What kind of radioactive radiation does it have? Types of radiation. Where does the radiation come from?

Everyone has heard about the negative impact of radiation on all living things. But not everyone knows whether it can be found in everyday life.

The word radiation itself came to us from Latin. Literally translated, the term means “ray”. By radiation, ordinary people mean all radiation known to modern science. Even ultraviolet and radio waves fall under this classification.

Not all forms of radioactive radiation are harmful. But even if they carry many side effects, in the minimum acceptable dosages they can be used for good.

Electromagnetic radiation and humans

The electromagnetic background of natural origin has always accompanied humans. But with the development of technology and breakthroughs in the scientific industry, people began to create artificial radiation. This worsened the situation, significantly affecting people's health.

Each type of radiation is different:

• by power,
• by the nature of the impact,
• wavelength.

The mechanism of radiation propagation remains the same in any case. This means that any radiation in the form of electromagnetic waves can propagate in the air. The rays are a mixture of electric and magnetic fields that change according to certain rules. The schematic classification of radiation involves sorting into operating ranges.

The functioning of the human body is based on electromagnetic nature. This means that all tissues and organ systems are exposed to any type of radiation. In ordinary life, background radiation does not pose any threat to the well-coordinated biological mechanism in the body. But if this dosage is exceeded, the functioning of the body is endangered. Artificial waves of electromagnetic origin introduce misinformation into the body.

This is how unhealthy conditions manifest themselves, leading to pathological changes. The nature of these changes can vary significantly.

If two people with approximately the same level of health are exposed to radiation under identical conditions, the health consequences for both will be different. It depends on genetic predisposition and latent diseases.

How does the irradiation mechanism work?

Even the most dangerous radiation for humans, with short-term exposure to the body, can cause less harm in the long term than long-term and regular relatively safe exposure.

The human body acts as a conductor provided it complies with frequencies less than 10 Hz. This is especially true for the nervous system, which is considered a particularly sensitive system of each organism.

A well-functioning heat transfer mechanism can cope with a banal increase in body temperature. But if we are talking about high-frequency electromagnetic waves, then another biological principle comes into play. The patient exhibits a noticeable increase in the temperature of the tissues exposed to irradiation. This leads to serious consequences, some of which are considered irreversible.

With an indicator of more than 50 microroentgens per hour, the patient develops cellular disorders. They will be expressed in the following negative consequences:

• disruption of the functioning of body systems;
• exacerbation of chronic diseases or development of acute ones;
• stillborn children.

Particularly dangerous types of radiation

The central threat posed by radiation is penetration. It is based on the process of radiation and subsequent absorption of energy. The process is carried out thanks to quanta - certain portions of energy. If the length of the sent wave is small, then the effect of the quanta will be as strong as possible.

By studying which type of radiation has the greatest penetrating power, researchers came to the conclusion that there are two of them:

• gamma radiation,
• X-ray.

Adding to the deceit is the fact that at the time of irradiation the victim may not feel anything at all. Radiation works for the future. The harmful effects often make themselves felt over time. The extent and severity of damage depends entirely on the type and depth of the beam, as well as the time of irradiation.

In addition to this type of influence, quanta carry another potential danger. Their ability to ionize atoms provokes various gene mutations. They are inherited, and it is practically impossible to correct them. A hereditary mutation can develop even with a minimal dose of radiation.

Because of all this information, some people begin to panic, refusing an x-ray examination when absolutely necessary. But all devices in medical institutions are configured so that the patient receives only the minimum forced dose of radiation. There's nothing to be afraid of.

In total, over a lifetime, accumulated radiation exposure in the body should not exceed the maximum permissible norm of 32 Roentgen. In practice, this is equivalent to hundreds of x-rays taken at short intervals.

The situation with gamma irradiation is much more complicated. It occurs due to the decay of certain radioactive elements.

The hard component of ultraviolet rays “can” not only ionize molecules. It also generates significant damage to the retina. After a series of studies, it became clear that the organs of vision are most affected by waves whose length corresponds to the light green color spectrum. This is equivalent to parameters from 555 nm to 565 nm.

