I am asking this because I recently bought an electronic cigarette, which is basically a nicotine vaporizer. I have not been able to find anything conclusive on the physical harms of nicotine-only products. I know that most stimulants have a negative effect on the cardiovascular system, and that pure nicotine is toxic at high(er) doses, but what about >30mg/day? I have been using the product with decreasing concentrations of nicotine solution to wean off of tobacco addiction. Links to appropriate studies are appreciated.