Getting the lead out

Lead poisoning has serious health consequences, especially for children, and there is no easy cure. The good news is that industrialized countries are succeeding in efforts to reduce lead exposure, resulting in lower levels of lead in the blood of both children and adults.

The United States has the largest reduction in blood lead levels among the 11 countries for which data are available, with an 82% reduction over 15 years. Canada, Italy and Sweden follow. Much of this progress is due to the reduction of lead in gasoline, but removing lead from other sources, especially the solder in food cans, has also helped. The US Environmental Protection Agency (EPA) reports that elimination of leaded gasoline saves the United States more than $400 million a year in children's health care costs.

Lead can damage a child's brain, kidneys and reproductive system, and at high levels of exposure can cause coma, convulsions and death. Even low levels are associated with reductions in IQ and attention span, learning disabilities, hyperactivity, behavioural problems, impaired growth and hearing loss.

Major sources of lead include leaded gasoline, paint, water pipes, food-can solder, ceramic glazes, cosmetics, patent medicines and lead-acid batteries, as well as factory emissions.

Over the past years, as evidence has mounted of lead toxicity at even low concentrations in the blood, medical authorities have repeatedly reduced the blood lead level deemed acceptable, and countries have taken steps to reduce exposure. In 1991, the United States set the 'level of concern' for lead in the blood of children at 10 micrograms per decilitre, and other countries have adopted this standard. However, no clearly defined safe threshold has been found.

The success of the industrialized countries in reducing lead exposure points to the need for global action, since children tested in developing countries have been found much more likely to carry high concentrations of lead in their blood.

Sources: Fanelli, James J., An analysis of worldwide studies detailing the effects of the reduction of gasoline lead on air lead and blood lead, Center for Energy and Environmental Studies, Princeton University, 1997; and Centers for Disease Control and Prevention, 'Update: Blood lead levels - United States, 1991-94', Mortality and Morbidity Weekly Report, vol. 46, no. 7, 1997.