An aerosol expert is casting doubt on reports that neck gaiters may be more harmful than wearing no face covering at all in preventing transmission of the coronavirus.
A widely circulated study by Duke University raised fears that neck gaiters and bandanas can actually break droplets into aerosols and therefore add to the amount of potentially virus-contaminated aerosols in the air than if the wearer was wearing no face covering at all.
But Dr. Linsey Marr, Virginia Tech Professor of Civil and Environmental Engineering and an expert in airborne disease transmission said Tuesday that conclusion was drawn from a minor footnote in the paper. "You’d almost have to read a little more than is there to come to that conclusion," she told KCBS Radio’s "Ask An Expert."
"I do not think neck gaiters are any worse than a cloth mask made out of the same type of fabric," she said.
Dr. Marr said according to a recent test in her lab, the type of fabric affects efficacy far more.
"We found that really, a lot of cloths are not great at blocking a certain size aerosol that’s very small and is pretty hard to block," she explained. "But once you get to larger aerosol sizes, one micron and larger - and still, one micron is pretty small - the neck gaiter and our cloth masks block about half of those, and once you get up to maybe four or five microns, we’re looking at 80-90% blockage."
The issue of blocking smaller aerosols has a very simple solution: double up the fabric.
"If we folded over the neck gaiter and had a double layer, it actually blocks well over 90% of everything from half a micron and larger, and that’s where we think a lot of transmission is taking place," said Dr. Marr.
As for the conclusions drawn from the Duke University study, Dr. Marr believes it had more to do with the specific neck gaiter that was used, and is not an issue that is general to most gaiters. The study’s finding is also difficult to repeat because they tested the gaiter on a real human, which introduces more variables to the experiment.