As long as the fungal ecology of the indoor environment is consistent with the outside environment, no elevated health risk exists. 

The property I managed was a 26 unit, 2-story single building, no frills, no balconies, showers only, old building, high ceilings, no elevator, with mainly tiny studios (about 250 square feet).  

And the elevators are dreadfully slow.

Having an elevator in an 8 story building is a reasonable accommodation, it's not an age issue, it's unreasonable to require a 5 year old or an 85 year old to climb those stairs carrying groceries. 

But they are predominantly ground floor elevations rather than having them negotiate stairs to a basement or upper floor unit.

However, landlords need not undertake changes that would seriously impair their ability to run their business, such as installing an elevator to the third floor to accommodate a wheelchair-bound tenant’s wish to live there.?"

If built after 1978, then an elevation certificate is required. 

These are higher in elevation than a standard toilet.

There were signs up all over the lobby and in the elevator, and in the laundry rooms all yelling at you.  

It says right in the article that people were letting their dogs poop in the halls, elevators, etc....and not even picking it up.