electromagnetic fields. Electromagnetic field

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Electromagnetic field

The electromagnetic field refers to the kind of matter that occurs around moving charges. It consists of electric as well as magnetic fields. Their existence is interconnected, since they cannot exist separately and independently of each other, because one field gives rise to another.

And now let's try to approach the topic of the electromagnetic field in more detail. From the definition, we can conclude that in the case of a change in the electric field, prerequisites for the emergence of a magnetic field appear. And since the electric field tends to change over time and cannot be called constant, the magnetic field is also variable.

When one field changes, another is generated. And no matter what the next field will be, the source will be the previous field, that is, the conductor with current, and not its original source.

And even in the case when the current is turned off in the conductor, the electromagnetic field will still not disappear anywhere, but will continue to exist and spread in space.

Properties of electromagnetic waves

Maxwell's theory. Vortex electric field

James Clerk Maxwell, a famous British physicist, wrote a work in 1857 in which he provided evidence that fields such as electric and magnetic are closely related.

According to his theory, it followed that an alternating magnetic field tends to create such a new electric field, which differs from the previous electric field created using a current source, since this new electric field is vortex.

And here we see that a vortex electric field is a field in which the lines of force are closed. That is, it should be noted that the lines of the electric field are as closed as those of the magnetic field.

From this follows the conclusion that an alternating magnetic field is capable of creating a vortex electric field, and a vortex electric field has the ability to make charges move. And as a result, we get an induction electric current. It follows from Maxwell's work that such fields as electric and magnetic closely exist with each other.

That is, a moving electric charge is necessary for the existence of a magnetic field. Well, the electric field is created due to the resting electric charge. Here such transparent interrelation exists between fields. From this we can draw another conclusion that different types of fields can be observed in different reference systems.

If we follow Maxwell's theory, then we can conclude that alternating electric and magnetic fields are not able to exist separately, because when a magnetic field changes, it generates an electric field, and a changing electric field generates a magnetic one.

Natural sources of electromagnetic fields

For a modern person, it is not a secret that electromagnetic fields, although they remain invisible to our eyes, surround us everywhere.

Natural sources of EMF include:

First, it is the permanent electric and magnetic field of the Earth.
Secondly, such sources include radio waves that transform such cosmic sources as the Sun, stars, etc.
Thirdly, these sources are also such atmospheric processes as lightning discharges, etc.

Anthropogenic (artificial) sources of electromagnetic fields

In addition to natural sources of EMF occurrence, they also arise due to anthropogenic sources. These sources include x-rays, which are used in medical institutions. They are also used to transmit information using various radio stations, mobile communication stations and also TV antennas. Yes, and the electricity that is in every outlet also forms an EMF, but it is true, at a lower frequency.

The impact of EMF on human health

Modern society currently cannot imagine its life without such benefits of civilization as the presence of various household appliances, computers, mobile communications. They, of course, make our lives easier, but they create electromagnetic fields around us. Naturally, you and I cannot see EMF, but they surround us everywhere. They are present in our homes, at work and even in transport.

We can safely say that modern man lives in a continuous electromagnetic field, which, unfortunately, has a huge impact on human health. With prolonged influence of the electromagnetic field on the human body, such unpleasant symptoms appear as chronic fatigue, irritability, sleep disturbance, attention and memory. Such prolonged exposure to EMF can cause headaches, infertility, disorders in the functioning of the nervous and cardiac systems, as well as the appearance of oncological diseases in a person.

1. Introduction. The subject of study in valeology.

3. The main sources of the electromagnetic field.

5. Methods for protecting people's health from electromagnetic exposure.

6. List of used materials and literature.

1. Introduction. The subject of study in valeology.

1.1 Introduction.

Valeology - from lat. "valeo" - "hello" - a scientific discipline that studies the individual health of a healthy person. The fundamental difference between valeology and other disciplines (in particular, from practical medicine) lies precisely in the individual approach to assessing the health of each specific subject (without taking into account general and average data for any group).

For the first time, valeology as a scientific discipline was officially registered in 1980. Its founder was the Russian scientist I. I. Brekhman, who worked at Vladivostok State University.

Currently, the new discipline is actively developing, scientific works are accumulating, and practical research is being actively conducted. Gradually, there is a transition from the status of a scientific discipline to the status of an independent science.

1.2 The subject of study in valeology.

The subject of study in valeology is the individual health of a healthy person and the factors affecting it. Also, valeology is engaged in the systematization of a healthy lifestyle, taking into account the individuality of a particular subject.

