Effect of perchloroethylene inhalation on nasal mucosa in mice.

An experimental group of 16 male pure-bred mice was exposed to perchloroethylene gas at 300 ppm for 6h daily for 5 days. Histopathological study of the nasal mucosa was performed sequentially 1, 2, 4, and 7 days after exposure. Erosion of the olfactory epithelium and dilatation of Bowman's glands were observed from 1 to 7 days after exposure. Atrophy of the olfactory nerves was observed from 4 to 7 days after exposure. At 4 days after exposure, regenerating epithelial cells were observed, indicating that these cells represented the first step of the repair process after exposure. Nonetheless, epithelial degeneration in the nasal mucosa without erosion was observed for 4-7 days after exposure. Such epithelial lesions were more severe in the olfactory mucosa and appeared earlier than in other sites in the respiratory mucosa. The present study revealed that perchloroethylene gas exerted a more potent harmful action on the olfactory mucosa than on the general respiratory mucosa.