Secondhand smoke is dangerous, especially for children. The best way to protect loved ones is to quit smoking. At the very least, make sure you have a smokefree home and car.
When you smoke a cigarette (or roll-up, pipe or cigar), most of the smoke doesn't go into your lungs, it goes into the air around you where anyone nearby can breathe it in.
Secondhand smoke is the smoke that you exhale plus the "sidestream" smoke created by the lit end of your cigarette.
When friends and family breathe in your secondhand smoke – what we call passive smoking – it isn't just unpleasant for them, it can damage their health too.