When twilight sets in, the sensitivity of human vision shifts somewhat towards short waves. They correspond to a length within a radius of 500 nm (blue).

Features of the influence of alpha radiation

In addition to harmful gamma radiation, there are also alpha particles. By nature, the last two categories are not very different. The only difference is the wavelength and penetrating power. But, compared to the harm from gamma rays, beta and especially alpha are considered more favorable to a living organism.

In terms of wavelength, alpha radiation is considered the most dangerous, as it has a huge impact force. But due to the same wavelength (it is very small) in everyday life, alpha radiation rarely causes significant damage to the body.

Damage to living cells followed by almost instantaneous death is a characteristic feature. But the good news is that such a beam loses its destructive power literally 3-4 centimeters from the object of radiation. If you protect a living organism from a radiation source even with an ordinary sheet of paper, its negative impact will disappear.

Sources of radiation in everyday life

Having established the most dangerous radiation for humans, conscious citizens begin to look for ways to protect themselves from it.

Any electrical device in a modern person’s home can be regarded as a primary source of electromagnetic radiation of artificial origin. Because of them, a person, unnoticed by himself, reduces his own immunity and worsens the current state of the endocrine system.

In the process of studying the connection between household radiation and its effect on the human body, a proven pattern was established. Scientists have proven that the formation of malignant tumors can directly depend on the place of residence of a person. If his house is located directly under a high-voltage transmission line, then the chances of receiving an oncological diagnosis increase.

To reduce the negative impact of household chemicals, experts recommend following simple tips:

• If possible, move more than a meter away from operating electrical appliances.
• Place electrical equipment in different parts of the house.
• Beware of small household appliances that cause impact in the head area. Such devices include hair dryers, electric razors and toothbrushes.

If you feel unsafe in your own home due to suspected elevated levels of radiation, take exposure measurements. A special dosimeter is provided for this. The instructions for the device will specify acceptable values ​​in different environments. However, evaluation criteria may vary in different countries.

When you don’t want to shell out money for special equipment, you can use the old “old-fashioned way.” Turn off all electrical appliances in the house and turn them on one at a time. When approaching each individual device that is turned on, bring the radio receiver to it. If crackling and other noise can be heard near the installation, this indicates strong electromagnetic radiation.

This way you can identify the most dangerous appliances in your home and try to avoid using them whenever possible.

Radiation is ionizing radiation that causes irreparable harm to everything around us. People, animals and plants suffer. The biggest danger is that it is not visible to the human eye, so it is important to know about its main properties and effects in order to protect yourself.

Radiation accompanies people throughout their lives. It is found in the environment and also within each of us. The greatest impact comes from external sources. Many people have heard about the accident at the Chernobyl nuclear power plant, the consequences of which are still encountered in our lives. People were not ready for such a meeting. This once again confirms that there are events in the world beyond the control of humanity.

Types of radiation

Not all chemicals are stable. In nature, there are certain elements whose nuclei are transformed, breaking up into separate particles with the release of a huge amount of energy. This property is called radioactivity. As a result of research, scientists have discovered several types of radiation:

1. Alpha radiation is a stream of heavy radioactive particles in the form of helium nuclei that can cause the greatest harm to others. Fortunately, they have low penetrating ability. In airspace they extend only a couple of centimeters. In fabric their range is a fraction of a millimeter. Thus, external radiation does not pose a danger. You can protect yourself by using thick clothing or a sheet of paper. But internal radiation is an impressive threat.
2. Beta radiation is a stream of light particles moving a couple of meters in the air. These are electrons and positrons that penetrate two centimeters into the tissue. It is harmful if it comes into contact with human skin. However, it poses a greater danger when exposed from the inside, but less than alpha. To protect against the influence of these particles, special containers, protective screens, and a certain distance are used.
3. Gamma and X-ray radiation are electromagnetic radiations that penetrate the body through and through. Protective measures against such exposure include the creation of lead screens and the construction of concrete structures. The most dangerous of irradiations for external damage, since it affects the entire body.
4. Neutron radiation consists of a stream of neutrons, which have a higher penetrating power than gamma. It is formed as a result of nuclear reactions occurring in reactors and special research facilities. Appears during nuclear explosions and is found in waste fuel from nuclear reactors. Armor against such impact is created from lead, iron, and concrete.

