In recent years, we can increasingly hear about the radioactive threat to all of humanity. Unfortunately, this is true, and, as the experience of the Chernobyl accident and the nuclear bomb in Japanese cities has shown, radiation can turn from a faithful assistant into a fierce enemy. And in order to know what radiation is and how to protect yourself from its negative effects, let's try to analyze all the available information.

Impact of radioactive elements on human health

Every person at least once in his life came across the concept of "radiation". But what is radiation and how dangerous it is, few people know. To understand this issue in more detail, it is necessary to carefully study all types of radiation effects on humans and nature. Radiation is the process of radiation of the flow of elementary particles of the electromagnetic field. The effect of radiation on human life and health is commonly referred to as irradiation. In the process of this phenomenon, radiation multiplies in the cells of the body and thereby destroys it. Radiation exposure is especially dangerous for young children, whose bodies have not sufficiently formed and become stronger. The defeat of a person by such a phenomenon can cause the most serious diseases: infertility, cataracts, infectious diseases and tumors (both malignant and benign). In any case, radiation does not benefit human life, but only destroys it. But do not forget that you can protect yourself and purchase a radiation dosimeter, with which you will always know about the radioactive level of the environment.

In fact, the body reacts to radiation, not to its source. Radioactive substances enter the human body through the air (during the respiratory process), as well as when eating food and water, which were initially irradiated with a stream of radiation rays. The most dangerous radiation, perhaps, is internal. It is carried out to treat certain diseases when radioisotopes are used in medical diagnostics.

Types of radiation

To answer the question of what radiation is as clearly as possible, one should consider its varieties. According to the nature and effects on humans, there are several types of radiation:

1. Alpha particles are heavy particles that have a positive charge and appear in the form of a helium nucleus. Their impact on the human body is sometimes irreversible.
2. Beta particles are ordinary electrons.
3. Gamma radiation - has a high level of penetration.
4. Neutrons are electrically charged neutral particles that exist only in those places where there is a nuclear reactor nearby. To an ordinary person not feel this type of radiation on your body, since access to the reactor is very limited.
5. X-rays are perhaps the safest form of radiation. Essentially similar to gamma radiation. However, the most a prime example X-ray exposure can be called the Sun, which illuminates our planet. Thanks to the atmosphere, people are protected from high radiation background.

Alpha, Beta and Gamma emitting particles are considered to be extremely dangerous. They can cause genetic diseases, malignant tumors and even death. By the way, according to experts, nuclear power plant radiation emitted into the environment is not dangerous, although it combines almost all types of radioactive contamination. Sometimes antiques and antiques are treated with radiation to avoid rapid deterioration of cultural heritage. However, radiation quickly reacts with living cells, and subsequently destroys them. Therefore, one should be wary of antiquities. Clothing serves as elementary protection against the penetration of external radiation. You should not count on complete protection from radiation on a sunny hot day. In addition, radiation sources may not give themselves away for a long time and be active at the moment when you are around.

How to measure the level of radiation

The level of radiation can be measured with a dosimeter both in industrial and domestic households. For those who live near nuclear power plants, or people who are simply concerned about their safety, this device will be simply indispensable. The main purpose of such a device as a radiation dosimeter is to measure the dose rate of radiation. This indicator can be checked not only with respect to a person and a room. Sometimes you have to pay attention to some items that can be dangerous to humans. Children's toys, food and building materials - each of the items can be endowed with a certain dose of radiation. For those residents who live near the Chernobyl nuclear power plant, where terrible disaster in 1986, it is simply necessary to buy a dosimeter in order to always be on the alert and know what dose of radiation is present in the environment at a particular moment. Fans of extreme entertainment, trips to places remote from civilization should provide themselves with items for their own safety in advance. It is impossible to clean the earth, building materials or food from radiation. Therefore, it is better to avoid adverse effects on your body.

Computer - source of radiation

Perhaps many people think so. However, this is not quite true. A certain level of radiation comes only from the monitor, and even then, only from the electro-beam. At the present time, manufacturers do not produce such equipment, which has been excellently replaced by liquid crystal and plasma screens. But in many homes, old electric beam TVs and monitors are still functioning. They are a rather weak source of X-ray radiation. Due to the thickness of the glass, this very radiation remains on it and does not harm human health. Therefore, do not worry too much.

Radiation dose relative to terrain

It can be said with extreme accuracy that natural radiation is a very variable parameter. Depending on the geographical location and a certain time period, this indicator may vary within a wide range. For example, the radiation rate on Moscow streets ranges from 8 to 12 micro-roentgens per hour. But on the mountain peaks, it will be 5 times higher, since there the protective capabilities of the atmosphere are much lower than in settlements that are closer to the level of the world ocean. It should be noted that in places of accumulation of dust and sand, saturated with a high content of uranium or thorium, the level of background radiation will be significantly increased. To determine the radiation background indicator at home, you should purchase a dosimeter-radiometer and perform appropriate measurements indoors or outdoors.

Radiation protection and its types

Recently, more and more often you can hear discussions on the topic of what radiation is and how to deal with it. And in the process of discussions, such a term as radiation protection emerges. Radiation protection is commonly understood as a set of specific measures to protect living organisms from the effects of ionizing radiation, as well as the search for ways to reduce the damaging effect of ionizing radiation.

