All atoms in an excited state are capable of emitting electromagnetic waves. To do this, they need to go to the ground state, in which they internal energy acquires . The process of such a transition is accompanied by the emission of an electromagnetic wave. Depending on the length, it has different properties. There are several types of such radiation.

Visible light

The wavelength is the shortest distance between the surface equal phases. Visible light is electromagnetic waves that can be perceived by the human eye. Light wavelengths range from 340 (violet light) to 760 nanometers (red light). The human eye perceives the yellow-green region of the spectrum best.

Infrared radiation

Everything that surrounds a person, including himself, are sources of infrared or thermal radiation(wavelength up to 0.5 mm). Atoms emit electromagnetic waves in this range when they collide chaotically with each other. With each collision, their kinetic energy turns into thermal energy. The atom gets excited and emits waves in the infrared range.

Only a small portion of infrared radiation reaches the Earth's surface from the Sun. Up to 80% is absorbed by air molecules and especially carbon dioxide which causes the greenhouse effect.

Ultraviolet radiation

The wavelength of ultraviolet radiation is much shorter than that of infrared radiation. The sun's spectrum also contains an ultraviolet component, but it is blocked ozone layer The earth does not even reach its surface. Such radiation is very harmful to all living organisms.

The length of ultraviolet radiation lies in the region from 10 to 740 nanometers. That small fraction of it that reaches the surface of the Earth along with visible light causes people to tan, like defensive reaction skin to harmful effects.

Radio waves

Using radio waves up to 1.5 km long, information can be transmitted. This is used in radios and television. Such a long length allows them to bend around the surface of the Earth. The shortest radio waves can be reflected from upper layers atmosphere and reach stations located on opposite side globe.

Gamma rays

Gamma rays are classified as particularly hard ultraviolet radiation. They are formed during an explosion atomic bomb, as well as during processes occurring on the surface of stars. This radiation is harmful to living organisms, but the Earth’s magnetosphere does not allow them to pass through. Gamma ray photons have ultra-high energies.

Ionizing radiation (hereinafter referred to as IR) is radiation whose interaction with matter leads to the ionization of atoms and molecules, i.e. this interaction leads to the excitation of the atom and the removal of individual electrons (negatively charged particles) from atomic shells. As a result, deprived of one or more electrons, the atom turns into a positively charged ion - primary ionization occurs. II includes electromagnetic radiation (gamma radiation) and flows of charged and neutral particles - corpuscular radiation (alpha radiation, beta radiation, and neutron radiation).

Alpha radiation refers to corpuscular radiation. This is a stream of heavy positively charged alpha particles (nuclei of helium atoms) resulting from the decay of atoms of heavy elements such as uranium, radium and thorium. Since the particles are heavy, the range of alpha particles in a substance (that is, the path along which they produce ionization) turns out to be very short: hundredths of a millimeter in biological media, 2.5-8 cm in air. Thus, a regular sheet of paper or the outer dead layer of skin can trap these particles.

However, substances that emit alpha particles are long-lived. As a result of such substances entering the body with food, air or through wounds, they are carried throughout the body by the bloodstream, deposited in organs responsible for metabolism and protection of the body (for example, the spleen or lymph nodes), thus causing internal irradiation of the body . The danger of such internal irradiation of the body is high, because these alpha particles create very big number ions (up to several thousand pairs of ions per 1 micron path in tissues). Ionization, in turn, determines a number of features of those chemical reactions, which occur in matter, in particular in living tissue (formation of strong oxidizing agents, free hydrogen and oxygen, etc.).

Beta radiation(beta rays, or stream of beta particles) also refers to the corpuscular type of radiation. This is a stream of electrons (β- radiation, or, most often, just β-radiation) or positrons (β+ radiation) emitted during the radioactive beta decay of the nuclei of certain atoms. Electrons or positrons are produced in the nucleus when a neutron converts to a proton or a proton to a neutron, respectively.

