PULMONARY CLEARANCE OF 59FE2O3 AND 51CR2O3 IN RATS AND DOGS EXPOSED TO CIGARETTE SMOKE

The inhibitory effects of cigarette smoke on tracheal ciliary activity have been reported by several authors. Because of the possible consequence of this effect on the toxicity of inhaled particles, preliminary studies were undertaken to determine whether cigarette smoke altered the clearance of particles from the lung. Acute exposures of rats to cigarette smoke did not influence the clearance of 59 Fe 2 O 3 or 51 Cr 2 O 3 particles from the lung. The possible effects of chronic cigarette smoking were examined in beagle dogs smoking 20 cigarettes per day. Deposition of inhaled insoluble particles was tested periodically by exposing the dogs to aerosols of 59 Fe 2 O 3 or 5l Cr 2 O 3 . Subsequent pulmonary clearance was measured by whole-body counting and body-scanning techniques. No effects were seen in dogs after smoking cigarettes five days per week for over a year.