I had a question in the comments to one of the posts about second- and third-hand smoke. I'm very strongly urged by the survivorship nurse to avoid both. One consequence of the chemo and radiation that I've undergone in order to kill as much of my cancer as possible (and to wipe out my original immune system) is that I'm forever more vulnerable to cancer than the average person. So avoiding the known carcinogens in tobacco smoke is pretty much a no-brainer. If, like me until a few weeks ago, you're unfamiliar with the concept of third-hand smoke, it's the residue that smokers have on their breath and clothing and, for smokers who smoke indoors, the residue in the carpet and furniture of their homes.