The chemicals in tobacco harm many parts of the body. Skin: Smoking ages the skin, causing it to wrinkle earlier than a nonsmoker's skin. Mouth, Teeth, and Throat: Cigarette smoke and smokeless tobacco lead to bad breath and stained teeth. Chemicals in tobacco cause mouth and throat cancers. Smokeless tobacco can cause leukoplakia--white sores in the mouth that can lead to cancer-- as well as tooth loss. It also wear away tooth enamel. Lungs: The tar in cigarette smoke coats the inside of the lungs. This prevents them from working well. Chemicals in tobacco smoke contribute to lung cancer.