In a new study published by the National Bureau of Economic Research, scientists from the University of California, Davis and the Harvard University Center for the Environment suggest that violent crime is precipitated by air pollution.
Evan Herrnstadt, a postdoctoral fellow at Harvard University Center for the Environment, and co-author Erich Muehlegger, assistant professor of economics at UC Davis, analyzed over two million crimes listed by the Chicago Police Department between 2001 and 2012, noting the direction of the wind as it blew across neighborhoods near five interstate highways, I-90, I-94, I-290, I-55 and I-57.
They catalogued the temperature, precipitation, wind speed, and wind direction from data gleaned from the National Climatic Data Center, and factored in ambient pollution levels delineated by the Environmental Protection Agency.
The researchers found that the percentage of more serious crimes such as homicide, rape, robbery, assault, and battery rose 2.2% in areas downwind of the interstates, leaving them with higher levels of nitrous oxides, while property crimes remained unchanged.
The researchers argue that the presence of additional ozone in the brain pollution-related crime causes pain, which causes the victim to act more aggressively; they estimate the additional crime caused by air pollution may cost taxpayers as much as $200 million annually.
A 2007 study asserted that children exposed to lead suffered brain damage, ADHD, or exhibited aggressive, hyperactive, and impulsive behaviors. A 1985 study published in the Journal of Personality and Social Psychology stated that a correlation may exist between air pollution and violent crime, noting increased levels of ozone triggered family disturbances. That study was echoed by a 1999 study asserting that the same correlation exists.
It is not clear whether the researchers were able to separate correlation from causation. Some of the world’s most polluted cities are in China, for example, and yet crime there is low.