A day of travel, as “seen” by a Aranet4 portable CO2 monitor.
Reading this: basically, CO2 levels are a measure of how well a space is ventilated, and can therefore be a handy proxy for a rough idea of how likely it could be that there might be infectious particles (flu, COVID, etc.) in the air. Lower CO2 = better ventilation and less chance of any bugs in the air, Higher CO2 = worse ventilation, stale air, and higher chance of other bugs in the air. It’s not a one-to-one connection, obviously, as there are other variables, such as number of people in the area, but it can be a good way to get a rough measure of the ventilation.
So here’s how my day went (all times shifted one hour from what’s shown on the graph due to the time change).
Until about 8am, I was at the hotel. Levels stayed in the green and slowly decreased through the night, then increased into the yellow as I woke up and was active and moving around, showering, packing, etc.
8-9am, outside and on the light rail to the airport. Nice and green.
9-noon, in the airport, often in the midst of lots of people as I went through the TSA lines. Even in the large, high-ceilinged airport areas, with lots of room for air to move, levels were generally in the yellow. This is part of why crowded situations, even in large or outdoor areas, are still good places to be masked.
Noon-2pm, on the airplane. Lots of people in a fairly small, confined space. Airplanes might have “good” ventilation, but there’s only so much that can be done, and it was solidly in the red the entire time. I was okay with my KN95 through the airport, but switched to an N95 from just before boarding until after disembarking in Seattle, didn’t eat on the plane, and used a straw when drinking to minimize intake of unfiltered air.
2-3pm: Getting my baggage and taking a Lyft home. Right back into the green.
This was a handy little gadget to have with me this week. That, plus masking, plus vaccination and boosters, and I’m feeling pretty confident in my safety measures.