Radon gas is a silent killer. Why is radon gas dangerous? Radon gas in our house

I am posting the article in the “Home Ecology” section, so I ask everyone who does not care about this issue and everyone who came here not out of interest in home ecology, but to prove something to someone, to refrain from opinions!

For anyone interested, information for thought and discussion:

Radon is an inert heavy gas (7.5 times heavier than air) that is released from the soil everywhere or is released from some building materials(for example, granite, pumice, red clay bricks).

Radon decay products are radioactive isotopes of lead, bismuth, polonium - tiny solid particles suspended in the air that can enter the lungs and settle there. Therefore, radon causes lung damage and leukemia in humans. Since radon is a gas, the most affected tissue is the lungs. Inhaling air with high concentrations of radon greatly increases the risk of developing lung cancer. Many scientists consider radon to be the second leading cause (after smoking) of lung cancer in humans.

Radon is especially active in the so-called “fault zones,” which are deep cracks in the upper part of the earth’s crust. Radon is also found in outdoor air, natural gas used for domestic purposes, and tap water. The highest concentrations of radon are observed in the Northwestern region on the Karelian Isthmus, in Leningrad region, as well as in Karelia, on Kola Peninsula, Altai Territory, Caucasian region mineral waters, Ural region.

Dosimetric instruments have recorded that there are radon-hazardous areas on the territory of St. Petersburg, the largest of which covers the southern districts of the city (Krasnoe Selo, Pushkin, Pavlovsk).

Radon is heavier than air, therefore, rising from the depths, it can accumulate in the basements of buildings, penetrating from there to the lower floors. Feature buildings during the heating period - a decrease in pressure in the premises relative to atmospheric pressure. This effect can lead not just to the diffusion of radon into the premises, but to the suction of radon from the ground by the building. The location of buildings within faults leads to increased concentrations of radon. Increased concentrations of radon indoors are often associated with the quality of construction and finishing materials used in the construction or renovation of a house (apartment).

This poses a danger to people, as well as to technological processes, since the concentration of radon in these cases increases hundreds of times. There are many cases where radon caused illness in people or interfered with the operation of equipment.

Radon has neither odor nor color, which means it cannot be detected without special devices- radiometers. This gas and its decay products emit very dangerous alpha particles that destroy living cells.

Experts from the International Commission on Radiation Protection believe that the most dangerous effects of radon are on children and young people under the age of 20. In all developed countries around the world, mapping of the territory has already been carried out or is currently underway in order to identify areas with high concentrations of radon. The reason for this interest of specialists and authorities is the danger posed to human health by the increased content of radon and its decay products in indoor air. Experts say that greatest contribution Radon gas contributes to the collective radiation dose of Russians.

A person receives the bulk of the radiation dose from radon indoors (by the way, in winter, the content of radon indoors, as measurements have shown, is significantly higher than in summer; and this is understandable, since ventilation conditions in winter are much worse). In regions with a temperate climate, according to experts, the concentration of radon in indoors on average approximately 5 - 8 times higher than in outside air.

Moreover, highly elevated concentrations of radon were found not only in underground workings (for example, mines for the extraction of radioactive raw materials), but also in residential buildings, offices and offices, in urban and rural areas. Sweden, rich in uranium deposits, seems to be seriously faced with this problem. Radon, as it turned out, seeps from underground and accumulates in quite large quantities in basements and on the first floors of buildings. It is generally accepted that an activity of 200 Bq/m3 (1 Bq - becquerel - means 1 radioactive decay per second) is already dangerous for the population, and in many Swedish houses this value is sometimes exceeded several times. The government of the country paid for the costs of homeowners rebuilding their houses in order to reduce the entry of radon into them (but provided that the initial activity was above 400 Bq/m3).

All isotopes of radon are radioactive and decay quite quickly: the most stable isotope 222Rn has a half-life of 3.8 days, the second most stable isotope 220Rn (thoron) - 55.6 s

Not everything is clear about the radon problem. The population of those areas of India, Brazil and Iran, where radioactivity is “off scale”, is not at all more sick than in other parts of these same countries.

More

Any home can have a radon problem. Radon is a radioactive gas. It comes from the natural breakdown of uranium, which is found in almost all soils. It usually moves upward from the ground into the air above it, and enters your home through cracks and other openings in the foundation.

Radon is a transparent gas, odorless and tasteless. But it could be a problem in your home. Globally, radon is responsible for many thousands of deaths every year. Therefore, breathing in air with high levels of radon can cause lung cancer. Doctors warn that radon is now the second leading cause of lung cancer in many countries. Only smoking causes more deaths from lung cancer.

Ways of radon gas entering the house:
The presence of radon in indoor air may be due to its intake from the following sources:

• soils underlying the building;
• enclosing structures made using building materials from rocks, incl. heavy, light and cellular concrete no more than 10% of all radon entering the house);
• outdoor air (especially in radon-prone areas and oil and gas production areas);
• water from the building’s water supply system (mainly when water is supplied from deep wells);
• fuel burned in the building (natural gas, coal, diesel fuel).

Radon is released from the soil over almost the entire surface of the earth. Although radon is 7.5 times heavier than air, it is pushed to the surface by excess pressure from the depths. The world average values ​​of volumetric activity of radon in the outside air at a height of 1 m from the earth's surface range from 7 to 12 Bq/m3 background value). In areas with radon-saturated soils, this value can reach 50 Bq/m3. There are known areas where radon activity in the outdoor air reaches 150-200 Bq/m3 or more.

