Frontiers in Medicine (Masks a biosafety concern)

FIM:

”While a number of studies have focused on the importance of face masks in the transmissions of respiratory viruses (2, 17, 26), accumulation of pathobionts on the masks due to human saliva and exhaled breath represents a possible underestimated biosafety concern. Microorganisms present on the skin and in the upper respiratory tract could be transferred to the face mask while wearing it. For optimal growth, bacterial cells need a surface to grow on, warmth, moisture, and nutrients, which is the environment created on the face mask due to exhaled air and water vapor (56). Growth of these microorganisms will also increase the amount of bacteria that are inhaled or could be transferred to the skin. This could theoretically cause some disturbance in the skin and nasal microbiome due to for instance the overgrowth of certain pathobionts, which are associated with an increased risk of inflammation and infections.”

“….Not-worn face masks were not used in this step as the amount of bacterial cells was too low to be detected using this method. The bacterial community residing in the cotton face masks after 4 h of wearing were mainly represented by Roseomonas, Paracoccus, and Enhydrobacter, with mean relative abundances of 15.23, 19.00, and 19.28%, respectively. In contrast, the microbial communities found on the surgical masks consisted mostly of Streptococcus (mean relative abundance 11.31%) and Staphylococcus (mean relative abundance 11.03%). These genera are also present on the cotton masks, but in lower relative abundances, 4% for Staphylococcus and 3% for Streptococcus.”