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
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."