A new scientific study has raised alarm over the presence of uranium in the breastmilk of lactating mothers across several districts of Bihar, putting thousands of infants at potential health risk. The research, published in Scientific Reports, marks the first-ever assessment of contamination in breastmilk from the Gangetic plains — a region already struggling with chronic exposure to heavy metals such as arsenic, lead, and mercury.
Table of Contents
All Breastmilk Samples Contaminated
The study analysed breastmilk samples from 40 lactating mothers aged 17–35 years from six districts — Bhojpur, Samastipur, Begusarai, Khagaria, Katihar, and Nalanda. Shockingly, every single sample tested positive for uranium (U-238).
“The present study reports 100% lactating mothers having their breastmilk highly contaminated with u-238,” the authors noted. Uranium levels varied case-to-case, with concentrations reaching as high as 5.25 µg/L.
Although no global health body has defined a “safe limit” for uranium in breastmilk, the detection of radioactive heavy metals in infant nutrition is considered a serious public health concern.
Khagaria Most Affected
District-wise mapping revealed striking variation in contamination:
- Khagaria recorded the highest mean level at 4.035 µg/L
- Katihar reported the highest single peak concentration at 5.25 µg/L
- Nalanda had the lowest mean level at 2.354 µg/L
The study’s spatial analysis indicates that contamination is likely linked to underlying hydrogeochemical patterns and environmental sources.
70% of Infants at Risk
Using a Monte Carlo simulation with 10,000 iterations, researchers evaluated infant exposure through breastmilk. The results were alarming:
Nearly 70% of breastfed infants were found to be at risk of non-cancer health effects if uranium intake continues at current levels.
While the study did not detect significant cancer risks at present, it emphasised concerns about non-carcinogenic toxicity, particularly in infants whose organs are still developing.
“Infants are highly vulnerable because they absorb heavy metals more readily, have lower body weight, and are less capable of excreting uranium,” the authors stated.
Health Effects of Uranium Exposure
The study highlights multiple risks associated with uranium ingestion in early life:
- Nephrotoxicity, leading to long-term kidney damage
- Neurological and developmental impairment
- Potential impact on cognitive and behavioural growth
- Interference with bone development and immune function
- Ability to cross blood-brain and placental barriers, directly affecting neurological development
Although uranium is radioactive, its chemical toxicity — especially on kidneys — poses a more immediate threat to infants.
Groundwater Contamination the Likely Source
While the study focused solely on breastmilk, it references earlier research by the same team showing widespread uranium contamination in groundwater across Bihar.
Some previously recorded groundwater concentrations include:
- 82 µg/L in Supaul
- 77 µg/L in Nalanda
- 66 µg/L in Vaishali
These values far exceed the WHO’s recommended limit of 30 µg/L for safe drinking water.
The likely causes of contamination include:
- Naturally occurring uranium-rich geological formations
- Over-extraction of groundwater
- Use of phosphate fertilisers
- Industrial discharge and untreated wastewater
With 11 districts reporting unsafe uranium levels, researchers warn that contamination is not localised but widespread across the state.
Why Breastmilk Still Shows Lower Levels
Interestingly, though groundwater contamination is significantly high, uranium levels in breastmilk remain in the microgram range. This is because uranium tends not to accumulate in breast tissue.
The study explains:
“Uranium binds to plasma proteins and preferentially accumulates in bones and kidneys rather than in breast milk.”
This suggests that breastmilk contamination reflects recent daily exposure, not long-term accumulation.
A Growing Public Health Concern
With Bihar heavily reliant on groundwater for drinking and agriculture, the spread of uranium contamination poses a significant public health challenge — particularly for infants dependent solely on breastfeeding.
The authors call for urgent:
- Large-scale water testing
- Mitigation strategies for contaminated regions
- Public health awareness for at-risk communities
- Policy intervention to monitor and regulate groundwater extraction
This groundbreaking study underscores an emerging environmental and health crisis in Bihar — one that demands immediate action to safeguard the state’s youngest and most vulnerable population.
For more updates, follow us on X (Twitter), Instagram & Facebook. And our website MED COLLEGE DARSHAN.
