SHORT-TERM CROCIDOLITE INHALATION STUDIES IN MICE - VALIDATION OF AN INHALATION CHAMBER

A nose-only inhalation chamber is described: this chamber being comput er automated has been particularly designed for mice on which it was v alidated using a crocidolite aerosol at a nominal concentration of 13. 6 mg/m(3), 6 h/day during 5 days. A month later the mice showed typica l inflammatory bronchoalveolar liquids with many polynucleated or acti vated macrophages and asbestos bodies. The burden of crocidolite fiber s ranged from 345000 to 1300000 fibers per mg of dried lung. This stud y demonstrates that during the month that followed a short-term mice e xposure to crocidolite fibers, the inflammatory response was still per sistent. These toxicological endpoints validate the nose-only inhalati on chamber to be useful for common or transgenic mice.