The risk of lung cancer of smokers is 13 times that of non-smokers. If you smoke more than 35 cigarettes a day, your risk is 45 times that of non-smokers. The mortality rate of lung cancer in smokers is 10~ 13 times higher than that in non-smokers. About 85% of lung cancer deaths are caused by smoking. If smokers are exposed to chemical carcinogens such as asbestos, nickel, uranium and arsenic at the same time,
PAHs in tobacco smoke are cytotoxic and mutagenic only after being metabolized by PAH hydroxylase, and the concentration of this hydroxylase in smokers is higher than that in non-smokers.
Smoking will reduce the activity of natural killer cells, thus weakening the body's function of monitoring, killing and clearing tumor cells, which further explains that smoking is a high risk factor for many cancers. The incidence of laryngeal cancer and bladder cancer in smokers is ten times higher than that in non-smokers, which may be related to β -naphthylamine in smoke.
In addition, smoking is also related to the occurrence of lip cancer, tongue cancer, oral cancer, esophageal cancer, gastric cancer, colon cancer, pancreatic cancer, renal cancer and cervical cancer. Clinical research and animal experiments show that carcinogens in smoke can also affect the fetus through the placenta, leading to a significant increase in the incidence of cancer in its offspring.
Extended data:
Smoking causes lung cancer:
A large number of studies have proved that the incidence of lung cancer in smokers is 20~25 times higher than that in ordinary people, and it is positively related to the amount of smoking and the length of smoking. The smoke from cigarette burning contains more than a thousand kinds of chemicals, among which 3,4-benzopyrene, nicotine and tar have been identified as carcinogens. In addition, radioactive elements polonium -2 10, carbon-14, arsenic and nickel also have carcinogenic effects.
By reducing tar content or adding filter tips to change the carcinogenic components in tobacco, the histological types of lung cancer can also be changed, which proves that smoking is closely related to the occurrence of lung cancer. After nicotine is inhaled into the human body, it will have adverse effects on the heart, blood vessels and other tissues, making the sympathetic nerve contract due to abnormal excitement, and the heart has to speed up its action, so the blood pressure will also rise.
Some scholars have reported that smoking only one or two cigarettes will change the index of blood pressure, so smoking dozens of packs a year will definitely have adverse effects for decades.
With further scientific research, it is found that smoking will multiply the "oxidative stress" reaction, produce more free radicals to damage body organs and tissues, aggravate insulin resistance, weaken the immunity of human immune system and accelerate the aging (oxidation) of human organs and tissues.
Smoking will promote the deterioration and development of oxidative stress diseases such as type 2 diabetes, hypertension, dyslipidemia and gout, so patients with oxidative stress diseases should absolutely ban smoking during treatment.
Smoking is harmful to people's health, especially to teenagers. According to the research of medical scientists, teenagers are in the period of growth and development, and their physiological systems and organs are not yet mature. Their resistance to harmful factors in the external environment is weaker than that of adults, and they are easy to absorb poisons and damage normal growth.
According to a survey of 25 states in the United States, the age of starting smoking is negatively correlated with the mortality rate of lung cancer. If the mortality rate of lung cancer in non-smokers is 1.00, the mortality rate of smokers below 15 is19.68; 20 ~ 24 years old is10.08; People over 25 4.08. It shows that the earlier you start smoking, the higher the incidence and mortality of lung cancer.
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