Types of radioactive radiation. Diseases that appear due to radiation How much radiation is there?

In addition, a person may be exposed to external radiation from a radiation source that is located outside his body.
Internal radiation is much more dangerous than external radiation.

5. IS RADIATION TRANSMITTED AS A DISEASE?

Radiation is created by radioactive substances or specially designed equipment. The radiation itself, acting on the body, does not form radioactive substances in it, and does not turn it into a new source of radiation. Thus, a person does not become radioactive after an X-ray or fluorographic examination. By the way, an X-ray image (film) also does not contain radioactivity.

An exception is the situation in which radioactive drugs are deliberately introduced into the body (for example, during a radioisotope examination of the thyroid gland), and the person becomes a source of radiation for a short time. However, drugs of this kind are specially selected so that they quickly lose their radioactivity due to decay, and the intensity of the radiation quickly decreases.

Of course, you can “contaminate” your body or clothing with radioactive liquid, powder or dust. Then some of such radioactive “dirt” - along with ordinary dirt - can be transferred upon contact to another person.

The transfer of dirt leads to its rapid dilution to safe limits, unlike a disease, which, transmitted from person to person, reproduces its harmful force (and can even lead to an epidemic)

6. IN WHAT UNITS IS RADIOACTIVITY MEASURED?


The measure of radioactivity is activity.
It is measured in Becquerels (Bq), which corresponds to 1 decay per second.
The activity content of a substance is often estimated per unit weight of the substance (Bq/kg) or volume (Bq/cubic meter).
There is also another unit of activity called the Curie (Ci).
This is a huge value: 1 Ci = 37000000000 Bq.

The activity of a radioactive source characterizes its power. Thus, in a source with an activity of 1 Curie, 37000000000 decays occur per second.

As mentioned above, during these decays the source emits ionizing radiation.
A measure of the ionization effect of this radiation on a substance is the exposure dose.
It is often measured in Roentgens (R).
Since 1 Roentgen is a fairly large value, in practice it is more convenient to use parts per million (μR) or thousandths (mR) of a Roentgen.

The operation of common household dosimeters is based on measuring ionization over a certain time, that is, the exposure dose rate.
The unit of measurement for exposure dose rate is micro-Roentgen/hour.

The dose rate multiplied by the time is called the dose.
Dose rate and dose are related in the same way as the speed of a car and the distance traveled by this car (path).


To assess the impact on the human body, the concepts of equivalent dose and equivalent dose rate are used. They are measured in Sieverts (Sv) and Sieverts/hour, respectively.
In everyday life, we can assume that 1 Sievert = 100 Roentgen.
It is necessary to indicate which organ, part or entire body the dose was given to.

It can be shown that the above-mentioned point source with an activity of 1 Curie,
(for definiteness, we consider a cesium-137 source), at a distance of 1 meter from itself it creates an exposure dose rate of approximately 0.3 Roentgen/hour, and at a distance of 10 meters - approximately 0.003 Roentgen/hour.
A decrease in dose rate with increasing distance from the source always occurs and is determined by the laws of radiation propagation.

Now the typical mistake of the media is absolutely clear when they report: “Today on such and such a street a radioactive source of 10 thousand roentgen was discovered when the norm is 20.”

* Firstly, the dose is measured in Roentgens, and the characteristic of the source is its activity. A source of so many X-rays is the same as a bag of potatoes weighing so many minutes.
Therefore, in any case, we can only talk about the dose rate from the source. And not just the dose rate, but with an indication at what distance from the source this dose rate was measured.

*Secondly, the following considerations can be made:
10 thousand roentgens/hour is quite a large value.
It can hardly be measured with a dosimeter in hand, since when approaching the source, the dosimeter will first show both 100 Roentgen/hour and 1000 Roentgen/hour!

It is very difficult to assume that the dosimetrist will continue to approach the source.
Since dosimeters measure dose rate in micro-Roentgens/hour, it can be assumed that
that in this case we are talking about 10 thousand micro-Roentgen/hour = 10 milli-Roentgen/hour = 0.01 Roentgen/hour.
Such sources, although they do not pose a mortal danger, are found on the street less often than 100 ruble bills, and this can be a topic for an information message. Moreover, the mention of the “standard 20” can be understood as a conditional upper limit of the usual dosimeter readings in the city, i.e. 20 micro-Roentgen/hour.
By the way, there is no such rule.

So the correct message would probably look like this:
“Today, on such and such a street, a radioactive source was discovered, close to which the dosimeter shows 10 thousand micro-roentgens per hour, despite the fact that the average value of background radiation in our city does not exceed 20 micro-roentgens per hour.”

