It is now well documented that smoking can cause chronic lung disease, coronary heart disease, and stroke, as well as cancer of the lungs, larynx, esophagus, mouth, and bladder. In addition, smoking is known to contribute to cancer of the cervix, pancreas, and kidneys. Researchers have identified more than 40 chemicals in tobacco smoke that cause cancer in humans and animals. Smokeless tobacco and cigars also have deadly consequences, including lung, larynx, esophageal, and oral cancer. The harmful effects of smoking do not end with the smoker. Women who use tobacco during pregnancy are more likely to have adverse birth outcomes, including babies with low birth weight, which is linked with an increased risk of infant death and with a variety of infant health disorders. The health of nonsmokers is adversely affected by environmental tobacco smoke (ETS). Each year, exposure to ETS causes an estimated 3,000 non-smoking Americans to die of lung cancer and causes up to 300,000 children to suffer from lower respiratory-tract infections. Evidence also indicates that exposure to ETS increases the risk of coronary heart disease.