Radiation - in accessible language. All about radiation and ionizing radiation Definition, standards, SanPiN

Many people associate radiation with inevitable diseases that are difficult to treat. And this is partly true. The most terrible and deadly weapon is called nuclear. Therefore, it is not without reason that radiation is considered one of the greatest disasters on earth. What is radiation and what are its consequences? Let's look at these questions in this article.

Radioactivity is the nuclei of some atoms, which are unstable. As a result of this property, the nucleus decays, which is caused by ionizing radiation. This radiation is called radiation. She has great energy. consists in changing the composition of cells.

There are several types of radiation depending on the level of its influence on

The last two types are neutrons and We encounter this type of radiation in everyday life. It is the safest for the human body.

Therefore, when talking about what radiation is, we need to take into account the level of its radiation and the harm caused to living organisms.

Radioactive particles have enormous energy power. They penetrate the body and collide with its molecules and atoms. As a result of this process, they are destroyed. The peculiarity of the human body is that it mostly consists of water. Therefore, the molecules of this particular substance are exposed to radioactive particles. As a result, compounds that are very harmful to the human body arise. They become part of all chemical processes occurring in a living organism. All this leads to the destruction and destruction of cells.

Knowing what radiation is, you also need to know what harm it causes to the body.

The effects of radiation on humans fall into three main categories.

The main damage is caused to the genetic background. That is, as a result of infection, the germ cells and their structure change and are destroyed. This is reflected in the offspring. A lot of children are born with disabilities and deformities. This mainly happens in those areas that are susceptible to radiation contamination, that is, they are located next to other enterprises of this level.

The second type of disease that occurs under the influence of radiation is hereditary diseases at the genetic level, which appear after some time.

The third type is immune diseases. The body under the influence of radioactive radiation becomes susceptible to viruses and diseases. That is, immunity decreases.

The salvation from radiation is distance. The permissible level of radiation for humans is 20 microroentgens. In this case, it has no effect on the human body.

Knowing what radiation is, you can protect yourself to a certain extent from its effects.

A little theory

Radioactivity is the instability of the nuclei of some atoms, which manifests itself in their ability to undergo spontaneous transformation (in scientific terms, decay), which is accompanied by the release of ionizing radiation (radiation).

The energy of such radiation is quite high, so it is capable of influencing matter, creating new ions of different signs. Cause radiation using chemical reactions You can’t, it’s a completely physical process.

There are several types of radiation

• Alpha particles are relatively heavy particles, positively charged, and are helium nuclei.
• Beta particles are ordinary electrons.
• Gamma radiation has the same nature as visible light, but has a much greater penetrating ability.
• Neutrons are electrically neutral particles that occur mainly in the vicinity of the working nuclear reactor, access there should be limited.
• X-rays are similar to gamma rays, but have less energy. By the way, the Sun is one of the natural sources of such rays, but protection from solar radiation is provided by the Earth’s atmosphere.

The most dangerous radiation for humans is Alpha, Beta and Gamma radiation, which can lead to serious illnesses, genetic disorders and even death.

The extent to which radiation affects human health depends on the type of radiation, time and frequency. Thus, the consequences of radiation, which can lead to fatal cases, occur both during a single stay at the strongest source of radiation (natural or artificial), and when storing weakly radioactive objects at home (antiques treated with radiation precious stones, products made of radioactive plastic).

Charged particles are very active and interact strongly with matter, so even one alpha particle can be enough to destroy a living organism or damage a huge number of cells. However, for the same reason, any layer of solid or liquid substance, for example, ordinary clothing, is a sufficient means of protection against this type of radiation.

According to experts, ultraviolet radiation or laser radiation cannot be considered radioactive.

What is the difference between radiation and radioactivity?

Sources of radiation are nuclear facilities (particle accelerators, reactors, X-ray equipment) and radioactive substances. They can exist for a considerable time without manifesting themselves in any way, and you may not even suspect that you are near an object of extreme radioactivity.

Units of measurement of radioactivity

Radioactivity is measured in Becquerels (BC), which corresponds to one decay per second. The content of radioactivity in a substance is also often estimated per unit of weight - Bq/kg, or volume - Bq/cub.m.

Sometimes there is such a unit as Curie (Ci). This is a huge value, equal to 37 billion Bq. When a substance decays, the source emits ionizing radiation, the measure of which is the exposure dose. It is measured in Roentgens (R). 1 Roentgen is a fairly large value, so in practice a millionth (µR) or thousandth (mR) fraction of a Roentgen is used.

