ABSTRACT
References .........................................................................................................102
It is well known that smoking is harmful for human health as is marked on any pack of cigarettes: “Smoking damages your health” (China); “Tobacco causes serious damage to your health” (U.S.); “Cigarette smoke contains carbon monoxide” (555); “Smoking causes cancer, heart disease, and emphysema and may complicate pregnancy” (Canada). It has been found by epidemiological studies that smoking causes high mortality by initiating heart diseases and cancer. The incidence of heart diseases is proportional to the number of cigarettes smoked, and about 30% of lung cancers are caused by cigarette smoking [1,2]. The excess risk was largely confined to long-term and heavy smokers, with significant twofold excess risk among men who smoked 40 or more packs per year. Among women, an 80% increase in risk was observed in both current and former smokers but dose-response trends were less consistent than among men [3,4]. The noxious pro-oxidant effects of smoking extend beyond the epicardial arteries to the coronary microcirculation and affect the regulation of myocardial blood flow, causing carotid-media thickness [5,6]. Cigarette smoking is also associated with significantly higher rates of both low birth weight and preterm and other diseases [7,8]. It had been considered in the past that nicotine in tobacco smoke is the most poisonous material. However, recent studies showed that the free radicals in smoke are closely related to the diseases caused by cigarette smoking [4-8]. The free radicals generated by cigarette smoke not only cause lung injury, lung cancer, and heart diseases, but also pollute the environment. Studies showed that some of the polycyclic aromatic hydrocarbon free radicals are direct chemical carcinogens.
