This Twitter Thread Explaining A New Study About The Effectiveness Of Face Masks Might Change The Way You Think About Social Distancing

A new study performed by scientists from the University of Göttingen and Cornell University in the peer-reviewed journal PNAS (Proceedings of the National of Academy Sciences) found that wearing a face mask — "even if it doesn't fit perfectly on the face" — is more protective against COVID-19 than social distancing.

The researchers conducted the study on seven adult human subjects "breathing normally through the nose." They found that when exposed to a typical COVID-19 viral load, social distancing alone — even with two speaking individuals at a distance of nearly ten feet away from each other — led to a "upper bound of 90 percent for risk of infection after a few minutes."

By contrast, the scientists discovered, for someone wearing a face mask with the infectious person speaking at a distance of about 5 feet, the "upper bound drops very significantly." They go on to observe, "[W]ith a surgical mask, the upper bound reaches 90 percent after 30 minutes, and, with an FFP2 mask, it remains at about 20 percent even after an hour. When both wear a surgical mask, while the infectious is speaking, the very conservative upper bound remains below 30 percent after 1 hour, but, when both wear a well-fitting FFP2 mask, it is 0.4 percent."

The research team concluded that "wearing appropriate masks in the community provides excellent protection for others and oneself, and makes social distancing less important."

It should be noted that "FFP2/N95 masks reduces risk compared to a surgical mask by almost 100 times."

Alex Huffman, associate professor of chemistry and aerosol science at the University of Denver, explained the results of this fascinating research in a viral Twitter thread.

In the thread, Huffman shows how the scientists presented their research, comparing FFP2 masks (which are comparable to N95 masks) with surgical mask usage.

Researchers found that lower-tech surgical masks still helped significantly reduce COVID-19 infection (though "not nearly as much as using tighter-fitting masks like FFP2 or N95.")

Huffman also explained the aspect of the study that showed how adjusting masks improved their effectiveness.

Surgical masks provided some protection but leaked substantially more and weren't as effective as tight-fitting masks, Huffman notes.

The researchers also provided a schematic that shows the difference in infection risk with mask type and exposure time.

[Read the full Twitter thread and the PDF of the peer-reviewed report.]