Zones of radioactive contamination. Chernobyl in Belarus - was, is and will be
We were exposed to natural radiation even before the accident at the Chernobyl nuclear power plant. TUT.BY visited four research institutions, studied documents, some of which have not yet been published, and found out how “natural exposure” to radon affects the health of Belarusians.
Belarusian scientists who have studied the problem are unanimous: radon affects the level of morbidity, including oncology, now much more than the echoes of Chernobyl. The problem of radon exposure exists in almost all countries, as well as ways to deal with it. But it is in Belarus that everyone is focused on the topic of Chernobyl radiation - there are foreign funds, there are grants to overcome the consequences of a man-made disaster. Radon, in terms of raising funds, is “uninteresting”, its own, with which the Belarusians should, in a good way, cope on their own. But in a crisis at the state level, funding for research on radon is being reduced and the problem is simply not advertised.
What kind of gas is this?
First, let's define what radon is. This is a gas that is formed during the decay of radium. It is 7.5 times heavier than air and therefore accumulates in basements and ground floors. Radon is odorless and cannot be "felt". Enters the body through the lungs - part of the cases of lung cancer can be explained by its effects.
Although with the word "radon" for many, the first association is the sanatorium of the same name. Like, what kind of cancer, we remember - radon is useful. But it's all about dosage. Here, as with the sun, without it - rickets, and spend a day in the sun in swimming trunks - burns, heat stroke, the threat of skin cancer.
“Radon is contained in soil air, water and can penetrate into premises if they are located in areas where its content is high, in particular, in zones of tectonic faults,” explains Director of the Institute of Nature Management of the National Academy of Sciences Alexander Karabanov. - In Belarus, at least 40% of the territory is potentially radon-hazardous. The maximum permissible norm for residential premises is considered to be 200 becquerels per cubic meter. The excess of radon was recorded in the premises of a number of settlements in the country, most often in the Grodno, Mogilev and Vitebsk regions. Minsk also stands on the faults, however, there is no exact map of them.
The main sources and ways of penetration of radon into buildings. Gas enters the premises from soil, water, building materials. Source: geoliss.ru
Scale of the problem
According to the UN, in the annual exposure of mankind, the share of exposure to products of various tests is 0.7%, from the operation of nuclear power plants - 0.3%, during medical examinations - 34%, natural factors - 22%, and radon decay products - 43%. This is indicated in the article "Radon Concentration in Soil Air", published on the website of the Institute of Nature Management of the National Academy of Sciences of Belarus.
“After almost 30 years, the radiation situation in Belarus has improved significantly. The contribution of "Chernobyl" radionuclides to the total exposure dose of the population of Belarus from all natural and man-made radiation sources currently does not exceed 5%," says the "Monitoring of radon in the air of buildings in settlements in the Brest region." But the value of the average annual effective doses of exposure to radon in four separate regions of the country exceeds the effective dose of exposure of the population from "Chernobyl" radionuclides by 2.4-13.8 times, in the Brest region - by 6 times.
- In a number of countries, relevant studies were carried out. Where the concentration of radon is higher, the incidence is higher, including cancer, - says Professor Alexander Karabanov.- A connection has also been established between gastritis, diabetes mellitus, rheumatism and long-term stay in such areas.
Chief Radiologist of the Mogilev Center for Hygiene and Epidemiology Leonid Lipnitsky participated in the study of the risks of disease from natural exposure.
“There is a misunderstanding of the radon problem in society,” he states. — The average annual effective doses of exposure per inhabitant of the Mogilev region were: from natural sources of ionizing radiation, including radon 2.5 mSv, from radioactive contamination due to the Chernobyl accident (for radioactively contaminated territories) — 0.34 mSv . The difference is significant.
This is not classified information. Volumes of scientific papers abroad are devoted to the problem of protecting public health from radon.
“At the same time, the radiation hazard of natural radon in Belarus was little covered. Until now, a national research program on the problem of radon and the protection of the population from exposure to this gas has not been developed. But epidemiological studies have long discovered a direct link between radon exposure and cancer, says Leonid Lipnitsky.
