I am a renter...been living in the same place about two years now. I pay some attention to current events and realize that homeowners insurance as it relates to mold coverage has been a big issue. How can you tell if your house is "infected"? My landlord told me when I moved in that the water heater had gushed out a significant amount of water during the previous renter's stay. Add to that the fact that our ceiling leaked significantly during some rain storms a few months ago. The worst thing is my bathroom starts going black out of the faucets and drain and along the tile walls within a few days after cleaning. This does not seem normal to me. Is this mold infestation? How can I find out? Speaking of which, what is mold, and what are some side effects of long-term exposure to mold? Is it really dangerous to humans, or only to the houses?