Double Eleven has passed, and Double Twelve is waving. At the end of the year, the shopping festival was intense, and many mobile phone manufacturers also took advantage of this to launch new products, stimulating people's consumption enthusiasm. However, a recent test result released by the French National Frequency Authority has left some mobile phone users feeling uneasy. The bureau has detected that a well-known brand of mobile phones abroad have exceeded the radiation limit, which has once again raised the popularity of the topic of electromagnetic radiation affecting health. So, what exactly is electromagnetic radiation? Why was a certain brand of mobile phones not found to have excessive radiation levels before being launched? Will excessive electromagnetic radiation from mobile phones cause harm to the human body? With these questions in mind, a reporter from Science and Technology Daily interviewed relevant experts. Electromagnetic radiation, which is fundamentally different from ionizing radiation, is a natural phenomenon. The interaction between electric and magnetic fields generates electromagnetic waves, which emit or leak into the air. The electromagnetic radiation and ionizing radiation that people often refer to are artificially defined. In fact, both high-frequency and low-frequency radiation naturally exist on Earth, "said Zhang Chi, a member of the China Association of Popular Science Writers and a PhD in communication, in an interview with Science and Technology Daily. There is a fundamental difference between electromagnetic radiation and the color changing ionizing radiation. Ionizing radiation with high frequency and high energy can disrupt chemical bonds in the human body and affect human health. Nuclear radiation is ionizing radiation. Compared to ionizing radiation, electromagnetic radiation has a lower frequency and weaker energy, and it does not break the chemical bonds of the human body. "Zhang Chi said that if electromagnetic radiation is high enough, its heating effect will cause harm to the human body. However, in daily life, people come into contact with mobile phones, routers, base stations, etc., which have lower frequency and weaker energy, far from reaching the intensity of harm to the human body. The impact is related to the radiation level. Before the mobile phone is launched, it needs to undergo radiation testing, but the test results at that time did not exceed the standard, which does not mean that it will not exceed the standard in the future. Zhang Chi introduced that mobile phone manufacturers usually upgrade their software to increase the transmission power in order to optimize user experience, thereby enhancing the signal. This also explains why phones were found to have excessive radiation only after being launched. The key to whether electromagnetic radiation has an impact on human health is the amount of radiation. At present, there are two main national standards related to electromagnetic radiation in China. One is the national standard "Electromagnetic Environment Control Limits" (GB8702-2014) released in 2014; Another standard that is more relevant to mobile phone radiation is the "Local Exposure Limits for Electromagnetic Radiation from Mobile Phones" (GB21288-2007), which stipulates that "the average specific absorption rate (SAR) value for any 10 grams of biological tissue and any continuous 6 minutes shall not exceed 2.0 watts/kg". When formulating electromagnetic radiation related standards, the country usually sets the "red line" at a position higher than the safety value. According to the data, the "Electromagnetic Environment Control Limits" are based on the International Committee on Non Ionizing Radiation Protection standards recommended by the World Health Organization, which adopt a safety factor of more than 5 times. At the same time, Zhang Chi added that even if the radiation value of a mobile phone slightly exceeds the standard, there is no need to worry because its maximum emission power cannot reach the level of harm to the human body. Scientific reality