3 ms·If nicotine isn't harmful in itself, why does chewing tobacco cause cancers of the mouth?by bashinator 13y agoIf nicotine isn't harmful in itself, why does chewing tobacco cause cancers of the mouth?radio4fan 13y agoBecause there are more than 70 carcinogenic compounds in tobacco.jlgreco 13y agoAre nicotine skin patches causing an epidemic of skin cancer where they are placed? Not all side effects are caused by the active ingredient.