Unwanted Burden — Environmental Contaminants in Human Breast Milk Across India

🗞️ Why in News A four-year study (2021–2024) by researchers from Mahavir Cancer Sansthan (Patna), NIPER (Hajipur), AIIMS (New Delhi), and Geological Survey of India detected uranium-238 in breast milk samples from 40 lactating mothers across 6 districts of Bihar’s Gangetic plains — the first such study in India. Published in Scientific Reports (November 2025), the study found that ~70% of infants could face potential non-carcinogenic health effects. Separately, over 100 environmental pollutants have been documented in breast milk samples across 13 Indian states.

Breast Milk — The “Living” Fluid

• WHO and public health authorities describe breast milk as a newborn’s first vaccine and primary defence against disease
• Composition: macronutrients, micronutrients, bioactive molecules, stem cells — adapts to infant’s specific evolving needs
• Benefits: strengthens immunity, aids neurodevelopment, dampens inflammation, shapes gut microbiome, lowers allergy and autoimmune risk, protects against obesity and respiratory infections
• The Lancet Global Health (2015): Longer breastfeeding duration associated with higher intelligence in adulthood, more schooling, greater earnings
• Components now explored as potential therapies for cancer, cardiovascular disease, arthritis, IBS
• Despite contaminants, breastfeeding remains the safest nutritional choice — medical consensus unchanged

The Uranium Discovery — Bihar’s Gangetic Plains

Background: Uranium in Groundwater

• Duke University study (2019–20) with Central Ground Water Board (CGWB): found 151 districts across 18 states had uranium in groundwater exceeding WHO’s provisional limit of 30 µg/l

The Study

• Lead author: Arun Kumar, Senior Scientist, Mahavir Cancer Sansthan, Patna
• Institutions involved: Mahavir Cancer Sansthan, NIPER Hajipur, AIIMS New Delhi, Geological Survey of India (and three others)
• Samples: 40 lactating mothers across 6 districts — Bhojpur, Samastipur, Begusarai, Khagaria, Katihar, Nalanda
• Analysis: Advanced instrumentation at NIPER
• Findings:
  • All 40 samples contained uranium concentrations — trace levels up to 5.25 µg/l (highest in Katihar)
  • Simulations: ~70% of infants could face potential non-carcinogenic effects — kidney damage, neurological impairment, cognitive/behavioural problems, increased cancer risk later in life
• Published: Scientific Reports, November 2025
• Caveat: Findings are model-based projections, not evidence of confirmed harm
• Prof. Ashok Kumar Ghosh (Mahavir Cancer Sansthan): U-238 has an extraordinarily long half-life and correspondingly low radioactive activity; neither WHO nor Bureau of Indian Standards has set permissible limits for breast milk uranium

Heavy Metals Beyond Uranium

The same research team detected three other heavy metals in 18 districts along the Ganga in Bihar:

Study Design

• Control groups in all 18 districts; 40 women per district
• Collected: blood, urine, hair, nail samples
• Objective: determine daily chemical intake via food and excretion in children’s urine

Findings

• Heavy metals (arsenic, mercury, lead) present in diet — rice, wheat flour, lentils, vegetables, potatoes
• 30–40% of samples contained traces of heavy metals
• Long-term consumption leads to accumulation in mothers’ bodies
• Lead in breast milk: 92% of samples showed high lead content; one sample had 1,309 µg/l (permissible limit: 5 µg/l — over 260 times the safe limit)
• Effects in breastfed children: reduced growth, most likely effect is cognitive impairment

Organochlorine Pesticides — Karnataka

Kalaburagi Study (2021)

• Lead researcher: Prashant V C
• Location: Rural areas of Kalaburagi district, Karnataka — a major agrarian region
• Samples: 66 healthy mothers post-delivery; all residents of the area for 8–10 years, working on farms
• Findings:
  • Trace levels of organochlorine pollutants (OCPs): DDT and its metabolites (o,p’-DDE and p,p’-DDE)
  • Metabolites found in 32 samples each; DDT in 8 samples
  • All levels below WHO “safe” limits — no harmful effects observed in participants
• Published: Journal of Population Therapeutics and Clinical Pharmacology, 2023
• Key insight: DDT was banned for agricultural use decades ago, but its persistence means residues remain in soil and fat tissue for generations
• Bioaccumulation: Animals fed contaminated fodder store chemicals in fat → humans consuming meat/dairy ingest residues
• OCP levels in breast milk are declining over time — 2021 levels lower than earlier studies, suggesting policy measures are working

The ExHuMId Database — National Picture

• Exposome of Human Milk Across India (ExHuMId) — online database created by researchers at Institute of Mathematical Sciences, Chennai and Homi Bhabha National Institute, Mumbai
• Published: Chemosphere, May 2021
• Compiled data from 36 studies across 13 states
• Over 100 environmental pollutants documented in breast milk samples nationwide
• Categories:
  • Heavy metals: arsenic, lead, mercury
  • Persistent Organic Pollutants (POPs): dioxins, furans, polychlorinated biphenyls (PCBs)
  • Organochlorine pesticides: DDT, hexachlorocyclohexane (HCH) — banned decades ago but still appearing
• Several are potential carcinogens, endocrine disruptors, and neurotoxins
• ExHuMId classifies chemicals into 6 groups: pollutants (67), consumer products (63), industry (54), agriculture (42), medical/healthcare (6), intermediates (3)

