The 19th National Cancer Awareness Week will be held nationwide from April 15-21, 2013. The theme of this week is “Protect the Environment, Stay Away from Cancer”. The incidence and prevention of lung cancer, which is closely related to environmental pollution/lifestyle, is introduced as follows: I. Atmospheric and environmental pollution The relationship between atmospheric and environmental pollution and lung cancer has been reported in many studies, such as the atmospheric pollution index, deposition index, smog index, BaP [Benzo(a)Pyrene] exposure dose and the probability of lung cancer. Data from epidemiological studies in Pakistan show that severe atmospheric pollution leads to high incidence of lung cancer, and the incidence of lung cancer is significantly higher in urban than rural areas, with incidence rates of 4%-9% and 1%-3%, respectively. In cities, automobile exhaust, industrial processes, asbestos, radioactive isotopes, aromatic compounds, rubber and plastic manufacturing industries emit harmful gases that lead to serious air pollution compared to rural areas. Scholars at the University of Birmingham explored the reasons for the increasing incidence of lung adenocarcinoma in the United States over the past 50 years by analyzing the changing distribution of lung adenocarcinoma in the U.S. The results showed that increased air pollution existed as early as 10 years before the rise in adenocarcinoma. These data are consistent with the increase in lung adenocarcinoma occurring 10 years later than the decrease in the incidence of squamous carcinoma, as the majority of smokers switched to low-tar cigarettes, and the decline in air pollution occurred 10 years later than the significant decline in smoking. The study also found that the incidence of adenocarcinoma in non-smokers increased in areas with a high density of automobiles. The study suggests that the current increase in lung adenocarcinoma is not consistent with the use of low-tar cigarettes, but rather with increasing air pollution. The incidence of lung cancer is closely related to smoking in both men and women. The incidence and death of lung cancer in men in developed countries in Europe and the United States has been on the decline, but the mortality rate of lung cancer in women has not decreased, and is even increasing, the main reason may be that smoking is more common among women in these countries and regions. 95% of lung cancer in women in the United States is related to smoking exposure, including personal smoking and environmental smoking (passive smoking). Passive smoking is also an important factor in the development of lung cancer in women. Particularly in developing countries passive smoking has become a major carcinogenic factor in the development of lung cancer in women. Public places such as homes, bars, restaurants, and offices can be places of passive smoking, and homes are the main places of passive smoking. The indoor environment pollution caused by smokers leads to lung cancer in their relatives, and smoking by husbands increases the risk of lung cancer in wives, which has become a direct cause of the dramatic increase in lung cancer in women in Japan. Indoor pollution Studies in many cities in northern, southern and central China have reported that indoor air pollution caused by coal cooking, heating and cooking fumes is an important cause of lung cancer, especially in women, and that high temperatures in cooking can make vegetable oil form strong mutagenic substances. The high incidence of lung cancer in women in Xuanwei, China is a typical example of indoor air pollution from coal combustion. Research also proves that indoor BaP pollution can cause BaP overload in human body. Dietary factors It is estimated that about 35% of the causes of human tumors are related to dietary factors, and smoking-related factors account for about 30% of them. High intake of fruits and vegetables is associated with a reduced risk of lung cancer due to the antioxidant properties of vitamins, other micronutrients and the ability to regulate cell growth and differentiation, especially beta-carotene. In addition, cooking meat at high temperatures produces heterocyclic amines, which have been found to increase the risk of lung cancer when consumed in excess. Many scholars believe that alcohol consumption is a risk factor for lung cancer, and ethanol, the first metabolite of alcohol, is thought to be associated with lung cancer development. Japanese studies have shown that alcohol consumption is significantly associated with lung cancer, and the risk of lung cancer is significantly higher when alcohol drinkers have ALDH2 and CYP2E1 variant alleles. Dietary phytoestrogens (PE) have estrogen-like effects and have been shown to have chemopreventive effects on lung cancer in in vitro studies. Results from the M.D. Anderson Cancer Center in the United States support that high dietary intake of PE may reduce the risk of lung cancer. V. Occupational exposure To determine whether a chemical or factor has a carcinogenic effect, there must be mutual verification by epidemiological studies and experimental studies. The chemicals and production processes that are now identified by IARC (International Agency for Research on Cancer) as capable of causing lung cancer include arsenic, asbestos, dichloromethane, t, tar, mustard gas, soot, vinyl chloride, nickel, as well as aluminum production, coal gasification, coke production, hematite smelting, and steel casting. In addition, the mortality rate of lung cancer among tin mine workers in Yunnan Province of China is as high as 300/105 or more. Tin mining and radon radiation in mines are also direct factors of lung cancer. Immune status Previous studies have shown that immune status may also have some influence on lung cancer occurrence. The results of the Norwegian study suggest that the risk of lung cancer after pneumonia is significantly higher after hospitalization and lasts for 3 years, suggesting that there may be a correlation between pneumonia and lung cancer. After several generations of hard work, the etiology of lung cancer is getting more and more researched, which will surely make more and more people away from the threat of lung cancer.