Cycling to work may seem the healthy option, but a study has shown that people riding in cities inhale tens of millions of toxic nanoparticles with every breath, at least five times more than drivers or pedestrians.The research involved fitting cyclists with devices that could count the particles, mostly emitted by car exhausts, in the air they were breathing.It showed that urban concentrations of nanoparticles, which measure just a few millionths of a millimetre, could reach several hundred thousand in a cubic centimetre of air.The particles, when inhaled, have been linked to heart disease and respiratory problems.Because they are exerting themselves, cyclists breathe harder and faster than other road users. The study found that they suck in about 1,000 cubic cm with each breath, meaning they may inhale tens of millions of the particles each time they fill their lungs, and billions during a whole journey.
For cyclists and other road users, the key question is what the health impact might be of inhaling so many particles.
New techniques for gathering and analysing data mean, however, that the health problems caused by particulates are emerging much more quickly.A study carried out in London, to be published soon in the journal Epidemiology, is expected to show that exposures to high concentrations of nanoparticles are associated with a higher risk of heart disease. It will also show an association between larger particulates and respiratory health.Other studies have shown that exposure to particulate pollution can have rapid short-term effects too — such as provoking asthma attacks.
In a 2007 study, published in the New England Journal of Medicine, researchers at Imperial College London asked 60 people with mild or moderate asthma to walk along the western end of the busy Oxford Street in central London, where only diesel-powered taxis and buses, plus cyclists, are permitted. The volunteers suffered asthma symptoms such as reduced breathing capacity and lung inflammation.
Diesel vehicles emit far higher levels of pollutant nanoparticles than petrol engines.
What alarms health researchers is that such particles are so small that they penetrate the lungs and circulate in the blood. They are then thought to accumulate in organs such as the heart and brain and cause inflammatory reactions.
In some way this creates an imagined community, because it causes us to associate ourselves with this whether we have asthma or know someone with asthema. Because people may be aware of these potential risks, this creates an imagined community. This is definitely something that grabbed my attention because I not only suffer with asthma, I ride my bike and am outside all of the time, therefore I am going to be alarmed by this.
No comments:
Post a Comment