1, radioactive radiation contamination into the pathway: (1) contaminated food and water ingestion: is one of the most important ways to avoid the main prevention, avoid eating contaminated seafood, do not drink desalinated water. Eat more seaweed nori and other foods containing iodine, but do not take iodine tablets at will. Treatment is required according to the doctor’s instruction, as excessive iodine can lead to iodine poisoning. (2) Polluted air inhalation: It is also one of the most important ways of environmental radioactive contamination. People who are in the contaminated area should avoid going out as much as possible and close the doors and windows. If you must go out, try to avoid a long stay, cover your mouth and nose with a wet towel, or bring a mask. The above two ways are also known as radioactive internal contamination. (3) Dust absorbed and deposited by the skin should be minimized in exposed areas, and it is especially important to wear long clothes (white is good) and neck (thyroid) areas. Bathe with soap daily. Avoid getting wet. 2.How to prevent the damage of nuclear radiation to the human body? Avoid contact with nuclear radiation, certain nutrition has a very important role in anti-radiation. Black sesame, purple amaranth, green tea, tomato red pigment, spirulina food, pollen food, ginkgo biloba products, vegetables and fruits containing more vitamin C have special effect on nuclear radiation prevention. 3.If you are within the range of radiation (nuclear contamination), what should you do? (1) immediately change a set of clothes and shoes, put them in a sealed plastic bag, close the bag, and then take a thorough and comprehensive shower; (2) in the car to keep the windows and vents closed, and use the car to circulate air; (3) indoors, close the air conditioning and other air intakes, go to a basement, and unless absolutely necessary, avoid using the telephone. 4, how much dose of radiation will produce health hazards to the human body? The natural radiation dose we receive in daily life is 2-4 mSv. A time less than 100 mSv radiation, clinically observed no change, no effect on the human body. A dose of 1000-2000 mSv may cause mild acute radiation sickness, which can generally be cured. In our daily life, we sit in an airplane for 10 hours, equivalent to receive 0.03 mSv radiation. Smoking a pack of cigarettes a day, a year down to the dose of 0.5-1 mSv. Chest, oral, limb X-ray diagnosis 0.01 mSv, breast, hip, spine, abdomen, pelvis X-ray diagnosis, head CT is 1 mSv, abdominal CT 10 mSv. Specify the maximum annual dose limit of 20 mSv for occupational personnel.