Transport noise linked to increased risk of dementia, study finds

https://www.theguardian.com/society/2021/sep/09/transport-noise-linked-to-increased-risk-of-dementia-study-finds

by adamjb • 5 years ago

95 82 5 years ago

ggm• 5 years ago

Very hard to see how they can discount confounding correlates to diesel particulate and other PM10 and finer materials, brake dust &c.

Not that I don't think the science is good, I'm sure they do and the article says they do, but I struggle to see how you can isolate noise from particulate exposure: they'd have semi identical square law dropoff by distance and volume.

WalterBright• 5 years ago

The article says:

“The results are strengthened by the authors controlling for levels of traffic pollution, which was recently shown to be associated with dementia as well as other diseases.”

jstanley• 5 years ago

How can you possibly control for traffic pollution in a way that is independent from traffic noise?

Goety3• 5 years ago

We dont have an accurate assessment of traffic pollution or air pollution in general. Thanks 'regulatory agencies'

dannyw• 5 years ago

Two ways I can think of:

1. Electric trains wont generate diesel particulate, but will generate road noise.

2. It's relatively straightforward to measure pollution and noise, so you can do analysis to try and separate them.

In many situations these would not be correlated exactly. For example, terrain, wind patterns, noise dampening structures, etc.

vladvasiliu• 5 years ago

1. Electric trains wont generate diesel particulate, but will generate road noise.

They don't generate diesel particulate, by they do generate "other PM10 and finer particulate", from the brakes for example.

In Paris there's a lawsuit against the RATP (local transit authority) for particulate pollution inside the stations. [0]

There's also the fact that, at least in Paris, some metros are running on tires. For those that run on metal wheels and rails, some turns are quite sharp, and you can hear the screeching of the metal. This is likely to contribute to particulate pollution.

I suppose for overground trains, this is less of an issue.

---

[0] https://www.rfi.fr/en/france/20210323-french-ngo-sues-paris-...

fighterpilot5• 5 years ago

Except road noise was associated with dementia and train noise wasn't, which suggests it's pollution related according to your (1)

The other problem is that people that live near noise are poorer. Did they control for wealth?

These epidemiological observational studies are so hard to take seriously. I get why so many of them are done though. It's a relatively lower effort way to get publications out the door, all you need is a dataset and a few days in python.

harperlee• 5 years ago

I also heard somewhere a saying that goes something like ‘windy places have more crazy people’.

eurasiantiger4• 5 years ago

The meaning of that saying is not literal; ”windy places” refers to unstable leadership in an organisation, with high-level executives often getting replaced.

lostlogin• 5 years ago

It could be both. Wellington, New Zealand is a touch blasted, and after a decent gale down there I’ve felt unhinged.

GuB-42• 5 years ago

I think it is literal.

In the region of Toulouse, France, "vent d'Autan", a strong wind that blows in that region is called "vent qui rend fou", the wind that drives people crazy. It is a bit of folk knowledge that seems to be verified: crimes rates are higher, people and animals are more agitated, ect...

And it is not the only occurrence where strong wind is associated with madness.

jopsen4• 5 years ago

Impressive study... as someone who just bought a house 100m from large road, I'm just going to make myself read the last paragraph a few extra times:

the best way to maintain brain health was to stay physically and mentally active, eat a healthy balanced diet, and keep your weight, cholesterol and blood pressure in check.

loloquwowndueo• 5 years ago

So the best way to maintain health is to … stay healthy?

jopsen4• 5 years ago

Yeah, and don't worry about noise pollution -- the stress might kill you :)

viktorcode2• 5 years ago

I'd suggest noise isolating the house. Triple pane windows do wonders in my case, but they aren't always desirable depending on where you live.

jopsen4• 5 years ago

I haven't moved in yet... But given that it's only 10 years old, I doubt we'll be able to hear much inside the house :)

In any case, noise isolation can make a huge difference.

yread• 5 years ago

I've recently looked into this, after I read this article https://link.springer.com/article/10.1007/s00395-019-0753-y . There are also noise isolating heavy curtains (FWIW the claim -20dBa). But the vibration stays and it might also have an effect

ncmncm9• 5 years ago

Install MERV #13+ and activated-carbon filters in your HVAC intakes, and ensure the fan runs even when the heat or a/c doesn't.

