All Los Angeles County residents are now required to wear a mask or face covering whenever they are out in public. The one exception is for individuals who are exercising alone, and even then, it is advisable to keep a mask or bandana on hand.
Health authorities stress that face coverings do not replace social distancing requirements. Instead, face coverings are an additional step to help slow the spread of COVID-19. In Los Angeles County, masks are recommended. Los Angeles County joined Riverside and San Bernardino counties in making masks mandatory. The new rule went into effect on April 13. Anyone who ignores the new requirement may end up having to pay a $1000 fine.
On February 29, U.S. Surgeon General Jerome Adams tweeted that masks are not effective in preventing the general public from catching Coronavirus. On April 4, Adams changed course, releasing a video on how to make a mask from a t-shirt and a couple of rubber bands. Within a week, face covering requirements were adopted in communities nationwide.
Anthony Fauci, the U.S. director of the National Institute of Allergy and Infectious Diseases, and the key infectious disease authority for the Trump Administration, also advocates for the use of face coverings. “If everybody [wears homemade masks], we’re protecting each other,” he said.
Adams and the CDC stress that N95 respirators and surgical masks must be reserved for medical professionals, but that non-medical face coverings are now recommended for the general public. That has left people scrambling to buy bandanas, or rummaging in closets for scarves and balaclavas, but not all face coverings are equally effective and knowing how to use face coverings is essential.
Research shows that all face coverings have the potential to reduce exposure to COVID-19 by blocking large particles ejected during a sneeze or cough, but that there is a lot of variation.
N95 masks filter nearly 95 percent of particles. Commercial surgical masks are less effective, filtering 65 percent of particles. A homemade pleated surgical-style mask could potentially be more effective than a commercial surgical mask depending on the material used to make it.
Studies indicate that fabrics with a high thread count, like the cotton material popular with quilters, may filter up to 70 percent of small particles. That news has caused a run on “fat quarters,” pre-cut quilt squares, but some household materials may give similar results. Flannel bed sheets are a good choice, so are tea-towels.
T-shirt material varies. Some of the denser materials tested filtered out 40 percent; thinner knits only screened 20 percent. Bandanas and scarves were at the bottom of the list, filtering only about 10 percent. Holding a piece of prospective mask-making fabric up to the light may help determine the fabric’s potential. The more light the fabric blocks, the tighter the weave, and the higher the chance that it will filter more particles. Adding an extra layer of fabric or a disposable filter made from a paper towel has been shown to boost protection, and even a bandana by itself is better than nothing, the experts say.
Jeremy Howard is a University of San Francisco researcher and the co-founder of Masks 4 All. He has looked at the evidence gathered during the pandemic and says the consensus is clear.