
Associations of Cognitive Function with Carbon Dioxide and Ventilation (2016) - homarp
https://dash.harvard.edu/handle/1/27662232
======
ggreer
I keep seeing these studies showing that tiny increases in CO2 impair
cognition, but I have trouble believing them. The US navy runs their
submarines with CO2 levels that vary from 300-11,300ppm.[1] Their own studies
show that CO2 levels of 4% (40,000ppm) do not affect cognition[2]:

> Thus, CO2 at 40,000 ppm for 2 weeks did not affect performance on multiple
> tests of cognitive function in physically fit young airmen, a population
> probably not unlike submariners.

CO2 tended to cause poor sleep, headache, and hand tremor before it caused
cognitive issues.

Another bit of evidence that makes me doubt these recent studies is that the
levels of CO2 in your lungs are much higher than what is in the atmosphere.
Exhaled air is around 5% CO2. Each breath doesn't replace 100% of the air in
your lungs. If you have a container that is 5% CO2 and you replace 80% of it
with air containing 400ppm CO2, you're down to 10,320ppm. Inhale 1,000ppm CO2
and your lungs will be at 10,800ppm CO2. In other words: a 250% increase in
atmospheric CO2 levels only causes a 4% increase in lung CO2 levels at the
beginning of a breath. If such tiny changes significantly affected cognition,
we would see impairment happen in many more circumstances (such as when
walking or smoking).

If something's impairing cognition in stuffy rooms, I don't think it's CO2.

1\.
[https://www.nap.edu/read/11170/chapter/5#47](https://www.nap.edu/read/11170/chapter/5#47)

2\.
[https://www.nap.edu/read/11170/chapter/5#54](https://www.nap.edu/read/11170/chapter/5#54)

~~~
lamontcg
More recent studies than those from the 60s and 70s though have found that
cognitive issues show up in different kinds of tasks:

[https://ehp.niehs.nih.gov/doi/full/10.1289/ehp.1104789](https://ehp.niehs.nih.gov/doi/full/10.1289/ehp.1104789)

Their measures of focused activity were nearly unchanged, while measures like
initiative and strategy declined somewhat at 1,000ppm and sharply at 2,500ppm.

~~~
lamontcg
And this study found:

[https://journals.sagepub.com/doi/10.1177/1541931214581192](https://journals.sagepub.com/doi/10.1177/1541931214581192)

"Within the limitations of this experiment, (1) breathing 4% CO2 for one hour
slows information processing by impairing the response selection stage of
processing and not the stimulus encoding stage and (2) with increasing time-
on-task information processing is increasingly impaired and the magnitude of
this effect is similar for each processing stage. These findings help define a
useful model of human information processing and identify the locus of CO2
impairment."

That could explain the null results found by the Navy.

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tjohns
The conference rooms at my office often have CO2 sensors on the wall.

In the interest of science, I discovered a few strong breaths of air next to
the sensor will kick the HVAC on full blast.

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curtis
I've often complained that flying is the most exhausting thing you can do that
involves not doing anything at all. Long meetings are number two on the
list...

~~~
travisjungroth
That's from hypoxia. Being in an airliner is equal to being at about 5,000'.
The reduced air density means less oxygen and you get fatigued (also reduces
cognition, coordination, vigilance and night vision).