Household dosimeters measure ionization over a certain time, that is, not the exposure dose itself, but its power. The unit of measurement is microroentgen per hour. It is this indicator that is most important for a person, as it allows one to assess the danger of a particular radiation source.

Radiation and human health

The effect of radiation on the human body is called irradiation. During this process, radiation energy is transferred to the cells, destroying them. Radiation can cause all sorts of diseases - infectious complications, metabolic disorders, malignant tumors and leukemia, infertility, cataracts and much more. Radiation has a particularly acute effect on dividing cells, so it is especially dangerous for children.

The body reacts to the radiation itself, and not to its source. Radioactive substances can enter the body through the intestines (with food and water), through the lungs (by breathing) and even through the skin during medical diagnostics using radioisotopes. In this case, internal exposure occurs.

In addition, external radiation has a significant impact on the human body, i.e. The source of radiation is outside the body. The most dangerous, of course, is internal radiation.

How to remove radiation from the body

This question certainly worries many. Unfortunately, especially effective and quick ways There is no removal of radionuclides from the human body. Certain foods and vitamins help cleanse the body of small doses of radiation. But if the radiation exposure is serious, then we can only hope for a miracle. Therefore, it is better not to take risks. And if there is even the slightest danger of being exposed to radiation, it is necessary to move your feet out of the area as quickly as possible. dangerous place and call specialists.

Is the computer a source of radiation?

This question, in the age of the spread of computer technology, worries many. The only part of the computer that could theoretically be radioactive is the monitor, and even then, only electro-beam. Modern displays, liquid crystal and plasma, do not have radioactive properties.

CRT monitors, like televisions, are a weak source of X-ray radiation. It appears on the inner surface of the glass of the screen, however, due to the significant thickness of the same glass, it absorbs most of the radiation. To date, no health effects have been found from CRT monitors. However, with the widespread use of liquid crystal displays, this issue is losing its former relevance.

Can a person become a source of radiation?

Radiation, affecting the body, does not form radioactive substances in it, i.e. a person does not turn into a source of radiation. By the way, X-rays, contrary to popular belief, are also safe for health. Thus, unlike a disease, radiation damage cannot be transmitted from person to person, but radioactive objects that carry a charge can be dangerous.

Radiation level measurement

You can measure the level of radiation using a dosimeter. Household appliances are simply irreplaceable for those who want to protect themselves as much as possible from the deadly effects of radiation.

The main purpose of a household dosimeter is to measure the radiation dose rate in the place where a person is located, to examine certain objects (cargo, building materials, money, food, children's toys). Buying a device that measures radiation is simply necessary for those who often visit areas of radiation pollution caused by the accident at the Chernobyl nuclear power plant (and such hot spots are present in almost all regions of European Russia).

The dosimeter will also help those who are in an unfamiliar area, far from civilization - on a hike, picking mushrooms and berries, or hunting. It is imperative to inspect for radiation safety the site of the proposed construction (or purchase) of a house, cottage, garden or land plot, otherwise, instead of benefit, such a purchase will only bring deadly diseases.

It is almost impossible to clean food, soil or objects from radiation, so the only way to protect yourself and your family is to stay away from them. Namely, a household dosimeter will help identify potentially dangerous sources.

Radioactivity standards

Regarding radioactivity exists large number norms, i.e. They try to standardize almost everything. Another thing is that dishonest sellers, in pursuit of big profits, do not comply with, and sometimes even openly violate, the norms established by law.

The basic standards established in Russia are set out in Federal law No. 3-FZ of December 5, 1996 “On radiation safety of the population” and in Sanitary rules 2.6.1.1292-03 "Radiation safety standards".

For inhaled air, water and food products, the content of both man-made (obtained as a result of human activity) and natural radioactive substances is regulated, which should not exceed the standards established by SanPiN 2.3.2.560-96.

IN building materials The content of radioactive substances of the thorium and uranium family, as well as potassium-40, is normalized; their specific effective activity is calculated using special formulas. Requirements for building materials are also specified in GOST.

In premises, the total content of thoron and radon in the air is regulated - for new buildings it should be no more than 100 Bq (100 Bq/m3), and for those already in use - less than 200 Bq/m3. In Moscow, additional standards MGSN2.02-97 are also applied, which regulate the maximum permissible levels ionizing radiation and radon content in building areas.

For medical diagnostics, dose limits are not indicated, but minimum requirements are put forward. sufficient levels exposure to obtain high-quality diagnostic information.

