299 comments

[ 3.8 ms ] story [ 306 ms ] thread
This is blogspam. Here's the original post: https://patrickcollison.com/pollution
Should I upvote despite that, or wait for somebody to post the original? I'm not sure of HN's norms here.
Better not to post the original if there's already an active thread, because that will either have no effect or split the discussion. We usually change URLs in cases like this. Best is to email hn@ycombinator.com because then we're sure to see it.
That would be a much better link than the one provided. Wasting energy on the "IQ" issue is not productive to the problem presented: that air pollution does, indeed, cause (hopefully only temporary) cognitive decline. It can be measured on a small scale, for example, see the Allen et al. [1] article showing cognitive decline in an office environment (conventional building vs Green+ building).

1. https://dash.harvard.edu/bitstream/handle/1/27662232/4892924...

If the effect were present, and as large as implied, you’d expect low IQ test results in ultra-polluted Chinese cities such as Shanghai and Beijing. And yet... http://www.city-data.com/forum/world/2348902-china-iq-map-pr...
Pardon my ignorance, but how is this IQ data obtained? It is reported by the government? Are IQ tests standardized?
>IQ tests standardized?

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.

Seems hilarious to assume they can be standardized within a culture too, whatever a culture may be.
but that's what IQ test are, standardized tests.

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

Yeah, the reality is that you'll never be able to get reliable/unadulterated data on something that is both as personally impactful and as loosely defined as "intelligence". Everyone is going to bias toward interpreting the mode of thought that is most similar to their own as the definition of "intelligent".

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.

> European history throughout the 20th century shows the horrifying, depraved danger in capitulating to a ruling intelligentsia.

If you're referring to communism and national socialism here, those were rabidly anti-intellectual (the later particularly so).

Yep. And that helps many IQ tests to be biased (consciously or not) in favor of the interests (and assumptions) that create the tests. EG a written test will inaccurately 'measure' the abilities of people who (for whatever reasons) can't read well. Those who are well-fed and -slept, secure, unfraid, healthy, and enjoy lots of educational opportunities will arrive for the test with an advantage.
All IQ tests are (ought to be) standardized for the target population.

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.

Intelligence researches don't use normalized IQ when they compare intelligence across target populations or across different times.

They use raw IQ score data.

Just because a test might have some component you can vaguely articulate as having some cultural influence does not make the test itself invalid for comparison across cultures. Claims that basic pattern recognition is somehow not a valid means of assessment across cultures are dubious at best.
>does not make the test itself invalid for comparison across cultures

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.

If it’s the best thing we have, then it’s worth using. You are proposing no alternative.
If you have only one poll with an unknown margin of error and it shows Candidate A at 51 and Candidate B at 49, then assuming Candidate A is winning just because it's the best thing we have is worse than just admitting we don't know.

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.

(comment deleted)
It's official data released by Chinese. Which helps explain why Han Chinese are on top of the list.
I don’t think that explains it. Especially when you compare results with other countries with a large Chinese population like Singapore, Malaysia, and Indonesia.
The whole point of IQ is that it tests common factor (as in factor analysis) underlying different tests. There is known correlation between different testing methods.
How long have they been that polluted though?

Looks like that map is from 2005.

No that is not what it is claimed. Pollution reduces your IQ, not that it makes your IQ lower than someone else's.

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.

The original post doesn't mention IQ. IQ is a terrible metric for studying short-term cognitive effects.
IQ has a bad rap (rightfully so, thus no disagreement there). In the cited works they use tests that in the past were called IQ tests - though here all are called cognitive-scores.

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.

> Why wouldn't IQ tests be great for studying short term cognitive effects?

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.

I believe that IQ tests (at least the majority of those that I took or seen) are mostly built as abstract problem-solving tasks, similar to those needed to be productive in modern society. Not sure how one would even measure the "intelligent behavior" that you mention.

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.