There are several types of radiation protection:

1. Chemical. This is a weakening of the negative effects of radiation on the body by introducing into it certain chemicals called radioprotectors.
2. Physical. This is the use of various materials that weaken the radiation background. For example, if the layer of earth that was exposed to radiation is 10 cm, then a mound 1 meter thick will reduce the amount of radiation by 10 times.
3. biological radiation protection. It is a complex of protective repairing enzymes.

For protection against different types radiation, you can use some household items:

• From alpha radiation - a respirator, paper, rubber gloves.
• From Beta radiation - a gas mask, glass, a small layer of aluminum, plexiglass.
• From Gamma radiation - only heavy metals(lead, cast iron, steel, tungsten).
• From neutrons - various polymers, as well as water and polyethylene.

Elementary methods of protection against radiation exposure

For a person who finds himself within the radius of the radiation contamination zone, the most important issue at this point will be his own protection. Therefore, anyone who has become an unwitting prisoner of the spread of radiation levels should definitely leave their location and go as far as possible. How faster man does so, the less likely it is to receive a certain and unwanted dose of radioactive substances. If leaving your home is not possible, then you should resort to other security measures:

• the first few days do not leave the house;
• do wet cleaning 2-3 times a day;
• shower and wash clothes as often as possible;
• in order to protect the body from harmful radioactive iodine-131, you should anoint a small area of ​​\u200b\u200bthe body with a solution of medical iodine (according to doctors, this procedure is effective for a month);
• in case of urgent need to leave the premises, it is worth putting a baseball cap and a hood on your head at the same time, as well as wet clothes in light colors made of cotton material.

It is dangerous to drink radioactive water, since its total radiation is quite high and can have negative impact on the human body. The easiest way to clean it is to pass it through a charcoal filter. Of course, the shelf life of such a filter cassette is drastically reduced. Therefore, you need to change the cassette as often as possible. Another untested method is boiling. The guarantee of cleaning from radon will not be 100% in any of the cases.

Proper diet in case of danger of radiation exposure

It is well known that in the course of discussions on the topic of what radiation is, the question arises of how to protect yourself from it, what to eat and what vitamins to use. There is a list of products that are the most dangerous for consumption. The largest number radionuclides accumulate in fish, mushrooms and meat. Therefore, it is worth limiting yourself in the use of these foods. Vegetables should be thoroughly washed, boiled and cut off the top peel. Sunflower seeds, offal - kidneys, heart, and eggs can be considered the best products for consumption during the period of radioactive radiation. You need to eat as much iodine-containing products as possible. Therefore, each person should buy iodized salt and seafood.

Some people believe that red wine will protect against radionuclides. There is some truth in this. When drinking 200 ml per day of this drink, the body becomes less vulnerable to radiation. But the accumulated radionuclides cannot be removed with wine, so the total radiation still remains. However, some substances contained in the wine drink can block the harmful effects of radiation elements. However, in order to avoid problems, it is necessary to remove harmful substances from the body with the help of medicines.

Medical radiation protection

A certain proportion of radionuclides that have entered the body can be tried to be removed using sorbent preparations. The simplest means that can weaken the effects of radiation include activated charcoal, which should be consumed 2 tablets before meals. A similar property is endowed with such medications as Enterosgel and Atoxil. They block harmful elements, enveloping them, and remove them from the body with the help of the urinary system. At the same time, harmful radioactive elements, even remaining in the body in small quantities, will not be able to have a significant impact on human health.

The use of herbal preparations against radiation

In the fight against the excretion of radionuclides, not only medicines purchased at a pharmacy can help, but also some types of herbs that will cost many times less. For example, lungwort, zamaniha and ginseng root can be attributed to radioprotective plants. In addition, to reduce the level of concentration of radionuclides, it is recommended to use an extract of Eleutherococcus in the amount of half a teaspoon after breakfast, drinking this tincture with warm tea.

Can a person be a source of radiation

When exposed to the human body, radiation does not create in it radioactive substances. It follows from this that a person by himself cannot be a source of radiation. However, things that have been touched by a dangerous dose of radiation are not safe for health. There is an opinion that it is better not to keep x-rays at home. But they won't really hurt anyone. The only thing to remember is that X-rays should not be done too often, otherwise it can lead to health problems, since there is still a dose of radioactive exposure.

Radiation is a stream of particles formed during nuclear reactions or radioactive decay. We all have heard about the danger of radioactive radiation for the human body and we know that it can cause a huge number of pathological conditions. But often most people do not know what exactly is the danger of radiation and how you can protect yourself from it. In this article, we examined what radiation is, what is its danger to humans, and what diseases it can cause.

What is radiation

The definition of this term is not very clear for a person who is not related to physics or, for example, medicine. The term "radiation" refers to the release of particles formed during nuclear reactions or radioactive decay. That is, this is the radiation that comes out of certain substances.

Radioactive particles have different ability to penetrate and pass through different substances. Some of them can pass through glass, the human body, concrete.

Based on the knowledge of the ability of specific radioactive waves to pass through materials, rules for protection against radiation are drawn up. For example, the walls of X-ray rooms are made of lead, through which radioactive radiation cannot pass.

