When there are big air pollution problems, people and municipalities usually install their own monitors.
Say, I live in a region with a very bad air quality in winter, and in the vicinity of my house there're at least 4 devices I can (and do) check - 2 from airly.eu (within 200m, installed by the village) and 2 from luftdaten.info (within ~1km, installed by the locals) and one mine