Associations between long-term PM2.5 and ozone exposure and mortality in the Canadian Census Health and Environment Cohort (CANCHEC), by spatial synoptic classification zone

Abstract

Studies suggest that long-term chronic exposure to fine particulate matter air pollution can increase lung cancer mortality. We analyzed the association between long term PM and ozone exposure and mortality due to lung cancer, ischemic heart disease, and chronic obstructive pulmonary disease, accounting for geographic location, socioeconomic status, and residential mobility. Subjects in the 1991 Canadian Census Health and Environment Cohort (CanCHEC) were followed for 20years, and assigned to regions across Canada based on spatial synoptic classification weather types. Hazard ratios (HR) for mortality, were related to PM and ozone using Cox proportional hazards survival models, adjusting for socioeconomic characteristics and individual confounders. An increase of 10μg/m in long term PM exposure resulted in an HR for lung cancer mortality of 1.26 (95% CI 1.04, 1.53); the inclusion in the model of SSC zone as a stratum increased the risk estimate to HR 1.29 (95% CI 1.06, 1.57). After adjusting for ozone, HRs increased to 1.49 (95% CI 1.23, 1.88), and HR 1.54 (95% CI 1.27, 1.87), with and without zone as a model stratum. HRs for ischemic heart disease fell from 1.25 (95% CI 1.21, 1.29) for exposure to PM, to 1.13 (95% CI 1.08, 1.19) when PM was adjusted for ozone. For COPD, the 95% confidence limits included 1.0 when climate zone was included in the model. HRs for all causes of death showed spatial differences when compared to zone 3, the most populated climate zone. Exposure to PM was related to an increased risk of mortality from lung cancer, and both ozone and PM exposure were related to risk of mortality from ischemic heart disease, and the risk varied spatially by climate zone.

Long-term exposure to NO2 and O3 and all-cause and respiratory mortality: A systematic review and meta-analysis

“…Twelve studies ( Crouse et al, 2015a , Lipsett et al, 2011 , Weichenthal et al, 2017 , Turner et al, 2016 , Lipfert et al, 2006 , Lipfert et al, 2006 , Bentayeb et al, 2015 , Cakmak et al, 2018 , Di et al, 2017 , Krewski et al, 2009 , Smith et al, 2009 , Cakmak et al, 2016 ) reported the association between warm season O 3 exposure and all-cause mortality. Seven studies ( Lipsett et al, 2011 , Weichenthal et al, 2017 , Turner et al, 2016 , Lipfert et al, 2006 , Bentayeb et al, 2015 , Cakmak et al, 2018 , Di et al, 2017 ) with most recent cohort results were included for pooled analysis ( Table 3 a). Meta-analysis result showed that a 10 μg/m 3 increase in O 3 exposure was associated with a RR of 1.01 (1.00, 1.02) per 10 μg/m 3 for all-cause mortality although the heterogeneity was high among studies (I 2 = 98%) ( Fig.…”

“…Only two studies reported the warm season O 3 exposure with COPD mortality ( Table 3 c). Turner 2016 ( Turner et al, 2016 ) showed that increased O 3 exposure was associated with higher risk of COPD mortality, while Cakmak 2018 ( Cakmak et al, 2018 ) found no significant association between O 3 exposure and COPD mortality.…”

Epidemiology and Survival Outcomes of Lung Cancer: A Population-Based Study

“…Indoor and outdoor air pollution has been deemed as a significant contributor for lung cancer, especially for lung adenocarcinoma and female patients; additionally, it might play a role in the observed urban-rural disparity of lung cancer in Taiwan [26]. e exposure-response relationship was demonstrated by several large cohorts where each 10 μg/ m 3 increase in the ambient PM 2.5 concentration was correlated with an increased risk of lung adenocarcinoma (hazard ratio 1.31; 95% CI � 0.87-1.97) in nonsmokers and an additional 15-27% risk of lung cancer mortality in lifelong never-smokers [26][27][28]. Former smokers had an additional risk of lung cancer in association with outdoor particular matter exposure compared with never-smokers [29].…”

Pollution and respiratory disease: can diet or supplements help? A review

“…Long-term exposure has been linked to premature respiratory mortality in adults [ 69 ] and to increased risk of death in susceptible populations with chronic cardiopulmonary diseases and diabetes [ 70 ]. Less evidence is available for an association between ozone and lung cancer, with one Canadian study finding an odds ratio for lung cancer incidence of 1.09 (0.85–1.39) with a 10-U increase in ozone [ 71 ] and another Canadian study found ozone was a non-significant contributor to lung cancer mortality [ 72 ].…”