7. WHAT ARE ISOTOPES?

There are more than 100 chemical elements in the periodic table.
Almost each of them is represented by a mixture of stable and radioactive atoms, which are called isotopes of a given element.
About 2000 isotopes are known, of which about 300 are stable.
For example, the first element of the periodic table - hydrogen - has the following isotopes:
- hydrogen H-1 (stable),
- deuterium N-2 (stable),
- tritium H-3 (radioactive, half-life 12 years).

Radioactive isotopes are usually called radionuclides.

8. WHAT IS HALF-LIFE?

The number of radioactive nuclei of the same type constantly decreases over time due to their decay.
The decay rate is usually characterized by a half-life: this is the time during which the number of radioactive nuclei of a certain type will decrease by 2 times.

The following interpretation of the concept of “half-life” is absolutely erroneous:
“if a radioactive substance has a half-life of 1 hour, this means that after 1 hour its first half will decay, and after another 1 hour the second half will decay, and this substance will completely disappear (disintegrate).”

For a radionuclide with a half-life of 1 hour, this means that after 1 hour its amount will become 2 times less than the original, after 2 hours - 4 times, after 3 hours - 8 times, etc., but will never completely disappear.
The radiation emitted by this substance will decrease in the same proportion.
Therefore, it is possible to predict the radiation situation for the future if you know what and in what quantities of radioactive substances create radiation in a given place at a given time.

Each radionuclide has its own half-life; it can range from fractions of a second to billions of years. It is important that the half-life of a given radionuclide is constant and cannot be changed.
Nuclei formed during radioactive decay, in turn, can also be radioactive. For example, radioactive radon-222 owes its origin to radioactive uranium-238.

Sometimes there are statements that radioactive waste in storage facilities will completely decay within 300 years. This is wrong. It’s just that this time will be approximately 10 half-lives of cesium-137, one of the most common man-made radionuclides, and over 300 years its radioactivity in waste will decrease almost 1000 times, but, unfortunately, will not disappear.

BASED ON ORIGIN, RADIOACTIVITY IS DIVIDED INTO NATURAL (natural) AND TECHNOGENIC:

9. WHAT IS RADIOACTIVE AROUND US?
(Diagram 1 will help to assess the impact on a person of certain sources of radiation - see figure below)

a) NATURAL RADIOACTIVITY.
Natural radioactivity has existed for billions of years and is literally everywhere. Ionizing radiation existed on Earth long before the origin of life on it and was present in space before the emergence of the Earth itself.

Radioactive materials have been part of the Earth since its birth. Every person is slightly radioactive: in the tissues of the human body, one of the main sources of natural radiation is potassium-40 and rubidium-87, and there is no way to get rid of them.

Let's take into account that modern people spend up to 80% of their time indoors - at home or at work, where they receive the main dose of radiation: although buildings protect against radiation from the outside,
the building materials from which they are built contain natural radioactivity.

b) RADON (makes a significant contribution to human irradiation both itself and its decay products)

The main source of this radioactive noble gas is the earth's crust.
Penetrating through cracks and crevices in the foundation, floor and walls, radon lingers indoors.
Another source of indoor radon is the building materials themselves (concrete, brick, etc.), which contain natural radionuclides that are a source of radon.

Radon can also enter homes with water (especially if it is supplied from artesian wells), when burning natural gas, etc.

Radon is 7.5 times heavier than air. As a result, radon concentrations in the upper floors of multi-story buildings are usually lower than on the ground floor.

A person receives the bulk of the radiation dose from radon while in a closed,
unventilated area;
Regular ventilation can reduce radon concentrations several times.

With prolonged exposure to radon and its products in the human body, the risk of lung cancer increases many times over.

Diagram 2 will help you compare the radiation power of different radon sources.
(see figure below - Comparative power of various radon sources)

c) MAN-MADE RADIOACTIVITY:

Man-made radioactivity arises as a result of human activity

Conscious economic activity, during which the redistribution and concentration of natural radionuclides occurs, leads to noticeable changes in the natural radiation background.

This includes the extraction and combustion of coal, oil, gas, and other fossil fuels, the use of phosphate fertilizers, and the extraction and processing of ores.

For example, studies of oil fields in Russia show a significant excess of permissible radioactivity standards, an increase in radiation levels in the area of ​​wells caused by the deposition of radium-226, thorium-232 and potassium-40 salts on the equipment and adjacent soil.

Operating and spent pipes are especially contaminated and often have to be classified as radioactive waste.

This type of transport, such as civil aviation, exposes its passengers to increased exposure to cosmic radiation.

And, of course, nuclear weapons testing, nuclear energy enterprises and industry make their contribution.

* Of course, accidental (uncontrolled) spread of radioactive sources is also possible: accidents, losses, thefts, spraying, etc.
Such situations, fortunately, are VERY RARE. Moreover, their danger should not be exaggerated.

