Personal exposures to traffic-related air pollution and acute respiratory health among Bronx schoolchildren with asthma

Environ Health Perspect. 2011 Apr;119(4):559-65. doi: 10.1289/ehp.1002653. Epub 2011 Jan 7.


Background: Previous studies have reported relationships between adverse respiratory health outcomes and residential proximity to traffic pollution, but have not shown this at a personal exposure level.

Objective: We compared, among inner-city children with asthma, the associations of adverse asthma outcome incidences with increased personal exposure to particulate matter mass ≤ 2.5 μm in aerodynamic diameter (PM(2.5)) air pollution versus the diesel-related carbonaceous fraction of PM2.5.

Methods: Daily 24-hr personal samples of PM(2.5), including the elemental carbon (EC) fraction, were collected for 40 fifth-grade children with asthma at four South Bronx schools (10 children per school) during approximately 1 month each. Spirometry and symptom scores were recorded several times daily during weekdays.

Results: We found elevated same-day relative risks of wheeze [1.45; 95% confidence interval (CI), 1.03-2.04)], shortness of breath (1.41; 95% CI, 1.01-1.99), and total symptoms (1.30; 95% CI, 1.04-1.62) with an increase in personal EC, but not with personal PM(2.5) mass. We found increased risk of cough, wheeze, and total symptoms with increased 1-day lag and 2-day average personal and school-site EC. We found no significant associations with school-site PM(2.5) mass or sulfur. The EC effect estimate was robust to addition of gaseous pollutants.

Conclusion: Adverse health associations were strongest with personal measures of EC exposure, suggesting that the diesel "soot" fraction of PM(2.5) is most responsible for pollution-related asthma exacerbations among children living near roadways. Studies that rely on exposure to PM mass may underestimate PM health impacts.

Publication types

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

MeSH terms

  • Air Pollution / statistics & numerical data*
  • Aircraft / statistics & numerical data*
  • Asthma / epidemiology*
  • Asthma / physiopathology
  • Child
  • Environmental Monitoring
  • Epidemiological Monitoring
  • Female
  • Humans
  • Inhalation Exposure / analysis
  • Inhalation Exposure / statistics & numerical data*
  • Male
  • New York City / epidemiology
  • Particle Size
  • Particulate Matter / analysis
  • Particulate Matter / toxicity
  • Vehicle Emissions / analysis*
  • Vehicle Emissions / toxicity


  • Particulate Matter
  • Vehicle Emissions