Q: I am having difficulty understanding how people can expose others to potential infection by a communicable disease by not wearing a mask or fact covering when they leave the house. Because of this, do you know if there are there any studies that show the most effective mask that I can wear? Thanks.

A: Duke University published results of a study they did. Following is a short summary.

Five Most Effective Masks

  1. Fitted N95 with no exhalation valve
  2. 3-layer surgical mask
  3. Cotton-polypropylene-cotton mask
  4. 2-layer polypropylene mask
  5. 2-layer cotton, pleated style mask (see full study for photos and specific design details of all masks tested. URL is below)

Three Least Effective Masks

  1. Gaiter-type neck fleece
  2. Double-layer bandana
  3. Knitted mask

https://advances.sciencemag.org/content/early/2020/08/07/sciadv.abd3083