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

Seriously?

Cyclists and motorists on the same streets breathe the same air, and are exposed to the same pollutants. But because cyclists are engaged in moderate physical exercise their metabolic rate is higher, and they process those pollutants more effectively. (Same goes for runners and people engaged in brisk walking.)

Even if it is true that cyclist take in three times the air that motorists do (and I've not seen that attested, but let's assume it is true) this doesn't just mean three times more pollutants; it also means three times more oxygen, etc. The concentration of pollutants in the air they breathe is unchanged, but their capacity to deal with it is enhanced.

Here's just one of many peer reviewed scientific studies on this subject everyone can read.

Another study this time based in Delhi.

US based one at "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4893018/"

Candaian one. "https://iopscience.iop.org/article/10.1088/1748-9326/ac1379"

This is a total exaguration. One study I read claimed more was emitted than the entire rubber in the tyre. These particles are heavy and they fall to ground and get washed away. Also rubber is not hazardous.

EVs use less brakes and my EV has same brake pads after 100,000km.

Exhaust fumes are bad particularly when cars engines are cold, but again cycling is far better for your lungs than any damage caused. Naturally try stay away from exhausts at traffic lights but the health benefits far outweigh any risks.

It is worth noting that cars use fairly large cabin air filters, so it would be reasonable to assume that particulate matter concentration inside a vehicle is less than outside.

It obviously filters much more air than I breath in, but it's usually fairly filthy when I change it.

Working in big data for decades myself im fully aware that i can get a study done to say any result i want, opposite sides of any argument - using the same dataset - at least until next week when im finished working - yippeee

So im not going to go linking to articles because we can all find ones that contradict each other depending on the source of them

So, I can only tell you what I feel.

When im cycling im breathing in deep and heavy. I can feel the pollutants going down my throat and deep into my lungs. I can taste it.

When im driving im relaxed and not breathing deep or heavy. I usually have the windows closed too and the Ac on when in traffic. There is a filter between me and the air. What it fitlers out i dont know, but i can tell myself the difference in the taste and feeling in my lungs between being in the car and cycling in the city.

You are probably just used to it so dont notice it. Most of the time I cycle outside the city. When I cycle in the city it is very, very noticeable.

Kind of like a smoker going into a smoky room with someone who doesnt normally smoke. Only one of them is going to notice the smoke they are breathing in.

I cycle from the countryside into the city centre at least a couple of days a week most weeks. Can't say that I've ever noticed an issue with filthy air being inhaled, other than when I'm behind a car/ truck/ bus that has a visibly defective exhaust. That said, I rarely notice anything in the car either. I don't think I'm going to convince you that you're not tasting pollution any more than you're going to convince me that I am inhaling it. And since we're not referencing any data/ studies, I guess the debate is over.

The question isn't "is it healthier to cycle down the quays or over the wicklow mountains" and it's not "is air quality in dublin city centre optimum for recreational cycling". I just can't accept that "air pollutants negate health benefits of cycling in city urban centres".

This is a very interesting question. You're spending less time on a bike but you're breathing more. No matter where I go whether it's commuting or a leisurely spin on the ebike I'm always going around 60-70% effort and breathing a fair bit more than when walking.

When walking I'm also not stuck behind a vehicles exhaust fumes. Cars generate 15-20kg of CO2 per 100km plus NOX and all other chemicals.

Plenty of older diesels on the roads in Ireland, lots of them emitting black smoke. Diesels on our roads account for twice as many new sales as the EU average.

A car isn't breathing in the same fumes because they have carbon filters in the climate system. Maybe not HEPA quality but better than nothing.

Whatever fumes you do breathe in I'm sure the physical benefits of cycling nore than make up for it.

The most harmful pollution is "odourless and invisible".

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.

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.