As we enter into what will likely be the most deadly months of the pandemic, safety is at the forefront of our minds. Of course, the best thing you can do to protect yourself is to stay home, but that just isn’t possible for everyone all of the time. The good news is that masks continue to provide an extra layer of protection for when you need to leave the house. But, all masks are not created equal. In the last months, we’ve learned a lot about which types of masks give you the best protection.
Cloth masks help, but we can make them better…
A recent study led by Linsey Marr, professor of civil and environmental engineering at Virginia Tech and one of the world’s leading aerosol scientists, tested 11 different mask materials to see which ones were most effective. What they found was that a properly fitted cloth mask does a good job of filtering out COVID-sized particles (around .125 microns). But, with just a few adjustments, we can make them even better. New York Times health writer Tara Parker-Pope detailed the following recommended adjustments, based on Marr’s research.
Dr. Marr recommends wearing masks with two tightly woven layers of outer material and a filter sandwiched in the middle. Surgical mask material or a piece of a vacuum bag can both be used as filters. Even a coffee filter would work. Another option is to wear your regular mask over a surgical one. The researchers found that wearing a well-fitting fabric mask with a third filter layer can stop 74 to 90 percent of risky particles.
Use flexible material.
The more that the mask contours around your face, the less possibility there is of letting in infected air. Masks made of tightly woven flexible material with a wire that can be molded around your nose are best.
Use ties instead of loops.
Again, the more the mask can be fitted to your face, the better. Masks with ties are easier to adjust and allow for less air to seep in. They also tend to be more comfortable.
Face shields aren’t enough.
While face shields do very little alone, they can be a helpful addition to a face mask by offering an additional layer of protection, especially for the eyes.
The fit of the mask determines how well the wearer is protected.
Dr. Marr and colleagues found that masks stop incoming germs at nearly the same rate as outgoing germs, meaning that both the person wearing the mask and the people around them will be protected. But, again, how much they’re protected depends on how well the masks fit. Masks that were made from stiff materials that were worn loosely did not give much protection.
Besides masks, how else can you protect yourself?
Even the best masks don’t offer complete protection. Staying home as much as possible is still your best option. But, if you have to work or share space with other people who aren’t in your household, there are some things you can do to help reduce the risk of transmission. Besides wearing a mask, it’s also important to address your indoor air quality in two key ways.
The COVID virus thrives in dry air. Increasing humidity can be an important part of decreasing transmission, especially as cooler weather forces more people indoors.
A peer-reviewed study by researchers from the University of Sydney (Australia) and the Fudan University School of Public Health in Shanghai estimated that for every 1 percent decrease in relative humidity, COVID-19 cases can increase by 7 percent to 8 percent. That means that a 10 percent drop in relative humidity could double COVID-19 infections.
The reason for higher transmission rates in dryer air is that airborne particles are smaller and can remain in the air longer in low humidity. Increasing the humidity makes the infectious particles heavier, causing them to drop from the air and land on surfaces.
Stephanie Taylor, infection control consultant at Harvard Medical School, has conducted multiple studies showing that an indoor humidity level of between 40% to 60% has the potential to drastically reduce infection rates.