All radioactivity on Earth can be divided into two main types: natural and artificial. The first includes radiation from space, soil, and gases. Artificial one appeared thanks to man using nuclear power plants, various equipment in medicine, and nuclear enterprises.

Natural sources

Naturally occurring radioactivity has always been present on the planet. Radiation is present in everything that surrounds humanity: animals, plants, soil, air, water. This low level of radiation is believed to have no harmful effects. Although, some scientists have a different opinion. Since people have no ability to influence this hazard, circumstances that increase the permissible values ​​should be avoided.

Varieties of natural sources

1. Cosmic radiation and solar radiation are powerful sources capable of eliminating all life on Earth. Fortunately, the planet is protected from this impact by the atmosphere. However, people have tried to correct this situation by developing activities that lead to the formation of ozone holes. Avoid being exposed to direct sunlight for a long time.
2. Radiation from the earth's crust is dangerous near deposits of various minerals. By burning coal or using phosphorus fertilizers, radionuclides actively seep inside a person with the air they inhale and the food they eat.
3. Radon is a radioactive chemical element found in building materials. It is a colorless, odorless and tasteless gas. This element actively accumulates in soils and comes out along with mining. It enters apartments along with household gas, as well as tap water. Fortunately, its concentration can be easily reduced by constantly ventilating the premises.

Artificial sources

This species appeared thanks to people. Its effect increases and spreads with their help. During the outbreak of a nuclear war, the strength and power of weapons is not as terrible as the consequences of radioactive radiation after explosions. Even if you are not caught by a blast wave or physical factors, radiation will finish you off.

Artificial sources include:

• Nuclear weapon;
• Medical equipment;
• Waste from enterprises;
• Certain gemstones;
• Some antique items taken from dangerous areas. Including from Chernobyl.

Norm of radioactive radiation

Scientists have been able to establish that radiation has different effects on individual organs and the entire body as a whole. In order to assess the damage resulting from chronic exposure, the concept of equivalent dose was introduced. It is calculated by the formula and is equal to the product of the dose received, absorbed by the body and averaged over a specific organ or the entire human body, by a weight multiplier.

The unit of measurement for equivalent dose is the ratio of Joule to kilograms, which is called the sievert (Sv). Using it, a scale was created that allows us to understand the specific danger of radiation for humanity:

• 100 Sv. Instant death. The victim has a few hours, a couple of days at most.
• From 10 to 50 Sv. Anyone who receives injuries of this nature will die in a few weeks from severe internal bleeding.
• 4-5 Sv. When this amount is ingested, the body copes in 50% of cases. Otherwise, the sad consequences lead to death a couple of months later due to bone marrow damage and circulatory disorders.
• 1 Sv. When absorbing such a dose, radiation sickness is inevitable.
• 0.75 Sv. Changes in the circulatory system for a short period of time.
• 0.5 Sv. This amount is enough for the patient to develop cancer. There are no other symptoms.
• 0.3 Sv. This value is inherent in the device for performing x-rays of the stomach.
• 0.2 Sv. Permissible level for working with radioactive materials.
• 0.1 Sv. With this amount, uranium is mined.
• 0.05 Sv. This value is the radiation exposure rate for medical devices.
• 0.0005 Sv. Permissible amount of radiation level near nuclear power plants. This is also the value of the annual exposure of the population, which is equal to the norm.

A safe dose of radiation for humans includes values ​​up to 0.0003-0.0005 Sv per hour. The maximum permissible exposure is 0.01 Sv per hour, if such exposure is short-lived.

