Pedaling toward my favorite coffee shop the other day, I was dismayed to encounter a long stretch of loose gravel presumably designed to test my ability to make rational decisions. I plunged ahead, of course, rumbling uncertainly over the shifting terrain and narrowly skirting disaster. Four blocks later, the silvery shards gave way to smooth black asphalt and I rolled on without further incident, celebrating my good fortune with a cool beverage and a fresh appreciation for the cost-benefit analysis that aging cyclists like myself silently calculate every time they mount their two-wheelers.
Despite a few memorable mishaps and a handful of minor injuries over the past 40-odd years, I’ve always argued that the benefits of biking (cheap transportation, convenient parking, pleasant exercise) outweighed its costs (potential life-threatening tragedies). After all, there are always ways to mitigate those risks: You can slow down, stay out of traffic, avoid loose gravel. Some people even wear helmets.
But you still need to breathe, and that could be a real problem.
As Richard Schiffman reported in the New York Times last week, people biking to and from work may not be doing their lungs any favors. Columbia University researchers have been tracking the effects of air pollution on 40 cyclists for the past two years; the results are not promising. “Our preliminary data shows that many bicyclists are getting a bit over half of their daily air pollution dose in only 6 to 8 percent of their day during their daily commutes,” said Steven Chillrud, a geochemist at Columbia’s Lamont-Doherty Earth Observatory.
That’s because cyclists are sucking in a lot more air when they’re pedaling than when they’re walking, or driving, or just standing around. Chillrud and his team found that one study participant inhaled 70 liters of air per minute when cycling compared with eight liters when resting. And those liters are full of PM 2.5, tiny particles of black carbon from soot that find their way into the lungs and blood stream, triggering inflammation and various respiratory illnesses. A 2015 study from Boston’s Beth Israel Deaconess Medical Center suggested that PM 2.5 may also be linked to brain aging.
“If you have a lung disease like asthma, cardiovascular problems or diabetes, or if you are a young child, a teen or elderly, you will likely be more susceptible to harm,” said Janice Nolan of the American Lung Association. “There is also evidence that women — whose lungs are slightly smaller than men’s — are more affected by pollution.”
Chillrud and his team will use the data from their study to design a street-level pollution map of the city and an app that will help cyclists avoid heavily polluted areas.
Thankfully, my humble burgh generally offers cleaner air than The Big Apple, where health department officials have linked PM 2.5 exposure to more than 2,000 premature deaths and 6,000 emergency room visits every year. But even if that wasn’t the case, I’m not sure I’d be pedaling around town wearing a face mask, like they do in Beijing. It’s all about trade-offs, after all. I may be filling my aging lungs with gunk or tempting fate on uncertain terrain every time I climb on my bike, but recent research suggests the upsides (besides convenient parking) are worth the gamble: Pedaling to work may reduce my risk of cancer and lower my stress levels.
Plus, like Stephanie Chan, one of the Columbia study participants, I’ve grown pretty fond of my daily bike rides. Chan told Schiffman that she often arrives home at the end of her afternoon commute carrying the sooty evidence of New York’s grungy air on her scalp and face. “I’ve always been aware that you are right in the middle of the traffic breathing in the car exhaust,” she said. But she can’t quite imagine giving up such an exhilarating mode of transportation. “It’s just one of those things where you take your chances.”