Green Cities

On edge? It might be what’s in the air

Dirty air isn’t just bad for your health. It can also lead to more violence.

That’s according to research out last week linking air pollution to more aggressive behavior. As poor air quality increases, so do violent crimes, said a paper published in a forthcoming issue of the Journal of Environmental Economics and Management.

The study from researchers at Colorado State University is one of the first to link air pollution to violence. The team analyzed data from nearly 400 counties across the United States, overlaying daily criminal activity with air pollution measurements and the presence of wildfire smoke plumes.

“The effect is saying that if the pollution goes up on one of those Mondays in that county, and at the same time the crime goes up on that Monday, then we’re finding a correlation,” Jesse Burkhardt, lead author of the study, told Earth Day Network. “I was actually surprised that [the correlation] was there and as strong as it was.”

The researchers found that a 10% increase in same day exposure to particulate matter — a common air pollutant — is connected to a 0.14% increase in violent crimes per country, per day. A 10% increase in exposure to ozone was even worse, tied to a 0.3% increase in violent crimes per county, per day.

That may not sound like much, but over time, the numbers add up: A 10% reduction in daily particulate matter and ozone would save $1.4 billion in crime costs per year, the paper reported.

So, why would air pollution make someone more aggressive? The authors suggest it has to do with how our bodies respond to poor air quality. Psychologically, air pollution can affect our mood, perception and impulsion. When discussing the origin of the study, Burkhardt spoke to the aggravation that could be associated with poor air quality.

“We had a bad fire season a couple of years ago, and the smoke was bad enough that it made my eyes burn and it made my lungs kind of burn,” he said. “After a couple of days of it, it just gets kind of frustrating.” That frustration, he thought, might have a connection with aggression and air quality.

Air pollution comes with obvious health costs — hospital bills, asthma-related issues, premature deaths — as well as environmental and economic costs. By tying air pollution to violent crimes, the authors suggest, we may be able to sway politicians to act on air pollution.

“From a policymaker perspective, they want to weigh the costs and benefits of addressing pollution,” said Burkhardt. “We’re just tipping the scales a little more towards the benefit side.”

But short of becoming a policymaker, what can one do to reduce air pollution?

Both city smog and rural wildfires cause poor air quality. Emissions from cars, buildings and factories can create smog, whereas dry, drought-ridden landscapes — more common in a climate-changed world — are prime conditions for wildfires to break out.

To reduce air pollution, we need to curb greenhouse gas emissions and pressure leaders to take bold action on climate change. April 22, 2020, is the 50th anniversary of Earth Day. Now is the time to mobilize: Join the movement.