Also note that they did 11 different tests, but didn't appear to correct for multiple comparisons 
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.
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.
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
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)
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".
If it is, the whatever dust that gets picked up ends up in filters in the first week of operation.
both. That is it varies between different units but also varies with local conditions, if your local conditions are "heavy-duty" (very high humidity, smog, area with lots of dust or lots of pollens etc.) you should consider replacing more frequently than rated intervals.
I'm also skeptical because houses we build today should be in use a 100 years from now. And it's really obvious that renewables aren't supply limited like oil and gas. But in the passive house world it's always 1980.
This obsession with mold looks to me as an exclusively US thing. I have no first-hand data but I guess it's due to insufficient air flow combined with air conditioners pushing humidity all the way up.
Cold climate results in low humidity. If you're mostly heating your home (as opposed to running aircon 24/7), air inside tends to be of lower humidity than outside. So low that it becomes uncomfortable and one has to use humidifiers.
The only place mold has any chance in those conditions are the leak spots on the fridge door seal.
Regardless, the point is that even if you don't have one of these super-airtight houses, you can still install an HRV/ERV for not a ton of money. I'm considering one for my vacation cabin where the primary heat is a wood stove.
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.
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.
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)
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.
These days IoT is so widespread that something like a $25 WeMo smart outlet is hard to beat. Hard wired is "best" but a million times more hassle and more expensive.
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.
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?
This also means that if you feel like you need to get a mask, you should probably get the most comfortable, least restrictive one, even with a worse rating because (say) 90% filtration all the time is better than 99% filtration 80% of the time (if the discomfort causes you to take it off 20% of the time)
I wore a mask all day Saturday while working on the insulation in my attic. I can report it was easier to breathe at the end of the day than times I've been in there without a mask. (fiber glass is not easy on the lungs - though there may be some other factor not related to the mask involved). However I also had red marks across the back of my head where the bands were digging in. It was also more tiring to breathe wearing the mask all day.
But if you live in places where the particulates are normally low then yeah, cutting from 50 to 5 is hard.
The main reason for a monitor is just to make sure your filtration is working and sized appropriately. Take it outside, take a reading, take it inside, see if it's a lot lower. I don't see a need to spend a lot for this or install something that connects to my wifi and needs to be updated etc.
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.
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.
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
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?
If you know you're in a polluted environment, why would you need instrumentation before taking action? To me it's like getting blood work done before you err on the side of exercising.
You need to keep enough ventilation going to ensure you don't exceed 800ppm CO2.
You also need to monitor the PM2.5 levels to ensure your air purifier is working.
An air quality monitoring device is an essential piece of equipment for anyone.
But if you don't have an air purifier, and you're concerned about air quality, surely you want to get one before you start worrying about whether or not it's working?
Or both at the same time, sure, my only point is that if there's already concern I don't see the point in monitoring before or without mitigating.
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.
I personally have a couple of devices (an Awair and a Flow). They seem to under-report PM2.5 compared to purpleair, airnow, and waqi.
After skimming the rest of the table, it looks like the PurpleAir II sensors might have some of the best field R^2 for PM 2.5 and PM 1.0
EDIT: The link we're discussing says this explicitly: "[...] These particle counts are processed by the sensor using a complex algorithm to calculate the PM1.0, PM2.5 & PM10 mass in ug/m3. [...] PurpleAir PA-II uses two identical PMS5003 sensor units attached to each other and placed in the same shelter. [...]"
I don't think you can recommend the PMS5003 as a substitute for the PurpleAir II.
The specs for particulate matter are identical:
You can't expect one sensor to give the same performance as two sensors plus correction logic. If it was that easy, PurpleAir could just put a case on a PMS sensor and be done with it.
You provide absolutely no data to back up your claims that there is extra logic on the PAII or that 2 sensors are better than one.
However, the damn thing turns on it's front display and backlight randomly at all hours of the day and night. If you are a sensitive sleeper this thing definitely can't be on your list of items. I contacted their support and was ignored. Generally wouldn't recommend.
Under the table is definition of R^2
>The coefficient of determination (R2) is a statistical parameter measuring the degree of relation between two variables. ....
The more - the better. Range [0; 1)
More device in your area === better quality of measurement
It's a useful tool if the locals in the area that you're interested in are using PurpleAir's sensors.
It logs temperature, relative humidity, air pressure, CO2, CO, TVOC, PM2.5, NO2, and ozone. They are about $300. The device itself doesn't have any UI; you need to connect to it via a phone app.
Couldn't you run a HEPA filter to reduce the particulates?
I personally use an IQAir Air Visual which is highly rated and meant to be very accurate as far as consumer grade stuff goes. It's solid, reliable and the iOS app has been great.
