Passing through matter, all kinds ionizing radiation cause ionization, excitation and decay of molecules. A similar effect is observed during irradiation of the human body. Since the bulk (70%) of the body is water, its damage during irradiation is carried out through the so-called indirect impact: first, the radiation is absorbed by water molecules, and then ions, excited molecules and fragments of decayed molecules enter into chemical reactions With biological substances that make up the human body, causing their damage. In the case of irradiation with neutrons, radionuclides can be additionally formed in the body due to the absorption of neutrons by the nuclei of the elements contained in the body.
Penetrating into the human body, ionizing radiation can cause serious illness. The physical, chemical and biological transformations of a substance during the interaction of ionizing radiation with it are called radiation effect, which can lead to such serious diseases as radiation sickness, leukemia (leukemia), malignant tumors, skin diseases. There may also be genetic consequences leading to hereditary diseases.
Ionization of living tissue leads to the breaking of molecular bonds and changes in the chemical structure of compounds. Changes in the chemical composition of molecules lead to cell death. In living tissue, water is split into atomic hydrogen and a hydroxyl group, which form new chemical compounds that are not characteristic of healthy tissue. As a result of the changes that have taken place, the normal course biochemical processes and metabolism are disturbed.
Irradiation of the human body can be external and internal. At external exposure, which is created by sealed sources, dangerous radiation with high penetrating power. Internal exposure occurs when radioactive substances enter the body by inhalation of air contaminated with radioactive elements, through the digestive tract (through eating, contaminated water and smoking) and in rare cases through the skin. The body is exposed to internal radiation until the radioactive substance decays or is excreted as a result of physiological metabolism, therefore, radioactive isotopes with a long half-life and intense radiation pose the greatest danger. The nature of the injuries and their severity are determined by the absorbed radiation energy, which primarily depends on the absorbed dose rate, as well as on the type of radiation, the duration of exposure, the biological characteristics and size of the irradiated part of the body, and the individual sensitivity of the organism.
When exposed different types radioactive emissions on living tissues, the penetrating and ionizing abilities of radiation are decisive. Penetrating power of radiation characterized run length 1– the thickness of the material required to absorb the flow. For example, the path length of alpha particles in living tissue is several tens of micrometers, and in air it is 8–9 cm. Therefore, during external irradiation, the skin protects the body from the effects of alpha and soft beta radiation, the penetrating power of which is low.
Different types of radiation at the same values of the absorbed dose cause different biological damage.
Illnesses caused by radiation can be acute or chronic. Acute lesions occur when irradiated with large doses in a short time. Very often, after recovery, early aging sets in, and previous diseases become aggravated. Chronic lesions ionizing radiation are both general and local. They always develop in a latent form as a result of systematic irradiation with doses exceeding the maximum allowable, obtained both during external exposure and when ingested. radioactive substances.
The danger of radiation injury largely depends on which organ has been exposed to radiation. According to the selective ability to accumulate in individual critical organs (with internal exposure), radioactive substances can be divided into three groups:
- - tin, antimony, tellurium, niobium, polonium, etc. are evenly distributed in the body;
- - lanthanum, cerium, actinium, thorium, etc. accumulate mainly in the liver;
- - uranium, radium, zirconium, plutonium, strontium, etc. accumulate in the skeleton.
The individual sensitivity of the body affects at low doses of radiation (less than 50 mSv/year), with increasing doses it manifests itself to a lesser extent. The body is most resistant to radiation at the age of 25–30 years. Disease nervous system and internal organs reduces the body's resistance to radiation.
When determining radiation doses, the main data are data on the quantitative content of radioactive substances in the human body, and not data on their concentration in the environment.
Details Views: 7330Under normal conditions, each person is continuously exposed to ionizing radiation as a result of cosmic radiation, as well as due to the radiation of natural radionuclides found in the earth, food, plants and in the human body itself.
The level of natural radioactivity caused by the natural background is low. This level of exposure is familiar to the human body and is considered harmless to it.
