Lead poisoning occurs when lead builds up in the body, often over months or years. Even small amounts of lead can cause serious health problems. Children younger than 6 years are especially vulnerable to lead poisoning, which can severely affect mental and physical development. At very high levels, lead poisoning can be fatal.
Lead poisoning is not a new concern. For more than a century, scientists have been aware that the naturally occurring metal has no biological function that can benefit the human body, but can cause devastating physical and developmental impacts.
However, despite the awareness, lead toxicity continues to be a public health concern. Half the children in India report high blood lead levels, reveals a 2020 report by the UN Children’s Fund (UNICEF) and Pure Earth, a US-based environmental health non-profit. The report says 275 million children in India record blood lead levels of beyond the tolerable limit of 5 µg/dL. Of these, 64.3 million children’s blood lead levels exceed 10 µg/dL.
Adults are also affected by lead toxicity. In July 2022, Union government think tank NITI Aayog and the Council of Scientific & Industrial Research (CSIR) conducted a meta analysis of 89 datasets from 36 studies between 1970 and 2014; its results validate the UNICEF-Pure Earth report.
In terms of average blood lead levels among the population, some 23 states exceed the 5 µg/dL margin; levels in the remaining 13 states and Union Territories cannot be determined as there is a lack of research and screening mechanisms to collect data.
We need to bear in mind that Lead in the body is distributed to the brain, liver, kidney and bones. It is stored in the teeth and bones, where it accumulates over time. Human exposure is usually assessed through the measurement of lead in blood.
Lead in bone is released into blood during pregnancy and becomes a source of exposure to the developing fetus.
There is no level of exposure to lead that is known to be without harmful effects.