The danger of second-hand smoke

Second-hand smoke is a mixture of the smoke from the burning tip of a cigarette and the smoke exhaled by a smoker. When second-hand smoke contaminates the air, especially in enclosed spaces, it is inhaled by everyone, exposing both smokers and non-smokers to its harmful effects. It causes lung cancer in non-smokers and increases the risk of coronary heart disease.

Although the majority of smokers are men, many women and children are affected by their second-hand smoke. Worldwide, second-hand smoke causes an estimated 600 000 premature deaths a year, the majority (64%) among women. In the Eastern Mediterranean Region 38% of students aged 13–15 are exposed to second-hand smoke at home, and in many countries only around a quarter of homes are smoke-free. Only around 50% of schools ban the use of tobacco products by teachers.

The harm to health from second-hand smoke

There are over 4000 known chemicals in tobacco smoke, many of which are harmful, with at least 40 that cause cancer. It also includes large quantities of carbon monoxide, a gas that hinders the blood’s ability to carry oxygen to vital organs such as the heart and brain, and substances that contribute to heart disease and stroke. Exposure to second-hand smoke has both immediate and long term effects, including the following:

Immediate effects include irritation of the eyes, nose, throat and lungs, and sometimes headaches, nausea and dizziness. Exposure can also trigger asthma attacks.

Long-term exposure to second-hand smoke causes lung cancer, coronary heart disease and cardiac death. Non-smokers who live with smokers are at increased risk of smoking-related illnesses. The risk of coronary heart disease is increased by 25%–30% and lung cancer by 20%–30%.