The menthol component of cigarettes adds an additional risk since menthol allows deeper lung penetration of tobacco smoke leading to a greater risk of deadly small cell lung cancer. The nicotine present in tobacco is the addictive component that enhances habit formation. Studies have shown it to be as addictive as opiates. While its link to cancer has been fully established, according to the book Nicotine Safety and Toxicity , the nicotine in tobacco has not been shown to be a carcinogen in any animal based studies. Nicotine acts as a vasoconstrictor, a stimulant, and an appetite suppressant.
Smokeless tobacco is equally as dangerous as smoked tobacco.
It has more nicotine by weight than smoked tobacco and is therefore considered more addictive. Smokeless tobacco also produces additional carcinogens when mixed with saliva. Extra care must be taken when working with smokeless tobacco cessation due to the heavier addiction to nicotine. The current fad with cigars is considered to be extremely dangerous. The average cigar is the diameter of an index finger and has 6 times the nicotine of a cigarette.