Biological effects of radiation on the human body. What is radiation and why is it dangerous. Consequences of the explosion at the Chernobyl nuclear power plant

« Biological action radiation per person

More than twenty centuries have passed, and humanity again faces a similar dilemma: the atom and the radiation it emits can become for us a source of prosperity or death, a threat or hope, a better or worse thing.

Goals of the work:

1) Identify the effects of radiation on the biological environment.

2) Identify the effects of radiation on humans.

3) Determine measures to protect against radiation background.

Tasks:

1) Study literary sources.

2) Using the information received, determine the pros and cons of radiation.

3) Visit KSTU to study the device that determines the radiation background.

4) Determine how the radiation background affects environment and a person.

5) Find out the measures of protection against radiation exposure.

In our world, there are many places and objects from which we receive radiation. For example, from the phone. Our mobile emits electromagnetic waves that expose our body to radiation. We are also irradiated when exposed to an ungrounded computer. When we do fluorography, we are also exposed to small radiation. There are many more things and factors due to which we are exposed to radiation.

Sources of radiation:

Natural: Cosmic, sun rays; radon gas, radioactive isotopes in rocks (uranium 238, thorium 232, potassium 40, rubidium 87); internal exposure of a person due to radionuclides (with water and food). Man made: Medical procedures and therapies, nuclear power, nuclear explosions, landfills, building materials, combustible fuel, household appliances.

Use of radiation:

Radiation is used in medicine for diagnostic purposes and for treatment. One of the most common medical devices is an x-ray machine. Research in the field - radiation genetics and radiation selection gave about a hundred new varieties of high-yielding cultivated plants resistant to various diseases.

Consequences of exposure to radiation:

Radiation sickness, infertility, genetic mutations, damage to the organs of vision, lesions nervous system, accelerated aging organism, violation of mental and mental development, cancer.

Security measures:

We do not leave the premises, 2-3 times a day we do wet (precisely wet!) cleaning;

We take a shower as often as possible (especially after going outside), wash things. Regular rinsing with saline of the mucous membranes of the nose, eyes and pharynx is not so important, since much large quantity radionuclides;

To protect the body from radioactive iodine-131, it is enough to lubricate a small area of ​​skin with medical iodine. According to doctors, this simple method of protection is valid for a month;

· if you have to go outside, it is better to wear light-colored clothes, preferably cotton and damp. It is recommended to wear a hood and a baseball cap on the head at the same time;

· in the first few days you need to be wary of radioactive fallout, that is, "hide and sit out."

Our research in the Kaliningrad center of the atom.

For our experience, we weighed people of different weight category. And our experience has shown that the greater the weight of a person, the higher his normal radiation background.

Dosimeter - instrument for measuring effective dose or power of ionizing radiation for a certain period of time. Dimension itself

called dosimetry. In our case, the dosimeter is a floor scale with a computer. As a result of the research, we have identified the pros and cons of radiation:

Pros:

use in medicine (X-ray diagnostics, radiation therapy, etc.);

radiation genetics and breeding;

radioactive lightning rod;

sterilization and food preservation;

photo recovery;

use of ionizing radiation in industry.

Minuses:

exposure; radioactive waste; the danger of "peaceful" radiation;

genetic consequences of exposure.

Conclusion: As a result of the research, we found that the greater the weight of a person, the higher his normal radiation background and that it does not depend on the age of the person.

Over the course of a lifetime, a person receives a dose of radiation from natural sources, and at normal condition environment, such exposure does not cause any changes in human organs and tissues.

But by its very nature, radiation is harmful to life. Small doses can "trigger" a not yet fully established chain of events leading to cancer or genetic damage. At large doses Ah, radiation can destroy cells, damage organ tissues, and cause an imminent death of the organism.

Damage caused by high doses of radiation usually shows up within hours or days. Cancers, however, do not appear until many years after irradiation—usually not earlier than one to two decades. And congenital malformations and others hereditary diseases caused by damage to the genetic apparatus, by definition, appear only in the next or subsequent generations: these are the children, grandchildren and more distant descendants of the individual exposed to radiation.

While it is not difficult to identify short-term (“acute”) effects from exposure to high doses of radiation, it is almost always very difficult to detect long-term effects from low doses of radiation. This is partly because they take a very long time to manifest. But even finding some effects. it is still necessary to prove that they are explained by the action of radiation, since both cancer and damage to the genetic apparatus can be caused not only by radiation, but also by many other reasons.

To cause acute damage to the body, radiation doses must exceed a certain level, but there is no reason to believe that this rule applies in the case of consequences such as cancer or damage to the genetic apparatus. By at least, theoretically, it is enough for this small dose. However, at the same time, no radiation dose leads to these consequences during all cases. Even with relatively high doses of radiation, not all people are doomed to these diseases: the repair mechanisms operating in the human body usually eliminate all damage. In the same way, any person exposed to radiation does not necessarily have to develop cancer or become a carrier of hereditary diseases; however, the likelihood risk, he has more such consequences than a person who has not been irradiated. And this risk is greater, the greater the dose of radiation.

UNSCEAR seeks to ascertain with all possible certainty what additional risk people are exposed to when various doses irradiation. Probably more research has been done on the effects of radiation on humans and the environment than on any other source. heightened danger. However, the more distant the effect and less dose, the less useful information that we currently have.

Acute lesion organism occurs at high doses of radiation. Radiation renders similar action, only starting from a certain minimum, or “threshold”, radiation dose.

A large amount of information was obtained from the analysis of the results of the application radiotherapy for the treatment of cancer. Many years of experience have allowed physicians to obtain extensive information about the response of human tissues to radiation. This reaction for various organs and tissues was not the same, and the differences are very large. The magnitude of the dose, which determines the severity of the damage to the body, depends on whether the body receives it immediately or in several doses. most organs have time to heal radiation damage to some extent and therefore tolerate a series of small doses better than the same total dose of radiation received at one time.

Of course, if one dose of radiation is large enough, the exposed person will die. In any case, very high radiation doses of the order of 100 Gy cause such severe damage to the central nervous system that death usually occurs within a few hours or days.

At radiation doses of 10 to 50 Gy for whole-body irradiation, CNS damage may not be severe enough to lead to lethal outcome, however, the exposed person is likely to die anyway in one to two weeks from hemorrhages in the gastrointestinal tract.

Even lower doses may not cause serious damage. gastrointestinal tract or the body will cope with them, and yet death can occur in one to two months from the moment of exposure, mainly due to the destruction of red bone marrow cells - the main component of the hematopoietic system of the body: from a dose of 3-5 Gy during irradiation of the whole body, one dies about half of those exposed.

Thus, in this range of radiation doses, large doses differ from smaller ones only in that death occurs earlier in the first case, and later in the second.

Of course, most often a person dies as a result of the simultaneous action of all these effects of exposure. Research in this area is necessary, since the data obtained are needed to assess the consequences of a nuclear war and the effects of large doses of radiation in the event of accidents in nuclear installations and devices.

Red Bone marrow and other elements of the hematopoietic system are most vulnerable to radiation and lose their ability to function normally already at radiation doses of 0.5-1 Gy. Fortunately, they also have a remarkable ability to regenerate, and if the radiation dose is not so high as to cause damage to all cells, hematopoietic system can fully restore its functions. If not the whole body was exposed to radiation, but some part of it. then the surviving brain cells are enough to completely replace the damaged cells.

The reproductive organs and eyes are also highly sensitive to radiation. A single irradiation of the testes at a dose of only 0.1 Gy leads to temporary sterility of men, and doses above two grays can lead to permanent sterility: only many years later the testes will be able to produce full-fledged sperm again. Apparently, the testicles are the only exception to general rule: the total dose of radiation received in several doses is more, not less dangerous for them than the same dose received at one time. The ovaries are much less sensitive to the effects of radiation, at least in adult women. But a single dose of more than three grays still leads to their sterility, although even larger doses with fractional irradiation do not affect the ability to bear children.