The most common definition of the concept of "health" at the moment is the definition proposed by the experts of the World Health Organization (WHO):

Health is a state of physical, mental and social well-being.

Modern valeology identifies the following main characteristics of individual health:

1. Life is the most complex manifestation of the existence of matter, which surpasses in complexity various physicochemical and bioreactions.

2. Homeostasis - a quasi-static state of life forms, characterized by variability over relatively large time periods and practical staticity - at short ones.

3. Adaptation - the property of life forms to adapt to changing conditions of existence and overload. With violations of adaptation or too sharp and radical changes in conditions, maladaptation occurs - stress.

4. Phenotype - a combination of environmental factors that affect the development of a living organism. Also, the term "phenotype" characterizes the totality of the developmental features and physiology of the organism.

5. Genotype - a combination of hereditary factors affecting the development of a living organism, which is a combination of the genetic material of the parents. When deformed genes are transmitted from parents, hereditary pathologies arise.

6. Lifestyle - a set of behavioral stereotypes and norms that characterize a particular organism.

Health (as defined by WHO).

2. Electromagnetic field, its types, characteristics and classification.

2.1 Basic definitions. Types of electromagnetic field.

An electromagnetic field is a special form of matter through which interaction between electrically charged particles is carried out.

Electric field - created by electric charges and charged particles in space. The figure shows a picture of field lines (imaginary lines used to visualize fields) of an electric field for two charged particles at rest:

Magnetic field - created when electric charges move through a conductor. The pattern of field lines for a single conductor is shown in the figure:

The physical reason for the existence of an electromagnetic field is that a time-varying electric field excites a magnetic field, and a changing magnetic field excites a vortex electric field. Continuously changing, both components support the existence of the electromagnetic field. The field of a stationary or uniformly moving particle is inextricably linked with a carrier (charged particle).

However, with the accelerated movement of carriers, the electromagnetic field “breaks away” from them and exists in the environment independently, in the form of an electromagnetic wave, without disappearing with the removal of the carrier (for example, radio waves do not disappear when the current disappears (movement of carriers - electrons) in the antenna emitting them).

2.2 Basic characteristics of the electromagnetic field.

The electric field is characterized by the strength of the electric field (designation "E", SI unit - V/m, vector). The magnetic field is characterized by the strength of the magnetic field (designation "H", SI dimension - A/m, vector). The module (length) of the vector is usually measured.

Electromagnetic waves are characterized by a wavelength (designation "(", SI dimension - m), a source emitting them - frequency (designation - "(", SI dimension - Hz). In the figure, E is the electric field strength vector, H is the magnetic field strength vector .

At frequencies of 3 - 300 Hz, the concept of magnetic induction can also be used as a characteristic of the magnetic field (designation "B", SI dimension - T).

2.3 Classification of electromagnetic fields.

The most widely used is the so-called "zonal" classification of electromagnetic fields according to the degree of remoteness from the source/carrier.

According to this classification, the electromagnetic field is divided into "near" and "far" zones. The “near” zone (sometimes called the induction zone) extends up to a distance from the source equal to 0-3 (, de (- the length of the electromagnetic wave generated by the field. In this case, the field strength decreases rapidly (proportionally to the square or cube of the distance to the source). In this zone generated electromagnetic wave is not yet fully formed.

The “far” zone is the zone of the formed electromagnetic wave. Here, the field strength decreases inversely with the distance to the source. In this zone, the experimentally determined relation between the strengths of the electric and magnetic fields is valid:

where 377 is a constant, vacuum impedance, Ohm.

Electromagnetic waves are usually classified according to frequencies:

| Extreme low, | | Hz | Decamegameter | Mm |

| Ultra-low, VLF | | Hz | Megameter | Mm |

| Very low, VLF | KHz | Myriameter | km |

| Low frequencies, LF | KHz|Kilometer | km |

| Average, midrange | | MHz | Hectometric | km |

| High, treble | | MHz | Decameter | m |

|Very high, VHF| MHz|Meter | m |

|Ultra-high, UHF| GHz | Decimeter | m |

| Ultra high, microwave | | GHz | Centimeter | cm |

| Extremely high, | | GHz|Millimeter | mm |

Usually only the electric field strength E is measured. At frequencies above 300 MHz, the energy flux density of the wave, or the Poynting vector, is sometimes measured (designation "S", SI unit - W / m2).

3. The main sources of the electromagnetic field.

The main sources of the electromagnetic field are:

Power lines.

Wiring (inside buildings and structures).