Where does radon come out?
In general, there are hundreds of faults under Belarus. Full size map of them
- On the territory of Minsk, one fault runs approximately along the Svisloch, the second - from the southwest to the northeast, the third - along the western part of the city, partly under Pushkin Avenue, - says Alexander Karabanov. - Faults can be more than a kilometer wide (it differs in different areas) and do not go in a straight line.
In the 1990s, in Belarus, measurements of the radon content were made above the faults, and there its concentration increased several times. In addition to it, anomalies of geophysical fields are noted in these places.
However, not only faults "fonyat".
“High concentrations of radon in the soil air are formed in the zones of distribution of gravel-pebble, moraine and some other clay deposits, as well as in the shallow occurrence of granite rocks,” notes engineer of the Joint Institute for Energy and Nuclear Research (Sosny) Lev Vasilevsky.- In the Gomel region - a fault on a fault, but there is less radon compared to Vitebsk. However, in the north they are less studied. Radon can come not only from faults, but also from boulders and stones.
Where is the "fonit" Minsk
The Joint Institute also carried out measurements in Minsk.
- We found an increased content of radon in Loshitsa, on the street. Mayakovsky, on Pushkin Avenue, but these are single premises, for example, the registry office of the Frunzensky district. There is a lot of this gas in the Sosen area. For example, in a quarry near the Moscow Ring Road, 800 Bq per cubic meter, which is four times higher than the norm set for residential premises, the specialist adds.
Chief Geophysicist of the Geophysical Expedition Alexander Belyashov agrees that where there are moraines (glacial deposits. - Approx. TUT.BY), there is increased radioactivity. It is higher in the north than in the south. There are many clay rocks.
“Our radiologists have mapped the correlation between cancer incidence and exposure dose rate. Conclusion: the composition of soils is associated with oncological and other diseases, the interlocutor clarifies.
Scheme of zoning according to the concentration of radon in the soil air (No. 1−4, 6 - potentially radon hazardous areas). Source: Institute of Nature Management NAS In general, when doctors say that they do not always understand why people in a certain area get sick more, they may simply not take into account the radon factor.
Logically, citizens living on the faults and in the "dark" territories should be warned about the danger.
- In these territories, special work should be carried out to prevent the penetration of radon into the premises, especially into residential areas, by concreting and in other ways. It is important! - insists Doctor of Geological and Mineralogical Sciences Alexei Matveev.
But people are not being warned. However, one cannot say that the problem is completely ignored in Belarus.
“In our country, during new construction, the measurement of radon in the soil is mandatory, and building materials are carefully monitored,” explains Alexander Belyashov.
Abroad, the problem has been given due attention for so long that no one notices that “anti-radon” protection is being done.
— A Swedish specialist came to us and advised on faults. They have a clear correlation between the amount of radon in the house and the incidence of cancer. The problem there intensified long ago, when energy-saving housing with insulated facades and airtight windows came into fashion. They began to save on heating, but the number of diseases, including cancer, has increased,” says Alexander Belyashov. - In countries with increased radon danger, there is forced sealing and ventilation of basements. It's in the building codes. And it's not even discussed.
Indeed, there are no other ways to deal with radon: only concreting and regular airing. It's enough.
Money ran out
Research on radon is carried out as far as funds are available Joint Institute for Energy and Nuclear Research, Institute for Nature Management of the National Academy of Sciences, Geophysical Expedition of the Scientific and Practical Center for Geology.
Through the efforts of Belarusian scientists, a radon risk map was created based on measurements in the air of buildings. It was introduced in 2015. Judging by the map, elevated radon concentrations are in the premises of the Vitebsk, Grodno, north-eastern districts of the Mogilev regions. There are "spots" with a dangerous concentration of radon in the range of 200-400 Bq per cubic meter in the regions of Vitebsk, Grodno and Mogilev regions. To map the radon risk, 3594 measurements in 454 settlements were used.
