Tobacco smoking is the practice of burning tobacco and ingesting the resulting smoke. The smoke may be inhaled, as is done with cigarettes, or simply released from the mouth, as is generally done with pipes and cigars. The practice is believed to have begun as early as 5000–3000 BC in Mesoamerica and South America. Tobacco was introduced to Eurasia in the late 17th century by European colonists, where it followed common trade routes. The practice encountered criticism from its first import into the Western world onwards but embedded itself in certain strata of a number of societies before becoming widespread upon the introduction of automated cigarette-rolling apparatus.Smoking is the most common method of consuming tobacco, and tobacco is the most common substance smoked. The agricultural product is often mixed with additives and then combusted. The resulting smoke is then inhaled and the active substances absorbed through the alveoli in the lungs or the oral mucosa. Many substances in cigarette smoke trigger chemical reactions in nerve endings, which heighten heart rate, alertness and reaction time, among other things. Dopamine and endorphins are released, which are often associated with pleasure.German scientists identified a link between smoking and lung cancer in the late 1920s, leading to the first anti-smoking campaign in modern history, albeit one truncated by the collapse of Nazi Germany at the end of World War II. In 1950, British researchers demonstrated a clear relationship between smoking and cancer. Evidence continued to mount in the 1960s, which prompted political action against the practice.
By 2030, the World Health Organization (WHO) forecasts that 10 million people a year will die of smoking-related illness, making it the single biggest cause of death worldwide, with the largest increase to be among women. WHO forecasts the 21st centurys death rate from smoking to be ten times the 20th centurys rate ("Washingtonian" magazine, December 2007). The tobacco industry is known to be one of the largest global enterprises in the world. The six biggest tobacco companies made a combined profit of $35.1 billion (Jha et al., 2014) in 2010. Social
Famous smokers of the past used cigarettes or pipes as part of their image, such as Jean-Paul Sartres Gauloises-brand cigarettes; Albert Einsteins, Douglas MacArthurs, Bertrand Russells, and Bing Crosbys pipes; or the news broadcaster Edward R. Murrows cigarette. Writers in particular seem to be known for smoking, for example, Cornell Professor Richard Kleins book Cigarettes are Sublime for the analysis, by this professor of French literature, of the role smoking plays in 19th and 20th century letters. The popular author Kurt Vonnegut addressed his addiction to cigarettes within his novels. British Prime Minister Harold Wilson was well known for smoking a pipe in public as was Winston Churchill for his cigars. Sherlock Holmes, the fictional detective created by Sir Arthur Conan Doyle, smoked a pipe, cigarettes, and cigars. The DC Vertigo comic book character John Constantine, created by Alan Moore, is synonymous with smoking, so much so that the first storyline by Preacher creator Garth Ennis centered around John Constantine contracting lung cancer.