women, who usually fetch the water, can't leave their family cluster of households unaccompanied. — CMAJ