
Air pollution causes ‘huge’ reduction in intelligence: study - neverminder
https://www.theguardian.com/environment/2018/aug/27/air-pollution-causes-huge-reduction-in-intelligence-study-reveals
======
stupidcar
What's really amazing to me is when you realise that the UK executive and
legislative branches are based in London. MPs, Lords, and often their partners
and children are all living and working in an extremely polluted environment
for years on end. Even so, with the knowledge that they are seriously harming
their own health and the health of their closest relatives, they persist in
resisting and blocking attempts at actions to improve air quality in London.

Whenever somebody defends the quality of democratic representation in the UK,
I just remind myself that these are people who would rather they and their own
children suffered illness and premature death than take action that might piss
off business and motorist lobbying groups.

~~~
Al-Khwarizmi
I think you're overthinking this a bit. I don't think politicians prefer
seeing their children suffering illness and premature death rather than
pissing off lobbies. The real problem is that most people see the results of
studies like this as something abstract, not as something that affects them
directly. It's clearly visible with smokers: it's not that they are especially
tolerant of dying a horrible death from lung cancer or a stroke (no one is),
it's mostly that they don't really think it will happen to _them_ (yes, I know
it might be an imperfect analogy because physiological addiction also factors
in... but I also know a smoker that found quitting "physically impossible"
until he had a stroke, and survived. Once he had saw death's face, and the
risk turned from abstract to very concrete, he quit smoking overnight).

~~~
antt
It doesn't help that studies like this are also usually wrong. Don't change
anything in your life until something has been replicated a dozen or more
times.

~~~
Silixon
There's a Pascal's wager in this situation. In the worst case, there's no
cognitive effect from pollution, but you clean up the environment anyway. Even
without the possibility of improving your ability to reason, there are many
other obvious benefits to reducing pollution, quitting smoking, and many other
major changes about which the effects have been debated and exaggerated over
time.

~~~
zeveb
> There's a Pascal's wager in this situation. In the worst case, there's no
> cognitive effect from pollution, but you clean up the environment anyway.

And, as with Pascal's wager, that's unconvincing: one could spend all that
money differently, on things one would like (just as in Pascal's wager,
choosing to believe in God isn't cost-free: it means loving others, being
charitable &c., even if one would rather not).

------
bobbyadamson
> Chen said air pollution was most likely to be the cause of the loss of
> intelligence, rather than simply being a correlation.

Why? You can't just say that and expect people to trust you. The fact that
they followed the same people may reduce the chances of certain DNA traits
having an effect but how does that rule out other commonalities in
environmental conditions. If you're in a polluted city it seems likely that
you're in a large city. So do all the common traits of a large city also
reduce your intelligence?

I want to read the study but I don't want to subscribe. If there is logical
proof in the study that this is not simply a correlation, the guardian piece
does not represent it.

~~~
carlmr
The Guardian is headquartered in London, which is a major polluted city, maybe
the effects are becoming visible.

~~~
throwawaymath
That’s vastly insufficient as far as empirical evidence is concerned. There
are many things that coincide with pollution, which is what the commenter is
saying. You need to demonstrate how you picked out pollution from everything
comingled with it. That’s what’s being asked about here.

EDIT: Disregard this stuffy reply, my humor detector was off.

~~~
Vinnl
The response was tongue-in-cheek: the commenter implied that the article was
insufficient due to the journalist being less intelligent due to living in a
polluted city.

~~~
throwawaymath
Hah, I see it now. Shame you had to spell that out for me :)

------
geomark
There was a recent large scale study that claims PM2.5 levels present in
cities have a significant effect on healthy children's lung capacity, that by
the age of eight children who live within 100 meters of a busy street have a
6% reduction in lung capacity compared to those who don't. Now this study.
Jeesh.

