The study states the main source of the uranium contamination as natural, but human factors such as groundwater table decline and prevalence of nitrate pollution may be exacerbating the problem.
Underlining rising concerns revolving around the environment, a new Duke University-led study has come out with serious findings of uranium contamination in India’s groundwater. The study has found contamination in the groundwater from aquifers in 16 states of India, highlighting the need for attention in the states to prevent collateral damage.
According to the report, sample water from 324 wells in the states of Rajasthan and Gujarat was taken and water chemistry was analyzed. In a subset of samples, they measured the uranium isotope ratios. They also analyzed similar data from 68 previous studies of groundwater geochemistry in Rajasthan, Gujarat and 14 other Indian states.
“Nearly a third of all water wells we tested in one state, Rajasthan, contained uranium levels that exceed the World Health Organization and U.S. Environmental Protection Agency’s safe drinking water standards,” report quoted Avner Vengosh, the lead author of the study and a professor of geochemistry and water quality at the School of the Environment.
”By analyzing previous water quality studies, we also identified aquifers contaminated with similarly high levels of uranium in 26 other districts in northwestern India and nine districts in southern or southeastern India,” he added.
It is to be understood here that several studies have proven harmful links between exposure to uranium in drinking water and kidney diseases.
The study brief states the main source of the uranium contamination as natural, but human factors such as groundwater table decline and prevalence of nitrate pollution may be exacerbating the problem, it noted.
The World Health Organization has set a provisional safe drinking water standard of 30 micrograms of uranium per litre, a level that is consistent with U.S. Environmental Protection Agency standards. Despite this, uranium is not yet included in the list of contaminants monitored under the Bureau of Indian Standards’ Drinking Water Specifications, the report noted.
Vengosh and his colleagues published their peer-reviewed study May 11 in Environmental Science & Technology Letters.
“Our analysis showed that the occurrence of uranium in these groundwater sources depends on several factors,” the report quoted Rachel M. Coyte, a PhD student in Vengosh’s lab.
These factors include the amount of uranium contained in an aquifer’s rocks, water-rock interactions that cause the uranium to be extracted from those rocks, oxidation conditions that enhance the extracted uranium’s solubility in water and the interaction of the extracted uranium with other chemicals in the groundwater, such as bicarbonate, which can further enhance its solubility.
The report states Rachel Coyte also saying, human activities, especially the over-exploitation of groundwater for agricultural irrigation, may contribute to the problem. Many of India’s aquifers are composed of clay, silt and gravel carried down from Himalayan weathering by streams or uranium-rich granitic rocks. When over-pumping of these aquifers’ groundwater occurs and their water levels decline, it induces oxidation conditions that, in turn, enhance uranium enrichment in the shallow groundwater that remains.
“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,” Avner Vengosh said in the report.
According to the information available on the university website, the study was funded by Mellon Foundation and the research was conducted with the scientists at the Gujarat Water Resources Development Corporation. Also part of the study was Union Ministry of Water Resources, River Development and Ganga Rejuvenation, the Rajasthan Government, World Bank Group Singapore Office and the University of Texas at El Paso.