And sometimes it's an entire city that's the problem. My girlfriend comes from a mountainous zone. We live in the city that I was born, a dusty place in the plains.
Guess what, within one year she developed respiratory problems. We are actually considering moving towns because it's literally impossible to get rid of the dust effectively, here.
When I worked in a cubicle farm, cubicles were not necessarily cleaned out if someone left. I have serious health issues, including respiratory problems, and I'm very sensitive to dust, germs, etc. My immediate boss was asthmatic and yadda.
There was an abandoned cubicle very near both of us that had about two linear feet of papers in it. They were covered in a visible layer of dust. I concluded this was negatively impacting my health. I knew no one would believe me or care. Everyone always acts like I have an overactive imagination.
I began quietly carting the papers out. Anything still usable got redistributed and re-used. Anything in such bad shape it couldn't be mailed to customers got dumped in the recycling bins a handful at a time.
It probably took me a week or two to do this in small enough amounts at a time so that no one would notice what I was doing. My asthmatic boss was on like round three of antibiotics for bronchitis that wouldn't clear up. After all the musty, dusty papers were removed, she "coincidentally" finally got better.