Not the OP but air quality monitors that measure particulates at different sizes? It's a pretty standard way of measuring air quality.
There's a map of official California monitors: https://ww2.arb.ca.gov/applications/air-monitoring-sites-int...
There's a map of official California monitors: https://ww2.arb.ca.gov/applications/air-monitoring-sites-int...
They offered it as a data point. I think it's fine form to question it.
Determining pollution exposure can be done anecdotally. I've done a number of long distance bike trips, the few times where I was next to a highway for upwards of 8 hours - having a nose bleed by the end of that is pretty common for me. In that vein, recognizing air pollution effects is not necessarily that difficult. Symptoms include: sore throat, headache, burning eyes, etc.. The other side, people do get used to low level irritants, and yeah - you don't really notice its there until you go somewhere else and realize "the air smells different."