Tar is made up of over 4,000 chemicals with at least 43 known to cause cancer. Some of these substances cause heart and respiratory diseases, all of which are disabling and can cause death. You might be surprised to know some of the chemicals and gases found in tobacco smoke. Tobacco use accounts for 30 percent, or one in three, of all cancer deaths in the United States. Smoking is responsible for almost 90 percent of lung cancers among men and more than 70 percent among women.
Smoking is a major risk factor for cancer of the mouth, larynx, esophagus, kidney and bladder.
Tobacco smoking causes several lung diseases. Chronic bronchitis is a common ailment for smokers. Smoking is also the major cause of emphysema. This disease slowly destroys a person's ability to breathe. Chronic bronchitis and emphysema together kill about 81,000 people each year.