The most vulnerable part of the eye to radiation is the lens. Dead cells become opaque, and the growth of cloudy areas leads first to cataracts, and then to complete blindness. The higher the dose, the greater the loss of vision. Cloudy areas can form at radiation doses of 2 Gy or less. A more severe form of eye damage - progressive cataract - is observed at doses of about 5 Gy. It has been shown that even occupational exposure associated with a number of works is harmful to the eyes: doses from 0.5 to 2 Gy received over a period of ten to twenty years lead to an increase in the density and clouding of the lens.

Children are also extremely sensitive to the effects of radiation. Relatively small doses of irradiation of cartilage tissue can slow down or completely stop their bone growth, which leads to abnormalities in the development of the skeleton. How less age child, the more bone growth is inhibited. A total dose of the order of 10 Gy, received over a period of several weeks with daily irradiation, is sufficient to cause some anomalies in the development of the skeleton. Apparently, there is no threshold effect for such action of radiation. It also turned out that irradiation of the child's brain during radiation therapy can cause changes in his character, lead to memory loss, and in very young children even to dementia and idiocy. The bones and brain of an adult are capable of withstanding much higher doses.

The fetal brain is also extremely sensitive to the effects of radiation, especially if the mother is exposed to radiation between the eighth and fifteenth weeks of pregnancy. During this period, the cerebral cortex is formed in the fetus, and there is big risk the fact that as a result of irradiation of the mother (for example, by X-rays), a mentally retarded child will be born. This is how 30 children who were irradiated during the intrauterine development during the atomic bombings of Hiroshima and Nagasaki. Although the individual risk is great, the consequences are particularly distressing. the number of women in this stage of pregnancy at any given time is only a small fraction of the total population. This, however, is the most serious effect of all known effects of irradiation of the human fetus, although after irradiation of fetuses and embryos of animals during their intrauterine development, many others have been discovered. serious consequences including malformations, underdevelopment and death.

Most adult tissues are relatively insensitive to the action of radiation. The kidneys can withstand a total dose of about 23 Gy received over five weeks without much harm, the liver at least 40 Gy per month, the bladder at least 55 Gy per four weeks, and the mature cartilage tissue- up to 70 Gr. The lungs - an extremely complex organ - are much more vulnerable, and in the blood vessels, slight but possibly significant changes can occur already at relatively small doses.

Of course, exposure to therapeutic doses, like any other exposure, can cause future cancer or lead to adverse genetic consequences. Therapeutic doses of radiation, however, are usually used to treat cancer when a person is terminally ill, and since patients are on average quite old, the likelihood that they will have children is also relatively small. However, it is far from easy to estimate how great this risk is at the much lower doses of radiation that people receive in their lives. Everyday life and at work, and in this regard, there are the most different opinions among the public.

Crayfish- the most serious of all the consequences of human exposure at low doses. at least directly to those people. that have been irradiated. Indeed, extensive surveys of some 100,000 survivors of the atomic bombings of Hiroshima and Nagasaki in 1945 have shown that cancer is so far the only cause of excess mortality in this population group.

According to available data, the first in the group cancer that affect the population as a result of exposure are leukemia. They cause death on average ten years after exposure - much earlier than other types of cancer.

The most common cancers caused by radiation were breast cancer and breast cancer. thyroid gland. UNSCEAR estimates that about ten out of a thousand people exposed have thyroid cancer, and ten out of a thousand women have breast cancer (per gray of individual absorbed dose).

However, both types of cancer are in principle treatable, and mortality from thyroid cancer is particularly low.

Lung cancer, on the other hand, is a merciless killer. It also belongs to the common varieties of cancer among exposed populations.

Cancer of other organs and tissues appears to be less common among exposed populations. According to UNSCEAR estimates, the chance of dying from cancer of the stomach or colon is about only 1/1000 for every gray of the average individual dose of radiation, and the risk of cancer of the bone tissue, esophagus. small intestine, Bladder, pancreas, rectum and lymphatic tissues is even smaller and is approximately 0.2 to 0.5 per thousand and per gray of the average individual dose of radiation.

Children are more sensitive to radiation. than adults, and with irradiation of the fetus, the risk of cancer seems to be even greater. Some studies have indeed reported that infant mortality from cancer is higher among children whose mothers were exposed during pregnancy. x-rays, but UNSCEAR is not yet convinced that the cause is correct.

Genetic Consequences of Radiation Their study is associated with even greater difficulties than in the case of cancer. First, very little is known about what damage occurs in the human genetic apparatus during irradiation; secondly, the full identification of all hereditary defects occurs only over many generations; and thirdly. as in the case of cancer, these defects cannot be distinguished from those that arose from completely different causes.

Approximately 10% of all live births have some form of genetic defect, ranging from mild physical handicaps type of color blindness and ending with such serious conditions as Down's syndrome, Huntington's chorea and various malformations. Many of the embryos and fetuses with severe hereditary disorders do not survive to birth; according to available data, about half of all cases of spontaneous abortion are associated with abnormalities in the genetic material. But even if children with hereditary defects are born alive, they are five times less likely to survive to their first birthday than normal children.

Genetic disorders can be classified into two main types: chromosomal aberrations, involving changes in the number or structure of chromosomes, and mutations in the genes themselves.

Gene mutations are further subdivided into dominant (which appear immediately in the first generation) and recessive (which can only appear if the same gene is mutated in both parents; such mutations may not appear for many generations or not be detected at all. ).

Both types of anomalies can lead to hereditary diseases in subsequent generations, or may not appear at all.

Plan Introduction Introduction The concept of "Biological effect of radiation" The concept of "Biological effect of radiation" Direct and indirect effect of radiation Direct and indirect effect of radiation The effect of radiation on individual organs and the body as a whole The effect of radiation on individual organs and the body as a whole Mutations Mutations The effect of large doses of radiation on biological objects The effect of large doses of radiation on biological objects Two types of body exposure: external and internal Two types of body exposure: external and internal How to protect yourself from radiation? How to protect yourself from radiation? The largest radiation accidents and disasters in the world The largest radiation accidents and disasters in the world

Introduction The radiation factor has been present on our planet since its formation. However, the physical effects of radiation began to be studied only in late XIX centuries, and its biological effects on living organisms in the middle of the XX. Radiation refers to those physical phenomena that are not felt by our senses, hundreds of specialists, working with radiation, received radiation burns from high doses of radiation and died from malignant tumors caused by overexposure. However, today world science knows more about the biological effects of radiation than about the effects of any other factors of physical and biological nature in the environment.

The concept of "Biological effect of radiation" And the changes caused in the life and structure of living organisms when exposed to short-wave electromagnetic waves ( x-ray radiation and gamma radiation) or streams of charged particles, beta radiation and neutrons. D=E/m 1Gy=1J/1Kg D - absorbed dose; E is the absorbed energy; m-body weight

When studying the effect of radiation on a living organism, the following features were determined: The effect of ionizing radiation on the body is not perceptible by a person. People do not have a sense organ that would perceive ionizing radiation. The effect of ionizing radiation on the body is not perceptible by a person. People do not have a sense organ that would perceive ionizing radiation. Action from small doses can be summed up or accumulated. Action from small doses can be summed up or accumulated. Radiation acts not only on a given living organism, but also on its offspring - the so-called genetic effect. Radiation acts not only on a given living organism, but also on its offspring - the so-called genetic effect. Various organs of a living organism have their own sensitivity to radiation. With a daily dose of 0.002-0.005 Gy, changes in the blood already occur. Various organs of a living organism have their own sensitivity to radiation. With a daily dose of 0.002-0.005 Gy, changes in the blood already occur. Not every organism as a whole perceives radiation in the same way. Not every organism as a whole perceives radiation in the same way. Irradiation is frequency dependent. Irradiation is frequency dependent. A single high-dose irradiation causes more profound consequences than fractionated irradiation. A single high-dose irradiation causes more profound consequences than fractionated irradiation.

Direct and indirect action of radiation Radio waves, light waves, thermal energy of the sun are all varieties of radiation. The action of radiation occurs at the atomic or molecular level, regardless of whether we are exposed to external radiation, or receive radioactive substances from food and water, which upsets the balance biological processes in the body and lead to adverse effects. The energy directly transferred to the atoms and molecules of biological tissues is called the direct action of radiation. Some cells, due to the uneven distribution of radiation energy, will be significantly damaged. In addition to direct irradiation, indirect or indirect action associated with the radiolysis of water.

direct action radiation One of the direct effects is carcinogenesis or the development of oncological diseases. Cancer tumor occurs when somatic cell gets out of control of the body and begins to actively divide. Getting into the cells, the radiation disrupts the balance of calcium and the coding of genetic information. Such phenomena can lead to malfunctions in protein synthesis, which is vital. important function of the whole organism, tk. defective proteins disrupt the immune system. Our body, in contrast to the processes described above, produces special substances that are a kind of "cleaners".

Indirect effect of radiation In addition to direct ionizing radiation, there is also an indirect or indirect effect associated with the radiolysis of water. During radiolysis, free radicals arise - certain atoms or groups of atoms that have high chemical activity. If the number of free radicals is low, then the body has the ability to control them. If there are too many of them, then the work of protective systems, the vital activity of individual functions of the body, is disrupted. Damage caused by free radicals increases rapidly in a chain reaction.

Impact of radiation on individual organs and the body as a whole In the structure of the body, two classes of systems can be distinguished: control (nervous, endocrine, immune) and life-supporting (respiratory, cardiovascular, digestive). The interaction of radiation with the body begins at the molecular level. Direct impact ionizing radiation, therefore, is more specific. An increase in the level of oxidizing agents is also characteristic of other influences. The radiosensitivity of an organism depends on its age. Small doses of radiation in children can slow or even stop their bone growth. The younger the child, the more skeletal growth is inhibited.

Mutations Every cell in the body contains a DNA molecule that carries the information for the correct reproduction of new cells. DNA is a deoxyribonucleic acid composed of long, rounded double helix molecules. Its function is to ensure the synthesis of most of the protein molecules that make up amino acids.

Radiation can either kill the cell or distort the information in the DNA so that defective cells eventually appear. Change genetic code cells are called mutations. A mutation that occurs in a germ cell is called a genetic mutation and can be passed on to subsequent generations. Permissible doses exposures were established long before the advent of methods to establish those sad consequences to which they can lead unsuspecting people and their descendants.

The effect of large doses of radiation on biological objects A living organism is very sensitive to the action of ionizing radiation. The higher a living organism is on the evolutionary ladder, the more radio sensitive it is. The "survival" of a cell after irradiation simultaneously depends on a number of factors: on the volume of genetic material, the activity of energy-supplying systems, the ratio of enzymes, and the intensity of formation of free radicals H and OH. The human body, as a perfect natural system, is even more sensitive to radiation. If a person has undergone general exposure to a dose of rad, then after a few days he will have signs radiation sickness in mild form. Large doses with prolonged exposure can cause irreversible damage individual bodies or the whole organism.

Two types of irradiation of the body: external and internal Radiation can affect a person in two ways. The first way is external exposure from a source located outside the body, which mainly depends on the radiation background of the area where the person lives or on other external factors. The second is internal exposure due to the ingestion of a radioactive substance into the body, mainly with food. External and internal exposure require different precautions to be taken against dangerous action radiation.

How to protect yourself from radiation? Time protection. the shorter the time spent near the radiation source, the lower the radiation dose received from it. Time protection. the shorter the time spent near the radiation source, the lower the radiation dose received from it. Protection by distance is that the radiation decreases with distance from a compact source. That is, if at a distance of 1 meter from a radiation source, the dosimeter shows 1000 microroentgens per hour, then at a distance of 5 meters it is about 40 microroentgens per hour, which is why radiation sources are often so difficult to detect. On the long distances they are “not caught”, you need to clearly know the place where to look. Protection by distance is that the radiation decreases with distance from a compact source. That is, if at a distance of 1 meter from a radiation source, the dosimeter shows 1000 microroentgens per hour, then at a distance of 5 meters it is about 40 microroentgens per hour, which is why radiation sources are often so difficult to detect. At long distances, they are “not caught”, you need to clearly know the place where to look. Substance protection. It is necessary to strive to ensure that there is as much space as possible between you and the source of radiation. more substance. The denser it is and the larger it is, the greater the part of the radiation that it can absorb. Substance protection. It is necessary to strive to ensure that there is as much substance as possible between you and the source of radiation. The denser it is and the larger it is, the greater the part of the radiation that it can absorb.

The largest radiation accidents and disasters in the world On the night of April 25-26, 1986 at the fourth block Chernobyl nuclear power plant(Ukraine) the largest nuclear accident in the world, with partial destruction of the reactor core and the release of fission fragments outside the zone. According to experts, the accident occurred due to an attempt to do an experiment to remove extra energy during the operation of the main nuclear reactor.

190 tons of radioactive substances were released into the atmosphere. 8 out of 140 tons of radioactive fuel from the reactor ended up in the air. Other dangerous substances continued to leave the reactor as a result of a fire that lasted almost two weeks. People in Chernobyl were exposed to 90 times more radiation than when the bomb fell on Hiroshima. As a result of the accident, radioactive contamination occurred within a radius of 30 km. An area of ​​160,000 square kilometers has been polluted. The northern part of Ukraine, Belarus and the west of Russia were affected. 19 Russian regions with a territory of almost 60 thousand square kilometers and a population of 2.6 million people.

On March 11, 2011, Japan was hit by the most powerful earthquake in the history of the country. As a result, a turbine was destroyed at the Onagawa nuclear power plant, a fire broke out, which was quickly eliminated. At the Fukushima-1 nuclear power plant, the situation is very serious - as a result of the shutdown of the cooling system, nuclear fuel melted in the reactor of block 1, a radiation leak was recorded outside the block, and evacuation was carried out in a 10-kilometer zone around the nuclear power plant.

An incredible tragedy in Hiroshima and Nagasaki, then a horrific accident in the Ukrainian Chernobyl. These events clearly demonstrated to the whole world how terrible and dangerous the effects of radiation on humans are. The consequences shocked the population of the entire globe. To date, in addition to the natural radiation of the Earth, we are affected by weak radiation and the danger associated with it from many objects around us: household appliances, power lines, X-ray equipment, mobile phones and other gadgets.

The radiation background has been present on Earth since the development of life. To control its value, units are used - micro Roentgen, Roentgen, Sievert and others. Scientists began to study its effect on organisms only in the 20th century. A special danger of ionization radiation is that it is dangerous to all organs and every cell of the body.

People whose work is connected with the study or who have fallen under its influence for other reasons often die from overexposure, the development of malignant tumors, and radiation burns. Radiation cannot be seen, you can only feel its effect on yourself after some time, noting the characteristic signs.

The effect of radiation on living organisms

A single dose of radiation acceptable for a person is an indicator of up to 0.05 Sievert. In this case, there is no negative effect on a person and a health hazard. If irradiation is received in the range from 0.05 to 0.2 Sv, then a person's risk of developing cancer increases several times.

The lethal dose is already considered to be from 1 to 2 Sv, but depending on the conditions of human exposure, the body can live from several months to a year. Instant death occurs when 10 Sv of radiation is received.

The study of ionization radiation made it possible to reveal the following features:

Radiation received in small doses gradually accumulates in the body;
after radiation, a person may not immediately show symptoms of radiation damage, because it passes " incubation period". The greater the dose of radiation received, the shorter this period;
the effect of radiation on living organisms is also dangerous in that it manifests itself in future offspring;
irreversible changes in the composition of the blood occur already at a dose of 0.002-0.005 Gy per day.

Consequences of radiation exposure in the human body

Each organ and tissue of the human body is differently susceptible to the doses received. The most vulnerable are the lungs, bone marrow, gonads, because it is here that the fastest cell division occurs. This is followed by the stomach, liver, esophagus, thyroid gland and skin. The biological impact is manifested by two groups of changes:

Somatic (bodily) - occur directly in the person who received the dose;

Genetic - appear in the offspring of a person affected by radiation.
The very first after radiation exposure suffers the immune system.

Human body becomes weakened, defenseless against the attack of viruses and infections. The thyroid gland stores about 30% of total number decay products of radionuclides.

Irradiation leads to radiation sickness, as a result of which the natural, the right process cell division. This leads to excessive growth and enlargement of tissues and organs, the formation of malignant tumors. From the dose received, the hair on the head and on the body falls out in a person, and the victim himself feels weakness, nausea, and a general deterioration in well-being.