When constructing a building, a radon-emitting area of ​​the earth's surface is isolated by the plinth or foundation of the building from the surrounding space. Therefore, radon released from the soils underlying the building cannot be freely dispersed in the atmosphere, and penetrates into the building, where its concentration in the indoor air becomes higher than in the outdoor air.

Studies have shown that the concentration of radon in residential buildings depends little on the material of the walls and the features of the architectural design. Radon concentrations in the upper floors of multi-story buildings are usually lower than on the ground floor. Studies conducted in Norway have shown that the concentration of radon in wooden houses is even higher than in brick houses, although wood emits a completely negligible amount of radon compared to other materials. This is explained by wooden houses, as a rule, have fewer floors than brick ones, and, therefore, the rooms in which measurements were taken were closer to the ground - the main source of radon.

According to the Protection Agency environment In the United States (EPA), one in fifteen homes nationwide has radon concentrations at or above the recommended safe radon concentration of 4 pCi/L (picocuries per liter of air).

The maximum concentration of radon is observed in basements, subfloors and on the first floors of buildings. When measuring the level of radon in the cities of the Republic of Belarus, it was found that in some basements the concentration of radon exceeds the sanitary and hygienic norm by 7 times, in semi-basements by 2.5 times and on the first floors by 1.5-2.5 times.

The concentration of radon is highest in buildings on closed strip foundations with free underground space, without insulation of the space under the house from the ground, and without ventilation of the underground space. Hatches in basements and subfloors, cracks in floors are excellent entry points for radon to enter the house. The radon-protective ability of a well-insulated enclosing structure can be practically reduced to zero if there are unsealed seams, joints and technological openings in it.

The entry of soil radon into premises is caused by its convective (together with air) transfer through cracks, crevices, cavities and openings in the building envelope, as well as by diffusion transfer through the pores of the enclosing structures. Concrete, brick and other “stone” structures are not an obstacle to the penetration of radon into the house.

Due to the temperature difference (hence the difference in density) of the air inside and outside the premises, a negative pressure gradient arises in the direction of radon movement from the ground to the building. Already at a pressure difference of 1 - 3 Pa, the mechanism of “suction” of radon into the building begins to operate. The cause of unfavorable pressure distribution can also be the wind effect on the building and the operation of the exhaust ventilation system, which creates a vacuum in the internal atmosphere of the building.

In radon-hazardous areas, exhaust ventilation is allowed only in underground areas or when the soil base is depressed. Ventilation of a house in radon-hazardous areas should be carried out through forced ventilation, which creates excess pressure in the interior of the building, which prevents radon from penetrating into the house.

Radon emissions from surface water sources, as well as from diesel fuel or natural gas burned in boilers, are usually negligible. Radon is highly soluble in water. Therefore, high levels of radon may be present in water supplied to buildings directly from deep wells. Experts from the International Agency for Research on Cancer estimate that up to 20% of radon comes from water into buildings.

Scheme. Ways of radon penetration into a residential building.

Therefore, with regard to radon safety, wells are preferable to wells in radon-hazardous areas. Although the concentration of radon in water is usually very low, it is released “drop by drop” from the water in the house from water jets from taps, when taking a shower, when washing clothes in a washing machine and accumulates indoors. Most radon with water enters the bathroom equipped with a shower.

In a survey of residential buildings in Finland, it was found that on average the radon concentration in the bathroom was approximately three times higher than in the kitchen and approximately 40 times higher than in living areas. A high concentration of radon in the bathroom lasts for 1.5 hours after taking a shower. Including radon, bathrooms in the house must have good system exhaust ventilation. In radon-prone areas, an additional exhaust fan in the bathroom at floor level may be required (radon is heavier than air).

Another less significant source of radon is building materials (including wood and brick). Particularly dangerous is blast furnace slag, which is used by many self-builders in the production of slag concrete. Alumina, fly ash, phosphogypsum and the familiar aluminosilicate brick are dangerous. However, building materials make up no more than 10% of the structure of radiation sources for people living in private houses.

If you think that there is no radon in the soil under your house, because no one has talked about it before, just find out in the Ministry of Emergency Situations or in the administration of your settlement maps of radon hazardous areas. In Novgorod, radon, for example, is the main factor of natural radiation. published If you have any questions on this topic, ask them to the experts and readers of our project.

The radioactive gas radon is constantly and everywhere released from the thickness of the Earth. The radioactivity of radon is integral part radioactive background of the area.

Radon is formed at one of the stages of the breakdown of radioactive elements contained in earth rocks, including those used in construction - sand, crushed stone, clay and other materials.

Radon is an inert gas, colorless and odorless, 7.5 times heavier than air. Radon provides approximately 55-65% of the radiation dose that every inhabitant of the Earth receives annually. The gas is a source of alpha radiation, which has low penetrating ability. A sheet of Whatman paper or human skin can serve as a barrier to alpha radiation particles.

Therefore, a person receives most of this dose from radionuclides that enter his body along with the inhaled air. All isotopes of radon are radioactive and decay quite quickly: the most stable isotope Rn(222) has a half-life of 3.8 days, the second most stable isotope Rn(220) has a half-life of 55.6 seconds.

