Children living in suburbs with higher lead levels are more likely to commit violent crimes in early adulthood, Australian research suggests.
Previous studies have linked childhood lead exposure with later life antisocial behaviours, including delinquency and crime.
Lead exposure is known to increase impulsivity, while crimes of aggression are typically related to impulsive actions, say the Macquarie University researchers.
They analysed air lead concentrations in six NSW suburbs - Earlwood, Lane Cove, Rozelle and Rydalmere in Sydney and regional Boolaroo and Port Kembla - where data was available for at least 30 years.
They also looked at crime data to see if exposure during childhood was related to rates of assault 15-24 years later, also considering state and national crime statistics.
The study, published in the journal Environmental Health, allowed for socio-demographic factors known to affect criminal behaviours such as age, finishing high school and household income.
Environmental lead level exposure during childhood was found to be the strongest predictor of assault rates later in life.
"When comparing results between suburbs in New South Wales we found that for every additional microgram of lead in the air, assault rates 21 years later rose by 163 assaults per 100,000 persons," said Professor Mark Taylor, one of the study's authors.
They found lead in the air concentrations accounted for 29.8 per cent of the variance in assault rates 21 years later in the six suburbs.
When they compared the suburb results to the link between lead exposure and fraud, a non-impulsive and non-aggressive crime, they found only a 5.5 per cent variance.
"The strong positive relationship between childhood lead exposure and subsequent rates of aggressive crime has important implications for public health globally," the researchers said.
"Measures need to be taken to ameliorate exposure to lead and other environmental contaminant with know neurodevelopmental consequences."