GREG TOPPO, USA TODAY - For decades, researchers have known that lead
poisoning lowers children's IQs and puts them at risk for severe
learning disabilities and more impulsive, sometimes violent behavior.
New research increasingly suggests that lead also affects long-term
juvenile and adult crime rates.
Among the most startling findings: a pair of studies by economist Rick
Nevin that suggest the nation's violent-crime rate in the second half of
the 20th century is closely tied to the widespread consumption of leaded
gasoline. Its gradual demise in the 1970s, he says, did more to stop
violent crime among people who came of age in its wake than any social
The sharp drop in violent crime in the 1990s has been attributed to the
dot-com boom, more police on the streets and, with a measure of
controversy, to the U.S. Supreme Court's 1973 Roe vs. Wade decision,
which legalized abortion. Nevin, a consultant to the U.S. Department of
Housing and Urban Development, began comparing leaded-gas consumption
through the 20th century with FBI crime statistics.
Researchers already knew lead inhibits children's ability to control
impulses. They also knew that people exposed to lead as youngsters were
more likely to have both juvenile and adult criminal records.
Nevin wondered whether millions of people exposed as babies to higher
levels of lead through car exhaust would commit more violent crimes than
those exposed to lower levels.
He found a "stunning" fit, he says. The trend lines match almost
perfectly: Leaded-gas use climbed in the 1940s and fell in the early
1970s; 23 years later, rates for violent crime followed in near unison.
He also studied lead-paint levels from 1879 over the next 60 years,
matching them to murder rates from 1900 to 1959.
Nevin published his work in the journal Environmental Research in 2000;
health advocates embraced the findings. . .
Nevin says a study published in April ties lead exposure and crime in
nine nations. "In light of all the other research, we should have a new
sense of urgency about eliminating the remaining risk of lead-paint
hazards," he says.