All about radiation and ionizing radiation Definition, standards, SanPiN. The benefits and harms of radioactive radiation

1. What is radioactivity and radiation?

The phenomenon of radioactivity was discovered in 1896 by the French scientist Henri Becquerel. Currently, it is widely used in science, technology, medicine, and industry. Radioactive elements natural origin present everywhere in surrounding a person environment. Artificial radionuclides are produced in large quantities, mainly as a by-product in the defense industry and nuclear power plants. When they enter the environment, they affect living organisms, which is where their danger lies. To correctly assess this danger, a clear understanding of the scale of environmental pollution, the benefits brought by production, the main or by-product of which are radionuclides, and the losses associated with the abandonment of these productions, the real mechanisms of action of radiation, the consequences and existing protective measures is necessary. .

Radioactivity- instability of the nuclei of some atoms, manifested in their ability to undergo spontaneous transformations (decay), accompanied by the emission of ionizing radiation or radiation

2. What kind of radiation is there?

There are several types of radiation.
Alpha particles: relatively heavy, positively charged particles that are helium nuclei.
Beta particles- it's just electrons.
Gamma radiation has the same electromagnetic nature as visible light, however, has much greater penetrating power. 2 Neutrons- electrically neutral particles arise mainly directly near an operating nuclear reactor, where access, of course, is regulated.
X-ray radiation similar to gamma radiation, but has less energy. By the way, our Sun is one of the natural sources of X-ray radiation, but earth's atmosphere provides reliable protection against it.

Charged particles interact very strongly with matter, therefore, on the one hand, even one alpha particle, when entering a living organism, can destroy or damage many cells, but, on the other hand, for the same reason, sufficient protection from alpha and beta -radiation is any, even a very thin layer of solid or liquid substance - for example, ordinary clothing (if, of course, the radiation source is outside).

It is necessary to distinguish between radioactivity and radiation. Sources of radiation- radioactive substances or nuclear technical installations (reactors, accelerators, X-ray equipment, etc.) - can exist for a considerable time, and radiation exists only until the moment of its absorption in any substance.

3. What can the effects of radiation on humans lead to?

The effect of radiation on humans is called irradiation. The basis of this effect is the transfer of radiation energy to the cells of the body.
Radiation can cause metabolic disorders, infectious complications, leukemia and malignant tumors, radiation infertility, radiation cataracts, radiation burns, and radiation sickness.
The effects of radiation have a greater impact on dividing cells, and therefore radiation is much more dangerous for children than for adults.

It should be remembered that much greater REAL damage to human health is caused by emissions from the chemical and steel industries, not to mention the fact that science does not yet know the mechanism of malignant degeneration of tissues from external influences.

4. How can radiation enter the body?

The human body reacts to radiation, not to its source. 3
Those sources of radiation, which are radioactive substances, can enter the body with food and water (through the intestines), through the lungs (during breathing) and, to a small extent, through the skin, as well as during medical radioisotope diagnostics. In this case they talk about internal radiation .
In addition, a person may be exposed to external radiation from a radiation source that is located outside his body.
Internal radiation is much more dangerous than external radiation. 5. Is radiation transmitted as a disease? Radiation is created by radioactive substances or specially designed equipment. The radiation itself, acting on the body, does not form in it radioactive substances, and does not turn it into a new source of radiation. Thus, a person does not become radioactive after an X-ray or fluorographic examination. By the way, an X-ray image (film) also does not contain radioactivity.

An exception is the situation in which radioactive drugs are deliberately introduced into the body (for example, during a radioisotope examination of the thyroid gland), and the person becomes a source of radiation for a short time. However, drugs of this kind are specially selected so that they quickly lose their radioactivity due to decay, and the intensity of the radiation quickly decreases.

6. In what units is radioactivity measured?

A measure of radioactivity is activity. It is measured in Becquerels (Bq), which corresponds to 1 decay per second. The activity content of a substance is often estimated per unit weight of the substance (Bq/kg) or volume (Bq/cubic meter).
There is also another unit of activity called the Curie (Ci). This is a huge value: 1 Ci = 37000000000 Bq.
The activity of a radioactive source characterizes its power. Thus, in a source with an activity of 1 Curie, 37000000000 decays occur per second.
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As mentioned above, during these decays the source emits ionizing radiation. The measure of the ionization effect of this radiation on a substance is exposure dose. Often measured in Roentgens (R). Since 1 Roentgen is a rather large value, in practice it is more convenient to use parts per million (μR) or thousandths (mR) of a Roentgen.
The operation of common household dosimeters is based on measuring ionization over a certain time, that is exposure dose rate. The unit of measurement for exposure dose rate is micro-Roentgen/hour.
The dose rate multiplied by time is called dose. Dose rate and dose are related in the same way as the speed of a car and the distance traveled by this car (path).
To assess the impact on the human body, concepts are used equivalent dose And equivalent dose rate. They are measured in Sieverts (Sv) and Sieverts/hour, respectively. In everyday life, we can assume that 1 Sievert = 100 Roentgen. It is necessary to indicate which organ, part or entire body the dose was given to.
It can be shown that the above-mentioned point source with an activity of 1 Curie (for definiteness, we consider a cesium-137 source) at a distance of 1 meter from itself creates an exposure dose rate of approximately 0.3 Roentgen/hour, and at a distance of 10 meters - approximately 0.003 Roentgen/hour. A decrease in dose rate with increasing distance from the source always occurs and is determined by the laws of radiation propagation.

