Many parts of Rajasthan may have high uranium levels in their groundwater, according to a study by researchers at the Duke University in North Carolina, United States, and the Central Groundwater Board of India.
The main source of uranium contamination was “natural,” but human factors such as groundwater table decline and nitrate pollution could be worsening the problem.
“Nearly a third of all water wells we tested in one State, Rajasthan, contained uranium levels that exceed the World Health Organization (WHO) and U.S. Environmental Protection Agency's (EPA) safe drinking water standards,” said Avner Vengosh, a professor of geochemistry and water quality at Duke’s Nicholas School of the Environment, in a press statement.
“By analysing previous water quality studies, we also identified aquifers contaminated with similarly high levels of uranium in 26 other districts in north-western India and nine districts in southern or south-eastern India,” he said.
While previous studies have referred to high uranium levels in some districts of India, this analysis gave a bird’s eye view into the extent of such contamination. The WHO has set a provisional safe drinking water standard of 30 micrograms of uranium per litre, a level that is consistent with the U.S. EPA standards. Despite this, uranium is not yet included in the list of contaminants monitored under the Bureau of Indian Standards’ Drinking Water Specifications.
Mr. Vengosh and his colleagues published their peer-reviewed study on May 11 in Environmental Science & Technology Letters .