In recent years, there has been much talk about the health effects of radiation. Many members of the public are concerned about the health effects of even low doses of radiation, especially for young people who are preparing to become mothers or fathers, and are worried about the effects of such low doses of radiation on future generations. In fact, after understanding the types and sources of radiation and the radiation protection measures taken by medical institutions in accordance with the law, you will find that radiation may not be as scary as you think. 1. What is ionizing radiation? The process of releasing one or more electrons from an atom, molecule or other bound state to form ions is called ionizing radiation. In a broader sense, light, electromagnetism, high frequency, etc. also belong to radiation, except that they are non-ionizing radiation. Types of ionizing radiation include α radiation, β radiation, γ radiation. x-ray radiation belongs to γ radiation, this radiation can spread a long distance in the air, and the penetrating force is very strong, but in some high atomic number of substances in the penetration weakened, so the commonly used lead plate, concrete block wall as a shielding material for x-ray radiation. Hospitals in the imaging section of the equipment room walls, doors and windows design, should be in line with the requirements of radiation protection regulations and in the qualification institutions tested and qualified before use. 2, sources of ionizing radiation. Many people may not realize that human beings from the day they came to Earth (including in the mother) will inevitably receive a variety of radiation, from within the Earth as well as the Earth’s external exposure to natural radiation, exposure to radiation from outer space known as cosmic radiation. Radiation is also produced by food, drinking water, and building materials associated with life. Of course, the doses of all these natural radiations are very weak, and there is no evidence that these low-dose radiations have any effect on human health. 3. Radiation protection measures taken by medical institutions in accordance with the law. It has long been recognized that large doses of ionizing radiation can damage human tissues. For this reason, the International Radiation Protection Organization (IRPO), which was gradually formed after 1928, formulated the basic principles of radiation protection aimed at avoiding radiation damage to human beings. The limits of the annual radiation doses received by members of the general public are set out in the Basic Program of Radiation Protection. When medical institutions use radiation for examination and treatment, they must firstly ensure that their actions are justified, i.e. whether the examination and treatment are necessary, and secondly ensure that the dose of radiation used is the lowest possible given the purpose of the medical act. It should be noted in particular that the radiation dose received during an examination or treatment in a hospital is not included in the limit of the annual radiation dose received by members of the general public on the grounds that the person concerned receives a direct benefit from the medical act, without which radiotherapy would be difficult to administer. Of course, medical institutions use a variety of methods to reduce the radiation dose to the person being examined, including the rationalization of the conditions of the parameters that produce radiation, the use of various shielding substances inside and outside the machine, and so on. Thanks to advances in equipment and the attention paid by radiation workers, the radiation dose received by the examinee under the same examination items is on the decline, for example, the radiation dose received during a chest X-ray examination is the same as that received during a one-hour flight in an airplane at an altitude of 8,000 meters, or the same as that received when watching television for one hour a day for one year. There is also an argument that there are now more opportunities for radiological examinations than before and that the radiation dose received has increased as a result. This argument is valid, but there are both benefits and risks in all aspects of daily life. For example, the popularization of family cars has facilitated people’s lives but brought the risk of traffic accidents, and cell phones and the Internet have facilitated the exchange of information but brought the risk of privacy and the leakage of electromagnetic radiation. On the other hand, it seems that we should also see that, along with the popularization of all kinds of medical examinations (including those with medical radiation), the quality of human life is improving and the life expectancy of human beings is increasing. It is believed that, as long as they are used rationally, the benefits associated with radiation protection will outweigh the risks.