Global patterns of nicotine and tobacco consumption.

Humans consume tobacco in dozens of guises, all of which are toxic; globally, a tenth of deaths among adults are caused by tobacco. Tobacco may be combusted (e.g., cigarettes, bidis, kreteks); heated (e.g., waterpipes, hookah, nargile); or taken orally or nasally (e.g., snuff, betel quid, chewing tobacco). The predominant forms vary among cultures, but the use of cigarettes has grown most dramatically in the past century. While smoking rates among women are comparable to those among men in Europe and North America, in other regions the rate is ten or more times higher among men; this gender gap is closing among young people. Per capita tobacco use in the USA doubled in the first half of the twentieth century, and has since declined to less than the 1900 levels. While cigarettes were only 2% of tobacco consumed in the USA in 1900 (half was chewing tobacco) 50 years later they were over 80%. A similar increase in tobacco consumption, and a shift to cigarettes, has been occurring globally, with a concomitant increase in tobacco-related death and disease that is not expected to peak for another two decades.