Why is radiation dangerous to life? Radiation: types, sources, effects of radiation on humans. What is radiation in simple terms

Creation date: 2015/04/25

The rapid development of the nuclear industry, new types of weapons, missiles with nuclear warheads on alert, accidents and radioactive radiation - this is the reality of today.

According to ancient legend, Prometheus stole fire from the gods and brought it to people. Those who erected this sculpture, of course, did not think that the famous hero would remain in the city in splendid isolation. According to the authors' plans, it was supposed to symbolize the triumph of the human mind, which “harnessed,” as they say, the atom. Today, alas, the symbol tells a different story. Looking at the photograph of an empty Pripyat with a lonely sculpture, you can’t help but think: the irony of fate is that the wise Prometheus witnessed how a peaceful, seemingly “homey” atom, which warmed and gave light, got out of control. Indeed, we somewhat overestimated the omnipotence of man, indeed, somewhat early we considered ourselves the kings of nature, indeed, having believed in scientific and technological progress and the power of reason, we forgot that there are such simple things in the world as order, the qualifications of engineers and technicians , responsibility of scientists for their decisions, accuracy in the execution of reasonable orders. When all this is missing, there is no guarantee of the security of our “power” over nature. Then, in peacetime, Prometheus's flame becomes uncontrollable. Then nature takes revenge cruelly and fearfully. And therefore Chernobyl and Pripyat Prometheus are also an eternal reproach to human doubt.

Naturally, many different conversations and rumors arise around this issue, which are sometimes completely groundless, that is, myths arise. “A myth is a living idea. A myth begins to live because millions begin to believe in it” (Losev, “Dialectics of Myth”).

Indeed, in our time it is very difficult to separate reality from myths. And the problem of mastering the atom and using it for the good, and sometimes against humanity, is not entirely clear to ordinary people.

Therefore, it is quite understandable why ionizing radiation has become the subject of rumors, legends and myths.

Reading the literature about ionizing radiation, one gets the impression that it is not that dangerous, and in fact many people have been harmed after receiving even a small dose of radiation. Why is this happening? CONTRADITIONS arise between literary data and reality. And that’s when myths are created around ionizing radiation. Extraordinary stories are told, events that sometimes never happened are eloquently described.

First of all, it is necessary to establish: why and how do myths penetrate science? This problem worries many.

Science is the human activity of producing knowledge. Science is a social phenomenon and its development is determined not only by the internal logic of scientists, but also by the fact that it is aimed at the needs of society and can be used both for the benefit of civilization and for its evil.

How did myths and legends penetrate science? There are a huge number of them. For example, each cosmic constellation is shrouded in the most extraordinary, beautiful and poetic legends and myths. The history of the creation of such myths goes back to ancient times, because our distant ancestors were very dependent on natural phenomena. Attempts to explain and overcome this dependence gave rise to myths.

Thus, myth is one of the forms of reflection of reality characteristic of man, and from the point of view of philosophy, it is a special form of thinking, distinguished by certain characteristic features. The myth merges completely contradictory elements. Therefore, the mythological form of thinking is fundamentally different from the dialectical one.

This problem needs to be solved as quickly as possible, because misconceptions in people’s minds sometimes give such sad results. People begin to fantasize, come up with various “fables” and this, unfortunately, can lead to radiophobia.

Radiation was invented by nuclear scientists

Many people believe that radiation was invented by nuclear scientists, and its very first victims were residents of the Japanese cities of Hiroshima and Nagasaki. Is this true? It turns out that people back in the 16th century received radiation doses from radioactive radiation! The first of them were miners from the Austrian city of Joachimsthal, who died at a young age from the terrible “altitude sickness”. In those distant times, they did not know that lead ores contained large concentrations of uranium. It was only in 1879 that it became known that “mountain sickness” was lung cancer. Soon, radioactivity was discovered as a phenomenon. This is why the ICRP was created in 1928.

In the 20s of the last century, radiologists worked with the first X-ray machines, and they all died. Until now, no one can determine the true cause of their death. And we are still undergoing X-ray examinations, which means we also receive a very small dose of radioactive radiation. In addition to the above facts, there is cosmic radiation, and people are also irradiated from the soil. It is known that there are rocks in the earth containing uranium and radium. Even in the human body there are radionuclides, often in large quantities.

Conclusion: therefore, humanity lived, lives, and will live in a radioactive world. Radiation will always exist, since it is an integral part of nature, and “nodding” at nuclear scientists that they allegedly invented radiation is not at all worth it! The most dangerous type of radiation comes from the radionuclide strontium - 90

What is the most dangerous type of radiation? Let's understand this confusing and complex issue. There is an opinion that the most dangerous radionuclide is strontium. Indeed, the peculiar fame of strontium-90 is associated with its half-life. What is half-life? The fact is that radionuclides differ from stable isotopes in that their nuclei are unstable and changeable. They decay over time - this is their half-life. With this decay, radionuclides turn into other isotopes, and most importantly, during their half-life, radionuclides emit the most ionizing radiation. Not all radionuclides have the same half-lives. There are radionuclides that decay very slowly, over tens, hundreds, thousands of years. They are classified as long-lived radionuclides (iodine-129, strontium-90, cesium-137, uranium-238, plutonium-239, potassium-400), there are also short-lived radionuclides (iodine-131), which decay in seconds, hours, days, months. But in any case, radioactive decay occurs according to the same law.

But there is still a persistent myth among the population that strontium-90 is the most dangerous of radionuclides. Why? The thing is that the half-life of strontium-90 is 29 years, that is, its effect can be traced by a person directly during his life. While, for example, plutonium-239 has a half-life of 24.1x10 cubic years. Its action is very difficult to trace.

Conclusion: based on the above, we can draw the following conclusion, no matter what properties and half-lives the radionuclides have, the effect produced on living organisms will be the same, but the degree of danger to humans will depend on the radiation dose received.

“Illness from radiation threatens everyone”

Is it true that most of our diseases are caused by radiation? Are we all at risk from radiation sickness? Let's look into this issue.

After the Chernobyl accident, people began to associate some of their illnesses with radiation. Indeed, there were serious reasons for such thoughts. Most of the liquidators of this accident are actually very sick people, their number is approximately 70%, and 30% did not get sick, which means... Liquidators get sick with a variety of diseases. And even we, who live far from Pripyat, were also affected by the Chernobyl nuclear power plant, albeit to a lesser extent. Does this mean that our diseases are caused by radiation? This point of view is common for ignorant people, not specialists. There is also an opposite point of view, which is held by scientists and specialists. They believe that the liquidators received only 0.3 ZV. Another example about the workers of the famous Mayak Production Association. In the post-war years, plutonium for nuclear charges was produced at a secret plant. Thousands of workers and engineers received a dose of 1.8 – 2.7 pollutants. But a high rise in diseases among Mayakovsk residents was not recorded. So the reason is not radiation? What then? One of the versions is radiophobia, as well as a general deterioration of the environmental situation. Is radiation sickness a threat to us? Radiation sickness is a serious, often fatal disease. But it does not threaten many. Why? Radiation sickness occurs with very high doses of radiation. Radiation doses are usually divided into 3 groups: large, medium, small. Large doses are usually received during serious accidents that get out of control (the cities of Hiroshima and Nagasaki, Mayak PA, the story of Bikini Island, nuclear weapons tests). A person can receive a large dose of radiation not only during an accident, but also during the treatment of cancer. In this case, irradiation occurs using special devices. Radiation from these machines kills cancer cells.

After the Chernobyl accident, many were afraid of the “ghost” of radiation, the “ghost” of radiation sickness and did not follow doctors’ orders. Today, it is impossible to irradiate a person with dangerous (large) doses, and even more so it is impossible to hide radiation sickness. But fears of cancer are justified, since, unfortunately, no one is immune from them.

And all diseases, including cancer, arise due to the action of free radicals. This theory was put forward by the American scientist D. Harmer. During the breakdown of substances, so-called “fragments of molecules and atoms” are formed - free radicals (for example O, H, OH). These are the ones that can cause many serious diseases. And when receiving a dose of radiation, the number of free radicals increases and, consequently, the risk of cancer increases. If we add to this chemical pollution of the environment (the water that a person drinks, food) and radiophobia, which is a great stress for the body, then the number of free radicals gets out of control, and then their frantic attack on the body begins. These three factors (radiation, psychological and emotional stress, chemical pollution) led to an increase in the level of morbidity among liquidators.

This leads to the conclusion: you should not be afraid of radiation (it is better to never receive it), but of stress, chemical pollution and, of course, you need to know the truth, and not read the “yellow” press. And if a person was able to cope with these factors, then he will overcome the disease from radiation.

Having received any dose of radiation, a person will certainly die, and the radiation will be inherited by children

Not all irradiated people die, and not even the majority, but a small part of them. After the bombings of Hiroshima and Nagasaki, American researchers and scientists monitored the irradiated residents of these cities. As a result, one feature was noticed that affected their health. People began to get sick and die more often from leukemia, and then from other forms of cancer. Thus, if the dose was not too large, we are not talking about any fatal threat and instant death from “cancer”. Smoking, for example, is much more dangerous. But radioactive radiation can lead to other undesirable effects on human health. For example, an irradiated man faces impotence, and a woman faces infertility. This is true, but only when we are talking about high-dose irradiation.

Irradiated parents give birth to mutant children, is this true? This is wrong. How many excess cases of handicapped children have been recorded among hibakushi (victims of the bombings of Hiroshima and Nagasaki)? Not a single one! It’s the same with the accident at Mayak and the Chernobyl nuclear power plant. And again, the phenomenon of radiophobia worked: a huge number of abortions were carried out through the fault of journalists, since a very large number of people believed them.

Are all liquidators doomed to death or serious illness? Of course, if we talk about those liquidators who were the first to eliminate the consequences of the explosion (fire crews, soldiers, etc.), then they will receive a very large dose. Cases of leukemia were found in many liquidators, but according to the results of medical studies, out of 55 cases of disease, only 12 were attributed to exposure to radiation, because medicine in most cases is not able to establish an objective diagnosis when it came to low doses of radiation (less than 0.138 pollutants). The bulk of the liquidators still experienced enormous psychological pressure from the media. This is a serious disease that can be caused by frequent and prolonged stress. The world-famous Professor Bole conducted a study, the results of which led him to the conclusion that constant expectation of trouble leads to trouble, any situation can be corrected with a serious approach to it and timely treatment. Conclusion: this means that by receiving a dose of radiation, overcoming stress and applying the necessary treatment, you can avoid the disease, this is also stated in the previous myth. And oncological diseases are not inherited, just as ionizing radiation is not inherited. Modern medicine can give an exact answer to this question, and cases in which irradiated women gave birth to children with “cancer” have not yet been registered.

People receive the most radiation in “closed cities”, when working at nuclear power plants and even during medical research

There is an opinion among people that a person can receive radiation during treatment with radon, in any home, when working at a nuclear power plant, and even just being in a “closed” city.

Many people, including workers at nuclear power plants and factories that produce nuclear energy, believe that they are receiving a gigantic dose of radiation. There is some truth in this: people who directly work with atoms (main production workshops) are of course irradiated. Other workers receive a lower dose of radiation than, for example, patients during an X-ray examination.

There are several types of radiation: natural, medical, man-made.

Humans have been exposed to natural radiation since ancient times:

• natural background radiation;
• exposure to building materials;
• irradiation from mineral fertilizers.

Medical exposure – primarily from X-ray diagnostic procedures. They include not only fluorography, but also various types of x-ray diagnostics, radiation therapy for cancer, and even radon baths. For each case, patients are provided with complete information about the planned and actual dose they receive during examination and treatment. In order to cause harm to your health, you need to get x-rayed at least 100 times in a row, which has not happened and cannot happen in medical practice.

Man-made exposure – includes several different types of exposure, such as:

• operation of nuclear power plants;
• the presence of a nuclear weapons complex and radioactive waste disposal sites;
• functioning of nuclear fuel cycle enterprises and emergency situations at these facilities.

If these enterprises operate without emergency situations, then a tiny amount of radionuclides enters the environment.

Closed cities - naturally, in such cities residents receive certain doses of radiation. In recent years, the incidence of cancer among the population of these cities has increased, but this indicator generally remains below the average for the Russian Federation. What are the reasons for this:

• deterioration of the socio-ecological situation on Earth;
• a sharp increase in the number of motor vehicles (there are a lot of them in closed cities, such cities are not adapted to mass motorization), that is, the proportion of chemical elements in the air has increased;
• in closed cities there are different levels of income per capita between workers at nuclear industry enterprises and all other residents (people lived better in these cities, but now living conditions have worsened and therefore such stress worsens the situation).

Conclusion: people began to get sick more often, but not from radiation exposure, but from the deterioration of the socio-political situation in the country and in the world, as well as from environmental pollution.

Thus, in our age of global environmental degradation, the age of stress and chemicals, people get sick and die more often and do not live to old age, although they have never been in closed cities and have not received ionizing radiation.

The events of recent decades have given rise to many discussions about the dangers of radiation for humans and how to avoid its influence. Radiation is the inherent ability of particles to emit or spread energy into space. The power of this energy affects substances, leading to the appearance of differently charged ions. Objects that emit ionizing radiation become radioactive.

Radiation and its features

The particles that create radiation fall from the nucleus of an atom of elements (uranium and others). Radioactive decay occurs in the core itself. One element can have several variants - isotopes, and some of them will be radioactive, while others will be stable.

Each of the radioactive isotopes has its own life period, ending with the decay of the nucleus. The time required for half of the isotope nuclei to decay is called the half-life. It can last from a fraction of a second to millions of years.

In nature, the formation of radioactive isotopes occurs naturally, but they can also be created artificially. This happens during the construction of nuclear power plants and nuclear tests.

Types of Radiation

Radiation is characterized by energy, composition and ability to penetrate; it comes in several types:

1. Alpha particles are heavy helium nuclei with a positive charge; they provide powerful ionization.
2. Beta particles are electrons with a charge in the form of a stream with a high ability to penetrate.
3. Gamma flow is short, penetrating into the structure of objects.
4. X-rays are electromagnetic waves with lower energy.
5. Neutrons are neutral particles that occur near operating nuclear reactors.

The number of radioactive nuclei that decay over a certain time is called activity. Its value reflects the number of ionizing particles emitted by the source per second.

The danger of radiation depends on its sources. They are natural and man-made. The former form a background radiation that affects all life on Earth. This type of radiation is global and constant. Natural radiation is created by cosmic rays and elements contained in earth rocks and the environment. All this creates external exposure of people.

Food products, water and air also contain a certain amount of radioactive components; they serve as a source of internal radiation.

Important! Every year, an inhabitant of the Earth receives approximately 180-220 millirem of radiation from natural sources. The internal radiation dose is twice as high.

Technogenic sources include equipment used:

• in the industrial sector;
• in the agricultural industry;
• In scientific developments;
• for nuclear energy generation;
• for the creation and testing of nuclear weapons.

Drugs and devices that are actively used in medicine have the ability to irradiate. This effect only affects certain organs and parts of the body.

The danger of radiation exposure to humans

Scientists have long proven the negative effects of radiation on humans. Suffice it to recall the Chernobyl accident and the number of people who participated in the liquidation of the consequences of the disaster who became ill with radiation sickness.

To understand what kind of radiation is dangerous to humans, you need to know that its source can be any radioactive substance or object. Such an influence cannot be felt or seen; it can only be assessed using a special device. How dangerous radiation exposure is depends on its type, duration and frequency of exposure.

The most dangerous is gamma radiation; alpha particles cause harm when directly penetrating the digestive organs or lungs. The mechanism of action is as follows:

1. Radiation causes the ionization of the body's molecules, they go into an excited state.
2. The redistribution of excess energy begins.
3. Molecules affected by radiation transfer energy to other particles.
4. The chemical stage starts.
5. Due to the disruption of molecular bonds, the structure of lipids, proteins and DNA changes.

Against the background of such changes, radiation sickness develops. The amount of energy transferred by radiation is called dose. The body is not able to create a barrier to such radiation; any molecule can be affected. This explains why radiation is life-threatening.

Consequences of infection

The effects of radiation on the body can be divided into two groups. The first consists of genetic effects: mutations at the gene level and chromosomal aberrations. The second includes somatic manifestations in the form of radiation sickness, local lesions, tumors, cancer, leukemia.

Long-term effects of radiation are manifested in:

• development of immunodeficiency;
• influence on heredity;
• increased sensitivity to infection;
• hormonal imbalance;
• development of cataracts;
• decreased life expectancy;
• mental development delays.

Radioactive danger is associated with the possibility of metabolic disorders, the appearance of birth defects in subsequent generations, infertility, miscarriages, and infectious diseases. Exposure to radiation can result in death. This happens in the case of even a single visit to areas with a powerful radiation source or when constantly receiving certain doses of radiation from objects, for example, when storing them at home.

Important! The source of radiation can be any thing, including antiques.

The main thing that makes radiation dangerous for children is its irreversible effect on growing cells. During the formation of the organism, radiation reacts in a shorter period of time. The effect of radiation on pregnant women is extremely undesirable; fetal cells are very susceptible to it.

Signs of exposure

Signs of radiation exposure are:

• vomit;
• disorientation;
• the appearance of ulcers on the body that cannot be treated;
• bleeding from the mouth, nose, rectum;
• bloody diarrhea;
• radiation burns on the skin;
• hair loss;
• feeling weak and tired;
• fainting, headache;
• sores on the lips and mouth;
• tremors, seizures;
• fever.

In people who have received a dose of radiation, blood pressure drops, heart function and vascular tone are disrupted. Hepatitis and cirrhosis of the liver may develop, and the functioning of the biliary system may malfunction. The level of leukocytes in the blood sharply decreases.

All this is far from a complete list of how radioactive substances are dangerous to humans. The changes that occur affect the entire body and have a negative impact on all its systems.

Preventive measures

Regular monitoring of background radiation helps to avoid such exposure. This applies to industrial and residential premises, water, and food. During measurements, the intensity of radiation and the degree of danger of the source are taken into account, and the time that is permissible to spend near it without unpleasant consequences is determined.

The unit of measurement for the radiation received is the sievert. The value shows the amount of energy absorbed by a kilogram of biological tissue over the course of an hour. The maximum permissible norm is considered to be 0.5 microsieverts per hour; the normal value should not be higher than 0.2 microsieverts per hour. Higher levels are a dangerous dose of radiation for humans. A reading of 5-6 sieverts is lethal.

People exposed to dangerous levels of radiation for humans must receive first aid. All clothing should be removed and disposed of immediately. You need to take a shower with detergents as soon as possible. In the future, the removal of harmful substances is carried out with the help of medical measures and drugs:

Dietary supplements bring certain benefits. They contain iodine to eliminate the effects of isotopes that accumulate in the thyroid gland, clays with zeolites, which bind radiation waste and remove it from the body. Calcium supplements help eliminate strontium.

How to remove radiation from the body?

The process of removing radiation can be accelerated through proper formulation of diets. To do this you need to include in the menu:

• grape juice with pulp;
• seafood and fish;
• persimmons;
• cold pressed vegetable oil;
• prunes and dried fruit decoction;
• quail eggs;
• oatmeal;
• beets;
• yeast of natural origin.

Honey, rice and pears will complement the diet well; the menu must include soups and a sufficient amount of liquid. Particular attention should be paid to products containing selenium (protects against the development of cancer), methionine (activates cellular regeneration), carotene (restores cellular structure).

Information about the benefits of alcohol for removing radiation is nothing more than a myth. Vodka, on the contrary, promotes the distribution of harmful substances throughout the body. Dry red grape wine can have a beneficial effect, but in very small quantities.

