  The use of facial masks played a pivotal role in combating COVID-19 during
the pandemic period, particularly in the absence of vaccines for the disease.
This study elucidates how this type of equipment can effectively contain
viruses and bacteria of nanometric dimensions, smaller than the pores of the
masks themselves. To achieve this, three types of masks were chosen: cloth,
surgical, and PFF2 masks. In order to compare the structure of each, a scanning
electron microscopy analysis was conducted, revealing the intricate filtration
layers within each mask type.
