http://www.theepochtimes.com/n3/2145046-lead-poisoning-a-significant-cause-of-inner-city-crime-say-researchers/
“….Lanphear and his colleagues found that in six-year-old children, every five micrograms per deciliter of increase in blood lead levels increased the risk of being arrested for a violent crime as a young adult by almost 50 percent, according to their 2008 study Association of Prenatal and Childhood Blood Lead Concentrations with Criminal Arrests in Early Adulthood, published in the journal PLOS.
Other studies have found similar results.
“Childhood lead exposure increases the likelihood of behavioral and cognitive traits such as impulsivity, aggressivity, and low IQ that are strongly associated with criminal behavior,” according to a study by Jessica Wolpaw Reyes from Amherst College for the National Bureau of Economic Research in 2007.
The study found that the phase-out of leaded gasoline was responsible for approximately a 56% decline in violent crime in the US….”