Technogenic exposure comes from man-made sources both under normal and emergency conditions.
Various types of radioactive radiation can cause certain changes in the tissues of the body. These changes are associated with the ionization of atoms and molecules of cells of a living organism that occurs during irradiation.
Working with radioactive substances in the absence of appropriate protective measures can lead to exposure to doses that have a harmful effect on the human body.
Contact with ionizing radiation poses a serious danger to humans. The degree of danger depends both on the magnitude of the absorbed radiation energy and on the spatial distribution of the absorbed energy in the human body.
The radiation hazard depends on the type of radiation (radiation quality factor). Heavy charged particles and neutrons are more dangerous than x-rays and gamma rays.
As a result of the impact of ionizing radiation on the human body, complex physical, chemical and biological processes can occur in the tissues. Ionizing radiation causes the ionization of the molecules and atoms of a substance, as a result of which the molecules and cells of the tissue are destroyed.
The ionization of living tissues is accompanied by the excitation of cell molecules, which leads to the breaking of molecular bonds and to a change in the chemical structure. various connections.
It is known that 2/3 of the total composition of human tissue is water. In this regard, the processes of ionization of living tissue are largely determined by the absorption of radiation by water cells, the ionization of water molecules.
The hydrogen (H) and hydroxyl group (OH) formed as a result of water ionization directly or through a chain of secondary transformations form products with high chemical activity: hydrated oxide (H02) and hydrogen peroxide (H202), which have pronounced oxidizing properties and high toxicity to to the fabric. Entering into compounds with molecules organic matter, and above all with proteins, they form new chemical compounds that are not characteristic of healthy tissue.
When irradiated with neutrons, radioactive substances can be formed in the body from the elements contained in it, forming induced activity, i.e., radioactivity created in the substance as a result of exposure to neutron fluxes.
Ionization of living tissue, depending on the radiation energy, mass, electric charge and ionizing ability of radiation, leads to the breaking of chemical bonds and changes in the chemical structure of various compounds that make up tissue cells.
In turn, changes in the chemical composition of the tissue, resulting from the destruction of a significant number of molecules, lead to the death of these cells. Moreover, many radiations penetrate very deeply and can cause ionization and, consequently, damage to cells in deeply located parts of the human body.
As a result of exposure to ionizing radiation, the normal course of biological processes and metabolism in the body are disrupted.
Depending on the radiation dose and duration of exposure and on individual characteristics organism, these changes can be reversible, in which the affected tissue restores its functional activity, or irreversible, which will lead to damage to individual organs or the whole organism. Moreover, the greater the dose of radiation, the greater its impact on the human body. It was noted above that along with the processes of damage to the body by ionizing radiation, protective and restorative processes also occur.
The duration of exposure has big influence on the effect of irradiation, and it should be considered that not even the dose, but the dose rate of irradiation is of decisive importance. With increasing dose rate damaging effect increases. Therefore, the fractional exposure to lower doses of radiation is less detrimental than receiving the same dose of radiation during a single exposure to the total dose of radiation.
The degree of damage to the body by ionizing radiation increases with an increase in the size of the irradiated surface. The impact of ionizing radiation is different depending on which organ is exposed to radiation.
The type of radiation affects the destructive ability of radiation when exposed to organs and tissues of the body. This influence takes into account the weighting factor for a given type of radiation, which was noted earlier.
The individual characteristics of the organism are strongly manifested at low doses of radiation. With an increase in the radiation dose, the influence of individual characteristics becomes insignificant.
A person is most resistant to radiation between the ages of 25 and 50. Young people are more sensitive to radiation than middle-aged people.
The biological effect of ionizing radiation largely depends on the state of the central nervous system and internal organs. Nervous diseases, as well as diseases of the cardiovascular system, hematopoietic organs, kidneys, endocrine glands reduce a person's endurance to radiation.
Features of the impact of radioactive substances that have entered the body are associated with the possibility of their long-term presence in the body and direct effects on internal organs.
