What is radiation? All about radiation and ionizing radiation Definition, standards, SanPiN

Today even small children are aware of the existence of invisible deadly rays. They scare us from computer and TV screens dire consequences radiation: post-apocalyptic films and games are still fashionable. However, only a few can give a clear answer to the question “what is radiation?” And one more thing fewer people realize how real the threat of radiation exposure is. Moreover, not somewhere in Chernobyl or Hiroshima, but in his own home.

What is radiation?

In fact, the term "radiation" does not necessarily mean "deadly rays." Thermal or, for example, solar radiation poses virtually no threat to the life and health of living organisms living on the surface of the Earth. Of all known species radiation poses a real danger only ionizing radiation, which physicists also call electromagnetic or corpuscular. This is the very “radiation” whose dangers are talked about on TV screens.

Ionizing gamma and x-ray radiation- that “radiation” that they talk about on TV screens

The peculiarity of ionizing radiation is that, unlike other types of radiation, it has extremely high energy and, when interacting with a substance, causes the ionization of its molecules and atoms. Particles of a substance that are electrically neutral before irradiation are excited, resulting in the formation of free electrons, as well as positively and negatively charged ions.

The four most common types of ionizing radiation are alpha, beta, gamma, and x-rays (has the same properties as gamma). They consist of different particles, and therefore have different energies and, accordingly, different penetrating abilities. The “weakest” in this sense is alpha radiation, which is a stream of positively charged alpha particles, unable to “leak through” even through an ordinary sheet of paper (or human skin). Beta radiation, consisting of electrons, penetrates the skin by 1-2 cm, but it is quite possible to protect yourself from it. But there is practically no escape from gamma radiation: high-energy photons (or gamma quanta) can only be stopped by a thick lead or reinforced concrete wall. However, the fact that alpha and beta particles can be easily stopped even by a minor barrier like paper does not mean that they will not enter the body. The respiratory organs, microtraumas on the skin and mucous membranes are “open gates” for radiation with low penetrating ability.

Units of measurement and norm of radiation

The main measure of radiation exposure is considered to be exposure dose. It is measured in P (roentgens) or derivatives (mR, μR) and represents the total amount of energy that the source of ionizing radiation managed to transfer to an object or organism during the irradiation process. Since different types of radiation have different degrees of danger with the same amount of transmitted energy, it is customary to calculate another indicator - the equivalent dose. It is measured in B (rem), Sv (sieverts) or their derivatives and is calculated as the product of the exposure dose by a coefficient characterizing the quality of radiation (for beta and gamma radiation the quality coefficient is 1, for alpha - 20). To assess the strength of the ionizing radiation itself, other indicators are used: exposure and equivalent dose power (measured in R/sec or derivatives: mR/sec, μR/hour, mR/hour), as well as flux density (measured in (cm 2 min) -1) for alpha and beta radiation.

Today it is generally accepted that ionizing radiation with a dose rate below 30 μR/hour is absolutely safe for health. But everything is relative... As recent studies have shown, different people have different resistance to the effects of ionizing radiation. Approximately 20% have hypersensitivity, the same amount - reduced. The consequences of low-dose radiation usually appear years later or do not appear at all, affecting only the descendants of the person affected by radiation. So, the safety of small doses (slightly exceeding the norm) still remains one of the most discussed issues.

Radiation and man

So, what is the effect of radiation on the health of humans and other living beings? As already noted, ionizing radiation penetrates the body in various ways and causes ionization (excitation) of atoms and molecules. Further, under the influence of ionization, free radicals are formed in the cells of a living organism, which disrupt the integrity of proteins, DNA, RNA and other complex biological compounds. Which in turn leads to massive cell death, carcinogenesis and mutagenesis.

In other words, the effect of radiation on the human body is destructive. With strong radiation negative consequences appear almost immediately: high doses cause radiation sickness of varying degrees of severity, burns, blindness, and the occurrence of malignant neoplasms. But small doses, which until recently were considered “harmless” (today an increasing number of researchers are coming to this conclusion), are no less dangerous. The only difference is that the effects of radiation do not appear immediately, but after several years, sometimes decades. Leukemia, cancerous tumors, mutations, deformities, disorders of the gastrointestinal tract, circulatory system, mental and mental development, schizophrenia - these are far from full list diseases that can cause low doses of ionizing radiation.

