Electromagnetic radiation is a disturbance of an electric field and a magnetic field that propagates in space.
Electromagnetic radiation can propagate in a vacuum, such as interplanetary space, in less dense media, such as the atmosphere, or in guide structures, such as wave guides.
Gamma radiation is a type of very high frequency electromagnetic radiation. Gamma radiation is generally produced by radioactive elements or subatomic processes or by astrophysical phenomena.
What Are the Types of Electromagnetic Radiation?
The range of all possible electromagnetic radiation is what is known as the electromagnetic spectrum. The different types of electromagnetic radiation that can form an electromagnetic spectrum are:
Infrared radiation (or thermal radiation).
Visible light (or visible spectrum).
Ultraviolet radiation .
Characteristics of Electromagnetic Radiation
The three characteristics that determine electromagnetic radiation are frequency, electromagnetic wavelength, and polarization.
The wavelength is directly related to the frequency through the speed of propagation (group) of the radiation. The group propagation speed of electromagnetic radiation in a vacuum is equal to the speed of light, in other environments this speed is lower.
High-energy physics deals with hard electromagnetic radiation at the short-wave end of the spectrum. According to modern concepts, at high energies electrodynamics ceases to be independent, combining into a theory with weak interactions and then at even higher energies, as expected, with all other fields of measurement.
There are theories that differ in details and degrees of generality, which allows modeling and studying the properties and manifestations of electromagnetic radiation. The most fundamental of the complete and verified theories of this type is quantum electrodynamics.
Some characteristics of electromagnetic waves from the point of view of the theory of oscillations and the concepts of electrodynamics are:
The presence of three mutually perpendicular vectors (in vacuum): wave vector, electric field vector E and magnetic field vector of intensity H.
Electromagnetic waves are transverse waves in which the electric and magnetic field force vectors oscillate perpendicular to the direction of propagation of the wave, but differ significantly from water and sound waves in that they can be transmitted from a source to a receiver. even through a void.
What Are the Effects of Electromagnetic Radiation on Human Health?
The effects of electromagnetic radiation on living beings depend mainly on two main factors:
the frequency of radiation
the type of radiation exposure (intensity of radiation, duration of exposure, part of the body exposed, etc.)
The amount of radiation absorbed is measured in grays, one gray corresponds to the absorption of one joule of energy radiated by one kilogram of matter. Another unit of measurement used in the field of nuclear energy is the sievert.
Regarding the frequency of radiation, it tends to differentiate between ionizing and non- ionizing radiation.
Ionizing Radiation: What Is It and What Effects Does It Have?
Ionizing radiations are those that have a frequency high enough to ionize the atoms or molecules of the exposed substances.
This type of radiation is capable of modifying the chemical structure of the substances on which they affect and can produce long-term biological effects on living beings. An example of this alteration would be the modification of the DNA of cells that can lead to cancer.
As a curiosity, Hisashi Ouchi, the man who has received the highest dose of ionizing radiation in the world, received between 10 and 20 Sieverts.
X-rays and gamma radiation would be two examples of highly ionizing electromagnetic radiation.
Non-ionizing Radiation: What Is It and What Effects Does It Have?
Non-ionizing radiations are those that do not have sufficient frequency to cause ionization of the exposed materials.
Examples of non-ionizing radiation include microwaves or radio waves. This type of radiation does not have enough energy to directly cause DNA mutations and therefore probably cannot initiate carcinogenesis but could be promoters.
From the point of view of its effects on health, non-ionizing radiation can be classified into three large groups:
Low Frequency Electromagnetic Fields (ELF): 3 to 30,000 Hz range).
Radio frequency and microwave fields: 30 kHz - 300 GHz range.
Optical radiation: from infrared light to ultraviolet light.
Uses and Applications of Electromagnetic Radiation
In general, two macro families of applications can be distinguished:
Information transport (radio communications such as radio, television, mobile phones, artificial satellites, radars, x-rays)
Transport of energy, such as the microwave oven.