Why does smoking raise cancer risk??

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Scientists say there are over 4,000 compounds in cigarette smoke. A sizeable number of them are toxic - they are bad for us and damage our cells. Some of them cause cancer - they are carcinogenic. Mainly of them are-

1) Nicotine - this is not carcinogenic. However, it is highly addictive. Smokers find it very hard to quit because they are hooked on the nicotine. Nicotine is an extremely fast-acting drug. It reaches the brain within 15 seconds of being inhaled. If cigarettes and other tobacco products had no nicotine, the number of people who smoke every day would drop drastically. Without nicotine, the tobacco industry would collapse.

Nicotine is used as a highly controlled insecticide. Exposure to sufficient amounts can lead to vomiting, seizures, depression of the CNS (central nervous system), and growth retardation. It can also undermine a fetus' proper development.

2) Carbon Monoxide - this is a poisonous gas. It has no smell or taste. The body finds it hard to differentiate carbon monoxide from oxygen and absorbs it into the bloodstream. Faulty boilers emit dangerous carbon monoxide, as do car exhausts.

If there is enough carbon monoxide around you and you inhale it, you can go into a coma and die. Carbon monoxide decreases muscle and heart function, it causes fatigue, weakness, and dizziness. It is especially toxic for babies still in the womb, infants and indifividuals with heart or lung disease.

3) Tar - consists of several cancer-causing chemicals. When a smoker inhales cigarette smoke, 70% of the tar remains in the lungs. Try the handkerchief test. Fill the mouth with smoke, don't inhale, and blow the smoke through the handkerchief. There will be a sticky, brown stain on the cloth. Do this again, but this time inhale and the blow the smoke through the cloth, there will only be a very faint light brown stain.