Write an explanatory article on the topic that smoking is harmful to health.

The harm of smoking is well known. As many as 2.5 million people die from smoking every year in the world, and smoking is the first killer of mankind. Consciously developing the personal hygiene habit of not smoking is not only beneficial to health, but also the embodiment of noble public health ethics. In the smoking room, especially in the environment with closed doors and windows in winter, the room is not only filled with carbon dioxide exhaled by human body, but also with carbon monoxide exhaled by smokers, which will make people feel headache, burnout and work efficiency decline. More seriously, the contents of tar and nicotine in the cold smoke exhaled by smokers are 1 times higher than those in the hot smoke inhaled by smokers, and benzopyrene is 2 times higher, carbon monoxide is 4 times higher and ammonia is 50 times higher.

Some data show that the incidence of lung cancer, laryngeal cancer and coronary heart disease in long-term smokers is 10-20 times, 6- 10 times and 2-3 times higher than that in non-smokers respectively. The incidence of circulatory system is 3 times higher, and the incidence of tracheitis is 2-8 times higher. A survey was conducted in 1000 families, and it was found that children under 0/6 years old in smoking families/kloc-had more respiratory diseases than children in non-smoking families. Among children under 5 years old, 33.5% of non-smoking families have respiratory symptoms, and 44.5% of smoking families have respiratory symptoms.

Smoking is especially dangerous for women. If women who smoke are using oral contraceptives, they will increase the risk of heart disease and venous thrombosis of lower limbs. Pregnant women who smoke are prone to premature delivery and underweight, and the immune function of infants and young children is reduced, which is easy to get sick; According to statistics, the teratogenic rate of pregnant women's passive smoking infants has increased significantly.

Smoking harms oneself and others, so we should consciously form a good health habit of not smoking.