Or your step dad may have gotten it regardless of smoking or second hand smoke. Some people get lung cancer who have never been around either. Once you hit around 70 the body starts to fall apart no matter what you do.
I agree, people get lung cancer for a variety of reasons. He was also a painting contractor so years and years of paint fumes could have contributed to his having lung cancer. If I remember correctly, my stepdad was 65 when he died.
We took my mom in after he died. In the almost three years she lived with us before she died, her heavy smoking habit stained our walls with nicotine and ruined the wallpaper in the downstairs bath. Even after painting and replacing the wallpaper you could still smell the nicotine when you first walked into the house.
I don't want to hear about bodies falling apart around 70. I am 75 and plan on being around for many more years.