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A report this week that crime in Los Angeles had dropped to a historic low for the tenth year in a row, has prompted the LAPD to take credit. While overall crime in the city dropped 1.5%, violent crime dropped 8.5%. The statistics are part of a growing trend nationwide and internationally and while law enforcement will cite increased numbers of cops on the street as explanation, many sociologists are scratching their heads. The conventional social wisdom on crime links crime rates to the economy – crimes are expected to increase as the economy worsens. Yet, current global and local trends defy such logic despite an on-going economic recession.

Now, a controversial correlation that could explain the historic rise and current fall in violent crime is gaining traction as scientists are refining studies of what drives violent crime. That correlation is the exposure of young children to lead and their tendency toward violent crime as adults. Writing for Mother Jones magazine, writer Kevin Drum questions the LAPD’s assertions, saying “violent crime in Los Angeles peaked more than 20 years ago, long before LA changed its policing tactics.” Drum published a wide ranging article this month entitled “America’s Real Criminal Element: Lead.”

Citing decades of scientific studies, Drum makes a compelling case that the phasing in and out of leaded gasoline in various countries, and American states, cities and even neighborhoods, correlates so strongly with the incidence of reported violent crime, that it is likely lead exposure drove the high crime rates of the 90s and that the phasing out of leaded gasoline 20 years ago now explains the drops in crime rates. If true, the implications are shocking.

Lead exposure is known to cause cerebral damage particularly in the developing brains of young children. It can also affect impulse control and those centers in the brain that control aggression.

Among the scientists whose work is cited in the Mother Jones article is Dr. Howard Mielke, a researcher at Tulane University in New Orleans, whose pioneering work on lead emissions exposure has found a strong correlation with violent crime. A 2012 collaborative project examined FBI crime statistics in the cities of Chicago, Indianapolis, Minneapolis, San
Diego, Atlanta, and New Orleans and found that trends in aerial lead emissions correlated strongly with crime statistics in those cities. Dr. Mielke has also conducted similar studies within the city of New Orleans that showed a striking correlation at the level of individual neighborhoods.

GUEST: Dr. Howard Mielke, research professor at Tulane University working on the state of urban environments

Click here to read Kevin Drum’s article in Mother Jones.