Long-term exposure to air pollution and incidence of mental disorders. A large longitudinal cohort study of adults within an urban area

Federica Nobile; Anna Forastiere; Paola Michelozzi; Francesco Forastiere; Massimo Stafoggia

doi:10.1016/j.envint.2023.108302

Long-term exposure to air pollution and incidence of mental disorders. A large longitudinal cohort study of adults within an urban area

Environ Int. 2023 Nov:181:108302. doi: 10.1016/j.envint.2023.108302. Epub 2023 Nov 4.

Authors

Federica Nobile¹, Anna Forastiere², Paola Michelozzi³, Francesco Forastiere⁴, Massimo Stafoggia³

Affiliations

¹ Department of Epidemiology, Lazio Region Health Service/ASL Rome 1, Rome, Italy. Electronic address: f.nobile@deplazio.it.
² Department of Mental Health, ASL Rieti, Italy.
³ Department of Epidemiology, Lazio Region Health Service/ASL Rome 1, Rome, Italy.
⁴ Environmental Research Group, Imperial College, London, UK; National Research Council, IFT, Palermo, Italy.

PMID: 37944432
DOI: 10.1016/j.envint.2023.108302

Abstract

Background: Recent epidemiological evidence suggests associations between air pollution exposure and major depressive disorders, but the literature is inconsistent for other mental illnesses. We investigated the associations of several air pollutants and road traffic noise with the incidence of different categories of mental disorders in a large population-based cohort.

Methods: We enrolled 1,739,277 individuals 30 + years from the 2011 census in Rome, Italy, and followed them up until 2019. In detail, we analyzed 1,733,331 participants (mean age 56.43 +/- 15.85 years; 54.96 % female) with complete information on covariates of interest. We excluded subjects with prevalent mental disorders at baseline to evaluate the incidence (first hospitalization or co-pay exemption) of schizophrenia spectrum disorders, bipolar, anxiety, personality, or substance use disorders. In addition, we studied subjects with first prescriptions of antipsychotics, antidepressants, and mood stabilizers. Annual average concentrations of fine particulate matter (PM_2.5), nitrogen dioxide (NO₂), Black Carbon (BC), ultrafine particles (UFP), and road traffic noise were assigned to baseline residential addresses. We applied Cox regression models adjusted for individual and area-level covariates.

Results: Each interquartile range (1.13 µg/m³) increase in PM_2.5 was associated with a hazard ratio (HR) of 1.070 (95 % confidence interval [CI]: 1.017, 1.127) for schizophrenia spectrum disorder, 1.135 (CI: 1.086, 1.186) for depression, 1.097 (CI: 1.030, 1.168) for anxiety disorders. Positive associations were also detected for BC and UFP, and with the three categories of drug prescriptions. Bipolar, personality, and substance use disorders did not show clear associations. The effects were highest in the age group 30-64 years, except for depression.

Conclusions: Long-term exposure to ambient air pollution, especially fine and ultrafine particles, was associated with increased risks of schizophrenia spectrum disorder, depression, and anxiety disorders. The association of the pollutants with the prescriptions of specific drugs increases the credibility of the results.

Keywords: Air pollution; Cohort study; Drug prescription; Mental health; Noise; Psychiatric disorder.

MeSH terms

Adult
Aged
Air Pollutants* / analysis
Air Pollution* / analysis
Cohort Studies
Depressive Disorder, Major*
Environmental Exposure / adverse effects
Environmental Exposure / analysis
Female
Humans
Incidence
Longitudinal Studies
Male
Middle Aged
Particulate Matter / adverse effects
Particulate Matter / analysis
Substance-Related Disorders*

Substances

Air Pollutants
Particulate Matter