Dust masks really block airborne particles
Blocking the air particles, wearing a face mask is the most effective method. Ordinary cotton yarn of mask and fashions a mask for PM2.5 have a certain amount of resistance.
Effect of surgical masks. Common N95 masks for PM2.5, KN90 and other models, the protective effect is very good. However, not everyone can wear such a mask, child, for instance, does not fit, special populations, such as asthma or emphysema, should consult a physician before wearing a respirator.
Gauze masks can be used again, but must be sterilized, N95 disposable masks, it is best not repeated use, avoid secondary pollution.