Long-term exposure to ambient fine particulate matter originating from traffic and residential wood combustion and the prevalence of depression

Abstract

IntroductionAir pollution has been suggested to be associated with depression. However, current evidence is conflicting, and no study has considered different sources of ambient particulate matter with an aerodynamic diameter below 2.5 µm (PM2.5). We evaluated the associations of long-term exposure to PM2.5 from road traffic and residential wood combustion with the prevalence of depression in the Helsinki region, Finland.MethodsWe conducted a cross-sectional analysis based on the Helsinki Capital Region Environmental Health Survey 2015–2016 (N=5895). Modelled long-term outdoor concentrations of PM2.5 were evaluated using high-resolution emission and dispersion modelling on an urban scale and linked to the home addresses of study participants. The outcome was self-reported doctor-diagnosed or treated depression. We applied logistic regression and calculated the OR for 1 μg/m3 increase in PM2.5, with 95% CI. Models were adjusted for potential confounders, including traffic noise and urban green space.ResultsOf the participants, 377 reported to have been diagnosed or treated for depression by a doctor. Long-term exposure to PM2.5 from road traffic (OR=1.23, 95% CI 0.86 to 1.73; n=5895) or residential wood combustion (OR=0.78, 95% CI 0.43 to 1.41; n=5895) was not associated with the prevalence of depression. The estimates for PM2.5 from road traffic were elevated, but statistically non-significant, for non-smokers (OR=1.38, 95% CI 0.94 to 2.01; n=4716).ConclusionsWe found no convincing evidence of an effect of long-term exposure to PM2.5 from road traffic or residential wood combustion on depression.

The Relationship between Ambient Fine Particulate Matter (PM2.5) Pollution and Depression: An Analysis of Data from 185 Countries

“…The discrepancies between the cross-sectional and longitudinal results in this study suggest the need for a more critical and in-depth analysis of the links between PM 2.5 exposure and depression, as has been pointed out by other researchers in this field [26,71,72]. The study findings also suggest that reductions in PM 2.5 levels over time may reduce the strength of the association between PM 2.5 exposure and depression in some cases.…”

Air pollution and mental health: associations, mechanisms and methods

“…Additionally, 2021 saw further interest in whether the source of air pollutants associated with depressive outcomes mattered in the context of better targeting clean air interventions. Examining household air pollutants large Chinese cohort [39,40], and cross-sectional [41] studies, demonstrated positive associations, and of a handful of cross-sectional studies in other settings some replicated these findings [42,43], with others examining specific elements of biomass-burning including black carbon [44] and bushfire smoke [45].…”

Relationship between socioeconomic status, household solid fuels use, sleep quality and depression in older adults: a cross-sectional study

“…The results of previous studies are inconsistent on the relationship between household solid fuels use and depressive symptoms [11,27,28,43,44]. Possible reasons for the inconsistent ndings on the association between depression and solid fuels maybe they have different methods to identify depression [45,46], different research subjects and different sample sizes.…”

“…Another survey of a total of 4,585 older adults in rural China also showed that those who used solid fuels for cooking were nearly 1.2 times more likely to suffer from depression than those who used clean fuels for cooking [26]. In contrast, a study in the Helsinki region, Finland found no convincing evidence of the effect of long-term exposure to PM2.5 from residential wood combustion on depression [27]. Four European general population cohorts of 70,928 individuals also found no clear evidence for the relationship between air pollution and depressive symptoms [28].…”