I recently came across this article about the effects of passive smoking on cats and the increased risk of feline lymphoma. I just thought it was worth a mention.
"Secondhand smoke poses risks for every member of the family, cats included. Research suggests that living with one smoker in the house doubles a kitty's risk of feline lymphoma, the most common cancer in cats, which kills 75% of its victims within a year of diagnosis. The risk triples when exposure to secondhand smoke occurs for 5 or more years, and quadruples with two smokers in the house.
Cats get a double whammy from secondhand smoke because they inhale the carcinogens AND they ingest them when grooming. Protect your cat's health by making the inside of your home a smoke-free zone"
A good reason to give up or at least smoke outside
.