“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.”

Every person in environment there are various phenomena that influence it. These include heat, cold, magnetic and normal storms, heavy rains, heavy snowfalls, strong winds, sounds, explosions, etc.

Thanks to the presence of sense organs assigned to him by nature, he can quickly respond to these phenomena with the help of, for example, a sunshade, 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 accompanying radiation (so-called ionizing) 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 are needed that would provide prompt information for making useful decisions before it passes. long time and undesirable or even disastrous consequences will 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 breaks 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.

Different types of radiation are accompanied by the release of different amounts of energy and have different penetrating powers; 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: only a thick lead or concrete slab can stop it. 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 entering premises 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 preliminary 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. Here is a far from complete list of areas of application of radiation: medicine, industry, Agriculture, chemistry, science, etc. A calming factor is the controlled nature of all activities related to the production and use of artificial radiation.

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 in terms of their impact on humans. However, only emergencies, type Chernobyl accident, can have an uncontrollable effect 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 of radioactive contamination. This is our life in the third millennium - the dosimeter becomes an attribute Everyday life, like a handkerchief, toothbrush, 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 the tissues of the body 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 that 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.

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 ionizing radiation, the maximum permissible dose is set at 50 mSv/year (5 rem/year), i.e. 28 µSv/h with a 36-hour work week.

According to hygienic standards NRB-96 (1996), permissible dose rate levels for external irradiation of the whole body from man-made sources for permanent residence of personnel are 10 μGy/h, for residential premises and areas where members of the public are permanently located - 0 .1 µGy/h (0.1 µSv/h, 10 µR/h).

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 by a solid), 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"

Passing through matter, all types of ionizing radiation cause ionization, excitation and decay of molecules. A similar effect is observed when the human body is irradiated. Since the bulk (70%) of the body is water, its damage during irradiation is carried out through the so-called indirect impact: First, radiation is absorbed by water molecules, and then ions, excited molecules and fragments of decayed molecules enter into chemical reactions with biological substances that make up the human body, causing them damage. In case of irradiation with neutrons, additional radionuclides can be formed in the body due to the absorption of neutrons by the nuclei of elements contained in the body.

Penetrating into the human body, ionizing radiation can cause serious illnesses. Physical, chemical and biological transformations of a substance when ionizing radiation interacts with it are called radiation effect, which can lead to such serious illnesses, such as radiation sickness, leukemia (leukemia), malignant tumors, skin diseases. There may also be genetic consequences leading to hereditary diseases.

Ionization of living tissue leads to the breaking of molecular bonds and changes in the chemical structure of compounds. Changes in chemical composition molecules lead to cell death. In living tissue, water splits into atomic hydrogen and a hydroxyl group, which form new chemical compounds that are not characteristic of healthy tissue. As a result of the changes that have occurred, the normal course of biochemical processes and metabolism are disrupted.

Irradiation of the human body can be external and internal. At external irradiation, which is created by closed sources, radiation with high penetrating power is dangerous. Internal exposure occurs when radioactive substances enter the body through inhalation of air contaminated with radioactive elements, through the digestive tract (through eating, contaminated water and smoking) and in rare cases through the skin. The body is exposed to internal irradiation until the radioactive substance decays or is eliminated as a result of physiological metabolism, therefore radioactive isotopes with a long half-life and intense radiation pose the greatest danger. The nature of the damage and its severity are determined by the absorbed radiation energy, which primarily depends on the absorbed dose rate, as well as on the type of radiation, duration of irradiation, biological characteristics and size of the irradiated part of the body and the individual sensitivity of the body.

When living tissues are exposed to different types of radioactive radiation, the penetrating and ionizing abilities of the radiation are decisive. Penetrating power of radiation characterized run length 1– the thickness of the material required to absorb the flow. For example, the path length of alpha particles in living tissue is several tens of micrometers, and in air it is 8–9 cm. Therefore, during external irradiation, the skin protects the body from the effects of alpha and soft beta radiation, the penetrating ability of which is low.

Different types of radiation with the same absorbed dose cause different biological damage.