That said after installing piHole I noticed it making 17000 DNS requests a day to a non-existent host:
Explains why the DNS Resolver on my router (pfSense) kept crashing at least.
I bought a small usb-to-serial adapter connected to Raspberry Pi Zero W.
Here's a combo with a similar device here:
There are plenty of comparisons available online, but there's a good overview site here:
- CO2: Sensirion SCD30
- Particulates: Amphenol SM-UART-04L
- VOC: Sensirion SGP30
- Temperature/humidity/pressure: Bosch BME680
After hooking everything up I just wrote some code to pipe sensor readings to InfluxDB, which is connected to Grafana.
In the end I have no way of properly testing accuracy but the sensors are consistent between units and behave as expected when exposed to fresh air, which is the most I can look at right now.
I've been tempted to get the purple sensors because at least the purple map seems reliable (so maybe their stuff is better?).
Small particle emissions can be anything, diesel cars emissions, stone dust and flour from bakeries. All small particles are bad for the lungs. Long term exposure of air pollution will lead to health problems.
> Stock market returns are lower on polluted days.
I don't want to dismiss the entire article, but I think this points to possibility that there is some bad statistics going on here. I don't see how daily stock returns are proof of, or even related to, cognitive ability on a daily basis.
This is exactly the type of finding you'd expect with p-hacking.
Traffic is probably generally higher on Mondays, though I have only anecdotal evidence.
How would lower cognitive ability make markets move lower on a daily basis? All I can think is higher pollution creating greater pessimism among traders.
People with impaired cognitive ability are more likely to make dumb mistakes. That seems pretty obvious to me. The only question is whether or not the effect is large enough to measure using a coarse statistic like this, but that's a quantitative argument.
Perhaps pollution just makes one more pessimistic and therefore bearish.
To be clear `Correlation => ^Causation` is different to `Correlation => TRUE`. (In other words, there is nothing you can deduce from correlation alone).
But your point stands. The paper has nothing to do with cognitive ability. So why is it being used as evidence?
Are you able to share any that aren't (or weren't) garbage?
The remarkable thing is that it has been well known for decades, and continues to work. Many fortunes have been made by systematically exploiting it.
As far as stocks, specificaly: really? People with cognitive trouble make bad stock picks all the time. Most of us have grandparents who have exhibited exactly this kind of mistake. While it's surely true that the bulk of analyst-driven trades are checked by methods that aren't sensitive to pollution (or just by analysts in different climates), there are certainly enough single-decider trades going on to show a small effect like this if it exists.
I mean, no, one oddball stock market paper doesn't prove much of anything. But in combination with a bunch of other research like this, it's worth taking seriously.
Good. Because you can't cherry-pick one dubious-seeming journal article and use it as a justification to ignore several completely unaffiliated articles.
Go to a massively unpopulated area and just breath. Feel the difference? Isn't it intoxicating?
Who gives a crap if umpires make worse calls? Just fight pollution because it's obvious pollution is bad for humans and the planet.
Normally I'm all for extra evidence, but in a situation like this come on. It's basically like immaterial evidence against genocide by saying, I don't know, saying the increased production of bullets to commit genocide reduces national science and health budgets by 12% (fake stat just for context). Who cares! It's just plain bad.
(ps - rant isn't against the article, but a broader frustration about the topic)
I agree with everything you said. Just wanted to stack my rant on yours there.
You haven't reduced the complexity, just hidden it behind the facade of taking "pragmatic economic decisions".
When I say waste, I mean the waste in the widest sense: potential, future, life, etc.
For what it's worth, since you mention it, I don't think that capitalism isn't compatible with an ecological society. It's just that if you're gonna replace all values with a price tag, you have to be accurate with your pricing. For example, the price of diesel has to reflect, among other things, the full effect on the environment.
Solution: everyone must consume less, cut unnecessary things, and there are many in most people lifestyles
New coal legislation was pushed through with an intensive study by the EPA....
They said it would kill up to 14,000 people.
Arguments against pollution would be valuable if someone were actually arguing in favour of pollution.
The people living in those cities form a so-called "self-selecting" sample. They are probably, on average better educated, and they recognize the value of education much better. They already would score higher than the others, that's why they moved to the city.
It might just as well be that the same people would score far higher in a non-polluted city.
Why wouldn't IQ tests be great for studying short term cognitive effects? I would trust their values for these type of studies the most: how does lack of sleep, being drunk, after exercise, etc affect your ability to solve abstract problems.
It has far fewer variables to account for than predicting someone's long term success.
IQ testing is designed to test for intelligent behaviour, which is largely based on long-term neurological development. The connections in the brain, densities of neurons, and long-term potentiations don't change greatly on a short-term basis. Measures which fluctuate based on spot-performance factors are typically deemed unreliable for the purpose of IQ testing.
