This is a most intriguing study.
A new study links leaded gasoline to violent crime rates in six cities.Posted by Jill Fallon at January 13, 2013 8:10 PM | Permalink
High lead levels have long been known to cause birth defects, lower intelligence and hearing problems - but now researchers are beginning to find that it also causes high levels of aggression.
Tulane University toxicologist Howard W. Mielke says high levels of lead exposure in children in the 1960s and 1970s resulted in a dramatic uptick in crime two decades later.
When the use of leaded gasoline declined in the 1980s, crime rates dropped off at corresponding rates.
Mielke found that in all six cities - Atlanta, Chicago, Indianapolis, Minneapolis, New Orleans, and San Diego - every one percent increase in the number of tons of lead released into the atmosphere resulted in a half percentage point increase in the aggravated assault rate 22 years later.
Dr Herbert Needleman, a University of Pittsburgh researcher, conducted a 1996 study that showed that children with high lead levels were much more likely to exhibit aggressive behavior than those with normal levels.
A 2002 study showed that youths had been arrested had far higher levels of lead in their bones, on average, than their non-delinquent peers.
Mother Jones writer Kevin Drum reports that the leaded gasoline theory is the only explanation for the dramatic rise and fall of violent crime across the country.
General Motors developed a lead additive for gasoline to prevent engine knock in the 1920s. The most popular additive was tetraethyllead, which soon became nearly universal.
By the 1970s, cars were being made with catalytic converters, which were incompatible with leaded gasoline.
Leaded gas was quickly phased out by the 1980s. It was banned for use in vehicles on U.S. roadways in 1996.