Abstract: There are a large amount of neural stem cells in the olfactory system which have an active proliferation, ongoing and directional differentiation and migration in order to adapt to the changing environment. The clinical findings showed that the early stages of some neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease all presented dysosmia. In recent years, the relationship between air pollution and dysosmia attracts public concerns. This article introduced some research progresses in this field.

Key words: dysosmia, neurodegenerative diseases, air pollution, review