Invited Commentary: Lead, Bones, Women, and Pregnancy—The Poison Within?

Extract

Received for publication July 29, 2002; accepted for publication August 1, 2002.

Twenty-five years ago, the exposure of the US general population to lead was relatively high. Combustion of leaded gasoline was at its peak, and lead was present as solder in food cans, as a component of residential paint, as a widespread contaminant in the workplace, and as an ingredient in many other consumer products. The price paid for such exposures was also very high. Some individuals experienced acute, symptomatic lead poisoning (blood lead levels generally greater than 40 µg/dl), and many others experienced significantly impaired function—manifesting as, for example, declines in intelligence quotient among children and increases in blood pressure and declines in renal function among adults.

Today, US environmental exposures are much lower. Active screening for lead poisoning and the removal of lead from gasoline and other consumer products has been largely responsible for a dramatic decline in overall lead exposure. For example, mean blood lead levels in the National Health and Nutrition Examination Surveys (NHANES), surveys of the US general population (1), decreased from 12.8 µg/dl (95 percent confidence interval: 12.3, 13.3) in 1976–1980 (NHANES II) to 2.8 µg/dl (95 percent confidence interval: 2.7, 3.0) in 1988–1991 (NHANES III)—arguably one of the greatest environmental health triumphs of governmental regulation in the United States in modern times.