For comparison, the contribution of Chernobyl to the total collective dose of radiation that Russians and Ukrainians living in contaminated areas will receive in the next 50 years will be only 2%, while 60% of the dose will be determined by natural radioactivity.

10. RADIATION SITUATION IN RUSSIA?

The radiation situation in different regions of Russia is covered in the state annual document "On the state of the natural environment of the Russian Federation."
Information on the radiation situation in individual regions is also available.


11.. WHAT DO COMMONLY FOUND RADIOACTIVE OBJECTS LOOK LIKE?

According to MosNPO Radon, more than 70 percent of all cases of radioactive contamination detected in Moscow occur in residential areas with intensive new construction and green areas of the capital.

It was in the latter that, in the 50-60s, household waste dumps were located, where low-level radioactive industrial waste, which was then considered relatively safe, was also dumped.
The situation is similar in St. Petersburg.

In addition, individual objects depicted in the pictures can be carriers of radioactivity. attached to the article (see description under the pictures), namely:

Radioactive switch (toggle switch):
A switch with a glow-in-the-dark toggle switch, the tip of which is painted with a permanent light composition based on radium salts. The dose rate for point-blank measurements is about 2 milliRoentgen/hour.

ASF aviation watch with radioactive dial:
A watch with a pre-1962 dial and hands that fluoresce thanks to radioactive paint. The dose rate near the clock is about 300 micro-Roentgen/hour.

— Radioactive pipes from scrap metal:
Scraps of spent stainless steel pipes that were used in technological processes at a nuclear industry enterprise, but somehow ended up as scrap metal. The dose rate can be quite significant.

— Portable container with a radiation source inside:
A portable lead container that may contain a miniature metal capsule containing a radioactive source (such as cesium-137 or cobalt-60). The dose rate from a source without a container can be very high.

12.. IS A COMPUTER A SOURCE OF RADIATION?

The only part of the computer that can be considered to be exposed to radiation are cathode ray tube (CRT) monitors;
This does not apply to displays of other types (liquid crystal, plasma, etc.).

Monitors, along with regular CRT televisions, can be considered a weak source of X-ray radiation arising from the inner surface of the glass of the CRT screen.

However, due to the large thickness of this same glass, it also absorbs a significant part of the radiation. To date, no impact of X-ray radiation from CRT monitors on health has been discovered, however, all modern CRTs are produced with a conditionally safe level of X-ray radiation.

Currently, regarding monitors, the Swedish national standards “MPR II”, “TCO-92”, -95, -99 are generally accepted for all manufacturers. These standards, in particular, regulate electric and magnetic fields from monitors.

As for the term “low radiation”, this is not a standard, but just a declaration by the manufacturer that he has done something, known only to him, in order to reduce radiation. The less common term “low emission” has a similar meaning.

When fulfilling orders for radiation monitoring of the offices of a number of organizations in Moscow, LRK-1 employees carried out a dosimetric examination of about 50 CRT monitors of different brands, with screen diagonal sizes from 14 to 21 inches.
In all cases, the dose rate at a distance of 5 cm from the monitors did not exceed 30 μR/hour,
those. with a threefold margin was within the permissible norm (100 μR/hour).

13. WHAT IS NORMAL BACKGROUND RADIATION or NORMAL RADIATION LEVEL?

There are populated areas on Earth with increased background radiation.

These are, for example, the highland cities of Bogota, Lhasa, Quito, where the level of cosmic radiation is approximately 5 times higher than at sea level.
These are also sandy zones with a high concentration of minerals containing phosphates with an admixture of uranium and thorium - in India (Kerala state) and Brazil (Espirito Santo state).
We can mention the area where waters with a high concentration of radium come out in Iran (Romser).
Although in some of these areas the absorbed dose rate is 1000 times higher than the average on the Earth's surface, population surveys have not revealed changes in the structure of morbidity and mortality.

In addition, even for a specific area there is no “normal background” as a constant characteristic; it cannot be obtained as a result of a small number of measurements.

Anywhere, even for undeveloped territories where “no man has set foot”,
background radiation changes from point to point, as well as at each specific point over time. These background fluctuations can be quite significant. In populated areas, additional factors of enterprise activity, transport operation, etc. are superimposed. For example, at airfields, thanks to the high-quality concrete pavement with granite crushed stone, the background is usually higher than in the surrounding area.

Measurements of radiation background in the city of Moscow allow us to indicate
TYPICAL BACKGROUND VALUES IN THE STREET (open area) - 8 - 12 microR/hour,
INDOOR - 15 - 20 microR/hour.

