weldondebusk.com

MASKS OUTDOORS?

...sure, if your face is cold. - Jan 30, 2022

The Seattle Times recently ran a story by Mitchell Willetts describing a paper from the journal Environmental Science and Technology that mathematically models the chance of contracting COVID-19 under various conditions. After describing a few scenarios, the author points out:

“Unsurprisingly, being outdoors, masked and surrounded by silence is the best way to avoid coronavirus, researchers found.”

What Willetts’ article fails to mention is that the paper clearly demonstrates the likelihood of COVID transmission outdoors is actually not affected by masking in real-world situations such as passing a pedestrian, or runner, or cyclist on a sidewalk or trail. Considering the number of people I see masked while they are walking outdoors, generally with no one else around, compared to the number of unmasked people I see in coffee shops and restaurants, the omission of this fact was a lost opportunity for public education.

The contact time used to arrive at the values in the table shown below (from the original paper but converted to percentages by the researchers in a separate article) used a value of one hour to calculate the risk for a short contact time. Even with that extremely generous definition for a short contact time, the difference between masked and not-masked was negligible. If it takes you an hour to pass by another pedestrian, you should be more worried that you are caught in a temporal anomaly than about your chances of catching COVID.

The real problem remains unchanged since the beginning of the pandemic: gathering indoors with other people, especially in poorly ventilated places. In the interest of public health, it remains essential to wear a mask when indoors in public spaces.

So when outside, go ahead and relax a bit and enjoy a nice, maskless walk. Get some fresh air and maybe even say hello to someone as they pass by. Saying hello will only increase your danger by another immeasurably small (as in "nonexistent") amount.