Multi-pollutant urban study on acute respiratory hospitalization and mortality attributable to ambient air pollution in Canada for 2001–2012
- DOI
- Language of the publication
- English
- Date
- 2021-10-19
- Type
- Article
- Author(s)
- Parajuli, Rajendra P.
- Shin, Hwashin H.
- Maquiling, Aubrey
- Smith-Doiron, Marc
- Publisher
- Elsevier
Abstract
Humans inhale a mixture of various air pollutants, and there is ambiguity whether these pollutants act independently or in an additive, synergistic, or antagonistic manner. We aimed to examine differences in adverse health effects of short-term exposure to air pollution through single-versus multi-pollutant models. We collected daily ambient air pollutants (O3, NO2 and PM2.5) concentrations from 24 Canadian urban centers from 2001 to 2012. We examined between-pollutant correlations and estimated their associations with respiratory hospitalization and mortality. We applied a generalized quasi-Poisson model to each city adjusting for one and/or two pollutants. Then we employed a Bayesian hierarchical model to pool the city-specific estimates for national estimates. We also examined 0- to 6-day air pollutant lagged effects by season. Overall, we found more frequently significant effects from single-pollutant models (vs. multi-pollutant models), for hospitalization (vs. mortality), for O3 (vs. NO2, PM2.5), for warm (vs. cold) season, and for lags ≤2 days (vs. 3–6 days). The most consistent effects appeared on respiratory hospitalization for 1-day lagged O3 and PM2.5, but not NO2. This study found little additive or antagonistic risk of respiratory health outcomes from multi-pollutant models due to low-to-medium correlations among the specified air pollutants.
Plain language summary
Adverse health effects from outdoor air pollution have been a growing concern for decades. Hospitalization and mortality are two important indicators of population health, and have been linked to air pollution exposures. However, there has been a question of whether these pollutants act independently or in an additive or antagonistic manner. This study aimed to examine differences in adverse health effects of short-term exposure to air pollution through single versus multi-pollutant models for ground-level ozone (O3), nitrogen dioxide (NO2) and fine particulate matter (PM2.5). In particular, we examined correlations between pollutants and estimated their associations with daily lung-related respiratory hospitalization and mortality, respectively, by season (warm versus cold) for 12 years (2001-2012). Overall, for hospitalization than mortality, more significant effects were found from single-pollutant models than multi-pollutant models, for O3 than NO2 and PM2.5, for warm than cold season, and for lags ≤ 2 days than 3-6 day lags. The most consistent effects over different models appeared on respiratory hospitalization for 1-day lagged O3 and PM2.5, but not NO2. This study found little additive or antagonistic risk of respiratory health outcomes from multi-pollutant models due to relatively low correlations among the specified air pollutants. To understand better if the multi-pollutants act independently or in an additive, synergistic, or antagonistic manner, further studies are necessary.
Subject
- Health,
- Health and safety