It's been more than a year since masks have become part of everyday life.You no longer enter establishments without the item, which works as the main measure to prevent COVID-19.A new study by the University of São Paulo (USP) compared masks made of different materials to understand which type is the most effective in protection.To understand the effectiveness of the masks, the study passed all of them through equipment that produces aerosol particles of controlled size to resemble the coronavirus.After the jet, the group measured the particle concentration of the mask.This analysis points out that the average effectiveness of cotton masks against coronavirus is 40%.The masks that showed the most effectiveness in the test were the surgical ones and the PFF2 and N95 types, since they were able to filter between 90% and 98% of the aerosol particles.As for TNT masks (made of polypropylene, a type of plastic), the efficiency ranged from 80% to 90%.In turn, fabric masks (with cotton and synthetic materials, such as lycra and microfiber, for example) had a filtration efficiency of 15% and 70%, with an average of 40%.It is worth remembering that scientists from USP and UFSCar discovered a fabric made from polyester, cotton and silver microparticles capable of inactivating fungi, bacteria and viruses.Enter your email address on Canaltech to receive daily updates with the latest news from the world of technology.