Even a small amount of radiation leads to catastrophic consequences. But radiation is especially dangerous for young children and the elderly. Thus, according to specialists on our website www.site, the likelihood of leukemia occurring during low-dose irradiation increases by 2 times for children under 10 years of age and 4 times for infants who were in the womb at the time of irradiation. Radiation and health are literally incompatible!

Radiation protection

A characteristic feature of radiation is that it does not “dissolve” in environment, like harmful chemical compounds. Even after eliminating the radiation source, the background for a long time remains elevated. Therefore, there is a clear and unambiguous answer to the question “how to deal with radiation?” still doesn't exist. It is clear that in case of nuclear war (for example) they have invented special means protection against radiation: special suits, bunkers, etc. But this is for “emergency situations”. But what about small doses, which many still consider “virtually safe”?

It is known that “saving drowning people is the work of the drowning people themselves.” While researchers are deciding which dose should be considered dangerous and which should not, it is better to buy a device that measures radiation yourself and walk around territories and objects a mile away, even if they “radiate” quite a bit (at the same time, the question “how to recognize radiation?” will be resolved, because With a dosimeter in hand, you will always be aware of the surrounding background). Moreover, in modern city radiation can be found in any, even the most unexpected places.

And finally, a few words about how to remove radiation from the body. To speed up cleansing as much as possible, doctors recommend:

1. Physical activity, bath and sauna - speed up metabolism, stimulate blood circulation and, therefore, help remove any harmful substances from the body naturally.

2. Healthy diet - special attention should be paid to vegetables and fruits rich in antioxidants (this is the diet prescribed to cancer patients after chemotherapy). Entire “deposits” of antioxidants are found in blueberries, cranberries, grapes, rowan berries, currants, beets, pomegranates and other sour and sweet-sour fruits of red shades.

Radiation and ionizing radiation

The word “radiation” comes from the Latin word “radiatio”, which means “radiance”, “radiation”.

The main meaning of the word “radiation” (in accordance with Ozhegov’s dictionary, published in 1953): radiation coming from some body. However, over time it was replaced by one of its narrower meanings - radioactive or ionizing radiation.

Radon actively enters our homes with household gas, tap water (especially if it is extracted from very deep wells), or simply seeps through microcracks in the soil, accumulating in basements and lower floors. Reducing the radon content, unlike other sources of radiation, is very simple: it is enough to regularly ventilate the room and the concentration dangerous gas will decrease several times.

Artificial radioactivity

Unlike natural sources radiation, artificial radioactivity arose and is spread exclusively by human forces. The main man-made radioactive sources include nuclear weapons, industrial waste, nuclear power plants, medical equipment, antiquities taken from “forbidden” zones after the accident Chernobyl nuclear power plant, some gems.

Radiation can enter our body in any way, often the culprit is objects that do not cause any suspicion in us. The best way to protect yourself is to check your home and the objects in it for the level of radioactivity or buy a radiation dosimeter. We are responsible for our own life and health. Protect yourself from radiation!

In the Russian Federation there are standards regulating permissible levels of ionizing radiation. From August 15, 2010 to the present, sanitary and epidemiological rules and regulations SanPiN 2.1.2.2645-10 “Sanitary and epidemiological requirements for living conditions in residential buildings and premises” have been in force.

Latest changes were introduced on December 15, 2010 - SanPiN 2.1.2.2801-10 “Changes and additions No. 1 to SanPiN 2.1.2.2645-10 “Sanitary and epidemiological requirements for living conditions in residential buildings and premises”.