Household electrical appliances.

Personal computers.

TV and radio transmitting stations.

Satellite and cellular communications (devices, repeaters).

Electric transport.

radar installations.

3.1 Power lines (TL).

The wires of a working power line create an electromagnetic field of industrial frequency (50 Hz) in the adjacent space (at distances of the order of tens of meters from the wire). Moreover, the field strength near the line can vary over a wide range, depending on its electrical load. The standards set the boundaries of sanitary protection zones near power lines (according to SN 2971-84):

| Operating voltage | 330 and below | 500 | 750 | 1150 |

| Size | 20 | 30 | 40 | 55 |

(in fact, the boundaries of the sanitary protection zone are established along the boundary line of the maximum electric field strength, which is the most distant from the wires, equal to 1 kV / m).

3.2 Wiring.

Electrical wiring includes: power cables for building life support systems, power distribution wires, as well as branching boards, power boxes and transformers. Electrical wiring is the main source of the industrial frequency electromagnetic field in residential premises. In this case, the level of the electric field strength emitted by the source is often relatively low (does not exceed 500 V/m).

3.3 Household electrical appliances.

Sources of electromagnetic fields are all household appliances that operate using electric current. At the same time, the level of radiation varies over the widest range, depending on the model, the device device and the specific mode of operation. Also, the level of radiation strongly depends on the power consumption of the device - the higher the power, the higher the level of the electromagnetic field during the operation of the device. The electric field strength near household appliances does not exceed tens of V/m.

The table below shows the maximum allowable levels of magnetic induction for the most powerful magnetic field sources among household electrical appliances:

| Device | Limit interval | |

| | values of magnetic induction, μT |

|Coffee maker | |

| Washing machine | |

| Iron | |

| Vacuum cleaner | |

| Electric stove | |

| Lamp "fluorescent light" (fluorescent lamps LTB, | | |

| Electric drill (motor | |

| Power W) | | |

| Electric mixer (power motor | |

| W) | |

|TV | |

| Microwave oven (induction, microwave) | | |

3.4 Personal computers.

The primary source of adverse health effects for a computer user is the monitor's display device (VOD). In most modern monitors, the CBO is a cathode ray tube. The table lists the main health impacts of SVR:

| Ergonomic | Factors of influence of electromagnetic | |

| | field cathode ray tube | |

| Significant reduction in contrast | Electromagnetic field in the frequency | |

| reproduced image in the conditions | MHz range. |

| external illumination of the screen with direct beams | | |

| light. | | |

| Mirror reflection of light rays from | Electrostatic charge on the surface | |

| Cartoon character | Ultraviolet radiation (range |

| image reproduction | wavelengths nm). |

| (high-frequency continuous update | |

| Discrete nature of the image | Infrared and X-ray |

| (subdivision into points). | ionizing radiation. |

In the future, we will consider only the factors of the influence of the electromagnetic field of the cathode-ray tube as the main factors of the influence of the SVR on health.

In addition to the monitor and the system unit, a personal computer may also include a large number of other devices (such as printers, scanners, network filters, etc.). All these devices work with the use of electric current, which means that they are sources of an electromagnetic field. The following table shows the electromagnetic environment near the computer (the contribution of the monitor is not taken into account in this table, as it was discussed earlier):

| Source | Frequency range generated | |

| | electromagnetic field | |

| System unit assembly. | |. |

| Input-output devices (printers, | Hz. |

| scanners, drives, etc.). | |

| Uninterruptible power supplies, |. |

| network filters and stabilizers. | | |

The electromagnetic field of personal computers has the most complex wave and spectral composition and is difficult to measure and quantify. It has magnetic, electrostatic and radiation components (in particular, the electrostatic potential of a person sitting in front of a monitor can range from -3 to +5 V). Given the fact that personal computers are now actively used in all branches of human activity, their impact on human health is subject to careful study and control.

3.5 TV and radio transmitting stations.

A significant number of radio broadcasting stations and centers of various affiliations are currently located on the territory of Russia.

Transmitting stations and centers are located in zones specially designated for them and can occupy rather large territories (up to 1000 ha). By their structure, they include one or more technical buildings where radio transmitters are located, and antenna fields, on which up to several dozen antenna-feeder systems (AFS) are located. Each system includes a radiating antenna and a feeder line that brings the broadcast signal.