Electrons are significantly smaller than alpha particles and can penetrate 10-15 centimeters deep into a substance (body) (cf. hundredths of a millimeter for alpha particles). When passing through matter, beta radiation interacts with the electrons and nuclei of its atoms, expending its energy on this and slowing down the movement until it stops completely. Due to these properties, to protect against beta radiation, it is enough to have an organic glass screen of appropriate thickness. The use of beta radiation in medicine for superficial, interstitial and intracavitary radiation therapy is based on these same properties.

Neutron radiation- another type of corpuscular type of radiation. Neutron radiation is a flow of neutrons (elementary particles that do not have electric charge). Neutrons have no effect ionizing action, however very significant ionizing effect occurs due to elastic and inelastic scattering on the nuclei of matter.

Substances irradiated by neutrons can acquire radioactive properties, that is, receiving so-called induced radioactivity. Neutron radiation is generated during the operation of particle accelerators, in nuclear reactors, industrial and laboratory installations, with nuclear explosions etc. Neutron radiation has the greatest penetrating power. The best materials for protection against neutron radiation are hydrogen-containing materials.

Gamma rays and x-rays belong to electromagnetic radiation.

The fundamental difference between these two types of radiation lies in the mechanism of their occurrence. X-ray radiation is of extranuclear origin, gamma radiation is a product of nuclear decay.

X-ray radiation was discovered in 1895 by the physicist Roentgen. This is invisible radiation capable of penetrating, although varying degrees, in all substances. It is electromagnetic radiation with a wavelength of the order of - from 10 -12 to 10 -7. The source of X-rays is an X-ray tube, some radionuclides (for example, beta emitters), accelerators and electron storage devices (synchrotron radiation).

The X-ray tube has two electrodes - the cathode and the anode (negative and positive electrodes, respectively). When the cathode is heated, electron emission occurs (the phenomenon of the emission of electrons by the surface solid or liquid). Electrons escaping from the cathode are accelerated electric field and hit the surface of the anode, where they are sharply decelerated, resulting in the generation of X-ray radiation. Like visible light, X-ray radiation causes blackening of photographic film. This is one of its properties, fundamental for medicine - that it is penetrating radiation and, accordingly, the patient can be illuminated with its help, and since tissues of different densities absorb x-rays differently - we can diagnose this on our own early stage many types of diseases of internal organs.

Gamma radiation is of intranuclear origin. It occurs during the decay of radioactive nuclei, the transition of nuclei from an excited state to the ground state, during the interaction of fast charged particles with matter, the annihilation of electron-positron pairs, etc.

The high penetrating power of gamma radiation is explained by its short wavelength. To weaken the flow of gamma radiation, substances with a significant mass number (lead, tungsten, uranium, etc.) and various compositions are used high density(various concretes with metal fillers).

Radioactivity was discovered in 1896 by the French scientist Antoine Henri Becquerel while studying the luminescence of uranium salts. It turned out that uranium salts, without external influence (spontaneously), emitted radiation of an unknown nature, which illuminated photographic plates isolated from light, ionized the air, penetrated through thin metal plates, and caused luminescence of a number of substances. Substances containing polonium 21084Po and radium 226 88Ra had the same property.

Even earlier, in 1985, X-rays were accidentally discovered by the German physicist Wilhelm Roentgen. Marie Curie coined the word "radioactivity".

Radioactivity is a spontaneous transformation (decay) of the nucleus of an atom of a chemical element, leading to a change in its atomic number or a change in mass number. With this transformation of the nucleus, radioactive radiation is emitted.

There is a distinction between natural and artificial radioactivity. Natural radioactivity is the radioactivity observed in unstable isotopes existing in nature. Artificial radioactivity is the radioactivity of isotopes obtained as a result of nuclear reactions.

There are several types radioactive radiation, differing in energy and penetrating ability, which have different effects on the tissues of a living organism.

Alpha radiation is a stream of positively charged particles, each of which consists of two protons and two neutrons. The penetrating ability of this type of radiation is low. It is retained by a few centimeters of air, several sheets of paper, and ordinary clothing. Alpha radiation can be dangerous to the eyes. It is virtually unable to penetrate the outer layer of skin and does not pose a danger until radionuclides emitting alpha particles enter the body through an open wound, food or inhaled air - then they can become extremely dangerous. As a result of irradiation with relatively heavy, positively charged alpha particles, serious damage to the cells and tissues of living organisms can occur over a certain period of time.

