Extrathoracic and intrathoracic removal of O3 in tidal-breathing humans.

摘要: We measured the efficiency of O3 removal from inspired air by extrathoracic and intrathoracic airways in 18 healthy, nonsmoking, young male volunteers. Removal efficiencies were as a function concentration (0.1, 0.2, 0.4 ppm), mode breathing (nose only, mouth oronasal), respiration frequency (12 24 breaths/min). Subjects placed controlled environmental chamber into which was introduced. A small polyethylene tube then inserted nose each subject, with tip positioned posterior pharynx. Samples collected pharynx through rapidly responding analyzer yielding inspiratory expiratory concentrations The computed use concentration, concentrations. mean for all measurements 39.6 +/- 0.7% (SE), 91.0 0.5%. Significantly less removed both extrathoracically intrathoracically when subjects breathed at breaths/min compared 12 (P than 0.001). had no effect on efficiency, but there significantly greater ppm 0.1 0.05). Mode affected during nasal either or oronasal 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)