The electromagnetic field emitted by the antennas of radio broadcasting centers has a complex spectral composition and an individual distribution of strengths depending on the configuration of the antennas, the terrain and the architecture of the adjacent buildings. Some averaged data for various types of radio broadcasting centers are presented in the table:

| | field, V / m. | A / m. | |

| DV - radio | 630 | 1.2 | Highest tension |

| kHz, | | | distances less than 1 length | |

|500 kW). | | | |

|200 kW). | | | |

| HF - radio | 44 | 0.12 | Transmitters can be | |

|MHz, | | | Densely built | |

|100 kW). | | | |

| MHz, | | | building level. | |

3.6 Satellite and cellular communication.

3.6.1 Satellite communications.

Satellite communication systems consist of a transmitting station on Earth and travelers - repeaters in orbit. Transmitting satellite communication stations emit a narrowly directed wave beam, the energy flux density in which reaches hundreds of W/m. Satellite communication systems create high electromagnetic field strengths at considerable distances from antennas. For example, a station with a power of 225 kW, operating at a frequency of 2.38 GHz, creates an energy flux density of 2.8 W/m2 at a distance of 100 km. Energy dissipation relative to the main beam is very small and occurs most of all in the area of \u200b\u200bthe direct placement of the antenna.

3.6.2 Cellular communication.

Cellular radiotelephony is today one of the most intensively developing telecommunication systems. The main elements of a cellular communication system are base stations and mobile radiotelephones. Base stations maintain radio communication with mobile devices, as a result of which they are sources of an electromagnetic field. The system uses the principle of dividing the coverage area into zones, or so-called "cells", with a radius of km. The following table presents the main characteristics of cellular communication systems operating in Russia:

| | | | | Tue. | km. |

|NMT450. | |

| Analog. |5] |5] | | | |

|AMPS. |||100 |0.6 | |

|DAMPS (IS – |||50 |0.2 | |

|136). | | | | | |

|CDMA. |||100 |0.6 | |

|GSM - 900. |||40 |0.25 | |

|GSM - 1800. | |

|Digital. |0] |5] | | | |

The radiation intensity of the base station is determined by the load, that is, the presence of cell phone owners in the service area of a particular base station and their desire to use the phone for a conversation, which, in turn, fundamentally depends on the time of day, location of the station, day of the week and other factors. At night, the loading of stations is almost zero. The radiation intensity of mobile devices depends largely on the state of the communication channel "mobile radiotelephone - base station" (the greater the distance from the base station, the higher the radiation intensity of the device).

3.7 Electric transport.

Electric transport (trolleybuses, trams, subway trains, etc.) is a powerful source of electromagnetic field in the Hz frequency range. At the same time, in the overwhelming majority of cases, the traction electric motor acts as the main emitter (for trolleybuses and trams, air current collectors compete with the electric motor in terms of the strength of the radiated electric field). The table shows data on the measured value of magnetic induction for some types of electric transport:

| Mode of transport and genus | Average value | Maximum value |

| Suburban trains. | 20 | 75 |

| Electric transport with | 29 | 110 |

| DC drive | | |

| (electric cars, etc.). | | |

3.8 Radar installations.

Radar and radar installations usually have reflector-type antennas (“dishes”) and emit a narrowly directed radio beam.

Periodic movement of the antenna in space leads to spatial discontinuity of radiation. There is also a temporary discontinuity of radiation due to the cyclic operation of the radar for radiation. They operate at frequencies from 500 MHz to 15 GHz, but some special installations can operate at frequencies up to 100 GHz or more. Due to the special nature of the radiation, they can create zones with a high energy flux density (100 W/m2 or more) on the ground.

4. The influence of the electromagnetic field on individual human health.

The human body always reacts to an external electromagnetic field. Due to the different wave composition and other factors, the electromagnetic field of various sources affects human health in different ways. Therefore, in this section, the impact of various sources on health will be considered separately. However, the field of artificial sources, which is sharply dissonant with the natural electromagnetic background, in almost all cases has a negative impact on the health of people in the zone of its influence.

Extensive studies of the influence of electromagnetic fields on health were started in our country in the 60s. It was found that the human nervous system is sensitive to electromagnetic effects, and that the field has a so-called information effect when exposed to a person at intensities below the threshold value of the thermal effect (the field strength value at which its thermal effect begins to manifest itself).

