RT Journal Article SR Electronic T1 Ambient nitrogen dioxide concentrations increase bronchial responsiveness in subjects with mild asthma JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 606 OP 612 DO 10.1183/09031936.93.01070606 VO 1 IS 7 A1 G Bylin A1 G Hedenstierna A1 T Lindvall A1 B Sundin YR 1988 UL http://erj.ersjournals.com/content/1/7/606.abstract AB Twenty subjects with mild asthma were exposed at rest in a body plethysmograph, to NO2 at 0, 260, 510 and 1,000 micrograms.m3, for 30 min on four separate days. Bronchial responsiveness (histamine inhalation test) was measured after each exposure session. Airway resistance (Raw), thoracic gas volume (TGV) and specific airway resistance (sRaw) were measured before, during and after exposure, and the breathing pattern was monitored during the whole session. Bronchial responsiveness increased significantly after 30 min exposure to 510 micrograms.m3 NO2 (p less than 0.01). There were also tendencies to an increased bronchial responsiveness after exposure to 260 and 1,000 micron.m3 NO2, but these changes were not statistically significant. Effects on airway resistance and breathing pattern were not demonstrated by exposure to 0-1,000 micrograms.m3 NO2. We conclude that short-term NO2 exposure at about 500 micrograms.m3 slightly affects human bronchial responsiveness in subjects with mild asthma.