Risk estimates of mortality attributed to low concentrations of ambient fine particulate matter in the Canadian community health survey cohort

Environmental Health

Research

Scott Weichenthal¹  Aaron van Donkelaar²  Randall V. Martin³  Richard T. Burnett⁴  Michael Brauer⁵  Lauren Pinault⁶  Michael Tjepkema⁶  Daniel L. Crouse⁷  Hong Chen⁸ 

[1] Air Health Effects Science Division, Health Canada, 269 Laurier Avenue West, K1A 0K9, Ottawa, ON, Canada;Department of Physics and Atmospheric Science, Dalhousie University, 6310 Coburg Road, Halifax, NS, Canada;Department of Physics and Atmospheric Science, Dalhousie University, 6310 Coburg Road, Halifax, NS, Canada;Harvard-Smithsonian Center for Astrophysics, 60 Garden St, 02138, Cambridge, MA, USA;Environmental Health Science and Research Bureau, Health Canada, 50 Columbine Driveway, Ottawa, ON, Canada;Faculty of Medicine/School of Population and Public Health, University of British Columbia, 2206 East Mall, V6T 1Z3, Vancouver, BC, Canada;Health Analysis Division, Statistics Canada, 100 Tunney’s Pasture Driveway, K1A 0T6, Ottawa, ON, Canada;New Brunswick Institute for Research, Data, and Training (NB-IRDT) and Department of Sociology, University of New Brunswick, PO Box 4400, E3B 5A3, Fredericton, NB, Canada;Public Health Ontario, Suite 300, 480 University Avenue, M5G 1V2, Toronto, ON, Canada;

关键词: PM;    Fine particulate matter;    Air pollution;    Cardiovascular mortality;    Respiratory mortality;   

DOI  :  10.1186/s12940-016-0111-6

 received in 2015-10-30, accepted in 2016-01-28,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundUnderstanding the shape of the relationship between long-term exposure to ambient fine particulate matter (PM2.5) concentrations and health risks is critical for health impact and risk assessment. Studies evaluating the health risks of exposure to low concentrations of PM2.5 are limited. Further, many existing studies lack individual-level information on potentially important behavioural confounding factors.MethodsA prospective cohort study was conducted among a subset of participants in a cohort that linked respondents of the Canadian Community Health Survey to mortality (n = 299,500) with satellite-derived ambient PM2.5 estimates. Participants enrolled between 2000 and 2008 were followed to date of death or December 31, 2011. Cox proportional hazards models were used to estimate hazard ratios (HRs) for mortality attributed to PM2.5 exposure, adjusted for individual-level and contextual covariates, including smoking behaviour and body mass index (BMI).ResultsApproximately 26,300 non-accidental deaths, of which 32.5 % were due to circulatory disease and 9.1 % were due to respiratory disease, occurred during the follow-up period. Ambient PM2.5 exposures were relatively low (mean = 6.3 μg/m3), yet each 10 μg/m3 increase in exposure was associated with increased risks of non-accidental (HR = 1.26; 95 % CI: 1.19-1.34), circulatory disease (HR = 1.19; 95 % CI: 1.07–1.31), and respiratory disease mortality (HR = 1.52; 95 % CI: 1.26–1.84) in fully adjusted models. Higher hazard ratios were observed for respiratory mortality among respondents who never smoked (HR = 1.97; 95 % CI: 1.24–3.13 vs. HR = 1.45; 95 % CI: 1.17–1.79 for ever smokers), and among obese (BMI ≥ 30) respondents (HR = 1.76; 95 % CI: 1.15-2.69 vs. HR = 1.41; 95 % CI: 1.04–1.91 for normal weight respondents), though differences between groups were not statistically significant. A threshold analysis for non-accidental mortality estimated a threshold concentration of 0 μg/m3 (+95 % CI = 4.5 μg/m3).ConclusionsIncreased risks of non-accidental, circulatory, and respiratory mortality were observed even at very low concentrations of ambient PM2.5. HRs were generally greater than most literature values, and adjusting for behavioural covariates served to reduce HR estimates slightly.

【 授权许可】

CC BY   
© Pinault et al. 2016