I have a question regarding second hand smoke and its dangers, I hope this is the right place to post it. I have been told how dangerous second hand cigarette smoke is, I have also been told that it is impossible to fail a urine test due to inhaling second hand MJ smoke. So which is it, second hand smoke is an efficient way to transfer toxins from one to another, or toxins cant be efficiently transported via second hand smoke? Or are there other reasons that I am overlooking why this is supposedly so? Thanks for any help.