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What are the long-term effects of chemicals on children's health, especially lead?

by the World Health Organization

Q: What are the long-term effects of chemicals on children's health, especially lead?

A: Chronic, low-level exposure to various chemicals may result in a number of adverse outcomes. In the case of lead exposure --- even at relatively low levels --- continuous exposure may have severe effects, such as anaemia, malaise, and damage to the nervous system. Children are particularly vulnerable to the neurotoxic effects of lead. Relatively low levels of exposure can reduce their IQ scores, cause learning disabilities, poor school performance, and violent behaviour, all of which may contribute to reduced lifetime earnings.

In some developing regions of the world, more than one third of all children are still affected by high levels of lead. In certain instances, cases of acute poisoning may still be seen in children who are chronically exposed and whose blood lead levels reach levels that interfere with normal functions. These children suffer severe headaches, nausea and vomiting, abdominal pain, lethargy and even coma. In severe cases, a life-threatening encephalitis can develop, which ends up in death or in irreversible neurological sequelae. However, what is more common is the low-level lead exposure that may cause unspecific signs and symptoms and remain undiagnosed.

In industrialized countries, children who live in poor urban areas (where leaded paint is still present) or belong to ethnic minorities that use traditional cosmetics or medicines tainted with lead have a higher risk of exposure to lead.

Sources of lead exposure vary according to local context and include leaded-gasoline (still in use in many countries) and paint, glazed ceramics, emissions from smelters, contaminated soil, battery recycling industries, and the use of lead pipes or lead containing solders for water supply. Lead can also occur as a contaminant in food or an ingredient in traditional medicines.

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