Radioactive substances can enter the human body by inhalation of air contaminated with radionuclides, through the digestive tract (when eating, drinking, smoking), through damaged and undamaged skin.
Gaseous radioactive substances (radon, xenon, krypton, etc.) easily penetrate through the respiratory tract, are quickly absorbed, causing a general lesion. Gases are relatively quickly excreted from the body, most of them are excreted through the respiratory tract.
Penetration into the lungs of dispersed radioactive substances depends on the degree of dispersion of the particles. Particles larger than 10 microns, as a rule, are retained in the nasal cavity and do not penetrate into the lungs. Particles less than 1 micron in size, which are inhaled into the body, are removed with air when exhaled.
The degree of danger of damage depends on the chemical nature of these substances, as well as on the rate of excretion of the radioactive substance from the body. Less dangerous radioactive substances:
quickly circulating in the body (water, sodium, chlorine, etc.) and not lingering in the body for a long time;
not absorbed by the body;
not forming compounds that make up tissues (argon, xenon, krypton, etc.).
Some radioactive substances are almost not excreted from the body and accumulate in it, while some of them (niobium, ruthenium, etc.) are evenly distributed in the body, others are concentrated in certain organs (lanthanum, actinium, thorium - in the liver, strontium, uranium, radium - in bone tissue), leading to their rapid damage.
When evaluating the effect of radioactive substances, one should also take into account their half-life and the type of radiation. Substances with a short half-life quickly lose activity and are therefore less dangerous.
Each dose of radiation leaves a deep trace in the body. One of the negative properties of ionizing radiation is its total, cumulative effect on the body.
The cumulative effect is especially strong when radioactive substances deposited in certain tissues enter the body. At the same time, being present in the body day after day for a long time, they irradiate nearby cells and tissues.
There are the following types of irradiation:
chronic (permanent or intermittent action of ionizing radiation for a long time);
acute (single, short-term radiation exposure);
general (radiation of the whole body);
local (irradiation of a part of the body).
The result of exposure to ionizing radiation both with external and internal exposure depends on the dose of exposure, duration of exposure, type of exposure, individual sensitivity and the size of the irradiated surface. With internal irradiation, the effect of exposure depends, in addition, on the physicochemical properties of radioactive substances and their behavior in the body.
On a large experimental material with animals, as well as by summarizing the experience of people working with radionuclides in in general terms It was found that when a person is exposed to certain doses of ionizing radiation, they do not cause significant irreversible changes in the body. Such doses are called limiting.
Dose limit - the value of the effective annual or equivalent dose of technogenic exposure, which should not be exceeded under normal operating conditions. Compliance with the annual dose limit prevents the occurrence of deterministic effects, while maintaining the probability of stochastic effects at an acceptable level.
Deterministic effects of radiation - clinically detectable harmful biological effects caused by ionizing radiation, in relation to which it is assumed that there is a threshold, below which there is no effect, and above - the severity of the effect depends on the dose.
Stochastic effects of radiation are harmful biological effects caused by ionizing radiation that do not have a dose threshold of occurrence, the probability of occurrence of which is proportional to the dose and for which the severity of manifestation does not depend on the dose.
In connection with the foregoing, the issues of protecting workers from the harmful effects of ionizing radiation are of a versatile nature and are regulated by various legal acts.
51. Ionizing radiation. Types of ionizing radiation, main characteristics.
AI are divided into 2 types:
Corpuscular radiation
- 𝛼-radiation is a stream of helium nuclei emitted by a substance during radioactive decay or during nuclear reactions;
- 𝛽-radiation - a stream of electrons or positrons arising from radioactive decay;
Neutron radiation (With elastic interactions, the usual ionization of matter occurs. With inelastic interactions, secondary radiation occurs, which can consist of both charged particles and quanta).
2. Electromagnetic radiation
- 𝛾-radiation is electromagnetic (photon) radiation emitted during nuclear transformations or interaction of particles;
X-ray radiation - occurs in the environment surrounding the radiation source, in x-ray tubes.
AI characteristics: energy (MeV); speed (km/s); mileage (in air, in living tissue); ionizing capacity (pair of ions per 1 cm path in air).
The lowest ionizing ability of α-radiation.
Charged particles lead to direct, strong ionization.
Activity (A) of a radioactive substance is the number of spontaneous nuclear transformations (dN) in this substance in a short period of time (dt):
1 Bq (becquerel) is equal to one nuclear transformation per second.
52. Ionizing radiation. Doses of ionizing radiation and units of their measurement.
Ionizing radiation (IR) is radiation, the interaction of which with the medium leads to the formation of charges of opposite signs. Ionizing radiation occurs during radioactive decay, nuclear transformations, as well as during the interaction of charged particles, neutrons, photon (electromagnetic) radiation with matter.
Radiation dose is the value used to assess exposure to ionizing radiation.
Exposure dose(characterizes the radiation source by the ionization effect):
Exposure dose at the workplace when working with radioactive substances:
where A is the activity of the source [mCi], K is the gamma constant of the isotope [Rcm2/(hmCi)], t is the exposure time, r is the distance from the source to the workplace [cm].
Dose rate(irradiation intensity) - the increment of the corresponding dose under the influence of this radiation per unit. time.
Exposure dose rate [rh -1 ].
Absorbed dose shows how much AI energy is absorbed by the unit. masses of the irradiated in-va:
D absorption = D exp. K 1
where K 1 - coefficient taking into account the type of irradiated substance
Absorption dose, Gray, [J/kg]=1Gy
Dose equivalent characterized by chronic exposure to radiation of arbitrary composition
H = D Q [Sv] 1 Sv = 100 rem.
Q is a dimensionless weighting factor for a given type of radiation. For X-ray and -radiation Q=1, for alpha-, beta-particles and neutrons Q=20.
Effective equivalent dose character sensitivity decomp. organs and tissues to radiation.
Irradiation of inanimate objects - Absorb. dose
Irradiation of living objects - Equiv. dose
53. The effect of ionizing radiation(AI) on the body. External and internal exposure.
The biological effect of AI is based on the ionization of living tissue, which leads to the breaking of molecular bonds and a change in the chemical structure of various compounds, which leads to a change in the DNA of cells and their subsequent death.
Violation of the vital processes of the body is expressed in such disorders as
Inhibition of the functions of the hematopoietic organs,
Violation of normal blood clotting and increased fragility of blood vessels,
Disorder of the gastrointestinal tract,
Decreased resistance to infections
Depletion of the body.
External exposure occurs when the source of radiation is outside the human body and there are no ways for them to get inside.
Internal exposure origin when the source of AI is inside a person; while the internal Irradiation is also dangerous due to the proximity of the IR source to organs and tissues.
threshold effects (Н > 0.1 Sv/year) depend on the IR dose, occur with lifetime exposure doses
Radiation sickness is a disease that is characterized by symptoms that occur when exposed to AI, such as a decrease in hematopoietic ability, gastrointestinal upset, and a decrease in immunity.
The degree of radiation sickness depends on the radiation dose. The most severe is the 4th degree, which occurs when exposed to AI with a dose of more than 10 Gray. Chronic radiation injuries are usually caused by internal exposure.
Non-threshold (stochastic) effects appear at doses of H<0,1 Зв/год, вероятность возникновения которых не зависит от дозы излучения.
Stochastic effects include:
Somatic changes
Immune changes
genetic changes
The principle of rationing – i.e. non-exceeding of permissible limits individual. Radiation doses from all AI sources.
Justification principle – i.e. prohibition of all types of activity on the use of AI sources, in which the benefit received for a person and society does not exceed the risk of possible harm caused in addition to natural radiation. fact.
Optimization principle - maintenance at the lowest possible and achievable level, taking into account the economic. and social individual factors. exposure doses and the number of exposed persons when using an AI source.