Beta radiation is a stream of negatively charged electrons moving at enormous speed, the size and mass of which are much smaller than alpha particles. This radiation has greater penetrating power compared to alpha radiation. You can protect yourself from it with a thin sheet of metal such as aluminum or a layer of wood 1.25 cm thick. If a person is not wearing thick clothing, beta particles can penetrate the skin to a depth of several millimeters. If the body is not covered with clothing, beta radiation can damage the skin; it passes into the body tissue to a depth of 1-2 centimeters.

Gamma radiation, like X-rays, it is electromagnetic radiation of ultra-high energies. This is radiation of very short wavelengths and very high frequencies. Anyone who has undergone a medical examination is familiar with X-rays. Gamma radiation has a high penetrating ability; you can only protect yourself from it with a thick layer of lead or concrete. X-rays and gamma rays do not carry an electrical charge. They can damage any organs.

All types of radioactive radiation cannot be seen, felt or heard. Radiation has no color, no taste, no smell. The rate of decay of radionuclides practically cannot be changed by known chemical, physical, biological and other methods. The more energy radiation transmits to tissues, the more damage it will cause in the body. The amount of energy transferred to the body is called dose. The body can receive a radiation dose from any type of radiation, including radioactive. In this case, radionuclides can be located outside the body or inside it. The amount of radiation energy that is absorbed per unit mass of the irradiated body is called the absorbed dose and is measured in the SI system in grays (Gy).

For the same absorbed dose, alpha radiation is much more dangerous than beta and gamma radiation. Impact level various types radiation per person is assessed using such a characteristic as equivalent dose. damage body tissues in various ways. In the SI system it is measured in units called sieverts (Sv).

Radioactive decay is the natural radioactive transformation of nuclei that occurs spontaneously. The nucleus undergoing radioactive decay is called the mother nucleus; the resulting daughter nucleus, as a rule, turns out to be excited, and its transition to the ground state is accompanied by the emission of a γ photon. That. Gamma radiation is the main form of reducing the energy of excited products of radioactive transformations.

Alpha decay. β-rays are a flux of helium He nuclei. Alpha decay is accompanied by the departure of an alpha particle (He) from the nucleus, which initially transforms into the nucleus of an atom of a new chemical element, the charge of which is 2 less and the mass number is 4 units less.

The speeds at which α-particles (i.e., He nuclei) fly out of the decaying nucleus are very high (~106 m/s).

Flying through matter, an α-particle gradually loses its energy, spending it on ionizing the molecules of the substance, and eventually stops. An alpha particle forms approximately 106 pairs of ions on its path per 1 cm of path.

The greater the density of the substance, the shorter the range of α-particles before stopping. In air at normal pressure, the range is several cm, in water, in human tissues (muscles, blood, lymph) 0.1-0.15 mm. α-particles are completely blocked by an ordinary piece of paper.

α-particles are not very dangerous in case of external irradiation, because may be delayed by clothing and rubber. But α-particles are very dangerous when they enter the human body, due to the high density of ionization they produce. Damage occurring in tissues is not reversible.

Beta decay comes in three varieties. The first - the nucleus, which has undergone a transformation, emits an electron, the second - a positron, the third - is called electron capture (e-capture), the nucleus absorbs one of the electrons.

The third type of decay (electron capture) is when a nucleus absorbs one of the electrons of its atom, as a result of which one of the protons turns into a neutron, emitting a neutrino:

The speed of movement of β-particles in a vacuum is 0.3 – 0.99 the speed of light. They are faster than alpha particles, fly through oncoming atoms and interact with them. β-particles have a lesser ionization effect (50-100 pairs of ions per 1 cm of path in the air) and when a β-particle enters the body, they are less dangerous than α-particles. However, the penetrating ability of β-particles is high (from 10 cm to 25 m and up to 17.5 mm in biological tissues).

