What type of radioactive radiation is the most dangerous. Radiation - in an accessible language. What is radioactivity and radiation

Streams of elementary particles, electromagnetic waves or microscopic fragments of atoms that have the ability to ionize substances or enter into interaction with them. chemical reactions. The process is accompanied by the absorption of heat and the formation of substances with higher energy, the decay of which provokes the emission or emission of positively, negatively charged free electrons. Under their influence, free radicals are formed in the cells of the human body, which disrupt the natural biological processes of metabolism, growth and development, and destroy the immune system. This is the mechanism of the emergence and action of radiation, which is the most dangerous ionizing radiation, both for all living organisms and for humans.

How radiation can enter the body

People are daily exposed to natural as well as artificially created household and industrial radionuclides or radioactive elements. surround a person everywhere:

cosmic or alpha rays;
solar thermonuclear reactions;
spontaneous radioactive decay of natural radiation. Radon, uranium, rubidium;
artificially created radioactive isotopes;
nuclear reactors. Release of radioactive strontium - 90, krypton - 85, cesium - 137;
modern accelerators of elementary charged particles, X-ray, MRI and radiation therapy. Used in medical institutions for the treatment of cancer;
internal exposure. Penetration of radiation is carried out by inhaled air, consumed liquid and food. Polonium, lead, uranium.

Invisible ionizing radiation leads to the defeat of all systems of vital organs without exception, provokes the most dangerous disease, like radiation sickness.

Radiation radiation: types and properties

A spontaneous unreasonable change in the chemical or internal composition of unstable nuclides, atomic nuclei that decay, leads to the formation of new elementary radioactive particles, the appearance of radiation. What types radioactive radiation there are:

alpha. The particle that chemical form represented by the nucleus of a helium atom. The speed of movement is 20 km / s. It quickly loses energy, so there is no risk of penetration of radionuclides during external exposure. Represents a danger when exposed internally, penetrating ability - 3-11 cm. Getting into the digestive and respiratory organs, provokes radiation sickness and death;
beta. A charged particle is formed as a result of beta decay. It propagates at almost the speed of light. The isotope causes severe radiation burns. May cause radiation sickness. The length of the run reaches 20 meters;
gamma. Electromagnetic radiation, which has a large penetrating power, 2 × 10-10 meters. Its properties are close to X-rays. The result of gamma radiation for a person is acute and chronic forms of radiation sickness, the appearance of oncological diseases;
neutron. Rays are formed from an electrically unstable particle. They are super fast. Provoke serious radiation damage;
x-ray. Photon energy. In medicine, they are obtained by charged particle accelerator and are widely used to diagnose diseases.

Provoke mutations, radiation sickness, burns.

To protect against alpha particles, there will be enough clothing that passes 50% of the beta radiation through itself. To prevent the penetration of this type of radiation, metal screens should be used, glazed windows will do. Ordinary water, polyethylene, paraffin will also help from neutron irradiation. But the most and most dangerous radiation for humans is the gamma flux. The best protection from him - lead.

Radiation exposure doses

To determine the biological mechanism of the action of ionizing electromagnetic radiation per unit mass of an organism's substance, the values \u200b\u200bof gray (Gy) or rad (rad) are used, indicating the absorbed dose of radiation. The equivalent dose calculates the penetration and effect of radionuclides on living organisms and is measured in grays (Gy). The exposure dose is the ionization of air in roentgens (P). The amount of radiation needed can be calculated individually using the effective equivalent dose in sieverts (Sv) or rems (rem).

What is the most common unit for measuring radiation?

1 Sv = 100 R
1 Sv = 100 rem;
1 µSv = 0.000001 Sv.

These indicators are used in accordance with the accepted International system of units of physical quantities. They are used to indicate the degree and level of ionizing radiation, to assess the damage to human health.

Dangerous dose of radiation

To calculate the impact of radiation on the human body, a unit of radioactivity was created, which is represented by the value of roentgen (R), its biological equivalent is rem (rem) or sievert (Sv). The formula for calculating the amount of radiation dose: 100 roentgens = 1 rem = 1 Sv. Consider the allowable radiation and the most dangerous, lethal value of radiation for humans in roentgens:

less than 25. Symptoms of the lesion are not detected;
50 . Temporary deterioration of health, weakness;
100 . Signs of poisoning, such as nausea, vomiting, upset of the intestines, stomach, decreased immunity;
150 . The received dose of radiation leads to death in 5% of cases. In the remaining patients, intoxication is observed;
200 . The production of antibodies by the immune system is impaired. Toxic damage lasts from 14 days to 21 days. Mortality is 25%;
300-350 . Severe symptoms of radiation exposure. Hair and skin integuments are disturbed, in men sexual impotence occurs;
350-500 . Dangerous dose of radiation. Manifested in the form of severe radiation sickness. Death occurs in 50% of people within 1 month;
over 500. The lethal dose of radiation for humans is 90-100%. Leads to death within 14 days. Complete destruction of the immune system, bone marrow and dysfunction of the digestive system, biliary system.

It is rather difficult to determine the level of radiation damage to a person in time, in small quantities it does not show symptoms characteristic of radiation sickness. And only with the help of a specially designed device, a dosimeter or a Geiger counter, it is possible to measure the value of electromagnetic exposure. In large doses, the most dangerous radiation for all representatives of the surrounding world, including humans, is radiation, ionizing radiation.

The impact of radiation on humans

The permissible dose of ionizing radiation should not exceed 0.3 μSv per 1 hour. According to the statistics of the World Health Organization, the effective equivalent human exposure dose per year in microsieverts, µSv, is:

cosmic radiation - 32;
nuclear power - 0.01;
medical diagnostics and therapeutic procedures - 169;
building materials - 37;
internal exposure - 38;
natural radiation - 126.

These quantitative indicators indicate that radiation is the most dangerous and threatening to human health. Its consequences are recorded annually in the form of genetic mutations and pathologies in newborn children, oncological diseases and disorders of the body in adults, weakening of the immune system. There is a sharp decline medium duration life up to 66 years.

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Radiation and types of radioactive radiation, the composition of radioactive (ionizing) radiation and its main characteristics. The action 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 the atom (protons, neutrons, electrons, photons) are ejected, otherwise we can say radiation occurs these elements. Such radiation is called ionizing radiation or what is more common radiation, or even easier radiation . Ionizing radiation also includes x-rays and gamma rays.

Radiation - this 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 of which it consists. Different types of radiation are caused by different microparticles and therefore have different energy effects on matter, different ability to penetrate through it and, as a result, 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

emitted: two protons and two neutrons
penetrating power: low
source exposure: up to 10 cm
radiation speed: 20,000 km/s
ionization: 30,000 pairs of ions per 1 cm of run
high

Alpha (α) radiation arises from 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 uranium, radium, and thorium atoms.

Alpha particles have a large mass and are emitted at a relatively low speed of 20,000 km/s on average, which is about 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 power of these particles is not great and even a simple sheet of paper can hold them.

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

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

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

Radioactive isotopes are not actually excreted from the body on their own, so when 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 the majority of radioactive isotopes that have entered the body.

neutron radiation

emitted: neutrons
penetrating power: high
source exposure: kilometers
radiation speed: 40,000 km/s
ionization: from 3000 to 5000 pairs of ions per 1 cm of run
biological effect of radiation: high

neutron radiation- this is man-made radiation that occurs in various nuclear reactors and during atomic explosions. Also, neutron radiation is emitted by stars in which active thermonuclear reactions take place.

Having no charge, neutron radiation, colliding with matter, weakly interacts with elements of atoms at the atomic level, therefore it has a high penetrating power. Neutron radiation can be stopped by using materials with a high hydrogen content, such as a container of water. Also, neutron radiation does not penetrate well through polyethylene.

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

beta radiation

emitted: electrons or positrons
penetrating power: average
source exposure: up to 20 m
radiation speed: 300,000 km/s
ionization: from 40 to 150 pairs of ions per 1 cm of run
biological effect of radiation: the average

Beta (β) radiation arises during the transformation of one element into another, while the processes occur in the very nucleus of the atom of matter with a change in the properties of protons and neutrons.

With beta radiation, a neutron is converted into a proton or a proton into a neutron, with this transformation an electron or positron (an antiparticle of the electron) 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 emitted elements are called beta particles.

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

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

If alpha radiation is dangerous 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 source of radiation.

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

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

Gamma radiation

emitted: energy in the form of photons
penetrating power: high
source exposure: up to hundreds of meters
radiation speed: 300,000 km/s
ionization:
biological effect of radiation: low

Gamma (γ) radiation- this is an 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 radiated 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 a radioactive decay of an atom occurs, then others are formed from some substances. The atom of newly formed substances are in an energetically unstable (excited) state. By acting on each other, neutrons and protons in the nucleus come to a state where the forces of interaction are balanced, and excess energy is emitted by the atom in the form of gamma radiation

Gamma radiation has a high penetrating power and easily penetrates through clothes, living tissues, and a little more difficultly through dense structures of a substance such as metal. To stop gamma radiation would require a significant thickness of steel or concrete. 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 overcome considerable distances and affect living organisms several hundred meters from the source of gamma radiation.

x-ray radiation

emitted: energy in the form of photons
penetrating power: high
source exposure: up to hundreds of meters
radiation speed: 300,000 km/s
ionization: from 3 to 5 pairs of ions per 1 cm of run
biological effect of radiation: low

x-ray radiation- this is an energetic electromagnetic radiation in the form of photons, arising from the transition of an electron inside an atom from one orbit to another.

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

Having considered 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 by elementary particles (alpha, beta and neutron radiation) to energy effects in the form of gamma and X-rays. cure.