7. What are isotopes?

There are more than 100 in the periodic table chemical elements. Almost each of them is represented by a mixture of stable and radioactive atoms, which are called isotopes of this element. About 2000 isotopes are known, of which about 300 are stable.
For example, the first element of the periodic table - hydrogen - has the following isotopes:
- hydrogen H-1 (stable),
- deuterium N-2 (stable),
- tritium H-3 (radioactive, half-life 12 years).

Radioactive isotopes are usually called radionuclides 5

8. What is half-life?

The number of radioactive nuclei of the same type constantly decreases over time due to their decay.
The decay rate is usually characterized half-life: this is the time during which the number of radioactive nuclei certain type will decrease by 2 times.
Absolutely wrong is the following interpretation of the concept of “half-life”: “if a radioactive substance has a half-life of 1 hour, this means that after 1 hour its first half will decay, and after another 1 hour the second half will decay, and this substance will completely disappear (disintegrate).”

For a radionuclide with a half-life of 1 hour, this means that after 1 hour its amount will become 2 times less than the original, after 2 hours - 4 times, after 3 hours - 8 times, etc., but will never completely disappear. The radiation emitted by this substance will decrease in the same proportion. Therefore, it is possible to predict the radiation situation for the future if you know what and in what quantities of radioactive substances create radiation in a given place in at the moment time.

Each radionuclide has its own half-life; it can range from fractions of a second to billions of years. It is important that the half-life of a given radionuclide is constant and cannot be changed.
Nuclei formed during radioactive decay, in turn, can also be radioactive. For example, radioactive radon-222 owes its origin to radioactive uranium-238.

Sometimes there are statements that radioactive waste in storage facilities will completely decay within 300 years. This is wrong. It’s just that this time will be approximately 10 half-lives of cesium-137, one of the most common man-made radionuclides, and over 300 years its radioactivity in waste will decrease almost 1000 times, but, unfortunately, will not disappear.

9. What is radioactive around us?
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The following diagram will help to assess the impact on a person of certain sources of radiation (according to A.G. Zelenkov, 1990).

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

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

Types of radiation

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

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

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

Natural sources

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

Varieties of natural sources

Cosmic radiation and solar radiation- 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. Avoid being exposed to direct sunlight for a long time.
Radiation from the earth's crust is dangerous near deposits of various minerals. By burning coal or using phosphorus fertilizers, radionuclides actively seep inside a person with the air they inhale and the food they eat.
Radon is a radioactive chemical element found in building materials. It is a colorless, odorless and tasteless gas. This element actively accumulates in soils and comes out along with mining. It enters apartments along with household gas, as well as tap water. Fortunately, its concentration can be easily reduced by constantly ventilating the premises.

Artificial sources

This species appeared thanks to people. Its effect increases and spreads with their help. During the start nuclear war The strength and power of weapons is not as terrible as the consequences of radioactive radiation after explosions. Even if you don't get hooked blast wave or physical factors - radiation will kill you.

Artificial sources include:

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

Norm of radioactive radiation

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

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

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

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

The effect of radiation on humans

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

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

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

Mutation after radiation

Consequences of radiation

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

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

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

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

Mutations

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

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

“People’s attitude towards a particular danger is determined by how well they know it.”

This material is a generalized answer to numerous questions that arise from users of devices for detecting and measuring radiation in domestic conditions.
Minimal use of the specific terminology of nuclear physics when presenting the material will help you 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 natural radioactive elements discovered was called radium.”
- translated from Latin - emitting rays, radiating.”

Each person in the environment is exposed to various phenomena that influence him. These include heat, cold, magnetic and normal storms, heavy rains, heavy snowfalls, strong winds, sounds, explosions, etc.

Thanks to the presence of sensory organs assigned to him by nature, he can quickly respond to these phenomena with the help of, for example, a sun canopy, clothing, shelter, medicine, 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 the radiation accompanying it (the so-called ionizing radiation) have always existed in the Universe. Radioactive materials are part of the Earth and even humans are slightly radioactive, because... Radioactive substances are present in the smallest quantities in any living tissue.

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 has passed and undesirable or even harmful 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.
However, enough of the mysteries. Let's talk about what radiation and ionizing (i.e. radioactive) radiation are.

Ionizing radiation

Any medium consists of tiny neutral particles - atoms, which consist of positively charged nuclei and negatively charged electrons surrounding them. Every atom is like solar system in miniature: “planets” move in orbit around a tiny core - electrons.
Atomic nucleus consists of several elementary particles - protons and neutrons, held together by nuclear forces.