The following table lists the most common complaints about the deterioration in the health of people who are in the zone of influence of the field of various sources. The sequence and numbering of sources in the table correspond to their sequence and numbering adopted in Section 3:

| Source | The most common complaints. |

| electromagnetic | |

|1. Lines | Short-term exposure (of the order of several minutes) is capable of |

| Power lines (power lines). | | lead to a negative reaction only in particularly sensitive | |

| | people or patients with certain types of allergic | |

| | various pathologies of the cardiovascular and nervous systems | |

| | (due to the imbalance of the subsystem of the nervous regulation). When |

| | ultra-long (about 10-20 years) continuous exposure | |

| | perhaps (according to unverified data) the development of some | |

| | oncological diseases. | |

|2. Internal | To date, data on complaints of deterioration | |

| electrical wiring of buildings | health, directly related to the work of internal | |

|3. Household | There are unverified data on complaints of skin, |

| | systematic use of microwave ovens old | |

| | Models (until 1995 release). | There are also similar |

| | data on the use of microwave ovens all | |

| | Models in a production environment (for example, to warm up | |

| | food in a cafe). In addition to microwave ovens, there is information about |

| | negative impact on people's health TVs in | |

| | as an imaging device cathode ray tube. | |

What is an electromagnetic field, how it affects human health and why measure it - you will learn from this article. Continuing to acquaint you with the assortment of our store, we will tell you about useful devices - indicators of the electromagnetic field strength (EMF). They can be used both in businesses and at home.

What is an electromagnetic field?

The modern world is unthinkable without household appliances, mobile phones, electricity, trams and trolleybuses, televisions and computers. We are used to them and do not think at all that any electrical device creates an electromagnetic field around itself. It is invisible, but affects any living organisms, including humans.

An electromagnetic field is a special form of matter that occurs when moving particles interact with electric charges. The electric and magnetic fields are interconnected with each other and can give rise to one another - which is why, as a rule, they are spoken of together as a single, electromagnetic field.

The main sources of electromagnetic fields include:

- power lines;
— transformer substations;
– electrical wiring, telecommunications, TV and Internet cables;
– cell towers, radio and TV towers, amplifiers, cell and satellite phone antennas, Wi-Fi routers;
— computers, TVs, displays;
- household electrical appliances;
– induction and microwave (MW) ovens;
— electric transport;
- radars.

Effect of electromagnetic fields on human health

Electromagnetic fields affect any biological organisms - plants, insects, animals, people. Scientists studying the effects of electromagnetic fields on humans have come to the conclusion that prolonged and regular exposure to electromagnetic fields can lead to:
- increased fatigue, sleep disturbances, headaches, decreased pressure, decreased heart rate;
- disorders in the immune, nervous, endocrine, sexual, hormonal, cardiovascular systems;
- the development of oncological diseases;
- the development of diseases of the central nervous system;
- allergic reactions.

EMI protection

There are sanitary standards that establish the maximum allowable levels of electromagnetic field strength depending on the time spent in the hazardous area - for residential premises, workplaces, places near sources of a strong field. If it is not possible to reduce the radiation structurally, for example, from an electromagnetic transmission line (EMF) or a cell tower, then service instructions, protective equipment for working personnel, and sanitary-quarantine restricted access zones are developed.

Various instructions regulate the time a person stays in the danger zone. Shielding nets, films, glazing, suits made of metallized fabric based on polymer fibers can reduce the intensity of electromagnetic radiation by thousands of times. At the request of GOST, EMF radiation zones are fenced off and equipped with warning signs “Do not enter, it is dangerous!” and sign of danger electromagnetic field.

Special services with the help of devices constantly monitor the level of EMF intensity at workplaces and in residential premises. You can take care of your own health by buying portable device "Impulse" or kit "Impulse" + nitrate tester "SOEKS".

Why do we need household devices for measuring the strength of the electromagnetic field?

The electromagnetic field negatively affects human health, so it is useful to know which places you visit (at home, in the office, in the garden, in the garage) can be dangerous. You must understand that an increased electromagnetic background can be created not only by your electrical appliances, telephones, televisions and computers, but also by faulty wiring, neighbors' electrical appliances, industrial facilities located nearby.

Experts have found that a short-term exposure to EMF on a person is practically harmless, but a long stay in an area with an increased electromagnetic background is dangerous. These are the zones that can be detected using devices of the "Impulse" type. So, you can check the places where you spend the most time; nursery and your bedroom; study. The device contains the values established by regulatory documents, so you can immediately assess the degree of danger to you and your loved ones. It is possible that after the examination, you decide to move the computer away from the bed, get rid of the cell phone with an amplified antenna, change the old microwave oven for a new one, replace the refrigerator door insulation with the No Frost mode.

