title: A New Method to Jointly Estimate the Mortality Risk of Long-Term Exposure to Fine Particulate Matter and its Components.
abstract: Most studies on the association between exposure to fine particulate matter (PM2.5) and mortality have considered only total concentration of PM2.5 or individual components of PM2.5, and not the combined effects of concentration and particulate composition. We sought to develop a method to estimate the risk of death from long-term exposure to PM2.5 and the distribution of its components, namely: sulphate, nitrate, ammonium, organic mass, black carbon, and mineral dust. We decomposed PM2.5 exposure into the sum of total concentration and the proportion of each component. We estimated the risk of death due to exposure using a cohort of ~2.4 million Canadians who were followed for vital status over 16 years. Modelling the concentration of PM2.5 with the distribution of the proportions of components together was a superior predictor for mortality than either total PM2.5 concentration alone, or all component concentrations modelled together. Our new approach has the advantage of characterizing the toxicity of the atmosphere in its entirety. This is required to fully understand the health benefits associated with strategies to improve air quality that may result in complex changes not only in PM2.5 concentration, but also in the distribution of particle components.
authors.affiliation: Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada.
authors.forename: Dan L
authors.initials: DL
authors.lastname: Crouse
authors.affiliation: Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada.
authors.forename: Sajeev
authors.initials: S
authors.lastname: Philip
authors.affiliation: Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada.
authors.forename: Aaron
authors.initials: A
authors.lastname: van Donkelaar
authors.affiliation: Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada.|Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts.
authors.forename: Randall V
authors.initials: RV
authors.lastname: Martin
authors.affiliation: Air Quality Assessment Section, Safe Environments Directorate, Health Canada, Ottawa, Ontario, Canada.
authors.forename: Barry
authors.initials: B
authors.lastname: Jessiman
authors.affiliation: Department of Sociology, University of New Brunswick, Fredericton, New Brunswick, Canada.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Peters
authors.affiliation: Air Health Science Division, Safe Environments Directorate, Health Canada, Ottawa, Ontario, Canada.
authors.forename: Scott
authors.initials: S
authors.lastname: Weichenthal
authors.affiliation: Air Quality Research Division, Environment Canada, Downsview, Canada.|Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Brook
authors.affiliation: US Environmental Protection Agency, Office of Air Quality Planning and Standards, Research Triangle Park, North Carolina.
authors.forename: Bryan
authors.initials: B
authors.lastname: Hubbell
authors.affiliation: Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada.
authors.forename: Richard T
authors.initials: RT
authors.lastname: Burnett
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000393:Air Pollutants; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis*; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality; D052638:Particulate Matter / Q000009:adverse effects* / Q000032:analysis*; D016016:Proportional Hazards Models; D062486:Public Health Surveillance; D018570:Risk Assessment; D013997:Time Factors
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter