How does ionizing radiation affect the human body? Everything you need to know about radiation The threat of radiation

Illustration copyright BBC World Service Image caption So far, experts believe that the threat to the health of the Japanese population is small

Radiation levels at the Fukushima Daiichi nuclear power plant briefly rose to levels that could cause harm to human health on Tuesday, Japanese authorities said.

To all residents settlements within a radius of 20 km from the nuclear power plant, it was ordered to immediately leave this area. Those who live at a distance of 20 to 30 km from the station were advised not to leave their homes and isolate their homes to reduce the risk of contaminated air entering them.

Experts say that these actions, if taken immediately, can reduce any negative impact on the human body to a minimum.

What are the first consequences of exposure to radioactive radiation on human health?

The dose of absorbed radiation is measured in grays (one gray is equal to one joule of energy per kilogram of mass of the irradiated substance).

A radiation dose of more than one gray is considered moderate, but even at such a dose symptoms of radiation sickness appear.

In the first hours after irradiation, nausea and vomiting often begin, followed by diarrhea, headaches and fever.

These symptoms disappear after a while, but new and more severe symptoms may appear within a few weeks.

At higher doses of radiation, symptoms of radiation sickness may appear immediately, along with multiple and potentially fatal lesions internal organs.

Radiation doses of 4 Gy are lethal to about half of healthy adults.

By comparison, when treating cancerous tumors with radiotherapy, patients receive several doses from 1 Gy to 7 Gy, but with radiotherapy the effect is on strictly limited areas of the body.

Different tissues of the body react differently to radioactive radiation. The average effect on biological tissue is measured in sieverts; one sievert is the amount of energy absorbed by a kilogram of biological tissue, equal in effect to 1 Gy.

Radiation doses
Radiation Dose (millisieverts per year unless otherwise noted)	Effect
2	Average background radiation (in Australia on average 1.5 mSv, in North America- 3 mSv)
9	Radiation exposure to the crew of the New York-Tokyo flight via the North Pole
20	Average limit for nuclear energy workers
50	Former radiation standards for nuclear energy workers. Also found naturally in parts of Iran, India and Europe
100	The threshold from which an increase in cancer incidence is clearly noticeable
350 mSv during life	Threshold for resettlement of people after the Chernobyl accident
Single dose of 1000 mSv	Causes short-term (non-fatal) radiation sickness with nausea and a decrease in white blood cell counts. The severity of the disease increases with the dose
Single dose of 5000 mSv	Up to half of those who receive such a dose of radiation die within a month.

How can radiation sickness be treated?

The first step is to limit the possibility of further infection by removing clothing and shoes. After this you need to wash with soap.

There are drugs that increase the formation of white blood cells; this helps combat the effects of radiation on the bone marrow and reduces the risk of infectious diseases resulting from a weakened immune system.

In addition, it is possible to use medications to reduce the effects of radiation on human internal organs.

How does radiation affect the human body?

Illustration copyright BBC World Service Image caption It is important to avoid eating foods contaminated with radiation.

Radioactive materials that undergo spontaneous decay emit ionizing radiation, which can cause serious damage to the internal processes of the human body. In particular, they violate chemical bonds between the molecules that make up human tissue.

The body tries to restore these connections, but often the scale of the damage does not allow this. Additionally, errors may occur during the natural recovery process.

The cells most susceptible to radiation are the cells of the stomach and gastrointestinal tract, as well as the bone marrow cells responsible for the production of white blood cells.

Damage to the body depends on the level and duration of radiation exposure.

What is the long-term effect of radiation on the body?

Most of all, the risk of cancer increases. Usually, the cells of the body simply die when they reach their age limit. However, when cells lose this property and continue to multiply uncontrollably, cancer occurs.

A healthy body usually does not allow cells to reach this state. However, radiation exposure disrupts these processes, dramatically increasing the risk of cancer.

Exposure to radiation also leads to irreversible changes - mutations - of the genetic fund, which, in turn, can be passed on to future generations, causing defects and deviations from normal development: reduction in the size of the brain and head, abnormal formation of the eyes, growth delays and learning difficulties.

Are children at greater risk?

Theoretically, yes, since in a young body the process of cell growth and reproduction actively continues. Accordingly, the possibility of deviations from the norm increases in the event of disruption of the normal functioning of cells.

Illustration copyright BBC World Service Image caption Radiation poses a particular danger to children and their growing bodies.

After Chernobyl disaster In 1986, the World Health Organization recorded a sharp increase in cases of thyroid cancer in children who lived near nuclear power plants.