Each of the considered radiations is dangerous!

Comparative table with the characteristics of various types of radiation

characteristic	Type of radiation
characteristic	alpha radiation	neutron radiation	beta radiation	Gamma radiation	x-ray radiation
radiated	two protons and two neutrons	neutrons	electrons or positrons	energy in the form of photons	energy in the form of photons
penetrating power	low	high	average	high	high
source exposure	up to 10 cm	kilometers	up to 20 m	hundreds of meters	hundreds of meters
radiation speed	20,000 km/s	40,000 km/s	300,000 km/s	300,000 km/s	300,000 km/s
ionization, vapor per 1 cm of run	30 000	from 3000 to 5000	from 40 to 150	3 to 5	3 to 5
biological effect of radiation	high	high	the average	low	low

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

coefficient k
Type of radiation and energy range	Weight multiplier
Photons all energies (gamma radiation)	1
Electrons and muons all energies (beta radiation)	1
neutrons with energy < 10 КэВ (нейтронное излучение)	5
Neutrons from 10 to 100 keV (neutron radiation)	10
Neutrons from 100 keV to 2 MeV (neutron radiation)	20
Neutrons from 2 MeV to 20 MeV (neutron radiation)	10
Neutrons> 20 MeV (neutron radiation)	5
Protons with energies > 2 MeV (except for recoil protons)	5
alpha particles, fission fragments and other heavy nuclei (alpha radiation)	20

The higher the "factor k" the more dangerous the action a certain kind radiation for the tissues of a living organism.

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Previously, people, in order to explain what they do not understand, invented various fantastic things - myths, gods, religion, magical creatures. And although a large number of people still believe in these superstitions, we now know that everything has its own explanation. One of the most interesting, mysterious and amazing topics is radiation. What does it represent? What kinds 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 motion of a certain object, which causes a consistent rarefaction or compression of the medium. An example is infrasound or ultrasound. Corpuscular radiation is a stream 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 combination 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, proteins.

About electromagnetic radiation

In the future, the article will be devoted exclusively to him. What does radiation in physics do, how does it affect us? EMP is an electromagnetic wave that is emitted by charged molecules, atoms, particles. Antennas or other radiating systems can act as large sources. The wavelength of the radiation (oscillation frequency) together with the sources is of decisive importance. So, depending on these parameters, gamma, x-ray, optical radiation is emitted. The latter is divided into a number of other subspecies. So, it is infrared, ultraviolet, radio emission, and also light. The range is up to 10 -13 . Gamma radiation is generated by excited atomic nuclei. X-rays can be obtained by deceleration of accelerated electrons, as well as by their transition to non-free levels. Radio waves leave their mark while moving along the conductors of radiating systems (for example, antennas) of alternating electric currents.

About ultraviolet radiation

Biologically, UV rays are the most active. Upon contact with the skin, they can cause local changes in tissue and cellular proteins. In addition, the effect on skin receptors is fixed. It reflexively affects the whole organism. Since it is a non-specific stimulant physiological functions, then 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 should also be mentioned about individual specific properties that a certain range of waves has. Thus, the effect of radiation on a person at a length of 320 to 400 nanometers contributes to the erythema-tanning effect. In the range from 275 to 320 nm, weak bactericidal and antirachitic effects are recorded. But ultraviolet radiation from 180 to 275 nm damages biological tissue. Therefore, care must be taken. Long-term direct solar radiation, even in a safe spectrum, can lead to severe erythema with swelling of the skin and a significant deterioration in health. Up to an increase in 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 characterize its influence. The visible spectrum affects the visual analyzer and the functional state of the central nervous system. And through the central nervous system and to 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 gamut of sunlight, that is, the entire spectrum of radiation. So, color perception depends on the wavelength and influences our emotional activity, as well as the functioning of various body systems.

Red 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 fun, while yellow is uplifting and stimulates the nervous system and vision. Green calms, is useful during insomnia, with overwork, increases the overall tone of the body. Purple color has a relaxing effect on the psyche. Blue calms the nervous system and keeps the muscles in good shape.

small digression

Why, considering what radiation is in physics, we are talking more about EMP? The fact is that it is in most cases that they mean it when they turn to the topic. The same corpuscular radiation and wave motion of the medium is an order of magnitude smaller and less known. Very often, when they talk about the types of radiation, they mean only those into which EMP is divided, which is fundamentally wrong. After all, speaking about what radiation is in physics, attention should be paid to all aspects. But at the same time, the emphasis is on the most important points.

About radiation sources

We continue to consider electromagnetic radiation. We know that it is a wave that occurs when an electric or magnetic field is disturbed. This process is interpreted by modern physics from the point of view of the theory of corpuscular-wave dualism. So it is recognized that the minimum portion of EMR is a quantum. But along with this, it is believed that it also has frequency-wave properties, on which the main characteristics depend. To improve the possibilities of classifying sources, different emission spectra of EMP frequencies are distinguished. So this:

Hard radiation (ionized);
Optical (visible to the eye);
Thermal (it is also infrared);
Radio frequency.