> Not sure how one would even measure the "intelligent behavior" that you mention.

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".

Large cities tend to concentrate IQ as smart young adults come to seek better fortune. Furthermore Chinese party selection system, which involves standardized tests and relocation of gifted children to better schools in big cities also contributes heavily.
How do you all monitor air quality?

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.

The South Coast (California) Air Quality Management District does some really thorough tests on the quality of the various low-cost sensors: https://www.aqmd.gov/aq-spec/evaluations/summary-pm
Anyone want to review this table and suggest a currently commercially available option in the $300 and lower price range? I may have time this afternoon but if anyone does go thorough it I'm interested to know.
Based on my reading of the table, the PurpleAir II sensors seemed to be the best of the sub $300 for PM1.0 (field R^2 of 0.96 to 0.98) and PM2.5 (field R^2 of 0.93 to 0.97). The PM10 readings were not as good (field R^2 of 0.66 to 0.70).

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

I agree, looking at devices around the sub-$300 price point that were lab tested, PA-II has good performance and seems to be readily available.
That sensor is also available from Adafruit: https://www.adafruit.com/product/3686 I got it hooked up to a RaspberryPi that exposes sensor readings in Prometheus format.
Do you have a PurpleAir II to compare against? I suspect that there will be some extra calibration or signal processing some to make it more accurate that will be missing in the raw sensor.

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.

That sensor available at Adafruit uses the same algorithm for calculating PM levels, it's literally the same chip. Maybe using 2 of them yields more accurate results though.

The specs for particulate matter are identical:

https://www2.purpleair.com/collections/air-quality-sensors/p...

https://cdn-shop.adafruit.com/product-files/3686/plantower-p...

The Adafruit sensor is just the sensor, the PurpleAir II is two sensors plus extra logic that processes the readings to give extra accuracy.

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.

If that was true, then why are the specs for the PurpleAir II identical with the Adafruit sensor ?

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.

>*Field R2

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

I have one of these and it's easy to hook it into your home automation stuff as it presents a CIFS share and it's simply a matter of attaching and reading a text file.

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.

you can try changing the power saving mode (under 'performance'). it lets you adjust when the screen auto turns off/on
If you just want a sensor rather than a full retail device I'd recommend the SPS30. I have one and it's very easy to work with and per that table, is very accurate, while not needing any extra software correction. It's also cheaper than that table suggests: you can buy it for ~$50USD from Mouser.
Dylos AQM is the gold standard. It's pricey though and has an old school interface (no fancy UI, IoT or "AI").
(comment deleted)
I have an Awair. I don't really trust the baseline values but I do trust the deltas. I mostly use it to inform me when I should open a window or turn the air purifier or humidifier on.
I have a uHoo and it’s been great. The readings are inline with some control sensors I got to test the readings.
I have a uHoo monitor (yes, it is a dumb name).

https://uhooair.com/

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.

I have an Awair and two Foobots, they're basically completely unreliable and the software for them is pretty bad.

I've been tempted to get the purple sensors because at least the purple map seems reliable (so maybe their stuff is better?).

Any idea how good the Awair monitors are? I recall a report saying they were just so-so but Awair recently updated them to be more accurate.

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: https://imgur.com/tPgwGoK

Explains why the DNS Resolver on my router (pfSense) kept crashing at least.

Do you act on this information? Is there really much you can do to mitigate the effects?
If you have central air, you can put a good filter in your air return. If you don’t, you can buy a standalone air purifier.
Personally I have a PurpleAir II filter (as mentioned in a different part of this thread.) I also turn wood in an indoor environment, and run a HEPA filter which reduces the PM2.5 in the air drastically, and quickly.
For me just running an evaporative cooler roughly halves the counts, but that's from over 100 to about 50 so it's a kinda of a mixed blessing. But since my rented house isn't airtight or even close to it, there's not a lot I can do other than move.
I have Xiaomi Mijia Air Detector and Xiaomi Mi Purifier 2S. The air detector reports CO2, PM2.5 and TVOC, Purifier reports only PM2.5.
I have an arduino uno hooked up to CCS811 (a tiny air sensor chip). We're floating around 550ppm C02 right now, but earlier I was terrified as I watched the levels spike to 4500.
I've built my own "IoT" Sensors by hooking up a bunch of components to an ESP32 on a breadboard. I ended up going with:

- 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.

