The researchers point to over-drainage of these water-bearing bodies as a probable cause.
Now, There is the added worry over uranium contamination.
However, the researchers point out that in India, human factors such as groundwater-table depletion, along with nitrate pollution may be exacerbating the problem.
"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," said Avner Vengosh, a professor of geochemistry and water quality at Duke’s Nicholas School of the Environment, according to Phys.org.
"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 said.
The scope of the study The research team gathered its data from 324 wells in the states of Rajasthan and Gujarat, as well as 68 previous studies on groundwater geochemistry in the same areas.
Much of the uranium found in India’s groundwater was brought there through the weathering of the Himalayan mountains, the rocks of which contain high levels of uranium.
A growing population, along with increased use of groundwater for agriculture, has been rapidly depleting reserves, which in turn allows for oxidation of the uranium found in rocks in the aquifer to escape and contaminate the water.
"The results of this study strongly suggest there is a need to revise current water-quality monitoring programs in India and re-evaluate human health risks in areas of high uranium prevalence," Vengosh said.
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