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

Nature of sources

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

When there is a perturbation of artificial origin.
Registration of radiation coming from a natural source.

What can be said about the first? Artificial sources are most often a side effect that occurs as a result of the operation of various electrical appliances and mechanisms. Radiation of natural origin generates the Earth's magnetic field, electrical processes in the planet's atmosphere, nuclear fusion in the bowels of the sun. The degree of intensity of the electromagnetic field 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 are:

Almost all devices equipped with a CRT display (such as a computer).
Various Appliances, ranging from climate systems to irons;
Engineering systems that provide electricity to various objects. Examples include power cables, sockets, electricity meters.

High-level electromagnetic radiation is possessed by:

Power lines.
All electric transport and its infrastructure.
Radio and television towers, as well as mobile and mobile communication stations.
Elevators and other lifting equipment where electromechanical power plants are used.
Devices for converting voltage in the network (waves coming from a distribution substation or transformer).

Separately allocate 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 relevant. 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:

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

Specific moments of influence

It all depends on the location. Absorption of radiation can be local or general. As an example of the second case, we can cite the effect that power lines have. An example of local exposure is electromagnetic waves emitted by an electronic watch or mobile phone. The thermal effect should also be mentioned. Due to the vibration of the molecules, the field energy is converted into heat. Microwave emitters work according to this principle, which are used for heating 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 irradiated. At work, at home, moving around the city. Over time, the negative effect only intensifies. Therefore, protection from electromagnetic radiation is becoming more and more important.

How can you protect yourself?

Initially, you need to know what you have to deal with. This will help a special device for measuring radiation. It will allow you to assess the security situation. In production, absorbing screens are used for protection. But, alas, they are not designed for use at home. There are three guidelines to start with:

Stay at a safe distance from devices. For power lines, television and radio towers, this is at least 25 meters. With CRT monitors and TVs, thirty centimeters is enough. Digital Watch must be no closer than 5 cm. A radio and Cell Phones it is not recommended to bring closer than 2.5 centimeters. You can choose a place using a special device - a fluxmeter. The permissible dose of radiation fixed by it should not exceed 0.2 μT.
Try to reduce the time you have to irradiate.
Always turn off electrical appliances that are not in use. After all, even when inactive, they continue to emit EMP.

About the silent killer

And let's finish the article with an important, albeit rather poorly known topic in wide circles - radiation. Throughout his life, development and existence, a person was irradiated by a natural background. Natural radiation can be conventionally 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 made generate a certain background.

Radiation radiation has a significant penetrating power, so it is problematic to stop it. So, in order to completely isolate the rays, it is necessary to hide behind a wall of lead, 80 centimeters thick. Internal exposure occurs when natural radioactive substances enter the body along with food, air, and water. In the bowels of the earth you can find radon, thoron, uranium, thorium, rubidium, radium. All of them are absorbed by plants, they can be in water - and when eating food, they enter our body.

Nuclear energy is quite actively used for peaceful purposes, for example, in the operation of an X-ray machine, an accelerator, which made it possible to propagate ionizing radiation in national economy. Given that a person is exposed to it on a daily basis, it is necessary to find out what the consequences of dangerous contact can be and how to protect yourself.

Main characteristic

Ionizing radiation is a kind of radiant energy that enters a specific environment, causing the process of ionization in the body. A similar characteristic of ionizing radiation is suitable for x-rays, radioactive and high energies, and much more.

Ionizing radiation has a direct effect on the human body. Despite the fact that ionizing radiation can be used in medicine, it is extremely dangerous, as evidenced by its characteristics and properties.

Known varieties are radioactive irradiations, which appear due to the arbitrary splitting of the atomic nucleus, which causes the transformation of chemical, physical properties. Substances that can decay are considered radioactive.

They are artificial (seven hundred elements), natural (fifty elements) - thorium, uranium, radium. It should be noted that they have carcinogenic properties, toxins are released as a result of exposure to humans can cause cancer, radiation sickness.

It is necessary to note the following types of ionizing radiation that affect the human body:

Alpha

They are considered positively charged helium ions, which appear in the case of the decay of the nuclei of heavy elements. Protection from ionizing radiation is carried out using a paper sheet, cloth.

Beta

- a stream of negatively charged electrons that appear in the event of the decay of radioactive elements: artificial, natural. The damaging factor is much higher than that of the previous species. As protection, you need a thick screen, more durable. These radiations include positrons.

Gamma

- a hard electromagnetic oscillation that appears after the decay of the nuclei of radioactive substances. There is a high penetrating factor, which is the most dangerous radiation of the three listed for the human body. To shield the rays, you need to use special devices. This will require good and durable materials: water, lead and concrete.

x-ray

Ionizing radiation is formed in the process of working with a tube, complex installations. The characteristic resembles gamma rays. The difference lies in the origin, wavelength. There is a penetrating factor.