Gamma radiation is electromagnetic radiation emitted by atomic nuclei during radioactive transformations, which propagates in a vacuum at a constant speed of 300,000 km/s. This radiation usually accompanies β-decay and, less frequently, α-decay.

γ-rays are similar to X-rays, but have much higher energy (at a shorter wavelength). γ-rays, being electrically neutral, are not deflected in magnetic and electric fields. In matter and vacuum, they propagate rectilinearly and evenly in all directions from the source, without causing direct ionization; when moving in the medium, they knock out electrons, transferring to them part or all of their energy, which produce the ionization process. For 1 cm of travel, γ-rays form 1-2 pairs of ions. In the air they travel from several hundred meters and even kilometers, in concrete - 25 cm, in lead - up to 5 cm, in water - tens of meters, and they penetrate through living organisms.

γ-rays pose a significant danger to living organisms as a source of external radiation.

Types of ionizing radiation

Ionizing radiation (IR) - flows of elementary particles (electrons, positrons, protons, neutrons) and quanta of electromagnetic energy, the passage of which through a substance leads to ionization (formation of oppositely polar ions) and excitation of its atoms and molecules. Ionization - transformation of neutral atoms or molecules into electrically charged particles - ions. cosmic rays, arise as a result of the radioactive decay of atomic nuclei (απ β-particles, γ- and X-rays), are created artificially at charged particle accelerators. Of practical interest are the most common types of IR - fluxes of a- and β-particles, γ-radiation, X-rays and neutron fluxes.

Alpha radiation(a) – flow of positively charged particles – helium nuclei. Currently, more than 120 artificial and natural alpha radioactive nuclei are known, which, when emitting an alpha particle, lose 2 protons and 2 neutrons. The speed of particles during decay is 20 thousand km/s. At the same time, α-particles have the lowest penetrating ability; their path length (the distance from the source to absorption) in the body is 0.05 mm, in air - 8–10 cm. They cannot even pass through a sheet of paper, but the ionization density per unit The range is very large (by 1 cm up to tens of thousands of pairs), so these particles have the greatest ionizing ability and are dangerous inside the body.

Beta radiation(β) – flow of negatively charged particles. Currently, about 900 beta radioactive isotopes are known. The mass of β-particles is several tens of thousands of times less than α-particles, but they have greater penetrating power. Their speed is 200–300 thousand km/s. The path length of the flow from the source in air is 1800 cm, in human tissue - 2.5 cm. β-particles are completely retained hard materials(3.5 mm aluminum plate, organic glass); their ionizing ability is 1000 times less than that of α particles.

Gamma radiation(γ) – electromagnetic radiation with a wavelength from 1 · 10 -7 m to 1 · 10 -14 m; emitted when fast electrons in a substance decelerate. It occurs during the decay of most radioactive substances and has great penetrating power; travels at the speed of light. In electric and magnetic fields, γ-rays are not deflected. This radiation has a lower ionizing ability than a- and beta-radiation, since the ionization density per unit length is very low.

X-ray radiation can be obtained in special X-ray tubes, in electron accelerators, during the deceleration of fast electrons in matter and during the transition of electrons from external electronic shells atom to internal ones when ions are created. X-rays, like γ-radiation, have a low ionizing ability, but a large penetration depth.

Neutrons - elementary particles atomic nucleus, their mass is 4 times less than the mass of α-particles. Their life time is about 16 minutes. Neutrons have no electrical charge. Run length slow neutrons in the air is about 15 m, in biological environment– 3 cm; for fast neutrons - 120 m and 10 cm, respectively. The latter have high penetrating ability and pose the greatest danger.

There are two types of ionizing radiation:

Corpuscular, consisting of particles with a rest mass different from zero (α-, β– and neutron radiation);

Electromagnetic (γ- and X-ray radiation) - with a very short wavelength.

