What are the external causes of esophageal cancer? 1.Esophageal cancer is a typical lifestyle cancer, which is related to living habits. Excessive smoking and drinking, irregular diet, unbalanced nutrition, long-term consumption of overheated, hard and irritating food can cause repeated damage, proliferation and degeneration of esophageal mucosa, which can further cause cancerous changes. 2.Long-term consumption of food contaminated by carcinogens can easily lead to esophageal cancer. The three strong carcinogens recognized worldwide are aflatoxin, benzo(a)pyrene and nitrosamines, all of which are closely related to the development of esophageal cancer. The three carcinogenic substances are not contained in food itself or their content is very small, but they are often contaminated during processing, storage, transportation and cooking. The following is a brief introduction of the three major carcinogenic substances: aflatoxin mainly exists in moldy grain, oil and peanuts, and there are more than 20 kinds, among which the strongest carcinogenic effect is aflatoxin B1, which is 75 times more toxic than nitrosamine and 68 times more toxic than arsenic. Aflatoxin is a heat-stable chemical that is not easily destroyed (cleavage temperature up to 280 ℃). People often eat fermented foods, such as tofu milk, bean paste, etc., such foods in the production process, such as improper methods, easy to produce aflatoxin. Benzo(a)pyrene is mainly produced in the combustion process of coal, oil, natural gas and other substances, fat, cholesterol, etc. can also form benzo(a)pyrene at high temperatures. It mainly enters food through the following ways: (1) Environmental pollution, soot and automobile exhaust contains a large amount of benzo(a)pyrene, through the leaves and roots into the plant body. (2) unreasonable processing methods, such as smoking and fire-roasted food, often due to the dripping of oil burning caused by food contamination. For example, the content of benzo(a)pyrene in smoked products is 60 times higher than that of ordinary meat. (3) production, processing, storage and transportation process oil contamination. Nitrosamines are commonly found in cereals, milk, meat, and drinking water. The content of nitrite is higher within foods that are not fresh. Nitrites are often added in the food processing industry as a color preservative in sausages and bacon. How to reduce the contamination of food by carcinogens? Anti-mold, avoid eating moldy food. Prevent environmental pollution, do not plant leafy vegetables and oil crops in industrial areas with serious air pollution and beside highways. Improve unreasonable smoking and fire baking process to prevent contamination by engine oil. Eat less unfresh salted meat, salted fish, shrimp skin and other foods. Eat more cruciferous plants such as cabbage and radish, which are rich in vitamin A. Take vitamin C to block the formation of nitrosamines, and garlic also has the effect of blocking nitrosamines.