Radon, having only short-lived isotopes, does not disappear from the atmosphere, since it constantly enters it from earthly sources; breeds The loss of radon is compensated by its supply, and a certain equilibrium concentration exists in the atmosphere.

For people, an unpleasant feature of radon is its ability to accumulate indoors, significantly increasing the level of radioactivity in places of accumulation. In other words, the equilibrium concentration of radon indoors can be significantly higher than outside.

The sources of radon entering the house are shown in Fig. 1. The figure also shows the power of radon radiation from a particular source.

The radiation power is proportional to the amount of radon. From the figure it is clear that The main source of radon entering the house is building materials and soil under the building.

Building regulations regulate the radioactivity of building materials and provide for monitoring compliance with established standards.

The amount of radon released from the soil under a building depends on many factors: the amount of radioactive elements in the earth, the structure of the earth’s crust, gas permeability and water saturation of the upper layers of the earth, climatic conditions, building design and many others.

The highest concentration of radon in the air of residential premises is observed in winter.

A building with a permeable floor can increase the flow of radon escaping from the ground beneath the building by up to 10 times compared to an open area. The increase in flow occurs due to the difference in air pressure at the boundary of the soil and the premises of the building. This difference is estimated on average to be about 5 Pa and is due to two reasons: the wind load on the building (a vacuum that occurs at the boundary of the gas stream) and the temperature difference between the air in the room and the air at the boundary of the ground (the chimney effect).

Therefore, building codes require the protection of buildings from the entry of radon from the soil under the building.

Figure 2 shows a map of Russia indicating areas of potential radon hazard.

Increased release of radon in the areas indicated on the map does not occur everywhere, but in the form of foci of varying intensity and size. In other areas, the presence of point centers of intense radon release is also possible.

Radiation monitoring is regulated and standardized by the following indicators:

• exposure dose rate (EDR) of gamma radiation;
• average annual equivalent equilibrium volumetric activity (ERVA) of radon.

DER gamma radiation:

- when allocating a land plot, it can be no more than 30 microR/hour;

- when putting a building into operation and in existing buildings - should not exceed the dose rate in open areas by more than 30 microR/hour.

EROA of radon should not exceed:
— in buildings put into operation — 100 Bq/m 3(Becquerels/m3);

When allocating a land plot, the following is measured:
— DER gamma radiation (gamma background);
— EROA content of soil radon.

Radiation monitoring indicators are usually determined during pre-design surveys of the construction site. According to current legislation, local authorities must transfer to citizens land plot for individual housing construction after radiation monitoring, provided that the indicators comply with established sanitary standards.

When purchasing a plot of land for development, you should ask the owner whether radiation monitoring has been carried out and its results. In any case, the private developer especially when the site is located in a potentially hazardous area for radon (see map), you need to know the radiation monitoring indicators at your site.

Local district administrations should have maps of radon-hazardous areas in the region. If information is missing, tests should be ordered from local laboratories. By teaming up with your neighbors, you can usually reduce the cost of doing this work.

Based on the results of assessing the radon hazard of the construction site, measures to protect the house are determined. The extent to which a person is exposed to radiation depends on the power of the radiation (amount of gas) and the duration of exposure.

In the case of radon, first of all, residential premises on the first and basement floors, where people stay for a long time, should be protected.

Outbuildings and premises - basements, bathrooms, baths, garages, boiler rooms - must be protected from radon to the extent that gas can penetrate from these premises into living rooms.

Ways to protect your home from radon

To protect residential premises from radon, install two lines of defense:

• Execute gas insulation enclosing building structures, which prevents the penetration of gas from the ground into the premises.
• Provide ventilation space between the ground and the protected room. Ventilation reduces the concentration of harmful gas at the boundary of the soil and the room, before it can penetrate into the premises of the house.

To reduce the entry of radon into residential floors Perform gas insulation (sealing) of building structures. Gas insulation is usually combined with waterproofing of the underground and basement parts of the building. This combination does not cause difficulties, since the materials used for waterproofing usually act as a barrier to gases.

A vapor barrier layer can also serve as a barrier to radon. It should be noted that polymer films, especially polyethylene, transmit radon well. Therefore, as a gas-hydro-vapor barrier for the basement of the building, it is necessary to use a polymer - bitumen roll materials and mastics.

Gas-waterproofing is usually installed at two levels: at the soil-building boundary and at the level of the basement floor.

If the house has a basement that is used for long-term stays of people or there is an entrance to the basement from the residential part of the first floor, then gas-waterproofing of the basement surfaces should be performed in a reinforced version.

In a house without a basement, with floors on the ground, gas and waterproofing is carefully carried out at the level of the ground floor preparation structures.

Developer! When choosing waterproofing options, remember the need to gas insulate your home from radioactive radon!

High-quality gas-waterproofing is carried out by gluing structures with special waterproofing materials. The joints of rolled gas-waterproofing materials laid dry must be sealed with adhesive tape.

Gas-waterproofing of horizontal surfaces must be hermetically sealed with a similar coating of vertical structures. Special attention pay attention to careful sealing of passages through ceilings and walls of communication pipelines.

A gas insulation barrier due to construction defects and damage to integrity during subsequent use of the building may not be sufficient to protect the building from soil radon.

