Air Pollution Linked To Depressive Symptoms In Teens

Monitoring the mental health of your kids is one of the most challenging parts of parenting teens. While we know that a lot of factors — school stress, relationships, Covid isolation — influence teens’ emotional health, new evidence suggests the quality of the air around them could affect how they’re feeling.

A study published this week in the journal Developmental Psychology shows a link between air pollution — specifically, higher ozone levels — to an increase in depressive symptoms in teens.

While previous studies have linked air pollution to respiratory viruses, asthma, and even preterm birth, there is less research on how air pollution impacts mental health — and this is the first study to show a link between ozone levels and depressive symptoms in adolescents.

You’ve likely heard of the ozone hole that appears over the South Pole every year, allowing entry of UV rays that a layer of the gas would normally absorb. Down closer to the earth’s surface, ozone is produced when air pollutants, like vehicle emissions, interact with sunlight. So measuring ozone levels is one way to monitor air pollution.

Researchers from the University of Denver and Stanford used data collected for a different study and compared it to air quality data from the California Environmental Protection agency. The 213 participants in the original study were between the ages of 9 and 13 when the four-year study began. They were screened for mental health conditions three times, at two-year intervals. By comparing the kids’ symptoms with air quality data based on their home addresses, researchers were able to determine that higher ozone levels correlated with an increase in depressive symptoms over time.

“I think our findings really speak to the importance of considering air pollution’s impact on mental health in addition to physical health,” said lead researcher Erika Manczak, PhD, an assistant professor of psychology at the University of Denver.

“Depressive symptoms” according to the study include “persistent feelings of sadness or hopelessness, difficulty with concentration, sleep disturbances and thoughts about suicide.” Interestingly, the association for anxious-depressed symptoms was not as strong as for withdrawn-depressed symptoms.

While the study does not show that air pollution causes depression, only that there is a link, one possible explanation is that both ozone and other contaminants can cause inflammation in the body, and inflammation is correlated with depression. It’s also possible that adolescents are more susceptible to the impacts of pollution because they spend more time outdoors, or perhaps pollution affects teen bodies differently.

Alarmingly, while researchers found that some neighborhoods (they used data related to census tracts) had higher ozone levels than others, none of them were over the National Ambient Air Quality Standard limit (.07ppm). In other words, even otherwise non-hazardous air conditions affected teen mental health.

“It was surprising that the average level of ozone was fairly low even in the communities with relatively higher ozone exposure,” Manczak said. “This really underscores the fact that even low levels of ozone exposure have potentially harmful effects.”

It’s important to note that while this study was corrected for sex, age, race, household income, parental education, and socioeconomic standing, it’s still a relatively small study that took place in one city. Larger studies that are less regional will need to be conducted before we can more clearly understand the link between air quality and teen mental health.

What can we do now to fight against the issue?

The authors suggested that communities consider moving youth sporting events indoors on days with poor air quality, or to limit driving during peak hours. While those suggestions might be the most realistic to implement on an individual level, they put a band-aid on the large issue of air pollution, which is tied to systematic, political, and societal issues on a much grander scale.