I am particular interested in these studies because my family lives in a very
clean rural mountainous area in Thailand and my son is attending a pretty good
international school here. But I am considering moving him to a bigger and
better school in Bangkok - a dirty, polluted, congested city. If this study is
true then am I really gaining anything? The difficult tradeoff was health
impact for improved educational opportunity. But if the pollution equates to a
one year loss of education then maybe there is little to no gain.

~~~
nopinsight
I have a lot of experience tutoring math in small classes to many students,
including a couple who went on to earn gold medals in International Physics
and Chemistry Olympiads. (I no longer teach due to my current research and
startup work.)

I'd say your child would gain much more from having good private tutors you
hand-pick from local schools/universities/private tutoring centers (depending
on the level of your son's attainment and the qualifications of the teachers).
Also, for certain subjects, you could be a great teacher yourself.

Even without taking pollution impact into account, using the hours saved from
commuting in a very congested city to study one-on-one or in a small group
would likely net a bigger gain than what quality difference there is between
the good local school and a top school in the capital city. The key conditions
are 1) having qualified tutors who fit with the student's personality and
interests and 2) regular schedule so the student does not spend the extra
hours playing mobile games instead.

Another key advantage is your child can use the best educational materials
available on the Web, paid and free, such as Khan Academy, 3Blue1Brown, and
the likes for learning. The presentations there are often head-and-shoulders
above the techniques most school teachers typically use to explain concepts in
class.

Edit: For a downvoter who I assume might disagree with the last paragraph, you
need to go visit average schools in a developing country to see how the
teaching is like.

~~~
geomark
I am glad to read your suggestions, coming from someone with experience. And
indeed I have been doing some of this. The teachers at his school are very
good. It's other issues that I'm not satisfied with (detailed in my other
comment
[https://news.ycombinator.com/item?id=17867556](https://news.ycombinator.com/item?id=17867556)).
I do teach him a lot. I'm an EE and can write code. So I have had him do a
bunch of code.org, robotics projects, maker projects, and we do lots of
reading together. He's strong in those areas. Currently do tutoring only in
Chinese and music. And yes, he has pretty strict limits on game playing time.
So maybe I should stay the course as you suggest, supplementing as needed.

~~~
mike_h
Keep in mind that one good thing about air pollution is it’s relatively
straightforward to mitigate once you’re aware of the problem. PM2.5 filters
can be had for relatively cheap (see Smart Air), and you can wear a mask when
you’re out on bad days. Unless you’re really lucky, his peers in Bangkok
probably won’t make him feel great about wearing a mask, but just having clean
air at home will help a lot. Then maybe you can talk the school into filters,
plus policies about athletics on bad days. I’d be surprised if they don’t have
these already.

------
stochastic_monk
This is no surprise to people who have lived in Salt Lake City. During the
winter, as a consequence of inversion (pollutants being trapped in the
mountain basin), it becomes the most polluted city in North America. During
this time, resident IQs also drop. [0]

[0]
[http://health.utah.gov/enviroepi/healthyhomes/epht/AirPollut...](http://health.utah.gov/enviroepi/healthyhomes/epht/AirPollution_PublicHealth.pdf)

~~~
mockingbirdy
> During this time

Do they perform on the normal level after the pollution? That would be a hint
that the results of the IQ tests just temporarily drop (I would be careful to
say that the intelligence dropped).

~~~
stochastic_monk
Correct. To be clear, this is a reversible and temporary response to the air
quality.

~~~
mockingbirdy
This puts the article in perspective.

If people leave the polluted area, they'll restore their normal intelligence.
When I hear "reduction in intelligence", I immediately think that they talk
about permanent reduction (because a big part of fluid intelligence is
genetics, the efficiency of synapses and the amount of neurons - although some
research [1] indicates that nurture and training can have significant effects
on fluid intelligence).

It's unclear if they talk about permanent and irreversible damage IMO. For me
it seems like they want to frame it that way which could be a bit clickbait-y
depending on the matter of facts.

