Thought you all would appreciate an article I had in the paper last week; it concerns us (commuters) most.
If anyone knows of similar articles/studies, I'd appreciate being pointed in their direction. Thanks...
The Herald Sun
DURHAM -- Some winter mornings, while riding in Cornwallis Road's new bike lanes, I can smell Counter Culture Coffee roasting those fairly traded coffee beans two or more miles to the south. The same still air that pools summertime ozone over the region's largest employment hub wafts the unique smell of coffee beans expanding in heat, releasing their caffeinated oils. Whenever I ride through one of those invisible, aromatic clouds, I breathe deeply.
Problem is, I can also smell the exhaust from the surrounding cars at every intersection.
No doubt, on-road cyclists are more vulnerable to their environments than drivers. It's not just that we're naked next to multi-ton hunks of steel hurtling past us (in either direction) at deadly speeds and proximities too close for comfort, but we’re also exposed to the gases of the landscape. Any winter bike commuter has observed that cold air appears to keep exhaust fumes closer to the ground. Which means that while waiting at each red light, we’re treated to a special dose of carbon monoxide, sulfur dioxide, and nitrogen dioxide, complete with that lovely smell (except for those biodiesel converts; then we’re tricked into thinking someone is cooking up French fries nearby).
Summertime cyclists know to check the ozone forecast just like the weather forecast. Summer ozone concentrations in NC can reach toxic levels, and athletes are sometimes advised not to engage in rigorous cardiovascular activity on those days.
So, I started wondering whether biking is actually an unhealthy thing to do. I mean, coasting up to each intersection, it sure feels like I'm breathing in more car exhaust than when I'm a passenger in a car. So who better to ask than public health specialists?
Doctoral students at UNC's School of Public Health and scientists at the National Institute of Environmental Health Sciences help tackle these questions -- Do cyclists have any reason to worry about what we're breathing in on our (supposedly healthy) ways to work? And if so, which is the greater health risk -- the colorless, odorless ozone in the summer or the pungent, cloudy exhaust fumes in the winter?
Dave Love says that "cycling is a balance of risks." Love, a PhD candidate in UNC's School of Public Health, says that "the risk of getting into an accident is probably the most serious risk a cyclist faces. But lets say you are a careful biker, then another one to consider is your concern about taking deep breaths of exhaust during exercise. You are breathing more deeply and faster than drivers, so you are getting exposed to more exhaust and ozone. But, to look on the bright side, our urban air quality is probably better than 150 years ago!"
While a cyclist might be breathing in more noxious gases than automobile drivers, it's worth pointing out that a car doesn't protect drivers from those gases. Since a car's air-conditioning and heating intake filters cannot filter out volatile organic compounds like benzene, drivers are exposed to the same gases as cyclists. At best, automobiles' ventilation systems only disguise the smell of roadways by filtering the air through activated charcoal filters.
NIEHS scientist and avid cyclist Jerry Phelps says that, from his experience, the amount of air pollution from car exhaust probably doesn't change from one season to the next. It's more visible in the winter because the air is colder and drier. The water vapor mixed in with car exhaust is what we're able to see leaking from the tailpipe. The same amount of exhaust hangs near the ground behind cars in the summer too, but since humidity levels are generally higher in the summer months, we just can't see it.
Whether there's more exhaust in the winter or not, there's still the question of what those gases are doing to our lungs. "It's likely that the health benefits of increased physical activity are greater than the risks incurred because of increased exposure to air pollution," says Audrey de Nazelle, also a doctoral student in UNC's School Of Public Health. "But, if you have respiratory problems to start out with, then it's another story."
People with asthma are much more sensitive to particulate matter and toxic gases, which is why asthma sufferers are warned about the ozone levels in the summer.
Stephanie J. London, M.D., a senior investigator in the epidemiology branch and laboratory of respiratory biology at NIEHS agrees with Nazelle. "It's hard to say whether ozone or exhaust fumes are worse since both are basically bad. And even though you would probably breathe more ozone riding your bike than traveling in a car, the exercise will probably outweigh the negative effects."
Reading Lance Armstrong’s It’s Not About the Bike, you learn two things. First, Armstrong is a lucky guy. The lottery of life granted him the abnormal lung capacity and the muscular distribution to become a world-class athlete. And second, the body’s ability to heal itself is the most powerful, restorative advantage we have when fighting disease. Armstrong couldn't have beaten testicular cancer without chemotherapy, but neither could he have recovered from the brutalized depths of chemotherapy without a resilient, toned body. The medical community surrounding Armstrong agrees that he recovered from cancer as well as he did because he is an athlete.
Exercise enhances the body’s ability to repair itself. Cardiovascular activity strengthens the immune system, and since both drivers and cyclists are exposed to the same toxins, the cyclists may come out better in the long run. In short, people who exercise have bodies that are better able to process the toxins we all take in.