~~~
caymanjim
Closer to 8000' in commercial airliners. While it's technically hypoxia,
insofar as it's less oxygen than at sea level, I don't know if 8000' is enough
to cause the effects you're describing. Anecdotally, I'm a fat smoker, and I
don't seem to notice any of those negative effects at 8000', but I certainly
notice them at around 12000' or so.

~~~
travisjungroth
I didn't realize it was that high. I guess I was remembering from the Cessna
421 I flew, but we were cruising at more like FL250. Looks like the 787 brings
it down to like 6k though.

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1e-9
Many residential buildings have horrible ventilation as they commonly rely on
the random forces of wind and thermal gradient to force fresh air through
cracks around windows and doors and through other holes in the building
envelope. This can lead to long periods of time with ventilation far below
ASHRAE standards. Conversely, if you are getting enough ventilation through
leakage, the quality of the air may be poor due to pollen or other pollutants.
One way to address this is to set up a positive pressure situation with a high
quality air purifier pulling fresh outside air through a ducting system like
[https://www.iqair.com/sites/default/files/documents/InFlowW1...](https://www.iqair.com/sites/default/files/documents/InFlowW125InstallationInstructions_105_20_20_11_Mar2012.pdf).
If you don't own your home or just don't want to run a duct through your wall,
you can add a window kit such as the LG COV31735301 Room Air Conditioner
Exhaust Duct.

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elchief
Just wait til atmospheric CO2 hits 600ppm!

~~~
arcticbull
I guess we found out how idiocracy actually happens haha

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PorterDuff
I've found that 5 minutes is about when the impairment starts.

~~~
oh_sigh
How many people/what size room?

~~~
BooneJS
It’s a joke.

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mattjaynes
David Heinemeier Hansson (DHH of Ruby on Rails fame) gave a great talk
recently on air quality:
[https://youtu.be/MRqh8oLY7Ik](https://youtu.be/MRqh8oLY7Ik)

Apparently his wife was showing signs of Formaldehyde poisoning after they
moved into a newly constructed home. This motivated him to investigate the air
quality in their house and he bought industrial-level air testing equipment to
figure out what was going on (since many of the consumer-grade devices were
wildly inaccurate). He also did a deep dive into the research on how air
quality impacts cognitive and creative performance. Fascinating talk, worth
watching.

~~~
keithpeter
Just reached 4:30 sec and he has mentioned lack of ventilation in their house,
which I know to be a common problem with new build housing through dealing
with condensation problems.

UK: most of the bog standard double glazed windows have a little vent up at
the top so you can open a fairly small slat and get a small air gap.

35min: his risk priorities are mould, particulate matter, volatile organic
chemicals, co2, on the grounds that CO2 is easier to manage

~~~
0db532a0
The problem is that if it’s cold enough outside that you need double glazing,
then opening the slats would negate the benefit. Heat exchangers really are
the only solution here, but of course the UK seems to be at least a century
behind on residential building standards compared to anywhere else I’ve lived
in Europe.

~~~
fulafel
The idea is to minimize heat loss from conductivity through the windows, but
accept the heat loss that comes with venting air.

Old single-pane windows were missing the vent probably because a) old building
codes let you have less ventilation or b) the old windows were leaking air
around the frames in addition to conductively leaking heat through the single-
pane glass.

~~~
keithpeter
Acoustic isolation is a motivator for double glazing in some locations. And
the vents are _small_ (6mm by 30cm full open).

Most Victorian era houses have 'air bricks' in various locations (terracotta
bricks with a small grid of holes in them) and the houses were pretty leaky.

UK government is moving to remove * cooking on open gas from the building
regulations for _new_ homes in a few years (big methane/burning fume
generator). Eventually as post above parent says we will move to more rational
ways of heating the houses. Piping an inflammable gas to millions of houses
has always struck me as a bit strange.

~~~
0db532a0
I really hope they don’t. One, electric cooking is shit however you wrap it
up. I have found a large correlation between people being okay with electric
cooking in places I’ve lived and also not cooking/not knowing how to cook.
That’s probably the only way electric cooking has become so prevalent in the
UK. Who would want to anyway if stuck with electric?

Two, I do not want to have to wait hours for the tank to heat up again after
someone takes half a minute too long in the shower.

The power just isn’t there when it comes to electric water heating. I am very
glad to live in a house with a combi gas boiler right now where the whole
house can have a shower on demand, straight after each other if need be.

Until we all have massive heat pumps or some other way of getting high-power
heat from domestic electric, it makes complete sense to me for us to pipe gas
around while most of our domestic energy usage in the UK goes to heat.

