Lead is toxic and exposure can affect many body systems, particularly affecting children and women of childbearing age.

Lead is found naturally in the earth's crust, and its widespread use has led to widespread environmental pollution, exposure to human damage and caused major public health problems in many parts of the world, according to the World Health Organization.

Sources of lead contamination

Lead is consumed worldwide mainly for the manufacture of lead-acid batteries for cars, but it is also used in several other products such as dyes, paints, welding, stained glass, crystal utensils, ammunition, glazed porcelain, jewelry, toys and some traditional cosmetics such as kohl, according to the WHO.

Lead may also appear in drinking water transported with pipes made of lead or pipes connected to lead welding.

Global lead exposure has declined dramatically since the phase-out of leaded gasoline, but several sources of lead remain, leading to adverse health and economic impacts, particularly in low- and middle-income countries, according to the WHO.

Lead in the body

Lead is distributed in the body over the brain, liver, kidneys and bones. It is stored in teeth and bones where it can accumulate over time. Human exposure to lead is usually assessed by measuring the level of lead in the blood.

Lead travels from the bones to the blood during pregnancy and the fetus becomes exposed to it in the developing phase.

There is no known level of lead exposure that does not have adverse effects, according to the WHO.

Young children are particularly exposed to the toxic effects of lead, which can cause serious and lasting damage to their health, particularly to brain and nervous system development. Lead also causes long-term harm to adults, including an increased risk of high blood pressure, cardiovascular problems and kidney failure.

High levels of exposure of pregnant women to lead can cause miscarriage, stillbirth, preterm birth, and low birth weight.

Methods of exposure to lead

  • Inhalation of lead particles from burning lead-containing materials, for example during smelting, recycling, removal of lead-based paint, depackaging of lead-based plastic cables and use of leaded aviation fuel.
  • Swallow lead-contaminated dust, drink water transported with lead pipes, and eat foods preserved in containers made of glazed lead or welded with lead, according to the WHO.

Lead and children

The World Health Organization says young children are particularly vulnerable to lead poisoning because 4 to 5 times more than an adult's body absorbs from a particular source of lead. In addition, children's innate curiosity and age-synthesized hand-in-mouth behavior lead them to ingest and ingest lead-containing or lead-coated objects.

Undernourished children are more likely to be poisoned by lead, because their bodies absorb more than if they lack other nutrients such as calcium or iron. Young children are most at risk of lead poisoning, with nervous system development being a particularly vulnerable period, according to the WHO.

Effects of lead exposure on children's health

Exposure to lead can have serious consequences for a child's health. If the brain and central nervous system are exposed to lead at high levels, they can be severely damaged, causing coma, convulsions and even death, according to the WHO.

Children who survive severe lead poisoning may develop permanent intellectual disability and behavior disorders.

Lead can particularly affect a child's brain development, leading to low IQ and behavioural changes such as shorter attention span, increased antisocial behaviour and lower educational attainment. Exposure to lead also causes anemia, high blood pressure, renal dysfunction and poisoning of the immune system and reproductive organs. It is believed that the neurological and behavioral effects of lead are incurable.

No known blood lead concentration level is considered safe, and blood lead concentration levels as low as 3.5 μg/dL may be associated with lower intelligence in children, behavioral difficulties and learning problems, according to the WHO.

Lead deaths

A study published in 2023 found that globally, lead exposure is associated with more than 5.5 million deaths from cardiovascular disease in adults in 2019, as well as a loss of 765 million IQ points in children under the age of 5.

The study was conducted by Bjørn Larsen, Ph.D., environmental economist and consultant to the World Bank, and Ernesto Sánchez Triana. It was published online on September 11 in The Lancet Planetary Health.

Drawing on various sources and studies, the researchers estimated global blood lead levels, the impact of lead exposure on cardiovascular disease deaths in 2019 among adults aged 25 and older, IQ loss in children under 5 years of age, and related economic costs.

The researchers estimated that there were more than 5.5 million deaths from adult cardiovascular disease due to lead exposure in 2019, with up to 90.2% of these deaths in low- and middle-income countries.

The estimated global IQ loss in children under 5 due to lead exposure was 765 million points in 2019, 95.3% of which occurred in low- and middle-income countries.

These estimates put lead exposure on par with ambient particulate matter and household air pollution combined, and ahead of unsafe household drinking water, sanitation and hand washing, as an environmental risk factor.