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

Neutrons neutral particles with no charge. The number of electrons in an atom is exactly equal to the number of protons in the nucleus, so each atom is generally neutral. 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 if the number of protons is the same. Such atoms, which have nuclei with the same number of protons but differ in the number of neutrons, are varieties of the same chemical element, called “isotopes” of that element. To distinguish them from each other, a number is assigned to the element symbol, equal to the sum 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 the uranium atom - 238. From time to time, a compact group of four particles bursts out of it: two protons and two neutrons - an “alpha particle (alpha)”. Uranium-238 thus turns 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 (beta) moving in their orbits: one of them becomes, as it were, superfluous, without a pair (proton), so it leaves the atom. The chain of numerous transformations, accompanied by alpha or beta radiation, ends with a stable lead nuclide. Of course, there are many similar chains of spontaneous transformations (decays) of different nuclides. The half-life is the period of time during which the initial number of radioactive nuclei on average decreases by half.
With each act of decay, energy is released, which is transmitted in the form of radiation. Often an unstable nuclide finds itself in an excited state, and the emission of a particle does not lead to complete removal of excitation; then it emits 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 entire process of spontaneous decay of an unstable nuclide is called radioactive decay, and the nuclide itself is called a radionuclide.

Various types of radiation are accompanied by the release different quantities energy and have different penetrating abilities; therefore, they have different effects on the tissues of a living organism. Alpha radiation is blocked, 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 with inhaled air or steam, for example, in a bath; then they become extremely dangerous. The beta particle has greater penetrating ability: it penetrates the body tissue to a depth of one to two centimeters or more, depending on the amount of energy. The penetrating power of gamma radiation, which travels 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 measurable physical quantities. These should include energy quantities. At first glance, it may seem that they are sufficient for recording and assessing the impact 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 different for different people. Therefore, average values are used.

Sources of radiation can be natural, present in nature, and independent of humans.

It has been established that of all natural sources of radiation, the greatest danger is radon, a heavy gas without taste, smell, and at the same time invisible; with its subsidiary products.

Radon is released from the earth's crust everywhere, but its concentration in the outside air varies significantly for different parts of the globe. Paradoxical as it may seem at first glance, a person receives the main radiation from radon while in a closed, unventilated room. Radon concentrates in the air indoors only when they are sufficiently isolated from the external environment. Seeping through the foundation and floor from the soil or, less commonly, being released from building materials, radon accumulates indoors. Sealing rooms for the purpose of insulation only makes matters worse, since this makes it even more difficult for radioactive gas to escape from the room. The radon problem is especially important for low-rise buildings with carefully sealed rooms (to retain 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 greater specific radioactivity.

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

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

Radon enters natural gas underground. As a result of pre-processing and during the storage of gas before it reaches the consumer, most of the radon evaporates, but the concentration of radon in the room can increase noticeably if kitchen stoves and other heating gas appliances are not equipped with an exhaust hood. In the presence of supply and exhaust ventilation, which communicates with the outside air, radon concentration does not occur in these cases. This also applies to the house as a whole - based on the readings of radon detectors, you can set a ventilation mode for the premises that completely eliminates the threat to health. However, given that the release of radon from the soil is seasonal, it is necessary to monitor the effectiveness of ventilation three to four times a year, avoiding exceeding the radon concentration standards.

Other sources of radiation, which unfortunately have potential dangers, 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 its dangerous nature for humans, radiation can be used to serve humans. Far from it full list 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.

The 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 out specially in terms of their impact on humans. However, only emergency situations, such as the Chernobyl accident, can have an uncontrollable impact on humans.
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. It is very simple to protect yourself and your loved ones from this danger. When buying milk, vegetables, fruits, herbs, and any other products, it is not superfluous to turn on the dosimeter and bring it to the purchased product. Radiation is not visible - but the device will instantly detect the presence radioactive contamination. This is our life in the third millennium - a dosimeter becomes an attribute of everyday life, like a handkerchief, toothbrush, and soap.

IMPACT OF IONIZING RADIATION ON BODY TISSUE

The damage caused in a living organism by ionizing radiation will be 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 located outside the body or inside it.

The amount of radiation energy absorbed by irradiated body tissues, 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 for 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, for the same equivalent dose of radiation, cancer is more likely to occur in the lungs than in the thyroid gland, and irradiation of the gonads is especially dangerous due to the risk of genetic damage. Therefore, human radiation doses should be taken into account with different coefficients. By multiplying the equivalent doses by the corresponding coefficients and summing them over all organs and tissues, we obtain an effective equivalent dose, reflecting the total effect of radiation on the body; it is also measured in Sieverts.

Charged particles.

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

Electrical interactions.

Within a time of about ten trillionths of a second after the penetrating radiation reaches the corresponding atom in the tissue of the body, an electron is torn off 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.

Physico-chemical changes.

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

Chemical changes.

Over the next millionths of a second, the resulting free radicals 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 within seconds or decades after irradiation and cause immediate cell death or changes in them.

UNITS OF MEASUREMENT OF RADIOACTIVITY
Becquerel (Bq, Bq); Curie (Ci, Cu)	1 Bq = 1 decay per second. 1 Ci = 3.7 x 10 10 Bq	Units of radionuclide activity. Represent the number of decays per unit time.
Gray (Gr, Gu); Glad (rad, rad)	1 Gy = 1 J/kg 1 rad = 0.01 Gy	Absorbed dose units. Represent the amount of energy of ionizing radiation absorbed by a unit of mass of any physical body, for example, body tissues.
Sievert (Sv, Sv) Rem (ber, rem) - “biological equivalent of an x-ray”	1 Sv = 1 Gy = 1 J/kg (for beta and gamma) 1 µSv = 1/1000000 Sv 1 ber = 0.01 Sv = 10 mSv Equivalent dose units.	Equivalent dose units. They represent a unit of absorbed dose multiplied by a coefficient 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. They represent the dose received by the body per unit of time.

