I think this is an important question to answer, but the shehab paper (the first link) provides vertically no useful information. They didn't blind the assessors carrying out the cognitive studies, which on its own invalidates their conclusion. They also didn't randomize the ordering, but appear to have "investigated for order effects", found "no statistically robust difference", then proceeded to have every participant do the "post exposure" test second, making it highly likely that fatigue alone could explain their effects. With only 30 subjects, their tests for ordering effects are likely underpowered.
Also note that they did 11 different tests, but didn't appear to correct for multiple comparisons [1]
This would be a really interesting problem to study, but you'd probably want to look at academic performance in college students before and after transfer between universities e.g urban vs rural (presuming you can measure differences in pollution) between the two, you'd expect to see a relative drop in academic performance going from rural to urban, now that would worry me. But this study is unhelpful.
Just want to say it's impossible to tell which paper you're referring to.
The first link on the page isn't a paper. The word shehab doesn't appear anywhere on the page. The word shehab doesn't appear anywhere in the first paper linked. The three quoted sentences / fragments you provide don't appear anywhere in the first paper linked. I opened some of the papers and didn't see any with n=30.
If the effects are permanent then your results would be inconclusive if studying the same people transferring between polluted and non polluted universities.
> "Exposure to CO2 and VOCs at levels found in conventional office buildings was associated with lower cognitive scores than those associated with levels of these compounds found in a Green building." – Allen et al 2016. The effect seems to kick in at around 1,000 ppm of CO2.
The last time this came up I bought a CO2 meter for my office. I was quite surprised how often it went over 1,000. Outside air runs around 450.
I increased the duty cycle of the house fan, and open a window when it reaches 800. Right now I'm at 505.
In the comments on that lesswrong post from a few years back, you raised a good question that is perhaps easily answered:
it has the same issue as Kurzban's blood-glucose/willpower
criticism: if the brain needs more oxygen than it's getting
why doesn't one simply breath a little more? While sedentary
during these sorts of tasks, you have far more breathing
capacity than you should need
Seems quite likely (or at least very possible) that we've outpaced evolution here, right?
Prior to the industrial revolution, seems our bodies would never have needed to adapt to a rapid spike in environmental CO2 levels. Our brains are necessarily good at signaling the body when they need more oxygen; they're not necessarily good at realizing when they're dealing with other issues they're not adapted to react to.
I believe there may be a common misunderstanding the relationship between CO2 levels and oxygen in one's body, at least as it was explained to me by doctors during my mom's struggles with COPD.
Blood oxygen saturation levels and CO2 levels are not inversely correlated. One of the problems with late-stage COPD and reduced lung function is that while it's relatively easy to get a person's oxygen levels up (just administer oxygen!) they still suffer the effects of excess CO2 in the blood. A late stage COPD sufferer can have > 95% O2 saturation in their bloodstream and still suffer the other effects (including cognitive issues) that result from the excess CO2.
(Apologies for responding you wrote four years ago)
Thanks for these links Gwern, down the rabbit hole I go.
But how would you summarize the situation? Is it that there's not a definite study that proves the whole thing?
One of the big trends in green/sustainable building is creating relatively air tight buildings in order to cut down on heating and cooling costs (see: Passiv Haus, Passive House, Pretty Good House). In order to do that, though, mechanical ventilation is needed. As a result, Heat-Recovery Ventilation & Enthalpy-Recovery Ventilation residential units can be installed for only $2k-$4K. Seems like a worthwhile investment (for when it’s not convenient or possible to open a window).
I live in a relatively new apartment building that has heat recovery system installed in all apartments by default. My apartment is 73sqm, the ventilation unit is rated at 300m3/h. The building is located in a busy part of town with lots of traffic around. The city has a humid continental climate (Dfb) so it does get pretty cold during winter.
It does help a lot and I couldn't imagine living without it.
- Removes CO2 - averages ~650ppm in all rooms, almost never goes higher than 1000ppm (3 person household).
- Retains up to 85% of heat (based on the specs) using the exchanger, but also has an active electric heater inside that can be turned on in winter for ultimate comfort.
- Removes moisture from the bathroom and kitchen and dumps it into the drain via a separate drain pipe.
- Isolates from the outside noise as you can keep your windows closed shut all the time.
It does have some drawbacks however:
- Up to +6dB noise in rooms when running at full power (I run it at 20% at night which only adds ~+1dB).
- F7 class filters need to be changed every 3-6 months (~50€).
- Air intake grill with a pre-filter mesh needs thorough cleaning every 6-12 months as it usually gets clogged with debris in spring and autumn.
