Toxic Truth: High correlation between children exposed to lead and violent crimes

June 1994: Boolaroo locals from left Mrs Joanne Victor, Blake Cox, Mrs Karen Phillip with Mitchell Tate and Mrs Theresa Pantalone and Mathew Pantalone. Picture: Eddie Cross
June 1994: Boolaroo locals from left Mrs Joanne Victor, Blake Cox, Mrs Karen Phillip with Mitchell Tate and Mrs Theresa Pantalone and Mathew Pantalone. Picture: Eddie Cross

CHILDREN who were exposed to high levels of lead pollution are more likely to commit violent crimes in later years, scientists believe.

A 2013 study based on NSW Bureau of Crime Statistics and Environment Protection Authority data found a high correlation between childhood lead exposure and assault.

The survey of seven sites including Boolaroo, Broken Hill, Port Kembla, Port Pirie and Mt Isa, showed higher levels of airborne lead resulted in higher assault rates 20 to 21 years later.

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While the sources varied (lead smelter emissions at Boolaroo and leaded petrol emissions at Earlwood) the pattern was consistent: the highest crime rates were associated with the highest levels of lead in the air.

‘‘The relationship is statistically significant,’’ Macquarie University environmental scientist Mark Patrick Taylor said. ‘‘There is a clear relationship between early life exposure to lead in air and later-life crime.’’

Research has also found that elevated blood lead levels are risk factors for social and behavioural problems including attention-deficit hyperactivity disorder (ADHD), oppositional/conduct disorders and delinquency.

‘‘Lead impacts the growing brain and is associated with damage to the frontal cortex and its consequent effects on executive functioning and disposition to increased impulsivity,’’ Professor Taylor said.

The current Australian childhood blood lead standard is less than 10 micrograms per decilitre.

A 1991 sample of Boolaroo Public School students found 84per cent had blood lead levels above 10.

The Australian findings are consistent with a 2008 US study of air lead emissions and assault records.

Researchers discovered that six-year-olds with elevated blood lead levels had a 50per cent greater chance of being arrested for violent crime as young adults.

Arrest rates involving violent crimes were shown to increase for each five microgram per decilitre increment increase in blood lead.

‘‘We’re not saying it’s a one-to-one relationship,’’ Professor Taylor, who has more than 200 publications and research reports in the field of environmental science, said. ‘‘What we are saying is that lead exposure is associated with violent activity.’’

Other studies about the impact of lead on development have supported the link between lead and crime.

The UK Avon longitudinal study found higher childhood blood levels were associated with lower reading, writing and spelling skills.

A 2012 study of multiple exposures in New Orleans showed elevated soil metals reduced student elementary school scores.