Poverty also reduces IQ by 13 points https://archive.is/bmj11
Has this study been replicated? It seems a lot like one of those terrible “priming” studies that won’t.

Statistics aside, the experimental methodology is terrible. You ask a bunch of people to think about being poor, or not, and that’s supposed to be a simulation of being poor or not?

I'm confused - is IQ a reliable way to measure intelligence between individuals, or is it a culturally biased measure that is scientifically bankrupt? I guess it depends on the context.
whatever skills IQ tests measure these do correlate (and better than other readily measurable predictors) with various long term successes

what throws most people off is that the skill that IQ test measure is not a just an innate ability but a learned skill that is in demand and often needed for success in that society

(comment deleted)
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.
That's brutal! We're poisoning ourselves.
Essentially all air filters filter nano particles.

https://smartairfilters.com/en/blog/can-hepa-filters-capture...

That's specific to HEPA filters. Most air filters are not as capable as HEPA filters.
Read the rest of the article. The cheap furnace filter filters nanoparticles too, just not as well. Both larger and smaller particles are pretty easy to filter. It's the ones around 0.3um that are the toughest to filter.
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.

Just google brands and find that they may be not so accurate or may be calibrated for some specific region of China

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

I'm assuming Delhi?

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

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.
(comment deleted)
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.
It's about the balance of positive and negative effects. There's always some kind of pollution and there's always some kind of benefit from exercise. The benefit from commuting on a bicycle is considerable. Question is how does the effect of pollution compare. If air quality is better indoors and you can do it indoors, great, but for many people commuting is one of the few opportunities to be physically active.
There's been studies done specifically on people cycling to work, and IIRC the conclusion was that the overall QALY result was significantly positive. But that does depend on your baseline - for someone who is fit and active anyway the marginal gain might be small, but for the average person the 10+ QALYS you get from being active vastly outweigh the combined (run over + pollution + injury) cost.

https://eos.org/articles/novel-air-pollution-study-gauges-in... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2920084/

Its not difficult, firstly buy a monitor which tracks CO2, PM2.5, VOC:

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...

Why is the first step to monitor it, not 'get a HEPA filter & fan / purifier'?

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?

Yeah, I'm confused by all the comments saying this too, especially since those detectors are yet another nontrivial expense.

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.

If you're closing up your house to avoid outside air pollution, you will spike your CO2 levels.

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.

> You also need to monitor the PM2.5 levels to ensure your air purifier is working.

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.

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.

> 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...

You can. However a mask on your face is not comfortable and so in practice I doubt you would wear it unless there was great need.

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.

Sure, but what about when you eat? What about when you're exercising? My point is that caring much about filtration efficiency quickly stops mattering after you've done the obvious things, because there are simply going to be times where you're not breathing filtered air, and those will very quickly become your main source of exposure.

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)

(comment deleted)
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.

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.)
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.
If you care about accuracy, my understanding is that the Purpleair is your best choice. I don't care about absolute accuracy, although it seems to agree within 10% or so with nearby putpleairs.

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.

Do you live in Beijing?

