The images of people walking around wearing facemasks are often seen on TV. The usual reason is air pollution or dust storms or to prevent transmission of respiratory diseases. The question is: do these facemasks really help? The usual pictures show people in Tokyo, Beijing or Seoul trying to protect themselves from air pollution, but do these facemasks really protect against inhaled irritants and toxins?

Facemasks are barriers between the nose and mouth and the outside environment. The traditional masks are made of cloth or paper. The standard surgical mask that we are familiar with is composed of non-woven paper and, although it can protect the wearer from some harmful substances (blood spatter in the operating room), these standard facemasks cannot protect against airborne particles or harmful bacteria. Part of the reason this is true is because the masks are not tight-fitting and allow the environment to sneak in around the edges. In Japan alone $230 million dollars are spent annually on surgical masks. Cloth masks which are cheaper and can be washed and reused may be worse than wearing no mask at all. A study in China and Vietnam showed that wearing a cloth mask actually increased the likelihood of infection. The basic reason appears to be the fact that these masks were not washed frequently or properly.

Tight-fitting masks with special filters offer the best protection but are impractical for regular daily use outside of institutions. Time to rethink the mask.