Smoking is the most important preventable cause of cancer in the world.
Cigarette smoking is harmful to the smoker and also nonsmokers who are exposed to the smoke. Smoking has negative health impacts on people at all stages of life. It harms unborn babies, infants, children, adolescents, adults and seniors.
Smoking harms almost every organ of the body and diminishes a personís overall health. The chances of smokers being affected by cancer are very high.
Several studies have shown that the various carcinogens in the cigarette smoke cause cancer. Cancers are most likely to occur in organs like lungs and oral cavity, which come into direct, contact with smoke. Cigarette smoke contains about 4,000 chemical agents, out of which 70 substances are carcinogenic.
Some of these harmful substances are - carbon monoxide, tar, arsenic, cyanide, benzene, formaldehyde, methanol, acetylene, ammonia, lead etc.
When the carcinogens in cigarette smoke are absorbed and spread through the human body, smoking causes cancer at various distant sites. Smoking causes many types of cancer, including cancers of the lung, esophagus, larynx, mouth, throat, kidney, liver, bladder, pancreas, stomach, cervix, bowel and also acute myeloid leukemia.
The risk of developing cancer is related to:
- Number of cigarettes smoked
- Duration of smoking
- Age at which smoking is started
- The type of cigarettes smoked
Types of smoking:
- Active smoking - Active smoking is the intentional inhalation of smoke using cigarettes and cigars.
- Passive smoking - Passive smoking is when a non-smoker breathes other people's smoke. It is also called as involuntary or secondhand smoking.