Tag Archives: Ontario Civil Liberties Association – D. G. Rancourt

COVID-19: DO MASKS WORK? A Review Of Science Relevant To Social Policy

April 2020 — Ontario Civil Liberties Association – D. G. Rancourt

KN95 Mask


There have been extensive randomized controlled trial (RCT) studies, and meta-analysis reviews of RCT studies, which all show that masks and respirators do not work to prevent respiratory influenza-like illnesses, or respiratory illnesses believed to be transmitted by droplets and aerosol particles.

Furthermore, the relevant known physics and biology, which I review, are such that masks and respirators should not work. It would be a paradox if masks and respirators worked, given what we know about viral respiratory diseases: The main transmission path is long-residence-time aerosol particles (< 2.5μm), which are too fine to be blocked, and the minimum-infective-dose is smaller than one aerosol particle.      Continue reading

%d bloggers like this: