Danger of radiation to the human body. Why are radiation leaks dangerous for health? Why is radioactive radiation dangerous?

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Radiation and types of radioactive radiation, the composition of radioactive (ionizing) radiation and its main characteristics. The effect of radiation on matter.

What is radiation

First, let's give a definition of what radiation is:

In the process of disintegration of a substance or its synthesis, the ejection of atomic elements (protons, neutrons, electrons, photons) occurs, otherwise we can say radiation occurs these elements. Such radiation is called - ionizing radiation or what is more common radioactive radiation, or even simpler radiation ... Ionizing radiation also includes X-ray and gamma radiation.

Radiation is the process of radiation by matter of charged elementary particles, in the form of electrons, protons, neutrons, helium atoms or photons and muons. The type of radiation depends on which element is emitted.

Ionization is the process of formation of positively or negatively charged ions or free electrons from neutrally charged atoms or molecules.

Radioactive (ionizing) radiation can be divided into several types, depending on the type of elements from which it consists. Different types radiations are caused by various microparticles and therefore have different energetic effects on the substance, different ability to penetrate through it and, as a consequence, different biological effects of radiation.

Alpha, beta and neutron radiation are radiation consisting of various particles of atoms.

Gamma and X-ray is the radiation of energy.

Alpha radiation

• emitted: two protons and two neutrons
• penetrating ability: low
• irradiation from the source: up to 10 cm
• emission rate: 20,000 km / s
• ionization: 30,000 ion pairs per cm of run
• high

Alpha (α) radiation arises from the decay of unstable isotopes elements.

Alpha radiation- this is the radiation of heavy, positively charged alpha particles, which are the nuclei of helium atoms (two neutrons and two protons). Alpha particles are emitted during the decay of more complex nuclei, for example, during the decay of uranium, radium, thorium atoms.

Alpha particles have a large mass and are emitted at a relatively low speed on average 20 thousand km / s, which is about 15 times less than the speed of light. Since alpha particles are very heavy, when in contact with a substance, the particles collide with the molecules of this substance, begin to interact with them, losing their energy and therefore the penetrating ability of these particles is not great and even a simple sheet of paper can detain them.

However, alpha particles carry a lot of energy and, when interacting with a substance, cause its significant ionization. And in the cells of a living organism, in addition to ionization, alpha radiation destroys tissues, leading to various damage to living cells.

Of all types of radiation, alpha radiation has the least penetrating ability, but the consequences of irradiation of living tissues with this type of radiation are the most severe and significant in comparison with other types of radiation.

Exposure to radiation in the form of alpha radiation can occur when radioactive elements enter the body, for example, with air, water, or food, or through cuts or wounds. Once in the body, these radioactive elements are carried by the blood stream throughout the body, accumulate in tissues and organs, exerting a powerful energetic effect on them. Since some types of radioactive isotopes emitting alpha radiation have a long lifespan, getting inside the body, they can cause serious changes in cells and lead to tissue degeneration and mutations.

Radioactive isotopes are not actually excreted from the body on their own, therefore, getting inside the body, they will irradiate tissues from the inside for many years until they lead to serious changes. The human body is not able to neutralize, process, assimilate or utilize most of the radioactive isotopes that have entered the body.

Neutron radiation

• emitted: neutrons
• penetrating ability: high
• irradiation from the source: kilometers
• emission rate: 40,000 km / s
• ionization: from 3000 to 5000 pairs of ions per 1 cm of run
• biological effect of radiation: high

Neutron radiation- This is man-made radiation that occurs in various nuclear reactors and atomic explosions. Also, neutron radiation is emitted by stars in which active thermonuclear reactions take place.

Having no charge, neutron radiation, colliding with matter, weakly interacts with elements of atoms at the atomic level, therefore it has a high penetrating ability. It is possible to stop neutron radiation using materials with a high hydrogen content, for example, a container with water. Neutron radiation also poorly penetrates polyethylene.

Neutron radiation, when passing through biological tissues, causes serious damage to cells, since it has a significant mass and a higher speed than alpha radiation.

Beta radiation

• emitted: electrons or positrons
• penetrating ability: average
• irradiation from the source: up to 20 m
• emission rate: 300,000 km / s
• ionization: from 40 to 150 pairs of ions per 1 cm of run
• biological effect of radiation: the average

Beta (β) radiation occurs when one element transforms into another, while processes occur in the very nucleus of an atom of a substance with a change in the properties of protons and neutrons.

With beta radiation, there is a transformation of a neutron into a proton or a proton into a neutron, with this transformation there is an emission of an electron or a positron (antiparticle of an electron), depending on the type of transformation. The speed of the emitted elements approaches the speed of light and is approximately equal to 300,000 km / s. The elements emitted in this case are called beta particles.

Having initially a high radiation speed and small dimensions of the emitted elements, beta radiation has a higher penetrating power than alpha radiation, but has a hundreds of times less ability to ionize matter compared to alpha radiation.

Beta radiation easily penetrates through clothing and partially through living tissues, but when passing through denser structures of matter, for example, through a metal, it begins to interact more intensively with it and loses most of its energy transferring it to the elements of the substance. A metal sheet of a few millimeters can completely stop beta radiation.

If alpha radiation is dangerous only in direct contact with a radioactive isotope, then beta radiation, depending on its intensity, can already cause significant harm to a living organism at a distance of several tens of meters from the radiation source.

If a radioactive isotope emitting beta radiation enters a living organism, it accumulates in tissues and organs, exerting an energetic effect on them, leading to changes in the structure of tissues and causing significant damage over time.

Some radioactive isotopes with beta radiation have a long decay period, that is, when they enter the body, they will irradiate it for years until they lead to tissue degeneration and, as a result, to cancer.

Gamma radiation

• emitted: energy in the form of photons
• penetrating ability: high
• irradiation from the source: up to hundreds of meters
• emission rate: 300,000 km / s
• ionization:
• biological effect of radiation: low

Gamma (γ) radiation is an energetic electromagnetic radiation in the form of photons.

Gamma radiation accompanies the process of decay of atoms of a substance and manifests itself in the form of radiated electromagnetic energy in the form of photons released when the energy state of the atomic nucleus changes. Gamma rays are emitted from the nucleus at the speed of light.

When the radioactive decay of an atom occurs, others are formed from some substances. The atom of newly formed substances is in an energetically unstable (excited) state. Acting on each other, neutrons and protons in the nucleus come to a state where the forces of interaction are balanced, and the excess energy is emitted by the atom in the form of gamma radiation

Gamma radiation has a high penetrating power and easily penetrates through clothing, living tissues, a little more difficult through dense structures of a substance such as metal. To stop gamma radiation, a significant thickness of steel or concrete is required. But at the same time, gamma radiation has a hundred times weaker effect on matter than beta radiation and tens of thousands of times weaker than alpha radiation.

The main danger of gamma radiation is its ability to travel long distances and affect living organisms several hundred meters from the source of gamma radiation.

X-ray radiation

• emitted: energy in the form of photons
• penetrating ability: high
• irradiation from the source: up to hundreds of meters
• emission rate: 300,000 km / s
• ionization: from 3 to 5 pairs of ions per 1 cm of run
• biological effect of radiation: low

X-ray radiation- This is energetic electromagnetic radiation in the form of photons, arising from the transition of an electron inside an atom from one orbit to another.

X-ray radiation is similar in effect to gamma radiation, but is less penetrating because it has a longer wavelength.

Having considered various types of radioactive radiation, it is clear that the concept of radiation includes completely different types of radiation that have different effects on matter and living tissues, from direct bombardment with elementary particles (alpha, beta and neutron radiation) to energy effects in the form of gamma and X-rays. healing.

Each of the considered emissions is dangerous!

Comparative table with characteristics of different types of radiation

characteristic	Radiation type
	Alpha radiation	Neutron radiation	Beta radiation	Gamma radiation	X-ray radiation
emitted	two protons and two neutrons	neutrons	electrons or positrons	energy in the form of photons	energy in the form of photons
penetrating power	low	high	average	high	high
source irradiation	up to 10 cm	kilometers	up to 20 m	hundreds of meters	hundreds of meters
emission rate	20,000 km / s	40,000 km / s	300,000 km / s	300,000 km / s	300,000 km / s
ionization, steam per 1 cm of run	30 000	from 3000 to 5000	from 40 to 150	from 3 to 5	from 3 to 5
biological effects of radiation	high	high	the average	low	low

As can be seen from the table, depending on the type of radiation, radiation at the same intensity, for example, 0.1 Roentgen, will have a different destructive effect on the cells of a living organism. To take into account this difference, a coefficient k was introduced, reflecting the degree of exposure to radioactive radiation on living objects.

Coefficient k
Type of radiation and energy range	Weight factor
Photons all energies (gamma radiation)	1
Electrons and muons all energies (beta radiation)	1
Neutrons with energy < 10 КэВ (нейтронное излучение)	5
Neutrons from 10 to 100 keV (neutron radiation)	10
Neutrons from 100 keV to 2 MeV (neutron radiation)	20
Neutrons from 2 MeV to 20 MeV (neutron radiation)	10
Neutrons> 20 MeV (neutron radiation)	5
Protons with energies> 2 MeV (except for recoil protons)	5
Alpha particles, fission fragments and other heavy nuclei (alpha radiation)	20

The higher the "coefficient k", the more dangerous the action of a certain type of radiation for the tissues of a living organism.

Video:

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

What is radiation

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

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

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

Radiation happens:

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

How radiation enters the human body

Radiation is dangerous to humans. When its level rises above the permissible norm, various diseases and lesions develop. internal organs and systems. Against the background of radiation exposure, malignant oncological pathologies can develop. Radiation is also used in medicine. With its help, diagnostics and treatment of many diseases are carried out.

Radiation can damage cells. The body's defense copes with this until the radiation doses exceed the natural background by hundreds and thousands of times. Higher doses lead to acute radiation sickness and increase the likelihood of cancer by several percent. Doses tens of thousands of times higher than background are lethal. Such doses in Everyday life can not be.

The death and mutation of cells in our body is another natural phenomenon that accompanies our life. In an organism of about 60 trillion cells, cells naturally age and mutate. Several million cells die every day. Many physical, chemical and biological agents, including natural radiation, also "spoil" cells, but in normal situations, the body can easily cope with this.

Compared to other damaging factors, ionizing radiation (radiation) is the best studied. How does radiation affect cells? When atomic nuclei fission, a large energy is released, capable of taking electrons from the atoms of the surrounding substance. This process is called ionization, and the energy-carrying electromagnetic radiation is called ionizing. The ionized atom changes its physical and Chemical properties... Consequently, the properties of the molecule it enters into change. The higher the radiation level, the more number acts of ionization, the more damaged cells will be.

For living cells, the most dangerous changes in the DNA molecule. The cell can "repair" the damaged DNA. Otherwise, she will die or give a changed (mutated) offspring.

The body replaces dead cells with new ones within days or weeks, and mutant cells are effectively discarded. This is what the immune system does. But sometimes defense systems fail. The long-term result can be cancer or genetic changes in offspring, depending on the type of damaged cell (normal or germ cell). Neither outcome is predetermined in advance, but both have some probability. Spontaneous cases of cancer are called spontaneous. If the responsibility of one or another agent for the occurrence of cancer is established, it is said that the cancer was induced.

If the radiation dose exceeds the natural background in hundreds of times, it becomes noticeable to the body. The important thing is not that it is radiation, but that it is more difficult for the body's defense systems to cope with the increased amount of damage. Due to the frequent failures, additional "radiation" cancers arise. Their number can be several percent of the number of spontaneous cancers.

Very large doses are - a thousand times above the background. At such doses, the main difficulties of the body are associated not with altered cells, but with the rapid death of tissues important for the body. The body cannot cope with the restoration of the normal functioning of the most vulnerable organs, first of all, the red bone marrow, which belongs to the hematopoietic system. There are signs of acute malaise - acute radiation sickness. If the radiation does not kill all the cells in the bone marrow at once, the body will recover over time. Recovery after radiation sickness takes more than one month, but then a person lives a normal life.

After recovering from radiation sickness, people are slightly more likely to get cancer than their non-irradiated peers. How much more often? By a few percent.

This follows from observations of patients in different countries of the world who underwent a course of radiotherapy and received sufficiently large doses of radiation, for the employees of the first nuclear enterprises, which did not yet have reliable systems radiation protection, as well as for the survivors of the atomic bombing of the Japanese, and the Chernobyl liquidators. Among the groups listed, the highest doses were in Hiroshima and Nagasaki. For 60 years of observation, 86.5 thousand people with doses 100 or more times higher than the natural background had 420 more cases of fatal cancer than in the control group (an increase of about 10%). Unlike the symptoms of acute radiation sickness, which appear after hours or days, cancer does not appear immediately, maybe after 5, 10 or 20 years. The latent period is different for different sites of cancer. Leukemia (blood cancer) develops most rapidly in the first five years. It is this disease that is considered an indicator of radiation exposure at radiation doses. hundreds and thousands of times higher than the background.

Why does cancer not occur immediately? For a cell with damaged DNA to become cancerous, a whole chain of rare events must occur to it. After each new transformation, she again needs to "slip through" the protective barrier. If immune defenses are effective, even a highly exposed person may not develop cancer. And if he gets sick, he will be cured.

Theoretically, in addition to cancer, there could be other consequences of high-dose radiation.

If radiation has damaged a DNA molecule in an egg or sperm, there is a risk that the damage will be inherited. This risk may add a small amount to spontaneous inherited disorders. Spontaneous genetic defects, ranging from color blindness to Down syndrome, are known to occur in 10% of newborns. For humans, the radiation addition to spontaneous genetic disorders is very small. Even among the Japanese survivors with high doses of radiation, contrary to the expectations of scientists, it was not possible to identify it. There were no additional radiation-induced defects after the accident at the Mayak plant in 1957, nor were they revealed after Chernobyl.

Radiation accidents in the USSR and the Russian Federation with clinically significant consequences:1949-2005

Accident type	Quantity accidents	Number of victims
		Total	incl. died
Radioisotope installations and their sources	92	170	16
X-ray facilities and accelerators	39	43	-
Reactor incidents and loss of criticality control	33	82	13
Cases with local radiation injuries at PA "Mayak" in 1949/56.	168	168	-
Nuclear submarine accidents	4	133	12
Other incidents	12	17	2
Chernobyl accident	1	134	28
TOTAL	176	747	71

Dose-related effects of radiation

People who died from radiation in Hiroshima and Nagasaki, as well as in Chernobyl, received doses tens of thousands of times above the background. At such doses, the body can no longer cope with the huge number of dead cells, and the person dies within days or weeks. In Hiroshima and Nagasaki, atomic bombings killed 210 thousand people. This is the total number of losses from the action of a shock wave, destruction of buildings and structures, thermal burns and radiation. During the accident at the Chernobyl nuclear power plant, on the first day, about 300 plant employees and firefighters received very high doses. It was not possible to save 28, but doctors cured 272 people.

And does this mean that our ecological situation is worse than in the country where the nuclear power plant accident occurred? What is the "phonite" in our cities and isn't it time to run for a dosimeter to measure the radiation level?

radiation level

Evgeny Vadimovich SHIROKOV, Associate Professor of the Physics Faculty of Moscow State University, Deputy Head of the Department of General Nuclear Physics.

Increased radiation levels: three main sources

The main sources of radiation:

1 Cosmic radiation, those of its particles that reach the Earth. But we have a very reliable and natural protection against this radiation - the atmosphere. Several tens of kilometers of dense air are a very strong barrier to radioactive radiation. The vast majority of them - 99.99% - get stuck in the atmosphere.

2 Radioactive isotopes found in the soil. In nature, there are a large number of radioactive isotope nuclei, which have a habit of decaying unpredictably, throwing out energy. This rather powerful energy, acting on a substance from the inside, can cause destruction or other effects.

3 Waste from some enterprises. Moreover, these are not necessarily nuclear-fueled stations (NPPs), but various enterprises, more often the chemical cycle, where a small amount of radioactive isotopes can be formed during the production process. When they are released into the atmosphere, there is an increased level of radiation.

But there are other sources of radiation, much less significant. For example, what usually amazes people is the radiation of the person himself! The fact is that our body contains two radioactive isotopes (they do not pose any danger to us, they are generally present in all organic matter) - this is the 14th carbon, the so-called radio-carbon, and the 40th potassium - it is contained in muscle tissue.

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Height. When you fly in an airplane at an altitude of 10 thousand km and you have it - by accident! - you will have a dosimeter with you, you will be surprised to find that the radiation level in the cabin of a passenger liner can be 15-20 times higher than the natural background radiation on the ground.

This is the effect of cosmic radiation. The higher we go, the less particles coming from space are trapped by the atmosphere. For example, those who live in the mountains, at a level of 4-5 km, are always under an increased radiation background. Moreover, the excess may even be an order of magnitude, that is, 10 times. For example, in the mountains of Tibet, in Lhasa, where the natural background radiation is 100-110 micro-roentgens per hour. For comparison: in Moscow, the standard radiation background is 12-14. But people in Lhasa live and feel good.

Granite structures... For example, at many metro stations, the background radiation is 2-3 times higher than the natural one, because granite is used for their facing. Or on the granite steps at the entrance to the main building of Moscow State University - if you measure the level of radiation, it will be 2 times higher than natural.

Features of perception

The main question is not that the background radiation is higher, but how much higher it is. I gave an example of air travel, because if we fly infrequently on average, then pilots, stewardesses, crew - almost all the time. But I have not heard that in this group, which belongs to the so-called category B (persons in an increased radiation background), there were diseases associated with radiation. We can confidently say that exceeding the permissible level of radiation by even 10 times does not harm health in most cases.

But there is a certain subtlety. It is due to the fact that all people have different susceptibility to radiation. For the most part, a certain dose of radiation per day is quite acceptable and safe for a person. However, due to the individuality of each organism, deviations are possible both in one direction and in the other. And, if a person who finds himself in an area where the background is significantly exceeded, clear signs of radiation were found, this is due to his individual intolerance to radiation.

Caged rays

Radioactive radiation acts on the cells of the body in two ways: the first is direct destruction, when the cell simply dies due to the impact from the inside. The second is considered more dangerous due to the formation of free radicals. The bottom line is that complicated organic molecule, of which we are composed, is destroyed not completely, but partially. And this liberated part is filled with a free radical, which can attach to itself anything from the environment, any particle, including radioactive, any atom, as long as it fits in its structure. And then harmless organic matter can turn into poison.

If ordinary cells simply die, then in the cells responsible for heredity, chromosomal changes are possible, which subsequently affect the offspring. True, both those and other processes are regulated by the regenerative abilities of our body. As a lizard grows a tail, so in ours part of the cells is restored. Naturally, up to a certain limit. When this limit is reached, we say that the body has been harmed.

Permissible radiation level

The radiation standards that are in force today have been created with a very large margin. And this is reasonable - in this area it is better to play it safe. However, after the events of March 11 in Japan, scientists started talking about revising them upward, that is, approaching the real ones.

After all, when they talk about exceeding the level of radiation, then the panic that occurs in such cases is very dangerous. When an increase of 1.5-2 times was registered in the cities of Japan, people rushed to buy iodine, take it, which in itself is quite harmful, not realizing that they are in a safe radiation situation. A really dangerous situation is now in a 1-2-kilometer zone from the Fukushima station - the background is really very high, and you can only work there for a very limited time, even in protective equipment. So, the panic arose due to a misunderstanding that even a small excess of the dose (up to 10 times) in 99.999% of cases is not dangerous for humans. That is, it is almost a natural background if you climb several kilometers into the mountains.

Dosimetrists do their job competently. The population is being illiterately notified. This applies to all countries: radiophobia is a widespread phenomenon.

For example, panic may arise when someone tells residents that their home is built with radioactive sand and people think they are doomed. Although the background overshoot can be 5%, this is simply nothing.

Therefore, the main problem is awareness. Moreover, in competent information. The sources of the real danger associated with radiation are quite specific, and in our everyday life it is extremely difficult to get under their influence, unless we specifically look for them.

Radiation in everyday life

Appliances. Now, due to the existence of strict radiation control in production, it is very difficult to find a household appliance in which any serious sources of radiation are found. For example, one of these devices is a smoke detector, which is installed in hotels and airports as a fire alarm. But the radioactive elements there are so microscopic that there is only one way to get harm from this device: disassemble it, find a dangerous element and swallow it. I don't think anyone in their right mind would do that.

X-ray scanners. Now they are installed in many airports around the world. But pregnant women and children may not go through it, and any person, if he does not want to “see through” for health reasons, can go through a standard body search.

As for harm, this short-term radiation is generally not dangerous. In fact, one pass through the scanner corresponds to 1/3 of the chest fluorography. Various forms of radiotherapy, which are used in severe stages of oncological diseases, especially radiation therapy, are really harmful to health. However, these are extreme measures that are taken already in the advanced stage of the disease, when it is necessary to divide cancer cells, while neighboring cells are also irradiated.

But in this case, doctors proceed from the principle of lesser evil. If a person is predicted to have only a few months to live, then after radiation therapy he gets the opportunity to live for several years.

When, for the purpose of diagnosis, a person is injected with sufficiently large doses of radioisotopes, then he becomes to some extent a source of radiation, it is especially dangerous for children if they are nearby. True, a certain distance is enough to minimize the danger to others.

But now scientists from the Physics Faculty of Moscow State University are participating in the construction of devices for a completely new method - electronic therapy in cooperation with the Cancer Center, and this, of course, is a certain progress in the treatment of cancer. These devices will be able to punctuate the tumor without damaging the adjacent tissue.

How to protect yourself from exposure to radiation

Oddly enough, this is a healthy lifestyle and proper nutrition. The absorption of harmful substances from the environment occurs due to the absence of a number of useful substances in the body. With a deficiency of certain minerals and vitamins, it, like a sponge, begins to absorb unnecessary substances from the environment.

Therefore, the guarantee of health and radiation safety is good nutrition, especially for children, rich in essential elements, primarily calcium and iron: these elements, when they are deficient, are first of all replaced by radioactive isotopes.

Calcium, for example, is easily replaced by radioactive strontium, if, of course, it is found in the surrounding atmosphere. Therefore, it is so important to get all the necessary elements in the diet, in this case, the risk of infection, even if the radiation source is nearby, is significantly reduced.

There are different opinions, including in the medical community, about substances that remove isotopes: red wine, red currants, gooseberries, etc. But the fact is that they accelerate the elimination of any substances from the body. Therefore, doctors recommend a sick person to drink a lot so that the metabolism accelerates and the body is cleansed of toxins.

But I do not recommend purchasing dosimeters for everyone. This should be done by professionals. If untrained people take measurements, then natural fluctuations in the background radiation can provoke panic in them.

Expert opinion

Galina Petrovna KORZHENKOVA,mammologist of the Russian Cancer Center, Ph.D., expert of the Avon charity program "Together Against Breast Cancer"

Is mammography dangerous?

The first thing to note is that mammography, as a study to prevent breast cancer at the earliest stage, is indicated only for women over 40 years of age. For women under 40, there are other types of research - using ultrasound and MRI, and X-ray screening is used only in cases of high genetic risk. But after 40 years it plays a leading role in the early diagnosis of breast cancer.

The reason why mammography is not recommended for women of younger age: firstly, their mammary gland tissue is still dense, and mammography cannot fulfill its main function.

In addition, international studies have shown that breast tissue is most sensitive to X-rays between the ages of 20 and 30. After 40 this sensitivity decreases by an order of magnitude, and after 50 - another 10 times. Therefore, X-ray screening programs, by decision of the WHO, are permissible only for women over the age of 40.

The dose that the woman receives at the time of the X-ray examination was calculated by Swedish scientists: on 4 mammographic images, it is equal to 30% of the background level of radiation that a person receives for 3 months.

Of all the regular studies that have now been introduced, except for fluorography, which can be done once a year, and mammography, which, as already mentioned, is acceptable from the age of 40, others are not recommended. Fluorography with us - if there is no urgent need - is allowed for children, or rather, adolescents, from the age of 15.

But when a woman prescribes X-ray examinations for herself - computed tomography, mammography - in one place, then for the sake of rechecking - in another clinic, then, of course, she is exposed to additional, obviously unnecessary and unhelpful radiation.

In general, the safety of radiography depends mainly not on the radiation dose, but on the quality of the study. Therefore, certification of all X-ray machines should be introduced.

How to protect yourself? A patient who comes for a mammogram should ask how many scans you are taking. If she is offered two, then it can be considered a low-quality study. There should be 4 pictures - 2 for each mammary gland. The situation can only change for cancer patients when more detailed research is required.

You should not be afraid of an increased level of radiation if you are offered to reshoot: this practice exists even in high-class medical centers, including those abroad. Up to 3-5% of cases is the norm. Now, if every second person takes repeated images, this is already a question for the healthcare organization. This process should be supervised by the clinic's management. And it's not just about technology, the human factor and the level of training of radiologists play an important role. And even if we equip the entire medical institution with expensive equipment, this does not at all guarantee perfect images that allow us to make an accurate diagnosis from the first shot. We need professionals who can fully work with this equipment.