Neutron

Neutron radiation is a stream of uncharged neutrons, which are part of nuclei, except for hydrogen. As a result of irradiation, substances receive a portion of radioactivity. There is the largest penetrating factor. All these types of ionizing radiation are very dangerous.

Main sources of radiation

Sources of ionizing radiation are artificial, natural. Basically, the human body receives radiation from natural sources, these include:

terrestrial radiation;
internal irradiation.

As for the sources of terrestrial radiation, many of them are carcinogenic. These include:

Uranus;
potassium;
thorium;
polonium;
lead;
rubidium;
radon.

The danger is that they are carcinogenic. Radon is a gas that has no smell, color, taste. It is seven and a half times heavier than air. Its decay products are much more dangerous than gas, so the impact on the human body is extremely tragic.

Artificial sources include:

nuclear power;
enrichment factories;
uranium mines;
burial grounds with radioactive waste;
x-ray machines;
nuclear explosion;
scientific laboratories;
radionuclides that are actively used in modern medicine;
lighting devices;
computers and telephones;
Appliances.

In the presence of these sources nearby, there is a factor of the absorbed dose of ionizing radiation, the unit of which depends on the duration of exposure to the human body.

The operation of sources of ionizing radiation occurs daily, for example: when you work at a computer, watch a TV show or speak on mobile phone, smartphone. All of these sources are to some extent carcinogenic, they can cause severe and fatal diseases.

The placement of sources of ionizing radiation includes a list of important, responsible work related to the development of a project for the location of irradiating installations. All radiation sources contain a certain unit of radiation, each of which has a certain effect on the human body. This includes manipulations carried out for installation, commissioning of these installations.

It should be pointed out that the disposal of sources of ionizing radiation is mandatory.

It is a process that helps to decommission generating sources. This procedure consists of technical, administrative measures that are aimed at ensuring the safety of personnel, the public, and there is also a factor in protecting the environment. Carcinogenic sources and equipment are a huge danger to the human body, so they must be disposed of.

Features of registration of radiation

The characteristic of ionizing radiation shows that they are invisible, they have no smell and color, so they are difficult to notice.

For this, there are methods for registering ionizing radiation. As for the methods of detection, measurement, everything is carried out indirectly, some property is taken as the basis.

The following methods for detecting ionizing radiation are used:

Physical: ionization, proportional counter, gas-discharge Geiger-Muller counter, ionization chamber, semiconductor counter.
Calorimetric detection method: biological, clinical, photographic, hematological, cytogenetic.
Fluorescent: Fluorescent and scintillation counters.
Biophysical method: radiometry, calculated.

Dosimetry of ionizing radiation is carried out with the help of devices that are able to determine the dose of radiation. The device includes three main parts - pulse counter, sensor, power supply. Radiation dosimetry is possible thanks to a dosimeter, a radiometer.

Influences on a person

The effect of ionizing radiation on the human body is especially dangerous. The following consequences are possible:

there is a factor of very deep biological change;
there is a cumulative effect of a unit of absorbed radiation;
the effect manifests itself over time, since a latent period is noted;
everyone has internal organs, systems have different sensitivity to a unit of absorbed radiation;
radiation affects all offspring;
the effect depends on the unit of absorbed radiation, radiation dose, duration.

Despite the use of radiation devices in medicine, their effects can be detrimental. The biological effect of ionizing radiation in the process of uniform irradiation of the body, in the calculation of 100% of the dose, is the following:

bone marrow - a unit of absorbed radiation 12%;
lungs - at least 12%;
bones - 3%;
testicles, ovaries– the absorbed dose of ionizing radiation is about 25%;
thyroid gland– unit of absorbed dose is about 3%;
mammary glands - approximately 15%;
other tissues - the unit of absorbed radiation dose is 30%.

As a result, various diseases can occur up to oncology, paralysis and radiation sickness. It is extremely dangerous for children and pregnant women, as there is an abnormal development of organs and tissues. Toxins, radiation - sources of dangerous diseases.

"People's attitude to this or that danger is determined by how well it is familiar to them."

This material is a generalized answer to numerous questions that arise from users of devices for detecting and measuring radiation in the home.
The minimal use of the specific terminology of nuclear physics in the presentation of the material will help you to freely navigate this environmental problem, without succumbing to radiophobia, but also without excessive complacency.

The danger of RADIATION real and imaginary

"One of the first naturally occurring radioactive elements discovered was called 'radium'"
- translated from Latin - emitting rays, radiating.

Each person in the environment lies in wait for various phenomena that affect him. These include heat, cold, magnetic and ordinary storms, heavy rains, heavy snowfalls, strong winds, sounds, explosions, etc.

Due to the presence of the sense organs assigned to him by nature, he can quickly respond to these phenomena with the help of, for example, a sunshade, clothing, housing, medicines, screens, shelters, etc.

