How often do disposable medical masks need to be replaced

The year 2020 is really an extraordinary year. The spread of novel coronavirus pneumonia makes people stay at home and cannot go out. Even if they need to go out, they must wear masks. Wearing masks is the most important measure to prevent novel coronavirus. How often do they need to change masks?
In order to prevent infection, some people may wear medical masks all day long, but this will make the nasal mucosa become fragile, lose the original physiological function of the nasal cavity, and reduce resistance. Therefore, it is not necessary to wear masks in places with low population density and high ventilation. It should be reminded that the protective effect of any type of respirator is time effective and must be replaced regularly. It is recommended to replace the respirator every 2-4 hours. If the mask is contaminated, it should be replaced at the first time.
When not in use, the medical mask should be folded and stored in a self sealing bag. It is not recommended to take it off and put it directly into the pocket or bag, which may easily cause secondary pollution of the medical mask. Be sure to fold it well and put it into a clean self sealing bag, and fold the side that touches the mouth and nose inward. In addition, experts remind that the current high incidence of respiratory infectious diseases in winter and spring, home and public places also need to maintain indoor air circulation.
The middle-aged and elderly should pay special attention. Wen Shenglan, the chief physician of the respiratory department of Run Run Run Shaw Hospital affiliated to Zhejiang University Medical College, suggested that the elderly at home should try not to go out. If they really want to go out, they must wear masks. If they have a fever, they should go to the fever clinic of the hospital as soon as possible. If their relatives and friends have a fever, they should try not to contact them. In addition, we should pay attention to cold protection, warmth preservation and personal hygiene; Strengthening physical exercise; Keep a light diet; Avoid activities in crowded places; When coughing or sneezing, wear a mask or cover your mouth and nose with paper towels and clothes.
Wash your hands frequently with soap and water, or alcohol based hand sanitizer with bactericidal and bacteriostatic effects, especially in the following situations: after coughing or sneezing, after nursing the patient, before, during and after food preparation, before eating, after going to the toilet, after contacting animals or handling animal feces, and after coming out. In order to keep novel coronavirus from getting worse, we all have a responsibility. We hope everyone can wear masks when going out!