Because the bacteria of the atypical pneumonia are tenacious and are mainly transmitted by droplets and close contact, it is generally recommended to wear a 12-layer mask and a 16-layer mask is also common in pharmacies. If you wear a thick masks, will feel very oppressed, especially for a long time to wear, will make the nasal mucosa become fragile, lost the original physiological function of the nasal cavity, but may lead to other diseases.