SanPiN 2.6.1.2523-09 "Norms radiation safety».
In accordance with this document, 3 gr. persons:
gr.A - these are faces, for sure. working with man-made sources of AI
gr .B - these are persons, conditions for the work of the cat nah-Xia in the immediate. breeze from the AI source, but deyat. these persons immediately. is not connected with the source.
gr .V is the rest of the population, incl. persons gr. A and B outside of their production activities.
The main dose limit is set. by effective dose:
For persons gr.A: 20mSv per year on Wed. for the next 5 years, but not more than 50 mSv in year.
For persons group B: 1mSv per year on Wed. for the next 5 years, but not more than 5 mSv in year.
For persons group B: should not exceed ¼ of the values for personnel group A.
In case of an emergency caused by a radiation accident, there is a so-called. peak increased exposure, cat. is allowed only in those cases when it is not possible to take measures excluding harm to the body.
The use of such doses can be justified only by saving lives and preventing accidents, additional only for men over 30 years of age with a voluntary written agreement.
AI protection m/s:
Qty protection
time protection
Distance protection
Zoning
Remote control
Shielding
For protection againstγ -radiation: metallic screens made with a large atomic weight (W, Fe), as well as from concrete, cast iron.
For protection against β-radiation: materials with a low atomic mass (aluminum, plexiglass) are used.
For protection against α-radiation: use metals containing H2 (water, paraffin, etc.)
Screen thickness К=Ро/Рdop, Ро – power. dose, measured per rad. place; Rdop - maximum allowable dose.
Zoning - division of the territory into 3 zones: 1) shelter; 2) objects and premises in which people can find; 3) zone post. stay of people.
Dosimetric control based on isp-ii trace. methods: 1. Ionization 2. Phonographic 3. Chemical 4. Calorimetric 5. Scintillation.
Basic appliances , used for dosimetric. control:
X-ray meter (for measuring powerful exp. doses)
Radiometer (to measure AI flux density)
Individual. dosimeters (for measuring exposure or absorbed dose).
ionizing radiation is any radiation that causes ionization of the medium , those. the flow of electric currents in this environment, including in the human body, which often leads to cell destruction, changes in blood composition, burns and other serious consequences.
Sources of ionizing radiation
Sources of ionizing radiation are radioactive elements and their isotopes, nuclear reactors, charged particle accelerators, etc. X-ray installations and high-voltage direct current sources are sources of x-ray radiation. It should be noted here that in the normal mode of their operation, the radiation hazard is negligible. It occurs when an emergency occurs and can manifest itself for a long time in the event of radioactive contamination of the area.
The population receives a significant part of the exposure from natural sources of radiation: from space and from radioactive substances located in the earth's crust. The most significant of this group is the radioactive gas radon, which occurs in almost all soils and is constantly released to the surface, and most importantly, penetrating into industrial and residential premises. It almost does not manifest itself, as it is odorless and colorless, which makes it difficult to detect.
Ionizing radiation is divided into two types: electromagnetic (gamma radiation and X-ray radiation) and corpuscular, which is a- and β-particles, neutrons, etc.
Types of ionizing radiation
Ionizing radiation is called radiation, the interaction of which with the medium leads to the formation of ions of various signs. The sources of these radiations are widely used in nuclear power engineering, engineering, chemistry, medicine, agriculture, etc. Working with radioactive substances and sources of ionizing radiation poses a potential threat to the health and life of people involved in their use.
There are two types of ionizing radiation:
1) corpuscular (α- and β-radiation, neutron radiation);
2) electromagnetic (γ-radiation and X-ray).
alpha radiation- this is the flow of nuclei of helium atoms emitted by matter during the radioactive decay of matter or during nuclear reactions. A significant mass of α-particles limits their speed and increases the number of collisions in matter, so α-particles have a high ionizing ability and low penetrating power. The range of α-particles in air reaches 8÷9 cm, and in living tissue - several tens of micrometers. This radiation poses no danger as long as the radioactive substances emitting a- particles will not enter the body through a wound, with food or inhaled air; then they become extremely dangerous.
Beta radiation- This is the flow of electrons or positrons arising from the radioactive decay of nuclei. Compared to α-particles, β-particles have a much smaller mass and a lower charge, therefore, β-particles have a higher penetrating power than α-particles, and the ionizing power is lower. The range of β-particles in air is 18 m, in living tissue - 2.5 cm.
neutron radiation- this is a stream of nuclear particles that do not have a charge, emitted from the nuclei of atoms during some nuclear reactions, in particular during the fission of uranium and plutonium nuclei. Depending on the energy, there are slow neutrons(with energy less than 1 keV), intermediate energy neutrons(from 1 to 500 keV) and fast neutrons(from 500 keV to 20 MeV). During the inelastic interaction of neutrons with the nuclei of atoms of the medium, secondary radiation arises, consisting of both charged particles and γ-quanta. The penetrating power of neutrons depends on their energy, but it is much higher than that of α-particles or β-particles. For fast neutrons, the path length in air is up to 120 m, and in biological tissue - 10 cm.
Gamma radiation is an electromagnetic radiation emitted during nuclear transformations or interaction of particles (10 20 ÷10 22 Hz). Gamma radiation has a low ionizing effect, but a high penetrating power and propagates at the speed of light. It freely passes through the human body and other materials. This radiation can only be blocked by a thick lead or concrete slab.
x-ray radiation also represents the electromagnetic radiation arising from the deceleration of fast electrons in matter (10 17 ÷10 20 Hz).
The concept of nuclides and radionuclides
The nuclei of all isotopes of chemical elements form a group of "nuclides". Most nuclides are unstable, i.e. they turn into other nuclides all the time. For example, an atom of uranium-238 occasionally emits two protons and two neutrons (a-particles). Uranium turns into thorium-234, but thorium is also unstable. Ultimately, this chain of transformations ends with a stable lead nuclide.
The spontaneous decay of an unstable nuclide is called radioactive decay, and such a nuclide itself is called a radionuclide.
With each decay, energy is released, which is transmitted further in the form of radiation. Therefore, it can be said that, to a certain extent, the emission of a particle consisting of two protons and two neutrons by the nucleus is a-radiation, the emission of an electron is β-radiation, and, in some cases, g-radiation occurs.
The formation and dispersion of radionuclides leads to radioactive contamination of air, soil, water, which requires constant monitoring of their content and the adoption of measures to neutralize them.
In everyday life, ionizing radiation is constantly encountered. We do not feel them, but we cannot deny their impact on animate and inanimate nature. Not so long ago, people learned to use them both for good and as weapons of mass destruction. With proper use, these radiations can change the life of mankind for the better.
Types of ionizing radiation
To understand the peculiarities of the influence on living and non-living organisms, you need to find out what they are. It is also important to know their nature.
Ionizing radiation is a special wave that can penetrate through substances and tissues, causing ionization of atoms. There are several types of it: alpha radiation, beta radiation, gamma radiation. All of them have a different charge and ability to act on living organisms.
Alpha radiation is the most charged of all types. It has tremendous energy, capable of causing radiation sickness even in small doses. But with direct irradiation, it penetrates only into the upper layers of human skin. Even a thin sheet of paper protects against alpha rays. At the same time, getting into the body with food or with inhalation, the sources of this radiation quickly become the cause of death.
Beta rays carry a slightly lower charge. They are able to penetrate deep into the body. With prolonged exposure, they cause death of a person. Smaller doses cause a change in the cellular structure. A thin sheet of aluminum can serve as protection. Radiation from within the body is also deadly.
The most dangerous is considered to be gamma radiation. It penetrates through the body. In large doses, it causes radiation burns, radiation sickness, and death. The only protection against it can be lead and a thick layer of concrete.
X-rays are considered to be a special kind of gamma radiation, which are generated in an X-ray tube.
