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CO2 make dumb
October 18, 2012 11:25 AM   Subscribe

Have you ever been in a room with lots of people and not great ventilation. Or even a room with normal ventilation. You may be cognitively impaired due to elevated levels of CO2 once considered safe now thought enough to make you a little dumb. 600ppm is now thought too much, but “there are plenty of buildings where you could easily see 2,500 ppm of CO2 — or close to it — even with ventilation designs that are fully compliant with current standards.. classrooms frequently exceed 1,000ppm."

The 36-page paper is freely available. The 2011 average annual concentration of CO2 in the atmosphere (Mauna Loa Observatory) is 391.57 ppm, and steadily rising.
posted by stbalbach (50 comments total) 55 users marked this as a favorite

 
Is there a way to test the CO2 content of the air in a room without spending like a couple hundred bucks on a gadget?
posted by kafziel at 11:27 AM on October 18, 2012 [6 favorites]


Here's a test kit for $20.95.
posted by swift at 11:35 AM on October 18, 2012 [3 favorites]


This so explains the lack of work I get done at work*, and why I feel much better after I open the window. I really should get a plant.

*metafilter has nothing to do with it
posted by jb at 11:36 AM on October 18, 2012 [3 favorites]


How many indoor plants would be needed to offset the CO2 production of 20 students?
posted by brenton at 11:37 AM on October 18, 2012 [4 favorites]


Finally, a theory that explains parties.
posted by DU at 11:39 AM on October 18, 2012 [31 favorites]


Ugh, I do three-hour lessons in a tiny attic classroom with very little ventilation. By hour 2.5 everything becomes a huge slog for everyone. I'm glad to know it might not just be poor teaching on my part.
posted by sundaydriver at 11:39 AM on October 18, 2012 [1 favorite]


One of my job duties is school indoor air quality. I try to explain about how CO2 levels are a benchmark for air quality. I sometimes do a demo in which I stand before a full classroom with the ventilation turned off, and explain my job to the class. Slowly, the kids start to mentally bounce off the walls, even with as riveting a speaker that I am.

Then I introduce ventilation, and everything mellows out. It is usually an "AHA" moment for the teachers, who generally learn something about how best to manage a classroom environment.

Up to now, I have believed that the cognition-impairment from high CO2 levels was due to all of the other stuff that comes off of, and out of, people's bodies, including skin dander, hair dander, carbon monoxide, etc. My technical word for all of this stuff is "cooties." I have always told people that it is NOT the CO2 that is causing the discomfort and eye irritation.

It is not uncommon, in an elementary classroom, especially after recess, for the CO2 to approach 2000ppm, especially in an old building equipped with unit ventilators. And just this year, while responding to a complaint, I found that the multizone ventilation/heating unit was not working for a wing of about 10 classrooms. It was just off and no one had noticed. This is more common than one would imagine.

So this is interesting, and I will need to change my thinking. Other than fresh air -> higher learning, which I always try to impart.

(and upon preview, I would be skeptical of cheap monitoring equipment)
posted by Danf at 11:41 AM on October 18, 2012 [41 favorites]


The reason CO2 is lower on Metafilter than Reddit and Youtube?

The Green.
posted by zippy at 11:42 AM on October 18, 2012 [23 favorites]


Finally, confirmation of my hypothesis that it's other people that make me stupid ...
posted by carter at 11:44 AM on October 18, 2012 [9 favorites]


brenton: How many indoor plants would be needed to offset the CO2 production of 20 students?

My offhand guess is 'way too many'. You are trying to counteract the biomass of 20 students (I'm guessing about 100-200 lb. each) with a fast, mammalian metabolism. Now, you're trying to counteract that with plants... which have slower metabolisms, aren't in natural sunlight, and have to respire as well as photosynthesize. My tentative estimation is that you'd need at least an equivalent biomass of plants, and probably way more than that, even.

