PM2.5 masks can protect against new crown pneumonia. PM2.5 masks can protect against particulate pollutants with particle size above 2.5μm. In addition, such as medical surgical masks, KN95, N95 masks, etc., can achieve the protective effect. Novel coronavirus pneumonia is mainly spread through droplets and close contact, and if the mask can protect the mouth and nose better, it can prevent the spread. Generally the smallest droplet particle size is above 5μm, PM2.5 mask can block the particle size above 2.5μm can not pass through the mask aperture, wear correctly, the protection effect is better. Content source: Dr. You Lai