The smoke produced by tobacco combustion is a complex mixture of more than 7,000 compounds, of which gas accounts for 95%, such as carbon monoxide, cyanogen hydride and volatile nitrosamines, and particulate matter accounts for 5%, including semi-volatile and non-volatile substances, such as tobacco tar and nicotine. Most of these compounds are harmful to human body, of which at least 69 are known carcinogens, such as polycyclic aromatic hydrocarbons and nitrosamines, and nicotine is an addictive substance.
Studies have shown that smoking is an important environmental risk factor for COPD, and at least 95% of COPD patients are smokers. Smoking can advance the onset time of coronary heart disease by 10 years, increase the risk of coronary heart disease by 2 times, and increase the relative risk of sudden cardiac death by more than 3 times.