Radiation happens:

• natural. It forms the natural radiation background to which we are all accustomed. The sun, soil, stones emit radiation. They are not dangerous to the human body.
• technogenic, that is, one that was created as a result of human activity. This includes the extraction of radioactive substances from the depths of the Earth, the use of nuclear fuels, reactors, etc.

How radiation enters the human body

Radiation is dangerous to humans. With an increase in its level above the permissible norm, various diseases and lesions of internal organs and systems develop. Against the background of radiation exposure, malignant oncological pathologies can develop. Radiation is also used in medicine. It is used to diagnose and treat many diseases.

Task (for warming up):

I'll tell you, my friends
How to grow mushrooms:
Need in the field early in the morning
Move two pieces of uranium...

Question: What must be the total mass of uranium pieces for a nuclear explosion to occur?

Answer(in order to see the answer - you need to highlight the text) : For uranium-235, the critical mass is approximately 500 kg. If we take a ball of such a mass, then the diameter of such a ball will be 17 cm.

Radiation, what is it?

Radiation (translated from English as "radiation") is radiation that is used not only for radioactivity, but also for a number of other physical phenomena, for example: solar radiation, thermal radiation, etc. Thus, with regard to radioactivity, it is necessary to use the adopted ICRP (International Commission on radiation protection) and the radiation safety rules the phrase "ionizing radiation".

Ionizing radiation, what is it?

Ionizing radiation - radiation (electromagnetic, corpuscular), which causes ionization (the formation of ions of both signs) of a substance (environment). The probability and number of formed pairs of ions depends on the energy of ionizing radiation.

Radioactivity, what is it?

Radioactivity - radiation of excited nuclei or spontaneous transformation of unstable atomic nuclei into the nuclei of other elements, accompanied by the emission of particles or γ-quantum (s). The transformation of ordinary neutral atoms into an excited state occurs under the influence of external energy of various kinds. Further, the excited nucleus seeks to remove excess energy by radiation (emission of alpha particles, electrons, protons, gamma quanta (photons), neutrons), until a stable state is reached. Many heavy nuclei (the transuranium series in the periodic table - thorium, uranium, neptunium, plutonium, etc.) are initially in an unstable state. They are able to spontaneously disintegrate. This process is also accompanied by radiation. Such nuclei are called natural radionuclides.

This animation clearly shows the phenomenon of radioactivity.

A cloud chamber (a plastic box cooled to -30°C) is filled with isopropyl alcohol vapor. Julien Simon placed a 0.3-cm³ piece in it radioactive uranium(mineral uraninite). The mineral emits α-particles and beta-particles, since it contains U-235 and U-238. On the way of movement of α and beta particles are molecules of isopropyl alcohol.

Since the particles are charged (alpha is positive, beta is negative), they can take an electron from an alcohol molecule (alpha particle) or add electrons to alcohol molecules of beta particles). This, in turn, gives the molecules a charge, which then attracts uncharged molecules around them. When the molecules are gathered together, noticeable white clouds are obtained, which can be clearly seen in the animation. So we can easily trace the paths of the ejected particles.

α particles create straight, thick clouds, while beta particles create long ones.

Isotopes, what are they?

Isotopes are a variety of atoms of the same chemical element, having different mass numbers, but including the same electric charge atomic nuclei and, therefore, occupying periodic system elements D.I. Mendeleev single place. For example: 131 55 Cs, 134 m 55 Cs, 134 55 Cs, 135 55 Cs, 136 55 Cs, 137 55 Cs. Those. charge largely determines the chemical properties of an element.

There are stable (stable) isotopes and unstable (radioactive isotopes) - spontaneously decaying. About 250 stable and about 50 natural radioactive isotopes are known. An example of a stable isotope is 206 Pb, which is the end product of the decay of the natural radionuclide 238 U, which, in turn, appeared on our Earth at the beginning of the formation of the mantle and is not associated with technogenic pollution.

What types of ionizing radiation exist?

The main types of ionizing radiation that are most often encountered are:

• alpha radiation;
• beta radiation;
• gamma radiation;
• x-ray radiation.

Of course, there are other types of radiation (neutron, positron, etc.), but we encounter them much less frequently in everyday life. Each type of radiation has its own nuclear-physical characteristics and, as a result, different biological effects on the human body. Radioactive decay can be accompanied by one of the types of radiation or several at once.

Sources of radioactivity can be natural or artificial. natural springs ionizing radiation - these are radioactive elements that are in the earth's crust and form a natural radiation background together with cosmic radiation.

Artificial sources of radioactivity, as a rule, are formed in nuclear reactors or accelerators based on nuclear reactions. Various electrovacuum physical devices, charged particle accelerators, etc. can also be sources of artificial ionizing radiation. For example: a TV kinescope, an X-ray tube, a kenotron, etc.

Alpha radiation (α-radiation) - corpuscular ionizing radiation, consisting of alpha particles (helium nuclei). Formed during radioactive decay and nuclear transformations. Helium nuclei have a sufficiently large mass and energy up to 10 MeV (Megaelectron-Volt). 1 eV = 1.6∙10 -19 J. Having an insignificant mileage in the air (up to 50 cm), they pose a high danger to biological tissues if they get on the skin, mucous membranes of the eyes and respiratory tract, if they get inside the body in the form of dust or gas ( radon-220 and 222). The toxicity of alpha radiation is due to the enormously high density of ionization due to the high energy and mass.