That's why, Along with gas insulation, a ventilation system is used. A ventilation device can also reduce the requirements for gas insulation, which will reduce the cost of construction.

To protect against soil radon, arrange, located under protected from radon indoors. Such ventilation intercepts harmful gas on its way to the protected area, up to the gas insulation barrier. In the space in front of the gas insulation barrier, the gas pressure is reduced or even a vacuum zone is created, which reduces and even prevents the flow of gas into the protected room.

Such a radon-intercepting ventilation system is also needed because conventional exhaust ventilation in protected areas draws in air from outside the room, increasing the flow of radon from the ground if there are defects in the gas insulation.

To protect operating basements or first floors of buildings from radon, exhaust ventilation of the space under the concrete floor preparation is arranged, Fig. 3.

To do this, a captage pillow with a thickness of at least 100 is made under the floor. mm. made of crushed stone, a receiving pipe with a diameter of at least 110 is inserted into the catchment pad mm. ventilation exhaust duct.

A drip cushion can also be made on top of a concrete floor preparation, for example, from expanded clay, mineral wool slabs or other gas-permeable insulation, thereby providing thermal insulation for the floor. A prerequisite in this option is the installation of a gas-vapor barrier layer on top of the insulation.

If the basement space under the floor of the first floor is uninhabited or rarely visited, then an example of an exhaust ventilation device for protection against radon on the first floor in this case is shown in Fig. 4.

A layer of polymer-bitumen roll gas-waterproofing will reduce the flow of ground moisture into the subfloor and reduce heat loss through the ventilation system in winter, without reducing the effectiveness of protection against soil gases.

In some cases, there is a need to increase the efficiency of exhaust ventilation by integrating an electric fan, usually of low power (about 100 W.). The fan can be controlled from a radon sensor installed in the protected room. The fan will turn on only when the radon concentration in the room exceeds the set value.

For a house with a total ground floor area of ​​up to 200 m 2 One exhaust ventilation channel is sufficient.

In accordance with sanitary standards, the content of radon in premises must be monitored in school buildings, hospitals, child care institutions, when commissioning residential buildings, and in industrial premises of enterprises.

Before starting construction of a house, take an interest in the results of radon monitoring in the buildings closest to your site. This information may be available from building owners, local laboratories that carry out measurements, Rospotrebnadzor authorities, and local design organizations.

Find out what radon control measures were used in these buildings. If the design of your home does not have a section on protection from radon, this knowledge will help you choose a fairly effective and cost-effective protection option.

Reducing the concentration of radon entering the protected premises from other sources: water, gas and outside air is ensured by conventional exhaust ventilation systems from the premises of the house.

Gas is easily adsorbed by filters with activated carbon or silica gel.

Upon completion of the construction of the house, take control measurements of the radon content in the premises, make sure that protection from radon ensures the safety of your family.

In Russia, the problem of protecting people in buildings from radon has only recently become a concern. Our fathers, and even more so our grandfathers, did not know about such a danger. Modern science states that radon radionuclides have a strong carcinogenic effect on human lungs.

Among the causes of lung cancer, inhalation of radon contained in the air is in second place in terms of danger after smoking tobacco. The combined effect of these two factors - smoking and radon, dramatically increases the likelihood of this disease.

Give yourself and your loved ones a chance to live longer - protect your home from radon!

Literature

INTRODUCTION

Everywhere and everywhere we are surrounded by atmospheric air. What does it consist of? The answer is not difficult: out of 78.08 percent nitrogen, 20.9 percent oxygen, 0.03 percent carbon dioxide, 0.00005 percent hydrogen, about 0.94 percent is the share of so-called inert gases. The latter were discovered only at the end of the last century. Radon is formed during the radioactive decay of radium and is found in negligible quantities in uranium-containing materials, as well as in some natural waters.

Relevance of the research. According to the International Commission on Radiological Protection (ICRP), the UN Scientific Committee on the Effects of Atomic Radiation (SCEAR), the largest part of the radiation dose (about 80% of the total) received by the population under normal conditions is associated precisely with natural sources radiation. More than half of this dose is due to the presence of radon gas and its daughter decay products (DDP) in the air of buildings in which people spend more than 70% of their time.

Radon is a noble inert gas that acquires everything in a person’s life. higher value. Unfortunately, it is predominantly negative - radon is radioactive and therefore dangerous. And since it is continuously released from the soil, it is distributed throughout earth's crust, in underground and surface water, in the atmosphere, present in every home.

Civilized society has already come to realize that the radon danger is a major and complex complex problem, since the radioecological processes caused by radon occur in three structural levels matter: nuclear, atomic-molecular and macroscopic. Therefore, its solution is divided into diagnostic tasks and technologies for subsequent neutralization of the effects of radon on humans and biological objects.

Currently, after a long refusal of the leading world powers to test nuclear weapons the risk of receiving a significant dose of radiation in the minds of most people is associated with the action nuclear power plants. Especially after Chernobyl disaster. However, you should know that there is a risk of exposure even if you are in your own home. The threat here is posed by natural gas - radon and heavy metal products of its decay. Humanity has experienced their effects throughout its entire existence.

Purpose of the work: Study the nature of radon, its compounds, impact on humans, as well as study the sources of radon entry into the building and evaluate the effectiveness of using various materials as radon-protective coatings.