Sources of Contamination — The Pathways

1. Uranium Pathways

• Contaminated groundwater — uranium enters food chain via crops irrigated with contaminated water
• Coal combustion in thermal power plants — enhances naturally occurring radioactivity (TENR — Technologically Enhanced Natural Radioactivity)
  • Study near Indira Gandhi Super Thermal Power Project, Jharli, Haryana: uranium levels 2.64–201.9 µg/l (mean: 47.59 µg/l) within 4 km radius
• Geological Survey of India (Akhouri Bishwapriya): Bihar has no uranium mining; 93% covered by alluvium — geological sources unlikely; medical or fertiliser sources more probable
• Phosphate fertilisers: Phosphate rock used in fertiliser production contains uranium as impurity
  • Germany example: 1951–2011, phosphate fertilisers deposited ~14,000 tonnes of uranium on farmland (~1 kg/ha)
  • Under oxidising conditions, uranium becomes soluble → leaches into groundwater
  • In Bihar’s Katihar district (highest uranium in breast milk): farmers apply urea and DAP in 50:50 ratio, 5 times per season — use has increased 3–4 times in the last decade

2. Heavy Metals (Arsenic, Lead, Mercury)

• Arsenic: Rivers originating from Himalayas carry arsenic in sediments → deposition across the Gangetic plain
• Deep borewells (now common across India) tap aquifers hundreds of metres below surface — water from deeper crust layers may intersect mineral layers containing heavy metals
• Once ingested → bloodstream → liver/kidneys eliminate most, but a fraction persists → reaches breast milk

3. Organochlorine Pesticides

• Persistent in soil for decades after banning
• Bioaccumulation through food chain: contaminated fodder → animal fat → meat/dairy → humans
• Spray drift, lack of protective gear, improper dilution increase farm worker exposure
• In Kalaburagi: farmers use glyphosate, emamectin benzoate, profenofos — often exceeding recommended doses

Ground Reality — DTE’s Field Visits

Bihar (Katihar and Nalanda Districts)

• Azampur Gola village: Decades-old well serves hundreds of households; algae on walls, greenish water; only a few have tap water access
• Reverse-osmosis plant tests show elevated iron and arsenic; gallstones becoming common — linked to gallbladder cancer risk
• Manihari village: Monsoon floods cut the area off; tap water has excessive iron; residents unaware of arsenic/lead/uranium threats
• Meyar village (Nalanda): Hand pump with visible iron deposits; government tap water scheme non-functional — tank built and never repaired
• Sadhu Saw installed submersible pump at 90+ metres depth at cost of ₹1 lakh — assumes deeper = safer (not necessarily true)

Karnataka (Kalaburagi)

• Parched landscape: dried scrub, barren fields, sparse trees
• Annual rainfall: ~750 mm; most farmers grow single kharif crop
• Heavy chemical input dependence: “Market pesticides kill pests in two days. That is how we keep our households running.”
• Farmers routinely exceed recommended pesticide doses
• DDT banned for agriculture but metabolites persist in environment and fat tissue

The Biological Mechanism — How Contaminants Enter Breast Milk

• During lactation, specialised transporters in mammary epithelial cells draw nutrients from mother’s bloodstream into the alveolar lumen of the mammary gland
• Milk composition shifts with nutritional status, diet, lactation stage, socio-demographic circumstances
• Fat-soluble chemicals accumulate in adipose tissue over a lifetime
• When lactation begins and fat stores are mobilised → lifetime accumulations of contaminants can pass to infant
• The same transport proteins that deliver vitamins, hormones, and beneficial compounds may also carry pesticide residues, heavy metals, and pollutants
• This is not a flaw — it reflects the total environmental burden the mother has absorbed

Critical Evaluation for UPSC Mains

The Regulatory Gap

• No permissible limits for uranium in breast milk (WHO or BIS)
• India has no national biomonitoring programme for breast milk contaminants
• Groundwater quality monitoring is fragmented — CGWB tests for basic parameters but uranium, arsenic, and heavy metals are not routinely checked in all states
• Fertiliser quality regulation: No mandatory limit on uranium content in phosphate fertilisers sold in India
• Pesticide regulation: Insecticides Act, 1968 (now being replaced by Pesticide Management Bill) — enforcement weak, especially in rural areas

The Development-Health Nexus

• Green Revolution legacy: Heavy fertiliser/pesticide use → soil and water contamination → food chain contamination → breast milk contamination
• Deep borewell proliferation: Driven by falling water tables → accesses geologically contaminated layers
• Urbanisation and industrialisation: Thermal plants, industrial waste, mining — all contribute to TENR and heavy metal dispersal
• The poor bear the greatest burden: Remote villages in Bihar and agricultural communities in Karnataka — least access to clean water, most exposed to contaminated food chains