Beta radiation (β radiation) - corpuscular electronic or positron ionizing radiation of the corresponding sign with a continuous energy spectrum. It is characterized by the maximum energy of the spectrum E β max , or the average energy of the spectrum. The range of electrons (beta particles) in the air reaches several meters (depending on the energy), in biological tissues the range of a beta particle is several centimeters. Beta radiation, like alpha radiation, is dangerous when exposed to contact (surface contamination), for example, when it enters the body, on mucous membranes and skin.

Gamma radiation (γ - radiation or gamma quanta) - short-wave electromagnetic (photon) radiation with a wavelength

X-ray radiation - in its physical properties, similar to gamma radiation, but having a number of features. It appears in an X-ray tube due to a sharp stop of electrons on a ceramic target-anode (the place where electrons hit is usually made of copper or molybdenum) after acceleration in the tube (continuous spectrum - bremsstrahlung) and when electrons are knocked out of internal electronic shells of the target atom ( line spectrum). The X-ray energy is low - from fractions of a few eV to 250 keV. X-ray radiation can be obtained using charged particle accelerators - synchrotron radiation with a continuous spectrum with an upper limit.

Passage of radiation and ionizing radiation through obstacles:

The sensitivity of the human body to the effects of radiation and ionizing radiation on it:

What is a radiation source?

Source of ionizing radiation (RSR) - an object that includes a radioactive substance or a technical device that creates or in certain cases is capable of creating ionizing radiation. Distinguish between closed and open sources of radiation.

What are radionuclides?

Radionuclides are nuclei subject to spontaneous radioactive decay.

What is a half-life?

Half-life is the period of time during which the number of nuclei of a given radionuclide is reduced by half as a result of radioactive decay. This quantity is used in the law of radioactive decay.

What is the unit of measure for radioactivity?

The activity of a radionuclide, in accordance with the SI measurement system, is measured in Becquerels (Bq) - named after the French physicist who discovered radioactivity in 1896), Henri Becquerel. One Bq is equal to 1 nuclear conversion per second. The power of the radioactive source is measured in Bq/s, respectively. The ratio of the activity of a radionuclide in a sample to the mass of the sample is called the specific activity of the radionuclide and is measured in Bq/kg (l).

In what units is ionizing radiation measured (X-ray and gamma)?

What do we see on the display of modern dosimeters that measure AI? The ICRP has proposed to measure human exposure to dose at a depth d of 10 mm. The measured dose at this depth is called the ambient dose equivalent, measured in sieverts (Sv). In fact, this is a calculated value, where the absorbed dose is multiplied by a weighting coefficient for a given type of radiation and a coefficient that characterizes the sensitivity of various organs and tissues to a particular type of radiation.

Equivalent dose (or the often used concept of “dose”) is equal to the product of the absorbed dose and the quality factor of exposure to ionizing radiation (for example: the quality factor of exposure to gamma radiation is 1, and alpha radiation is 20).

The equivalent dose unit is rem (the biological equivalent of a roentgen) and its submultiple units: millirem (mrem) microrem (mcrem), etc., 1 rem = 0.01 J / kg. The unit of measurement of the equivalent dose in the SI system is sievert, Sv,

1 Sv = 1 J/kg = 100 rem.

1 mrem \u003d 1 * 10 -3 rem; 1 microrem \u003d 1 * 10 -6 rem;

Absorbed dose - the amount of energy of ionizing radiation that is absorbed in an elementary volume, related to the mass of matter in this volume.

The absorbed dose unit is rad, 1 rad = 0.01 J/kg.

The unit of absorbed dose in the SI system is gray, Gy, 1 Gy=100 rad=1 J/kg

The equivalent dose rate (or dose rate) is the ratio of the equivalent dose to the time interval of its measurement (exposure), the unit of measure is rem / hour, Sv / hour, μSv / s, etc.

What units are alpha and beta radiation measured in?

The amount of alpha and beta radiation is defined as the particle flux density per unit area, per unit time - a-particles*min/cm 2 , β-particles*min/cm 2 .

What is radioactive around us?

Almost everything that surrounds us, even the person himself. Natural radioactivity is, to some extent, the natural habitat of man, if it does not exceed natural levels. There are areas on the planet with an increased relative to the average level of background radiation. However, in most cases, no significant deviations in the state of health of the population are observed, since this territory is their natural habitat. An example of such a piece of territory is, for example, the state of Kerala in India.

For a true assessment, frightening figures sometimes appearing in print should be distinguished:

• natural, natural radioactivity;
• technogenic, i.e. change in the radioactivity of the environment under the influence of man (mining, emissions and discharges of industrial enterprises, emergency situations, and much more).

Generally eliminate items natural radioactivity almost impossible. How can you get rid of 40 K, 226 Ra, 232 Th, 238 U, which are everywhere in the earth's crust and are found in almost everything that surrounds us, and even in ourselves?

