Air pollution, airway inflammation, and lung function in a cohort study of Mexico City schoolchildren

Environ Health Perspect. 2008 Jun;116(6):832-8. doi: 10.1289/ehp.10926.


Background: The biological mechanisms involved in inflammatory response to air pollution are not clearly understood.

Objective: In this study we assessed the association of short-term air pollutant exposure with inflammatory markers and lung function.

Methods: We studied a cohort of 158 asthmatic and 50 nonasthmatic school-age children, followed an average of 22 weeks. We conducted spirometric tests, measurements of fractional exhaled nitric oxide (Fe(NO)), interleukin-8 (IL-8) in nasal lavage, and pH of exhaled breath condensate every 15 days during follow-up. Data were analyzed using linear mixed-effects models.

Results: An increase of 17.5 microg/m(3) in the 8-hr moving average of PM(2.5) levels (interquartile range) was associated with a 1.08-ppb increase in Fe(NO) [95% confidence interval (CI), 1.01-1.16] and a 1.07-pg/mL increase in IL-8 (95% CI 0.98-1.19) in asthmatic children and a 1.16 pg/ml increase in IL-8 (95% CI, 1.00-1.36) in nonasthmatic children. The 5-day accumulated average of exposure to particulate matter <2.5 microm in aerodynamic diamter (PM(2.5)) was significantly inversely associated with forced expiratory volume in 1 sec (FEV(1)) (p=0.048) and forced vital capacity (FVC) (p=0.012) in asthmatic children and with FVC (p=0.021) in nonasthmatic children. Fe(NO) and FEV(1) were inversely associated (p=0.005) in asthmatic children.

Conclusions: Exposure to PM(2.5) resulted in acute airway inflammation and decrease in lung function in both asthmatic and nonasthmatic children.

Keywords: air pollution; airway inflammation; asthma; epidemiology; lung function; schoolchildren.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Pollution / adverse effects
  • Air Pollution / analysis*
  • Algorithms
  • Asthma / etiology
  • Asthma / physiopathology*
  • Child
  • Cities
  • Cohort Studies
  • Environmental Exposure / adverse effects
  • Environmental Exposure / analysis*
  • Female
  • Geography
  • Humans
  • Interleukin-10 / analysis
  • Interleukin-6 / analysis
  • Male
  • Mexico
  • Nasal Lavage Fluid / chemistry
  • Nitric Oxide / analysis
  • Respiratory Function Tests
  • Schools


  • Interleukin-6
  • Interleukin-10
  • Nitric Oxide