title: A reanalysis of fine particulate matter air pollution versus life expectancy in the United States.
abstract: A reduction in population exposure to fine particulate matter air pollution (PM2.5) has been associated with improvements in life expectancy. This article presents a reanalysis of this relationship and comments on the results from a study on the reduction of ambient air PM2.5 concentrations versus life expectancy in metropolitan areas of the United States. The results of the reanalysis show that the statistical significance of the correlation is lost after removing one of the metropolitan areas from the regression analysis, suggesting that the results may not be suitable for a meaningful and reliable inference.
  
  
  CONCLUSIONS
  The observed loss of statistical significance in the correlation between the reduction of ambient air PM2.5 concentrations and life expectancy in metropolitan areas of the United States, after removing one of the metropolitan areas from the regression analysis, may raise concern for the policymakers in decisions regarding further reductions in permitted levels of air pollution emissions.
authors.affiliation: Fraser Health, Environmental Health Services, New Westminster, British Columbia, Canada. Goran.Krstic@fraserhealth.ca
authors.forename: Goran
authors.initials: G
authors.lastname: Krstić
mesh_terms: D000397:Air Pollution / Q000706:statistics & numerical data*; D002947:Cities; D006801:Humans; D008017:Life Expectancy / Q000639:trends*; D052638:Particulate Matter; D014481:United States
chemical_list: D052638:Particulate Matter