On both sides of the Atlantic, new research into lead and crime is attracting attention. The New York Times and The Independent both reported on a new study by Amherst College economist Jessica Wolpaw Reyes, who found a correlation between blood lead levels and violent crime rates. Jascha Hoffman explains in the New York Times:
After moving out of an old townhouse in Boston when her first child was born in 2000, Reyes started looking into the effects of lead poisoning. She learned that even low levels of lead can cause brain damage that makes children less intelligent and, in some cases, more impulsive and aggressive. She also discovered that the main source of lead in the air and water had not been paint but rather leaded gasoline -- until it was phased out in the 1970s and '80s by the Clean Air Act, which took blood levels of lead for all Americans down to a fraction of what they had been. ''Putting the two together,'' she says, ''it seemed that this big change in people's exposure to lead might have led to some big changes in behavior.''
Reyes found that the rise and fall of lead-exposure rates seemed to match the arc of violent crime, but with a 20-year lag -- just long enough for children exposed to the highest levels of lead in 1973 to reach their most violence-prone years in the early '90s, when crime rates hit their peak.
Such a correlation does not prove that lead had any effect on crime levels. But in an article published this month in the B.E. Journal of Economic Analysis and Policy, Reyes uses small variations in the lead content of gasoline from state to state to strengthen her argument. If other possible sources of crime like beer consumption and unemployment had remained constant, she estimates, the switch to unleaded gas alone would have caused the rate of violent crime to fall by more than half over the 1990s.
In The Independent, Geoffrey Lean notes that this isnât the only study linking lead levels and criminal behavior:
Research at Pittsburgh University found that adolescents arrested for crime in the city had lead levels four times higher than their law-abiding contemporaries, and a study of 3,000 possible causes of criminality in 1,000 young people by Fordham University, New York, found that high lead levels were the best predictor of delinquent and violent behaviour.
Even though its gone from gasoline in many countries, leadâs effects linger. USA Today highlights the role of lead paint (which is still present in many older homes) in childrenâs lead poisoning and explains how lead stored in peopleâs bones can contribute to health problems years after the exposure occurred.
Lead paint was banned for general use in the United States in 1978. Today, however, more than 93,000 Delaware homes built before 1960 still rate as high-risk for lead paint use. Some 35,000 of that number, or 37 percent, stand in a handful of Wilmington-area ZIP codes where lead poisoning rates are triple the statewide average.
"We've done a lot of work, every year, to reduce the rates of poisoning," said Dr. Lucy Luta, director of the Division of Public Health's Office of Lead Poisoning Prevention. "It's mostly due to increasing education and awareness, and having federal funds that help us remove lead from older houses in Wilmington."
Now state officials are hoping to easily reach a goal of driving lead poisoning rates below 1 percent of children tested by the year 2010. The effort spans Delaware and includes a requirement for blood-lead testing in all children at about age 1.
Lead abatement has cost about $1 million a year for the past six years for Delaware alone, mostly paid for by federal taxpayers.
Leigh Jones reports that in Galveston, Texas, an average of 20 percent of the children tested every year have lead poisoning -- and researchers have been working to pinpoint the source:
Using data from lead poisoning cases reported between Nov. 16, 1992, and Jan. 31, 2006, researchers have created a map that predicts where children with elevated blood-lead levels are most likely to live â a good indication of where the poisoning takes place.
Winifred J. Hamilton, Baylorâs director of environmental health, said she hoped community leaders would use the map to test properties likely to have lead contamination and begin cleaning them up.
While the list of testing candidates is long, officials could take care of a big chunk of the problem properties by focusing on the studyâs short list â 434 of the 2,171 children poisoned in the last 15 years lived in properties owned by just 12 landlords.
We still have a long way to go to keep children free of lead poisoning. Perhaps the prospect of declining crime will be a good motivator.