Many studies have shown masks to be effective in preventing the spread of COVID-19, but the type of mask you wear does matter. A study by Duke University released the first week of August, 2020, studied different types of masks and their effectiveness in stopping the spread of respiratory droplets of COVID-19. The study showed that most cloth masks are pretty effective and near the effectiveness of surgical masks. However, there are a few options out there that should be avoided. The first is any mask with an exhalation valve. These valves were designed to protect the user from harmful outside debris, such as dust or pollution. Unfortunately, these valves allow the user’s respiratory particles to escape and therefore do not protect others, which is the most important effect of masks on COVID-19. Therefore, these are not recommended. The second is a simple bandana. The bandana (depending on construction) may actually break up larger droplets into smaller ones that can remain in the air for longer. They may look cool, but they do not effectively protect others from you. The last mask that is not recommended is a fleece neck gaiter. In the study, this was listed worse than not wearing any mask. Again, this is because the material allows larger respiratory droplets to be converted into smaller droplets that remain in the air for longer and can potentially more easily infect others. As we continue to learn more about this virus and how it spreads, these mask recommendations may still evolve. Below are links to the actual study and some summary articles on the topic.