Not sure if it's due to these drawbacks or lack of knowledge lots of residents don't actually use their unit. You can tell by the open windows all year round. Most say it's too noisy for them - most probably due to lack of maintenance. Others are just plain ignorant saying opening windows is the only way to get "fresh air".
The other upside to sealing plus mechanical ventilation (instead of leaky-building ventilation) is that your building is always fresh. Leak-driven ventilation leads to a building that is drafty on windy days and stuffy on calm days.
Trouble with passive houses is a) people open windows. b) hate fan noise. c) the designs are brittle and prone to catastrophic failure. d) energy consumption isn't going to an issue over the life of the building. e) In Europe and North America the replacement rate for housing is in the low single digits.
I did the same thing at my office and brought it into a conference room with 7 other people. We watched the CO2 climb to about 900 and then it started going down. Seems the climate control system is also tracking CO2 and it started pushing fresh air in when the level got too high. A nice surprise that we have systems managing this - I don't know how common that is in offices though.
Anecdotal, but I used to work in an IT department where some areas had good, or at least tolerable, ventilation and some very clearly did not. The difference in moods and productivity between teams in each was distinct enough to notice, but, at the time, I don't think anyone would have thought of CO2 levels as a confounding issue.
I learned long ago to not even try to write code when I'm above a certain threshold of tiredness. I just have to tear it all out again after a night's sleep.
I see low CO2 spaces becoming the next big thing for the privileged classes as CO2 levels rise. Weworks of the future will be advertising this as a definite selling point. Mansions with scrubbers getting it down to 200ppm
I recall reading once that the health of poorer people was better one or two hundred years ago because poorer people ate cheap food - i.e. vegetables - rather than a meat-heavy diet.
Seriously, I’ve always thought people in Sydney compared to France were taller and healthier because they have more oxygen... Not only they are outdoors often, but they also have less stuffy buildings. Classrooms in France are the epitome of “stuffy”, and it’s frequent for me to leave a theater because there is 400 people and the vents are off. The usual reaction is to imply I’m sensitive ;)
After watching this Tom Scott video https://www.youtube.com/watch?v=1Nh_vxpycEA I bought this CO2 monitor: https://amazon.com/gp/product/B00MB93CK8 It worked quite well and showed that I don't have anything to worry about. Now I'm trying to pass it on to someone else. I'll be willing to sell it for half price if anyone is interested.
If anyone is interested it seems you can find (more or less reliable) sensor modules for about $20, such as the MH-Z19, and read it from to an arduino or esp.
I put one in my son's bedroom and was blown away. He's 3, and calls me in to sleep with him sometimes. It's a small room, and we keep the doors closed so his sister doesn't wake him up and I was blown away by how high the CO2 got with both of us in there: https://www.reddit.com/r/dataisbeautiful/comments/cek4dm/co%...
What did you use to measure? Unfortunately all the ones I've seen linked here are too expensive for someone like me who doesn't live in America. I wonder if there are cheap ones out there that maybe not so precise but at least measure something.
Does anyone know of a cheap IoT type sensor for CO2? It can be any type, even RasberryPi or Arduino based. I'm not interested in sensors without connectivity options.
About the levels, I'm working on an IoT project and I've seen data from a public school that has heating with radiators (so no real ventilation). One classroom with the sensor would routinely rise above 1000 ppm, with peaks over 3000ppm. Then you'd observe a sudden drop in CO2 level and temperature as they would open up a window. It's insane how high it can get especially if the building lacks proper ventilation.
There are a bunch of raw sensor components that you can connect to an Arduino or Pi. I ended up going with the Sensirion SCD30 but also tested options from Amphenol's Telaire line. Both are pretty easy to communicate with using an Arduino.
I haven't tested an MH-Z19 but that's a popular cheap option.
I have a slightly more capable one but the results are similarly motivating. Right now I'm more concerned with the particulate counts... if 27 is bad, does 120 worse and going outside into 700+ me dumberer?
When I was living in Lakemba this prompted me to rig a HEPA filter outside and run my bedroom at positive pressure. That helped a lot. But I've had to move for work so now I'm renting a cardboard box (ok, technically it's "fibro" on piles with a leaky wooden floor. Outside ~= inside)
On the other hand, a paper on 'Effects of Exposure to Carbon Dioxide and Human Bioeffluents on Cognitive Performance' (2015) concludes that 'only exposures to bioeffluents when CO2 reached 3,000 ppm significantly affected performance of some cognitive tasks. Increased arousal level at this exposure can be used to explain the observed results.'.