Map of radon concentration in rooms (No. 5 - the darkest spots - 200-400 Bq). Radiation background and pollution maps
Download:
After the greatest nuclear disaster at the Chernobyl Nuclear Power Plant (ChNPP) in 1986, a large amount of radioactive fallout (radionuclides) fell on vast territories. We bring to your attention fragments of maps of contamination of the Brest region with Cesium-137 (half-life 30 years).
The distance from the Chernobyl nuclear power plant to Domachevo is 452 km.
Measurement data of gamma radiation dose rate (µSv/h) on the radiation monitoring network in the Republic of Belarus
The natural radiation background in Belarus is 0.10 µSv/h
Maps of Cesium-137 pollution in the Brest region
(Fig. 1) As of 1998
(orange color shows the pollution zone from 1 to 5 Ku/km²)
(purchased from www.beltc.info
)
(Fig. 2
→
(Fig. 3
(downloaded from www.chernobyl.gov.by )
(Fig. 4) Cesium-137 pollution map Domachevo and neighboring villages (1998)
Provided by: Administrator
Dosimeter readings Radex RD 1503 in Domachevo
Radex RD1503 is a household pocket device that evaluates the radiation situation by 
the magnitude of the ambient dose equivalent rate of gamma radiation (hereinafter referred to as the dose rate), taking into account the contamination of objects with sources of beta particles, or the magnitude of the exposure dose rate of gamma radiation (hereinafter referred to as the exposure dose rate), taking into account the contamination of objects with sources of beta particles. It is used to assess the level of radiation on the ground, indoors and to assess the radioactive contamination of materials and products.
For our area, the radiation background (natural) is 10-11 microR/h (micro-roentgen per hour). And everything above is a man-made factor - Chernobyl.
Photo:
(near the "band") 95.5KB
(near the abandoned monument to the dead border guards) 189KB
(near "system") 230KB
(near the abandoned monument to the dead border guards) 165KB
(as you all know, granite and other rocks emit ionizing radiation, which I was convinced of) 164KB
(on the background on the left is the Velcom antenna, and on the right is MTS) 73KB
(against the background of the Chabarok bar) 167KB
The signing of an agreement on the construction of a nuclear power plant against the backdrop of the disaster in Japan made the nerves of Belarusians, which had not been strengthened after the Chernobyl tragedy, shudder once again. What is radiation? How and in what doses does it affect a person? Can exposure be avoided in everyday life? We decided it would be useful to remind once again what is what in terms of the effect of radiation on a person.
Most often, when people talk about radiation, they mean "ionizing" radiation associated with radioactive decay. Although a person is also exposed to a magnetic field or ultraviolet light (non-ionizing radiation), says the chairman of the National Commission for Radiation Protection under the Council of Ministers Yakov Koenigsberg.
Radioactivity units
The most common units for measuring soil and food radioactivity are Becquerel (Bq) and Curie (Ci). Typically, activity is indicated per 1 kg of food. The maps indicate activity per unit area, for example, km 2 . But the level of contamination of the territory 1Ci/km2 in itself does not say anything about what kind of exposure people living in this territory received. A measure of the harmful effects of radioactive radiation on a person is the radiation dose, which is measured in Sieverts (Sv).
Term | Units | Unit ratio | Definition |
|
In the SI system | In the old system |
|||
Activity | Becquerel,Bq | 1 Ki \u003d 3.7 × 10 10 Bq | number of radioactive decays per unit time |
|
Dose rate | sievert per hour, Sv/h | roentgen per hour, R/h | 1 μR/h=0.01 μSv/h | radiation level per unit time |
Absorbed dose | radian, rad | 1 rad=0.01 Gy | amount of ionizing radiation energy transferred to a specific object |
|
Effective dose | Sievert, Sv | 1 rem=0.01 Sv | radiation dose, taking into account the different sensitivity of organs to radiation |
|
So, in sieverts per unit of time, the level of background radiation is measured. The natural background radiation on the earth's surface averages 0.1-0.2 µSv/h. A level above 1.2 µSv/h is considered dangerous for humans. By the way, yesterday the level of radiation 20 km from the emergency Japanese nuclear power plant "Fukushima-1" - a radiation level of 161 μSv / h was recorded. For comparison: according to some reports, after the explosion at the Chernobyl nuclear power plant, the radiation level in places reached several thousand μSv / h.
