Back in September, as youth around the world took to the streets for the Global Climate Strike, high schoolers in Richmond, California were dealing with the trauma of a shooting outside De Anza High School on the same day 17-year-old Petelavanh Owen Syharath was buried after dying from cancer.

The city’s residents—especially the youth—care about the environment and protecting the climate. However, striking for climate and environmental action is tough when dealing with shootings and deaths. Richmond, a largely black and Latinx city of 110,000 deals with deadly crimes that often go unsolved on a regular basis. It is also home to a major Chevron refinery that, as recently as August, has come under fire for reducing air quality.

Turns out that Richmond’s air pollution and violent crime rates may be more than a simple coincidence. Air pollution may, in fact, increase violence; a growing body of research is finding a correlation between air pollution and violent crime rates. Scientists still don’t quite understand how this relationship works, but enough evidence is growing to build a case for further study of the potential link. 

This poor air quality and exposure to violence are two symptoms of the same problem: systemic racism.


The U.S. has a troubled history around how it defines and handles so-called crime. Much of it comes back to race and class, though.

This nation leads the world in the number of incarcerated people—the people many in this country consider “criminals.” More than half a million people in local jails still haven’t been convicted of a crime, likely there because they can’t afford bail, according to the Prison Policy Initiative. Meanwhile, one in five incarcerated people are locked up due to drug-related offenses. Even though white and black people use and sell drugs at roughly the same rate, black people are 6.5 times as likely as white people at the state level to face incarceration due to drugs. People of color make up nearly 70 percent of the prison population despite being the minority of Americans outside bars. And that’s not by accident. It’s by design.

Slave patrols in the 18th century eventually went on to become police departments. After the passage of the 13th Amendment deemed slavery technically illegal in 1789, police were at the forefront of maintaining slave labor. They did so in part by enforcing black codes in the South—laws states passed to limit the behavior of formerly enslaved people and maintain the free labor enslaved people had previously offered by incarcerating them and putting them to work in prisons. States created laws that unfairly targeted formerly enslaved people—creating what they considered “crime” where there previously had been none—just to incarcerate black people and force them back onto plantations. For example, vagrancy laws criminalized unemployment and homelessness.

The system of mass incarceration we see in the U.S. today is what sociologist Michelle Alexander has called “the new Jim Crow,” replicating black codes and slavery under a new name. The lack of wealth and immense poverty many communities of color now face—but especially black communities—is a direct result of this racist history. And this legacy contributes immensely to the violence these communities now face.

“‘Crime’ is also a very problematic term, so we have to unpack that,” Antonio Lopez, the former executive director of Little Village Environmental Justice Organization (LVEJO) in Chicago, told Earther. “Its history—the notion of crime and criminal activity, the criminal justice system—it’s got an awful history. We’ve got folks with a lot of resources who are committing a tremendous amount of ‘crime’ who are not held accountable, but yet people surviving deep poverty and deep despair in communities like Little Village—that’s the image of the criminal.”

Segregation exacerbated the disenfranchisement slavery created. Laws literally separated white people from everyone else for a century, and when segregation became illegal, policymakers disguised it by deeming black and brown communities “risky investments” so that businesses wouldn’t move there, further avoiding integration. Research is finding that, at least in California, communities that experienced this practice—called redlining—are also suffering from higher rates of asthma emergency visits in the present day.

“When considering racial health disparities and inequities, we need to consider history,” Anthony Nardone, a medical student at the University of California at San Francisco and Berkeley’s Joint Medical Program who’s presented research on the topic, told Earther. “We have a responsibility to make sure that racist policies of the past aren’t still impacting health or prosperity today.”

As it stands, black and Latinx communities suffer disproportionately from high and harmful air pollution around the country. A recent study found that much of the air pollution they’re breathing is a result of the consumption from white communities. So systemic racism has everything to do with crime and air pollution. Now, what do they have to do with each other?


When experts talk about reducing crime rates, they don’t typically discuss air pollution. Some talk about increasing police presence for immediate impact, others opt for abolishing police altogether. But a common theme for nearly all experts is addressing the problem in the long-term by examining the root causes of the law-breaking behavior.

“It could be so many things,” Brian Higgins, an adjunct professor at John Jay University who’s served as a former police chief and director of public safety, told Earther. “It could be economic. It could be socioeconomic issues. It could be mental health issues. There’s a whole post of issues related to crime.”

