About fifty million people in the United States currently smoke a total of five hundred and seventy billion cigarettes each year. As recently as the 1940s, smoking was considered harmless, but laboratory and clinical research has since proved that cigarette smoke contains around four thousand chemicals, some of which are highly toxic. According to the American Cancer Society, smoking is the most preventable cause of death in America today. Under the study of smoking, people realize that the influences of tobacco smoke are not only the smokers, but also the non-smokers who inhale the tobacco smoke. Besides this, tobacco smoke affects the human body, too.
Smoking causes deaths because it greatly increases a smoker's risk for several diseases.
Many of the chemicals that are contained in cigarette smoke are carcinogenic, and the chemicals are not able to be removed from the body. The American Cancer Society estimates that cigarettes are responsible for about four hundred and nineteen thousand deaths in the United States each year. Chief among cancers caused by smoking is lung cancer, which accounts for thirty percent of all U.S. cancer deaths. Additionally, smokers are at increased paid for cancer of the larynx, oral cavity, esophagus, bladder, kidney, and pancreas. Smoking also contributes substantially to the rise of chronic bronchitis and emphysema, and increases the risk of stroke by forty to fifty percent among men and sixty percent among women.