If it were me in the situation I would look either at the most doors I could get for the buck in a stable market, like a $750,000 16-unit multi-family in my market that is currently c-class (window unit air conditioners, dated stylings, and 10+ year old appliances, etc), extremely well located, and, based on all that, probably a good target for adding value over time and increasing the appraisal value substantially. 

These chemicals and pesticides leach into our soils and water along with drifting over in the air for miles. 

Purchase an Air Purifier for their son's room and main living area.  2.

Turning a sunroom (or extra space) from a “hidden bedroom” into an under-air space that can either be another bedroom, or in your case an expansion of the master and kitchen.

If it was a gas station, repair shop, machine shop, drycleaner, etc. the is the possibility of pollution on the property. 

The house had new vinyl siding but it covered up rotted T1-11 siding, like literally the nails were attached to air.

I have thought about air bnb for short term rental but it wont be my first go to.

getting knee deep in Air bnb offers in several cities.

REally difficult to make Air BNB work here now. 

We are working to add air conditioner or heat pump to 15 new 14'x56' homes in SC.