husband is a smoker.

I used to smoke a few years ago. Regularly. And I quit because of this one line that someone told me. A visit to the cancer centre shows more wives of husbands who smoke. So why do they have smoke related cancers when they don't even smoke? Because of carcinogens. These chemicals released after smoking will cause to linger on walls, furniture despite having been cleaned thoroughly. I urge you to show him these facts. Maybe he can stop, knowing these effects affect his love ones more in the long run.