Long-term Exposure to Multiple Ambient Air Pollutants and Association With Incident Depression and Anxiety

Abstract

ImportanceAir pollution is increasingly recognized as an important environmental risk factor for mental health. However, epidemiologic evidence on long-term exposure to low levels of air pollutants with incident depression and anxiety is still very limited.ObjectivesTo investigate the association of long-term joint exposure to multiple air pollutants with incident depression and anxiety.Design, Setting, and ParticipantsThis prospective, population-based cohort study used data from the UK Biobank. The participants were recruited between March 13, 2006, and October 1, 2010, and included individuals who had never been diagnosed with depression or anxiety at baseline and had full information on exposure and covariates. Data were analyzed from May 1 to October 10, 2022.ExposuresAnnual mean air pollution concentrations of particulate matter (PM) with aerodynamic diameter of 2.5 μm or less (PM2.5) and PM with aerodynamic diameter between 2.5 μm and 10 μm (PM2.5-10). Nitrogen dioxide (NO2) and nitric oxide (NO) were estimated for each participant’s residential address using the land use regression model, and joint exposure to air pollution reflected by air pollution score was calculated by principal components analysis.Main Outcomes and MeasuresIncidence of diagnosed depression (F32-F33) and anxiety (F40-F48) were ascertained with International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes.ResultsDuring a median (IQR) follow-up of 10.9 (10.1-11.6) years, among 389 185 participants (mean [SD] age, 56.7 [8.1] years, 205 855 female individuals [52.9%]), a total of 13 131 and 15 835 patients were diagnosed with depression and anxiety, respectively. The median (IQR) concentration of pollutants was as follows: PM2.5, 9.9 (9.3-10.6) μg/m3; PM2.5-10, 6.1 (5.8-6.6) μg/m3; NO2, 26.0 (21.3-31.1) μg/m3; and NO, 15.9 (11.6-20.6) μg/m3. Long-term estimated exposure to multiple air pollutants was associated with increased risk of depression and anxiety, and the exposure-response curves were nonlinear, with steeper slopes at lower concentrations and plateauing trends at higher exposure. The hazard ratios (HRs) and 95% CIs for depression and anxiety were 1.16 (95% CI, 1.09-1.23; P < .001) and 1.11 (95% CI, 1.05-1.17; P < .001) in the highest quartile compared with the lowest quartile of air pollution score, respectively. Similar trends were shown for PM2.5, NO2, and NO. Subgroup analysis showed the association between PM2.5 and anxiety tended to be higher in male individuals than in female individuals (quartile 4: male individuals, 1.18; 95% CI, 1.08-1.29; female individuals, 1.07; 95% CI, 1.00-1.14; P = .009).Conclusions and RelevanceStudy results suggest that estimates of long-term exposure to multiple air pollutants was associated with increased risk of depression and anxiety. The nonlinear associations may have important implications for policy making in air pollution control. Reductions in joint exposure to multiple air pollutants may alleviate the disease burden of depression and anxiety.

Particulate matter exposure may increase the risk of irritable bowel syndrome: a large-scale prospective study based on the UK Biobank

“…Similar studies using the cohort of UK Biobank also failed to observe a statistically significant association between long-term PM 2.5-10 exposure and health outcomes including heart failure, depression, and anxiety. 31,32 Moreover, a smaller aerodynamic diameter of PM has a larger specific surface area and could adsorb more hazardous components including black carbon, heavy metals, and polycyclic aromatic hydrocarbons, 33 which may contribute to the different health impacts of PM 2.5 and PM 10 . Further investigations on the impact of smaller PM, including PM with an aerodynamic diameter of 1 μm or less (PM 1 ) and ultrafine particulate matter (UFP), on IBS is indispensable and the potential association remains to be revealed.…”

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“…These research designs provided another angle to causally identify the effect of air pollution on mental health, improving our understanding of the impact of air pollution 18. Air pollution-related mental health is a complex and interdisciplinary topic, and developments in measurement, data collection and research methodology vary across disciplines, potentially leading to differing and even conflicting conclusions 19–22. Therefore, systematic consideration of a broad range of mental health determinants from multiple disciplines is essential for conducting a comprehensive analysis of the evidence and bridge disciplinary divides.…”

“…Research on air pollution and mental health takes place across various disciplines, representing a fragmented landscape of niche discourses that hinders efforts to synthesise key insights and identify trends and evidence gaps 19 20 25 26. Exponentially increasing literature makes traditional evidence synthesis methods that require considerable human resources no longer sufficient or feasible.…”

Association of Antepartum and Postpartum Air Pollution Exposure With Postpartum Depression in Southern California

“…Growing epidemiologic evidence has shown a link between air pollution and mental health disorders among the general population . However, few studies have examined the association between air pollution exposure and PPD, and these studies have reported inconsistent findings .…”

“…7,8,[10][11][12][13] Growing epidemiologic evidence has shown a link between air pollution and mental health disorders among the general population. [14][15][16] However, few studies have examined the association between air pollution exposure and PPD, and these studies have reported inconsistent findings. 4,[17][18][19] Inconclusive results may be partially due to differences in study populations, sample sizes, methods of outcome assessments, exposure windows, and study regions with different levels and compositions of particulate matter less than or equal to 2.5 μm (PM 2.5 ).…”