The standards in force in Russia are set out in the document “Hygienic requirements for personal electronic computers and organization of work” (SanPiN SanPiN 2.2.2/2.4.1340-03)

14.. WHAT ARE THE RADIOACTIVITY STANDARDS?

There are a lot of standards regarding radioactivity - literally everything is regulated.
In all cases a distinction is made between the public and the staff, i.e. persons
whose work involves radioactivity (nuclear power plant workers, nuclear industry workers, etc.).
Outside of their production, personnel belong to the population.
For personnel and production premises, their own standards are established.

Further we will talk only about the standards for the population - that part of them that is directly related to normal life activities, based on the Federal Law “On Radiation Safety of the Population” No. 3-FZ dated 05.12.96 and “Radiation Safety Standards (NRB-99). Sanitary rules SP 2.6.1.1292-03".

The main task of radiation monitoring (measurements of radiation or radioactivity) is to determine the compliance of the radiation parameters of the object under study (dose rate in the room, content of radionuclides in building materials, etc.) with established standards.

a) AIR, FOOD, WATER:
The content of both man-made and natural radioactive substances is standardized for inhaled air, water and food.
In addition to NRB-99, “Hygienic requirements for the quality and safety of food raw materials and food products (SanPiN 2.3.2.560-96)” are applied.

b) BUILDING MATERIALS

The content of radioactive substances from the uranium and thorium families, as well as potassium-40 (in accordance with NRB-99) is normalized.
Specific effective activity (Aeff) of natural radionuclides in building materials used for newly constructed residential and public buildings (class 1),

Aeff = АRa +1.31АTh + 0.085 Ak should not exceed 370 Bq/kg,

where АRa and АTh are the specific activities of radium-226 and thorium-232, which are in equilibrium with other members of the uranium and thorium families, Ak is the specific activity of K-40 (Bq/kg).

* GOST 30108-94 also applies:
"Construction materials and products.
Determination of specific effective activity of natural radionuclides" and GOST R 50801-95 "
Wood raw materials, timber, semi-finished products and products made from wood and wood materials. Permissible specific activity of radionuclides, sampling and methods for measuring specific activity of radionuclides."

Note that according to GOST 30108-94, the result of determining the specific effective activity in the controlled material and establishing the class of the material is taken to be

Aeff m = Aeff + DAeff, where DAeff is the error in determining Aeff.

c) PREMISES

The total content of radon and thoron in indoor air is normalized:

for new buildings - no more than 100 Bq/m3, for those already in use - no more than 200 Bq/m3.

d) MEDICAL DIAGNOSTICS

There are no dose limits for patients, but there is a requirement for minimum sufficient exposure levels to obtain diagnostic information.

e) COMPUTER EQUIPMENT

The exposure dose rate of X-ray radiation at a distance of 5 cm from any point on a video monitor or personal computer should not exceed 100 µR/hour. The standard is contained in the document “Hygienic requirements for personal electronic computers and organization of work” (SanPiN 2.2.2/2.4.1340-03).

15. HOW TO PROTECT FROM RADIATION? DOES ALCOHOL HELP FROM RADIATION?

They are protected from the source of radiation by time, distance and substance.

- Time - due to the fact that the shorter the time spent near the radiation source, the lower the radiation dose received from it.

— By distance - due to the fact that radiation decreases with distance from the compact source (proportional to the square of the distance).
If at a distance of 1 meter from the radiation source the dosimeter records 1000 µR/hour,
then already at a distance of 5 meters the readings will drop to approximately 40 µR/hour.

- By substance - you must strive to have as much substance as possible between you and the source of radiation: the more of it and the denser it is, the more of the radiation it will absorb.

* As for the main source of indoor irradiation - radon and its decay products,
Then regular ventilation can significantly reduce its dose load.

* In addition, if we are talking about building or decorating your own home, which is likely to last for more than one generation, you should try to buy radiation-safe building materials - fortunately, their range is now extremely rich.

* Alcohol taken shortly before irradiation can, to some extent, reduce the effects of irradiation. However, its protective effect is inferior to modern anti-radiation drugs.

* There are also folk recipes that help fight and cleanse the body of radiation.
you will find out from them today)

16. WHEN TO THINK ABOUT RADIATION?

In everyday, still peaceful life, there is an extremely low probability of encountering a source of radiation that poses an immediate threat to health.
in places where radiation sources and local radioactive contamination are most likely to be detected - (landfills, pits, scrap metal warehouses).

Nevertheless, it is in everyday life that one should remember about radioactivity.
It's useful to do this:

When buying an apartment, house, land,
--when planning construction and finishing works,
--when choosing and purchasing construction and finishing materials for an apartment or house,
as well as materials for landscaping the area around the house (soil for bulk lawns, bulk coverings for tennis courts, paving slabs and paving stones, etc.).

