title: An integrated risk function for estimating the global burden of disease attributable to ambient fine particulate matter exposure.
abstract: BACKGROUND
  Estimating the burden of disease attributable to long-term exposure to fine particulate matter (PM2.5) in ambient air requires knowledge of both the shape and magnitude of the relative risk (RR) function. However, adequate direct evidence to identify the shape of the mortality RR functions at the high ambient concentrations observed in many places in the world is lacking.
  
  
  OBJECTIVE
  We developed RR functions over the entire global exposure range for causes of mortality in adults: ischemic heart disease (IHD), cerebrovascular disease (stroke), chronic obstructive pulmonary disease (COPD), and lung cancer (LC). We also developed RR functions for the incidence of acute lower respiratory infection (ALRI) that can be used to estimate mortality and lost-years of healthy life in children < 5 years of age.
  
  
  METHODS
  We fit an integrated exposure-response (IER) model by integrating available RR information from studies of ambient air pollution (AAP), second hand tobacco smoke, household solid cooking fuel, and active smoking (AS). AS exposures were converted to estimated annual PM2.5 exposure equivalents using inhaled doses of particle mass. We derived population attributable fractions (PAFs) for every country based on estimated worldwide ambient PM2.5 concentrations.
  
  
  RESULTS
  The IER model was a superior predictor of RR compared with seven other forms previously used in burden assessments. The percent PAF attributable to AAP exposure varied among countries from 2 to 41 for IHD, 1 to 43 for stroke, < 1 to 21 for COPD, < 1 to 25 for LC, and < 1 to 38 for ALRI.
  
  
  CONCLUSIONS
  We developed a fine particulate mass-based RR model that covered the global range of exposure by integrating RR information from different combustion types that generate emissions of particulate matter. The model can be updated as new RR information becomes available.
authors: Health Canada, Ottawa, Ontario, Canada.
authors: Richard T
authors: RT
authors: Burnett
authors: C Arden
authors: CA
authors: Pope
authors: Majid
authors: M
authors: Ezzati
authors: Casey
authors: C
authors: Olives
authors: Stephen S
authors: SS
authors: Lim
authors: Sumi
authors: S
authors: Mehta
authors: Hwashin H
authors: HH
authors: Shin
authors: Gitanjali
authors: G
authors: Singh
authors: Bryan
authors: B
authors: Hubbell
authors: Michael
authors: M
authors: Brauer
authors: H Ross
authors: HR
authors: Anderson
authors: Kirk R
authors: KR
authors: Smith
authors: John R
authors: JR
authors: Balmes
authors: Nigel G
authors: NG
authors: Bruce
authors: Haidong
authors: H
authors: Kan
authors: Francine
authors: F
authors: Laden
authors: Annette
authors: A
authors: Prüss-Ustün
authors: Michelle C
authors: MC
authors: Turner
authors: Susan M
authors: SM
authors: Gapstur
authors: W Ryan
authors: WR
authors: Diver
authors: Aaron
authors: A
authors: Cohen
mesh_terms: D017281:Cost of Illness; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D052638:Particulate Matter / Q000633:toxicity*
chemical_list: D052638:Particulate Matter