The moisture that is generated inside the mask when we breathe helps reduce the level of infection from respiratory diseases, something that can be applied to the SARS-CoV-2 virus, according to a study by the National Institute of Diabetes and Digestive and Kidney Diseases of the United States, according to Europa Press.
The study, published in the Biophysical Journal, indicates that elevated humidity levels can promote mucociliary clearance (a mechanism of the respiratory system to eliminate particles into the lungs), as well as reinforce the immune system by producing interferons, proteins that attack viruses. Therefore, the use of the mask would help protect the body by raising humidity levels.
“We found that face masks strongly increase humidity in inhaled air and we propose that Resulting hydration of the respiratory tract could be responsible for the documented finding linking lower severity of COVID-19 disease to wearing a mask“, explained the lead author of the study, Adriaan Bax, in statements collected by Europa Press.
The mask would serve, therefore, not only to protect against possible infections, but “humidification could limit its extension to the lungs by reducing the generation of droplets containing pathogens “, indicates the study.
Four types of masks were used
For the study, the researchers they made the volunteers breathe with four different types of masks in a closed steel box. It was about one N95 mask, a three-layer surgical disposable, a two-layer cotton-polyester, and a heavy cotton one. The box increased its humidity level when people were not wearing the masks and increased when they did. High-density foam rubber was used to prevent air leakage.
The measurement was made at different temperatures ranging from 7.7 to 37 degrees Celsius. The thick cotton mask achieved the highest levels of moisture in exhaled air at any temperature. The cold temperatures also increased humidity levels.
The researchers warn that the measurements were made without air leaks (something that is unthinkable in our day to day) and, especially, that non-KN95 masks leak heavily, which reduces the filtering of pathogens. This implies, according to research that “For everyday use, a tight N95 or KN95 mask is preferable.”