Naked Science Forum
General Science => General Science => Topic started by: Thor Håkon Lindstad on 12/07/2010 12:30:03
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Thor Håkon Lindstad asked the Naked Scientists:
Hello, Naked Scientists!
Being an active person, I spend a couple of hours every day running or road biking this summer. For biking I obviously need roads; roads which are also being driven on by cars. These cars emit a variety of dangerous gases through their exhaust, which I in turn breathe in, every time I ride my bike, I do so for 1,5 hours and in that time I am passed by approx. 250 cars.
Does the exhaust from these cars damage my lungs and heart more than my body benefits from the training; making biking in areas with cars pointless?
Greetings from Thor H. Lindstad, 15yrs., Norway
What do you think?
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Yes, you are right that several dangerous gases that are emitted from car exhausts such as carbon monoxide, nitrous oxides, buta-1,3-diene and particulate matter which can cause respiratory disease etc. if your exposure is prolonged. However, having said that, here is a statement from the report "Do Health Benefits of Cycling Outweigh the Risks?":
"For the individuals who shift from car to bicycle, we estimated that beneficial effects of increased physical activity are substantially larger (3 – 14 months gained) than the potential mortality effect of increased inhaled air pollution doses (0.8 – 40 days lost) and the increase in traffic accidents (5 – 9 days lost). Societal benefits are even larger due to a modest reduction in air pollution and greenhouse gas emissions and traffic accidents."
So you probably have no need to worry but if you are particularly concerned then you might want to find out annual average pollutant concentrations either by finding out if there is an automatic monitor on the roads you cycle on or by estimating it using a data model like the DMRB screening method which can be downloaded from the internet (although this is from the UK so I don't know how well it will apply to your roads) and then compare this to the safe pollutant concentraions recommended by the World Health Organisation- http://www.who.int/mediacentre/factsheets/fs313/en/index.html
However, I think the danger is more to people who live on the edges of busy roads so as your exposure time is a lot shorter, I probably wouldn't worry.
Hope this helps :)
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Thor
Lots of cyclists (myself included) wear face masks if they are going any distance. It make breathing a little weird but the crud that comes out on the filter is horrible; and I guess that crud would have to be filtered out by by the mucus areas of my nose and airways.
It's getting noticeably better in London - newer buses might not be as romantic as the old routemaster, but their diesels put out much less soot.
The unseen gases - who knows? Personally, I think the improvement in health from the regular exercise outweighs the possible negative consequences; but that is pure supposition on my part.
Matthew
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Well...there's always the 'blind red traffic light' syndrome that ewe cyclists seem to all suffer from !!...that's dangerous !! [;)] [;)]