—besides, we should always remember the likelihood of PD

It should still be noted that radiation is far from the most important reason for constant concern. According to the scale of relative dangers of various types of anthropogenic impact on humans developed in the United States, radiation is in 26th place, and the first two places are occupied by heavy metals and chemical toxins.

TOOLS AND METHODS FOR RADIATION MEASUREMENT


Dosimeters. These devices are becoming increasingly popular every day.

After the Chernobyl accident, the topic of radiation ceased to be of interest only to a narrow circle of specialists.

Many people have become more concerned about the danger it may pose. Nowadays it is no longer possible to be completely sure of the purity of food products sold in markets and stores, as well as the safety of water in natural sources.

This measuring device has ceased to be exotic and has become one of the household appliances that helps determine the safety of being in a particular place, as well as the “norm” (in this area) of purchased building materials, things, products, etc.

so let's figure it out

1. WHAT DOSIMETER MEASURES AND WHAT DOES NOT MEASURE.

The dosimeter measures the dose rate of ionizing radiation directly at the place where it is located.

The main purpose of a household dosimeter is to measure the dose rate in the place where this dosimeter is located (in the hands of a person, on the ground, etc.) and thereby check for radioactivity in suspicious objects.

However, most likely, you will only notice fairly serious increases in dose rate.

Therefore, an individual dosimeter will help primarily those who often visit areas contaminated as a result of the Chernobyl accident (as a rule, all these places are well known).

In addition, such a device can be useful in an unfamiliar area far from civilization (for example, when picking berries and mushrooms in fairly “wild” places), when choosing a place to build a house, or for preliminary testing of imported soil during landscaping.

Let us repeat, however, that in these cases it will be useful only in case of very significant radioactive contamination, which occurs infrequently.

Not very strong, but nevertheless unsafe contamination is very difficult to detect with a household dosimeter. This requires completely different methods that can only be used by specialists.

Regarding the possibility of checking using a household dosimeter the compliance of radiation parameters with established standards, the following can be said.

Dose indicators (dose rate in rooms, dose rate on the ground) for individual points can be checked. However, with a household dosimeter it is very difficult to examine the entire room and gain confidence that a local source of radioactivity has not been missed.

It is almost useless to try to measure the radioactivity of food or building materials using a household dosimeter.

The dosimeter is only capable of detecting VERY STRONGLY contaminated products or building materials, the radioactivity content of which is tens of times higher than permissible standards.

Let us recall that for products and building materials it is not the dose rate that is standardized, but the content of radionuclides, and the dosimeter fundamentally does not allow measuring this parameter.
Here again, other methods and the work of specialists are needed.

2. HOW TO USE THE DOSIMETER CORRECTLY?

The dosimeter should be used in accordance with the instructions supplied with it.

It is also necessary to take into account that during any radiation measurements there is a natural background radiation.

Therefore, first, a dosimeter is used to measure the background level characteristic of a given area of ​​the area (at a sufficient distance from the expected source of radiation), after which measurements are taken in the presence of the expected source of radiation.

The presence of a stable excess above the background level may indicate the detection of radioactivity.

There is nothing unusual in the fact that the dosimeter readings in an apartment are 1.5 - 2 times higher than on the street.

In addition, it must be taken into account that when measuring at the “background level” in the same place, the device can show, for example, 8, 15 and 10 μR/hour.
Therefore, to obtain a reliable result, it is recommended to take several measurements and then calculate the arithmetic mean. In our example, the average will be (8+15+10)/3 = 11 µR/hour.

3. WHAT ARE THERE ARE DOSIMETERS?

* Both household and professional dosimeters can be found on sale.
The latter have a number of fundamental advantages. However, these devices are very expensive (ten or more times more expensive than a household dosimeter), and situations when these advantages can be realized are extremely rare in everyday life. Therefore, you need to purchase a household dosimeter.

Special mention should be made about radiometers for measuring radon activity: although they are only available in professional versions, their use in everyday life can be justified.

* The vast majority of dosimeters are direct indicating, i.e. with their help you can get the result immediately after measurement.

There are also indirectly indicating dosimeters that do not have any power supply or display devices, and are extremely compact (often in the form of a key fob).
Their purpose is individual dosimetric monitoring at radiation hazardous facilities and in medicine.

Since such a dosimeter can only be recharged or its readings can be read using special stationary equipment, it cannot be used for making operational decisions.

* Dosimeters can be non-threshold or threshold. The latter make it possible to detect only excesses of the standard radiation level set by the manufacturer on a “yes-no” principle and, thanks to this, are simple and reliable in operation, and cost less than non-threshold ones by about 1.5 - 2 times.

As a rule, non-threshold dosimeters can also be operated in threshold mode.

