Recent Study Shows Uranium in Breastmilk: What It Means for Mothers and Babies

ByTarin Hussain
Updated: 12 Dec 2025, 12:00 pm

A recent study from Bihar, India, has found uranium in the breast milk of lactating parents living in areas where groundwater sometimes contains higher levels of this naturally occurring metal. While the amounts detected are small, the research raises important questions about how this might affect mothers and their breastfeeding babies.

Pregatips
Uranium is a naturally occurring element, but its presence in our environment can sometimes pose hidden health risks. Recent research in Bihar has revealed something that may surprise many parents: uranium has been detected in breastmilk. This discovery raises important questions about how it could affect mothers and their babies, especially since infants are very sensitive during the first months of life.
In this article:
As a parent, knowing this information is crucial because it helps you make smart choices for your baby’s nutrition and your family’s overall health.

Where Does Uranium Come From?

Uranium is present naturally in rocks and soil. In many parts of India, it dissolves into groundwater, especially when the water chemistry changes because of heavy pumping of wells or the use of certain fertilisers.

When mothers drink this water or eat food grown with it, tiny amounts can enter their bodies and, in some cases, pass into breast milk.

What the Bihar Study Found About Uranium in Breastmilk

Researchers tested breast milk from 40 mothers living in 6 districts of Bihar: Bhojpur, Samastipur, Begusarai, Khagaria, Katihar, and Nalanda. Key findings include:

  • Every single sample contained some uranium.
  • Levels ranged from just above 0 up to 5.25 micrograms per litre (µg/L).
  • The highest single reading came from Katihar district (5.25 µg/L).
  • Khagaria showed the highest average (around 4 µg/L), while Nalanda had the lowest (around 2.35 µg/L).
An important point to note is that there is no official safe limit for uranium in breast milk anywhere in the world. To assess potential risks, scientists often compare these levels to what is known about uranium exposure through water and food.

For comparison, the World Health Organization’s provisional safe limit for uranium in drinking water is 30 micrograms per litre. So the highest level found in breast milk was roughly 6 times lower than the drinking-water guideline.

How Much Uranium Are Babies Receiving Through Breastfeeding?

Using careful calculations and a method called Monte Carlo simulation (which looks at thousands of possible scenarios), the researchers worked out the daily uranium dose babies might receive through breast milk alone. They discovered:

  • On average, babies were getting a very small dose, about 0.00027 milligrams per kilogram of body weight per day.
  • In about 70 per cent of the cases, the “hazard quotient” (a measure of possible non-cancer health effects) was above 1, which suggests a potential concern for kidney-related or other non-cancer effects over time.
  • Thankfully, the cancer risk from this level of exposure through breast milk was extremely low and well within safe limits.
Babies drink only a small volume of breast milk compared with the amount of water an adult drinks every day. Because of this, the total daily uranium a breastfed baby receives is extremely small, far less than what an adult would get from drinking the same groundwater directly.

What Are the Health Risks for Infants Exposed to Uranium Through Breastmilk?

Even small amounts of uranium mainly affect the kidneys, because that’s the organ your body uses to filter it out. Long-term exposure in early life could, in theory, lead to:

  • Reduced kidney function later in childhood or adulthood.
  • Slight interference with bone growth (uranium can accumulate in bones).
  • Possible subtle effects on brain development, though the study did not find strong evidence of this at the levels seen.
The reassuring part is that the body clears most uranium through urine fairly quickly, and only a tiny fraction moves into breast milk. This means breast milk is not a major way babies get exposed compared to the water the family drinks directly.

How Does Uranium in Breastmilk Affect Mothers’ Health?

The uranium amounts passing into breast milk are so small that they are unlikely to harm the mother’s health in any noticeable way. The kidneys of a healthy adult can handle these low levels without trouble.

Should Mothers in Uranium-Affected Areas Stop Breastfeeding?

No. The study clearly states that breastfeeding remains the best and safest way to feed your baby. Breast milk provides essential nutrition, antibodies, helps with bonding, and protects against infections. These benefits are much greater than the very small risk from the uranium levels found in this research. Stopping breastfeeding is only advised if a doctor finds a specific medical reason.

What Steps Can Mothers Take to Reduce Uranium Exposure Through Breastmilk?

If you live in Bihar or any area known to have uranium in groundwater, consider these simple actions:

  • Get your drinking water tested, especially if it comes from a private borewell.
  • Use water from deeper wells when possible, as uranium is often higher in shallow groundwater.
  • Consider affordable home filtration systems (reverse osmosis or certain ion-exchange filters) that can remove uranium.
  • Continue breastfeeding confidently while working to improve household water quality.
This study is the first of its kind in Bihar and shows that even though uranium is present in the environment, the amount reaching babies through breast milk stays very low. The real concern remains the direct drinking water that the whole family uses every day. Breast milk is still nature’s perfect food. The small amounts of uranium found in this research do not change that fact for mothers in Bihar or similar regions.

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FAQs on Recent Study Shows Uranium in Breastmilk: What It Means for Mothers and Babies

  1. Does cooking or boiling water reduce uranium exposure?
    No, boiling water does not remove uranium. Safe filtration or treatment methods are needed to reduce uranium in drinking water.
  2. How do metals get into breast milk?
    Metals enter breast milk mainly through maternal exposure from drinking water, food, or the environment.
Disclaimer: Medically approved by Dr Aruna Kalra, Director, Obstetrics & Gynaecology, CK Birla Hospital, Gurugram

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