It’s in the Air: Neighborhood Ozone Predicts Trajectories of Internalizing Symptoms in Adolescents

• In Event: Multidimensional Effects of Neighborhood Socioeconomic Status and Toxin Exposure Across Development

Abstract

Exposure to ambient ozone is a well-documented risk factor for negative physical health outcomes, such as asthma and cardiovascular disease, but is considered less frequently as a predictor of mental health disorders. Recently, researchers have begun linking ozone to several psychiatric outcomes, such as greater use of antidepressants in communities with higher ozone exposure; however, little work has examined longitudinal associations or considered effects during youth (when individuals may be particularly sensitive to exposures). To address these gaps, we examined whether levels of neighborhood ozone predicted trajectories of internalizing symptoms over a four-year period in adolescents.
In a sample of 213 adolescents (ages 9-13 years at baseline; 57% female; 53% of minority race/ethnicity), participants self-reported internalizing symptoms up to three times across a 4 year-period using the Youth Self Report (YSR), the Children’s Depression Inventory-Short Form (CDI), and a modified version of the Multidimensional Anxiety Scale for Children (MASC). Home addresses were used to extract ambient ozone levels in their census tract using data from the California Environmental Protection Agency’s CalEnviro Report. We included a number of important confounding variables that commonly co-occur with air pollution, including personal, family, and neighborhood characteristics. For example, adolescents who live in areas with higher levels of ozone may also experience more stressful life events or may live in communities with fewer socioeconomic resources. To assess stressful life events, we used a semi-structured interview based on the Traumatic Events Screening Inventory for Children, and coded the severity of reported events using the UCLA Life Stress coding system. To assess neighborhood socioeconomic disadvantage, we used census tract data from the 2015 American Community Survey on rates of poverty, educational obtainment, and unemployment.
Results of growth curve modeling indicated that higher ambient ozone predicted steeper increases in internalizing symptoms across multiple measures of symptoms. For YSR internalizing symptoms, there was not a significant change in symptoms over time for participants living in neighborhoods at the 25th percentile of ozone (slope=.001, SE=.001, t=1.41, p=.139); however, for participants at the 50th and 75th percentiles, there was a significant increase in symptoms over time, with the increase becoming more dramatic at higher levels of ozone (50th percentile slope=.002, SE=.001, t= 2.600, p=.010; 75th percentile slope=.003, SE=.001, t= 3.175, p=.002). Furthermore, these patterns were not accounted for by participant sex, age at baseline, minority status, household income category, number of severe life stressors, or neighborhood disadvantage. Community ozone did not have a statistically significant effect on changes in internalizing symptoms as assessed by the MASC (p=.101).
Together, this work indicates that ozone exposure is an important dimension to consider in understanding the development of youth internalizing disorders, and underscores the importance of reducing air pollution for protecting and improving well-being.

Authors

• Erika Manczak
  Presenting Author

• Jonas G. Miller, Stanford University
  Non-Presenting Author

• Ian Gotlib, Stanford University
  Non-Presenting Author