4. HOUSEHOLD DOSIMETERS MAINLY DIFFER IN THE FOLLOWING PARAMETERS:

— types of registered radiation - only gamma, or gamma and beta;

— type of detection unit - gas-discharge counter (also known as Geiger counter) or scintillation crystal/plastic; the number of gas-discharge counters varies from 1 to 4;

— placement of the detection unit - remote or built-in;

— presence of digital and/or sound indicator;

— time of one measurement - from 3 to 40 seconds;

— the presence of certain measurement and self-diagnosis modes;

— dimensions and weight;

— price, depending on the combination of the above parameters.

5. WHAT SHOULD I DO IF THE DOSIMETER IS “OFF-ROCK” OR ITS READINGS ARE UNUSUALLY HIGH?

— Make sure that when you move the dosimeter away from the place where it is “off scale”, the readings of the device return to normal.

— Make sure that the dosimeter is working properly (most devices of this kind have a special self-diagnosis mode).

— The normal operation of the dosimeter’s electrical circuit can be partially or completely disrupted by short circuits, battery leaks, and strong external electromagnetic fields. If possible, it is advisable to duplicate the measurements using another dosimeter, preferably a different type.

If you are sure that you have discovered a source or area of ​​radioactive contamination, you should NEVER try to get rid of it yourself (throw it away, bury it or hide it).

You should somehow mark the location of your find, and be sure to report it to the services whose responsibilities include the detection, identification and disposal of orphan radioactive sources.

6. WHERE TO CALL IF A HIGH LEVEL OF RADIATION IS DETECTED?

Main Directorate of the Ministry of Emergency Situations of the Russian Federation for the Republic of Sakha (Yakutia), operational duty officer: tel: /4112/ 42-49-97
-Office of the Federal Service for Supervision of Consumer Rights Protection and Human Welfare in the Republic of Sakha (Yakutia) tel: /4112/ 35-16-45, fax: /4112/ 35-09-55
-Territorial bodies of the Ministry of Nature Protection of the Republic of Sakha (Yakutia)

(check in advance for phone numbers for such cases in your region)

7. WHEN SHOULD YOU CONTACT SPECIALISTS TO MEASURE RADIATION?

Approaches like “Radioactivity is very simple!” or “Dosimetry - with your own hands” do not justify themselves. In most cases, a non-professional cannot correctly interpret the number displayed on the dosimeter display as a result of the measurement. Accordingly, he cannot independently make a decision on the radiation safety of the suspicious object near which this measurement was carried out.

The exception is the situation when the dosimeter showed a very large number. Everything is clear here: move away, check the dosimeter readings away from the place of the anomalous reading and, if the readings become normal, then quickly notify the relevant services without returning to the “bad place”.

Specialists (in appropriately accredited laboratories) must be contacted in cases where an OFFICIAL conclusion is needed on the compliance of a particular product with current radiation safety standards.

Such conclusions are mandatory for products that can concentrate radioactivity from the place of growth: berries and dried mushrooms, honey, medicinal herbs. At the same time, for commercial batches of products, radiation monitoring will cost the seller only a fraction of a percent of the cost of the batch.

When purchasing a plot of land or an apartment, it does not hurt to make sure that its natural radioactivity complies with current standards, as well as the absence of man-made radiation contamination.

If you decide to buy yourself an individual household dosimeter, take this issue seriously.

(Laboratory of Radiation Control LRK-1 MEPhI)

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

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

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

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

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

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

Doses of dangerous radiation exposure

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

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

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

Signs of radiation exposure

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

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

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

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

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

Chronic radiation sickness: degrees and symptoms

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

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

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

Radioactive effects on humans

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

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

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

In recent years, we can increasingly hear about the radioactive threat to all humanity. Unfortunately, this is true, and, as the experience of the Chernobyl accident and the nuclear bomb in Japanese cities has shown, radiation can turn from a faithful assistant into a fierce enemy. And in order to know what radiation is and how to protect yourself from its negative effects, let’s try to analyze all the available information.

Impact of radioactive elements on human health

Every person has encountered the concept of “radiation” at least once in his life. But few people know what radiation is and how dangerous it is. To understand this issue in more detail, it is necessary to carefully study all types of radiation effects on humans and nature. Radiation is the process of emitting a stream of elementary particles of an electromagnetic field. The effect of radiation on human life and health is usually called irradiation. During this phenomenon, radiation multiplies in the cells of the body and thereby destroys it. Radiation exposure is especially dangerous for young children, whose bodies have not matured and become strong enough. A person affected by such a phenomenon can cause the most severe diseases: infertility, cataracts, infectious diseases and tumors (both malignant and benign). In any case, radiation does not bring benefit to human life, but only destroys it. But do not forget that you can protect yourself and purchase a radiation dosimeter, with which you will always know about the radioactive level of the environment.

