Abstract
A rhjnological investigation was done on 786 men working underground at Mitsubishi Metal Mine at Osarizawa, Akita Prefecture. Workers with silicosis were classfied according to the degree of severity of the disease, and the incidence of nasal affections in separate groups was compa red among them. The results were: (1) High incidence of the nasal affections was found among underground workers, (2) much higher incidence was found among the silicoticss revealed mainly by atrophic rhinitis. Such atrophic rhinitis is considered to be causally contributing to the occurrence of silicosis through decreased filtering function against silicious dusts. It is considered, on the other hand, that silica dusts are contributing to the occurrence of the atrophic rhinitis through their action on the nasal mucosa. Therefore, a functionally vicious circle is possible.
