Q. Can riding a bike in a city be hazardous to your health?
A. Yes. The first thing that may come to mind is simply getting hit by a car. That is the most obvious, and visible. But the exhaust from those cars is what might be the quiet killer for bikers in cities. I’ve thought about this often on my commute when I tuck in behind or alongside a big bus or truck in Sausalito and San Francisco. The other offenders are diesel cars. When it is really bad, I perform a diversionary tactic and get out of there.

Riding across the Golden Gate Bridge in the morning, you are on the bay side pathway, or east sidewalk. The exhaust from hundreds of cars is pushed right in to your face by the prevailing wind off the ocean. I’ve thought about air pollution there also. I’ve actually seen some bikers wearing strap-on dust masks. I have no idea if those are for allergies or air pollution, and I also have no idea if they would even help. Until the recent closure of the west sidewalk, I always thought how awesome it was to ride home on that side of the bridge because you take in nothing but fresh brisk air off the Pacific Ocean. Of course, every now and again you get a lung full of marine diesel from tankers passing below the bridge (you can really smell it, no kidding, and it is different from automobile diesel), but on a typical day you are breathing in pure Pacific air, perhaps laced with a hint of whale exhalations and guano from the Farallons. (OK, only kidding…but possible, no?)    

So, I’ve always thought of this in San Francisco, but a recent article in the Environmental Health News basically states this is an issue for bicyclists in cities around the world. However, there are ways to reduce exposure: Avoid busy streets. And, the other important message is simple—biking is still better than driving!

Are you ever concerned about breathing bad air when biking?



This sign in Copenhagen says: "Hello Biker, you are number 1,118 today and number 2,007,324 this year to bike past this point, have nice trip and thank you for biking in the city."

Golden Gate Bridge Speed Limit Update: The west sidewalk will be closed for months, and so I’ve come to the reluctant conclusion that it is now so difficult to ride across the bridge in the afternoons due to the crowds that  a ZERO speed limit is required! I’ve been going at a snails pace, weaving, ducking and coming to stops frequently. Unfortunately, there are still some real fellow biker jerks out there who think they own the sidewalk. I’ve seen two really bad ones in the past three weeks or so. I’ve actually witnessed them yelling at tourists to get out of their way and being complete idiots. Really too bad for the rest of us. After all, it is only a few minutes out of your ride.