Long-term ozone exposure and mortality from neurological diseases in Canada
- DOI
- Language of the publication
- English
- Date
- 2021-08-09
- Type
- Article
- Author(s)
- Zhao, Naizhuo
- Pinault, Lauren
- Toyib, Olaniyan
- Vanos, Jennifer
- Tjepkema, Michael
- Çakmak, Sabit
- Publisher
- ScienceDirect
Abstract
Abstract Background There is increasing interest in the health effects of air pollution. However, the relationships between ozone exposure and mortality attributable to neurological diseases remain unclear. Objectives To assess associations of long-term exposure to ozone with death from Parkinson’s disease, dementia, stroke, and multiple sclerosis. Methods Our analyses were based on the 2001 Canadian Census Health and Environment Cohort. Census participants were linked with vital statistics records through 2016, resulting in a cohort of 3.5 million adults/51,045,700 person-years, with 8,500/51,300/43,300/1,300 deaths from Parkinson’s/dementia/stroke/multiple sclerosis, respectively. Ten-year average ozone concentrations estimated by chemical transport models and adjusted by ground measurements were assigned to subjects based on postal codes. Cox proportional hazards models were used to calculate hazard ratios (HRs) for deaths from the four neurological diseases, adjusting for eight common demographic and socioeconomic factors, seven environmental indexes, and six contextual covariates. Results The fully adjusted HRs for Parkinson’s, dementia, stroke, and multiple sclerosis mortalities related to one interquartile range increase in ozone (10.1 ppb), were 1.09 (95% confidence interval 1.04–1.14), 1.08 (1.06–1.10), 1.06 (1.04–1.09), and 1.35 (1.20–1.51), respectively. The covariates did not influence significance of the ozone-mortality associations, except airshed (i.e., broad region of Canada). During the period of 2001–2016, 5.66%/5.01%/ 3.77%/19.11% of deaths from Parkinson’s/dementia/stroke/multiple sclerosis, respectively, were attributable to ozone exposure. Conclusions We found positive associations between ozone exposure and mortality due to Parkinson’s, dementia, stroke, and multiple sclerosis.
Plain language summary
Under the Addressing Air Pollution Horizontal Initiative (AAPHI), Health Canada conducts scientific research to evaluate the health risks of environmental factors, such as ambient air pollution. There is evidence that ambient air pollution can adversely affect health outcomes. Increasing evidence is available for an association between long-term ozone exposure, Parkinson’s disease, dementia, stroke, and multiple sclerosis mortality, although uncertainties remain around the strength of the causal link, due to difficulties accounting for the effect of smoking, changes in exposure over time, differences in the ambient pollution mix in different areas, and the long time period required for development of Parkinson’s disease, dementia, stroke, and multiple sclerosis. This study looks at the relationship between long-term ozone exposure and their association with Parkinson’s disease, dementia, stroke, and multiple sclerosis mortality in the Canadian Census Health and Environment Cohort (CanCHEC). These effects differ by air-shed. Ten-year average ozone concentrations estimated by chemical transport models and adjusted by ground measurements were assigned to subjects based on postal codes. Cox proportional hazards models were used to calculate hazard ratios (HRs) for deaths from the four neurological diseases, adjusting for eight common demographic and socioeconomic factors, seven environmental indexes, and six contextual covariates. The results suggest that exposure to higher ozone was associated with increased mortality risk from Parkinson’s disease, dementia, stroke, and multiple sclerosis. The results from this study will further enhance our understanding of human health risk associated with exposure to high ozone levels and may also be used in the development of Canadian Ambient Air Quality Standards.
Subject
- Health,
- Health and safety