Terrible consequences for the living from radiation after the explosion of a nuclear bomb

It has already been said above that receiving large doses of radiation has a destructive effect on cells and leads to consequences that are truly terrifying. This is evidenced by the number of victims after the dropped atomic bombs on Hiroshima and Nagasaki.

80 thousand inhabitants who were destined to be in Hiroshima at the epicenter of the explosion atomic bomb, just evaporated in a fraction of a second from high temperature. The bodies charred in seconds covered the territory of almost the entire city, and the hands of the clock everywhere froze at 8.15. Five years later, 160 thousand deaths were already announced, and today total The death toll in Hiroshima is estimated at 200,000 people. In Nagasaki, at the time of the explosion, 65 thousand people were killed, and five years later this figure increased to 140 thousand, taking into account all those who suffered from exposure.

An unbearably bright flash was accompanied by a powerful blast wave, suffocating and killing absolutely everything in its path. Those who managed to survive in these hellish conditions faced the first signs of radiation sickness within a few hours. Her symptoms and features at that time were poorly studied, therefore a huge number medicine has not been able to help people.

Consequences of the explosion at the Chernobyl nuclear power plant

At the time of the disaster, 2 employees died, within a few months another 32 people died from exposure. Over the course of 15 years, about a hundred people died after receiving a dose of radiation. Almost 62,000 liquidators with a high level of exposure acquired cancer.

At that time, not all rescuers had devices to measure the level of radiation. People were not immediately evacuated from the dangerous region. No one reported the threat of the most dangerous infection in a timely manner, fearing panic in society. To this day, talk has not subsided that the number of victims in Chernobyl after the explosion of a nuclear reactor could be significantly reduced.

Modern scientific data confirm the existence of mechanisms that ensure the adaptation of the body to natural levels of radiation exposure. However, if a certain level of NRF is exceeded, adaptation will be defective with one or another probability of development. pathological condition. lasting impact increased NRF leads to a decrease in radioresistance, to disturbances in immunological reactivity, and morbidity is associated with the latter.

After the accident at the Chernobyl nuclear power plant, the proportion of healthy people among the evacuated population decreased from 57 to 23%. The consequences of this accident affect the health of the children's population in the most negative way. The incidence of children affected by radiation exposure is 2-3 times higher, the proportion of frequently ill children with reduced immune status(82.6%), most of them have allergies, there is also an increase in the number somatic diseases. In the villages of the Totsky district of the Orenburg region, on the territory close to the test site, the prevalence of vegetative dystonia, pathology of the thyroid gland, pregnancy. The proportion of practically healthy children in these villages is 6-7%, with 15% in the control region; 50% of children have deviations of cardio-vascular system, diseases of the nervous system, as well as immunodeficiencies (20-30% of children with 7-8% in the control area), in the hair, the content of manganese - 7, copper - 8, arsenic - 20 times higher than normal.

The main biological effect of radiation is damage to the cell genome, which is manifested by an increase in the number of neoplasms and hereditary diseases.

Small doses of radiation increase the likelihood of cancer in humans. It is assumed that about 10% of oncological diseases per year are caused by ERF. Those forms of cancer that are caused by radiation can be induced by other agents. As a consequence of the disaster at the Chernobyl nuclear power plant, the radiation impact on thyroid gland the inhabitants of Russia. Retrospective and current analysis of the incidence of thyroid cancer in children and adolescents Bryansk region showed that the first clinical manifestations were noted 4-5 years after the accident, which corresponds to the minimum period for the development of oncopathology after irradiation. The natural distribution of thyroid cancer is no more than 1 case per 1 million children and adolescents. The dynamics of the number of cases of thyroid cancer in children in the Bryansk region is indicative: 1987. - one; 1988 – 0; 1989 – 0; 1990 - four; 1991 - four; 1992 - eight; 1993 - 12; 1994 – 19 cases. Approximately 50% of children and adolescents diagnosed with thyroid cancer lived in an area with high levels radioactive contamination soil. According to prognostic estimates, in 20 and 40 years after the accident, every fourth case of thyroid cancer will be due to radiation.

