Study: More Lead in Air, More Murders

F O R T C O L L I N S, Colo., May 16 -- A new study that suggests a correlation between airborne lead levels and the murder rate.

The research showed that in counties across the United States with thehighest airborne lead levels, the murder rate was correspondinglyhigh.

It said that the murder rate was four time higher in thecounties with the highest lead levels than in counties with thelowest.

Among the counties where the trend was most evident: Baltimore,Dallas, San Francisco and Cheboygan in Michigan.

The study was co-authored by Colorado State University assistant professor PaulStretesky, a sociologist, and Michael Lynch, a criminology professor at the University of South Florida, Tampa. It was published Tuesday in the online edition of theJournal of the American Medical Association.

No Direct Causal Relationship

The research does not show a direct causal relationship betweenairborne lead levels and higher homicide rates, but could mean thatpeople exposed to higher lead levels are predisposed toward violentbehavior, the authors said.

“If the association uncovered in this analysis is trulyreflective of a causal relationship, these findings may haveimportant policy implications that link the need for continuedefforts toward lead abatement,” the article reads.

The research studied 1990 data from all 3,111 U.S. counties except Alaska and Hawaii, comparing the murder rate with theEnvironmental Protection Agency’s estimates of air concentrationsof lead and blood levels of lead. It factored out other things likepoverty levels, race, other pollutants, and education levels.

Two previous studies concluded that there was a correlationbetween lead poisoning and delinquency. The latest research focusesexclusively on the murder rate.

Stretesky acknowledged that more work needs to be done toestablish a direct link between lead levels and the homicide rate.

“I think at this point it’s pretty much speculative and we needto do more research,” Stretesky said.