CO2 helps viruses stay alive longer in the air(statnews.com) |
CO2 helps viruses stay alive longer in the air(statnews.com) |
I live in a place that's generally cold for a large part of the year, so I have all windows shut for most of the time. I've discovered that tracking CO_2 levels is a very good proxy for general air quality, and a good measure of both when to open windows and for how long to keep windows open.
For my apartment, I was surprised that the amount of time I needed to keep the windows open was 5x longer than what I initially assumed (I assumed 5 mins would be enough. Data shows that I need about 25 mins to get CO2 levels down to around 500ppm). I was also surprised to see how much more rapidly CO2 builds up when I have just 2 additional people at home.
For anyone with a modern home that is sealed up average or better, an air monitor indoors is almost a must.
On the topic of the number of people and CO2, I'm tempted to have it alert me when I'm out of town and the CO2 rises. I have an alarm, but who would think to defeat the innocent looking air monitor on the shelf?
Here are some excerpts from Airthings T&Cs [1] that I find very problematic:
In 15.4. of Airthings T&C it writes: “We own and shall retain ownership of all rights to all data and information collected via the Services provided to you…”
Furthermore, in 15.2 Airthings claims all rights for modifications that you might carry out on the Airthings monitor: “You hereby assign to Airthings all right, title, and interest (including Intellectual Property Rights) that you may have in any custom developments, modifications, or derivative works of the Services and Products created or developed by or for you, including but not limited to design, artwork, technology, software, data, functionality, and documentation.”
I wrote about it in a review with our monitor [2].
[1] https://www.airthings.com/en/legal/terms-of-use
[2] https://www.airgradient.com/blog/airgradient-vs-airthings/
(Edited and included Airthings T&C)
I also noticed that just cracking a window doesn't seem to do much according to the CO2 monitor, except letting the heat escape.
The trick is to open multiple windows/doors wide and get some cross ventilation going. This gets CO2 down in only a few minutes. It's called stoßlüften in German.
I purchased an INKBIRD Air Pollution Monitor. It has an internal battery, doesn't connect to other devices or networks, is inexpensive, and is irrationally inaccurate sometimes.
A reviewer found the same behaviour and confirmed what I knew through tests with dry ice (solid CO2) and isopropanol alcohol. It measures CO2, not VOCs, but some constantly running calibration or data fitting algorithms lead to wild overshoot and undershooting compared to higher-quality monitors.
Finding an inexpensive and accurate CO2 monitor may be possible, and aliexpress.com is the home of inexpensive. But without testing and possibly a teardown, you will not likely get an accurate and affordable monitor.
It seems good enough for how I use it. I wouldn't conduct chemistry experiments using this as an instrument.
Atmospheric CO2 change acidifying the oceans is a well known effect [1]. Once it's pointed out it isn't surprising that a tiny bubble of water surrounded by atmosphere would change PH quickly in response to atmospheric CO2 levels (the surface area to volume ratio is huge compared to the ocean after all). Nor that that affects viruses.
[1] https://www.noaa.gov/education/resource-collections/ocean-co...
Pre-industrial CO2 levels were at 280ppm, currently we have 420ppm, rising & accelerating. Give it three or four decades and ventilation won't help anymore.
Edit: 420, not 480ppm
Ventilation good. CO2 bad. No challenge to old ventilation doctrine detected. (The article and the research seems much more nuanced than the silly title.)
I can vouch for the monotonic rise or fall in its displayed values as affected by ventilation.
Just to add a little context, here's a table from https://www.dhs.wisconsin.gov/chemical/carbondioxide.htm
400 ppm: average outdoor air level.
400–1,000 ppm: typical level found in occupied spaces with good air exchange.
1,000–2,000 ppm: level associated with complaints of drowsiness and poor air.
2,000–5,000 ppm: level associated with headaches, sleepiness, and stagnant, stale, stuffy air. Poor concentration, loss of attention, increased heart rate and slight nausea may also be present.
5,000 ppm: this indicates unusual air conditions where high levels of other gases could also be present. Toxicity or oxygen deprivation could occur. This is the permissible exposure limit for daily workplace exposures.
40,000 ppm: this level is immediately harmful due to oxygen deprivation.Where are you measuring 480? [0] says the recent global average is 419.3.
[0] https://www.climate.gov/news-features/understanding-climate/...