~~~
dangravell
Induction cooking is electrical cooking. Do you mean conductive electrical
cooking?

~~~
0db532a0
Yes, induction does have higher max power in comparison to the terrible
resistance hobs and the slightly less terrible ceramics. The problem with
induction is that it doesn't work when you don't have a completely even bottom
(on your cookware). Cookware warps over time. You can get induction wok
stoves, but that misses the point. You can also get a nice gas stove with a
massive centre hob for your wok needs.

Even forgetting the evenness issues, which ceramic stoves share too, the
modulation just isn't there. Lower power on induction and ceramic means
alternating the same power on and off. This does average out over the long
term to a lower power, but what if you need a constant lower power? The power
settings also tend to be discrete and far apart, which is again completely
useless for a lot of fine applications. It's completely useless for instance
you want your pilau rice to steam properly at the end of cooking at a low
power in a shallow, broad stainless steel pan (as it should be), rather than
sticking to the bottom of the pan.

~~~
DanBC
Warped cookware works fine with induction hobs.

------
dbg31415
Not just CO2, but heat lowers performance. Every time I go into an office and
the AC is set to like 75 or higher, I just feel groggy. Set it to like 72, or
lower, and it's a lot easier to stay awake. 65 or so in the winter is perfect,
I love it when it's brisk in the office -- I get in early intentionally and
before 8 AM it's nice and cool.

~~~
abootstrapper
Got a source on how heat lowers performance? Because anecdotally, I beg to
differ. I like it around 76F.

~~~
dbg31415
* Winter Wakes Up Your Mind--and Warm Weather Makes it Harder to Think Straight - Scientific American || [https://www.scientificamerican.com/article/warm-weather-make...](https://www.scientificamerican.com/article/warm-weather-makes-it-hard-think-straight/)

"Despite this minimal deviation in temperature, the researchers found
remarkable differences in cognitive functioning. In one lab study,
participants were asked to proofread an article while they were in either a
warm (77°) or a cool (67°) room. Participants in warm rooms performed
significantly worse than those in cool rooms, failing to identify almost half
of the spelling and grammatical errors (those in cool rooms, on the hand, only
missed a quarter of the mistakes). These results suggest that even simple
cognitive tasks can be adversely affected by excessive ambient warmth."

~~~
ordu
lol

When it is cold enough, body starts to shake, each muscle is convulsing,
consuming glucose and making it into heat.

Brains use a lot of power that comes from methabolism. Could it be that human
body tries to warm itself using brains to utilize glucose by doing cognitive
tasks?

What cognitive tasks are most energy consuming?

------
jey
Has this paper from 2015 been replicated or otherwise followed up since? I
tried a quick google search but all I found seemed to be referencing this one
study.

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PakG1
So if I want to pull one over various people in a meeting, I need to make
sure:

1\. Organize a long meeting.

2\. Invite as much people as possible.

3\. Pitch my stuff at the end of the meeting.

4\. Profit.

I jest.

edit: 5. Bring a small oxygen tank to keep myself sharp!

~~~
sametmax
No because when people are impaired, they tend to choose the path of least
resistance, which is often maintaining the status quo.

~~~
marcosdumay
So, add some people that you know will agree with you.

That has all the smell of a con artist, and some people are good on sensing
this. Others aren't, and if the population of the meeting is random enough,
many people will fall over it. It is also not a new discovery.

------
danw1979
I've only read the abstract but it seemed to imply that the well ventilated
office with artificially high levels of CO2 (labelled Green+ ?) resulted in
higher scores than the well ventilated environment with low CO2.

Am I reading this correctly ?

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chroem-
In real life this is a non-issue since all commercial buildings that have
undergone any sort of renovation in the last 25 years have CO2 monitoring
integrated into their HVAC control system.

~~~
lvturner
In which country and under which building standard? Because I can tell you,
I’ve been in plenty of modern buildings all over the world where there was
clearly not enough oxygen in several of the rooms.

~~~
antisthenes
Minor nitpick, but _not enough oxygen_ is not the same as too much CO2.

