大象传媒

Inside our chest, our lungs take in oxygen from the air we breathe. The oxygen is carried by the blood to the rest of the body. Air is about one fifth oxygen and oxygen releases the energy the body needs to stay alive. Healthy lungs can be damaged by smoking cigarettes. Tobacco smoke contains poisonous chemicals such as nicotine, carbon monoxide and tar. A cigarette smoking machine shows the tar built up after a few cigarettes.