I feel for ya... I have the same thing happen to me when I enter a building that is infected with mold. I can smell it as soon as I open the door! Not much we can do - just be very observant when looking for a place to live. I used to be a landlord myself - so I don't agree with everything you say - there are words for the type of people you are describing:
"slumlords"!! Stay away from those and try to get into something that has been taken care of or is new. The govt will not help you at any level. Good luck!