GENERAL INFORMATION ABOUT RADON

Already from the 16th century, people knew about the disastrous consequences of staying in certain areas and zones, but no one had any idea about the gas itself. In the mining villages in the mountains of southern Germany, women walked down the aisle several times: their husbands were carried away by a mysterious, fast-moving disease - “miner's consumption”. Doctors who practiced in those places mentioned the existence of pits in which, in the absence of proper ventilation, people experienced shortness of breath and increased heart rate, often lost consciousness and sometimes died. At the same time, no impurities were detected in the air either by taste or smell. Therefore, it is not surprising that they believed that people were being destroyed by disturbed mountain spirits. And only the great Paracelsus, who worked as a doctor in the same area, wrote about the need to purify the air in mines: “We are obliged to prevent the body from coming into contact with the emanations of metals, for if the body is damaged by them once, there can be no cure.”

The “miner’s consumption” was finally dealt with only in 1937, having established that this disease is nothing more than a form of lung cancer caused by high concentrations of radon.

The radon problem has been studied since the earliest stages of the development of nuclear physics, but it began to emerge especially seriously and on a large scale after the moratorium on nuclear explosions and thanks to the declassification of test sites. When comparing the effects of radiation, it turned out that each apartment, each room has its own local nuclear radon “test sites”.

Radon isotopes are sorbed (absorbed) by solids. Coal is the most productive in this regard, so coal mines should be under increased government attention. The same applies to all industries that consume this type fuel.

Sorbed radon atoms are very mobile and move from the surface of the solid into the deep layers. This applies to organic and inorganic colloids, biological tissues, which significantly increases the radon hazard. The sorbing properties of substances significantly depend on the temperature of previously adsorbed components, moisture saturation and many other parameters. It is desirable to involve these properties in the development of various anti-radon agents.

In Kazakh national university them. Al-Farabi measured altitude profiles of radon distribution on floors of buildings, indoors and on outdoors. Well-known patterns have been confirmed, but others have also been found that are used experimentally for the development of anti-radon technical means. It has been established that several times a month the radon content in the ground atmosphere can increase many times. These “radon storms” are accompanied by a sharp increase in radioactivity in the air, not only contributing to the development of lung cancer, but also causing functional impairment in practically healthy people - about 30% experience shortness of breath, rapid heartbeat, migraine attacks, insomnia, etc. Disturbances pose a particular danger to sick and elderly people, as well as children.

It turned out that the occurrence of radon-aeroion storms is associated with physical processes occurring on the Sun, with the appearance of dark spots on the surface of the star. An interesting suggestion about a possible mechanism linking solar activity with a significant increase in radon content was made by Moscow scientist A.E. Shemyi-Zadeh. Having analyzed the data on radon activity of the atmosphere obtained in Central Asia, Baltic states, Sweden, etc., he revealed a correlation between the level of radon activity earth's atmosphere with solar and geomagnetic processes in various years and in different regions.

The concentration of radon in micropores of rocks (common granites and basalts) is millions of times higher than in the surface atmosphere and reaches 0.5-5.0 Bq/m3. Radon activity is usually measured in the number of its decays in 1 m3 - 1 Becquerel (Bq) corresponds to one decay per second. This radon, as the scientist’s calculations showed, is “squeezed out” of micropores emerging on the surface due to magnetostrictive compression-tension in the high-frequency field of geomagnetic disturbances. The amplitude of magnetostriction occurring in a constant magnetic field of the Earth under the influence of small geomagnetic disturbances is proportional to the magnetite content in the rock (usually up to 4%), and the frequency is determined by geomagnetic variations. The amplitude of magnetostrictive compression of rocks in the field of geomagnetic disturbances is very small, but the effect of radon displacement is due, firstly, to high frequency disturbances, and secondly, high gas concentration. It turns out that if in the column atmospheric air With a cross-section of one kilometer, “stir” a layer isolated from rocks only one millimeter thick, then the concentration of radon in this column will increase 10 times.

OPENING HISTORY

After the discovery of radium, when scientists were eagerly exploring the secrets of radioactivity, it was found that solid substances that were in close proximity to radium salts became radioactive. However, a few days later the radioactivity of these substances disappeared without a trace.

Radon was discovered several times, and unlike other similar stories, each new discovery did not refute, but only complemented the previous ones. The fact is that none of the scientists dealt with the element radon - an element in our usual understanding of the word. One of the current definitions of an element is “a collection of atoms with total number protons in the nucleus,” that is, the difference can only be in the number of neutrons. Essentially, an element is a collection of isotopes. But in the first years of our century, the proton and neutron had not yet been discovered, and the very concept of isotonia did not exist.

While studying the ionization of air by radioactive substances, the Curies noticed that various bodies located near a radioactive source acquire radioactive properties, which persist for some time after the removal of the radioactive drug. Marie Curie-Skłodowska called this phenomenon induced activity. Other researchers, most notably Rutherford, tried in 1899/1900. explain this phenomenon by the fact that a radioactive body forms some radioactive outflow, or emanation (from the Latin emanare - to flow out and emanatio - outflow), permeating the surrounding bodies. However, as it turned out, this phenomenon is characteristic not only of radium preparations, but also of thorium and actinium preparations, although the period of induced activity in the latter cases is shorter than in the case of radium. It was also discovered that emanation is capable of causing phosphorescence of certain substances, for example, a precipitate of zinc sulfide. Mendeleev described this experiment, demonstrated to him by the Curies, in the spring of 1902.

