I.

Introduction

Smoking, inhalation and exhalation of the fumes of burning tobacco. Leaves of the tobacco plant are smoked in various ways. After a drying and curing process, they may be rolled into cigars or shredded for insertion into smoking pipes. Cigarettes, the most popular method of smoking, consist of finely shredded tobacco rolled in lightweight paper. About 46 million people in the United States smoke an estimated 420 billion cigarettes each year.

Until the 1940s smoking was considered harmless, but laboratory and clinical research has since confirmed that tobacco smoke presents a hazard to health. Smoke from the average cigarette contains around 4,000 chemicals, some of which are highly toxic and at least 43 of which cause cancer. Nicotine, a major constituent of tobacco smoke, is both poisonous and highly addictive. According to the American Cancer Society, smoking is the most preventable cause of death in America today.