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.
It’s called BlueAir I think? That life is behind me now. I love living in china, but the air pollution is a deal breaker.
David Heinemeier Hansson (DHH of Rails fame) gave a great talk on this recently, though he focused more on indoor air quality and its cognitive impact:

https://www.youtube.com/watch?v=MRqh8oLY7Ik

My takeaway from this: If you live in new construction (owner, or renter), buy new furniture in the spring/fall when you can leave the windows open. Same for paint.
I highly suspect toluene has something to do with it, seeing as how it's a potent neurotoxin and a byproduct of burning fossil fuels.
I thought IQ was not a reliable measure of anything?
I wouldn't call IQ a completely useless yardstick. Likely through examining all of the evidence regarding IQ and military performance, the United States government has come to the conclusion that an IQ below a certain level disqualifies the person for military service.

Unsurprisingly, US law is a bit complicated on this, but to summarize, it implies that an IQ below 81 (“tenth percentile”) is disqualifying, and dictates that persons with IQ's between 81 and 93 (“thirty-first percentile”) cannot comprise more than 20% of all enlistees.

It depends on how one defines intelligence and what specific things are considered material to the measurement. IQ tests measure the things that IQ tests measure. The challenge is that the things we often want to determine in trying to assess "intelligence" are multi-dimensional, multi-variate and have complex interactions.

Personally, I consider most typical assessments of a person's general "smartness" to approach zero utility.

Reading his bullet points, I am not sure why the correlation between daily stock market returns and air quality supports the argument that air pollution reduces IQ.
One hypothesis is that part of the short-term stock movements is causing about publicly visible stupid acts, causing either physical or PR disasters of various sizes. That would imply some correlation, but a relatively small one.
Many if not most trading decisions are not executed from a NYC office. The exchange servers aren’t in NYC either, but like that matters.
I wish the argument against pollution would be the simplest one.

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.

/rant

(ps - rant isn't against the article, but a broader frustration about the topic)

I like thinking of it as waste, as opposed to bad. Good-bad is the moral realm. Waste is the realm of practicality. The danger is in causing defensiveness, due to judgment, in people whose open-mindedness would be beneficial. I'm not being apologetic of anyone. It's just that this doesn't have to happen through a dramatic conflict of good v. evil (which probably wouldn't work anyway); there are much better alternatives.

I agree with everything you said. Just wanted to stack my rant on yours there.

I would like to agree with you as I also think trying to find a pragmatic solution is easier than thinking in abstract terms like good/bad, but ultimately waste just takes us to questions about what is being wasted, and wasteful to who. It's a no brainer than relocating to somewhere to avoid emissions can be seen as wasteful for some industries. Besides, framing waste in purely monetary terms, just means that we need to balance the equation for profit, not to what is best for people. The question of alignment between profit and human welfare is still am ethical one.

You haven't reduced the complexity, just hidden it behind the facade of taking "pragmatic economic decisions".

I'd argue that talking about waste exposes the complexity (reality in simpler terms), while ethics or morals obscure it.

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.

it's just that the amount of waste is way too large for the environment to digest

Solution: everyone must consume less, cut unnecessary things, and there are many in most people lifestyles

We need to quantify how bad pollution is exactly. How many people should be allowed to die because the ICE ambulance can’t reach them or the doctor isn’t able to travel to the hospital or food isn’t able to be delivered for a reasonable price etc.
> I wish the argument against pollution would be the simplest one

Arguments against pollution would be valuable if someone were actually arguing in favour of pollution.

Agreed. In a data-driven world, any claim not backed by data will be quickly dismissed :)
George Carlin - "The Planet is fine, the people are fucked ..."
You are right that there's a massive difference between populated and unpopulated areas. One is better because it doesn't have as many people. Just by breathing people create Co2. Just by existing people create waste. Not sure how that could be fixed.
From the original source:

> 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.

This is probably just a coincidence. Stock markets perform lower on Mondays: https://www.macroption.com/stock-market-performance-volatili...

Traffic is probably generally higher on Mondays, though I have only anecdotal evidence.

Heh, a rare example of the "proof of correlation isn't proof of the absence of causation" fallacy. No reason that stock markets couldn't perform worse on Mondays because of the extra traffic pollution.
But it's not like companies provide daily sales performance data to trade on. Markets move on speculation. They aren't actually pegged to company performance.

