Science / Medicine : Lead and Mental Development

Exposure to low levels of lead early in life is linked with subtle impairment of mental development in 4-year-old children, according to a study published in the New England Journal of Medicine. The study increases the growing body of research suggesting that small amounts of lead can hinder the growth of babies’ brains.

The researchers wrote that their findings suggest “that any adverse effect of lead is cumulative and may result in long-term impairment in development rather than a delay in development.”

Dr. Anthony J. McMichael and colleagues at the University of Adelaide, Australia, studied 537 children who lived in a town near a large lead-smelting plant.

The researchers determined the youngsters’ average blood lead concentrations during their first four years of life and gave them tests to assess their mental development. They found that those with lead levels of 32 micrograms of lead scored 7% lower than those with levels of 11 micrograms.