I'd just try to get a fan and an open window.
posted by Mitrovarr at 11:44 AM on October 18, 2012 [1 favorite]


MetaFilter: Make sure the windows are open before clicking post.
posted by phaedon at 11:47 AM on October 18, 2012 [3 favorites]


I guess this is a forcing downward on global IQ due to rising background CO2. Although there are other forcings upward that are probably stronger (health, diet, education). But at some point if the background levels reach 600+ it may be an issue, since the energy needed to ventilate a room below the outside level would be very high, and thus create even more CO2. We need to get smart before we get dumb.
posted by stbalbach at 11:50 AM on October 18, 2012 [1 favorite]


At 2,500 ppm, large and statistically significant reductions occurred in seven scales of decision-making performance (raw score ratios 0.06-0.56), but performance on the focused activity scale increased.

That last is interesting. So the teachers that snarled "Get back in your seat!" when a kid approached with a question, and were always seemingly engrossed in filling out district forms in class ..they weren't burned out, they had just been indoors all day?
posted by pernoctalian at 11:51 AM on October 18, 2012


I teach in a building that was completed at the beginning of 2011 so the designers have considered carbon dioxide levels and made an effort to improve air quality.

Each room has a little wall meter that tells us the CO2 ppm. On a normal day with doors and windows closed (like throughout winter) it regularly gets up to 1500. Now that we are watching it (no one had actually explained what it was for until a few months ago!), I notice that the children are a bit more lethargic and slow when the CO2 levels are up there. We open the skylights and windows to let air flow through and that gets the levels down to about 900ppm. It's been harder in winter - the cold air probably wakes us up a bit more - but now spring is here and I will be watching with interest how it affects the children's learning.
posted by tracicle at 11:53 AM on October 18, 2012 [2 favorites]



I guess this is a forcing downward on global IQ due to rising background CO2.


Wait, so rising CO2 levels explain why it is that people refuse to accept that CO2 levels are rising?
posted by stevis23 at 11:54 AM on October 18, 2012 [22 favorites]


This article sites the FAA CO2 standards aboard passenger planes as being compliant up to levels of 30,000 PPM - substantially higher during boarding and de-boarding.

That explains so much.
posted by rongorongo at 11:58 AM on October 18, 2012 [4 favorites]


Wait, so rising CO2 levels explain why it is that people refuse to accept that CO2 levels are rising?

Oh, this is a brilliant positive feedback cycle...
posted by six-or-six-thirty at 12:11 PM on October 18, 2012 [3 favorites]


Does this explain the presidential debates?
posted by bitslayer at 12:12 PM on October 18, 2012


I'll be The House of Representatives and The Senate have really poor ventilation.
posted by COD at 12:12 PM on October 18, 2012 [5 favorites]


Powerpoint has a similar effect.
posted by ErikaB at 12:17 PM on October 18, 2012 [3 favorites]


A related and not-terrible ted talk!
posted by jsturgill at 12:30 PM on October 18, 2012


Before somebody jumps in to say it's probably because of Oxygen displacement (somebody usually does, in CO2 discussions), it's not. CO2 is toxic in its own right; enough of it will kill you, even if you're breathing 80% Oxygen.
posted by Kirth Gerson at 12:33 PM on October 18, 2012 [1 favorite]


Interesting. I control to 800 ppm carbon dioxide in the buildings I design. Thanks for this, I'm going to show it to some folks involved in building automation.
posted by Sternmeyer at 1:02 PM on October 18, 2012 [3 favorites]


stbalbach: I guess this is a forcing downward on global IQ due to rising background CO2. Although there are other forcings upward that are probably stronger (health, diet, education). But at some point if the background levels reach 600+ it may be an issue, since the energy needed to ventilate a room below the outside level would be very high, and thus create even more CO2. We need to get smart before we get dumb.
Doubt that's at a noticeable level, though (IQ of the tester aside). The article discusses increases that are 50-200%; climate change is enacted by a couple percent change in CO2 levels.
posted by IAmBroom at 1:04 PM on October 18, 2012 [1 favorite]