IN computer technology The maximum radiation level for electro-ray (CRT) monitors is regulated. The X-ray dose rate at any point at a distance of 5 cm from a video monitor or personal computer should not exceed 100 µR per hour.

The level of radiation safety can only be reliably checked using a personal household dosimeter.

You can only check whether manufacturers comply with the statutory standards yourself, using a miniature household dosimeter. It is very simple to use, just press one button and check the readings on the liquid crystal display of the device with the recommended ones. If the norm is significantly exceeded, then this item poses a threat to life and health, and it should be reported to the Ministry of Emergency Situations so that it can be destroyed.

How to protect yourself from radiation

Everyone is well aware of high level radiation hazard, but the question of how to protect yourself from radiation is becoming increasingly relevant. You can protect yourself from radiation by time, distance and substance.

It is advisable to protect yourself from radiation only when its doses are tens or hundreds of times higher than the natural background. In any case, there must be fresh vegetables, fruits, and herbs on your table. According to doctors, even with a balanced diet, the body is only half provided with essential vitamins and minerals, which is responsible for the increase in cancer incidence.

As our research has shown, selenium is an effective protection against radiation in low and medium doses, as well as a means of reducing the risk of tumor development. It is found in wheat, white bread, cashew nuts, radishes, but in small doses. It is much more effective to take dietary supplements containing this element prescribed by your doctor.

Time protection

The shorter the time spent near a radiation source, the lower the radiation dose a person receives. Short-term contact with even the most powerful X-ray radiation during medical procedures will not cause much harm, but if the X-ray machine is left for a longer period, it will simply “burn” living tissue.

Protection from different types of radiation by shielding

Protection by distance is that radiation decreases with distance from a compact source. That is, if at a distance of 1 meter from a radiation source the dosimeter shows 1000 microroentgens per hour, then at a distance of 5 meters it shows about 40 microroentgens per hour, which is why radiation sources are often so difficult to detect. At long distances they are not “caught”; you need to clearly know the place where to look.

Substance protection

It is necessary to strive to ensure that there is as much substance as possible between you and the source of radiation. The denser it is and the more of it there is, the greater the portion of radiation that it can absorb.

Speaking about the main source of radiation in rooms - radon and its decay products, it should be noted that radiation can be significantly reduced by regular ventilation.

You can protect yourself from alpha radiation with an ordinary sheet of paper, a respirator and rubber gloves; for beta radiation you will already need a thin layer of aluminum, glass, a gas mask and plexiglass; heavy metals such as steel, lead, tungsten, cast iron, and Water and polymers such as polyethylene can save you from neutrons.

When building a house and interior decoration, it is recommended to use radiation-safe materials. Thus, houses made of wood and timber are much safer in terms of radiation than brick ones. Sand-lime bricks are smaller than bricks made from clay. Manufacturers have invented a special labeling system that emphasizes the environmental safety of their materials. If you are concerned about the safety of future generations, choose these.

There is an opinion that alcohol can protect against radiation. There is some truth in this, alcohol reduces susceptibility to radiation, but modern anti-radiation drugs are much more reliable.

To know exactly when to be wary of radioactive substances, we recommend purchasing a radiation dosimeter. This small device will always warn you if you find yourself close to a radiation source, and you will have time to choose the most appropriate method of protection.

Radiation is a stream of particles produced during nuclear reactions or radioactive decay . We have all 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 the dangers of radiation are and how they can protect themselves from it. In this article we looked at what radiation is, what its danger is to humans, and what diseases it can cause.

What is radiation

The definition of this term is not very clear to a person not connected with physics or, for example, medicine. The term “radiation” refers to the release of particles produced during nuclear reactions or radioactive decay. That is, this is radiation that comes out of certain substances.

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

Radiation protection rules are based on knowledge of the ability of specific radioactive waves to pass through materials. 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 nuclear fuels, reactors, etc.

How radiation enters the human body

Acute radiation sickness

This condition develops with a single massive exposure to human radiation.. This condition is rare.

It can develop during some man-made accidents and disasters.

The degree of clinical manifestations depends on the amount of radiation affecting the human body.

In this case, all organs and systems can be affected.

Chronic radiation sickness

This condition develops with prolonged contact with radioactive substances.. Most often it develops in people who interact with them on duty.

However, the clinical picture may develop slowly over many years. With prolonged and prolonged contact with radioactive sources irradiation causes damage to the nervous, endocrine, circulatory systems. The kidneys also suffer, and failures occur in all metabolic processes.

Chronic radiation sickness has several stages. It can occur polymorphically, clinically manifested by damage to various organs and systems.