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.

Markets aren't perfectly efficient. Some trades are dumb. People with lower cognitive ability are more likely to place an order and forget to check fundamentals first, forget to check competitor data, or quiet frankly make whopper mistakes like confusing a ticker symbol. Think of the loons you see on /r/wallstreetbets and other spots. They live on a spectrum, and all of us have bad days.

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.

Yes, but for most dumb trades, there is someone on the other end making a deal. So the 'dumb' trades would have to lean more towards selling rather than buying.

Perhaps pollution just makes one more pessimistic and therefore bearish.

??? Who ever said correlation => not causation.
Pretty much every internet comment section for the last 2 decades.
I don't think so. `Correlation => Causation` is used all the time - this is the bread and butter of clickbait headlines and articles "new study shows that...", but `Correlation => ^Causation` requires some sophistication to state ... while being wrong at the same time. Maybe a tactic used to mislead? I haven't seen it ever used.

To be clear `Correlation => ^Causation` is different to `Correlation => TRUE`. (In other words, there is nothing you can deduce from correlation alone).

The journal article explicitly calls out day of week and controls for it...
It's a review article. The paper you mention was just one of many cited. And sure, those are all different papers written by different authors and it's surely not unlikely that there are errors in there. But the reason for reviews like this one is to point out that all these different results support the same basic hypothesis.

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.

Read the linked journal article; the authors don’t actually claim it is about cognitive ability, they attribute it to lower risk taking on those days.
As someone who works for a quantitative hedge fund, you wouldn't believe how many similar results I see of researchers showing a statistically significant predictor of stock market returns. Almost every single one of them is garbage.

But your point stands. The paper has nothing to do with cognitive ability. So why is it being used as evidence?

> As someone who works for a quantitative hedge fund, you wouldn't believe how many similar results I see of researchers showing a statistically significant predictor of stock market returns. Almost every single one of them is garbage.

Are you able to share any that aren't (or weren't) garbage?

Ones that aren't garbage are valuable! Until the rest of the market adjusts, and then they're garbage.
He could share past insights that are no longer relevant. I obviously don't expect him to give away a stock tip worth millions of dollars.
Exactly, there is no actionable publicly known indicator. Because the moment it becomes known by a large enough group of traders, it becomes useless.
Here's a disappointingly simple and well known one: Momentum. It produces real, statistically significantly, excess risk-adjusted returns over an index.

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.

Is it even possible for a statistically significant predictor of stock market to be both known to the public and not garbage?
Maybe people are more negative because of traffic, noise and frustrated about getting to work later. I find it hard to imagine a way to control for this short of making people breathe these substances separately and seeing if they actually do have lower IQs. You can then control for the other factors. These all seem to be epidemiological studies that we can't show the pollution is for sure the root cause. It could, for example, be that pollution is 25% of the result for example with more noise, traffic, irritation etc. being the other 75%.
"I don't want to dismiss the entire article"

Good. Because you can't cherry-pick one dubious-seeming journal article and use it as a justification to ignore several completely unaffiliated articles.

To clarify, the paper studied "air quality in the vicinity of Wall Street".
So does this mean we can now expect populist politicians to crank up PM2.5 emitters at a massive scale prior to elections?
No need. Some people gleefully accept and partake in air pollution.

Out in the countryside where my parents live in Texas, people are even proud that they burn their trash as if they're sticking it to some sort of treehugger group rather than to the inner lining of their (and all their neighbors' and loved ones') lungs.

So logically living and working in the countryside is optimum for your IQ rather than polluted cities and areas?
The countryside can have some bad environmental problems too (expansion of fracking in the rural Midwest of America, etc).
Does fracking cause much air pollution of the type discussed in the article? I thought the main issue was groundwater and earth quakes , and methane gas release / flaring.

Plus there are many countryside areas with no oil.

