Report: Childhood Lead Exposure Linked to Criminal Behavior in Adulthood

CINCINNATI — Exposure to lead early in childhood may increase the risk for criminal behavior later in life, according to research by the University of Cincinnati.


The study found a statistically significant correlation between elevated concentrations of lead in the blood during prenatal and postnatal stages of development and higher criminal arrest rates during adulthood.


“Aggressive or violent behavioral patterns often emerge early and continue throughout life,” says Kim Dietrich, Ph.D., study principal and professor of environmental health at the University of Cincinnati.


Researchers found that after age 18, individuals with increased blood-lead levels during prenatal stages and early childhood exhibited higher rates of arrest for violent crimes than the rest of the study population.


“Identifying the risk factors that may place youth on an early trajectory toward a life of crime and violence should be a public health priority,” Dietrich says.


While the study reported the strongest correlation between increased lead exposure and violent-crime arrests, increased blood-lead levels also correlated with higher rates of arrest for nonviolent crimes.


Childhood lead exposure is a purported risk factor for antisocial behavior.


“Lower income, inner-city children remain particularly vulnerable to lead exposure,” Dietrich says. “Although we’ve made great strides in reducing lead exposure, our findings send a clear message that further reduction of childhood lead exposure may be an important and achievable way to reduce violent crime.”


Approximately 55 percent of subjects in the study, which monitored 250 participants for almost 30 years to assess the long-term health effects of lead exposure early in life, had at least one arrest. The majority involved drugs (28 percent) or serious motor vehicle violations (27 percent).


“I did not expect we would see an effect, much less a substantive effect,” says John Wright, Ph.D., a study co-author and member of the criminal justice faculty at the University of Cincinnati.


Although several studies have attempted to evaluate potential criminogenic effects of lead exposure during the early stages of development, the UC-led research effort is the first longitudinal study to determine the existence of an association between prenatal and childhood lead exposure and criminal behavior later in life.


“Previous studies either relied on indirect measures of exposure or failed to follow subjects into adulthood to examine the relationship between lead exposure and criminal activity in young adults,” Dietrich says.


Researchers recruited pregnant women from Cincinnati neighborhoods with high concentrations of old, lead-contaminated housing between 1979 and 1984.


The research team calculated cumulative lead exposure by measuring blood-lead levels of subjects during pregnancy and at regular intervals during childhood. Prenatal maternal blood-lead concentrations were measured during the first or second trimesters. Childhood blood-lead concentrations were measured quarterly or biannually for 6.5 years.


Researchers subsequently correlated blood-lead level data with criminal-arrest data from the public criminal justice records of Hamilton County, Ohio, which provided information about the number and nature of arrests.


Of the 376 subjects recruited, researchers studied 250 individuals, ages 19 to 24. Arrests were coded by category including violent, property, drugs, fraud, obstruction of justice, serious motor vehicle and disorderly conduct.


“The fact that we are able to detect the effects from childhood exposures now into adulthood stands as a testament to lead’s power to influence behavior over a long period of time,” Wright says.


The study is part of a long-term lead-exposure research initiative of the Cincinnati Children’s Environmental Health Center. The collaborative research effort, which is funded by the National Institute of Environmental Health Sciences and U.S. Environmental Protection Agency, brings together scientists from the UC College of Medicine and Cincinnati Children’s Hospital Medical Center.


Lead-exposure study co-authors include M. Douglas Ris, Ph.D., Richard Hornung, Ph.D., Stephanie Wessel, Bruce Lanphear, M.D., Mona Ho, and Mary Rae, Ph.D.