Diseases caused by radiation can be acute or chronic. Acute lesions occur when exposed to large doses over a short period of time. Very often, after recovery, early aging sets in and previous diseases worsen. Chronic lesions ionizing radiation can be both general and local. They always develop in a latent form as a result of systematic irradiation with doses exceeding the maximum permissible, obtained both through external irradiation and when radioactive substances enter the body.

The danger of radiation injury largely depends on which organ is exposed to radiation. Based on their selective ability to accumulate in individual critical organs (during internal irradiation), radioactive substances can be divided into three groups:

• – tin, antimony, tellurium, niobium, polonium, etc. are distributed evenly in the body;
• – lanthanum, cerium, actinium, thorium, etc. accumulate mainly in the liver;
• – uranium, radium, zirconium, plutonium, strontium, etc. accumulate in the skeleton.

The individual sensitivity of the body is affected at low doses of radiation (less than 50 mSv/year); with increasing doses, it manifests itself to a lesser extent. The body is most resistant to radiation at the age of 25–30 years. Disease nervous system and internal organs reduces the body's resistance to radiation.

When determining radiation doses, the main thing is information about the quantitative content of radioactive substances in the human body, and not data about their concentration in the environment.

In human daily life, ionizing radiation occurs constantly. We don’t feel them, but we cannot deny their impact on living and inanimate nature. Not long ago, people learned to use them both for good and as weapons of mass destruction. When used correctly, these radiations can change the lives of humanity for the better.

Types of ionizing radiation

To understand the peculiarities of the influence on living and non-living organisms, you need to find out what they are. It is also important to know their nature.

Ionizing radiation is a special wave that can penetrate substances and tissues, causing the ionization of atoms. There are several types of it: alpha radiation, beta radiation, gamma radiation. They all have different charges and abilities to act on living organisms.

Alpha radiation is the most charged of all types. It has enormous energy, capable of causing radiation sickness even in small doses. But with direct irradiation it penetrates only the upper layers of human skin. Even a thin sheet of paper protects from alpha rays. At the same time, when entering the body through food or inhalation, the sources of this radiation quickly become the cause of death.

Beta rays carry slightly less charge. They are able to penetrate deep into the body. With prolonged exposure they cause human death. Smaller doses cause changes in cellular structure. A thin sheet of aluminum can serve as protection. Radiation from inside the body is also deadly.

Gamma radiation is considered the most dangerous. It penetrates through the body. In large doses it causes radiation burns, radiation sickness, and death. The only protection against it can be lead and a thick layer of concrete.

A special type of gamma radiation is X-rays, which are generated in an X-ray tube.

History of research

The world first learned about ionizing radiation on December 28, 1895. It was on this day that Wilhelm C. Roentgen announced that he had discovered a special type of rays that could pass through various materials and the human body. From that moment on, many doctors and scientists began to actively work with this phenomenon.

For a long time, no one knew about its effect on the human body. Therefore, in history there are many cases of death from excessive radiation.

The Curies studied in detail the sources and properties of ionizing radiation. This made it possible to use it with maximum benefit, avoiding negative consequences.

Natural and artificial sources of radiation

Nature has created various sources of ionizing radiation. First of all, this is radiation from the sun's rays and space. Most of it is absorbed by the ozone ball, which is located high above our planet. But some of them reach the surface of the Earth.

On the Earth itself, or rather in its depths, there are some substances that produce radiation. Among them are isotopes of uranium, strontium, radon, cesium and others.

Artificial sources of ionizing radiation are created by man for a variety of research and production. At the same time, the strength of radiation can be several times higher than natural indicators.

Even in conditions of protection and compliance with safety measures, people receive radiation doses that are dangerous to their health.

Units of measurement and doses

Ionizing radiation is usually correlated with its interaction with the human body. Therefore, all units of measurement are in one way or another related to a person’s ability to absorb and accumulate ionization energy.

In the SI system, doses of ionizing radiation are measured in a unit called the gray (Gy). It shows the amount of energy per unit of irradiated substance. One Gy is equal to one J/kg. But for convenience, the non-system unit rad is more often used. It is equal to 100 Gy.

Background radiation in the area is measured by exposure doses. One dose is equal to C/kg. This unit is used in the SI system. The extra-system unit corresponding to it is called the roentgen (R). To receive an absorbed dose of 1 rad, you need to be exposed to an exposure dose of about 1 R.

