Can Air pollutants negate health benefits of cycling in city urban centres??

Flinty997

The most harmful pollution is "odourless and invisible".

https://www.boards.ie/discussion/comment/120893313#Comment_120893313

That's because your car is filtering out the smells of some of the pollutants. But you're getting more of the really bad stuff in the car. You just can't smell it because its invisible and odourless. So you will sit in the car (for longer) thinking its better. But its not.

DownByTheGarden

https://www.boards.ie/discussion/comment/120894313#Comment_120894313

Data can say anything. So going off and looking for a report in the internet you can get one to say whatever you want. Its much the same here as people saying they dont sweat or breathe deeper when they are cycling to when they are sitting down in a car. Biology says they are telling porkies, but im sure they can find a study somewhere that tells them they do if they look hard enough and go past all of the ones that say the opposite while they are looking.

On my commute (which I do on the bike whenever it is not raining or icy) I am flying all the way from Naul to Grand Canal dock. Im cycling at a fair clip all the way to maybe dorset street or phibsboro depending on which way i go, and then have to slow down a bit then. I would consider myself reasonably fit and im certainly not breathing anywhere near as easy as im breathing when driving with windows closed and aircon on either before or when i get to the city. People saying they dont breathe heavier and deeper on a bike than when in a car is just not true.

But each to their own. I personally can tell the difference between what I breathe in when at rest in a car in the city and when im on the bike in the city. In the car ive windows and a filter I guess. On the bike ive nothing. So when in the car at least some of it is getting filtered out. Sure you can even see the dirt on your sleeve when you wipe the sweat of face after cycling through the city.

If anyone wants to convince themselves that the air in the city is somehow healthier if you cycle isnt going to get it cleaned up for us.

I tried a mask on the bike for a couple of weeks a few years ago but couldnt really get used to it.

Flinty997

https://www.boards.ie/discussion/comment/120897053#Comment_120897053

Not everyone cycles like it's the tour de France. They cycle slower so they don't arrive drenched in sweat. Half my route is away from traffic, and I can do most of it off road if I like. Some people have eBikes.

You've convinced yourself that sitting in the middle of that pollution with it getting pumped into your cabin is healthy. It isn't.

Likewise you've decided to cycle (and drive) the busiest roads. Pollution is worst closest in the immediate proximity to the busiest roads. If you take routes that have less traffic you miss the worst of it. You can do that if you're not obsessed with "...cycling at a fair clip the whole way...."

What you should do to avoid pollution is cycle to the train. Get a job in the countryside away from farm pollution.

DownByTheGarden

https://www.boards.ie/discussion/comment/120897185#Comment_120897185

OK we get it. You dont breathe heavier or sweat when you cycle. You are superman and the rest of us mere mortals need more oxygen when we require more energy.

Flinty997

https://www.boards.ie/discussion/comment/120897204#Comment_120897204

Not if you cycle ... s...l...o...w...l...y.

... and no you don't get it.

Weepsie

https://www.boards.ie/discussion/comment/120897053#Comment_120897053

In the car you've windows? So you open them to let the polluted air in? Or keep them closed so the air that is coming in alcna hang around.

Go find a study if you want to be dismissive of the numerous studies that say you are wrong.

Flinty997

https://www.boards.ie/discussion/comment/120897248#Comment_120897248

They are magic windows.

magicbastarder

Is it any wonder that you can smell or taste fumes more easily on a bike though? On the working assumption that they build up in a car, the air quality inside a car is less variable and your sense of smell will adjust to filter out the sensation. On a bike the air quality peaks and troughs more, so you more easily get a sense of the immediate air quality around you.

Speaking of which, I found the vehicles I least liked getting stuck behind at lights while commuting were motorbikes. The stench off the exhaust on some of them were eye watering. IIRC catalytic converters were made mandatory on bikes quite a bit later than cars so maybe these were older bikes.

Paddigol

What a clusterf**k of a discussion this has turned into. It went fairly rapidly from a straightforward question - it's still there in the thread title if you glance up - to "I don't care what anyone says about the question that wasn't asked, I know I'm right and I don't need to prove it".

Good night and good luck.

kowloonkev

https://www.boards.ie/discussion/comment/120893313#Comment_120893313

I concur with this. I have lived in polluted cities in China and it is in such places where you really notice the difference between being in a car and outside. Outside you can taste the pollution and you get black phlegm build up in the throat and nose. Inside a car with windows closed and a/c turned on is comfortable and the air feels normal as there is no taste to it. Definitely the car filter is doing a job. I've also driven in very dusty areas and dust doesn't go inside the car.

However, in Dublin I wouldn't be able to notice the difference in air quality inside or outside a car but I am sure that the exhaust fumes from the car in front is not coming straight into my car unfiltered. I think anyone who has been in a car will know this.

DownByTheGarden

https://www.boards.ie/discussion/comment/120897226#Comment_120897226

Right if everyone cycles as slowly as you do they wont be needing deeper breaths. Gotcha. We will all do that then and that will save us breathing in toxins and particulates on our rides. You should write a book about that strategy and how you get the health benefits of cycling without requiring more oxygen than if you were sitting. You'll make a fortune.

