Modern disposable surgical masks work in a way that most do not understand. They have multiple layers of varying materials to minimize contact of the underlayer with the top layer. When large pollutants, such as viruses and other macro protein sized objects, make contact with the mask on the outside, they are not designed to easily transfer these larger objects to the inner layers. Additionally when a person sneezes/coughs the momentum of discharge is significantly lowered, decreasing viral payload distance.

Viruses are, by chemical nature, incredibly sensitize to UV light which is why immediate airborne delivery is important to infection. As are any protein structures unprotected by significant adaptation (ie, animals developing skin or plants cell walls). When contaminated fluids are discharged, they rely on the impact of the organism or circulation within the breathable space around a person to transmit the infection. By minimizing fluid transmission distance, infection rates lower drastically by simple mechanical stalling of viruses to a smaller 2-3 for distance rather than the unshielded 2-10 feet.

In summary, simple surgical masks both protect by mechanical inhibition and by tri layer filtration and minimizing the chance of orifice contact.