Wearing a mask is an essential practice as the COVID-19 pandemic continues to affect thousands across the United States. As a result of the pandemic, however, the effectiveness of masks in controlling the spread of disease is increasingly becoming a subject of public debate.
Face masks are routinely used in healthcare settings to protect doctors and nurses not only from bodily fluids during surgery, but also from various respiratory droplets that may carry disease. Similarly, masks provide protection to the general public as well. The virus travels through droplets, which can be emitted by breathing, talking or coughing. Fundamentally, a mask works to create a physical barrier that stops droplets from escaping into the air, where they could potentially infect others with the virus.
A study found that wearing a mask was 82% percent effective at preventing the transmission of the coronavirus and that masks are equally as beneficial for the public as they are for healthcare workers. Additional research from the University of Iowa has shown that mandating masks in public was associated with a 2% decrease in new daily COVID-19 cases just three weeks after the orders were put in place.
“Masks are very useful for a disease spread by respiratory droplets or aerosol transmission — smaller droplets in the air can go over long distances,” said Dr. Robert Kim-Farley, a professor-in-residence at the UCLA Fielding School of Public Health and former senior official at the World Health Organization. “They’re useful for what we call ‘source control’ as well as for the protection of the individual.”
By preventing droplet transmission, masks ensure that their wearer does not spread the disease to others.
“When it became clearer that people who were not symptomatic were transmitting it, the recommendation quickly became ‘Wear masks,’” Kim-Farley said.
Masks became standard once new research emerged on asymptomatic carriers, or individuals who have contracted COVID-19 but do not exhibit any of the typical signs of infection, such as a cough or sore throat.
“If everybody is wearing a mask,” Kim-Farley said, “you’re really protecting yourself because everyone around you is wearing a mask as well. You’re protecting them, and they’re protecting you.”
According to recent research, some masks are more effective than others. A study from Duke University last month found that N95 masks without valves worked best, followed by surgical masks, and then cotton masks. Compared to bandanas, cotton masks were more successful and most of the droplets were trapped.
Notably, neck gaiters — tube-like face coverings that stretch over the neck and lower half of the face — evidently did more harm than good; the study reported that the neck gaiters split droplets into even smaller droplets, which last longer in the air and increase others’ risk of infection.
However, the Duke researchers have since clarified that testing mask effectiveness was not the primary objective of that study. Preliminary follow-up testing has suggested that a single-layer neck gaiter was modestly effective against small particles, and a doubled-over gaiter was over ninety percent effective against all particles.
Other studies have explored the relative efficacy of different fabrics, indicating that silk may be more breathable and easier to clean and reuse in addition to being better at blocking moisture such as droplets. Medical-grade masks are the most effective, but experts highly recommend reusable cloth masks during times of supply shortages for essential healthcare workers.
Ultimately, experts agree that a good mask for everyday use should simply have at least two layers of well-fitted woven fabric, no matter the type. Infectious disease specialist Dr. Peter Chin-Hong at University of California, San Francisco said, “the best mask is one you can wear comfortably and consistently.”
Once people put on a mask, they should be mindful to wear it correctly and handle it with care to maximize its effectiveness, Mayo Clinic said. Proper mask use includes wearing masks over the nose and mouth, handling it only by the ear loops and washing your hands before and after use. People should wash their cloth masks regularly and gently to maintain their quality. The Mayo Clinic also stresses that masks are not a substitute for other precautions.
“Physical distancing six feet apart, mask use when out in public and frequent washing of hands — all of these are going to be important pieces in the puzzle until we do have a vaccine that is highly effective and long-lasting,” Kim-Farley said.
Nevertheless, as America surpasses 14,000,000 confirmed cases, experts firmly believe that wearing masks is still essential to stopping the spread of COVID-19. The most recent study from the Institute of Health Metrics and Evaluation published in Nature Medicine estimates that over 130,000 deaths could be avoided by December if 95% of the U.S. population were to start consistently wearing masks in public.
“[It’s our] duty to help others,” Kim-Farley said. “You do that by wearing a mask yourself.”