The following also apply regulatory documents regarding ionizing radiation:

In accordance with the current SanPiN, “the effective dose rate of gamma radiation inside buildings should not exceed the dose rate in open areas by more than 0.2 μSv/hour.” It does not say what the permissible dose rate is in open areas! SanPiN 2.6.1.2523-09 states that “ permissible effective dose value, caused by the total impact natural radiation sources, for the population not installed. Reducing public exposure is achieved by establishing a system of restrictions on public exposure from individual natural radiation sources,” but at the same time, when designing new residential and public buildings, it must be ensured that the average annual equivalent equilibrium volumetric activity of daughter isotopes of radon and thoron in indoor air does not exceed 100 Bq/m 3 , and in operating buildings the average annual equivalent equilibrium volumetric activity of the daughter products of radon and thoron in the air of residential premises should not exceed 200 Bq/m 3 .

However, SanPiN 2.6.1.2523-09 in Table 3.1 states that the limit of the effective radiation dose for the population is 1 mSv per year on average for any consecutive 5 years, but no more than 5 mSv per year. Thus, it can be calculated that maximum effective dose rate is equal to 5 mSv divided by 8760 hours (the number of hours in a year), which is equal to 0.57 μSv/hour.

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. IN large volumes artificial radionuclides are formed, mainly as a by-product in the defense industry and nuclear energy. 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 production, is necessary. real mechanisms effects of radiation, consequences and existing protective measures.

Radioactivity- instability of the nuclei of some atoms, manifested in their ability to 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.

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 stronger effect 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?

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?

Number radioactive nuclei of one 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 of a 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 this place at a given moment in 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).

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 removal 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 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 very large number ions (up to several thousand pairs of ions per 1 micron path in tissues). Ionization, in turn, determines a number of features of those chemical reactions, which occur in matter, in particular in living tissue (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, having no 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, receiving so-called induced radioactivity. Neutron radiation is generated during the operation of particle accelerators, in nuclear reactors, industrial and laboratory installations, during nuclear explosions, etc. Neutron radiation has the greatest penetrating ability. 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 to varying degrees, into 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 of a 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 because 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 various compositions are used high density(various concretes with metal fillers).

Radiation plays a huge role in the development of civilization at this time. historical stage. Thanks to the phenomenon of radioactivity, a significant breakthrough was made in the field of medicine and various industries industry, including energy. But at the same time, they began to appear more and more clearly negative aspects properties radioactive elements: 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 we learned about the effects of radiation on 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 inadequate perception this problem. Newspaper stories about six-legged lambs and two-headed babies are causing widespread panic. Problem radiation pollution has become one of the most relevant. 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 one that has existed since the late 1920s International Commission By radiation protection(ICRP), 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.

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 ((-particles) from the nucleus is called alpha radiation, the emission of an electron is called beta radiation, and both of these processes occur with the release of energy. Sometimes an additional release of pure energy occurs, called gamma radiation.

Radioactive decay is the entire process of spontaneous decay of an unstable nuclide. Radionuclide is an unstable nuclide capable of spontaneous decay. The half-life of an isotope is the time during which on average half of all radionuclides decay of this type in any radioactive source The radiation activity of a sample is the number of decays per second in a given radioactive sample; unit of measurement - becquerel (Bq) “Absorbed dose* - the 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 this type of radiation to damage body tissues. Effective equivalent dose*** - equivalent dose multiplied by a coefficient that takes into account the different sensitivity of different tissues to radiation. Collective effective equivalent dose**** is the effective equivalent dose received by a group of people from any radiation source. The total collective effective equivalent dose is 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)

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 often leads to complete or partial death of the body due to the destruction of tissue cells.

• * unit of measurement in the SI system - gray (Gy)
• ** unit of measurement in the SI system - sievert (Sv)
• *** unit of measurement in the SI system - sievert (Sv)
• ****unit of measurement in the SI system - man-sievert (man-Sv)

The difficulty in tracking the sequence of processes caused by irradiation is due to the fact that the effects of irradiation, especially when small doses, may not appear immediately, and the disease often takes years or even decades to develop. In addition, due to the different penetrating ability different types Radioactive radiation has 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 in 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 result in death 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 assess the likelihood of disease as a consequence of radiation exposure. 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. Probability Estimation fatal outcome for leukemia is more reliable than similar estimates 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 increased by other adverse 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, in the first approach it was established that a dose of 1 Gy received at low radiation background in males (estimates are less certain for women), causes 1,000 to 2,000 mutations with serious consequences and 30 to 1,000 chromosomal aberrations for every million live births. The second approach obtained the following results: chronic irradiation at a dose rate of 1 Gy per generation will lead to 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. The genetic consequences of radiation are expressed in 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.

