Answer:
Yes, even secondhand smoke can effect the lungs almost as much as a person who smokes themselves.
Second hand smoke can be from any source where anyone smokes. It could be at the work place, in a car, in bars, dance clubs, and can be from anyone.
To think that you are at the most risk by family living at home is incorrect, as is the fact that you have to be exposed in great amounts.
Smoking itself is harmful, and others that breathe in even small amounts are at risk for harmful effects that might not show up until many years later.