The effect of radiation on humans

Radioactivity has a huge impact on the population. Not only the people who come face to face with the danger are exposed to harmful effects, but also the next generation. Such circumstances are caused by the effect of radiation at the genetic level. There are two types of influence:

• Somatic. Diseases occur in a victim who has received a dose of radiation. Leads to the appearance of radiation sickness, leukemia, tumors of various organs, and local radiation injuries.
• Genetic. Associated with a defect in the genetic apparatus. It appears in subsequent generations. Children, grandchildren and more distant descendants suffer. Gene mutations and chromosomal changes occur

In addition to the negative impact, there is also a favorable moment. Thanks to the study of radiation, scientists were able to create a medical examination based on it that allows them to save lives.

Consequences of radiation

When receiving chronic radiation, restoration measures take place in the body. This leads to the fact that the victim acquires a smaller load than he would receive with a single penetration of the same amount of radiation. Radionuclides are distributed unevenly inside a person. Most often affected: the respiratory system, digestive organs, liver, thyroid gland.

The enemy does not sleep even 4-10 years after irradiation. Blood cancer can develop inside a person. It poses a particular danger to adolescents under 15 years of age. It has been observed that the mortality rate of people working with x-ray equipment is increased due to leukemia.

The most common result of radiation exposure is radiation sickness, which occurs both with a single dose and over a long period of time. If there is a large amount of radionuclides it leads to death. Breast and thyroid cancer are common.

A huge number of organs suffer. The victim's vision and mental state are impaired. Lung cancer is common in uranium miners. External radiation causes terrible burns of the skin and mucous membranes.

Mutations

After exposure to radionuclides, two types of mutations can occur: dominant and recessive. The first occurs immediately after irradiation. The second type is discovered after a long period of time not in the victim, but in his subsequent generation. Disorders caused by the mutation lead to deviations in the development of internal organs in the fetus, external deformities and mental changes.

Unfortunately, mutations are poorly studied, since they usually do not appear immediately. After time, it is difficult to understand what exactly had the dominant influence on its occurrence.

Article navigation:

Radiation and types of radioactive radiation, the composition of radioactive (ionizing) radiation and its main characteristics. The effect of radiation on matter.

What is radiation

First, let's define what radiation is:

In the process of decay of a substance or its synthesis, the elements of an atom (protons, neutrons, electrons, photons) are released, otherwise we can say radiation occurs these elements. Such radiation is called - ionizing radiation or what is more common radioactive radiation, or even simpler radiation . Ionizing radiation also includes x-rays and gamma radiation.

Radiation is the process of emission of charged elementary particles by matter, in the form of electrons, protons, neutrons, helium atoms or photons and muons. The type of radiation depends on which element is emitted.

Ionization is the process of formation of positively or negatively charged ions or free electrons from neutrally charged atoms or molecules.

Radioactive (ionizing) radiation can be divided into several types, depending on the type of elements from which it consists. Different types of radiation are caused by different microparticles and therefore have different energetic effects on matter, different abilities to penetrate through it and, as a consequence, different biological effects of radiation.

Alpha, beta and neutron radiation- These are radiations consisting of various particles of atoms.

Gamma and X-rays is the emission of energy.

Alpha radiation

• are emitted: two protons and two neutrons
• penetrating ability: low
• irradiation from source: up to 10 cm
• emission speed: 20,000 km/s
• ionization: 30,000 ion pairs per 1 cm of travel
• high

Alpha (α) radiation occurs during the decay of unstable isotopes elements.

Alpha radiation- this is the radiation of heavy, positively charged alpha particles, which are the nuclei of helium atoms (two neutrons and two protons). Alpha particles are emitted during the decay of more complex nuclei, for example, during the decay of atoms of uranium, radium, and thorium.

Alpha particles have a large mass and are emitted at a relatively low speed of an average of 20 thousand km/s, which is approximately 15 times less than the speed of light. Since alpha particles are very heavy, upon contact with a substance, the particles collide with the molecules of this substance, begin to interact with them, losing their energy, and therefore the penetrating ability of these particles is not great and even a simple sheet of paper can hold them back.