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 are talking about external irradiation. Another method of irradiation - when radionuclides enter the body with air, food and water - is called internal. Sources 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 substance (carbon-14).

Different types of radiation reach the surface of the Earth either from space or come from radioactive substances located in 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 are not the same for various areas. So, Northern and South poles more than the equatorial zone are exposed to cosmic rays due to the presence of a magnetic field near the Earth that deflects charged radioactive particles. In addition, the greater the distance from 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 2000 m above sea level receive, on average, an effective equivalent dose from cosmic rays several times greater than those living at sea level. When ascending from a height of 4000 m ( maximum height residence of people) up to 12,000 m (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. Total due to use 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 of natural origin are formed in the event of enrichment of certain types rocks uranium, thorium, in deposits of radioactive elements in various rocks, with the modern introduction of uranium, radium, radon into surface and underground waters, and the 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 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-mentioned areas in Brazil and India are the most studied in this aspect, but there are many other places with high levels of radiation, for example in France, Nigeria, and Madagascar.

Zones of increased radioactivity are also unevenly distributed throughout Russia and are known both in the European part of the country and in the Trans-Urals, Polar Urals, Western Siberia, Baikal region, on Far East, Kamchatka, 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 The main problem with radon is internal exposure to radon: the products formed during its decay in the form of tiny particles penetrate into the respiratory system, 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. Received in last decades information 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 Onega, Lake Ladoga and the Gulf of Finland, a wide area 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 artificial sources radiation radiation (except for radioactive fallout as a result of 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. Unknown exact quantity people undergoing such examinations and treatment, and the doses they receive, 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 overall rating 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 greater. 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 world population is approximately 1,600,000 man-Sv per year. The next source of radiation created by human hands is the radioactive fallout that fell as a result of the test nuclear weapons in the atmosphere, and, despite the fact that the bulk of the explosions were carried out back in the 1950s and 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, when normal operation 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 extraction and enrichment 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 cooler reservoir, and, accordingly, into nearby drainage reservoirs, groundwater, and the ground layer of the atmosphere. Its half-life is 3.82 days. Its disintegration is accompanied alpha radiation. Elevated concentrations This radioisotope has been detected in the natural environments of many nuclear power plants. So far we have been talking about normal work nuclear power plants, but using the example of the Chernobyl tragedy, we can draw a conclusion about the extremely great potential danger of nuclear energy: with any minimal failure of a nuclear power plant, especially a large one, it can have an irreparable impact on the entire ecosystem of the Earth.

Scale 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, there were 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 every day. 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 waste nuclear power, which is contrary to all norms. To the radiation emanating from the building itself is added natural radiation earthly origin. 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). Nuclear industry workers 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. When producing particularly thin optical lenses Thorium is used, 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.

In the introduction, they pointed out the fact that one of the most serious omissions today is the lack of objective information. However, a great deal of work has already been done to assess radiation pollution, and research results 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

List of used literature

radiation human body radiation

• 1. Lisichkin V.A., Shelepin L.A., Boev B.V. Decline of civilization or movement towards the noosphere (ecology from different sides). M.; "ITs-Garant", 1997. 352 p.
• 2. Miller T. Life in the environment / Transl. from English In 3 volumes. T.1. M., 1993; T.2. M., 1994.
• 3. Nebel B. Environmental Science: How the World Works. In 2 vols. / Transl. from English T. 2. M., 1993.
• 4. Pronin M. Be afraid! Chemistry and life. 1992. No. 4. P. 58.
• 5. Revelle P., Revelle Ch. Our habitat. In 4 books. Book 3.

Energy problems of humanity / Transl. from English M.; Science, 1995. 296 p.

6. Environmental issues: what is happening, who is to blame and what to do?: Tutorial/ Ed. prof. V.I. Danilova-Danilyana. M.: Publishing house MNEPU, 1997. 332 p.