Uranium in Breast Milk

Syllabus Areas:

GS III - S & T

A Bihar-based study reported traces of uranium (U-238) in breast milk of lactating mothers across six districts.

  • Initial public reaction: fear and panic, given uranium’s association with radioactivity and cancer.
  • But deeper analysis shows no immediate cancer risk from these levels.

What the Study Found

  • Study Title:“Discovery of uranium content in breast milk and assessment of associated health risks for mothers and infants in Bihar, India.”
  • Uranium Levels Detected:
    • Range: 0 to 5.25 µg/L
    • Highest: Katihar
  • No global benchmark exists for uranium in breast milk.
  • WHO provisional limit for drinking water: 30 µg/L → the breast milk values are well below this.
  • Study linked breast-milk uranium to groundwater contamination, supported by earlier studies.

What is U-238 and Why It Matters

  • U-238 = most common natural uranium isotope (99%).
  • Properties: weakly radioactive, very dense, naturally present in soil, rock, and water.
  • External exposure is not dangerous (alpha particles blocked by skin).
  • Internal exposure (ingestion) at high levels → possible bone/liver cancer, kidney impact.
  • The general population usually consumes trace uranium through food and water.

The Groundwater Problem

  • In India, 151 districts across 18 States show uranium-contaminated groundwater.
  • Bihar: About 7% of groundwater sources are affected.
  • Groundwater use for drinking → trace uranium enters the human system.

Impact on Mothers and Infants

  • Uranium detected in all samples, but well below harmful limits.
  • Low expected health impact on mothers and infants.
  • Uranium absorbed by mothers is primarily excreted through urine, not retained in breast milk.

Infant Health Assessment

  • Around 70% infants showed a “potential non-carcinogenic risk”, based on modelling
    → but actual risk is minimal, according to authors.
  • Breastfeeding should NOT be stopped, unless for clinical reasons.

Possible Concerns If Long-Term Exposure Continues

  • Could impact kidney development.
  • Potential cognitive/mental effects (low IQ, neurodevelopmental delay) over long-term high exposure.

Expert Clarifications to Prevent Panic

Inputs from Dr. Rajeev Jayadevan

  • The term “uranium” causes fear, but:
    • Uranium is naturally present in groundwater globally.
    • Most uranium consumed is safely excreted in urine.
    • Only a small fraction enters breast milk.
    • Levels found are 6 times lower than WHO safe limit for drinking water.
  • Infants drinking breast milk consume very tiny amounts compared to adults drinking water.
Uranium in Breast Milk

What Needs to Be Done

  • Conduct regular groundwater monitoring for uranium and heavy metals.
  • Larger-scale studies needed with:
    • Big sample size
    • Environmental uranium profiling (soil, water, food)
    • Isotope-specific measurements to understand mother-infant transfer kinetics
  • Expansion of such studies to other States already planned.

Prelims Questions:

1. Consider the following statements about U-238:
  1. It constitutes more than 99% of naturally occurring uranium.
  2. It is a strongly penetrating gamma emitter.
  3. It is a heavy metal in addition to being weakly radioactive.
Which of the statements given above is/are correct?
  1. 1 and 2 only
  2. 2 and 3 only
  3. 1 and 3 only
  4. 1, 2 and 3
2. With reference to uranium contamination in India, consider the following statements:
  1. More than 150 districts in India have reported groundwater uranium contamination.
  2. Bihar accounts for more than 10% of contaminated groundwater sources in the country.
  3. Groundwater uranium contamination has been reported in at least 18 States.
Which of the statements given above is/are correct?
  1. 1 and 3 only
  2. 1 only
  3. 1 and 2 only
  4. 2 and 3 only