Let me try this again. When all of us except Flinty are cycling we require more oxygen. This causes our breathing to be more rapid than if we were sitting down, increasing the amount of air going in and out of our lungs. Now if there are any particulates or chemicals in the air then they will be going into our lungs in greater volume because - well greater volume of air going through our lungs (unless we are flinty and he is getting so called health benefits from not breathing more than if he was sitting).

If you are in a car you keep your windows closed and your air filter filters out most of the large particulates, even if it doesnt filter out the chemicals. But you are also not using as much of the air because you are only breathing about 15 to 20 breaths per minute. No more than Flinty breaths when he is cycling. For the rest of us mere mortals we will be taking lots more breaths to get the oxygen we require to get the health benefits of the exercise of cycling. Its filtered air versus unfiltered air.

And im also not convinced that anyone here, even Flinty, isnt aware that you can actually tell that the air is more polluted yourself by the tatse of it cycling down the Rathmines road or along the canals compared to say, out in Blessington.

But yes, back to the question of the thread title. Im pretty sure that breathing in a whole load of diesel fumes as you cycle through the city is worse than sitting in a car going through the for you healthwise as if you are not Flinty you are breathing a lot more of it in. Unless of course you drive with the windows open the whole way taking deep breaths. The air in the city needs to be cleaned up either way because its filthy.

kirving

https://www.boards.ie/discussion/comment/120893275#Comment_120893275

I did say particulate matter, while the article is very broad in it's terms, and only mentions NOx specifically.

Making statements in the article such as "as far back as 2001" isn't necessarily relevant to say the least - emissions control and filtration within cars has moved a long way since then.

Perhaps it was that it was in fact a problem (ironically caused by vehicles themselves) but Tesla and Mercedes amongst others are putting in extremely large activated carbon HEPA filters to control particulate, SO2 and NOx, real time particulate monitoring both inside and out, to prove their vehicles have better air quality (in terms of particulate) inside than out.

https://autonews.autoua.net/en/novosti/28971-engineering-explained-reveals-mercedes-benz-eqs-tv-sized-cabin-air-filter.html

As part of my job, I design localised fume extraction, and equipment and processes which go into cleanrooms. Air flow is exceptionally difficult to predict outside of steady state scenarios, is non-linear, and it's very easy to bias an experiment one way or another to make a point and get exactly the data I'm looking for.

Perhaps air does tend to be dirtier in cars, but it's by no means a blanket statement. It's funny, I go to the US and can smell the petrol as soon as I walk out of the airport, but I think it's clean in Dublin. American friends come here and ask me what the smell is in the air. I don't notice it, but it's the diesel fumes.

DownByTheGarden

https://www.boards.ie/discussion/comment/120897355#Comment_120897355

Ive a couple of mates who are into bikes and they modify the exhausts quite a bit. When asked why its to get the noise right :)

So id bet that a lot of motorbikes going around dont have any sort of filter on the exhausts at all.

magicbastarder

The air in the city needs to be cleaned up either way because its filthy.

i think dublin generally has good air quality, though? not sure how relaible this is:

"In 2019 Dublin came in with a PM2.5 reading of 10.6 μg/m³, a number that placed it into the ‘good’ ratings bracket, which requires a PM2.5 reading of anywhere between 10 to 12 μg/m³ to be classified as such, making it a very fine margin of entry, and not far from the World Health Organizations (WHO) target goal of 10 μg/m³ or below, for the best quality of air, with closer to 0 of course being the most optimal.

This reading of 10.6 μg/m³ placed Dublin into 2357th place out of all cities ranked worldwide, which whilst it is a respectable rating, also came in at 1st place out of all cities ranked in Ireland, making it the most polluted city in the country, largely due to it sizeable population as well as various industries and other pollution causing activities.

So, whilst it came in with a good rating of air quality, it still stands that Dublin could improve its pollution issues, with a few pertinent problems in sight for its citizens, particularly those that are at risk, such as the young, elderly, immunocompromised or expectant mothers, with the last two being particularly vulnerable."

https://www.iqair.com/ireland/leinster/dublin

CramCycle

https://www.boards.ie/discussion/comment/120897053#Comment_120897053

As someone whose job for a few years was actually analysing huge biological datasets, you can find reports saying anything but if you drill down on the data it is easy to see which have justifiable claims and which have flaws that require further testing or analysis. This also brings me onto my other greatest hate in data analysis, the inability of a large number of journals to understand that the statistical analysis they have let through is inappropriate for the question asked.

Take for example your comment on sweating or breathing deeper. This is a language issue. They do sweat, and sweat more, but probably imperceptibly so for them. If I cycle into town, I know I sweated more but quite likely there is no noticeable sweat for me but put me in a metabolic chamber and I'm sure we could show it with ease. Same with breathing deeper. Your breathing rate increases walking around the house. The question you should be looking to answer is, if this is actually an issue in Irish cities. My wager is that you are looking at only one factor, higher breathing rate equates to more pollutants inhaled. What it fails to take into account is all the other factors, do you clear them better, is your immune system better, are you more metabolically healthy over time, are those pollutants at different levels with variation of height from the ground and the list goes on. Either way, while the specific data for those questions appears not to be there yet, the data showing that all cause mortality for cyclists is lower than both drivers and pedestrians is. So, big data isn't telling you why, and to answer the OPs question you don't need to know why. The answer is no.

