Deposition of sulfuric acid mists in the respiratory tract of beagle dogs.

Beagle dogs were exposed to 35S-labeled sulfuric acid mists. The size range of the mist droplets was 0.4-1.1 micrometer mass median aerodynamic diameter (MMAD), and the external relative humidity was 20 or 80%. Immediate isolation of the respiratory tract and measurement of radioactivity in specified portions allowed determination of regional deposition. It was found that inhaled sulfuric acid mists in the size ranges studied had deposition patterns similar to those for dry aerosols. The effect of hygroscopicity for these aerosols was not dominant in determining the site of deposition.