X-ray exposure: how to determine the acceptable level of radiation

High-tech X-ray scans can pose a risk of unnecessary radiation for us. Our tips will help you lower your dose.

We are exposed to X-rays about 5-7 times more than 30 years ago. There are two reasons for this: the increasingly widespread use of computed tomography (radiation is almost 500 more than a standard X-ray image) and the use of old-style X-ray equipment in many medical institutions. Modern digital diagnostic devices give several times lower radiation doses. Therefore, try to be examined in modern, well-equipped clinics.

Try to avoid unnecessary X-ray examinations. Of course, if you have a toothache or a broken arm, you cannot do without an X-ray. But for a number of diseases, the doctor can offer alternative diagnostic methods. If a stomach ulcer is suspected, for example, endoscopy is often used.

If the doctor still sent you for an x-ray, he should explain what happens if you abandon him and why alternative methods are not possible. The risk of rejecting an X-ray must be known to exceed the risk of exposure to radiation. For example, if there is clinical symptoms pneumonia, X-ray examination is the only way to confirm or exclude the diagnosis.

In order not to be irradiated once again, control your X-ray passport (embedded in the medical card), where the radiologist must enter the dose you received with each examination.

When preparing for the procedure, make sure so that the areas of the pelvis, thyroid gland, eyes and other parts of the body are protected by a special apron or collar with layers of lead. If you are taking pictures of your teeth, it is very important to shield the thyroid area. In children, in general, the entire body should be protected, except for the area of ​​interest.

Be sure to keep X-rays. Tell your doctor if you have had an X-ray taken at another clinic or hospital in the past 5 years. He will be able to double-check the results and "save" unnecessary radiation.

Record any contact with radiation (for example, if you constantly fly) and tell your doctor. There are types of diagnostic scans (MRI, ultrasound) that do not expose you to radiation.

Terminology issue

In the International System of Units, radiation is measured in sieverts. The concept of "X-ray" is familiar to us. What is the difference?

X-RAY - The dose of radiation in the atmospheric air. ZIVERT - radiation dose in biological tissue. Since this is a very large dose, the level of X-ray radiation is calculated in MICROCOVERS (μSv).

Radiation doses for X-ray examinations: 1 tooth image - 5 μSv 1 panoramic dental image - 15−20 μSv Chest X-ray - 100  μSv Image of the paranasal sinuses - 100−200 μSv Mammography - 400 μSv Fluorogram - 600 μSv Computed tomography of the intestine - 10,000 μSv CT of the abdominal cavity and pelvic organs - 15000 μSv

For comparison, the level of radiation in our life:

Daily 3-hour TV viewing - 5 μSv

Flight over a distance of 2400 km - 10 μSv

Average annual background environmental impact - 1000 μSv

Radioactive (or ionizing) radiation is energy that is released by atoms in the form of particles or waves of an electromagnetic nature. A person is exposed to this effect both through natural and through anthropogenic sources.

The beneficial properties of radiation made it possible to successfully use it in industry, medicine, scientific experiments and research, agriculture and other fields. However, with the spread of the use of this phenomenon, a threat to human health has arisen. A small dose of radioactive radiation can increase the risk of acquiring serious diseases.

The difference between radiation and radioactivity

Radiation, in a broad sense, means radiation, that is, the propagation of energy in the form of waves or particles. Radioactive radiation is divided into three types:

• alpha radiation - flux of helium-4 nuclei;
• beta radiation - electron flow;
• gamma radiation is a stream of high-energy photons.

The characterization of radioactive emissions is based on their energy, transmission properties and the type of emitted particles.

Alpha radiation, which is a flux of positively charged particles, can be trapped by air or clothing. This species practically does not penetrate the skin, but when it enters the body, for example, through cuts, it is very dangerous and has a detrimental effect on internal organs.

Beta radiation has more energy - electrons move at a high speed, and their size is small. Therefore, this type of radiation penetrates through thin clothing and skin deep into the tissues. Beta radiation can be shielded with a few millimeters of aluminum or a thick wooden board.

