Lead Shrinks Kids' Brains
Lead-Linked Brain Loss Permanent; Boys Especially Vulnerable
May 28, 2008 -- Lead shrinks children's brains, a long-term study strongly
suggests. The damage is permanent.
The findings come from the Cincinnati Lead Study, which recruited pregnant women living in
neighborhoods with historically high rates of childhood lead poisoning. The
study measured kids' lead exposures throughout childhood and then gave 157 of
brain scans when they were 19 to 24 years old.
None of the kids in the study had lead poisoning, according to the
University of Cincinnati spectroscopist Kim M. Cecil, PhD, and colleagues
found that the more lead a person had in his or her blood as a child, the more
certain parts of their brains shrank.
The shrinkage was in the gray matter of the brain, in areas linked to
problem solving, selective attention, complex motor control, error detection,
decision making, regulation of personal and social behavior, and emotional
These effects were particularly strong for males. Other human and animal
studies show that males are especially sensitive to the harmful effects of
"We found that early childhood lead exposure is associated with
structural volume loss in the brain," Cecil and colleagues conclude.
"Our findings are consistent with, and potentially explanatory for,
long-observed behavioral findings in children and adults with a history of lead
In an editorial accompanying the report in this week's issue of the online
journal PLoS Medicine, Harvard child neurologist David C. Bellinger,
PhD, notes that while the study does not prove that childhood lead exposure
causes brain damage, it rings a shrill alarm.
"The associations observed by Cecil and colleagues provide a clear
warning sign that early lead exposure disrupts brain development in ways that
are likely to be permanent," Bellinger writes.
In a second article in PloS Medicine, University of Cincinnati
criminologist John Paul Wright, PhD, and colleagues find that higher childhood
blood lead levels are linked to a higher risk of arrest for violent crime.
"We conclude that these data implicate early exposure to lead as a risk
factor for behaviors leading to criminal arrest," Wright and colleagues