[Studies on industrial styrene poisoning (part XII). Electron-microscopic observations on the mucosal membrane of respiratory tracts of rats exposed to styrene. (author's transl)].

The influences which are known to be caused by styrene on the human body are stimulation of the mucosal membrane and atrophy of the central nervous system. There are several clinical reports and animal experiments concerning the stimulation of the mucosal membrane, and styrene is presumed to stimulate the mucosal membrane of the nose. To the best of our knowledge, however, there have been no reports describing histological pathology of the mucosal membrane of the nose induced by exposure to styrene. Accordingly we made animal experiments using rats in order to see influences of styrene on the mucosal membrane of the upper and lower respiratory tracts including the mucosal membrane of the nose, and could confirm the following changes electron-microscopically: 1. Increases in the amount of mucous adhering to cilia, 2. Occasional formation of compound cilia, 3. Appearance of substances having a higher electron-microscopic density within the cytoplasm of various epithelial cells, 4. Degeneration of secretory granules of goblet cells--changes in electron-microscopic density, appearance of cores with a higher electron-microscopic density, 5. Nuclear pyknosis, 6. Vacuolization of various epithelial cells, and 7. Separation and falling-off of the epithelial cell layer.