To assess the impact ionizing radiation For any substances and living organisms, special quantities are used - radiation doses. The main characteristic of the interaction of ionizing radiation and the environment is the ionization effect. IN initial period development of radiation dosimetry most often had to deal with x-ray radiation, spreading in the air. Therefore, the degree of ionization of the air in X-ray tubes or devices was used as a quantitative measure of the radiation field. A quantitative measure based on the amount of ionization of dry air at normal atmospheric pressure, which is fairly easy to measure, is called the exposure dose.

Exposure dose defines the ionizing power of X-rays and γ-rays and expresses the radiation energy converted into kinetic energy charged particles per unit mass atmospheric air. Exposure dose is the ratio of the total charge of all ions of the same sign in an elementary volume of air to the mass of air in this volume. The SI unit of exposure dose is the coulomb divided by kilogram (C/kg). The non-systemic unit is the roentgen (R). 1 C/kg = 3880 R. When expanding the circle known species ionizing radiation and the spheres of its application, it turned out that the measure of the impact of ionizing radiation on a substance cannot be measured simple definition due to the complexity and diversity of the processes occurring in this case. The most important of them, giving rise to physicochemical changes in the irradiated substance and leading to a certain radiation effect, is the absorption of the energy of ionizing radiation by the substance. As a result, the concept of absorbed dose arose.

Absorbed dose shows how much radiation energy is absorbed per unit mass of any irradiated substance, and is determined by the ratio of the absorbed energy of ionizing radiation to the mass of the substance. The unit of measurement of absorbed dose in the SI system is the gray (Gy). 1 Gy is the dose at which 1 J of ionizing radiation energy is transferred to a mass of 1 kg. The extrasystemic unit of absorbed dose is the rad. 1 Gy = 100 rad. The study of individual consequences of irradiation of living tissues showed that with the same absorbed doses, different types of radiation produce different biological effect on the body. This is due to the fact that a heavier particle (for example, a proton) produces more ions per unit path in the tissue than a lighter particle (for example, an electron). For the same absorbed dose, the higher the radiobiological destructive effect, the denser the ionization created by the radiation. To take this effect into account, the concept of equivalent dose was introduced.

Equivalent dose is calculated by multiplying the value of the absorbed dose by a special coefficient - the coefficient of relative biological effectiveness (RBE) or quality coefficient. The coefficient values ​​for various types of radiation are given in table. 7.

Table 7

Relative biological effectiveness coefficient for various types of radiation

The SI unit of dose equivalent is the sievert (Sv). The value of 1 Sv is equal to the equivalent dose of any type of radiation absorbed in 1 kg of biological tissue and creating the same biological effect as the absorbed dose of 1 Gy of photon radiation. The non-systemic unit of measurement of equivalent dose is the rem (biological equivalent of rad). 1 Sv = 100 rem. Some human organs and tissues are more sensitive to the effects of radiation than others: for example, with the same equivalent dose, cancer is more likely to occur in the lungs than in thyroid gland, and irradiation of the gonads is especially dangerous due to the risk of genetic damage. Therefore, radiation doses different organs and fabrics should be taken into account different coefficient, which is called the radiation risk coefficient. Multiplying the equivalent dose value by the corresponding radiation risk coefficient and summing over all tissues and organs, we obtain effective dose, reflecting the total effect on the body. Weighted coefficients are established empirically and calculated in such a way that their sum for the entire organism is unity. The effective dose units are the same as the equivalent dose units. It is also measured in sieverts or rem.

Previously, people, in order to explain what they did not understand, came up with various fantastic things - myths, gods, religion, magical creatures. And although he still believes in these superstitions a large number of people, now we know that everything has its own explanation. One of the most interesting, mysterious and amazing topics is radiation. What is it? What types of it exist? What is radiation in physics? How is it absorbed? Is it possible to protect yourself from radiation?

general information

So, they highlight the following types radiation: wave motion of the medium, corpuscular and electromagnetic. Most attention will be given to the latter. Regarding the wave motion of the medium, we can say that it arises as a result of mechanical motion a certain object, which causes successive rarefaction or compression of the medium. Examples include infrasound or ultrasound. Corpuscular radiation is a flow atomic particles, such as electrons, positrons, protons, neutrons, alpha, which is accompanied by natural and artificial decay of nuclei. Let's talk about these two for now.

