Sources of radioactive contamination are mainly natural radioactivity and artificial radioactivity.
1, natural radioactivity
Natural sources of radiation are: cosmic rays and the nuclides derived from them; natural radionuclides, such as uranium, thorium, actinium.
Uranium, thorium is an important nuclear fuel, Ra and Ac can be used as a radioactive source and radioactive standard source. Uranium, thorium, the long-lived isotopes U, U and Th are three natural radioactive decay system of the "originator" nuclide. Polonium, radon, francium, radium, actinium, thorium, protactinium and some isotopes of uranium are members of these three radioactive decay systems.
2, artificial radioactivity
Artificial sources of radiation are: nuclear fuel mineral mining, smelting, nuclear fuel processing; reactors, nuclear power plants; agriculture, industry, medicine, scientific research use of radionuclides; nuclear tests produced by fission products.
Nuclear pollution refers to the release and proliferation of radioactive substances caused by the process of nuclear energy mining, production, transportation, use and waste disposal, causing potential harm to the environment and human health. Among them, nuclear contaminated water is an important source of pollution generated in the process of nuclear energy production. Nuclear contaminated water not only affects the surrounding environment, but also poses a serious threat to human health.
Radioactive substances to avoid the method:
In daily life, radiation is widespread, but we do not have to "talk about radiation color change". We should adhere to the principle of "keep the distance, the farther the better", through a reasonable way to minimize the harm of radiation on the body.
1, learn to recognize the radiation sign away from high-intensity radiation sources
When you find the nearby "three-leaf" sign as shown in the figure below, please stay away.
Radar, TV towers, communication signal towers, high-voltage substations and other large-scale equipment in operation, will produce high-intensity electromagnetic waves, you should try to stay away. Women who work in medical institutions and are at risk of occupational exposure should receive training to raise their awareness of protection and standardize the wearing of personal protective equipment at work, etc.
2, the rational use of electronic equipment
Research has shown that the phone just dialed when the radiation is the largest, after answering the radiation quickly weakened. After the call is connected, you can wait for a few moments, and then bring the cell phone close to your ear. Long-term, continuous operation of the computer, it is recommended that every 2 hours to leave the computer, rest a few minutes. Conditional, you can also install a layer of protective screen in front of the computer screen to improve the working environment and reduce the harm of electromagnetic radiation.
3, pay attention to diet
Research shows that if the human body lacks essential fatty acids and various vitamins, may lead to the body's tolerance to radiation is reduced. Vitamin A, C, E is a good antioxidant combination. It is recommended to eat more cruciferous vegetables such as oilseed rape, mustard greens, cabbage and radish as appropriate. People who use computers more can also eat Chinese wolfberry, chrysanthemum, green tea, and other foods.