How should people in smog protect their health?

Haze weather is a state of air pollution, and smog is a general term for all kinds of suspended particles in the atmosphere, especially PM2.5 (particles with aerodynamic equivalent diameter less than or equal to 2.5 microns) is considered as the "culprit" causing haze weather. With the deterioration of air quality, cloudy days are increasing and the harm is increasing. In many areas of our country, the smog weather phenomenon is combined with fog as an early warning and forecast of disastrous weather. Collectively referred to as "haze weather". It is recommended that friends who go out wear masks, such as masks with small oxygen; Personnel engaged in outdoor projects and fitness enthusiasts should wear sports masks; Minor children should wear children's masks when they go to school. Workers who need to walk around the construction site had better wear dust masks. It's nothing. It is best not to go out.