Electrical radiation is mainly electromagnetic radiation, and its principle is:

　　The electromagnetic wave generated by the alternating change of electric field and magnetic field, the phenomenon that electromagnetic wave is emitted or leaked into the air, called electromagnetic radiation. Electromagnetic radiation is a field that is invisible and intangible. The earth in which humans live is itself a large magnetic field, and its surface heat radiation and lightning can generate electromagnetic radiation, and the sun and other planets also continuously generate electromagnetic radiation from the outer space. Natural magnetic fields, sunlight, household appliances, etc. around the human body emit radiation of different intensities. Electromagnetic radiation is an external manifestation of the atoms and molecules inside a substance in motion [3].

　　Electromagnetic radiation (sometimes referred to as EMR) is in the form of self-propagating waves in a vacuum or in a substance. Electromagnetic radiation has an electric field and magnetic field component that oscillates energy in two mutually perpendicular directions. Electromagnetic radiation is divided into different types depending on frequency or wavelength. These types include (in order to increase frequency): power, radio waves, microwaves, terahertz radiation, infrared radiation, visible light, ultraviolet rays, X-rays and gamma rays. Among them, the wavelength of the radio wave is the longest and the wavelength of the gamma ray is the shortest. X-rays and gamma rays have strong ionization capabilities, and other electromagnetic radiations have relatively weak ionization capabilities.

　　Wavelength and frequency determine another characteristic of the electromagnetic field: electromagnetic waves are based on small particle photons. Photons of high-frequency (short-wavelength) electromagnetic waves carry more energy than photons of low-frequency (long-wavelength) electromagnetic waves. The energy carried by each photon of some electromagnetic waves can be as large as the ability to destroy the chemical bonds between molecules. In the electromagnetic spectrum, gamma rays, cosmic rays, and X-rays produced by radioactive materials have such characteristics and are called "ionizing radiation." An electromagnetic field in which the energy of a photon is insufficient to destroy a molecular chemical bond is called "non-ionizing radiation." Some artificial sources of electromagnetic fields that make up an important part of our modern life, such as electricity (transmission and transformation, household appliances, etc.), microwaves (microwave ovens, microwave signal transmission towers, etc.), radio waves (mobile phone mobile communications, radio and television transmission towers, etc.), At the end of the electromagnetic spectrum at relatively long wavelengths and low frequencies, their photons are incapable of destroying chemical bonds. Therefore, such electromagnetic waves are non-ionizing electromagnetic fields, which have immediate effects on the human body, similar to the influence of sound waves, and the influence of ionization on the human body is cumulative.

　　The energy derived from electromagnetic radiation depends on the frequency: the higher the frequency, the greater the energy. Extremely high X-rays and gamma rays produce large amounts of energy that can destroy molecules that make up human tissue. In fact, the energy of X-rays and gamma rays is large enough to ionize atoms and molecules, so they are classified as "ionizing" radiation. Although these two types of radiation are of medical use, excessive exposure will damage health. The electromagnetic energy generated by X-rays and gamma rays is different from the electromagnetic energy generated by RF transmitters. The electromagnetic energy of the radio frequency device belongs to the lower frequency end of the spectrum, and the chemical bond that binds the molecules together cannot be cracked, so it is classified as "non-ionizing" radiation. Where is there electromagnetic radiation? There are many sources of electromagnetic radiation. Both inside and outside the human body are covered with electrical and magnetic energy emitted by natural and artificial sources of radiation; lightning is one example of a natural source of radiation. As for artificial radiation sources, microwave ovens, radios, television broadcast transmitters, and satellite communication devices are included.

　　Electromagnetic radiation is divided into two levels, industrial frequency band radiation, and radio frequency electromagnetic waves. The electric field strength of the national standard is 4000v/m, the magnetic induction is 0.1mT; the unit of radio frequency electromagnetic wave is μW/cm2, the national standard limit is 40, and the value of the general public environmental assessment is 20%.