[1]:
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2383939/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2383939/)

~~~
yorwba
From the study TFA is based on (on Sci-Hub: [https://sci-
hub.tw/http://www.pnas.org/content/early/2018/08...](https://sci-
hub.tw/http://www.pnas.org/content/early/2018/08/21/1809474115) )

 _First, in general, air pollution inhibits respondents ’ test performance.
Except for the effects of 1-d and 7-d air pollution exposure on math test
scores (first and second columns in panel B), all of the coefficients for mean
APIs over a longer period are negative and statistically significant._

 _Second, the damage of air pollution on cognitive performance is more sizable
when using longer window of exposure measure. As shown at the bottom in panel
A, an increase in the 7-d-mean API by 1 SD lowers verbal test scores by 0.278
point (0.026 SD), while a 1 SD increase in average API over 3 y before the
interview is associated with 1.132 points (0.108 SD) drop in verbal test
scores._

 _Third, air pollution exposure appears to exert a more negative effect on
verbal test performance than math test performance._

That doesn't imply that the effect is irreversible, but it does mean that
there are long-term changes which accumulate with longer exposure to air
pollution.

~~~
mockingbirdy
Thanks. If air pollution decreases cognitive capacity in the short term, it's
clear that learning efforts have a lower return on investment for that period
of time. This means it directly affects parts of the crystallized
intelligence. It's like a temporary learning disorder which inhibits
neurogenesis and decreases working memory.

Please correct me if I'm wrong. Sounds very interesting and I hope that people
will finally fight against air pollution. Undoing it is not only healthier but
also economically relevant. Sad that such studies seem to be necessary, but
it's good that such revelations lead to more pressure for the policy makers.

------
paraschopra
As an Indian living in India, this saddens me a lot. India has perhaps the
world's biggest share of most polluted cities [1], and there are next to none
measures taken. PM 2.5 in Delhi regularly shoots beyond 200 (while general
guidelines for good quality air is <50).

The sad part really is that the pollution is more of a political and
enforcement problem than a technological one. And none of the wonders of our
technology will help us solve the "messy" problems that occur in a democracy
of heterogeneous people (of India).

~~~
cheeko1234
What does heterogenous have to do with it? U.S. is by far more of a melting
pot than India.

~~~
umanwizard
> U.S. is by far more of a melting pot than India.

What do you mean? Basically the only reason India is one country is because
the British ruled it as one country. It is about as culturally and
linguistically diverse as all of Europe.

~~~
_emacsomancer_
Not exactly the same entity (British India ended up stretching further east)
but Mughals ruled it as one country too, and the East India Company kept up
the fiction that the Mughals were still in charge for as long as possible.

------
dzdt
It is interesting to me that they use years of education as a measure of
intelligence. As an American I am more used to thinking of intelligence as an
innate, almost fixed characteristic (IQ). In that view education increases
knowledge and skills but isn't expected to much affect general intelligence.

But to this article's authors, "intelligence" is increased by education, so
harmful effects of pollution can be measured in years of education lost.

Is there a general cultural difference in how intelligence is thought of in
China as opposed to the US?

~~~
arethuza
I must admit that from perspective of the someone from the UK I've never
really understood the US obsession with the desire to represent intelligence
as a single number.

~~~
AmericanChopper
Fluid and crystallized intelligence (which is what IQ test measure) are the
most robust ways of measuring intelligence, and IQ is the single most reliable
metric ever discovered in psychology, in terms of making predictions. If
you're interesting in measuring how smart somebody is, there's no better way
of doing it than with that single number.

~~~
orwin
Which IQ test? IQ as a number alone mean nothing, as you can't make a
standardized test for it. And IQ number is a comparison (you calculate the
standard deviation). Also, even in clinical tests, multiple scales can be
used, and this mesure evolve. And there is no "single number", multple
subjects are tested, and now we have another limitation: those tests don't
mesure everything, or mesure thing that can evolve. I "scored" 123 on the
weshler when i was 8 (or 9) with a really bad spatial visualisation score of
90 (89?). Since i'm now able to play blindchess or to chart a course on a
marine map, either my spatial visualisation skills have improved, either
people i know hide a lot. And i'm sure i would score way less on the other
subjects too, looking back i was a pretty interesting kid, while now i'm an
average adult.

