Everywhere we are surrounded by electromagnetic fields. Depending on their wavelength range, they can act differently on living organisms. Non-ionizing radiation is considered more sparing, but they are sometimes unsafe. What are these phenomena, and what effect do they have on our body?
What are non-ionizing radiation?
Energy is distributed in the form of small particles and waves. The process of its emission and propagation is called radiation. By the nature of the impact on objects and living tissues, two main types are distinguished. The first - ionizing, is a stream of elementary particles that are formed as a result of fission of atoms. It includes radioactive, alpha, beta, gamma, x-ray, gravitational radiation and Hawking rays.
The second type of radiation includes non-ionizing radiation. In fact, these are electromagnetic waves, the length of which is more than 1000 nm, and the amount of released energy is less than 10 keV. It acts in the form of microwaves, resulting in the release of light and heat.
Unlike the first type, this radiation does not ionize the molecules and atoms of the substance it affects, that is, it does not break the bonds between its molecules. Of course, there are some exceptions. Thus, certain species, for example, UV rays, can ionize a substance.
Types of non-ionizing radiation
Electromagnetic radiation is a much broader concept than non-ionizing. High-frequency x-rays and gamma rays are also electromagnetic, but they are more rigid and ionize the substance. All other types of EMP are non-ionizing; their energy is not enough to interfere with the structure of matter.
The greatest length among them is possessed by radio waves, whose range varies from ultra-long (more than 10 km) to ultra-short (10 m - 1 mm). The waves of the remaining EM radiation are less than 1 mm. After radio emission is infrared or thermal, the wavelength of it depends on the temperature of heating.
Non-ionizing are also visible light and ultraviolet radiation. The first is often called optical. With its spectrum, it is very close to infrared rays and is formed when bodies are heated. Ultraviolet radiation is close to x-ray, therefore, it may have the ability to ionize. At a wavelength of 400 to 315 nm, it is recognized by the human eye.
Sources
Non-ionizing electromagnetic radiation can be of either natural or artificial origin. One of the main natural sources is the sun. It sends all kinds of radiation. Their full penetration on our planet is hindered by the earth's atmosphere. Thanks to the ozone layer, humidity, carbon dioxide, the effect of harmful rays is greatly softened.
For radio waves, lightning, as well as space objects, can serve as a natural source. Thermal infrared rays can be emitted by any body heated to the desired temperature, although the main radiation comes from artificial objects. So, its main sources are heaters, burners and ordinary incandescent bulbs, which are present in every house.
Radio waves are transmitted through any electrical conductors. Therefore, all electrical appliances, as well as devices for radio communications, for example, mobile phones, satellites, etc., become an artificial source. Ultraviolet rays propagate special fluorescent, mercury-quartz lamps, LEDs, and excilamps.
Human impact
Electromagnetic radiation is characterized by wavelength, frequency and polarization. The strength of its influence depends on all these criteria. The longer the wave, the less energy it transfers to the object, which means it is less harmful. Radiation in the decimeter-centimeter range is most destructive.
Non-ionizing radiation with prolonged exposure to humans can cause harm to health, although in moderate doses they can be useful. Ultraviolet rays can cause burns to the skin and eye cornea, cause various mutations. And in medicine with their help they synthesize vitamin D3 in the skin, sterilize equipment, disinfect water and air.
In medicine, infrared radiation is used to improve metabolism and stimulate blood circulation, disinfect food products. With excessive heating, this radiation can severely dry out the mucous membrane of the eye, and at maximum power, even destroy the DNA molecule.
Radio waves are used for mobile and radio communications, navigation systems, television and other purposes. The constant action of radio frequencies emanating from household appliances can increase the excitability of the nervous system, impair brain function, and adversely affect the cardiovascular system and reproductive function.