Of all natural radionuclides, the decay products of natural uranium (U-238) - radium (Ra-226) and the radioactive gas radon (Ra-222) pose the greatest danger to human health. The main "suppliers" of radium-226 to the environment are enterprises engaged in the extraction and processing of various fossil materials: mining and processing of uranium ores; oil and gas; coal industry; production of building materials; energy industry enterprises, etc.

Radium-226 is highly susceptible to leaching from minerals containing uranium. This property explains the presence of large amounts of radium in some types of groundwater (some of them enriched with radon gas are used in medical practice), in mine waters. The range of radium content in groundwater varies from a few to tens of thousands of Bq/L. The content of radium in surface natural waters is much lower and can range from 0.001 to 1-2 Bq/L.

A significant component of natural radioactivity is the decay product of radium-226 - radon-222.

Radon is an inert, radioactive gas, colorless and odorless, with a half-life of 3.82 days. Alpha emitter. It is 7.5 times heavier than air, so it is mostly concentrated in cellars, basements, basement floors of buildings, mine workings, etc.

It is believed that up to 70% of the exposure of the population to radiation is due to radon in residential buildings.

The main sources of radon in residential buildings are (in order of increasing importance):

• tap water and household gas;
• building materials (crushed stone, granite, marble, clay, slag, etc.);
• soil under buildings.

For more information about radon and devices for measuring it: RADIOMETERS FOR RADON AND THORON.

Professional radon radiometers cost a lot of money, for domestic use - we recommend that you pay attention to a household radon and thoron radiometer made in Germany: Radon Scout Home.

What are "black sands" and what danger do they pose?

"Black sands" (the color varies from light yellow to red-brown, brown, there are varieties of white, greenish and black) are the mineral monazite - anhydrous phosphate of the elements of the thorium group, mainly cerium and lanthanum (Ce, La) PO 4 , which are replaced by thorium. Monazite contains up to 50-60% oxides of rare earth elements: yttrium oxides Y 2 O 3 up to 5%, thorium oxides ThO 2 up to 5-10%, sometimes up to 28%. It occurs in pegmatites, sometimes in granites and gneisses. During the destruction of rocks containing monazite, it is collected in placers, which are large deposits.

Placers of monazite sands existing on land, as a rule, do not make any special changes to the resulting radiation environment. But the deposits of monazite located near the coastal strip of the Sea of ​​Azov (within the Donetsk region), in the Urals (Krasnoufimsk) and other areas create a number of problems associated with the possibility of exposure.

For example, due to the sea surf during the autumn-spring period on the coast, as a result of natural flotation, a significant amount of "black sand" is accumulated, characterized by a high content of thorium-232 (up to 15-20 thousand Bq / kg and more), which creates in local areas, the levels of gamma radiation are of the order of 3.0 or more μSv/h. Naturally, it is not safe to rest in such areas, therefore this sand is collected annually, warning signs are put up, and some parts of the coast are closed.

Means for measuring radiation and radioactivity.

To measure the levels of radiation and the content of radionuclides in different objects, special measuring instruments are used:

• to measure the exposure dose rate of gamma radiation, X-ray radiation, alpha and beta radiation flux density, neutrons, dosimeters and search dosimeters-radiometers of various types are used;
• To determine the type of radionuclide and its content in environmental objects, AI spectrometers are used, which consist of a radiation detector, an analyzer and a personal computer with an appropriate program for processing the radiation spectrum.

Currently, there are a large number of dosimeters of various types for solving various problems of radiation monitoring and having ample opportunities.

For example, dosimeters that are most often used in professional activities:

1. Dosimeter-radiometer MKS-AT1117M(search dosimeter-radiometer) - a professional radiometer is used to search for and identify sources of photon radiation. It has a digital indicator, the ability to set the threshold for the operation of an audible alarm, which greatly facilitates the work when examining territories, checking scrap metal, etc. The detection unit is remote. A NaI scintillation crystal is used as a detector. The dosimeter is a universal solution for various tasks; it is equipped with a dozen different detection units with different technical characteristics. Measuring blocks allow to measure alpha, beta, gamma, x-ray and neutron radiation.

   Information about detection units and their application:

Name of the detection unit	Measured radiation	Main feature (technical specification)	Application area
	DB for alpha radiation	Measurement range 3.4 10 -3 - 3.4 10 3 Bq cm -2	DB for measuring the flux density of alpha particles from the surface
	DB for beta radiation	Measuring range 1 - 5 10 5 parts / (min cm 2)	DB for measuring the flux density of beta particles from the surface
	DB for gamma radiation	Sensitivity 350 imp s -1 / µSv h -1 measurement range 0.03 - 300 µSv/h	The best option for price, quality, specifications. It is widely used in the field of gamma radiation measurement. A good search detection unit for finding radiation sources.
	DB for gamma radiation	Measuring range 0.05 µSv/h - 10 Sv/h	The detection unit has a very high upper threshold for measuring gamma radiation.
	DB for gamma radiation	Measurement range 1 mSv/h - 100 Sv/h Sensitivity 900 imp s -1 / µSv h -1	An expensive detection unit with a high measurement range and excellent sensitivity. Used to find radiation sources with strong radiation.
	DB for x-rays	Energy range 5 - 160 keV	Detection unit for x-rays. It is widely used in medicine and installations operating with the release of X-rays of low energy.
	DB for neutron radiation	measurement range 0.1 - 10 4 neutron/(s cm 2) Sensitivity 1.5 (imp s -1)/(neutron s -1 cm -2)
	DB for alpha, beta, gamma and x-rays	Sensitivity 6.6 imp s -1 / µSv h -1	Universal detection unit that allows you to measure alpha, beta, gamma and X-rays. It has low cost and poor sensitivity. Has found wide reconciliation in the field of workplace certification (AWP), where it is mainly required to measure a local object.

