Self-rated stress, distress, mental health, and health as modifiers of the association between long-term exposure to ambient pollutants and mortality
- DOI
- Language of the publication
- English
- Date
- 2020-08-15
- Type
- Article
- Author(s)
- Thomson, Errol M.
- Christidis, Tanya
- Pinault, Lauren
- Michael Tjepkema, Michael
- Colman, Ian
- Crouse, Daniel L.
- van Donkelaar, Aaron
- Martin, Randall V.
- Hystad, Perry
- Alain Robichaud, Alain
- Ménard, Richard
- Brook, Jeffrey R.
- Burnett, Richard T.
- Publisher
- Elsevier
Abstract
Background Individual and neighbourhood-scale socioeconomic characteristics modify associations between exposure to air pollution and mortality. The role of stress, which may integrate effects of social and environmental exposures on health, is unknown. We examined whether an individual's perspective on their own well-being, as assessed using self-rated measures of stress and health, modifies the pollutant-mortality relationship. Methods The Canadian Community Health Survey (CCHS)-mortality cohort includes respondents from surveys administered between 2001 and 2012 linked to vital statistics and postal codes from 1981 until 2016. Annual fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) exposure estimates were attached to a sample of cohort members aged 30–89 years (n = 398,300 respondents/3,848,400 person-years). We examined whether self-rated stress, distress, mental health, and general health modified associations between long-term exposure to each pollutant (three-year moving average with one-year lag) and non-accidental mortality using Cox survival models, adjusted for individual- (i.e. socioeconomic and behavioural) and neighbourhood-scale covariates. Results In fully-adjusted models, the relationship between exposure to pollutants and mortality was stronger among those with poor self-rated mental health, including a significant difference for NO2 (hazard ratio (HR) = 1.15, 95% CI 1.06–1.25 per IQR) compared to those with very good/excellent mental health (HR = 1.05, 95% CI 1.01–1.08; Cochran's Q = 4.01; p < 0.05). Poor self-rated health was similarly associated with higher pollutant-associated HRs, but only in unadjusted models. Stress and distress did not modify pollutant-mortality associations. Conclusions Poor self-rated mental and general health were associated with increased mortality attributed to exposure to ambient pollutants.
Plain language summary
Health Canada conducts studies that investigate factors underlying the health impacts of air pollutants. In the present study, Health Canada, Statistics Canada, and academic collaborators investigated whether people who said their lives were stressful, or who said their health or mental health was poor, were more at risk of dying from air pollution exposure. They found that the relationship between exposure to air pollution and mortality was stronger for individuals who said their mental health was poor compared to those who said it was good. The study provides insight into individual characteristics that contribute to susceptibility to air pollutants. Study results will help identify vulnerable populations and inform risk mitigation strategies.
Subject
- Health,
- Health and safety