I used kerosene heaters for heating and supplemental heat for many years...with the first experience in Florida in 1969/70. Then later in New Mexico and Utah. With the exception of starting and stopping they were odorless and clean burning. Never had any problems with them and would not hesitate to use them now. I had 6 kids and wife living at home at the time. I believe there are many things other than kerosene heaters that can lead to home air pollution. Just last night my Ashley fireplace insert was smoking like hell. It was here when we bought the house...but is coming out this summer. Anyway...it doesn't matter what you are doing, where you are doing it, or how you are doing it...somebody somewhere will discover a new way how the activity, or experience, is bad for you. I once read an article about how guitars cause serious physical and mental problems...something about the resonate vibrations from the strings and guitar body causing brain tumors and contrary behavior. The article went on to state that's why some guitarists in rock bands will bite heads off bats...etc, etc....and demonstrate generaly bad behavior. And then there is the infamous scientific study on the dangers of water. It was found that when rats were immersed for 10 minutes they died. Quite a stir there...almost got water banned. Ah well...I'm already 30 years older than anybody ever thought I'd live. Have fun.