Influence

Let's consider solar radiation. This is a powerful healing and preventive factor. The set of accompanying physiological and biochemical reactions that occur with the participation of light is called photobiological processes. They take part in the synthesis biologically important connections, serve to obtain information and orientation in space (vision), and can also cause harmful consequences, such as the appearance of harmful mutations, destruction of vitamins, enzymes, and proteins.

About electromagnetic radiation

In the future, the article will be devoted exclusively to him. What does radiation do in physics, how does it affect us? EMR is electromagnetic waves that are emitted by charged molecules, atoms, and particles. As large sources antennas or other radiating systems may protrude. The radiation wavelength (oscillation frequency) together with the sources has crucial. So, depending on these parameters, gamma, x-ray, optical radiation. The latter is divided into whole line other subspecies. So, this is infrared, ultraviolet, radio radiation, as well as light. The range is up to 10 -13. Gamma radiation is generated by excited atomic nuclei. X-rays can be obtained by decelerating accelerated electrons, as well as by their transition free levels. Radio waves leave their mark as they move alternating electric currents along the conductors of radiating systems (for example, antennas).

About ultraviolet radiation

Biologically, UV rays are the most active. If they come into contact with the skin, they can cause local changes in tissue and cellular proteins. In addition, the effect on skin receptors is recorded. It affects the whole organism in a reflex way. Because it is a nonspecific stimulant physiological functions, then it has a beneficial effect on immune system body, as well as on mineral, protein, carbohydrate and fat metabolism. All this manifests itself in the form of a general health-improving, tonic and preventive effect of solar radiation. It is also worth mentioning some specific properties, which a certain wavelength range has. Thus, the influence of radiation on a person with a length of 320 to 400 nanometers contributes to the erythema-tanning effect. In the range from 275 to 320 nm, weakly bactericidal and antirachitic effects are recorded. But ultraviolet radiation from 180 to 275 nm damages biological tissue. Therefore, caution should be exercised. Prolonged direct solar radiation, even in the safe spectrum, can lead to severe erythema with swelling of the skin and a significant deterioration in health. Up to increasing the likelihood of developing skin cancer.

Reaction to sunlight

First of all it should be mentioned infrared radiation. It has a thermal effect on the body, which depends on the degree of absorption of rays by the skin. The word “burn” is used to describe its effect. Visible spectrum affects the visual analyzer and the functional state of the central nervous system. And through the central nervous system and onto all human systems and organs. It should be noted that we are influenced not only by the degree of illumination, but also by the color scheme sunlight, that is, the entire spectrum of radiation. Thus, color perception depends on the wavelength and influences our emotional activity, as well as the functioning various systems body.

Red color excites the psyche, enhances emotions and gives a feeling of warmth. But it quickly tires, promotes muscle tension, increased breathing and increased blood pressure. Orange color evokes a feeling of well-being and fun, yellow is uplifting and stimulating nervous system and vision. Green is calming, useful during insomnia, fatigue, and improves the overall tone of the body. Purple has a relaxing effect on the psyche. Blue calms the nervous system and keeps muscles toned.

A small retreat

Why, when considering what radiation is in physics, we speak in to a greater extent about EMP? The fact is that this is precisely what is meant in most cases when the topic is addressed. The same corpuscular radiation and wave motion of the medium is an order of magnitude smaller in scale and known. Very often, when they talk about types of radiation, they mean exclusively those into which EMR is divided, which is fundamentally wrong. After all, when talking about what radiation is in physics, attention should be paid to all aspects. But at the same time, emphasis is placed on the most important points.

About radiation sources

We continue to consider electromagnetic radiation. We know that it represents waves that arise when electrical or magnetic field. This process modern physics interpreted from the point of view of the theory of wave-particle duality. Thus, it is recognized that the minimum portion of EMR is a quantum. But at the same time, it is believed that it also has frequency-wave properties, on which the main characteristics depend. To improve the ability to classify sources, different emission spectra of EMR frequencies are distinguished. So this:

1. Hard radiation (ionized);
2. Optical (visible to the eye);
3. Thermal (aka infrared);
4. Radio frequency.

Some of them have already been considered. Each radiation spectrum has its own unique characteristics.