The reason for this was the release of radioactive iodine, which accumulates in the thyroid gland.

How dangerous is the situation at the Fukushima nuclear power plant?

At the nuclear power plant itself, ionizing radiation of 400 millisieverts per hour was recorded.

According to radiation specialist Richard Wakeford, professor at the University of Manchester, exposure to radiation of such power is unlikely to lead to the development of radiation sickness. To do this, he said, the irradiation power should be twice as high.

However, even such irradiation can cause a slowdown in the formation of leukocytes in the bone marrow and increases the risk of developing cancer by 2-4%. The average risk of cancer in Japan is 20-25%.

At the same time, Professor Wakeford notes that only those who participated in emergency work at the nuclear reactor were exposed to such radiation. In addition, to reduce the level of exposure, these workers could be involved in work at nuclear power plants only for short period time.

The level of exposure of the population, including those living near the nuclear power plant, was much less.

What can Japanese authorities do to reduce negative health impacts?

Professor Wakeford believes that with quick and correct action by the authorities, the consequences of radiation exposure for the population may be minimal.

The main task, according to Wakeford, should be the evacuation of the population from nearby areas and the prevention of consumption of food products exposed to radiation.

To reduce the risk of radioactive iodine accumulation in the thyroid gland, the population may be given iodine tablets.

In addition, the Japanese diet is rich in iodine, so this may also help combat the effects of radiation.

Is it possible to compare the accident at the Fukushima nuclear power plant with the Chernobyl disaster?

As Professor Jerry Thomas, who studied the consequences of the Chernobyl accident, said, it is unlikely that what happened in Japan can be compared with Chernobyl.

"On Chernobyl nuclear power plant an explosion occurred, as a result of which the reactor was completely destroyed, and in environment a huge amount of radioactive substances got in,” says Jerry Thomas.

Professor Thomas emphasizes that the consequences of the Chernobyl accident were mainly observed in those who lived near the nuclear power plant and, mainly, in children.

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

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

The danger of RADIATION, real and imaginary

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

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

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

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

The most unpleasant property of radioactive (ionizing) radiation is its effect on the tissues of a living organism, therefore, appropriate measuring instruments are needed that would provide prompt information for making useful decisions before a long time has passed and undesirable or even fatal consequences appear. will not begin to feel immediately, but only after some time has passed. Therefore, information about the presence of radiation and its power must be obtained as early as possible.
However, enough of the mysteries. Let's talk about what radiation and ionizing (i.e. radioactive) radiation are.

Ionizing radiation

Any medium consists of tiny neutral particles - atoms, which consist of positively charged nuclei and negatively charged electrons surrounding them. Every atom is like solar system in miniature: “planets” move in orbit around a tiny core - electrons.
Atomic nucleus consists of several elementary particles - protons and neutrons, held together by nuclear forces.

Protons particles having a positive charge equal to absolute value charge of electrons.

Neutrons neutral particles with no charge. The number of electrons in an atom is exactly equal to the number of protons in the nucleus, so each atom is generally neutral. The mass of a proton is almost 2000 times more mass electron.

The number of neutral particles (neutrons) present in the nucleus can be different if the number of protons is the same. Such atoms, which have nuclei with the same number of protons but differ in the number of neutrons, are varieties of the same chemical element, called “isotopes” of that element. To distinguish them from each other, a number is assigned to the symbol of the element equal to the sum of all particles in the nucleus of a given isotope. So uranium-238 contains 92 protons and 146 neutrons; Uranium 235 also has 92 protons, but 143 neutrons. All isotopes of a chemical element form a group of “nuclides”. Some nuclides are stable, i.e. do not undergo any transformations, while others emitting particles are unstable and turn into other nuclides. As an example, let's take the uranium atom - 238. From time to time, a compact group of four particles breaks out of it: two protons and two neutrons - an “alpha particle (alpha)”. Uranium-238 thus turns into an element whose nucleus contains 90 protons and 144 neutrons - thorium-234. But thorium-234 is also unstable: one of its neutrons turns into a proton, and thorium-234 turns into an element with 91 protons and 143 neutrons in its nucleus. This transformation also affects the electrons (beta) moving in their orbits: one of them becomes, as it were, superfluous, without a pair (proton), so it leaves the atom. The chain of numerous transformations, accompanied by alpha or beta radiation, ends with a stable lead nuclide. Of course, there are many similar chains of spontaneous transformations (decays) of different nuclides. The half-life is the period of time during which the initial number of radioactive nuclei on average decreases by half.
With each act of decay, energy is released, which is transmitted in the form of radiation. Often an unstable nuclide finds itself in an excited state, and the emission of a particle does not lead to complete removal of excitation; then it emits a portion of energy in the form of gamma radiation (gamma quantum). As with X-rays (which differ from gamma rays only in frequency), no particles are emitted. The entire process of spontaneous decay of an unstable nuclide is called radioactive decay, and the nuclide itself is called a radionuclide.

