Pollution is widely known to be a risk to individual’s physical health, but can it have adverse effects on mental health as well? A study published in Developmental Psychology suggests that exposure to ozone can be a risk factor for depression in adolescents.
Depression is a highly prevalent mental illness that can occur throughout the lifespan. When depression occurs in childhood, it can lead to negative outcomes, specifically problems with school or social functioning. This can have profound, lasting effects on their lives and cause significant distress. While factors affecting depression in youths has been researched extensively, the effect of physical environment has been largely disregarded. This research seeks to bridge that gap by exploring the effect of living in an area with high ozone exposure, due to ozone’s role as a pollutant.
For their study, lead researcher Erika M. Manczak and colleagues collected data over the course of 3 waves over 4 years, utilizing 213 participants aged 9-13 years old for wave one and collecting data from 125 retained participants in wave 3. Researchers utilized data compiled by the California EPA to ascertain ozone levels and data from the US census to determine poverty levels, residents with less than a high school diploma, and residents who are eligible to work but are unemployed. Participants completed measures on stressful life events, demographics, and mental health.
Results showed that adolescents who lived in areas with higher levels of ozone showed more depressive symptoms than adolescents that lived in areas with lower levels of ozone.
“I think our findings really speak to the importance of considering air pollution’s impact on mental health in addition to physical health,” said Manczak, an assistant professor of psychology at the University of Denver.
This relationship existed even when the ozone levels were lower than the national standard. The association between ozone and depressive symptoms was stronger for withdrawn/depressed symptoms than it was for anxious/depressed symptoms. The relationship between ozone exposure and depression is especially significant for youths and adolescents, as they are a group that tends to spend a lot of time outside.
“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.”
This study took strides into understanding ozone’s potential impact on mental health. Despite this, there are limitations to note. Due to the nature of the data, it is impossible to infer causality from the results. Additionally, adolescence is a time period where many people start experiencing depression for the first time, making it difficult to pinpoint ozone as a major contributing factor. Lastly, this study didn’t account for how much time participants spent outside, which could change their ozone exposure.
“I believe state and federal air quality standards should be stricter, and we should have tighter regulations on industries that contribute to pollution,” Manczak said. “Our findings and other studies suggest that even low levels of ozone exposure can pose potentially serious risks to both physical and mental health.”
The study, “Census Tract Ambient Ozone Predicts Trajectories of Depressive Symptoms in Adolescents“, was authored by Erika M. Manczak, Jonas G. Miller, and Ian H. Gotlib.