Oncological malignant pathologies

Scientists have proven that radiation can provoke cancer pathologies. Most often, skin or thyroid cancer develops; there are also frequent cases of leukemia, a blood cancer, in people suffering from acute radiation sickness.

According to statistics, the number of oncological pathologies after the accident at the Chernobyl nuclear power plant increased tens of times in areas affected by radiation.

Use of radiation in medicine

Scientists have learned to use radiation for the benefit of humanity. A huge number of different diagnostic and therapeutic procedures are related in one way or another to radioactive radiation. Thanks to sophisticated safety protocols and state-of-the-art equipment this use of radiation is practically safe for the patient and medical personnel, but subject to all safety rules.

Diagnostic medical techniques using radiation: radiography, computed tomography, fluorography.

Treatment methods include various types radiation therapy, which is used in the treatment of oncological pathologies.

The use of radiation diagnostic methods and therapy should be carried out by qualified specialists. These procedures are prescribed to patients solely for indications.

Basic methods of protection against radiation radiation

Having learned to use radioactive radiation in industry and medicine, scientists took care of the safety of people who may come into contact with these dangerous substances.

Only careful adherence to the basics of personal prevention and protection from radiation can protect a person working in a dangerous radioactive zone from chronic radiation sickness.

Basic methods of protection against radiation:

• Protection through distance. Radioactive radiation has a certain wavelength beyond which it has no effect. That's why in case of danger, you must immediately leave the danger zone.
• Shielding protection. The essence of this method is to use substances for protection that do not allow radioactive waves to pass through them. For example, paper, a respirator, and rubber gloves can protect against alpha radiation.
• Time protection. All radioactive substances have a half-life and decay time.
• Chemical protection. Substances that can reduce the negative effects of radiation on the body are given to a person orally or injected.

People working with radioactive substances have protocols for protection and behavior in different situations. As a rule, dosimeters are installed in the work areas - devices for measuring background radiation.

Radiation is dangerous for humans. When its level increases above 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.

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

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

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

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

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

Neutron radiation- another type of corpuscular type of radiation. Neutron radiation is a flux of neutrons ( elementary particles, without electric charge). Neutrons do not have an ionizing effect, but a very significant ionizing effect occurs due to elastic and inelastic scattering on the nuclei of matter.

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

Gamma rays and x-rays belong to electromagnetic radiation.

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

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

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

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

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

What is radiation?
The term "radiation" comes from Lat. radius is a ray, and in the broadest sense it covers all types of radiation in general. Visible light and radio waves are also, strictly speaking, radiation, but by radiation we usually mean only ionizing radiation, that is, those whose interaction with matter leads to the formation of ions in it.
There are several types of ionizing radiation:
- alpha radiation - is a stream of helium nuclei
- beta radiation - a flow of electrons or positrons
- gamma radiation - electromagnetic radiation with a frequency of about 10^20 Hz.
— X-ray radiation is also electromagnetic radiation with a frequency of the order of 10^18 Hz.
- neutron radiation - neutron flux.

What is alpha radiation?
These are heavy positively charged particles consisting of two protons and two neutrons tightly bound together. In nature, alpha particles arise from the decay of atoms of heavy elements such as uranium, radium and thorium. In the air, alpha radiation travels no more than five centimeters and, as a rule, is completely blocked by a sheet of paper or the outer dead layer of skin. However, if a substance that emits alpha particles enters the body through food or inhaled air, it irradiates internal organs and becomes potentially dangerous.

What is beta radiation?
Electrons or positrons, which are much smaller than alpha particles and can penetrate several centimeters deep into the body. You can protect yourself from it with a thin sheet of metal, window glass, and even ordinary clothing. When beta radiation reaches unprotected areas of the body, it usually affects the upper layers of the skin. If a substance that emits beta particles enters the body, it will irradiate internal tissues.

What is neutron radiation?
Flow of neutrons, neutrally charged particles. Neutron radiation is produced during the fission of an atomic nucleus and has a high penetrating ability. Neutrons can be stopped by a thick concrete, water or paraffin barrier. Fortunately, in peaceful life nowhere except directly nearby nuclear reactors, neutron radiation is practically non-existent.

What is gamma radiation?
An electromagnetic wave that carries energy. In the air it can travel long distances, gradually losing energy as a result of collisions with atoms of the medium. Intense gamma radiation, if not protected from it, can damage not only the skin, but also internal tissues.

