What we do know about cigarette smoke is the most harmful toxin of the 4,000+ chemicals present when inhaled in the human lung is carbon monoxide (CO). This is the same deadly element found in car exhaust. It is a product of smoke inhalation and has nothing to do with nicotine.
Mammals actually produce carbon monoxide naturally in very low levels, exhaled as a byproduct of hemoglobin breakdown. Colorless, odorless, tasteless and highly toxic, when actually drawn into your respiratory system, from cigarettes or industrial pollution, carbon monoxide is extremely fatal in large enough doses.
Blood poisoning from carbon monoxide effectively starves your body of oxygen. When absorbed by the bloodstream, CO effectively replaces oxygen (O2). So your heart has to work harder and harder with the more CO your bloodstream absorbs to circulate the diminishing supply of oxygen in your system. This is why smoking traditional cigarettes causes heart disease.
For the same nicotine fix without the fatal carbon monoxide inhalation, there are electronic vapor cigarettes. Water vapor in place of cigarette smoke is the crucial component to reducing CO in your nicotine intake. Field tests have proven the CO levels in non-smokers and vapor cigarette exhale is exactly the same. But in regular cigarette smoke output, CO levels are just over ten times as high.
Doctors link nicotine intake to caffeine consumption. A naturally occurring stimulant, nicotine has very minimal long term effects on the human body when not inhaled with harmful smoke from a traditional cigarette. The substance has been associated with therapeutic health benefits, ironically, the circulatory system.
Carbon monoxide presence kills thousands of people every year around the globe. It is the gas that leaks into homes and sickens entire families. It is the deadly element in car exhaust which can suffocate you. And we know it is present in traditional paper cigarettes, but not in electronic vapor cigarettes.