Tracheal mucous velocity was determined in eight purebred beagle dogs exposed intermittently to 1 ppm sulfur dioxide for 12 mth. Three control dogs were also studied. Teflon disks filmed at constant speed through a bronchofiberscope served as indicators of mucous motion. An average of 16 disks were analyzed in each dog. Although there was no significant difference in average velocity for controls and the SO2 exposed animals, the frequency distribution curve of individual disk velocities in SO2 exposed dogs revealed significant slowing. No significant differences in mechanics of breathing and gas exchange were found between the two groups. It appears that long term exposure to low levels of SO2 produces an impairment of mucociliary activity as one of the first signs of pulmonary dysfunction.
ASJC Scopus subject areas
- Environmental Chemistry
- Environmental Science(all)
- Public Health, Environmental and Occupational Health
- Health, Toxicology and Mutagenesis