For information, and not to intimidate, especially people who decide to devote themselves to working with ionizing radiation, you should know the maximum permissible doses. The units of measurement of radioactivity are given in Table 1. According to the conclusion of the International Commission on Radiation Protection in 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 higher 0.5 Sv (50 rem). When radiation exposure exceeds a certain threshold, radiation sickness occurs. There are chronic and acute (with a single massive exposure) forms of this disease. Acute radiation sickness is divided into four degrees by 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). Stage 4 can be fatal.

The 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).
For medical diagnostic procedures - x-rays, etc. - a person receives approximately another 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 emissions from modern coal-fired thermal power plants and when flying on an airplane, a person receives up to 4 mSv/year. In total, the 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 reserve. For personnel working with sources of ionizing radiation, the maximum permissible dose 50 mSv/year (5 rem/year), i.e. 28 µSv/h with a 36-hour work week.

According to hygienic standards NRB-96 (1996), the permissible dose rate levels for external irradiation of the whole body from man-made sources for permanent residence of personnel is 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).

HOW DO YOU MEASURE RADIATION?

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 body), scintillation, luminescent, photographic. These methods form the basis of the work dosimeters radiation. Gas-filled ionizing radiation sensors include ionization chambers, fission chambers, proportional counters, and Geiger-Muller counters. The latter are relatively simple, the cheapest, and not critical to operating conditions, which led to their widespread use in professional dosimetric equipment designed to detect and evaluate beta and gamma radiation. When the sensor is a Geiger-Muller counter, any ionizing particle that enters the sensitive volume of the counter causes a self-discharge. Precisely falling into the 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 penetrate the device body, will not enter the sensitive element and will not be detected.

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

IN modern world It so happens that we are surrounded by many harmful and dangerous things and phenomena, most of which are the work of man himself. In this article we will talk about radiation, namely: what is radiation.

The concept of “radiation” comes from the Latin word “radiatio” - radiation. Radiation is ionizing radiation propagating in the form of a stream of quanta or elementary particles.

What does radiation do?

This radiation is called ionizing because radiation, penetrating through any tissue, ionizes its particles and molecules, which leads to the formation of free radicals, which lead to massive death of tissue cells. The effect of radiation on the human body is destructive and is called irradiation.

In small doses, radioactive radiation is not dangerous unless doses dangerous to health are exceeded. If exposure standards are exceeded, the consequence may be the development of many diseases (including cancer). The consequences of minor exposures are difficult to track, since diseases can develop over many years and even decades. If the radiation was strong, then this leads to radiation sickness and the death of a person; such types of radiation are possible only during man-made disasters.

A distinction is made between internal and external exposure. Internal exposure can occur by eating irradiated foods, inhaling radioactive dust, or through the skin and mucous membranes.

Types of radiation

Alpha radiation is a stream of positively charged particles formed by two protons and neutrons.
Beta radiation is the radiation of electrons (particles with a charge -) and positrons (particles with a charge +).
Neutron radiation is a stream of uncharged particles - neutrons.
Photon radiation (gamma radiation, x-rays) is electromagnetic radiation, having great penetrating ability.

Sources of radiation

Natural: nuclear reactions, spontaneous radioactive decay of radionuclides, cosmic rays and thermonuclear reactions.
Artificial, that is, created by man: nuclear reactors, particle accelerators, artificial radionuclides.

How is radiation measured?

For ordinary person It is enough to know the magnitude of the dose and the dose rate of radiation.

The first indicator is characterized by:

Exposure dose, it is measured in Roentgens (P) and shows the strength of ionization.
The absorbed dose, which is measured in Grays (Gy) and shows the extent of damage to the body.
Equivalent dose (measured in Sieverts (Sv)), which is equal to the product of the absorbed dose and the quality factor, which depends on the type of radiation.
Each organ of our body has its own radiation risk coefficient; multiplying it by the equivalent dose, we get an effective dose, which shows the magnitude of the risk of radiation consequences. It is measured in Sieverts.

The dose rate is measured in R/hour, mSv/s, that is, it shows the strength of the radiation flux during a certain time of its exposure.

Radiation levels can be measured using special devices - dosimeters.

Normal background radiation is considered to be 0.10-0.16 μSv per hour. Radiation levels up to 30 μSv/hour are considered safe. If the radiation level exceeds this threshold, then the time spent in the affected area is reduced in proportion to the dose (for example, at 60 μSv/hour, the exposure time is no more than half an hour).

How radiation is removed

Depending on the source of internal exposure, you can use:

For releases of radioactive iodine, take up to 0.25 mg of potassium iodide per day (for an adult).
To remove strontium and cesium from the body, use a diet high in calcium (milk) and potassium.
To remove other radionuclides, juices of strongly colored berries (for example, dark grapes) can be used.

Now you know how dangerous radiation is. Be aware of signs indicating contaminated areas and stay away from these areas.