I'm very sensitive to lack of oxygen in a room. Our office is old and some days they don't run the A/C if it's not hot enough outside, and I feel like I'm suffocating and my productivity suffers.
One of these days I'm going to have to rig up something to start the house fan when the CO2 goes above 800 ppm and I think you'd need a different sensor with a realtime output port for something like that.
It frustrates me that there are so many of these networks and they don't talk to each other. I deliberately went with a system that measures multiple values, but then I see other people going "we only measure one thing instead of nine so our units cost half as much".
I should try to script at least my systems so they write into as many of the open networks as I can manage.
Unfortunately, yes, the space is fragmented. A long while ago I chose https://luftdaten.info/en/ because sensor firmware, DB, and tools are truly open source (GPL, ODbL, MIT). Next to supporting many sensors, it also allows for your own back-ends (API, InfluxDB). The community is awesome and has hacker values.
The inexpensive part makes citizen science viable in sub-economic and hobbyist settings.
https://openaq.org/ is trying to consolidate air quality data, but I'm uncertain of their licensing and goals.
Sorry for a pointless post, but this project gives me the CCC vibes. Y'all should attend one day, it's brilliant! In fact it's so rich in things and hacker exhibitions that you don't even have to go to the talks!
From Western Europe I moved to Mexico City. I work and live here now, and this city suffers intense amounts of pollution almost every day. When you take an Uber somewhere they all drive with their windows open (airco's are expensive to run) and you get the full blast of diesel trucks and older cars' fumes.
I came here for a girl. I'm leaving because of pollution. The city is amazing in its own right, but I feel like I'm breathing lung cancer.
Damn, I’m about to go to Mexico City—was planning to stay for a few months, but I hate dirty air. Is it like that all over the city, or just certain parts?
I stayed for a week for work ( lot of traffic that seemed typical after walking around, San Miguel Chapultepec, Mexico City, Federal District) in mornings when I awoke and blew my nose into paper tissue it was dark with the dirt? filtered by I guess my nose/respiratory system.
This has never happened to me in Northern California or living near downtown Houston/Austin, Texas.
I don't know you, but in every lecture in college that was done in a room with no air flow, I got distracted every five minutes or so. If the proportion of C02 had a cognitive effect that I could feel, then I wouldn't be surprised if other kinds of contaminants do the same.
Can’t find a source, but there’s a similar thing with long meetings — after two hours in a conference room, you’ve added enough CO2 to affect cognitive function.
This is fantastic stuff. Some personal anecdotes, moving from Ireland to a heavily industrialized city in Northern China definitely felt like a kick to the head to my output.
I've felt similar effects since moving from Sydney to Kathmandu. Looking forward to my eventual move back to Ireland in the coming years not only for my own health but for that of my children. Unfortunately Kathmandu is going down the path of major Indian cities; there are improvements but the lack of oversight on construction / dust as well as older vehicles with poor fuel makes for a lethal combination causing a dust bowl effect.
This really bothers me. I live in a VERY polluted place, and unfortunately moving away won't be an option for me for at least half a decade. What can I do to minimise the health effects of such an atmosphere? I'm planning on getting an indoor air filter for my home.
Buy a cheap PM detector (There are a few on Amazon using the Plantower sensor that are ~$50.) Buy any HEPA air filter for your home. Buy the best cabin air filter you can for your car (Bosch makes HEPA filters for some cars), and try to get your office to install something, or just buy one for your desk.
The hard math of it is that no matter what you do, you aren't going to be able to reduce your exposure by more than 75% or so, because you have to go outside sometimes, so going super high end on filtration makes essentially no difference in terms of total exposure.
As an aside, I recently bought a car that has a cabin air filter, a first for me. I am genuinely surprised at how much of a difference it makes, especially on air quality alert days. (I live in the Bay Area, which isn't too bad, but we've had plenty of Spare the Air alerts this year.)
> The hard math of it is that no matter what you do, you aren't going to be able to reduce your exposure by more than 75% or so, because you have to go outside sometimes, so going super high end on filtration makes essentially no difference in terms of total exposure.
I think it's more like 99% on particularly bad days, because where I live over 100 ug/m3 is common during the fire season (which is apparently now November to April)
But if you live in places where the particulates are normally low then yeah, cutting from 50 to 5 is hard.
Is the Plantower sensor a very precise one? I'd like to buy an air monitor, but of course there's no way (at least for me) to know which ones are precise and which aren't.
Starts with monitoring. Awair or laseregg are good quality monitors. Then you can assess how well filters work.
I think there are masks you can use outside too. You can also check which times of day/days are worst. And which streets. You can carry the laseregg around for local measures.