I'm not saying it's useless, but to me it is way overvaluated by some people.
Maybe you can approximate intelligence with an IQ test, but the number itself
is meaningless imho. The classification can be used though.

~~~
Symmetry
The hypothetical g which IQ tests are trying to find is the extent to which
every test of mental abilities that anyone has ever devised plus some things
like reflex speed all seem to be fairly strongly correlated with each other
and all seem to be correlated via a common factor. You can certainly be more
skilled at one test than another. These tests are also fairly noisy when
applied to individuals.

For individuals the results of IQ tests probably are oversold as you say given
their noisiness. But for public health problems like air pollution where the
results are averaged over populations they're probably undervalued if
anything.

------
nopinsight
From the paper:

> Cutting annual mean concentration of particulate matter smaller than 10 μm
> (PM10) in China to the Environmental Protection Agency’s standard (50 μg/m3)
> would move people from the median to the 63rd percentile (verbal test
> scores) and the 58th percentile (math test scores), respectively.

It seems like HEPA air purifiers should help quite a bit if one spends on a
lot of time indoor. At least having one in the bedroom would reduce exposure
time by at least one-third, which should be useful.

It also sounds like by investing modestly in air purifiers, most offices in
polluted cities could even net productivity gains from healthier employees who
suffer less from allergy and congested airways, in addition to long-term
maintenance of their cognitive function.

~~~
rcMgD2BwE72F
Why spend money in air purifiers when you can invest in things that reduce the
emissions of pollutants at the source?

Don't production, usage and waste treatment of air purifiers contribute to air
pollution over their entire product life cycle?

~~~
nopinsight
That is an ideal situation most of us do not have much influence on. We can
help lobby/advocate at the margin but check out who we are up against esp in
developing countries, where the problems are most acute.

In the meantime, air purifiers reduce the extent that our health deteriorates.
The effect of air purifiers production is relatively tiny compared to
pollutants from the rest of the economy.

------
majjam
Discussed on reddit here
[https://www.reddit.com/r/worldnews/comments/9as5p3/air_pollu...](https://www.reddit.com/r/worldnews/comments/9as5p3/air_pollution_causes_a_huge_reduction_in/e4xvev4/)
in particular /u/gen_0 looked into if/how the study controlled for poverty,
household income and other factors (they do).

------
0xcde4c3db
There are also studies hinting at a potential pathway involved in this:
exposure to particulate air pollution appears to reduce the activity of brain-
derived neurotrophic factor (BDNF). [1] [2]

[1]
[https://www.ncbi.nlm.nih.gov/pubmed/21708224](https://www.ncbi.nlm.nih.gov/pubmed/21708224)

[2]
[https://www.ncbi.nlm.nih.gov/pubmed/25816123](https://www.ncbi.nlm.nih.gov/pubmed/25816123)

------
agumonkey
Any tricks to improve the air around and in your house ? without resorting to
air filtering machinery if possible.

~~~
steve_musk
I didn’t do much research into this but there are a number of house plants
that NASA says improve air quality.

~~~
trukterious
There's a list of some of these plants here:

[https://learn.allergyandair.com/houseplants-indoor-air-
quali...](https://learn.allergyandair.com/houseplants-indoor-air-quality/)

One minor trick I use when walking down the street is to rapidly exhale if
I've breathed in a particularly bad volume of exhaust pollution, like
concentrated diesel fumes, walking on a few paces before re-inhaling. I expect
it takes ~1s to detect the bubble of bad air and the surrounding air is
polluted too. So just mitigation.

------
stephengillie
Based on the amount of carbon monoxide and other pollutants that enter a car's
cabin at highway speeds, this is likely a huge cause of road rage, speeding,
and other reckless driving behaviors. These strong emotional states don't
always end when we exit our vehicle, and so may affect us through our day. Our
commuting time becomes a divisor of our overall daily intelligence, and
quality of life.

~~~
acct1771
I speed in reverse out of my drive, friend; how do you account for that?

------
growlist
In hindsight, European car makers' decision to go all out for diesel was a
spectacular blunder, with horrendous consequences for health. Looking forward
to the day they finally ban this filthy, choking fuel.

------
black_puppydog
> The study followed the same individuals as air pollution varied from one
> year to the next, meaning that many other possible causal factors such as
> genetic differences are automatically accounted for.

That's already much better than what I had feared. Not perfect, of course, but
better than the usual "corellation == causation" journalism.

