Back in college, I worked on a project whose goals were to examine the effects of closed room vs. fresh air cognition. The solution was a partnership between the Architecture and Biotech departments to develop so-called "living walls" to continuously recycle air. In accordance with this article, test subjects showed improved cognition and memory working in fresh, low co2 ppm air.
Plus the comment 4 levels up had "C02" rather than "CO2".
<rant>
I searched for why people do this 1337-substitution [1], and apparently the justification's that "C02" can be quicker to type on some mobile keyboards since "0" is a single press while "O" requires hitting Shift too.
But in chemistry, we'd often write chemical formulae in linear format. For example, "H2O" is water while "C6H12O6" refers to some simple sugars. The basic rule is that digits after any letters are in a subscript position, while digits before any letters are a scalar multiplicand.
So, when I see "C02", I immediately parse it to "{C}_{02}" rather than "{C0}_{2}". This reduces to "{C}_{2}", which obviously doesn't make sense, so then I have to figure out what's going on. Obviously it's not too tough to figure out from context that "CO2" was meant, but since I have to infer that from context rather than from direct parsing, it comes off as an obnoxious typo. For example, if someone wrote "C2O", I could figure out what they meant from context too, but it's still annoying to have to be like, "What?".
Then I don't even know why it exists. I mean, who talks about CO2 so much more than other chemical species to memorize a 1337-alteration that saves them having to hit a Shift key? It seems like a rather niche micro-optimization that certainly can't be worthwhile to too many typists, even if we ignore the obnoxiousness it imposes on readers.
Which, tl;dr, my point's just that "C02" might be a cute 1337 substitution if you don't usually read a lot of chemical formulae, but if you do, it invokes a parsing error that you either have to consciously resolve or else memorize a new slang term to avoid.
It wasn't a deliberate substitution, just a result of typing quickly, having 'O' next to '0', and having them be hard to distinguish with the font I was using.
The objective was to find an eco-friendly method to do so. Thus the living walls, and not just outdoor air intake (which would cost power to run the fans, similar to the energy footprint of running an AC). I can't comment on average outdoor air, but plants certainly helped.
Were the visual and odor aspects hidden from the participants? If you put some monkeys in a blank white room to do some tasks and some others in a room with visible Flora and the smell of Earth and plants, I suspect the lattre group would perfo better even with O2 an CO2 levels constant.
Sorry.. I meant do expirements measuring cognitive performance relative to co2, find an optimal level, and if so is that level what you'd typically get outdoors?
I unfortunately do not have a paper but I did find an article about it and it seems they've deployed it in real life with success: https://www.architectmagazine.com/technology/breathe-in-case...