I am chemically stupid. Could someone explain the difference between carbon monoxide and carbon dioxide?
posted by RandlePatrickMcMurphy at 1:06 PM on October 18, 2012


The OSHA PEL (Permissible Exposure Limit) for CO2 is 5000ppm. It would be hard to get to the level with just breathers in a closed room. In fact, the only time I have personally seen levels to excess of 5000ppm is when we were doing a mold abatement job using blasting of dry ice. Since dry ice is CO2, it was a DOH moment, because we had the doors closed due to winter outside.
posted by Danf at 1:07 PM on October 18, 2012 [1 favorite]


RandlePatrickMcMurphy: I am chemically stupid. Could someone explain the difference between carbon monoxide and carbon dioxide?
Carbon dioxide = CO2= C + O + O. Pretty darned stable, but it forms a weak acid when mixed with water (such as in soda pop), and is key to your body's suffocation-detection system: your body doesn't know how much oxygen is in your blood, but it does put out warnings if the CO2 gets too high. Most of the time, it's the same thing.

Carbon monoxide = CO = C + O. Highly reactive. Once dissolved in your bloodstream, forms all sorts of random chemicals that you don't want, and fucks everything up fast. Again, you can't detect it - it doesn't even have a smell. Usually formed by fires that don't get enough oxygen - like in poorly mixed engines, or by candles in a closed-off-room.
posted by IAmBroom at 1:15 PM on October 18, 2012 [3 favorites]


RandlePatrickMcMurphy, you actually just explained the difference yourself without realizing it, when you wrote the names of the molecules. That's one of the cool things about chemical names -- they tend to explain themselves as long as you know how to read them. In chemistry, "mono" means one and "di" means two. Oxide means oxygen that's attached to something else. Carbon monoxide is one carbon atom with one oxygen atom attached. Carbon dioxide is one carbon plus two oxygen atoms.

What makes carbon monoxide so much more immediately toxic to humans than carbon dioxide is that the single oxygen atom in the molecule is kinda dangling there, wanting to bond to other things (oxygen really likes to bond to things, a lot).

If you breathe in carbon monoxide, the CO winds up binding to the places in your body that regular oxygen is supposed to bind to. It sticks to your red blood cells where the oxygen usually sticks, preventing the cells from taking up and transporting oxygen through your body.

Which can cause you to suffocate in a room full of perfectly useful oxygen!

Science is a wonderful tool for learning all the ways the world can kill you.
posted by BlueJae at 1:17 PM on October 18, 2012 [5 favorites]


key to your body's suffocation-detection system: your body doesn't know how much oxygen is in your blood, but it does put out warnings if the CO2 gets too high

This reminded me that there is a fire suppression system based on lowering the oxygen available for fires. People can survive in these lower O2 atmospheres because a component of Inergen is carbon dioxide, which allows the human body to adapt to the environment of reduced oxygen that is present after discharge of agent. Discharge of Inergen results in an approximate 2% concentration of carbon dioxide within the space. This directs the human body to take deeper breaths and to make more efficient use of the available oxygen.

I have allowed myself to be a guinea pig, allowing myself to be in a chamber with 14% O2 but higher CO2. Ordinarily, I would have passed out and eventually died, but with the higher O2 uptake, I did just fine, at least for a few minutes.
posted by Danf at 1:25 PM on October 18, 2012 [5 favorites]


It occurs to me that this CO2 business could also go a fair way to explain the stupid behavior of mall shoppers during the holiday season, crowds leaving stadiums, etc.

According to my quick and dirty internet research, both Bayer (a bit biased) and NASA (presumably less so) recommend one average sized houseplant for every 100 square feet to filter the air in an average home. I'm not clear on whether that estimate is specifically for filtering CO2 or the more nasty-sounding stuff plants can also take care of, like formaldehyde and benzene.