In fact, the body reacts to radiation, not to its source. Radioactive substances enter the human body through the air (during the respiratory process), as well as by consuming food and water that were initially irradiated by a stream of radiation rays. The most dangerous exposure is perhaps internal. It is carried out for the purpose of treating certain diseases when radioisotopes are used in medical diagnostics.

Types of radiation

In order to answer the question as clearly as possible what radiation is, we should consider its types. Depending on the nature and impact on humans, several types of radiation are distinguished:

1. Alpha particles are heavy particles that have a positive charge and protrude in the form of a helium nucleus. Their impact on the human body is sometimes irreversible.
2. Beta particles are ordinary electrons.
3. Gamma radiation - has a high level of penetration.
4. Neutrons are electrically charged neutral particles that exist only in places where there is a nearby nuclear reactor. An ordinary person cannot feel this type of radiation on his body, since access to the reactor is very limited.
5. X-rays are perhaps the safest type of radiation. In essence it is similar to gamma radiation. However, the most striking example of X-ray radiation is the Sun, which illuminates our planet. Thanks to the atmosphere, people are protected from high background radiation.

Alpha, Beta and Gamma emitting particles are considered extremely dangerous. They can cause genetic diseases, malignant tumors and even death. By the way, the radiation from nuclear power plants emitted into the environment, according to experts, is not dangerous, although it combines almost all types of radioactive contamination. Sometimes antiques and antiques are treated with radiation to avoid rapid damage to cultural heritage. However, radiation quickly reacts with living cells and subsequently destroys them. Therefore, you should be wary of antiquities. Clothing serves as basic protection against the penetration of external radiation. You should not count on complete protection from radiation on a sunny, hot day. In addition, radiation sources may not reveal themselves for a long time and become active at the moment when you are nearby.

How to measure radiation levels

Radiation levels can be measured using a dosimeter both in industrial and domestic conditions. For those who live near nuclear power plants, or people who are simply concerned about their safety, this device will be simply irreplaceable. The main purpose of such a device as a radiation dosimeter is to measure the radiation dose rate. This indicator can be checked not only in relation to a person and a room. Sometimes you have to pay attention to certain objects that may pose a danger to humans. Children's toys, food and building materials - each item can be endowed with a certain dose of radiation. For those residents who live near the Chernobyl nuclear power plant, where a terrible disaster occurred in 1986, it is simply necessary to buy a dosimeter in order to always be on alert and know what dose of radiation is present in the environment at a particular moment. Fans of extreme entertainment and trips to places remote from civilization should provide themselves with items for their own safety in advance. It is impossible to cleanse soil, building materials or food from radiation. Therefore, it is better to avoid adverse effects on your body.

Computer is a source of radiation

Perhaps many people think so. However, this is not entirely true. A certain level of radiation comes only from the monitor, and even then, only from the electro-beam one. At the present time, manufacturers do not produce such equipment, which has been excellently replaced by liquid crystal and plasma screens. But in many homes old electro-ray televisions and monitors are still functioning. They are a fairly weak source of X-ray radiation. Due to the thickness of the glass, this radiation remains on it and does not harm human health. So don't worry too much.

Radiation dose relative to terrain

We can say with utmost certainty that natural radiation is a very variable parameter. Depending on the geographical location and a certain time period, this indicator may vary within a wide range. For example, the radiation rate on Moscow streets ranges from 8 to 12 microroentgens per hour. But on mountain peaks it will be 5 times higher, since there the protective capabilities of the atmosphere are much lower than in populated areas that are closer to sea level. It is worth noting that in places where dust and sand accumulate, saturated with a high content of uranium or thorium, the level of background radiation will be significantly increased. To determine the background radiation level at home, you should purchase a dosimeter-radiometer and take appropriate measurements indoors or outdoors.

Radiation protection and its types

Recently, one can increasingly hear discussions on the topic of what radiation is and how to deal with it. And during the discussions, a term such as radiation protection comes up. Radiation protection is generally understood as a set of specific measures to protect living organisms from the effects of ionizing radiation, as well as the search for ways to reduce the damaging effects of ionizing radiation.

There are several types of radiation protection:

1. Chemical. This is the weakening of the negative effects of radiation on the body by introducing into it certain chemicals called radioprotectors.
2. Physical. This is the use of various materials that weaken background radiation. For example, if the layer of earth that was exposed to radiation is 10 cm, then a 1 meter thick embankment will reduce the amount of radiation by 10 times.
3. Biological radiation protection. It is a complex of protective repair enzymes.

