Tobacco is obtained from the plant Nicotina tabacum and contains the addictive drug known as nicotine, says "The Tobacco Atlas." Several other harmful substances are also found in tobacco and/or tobacco smoke, including arsenic, acetone and cyanide. Tobacco is used by people all over the world and can be inhaled or absorbed through the mucous membranes of the mouth.
Inhalation
The most common form of tobacco use is inhalation of the burning substance in cigarettes, according to the text, "Tobacco or Health?" It is also used this way in cigars and pipes. The National Institute on Drug Abuse explains that nicotine in tobacco fumes is readily absorbed into the bloodstream through the lungs. Nicotine in the bloodstream triggers the release of adrenaline. This affects the rest of the body by increasing heart rate, elevating blood pressure, constricting the blood vessels, decreasing appetite and raising blood sugar levels. Additionally, nicotine affects the brain, making users feel alert and increasing the activity of a neurotransmitter known as dopamine; this is what makes smoking feel pleasurable. Tobacco smoking is believed to be responsible for 90 percent of all lung cancers and 75 percent of emphysema cases, according to "The Tobacco Atlas."
Oral Use
Smokeless tobacco is used by putting the substance into contact with the mucous membranes of the mouth. Snuff is moist or dry powder that is held in the mouth between the gums and cheek, explains "The Tobacco Atlas." Chewing tobacco is the dried, shredded leaves of the tobacco plant. It is chewed to release the nicotine-rich juice. According to the National Cancer Institute, smokeless tobacco products deliver three to four times more nicotine per use than the average cigarette. Oral delivery of nicotine takes longer to affect the body, but it remains in the bloodstream for a longer period of time. Use of smokeless tobacco products is associated with increased risks of oral cancers and gum disease, according to the National Cancer Institute.
Secondhand Smoke
People who do not directly use tobacco products are not necessarily immune to the health problems caused by tobacco. Secondhand smoke is defined by the Centers for Disease Control and Prevention (CDC) as smoke given off by the end of a burning cigarette and smoke exhaled into the environment. Secondhand smoke contains at least 50 chemicals that have been shown to cause cancer. Nonsmokers who are exposed to secondhand smoke at home or work have a 30 percent increased risk for lung cancer and heart disease, according to the CDC. "The Tobacco Atlas" points out that at least 200 other toxic chemicals are in secondhand smoke, including the active agents used in pesticides and industrial cleaning agents.
References
- "The Tobacco Atlas;" Judith Mackay and Michael Eriksen; 2003
- "Tobacco or Health? Physiological and Social Damages Caused by Tobacco Smoking (Second Edition);" Knut-Olaf Haustein and David Groneberg; 2010
- The National Institute on Drug Abuse (NIDA): NIDA InfoFacts: Cigarettes and Other Tobacco Products
- National Cancer Institute: Smokeless Tobacco and Cancer: Questions and Answers
- Centers for Disease Control and Prevention: Secondhand Smoke