However, alpha particles carry a lot of energy and, when interacting with matter, cause significant ionization. And in the cells of a living organism, in addition to ionization, alpha radiation destroys tissue, leading to various damage to living cells.

Of all types of radiation, alpha radiation has the least penetrating power, but the consequences of irradiation of living tissues with this type of radiation are the most severe and significant compared to other types of radiation.

Exposure to alpha radiation can occur when radioactive elements enter the body, for example through air, water or food, or through cuts or wounds. Once in the body, these radioactive elements are carried through the bloodstream throughout the body, accumulate in tissues and organs, exerting a powerful energetic effect on them. Since some types of radioactive isotopes emitting alpha radiation have a long lifespan, when they enter the body, they can cause serious changes in cells and lead to tissue degeneration and mutations.

Radioactive isotopes are actually not eliminated from the body on their own, so once they get inside the body, they will irradiate the tissues from the inside for many years until they lead to serious changes. The human body is not able to neutralize, process, assimilate or utilize most radioactive isotopes that enter the body.

Neutron radiation

• are emitted: neutrons
• penetrating ability: high
• irradiation from source: kilometers
• emission speed: 40,000 km/s
• ionization: from 3000 to 5000 ion pairs per 1 cm of run
• biological effects of radiation: high

Neutron radiation- this is man-made radiation arising in various nuclear reactors and during atomic explosions. Also, neutron radiation is emitted by stars in which active thermonuclear reactions occur.

Having no charge, neutron radiation colliding with matter weakly interacts with the elements of atoms at the atomic level, and therefore has high penetrating power. You can stop neutron radiation using materials with a high hydrogen content, for example, a container of water. Also, neutron radiation does not penetrate polyethylene well.

Neutron radiation, when passing through biological tissues, causes serious damage to cells, since it has a significant mass and a higher speed than alpha radiation.

Beta radiation

• are emitted: electrons or positrons
• penetrating ability: average
• irradiation from source: up to 20 m
• emission speed: 300,000 km/s
• ionization: from 40 to 150 ion pairs per 1 cm of travel
• biological effects of radiation: average

Beta (β) radiation occurs when one element transforms into another, while the processes occur in the very nucleus of the atom of the substance with a change in the properties of protons and neutrons.

With beta radiation, a neutron is transformed into a proton or a proton into a neutron; during this transformation, an electron or positron (electron antiparticle) is emitted, depending on the type of transformation. The speed of the emitted elements approaches the speed of light and is approximately equal to 300,000 km/s. The elements emitted during this process are called beta particles.

Having an initially high radiation speed and small sizes of emitted elements, beta radiation has a higher penetrating ability than alpha radiation, but has hundreds of times less ability to ionize matter compared to alpha radiation.

Beta radiation easily penetrates through clothing and partially through living tissue, but when passing through denser structures of matter, for example, through metal, it begins to interact with it more intensely and loses most of its energy, transferring it to the elements of the substance. A metal sheet of a few millimeters can completely stop beta radiation.

If alpha radiation poses a danger only in direct contact with a radioactive isotope, then beta radiation, depending on its intensity, can already cause significant harm to a living organism at a distance of several tens of meters from the radiation source.

If a radioactive isotope emitting beta radiation enters a living organism, it accumulates in tissues and organs, exerting an energetic effect on them, leading to changes in the structure of the tissue and, over time, causing significant damage.

Some radioactive isotopes with beta radiation have a long decay period, that is, once they enter the body, they will irradiate it for years until they lead to tissue degeneration and, as a result, cancer.

Gamma radiation

• are emitted: energy in the form of photons
• penetrating ability: high
• irradiation from source: up to hundreds of meters
• emission speed: 300,000 km/s
• ionization:
• biological effects of radiation: low

Gamma (γ) radiation is energetic electromagnetic radiation in the form of photons.

