Radiation refers to a part of the electromagnetic energy from the source of the field out of the source of propagation to the distance, and then return to the field source of the phenomenon, the energy in the form of electromagnetic waves or particles (such as alpha particles, beta particles, etc.) to the outside of the diffusion. All objects in nature can emit electromagnetic radiation as long as their own temperature is greater than absolute zero, and there is no object in the world with a temperature equal to or lower than absolute zero. Therefore, all objects in people's neighborhood are emitting electromagnetic radiation at all times. Nonetheless, the only electromagnetic waves that are visible are those that are within the visible light frequency domain.
Electromagnetic radiation pollution: any charged body has electromagnetic radiation, when the intensity of electromagnetic radiation exceeds the national standard, it will produce negative effects, causing different lesions and hazards of the human body, this part of the radiation that exceeds the standard electromagnetic field strength is called electromagnetic radiation pollution.
Common sources of electromagnetic radiation : Generally speaking, radar systems, television, cell phone and radio transmission systems, radio frequency induction and dielectric heating equipment, radio frequency and microwave medical equipment, a variety of electro-processing equipment, communications transmission stations, satellite earth communication stations, large electric power generating stations, power transmission and transformation equipment, high-voltage and ultra-high-voltage power transmission lines, subway trains and electrical trains, and most of the household electrical appliances are Can produce various forms, different frequencies, different intensity of electromagnetic radiation sources. Any charged body has electromagnetic radiation, when the intensity of electromagnetic radiation exceeds the national standard, it will produce negative effects, causing different lesions and harm to the human body, this part of the radiation exceeding the standard electromagnetic field strength called electromagnetic radiation pollution.