Cell phones have been in use for more than 10 years. In the early days, cell phone applications were not associated with human diseases, but in recent years cell phones have gained unprecedented widespread use, and according to the latest news released by China’s Ministry of Industry and Information Technology, cell phone users in China have exceeded one billion. With the increasing penetration of cell phones into people’s lives, there are more and more worries about cell phones. Some people have started to worry that applying cell phones close to their heads may lead to brain tumors, especially after WHO (World Health Organization) listed cell phone radiation as a risk factor for cancer last year, people have become panic about the application of cell phones and even influenced the way people use them. WHO’s conclusion is based on data from several clinical surveys, but it should be noted that only some of the survey results suggest that there may be an association between cell phone applications and brain tumors, and some other results including the famous large-scale interphone survey results show that there is no association between cell phone applications and brain tumors, and there is no direct evidence to prove that there is a causal relationship between cell phone applications and brain tumors. There is no direct evidence of causal relationship between mobile phone applications and brain tumors. However, brain tumor, especially glioma, is a catastrophic disease, so it is understandable that people dare not take any chances and would rather believe it than not. It may also be for this reason that WHO has published a risk warning for cell phone applications. Yet cell phones are such a must that do we really need to live in fear? How should we view the use of cell phones properly? Wait for further investigation by scientists or medical doctors? According to common sense, such investigations and debates may last for decades, and should we all spend these decades in panic? In fact, we can think about this issue from another perspective. First we should figure out a few questions: What is cell phone radiation? How does cell phone radiation act on human body? What is the basis of cancer generation? When we apply cell phone, the cell phone needs to transmit signal to contact with the base station, the signal emitted by the cell phone is what we often call cell phone radiation, which is actually a kind of electromagnetic radiation. Some people may not be clear about the concept of electromagnetic radiation and find it quite scary. In fact, there is a kind of electromagnetic radiation that we are in contact with every day and cannot survive without it – sunlight. Electromagnetic radiation has a certain frequency, according to the frequency of the low to high arrangement is the electric wave (including radio, television, cell phones, etc.), microwave, infrared, visible light, ultraviolet, x-ray, r-ray. The higher the frequency of electromagnetic waves, the greater the energy, the more likely to cause damage to the human body. It is now clear that higher energy ultraviolet, x-rays, and r-rays can damage human cells and cause tumor production. These radiations are also called ionizing radiations, meaning that they are so energetic that they can detach electrons from the nucleus of cells, which in living organisms can lead to DNA mutations that can produce tumors, and it has been proven that DNA damage can lead to tumor production. The lower energy electric waves, microwaves, external rays, and visible light are called non-ionizing radiation, which cannot damage the structure of cells, but can only speed up the movement of water molecules and generate heat, which is why we feel hot when exposed to the sun. In fact, scientists have calculated that a cell phone to the head of the energy transfer less than 0.125W, while the sun can transfer about 43.8W, is 380 times the cell phone, why we do not worry about the sun and worry about the cell phone? Not to mention that sunlight also contains ultraviolet radiation with ionizing effect. In fact, it is less likely that electric waves penetrate the skin and skull, and even if there is a destructive effect, it should first act on the skin to produce skin cancer, and the actual situation is that although there are more than 1 billion cell phone users in China, there is no reported case of skin cancer near the ear after applying cell phones. In fact, in our life, electromagnetic radiation similar to electric waves is everywhere, and we should not panic about electromagnetic radiation from cell phones. My beloved often asks me, how can you prove that this thing does not exist? That’s a good question, I can’t prove it, just like I can’t prove that God doesn’t exist, but we have a body of knowledge and reasoning that has been developed over thousands of years, and this knowledge has created the wonderful life we have now, and we should believe it. Therefore, in the name of knowledge, I can say that cell phone radiation is harmless to human body and you can use it without any worries. In a sense, it is as unconscionable and unbelievable for cell phone radiation to produce brain tumors as it is for sunbathing to produce brain tumors.