Why is smoking bad for you?
Bad breath, a chronic hacker's cough, emphysema, heart disease, cancer all these, and more, can be blamed at least partly on smoking.
The smoke of burning tobacco contains many irritants and poisonous gases. First among them is carbon monoxide, the substance also found in the deadly fumes of automobile exhaust. What makes carbon monoxide dangerous is its extraordinary ability to combine with hemoglobin, the substance is the blood that caries life-giving oxygen to tissues. Carbon monoxide wins out ever oxygen, so that heavy smokers deprive themselves of to 10 percent of the oxygen-carrying capacity of the blood.
Lack of oxygen leads to a number of harmful changes in the way the body functions. For one thing, the heart must pump faster to supply oxygen. Smoking also constricts the blood vessels in the fingers and toes, causing poor circulation. Compared to a nonsmoker, the average smoker has more than twice a chance of suffering a heart attack. In addition, women who smoke and use oral contraceptives are 20 times more likely to develop heart disease than nonsmokers. There may be other, still unknown changes in the smoker's blood chemistry.
What substance in smoke cause cancer?
Sticky black or brown substances not unlike the stuff used on highways, tobacco tars are the chief carcinogens in smoke. They collect on the sensitive tissues of the respiratory system, irritate them, and after a few years cause such disorders as chronic bronchitis and cancer.
Cigarette smoking can lead to cancer in many parts of the body, but not surprisingly, most of the damage it does is to the lungs. Lung cancer is now the most common form of cancer in the Western world. Men who have smoked heavily for 20 years or more are 20 times as susceptible to it as nonsmokers. Women, in the whom lung cancer was once rare, are now increasingly subject to the disease as they join the ranks of heavy smokers.