2. Dosimeter-radiometer DKS-96– designed to measure gamma and x-ray radiation, alpha radiation, beta radiation, neutron radiation.

In many respects it is similar to a dosimeter-radiometer.

• measurement of dose and ambient dose equivalent rate (hereinafter dose and dose rate) H*(10) and H*(10) of continuous and pulsed X-ray and gamma radiation;
• measurement of alpha and beta radiation flux density;
• measuring the dose H*(10) of neutron radiation and the dose rate H*(10) of neutron radiation;
• gamma radiation flux density measurement;
• search, as well as localization of radioactive sources and sources of pollution;
• measurement of flux density and exposure dose rate of gamma radiation in liquid media;
• radiation analysis of the area, taking into account geographical coordinates using GPS;

The two-channel scintillation beta-gamma spectrometer is designed for simultaneous and separate determination of:

• specific activity of 137 Cs, 40 K and 90 Sr in samples of various environments;
• specific effective activity of natural radionuclides 40 K, 226 Ra, 232 Th in building materials.

Allows for express analysis of standardized samples of metal melts for the presence of radiation and contamination.

9. Gamma spectrometer based on an HPGe detector Spectrometers based on coaxial detectors made of HPG (high purity germanium) are designed to detect gamma radiation in the energy range from 40 keV to 3 MeV.

Spectrometer beta and gamma radiation MKS-AT1315



Lead-shielded spectrometer NaI PAK



Portable NaI spectrometer MKS-AT6101





Wearable HPG spectrometer Eco PAK



Portable HPG spectrometer Eco PAK



Spectrometer NaI PAK automotive version



Spectrometer MKS-AT6102



Eco PAK spectrometer with electric machine cooling



Manual PPD spectrometer Eco PAK

See other measuring instruments for measuring ionizing radiation, you can on our website:

• when conducting dosimetric measurements, if they are meant to be carried out frequently in order to monitor the radiation situation, it is necessary to strictly observe the geometry and measurement technique;
• to increase the reliability of dosimetric monitoring, it is necessary to carry out several measurements (but not less than 3), then calculate the arithmetic mean;
• when measuring the background of the dosimeter on the ground, select areas that are 40 m away from buildings and structures;
• measurements on the ground are carried out at two levels: at a height of 0.1 (search) and 1.0 m (measurement for the protocol - while rotating the sensor in order to determine the maximum value on the display) from the ground surface;
• when measuring in residential and public premises, measurements are taken at a height of 1.0 m from the floor, preferably at five points using the “envelope” method. At first glance, it is difficult to understand what is happening in the photo. A giant mushroom seems to have grown from under the floor, and ghostly people in helmets seem to be working next to it...

  At first glance, it is difficult to understand what is happening in the photo. A giant mushroom seems to have grown from under the floor, and ghostly people in helmets seem to be working next to it...

  There is something inexplicably creepy about this scene, and for good reason. You're seeing the largest accumulation of probably the most toxic substance ever created by man. This is nuclear lava or corium.

  In the days and weeks after the accident at the Chernobyl nuclear power plant on April 26, 1986, simply walking into a room with the same pile of radioactive material - grimly nicknamed "elephant's foot" - meant certain death in a few minutes. Even a decade later, when this photograph was taken, probably due to radiation, the film behaved strangely, which manifested itself in a characteristic grainy structure. The man in the photo, Arthur Korneev, most likely visited this room more often than anyone else, so he was exposed to, perhaps, the maximum dose of radiation.

  Surprisingly, in all likelihood, he is still alive. The story of how the U.S. got into possession of a unique photograph of a man in the presence of an incredibly toxic material is itself shrouded in mystery - as well as the reasons why someone needed to take a selfie next to a hump of molten radioactive lava.

  The photograph first came to America in the late 90s, when the new government of newly independent Ukraine took control of the Chernobyl nuclear power plant and opened the Chernobyl Center for Nuclear Safety, Radioactive Waste and Radioecology. Soon the Chernobyl Center invited other countries to cooperate in nuclear safety projects. The US Department of Energy ordered assistance by sending an order to the Pacific Northwest National Laboratories (PNNL) - a crowded research center in Richland, pc. Washington.

  At the time, Tim Ledbetter was one of the newcomers to PNNL's IT department and was tasked with building a digital photo library for the Department of Energy's Nuclear Security Project, that is, to show photos to the American public (or rather, to that tiny part of the public which then had access to the Internet). He asked the project participants to take photos during trips to Ukraine, hired a freelance photographer, and also asked for materials from Ukrainian colleagues at the Chernobyl center. Among the hundreds of photographs of clumsy handshakes of officials and people in lab coats, however, there are a dozen pictures of the ruins inside the fourth power unit, where a decade earlier, on April 26, 1986, an explosion occurred during a test of a turbogenerator.

