How toxins enter breastmilk: water, soil, food, the hidden chain
A new Bihar study reveals how toxic metals like lead can enter breastmilk through water, soil, food and cookware. Doctors warn of irreversible harm to infants and pregnant women — and why this hidden chain is so dangerous.
Recent findings on elevated blood lead levels in children and pregnant women in Bihar are extremely alarming, because lead is a potent neurotoxin with absolutely no safe threshold for exposure. In children, even relatively small increases can result in irreversible brain injury, reduced IQ, learning difficulties, attention problems and persistent behavioural challenges.
The research, published in Scientific Reports, is the first assessment of uranium contamination in breastmilk in the Gangetic plains of Bihar – a region previously recognised for harmful exposure to heavy metals like arsenic, lead and mercury.
Levels above 10 µg/dL dramatically heighten the risk of long-term cognitive harm. For pregnant women, lead crosses the placenta with ease, raising the likelihood of miscarriage, preterm birth, low-birthweight infants and impaired fetal brain development. Equally worrying is the hidden chain through which toxins enter the body and eventually reach breastmilk.
How is this harmful?
According to Dr Bhanu Mishra, Consultant Physician & Nephrologist, Fortis Hospital, Shalimar Bagh, elevated levels of blood lead are extremely hazardous to developing bodies. In children, lead inhibits the proper development of the brain, reducing intelligence quotient, attention span, and the ability to learn. It also affects behaviour, immunity, and growth. During pregnancy, lead crosses the placenta, increasing risks of miscarriage, premature birth, low birth weight, and lifelong developmental problems for the baby. Even low levels cause lasting, irreversible damage.
Dr Aakash Shah, Vice President-Technical, Neuberg Diagnostics, also shared his take on the issue and said, "Lead enters the body and the blood system well before it leaves the body in breast milk. Contaminated underground water and soil, old school plumbing, battery recycling, lead dust from industrial facilities, and lead-containing traditional spices and cosmetics form a hidden exposure chain. During pregnancy and breastfeeding, women, bone lead can move directly from the bone to the blood system and then to the breast milk. Due to the high levels of unformed structures in an infant’s body, especially the brain, they are especially vulnerable to higher levels of lead exposure. Household water safety, monitoring and control of ambient food and soil lead levels, and broad community centre lead screening can help reduce exposure to high levels of lead in children of childbearing women."
How toxins enter breastmilk: water, soil, food, the hidden chain
In the case of lead and other neurotoxins, the pathway involves water, soil, food, cookware, spices, or air that a mother is exposed to, which in turn contaminates her breast milk. Toxin levels build up over time in the body-mostly in bones-and can be released into the blood during pregnancy and lactation, transferring into milk. This hidden chain exposes infants to toxic substances at critical times in the brain and body development.
Although breastfeeding remains profoundly beneficial for infants, reducing environmental contamination is essential to safeguard both maternal and child health. These findings underscore the urgent need for safer water systems, stronger food-quality monitoring, responsible industrial practices and comprehensive public health action to prevent toxic exposure before it reaches vulnerable families.
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