Main literary sources,

II. What is radiation?

III. Basic terms and units of measurement.

IV. The effect of radiation on the human body.

V. Sources of radiation:

1) natural sources

2) sources created by man (technogenic)

I. Introduction

Radiation plays a huge role in the development of civilization at this historical stage. Thanks to the phenomenon of radioactivity, significant breakthroughs have been made in the field of medicine and in various industries, including energy. But at the same time, the negative aspects of the properties of radioactive elements began to appear more and more clearly: it turned out that the effects of radiation on the body can have tragic consequences. Such a fact could not escape the attention of the public. And the more that became known about the effects of radiation on the human body and the environment, the more controversial opinions became about how large a role radiation should play in various fields human activity.

Unfortunately, the lack of reliable information causes an inadequate perception of this problem. Newspaper stories about six-legged lambs and two-headed babies are causing widespread panic. The problem of radiation pollution has become one of the most pressing. Therefore, it is necessary to clarify the situation and find the right approach. Radioactivity should be considered as an integral part of our life, but without knowledge of the patterns of processes associated with radiation, it is impossible to really assess the situation.

For this purpose special international organizations, dealing with radiation problems, including the International Commission on Radiation Protection (ICRP), which has existed since the late 1920s, as well as the Scientific Committee on the Effects of Atomic Radiation (SCEAR), created in 1955 within the UN. In this work, the author made extensive use of the data presented in the brochure “Radiation. Doses, effects, risk”, prepared on the basis of the committee’s research materials.

II. What is radiation?

Radiation has always existed. Radioactive elements have been part of the Earth since the beginning of its existence and continue to be present to the present day. However, the phenomenon of radioactivity itself was discovered only a hundred years ago.

In 1896, the French scientist Henri Becquerel accidentally discovered that after prolonged contact with a piece of mineral containing uranium, traces of radiation appeared on photographic plates after development. Later, Marie Curie (the author of the term “radioactivity”) and her husband Pierre Curie became interested in this phenomenon. In 1898, they discovered that radiation transforms uranium into other elements, which the young scientists named polonium and radium. Unfortunately, people who deal with radiation professionally have put their health and even their lives in danger due to frequent contact with radioactive substances. Despite this, research continued, and as a result, humanity has very reliable information about the process of reactions in radioactive masses, which are largely determined by the structural features and properties of the atom.

It is known that the atom contains three types of elements: negatively charged electrons move in orbits around the nucleus - tightly coupled positively charged protons and electrically neutral neutrons. Chemical elements are distinguished by the number of protons. The same number of protons and electrons determines the electrical neutrality of the atom. The number of neutrons can vary, and the stability of the isotopes changes depending on this.

Most nuclides (the nuclei of all isotopes of chemical elements) are unstable and constantly transform into other nuclides. The chain of transformations is accompanied by radiation: in a simplified form, the emission of two protons and two neutrons (a-particles) by a nucleus is called alpha radiation, the emission of an electron is beta radiation, and both of these processes occur with the release of energy. Sometimes there is an additional release of pure energy called gamma radiation.

III. Basic terms and units of measurement.

(SCEAR terminology)

Radioactive decay– the entire process of spontaneous decay of an unstable nuclide

Radionuclide– unstable nuclide capable of spontaneous decay

Isotope half-life– the time during which, on average, half of all radionuclides of a given type in any radioactive source decay

Radiation activity of the sample– number of decays per second in a given radioactive sample; unit of measurement – becquerel (Bq)

« Absorbed dose*– energy of ionizing radiation absorbed by the irradiated body (body tissues), calculated per unit mass

Equivalent dose**– absorbed dose multiplied by a coefficient reflecting the ability of a given type of radiation to damage body tissues

Efficient equivalent dose***– equivalent dose multiplied by a coefficient taking into account the different sensitivity of different tissues to radiation

Collective effective equivalent dose****– effective equivalent dose received by a group of people from any source of radiation

Total collective effective equivalent dose– the collective effective equivalent dose that generations of people will receive from any source over the entire period of its continued existence” (“Radiation...”, p. 13)

IV. The effect of radiation on the human body

The effects of radiation on the body can vary, but they are almost always negative. In small doses, radiation can become a catalyst for processes leading to cancer or genetic disorders, and in large doses it often leads to complete or partial death of the body due to the destruction of tissue cells.

————————————————————————————–

* gray (Gr)

** SI unit of measurement – sievert (Sv)

*** SI unit of measurement – sievert (Sv)

**** SI unit of measurement – man-sievert (man-Sv)

The difficulty in tracking the sequence of events caused by radiation is that the effects of radiation, especially at low doses, may not appear immediately and often take years or even decades for the disease to develop. In addition, due to the different penetrating ability of different types of radioactive radiation, they have different effects on the body: alpha particles are the most dangerous, but for alpha radiation even a sheet of paper is an insurmountable barrier; beta radiation can pass into body tissue to a depth of one to two centimeters; the most harmless gamma radiation is characterized by the greatest penetrating ability: it can only be stopped by a thick slab of materials with a high absorption coefficient, for example, concrete or lead.

The sensitivity of individual organs to radioactive radiation also varies. Therefore, in order to obtain the most reliable information about the degree of risk, it is necessary to take into account the corresponding tissue sensitivity coefficients when calculating the equivalent radiation dose:

0.03 – bone tissue

0.03 – thyroid gland

0.12 – red bone marrow

0.12 – light

0.15 – mammary gland

0.25 – ovaries or testes

0.30 – other fabrics

1.00 – the body as a whole.

