The main causes of lung cancer in women are mostly the same as in men. Environmental factors are now believed to be the initiating factors for tumor development, while individual genetic characteristics determine susceptibility to tumors. The main causes include smoking and secondhand smoke, and studies have shown that about 80-90% of lung cancers worldwide can be attributed to smoking and secondhand smoke. Tobacco is harmful to human health, mainly from the chemical composition of tobacco mist, the local temperature of tobacco can be as high as 900-1000 ℃ when burning, so that a series of thermal decomposition and thermal synthesis reactions. Smoke contains more than 4700 chemical components, most of which are harmful to humans, including tobacco tar, benzo(a)pyrene, nitroso, nicotine and other major carcinogenic components. In addition, indoor air pollution, including living fuel and indoor coal-fired air pollution, is especially important in relation to the development of lung cancer in women.