Harmful substances in smoke

Many people know that smoking is harmful to health, but because they are controlled by nicotine, many people become addicted to smoking and have no way to quit smoking. There are many harmful substances in cigarettes, which are very harmful to people's bodies. Many smokers are more likely to suffer from lung diseases. And the people who are most harmed are those who are often forced to inhale secondhand smoke. So what are the harmful substances in smoke? Let’s take a look.

There are more than 300 million smokers in my country, and 740 million non-smokers are exposed to secondhand smoke. The number of smokers in the country is increasing year by year, with the smokers becoming younger and the number of female smokers increasing year by year. If not stopped, the number of lung cancer patients dying from smoking in my country will reach 1 million by 2025. Smoking has become a pressing issue that seriously endangers the health and survival of our people.

The dangers of smoking

There are many toxic chemicals produced when cigarettes burn, among which the more harmful ones are carbon monoxide, nicotine, tar and benzopyrene.

1) The harm of carbon monoxide to human body: Carbon monoxide is the product of incomplete combustion of cigarettes. A cigarette produces about 2000 ml of smoke, of which about 369 ml is carbon monoxide. The affinity of carbon monoxide to hemoglobin is 250 times higher than that of oxygen. Hemoglobin combined with carbon monoxide loses its oxygen transport function. Long-term smoking will put the human body in a state of chronic hypoxia. Hypoxia can cause organ damage, promote the uptake of low-density lipoprotein cholesterol by smooth muscle cells, promote atherosclerosis, increase blood pressure, and in severe cases, cerebral infarction or even stroke.

2) The harm of nicotine to the human body: Nicotine enters the lungs through the trachea along with the smoke, enters the blood through the alveolar epithelial cells, and enters the brain after 8 seconds. In the midbrain, nicotine binds to nicotinic acetylcholine receptors, releasing excitatory neurotransmitters such as dopamine, which gives people a short-term sense of pleasure, eliminates fatigue, improves mood, and increases concentration. But nicotine is quickly cleared from the body, and repeated use is needed to maintain a feeling of well-being. Once you stop smoking for too long, the nicotine level in the body will drop, and the smoker will feel uncomfortable such as restlessness, irritability and restlessness. Therefore, tobacco is a chronically addictive drug.

Nicotine causes nerve endings to release adrenaline and norepinephrine, which increases blood pressure, speeds up heart rate, and reduces blood flow to other tissues. Nicotine can also promote platelet adhesion and aggregation, forming blood clots. Nicotine can also interfere with lipid metabolism, promote arteriosclerosis, thicken the middle layer of the arterial wall, and narrow the lumen. These factors are important reasons why nicotine causes cardiovascular and cerebrovascular diseases such as hypertension, cerebral infarction, myocardial infarction and stroke.

3) The harm of tobacco tar to human body: Tobacco tar is the product of incomplete combustion of cigarettes under high temperature and oxygen-deficient conditions, and contains a variety of carcinogenic and cancer-promoting substances. Tobacco tar enters the smoker's respiratory tract with the smoke flow and can adhere to the surface of the pharynx, larynx, trachea and bronchial mucosa. About 90% of it is carried into the lungs in the form of aerosol particles, inducing diseases such as bronchitis, asthma and chronic obstructive pulmonary disease. This is also the reason why many middle-aged and elderly smokers suffer from long-term coughing. The tar from tobacco that enters the lungs is difficult to exhale due to its fat solubility and adhesion. The carcinogens and cancer promoters in it can act synergistically to damage lung tissue cells and cause them to become cancerous. This is also the main reason why smokers are susceptible to lung cancer.

4) The harm of benzopyrene to human body: Benzopyrene is one of the 69 known carcinogens produced during smoking. Benzopyrene enters the respiratory tract of smokers with tar smoke, and under the action of oxygenase and hydroxylase, it generates polycyclic aromatic hydrocarbon epoxides that can attack DNA. These carcinogenic epoxides can enter other organs and tissues with the blood, induce gene mutations, and lead to multi-organ and multi-tissue cancers, such as lung cancer, oral and nasopharyngeal cancer, esophageal cancer, gastric cancer, liver cancer, and kidney cancer.