The likelihood of tissue damage depends on the total dose and the dosage size, since, thanks to their repair abilities, most organs have the ability to recover after a series of small doses.

However, there are doses at which death is almost inevitable. For example, doses of the order of 100 Gy lead to death after a few days or even hours due to damage to the central nervous system, from hemorrhage as a result of a radiation dose of 10-50 Gy, death occurs in one to two weeks, and a dose of 3-5 Gy threatens to be fatal for approximately half of those exposed. Knowledge of the body’s specific response to certain doses is necessary to assess the consequences of high doses of radiation during accidents of nuclear installations and devices or the danger of exposure during prolonged stay in areas of increased radiation, both from natural sources and in the case of radioactive contamination.

The most common and serious damage caused by radiation, namely cancer and genetic disorders, should be examined in more detail.

In the case of cancer, it is difficult to estimate the likelihood of disease as a consequence of radiation. Any, even the smallest dose, can lead to irreversible consequences, but this is not predetermined. However, it has been established that the likelihood of disease increases in direct proportion to the radiation dose.

Among the most common cancers caused by radiation are leukemia. Estimates of the likelihood of death from leukemia are more reliable than those for other types of cancer. This can be explained by the fact that leukemia is the first to manifest itself, causing death on average 10 years after the moment of irradiation. Leukemias are followed “in popularity” by: breast cancer, thyroid cancer and lung cancer. The stomach, liver, intestines and other organs and tissues are less sensitive.

The impact of radiological radiation is sharply enhanced by other unfavorable environmental factors (the phenomenon of synergy). Thus, the mortality rate from radiation in smokers is noticeably higher.

As for the genetic consequences of radiation, they manifest themselves in the form of chromosomal aberrations (including changes in the number or structure of chromosomes) and gene mutations. Gene mutations appear immediately in the first generation (dominant mutations) or only if both parents have the same gene mutated (recessive mutations), which is unlikely.

Studying the genetic effects of radiation is even more difficult than in the case of cancer. It is not known what genetic damage is caused by irradiation; it can manifest itself over many generations; it is impossible to distinguish it from those caused by other causes.

It is necessary to evaluate the occurrence of hereditary defects in humans based on the results of animal experiments.

When assessing risk, SCEAR uses two approaches: one determines the immediate effect of a given dose, and the other determines the dose at which the frequency of occurrence of offspring with a particular anomaly doubles compared to normal radiation conditions.

Thus, with the first approach, it was established that a dose of 1 Gy received at a low radiation background by male individuals (for women, estimates are less certain) causes the appearance of from 1000 to 2000 mutations leading to serious consequences, and from 30 to 1000 chromosomal aberrations per every million live newborns.

With the second approach, the following results were obtained: chronic irradiation at a dose rate of 1 Gy per generation will lead to the appearance of about 2000 serious genetic diseases for every million live newborns among children of those who were exposed to such radiation.

These estimates are unreliable, but necessary. Genetic consequences exposures are expressed by such quantitative parameters as a reduction in life expectancy and period of disability, although it is recognized that these estimates are no more than a first rough estimate. Thus, chronic irradiation of the population with a dose rate of 1 Gy per generation reduces the period of working capacity by 50,000 years, and life expectancy by 50,000 years for every million living newborns among children of the first irradiated generation; with constant irradiation of many generations, the following estimates are obtained: 340,000 years and 286,000 years, respectively.

V. Sources of radiation

Now that we have an understanding of the effects of radiation exposure on living tissue, we need to find out in what situations we are most susceptible to this effect.

There are two methods of irradiation: if radioactive substances are outside the body and irradiate it from the outside, then we're talking about about external exposure. Another method of irradiation - when radionuclides enter the body with air, food and water - is called internal.

Sources of radioactive radiation are very diverse, but they can be combined into two large groups: natural and artificial (man-made). Moreover, the main share of radiation (more than 75% of the annual effective equivalent dose) falls on the natural background.

Natural sources of radiation

Natural radionuclides are divided into four groups: long-lived (uranium-238, uranium-235, thorium-232); short-lived (radium, radon); long-lived solitary, not forming families (potassium-40); radionuclides resulting from the interaction of cosmic particles with the atomic nuclei of the Earth's matter (carbon-14).

Various types of radiation reach the Earth's surface either from space or from radioactive substances in the Earth's crust, with terrestrial sources responsible on average for 5/6 of the annual effective dose equivalent received by the population, mainly due to internal exposure.

Radiation levels vary across different areas. So, Northern and South poles more than equatorial zone, exposed to cosmic rays due to the presence of a magnetic field near the Earth, which deflects charged radioactive particles. In addition, the greater the distance from the earth's surface, the more intense the cosmic radiation.

In other words, living in mountainous areas and constantly using air transport, we are exposed to an additional risk of exposure. People living above 2000m above sea level receive, on average, an effective equivalent dose from cosmic rays several times greater than those living at sea level. When rising from a height of 4000m ( maximum height residence of people) up to 12000m (the maximum flight altitude of passenger air transport), the level of exposure increases by 25 times. The approximate dose for the flight New York - Paris according to UNSCEAR in 1985 was 50 microsieverts for 7.5 hours of flight.

