A study, published in the journal 'Developmental Psychology', is the first to link ozone levels to 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. Higher 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 depressionsymptoms in adolescents over time. Those symptoms may include persistent feelings of sadness or hopelessness, difficulty with concentration, sleep disturbances and thoughts about suicide. "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.
The researchers analysed data from a previous study about early life stress with 213 adolescent participants (aged 9 to 13 years old) in the San Francisco Bay area. The researchers compared data about the adolescents' mental health over a four-year period with Census tracts for their home addresses and air quality data for those tracts from the California Environmental Protection Agency.
Adolescents who lived in areas with relatively higher ozone levels showed significant increases in depressive symptoms over time, even though the ozone levels in their neighbourhoods didn't exceed state or national air quality standards. The findings weren't affected by participants' sex, age, race, household income, parental education or socioeconomic characteristics of their neighbourhoods.