Research History
For the first time, the world learned about ionizing radiation on December 28, 1895. It was on this day that Wilhelm K. Roentgen announced that he had discovered a special kind of rays that could pass through various materials and the human body. From that moment, many doctors and scientists began to actively work with this phenomenon.
For a long time, no one knew about its effect on the human body. Therefore, in history there are many cases of death from excessive exposure.
The Curies have studied in detail the sources and properties that ionizing radiation has. This made it possible to use it with maximum benefit, avoiding negative consequences.
Natural and artificial sources of radiation
Nature has created a variety of sources of ionizing radiation. First of all, it is the radiation of sunlight and space. Most of it is absorbed by the ozone layer, which is high above our planet. But some of them reach the surface of the Earth.
On the Earth itself, or rather in its depths, there are some substances that produce radiation. Among them are isotopes of uranium, strontium, radon, cesium and others.
Artificial sources of ionizing radiation are created by man for a variety of research and production. At the same time, the strength of radiation can be several times higher than natural indicators.
Even in conditions of protection and compliance with safety measures, people receive doses of radiation that are hazardous to health.
Units of measurement and doses
Ionizing radiation is usually correlated with its interaction with the human body. Therefore, all units of measurement are somehow related to the ability of a person to absorb and accumulate ionization energy.
In the SI system, doses of ionizing radiation are measured in units called grays (Gy). It shows the amount of energy per unit of irradiated substance. One Gy equals one J/kg. But for convenience, the off-system unit rad is more often used. It is equal to 100 Gr.
The radiation background on the ground is measured by exposure doses. One dose is equal to C/kg. This unit is used in the SI system. The off-system unit corresponding to it is called the roentgen (R). To obtain an absorbed dose of 1 rad, one must succumb to an exposure dose of about 1 R.
Since different types of ionizing radiation have a different charge of energy, its measurement is usually compared with biological influence. In the SI system, the unit of such an equivalent is the sievert (Sv). Its off-system counterpart is rem.
The stronger and longer the radiation, the more energy absorbed by the body, the more dangerous its influence. To find out the permissible time for a person to stay in radiation pollution, special devices are used - dosimeters that measure ionizing radiation. These are both devices for individual use, and large industrial installations.
Effect on the body
Contrary to popular belief, any ionizing radiation is not always dangerous and deadly. This can be seen in the example of ultraviolet rays. In small doses, they stimulate the generation of vitamin D in the human body, cell regeneration and an increase in melanin pigment, which gives a beautiful tan. But prolonged exposure causes severe burns and can cause skin cancer.
In recent years, the effect of ionizing radiation on the human body and its practical application has been actively studied.
In small doses, radiation does not cause any harm to the body. Up to 200 milliroentgens can reduce the number of white blood cells. The symptoms of such exposure will be nausea and dizziness. About 10% of people die after receiving such a dose.
Large doses cause digestive upset, hair loss, skin burns, changes in the cellular structure of the body, the development of cancer cells and death.
Radiation sickness
Prolonged action of ionizing radiation on the body and its receipt of a large dose of radiation can cause radiation sickness. More than half of the cases of this disease are fatal. The rest become the cause of a number of genetic and somatic diseases.
At the genetic level, mutations occur in germ cells. Their changes become evident in the next generations.
Somatic diseases are expressed by carcinogenesis, irreversible changes in various organs. Treatment of these diseases is long and rather difficult.
Treatment of radiation injuries
As a result of the pathogenic effects of radiation on the body, various lesions of human organs occur. Depending on the dose of radiation, different methods of therapy are carried out.
First of all, the patient is placed in a sterile ward to avoid the possibility of infection of open affected skin areas. Further, special procedures are carried out that contribute to the rapid removal of radionuclides from the body.
For severe lesions, a bone marrow transplant may be needed. From radiation, it loses the ability to reproduce red blood cells.
But in most cases, the treatment of mild lesions comes down to anesthesia of the affected areas, stimulating cell regeneration. Much attention is paid to rehabilitation.
