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U.S. Department of Energy
Office of Scientific and Technical Information

Effects of air pollution on airway function. Final report May 80-May 81

Technical Report ·
OSTI ID:6304252

Asthmatic individuals can develop bronchoconstriction on brief exposure to levels of sulfur dioxide (SO2) observed in urban air. In these studies conducted at rest, asthmatics breathing 1 and 3 ppm SO2 developed significant bronchoconstriction; whereas nonasthmatic subjects developed bronchoconstriction only after breathing 5 ppm. Exercise potentiates this response in asthmatics: exposure to SO2 for 10 minutes while performing light to moderate exercise caused bronchospasms at 0.5 and 0.25 ppm. Bronchoconstriction during light exercise caused by SO2 is less with oronasal breathing (facemask) when compared to oral breathing (mouthpiece). At higher levels of exercise the protection of oronasal breathing is lost probably because more air is taken in through the mouth as ventilation increases.

Research Organization:
California Univ., San Francisco (USA). School of Medicine
OSTI ID:
6304252
Report Number(s):
PB-83-130252
Country of Publication:
United States
Language:
English