One of the most striking findings is thus very straightforwardly stated in the paper: “The present study reports 100% lactating mothers having their breastmilk highly contaminated with uranium.”
Although the concentration varied from sample to sample, every single sample of breast milk showed detectable uranium (U-238), with values up to 5.25 g/l.
The investigation mapped uranium levels district by district. In the data tables presented, Khagaria is shown to bear the highest average burden. In the decreasing order, the mean exposure to uranium [U238] contamination was found to be as follows: Khagaria > Samastipur > Begusarai > Katihar > Bhojpur > Nalanda.
The highest single peak uranium concentration of 5.25 g/L was recorded at Katihar.
Khagaria had the highest mean contamination level, with 4.035 g/L.
The lowest mean was recorded by Nalanda, at 2.354 g/L.
The spatial map for the study visually represents uranium spread across these districts and also points to an underlying hydrogeochemical pattern and environmental source.
INFANTS FACE HIGHER RISK THAN MOTHERS
In order to understand how uranium exposure may affect babies, the researchers estimated how much uranium infants can ingest through breast milk. Using a Monte Carlo simulation, a statistical technique that ran 10,000 iterations to predict possible risk scenarios, the analysis revealed that about 70% of the infants were at risk of developing non-cancer health effects if exposure continued.
The study also notes that "infants are highly vulnerable in comparison to their mothers" because of their still-developing organs, low body weight, and inability to excrete uranium as effectively. Because of this, small amounts of uranium can have a proportionally larger impact on infants.
The researchers examined not only possible kidney-related effects but also long-term cancer risks.
While uranium is considered more for its radioactivity, its chemical toxicity is of more immediate concern—particularly for infants. The study details that infants have a higher absorption rate of heavy metals compared to adults due to low body weight and underdeveloped organs. The authors indicate multiple dangers:
Uranium exposure can present several potential effects on infant health, including "nephrotoxicity. long-term kidney damage." It may affect neurological development and lead to "cognitive and behavioral problems."
Uranium exposure may also "increase the risk of developing cancer later in life." It can cross both the blood-brain and placental barriers, posing a threat to normal brain development. Researchers also refer to a broader literature on how uranium can interfere with bone growth in early life, immune system development, and even motor skills.
According to the researchers: “Uranium binds to plasma proteins and preferentially accumulates in bones and kidneys. rather than in breast milk.”
Thus, while contamination of breastmilk is real, it may reflect recent exposure rather than the mother's long-term uranium burden. This hypothesis is supported by the fact that in this study, only a "weak positive association" was determined between levels and duration of residence, indicating that the contamination likely reflects recent daily intake-such as water and diet-rather than bioaccumulation over long periods of time.
SHOULD MOTHERS STOP BREASTFEEDING?
The authors say: “It is also recommended to emphasise that breastfeeding is the optimal method for infant nutrition, and its discontinuation should only occur based on clinical indication.” They note that breastmilk offers unmatched nutritional and immunological benefits, and the uranium levels detected, though of concern, do not justify the halt of breastfeeding without medical advice.
Further research into uranium mobility in water, soil, and food chains Access to safer water, including filtration methods that can remove uranium (e.g., RO systems) The authors emphasize that: “There is also a need for biomonitoring of U238 in these regions at a broader level.”
GROWING PUBLIC HEALTH CONCERN
In the last ten years, Bihar has already hit headlines for its arsenic, lead, and mercury contamination, with various studies - including some of the same research team - reporting heavy metal exposure in mothers and infants alike. This latest uranium study reinforces a familiar refrain: the environmental burden carried by Bihar's families, most of all in rural districts where groundwater is lifeline. The final conclusion of the study is measured but clear: While the levels of uranium present in the breast milk were not sufficient to present an immediate cancer risk, the researchers found that 70% of infants carry a risk of non-carcinogenic effects. This is because infants have a much lower body weight and developing kidneys, making them susceptible to toxicity even at concentrations that might be considered "safe" for adults. Speaking on the findings, Dr Ashok Sharma, Additional Professor, AIIMS Delhi said, "Though uranium exposure is associated with certain risks like disturbed neurological development and reduced IQ, breastfeeding should not be discontinued." He further explained, ".the uranium concentration in the breast milk sample is 5.25 micrograms per litre, which is well below the WHO permissible limit. The study still concludes that the actual impact of the infant's health is likely low, and most uranium absorbed by the mother is excreted primarily through the urine, not concentrated in the breast milk. Thus, breastfeeding is still recommended unless a clinical indication suggests otherwise."
