Airway responses to nitrogen dioxide in asthmatic subjects

J Toxicol Environ Health. 1987;22(4):371-80. doi: 10.1080/15287398709531080.


Nitrogen dioxide is a common indoor air pollutant. In order to characterize the respiratory responses to this gas, 10 asthmatics (mean age +/- SD = 30 +/- 8 yrs) were exposed to air and 0.5 ppm NO2 gas for 1 h in a 30-m3 environmental chamber on different days in a double-blind randomized fashion. The forced vital capacity, (VC), functional residual capacity, forced expiratory volume in 1 s, partial expiratory flow at 40% VC (Vp 40), and specific airway conductance were measured before and after exposure. Airway reactivity to methacholine inhalation was determined after each exposure. The dose of methacholine in milligrams per milliliter to cause a 40% decrease in Vp 40 was measured. None of the subjects reported any significant symptoms after exposure. Significant potentiation of airway reactivity was noted after NO2 exposure in asthmatic subjects as a group [PD40(AIR) = 9.2 +/- SD 15.0 versus PD40(NO2) = 4.6 +/- SD 8.2 mg/ml, p = 0.042]. No significant changes were noted in other lung functions after NO2 exposure. These findings indicate that asthmatics exposed to 0.5 ppm NO2 develop heightened airway reactivity.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Air Pollutants / toxicity*
  • Asthma / physiopathology*
  • Female
  • Humans
  • Lung / drug effects
  • Lung / physiopathology
  • Male
  • Methacholine Chloride
  • Methacholine Compounds
  • Microclimate
  • Nitrogen Dioxide / toxicity*
  • Respiratory Function Tests
  • Respiratory System / drug effects
  • Respiratory System / physiopathology*


  • Air Pollutants
  • Methacholine Compounds
  • Methacholine Chloride
  • Nitrogen Dioxide