A new study published in the medical journal The Lancet reveals that one in five deaths in the Asian nation of Bangladesh, which has a population estimated to be more than 150 million, are caused by arsenic poisoning, according to Physorg.com.
Exposure to the deadly toxin has come from contaminated drinking water, a problem which began more than 30 years ago when a vast system of tube wells were installed around the country. The installations were originally part of well-intentioned efforts by international aid and development agencies to control waterborne diseases.
No one anticipated that tube wells would increase arsenic levels in the water. At the time of the wells' installation in the 1970s, the biggest health threat from water contamination came from diseases such as cholera and dysentery, diseases reduced by the use of tube wells.
The study also identified a surprising dose-related effect that showed an increased mortality rate at levels of arsenic exposure that Bangladeshi and world health officials typically consider safe.
For instance, the Bangladesh safety standard for arsenic is 50 micrograms per liter of water, and the World Health Organization's recommended standard is a more stringent 10 micrograms per liter of water. Both of those levels were deemed unsafe by the study.
The study tracked 12,000 people in Bangladesh over the course of a decade. Researchers ventured into the field and took samples from each of the 12,000 participants every two years. Lifestyle and health data were carefully tracked, so that the effects of arsenic could be determined. Nearly 6,000 wells were also tested to establish the arsenic concentration of each participant's water source.
With the shocking news, the study also offers some solutions. Arsenic poisoning can be avoided by digging deeper wells, and a program has been enacted which has already improved drinking water for about 100,000 people. But for the 33 to 77 million people in Bangladesh already exposed to arsenic, the changes can't come soon enough.
"The need for a global response is apparent because the situation goes far beyond the Bangladesh borders," said Dr. Joseph Graziano, who led the study. "Arsenic in groundwater is affecting 140 million people across many countries and especially in South Asia."
Related Articles on Mother Nature Network:
Bryan Nelson is reporter for the Mother Nature Network. This post originally appeared on MNN.
Image by Zuma Press via Mother Nature Network.