Ozone Exposure (Outdoor-Indoor-Personal) and Mental Health in Young Adults.

The prevalence of anxiety symptoms, depressive symptoms, and sleep disturbance among young adult participants was 14%, 19%, and 39%, respectively.

• Study included 13,028 participants from a nationwide cross-sectional survey conducted in 2023-2024.
• Survey spanned 261 Chinese municipalities.
• Anxiety symptoms were assessed using GAD-7, depressive symptoms using PHQ-9, and sleep quality using PSQI.
• Participants were young adults.

Higher outdoor ozone exposure was associated with increased odds of anxiety and depressive symptoms.

• Per interquartile range increase in outdoor ozone concentration, the odds ratio for anxiety symptoms was 1.17.
• Per interquartile range increase in outdoor ozone concentration, the odds ratio for depressive symptoms was 1.14.
• Annual maximum 8-hour ozone concentrations over the preceding year were used as the exposure metric.
• Estimates were adjusted for sociodemographic, behavioral, and health condition covariates using multivariable logistic regression.

Higher indoor ozone exposure was associated with increased odds of anxiety and depressive symptoms.

• Per interquartile range increase in indoor ozone concentration, the odds ratio for anxiety symptoms was 1.19.
• Per interquartile range increase in indoor ozone concentration, the odds ratio for depressive symptoms was 1.13.
• Associations with indoor exposure were modestly different from those with outdoor exposure.
• Indoor ozone concentrations were estimated at the indoor exposure level based on annual maximum 8-hour concentrations.

Higher personal ozone exposure was associated with increased odds of anxiety and depressive symptoms.

• Per interquartile range increase in personal ozone concentration, the odds ratio for anxiety symptoms was 1.14.
• Per interquartile range increase in personal ozone concentration, the odds ratio for depressive symptoms was 1.10.
• Personal exposure estimates were distinct from ambient measurements and intended to better represent actual individual exposure.
• Associations with personal exposure varied modestly compared to outdoor and indoor metrics.

Sleep quality mediated a significant portion of the associations between ozone exposure and both anxiety and depressive symptoms.

• Sleep quality mediated 10-30% of the association between ozone exposure and anxiety symptoms across outdoor, indoor, and personal exposure metrics.
• Sleep quality mediated 16-49% of the association between ozone exposure and depressive symptoms across outdoor, indoor, and personal exposure metrics.
• Mediation analysis was conducted within a logistic framework.
• Sleep disturbance was assessed using the Pittsburgh Sleep Quality Index (PSQI).
• The mediation proportion was larger for the ozone-depression association than for the ozone-anxiety association.

Associations between ozone and mental health outcomes varied only modestly across outdoor, indoor, and personal exposure metrics.

• Odds ratios for anxiety were 1.17, 1.19, and 1.14 for outdoor, indoor, and personal exposure, respectively.
• Odds ratios for depression were 1.14, 1.13, and 1.10 for outdoor, indoor, and personal exposure, respectively.
• The authors noted that 'associations with anxiety and depressive symptoms varied modestly across outdoor, indoor, and personal ozone exposure.'
• Incorporating indoor and personal exposure metrics was suggested to 'provide additional insight into ozone-related mental health risks.'

The study estimated ozone exposure at three distinct levels—outdoor, indoor, and personal—using annual maximum 8-hour concentrations over the preceding year.

• This approach was used to address the concern that 'reliance on ambient measurements may misrepresent personal exposure.'
• The study was designed as a nationwide cross-sectional survey across 261 Chinese municipalities.
• Survey was conducted during 2023-2024.
• Multivariable logistic regression was used for primary analyses, adjusting for sociodemographic, behavioral, and health condition covariates.