Not long ago, a special work-related injury case attracted attention. After a Korean Airlines flight attendant passed away due to stomach cancer, the relevant authorities in South Korea have identified this incident as a cosmic radiation work-related injury for the first time. The South Korean Labor Welfare Corporation revealed that the flight attendant flew an average of 1022 hours per year from 1995 to 2021. This incident has sparked public attention to the radiation issue of air travel. So, what is cosmic radiation? Will cosmic radiation have an impact on the human body? The reporter interviewed relevant experts on this matter. Many people's immediate reaction to exposure to radiation within a safe range during a flight is panic. In fact, radiation is just a universal concept, and its types are diverse and ubiquitous. Professor Liu Libo from the School of Public Health at Jilin University stated that the main topic discussed in daily life that may have an impact on the human body is ionizing radiation, including radiation generated by hospital CT examination equipment, X-ray machines, etc. During the flight of an aircraft, the radiation received by the personnel on board also belongs to ionizing radiation. Bian Yueyue, a senior engineer at the China Geological Museum, introduced that ionizing radiation can also be subdivided into artificial radiation and natural radiation, the latter of which is also known as background radiation. Artificial radiation mainly comes from human nuclear technology applications, such as radiation generated by CT examination equipment. And background radiation is a radiation that already exists in nature, mainly derived from cosmic rays and radioactive isotopes in the Earth's crust, and has existed on Earth for a longer time than humans. Aviation radiation is generated when cosmic rays penetrate the Earth's atmosphere. These cosmic rays typically have extremely high energy and travel through space at speeds close to the speed of light. The equatorial region receives the least cosmic radiation, while the polar regions receive the most. Due to the obstruction of the Earth's magnetic field and atmosphere, the vast majority of cosmic rays are already depleted upon reaching the surface, with minimal impact on the human body. However, the higher the altitude at which people are located, the more cosmic radiation they will receive. Research has shown that for every 2000 meters increase in aircraft altitude, the dose of cosmic radiation to the human body doubles. The unit of measurement for the dose of radiation to the human body is usually millisieverts (mSv). Bian Yueyue introduced that for people living in low altitude areas, radioactive isotopes in the crust are the main source of background radiation, which are hidden in soil, rocks, and oceans. The average background radiation in China is about 3.1 mSv. When flying at an altitude of 10000 meters above the ground, the radiation dose brought by cosmic rays is approximately 0.006mSv per hour. If taking a flight from Beijing to Shanghai, the radiation dose to passengers during the approximately 2-hour flight is only about 0.012mSV, which is completely within the safe range. In daily life, there is no need for additional protection. The National Nuclear Safety Administration has formulated the Basic Standards for Ionizing Radiation Protection and Radiation Source Safety (hereinafter referred to as the "Standards") in accordance with the relevant recommendations of the International Committee on Radiation Protection. The Standard mainly focuses on the protection against ionizing radiation in the field of nuclear science and technology, and is mainly applicable to professionals who are exposed to ionizing radiation during work. For this group of professionals, the standard stipulates that their average annual effective radiation dose for 5 consecutive years shall not exceed 20mSv, and any