Happy Tuesday, friends!
Way back in April during my first post, I shared instructions for a no-sew face mask, and in my second post, I shared a study that investigated which materials were the most effective for homemade masks.
There have been many studies over the years on the effectiveness of medical grade masks (like surgical masks or N95s, but less is known about the cloth face coverings that many of us are wearing -which range from bandanas to sewn cloth masks.
So: How effective are cloth face coverings, really?
A new study published on June 30 in the journal, Physics of Fluids set out to investigate this exact question. There are some nifty pictures in the article, but to summarize:
In this study, they fitted a mannikin with different kinds of mask and then simulated a cough or sneeze with a fog machine that was fed a mixture of water and glycerin. A laser sheet illuminated the jets of fluid coming out of their setup so that they could visualize and measure just how far the droplets traveled.
There were three interesting observations from this study:
- Droplets from a simulated heavy cough traveled up to 12 feet in less than 1 minute, which is twice the CDC’s recommended distancing guideline of 6 feet.
- Loosely folded face masks or bandana-style face coverings fared the worst in stopping the respiratory droplets from dispersing and provided minimal protection.
- Well-fitted homemade masks with multiple layers of fabric and purchased fabric cone style mask were the most effective in blocking the dispersal of droplets.