As stores were running out of masks, a lot of people got creative making their own. But not all masks are created equal.
A new study out of the University of Arizona reveals what are the best and worst materials to make masks out of. The researchers compared wearing masks to wearing nothing during 20-minute and 30-second exposures to the virus.
They found that masks reduced infection risks by 24-94% or by 44-99% depending on the type of mask and exposure duration.
"N99 masks, which are even more efficient at filtering airborne particles than N95 masks, are obviously one of the best options for blocking the virus, as they can reduce average risk by 94-99% for 20-minute and 30-second exposures, but they can be hard to come by, and there are ethical considerations such as leaving those available for medical professionals," said lead author Amanda Wilson, an environmental health sciences doctoral candidate in the Department of Community Environment, and Policy in the Mel and Enid Zuckerman College of Public Health.
The next best options were N95, surgical masks, and masks equipped with vacuum cleaner filters. Yes, you read that right! Vacuum cleaner filters can be inserted into pockets in cloth masks making them more efficient.
The vacuum cleaner filters reduced infection risk by 83% for a 30-second exposure and 58% for a 20-minute exposure. Tea towels, cotton-blend fabrics, and antimicrobial pillowcases were the next best options for protection.
Scarves and cotton t-shirts, however, were not such great options reducing infection risk only by 44% after 30 seconds and 24% after 20 minutes.
"We knew that masks work, but we wanted to know how well and compare different materials' effects on health outcomes," said Wilson. As such, Wilson and her team collected data from various studies on mask efficacy and developed a computer model to simulate infection risk.