However, in nature there is a phenomenon to which a person, due to the lack of the necessary sense organs, cannot instantly react - this is radioactivity. Radioactivity is not a new phenomenon; radioactivity and its accompanying radiation (the so-called ionizing radiation) have always existed in the Universe. Radioactive materials are part of the Earth, and even a person is slightly radioactive, because. Every living tissue contains trace amounts of radioactive substances.

The most unpleasant property of radioactive (ionizing) radiation is its effect on the tissues of a living organism, therefore, appropriate measuring instruments are needed that would provide operational information for making useful decisions before a long time passes and undesirable or even fatal consequences appear. will not begin to feel immediately, but only after some time has passed. Therefore, information about the presence of radiation and its power must be obtained as early as possible.
But enough of the mysteries. Let's talk about what radiation and ionizing (i.e. radioactive) radiation are.

ionizing radiation

Any environment consists of the smallest neutral particles-atoms, which consist of positively charged nuclei and negatively charged electrons surrounding them. Each atom is like a miniature solar system: around a tiny nucleus, “planets” move in orbits - electrons.
atom nucleus consists of several elementary particles - protons and neutrons held by nuclear forces.

Protons particles with a positive charge equal in absolute value to the charge of electrons.

Neutrons neutral, uncharged particles. The number of electrons in an atom is exactly equal to the number of protons in the nucleus, so each atom is neutral as a whole. The mass of a proton is almost 2000 times the mass of an electron.

The number of neutral particles (neutrons) present in the nucleus can be different for the same number of protons. Such atoms, having nuclei with the same number of protons, but differing in the number of neutrons, are varieties of the same chemical element, called "isotopes" of this element. To distinguish them from each other, a number equal to the sum of all particles in the nucleus of a given isotope is assigned to the element symbol. So uranium-238 contains 92 protons and 146 neutrons; Uranium 235 also has 92 protons, but 143 neutrons. All isotopes of a chemical element form a group of "nuclides". Some nuclides are stable, i.e. do not undergo any transformations, while others emitting particles are unstable and turn into other nuclides. As an example, let's take an atom of uranium - 238. From time to time, a compact group of four particles escapes from it: two protons and two neutrons - "alpha particle (alpha)". Uranium-238 is thus converted into an element whose nucleus contains 90 protons and 144 neutrons - thorium-234. But thorium-234 is also unstable: one of its neutrons turns into a proton, and thorium-234 turns into an element with 91 protons and 143 neutrons in its nucleus. This transformation also affects the electrons moving in their orbits (beta): one of them becomes, as it were, superfluous, without a pair (proton), so it leaves the atom. A chain of numerous transformations, accompanied by alpha or beta radiation, ends with a stable lead nuclide. Of course, there are many similar chains of spontaneous transformations (decays) of different nuclides. The half-life is the period of time during which the initial number of radioactive nuclei is on average halved.
With each act of decay, energy is released, which is transmitted in the form of radiation. Often an unstable nuclide is in an excited state, and the emission of a particle does not lead to a complete removal of the excitation; then he throws out a portion of energy in the form of gamma radiation (gamma quantum). As with X-rays (which differ from gamma rays only in frequency), no particles are emitted. The whole process of spontaneous decay of an unstable nuclide is called radioactive decay, and the nuclide itself is called a radionuclide.

Different types of radiation are accompanied by the release of different amounts of energy and have different penetrating power; therefore, they have a different effect on the tissues of a living organism. Alpha radiation is delayed, for example, by a sheet of paper and is practically unable to penetrate the outer layer of the skin. Therefore, it does not pose a danger until radioactive substances emitting alpha particles enter the body through an open wound, with food, water or inhaled air or steam, for example, in a bath; then they become extremely dangerous. A beta particle has a greater penetrating power: it passes into the tissues of the body to a depth of one or two centimeters or more, depending on the amount of energy. The penetrating power of gamma radiation, which propagates at the speed of light, is very high: it can only be stopped by a thick lead or concrete slab. Ionizing radiation is characterized by a number of measured physical quantities. These include energy quantities. At first glance, it may seem that they are enough to register and evaluate the effects of ionizing radiation on living organisms and humans. However, these energy values do not reflect the physiological effects of ionizing radiation on human body and other living tissues are subjective and different for different people. Therefore, average values are used.

Sources of radiation are natural, present in nature, and not dependent on man.

It has been established that of all natural sources of radiation, radon, a heavy, tasteless, odorless and invisible gas, poses the greatest danger; with their child products.