  As radioactive smoke rose from the village, poisoning the surrounding land, the rods liquefied from below, melting through the walls of the reactor to form a substance called corium.

  When radioactive smoke rose above the village, poisoning the surrounding land, the rods liquefied from below, melting through the walls of the reactor and forming a substance called corium .

  Corium has been formed outside of research labs at least five times, says Mitchell Farmer, lead nuclear engineer at Argonne National Laboratory, another US Department of Energy facility near Chicago. Corium formed once at the Three Mile Island reactor in Pennsylvania in 1979, once at Chernobyl, and three times at the Fukushima reactor meltdown in 2011. In his lab, Farmer created modified versions of Corium to better understand how to avoid similar incidents in the future. The study of the substance showed, in particular, that watering after corium formation actually prevents the decay of some elements and the formation of more dangerous isotopes.

  Of the five cases of corium formation, only in Chernobyl was nuclear lava able to escape from the reactor. Without a cooling system, the radioactive mass crawled through the power unit for a week after the accident, absorbing molten concrete and sand, which mixed with molecules of uranium (fuel) and zirconium (coating). This poisonous lava flowed down, eventually melting the floor of the building. When the inspectors finally entered the power unit a few months after the accident, they found an 11-ton, three-meter landslide in the corner of the steam distribution corridor below. Then it was called "elephant foot". Over the following years, the "elephant's foot" was cooled and crushed. But even today, its remains are still several degrees warmer than the environment, as the decay of radioactive elements continues.

  Ledbetter can't remember exactly where he got these photos. He compiled a photo library almost 20 years ago and the website that hosts them is still in good shape; only thumbnails of the images were lost. (Ledbetter, still at PNNL, was surprised to learn that the photos are still available online.) But he remembers for sure that he did not send anyone to photograph the "elephant's foot", so it was most likely sent by one of his Ukrainian colleagues.

  The photo began to circulate on other sites, and in 2013 Kyle Hill stumbled upon it while writing an article about the "elephant foot" for Nautilus magazine. He traced her origins back to the PNNL lab. A long-lost description of the photo was found on the site: "Artur Korneev, deputy director of the Shelter object, studies nuclear lava "elephant's foot", Chernobyl. Photographer: unknown. Autumn 1996." Ledbetter confirmed that the description matched the photo.

  Artur Korneev- an inspector from Kazakhstan, who has been educating employees, telling and protecting them from the "elephant's foot" since its formation after the explosion at the Chernobyl nuclear power plant in 1986, a lover of dark jokes. Most likely, the NY Times reporter last spoke to him in 2014 in Slavutych, a city specially built for evacuated personnel from Pripyat (Chernobyl).

  The shot was probably taken at a slower shutter speed than the other photos to give the photographer time to enter the frame, which explains the effect of movement and why the headlamp looks like lightning. The graininess of the photo is probably caused by radiation.

  For Korneev, this particular visit to the power unit was one of several hundred dangerous trips to the core since his first day of work in the days following the explosion. His first assignment was to identify fuel deposits and help measure radiation levels (an "elephant's foot" originally "glowed" at more than 10,000 roentgens per hour, which kills a person at a distance of a meter in less than two minutes). Shortly thereafter, he led a cleanup operation that sometimes had to remove whole chunks of nuclear fuel out of the way. More than 30 people died from acute radiation sickness during the cleaning of the power unit. Despite the incredible dose of radiation he received, Korneev himself continued to return to the hastily built concrete sarcophagus again and again, often with journalists to protect them from danger.

  In 2001, he led an Associated Press reporter to the core, where the radiation level was 800 roentgens per hour. In 2009, renowned novelist Marcel Theroux wrote an article for Travel + Leisure about his trip to the sarcophagus and about a crazy guide without a gas mask who mocked Theroux's fears and said that it was "pure psychology". Although Theroux referred to him as Viktor Korneev, in all likelihood the person was Arthur, as he dropped the same dirty jokes a few years later with a journalist from the NY Times.

  His current occupation is unknown. When the Times found Korneev a year and a half ago, he was helping build the vault for the sarcophagus, a $1.5 billion project due to be completed in 2017. It is planned that the vault will completely close the Vault and prevent the leakage of isotopes. In his 60-something years, Korneev looked sickly, suffered from cataracts, and was banned from visiting the sarcophagus after being repeatedly irradiated in previous decades.

  However, Korneev's sense of humor remained unchanged. He seems to have no regrets about his life's work: "Soviet radiation," he jokes, "is the best radiation in the world." .

  
  

Radiation is ionizing radiation that causes irreparable harm to everything around. People, animals and plants suffer. The biggest danger lies in the fact 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 as well as within each of us. External sources have a huge impact. Many 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, the nuclei of which 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 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 are characterized by low penetrating power. IN airspace they extend only a couple of centimeters. In tissue, their range is fractions 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 exposure is a formidable threat.
2. Beta radiation is a stream of light particles moving in the air for a couple of meters. These are electrons and positrons penetrating two centimeters into the tissue. It is harmful in contact with human skin. However, it gives a greater danger when exposed from the inside, but less than alpha. To protect against the influence of these particles, special containers, protective screens, a certain distance are used.
3. Gamma and X-rays are electromagnetic radiations penetrating the body through and through. Protective measures against such exposure include the creation of lead screens, the construction of concrete structures. The most dangerous of irradiations with external damage, as it affects the entire body.
4. Neutron radiation consists of a stream of neutrons that 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 from such an impact is created from lead, iron, concrete.