Because the different types ionizing radiation has a different energy charge, its measurement is usually compared with biological influence. In the SI system, the unit of such equivalent is the sievert (Sv). Its off-system analogue is the rem.

The stronger and longer the radiation, the more energy is absorbed by the body, the more dangerous its influence. To find out the permissible time for a person to remain in radiation contamination, special devices are used - dosimeters that measure ionizing radiation. These include both individual devices and large industrial installations.

Effect on the body

Contrary to popular belief, any ionizing radiation is not always dangerous and deadly. This can be seen in the example of ultraviolet rays. In small doses, they stimulate the generation of vitamin D in the human body, cell regeneration and an increase in melanin pigment, which gives a beautiful tan. But prolonged exposure to radiation causes severe burns and can cause skin cancer.

IN last years The effect of ionizing radiation on the human body and its practical application are being actively studied.

In small doses, radiation does not cause any harm to the body. Up to 200 miliroentgen can reduce the number of white blood cells. Symptoms of such exposure will be nausea and dizziness. About 10% of people die after receiving this dose.

Large doses cause digestive upset, hair loss, skin burns, changes in the cellular structure of the body, the development of cancer cells and death.

Radiation sickness

Prolonged exposure to ionizing radiation on the body and receiving a large dose of radiation can cause radiation sickness. More than half of cases of this disease lead to death. The rest become the cause of a number of genetic and somatic diseases.

At the genetic level, mutations occur in germ cells. Their changes become evident in subsequent generations.

Somatic diseases are expressed by carcinogenesis, irreversible changes in various organs. Treatment of these diseases is long and quite difficult.

Treatment of radiation injuries

As a result of the pathogenic effects of radiation on the body, various damage to human organs occurs. Depending on the radiation dose, different methods of therapy are carried out.

First of all, the patient is placed in a sterile room to avoid the possibility of infection of exposed skin areas. Next, special procedures are carried out to facilitate rapid removal of radionuclides from the body.

If the lesions are severe, a bone marrow transplant may be needed. From radiation, he loses the ability to reproduce red blood cells.

But in most cases, treatment of mild lesions comes down to anesthetizing the affected areas and stimulating cell regeneration. Much attention is given to rehabilitation.

Effect of ionizing radiation on aging and cancer

In connection with the influence of ionizing rays on the human body, scientists have conducted various experiments proving the dependence of the aging process and carcinogenesis on the radiation dose.

Groups of cell cultures were exposed to irradiation in laboratory conditions. As a result, it was possible to prove that even minor radiation accelerates cell aging. Moreover, the older the culture, the more susceptible it is to this process.

Long-term irradiation leads to cell death or abnormal and rapid division and growth. This fact indicates that ionizing radiation has a carcinogenic effect on the human body.

At the same time, the impact of the waves on the affected cancer cells led to their complete death or stopping their division processes. This discovery helped develop a method for treating human cancers.

Practical applications of radiation

For the first time, radiation began to be used in medical practice. Using X-rays, doctors were able to look inside the human body. At the same time, practically no harm was done to him.

Then they began to treat cancer with the help of radiation. In most cases, this method has a positive effect, despite the fact that the entire body is exposed to strong radiation, which entails a number of symptoms of radiation sickness.

In addition to medicine, ionizing rays are also used in other industries. Surveyors using radiation can study the structural features of the earth's crust in its individual areas.

The ability of some fossils to secrete a large number of Humanity has learned to use energy for its own purposes.

Nuclear power

The future of the entire population of the Earth lies with atomic energy. Nuclear power plants provide sources of relatively inexpensive electricity. Provided they are operated correctly, such power plants are much safer than thermal power plants and hydroelectric power plants. From nuclear power plants much less environmental pollution from both excess heat and production waste.

At the same time, based on atomic energy scientists have developed weapons of mass destruction. At the moment, there are so many atomic bombs on the planet that launching a small number of them could cause a nuclear winter, as a result of which almost all living organisms inhabiting it will die.

Means and methods of protection

The use of radiation in everyday life requires serious precautions. Protection against ionizing radiation is divided into four types: time, distance, quantity and source shielding.

Even in an environment with a strong background radiation, a person can remain for some time without harm to his health. It is this moment that determines the protection of time.

