[homeles_ot-l] Lead tied to criminal behavior

[Kelly O'Grady]

 baltimoresun.com

 

Lead tied to criminal behavior

 

Poisoning damages crucial brain matter, studies find

 

By Frank D. Roylance

Sun reporter

 

May 28, 2008

 

Two new studies of young adults who grew up in poor, inner-city
neighborhoods in Cincinnati have found that childhood exposure to lead is
linked to a significant loss of critical brain matter and to an increased
risk of criminal behavior.

 

Researchers followed hundreds of children from the womb into their 20s and
found an average loss of 1.2 percent in the volume of gray matter in the
brain by the time they reached adulthood.

 

That sounds minor, but researchers at the University of Cincinnati said the
losses were concentrated in brain regions responsible for critical
"executive" functions, such as impulse control, emotional regulation,
judgment and the anticipation of consequences. That squares with previous
research linking childhood lead exposure to behavioral problems. The
research found that the losses were greater - 1.7 percent

- among males.

 

A second study of the same young adults found evidence that such brain
damage might also have grave consequences for society. The higher their
blood lead concentrations during childhood, the study found, the more likely
and the subjects were to be arrested during adulthood, especially for
violent offenses. The correlations held even when the data were controlled
for such factors as the mother's IQ, education and socioeconomic status.

 

Taken together, the two studies provide powerful evidence for the
potentially devastating consequences of childhood lead exposure, said Ellen
K. Silbergeld, professor of health sciences at the Johns Hopkins Bloomberg
School of Public Heath. Silbergeld has studied Baltimore's similar lead
poisoning problem but was not involved in either Cincinnati study.

 

Because researchers followed the same group into adulthood and controlled
for so many other factors, "we have ... a fair degree of confidence that
these findings are very likely to be related specifically to lead and are
not explainable by other possible exposures these adults could have had,"
she said.

 

Silbergeld said the findings also suggest that the Bush administration's
recent refusal to lower key lead safety levels to standards recommended by
many scientists was inconsistent with the latest research. These two studies
"strongly challenge these recent decisions, and in the minds of many of us
indicates there was very little scientific justification for these
decisions," she said.

 

Both studies were published yesterday by the online journal PLoS, sponsored
by the Public Library of Science, a nonprofit organization founded to
provide free and immediate access to peer-reviewed studies.

 

The first, led by Kim M. Cecil, an imaging scientist at the University of
Cincinnati College of Medicine, conducted MRI scans of the brains of 157
people. All had been part of the Cincinnati Lead Study since infancy.

 

The scans broke each of the participants' brain images into millions of
volume elements and compared them to one other. Those data were then
compared with blood lead levels measured every three months until the
participants were 5 years old, every six months until they were 6 or 7 years
old, and several more times during their teen years.

 

There was strong statistical evidence that those who had the highest lead
exposures as children had significantly smaller brain volumes. And the
deficits were focused mainly in areas of the brain called the pre-frontal
cortex and anterior cingulate cortex, associated with judgment, attention,
decision-making, and impulse control.

 

That "corresponds nicely," Cecil said, with previous epidemiological and
psychological studies that have found those kinds of behavioral problems
among children exposed to lead.

 

And because they had a wealth of other data gathered during their subjects'
childhood, the researchers were able to sort through potential factors that
might explain the brain losses, such as birth weight, smoking, alcohol or
drug use by mothers or children as they grew up.

 

The fact that nearly all of the subjects were black and grew up in
inner-city poverty eliminated other socioeconomic variables that might
obscure the links between lead and brain loss.

 

In the second study, researchers led by Kim N. Dietrich, also at the
University of Cincinnati College of Medicine, followed the same subjects and
measured their blood lead exposure against their arrests at age 18 and
older.

 

Although previous studies have found correlations between lead exposure in
urban settings and crime rates, this is the first to measure lead

 

 

Kelly O'Grady, RN

Executive Director,

The First Six Years

219 Welland St.,
Pembroke, ON CANADA
K8A 5Y5
Tel: 613-735-0717
Fax: 613-732-2859

Email: lead at nrtco.net

Web:  <http://www.first6years.org/> www.first6years.org 

 

The First Six Years is a grass roots organization  whose primary mandate is
the promotion of optimal social, physical, and environmental conditions for
the development of healthy productive children.  We achieve this goal
through the use of  environmental monitoring and surveillance and public and
professional education.

 

We recognize that the first six years of a child's life is an important
period of brain and nervous system development.  Childhood, extending from
the prenatal period to approximately age five years is a time of rapid
growth and development.  This makes children highly susceptible to the toxic
influences of environmental threats such as lead, mercury, PCBs, pesticides
and ionizing radiation

 

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