What type of radiation is used in fluoroscopy?
X-ray radiation is electromagnetic radiation with a frequency of about 10^18 Hz.
Occurs when electrons moving at high speeds interact with matter. When electrons collide with atoms of any substance, they quickly lose their kinetic energy. In this case, most of it turns into heat, and a small fraction, usually less than 1%, is converted into x-ray energy.
In relation to X-ray and gamma radiation, the definitions “hard” and “soft” are often used. This is a relative characteristic of its energy and the associated penetrating power of radiation: “hard” - greater energy and penetrating ability, “soft” - less. X-ray radiation is soft, gamma radiation is hard.

Is there a place without radiation at all?
Almost none. Radiation is an ancient factor environment. There are many natural sources of radiation: these are natural radionuclides contained in earth's crust, building materials, air, food and water, as well as cosmic rays. On average, they account for more than 80% of the annual effective dose received by the population, mainly due to internal exposure.

What is radioactivity?
Radioactivity is the property of atoms of an element to spontaneously transform into atoms of other elements. This process is accompanied by ionizing radiation, i.e. radiation.

How is radiation measured?
Given that “radiation” itself is not a measurable quantity, there are different units for measuring different types of radiation, as well as pollution.
The concepts of absorbed, exposure, equivalent and effective dose, as well as the concept of equivalent dose rate and background are used separately.
In addition, for each radionuclide (radioactive isotope of an element), the activity of the radionuclide, the specific activity of the radionuclide, and the half-life are measured.

What is absorbed dose and how is it measured?
Dose, absorbed dose (from Greek - share, portion) - determines the amount of ionizing radiation energy absorbed by the irradiated substance. Characterizes the physical effect of radiation in any environment, including biological tissue, and is often calculated per unit mass of this substance.
It is measured in units of energy that is released in a substance (absorbed by the substance) when ionizing radiation passes through it.
Units of measurement are rad, gray.
Rad (rad – short for radiation absorbed dose) is a non-systemic unit of absorbed dose. Corresponds to a radiation energy of 100 erg absorbed by a substance weighing 1 gram
1 rad = 100 erg/g = 0.01 J/kg = 0.01 Gy = 2.388 x 10-6 cal/g
With an exposure dose of 1 roentgen, the absorbed dose in air will be 0.85 rad (85 erg/g).
Gray (Gr.) is a unit of absorbed dose in the SI system of units. Corresponds to 1 J of radiation energy absorbed by 1 kg of substance.
1 Gr. = 1 J/kg = 104 erg/g = 100 rad.

What is exposure dose and how is it measured?
The exposure dose is determined by the ionization of air, that is, by the total charge of ions formed in the air when ionizing radiation passes through it.
Units of measurement are roentgen, pendant per kilogram.
Roentgen (R) is a non-systemic unit of exposure dose. This is the amount of gamma or x-ray radiation that in 1 cm3 of dry air (which under normal conditions weighs 0.001293 g) forms 2.082 x 109 ion pairs. When converted to 1 g of air, this will be 1.610 x 1012 ion pairs or 85 erg/g of dry air. Thus, the physical energy equivalent of a roentgen is 85 erg/g for air.
1 C/kg is a unit of exposure dose in the SI system. This is the amount of gamma or x-ray radiation that in 1 kg of dry air forms 6.24 x 1018 pairs of ions that carry a charge of 1 coulomb of each sign. The physical equivalent of 1 C/kg is equal to 33 J/kg (for air).
The relationships between X-rays and C/kg are as follows:
1 P = 2.58 x 10-4 C/kg - exactly.
1 C/kg = 3.88 x 103 R - approx.