You don't need HEPA filters if the air circulates, because what doesn't get caught on one round probably gets caught on the next. Five rounds at 75% is as good as 99.9% once.

jcims2• 5 years ago

Placing tight filtration on the HVAC system can substantially reduce airflow over the coils and/or heat tubes, decreasing efficiency and possibly causing the system to malfunction.

The HVAC system just needs enough filtering to avoid impacting its operation. Any additional air particulate removal should be done separately.

numpad0• 5 years ago

Fun fact: electric cars make larger, not smaller, road noises.

This is because wind and tire rolling noises take over any engine noise at > 15mph, and because electric vehicles are usually substantially larger and heavier than its counterparts.

Those whooosh noise of a car passing is mostly the sound of an 1.75t object rolling through displacing air.

mfgs• 5 years ago

Interesting. I'm definitely looking forward to electric buses and trucks though. Standing on the sidewalk when a bus accelerates next to you can be offensively loud.

eurasiantiger4• 5 years ago

Breathing in the exhaust is worse than the sound, though.

sva_• 5 years ago

A city in Germany (Osnabrueck) has switched all their buses to electric. They are much more silent, for sure.

I also don't feel like electric cars are more loud, at least at moderate speeds. I always had the impression that they're a lot more silent inside cities. Maybe on a highway that would be different, I can't say.

The biggest offenders of background noise are obviously trucks though.

dotancohen• 5 years ago

Does the mass really affect the sound through the air? I'm sure that the shape and size of the vehicle will affect the wind noise, but I fail to see how the mass of the object directly affects the wind noise.

Tire noise, possibly, as the tire is holding that mass.

jsilence4• 5 years ago

I fail to see why electric cars are significantly heavier than gasoline cars. Signifikant in the sense that it makes a differenc in noise.

ncmncm9• 5 years ago

They have a battery that weighs much more than 15 gallons of gasoline.

viktorcode2• 5 years ago

That is incorrect. In different measurements the noise level was the same at higher speeds, while being much lower for EV at urban driving speeds.

One example: https://www.toi.no/getfile.php/1340825-1434373783/mmarkiv/Fo...

kmlx• 5 years ago

is 2-4db reduction under 30km/h “much lower”?

7952• 5 years ago

And probably lower variance in noise compared to ice cars which are sometimes designed or modified to have excess noise as a feature.

codingdave• 5 years ago

At what distance? I live in the country, where there often is not a vehicle moving within a mile or so, and can guarantee that when cars do come nearby, it is the engines I hear, not the wind and tires.

ncmncm9• 5 years ago

I hear mostly air and tires.

alphabettsy• 5 years ago

Are they accelerating? Or you hear them at a constant volume?

bserge• 5 years ago

I can hear the engines very well. Unmistakeable, loud sound.

kwertyoowiyop• 5 years ago

This seems wrong. Do you have a source you can cite?

senectus1• 5 years ago

wait.. electric cars are larger and heavier?

I must have missed seeing the commercial launches of all those bigger than Chrysler C's bigger than Toyota Landcruiser's, bigger than Ford F150's etc that must have been selling like hotcakes.

That claim alone is enough to discount your entire comment.

Symbiote3• 5 years ago

This looks to be the study.