Gamma radiation accompanies the process of decay of atoms of matter and manifests itself in the form of emitted electromagnetic energy in the form of photons, released when the energy state of the atomic nucleus changes. Gamma rays are emitted from the nucleus at the speed of light.

When the radioactive decay of an atom occurs, other substances are formed from one substance. The atom of newly formed substances is in an energetically unstable (excited) state. By influencing each other, neutrons and protons in the nucleus come to a state where the interaction forces are balanced, and excess energy is emitted by the atom in the form of gamma radiation

Gamma radiation has a high penetrating ability and easily penetrates clothing, living tissue, and a little more difficult through dense structures of substances such as metal. To stop gamma radiation, a significant thickness of steel or concrete will be required. But at the same time, gamma radiation has a hundred times weaker effect on matter than beta radiation and tens of thousands of times weaker than alpha radiation.

The main danger of gamma radiation is its ability to travel significant distances and affect living organisms several hundred meters from the source of gamma radiation.

X-ray radiation

• are emitted: energy in the form of photons
• penetrating ability: high
• irradiation from source: up to hundreds of meters
• emission speed: 300,000 km/s
• ionization: from 3 to 5 pairs of ions per 1 cm of travel
• biological effects of radiation: low

X-ray radiation- this is energetic electromagnetic radiation in the form of photons that arise when an electron inside an atom moves from one orbit to another.

X-ray radiation is similar in effect to gamma radiation, but has less penetrating power because it has a longer wavelength.

Having examined the various types of radioactive radiation, it is clear that the concept of radiation includes completely different types of radiation that have different effects on matter and living tissues, from direct bombardment with elementary particles (alpha, beta and neutron radiation) to energy effects in the form of gamma and x-rays cure.

Each of the radiations discussed is dangerous!

Comparative table with characteristics of different types of radiation

As can be seen from the table, depending on the type of radiation, radiation at the same intensity, for example 0.1 Roentgen, will have a different destructive effect on the cells of a living organism. To take this difference into account, a coefficient k was introduced, reflecting the degree of exposure to radioactive radiation on living objects.

The higher the “k coefficient”, the more dangerous the effect of a certain type of radiation is on the tissues of a living organism.

Video:

After the accident at the Fukushima nuclear power plant, the world was overwhelmed by another wave of panicky radiophobia. In the Far East, iodine disappeared from sale, and manufacturers and sellers of dosimeters not only sold out all the devices in warehouses, but also collected pre-orders for six months to a year in advance. But is radiation really that bad? If you wince every time you hear this word, this article is written for you.

Igor Egorov

What is radiation? This is the name given to various types of ionizing radiation, that is, that which is capable of removing electrons from the atoms of a substance. The three main types of ionizing radiation are usually designated by the Greek letters alpha, beta and gamma. Alpha radiation is a stream of helium-4 nuclei (virtually all helium from balloons was once alpha radiation), beta is a stream of fast electrons (less commonly positrons), and gamma is a stream of high-energy photons. Another type of radiation is a flux of neutrons. Ionizing radiation (with the exception of X-rays) is the result of nuclear reactions, so neither mobile phones nor microwave ovens are sources of it.

Loaded Weapon

Of all the types of art, the most important for us, as we know, is cinema, and of the types of radiation - gamma radiation. It has a very high penetrating ability, and theoretically no barrier can completely protect against it. We are constantly exposed to gamma radiation, it comes to us through the thickness of the atmosphere from space, breaks through the soil layer and the walls of houses. The downside of such pervasiveness is a relatively weak destructive effect: of a large number of photons, only a small part will transfer its energy to the body. Soft (low-energy) gamma radiation (and x-rays) mainly interacts with matter, knocking electrons out of it due to the photoelectric effect, hard radiation is scattered by electrons, while the photon is not absorbed and retains a noticeable part of its energy, so the probability of destruction of molecules in such the process is much less.

Beta radiation is close in its effects to gamma radiation - it also knocks electrons out of atoms. But with external irradiation, it is completely absorbed by the skin and the tissues closest to the skin, without reaching the internal organs. However, this leads to the fact that the flow of fast electrons transfers significant energy to the irradiated tissues, which can lead to radiation burns or provoke, for example, cataracts.