What Needs to Be Done

1. Mandatory uranium limits in fertilisers and drinking water (India currently follows WHO guidelines but doesn’t enforce them universally)
2. National biomonitoring programme for breast milk — using ExHuMId as a foundation
3. Groundwater quality mapping at district level — especially for heavy metals and radioactive elements
4. Safe water infrastructure — Jal Jeevan Mission must prioritise contaminant testing, not just pipe connections
5. Agricultural transition — reduce chemical dependency; promote Integrated Pest Management (IPM) and organic practices
6. Despite all this, breastfeeding must be promoted — the benefits vastly outweigh the risks; the solution is to reduce contamination, not to discourage breastfeeding

UPSC Angle

• Prelims: ExHuMId, TENR, organochlorine pollutants, DDT, HCH, POPs, PCBs, uranium-238 half-life, CGWB, NIPER, phosphate fertiliser contamination, WHO guideline for uranium in water (30 µg/l), Jal Jeevan Mission, IPM
• Mains GS-2: Governance — regulatory gaps in groundwater monitoring, fertiliser quality control, Jal Jeevan Mission implementation failures, safe drinking water as a fundamental right (Article 21)
• Mains GS-3: Environment — bioaccumulation, persistent organic pollutants, groundwater contamination, uranium in food chain, Green Revolution’s environmental legacy, phosphate fertiliser contamination
• Mains GS-3: Science & Technology — biomonitoring, environmental epidemiology, mammary biology, transport proteins, ExHuMId database
• GS-4 (Ethics): Intergenerational transfer of pollution burden, environmental justice, duty of care to the most vulnerable (infants)
• Essay: “The first food a child receives should not carry the sins of its environment”

📌 Facts Corner — Knowledgepedia

Uranium in Breast Milk Study (2025):

• Published: Scientific Reports, November 2025
• Lead author: Arun Kumar, Mahavir Cancer Sansthan, Patna
• Samples: 40 mothers across 6 Bihar districts (Bhojpur, Samastipur, Begusarai, Khagaria, Katihar, Nalanda)
• Highest uranium: 5.25 µg/l (Katihar)
• ~70% of infants at risk of non-carcinogenic effects (model-based projection)
• WHO uranium limit in water: 30 µg/l (no limit set for breast milk)

Uranium in Groundwater (Duke University, 2019–20):

• 151 districts across 18 states affected
• Worst: Punjab (24.2%), Haryana (19.6%), Delhi (11.7%), Telangana (10.1%)
• Conducted with CGWB (Central Ground Water Board)

Heavy Metals in Bihar:

• Lead in breast milk: 92% of samples positive; one sample at 1,309 µg/l (limit: 5 µg/l)
• 30–40% of food samples (rice, wheat, lentils, vegetables) contained heavy metal traces
• Arsenic source: Himalayan river sediments deposited across Gangetic plain

Organochlorine Pesticides (Kalaburagi, 2021):

• 66 mothers tested; DDT metabolites in 32 samples each; DDT in 8 samples
• All below WHO safe limits
• Published: Journal of Population Therapeutics and Clinical Pharmacology, 2023
• OCP levels declining over time — policy measures showing effect

ExHuMId Database:

• Full name: Exposome of Human Milk Across India
• Created by: Institute of Mathematical Sciences (Chennai) + HBNI (Mumbai)
• Published: Chemosphere, May 2021
• Data: 36 studies, 13 states, 100+ pollutants documented
• 6 chemical groups: pollutants (67), consumer products (63), industry (54), agriculture (42), medical (6), intermediates (3)

Phosphate Fertiliser–Uranium Link:

• Phosphate rock contains uranium as impurity
• Germany (1951–2011): ~14,000 tonnes uranium deposited on farmland via fertilisers
• Indira Gandhi STPP, Haryana: uranium 2.64–201.9 µg/l within 4 km
• TENR: Technologically Enhanced Natural Radioactivity (from coal combustion)

Breast Milk Biology:

• Mammary epithelial cell transporters draw nutrients from bloodstream
• Fat-soluble chemicals stored in adipose tissue → mobilised during lactation → passed to infant
• Same transport proteins carry both essential nutrients and contaminants
• Breast milk remains safest nutritional choice — medical consensus unchanged (WHO)

Other Relevant Facts:

• The Lancet Global Health (2015): longer breastfeeding = higher adult intelligence, more schooling, greater earnings
• DDT: banned for agricultural use in India; still used for malaria vector control under Stockholm Convention exemption
• POPs: governed by Stockholm Convention (2001; India ratified 2006)
• HCH (Lindane): banned in India since 1997
• Insecticides Act, 1968: being replaced by Pesticide Management Bill
• Jal Jeevan Mission: target — tap water to all rural households by 2024 (deadline extended)
• IPM: Integrated Pest Management — biological + cultural + chemical methods combined
• CGWB: under Ministry of Jal Shakti (formerly Ministry of Water Resources)

Sources: Down to Earth, Scientific Reports, Chemosphere, Duke University, Central Ground Water Board, WHO