Researchers looking at the linkage between crime and air pollution know this. They aren’t saying that air pollution causes violent crime, per se, especially since most aren’t sociologists, criminal justice wonks, or other types of scientists who work specifically on crime. Rather, most are largely environmental economists trying to estimate the cost of air pollution.

There’s plenty of long-standing research that has solidified the way air pollution hurts health, including degenerative eye disease, lung damage, brain issues, premature mortality, and more. Economists have been increasingly finding, however, that air pollution may do more than hurt health. It can take an economic toll by reducing worker productivity. Additionally, neighborhoods that experience a period of increased air pollution also see a recorded rise in crime.

Even short-term exposure to air pollution can coincide with a rise in violent crime, according to a study published in September in the Journal of Environmental Economics and Management. This study zoomed into county-level air pollution and FBI-managed criminal activity data. Researchers found that over a 10-year period, a 10 percent increase in daily exposure to air pollution increased violent crimes by 0.14 percent. That is a relatively small increase, though, and the research doesn’t delve into the causation behind the relationship. It also only looked at only 397 U.S. counties that cover a little more than a quarter of the U.S. population. Still, the research found a pattern was clear that requires further examination.

“The effect size that we’re finding is pretty small,” lead author Jesse Burkhardt, an assistant professor of environment and natural resource economics at Colorado State University, told Earther. “For me, what’s really interesting is that the effect was there in the first place. I was skeptical that I would be able to find it in aggregate crime data, but now that we’ve been able to find it, it really makes me curious about what’s happening. If it’s true, why are people responding in this way?”

Burkhardt’s study isn’t the first to find this connection. And this link doesn’t exist only in the U.S. In the UK, researchers examined the way air pollution was impacting crime rates in London. This study, published last year, is the first to examine this connection outside of the U.S.

While the Colorado State University study looked at crime and air quality data, the London study analyzed the influence of air pollution spikes higher than the ward average and their correlation with crime rates. The researchers found that a mere 10 point increase on the Air Quality Index—the metric used to measure air pollution—correlated with a 0.9 percent increase in the city’s crime rate. When air quality scored higher than 35 points on the index—a rating that’s still considered “good”—the study found that 2.8 percent more crimes occurred.

This is yet again another study offering some strong proof for this connection, but these researchers analyzed only two years’ worth of data (2004 and 2005) and in a single city. Plus, they saw connections on violent crime and non-violent crime, such as property damage, which hasn’t been as common in other studies. The fact they were able to find this connection elsewhere on the planet, though, shows that there could be something here to dig into.

“We may expect that the effect of air pollution on human health and behavior should be similar across countries, so it’s good to see that we actually find in the UK similar patterns to what other studies find in the United States,” author Lutz Sager, an assistant professor of public policy at Georgetown University, told Earther. “So the evidence that’s accumulating with our study and other studies is starting to be quite robust.”

Scientists at the Columbia Business School looked at cities across the U.S. and found similar results. These researchers—who are psychologists—went even further and created a psychological experiment to measure how ethical participants who imagined living in dirtier air would behave next to those who imagined being surrounded by cleaner air.

The scientists measured this by creating a simple test: Each participant was shown cue words on a screen. Each word was linked with another, which participants were challenged to identify. They won 50 cents for every correct answer—and a supposed glitch made the correct answer visible when participants hovered their mouse over the answer box. The study authors found that those assigned a polluted location snuck a peek at the answer more often than those who imagined living in a clean location.

In Chicago, researchers found similar patterns between air pollution and crime. The increases aren’t huge, but they’re enough for economists to argue that improving air quality may reduce the costs associated with crime.

What none of the researchers understand, however, is how this could be happening. Psychological research suggests that pollution may be a source of stress, which can result in aberrant behavior. But scientists can’t rule out the potential that this link may be physiological. Air pollution, after all, is tiny dirty air particles that make their way into our bodies when we breathe.

Once they’re there, they reach the lungs and eventually the bloodstream, which can transport these potentially toxic particles into our hearts and brains. If they’re entering our bodies through our nose, they can get a straight shot to the brain. In rodents, scientists have observed air pollution particles causing inflammation in the brain, which may cause further distress to the neural system. Scientists have also documented neuroinflammation among humans exposed to air pollutants. Previous research has linked this inflammation with aggressive behavior in people, but more research is needed on the topic of violent crime, in particular.