Alpha radiation carries significant energy and high momentum, which allows it to knock electrons out of atoms and even atoms themselves out of molecules. Therefore, the “destruction” caused by it is much greater - it is believed that by transferring 1 J of energy to the body, alpha radiation will cause the same damage as 20 J in the case of gamma or beta radiation. Fortunately, the penetration power of alpha particles is extremely low: they are absorbed by the very top layer of the skin. But when ingested, alpha-active isotopes are extremely dangerous: remember the infamous tea with alpha-active polonium-210, which poisoned Alexander Litvinenko.

Neutral danger

But the first place in the danger rating is undoubtedly occupied by fast neutrons. A neutron has no electrical charge and therefore interacts not with electrons, but with nuclei - only with a “direct hit”. A flow of fast neutrons can pass through a layer of matter on average from 2 to 10 cm without interacting with it. Moreover, in the case of heavy elements, when colliding with a nucleus, the neutron only deviates to the side, almost without losing energy. And when it collides with a hydrogen nucleus (proton), the neutron transfers approximately half of its energy to it, knocking the proton out of its place. It is this fast proton (or, to a lesser extent, the nucleus of another light element) that causes ionization in the substance, acting like alpha radiation. As a result, neutron radiation, like gamma rays, easily penetrates into the body, but is almost completely absorbed there, creating fast protons that cause great destruction. In addition, neutrons are the same radiation that causes induced radioactivity in irradiated substances, that is, converts stable isotopes into radioactive ones. This is an extremely unpleasant effect: for example, alpha, beta and gamma active dust can be washed off from vehicles after being in the source of a radiation accident, but it is impossible to get rid of neutron activation - the body itself emits radiation (by the way, this is what the the damaging effect of a neutron bomb that activated the armor of tanks).

Dose and power

When measuring and assessing radiation, so many different concepts and units are used that it is easy for an ordinary person to get confused.
The exposure dose is proportional to the number of ions created by gamma and x-ray radiation per unit mass of air. It is usually measured in roentgens (R).
The absorbed dose shows the amount of radiation energy absorbed per unit mass of a substance. Previously it was measured in rads (rad), but now it is measured in grays (Gy).
The equivalent dose additionally takes into account the difference in the destructive ability of different types of radiation. Previously, it was measured in “biological equivalents of rads” - rem (rem), and now - in sieverts (Sv).
The effective dose also takes into account the different sensitivity of different organs to radiation: for example, irradiating the arm is much less dangerous than the back or chest. Previously it was measured in the same rem, now - in sieverts.
Converting one unit of measurement to another is not always correct, but on average it is generally accepted that an exposure dose of gamma radiation of 1 R will cause the same harm to the body as an equivalent dose of 1/114 Sv. Converting rads to grays and rem to sieverts is very simple: 1 Gy = 100 rad, 1 Sv = 100 rem. To convert the absorbed dose into an equivalent dose, the so-called a "radiation quality factor" equal to 1 for gamma and beta radiation, 20 for alpha radiation, and 10 for fast neutrons. For example, 1 Gy of fast neutrons = 10 Sv = 1000 rem.
The natural equivalent dose rate (EDR) of external exposure is usually 0.06 - 0.10 µSv/h, but in some places it can be less than 0.02 µSv/h or more than 0.30 µSv/h. A level of more than 1.2 μSv/h in Russia is officially considered dangerous, although in the aircraft cabin during a flight the EDR can be many times higher than this value. And the ISS crew is exposed to radiation with a power of approximately 40 μSv/h.

In nature, neutron radiation is very insignificant. In fact, the risk of being exposed to it exists only during a nuclear bombardment or a serious accident at a nuclear power plant with the melting and release of most of the reactor core into the environment (and even then only in the first seconds).

