What are the dangers of secondhand smoke? What diseases may be caused?

If people often inhale secondhand smoke in their daily life, it will cause great harm to their health. In addition, the probability of suffering from various physical diseases is also significantly increased. This group of people is more likely to suffer from lung cancer, asthma, pneumonia, ear inflammation, coronary heart disease and other diseases. It can be seen from this that the harm caused by secondhand smoke cannot be ignored.

1. Lung cancer

Data shows that secondhand smoke often contains more harmful substances than mainstream smoke, for example, twice the nicotine, three times the tar, five times the carbon monoxide and about 50 times the carcinogens. It has been calculated that in a poorly ventilated place, the amount of smoke inhaled by a non-smoker in one hour is, on average, equivalent to the dose inhaled by one cigarette. According to a survey, smokers are significantly more likely to develop lung cancer than non-smokers. By analyzing the smoke inhaled by smokers, it was found that the smoke contains dozens of carcinogens. The risk of lung cancer is related to the length of time you smoke. The earlier you start smoking, the greater the risk. The longer you smoke, the higher the incidence and mortality of lung cancer.

Compared with men, women are more harmed by tobacco. Some women who live with smokers have a 6 times higher risk of developing lung cancer than normal people. It should be noted that the risk of lung cancer for female smokers is more serious, which is 1.9 times that of male smokers. The harm of secondhand smoke to passive smokers is no less than that to active smokers, and it is especially serious for pregnant women and children. Studies have shown that if a person spends more than 15 minutes with a smoker every day, the harm caused by second-hand smoke is equivalent to that of a smoker. 75% of lung cancer patients can be traced back to smoking.

2. Harm to memory

Nicotine and other harmful substances in smoke can stimulate the brain and cause hardening of cerebral blood vessels, thus affecting brain function. The intellectual development of children who are exposed to passive smoking for a long time is significantly worse than that of children who grow up in a non-smoky environment.

Non-smokers who were regularly exposed to secondhand smoke scored 20 percent lower on memory tests than another group of non-smokers. Smokers performed even worse, scoring 30 percent lower than non-smokers who were not frequently exposed to secondhand smoke.

3. Cause asthma, pneumonia, and ear inflammation in children

Children are the biggest victims of environmental pollution. Children generally experience higher environmental exposures than adults because they breathe more air and, therefore, inhale more pollutants than adults. In addition, children are active, have poor self-protection abilities, and have incomplete immune functions, making them most vulnerable to harm from pollutants. If the father smokes at home, the children will not object at all, nor will they take any measures to protect themselves. They can only be forced to inhale secondhand smoke. However, the main hazards of secondhand smoke to children's health include: causing baby asthma, sudden infant death syndrome, bronchitis, pneumonia and ear inflammation.

4. Coronary heart disease

Smoking causes heart disease, not only for those who actually smoke, but also for non-smokers who are exposed to secondhand smoke. It is biologically proven that exposure to secondhand smoke can cause acute coronary heart disease. Even short-term exposure to secondhand smoke can dramatically increase the risk of coronary heart disease.

Smoking increases the risk of coronary heart disease in men by 4 to 6 times and in women by 6 to 9 times; exposure to environmental tobacco smoke increases the risk of death from heart disease in non-smoking women, and secondhand smoke significantly increases the incidence of coronary heart disease, ischemic stroke, and peripheral vascular disease in women. The reason why passive smoking leads to coronary heart disease is that the chemicals inhaled from passive smoking can cause abnormal blood lipids, blood viscosity, damage myocardial tissue, and reduce the blood vessels' ability to regulate blood pressure and blood flow, thereby increasing the risk of myocardial infarction.

5. Harm to pregnant women and infants

Nicotine and other harmful substances can be detected in the amniotic fluid of 90% of pregnant women who are passively exposed to secondhand smoke, indicating that tobacco smoke directly pollutes the intrauterine environment where the fetus grows. China Food Network reminds that secondhand smoke exposure is an important risk factor for pregnant women to develop gestational hypertension and pregnancy complications; at the same time, secondhand smoke exposure has many serious effects on their physical health starting from the fetal period. Exposure to secondhand smoke also affects embryonic cell proliferation and differentiation, leading to abnormal embryonic development, which is manifested in developmental disorders of the nervous system and intrauterine growth retardation.

Due to the carcinogens in tobacco, the proportion of adults and children suffering from blood diseases, especially leukemia, has greatly increased. According to statistics, smokers inhale 10 times more benzene than non-smokers, and therefore smokers are 6-7 times more likely to develop leukemia than non-smokers. Statistics on the causes of childhood leukemia at Xinhua Hospital show that more than 60% of children with leukemia come from families exposed to secondhand smoke. This shows that smoking plays an important role in the risk of leukemia.