Scientists studying the effects of radiation on living organisms are seriously concerned about its widespread occurrence. As one of the researchers said, modern humanity is swimming in an ocean of radiation. Invisible to the eye, radioactive particles are found in soil and air, water and food, children's toys, body jewelry, building materials, and antiques. The most harmless object at first glance can turn out to be dangerous to health.

Our body can also be called radioactive to a small extent. Its tissues always contain the chemical elements it needs - potassium, rubidium and their isotopes. It’s hard to believe, but thousands of radioactive decays occur in us every second!

What is the essence of radiation?

The atomic nucleus consists of protons and neutrons. Their arrangement for some elements may, to put it simply, not be entirely successful, which is why they become unstable. Such nuclei have excess energy, which they try to get rid of. You can do this in the following ways:

• Small “pieces” of two protons and two neutrons are ejected (alpha decay).
• In the nucleus, a proton turns into a neutron, and vice versa. In this case, beta particles are emitted, which are electrons or their counterparts with the opposite sign - antielectrons.
• Excess energy is released from the nucleus in the form of an electromagnetic wave (gamma decay).

In addition, the nucleus can emit protons, neutrons and completely fall apart into pieces. Thus, despite the type and origin, any type of radiation represents a high-energy stream of particles with enormous speed (tens and hundreds of thousands of kilometers per second). It has a very detrimental effect on the body.

Consequences of radiation on the human body

In our body, two opposing processes continuously continue - cell death and regeneration. Under normal conditions, radioactive particles damage up to 8 thousand different compounds in DNA molecules per hour, which the body then independently repairs. Therefore, doctors believe that small doses of radiation activate the body’s biological defense system. But the big ones destroy and kill.

Thus, radiation sickness begins already after receiving 1-2 Sv, when doctors record its 1st degree. In this case, monitoring and regular follow-up examinations for cancer are necessary. A dose of 2-4 Sv already means the 2nd degree of radiation sickness, which requires treatment. If help arrives on time, there will be no death. A dose of 6 Sv is considered lethal, when even after a bone marrow transplant only 10th of the patients can be saved.

Without a dosimeter, a person will never understand that he is being exposed to dangerous radiation. At first, the body does not react to this. Only after a while can nausea appear, headaches, weakness, and fever begin.

At high doses of radiation, radiation primarily affects the hematopoietic system. There are almost no lymphocytes left in it, the number of which determines the level of immunity. At the same time, the number of chromosomal breakdowns (dicentrics) in cells is growing.

On average, the human body should not be exposed to radiation doses of more than 1 mlSv per year. When exposed to 17 Sv of radiation, the probability of developing incurable cancer approaches its maximum value.

Read more about how radiation affects the human body

Damage to cell atoms. The process of exposure of the body to radiation is called irradiation. This is an extremely destructive force that transforms cells, deforms their DNA, leading to mutations and genetic damage. The destructive process can be started by just one particle of radiation.

Experts compare the effect of ionizing radiation to a snowball. It all starts small, then the process increases until irreversible changes occur. At the atomic level it happens like this. Radioactive particles fly at enormous speeds, knocking electrons out of atoms. As a result, the latter acquire a positive charge. The “dark” matter of radiation lies only in this. But the consequences of such transformations can be catastrophic.

A free electron and an ionized atom enter into complex reactions that result in the formation of free radicals. For example, water (H 2 O), which makes up 80% of a person’s mass, decomposes under the influence of radiation into two radicals - H and OH. These pathologically active particles react with important biological compounds - molecules of DNA, proteins, enzymes, fats. As a result, the number of damaged molecules and toxins in the body increases, and cellular metabolism suffers. After some time, the affected cells die or their functions are seriously impaired.

What happens to an irradiated organism? Due to DNA damage and gene mutations, the cell cannot divide normally. This is the most dangerous consequence of radiation exposure. When receiving a large dose, the number of affected cells is so large that organs and systems may fail. The tissues in which active cell division occurs are the hardest to perceive radiation:

• bone marrow;
• lungs,
• gastric mucosa,
• intestines,
• genitals.

Moreover, even a weakly radioactive object with prolonged contact causes harm to the human body. So, your favorite pendant or camera lens can become a time bomb for you.

The enormous danger of the influence of radiation on living organisms is that for a long time it does not manifest itself in any way. The “enemy” penetrates through the lungs, gastrointestinal tract, skin, and the person does not even suspect it.

Depending on the degree and nature of exposure, its results are:

• acute radiation sickness;
• dysfunction of the central nervous system;
• local radiation injuries (burns);
• malignant neoplasms;
• leukemia;
• immune diseases;
• infertility;
• mutations.

Unfortunately, nature has not provided human senses that could give him signals of danger when approaching a radioactive source. Protect yourself from such “sabotage” without always having it at hand household dosimeter impossible.

How to protect yourself from excessive doses of radiation?

It is easier to protect yourself from external sources. Alpha particles will be blocked by a regular cardboard sheet. Beta radiation does not penetrate glass. A thick lead sheet or concrete wall can “cover” from gamma rays.