~~~
caymanjim
That's not a minor nitpick. It's important to note the difference. If you
double the amount of CO2 in a room, that's still not a lot of CO2, and if you
displace oxygen to double it, you've still got tons of oxygen. Humans are
hyper-sensitive to higher CO2 levels, even while still getting a lot of
oxygen.

------
ianlevesque
2 hour meetings? At my workplace anything >30 requires some serious
justification.

~~~
staticassertion
Sure but one room is probably hosting > 2 hours of meetings in a day.

Doors opening probably helps though?

~~~
jey
Most commercial office buildings have forced air ventilation systems (in the
USA).

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em3rgent0rdr
didn't read it, but what if you instead crank extra O2 in the office...do
people's cognitive function improve?

~~~
i_am_proteus
Submarine anecdote: we'd bump up oxygen levels a little bit to make the crew
more alert. Oxygen had a max spec that we worried about because high oxygen
could cause fires.

Anecdotally a submarine crew is too exhausted to feel effects from CO2 when
it's in spec. If atmospheric controls were down and CO2 shot up, headaches
were normal. Far from a controlled experimental environment.

------
tootie
I had 8 hour meetings two days in a row last week. And we were all feeling it
at the end.

------
mettamage
A former client of mine, Healthy Workers, is solving this problem by creating
smart buildings that measure things such as CO2 and O2.

They are hiring a backend developer and other non-technical roles in
Amsterdam.

[https://healthyworkers.recruitee.com/](https://healthyworkers.recruitee.com/)

~~~
chroem-
But virtually all buildings already do this. In fact, it's often part of the
(legal) building code.

~~~
JamesCoyne
No. Building Codes typically refer to a standard like ASHRAE 62, which
basically prescribes a fresh-air rate for a space by size and occupancy.
Demand based ventilation is not common in my experience (small commercial
buildings).

~~~
chroem-
I suppose it could be the difference between high rises and smaller
structures. My projects have been very particular about it.

~~~
JamesCoyne
Probably right. Many clients view it only as an added expense for equipment.
Beyond that, there is a certain type of client/owner who is skeptical of any
automation beyond a bi-metallic thermostat.

------
booleandilemma
This explains why we went with Node for our next project.

~~~
quickthrower2
Did you reply to the wrong thread?

~~~
war1025
He's suggesting that the impaired cognitive function from the increased CO2 is
why they picked Node. (I.e: a joke)

~~~
quickthrower2
Ah ok. That went over my head, but I get it now.

------
buttslasher69
Wow. I wonder what sleeping in a closed room does every night.

~~~
Simon_says
A while back there was a long thread on slatestarcodex on people's anecdotes
about this question.

~~~
jfkw
[https://slatestarcodex.com/2018/08/23/carbon-dioxide-an-
open...](https://slatestarcodex.com/2018/08/23/carbon-dioxide-an-open-door-
policy/)

------
leemailll
I suspect the effect kicks in much sooner than 2hrs

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ambicapter
Can't imagine what the CO2 level of Congress is like.

------
crankylinuxuser
At the PPM required for cognitive impairment, how long does someone need to be
in the area for this to measurably affect them?

I know at my workplace, we tend to have short meetings (thankfully!). However
we inhabit the upper sections of old downtown square, which was 7 different
buildings architecturally "glued" together. But when we do have meetings,
they're back to back with other meetings given the shared meeting space.

But this is even more sinister if what I'm thinking is correct: the toxins
accumulate even if it doesn't impair the first meeting (or 3), and effects
worsen through the day for anyone in there.

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0815test
All that extra CO2 could also raise temperature locally inside the meeting
room, at least if it's got sunlight shining into it somehow. And the increased
temperature will probably make the people involved feel even less comfortable
and thus less able to think clearly! We'll need to develop radically new
technology to scrub all this CO2 out of the planet's meeting rooms and save
the world from its detrimental effects.

~~~
saagarjha
The greenhouse effect is not appreciable at this scale.

