In a proof-of-concept study appearing online Aug. 7 in the journal Science Advances, Fischer, Westman and colleagues report that the simple, low-cost technique provided visual proof that face masks are effective in reducing droplet emissions during normal wear.
“We confirmed that when people speak, small droplets get expelled, so disease can be spread by talking, without coughing or sneezing,” Fischer said. “We could also see that some face coverings performed much better than others in blocking expelled particles.”
Notably, the researchers report, the best face coverings were N95 masks without valves – the hospital-grade coverings that are used by front-line health care workers and surgical or polypropylene masks. But hand-made cotton face coverings also provided good coverage, eliminating a substantial amount of the spray from normal speech. Our masks were designed to provide the best safety level below medical grade masks, and fall within the cotton-made face coverings by addressing several safety categories: