City cyclists saddled with health dilemma
Many of the obvious health benefits from bike riding are being undermined in British cities by the cocktail of smog and exhaust fumes cyclists must often plough through.The British Heart Foundation has awarded almost £1.2 million to researchers at the Centre for Cardiovascular Sciences at the Royal Infirmary of Edinburgh in an attempt to unravel the links between traffic pollution and sickness in blood vessels that can lead to heart disease and circulation problems.
The BHF has played down the potential harm cyclists can do to their bodies, stressing that riding bikes is, for the main, a good way to keep fit and keep the heart healthy.
"We are a long way from proving a link between heart attacks and pollution but the results of the research will help us better understand which microscopic particles in exhaust fumes could cause problems," said a spokesman for the BHF.
"Armed with these results we will be in a better position to protect cyclists in the future."
But the research fund has found that exposure to the particles and pollutants from diesel engine emissions affect the cells that line blood vessels, reducing their ability to contract and relax and to break down dangerous blood clots in the heart.
These effects are similar to those caused by smoking.
And there are suggestions that cycling hard - and therefore burning more calories and getting more exercise - could actually be more harmful, as the lungs require more air so riders will breathe harder, taking in more fumes.
The new research efforts will aim to solve some of the biological unknowns behind these harmful processes, as well as defining the components and levels of polluted air that are most dangerous, and the length of time after exposure that people are vulnerable to the ill effects.
The research programme will measure blood pressure, blood flow, and biological indicators of inflammation - a risk factor in heart and circulatory disease - after volunteers have been exposed to polluted or clean air.
Dr David Newby, who is leading the research, said: "We have already shown that diesel exhaust impairs two important and complementary aspects of heart and circulation health, therefore contributing to the development of heart disease.
"Now, with further support from the BHF, we can investigate and define why, when and how our health is affected by air pollution. This will help to mold future pollution control strategies and help to protect those most at risk."
Professor Peter Weissberg, medical director of British Heart Foundation, says: "There is some evidence around the world that people with heart disease should limit outdoor activities when pollution is high.
"This BHF research will help us to provide clear, evidence-based advice for UK heart patients and healthy people that have high risk of heart disease, as well as feeding into future environment policy."
By Sam Bond