You’ve probably heard it said that the air in airplane cabins is ‘actually really clean’. Does that sound right to you? Sure, it sounds good……but does it sound accurate?

If it were true, why is it that I always feel like crap at the end of a flight? And why does de-boarding at the end of a long flight seem to bring out the absolute worst in people?

Every time I get on a plane, my laptop comes out and I’m eager to knock out a few hours of completely uninterrupted work (or perhaps read a few novels).

It. Never. Happens.

15 minutes into it, my focus starts to waiver.

Suddenly I realize I’m exhausted, despite it being 11am and having crushed 2 cups of coffee just hours earlier.

“What the heck is going on?” I ask myself. I boarded SO energized and focused.

I struggle for another 15 minutes or so, making feeble attempts to reclaim my focus, until I just give up. The laptop closes, and the books go back into the bag.

Time for music, podcasts, and movies.

On my most recent trip, however, I had a revelation. What if there was something else to blame other than my apparent lack of resolve, and perhaps work ethic?

Was I feeling very hopeful? Yes. Very much so.

You see, over the last year or so, I became fairly in-tune with my body’s response to high carbon dioxide environments. This was actually pretty easy to do by just carrying a portable CO2 sensor around with me. When I found myself feeling groggy in my home, office, or any given meeting room, I would whip that thing out and start measuring. Much to my surprise, my lack of focus or general lethargy could, 99 times out of 100, be attributed to very elevated CO2 levels in my environment. At 800 ppm CO2, I would find that I was slightly less sharp, and by 1400 ppm, I was downright useless.

Now, on my flights this past weekend, I realized that maaaaaybe all the stuff I’ve heard about the quality of cabin air might not be, well, 100% true.

I showed up armed. Not in TSA-is-gonna-take-me-away sense. Just with my air quality monitor.

And so the testing began.

The monitor came out right after I sat down. It was a Southwest flight, so I was conveniently able to choose an aisle seat in the dead center of the plane.

This is when the surprises began. I figured that with the front and back plane cabin doors having been open for ~40 minutes (during the last flight’s de-boarding, the cleaning, and now our boarding) and every single air vent cranking, the CO2 levels should be at least fairly close to atmospheric: in between 400 and 500 ppm.

Nope.

It was double.

The CO2 monitor steadied at a level of ~800 ppm.

Not exactly ideal.

Despite, this being the case, I, yet again, pulled out my laptop to start a write-up.

As per usual, this silliness lasted about 15 minutes.

I turned the CO2 monitor back on and am now a bit perturbed. The CO2 level had risen to about 970 ppm. The PM 2.5’s and total particulates, did however, look pretty great:

I was unimpressed. I kept monitoring for the next 30 minutes to see how things developed.

“Not that well” – if I had to put a label on it.

Sure enough, the CO2 level kept climbing.

At the end of 30 minutes, we had reached 1195 ppm, with no real signs of slowing down. The particulates in the air, however, were still looking quite good:

I decided to turn it off at this point. I didn’t need the anxiety……….and maybe my drink and weird pretzels just showed up.

The rest of the plane ride went smoothly. I sipped my seltzer water, nibbled the weirdest tasting pretzels, and watched a Gladiator 2 – an excellent airplane movie, if you get my gist.

As we approached our destination (maybe 40 minutes since I had last check the CO2 levels), I nervously pulled the monitor back out and turned it on.

At this point, you probably get the idea: It was higher. Over 1400 ppm.

I braced for the inevitable uncomfortable de-boarding experience, full of nudges and unnecessary attempts to be the first off.

15 minutes after having left the plane, I was once again feeling pretty good. Out came the monitor, because I just had to know how well the Atlanta airport was managing their air.

Very well, as it turned out. Way to go Atlanta:

My takeaways:

1. Claims of airplane cabin air being “totally replaced” every 2 minutes are absolute nonsense. Likely, the air is entirely “filtered” at about that rate. Sadly, filtration does nothing to address rising CO2 levels.
2. I would be willing to guess that a longer flight would equate to proportionally higher levels of CO2, and plan to test that in the very near future.

Anyways, this was just the first test of hopefully a few. For those of you that are curious – the plane type was a Boeing 737-MAX 8, and the total flight time was about 1 hour and 45 minutes.