In total, through the use of air transport, the Earth's population received an effective equivalent dose of about 2000 man-Sv per year.

Levels of terrestrial radiation are also distributed unevenly over the Earth's surface and depend on the composition and concentration of radioactive substances in the earth's crust. So-called anomalous radiation fields natural origin are formed in case of enrichment of certain types rocks uranium, thorium, at deposits of radioactive elements in various breeds, with the modern introduction of uranium, radium, radon into surface and groundwater, geological environment.

According to studies conducted in France, Germany, Italy, Japan and the USA, about 95% of the population of these countries live in areas where the radiation dose rate ranges on average from 0.3 to 0.6 millisieverts per year. These data can be taken as global averages, since the natural conditions in the above countries are different.

There are, however, a few "hot spots" where radiation levels are much higher. These include several areas in Brazil: the area around Poços de Caldas and the beaches near Guarapari, a city of 12,000 people where approximately 30,000 holidaymakers come annually to relax, where radiation levels reach 250 and 175 millisieverts per year, respectively. This exceeds the average by 500-800 times. Here, as well as in another part of the world, on the southwestern coast of India, a similar phenomenon is due to the increased content of thorium in the sands. The above areas in Brazil and India are the most studied in this aspect, but there are many other places with high level radiation, for example in France, Nigeria, Madagascar.

Throughout Russia, zones of increased radioactivity are also distributed unevenly and are known both in the European part of the country and in the Trans-Urals, Polar Urals, Western Siberia, the Baikal region, the Far East, Kamchatka, and the Northeast.

Among natural radionuclides, the largest contribution (more than 50%) to the total radiation dose is made by radon and its daughter decay products (including radium). The danger of radon lies in its wide distribution, high penetrating ability and migration mobility (activity), decay with the formation of radium and other highly active radionuclides. The half-life of radon is relatively short and amounts to 3.823 days. Radon is difficult to identify without the use of special instruments, since it has no color or odor.

One of the most important aspects of the radon problem is internal exposure to radon: products formed during its decay in the form tiny particles penetrate into the respiratory organs, and their existence in the body is accompanied by alpha radiation. Both in Russia and in the West, much attention is paid to the radon problem, since as a result of studies it has been revealed that in most cases the content of radon in indoor air and in tap water exceeds the maximum permissible concentration. Thus, the highest concentration of radon and its decay products recorded in our country corresponds to an irradiation dose of 3000-4000 rem per year, which exceeds the MPC by two to three orders of magnitude. Information obtained in recent decades shows that in the Russian Federation radon is also widespread in the surface layer of the atmosphere, subsurface air and groundwater.

In Russia, the problem of radon is still poorly studied, but it is reliably known that in some regions its concentration is especially high. These include the so-called radon “spot”, covering Lakes Onega, Lake Ladoga and the Gulf of Finland, a wide zone extending from the Middle Urals to the west, southern part Western Urals, Polar Urals, Yenisei Ridge, Western Baikal region, Amur region, north Khabarovsk Territory, Chukotka Peninsula (“Ecology,...”, 263).

Sources of radiation created by man (man-made)

Artificial sources of radiation exposure differ significantly from natural ones not only in their origin. First, individual doses received vary greatly different people from artificial radionuclides. In most cases, these doses are small, but sometimes exposure from man-made sources is much more intense than from natural sources. Secondly, for technogenic sources the mentioned variability is much more pronounced than for natural ones. Finally, pollution from man-made radiation sources (other than fallout from nuclear explosions) is easier to control than naturally occurring pollution.

Atomic energy is used by humans for various purposes: in medicine, for energy production and fire detection, for making luminous watch dials, for searching for minerals and, finally, for creating atomic weapons.

The main contribution to pollution from artificial sources comes from various medical procedures and treatments involving the use of radioactivity. The main device that no large clinic can do without is an X-ray machine, but there are many other diagnostic and treatment methods associated with the use of radioisotopes.

The exact number of people undergoing such examinations and treatment and the doses they receive are unknown, but it can be argued that for many countries the use of the phenomenon of radioactivity in medicine remains almost the only man-made source of radiation.

In principle, radiation in medicine is not so dangerous if it is not abused. But, unfortunately, unreasonably large doses are often applied to the patient. Among the methods that help reduce risk are reducing the area of the X-ray beam, its filtration, which removes excess radiation, proper shielding and the most banal thing, namely the serviceability of the equipment and its proper operation.

Due to the lack of more complete data, UNSCEAR was forced to accept as a general estimate the annual collective effective equivalent dose from at least radiological examinations in developed countries based on data submitted to the committee by Poland and Japan by 1985, a value of 1000 man-Sv per 1 million inhabitants. Most likely, for developing countries this value will be lower, but individual doses may be higher. It is also estimated that the collective effective equivalent dose from radiation for medical purposes in general (including the use of radiotherapy for the treatment of cancer) for the entire global population is approximately 1,600,000 man-Sv per year.

The next source of radiation created by human hands is radioactive fallout that fell as a result of testing nuclear weapons in the atmosphere, and, despite the fact that the bulk of the explosions were carried out back in the 1950s-60s, we are still experiencing their consequences.

