The study, published in the journal Developmental Psychology, is the first to link ozone levels with the development of depression in adolescents over time. Ozone is a gas that is produced when various pollutants from motor vehicle exhaust, power plants and other sources react to sunlight. High ozone levels have been linked to various physical ailments, including asthma, respiratory viruses, and premature death from respiratory causes.
This study explores the link between ozone levels and the development of depression symptoms in adolescents over time. Those symptoms may include persistent feelings of sadness or hopelessness, difficulty concentrating, sleep disturbances, and thoughts about suicide.
“I think our findings really speak to the importance of considering the impact of air pollution on mental health in addition to physical health,” said lead researcher Erika Manzak, PhD, assistant professor of psychology at the University of Denver.
Researchers analyzed data from a previous study about early life stress with 213 adolescent participants (ages 9 to 13) in the San Francisco Bay Area. Researchers compared data about teens’ mental health over a four-year period with census tracts for their home addresses and air quality data for those areas from the California Environmental Protection Agency.
Adolescents living in areas with relatively high ozone levels showed a significant increase in depressive symptoms over time, even when ozone levels in their neighborhood did not exceed state or national air quality standards.
Findings were not affected by participants’ gender, age, race, household income, parental education, or the socioeconomic characteristics of their neighborhood.
“It was surprising that even communities with relatively high ozone exposure had significantly lower average levels of ozone. This really underscores the fact that even low levels of ozone exposure have potentially harmful effects,” Manczak said.
Ozone and other components of air pollution may contribute to high levels of inflammation in the body, which has been linked to the onset and development of depression. Teens may be especially sensitive to these effects because they spend more time outside.
The study included a relatively small sample size from one region of the United States. The findings are correlative so it cannot be proven that ozone levels increased depressive symptoms, only a link between them. It is also possible that other components of air pollution besides ozone may also be a factor.
Because air pollution disproportionately affects marginalized communities, ozone levels can contribute to health inequalities, Manchak said.
Communities should also consider ways to reduce ozone exposure, such as holding youth sporting events indoors when necessary and limiting driving during peak hours of air pollution alerts.
Investing in clean and renewable energy sources that reduce air pollution can also be helpful.
“I believe that state and federal air quality standards should be stricter, and we should have stricter regulations on the industries that contribute to pollution,” Manjak said.
“Our findings and those of other studies suggest that even low levels of ozone exposure can pose potentially serious risks to both physical and mental health,” Manjak concluded.
First published:March 15, 2022, 5:41 pm