A new study has found that N95 masks are more effective than surgical, and cloth coverings guarding against COVID-19. 

"The results show that a standard surgical and three-ply cloth masks ... filter at apparent efficiencies of only 12.4% and 9.8%, respectively," according to the University of Waterloo Study's conclusion.

The results also show that KN95 and N95 masks provide "substantially higher apparent filtration efficiencies (60% and 46% for N95 and KN95 masks, respectively) than the more commonly used cloth (10%) and surgical masks (12%), and therefore are still the recommended choice in mitigation airborne disease transmission indoors," according to a summary of the study published July 21.

The higher quality, and therefore more expensive KN95 and N95 masks "filtered out more than 50% of the exhaled aerosols that can accumulate indoors and spread the COVID-19 virus when inhaled by other people," the study found.

Published in the journal Physics of Fluids, the study was conducted in a large, indoor and unventilated room.

According to one of the authors of the study, there are substantial differences in the effectiveness of different masks.

"There is no question it is beneficial to wear any face covering, both for protection in close proximity and at a distance in a room," said Serhiy Yarusevych, a professor of mechanical and mechatronics  engineering. "However, there is a very serious difference in the effectiveness of different masks when it comes to controlling aerosols."

Mr. Yarusevych described that the study's results aligned with "common sense" and well-known health-care practices.

"There is a reason, for instance, that medical practitioners wear N95 masks -- they work much better. The novelty here is that we have provided solid numbers and rigorous analysis to support that assumption," he explained.