It's odd that the Guardian neither links to it, nor even names the researchers or their institution.

https://doi.org/10.1136/bmj.n1954

jsilence4• 5 years ago

I loathe this every time when I have to fish and dig for the actual study that is being reported on in any media. To me that is bad journalism.

fighterpilot5• 5 years ago

It's good business, though. They want you to click on another link or ad on their site. If they even shared identifying information of the authors, you're more likely to go to google and search for it.

snarf21• 5 years ago

This is a misalignment of incentives. They want to click bait you to watching ads, you just want unbiased information.

vanderZwan• 5 years ago

These associations showed a general pattern of higher hazard ratios with higher noise exposure, but with a levelling off or even small declines in risk at higher noise levels

I wouldn't be surprised further study will show the last bit is due to earplugs at higher noise levels, resulting in a relative reduction in sleep disruption. Unless they also took earplug use into account already, then I'm genuinely curious what could be the reason

Symbiote3• 5 years ago

Along the same lines, it could be due to people having windows open or closed at night.

ekianjo• 5 years ago

as usual they either want to control the narrative or think their audience is too stupid to read

paisawalla• 5 years ago

I hope this translates into stronger enforcement against very loud motorcycle exhaust. These seem designed to be unconscionably loud for the purpose of offending as many around as possible.

WarOnPrivacy2• 5 years ago

I am told the extra loudness is from owners removing the exhaust baffles

https://duckduckgo.com/?q=harley+davidson+remove+baffles

ncmncm9• 5 years ago

The most astonishing recent news about dementia surfaced in April, here on HN: A recent Tdap vaccination correlates very, very robustly with a 40% reduction in dementia risk (doi:10.1093/gerona/glab115).

Nobody knows how to interpret it. 40% is a huge effect size! (I doubt aspirin shows up as more effective against headache.) Is it the tetanus, the diphtheria, the pertussis antigen? Something else they put in the vaccine?

You can get a Tdap at any pharmacy, on demand. I did.

akoluthic• 5 years ago

This isn't a randomized controlled trial, so I wouldn't put much stock in the results, although it should provide a catalyst for further study (if it hasn't already).

ncmncm9• 5 years ago

Fetishizing RCTs is a source of much harm in medical policy.

A correctly-designed RCT can give more confidence in a result, particularly to non-statisticians, but very large effect and cohort sizes should not be ignored. We could tell just from the topical statistics that smoking was a major cause of lung cancer and other harms, despite the tobacco industry insisting nothing was proven.

Typical RCTs with only a few hundred patients deliver much less resolution than this result. We do still need trials to home in on the molecular agent, but Tdap is already proven safe, and wise to stay current on, so it would be foolish to "wait and see". If it turns out Tdap (e.g.) protects only some patients from dementia, you are anyway safe from tetanus infection.

It is similar to the case where arginine supplements appear to cut epithelial tissue side effects of SARS-2 vaccines. It needs more study, but arginine is cheap and perfectly safe, so starting immediately to administer arginine supplements alongside vaccination is the prudent course.

Some RCTs even yield spurious results, as a consequence of poor design or execution, such as those lately promoted as showing that anti-depressants have no effect.

Fetishism should have no place in medicine.

barrenko• 5 years ago

I was hiking once in my home rural area after they "terraformed" a highway through the mountains. The main thought in my mind was - it will never be quiet here again.

Goety3• 5 years ago

Maybe it is toxic air?

Where is my nobel?

FullKirby• 5 years ago

No, no. Noise leads to poorer sleep quality, which increases dementia risk. I'll take that nobel, thank you

Goety3• 5 years ago

they probably didnt control for occupation on sleep quality so

ksaj• 5 years ago

Interestingly I've heard the same thing said about hearing loss. They may or may not be connected. But I think the people here adding diesel and braking particulates into the equation are probably onto something.

Have they studied if air conditioner or fan sounds have a similar effect?

morninglight• 5 years ago

The negative health outcomes in this study correlate well with those found in lead poisonig studies. Enormous quantities of lead were deposited along our roadways over a period greater than 50 years. It would be very difficult to decouple "transport noise" from the lead pollution that is known to exist along those transport routes.

https://en.wikipedia.org/wiki/Tetraethyllead https://www.pbs.org/wgbh/nova/article/herbert-needleman/ https://en.wikipedia.org/wiki/Thomas_Midgley_Jr.

Transport noise linked to increased risk of dementia, study finds

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