The worst situation is with internal radiation, in which the source is located inside the body, getting there, for example, after inhaling radioactive dust or dining on mushrooms “flavored” with cesium. In this case, the consequences of radiation are much more serious.

The best protection against household ionizing radiation is timely detection of its sources. They will help you with this household dosimeters RADEX. With such devices at hand, life is much calmer: at any moment you can examine anything for radiation contamination.

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

This material is a generalized answer to numerous questions that arise from users of devices for detecting and measuring radiation in domestic conditions.
Minimal use of the specific terminology of nuclear physics when presenting the material will help you freely navigate this environmental problem, without succumbing to radiophobia, but also without excessive complacency.

The danger of RADIATION, real and imaginary

“One of the first natural radioactive elements discovered was called radium.”
- translated from Latin - emitting rays, radiating.”

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

Thanks to the presence of sensory organs assigned to him by nature, he can quickly respond to these phenomena with the help of, for example, a sun canopy, clothing, shelter, medicine, screens, shelters, etc.

However, in nature there is a phenomenon to which a person, due to the lack of the necessary sense organs, cannot instantly react - this is radioactivity. Radioactivity is not a new phenomenon; Radioactivity and the radiation accompanying it (the so-called ionizing radiation) have always existed in the Universe. Radioactive materials are part of the Earth and even humans are slightly radioactive, because... Radioactive substances are present in the smallest quantities in any living tissue.

The most unpleasant property of radioactive (ionizing) radiation is its effect on the tissues of a living organism, therefore, appropriate measuring instruments are needed that would provide prompt information for making useful decisions before a long time has passed and undesirable or even fatal consequences appear. will not begin to feel 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. Each atom is like a miniature solar system: “planets” move in orbit around a tiny nucleus - 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 symbol of the element equal to the sum of all particles in the nucleus of a given isotope. So uranium-238 contains 92 protons and 146 neutrons; Uranium 235 also has 92 protons, but 143 neutrons. All isotopes of a chemical element form a group of “nuclides”. Some nuclides are stable, i.e. do not undergo any transformations, while others emitting particles are unstable and turn into other nuclides. As an example, let's take the uranium atom - 238. From time to time, a compact group of four particles bursts out of it: two protons and two neutrons - an “alpha particle (alpha)”. Uranium-238 thus turns into an element whose nucleus contains 90 protons and 144 neutrons - thorium-234. But thorium-234 is also unstable: one of its neutrons turns into a proton, and thorium-234 turns into an element with 91 protons and 143 neutrons in its nucleus. This transformation also affects the electrons (beta) moving in their orbits: one of them becomes, as it were, superfluous, without a pair (proton), so it leaves the atom. The chain of numerous transformations, accompanied by alpha or beta radiation, ends with a stable lead nuclide. Of course, there are many similar chains of spontaneous transformations (decays) of different nuclides. The half-life is the period of time during which the initial number of radioactive nuclei on average decreases by half.
With each act of decay, energy is released, which is transmitted in the form of radiation. Often an unstable nuclide finds itself in an excited state, and the emission of a particle does not lead to complete removal of excitation; then it emits a portion of energy in the form of gamma radiation (gamma quantum). As with X-rays (which differ from gamma rays only in frequency), no particles are emitted. The entire process of spontaneous decay of an unstable nuclide is called radioactive decay, and the nuclide itself is called a radionuclide.

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 indoors is water and natural gas used for cooking and heating homes.

The concentration of radon in commonly used water is extremely low, but water from deep wells or artesian wells contains very high levels of radon. However, the main danger does not come from drinking water, even with a high radon content. Typically, people consume most of their water in food and hot drinks, and when boiling water or cooking hot food, radon is almost completely dissipated. 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. This is not a 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 specially in terms of their impact on humans. However, only emergency situations, such as the Chernobyl accident, can have an uncontrollable impact on humans.
The rest of the work is easily controlled at a professional level.

When radioactive fallout occurs in some areas of the Earth, radiation can enter the human body directly through agricultural products and food. It is very simple to protect yourself and your loved ones from this danger. When buying milk, vegetables, fruits, herbs, and any other products, it is not superfluous to turn on the dosimeter and bring it to the purchased product. Radiation is not visible - but the device will instantly detect the presence of radioactive contamination. This is our life in the third millennium - a dosimeter becomes an attribute of everyday life, like a handkerchief, toothbrush, and soap.

IMPACT OF IONIZING RADIATION ON BODY TISSUE

The damage caused in a living organism by ionizing radiation will be greater, the more energy it transfers to tissues; the amount of this energy is called a dose, by analogy with any substance entering the body and completely absorbed by it. The body can receive a dose of radiation regardless of whether the radionuclide is located outside the body or inside it.

The amount of radiation energy absorbed by irradiated body tissues, calculated per unit mass, is called the absorbed dose and is measured in Grays. But this value does not take into account the fact that for the same absorbed dose, alpha radiation is much more dangerous (twenty times) than beta or gamma radiation. The dose recalculated in this way is called the equivalent dose; it is measured in units called Sieverts.

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

Charged particles.

