Did the rise and fall of the use of products containing lead help cause the rise and fall of violent crime? No one is sure, but one doctor says lead exposure to children can cause changes to their brains.

Several studies have been published showing that increases and decreases in crime in several cities came roughly 20 years after the liberal use of products such as lead-based paint and leaded gasoline.  The studies show that many cities have seen a decrease in overall violent crime in recent years, as the use of lead-based material has been phased out since the late 1970‘s.

While those studies don‘t claim that lead exposure caused some people to become more violent, emergency room Dr. Ryan Venis at St. Vincent Hospital in Indianapolis says exposure does affect the brain.  “Specifically, what‘s been looked at is impulse control,” said Venis.  “There‘s been some thought that lead acts on the part of the brain that may control our impulses to do certain things.  So, if a person who is not lead-exposed has an impulse to pocket a candy bar in the store, then that part of the brain lets them know not to do that.”

While exposure to lead is never safe at any level, Venis says changes to the brain typically only happen to those who are exposed as children, especially between the ages of one and five.   He says this has also been demonstrated in intelligence tests. “If you look at groups of children, say one subset of a population that lives in a housing development that has lead paint, compared to their non-lead exposed peers, their IQ may be a few points lower.”

Leaded gasoline has been phased out in the U-S since 1973 and was banned outright by the Clean Air Act of 1996.  The use of lead-based paint was made illegal in 1978.   But Venis says that while it is less common, lead exposure can still happen.  “Because of the combustion of leaded gas and other parts of the world where lead has not been outlawed, there is still lead in the environment,” Venis said, adding that some lead could be found in the soil in the U-S for many years to come.