If the mask worn is a disposable ordinary mask, it is not effective in preventing the new coronavirus, and the protection level is relatively low, and the probability of contracting the new coronavirus will be relatively high. If the mask worn is a disposable medical surgical mask, it can block particles larger than 5μm in the air, and the droplets in the general respiratory tract can block 90%. Of course, in an open environment, if the people are not very dense, the chance of infection can be said to be very small, unless there is no air circulation in a closed environment, if the people are very dense, the possibility of infection is not excluded. If you are wearing an N95 mask, it can also block aerosols in a closed environment, so wearing a medical protective mask will basically not be infected with the new coronavirus.

If you can’t distinguish the front and back of the mask, you can distinguish it by looking at the appearance of the mask. Generally, the folds on the front of the mask are facing down, the ear straps are welded to the front of the mask, and the nose bridge is also on the front of the mask. Remember that the front of the mask is worn outside, and the back is close to the face.