Presentation on the topic of radiation in life sciences. Presentation on life safety on the topic “Radiation around us” (8th grade)

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The nature of radiation

RADIOACTIVITY (from Latin radio - emit rays and activus - effective), the spontaneous transformation of unstable atomic nuclei into the nuclei of other elements, accompanied by the emission of particles or g-quanta. 4 types of radioactivity are known: alpha decay, beta decay, spontaneous fission of atomic nuclei, proton radioactivity (two-proton and two-neutron radioactivity have been predicted, but have not yet been observed). Radioactivity is characterized by an exponential decrease in the average number of nuclei over time. Radioactivity was first discovered by A. Becquerel in 1896.

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A little information…

RADIOACTIVE WASTE, various materials and products, biological objects, etc., which contain radionuclides in high concentrations and are not subject to further use. The most radioactive waste - spent nuclear fuel - is kept in temporary storage facilities (usually with forced cooling) from several days to tens of years before reprocessing in order to reduce activity. Violation of storage conditions can have catastrophic consequences. Gaseous and liquid radioactive waste, purified from highly active impurities, is discharged into the atmosphere or water bodies. High-level liquid radioactive waste is stored in the form of salt concentrates in special tanks in the surface layers of the earth, above the groundwater level. Solid radioactive waste is cemented, bituminized, vitrified, etc. and buried in stainless steel containers: for tens of years - in trenches and other shallow engineering structures, for hundreds of years - in underground workings, salt layers, at the bottom of the oceans. There are still no reliable, absolutely safe methods of disposal for radioactive waste due to the corrosive destruction of containers.

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Natural sources

The population, as already mentioned, receives the bulk of the radiation dose from natural sources. Most of them are simply impossible to avoid.

A person is exposed to two types of radiation: external and internal. Radiation doses vary greatly and depend mainly on where people live.

Terrestrial sources of radiation together account for more than 5/6 of the annual effective equivalent dose received by the population. In concrete numbers it looks something like this. Irradiation of terrestrial origin: internal - 1.325, external - 0.35 mSv/year; of cosmic origin: internal - 0.015, external - 0.3 mSv/year.

• External exposure
• Internal exposure

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Artificial sources

Over the past decades, people have been intensively studying the problems of nuclear physics. He created hundreds of artificial radionuclides, learned to use the capabilities of the atom in a wide variety of industries - in medicine, in the production of electrical and thermal energy, in the manufacture of luminous watch dials, many instruments, in the search for minerals and in military affairs. All this, naturally, leads to additional exposure of people. In most cases, the doses are small, but sometimes man-made sources are many thousands of times more intense than natural ones.

• Appliances
• Uranium mines and processing plants
• Nuclear explosions
• Nuclear power

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Radiation units

Units of physical quantities”, which provide for the mandatory use of the International SI System.

In table 1 shows some derived units used in the field of ionizing radiation and radiation safety. The relationships between systemic and non-systemic units of activity and radiation doses that were supposed to be withdrawn from use since January 1, 1990 (roentgen, rad, rem, curie) are also given. However, the need for significant costs, as well as economic difficulties in the country, did not allow a timely transition to SI units, although some household dosimeters are already calibrated in new measurements (bek-vrel, eivert

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APPLICATIONS OF RADIATION

Medical procedures and treatment methods associated with the use of radioactivity make the main contribution to the dose received by humans from man-made sources. Radiation is used for both diagnosis and treatment. One of the most common devices is the X-ray machine. Radiation therapy is the main way to fight cancer. Of course, radiation in medicine is aimed at healing the patient. In developed countries, there are from 300 to 900 examinations per 1000 inhabitants

Other Applications

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RADIATION is one of the damaging factors of nuclear weapons

Penetrating radiation is invisible radioactive radiation (similar to X-rays) spreading in all directions from the zone of a nuclear explosion. As a result of its exposure, people and animals can develop radiation sickness.

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Low doses of ionizing radiation and health

According to some scientists, radioactive radiation in small doses not only does not harm the body, but has a beneficial stimulating effect on it. Adherents of this point of view believe that small doses of radiation, always present in the external environment of background radiation, played an important role in the development and improvement of life forms existing on Earth, including man himself.

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METHODS OF PROTECTION AGAINST RADIATION

A feature of radioactive contamination of an area is a relatively rapid decrease in the level of radiation (degree of contamination). It is generally accepted that the radiation level decreases by about 10 times 7 hours after the explosion, 100 times after 49 hours, etc.

For protection in hazardous areas, it is necessary to use protective structures - shelters, radiation shelters, basements, cellars. To protect the respiratory system, personal protective equipment is used - respirators, anti-dust fabric masks, cotton-gauze bandages, and when they are not available, a gas mask. The skin is covered with special rubberized suits, overalls, raincoats, and a little more detail

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Conclusions:

Radiation is truly dangerous: in large doses it leads to damage to tissues and living cells; in small doses it causes cancer and promotes genetic changes.

However, it is not the sources of radiation that are most talked about that pose the danger. Radiation associated with the development of nuclear energy is only a small fraction; a person receives the largest dose from natural sources - from the use of X-rays in medicine, during an airplane flight, from coal burned in countless quantities by various boiler houses and thermal power plants, etc. .

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CONTACT INFORMATION

429070, Chuvash Republic, Yadrino district, Yadrino village, secondary school.

Life safety and computer science teacher Savelyev A.V.

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Increased radiation and the most rational diet Residents of many regions of Russia live in remote places near nuclear power plants and in conditions of increased radiation, consuming the gifts of nature, dachas and, of course, shops. Many people use cheaper products that have not been tested than in government (controlled by the radiation service) trade. This suggests a conclusion... do not buy untested food products. When exposed to ionizing radiation, the human body experiences serious changes.... Disorders of fat, vitamin and mineral metabolism occur. Diseases can manifest themselves in the form of pathologies of the hematopoietic organs, digestive, nervous, etc. systems, a weakening of the body’s immunoprotective function, which leads to a decrease in its activity and general resistance to various types of influences. The nutrition of persons exposed to radiation must satisfy a number of principles.

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Mushrooms now contain higher levels of cesium-137. Many types of technological and culinary processing of mushrooms can reduce the content of radionuclides in them. Thus, washing with running water can reduce the activity of cesium-137 by 18-32%. Soaking dry mushrooms for 2 hours reduces the isotope activity by 81%, and dry white mushrooms by 98%. Cook mushrooms once for 10 minutes. reduces the activity of cesium-137 by 80%, boiling twice for 10 minutes. - by 97%. Therefore, boil the mushrooms twice for 10 minutes. allows you to practically free them from radionuclides.

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Reducing the intake of radionuclides. thorough washing of products; exclusion of meat and bone broth products from the diet; preliminary soaking of meat and root vegetables for 1-2 hours.

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Acceleration of the release of radioactive substances. introduction of additional liquids 500 ml per day (tea, juices); - taking herbal infusions that have a weak diuretic and choleretic effect (chamomile, mint, rosehip, dill); - regular bowel movements, ensured by the use of (whole bread, cabbage, beets, prunes, etc.); -introduction to the menu of products rich in peptides - for binding radionuclides (juices with pulp, apples, citrus fruits, green peas, etc.).

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Using the radioprotective properties of food by introducing proteins that reduce the absorption of radioactive substances and increase immunity (meat, dairy products, eggs, legumes); - use of foods high in polyunsaturated fatty acids (nuts, fish, pumpkin seeds, sunflower seeds); - consumption of vitamins A - rose hips, carrots, garlic, beef liver, etc. C – rose hips, dill, citrus fruits, black currants, etc. B – meat, dairy products, buckwheat, oats, fruits, etc. E – sea buckthorn, eggs, corn, fish, walnuts, etc.

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Enrichment of the diet with mineral salts to replace radionuclides and replenish the deficiency of micro- and macroelements iodine - eggs, oats, legumes, radishes, iodized salt, etc. cobalt - sorrel, dill, fish, beets, cranberries, rowan, etc. potassium – raisins, dried apricots, prunes, pomegranates, apples, potatoes, etc. calcium - cottage cheese, cheese, legumes, turnips, horseradish, eggs, etc. iron – meat, fish, apples, raisins, chokeberry, etc.

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Use of food Introduction to diet pharma. Preparations: activated carbon tablets, ascorbic acid, vitamin A, vitamin E, tablets containing calcium. Eating salads, juices, infusions, honey, wheat bran (steamed), this restores the magnetic field and frequency characteristics of cells damaged by radiation. The use of natural dairy products, in particular cottage cheese, cream, sour cream, butter, but not whey in which radioactive elements are concentrated. When preparing boiled meat, the first broth is removed, the meat is again filled with water and cooked until cooked. If the meat is used for cooking, for example borscht, then it is best to use meat that has been boiled twice. Since ruminant herbivores eat large quantities of grass, which may contain radionuclides that pass into the animal's tissue, beef is less preferable than pork. Pork fat is considered absolutely pure, because... radionuclides do not accumulate in it. For this reason, it is healthy and safe to consume lard. Broths, jellied meat, bones, and bone fat should not be consumed.

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In connection with recent events in Japan, which suffered from natural and man-made disasters: earthquakes and tsunamis led to fires and explosions at nuclear power plants. It has now been proven that even small doses of increased radiation can cause a mild form of radiation sickness, decreased immunity and a wide variety of negative consequences in the future. Ingested radionuclides are especially dangerous due to their ability to accumulate in the most vulnerable organs; they are slowly eliminated from the body. Vitamin deficiency increases a person's radiosensitivity and aggravates the course of radiation injury. Ionizing radiation itself can cause pre-existing vitamin deficiencies. A decrease in the body's resistance to radiation exposure serves as a compelling reason for the widespread use of vegetable products in nutrition.

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Reducing the content of radionuclides in food products is facilitated by their correct technological and culinary processing. In carrot roots, when washed, the content of cesium-137 decreases by 6.7 times, and when peeled, by 4.3 times: potatoes must be peeled. At the same time, the activity of cesium-137 and strontium-90 decreases by 30-40%. Removing the covering leaves of white cabbage helps reduce the content of radioactive substances in the cabbage by 5 or more times.

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Reducing the content of radionuclides in food products is facilitated by their correct technological and culinary processing. Cooking (boiling) vegetables in salted water makes it possible to reduce the content of radionuclides by 50%, and in fresh water - by 30%. The same thing happens with other products: meat, fish. After boiling potatoes in salted water, the amount of cesium and strontium isotopes in it decreases by 60-80%. Frying does not reduce the content of radionuclides in food. It is better to fry after preliminary boiling.

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Reducing the content of radionuclides in food products is facilitated by their correct technological and culinary processing. The simplest technological processing of vegetable products (fermentation, pickling, pickling, etc.) helps to further reduce radioactive contamination. It allows you to eliminate the consumption of products contaminated with radionuclides above established hygienic standards. Salting cucumbers, tomatoes, watermelons, the brine of which is undesirable for food, protects from radiation. In these cases, the activity of cesium-137 entering the diet with salted vegetables will be approximately two times less than its activity in the original fresh products.

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Household sources of radiation - Christmas tree decorations These frequent inhabitants of mezzanines in the 1950s were produced with SPD. Due to the shedding of light mass from old age, they create deadly dust, and Radium-226, which is part of the SPD, when decaying, emits radon in huge quantities. The excess of the natural background in the immediate vicinity of such toys ranges from 100 to 1000 times. The dose rate of some specimens exceeds 10,000 microroentgens/hour.

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Household sources of radiation - minerals and jewelry Radioactive minerals are not uncommon - the most common and dangerous, in my opinion, is the mineral charoite - a beautiful semi-precious stone, often inlaid into rings, necklaces and earrings. And although charoite itself is not radioactive, it often contains inclusions of radioactive thorium-232 (usually black inclusions).

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Radioactive wrist and table clocks Wristwatches are one of the most common radioactive items; they are often handed down from grandparents and kept as a memory, irradiating everything around them. The place where such watches are disassembled or broken turns into a hotbed of radioactive dust, the inhalation of which is guaranteed (sooner or later) to lead to a diagnosis of cancer. They also emit the radioactive gas radon-222, and even if the watch is far from you, inhaling the radioactive gas for years is a big risk. The excess of the natural background in the immediate vicinity of such clocks ranges from 100 to 1000 times. The dose rate of some specimens exceeds 10,000 µR/h

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Household sources of radiation - dishes Old, antique tableware can pose a danger in terms of increased background radiation due to the fact that the radioactive element Uranium was used in its manufacture. It was included in the composition of colored glaze for coating porcelain products and in the composition of the charge for melting colored glass. The daughter products of the decay of Uranium-238 are Radium-226, the radioactive gas Radon-222, the infamous Polonium-210 and a number of other isotopes. All this together is the reason for the significant radioactive radiation that such dishes possess. The equivalent dose rate from such household items can reach 15 microsieverts per hour, or 1500 microroentgens, which is more than 100 times higher than the normal natural background!

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Household sources of radiation - food Radioactive food is a very common occurrence; every summer in Moscow alone, large quantities of radioactive berries and mushrooms are confiscated. If you bought mushrooms or berries outside official markets, you can say with a high degree of certainty that you purchased products contaminated with radiation. Such huge volumes of radioactive products are due to the fact that the Chernobyl accident and accidents at the Mayak enterprise, as well as a huge number of nuclear tests, significantly contaminated the territory of the USSR with isotopes - the Chernobyl imprint can be traced in the territories from Bryansk to Ulyanovsk, where berries such as blueberries or cranberries , as well as almost all mushrooms literally absorb such dangerous isotopes as Cesium-137 and Strontium-90 from the soil.

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Household sources of radiation - photographic lenses Some lenses contain lenses with radioactive thorium dioxide-232; these lenses have a rare low-dispersity property. For a long time, companies such as Kodak, Canon, GAF, Takumar, Yasinon, Flektogon, Minolta, ROKKOR, ZUIKO could not make such lenses without Thorium-232, and the effects of radiation exposure were not sufficiently studied, which made it possible to produce such lenses until the 1980s. A photographer with such equipment in a 12-hour working day receives more than 3,600 micro-roentgens of accumulated dose instead of 120 micro-roentgens, which he would receive without a lens - in a couple of years a solid dose is accumulated and the risk of cancer increases proportionally.

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Military and civilian equipment - compasses Military and civilian equipment - toggle switches Military and civilian equipment - military devices (radiation dosimeter) Military and civilian equipment (smoke detectors) Military and civilian equipment - electronics (lamp equipment). Military and civil equipment - electronics (lamp equipment). ...deadly dangerous Plutonium-239 The most common of them are Hadrianov compasses. For a long time they were the main compasses in the USSR; until the 70s they were produced with SPD. They have a leaky housing through which radioactive dust spills out; other models of compasses had radioactive paint applied to the surface of the device, which was not protected by anything except a small recess on the body. The excess of the natural background in the immediate vicinity of such compasses ranges from 10 to 500 times. The dose rate of some specimens exceeds 5,000 µR/h

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The word radiation comes from the Latin word radiatio - emission of radiation. In the modern language of natural sciences, radiation is radiation (ionizing, radioactive) and propagation in the form of a stream of elementary particles and quanta of electromagnetic radiation. The word radiation comes from the Latin word radiatio - emission of radiation. In the modern language of natural sciences, radiation is radiation (ionizing, radioactive) and propagation in the form of a stream of elementary particles and quanta of electromagnetic radiation.

Ionizing radiation is one of many types of radiation and natural environmental factors. It existed on Earth long before the origin of life on it and was present in space even before the emergence of the Earth itself. All life on Earth arose and developed under the influence of ionizing radiation, which became a constant companion of man. Radioactive materials have been part of the Earth since its inception.

There are several types of radiation: * Alpha particles are relatively heavy particles, positively charged, and are helium nuclei. * X-rays are similar to gamma rays, but have lower energy. By the way, the Sun is one of the natural sources of such rays, but protection from solar radiation is provided by the Earth’s atmosphere. * Beta particles are ordinary electrons. * Neutrons are electrically neutral particles that arise mainly near an operating nuclear reactor; access there should be limited. * Gamma radiation has the same nature as visible light, but has a much greater penetrating power.

The effect of radiation on the human body is called irradiation. During this process, radiation energy is transferred to the cells, destroying them. Radiation can cause all sorts of diseases: infectious complications, metabolic disorders, malignant tumors and leukemia, infertility, cataracts and much more. Radiation has a particularly acute effect on dividing cells, so it is especially dangerous for children. The body reacts to the radiation itself, and not to its source. Radioactive substances can enter the body through the intestines (with food and water), through the lungs (during breathing) and even through the skin during medical diagnostics using radioisotopes. In this case, internal exposure occurs. In addition, external radiation has a significant impact on the human body, i.e. The source of radiation is outside the body. The most dangerous, of course, is internal radiation.

The most dangerous radiation for humans is Alpha, Beta and Gamma radiation, which can lead to serious illnesses, genetic disorders and even death. Charged particles are very active and interact strongly with matter, so even one alpha particle can be enough to destroy a living organism or damage a huge number of cells. However, for the same reason, any layer of solid or liquid substance, for example, ordinary clothing, is a sufficient means of protection against this type of radiation.

To protect against alpha radiation, a simple sheet of paper is enough. Effective protection against beta particles will be provided by an aluminum plate with a thickness of at least 6 mm; Gamma radiation has the greatest penetrating ability. To protect against it, you need a screen made of lead plates or thick concrete slabs.

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Due to their low penetrating power, alpha and beta radiation usually do not pose a great danger when exposed to external radiation. Tight clothing can absorb a significant portion of beta particles and does not allow alpha particles to pass through at all. However, when ingested by the human body through food, water and air, or when the surface of the body is contaminated with radioactive substances, alpha and beta radiation can cause serious harm to humans. Alpha and beta radiation

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Fluxes of gamma quanta and neutrons are the most penetrating types of ionizing radiation, therefore, with external irradiation, they pose the greatest danger to humans. Gamma rays

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A universal measure of the effect of any type of radiation on a substance is the absorbed dose of radiation, equal to the ratio of the energy transferred by ionizing radiation to the substance to the mass of the substance: D=E/m Absorbed dose of ionizing radiation Individual device for measuring the absorbed dose

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The SI unit of absorbed dose is the gray (Gy). 1 Gy is equal to the absorbed dose of radiation at which an ionizing radiation energy of 1 J is transferred to an irradiated substance weighing 1 kg: 1 Gy = 1 J/1 kg = 1 J/kg An off-system unit is used: 1 rad = 0.01 Gy. The ratio of the absorbed dose of radiation to the time of irradiation is called the radiation dose rate: D=D/t Unit of absorbed dose rate in SI – gray per second (Gy/s) Unit of absorbed dose

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The physical effect of any ionizing radiation on matter is primarily associated with the ionization of atoms and molecules. A quantitative measure of the effect of ionizing radiation is the exposure dose, which characterizes the ionizing effect of radiation on air. An off-system unit of exposure dose is used - the X-ray (R): 1Р=2.58 10-4 C/kg When irradiating the soft tissues of the human body with X-ray or gamma radiation, the exposure dose 1Р corresponds to an absorbed dose of 8.8 mGy. Exposure dose

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The biological impact of different types of radiation on the organisms of animals and plants is not the same with the same radiation dose absorption. For example, an absorbed dose of 1 Gy of radiation from alpha particles has approximately the same biological effect on a living organism as an absorbed dose of 20 Gy of X-ray or gamma radiation. The difference in the biological effects of different types of radiation is characterized by the coefficient of relative biological effectiveness (RBE), or quality factor k. Relative biological effectiveness

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The absorbed dose D, multiplied by the quality factor k, characterizes the biological effect of the absorbed dose and is called the equivalent dose H: H=Dk The SI unit of equivalent dose is the sievert (Sv). 1Sv is equal to the equivalent dose at which the absorbed dose is 1 Gy and the quality factor is equal to unity. The off-system unit used is the biological equivalent of a roentgen: 1rem=0.01Sv Equivalent dose Clock measuring equivalent dose

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The basis of the physical impact of nuclear radiation on living organisms is the ionization of atoms and molecules in cells. When a person is irradiated with a lethal dose of gamma radiation equal to 6 Gy, his body releases energy equal to approximately: E = mD = 70 kg 6 Gy = 420 J The mammal's body consists of approximately 75% water. At a dose of 6 Gy in 1 cm3 of tissue, approximately 1015 water molecules are ionized. Biological effects of ionizing radiation

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Acute injury is damage to a living organism caused by high doses of radiation and manifests itself within several hours or days after exposure. The first signs of general acute damage to the body of an adult are detected starting at approximately 0.5-1.0 Sv Acute damage

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A significant proportion of exposures caused by radiation in living cells are irreversible. The likelihood of cancer increases in proportion to the radiation dose. Equivalent exposure to 1 Sv on average leads to 2 cases of leukemia, 10 cases of thyroid cancer, 10 cases of breast cancer in women, 5 cases of lung cancer per 1000 exposed. Cancers of other organs caused by radiation occur much less frequently. Long-term effects of radiation

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The problem of the biological influence of ionizing radiation on living organisms and establishing the values ​​of relatively safe radiation doses is closely related to the fact of the existence of a natural background of ionizing radiation on the Earth's surface. Radioactivity was not invented by scientists, but only discovered by them. Natural background irradiation

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The essence of the matter is that anywhere on the surface of the Earth, underground, in water, in atmospheric air and in outer space, there is ionizing radiation of various types and of different origins. This radiation existed when there was no life on Earth, it exists now and will exist when the Sun goes out. Natural background irradiation

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Under the conditions of the existence of a natural radiation background, life arose on Earth and went through the path of evolution to its present state. Therefore, we can say with confidence that radiation doses close to the natural background level do not pose any serious danger to living organisms. Natural background irradiation

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In addition to external radiation, every living organism is exposed to internal radiation. It is due to the fact that various chemical elements with natural radioactivity enter the body with food, water and air: carbon, potassium, uranium, thorium, radium, radon. The most significant contribution to the internal radiation dose in most places on Earth comes from radioactive radon and its decay products, which enter the human body through breathing. Radon is constantly formed in soil everywhere on Earth.

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Currently, all people on Earth are exposed to ionizing radiation, not only of natural but also of artificial origin. Artificial sources of radiation created by man include X-ray and therapeutic installations, various automatic monitoring and control equipment using radioactive isotopes, nuclear power and research reactors, charged particle accelerators and various high-voltage electric vacuum devices, waste from thermal and nuclear power plants, and products of nuclear explosions. Chernobyl nuclear power plant

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The maximum permissible dose (MAD) of radiation for persons professionally associated with the use of sources of ionizing radiation is 50 mSv per year. Sanitary standards establish the permissible level of one-time emergency exposure for the population – 0.1 Sv. An equivalent radiation dose of 5 mSv per year has been established as the maximum permissible dose for systematic exposure of the population, i.e. 0.1 traffic rules. Over the entire lifetime of a person (70 years), the permissible radiation dose for the population is 350 mSv = 0.35 Sv = 35 rem. Maximum permissible doses

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Good luck in life. Take care of yourself and your loved ones! Let your life become more beautiful without RADIATION. The presentation was made by 8a grade student Ruslan Timofeev