Drugs exist that will bind to lead and remove the toxic heavy metal from a person's blood. This therapy, called chelation, has saved the lives of people suffering from acute poisoning. However, a major study now finds that for children who have had moderate exposure to lead, chelation fails to prevent brain impairments.
Behavioral problems, difficulty with reasoning, and a permanently diminished IQ are hallmarks of excessive lead. Federal guidelines define as excessive any childhood exposures that result in lead concentrations of at least 10 micrograms per deciliter (g/dl) of blood.
Nearly 1 million U.S. children under 6 years of age show such concentrations in their blood, mostly from exposure to lead-based paint. However, even youngsters whose lead concentrations peaked at well below 10 g/dl may suffer notable IQ drops, recent studies have shown (SN: 5/5/01, p. 277).