There's not much doubt that high levels of particulates from vehicle exhausts in the air can contribute to poor health, including lung conditions. But scientists in the US have uncovered a possible link between vehicle particulates and antisocial behaviours – including practices as severe as theft, arson, vandalism and drug abuse.
The study, conducted over nine years, tracked 682 children in the Greater Los Angeles area. Air quality monitors tracked the levels of toxic "PM2.5" particles outside each participants home, while the children's parents completed a "rule-breaking" checklist – encompassing delinquent behaviours such as lying and cheating, truancy, theft and substance abuse.
Three-quarters of the participants were found to be breathing in dangerous levels of the particulates, which can enter the bloodstream through the lungs. Lead researcher Dr Diana Younan, from the Keck School of Medicine, said: "These tiny, toxic particles creep into your body, affecting your lungs and your heart.
"Studies are beginning to show exposure to various air pollutants also causes inflammation in the brain. PM2.5 is particularly harmful to developing brains because it can damage brain structure and neural networks and, as our study suggests, influence adolescent behaviours."
Perhaps unsurprisingly, higher levels of the particulates were identified near major roads and in neighbourhoods with limited green space. The researchers noted that poorer members of society were most likely to live in these areas.
"Poor people, unfortunately, are more likely to live in urban areas in less than ideal neighbourhoods," said Dr Younan.
"Many affordable housing developments are built near freeways. Living so close to freeways causes health problems such as asthma and, perhaps, alters teenagers' brain structures so that they are more likely to engage in delinquent behaviour."