I'm not sure what _VERY_ polluted means, but you might consider taking up more physical activity. On GCN youtube cycling channel they argued (including interviews with some health professionals) that even if you live in a city with considerable pollution, the positive effects of commuting on a bicycle outweigh the negative effects of air pollution. They were primarily talking about Britain-scale pollution of course. The principle might change if transfered to a more extreme environment. Something to look into.
My hunch is OP lives in an Indian metro. I absolutely do not recommend commuting on a bike or exposing self to outdoor air in any way during a commute in an Indian metro.
Any physical exertion that makes you breathe harder will cause you to take in more pollution, worsening the effects. Even if exercise helps to offset the damage, your best bet in a polluted place would be to do it inside.
We got an expensive swedish air purifier but it still sucked hard (noisy, made the air smell very stale). You might be able to mitigate some of the effects, but not all of them. And if young kids are involved (or you are expecting), screw the career, move.
Did you get an IQAir? I bought the GCmultiGas and I get the kind of stale air, I think it is just hyper sanitized or something. That filter cleared up my sinus issues in like two days.
I don’t believe the nature study results presented there. The MMSE is such a basic test that it is almost impossible to score less than full marks unless you are cognitively impaired. I’ve run through it hundreds of times with patients. The other tests are more cognitively demanding.
Looking at the Table 1 of that nature study, there appears as if there would be a significant difference in the distribution of ages - couple extra older people in one of the study groups. I think this is a false positive result
Readit News
Also note that they did 11 different tests, but didn't appear to correct for multiple comparisons [1]
This would be a really interesting problem to study, but you'd probably want to look at academic performance in college students before and after transfer between universities e.g urban vs rural (presuming you can measure differences in pollution) between the two, you'd expect to see a relative drop in academic performance going from rural to urban, now that would worry me. But this study is unhelpful.
[1] https://en.m.wikipedia.org/wiki/Multiple_comparisons_problem
The first link on the page isn't a paper. The word shehab doesn't appear anywhere on the page. The word shehab doesn't appear anywhere in the first paper linked. The three quoted sentences / fragments you provide don't appear anywhere in the first paper linked. I opened some of the papers and didn't see any with n=30.
The last time this came up I bought a CO2 meter for my office. I was quite surprised how often it went over 1,000. Outside air runs around 450.
I increased the duty cycle of the house fan, and open a window when it reaches 800. Right now I'm at 505.
Buying the meter was a really good investment.
Prior to the industrial revolution, seems our bodies would never have needed to adapt to a rapid spike in environmental CO2 levels. Our brains are necessarily good at signaling the body when they need more oxygen; they're not necessarily good at realizing when they're dealing with other issues they're not adapted to react to.
I believe there may be a common misunderstanding the relationship between CO2 levels and oxygen in one's body, at least as it was explained to me by doctors during my mom's struggles with COPD.
Blood oxygen saturation levels and CO2 levels are not inversely correlated. One of the problems with late-stage COPD and reduced lung function is that while it's relatively easy to get a person's oxygen levels up (just administer oxygen!) they still suffer the effects of excess CO2 in the blood. A late stage COPD sufferer can have > 95% O2 saturation in their bloodstream and still suffer the other effects (including cognitive issues) that result from the excess CO2.
(Apologies for responding you wrote four years ago)
https://news.ycombinator.com/item?id=14738010
https://news.ycombinator.com/item?id=21237875
https://news.ycombinator.com/item?id=18959796
https://news.ycombinator.com/item?id=19845029
https://news.ycombinator.com/item?id=14738010
http://lesswrong.com/r/discussion/lw/nk0/what_is_up_with_car...
It does help a lot and I couldn't imagine living without it.
- Filters out particle pollution - https://twitter.com/eugenijusr/status/1105740301493260289
- Removes CO2 - averages ~650ppm in all rooms, almost never goes higher than 1000ppm (3 person household).
- Retains up to 85% of heat (based on the specs) using the exchanger, but also has an active electric heater inside that can be turned on in winter for ultimate comfort.
- Removes moisture from the bathroom and kitchen and dumps it into the drain via a separate drain pipe.
- Isolates from the outside noise as you can keep your windows closed shut all the time.
It does have some drawbacks however:
- Up to +6dB noise in rooms when running at full power (I run it at 20% at night which only adds ~+1dB).
- F7 class filters need to be changed every 3-6 months (~50€).
- Air intake grill with a pre-filter mesh needs thorough cleaning every 6-12 months as it usually gets clogged with debris in spring and autumn.
