Some hazards of passive smoking.

Non-smokers are exposed to three types of cigaret smoke: mainstream, sidestream and diffusional smoke, of which sidestream (produced while the cigaret smolders in an ashtray) is the most toxic. Studies of passive smoking show that while smoke is an unpleasant irritant, it appears to have no lasting effects on healthy passive smokers. It may, however, be a particular irritant to already sensitive individuals such as asthmatics, and to young children chronically exposed. Such children show an increase of respiratory disorders, and adults show an increase of small airway disease with a possible risk of lung cancer. More stringent legislation on smoking is desirable.