What is the Best Mask to Wear? Can Some Actually Make Things Worse?

The science is clear: face masks can prevent the spread of coronavirus, protecting both the wearer and others around them.  Modeling by the University of Washington predicted that at least 45,000 deaths could be prevented by November if 95% of the population wore face masks in public.  

Some masks, however, are better than others.  And how well the mask fits the wearer is a crucial and often overlooked concern.  A mask that droops or hangs below the nose, or all the way down to the chin is about as effective as a toddler wearing a diaper that hangs down to the knees.  WHO recommends that fabric masks have three layers: an inner layer that absorbs, a middle layer that filters, and an outer layer made from a synthetic, nonabsorbent material like polyester.  It should fit the face well and attach snugly using ear loops or ties.

In general any mask is better than nothing, with the potential exception of some neck gaiters, which may be worse than wearing no mask at all.   A recent Duke study evaluated 14 different types of masks by estimating the number of droplets that were able to pass through the mask.  The results below, in an easier to read chart by USA Today, show the best masks at the top and worst at the bottom.

Of the non-medical masks, the winners seem to be the Cotton-Polypropylene-Cotton mask and the double-layer Polypropylene mask.  Polypropylene is a soft and easy to clean synthetic fabric, one of the most popular materials for masks, and has inherent antiviral and antibacterial qualities.

Sky Pittson, MD, August 17, 2020