Cui Jie, Liu Junhua, Zheng Dong, Department of Radiology Diagnosis, Characteristic Medical Center (formerly 306 Hospital).
Edited by Liu Yan/Cui Yan, Medical Science Popularization Center
In occupational diseases, radioactive materials often attract much attention. In recent years, with the wide application of radioisotopes and radiation devices in various fields such as industry and agriculture, medical treatment, and scientific research, the possibility of radiation hazards has gradually increased.
What are the symptoms of contamination with radioactive material?
(1) Symptoms of acute radiation sickness: This is the earliest symptom that may appear after contamination with radioactive materials, usually appearing within a few hours to a few days after exposure. It has been recorded in the relevant literature that when the irradiation dose is greater than 1 Gy, nausea reaction will occur, when the dose is greater than 2 Gy, vomiting will occur, if frequent vomiting occurs, it means that the irradiation dose has exceeded 4 Gy, and there will be multiple vomiting in about 30 minutes, loss of appetite, and diarrhea in severe cases, which will also cause insomnia.
(2) Skin symptoms: If the exposed radioactive material is of high quality, it may cause symptoms such as blisters, redness, heat, peeling and hair loss on the skin, and in severe cases, pain and ulcers may occur.
(3) Hematologic symptoms: Because radioactive substances can destroy the hematopoietic cells in the bone marrow, it may lead to a decrease in the number of white blood cells, a decrease in immunity, and symptoms such as susceptibility to infection and bleeding. In addition to this, it may also cause symptoms such as anemia and thrombocytopenia.
(4) Nervous system symptoms: radioactive substances can cause nervous system dysfunction, resulting in functional excitement or inhibition, insomnia, dreaminess, dizziness and other symptoms.
(5) Carcinogenicity: Radioactive substances contain a large number of carcinogens, which damage DNA, which may lead to cell death or mutations, increasing the risk of cancer and other diseases.
(6) Teratogenicity: Radiation can penetrate the human body, cause physical and chemical changes in tissue cells and body fluids, and cause gene mutations and chromosomal aberrations. The embryo or fetus is highly sensitive to X-rays and various rays, and depending on the amount of irradiation and the irradiation period, it can also cause mental retardation, teratogenicity, and death.
Harm Principle
The biological effects caused by radiation are mainly through ionization that disrupt the normal functioning of biological organisms. This effect can be direct, that is, the radiation directly acts on the proteins, carbohydrates, enzymes, etc. that make up the body, causing ionization and excitation, and causing changes in the atomic structure of these substances, causing changes in the life process of the human body;
Contamination pathways
(1) inhalation, (2) ingestion, (3) penetration through the skin, (4) invasion through the wound.
Protective measures
The degree of harm caused by radiation to a biological organism is closely related to the radiation energy absorbed by the body. How can it be protected to reduce the harm of rays?
1. Basic methods of external radiation protection
(1) Strong control source. For places where radiation sources are used, it is necessary to select appropriate radiation sources and corresponding radiation devices according to the needs of the work, so as to ensure the quality of radiation and reduce unnecessary radiation components.
(2) Time protection. The longer the staff operates or comes into contact with the radioactive source, the greater the amount of radiation received by the human body, and the rotation of the staff can be increased to reduce the irradiation time of each person and reduce the radiation dose received by the body, so as to achieve the purpose of protection.
(3) Distance protection. The closer a person is to the radiation source, the greater the amount of illumination. It has been experimentally proved that the irradiation rate caused by the point source is inversely doubled by the square of the distance from the source, and the irradiation rate will be one-fourth of the original one, so it should be operated at a long distance to reduce the effects of radiation on the human body.
(4) Shielding protection. Shielding protection is based on the principle that the ionizing radiation of the radiation source is weakened when it passes through the substance, and a suitable shielding material is placed between the radioactive source and the human body, and the absorption of radiation by the shielding material is used to reduce the external radiation dose, so as to reduce the radiation exposure to the human body.
(5) α, β, γ radiation protection. (1) Protection against α rays. Due to the weak penetration of α rays and the short range, they can be absorbed with a few pieces of paper or a thin aluminum film, or use closed gloves to avoid entering the human surface and body bones to cause radiation, mainly to prevent inhalation of polluted air and ingestion of polluted things, and to prevent skin and wounds from being polluted. (2) Protection against β rays. β rays have stronger penetration than α rays, but they are easier to shield, and materials with low atomic number, such as aluminum, plexiglass, and alkene-based plastics, are commonly used. The penetration of β rays is stronger than that of α rays and weaker than that of γ rays, and shielding measures should be strengthened on the basis of α ray protection if necessary. (3) Protection against γ rays. γ rays are very penetrating and extremely harmful, and are often shielded by high-density substances. Considering economic factors, materials such as iron, lead, cement, and water are commonly used. γ rays should be exposed to reduce the irradiation time, increase the radiation distance, and take shielding measures.
2. Basic methods of internal radiation protection
(1) Prevent respiratory absorption. Gas radionuclides can be absorbed by the respiratory tract into the human body, and the absorption rate is proportional to the solubility of the radionuclide. Depending on the characteristics of the radiation source, choose the appropriate protective equipment to avoid inhaling dust, gases or fumes containing radioactive materials.
(2) Prevent gastrointestinal absorption. Food and water contaminated with radionuclides enter the human body through the gastrointestinal tract through the mouth, and the absorption rate depends on the chemical characteristics of the radionuclides. Pay attention to food hygiene and avoid eating food or liquids containing radioactive materials.
(3) Prevent skin penetration. Wash your hands before and after handling radioactive materials and ensure thorough hygiene of your hands and body. Clean the workplace and equipment regularly, including body protective equipment.
(4) Prevent absorption by wounds. Some radionuclides can enter the human body through intact skin, and the absorption rate increases slowly over time, when there is a wound on the skin, the absorption rate will increase dozens of times, and the wound is stained and difficult to heal.
In general, if you have symptoms and the possibility of exposure to radioactive materials, you should seek medical attention as soon as possible and avoid contact with others as much as possible to reduce the risk of radiation exposure.
(The picture comes from the Internet)