Currently during the COVID-19 pandemic, masks have been a suggestion by scientists and health officials to help prevent the spread of the virus, along with hand washing and socially distancing. Here is information regarding the science of how mask wearing helps prevent the spread and which materials are best. The information included is from the Center for Disease Control (CDC) and other relevant websites.
The CDC recommends that everyone wear masks in public, particularly in settings where it is hard to maintain social distancing (at least 6 feet between people). Masks made of the right material prevent respiratory droplets, which are possible transmission methods for harmful bacteria and the virus. A study done by a microbiologist demonstrates the distance that respiratory particles can spread both with and without masks. This demonstration included using petri dishes and performing the many ways particles can spread. For example the microbiologist coughed for 15 seconds into the dishes from 2, 4, and 6 feet away. The farther the distance, the less bacteria growth on the dish, but with a mask, the growth was even less for each distance compared to without.
Not all masks are the same. Some are more effective in preventing the spread of COVID than others depending on the material. Masks that are proven to be most effective are N-95 or KN-95. These are difficult to get these days because they are reserved for healthcare workers and certain essential workers. Surgical masks are more available for the public and are the next best material. Amongst the cloth and homemade masks, these materials are next effective when in combination with each other: tightly woven cotton combined with chiffon, and cotton combined with natural silk.
The CDC recommends the best way to protect yourself during this pandemic is frequent hand washing, frequent cleaning and disinfecting of high touch surfaces, social distancing and covering your nose and mouth with a mask in public places.