health risks associated with smoking cigarettes Health Effects of Smoking on

"When you're sucking on that chewing tobacco, you've got it between your teeth and gums

(2005) in a landmark randomized clinical trial

While smokeless tobacco has demonstrably less carcinogens and toxins than cigarette smoke, said Hecht, smokeless tobacco still has remarkably high levels of carcinogenic tobacco-specific nitrosamines levels that are 100 to 1,000 times higher than in any other consumer product that is designed for oral consumption. In a separate study, the team evaluated carcinogen biomarker levels in individuals using these products

doi:10.1136/bmj.r1895

To put this in perspective, just one drop of pure nicotine can kill a person and 60 mg can be deadly