If a tree were planted every time a modern European politician uttered the phrase 'sustainable development', loss of forest would probably be a thing of the past.

From BBC News.

The Washington Post has a story today covering research that seems to show a clear link between levels of lead poisoning and violent crime. Apparently, Rudi Giuliani's zero tolerance policy just happened to be occuring at the same time that lead reduction policies from 20 years ago were starting to affect young people's tendency for violent crime:

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 is the only factor behind crime, but he says it is the biggest factor.

The same pattern has been found all over:

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 lead."