Nature of the sources

Depending on their origin, electromagnetic waves can arise in two cases:

1. When there is a disturbance of artificial origin.
2. Registration of radiation coming from a natural source.

What can you say about the first ones? Artificial sources most often represent side effect, which arises as a result of the work of various electrical appliances and mechanisms. Radiation natural origin generates the Earth's magnetic field, electrical processes in the planet's atmosphere, nuclear fusion in the depths of the sun. The degree of tension depends on the power level of the source electromagnetic field. Conventionally, the radiation that is recorded is divided into low-level and high-level. The first ones include:

1. Almost all devices equipped with a CRT display (such as a computer).
2. Various household appliances, ranging from climate systems and ending with irons;
3. Engineering systems that provide electricity supply to various objects. Examples include power cables, sockets, and electricity meters.

High-level electromagnetic radiation is produced by:

1. Power lines.
2. All electric transport and its infrastructure.
3. Radio and television towers, as well as mobile and mobile communication stations.
4. Elevators and other lifting equipment using electromechanical power plants.
5. Network voltage conversion devices (waves emanating from a distribution substation or transformer).

Separately, there is special equipment that is used in medicine and emits hard radiation. Examples include MRI, X-ray machines and the like.

The influence of electromagnetic radiation on humans

In the course of numerous studies, scientists came to the sad conclusion - long-term EMR influence contributes to a real explosion of diseases. However, many violations occur on genetic level. Therefore, it is important to protect against electromagnetic radiation. This is due to the fact that EMR has high level biological activity. In this case, the result of the influence depends on:

1. The nature of the radiation.
2. Duration and intensity of influence.

Specific moments of influence

It all depends on the localization. Absorption of radiation can be local or general. An example of the second case is the effect that power lines have. An example of local influence is the electromagnetic waves emitted by electronic watches or mobile phone. Thermal effects should also be mentioned. Due to the vibration of molecules, the field energy is converted into heat. Microwave emitters that are used for heating work on this principle. various substances. It should be noted that when influencing a person, the thermal effect is always negative, and even harmful. It should be noted that we are constantly exposed to radiation. At work, at home, moving around the city. Over time, the negative effect only intensifies. Therefore, protection against electromagnetic radiation is becoming increasingly important.

How can you protect yourself?

Initially, you need to know what you are dealing with. A special device for measuring radiation will help with this. It will allow you to assess the security situation. In production, absorbent screens are used for protection. But, alas, they are not designed for use at home. To get started, here are three tips you can follow:

1. Should stay on safe distance from devices. For power lines, television and radio towers, this is at least 25 meters. With CRT monitors and televisions, thirty centimeters is enough. Electronic watches should be no closer than 5 cm. And radio and Cell Phones It is not recommended to bring it closer than 2.5 centimeters. You can find a location using special device- fluxmeter. The permissible dose of radiation recorded by it should not exceed 0.2 µT.
2. Try to reduce the time you have to be exposed to radiation.
3. You should always turn off electrical appliances when not in use. After all, even when inactive, they continue to emit EMR.

About the silent killer

And we will conclude the article with an important, although rather poorly known in wide circles, topic - radiation. Throughout his life, development and existence, man was irradiated by natural background. Natural radiation can be roughly divided into external and internal exposure. The first includes cosmic radiation, solar radiation, influence earth's crust and air. Even Construction Materials, from which houses and structures are created, generate a certain background.

Radiation has a significant penetrating force, so stopping it is problematic. So, in order to completely isolate the rays, you need to hide behind a lead wall 80 centimeters thick. Internal exposure occurs in cases where natural radioactive substances enter the body along with food, air, and water. Radon, thoron, uranium, thorium, rubidium, and radium can be found in the bowels of the earth. All of them are absorbed by plants, can be in water - and when consumed food products enter our body.