As for the Becquerel, it serves as a unit for measuring the radioactivity of water, soil, etc. per unit in which this water, soil is measured ... Thus, according to the latest data in Tokyo, the level of radiation in tap water has been exceeded: the content of radioactive iodine in water is 210 becquerels per liter.
And Gray is needed to measure the absorbed dose of radiation by a particular object.
But back to the Sieverts:
In accordance with Belarusian legislation, the allowable radiation dose for the population is 1 mSv per year, and for professionals working with sources of ionizing radiation - 20 mSv per year.
In addition, the impact of radioactive radiation on a person was previously calculated in such a unit as rem (the biological equivalent of a roentgen). Today, Sieverts are used for this. In this unit, you can evaluate the influence of radiation sources in everyday life, for example. So, the annual dose from watching TV for 3 hours a day is 0.001 mSv. The annual dose from smoking one cigarette a day is 2.7 mSv. One fluorography - 0.6 mSv., One radiography - 1.3 mSv, one fluoroscopy - 5 mSv. Calculate and compare: 20 mSv is the average allowable level of exposure for workers in the nuclear industry per year.
Additionally, the radiation of concrete dwellings is also taken into account - up to 3 mSv per year and the natural dose of radiation from the environment - more than 2 mSv per year. An interesting comparison: natural exposure near monazite deposits in Brazil is 200 mSv per year. And people live with it!
The effect of radiation on the human body
Radiation in the usual human sense (i.e. ionizing radiation) has a certain effect on the human body. The effect of radiation on humans is called irradiation. The basis of this effect is the transfer of radiation energy to the cells of the body. So, one of the effects of exposure - deterministic - manifests itself from a certain threshold and depends on the dose of radiation.
"Its most striking manifestation when irradiating a part or the whole body is acute radiation sickness, which develops only from a certain threshold and has varying degrees of severity. Theoretically, radiation sickness can manifest itself when exposed to a dose of 1 sievert (this is the weakest degree of radiation sickness),” says Yakov Kenigsberg. For comparison: according to our table, a dose of 0.2 sievert increases the risk of cancer, and 3 sievert threatens the life of the exposed .
Also referred to as a deterministic effect radiation burns, which occur both when a person is exposed to large doses of radiation, and in contact with the skin. Very large doses lead to the death of the skin, up to damage to muscles and bones. Such burns, by the way, are treated much worse than chemical or thermal ones.
On the other hand, radiation can manifest itself long after exposure, causing the so-called. stochastic effect. This effect is expressed in the fact that among exposed people the frequency of certain oncological diseases. Theoretically, genetic effects are also possible, but at the moment, experts attribute them to theory, since they have never been identified in humans. According to scientists, even in the 78,000 Japanese children who survived the atomic bombing of Hiroshima and Nagasaki, no increase in the incidence of hereditary diseases was found.
Besides, various experts note that irradiation, in addition to burns and radiation sickness, can cause metabolic disorders, infectious complications, radiation infertility, and radiation cataracts.The consequences of irradiation have a stronger effect on dividing cells, so radiation exposure is much more dangerous for children than for adults.
"We cannot say for sure which specific disease, even when receiving the same dose of radiation, may develop or not develop any oncological disease," notes J. Koenigsberg.
In a country with a large number of exposed people, an increase in the incidence of cancer is possible. At the same time, diseases can be caused both by radiation and chemical harmful substances, viruses, etc. For example, in the Japanese irradiated after the bombing of Hiroshima, the first effects in the form of an increase in the incidence began to appear only after 10 years or more, and some - after 20 years.
To date, it is known which tumors can be associated with radiation. Among them - thyroid cancer, breast cancer, cancer of certain parts of the intestine.
***By the way, in addition to artificial radionuclides (iodine, cesium, strontium), which “hit” the Belarusians after the Chernobyl tragedy, natural radionuclides. The most common among them are potassium-40, radium-226, polonium-210, radon-222, -220. For example, a person receives the bulk of the exposure dose from radon while in a closed, unventilated room (radon is released from the earth's crust and concentrated in indoor air only when they are sufficiently isolated from the external environment). Relatively little radon is emitted by building materials such as wood, brick and concrete. For example, granite and pumice, which are also used as building materials, have a higher specific radioactivity.