Different types of radiation are accompanied by the release of different amounts of energy and have different penetrating powers; therefore, they have different effects on the tissues of a living organism. Alpha radiation is blocked, for example, by a sheet of paper and is practically unable to penetrate the outer layer of the skin. Therefore, it does not pose a danger until radioactive substances emitting alpha particles enter the body through an open wound, with food, water, or with inhaled air or steam, for example, in a bath; then they become extremely dangerous. The beta particle has greater penetrating ability: it penetrates the body tissue to a depth of one to two centimeters or more, depending on the amount of energy. The penetrating power of gamma radiation, which travels at the speed of light, is very high: it can only be stopped by a thick lead or concrete slab. Ionizing radiation is characterized by a number of measurable physical quantities. These should include energy quantities. At first glance it may seem that they are sufficient for recording and assessing impact ionizing radiation on living organisms and humans. However, these energy values do not reflect the physiological effects of ionizing radiation on the human body and other living tissues; they are subjective, and for different people are different. Therefore, average values are used.

Sources of radiation can be natural, present in nature, and independent of humans.

It has been established that of all natural sources of radiation, the greatest danger is radon, a heavy gas without taste, smell, and at the same time invisible; with its subsidiary products.

Radon is released from earth's crust everywhere, but its concentration in the outside air varies significantly for different parts of the globe. Paradoxical as it may seem at first glance, a person receives the main radiation from radon while in a closed, unventilated room. Radon concentrates in indoor air only when they are sufficiently insulated from external environment. Seeping through the foundation and floor from the soil or, less commonly, being released from building materials, radon accumulates indoors. Sealing rooms for the purpose of insulation only makes matters worse, since this makes it even more difficult for radioactive gas to escape from the room. The radon problem is especially important for low-rise buildings with carefully sealed rooms (to retain heat) and the use of alumina as an additive to building materials (the so-called “Swedish problem”). The most common building materials - wood, brick and concrete - emit relatively little radon. Granite, pumice, products made from alumina raw materials, and phosphogypsum have much greater specific radioactivity.

Another, usually less important, source of radon indoors is water and natural gas used for cooking and heating homes.

The concentration of radon in commonly used water is extremely low, but water from deep wells or artesian wells contains very high levels of radon. However, the main danger does not come from drinking water, even with a high radon content. Typically, people consume most of their water in food and hot drinks, and when boiling water or cooking hot food, radon is almost completely dissipated. A much greater danger is the ingress of water vapor with a high radon content into the lungs along with inhaled air, which most often occurs in the bathroom or steam room (steam room).

Radon enters natural gas underground. As a result of pre-processing and during the storage of gas before it reaches the consumer, most of the radon evaporates, but the concentration of radon in the room can increase noticeably if kitchen stoves and other heating gas appliances are not equipped with an exhaust hood. In the presence of supply and exhaust ventilation, which communicates with the outside air, radon concentration does not occur in these cases. This also applies to the house as a whole - based on the readings of radon detectors, you can set a ventilation mode for the premises that completely eliminates the threat to health. However, given that the release of radon from the soil is seasonal, it is necessary to monitor the effectiveness of ventilation three to four times a year, avoiding exceeding the radon concentration standards.

Other sources of radiation, which unfortunately have potential dangers, are created by man himself. Sources of artificial radiation are artificial radionuclides, beams of neutrons and charged particles created with the help of nuclear reactors and accelerators. They are called man-made sources of ionizing radiation. It turned out that along with its dangerous nature for humans, radiation can be used to serve humans. Here is a far from complete list of areas of application of radiation: medicine, industry, Agriculture, chemistry, science, etc. A calming factor is the controlled nature of all activities related to the production and use of artificial radiation.

Tests stand out in their impact on humans nuclear weapons in the atmosphere, accidents at nuclear power plants and nuclear reactors and the results of their work, manifested in radioactive fallout and radioactive waste. However, only emergency situations, such as the Chernobyl accident, can have an uncontrollable impact on humans.
The rest of the work is easily controlled at a professional level.

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

IMPACT OF IONIZING RADIATION ON BODY TISSUE

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

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

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

Charged particles.

Alpha and beta particles penetrating into body tissues lose energy due to electrical interactions with the electrons of the atoms near which they pass. (Gamma rays and X-rays transfer their energy to matter in several ways, which ultimately also lead to electrical interactions.)

Electrical interactions.

Within a time of about ten trillionths of a second after the penetrating radiation reaches the corresponding atom in the tissue of the body, an electron is torn off from this atom. The latter is negatively charged, so the rest of the initially neutral atom becomes positively charged. This process is called ionization. The detached electron can further ionize other atoms.

Physico-chemical changes.

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

Chemical changes.

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

Biological effects.

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

UNITS OF MEASUREMENT OF RADIOACTIVITY
Becquerel (Bq, Bq); Curie (Ci, Cu)	1 Bq = 1 decay per second. 1 Ci = 3.7 x 10 10 Bq	Units of radionuclide activity. Represent the number of decays per unit time.
Gray (Gr, Gu); Glad (rad, rad)	1 Gy = 1 J/kg 1 rad = 0.01 Gy	Absorbed dose units. Represent the amount of energy of ionizing radiation absorbed by a unit of mass of any physical body, for example, body tissues.
Sievert (Sv, Sv) Rem (ber, rem) - “biological equivalent of an x-ray”	1 Sv = 1 Gy = 1 J/kg (for beta and gamma) 1 µSv = 1/1000000 Sv 1 ber = 0.01 Sv = 10 mSv Equivalent dose units.	Equivalent dose units. They represent a unit of absorbed dose multiplied by a coefficient that takes into account the unequal danger of different types of ionizing radiation.
Gray per hour (Gy/h); Sievert per hour (Sv/h); Roentgen per hour (R/h)	1 Gy/h = 1 Sv/h = 100 R/h (for beta and gamma) 1 μSv/h = 1 μGy/h = 100 μR/h 1 μR/h = 1/1000000 R/h	Dose rate units. They represent the dose received by the body per unit of time.

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

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

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

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

According to the hygienic standards NRB-96 (1996), the permissible dose rate levels for external irradiation of the whole body from man-made sources for permanent residence of personnel are 10 μGy/h, for residential premises and areas where members of the public are permanently located - 0 .1 µGy/h (0.1 µSv/h, 10 µR/h).

HOW DO YOU MEASURE RADIATION?

A few words about registration and dosimetry of ionizing radiation. There are various methods of registration and dosimetry: ionization (associated with the passage of ionizing radiation in gases), semiconductor (in which the gas is replaced solid body), scintillation, luminescent, photographic. These methods form the basis of the work dosimeters radiation. Gas-filled ionizing radiation sensors include ionization chambers, fission chambers, proportional counters, and Geiger-Muller counters. The latter are relatively simple, the cheapest, and not critical to operating conditions, which led to their widespread use in professional dosimetric equipment designed to detect and evaluate beta and gamma radiation. When the sensor is a Geiger-Muller counter, any ionizing particle that enters the sensitive volume of the counter causes a self-discharge. Precisely falling into the sensitive volume! Therefore, alpha particles are not registered, because they can't get in there. Even when registering beta particles, it is necessary to bring the detector closer to the object to make sure that there is no radiation, because in the air, the energy of these particles may be weakened, they may not overcome the body of the device, and will not fall into sensing element and will not be detected.

Doctor of Physical and Mathematical Sciences, Professor at MEPhI N.M. Gavrilov
The article was written for the company "Kvarta-Rad"

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

What is radiation

First, let's define what radiation is:

In the process of decay of a substance or its synthesis, the elements of an atom (protons, neutrons, electrons, photons) are released, otherwise we can say radiation occurs these elements. Such radiation is called - ionizing radiation or what is more common radioactive radiation, or even simpler radiation . Ionizing radiation also includes x-rays and gamma radiation.

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

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

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

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

Gamma and X-rays is the emission of energy.

Alpha radiation

emitted: two protons and two neutrons
penetrating ability: low
irradiation from source: up to 10 cm
emission speed: 20,000 km/s
ionization: 30,000 ion pairs per 1 cm of travel
high

Alpha (α) radiation occurs during the decay of unstable isotopes elements.

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

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

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

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

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

Radioactive isotopes are actually not eliminated from the body on their own, so once they get inside the body, they will irradiate the tissues from the inside for many years until they lead to serious changes. The human body is not able to neutralize, process, assimilate or utilize most radioactive isotopes that enter the body.

Neutron radiation

emitted: neutrons
penetrating ability: high
irradiation from source: kilometers
emission speed: 40,000 km/s
ionization: from 3000 to 5000 ion pairs per 1 cm of run
biological effects of radiation: high

Neutron radiation- this is man-made radiation arising in various nuclear reactors and during atomic explosions. Also, neutron radiation is emitted by stars in which active thermonuclear reactions occur.

Having no charge, neutron radiation colliding with matter weakly interacts with the elements of atoms at the atomic level, and therefore has high penetrating power. You can stop neutron radiation using materials with a high hydrogen content, for example, a container of water. Also, neutron radiation does not penetrate polyethylene well.

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

Beta radiation

emitted: electrons or positrons
penetrating ability: average
irradiation from source: up to 20 m
emission speed: 300,000 km/s
ionization: from 40 to 150 ion pairs per 1 cm of travel
biological effects of radiation: average

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

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

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

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

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

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

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

Gamma radiation

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

Gamma (γ) radiation- it's energetic electromagnetic radiation in the form of photons.

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

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

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

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

X-ray radiation

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

X-ray radiation- this is energetic electromagnetic radiation in the form of photons that arise when an electron inside an atom moves from one orbit to another.

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

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

Each of the radiations discussed is dangerous!

Comparative table with characteristics of different types of radiation

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

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

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

The higher the “k coefficient,” the more dangerous the effect of a certain type of radiation is on the tissues of a living organism.

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

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

What is the essence of radiation?

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

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

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

Consequences of radiation on the human body

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

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

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

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

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

How to protect yourself from excessive doses of radiation?

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

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

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

In the human environment there are many phenomena that influence him. These include rain, wind, changes in atmospheric pressure, heat, landslides, tsunamis, and so on. Thanks to the presence of perception with the help of the senses, a person can protect himself from adverse external influences: from the sun - with sunscreen, from rain - with an umbrella, and the like. But in nature there are phenomena that a person cannot determine with the help of his perception, one of them is radiation.

Definition of radiation

Before we look at why radiation is dangerous, let’s first consider its definition. Radiation is a flow of energy in the form of radio waves that comes from some source. This phenomenon first became known in 1896. The most unpleasant property of radiation is its effect on the cells and tissues of the body. Determination requires special instruments. What is it for? The thing is that the further tactics of the doctor/paramedic depend on the level of radiation: treat or provide palliative care (reducing suffering to the point of death).

How is radiation dangerous for humans?

The question is quite common. Almost everyone who is asked: “Why is radiation dangerous?” will answer, but, unfortunately, not always correctly. Let's figure it out.

All tissues of living organisms are made up of cells. There are two parts of the cell that are most susceptible to damage: the nucleus and the mitochondria. As is known, DNA is located in the nucleus, and when exposed to irradiation, genetic damage occurs to subsequent generations. If during pregnancy a woman receives a dose of radiation, then the embryo is affected, which leads to its defective development. This is the first answer to the question why radiation is dangerous for humans. Further:

Changes in somatic cells. Somatic cells are the cells of the body. When they are irradiated, a mutation occurs, resulting in the formation of tumor diseases of various localizations. Most often, the hematopoietic system is affected and leukemia develops. If we recall history, Marie Curie and her daughter died of leukemia. When strict rules had not yet been introduced in their own protection when performing X-ray examinations, there was such terminology as “cancer and leukemia of radiologists.”
Genetic mutations. In this case, the mutation occurs in one or both germ cells: the sperm and the egg. Not only the fetus that develops from these cells will suffer, but also subsequent generations. With this type of mutation, a fetus is more often born with external and internal pathologies (absence of one/all limbs, pathologies of internal organs, for example, absence of cardiac septum), which in many cases are incompatible with life, at least long-term.
Cell death.

What diseases can it lead to?

Tumor diseases
Leukemia

The last point requires special attention.

Radiation sickness is a condition that develops when a person is exposed to radiation in doses exceeding the permissible threshold and affects the hematopoietic organs, nervous system, gastrointestinal tract and other organs and systems.

There are two forms of radiation sickness: acute and chronic. The chronic form develops with constant or frequent exposure to a low dose, but still exceeding the permissible threshold. Acute radiation sickness develops with a single exposure to a large dose. The degree of severity is determined by an individual dosimeter (what dose a person received) and by symptoms.