Impact of ionizing radiation on aging and cancer
In connection with the influence of ionizing rays on the human body, scientists conducted various experiments proving the dependence of the processes of aging and carcinogenesis on the dose of radiation.
Groups of cell cultures were irradiated under laboratory conditions. As a result, it was possible to prove that even slight irradiation contributes to the acceleration of cell aging. Moreover, the older the culture, the more it is subject to this process.
Prolonged irradiation leads to cell death or abnormal and rapid division and growth. This fact indicates that ionizing radiation has a carcinogenic effect on the human body.
At the same time, the impact of waves on the affected cancer cells led to their complete death or to a stop in their division processes. This discovery helped develop a technique for treating human cancers.
Practical applications of radiation
For the first time, radiation began to be used in medical practice. With the help of X-rays, doctors managed to look inside the human body. At the same time, almost no harm was done to him.
Further, with the help of radiation, they began to treat cancer. In most cases, this method has a positive effect, despite the fact that the whole body is exposed to a strong effect of radiation, which entails a number of symptoms of radiation sickness.
In addition to medicine, ionizing rays are used in other industries. Surveyors using radiation can study the structural features of the earth's crust in its individual sections.
The ability of some fossils to release a large amount of energy, humanity has learned to use for its own purposes.
Nuclear power
Nuclear energy is the future of the entire population of the Earth. Nuclear power plants are sources of relatively inexpensive electricity. Provided that they are properly operated, such power plants are much safer than thermal power plants and hydroelectric power plants. Much less pollution from nuclear power plants environment both excess heat and production waste.
At the same time, on the basis of atomic energy, scientists developed weapons of mass destruction. At the moment, there are so many atomic bombs on the planet that the launch of a small number of them can cause a nuclear winter, as a result of which almost all living organisms that inhabit it will die.
Means and methods of protection
The use of radiation in everyday life requires serious precautions. Protection against ionizing radiation is divided into four types: time, distance, number and shielding of sources.
Even in an environment with a strong radiation background, a person can stay for some time without harm to his health. It is this moment that determines the protection of time.
The greater the distance to the radiation source, the lower the dose of absorbed energy. Therefore, close contact with places where there is ionizing radiation should be avoided. This is guaranteed to protect against unwanted consequences.
If it is possible to use sources with minimal radiation, they are given preference in the first place. This is protection by quantity.
Shielding, on the other hand, means creating barriers through which harmful rays do not penetrate. An example of this is the lead screens in x-ray rooms.
household protection
In the event of a radiation disaster being declared, all windows and doors should be immediately closed, and try to stock up on water from closed sources. Food should only be canned. When moving in an open area, cover the body as much as possible with clothing, and the face with a respirator or wet gauze. Try not to bring outerwear and shoes into the house.
It is also necessary to prepare for a possible evacuation: collect documents, a supply of clothes, water and food for 2-3 days.
Ionizing radiation as an environmental factor
There are quite a lot of areas contaminated with radiation on planet Earth. The reason for this is both natural processes and man-made disasters. The most famous of them are the Chernobyl accident and the atomic bombs over the cities of Hiroshima and Nagasaki.
In such places, a person cannot be without harm to his own health. At the same time, it is not always possible to find out in advance about radiation pollution. Sometimes even a non-critical radiation background can cause a disaster.
The reason for this is the ability of living organisms to absorb and accumulate radiation. At the same time, they themselves turn into sources of ionizing radiation. The well-known "black" jokes about Chernobyl mushrooms are based precisely on this property.
In such cases, protection against ionizing radiation is reduced to the fact that all consumer products are subject to careful radiological examination. At the same time, there is always a chance to buy the famous "Chernobyl mushrooms" in spontaneous markets. Therefore, you should refrain from buying from unverified sellers.
The human body tends to accumulate dangerous substances, resulting in a gradual poisoning from the inside. It is not known when exactly the effects of these poisons will make themselves felt: in a day, a year or a generation.
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