| > Location is generally less important than wind direction here My experience (and my nose) strongly disagrees with this assertion. YMMV. The urban-vs-rural divide in my area is shockingly detectable just by the smell of combustion byproducts alone. > you aren’t tracking [wind direction] Who says I'm not? Tall flagpoles make for nice, ubiquitous windsocks. I wouldn't use it to land a plane, but for this purpose it works just fine. And yes, it's absolutely a hard problem. Just look at all the ink I've spilled... The human nose (especially mine) is still a remarkable chemical sensor, with only a few blind spots. In practice the major blind spots, namely CO, correlate well with detectable combustion byproducts. I appreciate your concern, but you worry for no good reason! --- I'll share one final trick, which should be pretty obvious: avoid sucking in the packet of air a bunch of cars (or one diesel truck) just accelerated through. In practice, usually this means turning on recirculate when stopping behind a line of cars, and then waiting to turn off recirculate until a short distance after going through the light. Just to preempt the seemingly-inevitable negativity reflex: if you don't believe such hyper-local variations in pollution make a big difference, I guess you've never cycled before. ;) To good air and good health! Cheers |
https://en.wikipedia.org/wiki/Olfactory_fatigue
Urban/suburban areas provide a different variety of smells which is easy to confuse with overall toxicity levels. Chemical sensors will sometimes line up with your expectations and other times be very different.