Radon is released from the earth's crust everywhere, but its concentration in the outdoor air varies significantly for different parts of the globe. Paradoxical as it may seem at first glance, but a person receives the main radiation from radon while in a closed, unventilated room. Radon is concentrated in indoor air only when they are sufficiently isolated from the external environment. Seeping through the foundation and floor from the soil or, less often, being released from building materials, radon accumulates in the room. Sealing rooms for the purpose of insulation only exacerbates the matter, since it makes it even more difficult for the radioactive gas to escape from the room. The problem of radon is especially important for low-rise buildings with careful sealing of premises (in order to preserve heat) and the use of alumina as an additive to building materials(the so-called "Swedish problem"). The most common building materials - wood, brick and concrete - emit relatively little radon. Granite, pumice, products made from alumina raw materials, and phosphogypsum have much higher specific radioactivity.

Another, usually less important, source of indoor radon is water and natural gas used for cooking and home heating.

The concentration of radon in commonly used water is extremely low, but water from deep wells or artesian wells contains a lot of radon. However, the main danger does not come from drinking water, even with a high content of radon in it. Usually people consume most of the water in food and in the form of hot drinks, and when boiling water or cooking hot dishes, radon almost completely disappears. A much greater danger is the ingress of water vapor with a high content of radon into the lungs along with the inhaled air, which most often occurs in the bathroom or steam room (steam room).

In natural gas, radon penetrates underground. As a result of preliminary processing and during the storage of gas before it enters the consumer, most of the radon escapes, but the concentration of radon in the room can increase markedly if stoves and other gas heating appliances are not equipped with an exhaust hood. In the presence of supply and exhaust ventilation, which communicates with the outside air, the concentration of radon in these cases does not occur. This also applies to the house as a whole - focusing on the readings of radon detectors, you can set the ventilation mode of the premises, which completely eliminates the threat to health. However, given that the release of radon from the soil is seasonal, it is necessary to control the effectiveness of ventilation three to four times a year, not allowing the concentration of radon to exceed the norms.

Other sources of radiation, which unfortunately have a potential danger, are created by man himself. Sources of artificial radiation are artificial radionuclides, beams of neutrons and charged particles created with the help of nuclear reactors and accelerators. They are called man-made sources of ionizing radiation. It turned out that along with a dangerous character for a person, radiation can be put at the service of a person. Here is a far from complete list of areas of application of radiation: medicine, industry, Agriculture, chemistry, science, etc. A calming factor is the controlled nature of all activities related to the production and use of artificial radiation.

Tests stand apart in their impact on humans. nuclear weapons in the atmosphere, accidents at nuclear power plants and nuclear reactors and the results of their work, manifested in radioactive fallout and radioactive waste. However, only emergencies, such as the Chernobyl accident, can have an uncontrollable impact on a person.
The rest of the work is easily controlled at a professional level.

When radioactive fallout occurs in some areas of the Earth, radiation can enter the human body directly through agricultural products and food. Protecting yourself and your loved ones from this danger is very simple. When buying milk, vegetables, fruits, herbs, and any other products, it will not be superfluous to turn on the dosimeter and bring it to the purchased products. Radiation is not visible - but the device will instantly detect the presence of radioactive contamination. This is our life in the third millennium - the dosimeter becomes an attribute Everyday life like handkerchief, toothbrush, soap.

IMPACT OF IONIZING RADIATION ON TISSUES OF THE BODY

Damage caused in a living organism by ionizing radiation will be the greater, the more energy it transfers to tissues; the amount of this energy is called a dose, by analogy with any substance entering the body and completely absorbed by it. The body can receive a dose of radiation regardless of whether the radionuclide is outside the body or inside it.

The amount of radiation energy absorbed by the irradiated tissues of the body, calculated per unit mass, is called the absorbed dose and is measured in Grays. But this value does not take into account the fact that with the same absorbed dose, alpha radiation is much more dangerous (twenty times) than beta or gamma radiation. The dose recalculated in this way is called the equivalent dose; It is measured in units called Sieverts.

It should also be taken into account that some parts of the body are more sensitive than others: for example, at the same equivalent dose of radiation, the occurrence of cancer in the lungs is more likely than in the thyroid gland, and irradiation of the gonads is especially dangerous due to the risk of genetic damage. Therefore, human exposure doses should be taken into account with different coefficients. Multiplying the equivalent doses by the corresponding coefficients and summing up over all organs and tissues, we obtain the effective equivalent dose, which reflects the total effect of irradiation on the body; it is also measured in Sieverts.

charged particles.

Alpha and beta particles penetrating into the tissues of the body lose energy due to electrical interactions with the electrons of those atoms near which they pass. (Gamma rays and X-rays transfer their energy to matter in several ways, which eventually also lead to electrical interactions.)

Electrical interactions.

In the order of ten trillionth of a second after the penetrating radiation reaches the corresponding atom in the tissue of the body, an electron is detached from this atom. The latter is negatively charged, so the rest of the initially neutral atom becomes positively charged. This process is called ionization. The detached electron can further ionize other atoms.

Physical and chemical changes.

Both a free electron and an ionized atom usually cannot remain in this state for long, and over the next ten billionths of a second, they participate in a complex chain of reactions that result in the formation of new molecules, including extremely reactive ones such as "free radicals".

chemical changes.

