DENVER (KDVR) — Masks are back in schools, and in a repeat of last fall’s events some parents are upset because they don’t believe the mandates will do anything to curb COVID case rates.
Districts including Cherry Creek schools and Adams 12 Five Star schools have each recently joined Jefferson County schools in requiring masks for all students. The Tri-County Health Department made a similar order for schools in Adams, Arapahoe and Douglas counties.
Cheyenne Mountain School District 12 Board of Education hosted a meeting on Monday to discuss mask mandates. Parents brought up a University of Waterloo study that rated the filtration capacity of cloth masks, which the school could require and provide.
Not all masks are created equally, research has shown.
The Waterloo study put percentages on the filtration efficiency of various mask types. Parents opposed to in-school masking mandates have a point: certain masks simply don’t cut it the way education or health officials would like.
Cloth masks and the loose-fitting surgical masks favored by the public have relatively low abilities to filter aerosols. Cloth masks only filter 10%, while the blue ear-looped surgical masks only filter 12%.
The high-efficiency masks used by medical personnel do a much better job. KN95 masks filter 46% of aerosols and R95 masks filter 60%.
Much of the masks ability to filter come from fit rather than material, another U.S. Environmental Protection Agency study found.
Looser-fitting masks or masks with filters in them have lower rates of filtration efficiency.
Cotton masks with loops, the EPA study found, only filtered out 26.5% of test particles.
Another cloth mask with better fittings has a much higher rate – a two-layer woven nylon mask with an aluminum nose bridge and no filter has a 79% filtration efficiency. Even a standard cotton bandana tied in the traditional bandit style covers enough of the facial area to bump cotton’s filtration efficiency to 49%.