Lead Exposure: a Top Indicator of Delinquency
Herbert Needleman, a pioneering researcher in childhood lead exposure, has found that delinquent kids - both white and black - have higher blood lead levels than kids from similar backgrounds without a criminal history. This study, like some of his earlier work, was funded by the National Institute of Environmental Health Sciences.
When other factors were adjusted for, delinquents in the legal system proved four times more likely to have bone lead concentrations greater than 25 parts per million than the youths in the control group, according to the study.
Researchers recruited 549 males in Allegheny County, Pa. Controls were recruited from six county high schools. "Elevated body lead burdens, measured by bone lead concentrations, are associated with elevated risk for adjudicated delinquency," the study concluded.
The findings reinforce conclusions found in previous research, including previous Needleman studies at the University of Pittsburgh School of Medicine. This is the last of 12 years of NIEHS funding under the current grant.
Many of the participants were African-American, and that was considered a "risk factor" second only to only single-parent status. For white kids, the effects of lead emerged as a stronger predictor of delinquency, the study found.
For years, pediatricians who treat lead-exposed children have been hearing from parents about the aggressiveness and outright violent tendencies their children exhibit.
Researchers have known for some time that alcohol, amphetamines and abuse of other drugs increase the likelihood of violent behavior, but they now may begin to include lead exposure in that grouping of neurotoxins.
Annette Kirshner, grant administrator in the Organ Systems Toxicology Branch at NIEHS, said Needleman's work has driven lead-removal efforts. Over the years, the so-called "safe" level for lead exposure has continued to drop.
"There probably is no safe level for lead," Kirshner said, noting research that shows lingering effects from even low levels of lead exposure, and even with chelation intervention to wash the lead from the body. In the absence of effective treatments, she said, the public health focus must be on prevention.
"Our lead program has been ongoing and extremely influential for setting policy for lead prevention and intervention," Kirshner said.
NIEHS, which is one of the National Institutes of Health, is located in Research Triangle Park, N.C.