The Ecology of Face Coverings

I conducted this project as part of Professor Pringle’s EEB321 class at Princeton University.

As COVID-19 coasts into its long-anticipated third wave, I’d say that, by now, I’ve become well-acquainted with the diversity of face coverings on the market. In my beloved minivan, I’ve stowed a box of cotton masks in the glovebox, and on ambulance shifts, I keep a couple duck-billed N95’s in my back pocket. I’ve seen people improvise with scarves, bandanas, and shawls. As for my own mother, she has become engulfed by the DIY arts-and-crafts craze that has swept across the bored, quarantined masses, so this past summer, she dragged our ancient sewing machine out of the closet. Sure enough, she’s been cutting up ratty T-shirts, shrunken blouses, and abandoned jeans, feverishly cranking out homespun masks of all colors and sizes. 

A layer of an N95 under a Foldscope.

Face coverings are a good thing in the face of a global respiratory pandemic. After months of waffling back and forth on the matter, the CDC has, at long last, stood in firm defense of this no-brainer of a public health practice. And the New York Times produced a stunning infographic showcasing how the criss-crossing of fibers serves as a matrix of hurdles that can halt the transmission of wayward particles. N95’s present a dense, convoluted mesh that is, in theory, 95% successful in stopping COVID-19 in its tracks. Cloth masks, on the other hand, aren’t as effective, but they still serve as a fibrous labyrinth capable of inhibiting the migration of infectious droplets. 

I wondered if our little Foldscopes could help me visualize this anti-transmission matrix threaded within my silly duck-billed N95. After snipping off a little square and mounting it onto a slide, I could see the jungle of fibers standing between COVID-19 and my respiratory tract. The picture I’ve attached is only one of many layers stacked atop one another to form the thick material of an N95. As an added protective bonus, I had to remove a plastic-like outer film to access these fibrous layers. On scene, I may look ridiculous with my duck-bill and safety goggles—but I can certainly relish in some peace-of-mind, knowing that I’m equipped with damn good personal protective equipment.

Interestingly, this N95 layer bears a striking resemblance to… toilet paper. A new DIY project for my mother, perhaps? Unclear if she’ll hit 95% efficacy with Charmin Ultra, but maybe we can shoot for N30 to N50?

I wonder what this diverse landscape of face coverings holds for the evolution of COVID-19 transmission. What strategies will COVID-19 develop to better worm past these fibrous meshes? I certainly hope they’re nowhere that wily, but I do wonder how these selective pressures will nudge shifts in certain traits.

Toilet paper under a foldscope.

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