Friday, 27 July 2007


An economist in Fairfax who has argued in a series of little-noticed papers that the "New York miracle" was caused by local and federal efforts decades earlier to reduce lead poisoning.

The theory offered by the economist,Rick Nevin,is that lead
poisoning accounts for much of the variation in violent crime in the
United States.It offers a unifying new neurochemical theory for
fluctuations in the crime rate,and it is based on studies linking
children's exposure to lead with violent behavior later in their

What makes Nevin's work persuasive is that he has shown an identical,decades-long association between lead poisoning and crime rates in nine countries.

"It is stunning how strong the association is,"Nevin said in an
interview."Sixty-five to ninety percent or more of the substantial
variation in violent crime in all these countries was explained by

Through much of the 20th century,lead in U.S. paint and gasoline
fumes poisoned toddlers as they put contaminated hands in their
mouths.The consequences on crime, Nevin found, occurred when
poisoning victims became adolescents. Nevin does not say that lead isthe only factor behind crime,but he says it is the biggest factor.

Nevin says his data not only explain the decline in crime in
the 1990s,but the rise in crime in the 1980s and other fluctuations
going back a century. His data from multiple countries,which have
different abortion rates,police strategies,demographics and economic conditions,indicate that lead is the only explanation that can account for international trends.

Because the countries phased out lead at different points,they
provide a rigorous test:In each instance,the violent crime rate
tracks lead poisoning levels two decades earlier.

"In Britain and most of Europe,they did not have meaningful
constraints[on leaded gasoline]until the mid-1980s and even early
1990s,"he said."This is the reason you are seeing the crime rate
soar in Mexico and Latin America,but[it]has fallen in the United

Lead levels plummeted in New York in the early 1970s,driven by
federal policies to eliminate lead from gasoline and local policies to reduce lead emissions from municipal incinerators.Between 1970 and 1974,the number of New York children heavily poisoned by lead fell by more than 80 percent, according to data from the New York City Department of Health.

The later drop in violent crime was dramatic.In 1990,31 New Yorkers out of every 100,000 were murdered.In 2004, the rate was 7 per 100,000--lower than in most big cities.The lead theory also may explain why crime fell broadly across the United States in the 1990s,not just in New York.

The centerpiece of Nevin's research is an analysis of crime rates and lead poisoning levels across a century.

Other evidence has accumulated in recent years that lead is a
neurotoxin that causes impulsivity and aggression,but these studies
have also drawn little attention.In 2001, sociologist Paul B.
Stretesky and criminologist Michael Lynch showed that U.S. counties
with high lead levels had four times the murder rate of counties with low lead levels, after controlling for multiple environmental and socioeconomic factors.

In 2002,Herbert Needleman,a psychiatrist at the University of
Pittsburgh, compared lead levels of 194 adolescents arrested in
Pittsburgh with lead levels of 146 high school adolescents:The
arrested youths had lead levels that were four times higher.

"Impulsivity means you ignore the consequences of what you do,"said
Needleman, one of the country's foremost experts on lead poisoning,
explaining why Nevin's theory is plausible.Lead decreases the ability to tell yourself, "If I do this, I will go to jail."

Nevin's work has been published mainly in the peer-reviewed journal
Environmental Research

Nevin's finding may even account for phenomena he did not set out to
address.His theory addresses why rates of violent crime among black
adolescents from inner-city neighborhoods have declined faster than
the overall crime rate--lead amelioration programs had the biggest
impact on the urban poor. Children in inner-city neighborhoods were
the ones most likely to be poisoned by lead, because they were more
likely to live in substandard housing that had lead paint and because public housing projects were often situated near highways.

(From The Washington Post)

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