Alpha and beta particles penetrating into 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 this atom. The latter is negatively charged, so the rest of the initially neutral atom becomes positively charged. This process is called ionization. The detached electron can further ionize other atoms.

Physico-chemical changes.

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

Chemical changes.

Over the next millionths of a second, the resulting free radicals react both with each other and with other molecules and, through a chain of reactions not yet fully understood, can cause chemical modification of biologically important molecules necessary for the normal functioning of the cell.

Biological effects.

Biochemical changes can occur within seconds or decades after irradiation and cause immediate cell death or changes in them.

For information, and not to intimidate, especially people who decide to devote themselves to working with ionizing radiation, you should know the maximum permissible doses. The units of measurement of radioactivity are given in Table 1. According to the conclusion of the International Commission on Radiation Protection in 1990, harmful effects can occur at equivalent doses of at least 1.5 Sv (150 rem) received during the year, and in cases of short-term exposure - at doses higher 0.5 Sv (50 rem). When radiation exposure exceeds a certain threshold, radiation sickness occurs. There are chronic and acute (with a single massive exposure) forms of this disease. Acute radiation sickness is divided into four degrees by severity, ranging from a dose of 1-2 Sv (100-200 rem, 1st degree) to a dose of more than 6 Sv (600 rem, 4th degree). Stage 4 can be fatal.

The doses received under normal conditions are negligible compared to those indicated. The equivalent dose rate generated by natural radiation ranges from 0.05 to 0.2 μSv/h, i.e. from 0.44 to 1.75 mSv/year (44-175 mrem/year).
For medical diagnostic procedures - x-rays, etc. - a person receives approximately another 1.4 mSv/year.

Since radioactive elements are present in brick and concrete in small doses, the dose increases by another 1.5 mSv/year. Finally, due to emissions from modern coal-fired thermal power plants and when flying on an airplane, a person receives up to 4 mSv/year. In total, the existing background can reach 10 mSv/year, but on average does not exceed 5 mSv/year (0.5 rem/year).

Such doses are completely harmless to humans. The dose limit in addition to the existing background for a limited part of the population in areas of increased radiation is set at 5 mSv/year (0.5 rem/year), i.e. with a 300-fold reserve. For personnel working with sources of ionizing radiation, the maximum permissible dose is set at 50 mSv/year (5 rem/year), i.e. 28 µSv/h with a 36-hour work week.

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

Radiation acute or chronic poisoning, the cause of which is the action of ionizing electromagnetic radiation, is called radioactive exposure. Under its influence, free radicals and radionuclides are formed in the human body, which change biological and metabolic processes. As a result of radiation exposure, the integrity of protein and nucleic acid structures is destroyed, the DNA sequence changes, mutations and malignant neoplasms appear, and the annual number of cancer diseases increases by 9%.

Sources of radioactive radiation

The spread of radiation is not limited to modern nuclear power plants, nuclear power facilities and power lines. Radiation is found in all natural resources without exception. Even the human body already contains the radioactive elements potassium and rubidium. Where else does natural radiation occur:

1. secondary cosmic radiation. In the form of rays, it is part of the background radiation in the atmosphere and reaches the Earth's surface;
2. solar radiation. Directed flow of electrons, protons and nuclei in interplanetary space. Appear after strong solar flares;
3. radon. Colorless inert radioactive gas;
4. natural isotopes. Uranium, radium, lead, thorium;
5. internal irradiation. The most commonly found radionuclides in food are strontium, cesium, radium, plutonium and tritium.

People's activities are constantly aimed at searching for sources of powerful energy, durable and reliable materials, methods for accurate early diagnosis and intensive effective treatment of serious diseases. The result of long-term scientific research and human impact on the environment is artificial radiation:

1. nuclear energy;
2. medicine;
3. nuclear tests;
4. building materials;
5. radiation from household appliances.

The widespread use of radioactive substances and chemical reactions has led to a new problem of radiation exposure, which annually causes cancer, leukemia, hereditary and genetic mutations, decreased life expectancy and a source of environmental disasters.

Doses of dangerous radiation exposure

To prevent the occurrence of consequences that result from radiation, it is necessary to constantly monitor the background radiation and its level at work, in residential premises, in food and water. In order to assess the degree of possible damage to living organisms and the impact of radiation exposure on people, the following quantities are used:

• exposure dose. Exposure to ionizing gamma and x-ray radiation in the air. It has the designation kl/kg (pendant divided by kilogram);
• absorbed dose. The degree of influence of radiation on the physical and chemical properties of a substance. The value is expressed in a unit of measurement - gray (Gy). In this case, 1 C/kg = 3876 R;
• equivalent, biological dose. The penetrating effect on living organisms is measured in sieverts (Sv). 1 Sv = 100 rem = 100 R, 1 rem = 0.01 Sv;
• effective dose. The level of radiation damage, taking into account radiosensitivity, is determined using sievert (Sv) or rem (rem);
• group dose. Collective, total unit in Sv, rem.

Using these conditional indicators, you can easily determine the level and degree of danger to human health and life, select the appropriate treatment for radiation exposure and restore the functions of the body affected by radiation.

