We have all heard that radiation causes cancer. But radiation includes thousands of kinds, from ultraviolet rays emitted from the sun to cell phone signals are all considered radiation. Is there any basis for the rumors on the Internet that cell phone radiation causes cancer, microwave ovens cause cancer, Wi-Fi causes cancer, etc.? First of all, we need to understand that cancer occurs from genetic mutation, so if we want to determine whether radiation can cause cancer, then we need to see whether radiation can cause genetic mutation. What kind of radiation can cause genetic mutation? Radiation is divided into two major categories: ionizing radiation and non-ionizing radiation. It is worth noting that ionizing radiation is high in energy and can directly cause DNA damage and gene mutation, so it may cause cancer, while non-ionizing radiation is low in energy and not enough to directly cause gene mutation, so it is generally considered not to cause cancer. I wonder if you know which of the cell phone radiation, microwave oven radiation, high-voltage electric box radiation, Wi-Fi, etc. that appear in our lives are ionizing radiation? –Actually, none of them is! These four common types of radiation are all non-ionizing radiation. There is no conclusive evidence that they are carcinogenic, either from epidemiological studies or from laboratory animal studies. But here we would like to mention about cell phone radiation. Some people are always worried that the radiation from cell phones can cause brain tumors, because an article published in JAMA stated that although no direct relationship was found between cell phones and tumor development, among patients with brain tumors, the onset of the disease was mostly seen on the side where the cell phone was frequently used. Cell phone is an electronic product that almost everyone can’t live without in today’s society. Although there is no direct connection with tumor, prolonged use of cell phone will cause optic nerve fatigue. Using cell phone in dark environment at night before going to bed will cause large secretion of melatonin, thus affecting sleep. The above mentioned is the radiation that we can often encounter in our life and does not directly affect our health. So what kind of radiation is electric (zhi) ionizing (ai) radiation? 1, nuclear pollution: nuclear bomb explosions and nuclear leaks have caused a large number of cancer patients; 2, medical instruments: CT, PET, X-rays are sources of ionizing radiation, children should try to avoid using; 3, natural radioactive sources: nature has many radioactive elements such as: uranium (U), thorium (Th) and radium (Ra).