What is an equivalent dose and how is it measured?
The equivalent dose is equal to the absorbed dose calculated for a person, taking into account coefficients that take into account different abilities different types radiation damage body tissues.
For example, for x-ray, gamma, beta radiation, this coefficient (it is called the radiation quality factor) is 1, and for alpha radiation - 20. That is, with the same absorbed dose, alpha radiation will cause 20 times more harm to the body than, for example, gamma radiation.
Units of measurement are rem and sievert.
The rem is the biological equivalent of a rad (formerly an x-ray). Non-systemic unit of measurement of equivalent dose. In general:
1 rem = 1 rad * K = 100 erg/g * ​​K = 0.01 Gy * K = 0.01 J/kg * K = 0.01 Sievert,
where K is the radiation quality factor, see the definition of equivalent dose
For x-rays, gamma rays, beta radiation, electrons and positrons, 1 rem corresponds to an absorbed dose of 1 rad.
1 rem = 1 rad = 100 erg/g = 0.01 Gy = 0.01 J/kg = 0.01 Sievert
Considering that with an exposure dose of 1 roentgen, air absorbs approximately 85 erg/g (physical equivalent of a roentgen), and biological tissue absorbs approximately 94 erg/g (biological equivalent of a roentgen), we can assume with minimal error that an exposure dose of 1 roentgen for biological tissue corresponds to an absorbed dose of 1 rad and an equivalent dose of 1 rem (for x-rays, gamma, beta radiation, electrons and positrons), that is, roughly speaking, 1 roentgen, 1 rad and 1 rem are the same thing.
Sievert (Sv) is the SI unit of equivalent and effective dose equivalent. 1 Sv is equal to the equivalent dose at which the product of the absorbed dose in Grays (in biological tissue) by the coefficient K will be equal to 1 J/kg. In other words, this is the absorbed dose at which 1 J of energy is released in 1 kg of substance.
In general:
1 Sv = 1 Gy * K = 1 J/kg * K = 100 rad * K = 100 rem * K
At K=1 (for x-rays, gamma-rays, beta radiations, electrons and positrons) 1 Sv corresponds to an absorbed dose of 1 Gy:
1 Sv = 1 Gy = 1 J/kg = 100 rad = 100 rem.

The effective equivalent dose is equal to the equivalent dose, calculated taking into account the different sensitivity of various organs of the body to radiation. The effective dose takes into account not only that different types of radiation have different biological effectiveness, but also that some parts of the human body (organs, tissues) are more sensitive to radiation than others. For example, at the same equivalent dose, lung cancer is more likely to occur than thyroid cancer. Thus, the effective dose reflects the total effect of human exposure in terms of long-term consequences.
To calculate the effective dose, the equivalent dose received by a specific organ or tissue is multiplied by the appropriate coefficient.
For the whole organism this coefficient is equal to 1, and for some organs it has the following values:
bone marrow (red) - 0.12
thyroid gland - 0.05
lungs, stomach, large intestine - 0.12
gonads (ovaries, testes) - 0.20
leather - 0.01
To estimate the total effective equivalent dose received by a person, the indicated doses for all organs are calculated and summed.
The unit of measurement is the same as that of the equivalent dose - “rem”, “sievert”

What is equivalent dose rate and how is it measured?
The dose received per unit time is called dose rate. The higher the dose rate, the faster the radiation dose increases.
For equivalent dose in SI, the dose rate unit is sievert per second (Sv/s), the non-system unit is rem per second (rem/s). In practice, their derivatives are most often used (μSv/hour, mrem/hour, etc.)

What is background, natural background, and how are they measured?
Background is another name for the exposure dose rate of ionizing radiation in a given location.
Natural background - the power of the exposure dose of ionizing radiation in a given place, created only natural sources radiation.
The units of measurement are rem and sievert, respectively.
Often the background and natural background are measured in roentgens (micro-roentgens, etc.), approximately equating roentgens and rem (see the question about equivalent dose).

What is radionuclide activity and how is it measured?
Quantity radioactive substance is measured not only in units of mass (gram, milligram, etc.), but also by activity, which is equal to the number of nuclear transformations (decays) per unit of time. The more nuclear transformations the atoms of a given substance undergo per second, the higher its activity and the greater the danger it can pose to humans.
The SI unit of activity is decays per second (dec/s). This unit is called the becquerel (Bq). 1 Bq equals 1 rpm/s.
The most commonly used extra-systemic unit of activity is the curie (Ci). 1 Ci equals 3.7 * 10 in 10 Bq, which corresponds to the activity of 1 g of radium.

What is the specific surface activity of a radionuclide?
This is the activity of a radionuclide per unit area. Typically used to characterize the radioactive contamination of an area (radioactive contamination density).
Units of measurement - Bq/m2, Bq/km2, Ci/m2, Ci/km2.

What is half-life and how is it measured?
Half-life (T1/2, also denoted Greek letter“lambda”, half-life) is the time during which half of the radioactive atoms decay and their number decreases by 2 times. The value is strictly constant for each radionuclide. The half-lives of all radionuclides are different - from fractions of a second (short-lived radionuclides) to billions of years (long-lived).
This does not mean that after a time equal to two T1/2 the radionuclide will decay completely. After T1/2 the radionuclide will become twice as small, after 2*T1/2 it will be four times less, etc. Theoretically, a radionuclide will never decay completely.

Limits and norms of exposure

(how and where can I get irradiated and what will happen to me for this?)

