M.L.
I don't have a medical answer per se, but I have worked as a elderly care provider and can tell you from experience that prolonged exposure to the high ammonia concentration does affect the membranes of the nose and throat. We have a cat that has been a bit of a problem pee-er and have found that Bio-Kleen Bac-Out gets the odor out. I've never tried it on a large area (such as the entire bed mattress), but have used it quite successfully on smaller areas such as the carpet or couch.