Over the next millionths of a second, the free radicals formed react both with each other and with other molecules and, through a chain of reactions not yet fully understood, can cause chemical modification of biologically important molecules necessary for the normal functioning of the cell.

biological effects.

Biochemical changes can occur both in a few seconds and decades after irradiation and cause immediate cell death or changes in them.

RADIOACTIVITY UNITS
Becquerel (Bq, Vq); Curie (Ki, Si)	1 Bq = 1 disintegration per second. 1 Ki \u003d 3.7 x 10 10 Bq	Radionuclide activity units. Represent the number of decays per unit time.
Gray (Gr, Gu); Glad (rad, rad)	1 Gy = 1 J/kg 1 rad = 0.01 Gy	units of absorbed dose. They represent the amount of ionizing radiation energy absorbed by a unit of mass of a physical body, for example, body tissues.
Sievert (Sv, Sv) Rem (ber, rem) - "X-ray biological equivalent"	1 Sv = 1 Gy = 1 J/kg (for beta and gamma) 1 µSv = 1/1000000 Sv 1 ber = 0.01 Sv = 10 mSv Dose equivalent units.	Units of equivalent dose. They are a unit of absorbed dose multiplied by a factor that takes into account the unequal danger of different types of ionizing radiation.
Gray per hour (Gy/h); Sievert per hour (Sv/h); Roentgen per hour (R/h)	1 Gy/h = 1 Sv/h = 100 R/h (for beta and gamma) 1 µSv/h = 1 µGy/h = 100 µR/h 1 µR/h = 1/1000000 R/h	Dose rate units. Represent the dose received by the body per unit of time.

For information, and not for intimidation, especially people who decide to devote themselves to working with ionizing radiation, you should know the maximum allowable doses. The units of measurement of radioactivity are given in Table 1. According to the conclusion of the International Commission on Radiation Protection for 1990, harmful effects can occur at equivalent doses of at least 1.5 Sv (150 rem) received during the year, and in cases of short-term exposure - at doses above 0.5 Sv (50 rem). When exposure exceeds a certain threshold, radiation sickness occurs. There are chronic and acute (with a single massive impact) forms of this disease. Acute radiation sickness is divided into four degrees of severity, ranging from a dose of 1-2 Sv (100-200 rem, 1st degree) to a dose of more than 6 Sv (600 rem, 4th degree). The fourth degree can be fatal.

Doses received under normal conditions are negligible compared to those indicated. The equivalent dose rate generated by natural radiation ranges from 0.05 to 0.2 µSv/h, i.e. from 0.44 to 1.75 mSv/year (44-175 mrem/year).
In medical diagnostic procedures - X-rays, etc. - a person receives about 1.4 mSv/year.

Since radioactive elements are present in brick and concrete in small doses, the dose increases by another 1.5 mSv/year. Finally, due to the emissions of modern coal-fired thermal power plants and air travel, a person receives up to 4 mSv / year. The total existing background can reach 10 mSv/year, but on average does not exceed 5 mSv/year (0.5 rem/year).

Such doses are completely harmless to humans. The dose limit in addition to the existing background for a limited part of the population in areas of increased radiation is set at 5 mSv / year (0.5 rem / year), i.e. with a 300-fold margin. For personnel working with sources of ionizing radiation, the maximum allowable dose is 50 mSv/year (5 rem/year), i.e. 28 μSv/h for a 36-hour work week.

According to the hygienic standards NRB-96 (1996) acceptable levels dose rate for external exposure of the whole body from technogenic sources for permanent residence of personnel - 10 μGy/h, for residential premises and areas where members of the public are permanently located - 0.1 μGy/h (0.1 μSv/h, 10 μR/h).

WHAT IS RADIATION MEASURED

A few words about registration and dosimetry of ionizing radiation. There are various methods of registration and dosimetry: ionization (associated with the passage of ionizing radiation in gases), semiconductor (in which the gas is replaced solid), scintillation, luminescent, photographic. These methods form the basis of the work dosimeters radiation. Among the gas-filled sensors of ionizing radiation, one can note ionization chambers, fission chambers, proportional counters and Geiger-Muller counters. The latter are relatively simple, the cheapest, and not critical to the working conditions, which led to their widespread use in professional dosimetric equipment designed to detect and evaluate beta and gamma radiation. When the sensor is a Geiger-Muller counter, any ionizing particle that enters the sensitive volume of the counter will cause self-discharge. Precisely falling into a sensitive volume! Therefore, alpha particles are not registered, because they can't get in there. Even when registering beta - particles, it is necessary to bring the detector closer to the object to make sure that there is no radiation, because. in the air, the energy of these particles may be weakened, they may not pass through the body of the device, they will not fall into the sensitive element and will not be detected.

Doctor of Physical and Mathematical Sciences, Professor of MEPhI N.M. Gavrilov
the article was written for the company "Kvarta-Rad"