A Review of Smoking on Cardiovascular Disease: Impact on Human Health

Tobacco is consumed by over a billion people around the word1 . Smoking is the most common mode of its use2 . This is done using products like cigarettes, e-cigarettes and water pipes3 . Smoking tobacco exposes individuals to tobacco related noxious gaseous and particulate matter in several ways4-6 . Most commonly, smoke enters the smoker’s mouth directly from the cigarette being smoked and this is known as the first-hand smoke or mainstream smoke4 . Side-stream cigarette smoke emanates from the burning ends of a cigarette and along with the exhaled main-steam smoke, results in second-hand smoke that could be inhaled by others5 . Third-hand smoke is the residue from tobacco products that cling to surfaces such as skin, hair, clothing, and furniture6 . These pollutants resist removal with traditional cleaning methods and may persist on these surfaces for several months. Tobacco is also consumed by non-smoking methods7 . The smokeless tobacco products include loosely chewed tobacco leaves, tobacco paste and several tobacco-based concoctions such as naswar, gutka, and snuff8 . The ingredients in these products are mainly absorbed via the mucous membranes of the mouth and nose. 

Tobacco is highly addictive, primarily due to its nicotine content9,10. All tobacco forms provide, besides nicotine, a plethora of harmful substances, many being extremely toxic and cancer provoking11. These include many harmful nitrosamines and polycyclic aromatic hydrocarbons12,13. Water pipe smoking results in large amounts of smoke being inhaled during a single smoking session and exposes the smoker to similar harmful substances as are present in cigarette smoke14. Inhaled e-cigarette vapor is usually lower in carcinogens and other toxins but is still harmful15. Smokeless tobacco also contains nicotine and more than 20 carcinogens, which enter the body via the oral and nasal mucous membranes16 . 

Tobacco smoking adversely affects literally every organ in the human body17. Tobacco smoke has a several thousand compounds, including several toxic ones, such as benzene, formaldehyde, benzopyrene, carbon monoxide, acrolein, and metals18. The respiratory tract is the first to be hit with these, (before disseminating all over the body via the blood stream) causing inflammation, irritation, asphyxiation, carcinogenesis, and other deleterious effects19. Further dissemination, mainly via the blood stream, results in the development of many other serious disorders including several forms of cancer20 . Smoking also affects pregnancy, causing a wide range of complications21. Infants exposed to cigarette smoke, either during the prenatal period or after birth have an increased risk of sudden death, orofacial clefts, periodontal disease, and dental caries22. Smoking accelerates aging, and smokers often develop wrinkles prematurely23.