Instruction

Take two batteries and connect them with electrical tape. Connect the batteries so that their ends are different, that is, the plus is opposite the minus and vice versa. Use paper clips to attach a wire to the end of each battery. Next, place one of the paper clips on top of the batteries. If the paperclip does not reach the center of each, you may need to straighten it to the desired length. Secure the design with tape. Make sure the ends of the wires are free and the edges of the paper clip reach the center of each battery. Connect the batteries from above, do the same on the other side.

Take copper wire. Leave about 15 centimeters of the wire straight, and then start wrapping it around the glass. Do about 10 turns. Leave straight another 15 centimeters. Connect one of the wires from the power supply to one of the free ends of the resulting copper coil. Make sure the wires are well connected to each other. When connected, the circuit gives a magnetic field. Connect the other wire of the power supply to the copper wire.

At that, when current flows through the coil, placed inside will be magnetized. Paper clips will stick together, as well as parts of a spoon or fork, screwdrivers will become magnetized and attract other metal objects while current is applied to the coil.

note

The coil may be hot. Make sure there are no flammable substances nearby and be careful not to burn your skin.

Useful advice

The most easily magnetized metal is iron. Do not select aluminum or copper when checking the field.

In order to make an electromagnetic field, you need to make its source radiate. At the same time, it must produce a combination of two fields, electric and magnetic, which can propagate in space, giving rise to each other. An electromagnetic field can propagate in space in the form of an electromagnetic wave.

You will need

- insulated wire;
- nail;
- two conductors;
- Ruhmkorff coil.

Instruction

Take insulated wire with low resistance, copper is best. Wind it on a steel core, a regular nail 100 mm long (weave) will do. Connect the wire to a power source, a regular battery will do. There will be an electric field, which generates an electric current in it.

The directional movement of the charged (electric current) will in turn generate a magnetic field, which will be concentrated in a steel core, with a wire wound around it. The core turns and is attracted to itself by ferromagnets (, nickel, cobalt, etc.). The resulting field can be called electromagnetic, because the electrical field magnetic.

To obtain a classical electromagnetic field, it is necessary that both the electric and magnetic field changed over time, then the electrical field will generate magnetic and vice versa. For this it is necessary that the moving charges receive acceleration. The easiest way to do this is to make them oscillate. Therefore, to obtain an electromagnetic field, it is enough to take a conductor and plug it into a normal household network. But it will be so small that it will not be possible to measure it with instruments.

To obtain a sufficiently powerful magnetic field, make a Hertz vibrator. To do this, take two straight identical conductors, fix them so that the gap between them is 7 mm. This will be an open oscillatory circuit, with a small electrical capacity. Attach each of the conductors to Ruhmkorf clamps (it allows you to receive high voltage pulses). Connect the circuit to the battery. Discharges will begin in the spark gap between the conductors, and the vibrator itself will become a source of an electromagnetic field.

The nature of the electromagnetic field

The electromagnetic field is a special kind of matter. It occurs around conductors along which electric charges move. The force field consists of two independent fields - magnetic and electric, which cannot exist in isolation from one another. The electric field, when it arises and changes, invariably generates a magnetic one.

One of the first to investigate the nature of variable fields in the middle of the 19th century was James Maxwell, who is credited with creating the theory of the electromagnetic field. The scientist showed that electric charges moving with acceleration create an electric field. Changing it generates a field of magnetic forces.

The source of an alternating magnetic field can be a magnet, if you set it in motion, as well as an electric charge that oscillates or moves with acceleration. If the charge moves at a constant speed, then a constant current flows through the conductor, which is characterized by a constant magnetic field. Propagating in space, the electromagnetic field carries energy, which depends on the magnitude of the current in the conductor and the frequency of the emitted waves.

The impact of the electromagnetic field on a person

The level of all electromagnetic radiations that are created by technical systems designed by man is many times higher than the natural radiation of the planet. This is a thermal effect, which can lead to overheating of body tissues and irreversible consequences. For example, prolonged use of a mobile phone, which is a source of radiation, can lead to an increase in the temperature of the brain and the lens of the eye.

Electromagnetic fields generated by the use of household appliances can cause malignant neoplasms. In particular, this applies to the children's body. Long-term presence of a person near the source of electromagnetic waves reduces the efficiency of the immune system, leads to diseases of the heart and blood vessels.

Of course, it is impossible to completely abandon the use of technical means that are the source of the electromagnetic field. But you can apply the simplest preventive measures, for example, use the phone only with a headset, do not leave appliance cords in electrical outlets after using the equipment. In everyday life, it is recommended to use extension cords and cables with protective shielding.

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