Radon is potentially dangerous to humans. A significant part of its decay products is retained in the lungs. The surface of the lungs is several square meters. it good filter, depositing radioactive aerosols, which thus cover the pulmonary surface. Radioactive isotopes of polonium (a decay product of radon) "shell" the surface of the lungs with alpha particles and cause over 97% of the dose associated with radon. The main medical and biological effect of high concentrations of radon is lung cancer. in the mines increased content radon significantly increases the frequency of death of miners from lung cancer, and the dependence is linear and non-threshold. Calculations show that with an average concentration of radon in residential buildings of 20-25 Bq/m 3, one out of three hundred people living today will die from lung cancer caused by radon.

Recognizing adaptation to NRF as one of the obligatory conditions of life on Earth, it is impossible to deny the influence of elevated levels on heredity. Elevated levels of NRF lead to an increase in malformations in newborns in mountainous areas, in areas with igneous rocks. The results of experiments on animals and cell cultures convince that mutations under the influence of radiation (mutational consequences, which are expressed in the preservation of genetic damage and the occurrence of instability of the chromosomal apparatus) can be transmitted to future generations. The probability of hereditary defects is lower than the probability of cancer, and increases with increasing dose of exposure to the number of persons in the entire population exposed to radiation, and the number of marriages between exposed persons. Experts estimate that a NRF of 2 mSv probably causes 0.1-2% of all genetic mutations. With the growth of its level, this percentage increases.

Thus, the recognition of the NRF as an obligate factor in the environment of existence, under the conditions of which it arose, developed and exists biological life, allows us to speak about the existence of an optimal level of NRF for life. Wide range of radiosensitivity characteristic of different groups population, their adaptation to different levels NRF - all this suggests the existence of a wide transitional range from medium to high levels of NRF.

Preventive actions

Identification and study of the mechanisms of interaction of radiation factors with the human body, including the study of the patterns of the body's response to the radiation effect of background and elevated levels in specific environmental conditions, is possible only with the accumulation of actual data. In our country, the Unified State System for Accounting and Controlling Individual Exposure Doses of Citizens (ESKID) operates. It is based on permanent monitoring of natural background radiation levels, control of medical exposure doses and accounting for individual exposure doses of personnel working with sources of ionizing radiation.

Standards have been created for the use of natural building materials and production waste in construction. As such standards for materials used in the construction of residential buildings and public buildings, the values ​​of the effective concentration of radionuclides of 370 Bq/kg were proposed. Not a single construction can be started without a survey of the soil and building materials; everything that is being built must undergo mandatory control for radioactivity, including radon, with the issuance of an appropriate conclusion. Standards have been established that regulate the content of radon in residential premises: the average annual equilibrium activity of radon in newly constructed buildings should not exceed 100 Bq/m 3 , and in old buildings - 200 Bq/m 3 . If the concentration of radon is more than 200 Bq/m 3, then in these buildings it is necessary to take measures to reduce its concentration (ventilation of basements, decorative repairs with wallpapering the walls and ceilings, covering the floors with parquet, carpeting, etc.). The concentration of radon in the premises of 400 Bq/m 3 and above requires the relocation of residents and the re-profiling of the building. In industrial buildings, the admissible activity of radon is 310 Bq/m 3 .

In order to reduce the levels of the radiation background of the biosphere, it is necessary to purposefully and consistently carry out the entire complex of health-improving environmental measures (technological, sanitary-technical, organizational, architectural and planning).

The concept of stage-by-stage specialized medical examination of the population living in the territory contaminated with radionuclides has also been developed. It provides for the assessment of the state of health according to clinical and laboratory data; clarification of diagnoses of diseases that may be associated with exposure to radiation; verification of information on radiation doses; individual medical and dosimetric investigation of the relationship of diseases with radiation exposure; treatment and rehabilitation.

The established Russian Scientific Commission on Radiation Protection (RNZ) assumes A complex approach on radiation protection and rehabilitation of the population, i.e. creation and development social protection population and prevention of possible adverse effects for the health of the population exposed elevated levels the action of radiation.

It is important to eliminate the environmental illiteracy of society, including the formation of environmental thinking on radiation safety issues. Qualified informational assistance is needed, including from medical workers, on prevention radiophobia at the population.