From the Dentist’s Mouth
Given those credentials, his opinion on masks should carry a ton of weight:
Surgical masks have been worn by health professionals, to protect against cross contamination of Blood-borne viruses, not Respiratory viruses.
Having worked as a microbiologist, or a dentist, throughout my professional career, I am very familiar with wearing a disposable surgical mask. I wore one to minimize the cross contamination of body fluids or tissues. This has been a concern due to blood-borne viruses.
Some people ask, “If masks don’t work, then why do medical personnel wear them?”
Blood-borne viruses (BBVs) are transmitted by blood or other body fluids containing virus. This happens when the blood or fluids enter into the body or onto the mucosa of a susceptible person. I had never worn a mask with the intention of minimizing respiratory viral infections because they have been proven to be ineffective against respiratory viruses. Viral respiratory infections (VRIs) include colds, the flu and bronchiolitis. Respiratory means something that affects the lungs and airways (breathing passages). VRIs may cause coughing, sneezing, runny noses, sore throats or fever in a healthy patient, and more serious complications in patients with a weak immune system or co-morbidities.