title: Sulfur dioxide and tracheobronchial clearance in man.
abstract: Tracheobronchial clearance was measured in nine healthy, nonsmoking adults. Technetium Tc 99m albumin aerosol (mass median diameter, 3 mu; geometric standard deviation, 1.6) was inhaled as a bolus under controlled conditions to achieve reproducible deposition in large airways. Each subject was studied in three seperate three-hour experiments: twice under control conditions and once exposed to 5 ppm sulfur dioxide (pollutant exposure after aerosol inhalation). Lung retention of activity was measured using a gamma camera interfaced to a data storage and retrieval system. The study showed that (1) Both deposition and clearance were highly reproducible in individuals in repeat control studies. (2) Acute exposure to 5 ppm sulfur dioxide had no significant effect (P greater than .05) on mucocillary clearance in resting healthy subjects, except perhaps for a small transient change (P=.05) after one hour. (3) Pulmonary function tests showed a decrease in maximal midexpiratory flow (P less than .01) but no other significant changes.
mesh_terms: D000328:Adult; D000336:Aerosols; D000388:Air; D001980:Bronchi / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D011877:Radionuclide Imaging; D012129:Respiratory Function Tests; D013458:Sulfur Dioxide / Q000009:adverse effects* / Q000378:metabolism; D013667:Technetium; D014132:Trachea / Q000187:drug effects / Q000378:metabolism*
chemical_list: D000336:Aerosols; D013458:Sulfur Dioxide; D013667:Technetium