In regards your car appearing better, it might be, it might not. The number of people I know who don't change their filters regularly is shocking but also that they are pretty much heavy filters in most cars, they aren't filtering out small particulates. Certainly are not filtering out some of the pollutants that were mentioned as they simply can't. Most of us will recognise this from the smells passing a piggery, or slurry spreading or when that van on the M50 is pumping out black smoke like it's a special effect in a Marvel movie. It's like in my labs, we have HEPA filters for over a certain sized particle but solvent vapour etc, gets done in a fume hood. You can't filter it so it is simply extracted to the environment at a height that it is diluted beyond the point for concern.

No one said it was healthier, that wasn't the question. It was does pollution negate the health benefits of cycling. in comparison to driving or walking, I would imagine it does not negate the benefits. As for the reason it is healthier, I can make educated guesses but can't guarantee if they are correct or not, just that the data (not the reports) shows this to be the case in a broadly equivalent society.

Flinty997

https://www.boards.ie/discussion/comment/120897505#Comment_120897505

Maybe they can hear pollution...

Flinty997

https://www.boards.ie/discussion/comment/120897488#Comment_120897488

Consider that the reason they put different filters in some of their cars (I don't think all mercedes have them) is exactly because most usual car filters don't filter this stuff out.

DownByTheGarden

https://www.boards.ie/discussion/comment/120897675#Comment_120897675

So basically youve said about the data and reports what ive said in my first post but with more words :)

So I gave my own opinion which Flinty took issue with, as you can see. i think he is hurt by being wrong or something.

When I mentioned sweating and breathing it was only to counter Flinty who thinks he doesnt breath more when cycling in the city. The only reason I brought sweat into it is that thats what causes you to wipe your face in your sleeve and then you can see the black on your sleeve from tyhe dirt that is on your face. This dirt does not appear when you wipe off sweat when are cycling in the countryside. Well you get some sometimes but its more a muck colour than black which it is in the city.

Flinty997

https://www.boards.ie/discussion/comment/120897464#Comment_120897464

I think you're going to have to decide if cycling is better for fitness and health than sitting in a car pumping invisible odourless pollutants into it.

DaveyDave

https://www.boards.ie/discussion/comment/120897355#Comment_120897355

Mythbusters did a test comparing bikes Vs cars and found they polluted less CO2 but were a massive increase across the board in every other pollutant and unlike cars that has gotten cleaner in the last 30 years there wasn't a huge improvement in motorbikes. Obviously a small sample size but it was an interesting find. I'd expect EU emissions to be different though, I think newer bikes are a lot quieter. Maybe they have an OPF filter on them? A lot of bikes on the road seem to be 90s/00s and older than the average car.

magicbastarder

i saw that, and IIRC the motorbikes they tested didn't have cats. which would make a huge difference (if my memory is correct)

CramCycle

https://www.boards.ie/discussion/comment/120897859#Comment_120897859

MOD VOICE: Play the post, not the poster. This is a discussion forum. No more comments from people about being upset to deflect from the discussion.

Flinty997

https://www.boards.ie/discussion/comment/120897675#Comment_120897675

You're arguing look at the data, don't assume get metrics, measure it. To counter a argument which deliberately isn't looking at the data or studies.

The thread title is one thing, what they posted was another, and argument of cars being healthier is entirely another.

As you say you have to look at holistically. For example if your route is via a green way it's vastly less polluted then going down the busiest congested routes. Studies show the effects of proximity even a street away. Same with sitting in a car with it's air intake in front of a cars exhaust. A cyclist don't spend anything like that time near an exhaust.

Same with cycling vs walking. You're going to spend less time and less energy cycling the same distance in the city. You could walk at a pace that gets you dripping in sweat. Most people don't though.

Flinty997

https://www.boards.ie/discussion/comment/120897464#Comment_120897464

I assume most people can't smell or taste odourless invisible pollutants. Which is why they measure it. But measuring leads to data.

Large bottle small glass

Aside from pollution a big benefit to cycling (and indeed walking, scooter etc) to work in morning is in resetting your circadian rhythm.

We have light sensors independent of sight (shared with amphibians and others) which need about 15 mins of outside exposure to reset.

Today on a sh1tty Irish day in my subjectively bright car cabin the outside light level is 6 times more intense.

Once you reset circadian rhythm, on which all cells, organs run to, or bodies just work better. Even you have trouble sleeping or **** sleep first step should be waking up naturally using sunlight. If you work shift you will die younger and be at higher risk to all sorts of common diseases 😰

2hr discussion with the scientist who made the discovery here

https://open.spotify.com/episode/2pHLc3vOUzHRgKvYqRUQza?si=OdTdEPsXTOq4T-CwLVvKeg