Masks have become a regular part of our lives for way more than a year. There has been a fair amount of research going on into how face masks can be used to protect yourself from airborne infections and the like, as well misinformation regarding the efficacy of masks. For instance, there have been misleading articles proclaiming that masks are useless or even dangerous for someone’s health. These claims have been refuted in time, stating that masks do manage to block respiratory droplets while being safe for the health of those wearing them.
One of the most common claims was that surgical masks are ineffective against respiratory particles, as the fabric pores are too large and the droplets can pass through them. An experiment done by the immunologist Byram Birdle on his YouTube channel showed that water vapour condensation could pass through five masks. Nonetheless, the evidence claimed in the video does not apply in the case of COVID-19 infections. Here are the reasons why:
The types of respiratory droplets can be divided into two categories according to the CDC: big droplets that are larger than 5 micrometres and only be expelled over tiny distances and tiny droplets that are smaller than 5 micrometres in diameter. On the other hand, the pores of masks can go from 30 micrometres to 33 and 47 for different types of masks (N95, surgical and reusable). Nevertheless, the fabric still intercepts even the smallest droplets because they do not move in a straight line.
“Tiny particles don’t just move in a straight path—they are subject to Brownian motion—darting about randomly. Due to this—the masks catch more than you would imagine in both directions. They protect and prevent much of the viral particles in droplets from dispersing into ambient air,” explained professor Pierre Heckes from the State University School of Molecular Sciences in Arizona.