Penetration of radionuclides into foodRadionuclides enter the body with food, water and through polluted air. For example, as a result of nuclear tests, almost the entire globe was contaminated with long-lived radionuclides. From the soil they got into the plants, from the plants - into the organisms of animals. And to a person - with milk and meat of these animals, for example, says Yakov Konigsberg.
“Today, all products that are produced in Belarus in the public and private sectors are controlled,” he notes. “Besides, there are special maps in the leshozes, which indicate the places where you can and where you cannot pick mushrooms and berries.”
If a person can check the level of radiation in the air on his own by purchasing an appropriate device, then in order to check, for example, the content of radionuclides in "gifts of nature", you need to contact a special laboratory. There are such laboratories in every regional center - in the system of the Ministry of Agriculture and Food, the Ministry of Health, Belkooperatsiya.
In addition, you can reduce the risk of radioactive contamination through food if you cook food in a certain way.
More than 1.15 million people (12% of the total population) live in Belarus in areas of radioactive contamination. Of these, 115.7 thousand are residents of the Mogilev region.
Official statistics published on the eve of the 25th anniversary of the explosion at the Chernobyl nuclear power plant indicate that the consequences of the tragedy in Belarus have not yet been overcome. People continue to live in contaminated with radionuclides (mainly cesium-137 - approx. website) towns and villages.
So, according to Belstat, at the beginning of 2011, this list included 29 cities and urban-type settlements and 2372 rural settlements (10.1% of all settlements of the republic).
Of the 1140.4 thousand inhabitants of these settlements, the majority (782.5 thousand) are city dwellers. Children aged 0 to 17 years old make up 219.6 thousand (19.3%), and they are also predominantly city dwellers.
For the three most affected areas, the statistics are as follows:
- Gomel region - 879.3 thousand people (61.3% of the total population of the region);
- Brest region - 116 thousand people (8.3%);
- Mogilev region - 115.7 thousand people (10.6%).
How the situation has changed
The data of the statistical report show that since 1991 the number of citizens living in the zones of radioactive contamination has decreased by 712.6 thousand people.
This happened as a result of resettlement from these zones, as well as due to the "improvement of the radioactive situation."
The half-life of cesium-137 is 30 years. Forests are being planted in Belarus to prevent the spread of radionuclides in the territories adjacent to the zones of contamination with cesium-137. In 2010, 1.8 thousand hectares (ha) of forest were planted in the Mogilev region, and 0.4 thousand hectares in the Gomel region, Belstat notes.
As reported on the website of the Mogilev Regional Executive Committee, in the region "1252.984 thousand hectares of land are contaminated with radionuclides, including 804.184 thousand hectares of agricultural land and 448.8 thousand hectares of forest land."
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Radiation control of these territories is carried out by the Mogilev State Production Forestry Association.
To resolve issues related to overcoming the consequences of the catastrophe at the Chernobyl nuclear power plant (distribution and control of financial resources, benefits), a special department operates in the regional executive committee.
The conclusions of scientists about the causes of the disaster at the Fukushima-1 nuclear power plant should be taken into account when building a nuclear power plant in Belarus. As the BelaPAN agency reported, this was stated on April 25 in Minsk by the charge d'affaires ad interim of Japan in Belarus Matsuzaki Kiyoshi.
The Japanese diplomat noted that “each government, state has the right to decide for itself whether to build or not to build a nuclear power plant”, and wished the Belarusian side that the work “goes on successfully”. He knows that Belarus "consulted with the IAEA" on this issue.
What financial losses did Belarus suffer from the Chernobyl accident?
The total concentration of cesium-137 in European countries
The half-life of cesium-137 has ended, the half-life of benefits for Chernobyl victims continues, and the half-life of secrets has begun (publication of the Komsomolskaya Pravda newspaper, 2003)
