Tobacco Smoking

Considering the globe, the adverse effects of tobacco smoking out number all the effects of other pollutants.   It is considered as one of the most important preventable causes of death in the United States.  In our society also even though its health impacts are not so pronounced it still has series health damage.  Tobacco smoking affects not only those who are actively smoking but it also has an adverse consequence on the health of those who are by the vicinity of the smoker.  These individuals are termed as passive Smokers.

Active Smoking and disease

The cigarette smoke that is taken through the mouth into the lung has several types of chemicals that have diverse & serious effects on our health.  The composition depends on the type of tobacco, length of the cigarette, and presence and effectiveness of filter tips. Usually present are (1) Carcinogens whose effects have been verified in lower animals (e.g.polycyclic hydrocarbons, betanaphthylamine, nitrosamines). (2) Cell irritants and toxins (e.g. Ammonia, formaldehyde, and oxides of nitrogen). (3) Carbon monoxide, and (4) nicotine, which has various effects on the sympathetic nervous system, blood pressure heart late and the like.

The more common adverse health effects of tobacco are lung cancer, coronary heart disease, COPD (Chronic bronchitis, emphysema), and systemic atherosclerosis. And the less common effects are peptic ulcer, Cancer that can originate from larynx, esophagus, pancreas, bladder & kidneys. Cigarette smoking also causes COPD, which are chronic bronchitis and Emphysema, which have a tremendous health impact. Systemic arteriosclerosis and other forms of cancer are also diseases caused by cigarette smoking, which collectively contribute to many deaths.  In general smoking is the single most important cause of cancer mortality in the United States.   Fetuses are also adversely affected by maternal smoking. Several studies have shown that maternal smoking could cause low birth weight, prematurity, still birth and infant mortality. Moreover other complications of pregnancy like abruptio placentae, placenta previa, and premature rupture of membranes have been found to be caused by maternal smoking. 

The risk of mortality is dose dependent. The number of pack years i.e. number of packs per day times number of years is directly related to mortality rate. The more pack years of smoking the higher the risk of mortality. Coronary heart disease causes most of the deaths when it comes to effects of cigarette smoking. Lung cancer closely follows causing a huge number of deaths.

Involuntary smoke exposure (Passive Smoking)

The effect of passive smoking has been identified during the last few decades. Its effect comes when non-smoking people inspire the ambient air, which is polluted by cigarette smoke. The health impact depends on the volume of the air in the room, number of active smokers, rate of air exchange and duration of exposure. Data from different countries show that the risks of lung cancer increase by 1.5 due to passive smoking. There is also increased risk of cardiovascular diseases specially MI, and high incidence of lower respiratory tract diseases in infants & children of smoking parents. Children & infants of smoking mothers will have an obvious intense exposure and hence retardation of physical and intellectual growth is likely to occur.

Benefits of cessation or reducing exposure to cigarette smoke

When a person stops smoking the risks of diseases and subsequent death start to decline The risk to reach to that of non-smoking people may take 20 years of smoke-free period. The amount of cigarettes smoked daily, and duration of smoking determines the rate of decrease of risks. The relative risk of lung cancer and laryngeal cancer start to decline after 1 to 2 smoke free years. However considering lung cancer former smokers will have slightly higher risk than non-smokers even after 30 years of smoke-free years.

When it comes to coronary diseases the decline of risk is rapid and it can level with those of non-smokers after 5 to 20 years.  Once COPD has been developed quitting does not have any significant effect in reversing the situation.

References

Bezabeh ,M. ; Tesfaye,A.; Ergicho, B.; Erke, M.; Mengistu, S. and Bedane,A.; Desta, A.(2004). General Pathology. Jimma University, Gondar University Haramaya University, Dedub University.