Two scientists from the University of Navarra are evaluating the quality and effectiveness of some protective masks used by health professionals. They are Arturo Ariño, director of the Department of Environmental Biology of the University of Navarra, and Jesús Miguel Santamaría, director of the Institute for Research in Biodiversity and Environment of the academic center.

Although the first requests for analysis came from the Clínica Universidad de Navarra, more than 60 tests have already been carried out on samples from other entities and individuals. In total, 40 types of masks from 18 different suppliers have been analyzed.

The aim of this work, says Ariño, is to "protect those who protect us", i.e. to analyze the quality of new and recycled face masks to find out which ones can reduce the possibility of contagion of healthcare professionals who provide front-line care to people infected by coronavirus. "Their work is fundamental for the well-being of everyone and we must do everything in our power to protect them," adds Santamaría.

The aim of this study is to find out what capacity the masks have to block the entry of particles. "The droplets exhaled by people can have a diameter of slightly less than 5 microns and we are checking whether these particles, as well as those of the same size as viruses (less than a third of a micron), are capable of crossing the protective barriers," Santamaría explains.

These scientists from the Faculty of Science use a technique based on laser light scattering to quantify the particles in the air that pass through the masks. "We use a medical mannequin that we force to 'breathe' through the mask, taking 74 readings every 6 seconds that are transmitted to computers and then analyzed," Ariño points out. 

Recommendation for the use of approved face masks

Ariño and Santamaría are forceful in their recommendation to use approved masks, since handmade masks have a lower level of protection, due to the materials used in their manufacture. In this sense, these researchers recommend both companies that have reconverted their commercial activity to the manufacture of health protection material and people who are making masks individually to follow the instructions of the health authorities. "The usefulness of handmade masks as personal protection is very limited. Blindly relying on them to protect oneself can end up making the problem worse, as it gives us a false sense of security and we can lower our guard, neglecting other necessary measures," Ariño points out.  

These researchers also reflect on the importance of fitting masks properly during use. "We have found that very efficient masks are useless if they are not perfectly adjusted, so it is vital to make an effort to put them on correctly," concludes Santamaría.