Installing air filters in classrooms has large educational benefits?
vox.com
vox.com
https://statmodeling.stat.columbia.edu/2020/01/09/no-i-dont-...
This is important stuff - you can already see people researching air filters in other comments, taking the supposed results of this study as settled truth.
Even if the Vox article is potentially flawed you need to read both to grasp the full picture.
Normally we'd merge these submissions but the topics are sufficiently different that I think that might add confusion. I've moved most of the comments from this subthread to that one, though.
All: if you want to comment on the Gelman article, please do so in the other thread, where your comment will feel more at home and get more attention.
It would be interesting if we could monitor productivity in the major Australian CBDs these days. A lot of the big office buildings don't have the capability to filter the unhealthy / toxic bushfire smoke, and the workers get to suffer.
And on that, good luck trying to find any purifiers, anywhere in Australian stores.
I'm in Canada and have had days of smoke from the Fort Mac fires roll through -- it's rough.
Here is a common air quality problem. Anybody have ideas?
My house is in a hot and humid area, so I run the air conditioning most of the year. The duct work appears to be made of bare fiberglass pressed into sheets, with foil on the outside. This is cheap, quiet, and thermally insulating. It does however have a soft highly porous surface that collects black mold.
It doesn't appear possible to do anything about the mold. Thanks to the soft porous surface, scrubbing would tear up the ducts and be ineffective.
Ideally the ducts would have a polished bare silver surface, sturdy enough to scrub. Well, nobody has that, it would be expensive, and I'd have to rip out the drywall of nearly every room in order to install something like that.
What do I do?
Ductless mini split units.
Regardless of what you have periodic maintenance is what makes a difference.
FWIW, I removed the galvanized steel ducts from my house. The insides were disgusting, despite the professional vacuum service. My allergy symptoms and whatnot improved quite a bit afterwards.
Good luck. Please post whatever experiments you try.
The TL;DR is that you're not likely to have enough plants to make a significant difference in terms of CO2/oxygen.
Doesn't mean there's no positive effect, but it's probably not due to oxygen levels.
Interesting, I wonder how that'll contribute to the snowball effect of global warming since as it gets hotter I'm sure they'll perspire more.
So, it won't be a noticeable effect.
* On average, not constantly. Since they can't do photosynthesis in the dark, they release CO2 at night.
https://www.theatlantic.com/science/archive/2019/03/indoor-p...
If you want your plants to provide even 10% of that number - 40L, your houseplants will need to take CO2 out of the air, store the carbon, and release the oxygen.
This means that they will need to grow by ~300g - nearly a pound, a day, in order to produce 40L of oxygen.
Unless your home is a wild, gymnasium-sized jungle, your houseplants aren't producing any measurable amounts of oxygen. And, as a bonus point, they aren't even cleaning your air. (Although they do provide a lot of new surfaces for dust to settle, that you have to clean.)
If you want to breathe better, open your windows. If your outside air has too much crap in it, buy a HEPA filter. If you breathe fine, and there's too much crap in the air, buy a fan with a HEPA filter attached to it (Also known as an air purifier.)
If you want plants near you, buy plants.
Ignoring plants, there's gotta be some solution to this. What do they do to recycle the air up at the International Space Station?
You pack up, and move somewhere that's not the equivalent of sitting in the middle of a crude oil refinery.
Plants won't deal with these problems, either.
> What do they do to recycle the air up at the International Space Station?
For the most part, they chemically scrub the CO2 out[1], use the equivalents of catalytic converters to pull things like trace ammonia out of the air, and move on with life. There isn't a lot of heavy industry that happens inside the ISS.
If the air outside your window is literal poison, your house isn't sufficiently hermetically sealed for this to work.
[1] The actual process they use is the Sabatier process:
2H20 + E => 2H2 + O2
CO2 + 2H2 => CH4 + O2.
The water is brought up in resupply missions, the methane is vented into space. It's not a closed cycle (Which would require an enormous amount of plants), and its never going to have one, because it's going to be decommissioned in the next ~15 years.
I would posit that for many people (e.g. citizens of China or India), "moving somewhere" where you're not constantly exposed to small-molecule pollutants would require more effort (e.g. acquiring a different citizenship) than would be required to atmospherically decouple your house.
For that kind of money, you may as well just buy an investor visa.
[0] https://en.wikipedia.org/wiki/Carbon_filtering
[1] https://www.cowaymega.com/product/coway-airmega-400s-white/
Changes in the brain chemistry or composition are likely more plausible channels between air pollution and cognition. It is beyond the scope of this paper to test the exact mechanism, so we leave it as agenda for future research.
> It's not clear precisely how pollution impacts cognitive decline, though Chen suggests that pollution may have a negative effect on the brain's white matter, which could vary between men and women. As NPR has reported, "the brain's white matter coordinates communication among brain regions."
> James Hendrix, the director of Global Science Initiatives at the Alzheimer's Association, was skeptical of the claim that pollution impacts white matter. "I think that's speculation. I think we don't have a direct cause and effect that can be proven," he said.
The mechanisms by which cigarettes cause lung cancer are surprisingly complex and weren't fully understood for a long time, but it's obvious that some kind of mechanism is plausible.
So usually the bar for taking something seriously is: statistical evidence of a significant harmful effect, and at least one plausible hypothesis for a mechanism. But you don't have to be sure of the mechanism.
To find out more about the underlying cause of those behavioral changes, Nelson compared the brains of mice that had been exposed to dirty air with brains of mice that hadn't. He found a number of striking differences. For starters, mice exposed to particulate matter had increased levels of cytokines in the brain. (Cytokines are cell-signaling molecules that regulate the body's inflammatory response.) That wasn't entirely surprising, since previous studies investigating the cardiovascular effects of air pollution on mice had found widespread bodily inflammation in mice exposed to the pollution.
More surprisingly, Nelson also discovered physical changes to the nerve cells in the mouse hippocampus, a region known to play a role in spatial memory. Exposed mice had fewer spines on the tips of the neurons in this brain region. "Those [spines] form the connections to other cells," Nelson says. "So you have less dendritic complexity, and that's usually correlated with a poorer memory."
The changes are alarming and surprising, he says. "I never thought we'd actually see changes in brain structure."
Edit: Example @ https://aqicn.org/sensor/sds011/
I realised I pasted the wrong link above, although still of interest. Anyway, here's a Pie specific article: https://www.raspberrypi.org/blog/monitor-air-quality-with-a-...