Not sure if it's due to these drawbacks or lack of knowledge lots of residents don't actually use their unit. You can tell by the open windows all year round. Most say it's too noisy for them - most probably due to lack of maintenance. Others are just plain ignorant saying opening windows is the only way to get "fresh air".
I recall reading once that the health of poorer people was better one or two hundred years ago because poorer people ate cheap food - i.e. vegetables - rather than a meat-heavy diet.
Deleted Comment
About the levels, I'm working on an IoT project and I've seen data from a public school that has heating with radiators (so no real ventilation). One classroom with the sensor would routinely rise above 1000 ppm, with peaks over 3000ppm. Then you'd observe a sudden drop in CO2 level and temperature as they would open up a window. It's insane how high it can get especially if the building lacks proper ventilation.
I haven't tested an MH-Z19 but that's a popular cheap option.
inside: https://www.uradmonitor.com/tools/dashboard-04/?open=8200009...
outside: https://www.uradmonitor.com/tools/dashboard-04/?open=8200011...
In the office at work is better: https://www.uradmonitor.com/tools/dashboard-04/?open=8200011...
When I was living in Lakemba this prompted me to rig a HEPA filter outside and run my bedroom at positive pressure. That helped a lot. But I've had to move for work so now I'm renting a cardboard box (ok, technically it's "fibro" on piles with a leaky wooden floor. Outside ~= inside)
https://backend.orbit.dtu.dk/ws/portalfiles/portal/125818556...
https://www.youtube.com/watch?v=PoKvPkwP4mM
I'm very sensitive to lack of oxygen in a room. Our office is old and some days they don't run the A/C if it's not hot enough outside, and I feel like I'm suffocating and my productivity suffers.
https://www.amazon.com/gp/product/B001PDGFR8/
One of these days I'm going to have to rig up something to start the house fan when the CO2 goes above 800 ppm and I think you'd need a different sensor with a realtime output port for something like that.
Build your own inexpensive sensor, contribute to the global network. See also https://github.com/opendata-stuttgart
I should try to script at least my systems so they write into as many of the open networks as I can manage.
https://www.uradmonitor.com/
The inexpensive part makes citizen science viable in sub-economic and hobbyist settings.
https://openaq.org/ is trying to consolidate air quality data, but I'm uncertain of their licensing and goals.
I was expecting China and India to be dark purple
...you simply select the English firmware `latest_en.bin`. Or one of the languages you prefer.
I came here for a girl. I'm leaving because of pollution. The city is amazing in its own right, but I feel like I'm breathing lung cancer.
I've felt similar effects since moving from Sydney to Kathmandu. Looking forward to my eventual move back to Ireland in the coming years not only for my own health but for that of my children. Unfortunately Kathmandu is going down the path of major Indian cities; there are improvements but the lack of oversight on construction / dust as well as older vehicles with poor fuel makes for a lethal combination causing a dust bowl effect.
The hard math of it is that no matter what you do, you aren't going to be able to reduce your exposure by more than 75% or so, because you have to go outside sometimes, so going super high end on filtration makes essentially no difference in terms of total exposure.
Couldn't you get a mask for outdoor use?
https://www.guidingtech.com/62349/whats-difference-n95-n99-p...
But if you live in places where the particulates are normally low then yeah, cutting from 50 to 5 is hard.
I think there are masks you can use outside too. You can also check which times of day/days are worst. And which streets. You can carry the laseregg around for local measures.
https://smartairfilters.com/en/blog/how-accurate-are-common-...
So may be better solution are local laboratories with calibrated equipment
Masks are tricky.
Most "light" masks are for huge particles and can't defend against most of dangerous chemicals
Military and science masks are working good against some chemicals and do not protect from another. Except solutions with O2 tanks on your back
Not sure how it compares with Awair or laseregg.
I have no affiliation with PurpleAir, but they are pretty popular in Utah.
Deleted Comment
Not much you can do except get out. I've already started moving out for the first 2-3 weeks of November and working from a city like Panjim
https://www.aliexpress.com/item/32887570197.html?spm=a2g0s.9...
Tracking CO2 is very useful for internal spaces.
And an Air purifier: https://www.amazon.com/Purifier-Display-Formaldehyde-Sterili...
Monitoring seems like it's interesting to do if you want to, but if you already know it's an issue, just start addressing it?
We got an expensive swedish air purifier but it still sucked hard (noisy, made the air smell very stale). You might be able to mitigate some of the effects, but not all of them. And if young kids are involved (or you are expecting), screw the career, move.
https://www.bbc.com/future/article/20191113-the-toxic-killer...
https://smartairfilters.com/en/blog/can-hepa-filters-capture...