Wait, so bateria that are in your home are getting sucked into the filter like they're supposed to do, die and release endotoxins. But they're going to die anyway and still release those endotoxins but it's just going to be all over my couch that I sit on every day. Ok, maybe that nasty filter you haven't changed in a year provided an environment for the bacteria to grow and the fan disperses it. Sure, I get it if it's some nasty filter you haven't changed in over a year. That's why you don't wait a year to change them. That's like saying, "Bathrooms may provide a breeding ground for mould and bacteria making your home less hygienic!." Ya, no kidding. That's why you clean your bathroom.