Is it true that when flying on an airplane you can get an additional dose of radiation?
In general, yes. Specific figures depend on the flight altitude, type of aircraft, weather and route; the background in the aircraft cabin can be approximately estimated as 200-400 µR/H.

Is it dangerous to do fluorography or radiography?
Although the image takes only a fraction of a second, the radiation power is very high and the person receives a sufficient dose of radiation. It’s not for nothing that the radiologist hides behind a steel wall when taking pictures.
Approximate effective doses for irradiated organs:
fluorography in one projection - 1.0 mSv
X-ray of the lungs - 0.4 m3
photograph of the skull in two projections - 0.22 mSv
dental image – 0.02 mSv
photograph of the nose (maxillary sinuses) - 0.02 mSv
image of the lower leg (legs due to a fracture) - 0.08 mSv
The indicated figures are correct for one image (unless specifically noted), with a working X-ray machine and the use of protective equipment. For example, when taking pictures of the lungs, it is not at all necessary to irradiate the head and everything below the waist. Demand a leaded apron and collar, they should give you one. The dose received during the examination must be recorded in the patient’s personal card.
And finally, any doctor who sends you for an x-ray must evaluate the risk of excess radiation compared to how much your images will help him for more effective treatment.

Radiation at industrial sites, landfills, abandoned buildings?

Radiation sources can be found anywhere, even in a residential building, for example. once used Radioisotope smoke detectors (RSD), which used isotopes emitting Alpha, Beta and Gamma radiation, all kinds of scales of devices produced before the 60s, on which paint was applied, which contained Radium-226 salts, were found in landfills gamma flaw detectors, test sources for dosimeters, etc.

Control methods and devices.

What instruments can measure radiation?
: The main instruments are a radiometer and a dosimeter. There are combined devices - dosimeter-radiometer. The most common are household dosimeters-radiometers: Terra-P, Pripyat, Sosna, Stora-Tu, Bella, etc. There are military devices such as DP-5, DP-2, DP-3, etc.

What is the difference between a radiometer and a dosimeter?
The radiometer shows the radiation dose rate here now and now. But to assess the effect of radiation on the body, it is not the power that is important, but the dose received.
A dosimeter is a device that, by measuring the radiation dose rate, multiplies it by the time of exposure to radiation, thereby calculating the equivalent dose received by the owner. Household dosimeters, as a rule, measure only the dose rate of gamma radiation (some also beta radiation), the weighting factor of which (radiation quality factor) is equal to 1.
Therefore, even if the device does not have a dosimeter function, the dose rate measured in R/h can be divided by 100 and multiplied by the irradiation time, thus obtaining the desired dose value in Sieverts. Or, which is the same thing, multiplying the measured dose rate by the irradiation time, we obtain the equivalent dose in rem.
A simple analogy - the speedometer in a car shows the instantaneous speed “radiometer” and the kilometer counter integrates this speed over time, showing the distance traveled by the car (“dosimeter”).

Deactivation.

Methods for decontaminating equipment
Radioactive dust on contaminated equipment is held by forces of attraction (adhesion); the magnitude of these forces depends on the properties of the surface and the environment in which the attraction occurs. Adhesion forces in air are much greater than in liquid. In the event of contamination of equipment covered with oily contaminants, the adhesion of radioactive dust is determined by the adhesion strength of the oily layer itself.
During decontamination, two processes occur:
· separation of radioactive dust particles from a contaminated surface;
· removing them from the surface of the object.

Based on this, decontamination methods are based either on the mechanical removal of radioactive dust (sweeping, blowing away, dust extraction) or on the use of physicochemical washing processes (washing off radioactive dust with detergent solutions).
Due to the fact that partial decontamination differs from complete decontamination only in the thoroughness and completeness of processing, the methods of partial and complete decontamination are almost the same and depend only on the availability of technical means of decontamination and decontamination solutions.

