Is second-hand smoke bad?

Yes. Secondhand smoke, also know as environmental tobacco smoke (ETS), is a mixture of the smoke given off by the burning end of a cigarette, pipe, or cigar and the smoke exhaled from the lungs of smokers. It is involuntarily inhaled by nonsmokers, lingers in the air hours after cigarettes have been out, and can cause a wide range of illnesses, including cancer, respiratory infections, and asthma.