Charles Harvey traces the source of widespread arsenic poisoning in Bangladesh, setting the stage for programs that could benefit 20 million people.
Millions of people in developing countries drink groundwater contaminated with much higher levels of arsenic than the old U.S. standard, every day…Cruelly, Bangladeshis were getting sick because they followed the advice of international development agencies.
When Harvey and his colleagues started drilling wells to determine why arsenic levels were so high, they found that concentrations peaked at depths of about 30 meters — unfortunately, the same level at which many tube wells drew their drinking water. Testing groundwater at this depth, they found that it contained high levels of methane, which is released when microbes break down organic materials under oxygen-free conditions — for example, when they are buried in saturated soil.
As Harvey sees it, arsenic contamination in Bangladesh is an example of a larger problem occurring in many places around the world: Land-use changes over the past 50 years have had delayed impacts – underground. Harvey’s findings in Bangladesh, therefore, may help mitigate arsenic poisoning in other countries.
By Jennifer Weeks