RADIATION HAZARD
IN THE AIR - RADON

“...more than half the annual dose from all
natural sources of human radiation
receives through the air, irradiating with radon
your lungs while breathing"
SOROS EDUCATIONAL JOURNAL, VOLUME 6, NO. 3, 2000

WHAT IS IT USEFUL TO KNOW ABOUT RADON AND THE DETECTOR - RADON INDICATOR “SIRAD MP106”?

1. INTRODUCTION

2. NEO ESSENTIAL KNOWLEDGE ABOUT RADON

What is radon?
Where does radon come from?
How does radon affect health?
How does radon lead to lung cancer?
When did radon become a problem?
Do I need to have my home inspected? Yes.
How does radon enter a home?

3. HOME INSPECTION

How to detect radon?
How to organize a home inspection?
What do the test results mean?
Urgency of taking protective measures.
Do other factors need to be taken into account?

4. ADDITIONAL INFORMATION

1. INTRODUCTION

Historically, the harmful effects of natural air radioactivity on human body was noticed back in the 16th century, when the mysterious “mountain sickness” of miners attracted the attention of doctors: mortality from lung diseases among miners in some mines in the Czech Republic and Germany was 50 times higher than among the rest of the population. The reason for this was explained in our time - there was a high concentration of radon in the air of these mines.
Speculation about the possibility of radiologically harmful effects of radon on the population arose in the late 1960s, when American experts discovered that the concentration of radon in the air of residential buildings, especially one-story buildings, often exceeded levels considered dangerous even for mines. Until 1980, no country in the world established standards for indoor radon levels, and only in recent decades have standards been introduced for existing and planned buildings, recommended by the International Commission on Radiological Protection. NATO even created a special committee on this problem, and in the United States, almost every home now has radon level sensors.
In our country, standards for the content of radon in the air of residential buildings were adopted in 1990, but the equipment was purely professional, and the “radon problem” until now remained an area of ​​interest only for specialists in the field of radiometry. The emergence of new household appliances - “radon indicators” - has made it possible to conduct an inspection of your home (apartment) yourself. The required minimum knowledge for conducting the examination is given in Sections 2 and 3. When compiling these sections, the literature was used, the data of which is given in Section 4. When conducting the examination yourself, remember that you must carefully study the device manufacturer’s instructions and strictly follow all its requirements, so how the cost of protective measures directly depends on the results obtained, and therefore on the accuracy of the examination.

So, radon - how to detect it, assess the reality of the danger and protect yourself from this threat?

2. NECESSARY KNOWLEDGE ABOUT RADON.

What is radon?

Radon is a radioactive gas that is ubiquitous in nature. It is almost 7.5 times heavier than air, is highly soluble in water, and has no color, taste or smell.

Where does radon come from?

Radon is formed by the natural radioactive decay of uranium, so radon is found in high concentrations in soil and rocks that contain radioactive elements. Radon can also be released from soils containing certain types of industrial waste, such as waste rock from mining plants and mines.
In open spaces, radon concentrations are so low that they are not usually a concern. However, radon accumulates inside closed spaces (such as a home). The level of radon in a building is determined by both the composition of building materials and the concentration of radon in the soil under the building. Another source of radon entering residential premises is water and natural gas. The concentration of radon in tap water is extremely low. However, water from some sources, especially from deep wells or artesian wells, contains a lot of radon - up to 1400 kBq/m3*, or 3,000,000 times more than in lake or river water. Radon enters natural gas underground. During processing and 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 stoves, heating and other heating devices in which gas is burned are not equipped with an exhaust hood.

How does radon affect health?

The main health impact of radon is an increased risk of lung cancer. Of course, not every level above the level leads to the development of lung cancer, but evidence shows that the risk of developing lung cancer from radon exposure depends on the concentration of radon.

*Bq (becquerel) is a unit of measurement of the activity of a radionuclide, equal to one spontaneous transition from a certain nuclear energy state of the nuclide in 1 s.

How does radon lead to lung cancer?

Radon itself naturally decays and forms radioactive decay products. When radon and its decay products are inhaled into the lungs, the decay process continues. This leads to small bursts of released energy already inside the lung tissues; they can be destroyed, contributing to the appearance of cancer.

When did radon become a problem?

Concerns about unusually high indoor radon levels first arose in the late 1960s, when homes built with materials containing industrial waste were examined in the western United States. Then Europe encountered this problem as well. In Sweden, Finland (especially Helsinki) and the UK, houses were found in which radon concentrations were thousands of times higher than typical values in the outside air. The reasons are the radon hazard of soil and building materials, as well as the struggle to save energy. To reduce heat loss, houses began to be especially carefully sealed in those years. As a result, for every kilowatt of electricity saved on heating due to sealing the premises, the Swedes received an additional dose of radiation. In addition, in Sweden, for several decades, local aluminas were used in the production of concrete - about 700 thousand houses were built with their use, and subsequently it was discovered that these aluminas are very radioactive. Other building materials often mentioned are granite and pumice, which were widely used in Germany and Russia. Another popular material is phosphogypsum (a by-product obtained from the processing of phosphorus ores, a cheap substitute natural gypsum), was widely used in the manufacture of building blocks, plaster, partitions and cement. In Japan alone, 3 million tons of this material were consumed in 1974. People living in "phosphogypsum" houses were exposed to radiation 30% more intense than in ordinary dwellings. Aluminum production waste - red clay - and, accordingly, bricks made from this raw material are highly radioactive.