But of course, offices and schools are much more heavily populated during the daytime than the average home. I wonder three or four plants per classroom in a typically sized U.S. school would have any impact? That seems like a manageable number. Other studies have shown that natural light helps students learn. Maybe schools should be investing in skylights.
posted by BlueJae at 1:36 PM on October 18, 2012 [1 favorite]


Wow. I just assumed I got more done at work in the early hours (before everyone else shows up) only because I was fresh and had fewer distractions.
I'm definitely going to make more trips outdoors for fresh air now.
posted by orme at 1:37 PM on October 18, 2012 [2 favorites]


There is a great scene in Apollo 13 where the astronauts get very close to freaking out while breathing too much carbon dioxide. Some of my neighbors never open their windows. The manager even sends out crime fight notices every few months instructing us to keep our windows closed.

The first thing I do when I wake up every morning is open the windows and air the place out. Unless I have to pee. If I have to pee I do that first.
posted by bukvich at 1:48 PM on October 18, 2012


The first thing I do when I wake up every morning is open the windows and air the place out. Unless I have to pee. If I have to pee I do that first.

Combining the tasks would make you super-efficient, if not too popular with your downstairs neighbors.
posted by maxwelton at 1:57 PM on October 18, 2012 [5 favorites]


According to my quick and dirty internet research, both Bayer (a bit biased) and NASA (presumably less so) recommend one average sized houseplant for every 100 square feet to filter the air in an average home

B.C. Wolverton, the source of the so-called NASA info, is primarily concerned with volatile organic chemicals (formaldehyde, etc.). I interviewed him once -- he's a super-interesting guy*, and 15 years ago he really anticipated a lot of now-mainstream environmental concerns (off-gassing of carpets, mattresses, other manufactured home stuff; stinky chemicals in unventilated spaces). He attributed so-called Sick Building syndrome to VOCs. I wonder what he would have to say about this.

Great post.

*I didn't write this. My story is lost to the great black hole of the pre-internet era.
posted by purpleclover at 2:01 PM on October 18, 2012


Combining the tasks would make you super-efficient, if not too popular with your downstairs neighbors.

I was woken one morning by a splattering sound coming from outside. Turned out the guy across the street was straight peeing out of his third floor window, onto his own house's porch. Thankfully he was shielded somewhat by the curtains, but I think it was the son of the house, because shortly afterwards I saw the dad peering out of the second floor window looking confused at the tiny splash of "rain".
posted by lucidium at 2:16 PM on October 18, 2012


Gah, VOCs are volatile organic compounds, not chemicals. (I mean, they're also chemicals, but that's not what the C in VOC stands for.)
posted by purpleclover at 2:33 PM on October 18, 2012


If you have radiant heating (electric or boiler) and don't want to open your windows (say if it's like -30 outside), get a heat-recovery ventilator (HRV) or fancoil. Especially important in a house that is well-insulated.
posted by Pruitt-Igoe at 2:35 PM on October 18, 2012 [1 favorite]


Combining the tasks would make you super-efficient, if not too popular with your downstairs neighbors.

This explains the unpopularity of trickle-down economics with those on the ground floor.
posted by zippy at 2:37 PM on October 18, 2012 [4 favorites]


This may constitute just the excuse I've been looking for...
posted by Fists O'Fury at 3:52 PM on October 18, 2012 [1 favorite]


BlueJae: Bayer (a bit biased) and NASA (presumably less so) recommend one average sized houseplant for every 100 square feet to filter the air in an average home

Bayer is probably using NASA's research, which is also the basis of the TED talk linked above. The research was also lead to the publication of How to Grow Fresh Air.
posted by Decimask at 4:47 PM on October 18, 2012


I had not considered this issue re: classrooms. Thanks for posting this.
posted by LobsterMitten at 5:26 PM on October 18, 2012


If the internal carbon dioxide monitor looks at carbon dioxide dissolved in some bodily fluid rather than assessing the amount in air directly (somehow), and this effect is independent of oxygen concentration over a few percentage points, as seems to be the case, then it might be possible to defend oneself against it (through an application of LeChatlier's principle) by increasing one's overall acidity, since CO2 itself raises acidity when it dissolves in water.

