Topics Covered: Conservation, environmental pollution and degradation, environmental impact assessment.
Uranium Contamination in Ground Water
What to study?
For Prelims: Uranium and contamination, affected states.
For Mains: Effects, concerns and ways to prevent.
Context: A new study conducted by the University of Manchester, UK and Mahavir Cancer Institute and Research Centre, Phulwarisharif in Patna has found uranium contaminating the groundwater in 10 districts of Bihar.
- Supaul, Gopalganj, Siwan, Saran, Patna, Nalanda, Nawada, Aurangabad, Gaya and Jehanabad are the 10 districts.
- Uranium concentrations are elevated mostly in the North West-South East band along and to the east of Gandak river and running south of the Ganga river.
- The maximum uranium content was in Supaul, 80 microgram of uranium per litre of water.
What is the acceptable limit?
The Indian Standard IS 10500: 2012 for Drinking Water specification has specified the maximum acceptable limits for radioactive residues as alpha and beta emitters, values in excess of which render the water not suitable.
These requirements take into account all radioactive elements including uranium. No individual radioactive elements have been specifically identified.
As per Bureau of Indian Standard (BIS), maximum permissible limit of Uranium is 0.03 mg/l (as per WHO provisional guidelines) in all drinking water standards after following due process.
A report brought out by Duke University, USA in association with Central Ground Water Board and State Ground Water departments states that Andhra Pradesh, Chhattisgarh, Gujarat, Haryana, Himachal Pradesh, Jharkhand, Karnataka, Maharashtra, Odisha, Punjab, Rajasthan, Tamil Nadu, Telangana, Uttar Pradesh, West Bengal and Jammu & Kashmir have localised occurrence of Uranium concentration.
Main factors responsible for uranium contamination:
- 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.
- The interaction of the extracted uranium with other chemicals in the groundwater, such as bicarbonate, which can further enhance its solubility.
- Human factors such as groundwater-table decline and nitrate pollution may be exacerbating the problem.
What needs to be done?
- 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.
- Implementation of preventive management practices to address this problem.
- 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.
What is Uranium?
- Uranium is weakly radioactive and remains so because of its long physical half-life (4.468 billion years for uranium-238).
- The biological half-life (the average time it takes for the human body to eliminate half the amount in the body) for uranium is about 15 days.
- It is a naturally occurring element found in low levels within all rock, soil, and water.
- This is the highest-numbered element to be found naturally in significant quantities on earth.
- It is considered to be more plentiful than antimony, beryllium, cadmium, gold, mercury, silver, or tungsten.
- It is about as abundant as tin, arsenic or molybdenum.
- Radioactive vs non radioactive elements.
- What is half life of an element? How is it measures?
- Abundance of various elements in earth’s crust.
- How uranium contaminates ground water?
- Uranium limits- BIS vs WHO.
A recent report has highlighted uranium contamination in India’s groundwater. Discuss the causes, its effects and ways to address the issue?
Sources: down to earth.