What can it do?

Question

My boyfriend has lived in a house with about 3 smokers for 18 years. He smoked for one year in his early teens, but quit.
I am wondering what possible damage could have been done to him, and what he should get checked for and what could be done to, I don't know, detoxify him or something.
We now live together and nobody smokes.

Answer 1

He is probably still young enough to not have to worry.
But he could have chest xrays to make sure. There is no way to detoxify him now. Living a smoke free life is his best bet now.