City cyclists suck in soot
Cyclist commuters in London had more than twice as much black soot in their lungs than did walking commuters.
From Scientific American:
Out of control drivers aren't the only thing city cyclists have to worry about. New research suggests that cyclists are at increased risk of lung damage because of soot.
A study compared people who walk or bike to work, to see how much black carbon they were exposed to. And cyclists had more soot in their lungs than walkers.
The research was presented at the European Respiratory Society's Annual Congress in Amsterdam on Sunday. [Chinedu Nwokoro et al., "Inhaled black carbon in the lower airways of London cyclists"]
Researchers at the London School of Medicine collected sputum samples from healthy non-smokers who walk or bike to see how much black carbon was in airway macrophages -- a type of white blood cell that takes in foreign material. The analysis found that cyclists had 2.3 times more soot in their airway cells.
Cyclists take in more black carbon because they breathe faster and deeper than walkers. And they're on the road, closer to exhaust fumes than sidewalk pedestrians are.
The ongoing study will address more questions about benefits and risks of healthy modes of transportation. But for now, I'd steer clear of high traffic areas.