A Breath Of Fresh Air For Cyclists

Low traffic routes reduce pollution exposure for cyclists

(RxWiki News) Cycling seems like a good way to exercise, reduce traffic on roads and save on transportation costs, but riding behind exhaust fumes from vehicles can be more than unpleasant. Cities like Berkeley in California are designing alternative route to allow cyclists to commute without the unwanted extras.

A recent small study compares cyclists' exposure to pollution and their lung function on high-traffic and low-traffic routes in Berkeley, California. The study found that low-traffic routes can reduce exposure to pollution from vehicles.

"Consider a low-traffic route when commuting by bicycle."

The exercise experienced by cyclists results in elevated respiratory rates. The authors speculated that the respiratory rate combined with the close distance cyclists travel from cars and trucks puts cyclists at a higher risk of exposure to pollution.

The City of Berkeley implemented the Berkeley Bicycle Plan in 2000. It is a system designed to promote safe bicycle commuting through a network of alternative routes called Bicycle Boulevards.

Bicycle Boulevards currently consist of seven routes through low-volume residential streets. The streets have signs, pavement markings and traffic calming devices for safe and easy commuting via bike or on foot.

Sarah Jarjour of the University of Berkeley and colleagues recruited 15 healthy adults who regularly cycled more than once a week to complete both a Bicycle Boulevard route and a high-traffic route. The Bicycle Boulevard took an average of 37 minutes to complete and the high-traffic route took an average of 40 minutes to complete.

Each bicycle was fitted with a global positioning system (GPS) and pollutant monitor. Lung function of the cyclist was calculated before, immediately after and four hours after each bike ride.

The study found elevated rates of pollution on the high-traffic route compared to the Bicycle Boulevard. There was no difference in the cyclists' lung function between the two routes.

"This is an interesting article that highlights that even attempting to perform an activity as healthy as cycling may have potentially unhealthy consequences," said John Oppenheimer, MD, a pulmonary and allergy specialist and dailyRx Contributing Expert.

The authors note that a longer study of cycling and lung function is needed to understand the long-term effects. They hope that more research like this will encourage lawmakers to promote safe and healthy bicycle commuting and support the necessary infrastructure.

"The million dollar question is does exercising/cycling in a highly polluted area over years have a negative impact on those with underlying lung disease or even those without?" said Dr. Oppenheimer.

The study was published in Environmental Health.

The authors report no conflicts of interest.

Review Date: 
February 21, 2013