Alert! Breastmilk samples ‘highly’ contaminated with Uranium in six Bihar districts, shows study—are babies at risk?

Breastmilk samples of 40 lactating mothers were found to be "highly contaminated" with uranium, according to a study published in the Nature journal. It, however, noted that contamination had "very least impact on the health of mother and infants."

As many as 40 mothers, aged between 17 and 35 years, took part in the research. This study was conducted in selected districts of Bihar, which included Bhojpur, Samastipur, Begusarai, Khagaria, Katihar and Nalanda. The study was carried out between October 2021 to July 2024.

What did the study reveal

Breastmilk samples from women across six Bihar districts were analysed. These districts were Bhojpur, Samastipur, Begusarai, Khagaria, Katihar and Nalanda.

The study revealed that “all the samples had the uranium contents." It said, “The present study reports 100% lactating mothers having their breastmilk highly contaminated with uranium.”

The highest Uranium concentration in breastmilk was observed in the Katihar district — as 5.25 µg/L. The study indicated that Katihar district samples had "hazardous levels" of Uranium (U238) in the breastmilk samples.

The decreasing order of exposure to Uranium contamination in the districts was as such: Katihar > Samastipur > Nalanda > Khagaria > Begusarai > Bhojpur.

"However, the reported concentrations are below the permissible limits; hence, there could be least significant health threat from uranium exposure," the study added.

Is there any permissible limit for Uranium in breastmilk?

No. Presently, there is no specified permissible limit or benchmark for uranium concentration in breast milk. However, the World Health Organisation (WHO) sets permissible Uranium levels in groundwater at 30 µg/L.

What's the source of Uranium?

The study revealed a significant presence of uranium in groundwater samples from Bihar. "The source of Uranium contamination in the six studied districts could be drinking water sources or the food source cultivated in the same location," the study stated.

It revealed that the maximum uranium concentration in groundwater samples was reported as 82 µg/L in the Supaul district, followed by 77 µg/L in the Nalanda district and 66 µg/L in the Vaishali district of Bihar.

The study also noted that the extensive use of groundwater for drinking and irrigation led to the contamination of the groundwater with various pollutants in the eastern state of Bihar.

"The discharge of untreated or inadequately treated industrial effluents into rivers and other water bodies contributes to the pollution of the aquatic ecosystem," it said.

"This pollution can introduce heavy metals and other toxic substances into the food chain, ultimately affecting human health. The use of chemical fertilisers and pesticides in agriculture can lead to the contamination of soil and water resources with these harmful substances," it added.

Meanwhile, co-author Dr Ashok Sharma of AIIMS was quoted by the Times of India as saying that the source of contamination remains unclear and the Geological Survey of India is also trying to find out.

He, however, suggested that uranium comes from the food chain and causes cancer, neurological disorders and affects the growth of children, which is a very serious concern.

How the Uranium concentration in breastmilk can impact?

The study indicated that Uranium contamination in breastmilk could pose health concerns among the exposed infants and it can lead to low IQ, deteriorated neurological development and many mental health issues.

However, the study indicated that uranium toxicity has the least impact on the exposed mother and their infants. Here's why:

"Its exposure may affect the neurological development of infants, potentially leading to cognitive and behavioural problems," the study mentioned. "It can also increase the risk of developing cancer later in life," it added.

But, Uranium preferentially accumulates in bones and kidneys due to its affinity for phosphates and carbonate groups, rather than in breast milk.

"Its low affinity for milk components [lipids, proteins, and water], combined with the absence of specific transport mechanisms, results in low uranium concentrations in breast milk," it said.

"The primary route of excretion is through urine which may lower the impact of uranium in the infant’s body," it added.

Who conducted the study?

The study was carried out at the Mahavir Cancer Sansthan and Research Centre, Patna, Bihar. The researchers received assistance from the Indian Council of Medical Research, Government of India and the National Institute of Pharmaceutical Education and Research (NIPER)-Hajipur, Vaishali, Bihar.