Evidence continued to mount in the 1960s, which prompted political action against the practice. In 1950, British researchers demonstrated a clear relationship between smoking and cancer. 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. Dopamine and endorphins are released, which are often associated with pleasure. Many substances in cigarette smoke trigger chemical reactions in nerve endings, which heighten heart rate, alertness and reaction time, among other things. The resulting smoke is then inhaled and the active substances absorbed through the alveoli in the lungs or the oral mucosa. The agricultural product is often mixed with additives and then combusted. Smoking is the most common method of consuming tobacco, and tobacco is the most common substance smoked. 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. Tobacco was introduced to Eurasia in the late 17th century by European colonists, where it followed common trade routes. The practice is believed to have begun as early as 5000–3000 BC in Mesoamerica and South America. The smoke may be inhaled, as is done with cigarettes, or simply released from the mouth, as is generally done with pipes and cigars. Tobacco smoking is the practice of burning tobacco and ingesting the resulting smoke. A woman smoking a cigarette, the most common method of tobacco smoking

Cigarette celephane smoke waterfall