Or is there some reliable way we can measure in retrospect?
"Ancient air pockets changing the history of Earth’s oxygen"
https://www.sciencedaily.com/releases/2016/08/160822174234.h...
I mean we might all have headaches and covid, but not directly because of CO2 at outdoor concentrations.
* 2.8ppm in 2022-2023, the rate at which CO2 is increasing is very slowly increasing but it's close enough to constant for rough calculations, especially after rounding up to 3.
At that approx +3ppm/yr, it would be about 300 years before we are there. Which is about 10 human generations, which is roughly the grandchildren of your grandchildren's grandchildren.
At +8 on top of wherever the temp is then, my understanding is that is effectively talking runaway greenhouse effect and a hothouse earth.
To make it more grim, the ocean has been acting as a carbon dioxide and heat sponge, and is possibly getting saturated. The rate of human emission increases is only starting to level (still increasing though [going from recollection, please correct me if wrong]). And to make things even more grim, that is still not counting other feedback loops like permafrost melting and boreal forests burning.
[0] https://www.sciencealert.com/high-levels-of-co2-could-stop-t...
More seriously, a house air filter with CO2 scrubber is not really something that would be difficult to make.
A plant that isn't growing, like, a LOT, can't possibly be removing much CO2.
For example, under the "proxy" model, if you're worried about infection risk it's sufficient to filter the air, but under the new model filtering will work less well than you'd expect because the viruses you miss will stay active longer.
That's not accurate, though. CO2 is, on its own, an air quality concern.
It has also been known, or at least part of the conversation, since Florence Nightingale's time, that fresh air reduces infections (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9300299/). This research makes a small tweak to our understanding, but it's also something that's been suspected/suggested by others for decades.
This research isn't "challenging" anything, it's merely expanding our understanding of causation about previously observed correlations. It's good to know what's happening. It's silly to make it out to be something it's not.
This sort of aggressive argument obscures the meaning and intent of the actual article in favor of some kind of editorial flavoring issue.
This behavior is warranted at times but here it just argumentative for no purpose.
In what we did over the pandemic with masking, we drove some flu variants extinct. Is this an alternative to accomplish the same effect?
Are hospitals already doing this with existing ventilation?
Increasing ventilation is unsurprisingly recommended by the CDC, the EPA, and basically every other relevant group. The EPA has a list of papers here if you're interested in scientific measurements backing this (but can I also say it's just common sense?): https://www.epa.gov/indoor-air-quality-iaq/indoor-air-and-co...
Tangentially, too much O2 is even more dangerous (as O2 is extremely reactive unlike CO2), but it too is "self modulating".
I think the article is more insightful around I indoor air quality rather than outdoor. With respect to outdoor, if CO2 were fully self modulating, isn't the fact it has been consistently raising a counter point to that idea? How does self modulation explain the data showing increases?
Though... 40k ppm is talking extinction of all mammals, probably more. The greenhouse effect at that level is probably insane, I wonder if we might lose liquid water well before that point.
This source [0] states it well: "The end-Permian mass extinction, the largest biological crisis in Earth history, is currently understood in the context of Siberian Traps volcanism introducing large quantities of greenhouse gases to the atmosphere, culminating in the Early Triassic hothouse. In our study, the late Permian and Early Triassic atmospheric CO2 history was reconstructed by applying the paleosol pCO2 barometer. Atmospheric pCO2 shows an approximate 4× increase from mean concentrations of 412–919 ppmv in the late Permian (Changhsingian) to maximum levels between 2181 and 2610 ppmv in the Early Triassic (late Griesbachian)."
[0] https://pubs.geoscienceworld.org/gsa/geology/article/50/6/65...
* looks like we can quibble on 2k ppm or 5k ppm, the salient part is the global mass extinction part. Whether that was a correlation or caused by CO2 is not defined, at any rate it is not really speaking to a very habitable earth for humans.
I'm finding I can't really tell any difference in mood/alertness/whatever despite what my sensor thing reports. To the point that I don't know why I bother keeping this thing in the office.
My suspicion is these devices just can't really tell you much about how localized the readings are. And comparing a number for a large room to a converted closet is not at all meaningful.
There is of course the small problem of it being a volcano. Other measurements come from a collection of sensors on TV or telecom towers. Some of them come from planes.