All decontamination methods can be divided into two groups: liquid and liquid-free. An intermediate method between them is the gas-droplet decontamination method.
Liquid methods include:
· washing off the radioactive substances with decontaminating solutions, water and solvents (gasoline, kerosene, diesel fuel, etc.) using brushes or rags;
· washing off the radioactive substances with a jet of water under pressure.
When processing equipment using these methods, the detachment of radioactive substance particles from the surface occurs in a liquid medium, when the adhesion forces are weakened. Transportation of detached particles during their removal is also provided by liquid flowing from the object.
Since the speed of movement of the layer of liquid directly adjacent to the solid surface is very small, the speed of movement of dust particles, especially very small ones, completely buried in a thin boundary layer of liquid, is also low. Therefore, to achieve sufficient completeness of decontamination, it is necessary, simultaneously with the supply of liquid, to wipe the surface with a brush or rag, to use solutions of detergents that facilitate the removal of radioactive contaminants and to retain them in solution, or to use a powerful jet of water with high pressure and liquid flow per unit surface.
Liquid treatment methods are highly effective and versatile; almost all existing standard decontamination technical means are designed for liquid treatment methods. The most effective of them is the method of washing off the radioactive substances with decontaminating solutions using brushes (allows you to reduce the contamination of an object by 50 - 80 times), and the fastest in implementation is the method of washing off the radioactive substances with a stream of water. The method of washing off radioactive substances with decontamination solutions, water and solvents using rags is used mainly for decontamination of the internal surfaces of the car cabin, various devices sensitive to large volumes of water and decontamination solutions.
The choice of one or another liquid treatment method depends on the availability of decontaminating substances, the capacity of water sources, technical means and the type of equipment to be decontaminated.
Liquid-free methods include the following:
· sweeping away radioactive dust from the site with brooms and other auxiliary materials;
· removal of radioactive dust by dust extraction;
Blowing away radioactive dust compressed air.
When implementing these methods, the separation of radioactive dust particles is carried out in air environment when adhesion forces are high. Existing methods (dust extraction, air jet from a car compressor) cannot create a sufficiently powerful air flow. All these methods are effective in removing dry radioactive dust from dry, non-oily and not heavily contaminated objects. The standard technical means for decontaminating military equipment using a liquid-free method (dust extraction) is currently the DK-4 kit, which can be used to treat equipment using both liquid and liquid-free methods.
Liquid-free decontamination methods can reduce the contamination of objects:
· overcasting - 2 - 4 times;
· dust extraction - 5 - 10 times;
· blowing with compressed air from the car compressor - 2-3 times.
The gas-droplet method involves blowing an object with a powerful gas-droplet flow.
The source of the gas flow is an air-jet engine; at the exit from the nozzle, water is introduced into the gas flow, which is crushed into small droplets.
The essence of the method is that a film of liquid is formed on the surface being treated, due to which the adhesion forces of dust particles to the surface are weakened and a powerful gas flow blows them away from the object.
The gas-droplet decontamination method is carried out using heat machines (TMS-65, UTM), it eliminates manual labor when carrying out special processing of military equipment.
The decontamination time of a KamAZ vehicle with a gas-droplet flow is 1 - 2 minutes, water consumption is 140 liters, contamination is reduced by 50 - 100 times.
When decontaminating equipment using any of the liquid or liquid-free methods, the following processing procedure must be followed:
· the object begins to be processed from upper parts, gradually falling down;
· consistently process the entire surface without skipping;
· treat each surface area 2-3 times, treat rough surfaces especially carefully with increased liquid consumption;
· when treating with solutions using brushes and rags, thoroughly wipe the surface to be treated;
· when treating with a stream of water, direct the stream at an angle of 30 - 60° to the surface, being 3 - 4 m from the object being treated;
· ensure that splashes and liquid flowing from the object being treated do not fall on people performing decontamination.

Behavior in situations of potential radiation hazard.

If I was told that a nuclear power plant exploded nearby, where should I run?
Don't run anywhere. Firstly, you could have been deceived. Secondly, in case of real danger, it is best to trust the actions of professionals. And in order to find out about these very actions, it is advisable to be at home, turn on the radio or TV. As a precautionary measure, it is recommended to close windows and doors tightly, do not let children and pets outside, and wet clean the apartment.

What medications should you take to prevent harm from radiation?
During accidents at nuclear power plants, it is released into the atmosphere large number radioactive isotope iodine-131, which accumulates in the thyroid gland, which leads to internal radiation of the body and can cause thyroid cancer. Therefore, in the first days after contamination of the territory (or better before this contamination), it is necessary to saturate the thyroid gland with ordinary iodine, then the body will be immune to its radioactive isotope. Drinking iodine from a bottle is extremely harmful; there are various tablets - regular potassium iodide, iodine active, iodomarin, etc., all of them are the same potassium iodine.
If there is no potassium-iodine nearby, and the area is polluted, then, as a last resort, you can drop a couple of drops of regular iodine into a glass of water or jelly and drink.
The half-life of iodine-131 is just over 8 days. Accordingly, after two weeks you can, in any case, forget about taking iodine orally.

Radiation dose table.