Recommendation:  "avoid busy streets"  Yeah, right, so this means, move the country?

http://www.environmentalhealthnews.org/ehs/news/exhaust-ing-ride-fo...

Exhaust-ing ride for cyclists: Air pollutants trigger heart risk

  In big cities around the world, cyclists breathe an array of pollutants from exhaust-spewing cars. A new study has now found a link between cycling on high traffic roads and heart risks. Even healthy cyclists had harmful changes in their heart rates. Experts say cyclists should stick to their two-wheels, however, pointing to simple solutions to reduce exposure. 

By Brett Israel
  Environmental Health News

July 6, 2011

  NEW YORK – [ * * * ]

Pedaling behind pollutant-spewing cars and trucks may not seem as scary as being hit by one, but scientists say it can pose invisible dangers.

Now, for the first time, cycling in heavy traffic has been linked to a heart health risk, Canadian researchers reported last month. A new study found cyclists in Ottawa, Ontario, had heart irregularities in the hours after their exposure to a variety of air pollutants on busy roads.

Pedaling behind pollutant-spewing cars and trucks may not seem as scary as being hit by one, but scientists say it can pose invisible dangers.

"Our findings suggest that short-term exposure to traffic may have a significant impact on cardiac autonomic function in healthy adults," the scientists from Health Canada, Environment Canada and the University of Ottawa wrote in the journal Environmental Health Perspectives.

The study does not suggest that bikers would be better off driving, experts say. Rather, the findings intensify the scrutiny on cyclists' pollution exposure, and point to simple solutions for a cleaner ride, such as avoiding busy roads like 8th Avenue whenever possible.

"It's something that actually concerns a lot of people that do cycle," said Michael Brauer, a cyclist and atmospheric scientist at the University of British Columbia who was not involved in the new study. "People want to understand their risk. They're just thinking all the time, 'Is this good for me? Is this bad for me? I'm doing my part, but there's this car that's throwing this exhaust in my face.' "

For the study, 42 healthy, non-smoking cyclists wore heart monitors before, during and after cycling for one hour on high- and low-traffic roads between May and September last year. Instruments on the bikes' panniers measured exposure to air pollution.

Study results point to simple solutions for a cleaner ride, such as avoiding busy roads whenever possible.

Short-term exposure to heavy traffic significantly decreased heart rate variability in the cyclists for up to three hours after they finished cycling. Experts say reduced heart rate variability is associated with a higher risk of heart attacks.

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"In general, you're better off cycling than not," Brauer said. "The physical activity benefits outweigh negative impacts. But you'd like there to be no impacts."

Exposure to dirty air adds to the perception problem that cycling is unsafe, said C.H. Christine Bae, an urban planner at the University of Washington in Seattle, who specializes in how bike facilities affect air pollution exposure.

The Canadian study authors have a simple solution. Avoid busy streets.

"In general, you're better off cycling than not. The physical activity benefits outweigh negative impacts. But you'd like there to be no impacts." – Michael Brauer, cyclist and atmospheric scientist, University of British Columbia

"When possible it may be prudent to select cycling routes that reduce exposure to traffic and/or to avoid cycling outdoors or exercise indoors on days with elevated air pollution levels," the research team wrote.

    [ * * *  ]

Getting cyclists out from behind the cars helps, too. In Portland, when traffic stops at a red light, cyclists have a designated area at the front of the line of cars, called a bicycle box, which helps them navigate turns and flee the tailpipe fumes.

Solutions like this bicycle box in Portland help cyclists flee tailpipe fumes.

"Little things like that can help a lot to reduce exposure to cyclists," Bae said.

If a little is good, more is better. Brauer says the preliminary results of his lab's work suggest that bike lanes are best when built one block from a major traffic artery. Despite the emerging research, Bae said that she does not know of any cities that consider cyclists' pollution exposure when designing bike lanes.

Including Vancouver, where Brauer cycles, many of the cities that built bike lanes one block away from a major road thought about cost, not pollution.

"Most were done by accident, because they were cheaper," Brauer said. "But they actually give you an air pollution benefit."