Gamma radiation is a high-energy radiation of an electromagnetic nature that has a strong penetrating power. To protect against it, you need to use a thick layer of concrete or a plate of heavy metals such as platinum and lead.

The phenomenon of radioactivity was discovered in 1896. The discovery was made by the French physicist Becquerel. Radioactivity - the ability of objects, compounds, elements to emit ionizing study, that is, radiation. The reason for the phenomenon lies in the instability of the atomic nucleus, which releases energy during decay. There are three types of radioactivity:

• natural - typical for heavy elements, the ordinal number of which is more than 82;
• artificial - initiated specifically by nuclear reactions;
• directed - characteristic of objects that themselves become a source of radiation if they are strongly irradiated.

Elements with radioactivity are called radionuclides. Each of them is characterized by:

• half-life;
• the type of radiation emitted;
• radiation energy;
• and other properties.

Sources of radiation

The human body is regularly exposed to radioactive radiation. Cosmic rays account for approximately 80% of the amount received annually. Air, water and soil contain 60 radioactive elements that are sources of natural radiation. The main natural source of radiation is considered to be the inert gas radon, which is released from the ground and rocks. Radionuclides also enter the human body with food. Some of the ionizing radiation that humans are exposed to comes from anthropogenic sources, ranging from nuclear power generators and nuclear reactors to radiation used for treatment and diagnosis. Today, common artificial radiation sources are:

• medical equipment (the main anthropogenic source of radiation);
• radiochemical industry (mining, enrichment of nuclear fuel, processing of nuclear waste and their recovery);
• radionuclides used in agriculture, light industry;
• accidents at radiochemical plants, nuclear explosions, radiation emissions
• Construction Materials.

Radiation exposure, according to the method of penetration into the body, is divided into two types: internal and external. The latter is typical for radionuclides (aerosol, dust) sprayed into the air. They come into contact with skin or clothing. In this case, the sources of radiation can be removed by flushing them. External radiation causes burns to the mucous membranes and skin. In the internal type, the radionuclide enters the bloodstream, for example, by injection into a vein or through wounds, and is removed by excretion or therapy. Such radiation provokes malignant tumors.

The radioactive background significantly depends on geographic location- in some regions, the radiation level can exceed the average by hundreds of times.

The effect of radiation on human health

Due to the ionizing effect, radioactive radiation leads to the formation of free radicals in the human body - chemically active aggressive molecules that cause damage to cells and their death.

Cells of the gastrointestinal tract, reproductive and hematopoietic systems are especially sensitive to them. Radioactive irradiation disrupts their work and causes nausea, vomiting, stool disturbances, and fever. By acting on the tissues of the eye, it can lead to radiation cataract. The consequences of ionizing radiation also include damage such as vascular sclerosis, deterioration of immunity, and a violation of the genetic apparatus.

The system of transmission of hereditary data has a fine organization. Free radicals and their derivatives are capable of disrupting the structure of DNA - the carrier of genetic information. This leads to the emergence of mutations that affect the health of subsequent generations.

The nature of the effect of radioactive radiation on the body is determined by a number of factors:

• type of radiation;
• radiation intensity;
• individual characteristics of the organism.

The results of radiation exposure may not appear immediately. Sometimes its consequences become noticeable after a considerable period of time. Moreover, a large single dose of radiation is more dangerous than long-term exposure to low doses.

The absorbed amount of radiation is characterized by a quantity called Sievert (Sv).

• The normal background radiation does not exceed 0.2 mSv / h, which corresponds to 20 microroentgens per hour. When a tooth is X-rayed, a person receives 0.1 mSv.

• The lethal single dose is 6-7 Sv.

Application of ionizing radiation

Radioactive radiation is widely used in technology, medicine, science, military and nuclear industries and other spheres of human activity. The phenomenon underlies such devices as smoke detectors, power generators, icing alarms, and air ionizers.

In medicine, radioactive radiation is used in radiation therapy to treat cancer. Ionizing radiation has made it possible to create radiopharmaceuticals. With their help, diagnostic examinations are carried out. On the basis of ionizing radiation, devices are arranged for the analysis of the composition of compounds, sterilization.

The discovery of radioactive radiation was, without exaggeration, revolutionary - the use of this phenomenon brought humanity to a new level of development. However, this also caused a threat to the environment and human health. In this regard, maintaining radiation safety is important task modernity.