The greater the distance to the radiation source, the lower the dose of absorbed energy. Therefore, you should avoid close contact with places where there is ionizing radiation. This is guaranteed to protect you from unwanted consequences.

If it is possible to use sources with minimal radiation, they are given preference first. This is defense in numbers.

Shielding means creating barriers through which harmful rays do not penetrate. An example of this is lead screens in x-ray rooms.

Household protection

If a radiation disaster is declared, you should immediately close all windows and doors and try to stock up on water from closed sources. Food should only be canned. When moving in open areas, cover your body with clothing as much as possible, and your face with a respirator or wet gauze. Try not to bring outerwear and shoes into the house.

It is also necessary to prepare for a possible evacuation: collect documents, a supply of clothing, water and food for 2-3 days.

Ionizing radiation as an environmental factor

There are quite a lot of radiation-contaminated areas on planet Earth. The reason for this is both natural processes and man-made disasters. The most famous of them are the Chernobyl accident and the atomic bombs over the cities of Hiroshima and Nagasaki.

A person cannot be in such places without harm to his own health. At the same time, it is not always possible to find out in advance about radiation contamination. Sometimes even non-critical background radiation can cause a disaster.

The reason for this is the ability of living organisms to absorb and accumulate radiation. At the same time, they themselves turn into sources of ionizing radiation. The well-known “dark” jokes about Chernobyl mushrooms are based precisely on this property.

In such cases, protection from ionizing radiation comes down to the fact that all consumer products are subject to thorough radiological examination. At the same time, in spontaneous markets there is always a chance to buy the famous “Chernobyl mushrooms”. Therefore, you should refrain from purchasing from unverified sellers.

The human body tends to accumulate hazardous substances, resulting in gradual poisoning from the inside. It is not known exactly when the consequences of these poisons will make themselves felt: in a day, a year or a generation.

Humans are exposed to ionizing radiation everywhere. To do this, it is not necessary to get into the epicenter of a nuclear explosion; it is enough to be under the scorching sun or conduct an X-ray examination of the lungs.

Ionizing radiation is a flow of radiation energy generated during decay reactions of radioactive substances. Isotopes that can increase the radiation fund are found in the earth’s crust, in the air; radionuclides can enter the human body through the gastrointestinal tract, respiratory system and skin.

Minimum levels of background radiation do not pose a threat to humans. The situation is different if ionizing radiation exceeds permissible standards. The body will not immediately react to harmful rays, but years later they will appear. pathological changes, which can lead to disastrous consequences, including death.

What is ionizing radiation?

The release of harmful radiation occurs after the chemical decay of radioactive elements. The most common are gamma, beta and alpha rays. When radiation enters the body, it has a destructive effect on humans. All biochemical processes are disrupted under the influence of ionization.

Types of radiation:

1. Alpha rays have increased ionization, but poor penetrating ability. Alpha radiation hits human skin, penetrating to a distance of less than one millimeter. It is a beam of released helium nuclei.
2. Electrons or positrons move in beta rays; in an air flow they are able to cover distances of up to several meters. If a person appears near the source, beta radiation will penetrate deeper than alpha radiation, but the ionizing ability of this species is much less.
3. One of the highest-frequency electromagnetic radiations is the gamma-ray variety, which has increased penetrating ability but very little ionizing effect.
4. characterized by short electromagnetic waves that arise when beta rays come into contact with matter.
5. Neutron - highly penetrating beams of rays consisting of uncharged particles.

Where does the radiation come from?

Sources of ionizing radiation can be air, water and food. Harmful rays occur naturally or are created artificially for medical or industrial purposes. There is always radiation in the environment:

• comes from space and makes up a large part of the total percentage of radiation;
• radiation isotopes are freely found in familiar natural conditions and are contained in rocks;
• Radionuclides enter the body with food or by air.

Artificial radiation was created in the context of developing science; scientists were able to discover the uniqueness of X-rays, with the help of which it is possible to accurately diagnose many dangerous pathologies, including infectious diseases.

On an industrial scale, ionizing radiation is used for diagnostic purposes. People working at such enterprises, despite all the safety measures applied according to sanitary requirements, are in harmful and hazardous conditions labor that adversely affects health.

What happens to a person when exposed to ionizing radiation?

The destructive effect of ionizing radiation on the human body is explained by the ability of radioactive ions to react with cell components. It is well known that eighty percent of man consists of water. When irradiated, water decomposes in cells as a result chemical reactions hydrogen peroxide and hydrate oxide are formed.

Subsequently, oxidation occurs in the organic compounds of the body, as a result of which the cells begin to collapse. After a pathological interaction, a person’s metabolism at the cellular level is disrupted. The effects can be reversible when exposure to radiation was insignificant, and irreversible with prolonged exposure.

The effect on the body can manifest itself in the form of radiation sickness, when all organs are affected; radioactive rays can cause gene mutations that are inherited in the form of deformities or severe diseases. There are frequent cases of degeneration of healthy cells into cancer cells with the subsequent growth of malignant tumors.

Consequences may not appear immediately after interaction with ionizing radiation, but after decades. The duration of the asymptomatic course directly depends on the degree and time during which the person received radiation exposure.

Biological changes under the influence of rays

Exposure to ionizing radiation entails significant changes in the body, depending on the extent of the area of ​​skin exposed to radiation energy, the time during which the radiation remains active, as well as the condition of organs and systems.

To indicate the strength of radiation over a certain period of time, the unit of measurement is usually considered to be the Rad. Depending on the magnitude of the missed rays, a person may develop the following conditions:

• up to 25 rad – general health does not change, the person feels good;
• 26 – 49 rad – the condition is generally satisfactory; at this dosage, the blood begins to change its composition;
• 50 – 99 rad – the victim begins to feel general malaise, fatigue, bad mood, pathological changes appear in the blood;
• 100 – 199 rad – the exposed person is in poor condition, most often the person cannot work due to deteriorating health;
• 200 – 399 rad – a large dose of radiation, which develops multiple complications and sometimes leads to death;
• 400 – 499 rad – half of the people who find themselves in a zone with such radiation values ​​die from frolicking pathologies;
• exposure to more than 600 rad does not give a chance for successful outcome, a fatal disease takes the lives of all victims;
• a one-time exposure to a dose of radiation that is thousands of times greater than the permissible figures - everyone dies directly during the disaster.

A person’s age plays a big role: those who are most susceptible to negative influence ionizing energy children and young people under twenty-five years of age. Receiving large doses of radiation during pregnancy can be compared with exposure in early childhood.

Brain pathologies occur only from the middle of the first trimester, from the eighth week to the twenty-sixth inclusive. The risk of cancer in the fetus increases significantly with unfavorable background radiation.

What are the dangers of being exposed to ionizing rays?

A one-time or regular exposure of radiation to the body tends to accumulate and cause subsequent reactions over a period of time from several months to decades:

• inability to conceive a child, this complication develops in both women and men, making them sterile;
• the development of autoimmune diseases of unknown etiology, in particular multiple sclerosis;
• radiation cataract, leading to vision loss;
• the appearance of a cancerous tumor is one of the most common pathologies with tissue modification;
• diseases of an immune nature that disrupt the normal functioning of all organs and systems;
• a person exposed to radiation lives much shorter;
• the development of mutating genes that will cause serious developmental defects, as well as the appearance of abnormal deformities during fetal development.

Remote manifestations may develop directly in the exposed individual or be inherited and occur in subsequent generations. Directly at the sore spot through which the rays passed, changes occur in which the tissues atrophy and thicken with the appearance of multiple nodules.

This symptom can affect the skin, lungs, blood vessels, kidneys, liver cells, cartilage and connective tissue. Groups of cells become inelastic, harden and lose the ability to fulfill their purpose in the body of a person with radiation sickness.

Radiation sickness

One of the most dangerous complications, different stages of development of which can lead to the death of the victim. The disease can have an acute course with a one-time exposure to radiation or a chronic process with constant presence in the radiation zone. Pathology is characterized by persistent changes in all organs and cells and the accumulation of pathological energy in the patient’s body.