Gas discharge meters

Radiation can be detected and measured using a variety of sensors. The simplest of them are ionization chambers, proportional counters and gas-discharge Geiger-Muller counters. They are a thin-walled metal tube filled with gas (or air), along the axis of which a wire, an electrode, is stretched. A voltage is applied between the housing and the wire and the current flow is measured. The fundamental difference between the sensors is only in the magnitude of the applied voltage: at low voltages we have an ionization chamber, at high voltages we have a gas-discharge counter, somewhere in the middle we have a proportional counter.

The plutonium-238 sphere glows in the dark, like a one-watt light bulb. Plutonium is toxic, radioactive and incredibly heavy: one kilogram of this substance fits in a cube with a side of 4 cm.

Ionization chambers and proportional counters make it possible to determine the energy that each particle transferred to the gas. The Geiger-Muller counter only counts particles, but readings from it are very easy to obtain and process: the power of each pulse is sufficient to directly output it to a small speaker! An important problem of gas-discharge counters is the dependence of the counting rate on the radiation energy at the same radiation level. To level it out, special filters are used that absorb part of the soft gamma and all beta radiation. To measure the flux density of beta and alpha particles, such filters are made removable. In addition, to increase sensitivity to beta and alpha radiation, “end counters” are used: this is a disk with a bottom as one electrode and a second spiral wire electrode. The cover of the end counters is made of a very thin (10−20 microns) mica plate, through which soft beta radiation and even alpha particles easily pass.

Previously, people, in order to explain what they did not understand, came up with various fantastic things - myths, gods, religion, magical creatures. And although a large number of people still believe in these superstitions, we now know that there is an explanation for everything. 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, the following types of radiation are distinguished: wave motion of the medium, corpuscular and electromagnetic. Most attention will be paid to the latter. Regarding the wave motion of the medium, we can say that it arises as a result of the mechanical movement of a certain object, which causes a successive rarefaction or compression of the medium. Examples include infrasound or ultrasound. Corpuscular radiation is a flow of 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

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 of biologically important compounds, serve to obtain information and orientation in space (vision), and can also cause harmful consequences, such as the appearance of harmful mutations, the 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. Large sources can be antennas or other radiating systems. The wavelength of the radiation (oscillation frequency) together with the sources is of decisive importance. So, depending on these parameters, gamma, x-ray, and optical radiation are distinguished. The latter is divided into a number of 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 from non-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. Since it is a nonspecific stimulator of physiological functions, it has a beneficial effect on the body’s immune system, 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 worth mentioning some specific properties that a certain wave 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, infrared radiation should be mentioned. 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. The 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 range of 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 of various body systems.

Red color excites the psyche, enhances emotions and gives a feeling of warmth. But it quickly tires, contributes to muscle tension, increased breathing and increased blood pressure. Orange evokes a feeling of well-being and cheerfulness, while yellow lifts the mood and stimulates the nervous system and vision. Green is calming, useful during insomnia, fatigue, and improves the overall tone of the body. The color violet 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, do we talk mostly about EMR? 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 an electric or magnetic field is disturbed. This process is interpreted by modern physics 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 a side effect that occurs as a result of the operation of various electrical devices and mechanisms. Radiation of natural origin generates the Earth’s magnetic field, electrical processes in the planet’s atmosphere, and nuclear fusion in the depths of the sun. The degree of electromagnetic field strength depends on the power level of the source. 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, from climate control systems to 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 have come to the sad conclusion that long-term exposure to EMR contributes to a real explosion of diseases. However, many disorders occur at the genetic level. Therefore, protection against electromagnetic radiation is important. This is due to the fact that EMR has a high level of 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 exposure is the electromagnetic waves emitted by a digital watch or mobile phone. Thermal effects should also be mentioned. Due to the vibration of molecules, the field energy is converted into heat. Microwave emitters operate on this principle and are used to heat 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. You should stay at a 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 it is not recommended to bring radios and cell phones closer than 2.5 centimeters. You can select a location using a special device - a flux meter. 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, the influence of the earth's crust and air. Even the building 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 radiation occurs when 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 eaten, they enter our body.