The same chemicals that cause lung cancer and heart disease in smokers are present in environmental tobacco smoke. Second-hand smoke irritates the eyes and delicate tissue in the throat, nose, and lungs. Nonsmokers, who are generally more sensitive to the toxic effects of tobacco smoke than smokers, may experience headaches, sore throat, nausea, and dizziness. Second-hand smoke places extra stress on the heart and affects the body's ability to take in and use oxygen. Up to one-quarter of lung cancer deaths in nonsmokers are related to secondhand smoke.
Children are especially sensitive to the effects of second-hand smoke.
3 Young children exposed to second-hand smoke are more vulnerable to respiratory illnesses such as bronchitis, asthma, and ear infections. Middle ear infections are also more common in the young children of smoking parents. Approximately 300,000 Canadian children and adolescents have asthma. These children are more likely to take up smoking themselves as they approach adolescence. In Nova Scotia, the average age for beginning to smoke is 12 years.