Air pollution and acute respiratory infections among children 0-4 years of age: an 18-year time-series study

Am J Epidemiol. 2014 Nov 15;180(10):968-77. doi: 10.1093/aje/kwu234. Epub 2014 Oct 16.


Upper and lower respiratory infections are common in early childhood and may be exacerbated by air pollution. We investigated short-term changes in ambient air pollutant concentrations, including speciated particulate matter less than 2.5 μm in diameter (PM2.5), in relation to emergency department (ED) visits for respiratory infections in young children. Daily counts of ED visits for bronchitis and bronchiolitis (n = 80,399), pneumonia (n = 63,359), and upper respiratory infection (URI) (n = 359,246) among children 0-4 years of age were collected from hospitals in the Atlanta, Georgia, area for the period 1993-2010. Daily pollutant measurements were combined across monitoring stations using population weighting. In Poisson generalized linear models, 3-day moving average concentrations of ozone, nitrogen dioxide, and the organic carbon fraction of particulate matter less than 2.5 μm in diameter (PM2.5) were associated with ED visits for pneumonia and URI. Ozone associations were strongest and were observed at low (cold-season) concentrations; a 1-interquartile range increase predicted a 4% increase (95% confidence interval: 2%, 6%) in visits for URI and an 8% increase (95% confidence interval: 4%, 13%) in visits for pneumonia. Rate ratios tended to be higher in the 1- to 4-year age group compared with infants. Results suggest that primary traffic pollutants, ozone, and the organic carbon fraction of PM2.5 exacerbate upper and lower respiratory infections in early life, and that the carbon fraction of PM2.5 is a particularly harmful component of the ambient particulate matter mixture.

Keywords: air pollution; bronchiolitis; children; lower respiratory infection; pneumonia; upper respiratory infection.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Acute Disease
  • Air Pollution / adverse effects*
  • Antimetabolites / adverse effects
  • Bronchiolitis / chemically induced
  • Bronchitis / chemically induced
  • Carbon Monoxide / adverse effects
  • Child, Preschool
  • Emergency Service, Hospital / statistics & numerical data*
  • Female
  • Georgia
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Nitrogen Dioxide / adverse effects
  • Ozone / adverse effects*
  • Particulate Matter / adverse effects*
  • Pneumonia / chemically induced
  • Respiratory Tract Infections / chemically induced*
  • Respiratory Tract Infections / epidemiology*
  • Retrospective Studies
  • Socioeconomic Factors
  • Time Factors


  • Antimetabolites
  • Particulate Matter
  • Ozone
  • Carbon Monoxide
  • Nitrogen Dioxide