So would you like coffee or orange juice this morning?
posted by jamjam at 6:05 PM on October 18, 2012


For the Drosophila geneticists: This is why you can't spend the whole day in the flyroom. It makes you derptacular and weird, empirically. ALSO this is why you should always make sure the CO2 is off at your station when not in use.
And from now on, when ordering the CO2 canisters I will inwardly call it the "stupid juice".
posted by Cold Lurkey at 6:13 PM on October 18, 2012 [4 favorites]


The college I went do, with buildings designed by all kinds of famous Brutalist architects, had giant windows that didn't open, and absolutely no air flow of any kind. I would sit there for 3 hours at a time, struggling to focus, struggling to breathe, listening to my brain cells singing their swan songs and dying off one by one. It's pure torture. But they were such brilliant, famous architects so obviously they knew how to design buildings.
posted by bleep at 6:22 PM on October 18, 2012 [3 favorites]


Danf: "This reminded me that there is a fire suppression system based on lowering the oxygen available for fires."

Halon is still more awesome, and is also easily survivable.

As far as CO2 stupidity goes, I'm glad my house is poorly insulated. At least during the months when it's not stupid cold or stupid hot. During that half of the year, the heating/cooling bill cures me of the desire to have air exchange.
posted by wierdo at 7:43 PM on October 18, 2012


If you have radiant heating (electric or boiler) and don't want to open your windows (say if it's like -30 outside), get a heat-recovery ventilator (HRV) or fancoil. Especially important in a house that is well-insulated.
posted by Pruitt-Igoe at 5:35 PM on October 18


This sounds pretty good, but any idea how effective it would be when your home lacks ductwork? Would it be a waste to install one without the ability to circulate the fresh air around the house?
posted by orme at 4:16 AM on October 19, 2012


Halon is still more awesome, and is also easily survivable.

Yes it is. But the knock on Halon is that it has been linked with ozone depletion.
posted by Danf at 8:43 AM on October 19, 2012


COD: "I'll be The House of Representatives and The Senate have really poor ventilation."

Can't speak for the House, but the Senate's got a pretty epic circulation/HVAC system in place to prevent the Senators from being cooked by the TV Lights (2kW PAR64s, IIRC. The rest of the world long ago moved on to dichroic reflectors and LEDs to avoid cooking their talent, but every upgrade we've planned for the Senate Chamber has been gotten bogged down in the planning/funding process.)

(Also, *cough* the room's almost never full. I think I can count on one hand how many times I saw more than a few people present in the chamber this year...)
posted by schmod at 9:38 AM on October 19, 2012 [3 favorites]


Edit window's gone, but I swear I didn't mean to write "has been gotten" up there. *Opens window, turns on fan*
posted by schmod at 10:13 AM on October 19, 2012


RE: HRVs
Generally you want .3 to .5 complete air changes per hour. What that means is if your house's volume is 1000 cubic feet you need to bring in 300-500 cubic feet of air every hour. A HRV allows you to recover some of the heat (or lack of heat in the summer) from the exhaust air stream instead of just venting it to the atmoshpere there by reducing your heating (cooling) costs.

If you don't duct that air into individual rooms or alternately suck the air from individual rooms then the effect is going to be concentrated in the the room with the HRV. It's still better than no exchange but it isn't ideal.

HRVs aren't really all that expensive; a house without ducting that has a problem spot or two can be addressed with two smaller units rather than one whole house unit.

A house built without taking specific steps to mitigate infiltration is going to reach that .5 easily without powered air exchange. It'll also lose a lot of heat via that air exchange.
posted by Mitheral at 3:41 AM on October 23, 2012


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