In this period there is an increasing need for masks. Here is the most sold on amazon
Dust Masks with Valve, EN 149 FFP2 Disposable Masks against Particles / Dust / PM 2.5 / Pollen / Bacteria Permanent Quality Use at Home / Outdoors (20 Pack)
Compared to the normal mask, an exhalation valve mask can provide a more comfortable breathing experience.
Helps to reduce the collection of hot air inside the mask and to increase the oxygen supply while in a dusty environment.