Well to their point, there is more wood, brush or other similar types of burning in rural areas. Especially wood in the US as it is the source of heating homes in rural areas. Bonfires, etc are also more likely.

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.

Wondering where the optimum place for humans to live is, assuming around healthy agricultural practices (away from BigAg) without to much wood smoke pollution
Pretty sure there's more smoke from forest fires near California cities than smoke from brush fires in rural towns.

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.

The bushfires act as a counterbalance in Australia ...
Too true. I live near a significant recent bush fire & had my first run for a couple of weeks this morning - clear breathable air is a joy! These periods are pretty uncommon however - compared to the regular temp inversions & associated low air quality in Brisbane, for example.

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.

Pollution, IQ, who cares?!? We've got carbon dioxide to fight, a benign gas that for some reason we believe is the root of all evil! Climate change is the most important issue of our time, not pollution (which is actually real and not forged by IPCC, but who cares about reality when there is Greta Thunberg)
Things like this make it really hard to follow a discussion as it evolves over time.
Yes, there's some churn, though we do what we can to minimize it, e.g. posting the URL change in the thread. But the benefit of switching to original or better sources is greater than the cost of the churn. Discussions gradually become higher-quality. Also, not switching to original sources also creates noise in the threads, e.g. complaints about blogspam.
Most small particles are bad for health.

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.

Although all small particles are bad for the lungs, there must be a difference in their effects on brain and organs, depending on what those small particles are made of since PM 2.5 particles pass through lung lining and into the blood to be distributed around the body.
Plug: if you care about this topic and are interested in working on this problem, we're hiring at Aclima. We've got contracts with the major air quality regulators in California, and are looking to scale. Ping me at igor@aclima.io
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.
Sydney is having a bad day :-( https://aqicn.org/city/sydney/
We would call 159 a clean air day in Beijing.

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.

Sydney radio loves comparing it to Beijing. Then reminding us that we've just got that for a day.
short of plants, i want to find a device i can put in my area that reduces the co2 in the air. (my space doesn't support plants, it's too cold).
Most CO2 scrubbing systems either use plants (sometimes algae) or expend chemical ingredients (not very practical for long term daily use). Id recommend looking at systems designed for survivalist bunkers.

I did find this interesting project for using a thermosiphon to separate CO2 from air which looks pretty cool, but would likely require a good bit of sun to work well. I imagine it could work with an electric heating element instead of the sun, however.

https://www.instructables.com/id/Solar-powered-CO2-Scrubber/

Anyone interested should also check out the open source citizen science project https://luftdaten.info/en/

Build your own inexpensive sensor, contribute to the global network. See also https://github.com/opendata-stuttgart

For people living in the US like me, this is where you find US pollution maps: https://usa.maps.luftdaten.info/
Holy cow, that must be a German project; Germany has nearly 100% coverage, the USA has almost none.

I was expecting China and India to be dark purple

If you want a more international / american version, check out purple air: https://www2.purpleair.com/
Is purple air the proprietary version?
No it's another independent community effort, go read it's about page.
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.

https://www.uradmonitor.com/

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!
What is CCC? Searching brings up many things.
Given this is HN and OP mentions attending, they are likely referring to the Chaos Computer Congress, a German tech/hacker conference.
For clarification: CCC is used for Chaos Computer Club, who organizes the C3, the Chaos Communication Congress. Confusion guaranteed ;) for more info visit https://events.ccc.de/
The 36th Chaos Communication Congress organized by the Chaos Computer Club, a traditional event run by the community for the community. Takes place from Dec 26 to Dec 30 in Leipzig (Germany). Tickets are available on this Thursday (November 21th) from 21:00:00 CET till, judging from past experience, 21:00:01 CET.
All of these publications are junk science, nothing but spurious correlations, using the nonsensical linear no-threshold model.

(waiting for the internet to correct me so I don't have to do any research myself)