Do I need to have my home inspected? Yes.

The problem is that it is necessary to conduct an individual inspection of each house and, if necessary, choose a method of protection against radon (ensuring sufficient air exchange, concreting basements, covering the surfaces of building structures with a sealing compound, etc.). If you suspect elevated radon levels in your home, you should decide to either conduct a survey yourself or contact your regional radiation protection center to determine the radon level.

How does radon enter a home?

Radon is a gas that can diffuse through voids in the soil and materials that make up your home. Radon can seep through dirt floors, cracks in concrete floors and walls, floor drains, gutters, joints, cracks or pores in hollow block walls.
Radon is highly soluble in water, so it is found in all natural waters, and in deep groundwater there is, as a rule, noticeably more of it than in surface drains and reservoirs. For example, in groundwater its concentration can be a million times higher than in lakes and rivers.
Radon enters the room atmosphere from water, released from air bubbles contained in the water. This occurs most intensely when water splashes, evaporates or boils (for example, in a shower or steam room). When using large public water storage tanks, radon usually does not cause harm, because evaporates before the water reaches the house.
Radon is released from building materials if materials with a relatively high content of radium (uranium, thorium) or capable of releasing radioactive gases were used, while low radioactivity for other types of radiation does not guarantee safety for radon.
However, the main, most likely way of radon accumulation in premises is associated with the release of radon directly from the soil on which the building is built.
In practice geological research There are frequent cases when weakly radioactive rocks contain radon in their voids and cracks in quantities hundreds and thousands of times greater than more radioactive ones rocks. With seasonal fluctuations in temperature and air pressure, radon is released into the atmosphere. The construction of buildings and structures directly above such cracked zones results in a continuous flow of ground air containing high concentrations of radon entering these structures from the bowels of the Earth, which, accumulating in the indoor air, creates a serious radiological hazard for the people in them. There are known cases when in industrial basements equipped with exhaust ventilation, the concentration of radon due to air suction from the soil reached 8000 - 10,000 Bq/m3, which exceeded the norm by 40 - 50 times.
By now in various countries Quite extensive information has been accumulated on the content of radon in residential and office premises. This data is constantly updated and refined, so ideas about average and limit concentrations radon levels in buildings are undergoing changes. From this point of view, the results of the house survey are interesting.

Radon content in buildings.

The level of radon concentration in the atmosphere of houses significantly depends on the natural and artificial ventilation of the room, the thoroughness of the sealing of windows, wall joints and vertical communication channels, the frequency of room ventilation, etc. For example, the highest concentrations of radon in residential buildings are observed during the cold season, when measures are traditionally taken to insulate premises and reduce air exchange with the environment. However, properly executed supply and exhaust ventilation gives the best results in reducing radon risk in existing buildings. An analysis of radon activity shows that even a single air exchange per hour reduces the radon concentration by almost a hundred times.

3.HOME INSPECTION

How to detect radon?

Because it is impossible to see or smell radon, special equipment is needed to detect it. There is a variety of equipment (both professional and household) designed for continuous or periodic monitoring of radon content in premises and providing for obtaining data during the inspection process. These are “AIR-CHEK” USA, “RADHOME” France and others. Similar in Russia Appliances are produced under the brand name of the Moscow Engineering Physics Institute ( State University). The radon detector-indicator “SIRAD MR-106” is the first household indicator of air radioactivity developed in Russia - one of the most dangerous types of radioactivity due to its high biological efficiency (20 times higher than other types of radiation), and leading to internal exposure. It is impossible to do without air, so it should not be dangerous. Using "SIRAD MR-106" to periodically check the atmosphere of your home, you will always be sure that neither natural nor man-made (arising as a result of technical activities) air radioactivity threatens anyone living in your home.

How to organize a home inspection?

When conducting an examination, remember that you must carefully study the device manufacturer’s instructions and strictly follow all its requirements, since the cost of protective measures directly depends on the results obtained, and therefore on the accuracy of the examination.

What do the test results mean?

Remember that you can almost completely protect yourself from radon, it’s just that the cost of protective work directly depends on how carefully the examination is carried out and how reliable the results are.
If the danger is small, then the costs will be small - often it is enough to thoroughly paint or paper the walls of the premises.
The survey results allow you to imagine the real risk from the presence of radon in your home. A clear way to visualize the risk associated with radon exposure is to compare it with the risk from other harmful exposures. According to the US Department of Health, being in a room with a radon concentration of 7400 Bq/m^3 is 60 (sixty!) times more dangerous than smoking two packs of cigarettes a day, and exposure to air with a concentration of 370 Bq/m^3 over the course of a year is comparable with 500-fold irradiation of the lungs during fluoroscopy.

Urgency of taking protective measures.

Whether to do anything and how urgently is explained by the recommendations below, based on the results of the survey. Obviously, it is necessary to try to reduce radon levels as much as possible. Taking into account recent information, it is believed that the level in most buildings can be reduced to 100...150 Bq/m^3 (in Russia, the norm for commissioned buildings is 100 Bq/m^3, and for buildings in operation - 200 Bq/m^3. ). Remember, the urgency of action depends on the radon concentration. The higher the radon level in a home, the faster the situation needs to improve.