Investigating this hypothesis is tricky, though. Researchers can’t intentionally expose humans to pollution particles to study the impacts. And it’s tough to study individuals outside a lab setting because we’re exposed to more than air pollution in the real world. That makes singling out the role air quality plays in offensive behavior next to impossible. This research isn’t meant to prove air pollution causes crime, though. It’s meant to highlight yet another way poor air quality is ruining lives and societies.

For community members who regularly deal with poor air quality and violence, some solutions could, in part, address both issues. For example, cleaner, greener spaces have been shown to help reduce crime rates. Along with sustainable economic investment and more equitable labor practices nationwide, attention to what historically neglected communities want to see in their environment is paramount to counteracting the effects of decades of systematic racism.


Antonio Lopez coordinates the Mi Parque Program with LVEJO in Chicago. The organization developed the program to help protect a park the city built in 2014 on top of a former Superfund site from drugs and crime with little police intervention. The park itself has been free of the shootings or killings that tend to affect the neighborhood.

The park followed greater efforts from the community to remove polluters such as two major coal-fired power plants they shut down, all part of an effort to improve the environmental health of the neighborhood and the lives of the people who live there.

Creating a cleaner environment means kicking out polluters and creating green spaces that foster a safer, more connected community. The way Lopez sees it, guns and power plants are both a form of violence; one just kills you quicker.

“[Pollution] is a form of racial violence,” Lopez told Earther. “For us, it’s less about trying to contrast or find causation and trying to say air pollution is causing more or less ‘criminal activity’ in our neighborhood. I think it’s about sharing that, as people of color, as Latinos and black folks, that we’re vulnerable to all of these forms of violence. It’s disproportionate and that it’s all rooted in the same system.”

He appreciates the ongoing research to learn about the link between air pollution and violence, but he feels that communities of color have been making the connection for some time. That’s what environmental justice is all about: drawing connections between the environment and other socioeconomic issues disenfranchised communities face, and Lopez has always thought about violence as it relates to the other stressors people are dealing with.

The same is true for organizers in California. Allen Hernandez, the executive director of the Center for Community Action and Environmental Justice, told Earther the growing body of air pollution and crime research looks at the problem too simply.

“There’s a bigger story to tell,” he said, one of the poverty and racism these communities have suffered. “Yeah, the study shows a correlation. I think there’s a deeper one as far as, well, why? And I think the answer there is these are low-income communities of color. These are the frontline communities. This is where there’s a direct environmental racism happening, where it’s like, ‘We’re going to place this project here,’ instead of South Orange County or Beverly Hills.”

In short: Air pollution and violence are both symptoms of a failed system where officials let polluters into these communities instead of opting to use that land for a park or community center. Analyzing this connection with a lens on the history and racial make-up of a community may reveal more behind what’s driving the correlation.

“Environmental justice is economic justice is social justice is immigrant justice is racial justice,” Hernandez said. “And I think the research is onto something. It would be really good if the research went deeper to add those elements, as well.”

After all, the air in some communities may be especially bad on only certain days, but the struggles they face—poverty, social isolation, racism—are a constant. They deal with these issues on the daily, no matter the air quality, said Megan Zapanta, the organizing director in Richmond, California for the Asian Pacific Environmental Network.

Once this science goes beyond the economics and enters the sociology of it all, perhaps we’ll have an improved understanding of how history has created the conditions people suffer from today. We could better appreciate proposals like a Green New Deal because they bring together financial and social solutions for our current societal crises. 

Such a proposal is about transforming communities, to take them from surviving to thriving. It’s about removing polluters from neighborhoods while at the same time improving the community members’ quality of life and creating equitable jobs that fight the underlying causes behind its social distress.

In a better, more just world, individuals wouldn’t have to resort to harming one another because of gang peer pressure or to make a buck. In that world, they could step outside and breathe clean air without the worry of a stray bullet or drive-by. And they could have economic opportunities that don’t rely on polluting the planet. That world is possible, and as this research continues, we may build a better case to convince world leaders to finally invest in the neighborhoods they’ve thrown to the side for way too long.

Senior staff writer, Earther. All things environmental justice, please. I'm addicted to Stardew and love few things more than I love my cat.

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