I was around my paternal grandparents who smoked before anything was known about how bad second hand smoke was. Everytime I spent time at their home (a small mobile home) I came home & got sick with bronchitis. I hated going to visit them for more reasons than that but that was my biggest reason. My parents were were totally oblivious to seeing any correlation either. But my lungs could never tolerate smoke of any kind....even fireplaces & I ended up in the medical hospital for 10 days after forest fire smoke in 2004 covered the valley I lived in.