Signs of radiation exposure

The damaging ability of invisible ionizing radiation is associated with the impact on humans of alpha, beta and gamma particles, x-rays and protons. Due to the latent, intermediate stage of radiation exposure, it is not always possible to determine in time the moment of onset of radiation sickness. Symptoms of radioactive poisoning appear gradually:

1. radiation injury. The effect of radiation is short-term, the radiation dose does not exceed 1 Gy;
2. typical bone marrow form. Irradiation rate - 1-6 Gy. Death from radiation occurs in 50% of people. In the first minutes, malaise, low blood pressure, and vomiting are observed. Replaced by visible improvement after 3 days. Lasts up to 1 month. After 3-4 weeks the condition worsens sharply;
3. gastrointestinal stage. The degree of irradiation reaches 10-20 Gy. Complications in the form of sepsis, enteritis;
4. vascular phase. Poor circulation, changes in blood flow speed and vascular structure. Blood pressure surges. The dose of radiation received is 20-80 Gy;
5. cerebral form. Severe radiation poisoning at a dose of more than 80 Gy causes cerebral edema and death. The patient dies from 1 to 3 days from the moment of infection.

The most common forms of radioactive poisoning are bone marrow and gastrointestinal damage, the consequences of which are severe changes in the body. Characteristic symptoms also appear after exposure to radiation:

• body temperature from 37 °C to 38 °C, in severe form the indicators are higher;
• arterial hypotension. The source of low blood pressure is a violation of vascular tone and heart function;
• radiation dermatitis or hyperemia. Skin lesions. Expressed by redness and allergic rash;
• diarrhea. Frequent loose or watery stools;
• baldness. Hair loss is a characteristic symptom of radiation exposure;
• anemia. Lack of hemoglobin in the blood is associated with a decrease in red blood cells, oxygen cellular starvation;
• hepatitis or cirrhosis of the liver. Destruction of the gland structure and changes in the functions of the biliary system;
• stomatitis. The reaction of the immune system to the appearance of foreign bodies in the body in the form of damage to the oral mucosa;
• cataract. Partial or complete loss of vision is associated with clouding of the lens;
• leukemia. Malignant disease of the hematopoietic system, blood cancer;
• agranulocytosis. Decreased leukocyte levels.

Exhaustion of the body also affects the central nervous system. Most patients experience asthenia or pathological fatigue syndrome after radiation injury. Accompanied by sleep disturbances, confusion, emotional instability and neuroses.

Chronic radiation sickness: degrees and symptoms

The course of the disease is long. Diagnosis is also complicated by the mild nature of slowly emerging pathologies. In some cases, the development of changes and disorders in the body manifests itself from 1 to 3 years. Chronic radiation injuries cannot be characterized by one symptom. Symptoms of intense radiation exposure form a number of complications depending on the degree of exposure:

• light. The functioning of the gallbladder and biliary tract is disrupted, women's menstrual cycle is disrupted, men suffer from sexual impotence. Emotional changes and disturbances are observed. Associated symptoms include lack of appetite and gastritis. Treatable with timely consultation with specialists;
• average. People exposed to radiation poisoning suffer from vegetative-vascular diseases, which are expressed by persistent low blood pressure and periodic bleeding from the nose and gums, and are susceptible to asthenic syndrome. The average degree is accompanied by tachycardia, dermatitis, hair loss and brittle nails. The number of platelets and leukocytes decreases, problems with blood clotting begin, and the bone marrow is damaged;
• heavy. Progressive changes in the human body, such as intoxication, infection, sepsis, tooth and hair loss, necrosis and multiple hemorrhages result in death.

A long process of irradiation at a daily dose of up to 0.5 Gy, with a total quantitative indicator of more than 1 Gy, provokes chronic radiation injury. Leads to death from severe radioactive poisoning of the nervous, cardiovascular and endocrine systems, dystrophy and organ dysfunction.

Radioactive effects on humans

To protect yourself and your loved ones from severe complications and negative consequences of radiation exposure, it is necessary to avoid exposure to high amounts of ionizing radiation. To this end, it is better to remember where radiation is most often found in everyday life and how great its impact on the body is in one year in mSv:

1. air - 2;
2. food consumed - 0.02;
3. water - 0.1;
4. natural sources (cosmic and solar rays, natural isotopes) - 0.27 - 0.39;
5. inert gas radon - 2;
6. residential premises - 0.3;
7. watching TV - 0.005;
8. consumer goods - 0.1;
9. radiography - 0.39;
10. computed tomography - from 1 to 11;
11. fluorography - 0.03 - 0.25;
12. air travel - 0.2;
13. smoking - 13.

The permissible safe dose of radiation that will not cause radioactive poisoning is 0.03 mSv for one year. If a single dose of ionizing radiation exceeds 0.2 mSv, the level of radiation becomes dangerous for humans and can cause cancer, genetic mutations of subsequent generations, disruption of the endocrine, cardiovascular, and central nervous systems, and provoke disorders of the stomach and intestines.