Lead is a vicious pollutant. At high levels in the human body, it can cause a host of disorders, including anemia, mental retardation, kidney damage and even death. So in 1970 Congress passed the Clean Air Act, which mandated the elimination of lead, a common additive, from gasoline. The results have been a great triumph of environmental policy — as it turns out, even greater than anyone could have predicted.
In the 1970s, 88 percent of American children had elevated levels of lead in their blood. Today, it’s 1 percent. That progress averted a huge number of serious health problems.
But it did more than that: It apparently made America safer. At the time of the Clean Air Act, crime was on the rise, and it kept rising for years afterward. But starting in the early 1990s, both violent crime and property crime began to fall, and today they are far below the peaks.
Is it a coincidence that once lead exposure was reduced, crime began to ebb as well? Two new studies say no. Researchers at the University of Cincinnati followed 250 inner-city children born between 1979 and 1984 and found that those with high lead levels in their early years were far more likely to end up in jail than those with lower levels. Each 5 microgram-per-deciliter increase produced a 50 percent rise in the likelihood of arrest for a violent crime.
That finding dovetails with a study by Amherst College economist Jessica Wolpaw Reyes for the National Bureau of Economic Research. She looked at violent-crime rates in every state, compared them to average lead exposure 20 to 30 years earlier and found that the bigger the drop in lead exposure, the bigger the drop in crime.
Looking at the decline in violent crime from 1992 to 2002, Reyes attributes 56 percent of the improvement to the removal of lead from gasoline. She expects “up to a 70 percent drop in violent crime by the year 2020.”
These results are consistent with what we know about the brain. Lead exposure, as the Cincinnati researchers noted, impairs brain function, fostering aggression and poor self-control, and these resulting tendencies can lead to criminal conduct. Damaged people often inflict damage on others. Healthy minds are more prone to healthy behavior.
By protecting millions of young brains from lead, the Clean Air Act inadvertently also did much to protect society. It’s well-known that government actions often have completely unintended consequences. It’s a relief to find that some of them are good.
The Illinois legislature has an opportunity to produce an entirely intended consequence. A House committee on Wednesday approved a bill that would require manufacturers to put a warning label on any product that is used by children and has more than a trace amount of lead. Parents would have the knowledge they need to avoid buying products that might be unsafe.
So here’s one more reason for members of the House and Senate to vote for this bill. Don’t just think of it as a pro-health bill, think of it as an anti-crime bill.