To protect against different types of radiation, you can use some household items:

• From Alpha radiation - a respirator, paper, rubber gloves.
• From Beta radiation - a gas mask, glass, a small layer of aluminum, plexiglass.
• From Gamma radiation - only heavy metals (lead, cast iron, steel, tungsten).
• From neutrons - various polymers, as well as water and polyethylene.

Elementary methods of protection against radiation exposure

For a person who finds himself within the radius of a radiation contamination zone, the most important issue at this moment will be his own protection. Therefore, anyone who has become an involuntary prisoner of the spread of radiation levels should definitely leave their location and go as far as possible. The faster a person does this, the less likely it is to receive a certain and unwanted dose of radioactive substances. If it is not possible to leave your home, then you should resort to other security measures:

• do not leave the house for the first few days;
• do wet cleaning 2-3 times a day;
• shower and wash clothes as often as possible;
• to ensure the body’s protection from harmful radioactive iodine-131, a small area of ​​the body should be anointed with a solution of medical iodine (according to doctors, this procedure is effective for a month);
• If there is an urgent need to leave the room, you should put on a baseball cap and a hood at the same time, as well as wet clothes in light colors made of cotton material.

It is dangerous to drink radioactive water, since its total radiation is quite high and can have a negative effect on the human body. The easiest way to clean it is to pass it through a carbon filter. Of course, the shelf life of such a filter cassette is sharply reduced. Therefore, you need to change the cassette as often as possible. Another untested method is boiling. The guarantee of radon removal will not be 100% in any case.

Proper diet in case of danger of radiation exposure

It is well known that in the process of discussions on the topic of what radiation is, the question arises of how to protect yourself from it, what you should eat and what vitamins you should take. There is a certain list of products that are most dangerous for consumption. The largest amount of radionuclides accumulates in fish, mushrooms and meat. Therefore, you should limit yourself in consuming these foods. Vegetables must be thoroughly washed, boiled and the outer skin cut off. The best products for consumption during the period of radioactive radiation can be considered sunflower seeds, offal - kidneys, heart, and eggs. You need to eat as much iodine-containing products as possible. Therefore, every person should buy iodized salt and seafood.

Some people believe that red wine will protect against radionuclides. There is some truth in this. When drinking 200 ml per day of this drink, the body becomes less vulnerable to radiation. But you can’t remove the accumulated radionuclides with wine, so the total radiation still remains. However, some substances contained in wine drink help block the harmful effects of radiation elements. However, to avoid problems, it is necessary to remove harmful substances from the body with the help of medications.

Drug protection against radiation

You can try to remove a certain proportion of radionuclides that enter the body using sorbent preparations. The simplest means that can reduce the effects of radiation include activated carbon, which should be taken 2 tablets before meals. Such medications as Enterosgel and Atoxil are endowed with a similar property. They block harmful elements by enveloping them and remove them from the body through the urinary system. At the same time, harmful radioactive elements, even remaining in the body in small quantities, will not have a significant impact on human health.

The use of herbal remedies against radiation

In the fight against the removal of radionuclides, not only medications purchased at the pharmacy can help, but also some types of herbs, which will cost several times less. For example, radioprotective plants include lungwort, honeydew and ginseng root. In addition, to reduce the concentration of radionuclides, it is recommended to use Eleutherococcus extract in the amount of half a teaspoon after breakfast, washing down this tincture with warm tea.

Can a person be a source of radiation?

When exposed to the human body, radiation does not create radioactive substances in it. It follows from this that a person himself cannot be a source of radiation. However, things that have been touched by a dangerous dose of radiation are unsafe for health. There is an opinion that it is better not to store x-rays at home. But they won't actually harm anyone. The only thing to remember is that x-rays should not be taken too often, otherwise it can lead to health problems, since there is still a dose of radioactive radiation.

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

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

The danger of RADIATION, real and imaginary

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

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

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

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

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

Ionizing radiation

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

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

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

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

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

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

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

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

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

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

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

Other sources of radiation, which unfortunately have potential dangers, are created by man himself. Sources of artificial radiation are artificial radionuclides, beams of neutrons and charged particles created with the help of nuclear reactors and accelerators. They are called man-made sources of ionizing radiation. It turned out that along with its dangerous nature for humans, radiation can be used to serve humans. This is not a complete list of areas of application of radiation: medicine, industry, agriculture, chemistry, science, etc. A calming factor is the controlled nature of all activities related to the production and use of artificial radiation.

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

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

IMPACT OF IONIZING RADIATION ON BODY TISSUE

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

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

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

Charged particles.

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

Electrical interactions.

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

Physico-chemical changes.

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

Chemical changes.

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

Biological effects.

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

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

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

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

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

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

HOW DO YOU MEASURE RADIATION?

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

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