The disease manifests itself with the following symptoms:

• general intoxication of the body with vomiting, diarrhea and elevated body temperature;
• from the outside of cardio-vascular system development of hypotension is noted;
• a person gets tired quickly, collapses may occur;
• with large doses of exposure, the skin turns red and becomes covered with blue spots in areas that lack oxygen supply, muscle tone decreases;
• the second wave of symptoms is total hair loss, deterioration of health, consciousness remains slow, general nervousness, atony of muscle tissue, and disorders in the brain are observed, which can cause clouding of consciousness and cerebral edema.

How to protect yourself from radiation?

Determining effective protection against harmful rays underlies the prevention of human damage in order to avoid the occurrence of negative consequences. To save yourself from radiation exposure you must:

1. Reduce the time of exposure to isotope decay elements: a person should not stay in the danger zone for a long period. For example, if a person works in a hazardous industry, the worker’s stay in the place of energy flow should be reduced to a minimum.
2. To increase the distance from the source, this can be done by using multiple tools and automation tools that allow you to perform work at a considerable distance from external sources with ionizing energy.
3. It is necessary to reduce the area on which the rays will fall with the help of protective equipment: suits, respirators.

Under normal conditions, every person is continuously exposed to ionizing radiation as a result of cosmic radiation, as well as due to the radiation of natural radionuclides found in the earth, food, plants and in the human body itself.

The level of natural radioactivity caused by the natural background is low. This level of radiation is familiar to the human body and is considered harmless to it.

Man-made exposure occurs from man-made sources both under normal and emergency conditions.

Various types of radioactive radiation can cause certain changes in the tissues of the body. These changes are associated with the ionization of atoms and molecules of the cells of a living organism that occurs during irradiation.

Working with radioactive substances in the absence of appropriate protective measures can lead to exposure to doses that have a harmful effect on the human body.

Contact with ionizing radiation poses a serious danger to humans. The degree of danger depends both on the amount of absorbed radiation energy and on the spatial distribution of absorbed energy in the human body.

Radiation hazard depends on the type of radiation (radiation quality factor). Heavy charged particles and neutrons are more dangerous than x-rays and gamma radiation.

As a result of exposure to ionizing radiation on the human body, complex physical, chemical and biological processes can occur in tissues. Ionizing radiation causes the ionization of molecules and atoms of matter, as a result of which molecules and tissue cells are destroyed.

Ionization of living tissues is accompanied by excitation of cell molecules, which leads to the breaking of molecular bonds and to a change in the chemical structure of various compounds.

It is known that 2/3 of the total composition of human tissue is water. In this regard, the processes of ionization of living tissue are largely determined by the absorption of radiation by cell water and the ionization of water molecules.

The hydrogen (H) and hydroxyl group (OH) formed as a result of the ionization of water, directly or through a chain of secondary transformations, form products with high chemical activity: hydrated oxide (H02) and hydrogen peroxide (H202), which have pronounced oxidizing properties and high toxicity towards to the fabric. Combining with molecules of organic substances, and primarily with proteins, they form new chemical compounds that are not characteristic of healthy tissue.

When irradiated by neutrons, radioactive substances can be formed in the body from the elements it contains, forming induced activity, that is, radioactivity created in a substance as a result of exposure to neutron fluxes.

Ionization of living tissue, depending on the radiation energy, mass, electrical charge and ionizing ability of the radiation, leads to the breaking of chemical bonds and a change in the chemical structure of various compounds that make up the tissue cells.

In turn, changes in the chemical composition of the tissue, resulting from the destruction of a significant number of molecules, lead to the death of these cells. Moreover, many radiations penetrate very deeply and can cause ionization, and therefore damage to cells in deep parts of the human body.

As a result of exposure to ionizing radiation, the normal course of biological processes and metabolism in the body is disrupted.

Depending on the radiation dose and duration of exposure and on the individual characteristics of the organism, these changes can be reversible, in which the affected tissue restores its functional activity, or irreversible, which will lead to damage to individual organs or the entire organism. Moreover, the higher the radiation dose, the greater its impact on the human body. It was noted above that along with the processes of damage to the body by ionizing radiation, protective and restorative processes also occur.

The duration of irradiation has a great influence on the effect of irradiation, and it should be considered that it is not the dose that is decisive, but the dose rate of the irradiation. As the dose rate increases, the damaging effect increases. Therefore, fractional exposure to lower doses of radiation is less harmful than receiving the same dose of radiation during a single exposure to a total dose of radiation.

