Recent studies have found widespread uranium contamination in groundwater from aquifers across 16 states in India, much above the WHO provisional standard for the country. What are the reasons for such high uranium concentration and what measures can India take to control its occurrence? (200 words)
Refer – The Hindu
Enrich the answer from other sources, if the question demands.
IAS Parliament 6 years
KEY POINTS
· The WHO has set a provisional safe drinking water standard of 30 micrograms of uranium per litre for India.
· The recent data on contamination shows a high prevalence of uranium concentrations above the WHO provisional guideline value across India.
Reasons
· Uranium is not yet included in the list of contaminants monitored under the Bureau of Indian Standards’ Drinking Water Specifications.
· 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.
· 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.
· The occurrence of uranium in these groundwater sources depends on several factors which include –
a) the amount of uranium contained in an aquifer’s rocks
b) water-rock interactions that cause the uranium to be extracted from those rocks
c) oxidation conditions that enhance the extracted uranium’s solubility in water
d) the interaction of the extracted uranium with other chemicals in the groundwater, such as bicarbonate, which can further enhance its solubility
· Human activities, especially the over-exploitation of groundwater for agricultural irrigation, may contribute to the problem.
· In many parts of India, these factors co-occur and result in high uranium concentrations in the groundwater.
· Several studies have linked exposure to uranium in drinking water to chronic kidney disease.
Suggestions
· Revise the current water quality monitoring program in India
· Evaluate human health risks in areas of high uranium prevalence
· Develop adequate remediation technologies
· Above all, implement preventive management practices
Preventive management practices
· Include uranium standard in the Bureau of Indian Standards’ Drinking Water Specification.
· Establish monitoring systems to identify at-risk areas
· Groundwater contamination across India must be probed and mapped, and safe sources need to be identified.
· Exploring new ways to prevent or treat uranium contamination
· This will help ensure access to safe drinking water for tens of millions in India.
