Why in news?

The occurrence of uranium in groundwater beyond the permissible limits was observed in around 409 samples against 14,377 samples analysed in 18 states, the Jal Shakti Ministry said.

Highlights:

• Minister of State for Jal Shakti Bishweswar Tudu said Central Ground Water Board (CGWB) has carried out a study to map areas with uranium contaminated groundwater during 2019.
• As per this study, the occurrence of uranium in groundwater beyond the BIS permissible limits (0.03 mg/l) of water was observed in around 409 groundwater samples against 14,377 samples analysed by the CGWB in around 18 states.
• In addition, under the ministry, while allocating the funds to states/UTs, 10% weightage is given to the population residing in habitations affected by chemical contaminants, including heavy metals, and while planning for potable water supply to households through tap connection, priority is to be given to quality-affected habitations.
• As per Department of Atomic Energy, hydrogeological and stable isotope tracer investigations carried out in the groundwater around the Tummalapalle uranium mining project have confirmed that there is no association between uranium mining industry and elevated uranium levels in groundwater.

What are the health effects?

• Preliminary studies on the health effects of drinking uranium-tainted water among animals and humans have revealed that it causes kidney damage.
• Notably, this is said to be caused by the chemical effect of uranium, rather than a radiological, even though uranium is radioactive.
• Nonetheless, we need more comprehensive systematic studies to establish the chronic health effects of uranium exposure.

How does uranium enter ground water?

• The mechanism by which uranium enters groundwater is still under research.
• Two types of terrains have been identified with heavy contamination, namely:
• Alluvial aquifers in Rajasthan and other north-western regions
• Crystalline rocks such as granite in southern regions like Telangana.
• Some researchers have hypothesized that over-extraction of ground water exposes uranium to air, which triggers its release from the rocks.
• Further research is needed in this regard as it would help in identifying regions where safer water can be found.
• Notably, even information of how uranium accumulated with the rocks (during sedimentation), would help in estimating the regions of prevalence.

About uranium:

• Uranium deposits occur in Singhbhum and Hazaribagh districts of Jharkhand, Gaya district of Bihar, and in the sedimentary rocks in Saharanpur district of Uttar Pradesh.
• But the largest source of uranium comprise the monazite sands.
• Monazite sands occur on east and west coasts and in some places in Bihar. But the largest concentration of monazite sand is on the Kerala coast.
• Over 15,200 tonnes of uranium is estimated to be contained in monazite.
• Some uranium is found in the copper mines of Udaipur in Rajasthan.

• India produces about 2 per cent of world’s uranium. The total reserves of uranium are estimated at 30,480 tonnes.