Cognitive deficits caused by exposure to drugs and other substances tend to impact functioning of the neurons, and are detrimental to measures of intelligence, but are more appropriately measured by more specific tests, which focus on factors such as reaction time, or motor accuracy. Consider the cognitive tests performed by police when driving under the influence of alcohol is expected, for instance. Such cognitive tests also help provide a clearer picture of how a substance affects the brain.
In addition, to me, it sounds that you are arguing that a test on which you do worse when tired, sleepy, hungry etc. is not an appropriate test because it fluctuates depending on your state of mind. I don't get that.
I meant behaviour in the general psychological / cognitive sense; how an actor responds to stimuli.
Current popular IQ tests are designed to test many facets of intelligent behaviour -- verbal comprehension, arithmetic, working memory, symbol searching, etc. Abstract problem solving is only one category of testing.
I'm arguing that to study short-term cognitive deficits, it makes more sense to use other measures of cognition. It appears this is actually what was done, but this was incorrectly re-reported as "IQ".
IQ tests can't be standardized across cultures. Even something like Raven's Progressive Matrices has a cultural component. https://www.apa.org/monitor/feb03/intelligence
Also China has some issues with the way they report scholastic achievement that make their results appear higher than they should. China is very selective about which students take standardized tests that are used for global comparisons--they aren't random samples.
If you can't accurately quantify the cultural component, then yes it does.
>Claims that basic pattern recognition is somehow not a valid means of assessment across cultures are dubious at best.
Basic pattern recognition isn't the only thing that's being measured--that's the problem. Even something as simple as how often a student has been exposed to a matrix of rows and columns has an impact on performance. Repeated exposure to similar tests also increases performance.
Wrong information is often worse than no information.
That's one of the problems with PISA results. Policy makers look at other countries with higher scores and try to emulate them without understanding why their scores are higher. In that case it's just cargo culting education.
This doesn't mean that standardized testing is completely useless, but you have to know the limitations, and comparing results between cultures is one of the limitations.
The median IQ should be 100, with a standard deviation of 15.
If the median IQ is not 100 over the population, the test is flawed.
They use raw IQ score data.
not sure where hilarity comes into play ... it has well defined statistical properties
perhaps you mean that the results of IQ tests can be, and often are grossly misinterpreted, that is not related to standardization
Very few adults are comfortable with the idea that any substantial group of people are objectively more intelligent than themselves, because admitting that comes uncomfortably close to relinquishing autonomy, at least in contemporary Western understanding that says the more intelligent should rule.
European history throughout the 20th century shows the horrifying, depraved danger in capitulating to a ruling intelligentsia. We should earnestly hope that no group allows their self-interest, protected by native instinct, to be overridden by the despotic, unfeeling ideologies of "intelligent" rulership. That philosophy has shown itself over and over again to be a quick route to starvation, genocide, and widespread desolation.
Nevertheless, IQ is the most general/objective measurement we have, and it seems to be a reasonably good approximation on aggregate.
If you're referring to communism and national socialism here, those were rabidly anti-intellectual (the later particularly so).
Looks like that map is from 2005.
I believe cognitive cost would also be a good denominator. Something like "we find that an increase of 10 µg/m³ raises the probability of a chess player making an error by 1.5 percentage points. The same 1.5 percentage points would be caused by smoking 2 cigarettes per day."
Plug: I'm the author of an open-source mobile app which does this pollution-cigarettes conversion. I think cigarettes gives a strong image of air quality for those who are unfamiliar with AQI.
Plus there are many countryside areas with no oil.
Whether or not that translates into more risk for your exposure to small particles is probably related to where you are (e.g. are you inside the house while the wood is burning, probably, so you are close to the source of it and probably have a lot of small particles around your house that get brought in every-time you open the door).
If its so rural that its just you for some distance then this might offset the fact that your wood burning stove is (probably) not providing any sort of filtering that a catalytic converter, control systems to more fully burn the fuel (so there aren't as many byproducts), or other devices normally used to remove byproducts of combustion. So it comes down to which of those byproducts are most toxic to you comparatively to other forms of pollution, the density of those particles and where you are in relation to them is going to determine your daily exposure in your environment.
I don't know of anyone who uses a wood stove. Most would use natural gas, propane, or electric. Electric is common until you get too far North, then it's cheaper to get fuel.
It's very nice to live out here. You can see the stars and breathe fresh air.
Source: live in rural town.
Admittedly with the current climate collapse gaining pace at breakneck speed, it's possible that this may be the 'new normal' for the Australian bush very soon.
Forest and bush fires suck. Even Seattle air can smell bad when the wind blows in smoke from a big forest fire up in BC.