The concentration of acetaldehyde in the blood increases more than six times after drinking alcohol. Long-term alcohol abuse leads to the accumulation of acetaldehyde in the body, which may eventually lead to the development of liver cancer. The risk of liver cancer is 3.51 times higher for those who drink more than 3 kg (60 taels) of alcohol per month than for those who are normal gene carriers and do not drink alcohol. The relationship between viral hepatitis and liver cancer is mainly between hepatitis B and C, i.e. HBV and HCV. about 1/3 of patients with liver cancer have a history of chronic hepatitis, and hepatitis C virus infection has been found to be as closely related to liver cancer development as hepatitis B infection, and hepatitis B virus and hepatitis C virus are definitely one of the cancer-promoting factors. About 50%-90% of liver cancer patients have cirrhosis in combination. In recent years, it has been found that the proportion of viral hepatitis C developing into cirrhosis is no less than that of hepatitis B. Animal experiments have shown that aflatoxin B1, a metabolite of aflatoxin, has a strong carcinogenic effect and is present in moldy corn, peanuts and other foods, and the incidence of liver cancer is higher in areas where food is heavily contaminated with aflatoxin B1. Nitrosamines, azo mustards, alcohol, organochlorine pesticides, etc. are all suspected carcinogens. Some drinking water is often contaminated by PCBs and chloroform, etc. In recent years, blue-green algae growing in ponds have been found to be strong carcinogenic plants, which can contaminate water sources. Parasitic diseases such as Toxoplasma gondii infection can stimulate bile duct epithelial proliferation, which can lead to primary bile duct cancer.