*If your results are 7400 Bq/m^3 or higher:

This level is the highest found in homes. Residents should take all necessary steps to reduce levels as low as possible. It is recommended to do this over several weeks. If possible, you should consult with regional center health or radiation protection center and determine the advisability of temporary relocation until the radon level in the house is reduced.

*If your results are 740 -7400 Bq/m^3:

This level is significantly higher than acceptable for residential buildings. You must do everything necessary to reduce the level as low as possible. It is recommended to do this over several months.

*If your results are 200 -740 Bq/m^3:

This level is higher than acceptable for residential buildings. You must do everything necessary to reduce the level to 150 Bq/m^3 or below. We recommend doing this over a period of several years, or sooner if the results are closer to the high end of the interval.

*If your results do not exceed 150 Bq/m^3:

This level is acceptable for housing or slightly exceeds it.

Do other factors need to be taken into account?

The basic risk information provided in this communication, as well as recommendations for reducing the risk, apply to general case. Your specific living conditions may affect your risk and may require additional measures. The risk of radon exposure depends on the amount of radon entering the room and the time you spend in it. The following steps will help immediately reduce your risk from radon exposure. These measures can be taken quickly and at little cost.

*Stop smoking in the house - smoking increases exposure to radon, and radon-related lung cancer is three times higher among smokers than non-smokers.
*Spend less time in areas of the home with high radon concentrations, such as the basement.
*Open windows and turn on fans more often to allow more outside air into your home. This is especially important for basements.
*If in your house there is a ventilated space between the floor of the first floor and the ground, keep the air dampers open on all sides of the house at all times.

Having completed the above, proceed to radical, long-lasting measures that exclude the penetration of radon into your home. We recommend that you carry out control examinations during reconstruction, making sure that measures taken, let the atmosphere of your home be truly clean and healthy.

Doctor of Physical and Mathematical Sciences,
MEPhI professor N.M. Gavrilov

4. ADDITIONAL INFORMATION.

Consolidated telephone directory of organizations operating
in the field of nature conservation and human health protection.

Interregional Association of Neutralization
radioactive waste - special plants "RADON".

Sixteen special plants "RADON" make up an extensive interregional system for neutralizing radioactive waste. In 2000, special plants united into their own Association. The following territories are assigned to each plant:

1. MosNPO"Radon"— Moscow, Bryansk, Kaluga, Tver, Yaroslavl, Vladimir, Tula, Ryazan, Kostroma, Smolensk regions.
2. Leningradsky SK- Leningradskaya, Pskovskaya, Novgorodskaya, Vologdaskaya, Kaliningrad region, Karelia.
3. Volgograd SC- Volgogradskaya, Astrakhan region, Kalmykia.
4. Nizhny Novgorod SC— Nizhny Novgorod, Ivanovskaya, Kirov region, Mordovia, Komi Republic.
5. Groznensky SK — North Ossetia, Dagestan, Chechen, Ingush, Kabardino-Balkarian republics.
6. Irkutsk SC— Irkutsk, Chita regions, Buryat Republic, Republic of Tyva.
7. Kazan SC— Tatarstan, Republic of Mari El, Chuvash, Udmurd republics.
8. Samara SC— Samara, Ulyanovsk, Orenburg regions.
9. Murmansk SK— Murmansk, Arkhangelsk regions.
10. Novosibirsk SC-Novosibirsk, Tomsk, Kemerovo, Omsk regions.
11. Rostov SC - Rostov region, Stavropol, Krasnodar region.
12. Saratov SC— Saratov, Penza, Belgorod, Lipetsk, Kursk, Oryol, Tambov regions.
13. Sverdlovsk SC— Sverdlovsk, Perm, Tyumen regions, Khanty-Mansiysk, Yamalo-Nenets national districts.
14. Ufa SC- Bashkortostan.
15. Chelyabinsk SC— Chelyabinsk, Kurgan regions.
16. Khabarovsk SK- Kamchatka, Sakhalin, Magadan, Amur region, Khabarovsk, Primorsky Territories, Republic of Sakha (Yakutia).

Literature used, in which, in addition, you can find additional information about the “radon problem”

1. RADON REMINDER FOR CITIZENS. “What is this and how to deal with it?” U.S. Environmental Protection Agency, Atmospheric and Radiation Service. US Department of Health and Human Services, Center for Disease Control. August 1986 ORA 86 004.
2. RADIATION: Doses, effects, risks. Per. from English, M.: Mir, 1998.
3. SOROS EDUCATIONAL JOURNAL, VOLUME, NO. 1, 1997
Utkin V.I. Gas respiration of the earth.
4. SOROS EDUCATIONAL JOURNAL, VOLUME 6, NO. 3, 2000
Utkin V. I. Radon problem in ecology.
5. ECOLOGICAL BULLETIN “Green Leaf” No. 6(25), 2001, p.4."ATTENTION, RADON!"
6. A.D.Vlasov, B.P.Murin. UNITS OF PHYSICAL QUANTITIES IN SCIENCE AND TECHNOLOGY. Directory, M.: EAI, 1990, p. 63-64.