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

natural sources

Radioactivity of natural origin has always been on the planet. Radiation is present in everything that surrounds humanity: animals, plants, soil, air, water. This small level of radiation is believed to have no harmful effects. However, some scholars are of a different opinion. Since people do not have the opportunity to influence this danger, circumstances that increase the allowable values ​​should be avoided.

Varieties of sources of natural origin

1. Cosmic radiation and solar radiation are the most 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. Do not stay in direct sunlight for a long time.
2. The radiation of the earth's crust is dangerous near deposits of various minerals. By burning coal or using phosphorus fertilizers, radionuclides actively seep into a person with the inhaled air and the food he eats.
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 goes outside along with mining. It enters apartments along with household gas, as well as with tap water. Fortunately, its concentration can be easily reduced by constantly ventilating the premises.

artificial sources

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

Artificial sources include:

• Nuclear weapon;
• Medical equipment;
• Waste from enterprises;
• Certain gems;
• Some vintage items removed from hazardous areas. Including from Chernobyl.

The norm of radioactive radiation

Scientists were able to establish that radiation affects individual organs and the whole organism in different ways. In order to assess the damage arising from chronic exposure, the concept of equivalent dose was introduced. It is calculated according to the formula and is equal to the product of the received dose, absorbed by the body and averaged over a specific organ or the entire human body, by a weight factor.

The unit of equivalent dose is the ratio of joules to kilograms, which is called sievert (Sv). With its use, a scale was created that allows you to understand the specific danger of radiation for humanity:

• 100 Sound Instant death. The victim has a few hours, a maximum of a couple of days.
• From 10 to 50 Sv. Those who have received injuries of this nature will die in a few weeks from severe internal bleeding.
• 4-5 Sound When this amount is ingested, the body copes in 50% of cases. Otherwise, the sad consequences lead to death after a couple of months due to damage to the bone marrow and circulatory disorders.
• 1 Sound With the absorption of such a dose, radiation sickness is inevitable.
• 0.75 Sound Changes in the circulatory system for a short period of time.
• 0.5 Sv. This amount is enough for the patient to develop cancer. The rest of the symptoms are absent.
• 0.3 Sv. This value is inherent in the apparatus for conducting x-rays of the stomach.
• 0.2 Sv. Permissible level for work with radioactive materials.
• 0.1 Sv. With this amount, uranium is mined.
• 0.05 Sound This value is the norm for irradiation of medical devices.
• 0.0005 Sv. Permissible amount of radiation level near the nuclear power plant. Also, this is the value of the annual exposure of the population, which is equated to the norm.

The 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 people who are faced with danger are exposed to harmful effects, but also the next generation. Such circumstances are caused by the action 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, local radiation injuries.
• Genetic. Associated with a defect in the genetic apparatus. Shows up in later 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 have managed to create on its basis a medical examination that can save lives.

Mutation after radiation

Consequences of irradiation

Upon receipt of chronic irradiation, recovery measures take place in the body. This leads to the fact that the victim acquires a lower 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 exposure. Blood cancer can develop inside a person. It is especially dangerous for teenagers under the age of 15. It has been observed that the mortality of people working with x-ray equipment is increased due to leukemia.

The most frequent result of irradiation is radiation sickness, which occurs both with a single dose and with a long one. With a large number of radionuclides leads to death. Breast and thyroid cancer is common.

A huge number of organs suffer. vision is impaired and mental condition victim. Lung cancer is common among uranium miners. External irradiation causes terrible burns of the skin and mucous membranes.

Mutations

After exposure to radionuclides, two types of mutations are possible: dominant and recessive. The first occurs immediately after irradiation. The second type is found after a long period of time not in the victim, but in his next generation. Violations caused by mutation lead to deviations in the development of internal organs in the fetus, external deformities and changes in the psyche.

Unfortunately, mutations are poorly understood, as they usually do not appear immediately. After a while, it is difficult to understand what exactly had a dominant influence on its occurrence.

"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 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, which would provide operational information for making useful decisions before a long time passes and undesirable or even disastrous consequences appear. that a person will not begin to feel its impact 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 that have a positive charge absolute value 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 is assigned to the symbol of the element, equal to the sum of all particles in the nucleus of a given isotope. 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, terminates 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 the human body and other living tissues, they are subjective, and are different for different people. Therefore, average values ​​are used.

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

Radon has been found to be the most dangerous of all natural sources of radiation. - heavy gas tasteless, odorless and invisible; 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 of 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, stand apart in their impact on humans. 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. Such is our life in the third millennium - the dosimeter becomes an attribute of everyday life, like a 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), the permissible dose rates for external exposure of the whole body from man-made sources for the permanent residence of personnel members are 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 entering the sensitive volume of the counter causes 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"