You can see a map of sites here:
https://gml.noaa.gov/dv/iadv/index.php?code=sgi
The trend is the same in every site, although absolute readings vary somewhat. There are cleaner sites than Mauna Loa, like in Antarctica, but those show about 10ppm lower. Others give the same reading as at Mauna Loa but with more seasonal variance. It's unclear whether these differences really matter and they tend to be ignored.
Everyone was gone today at the same time (rare with WFH and home school). I can see within about a minute when we arrived home.
This only clicked for me when I started wondering why you never have to refill the soil for a houseplant even when it grows.
https://21sci-tech.com/Subscriptions/Spring%202008%20ONLINE/...
Everything else I found was unfortunately hand-wavy "scientific consensus says" and the ubiquitous "280ppm" coupled with "pre-industrial" repeated again without reference, nor apparent empirical basis.
Not convincing, which for "the science is settled" I'd expect a bit of a higher standard.
If you can feed off your house plants alone, then you have a chance of closing the carbon loop. This was tried (e.g. biosphere2) and it's extremely hard even at the industrial scale.
Chemistry means converting 1kg of CO2 > O2 would mean removing ~273 grams of carbon. Hydrogen and Wet vs dry weight more than offsets this, but you’re at closer to 2kg than tens of kilos.
This still assumes an air tight system where people never leave home, so plants can make a difference long before they are a 1:1 replacement.
Feed me Seymour.
https://medium.com/@candidegardening/how-many-plants-would-i...
We don't just eat random (average) parts of plants, we eat selected ones, primarily things like fruits and bulbs that plants store energy in. If you just tried to eat, say, lettuce... at 2000 calories per day you would need roughly 14kgs [1, 2]. Which is surprisingly close to GPs 10s of kg number all things considered.
Either way, growing 2kg of plant/day or 20kg of plant/day... seems impractical to me. There's also the issue that if you equalize CO2 levels with the outdoors during the day as you open doors and windows, you're going to make night worse as both you and the plants output CO2 during the night.
[1] Lettuce is 14 calories / 100g - https://www.fatsecret.com/calories-nutrition/generic/lettuce...
[2] Math here: https://www.wolframalpha.com/input?i=2000+calories+%2F+%2814...
We can’t digest cellulose which throws off the calculations based on what calories are available to us. The question was the minimums not the worst case. Obviously most carbon sequestered by trees isn’t available to us a calories.
In a closed environment simply eating plants wouldn’t result in the correct carbon balance long term. We would need to breakdown our waste via microbes, fungi, or burning.
It's already being used on the ISS to keep the air fresh. It'll also be a key component on Mars. There you have basically unlimited CO2 and unlimited hydrogen which yields unlimited methane and unlimited water. Carry out electrolysis on some of the water and you get hydrogen + oxygen. The hydrogen can be fed back into the original cycle, and so you end up left with methane + oxygen which is also known as rocket fuel, uncoincidentally the exact sort SpaceX's Starship is using.
Back on Earth you could use this reaction to create practically endless carbon neutral fuel so long as the CO2 was sourced from either the air or a regrown natural capture source like trees or what not. Rockets using this fuel would even have a negative carbon footprint since some of that fuel will get burnt outside the atmosphere. It all seriously feels like a video game where there's just this perfect, but just utterly contrived, rule allowing you to thrive on the next level of difficulty.
(1) It presumably requires concentrated CO2. It's not trivial to concentrate CO2 from the air without the appropriate technology.
(2) Pure hydrogen can risk an explosion.
(3) What does one do with the methane? Also, it too can risk a fire.
For these reasons, this is not a reaction that one would seek to do at home.
Manned space programs must remove CO2 air breathed by astronauts. They used lithium hydroxide for decades (including famously in Apollo 13) but ISTR the international space station has a more sophisticated process.
<rant> There's no grand technologies required for any of these things. The only reason it's not done at scale is the same reason we can't have nice things in general. Governments are far more interested in war and cock measuring contests than actually solving problems. We spent literally trillions of dollars on Iraq and Afghanistan, and the latest wars will probably dwarf that. Just imagine all the crazy sci-fi scale of things we could have done with all that money. Alas, humanity seems to be running on loop, except now we have nukes, paired alongside what are likely some of the most idiotic 'leaders' in centuries. Want to know the answer to the Fermi Paradox? </rant>