A recent report conducted by researchers with support from the Air Quality Research Center Director, Anthony Wexler, demonstrated that N95 and surgical masks did reduce the amount of aerosolized particles emitted while speaking and breathing. However, they found that the fabric of the face coverings released a large number of fibers into the air. This accentuates the importance of washing them frequently. This recent study tested the different face masks most commonly used and the amount of outward transmission of particles there was. 

In all the test scenarios, surgical and N95 masks blocked as much as 90 percent of particles, compared to not wearing a mask. Face coverings also reduced airborne particles from the superemitter.

Homemade cotton masks actually produced more particles than not wearing a mask. These appeared to be tiny fibers released from the fabric. Because the cotton masks produced particles themselves, it’s difficult to tell if they also blocked exhaled particles. They did seem to at least reduce the number of larger particles.

The results confirm that masks and face coverings are effective in reducing the spread of airborne particles, Ristenpart said, and also the importance of regularly washing cloth masks.

Read more from Andy Fell, News and Media Relations, UC Davis here or read the scientific report here in the Nature Research Journal.