Living Car Free - Which is better - bike + diesel exposure, or not riding

deleted

I guess the thing to remember is that sitting in a car behind a diesel exhaust source instead of behind it on a bike doesn't really reduce your exposure to it. Since, even with the fan or ac on its still drawing in air from the outside (unless you have the recirculate setting). But you highlighted why I don't sit behind vehicles in traffic and prefer to filter to the front.

Other studies show that air quality is worse inside cars than next to them. I am not sure if that includes newer ones with cabin filters.

Also I think most of the bad diesel claims are for semi's. Light trucks have smaller engines that are designed to be more efficient at a much smaller load - there is less "black smoke" when starting a light truck than when starting a semi whose engine is designed to be efficient when pulling a couple of thousand pound trailer at 55mph.

(ie. if you're biking around truckstops, maybe you should look into a particulate filter, but otherwise your other life choices are probably going to be worse than the trucks)

It amazes me that we've gotten to the point where, in many cities, there are days where people young & old and those in between with medical conditions (like asthma) are advised to NOT GO OUTDOORS!

Why this isn't treated more seriously is beyond me other than that there are powerful interests satisfied with the status quo.

Back to the OP - seek to limit your exposure by:
1) On code red days don't cycle. Run on a treadmill indoors if you must.
2) Distance your self away from large concentrations of traffic as much as possible. Your exposure drops dramatically if you ride a MUP instead of in traffic. Much less if you can find an alternate less busy route.
3) Think about riding before/after rush hour and so avoid the worst of the car pollution.

I have never seen pollution so bad in the USA that it would knock you over, but I did bicycle from Beijing to the Great Wall of China a couple of years ago. They were still adding lead into their already leaded gasoline. The engines were terribly polluting.

The air was heavy with pollution. I was dizzy and sick three hours into the trip. By the end of the trip, I was just about horizontal. My lungs ached. I was sick for more than two weeks after that trip with severe respiritory problems.

So I can attest that excersizing and bicycling in really badly polluted air CAN be worse than doing nothing at all.