The degree of damage to the body by ionizing radiation increases with increasing size of the irradiated surface. The impact of ionizing radiation varies depending on which organ is exposed to radiation.

The type of radiation affects the destructive ability of radiation when affecting organs and tissues of the body. This influence takes into account the weighting factor for a given type of radiation, as noted earlier.

The individual characteristics of the body are strongly manifested at low doses of radiation. As the radiation dose increases, the influence of individual characteristics becomes insignificant.

A person is most resistant to radiation between the ages of 25 and 50 years. Young people are more sensitive to radiation than middle-aged people.

The biological effects of ionizing radiation largely depend on the state of the central nervous system and internal organs. Nervous diseases, as well as diseases of the cardiovascular system, hematopoietic organs, kidneys, and endocrine glands reduce a person’s tolerance to radiation.

Features of the impact of radioactive substances that have entered the body are associated with the possibility of their long-term presence in the body and direct impact on internal organs.

Radioactive substances can enter the human body by inhaling air contaminated with radionuclides, through the digestive tract (eating, drinking, smoking), and through damaged and undamaged skin.

Gaseous radioactive substances (radon, xenon, krypton, etc.) easily penetrate the respiratory tract and are quickly absorbed, causing symptoms of general damage. Gases are released from the body relatively quickly, most of them are released through the respiratory tract.

Penetration of sprayed radioactive substances into the lungs depends on the degree of particle dispersion. Particles larger than 10 microns usually remain in the nasal cavity and do not penetrate into the lungs. Particles smaller than 1 micron in size that are inhaled into the body are removed with air when exhaled.

The degree of danger of damage depends on the chemical nature of these substances, as well as on the rate of removal of the radioactive substance from the body. Less dangerous radioactive substances:

quickly circulating in the body (water, sodium, chlorine, etc.) and not remaining in the body for a long time;

not absorbed by the body;

not forming compounds included in tissues (argon, xenon, krypton, etc.).

Some radioactive substances are almost not excreted from the body and accumulate in it, while some of them (niobium, ruthenium, etc.) are evenly distributed in the body, others are concentrated in certain organs (lanthanum, actinium, thorium - in the liver, strontium, uranium, radium - in bone tissue), leading to their rapid damage.

When assessing the effects of radioactive substances, their half-life and type of radiation should also be taken into account. Substances with a short half-life quickly lose activity and are therefore less dangerous.

Each dose of radiation leaves a deep mark on the body. One of the negative properties of ionizing radiation is its total, cumulative effect on the body.

The cumulative effect is especially strong when radioactive substances deposited in certain tissues enter the body. At the same time, being present in the body day after day for a long period of time, they irradiate nearby cells and tissues.

The following types of irradiation are distinguished:

chronic (continuous or intermittent exposure to ionizing radiation for a long time);

acute (single, short-term radiation exposure);

general (irradiation of the whole body);

local (irradiation of a part of the body).

The result of exposure to ionizing radiation, both external and internal, depends on the dose of radiation, duration of exposure, type of radiation, individual sensitivity and size of the irradiated surface. With internal irradiation, the effect of exposure depends, in addition, on the physicochemical properties of radioactive substances and their behavior in the body.

Using a large amount of experimental material with animals, as well as by summarizing the experience of people working with radionuclides, it was generally established that when a person is exposed to certain doses of ionizing radiation, they do not cause significant irreversible changes in the body. Such doses are called maximum doses.

Dose limit is the value of the effective annual or equivalent dose of man-made radiation, which should not be exceeded under normal operating conditions. Compliance with the annual dose limit prevents the occurrence of deterministic effects, while the likelihood of stochastic effects remains at an acceptable level.

Deterministic radiation effects are clinically detectable harmful biological effects caused by ionizing radiation, for which the existence of a threshold is assumed to exist, below which there is no effect, and above which the severity of the effect depends on the dose.

Stochastic effects of radiation are harmful biological effects caused by ionizing radiation that do not have a dose threshold of occurrence, the probability of occurrence of which is proportional to the dose and for which the severity of the manifestation does not depend on the dose.

In connection with the above, the issues of protecting workers from the harmful effects of ionizing radiation are multifaceted and regulated by various legal acts.