Symptoms of radiation sickness

In the symptoms of radiation sickness, the volume of the radiation dose and the area of the area play a large role.

There are four degrees of the disease:

1) First degree (mild) - irradiation with a dosage of 1-2 Gray.

2) Second degree (medium) - irradiation with a dosage of 2-4 Gray.

3) Third degree (severe) - irradiation with a dosage of 4-6 Gray.

4) Fourth degree (extremely severe) - irradiation with a dosage of 6-10 Gray.

Periods of radiation sickness:

Primary reaction. It begins after irradiation, and the higher the radiation dose, the faster the primary reaction develops. Characteristic symptoms are nausea, vomiting, depression of consciousness or, conversely, psychomotor agitation, diarrhea. During this period there is a high probability of death, which is why radiation is dangerous to life at this stage.
Second period (imaginary well-being): the patient feels better, the condition improves, but the disease is still progressing, as reflected by a blood test. It is for this reason that the period is called a period of imaginary prosperity.
The third period (the height of the disease) is characterized by the appearance of all the symptoms of the disease, the features of toxic poisoning of the body by radiation are determined. Symptoms of damage to the central nervous system increase, headaches reappear and intensify, which are not relieved by taking/administering analgesics. Dizziness and vomiting are common. This period is almost always accompanied by fever.
The fourth period is the period of convalescence (recovery) or death.

How to protect yourself from radiation?

To prevent radiation sickness, personal protective equipment is used: gas masks and special clothing. However, having learned how dangerous radiation is, no person will want to come into contact with it. But what to do if such a disaster occurs and there is no personal protective equipment?

For this purpose, means are recommended to reduce the radiosensitivity of cells and tissues of the body to radiation, as well as slow down radiochemical reactions. According to experts, the most suitable remedy for such purposes is the drug Cystamine. This drug reduces the oxygen content inside the cell, and, as many studies have shown, the cell’s resistance to radioactive radiation increases when it is hypoxic (oxygen starvation). The drug begins to act 30-40 minutes after administration and lasts about 4-5 hours. It is low toxic and can be reused.

Triage of casualties

The introduction of the article made the assumption that not all patients who received a large dose of radiation will survive. It is this group of people who receive only palliative care (reduction of suffering). But why? Below is a table that shows how to determine the degree of the disease based on symptoms:

The severity is determined by vomiting. The earlier vomiting occurred after irradiation, the worse the prognosis. Vomiting that occurs within 5 minutes is a fact that a person is living his last 24 hours. Such a patient is provided with assistance in the form of pain relief, lowering body temperature, administering drugs to stop vomiting and simple nursing care.

First aid

Understanding how dangerous human radiation is, when such a catastrophe occurs involving people, the first thought is to provide ambulance to the victims. What needs to be done?

Firstly, when entering the affected area, you must wear personal protective equipment. This is taboo if you do not want to lie next to the victim. Next, we remove the victim from the source of the lesion and carry out decontamination (special treatment against radiation).

It includes:

removing clothes;
mechanical removal of all contaminants and dust that have absorbed radiation;
washing the skin and visible mucous membranes;
Gastric lavage without using a gastric tube. Let the victim take the iodized sorbent, then mechanically induce vomiting (two fingers in the mouth) and give the sorbent again. We repeat this procedure several times.

We perform all of the above actions and wait for the doctor to arrive.

Chernobyl: is it dangerous today?

Talking for a long time about this topic, the thought of the accident at the Chernobyl nuclear power plant in 1986 involuntarily comes to mind. On that day, April 26, a power unit exploded with subsequent release large quantity radioactive substances into the environment. Not only Chernobyl was damaged, but also the nearby city of Pripyat. According to statistics, about 600 thousand people died from acute radiation sickness and about 4 thousand from cancer and tumor diseases of the hematopoietic system.

This happened more than 30 years ago, but why is radiation in Chernobyl still dangerous? The thing is that the decay period of radioactive substances is very long. Today, only half-lives have occurred in Chernobyl and Pripyat. Every next 30 years, it is important to reduce their activity by exactly half. Based on these facts, scientists have concluded that these cities are approximately relatively safe: viability will be restored only after several decades.

By the way, now some organizations conduct excursions in Chernobyl and Pripyat, naturally, wearing personal protective equipment. For such unusual services the price is quite high.

Therefore, the answer to the question of why radiation in Chernobyl is dangerous for humans will be this article about radiation and statistics on mortality during the accident itself.