As a result of the explosion, some of the radioactive substances fall out near the test site, some are retained in the troposphere and then, over the course of a month, are transported by the wind over long distances, gradually settling on the ground, while remaining at approximately the same latitude. However, a large proportion of radioactive material is released into the stratosphere and remains there for a longer time, also dispersing over the earth's surface.

Radioactive fallout contains large number various radionuclides, but of these, the most important are zirconium-95, cesium-137, strontium-90 and carbon-14, whose half-lives are respectively 64 days, 30 years (cesium and strontium) and 5730 years.

According to UNSCEAR, the expected total collective effective equivalent dose from all nuclear explosions carried out by 1985 was 30,000,000 man Sv. By 1980, the world's population received only 12% of this dose, and the rest is still receiving and will continue to receive for millions of years.

One of the most discussed sources of radiation today is nuclear energy. In fact, during normal operation of nuclear installations, the damage from them is insignificant. The fact is that the process of producing energy from nuclear fuel is complex and takes place in several stages.

The nuclear fuel cycle begins with the extraction and enrichment of uranium ore, then the nuclear fuel itself is produced, and after the fuel has been processed at a nuclear power plant, it is sometimes possible to reuse it through the extraction of uranium and plutonium from it. The final stage of the cycle is, as a rule, the disposal of radioactive waste.

At each stage, radioactive substances are released into the environment, and their volume can vary greatly depending on the design of the reactor and other conditions. In addition, a serious problem is the disposal of radioactive waste, which will continue to serve as a source of pollution for thousands and millions of years.

Radiation doses vary depending on time and distance. The further a person lives from the station, the lower the dose he receives.

Among the products of nuclear power plants, tritium poses the greatest danger. Due to its ability to dissolve well in water and evaporate intensively, tritium accumulates in the water used in the energy production process and then enters the cooling pond, and, accordingly, into nearby drainage reservoirs, groundwater, and the ground layer of the atmosphere. Its half-life is 3.82 days. Its decay is accompanied by alpha radiation. Increased concentrations of this radioisotope were recorded in natural environments many nuclear power plants.

Until now we have been talking about the normal operation of nuclear power plants, but using the example of the Chernobyl tragedy we can conclude that potential danger nuclear energy: with any minimal failure of a nuclear power plant, especially a large one, can have an irreparable impact on the entire ecosystem of the Earth.

The scale of the Chernobyl accident could not but arouse keen interest from the public. But few people realize the number of minor malfunctions in the operation of nuclear power plants in different countries of the world.

Thus, the article by M. Pronin, prepared based on materials from the domestic and foreign press in 1992, contains the following data:

“...From 1971 to 1984. There were 151 accidents at nuclear power plants in Germany. In Japan at 37 operating nuclear power plants from 1981 to 1985 390 accidents were registered, 69% of which were accompanied by the leakage of radioactive substances... In 1985, 3,000 system malfunctions and 764 temporary shutdowns of nuclear power plants were recorded in the USA...", etc.

In addition, the author of the article points to the relevance, at least in 1992, of the problem of deliberate destruction of enterprises in the nuclear fuel energy cycle, which is associated with the unfavorable political situation in a number of regions. We can only hope for the future consciousness of those who “digging under themselves” in this way.

It remains to indicate several artificial sources of radiation pollution that each of us encounters on a daily basis.

These are, first of all, building materials that are characterized by increased radioactivity. Among such materials are some varieties of granites, pumice and concrete, in the production of which alumina, phosphogypsum and calcium silicate slag were used. There are known cases when building materials were produced from nuclear energy waste, which is contrary to all standards. Natural radiation of terrestrial origin is added to the radiation emanating from the building itself. The simplest and most affordable way to at least partially protect yourself from radiation at home or at work is to ventilate the room more often.

The increased uranium content of some coals can lead to significant emissions of uranium and other radionuclides into the atmosphere as a result of fuel combustion at thermal power plants, in boiler houses, and during the operation of vehicles.

There are a huge number of commonly used items that are sources of radiation. This is, first of all, a watch with a luminous dial, which gives an annual expected effective equivalent dose 4 times higher than that caused by leaks at nuclear power plants, namely 2,000 man-Sv (“Radiation ...”, 55). Workers of nuclear industry enterprises and airline crews receive an equivalent dose.

Radium is used in the manufacture of such watches. Most at risk In this case, it is primarily the owner of the watch who is exposed.

Radioactive isotopes are also used in other luminous devices: entry-exit signs, compasses, telephone dials, sights, chokes for fluorescent lamps and other electrical appliances, etc.

When producing smoke detectors, their operating principle is often based on the use of alpha radiation. Thorium is used to make especially thin optical lenses, and uranium is used to give artificial shine to teeth.

Radiation doses from color televisions and X-ray machines for checking passengers' luggage at airports are very small.

VI. Conclusion

In the introduction, the author pointed out the fact that one of the most serious omissions today is the lack of objective information. However, a huge amount of work has already been done to assess radiation pollution, and the results of research are published from time to time, both in specialized literature, and in the press. But to understand the problem, it is necessary to have not fragmentary data, but a clear picture of the whole picture.

And she is like that.

We do not have the right and opportunity to destroy the main source of radiation, namely nature, and we also cannot and should not give up the advantages that our knowledge of the laws of nature and the ability to use them gives us. But it is necessary

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