------
rooam-dev
Educated guess #1 - more toxins + less oxygen = bad for your brain, body and
adds distraction (can you study/focus when you have health issues?)

Educated guess #2 - less pollution = better environment, country side and/or
nature rich + less stress

------
JTbane
Hopefully electric vehicles can alleviate at least some of the air pollution
in major cities- I applaud efforts to restrict ICE cars and trucks.

------
nnain
If this was absolutely true, China and India would stop having any
maths/science/arts/medicine/CS people.

Pollution control is on my mind constantly, and I hope we get a hold on
pollution soon. But to be honest, the western media is after it a bit like how
they were after Salt or Egg yokes earlier. I don't know why but the press
constantly needs a target to pile everything on.

------
dunpeal
> Impact of high levels of toxic air ‘is equivalent to having lost a year of
> education’

Since when is education equivalent to intelligence?

I thought that the current definition of intelligence is a relatively stable
performance measure that is entirely independent of education (though it does
predict academic performance).

------
nerdponx
As usual, the actual scientific results are paywalled [0]. I guess we just
have to make informed opinions based on science journalism, which is pretty
much impossible.

[0]:
[http://www.pnas.org/content/early/2018/08/21/1809474115](http://www.pnas.org/content/early/2018/08/21/1809474115)

~~~
ShorsHammer
May I introduce you to my bird friend?

[https://sci-hub.tw/http://www.pnas.org/content/early/2018/08...](https://sci-
hub.tw/http://www.pnas.org/content/early/2018/08/21/1809474115)

~~~
nerdponx
The only reason I posted this in the first place is that I was having trouble
verifying the captcha on my phone, and it made me think about how this site
shouldn't even need to exist.

------
alexandercrohde
The crazy thing is, as far as I'm aware, it wouldn't be a difficult
engineering feat to get standard air-filters on exhaust pipes. Most air
filters are merely a sac of activated-charcoal.

~~~
jhpankow
I don't even know where to start. Activated charcoal stuck in a car exhaust
would not filter PM2.5 and wouldn't even do what was intended once it becomes
saturated.

~~~
alexandercrohde
Maybe you should start with a little bit of humility, and citing sources?

Once it became saturated, you'd obviously replace it, likely at an annual
exhaust inspection.

[1]
[https://www.sciencedirect.com/science/article/pii/0016236189...](https://www.sciencedirect.com/science/article/pii/0016236189903141)
[2]
[https://university2.taylors.edu.my/EURECA/2014/downloads/46....](https://university2.taylors.edu.my/EURECA/2014/downloads/46.pdf)

------
snarfybarfy
Reminds me of the studies that claim that putting lead in our petrol for
decades also decreased the average IQ globally by 2-3 points.

------
Illniyar
A conclusion like that seems very prone to data misinterpretation and bad
methodology. Skimming the article I couldn't find any mention of the method
used to reach the conclusion. Can anyone shed a light on the method used in
the study?

------
liftbigweights
Sigh. Average IQs have significantly increased as pollution has significantly
increased. We have objective data on this.

[https://ourworldindata.org/intelligence](https://ourworldindata.org/intelligence)

[https://ourworldindata.org/air-pollution](https://ourworldindata.org/air-
pollution)

We have decades of data to show this positive correlation. Now I'm wondering
how the study measured intelligence and of course who funded this study.

Edit: Seems like a lot of people are misunderstanding my point. I'm not saying
air pollution is good. I think air pollution is bad. I'm just pointing out raw
objective data which contradicts the study.

~~~
dignick
Perhaps IQs would have increased more without pollution?

~~~
liftbigweights
Sure. The objective data I provided shows a correlation and not a causation.
But it contradicts the study of a "huge" reduction in intelligence due to air
pollution.

If air pollution causes reduction in intelligence, IQs would not have
increased so much in the past 100 years as air pollution skyrocketed.

Can't say air pollution causes huge reduction in intelligence while IQs have
drastically increased in an increasing air pollution environment.

The study claims a causal relationship - air pollution causes huge reduction
in intelligence. The objective data of the last 100 years clearly shows that's
not true.

