Scientists have found widespread uranium contamination in groundwater from aquifers across 16 states in India, much above the WHO provisional standard for the country.
The researchers from Duke University in the US unveiled new data showing that the occurrence in uranium in Indian groundwater – a primary source of drinking water and irrigation – is an emerging and widespread phenomenon.
They compiled data on groundwater uranium from 16 Indian states and new data from 324 wells in Rajasthan and Gujarat that shows a high prevalence of uranium concentrations above the World Health Organization (WHO) provisional guideline value across India.
Several studies have linked exposure to uranium in drinking water to chronic kidney disease.
While the primary source of uranium is geogenic (naturally occurring), anthropogenic (human caused) factors such as groundwater table decline and nitrate pollution may further enhance uranium mobilisation.
Using geochemical and uranium isotope data, it suggests factors that may drive high uranium concentrations in groundwater, including uranium content in aquifer rocks, oxidation state, and groundwater chemistry that promotes the formation of soluble uranyl carbonate complexes.
"In many parts of India, these factors co-occur and result in high uranium concentrations in the groundwater," Coyte said.
Human activities, especially the over-exploitation of groundwater for agricultural irrigation, may contribute to the problem, said Coyte.
“The study strongly suggests the need for revision of the current water quality monitoring program in India, evaluation of human health risks in areas of high uranium prevalence, development of adequate remediation technologies, and, above all, implementation of preventive management practices to address this problem,” said Vengosh.
"Including a uranium standard in the Bureau of Indian Standards’ Drinking Water Specification based on uranium’s kidney-harming effects, establishing monitoring systems to identify at-risk areas, and exploring new ways to prevent or treat uranium contamination will help ensure access to safe drinking water for tens of millions in India," he said.