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A recent study has concluded that the benefits of physical activity almost always outweigh the negative effects of pollution for those cycling in urban areas. Researchers say their findings should encourage people out of their cars and onto their bikes and in so doing reduce pollution levels further.

London’s air pollution, which is caused primarily by traffic and diesel fumes, is responsible for 9,500 premature deaths each year, according to a 2015 study by King’s College, London. Thanks to their proximity to traffic and deeper breathing, a cyclist can expect greater exposure to that threat than most.

According to a 2011 study by researchers from the London School of Medicine, a cycle commuter inhales more than twice the amount of black carbon particles as a pedestrian making a comparable trip. Stopped on your bike at a set of traffic lights, wallowing in the fumes, these kinds of things have probably crossed your mind.

But how dangerous is it? The FT reports that a recent Cambridge University study found that the health benefits of cycling outweigh the risks caused by air pollution in 99 per cent of cities. Is the capital one of them? How long would you have to cycle in London before the effects of pollution started to outweigh the benefits of cycling?

The researchers established tipping points for each of the cities they looked at – the length of time after which the impact of pollution started to outweigh the positives that come with being more active.

Dr Marko Tainio from the MRC Epidemiology Unit at the University of Cambridge, who led the study, said: “Our model indicates that in London health benefits of active travel always outweigh the risk from pollution.”

If air pollution were constantly at the city’s record monthly high, it would take nine hours and 50 minutes of cycling a day for harm from pollutants to exceed the overall benefit from physical activity – and anything less than that would reduce your mortality risk relative to not cycling. At average or rush hour levels of pollution, the benefits of cycling in London will always outweigh the negatives.

Tainio said that in Delhi – which has pollution levels ten times as high as in London – people would need to cycle for over five hours per week before the pollution risks outweighed the health benefits.

Senior author Dr James Woodcock, from the Centre for Diet and Activity Research (CEDAR), said: “Whilst this research demonstrates the benefits of physical activity in spite of air quality, it is not an argument for inaction in combatting pollution. It provides further support for investment in infrastructure to get people out of their cars and onto their feet or their bikes – which can itself reduce pollution levels at the same time as supporting physical activity.”

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11 comments

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Yorkshire wallet [1423 posts] 1 year ago
4 likes

I think pollution is the least of your worries cycling there.

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700c [1150 posts] 1 year ago
2 likes
Yorkshire wallet wrote:

I think pollution is the least of your worries cycling there.

With 9,500 premature deaths per year caused by pollution, it should be one of your greatest concerns, surely.

Just because keeping fit through cycling negates some of that risk, doesn't mean cyclists' lives aren't being foreshortened by it. Think how much longer you'd live cycling without the traffic.

Too much complacency on this issue by authorities. Even cyclists.

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tritecommentbot [2268 posts] 1 year ago
1 like

I was going to ask how many of these deaths were cyclists, for example. But then I had a niggling feeling these figures are not actual deaths. Found the study and looked up the methodology, and yes, the whole thing is basically a model based on previous models using estimates for data. 

Can't copy and paste the text from it, but here it is, goto: 1:2, Page 18.

https://www.scribd.com/document/271641490/King-s-College-London-report-o...

We don't really know how many people are in hospital dying from pollution and what types of lifestyles these people would have.

Shame, if our NHS was more technologically advanced with a national, well thought out database then working this stuff out should be as simple as a FOI request.

Not to discredit the study of course, it's just not able to tell me what I want. The whole thing was basically a cost analysis for transport.

 

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Leviathan [2772 posts] 1 year ago
2 likes

I don't cycle in London, win, win.

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700c [1150 posts] 1 year ago
1 like

Yes I'm sure determining causes of premature deaths in big populations is more of an educated guess (this is a study and can't control variables. They've not got death certificates where 'pollution inhalation' is listed).

Nevertheless it is a serious problem, in some ways worse than the numbers of people being hit by vehicles; just less obvious.

These studies are important to putting pressure on authority to act and penalise where appropriate.

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cyclisto [274 posts] 1 year ago
1 like
Yorkshire wallet wrote:

I think pollution is the least of your worries cycling there.

Sorry but I totally disagree. I am aware of the dangers of urban cycling but having taken all necessary precautions I don't feel that threatened as when an HGV, a rusty diesel passenger car or a Chelsea tractor overtakes me when going uphill. We all can feel the black breath of cancer entering in our lungs and we cannot actually do virtually anything! I have tried various types of masks and aside from their dubious results they make us look like something between aliens and chicken flu phobics and of course they are highly uncomfortable.

To me better air quality is the No 1 thing we should protest about...

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Nick Forster [14 posts] 1 year ago
0 likes
cyclisto wrote:

Sorry but I totally disagree. I am aware of the dangers of urban cycling but having taken all necessary precautions I don't feel that threatened as when an HGV, a rusty diesel passenger car or a Chelsea tractor overtakes me when going uphill. We all can feel the black breath of cancer entering in our lungs and we cannot actually do virtually anything! I have tried various types of masks and aside from their dubious results they make us look like something between aliens and chicken flu phobics and of course they are highly uncomfortable. To me better air quality is the No 1 thing we should protest about...

You forgot buses and black cabs - Oxford Street has just about the worst air in London and is more or less the exclusive preserve of them.

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Ratfink [157 posts] 1 year ago
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Not sure how accurate it is but it's been reported locally that the air pollution around Charlie Browns roundabout in Woodford is 4X Oxford St.

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Simon E [3095 posts] 1 year ago
0 likes
Leviathan wrote:

I don't cycle in London, win, win.

Have all the vehicles in your quiet village converted to electric?

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Hipshot [61 posts] 1 year ago
0 likes
Leviathan wrote:

I don't cycle in London, win, win.

 

Neither do I, but with that level of affinity with your fellow men, woman and children in another part of the country - fellow cyclists to boot! - no wonder this country is in such great effing shape.

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sm [405 posts] 1 year ago
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Much also depends on the route you take and how hard you are cycling. Take the residential routes away from the main roads and the pollution levels are significantly lower. 

Ride hard and you  breathe more heavily taking in more pollutants. So take it easy on the back roads.