Groundwater uranium contamination
Key findings
A multi-agency Indian study published in Nature detected high levels of uranium-238 in breast milk of lactating women in Bihar.
Samples: 40 women, six districts of Bihar.
All samples contained uranium-238, up to 6 µg/L.
WHO limit for uranium in drinking water = 30 µg/L, but no global safety standard exists for breast milk.
The current permissible limit for uranium in drinking water in India, set by the Bureau of Indian Standards, is 30 micrograms per litre (µg/l) i.e. 0.03 mg/l, according to the statement.
However, for radiological safety, the Atomic Energy Regulatory Board (AERB) continues to prescribe a separate, higher limit of 60 µg/l i.e. 0.06 mg/l considering both international benchmarks and practical remediation factors
Earlier findings
High groundwater uranium concentrations found in 151 districts across 18 states.
States with earlier reported elevated levels:
Andhra Pradesh, Bihar, Chhattisgarh, Haryana, Jammu & Kashmir, Jharkhand, Himachal Pradesh, Karnataka, Kerala, Punjab, Rajasthan, Uttar Pradesh, West Bengal.
Why uranium is found in groundwater
Natural causes
Weathering of uranium-rich rocks
Geogenic processes
Human activities
Uranium mining
Coal and fuel combustion
Nuclear industry emissions
Use of phosphate fertilisers (contain uranium as impurity)
Groundwater over-extraction
Excessive borewell drilling
Heavy pumping increases mineral dissolution → higher uranium concentration.
Health risks (especially to infants)
Uranium is both chemically toxic and radiologically harmful.
Uranium from breast milk can:
Enter infant cellular systems → damage or kill cells
Cross the blood–brain barrier
Cross the placental barrier → affect foetal development
Major risks include:
Kidney damage (uranium is nephrotoxic)
Cancers in later life
Neurodevelopmental disorders: delayed cognition, impaired motor skills, reduced IQ
Immune dysfunction → susceptibility to infections and autoimmune disorders
Why this is a national concern
India’s heavy dependence on groundwater, especially in rural areas, for drinking and irrigation.
Infants and pregnant women face highest vulnerability.
The scale (151 districts) suggests the issue is systemic, not localised.
Required actions (curative and preventive)
Monitoring and surveillance
Regular uranium testing in groundwater, piped supply and hand pumps.
Mapping of high-risk districts.
Source substitution
Provide access to surface water, treated piped water, or community RO-based systems.
Promote safe water schemes in high-risk regions.
Regulation of fertilisers and industrial activity
Strict limits on uranium in phosphate fertilisers.
Monitoring emissions from mining and nuclear sectors.
Groundwater governance
Regulate borewell drilling.
Encourage aquifer recharge and sustainable extraction.
Public health interventions
Screen infants and mothers in high-risk zones.
Awareness on safe drinking water practices.
Research gaps
Set clear permissible limits for uranium in breast milk.
Evaluate long-term developmental and epidemiological impacts.
Prelims Practice MCQs
Q. Which of the following factors contribute to elevated uranium levels in groundwater in India?
Weathering of uranium-bearing rocks
Excessive extraction of groundwater
Use of phosphate fertilisers
Marine aerosol deposition in inland regions
A. 1, 2 and 3 only
B. 1 and 4 only
C. 2 and 3 only
D. 1, 2, 3 and 4
Correct answer: A
Explanation: Uranium contamination arises from natural geology, over-extraction (increases dissolution), and fertiliser impurities. Marine aerosols do not contribute.
Q. Uranium in breast milk poses significant risks to infants primarily because:
A. Uranium cannot be filtered by kidneys at any age
B. It cannot cross biological barriers in early development
C. It easily crosses the blood–brain and placental barriers
D. It is a nutrient analogue mistaken by the body for iron
Correct answer: C
Explanation: Uranium-238 can cross the blood–brain barrier and the placental barrier, harming neurological and foetal development.