Lead Is Still a Threat to Children, Researchers Find
WebMD News Archive
Jan. 11, 2000 (New York) -- Lead poisoning hasn't been in the news lately, but it is still a problem for children, and it has an effect at levels that have long been considered acceptable. A recent study, conducted at New York City's Bellevue Hospital Center, found that even low-level lead exposure can have an effect on intellectual development in children.
The study, which appeared in the December issue of the Journal ofDevelopmental and Behavioral Pediatrics, compared 68 toddlers (average age 22.9 months) who had blood levels within the acceptable range with children who were either well below that range or had no blood lead level. "For a 10 point increase [in lead levels] there was a six point decrease in the Bayley Mental [Development Index] Scales," Alan L. Mendelsohn, MD, the study's lead author, tells WebMD. The Bayley Mental Development Index Scales assess mental development in children. Mendelsohn is assistant professor of clinical pediatrics at the New York University School of Medicine and Bellevue Hospital Center.
In the study, Mendelsohn and his colleagues write that the six-point decrease of MDI could be compared, loosely, to IQ level. A study of school age IQ estimated that a 10-point increase in blood lead level was associated with an almost three-point decrease in IQ.
Many people think that with the advent of unleaded gasoline, lead free paint, and other efforts to remove lead in the environment, the risk of lead poisoning in children has been all but eradicated. However, according the Herbert L. Needleman, founder of the Alliance to End Childhood Lead Poisoning, who was not part of Mendelsohn's research team, there are still approximately 30 million homes built before 1960 that have lead in them.
"The removal of lead in gasoline was probably the biggest public health triumph in the last 40 years," Needleman tells WebMD. The same can be done for the still-lead infected housing, he says. "It would be a terrific jobs program," he says. "The same places where these houses are in excess, are the same places [where] there are a log of unemployed men."