Composition of Cigarette Smoke
"Cigarette smoke is a complex mixture of chemical compounds that are bound to aerosol particles or are free in the gas phase. Chemical compounds in tobacco can be distilled into smoke or can react to form other constituents that are then distilled to smoke. Researchers have estimated that cigarette smoke has 7,357 chemical compounds from many different classes (Rodgman and Perfetti 2009). In assessing the nature of tobacco smoke, scientists must consider chemical composition, concentrations of components, particle size, and particle charge (Dube and Green 1982). These characteristics vary with the cigarette design and the chemical nature of the product."
US Department of Health and Human Services. "How Tobacco Smoke Causes Disease: The Biology and Behavioral Basis for Smoking-Attributable Disease: A Report of the Surgeon General." Atlanta, GA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, 2010, p. 29.