an indicator of genotoxicity. These effects lead to further DNA damage and, eventually, oral cancer. Smokeless tobacco can cause white or gray patches inside the mouth (leukoplakia) that can lead to cancer. The World Health Organization has classified smokeless tobacco products as human carcinogenic compounds, in particular tobacco-specific nitrosamines, which account for 76 to 91% of the total N-nitroso compound (NOC) burden. A 2014 review found there is "a number of ethnically linked smokeless tobacco types that contain areca nut, a Group 1 carcinogen. Use of areca nut-containing smokeless tobacco is known to cause oral cancer, yet despite this, prevalence is increasing in the Western Pacific." N-nitrosonornicotine and ketone are group 1 carcinogens to humans. These two nitrosamines found in smokeless tobacco products are the main agents for the majority of cancers in smokeless tobacco users. Effects during pregnancy It is correlated with adverse reproductive effects including stillbirth, premature birth, low birth weight. Using smokeless tobacco during pregnancy can increase the risk for early delivery and stillbirth. Nicotine in smokeless tobacco products that are used during pregnancy can affect how a baby's brain develops before birth. Management Due to smokeless tobacco harms, it should be treated. some medications shows some benefits are varenicline, nicotine lozenges. some behavioural interventions may help, however a cochrane review mentioned that there components need to be clearer. History Smokeless tobacco was first discussed in the English language in 1683 as a powdered tobacco for breathing into the nose. People have used it for over a thousand years. Cigarette manufacturers have penetrated the smokeless tobacco market. Public perceptions Many people who use smokeless tobacco may think it is safer than smoking, but all tobacco products contain toxicants, and use of smokeless tobacco poses its own significant health risks. In South and South-East Asia these products are considered part of the cultural heritage and there is little enthusiasm for regulation. Around 80% of users live in these regions. See also Herbal cigarette Herbal smokeless tobacco Tobacco Tobacco usage in sport Tobacco packaging warning messages#Smokeless tobacco References Tobacco products Carcinogens IARC Group 1 carcinogens Articles containing video clips