When public officials recommended masks to protect against spreading the COVID-19 virus, millions of us took to the internet and stores to buy a few boxes. Then when public officials instituted “mask mandates”, millions more of us stocked our pockets, purses, and vehicle glove compartments so we would have an extra one handy.
Now we are months into the pandemic, and mask mandates are loosening in some areas and still in force in others. However, the urgency to buy more masks has begun to wane as many reuse the ones they have, hastily placing them on their face when they walk into a restaurant or store and putting it back in their pockets to reuse the next time they’re in public.
But what pathogens do these reused masks carry? In medical settings, we have striven to change out our mask after each patient, but non-health professionals, who don’t have access to new, fresh masks, may reuse their face coverings out of cost or convenience.
So I set out to see how contaminated our used masks are.
Hence I chose to evaluate and culture the following face coverings:
A. Fresh unused mask
B. Double layer thick face mask – used and stored in a purse/pocket
C. Double-layer thin face mask – used and stored in a purse/pocket
D. Cloth gator – used and stored in a purse/pocket
E. Disposable surgical mask – used, stored in a pocket
F. Disposable face mask – recently worn for one hour
Using sterile cotton tip applicators, samples were extracted from the inner (face touching) side of each mask and swabbed onto Luria Broth(LB) agar plates, and incubated between 85-95 degrees.
After 5 days each Agar plate exhibited the following:
Fresh unused mask after 5 days growth
Double layer thick face mask – used and stored in a purse/pocket
Double layer thin face mask – used and stored in a purse/pocket after 5 days of growth
Cloth gator – used and stored in a purse/pocket after 5 days of growth
Disposable surgical mask – used, stored in the pocket after 5 days of growth
Disposable face mask – recently worn for one hour after 5 days of growth
As expected the clean unused face mask by Day 5 of growth had no noticeable colonies on the agar plate.
The thicker used cloth mask “B” appeared to have the most growth on the agar plate.
The used cloth gator and surgical mask reused and stored in one’s pocket had the least amount of growth by Day 5.
Interestingly, the mask worn for only one hour had more growth than the gator or pocketed used surgical mask. This could be because the fresh respiratory droplets had not dried and pathogens from fresh samples could have been more viable.
This study did not type and identify the actual pathogens growing but instead demonstrated reused masks can have a plethora of germs that are being reintroduced to our facial orifices.
The moral: A new fresh mask has the least amount of germs and safer to apply to your face than a used, dirty mask that has sat in your purse or pocket for days. Throw out your used, disposable mask or clean your cloth masks thoroughly before their reuse.
Daliah Wachs, MD, FAAFP is a nationally syndicated radio personality on GCN Network, KDWN, iHeart Radio and is a Board Certified Family Physician