КАРТА РАДОНОВОЙ ОПАСНОСТИ ТЕРРИТОРИИ РЕСПУБЛИКИ БЕЛАРУСЬ

Radon is the major contributor to the background exposure of the population. In the world practice, the radon risk or radon potential mapping are used for the radon dose assessment.The aim of this work was a radon danger mapping of the Republic of Belarus to assess the radiation situation and determine the radon hazard critical areas.Materials and methods: The mapping is based on measured values of radon volume activity in the living rooms of different buildings on the territory of the six regions of the Republic of Belarus. We have performed more than 4000 measurements. Integral track radon radiometers based on the polymer Kodak LR-115 film were used to evaluate radon volume activity. Exposure time ranged from 90 to 120 days. The cartogram was built with using the MAPINFO software package.Results: The low levels of radon concentrations were determined in the Brest and Gomel regions, as well as in the southern districts of Minsk and south-western districts of the Mogilev region. The high levels radon concentrations were determined in some districts of the Vitebsk and Grodno regions, as well as in the north-eastern districts of the Mogilev region. About 2–5 times nonuniformity of radon distribution in settlements of the Republic was observed. The radon hazard critical areas with radon concentrations in the range of 200–400 Bq/m3 were found in some districts of the Vitebsk, Grodno and Mogilev regions.Conclusions: The radon risk map of the Republic of Belarus gives the possibility to estimate the existing radiation risk. Taking into account the low efficiency of countermeasures long after the Chernobyl accident, it is necessary to increase the level of radiation protection through the radon mitigation activities or to change the radon normative documents.В условиях определения суммарных доз облучения населения важной является естественная компонента радиационного фона, обусловленная, в основном, радоном. В мировой практике для расчета радоновой составляющей применяют картирование территории по радоновому риску или радоновому потенциалу.Целью настоящей работы являлось картирование территории Республики Беларусь по радоновому риску для оценки радоновой обстановки и определению критических зон радоноопасности.Материалы и методы: основой для построения карты являлись измеренные значения объемной активности радона в жилых помещениях различных населенных пунктов 6 областей Республики Беларуси – более 3500 измерений. Объемная активность определялась при помощи интегральных трековых радиометров радона на основе полимерной пленки Kodak LR-115. Время экспозиции находилось в диапазоне 90–120 суток. Картограмма была по- строена при помощи пакета прикладных программ MAPINFO.Результаты: были установлены низкие концентрации радона в Брестской и Гомельской областях, а также в южных районах Минской и юго-западных районах Могилевской области. Отмечены высокие концентрации радона в ряде районов Витебской и Гродненской областей, а также в северо-восточных районах Могилевской области. Неравномерность распределения радона по населенным пунктам республики в среднем составляет 2–5 раз. Отмечено наличие критических зон радоновой опасности с концентрацией радона в пределах 200–400 Бк/м3 в некоторых районах Витебской, Гродненской и Могилевской областей.Заключение: картирование территории Республики Беларусь по радоновой опасности позволяет в полной мере и адекватно оценить существующие радиационные риски возможных радиационных эффектов и, с учетом низкой эффективности контрмер в отдаленном периоде после чернобыльской аварии, повысить уровень радиационной безопасности путем проведения противорадоновых мероприятий или изменения подхода к нормированию облучения

ОЦЕНКИ ДОЗ ОБЛУЧЕНИЯ НАСЕЛЕНИЯ В ОТДАЛЁННОМ ПЕРИОДЕ АВАРИИ НА ЧАЭС: ОПЫТ МЕЖДУНАРОДНОГО СОТРУДНИЧЕСТВА

The study which had been conducted in the period from 1990 to 2000’s in the settlements ofGomelregion showed that the average internal exposure doses of population living in the settlements situated on territories with equal levels of contamination density were considerably different. The reasons for the difference have been revealed. It was shown that not only radiation contamination of territory but also a range of factors of non-radiation origin have influence on formation of internal exposure dose. The hypothesis has been approved that internal exposure dose of each individual and also of each family has its certain place, constant in time at a dose distribution curve. This appropriateness had been used as a methodological basis for reconstruction of subjects’ individual doses for any time period. Method for estimating the average annual effective exposure doses of inhabitants living in contaminated settlements of theBelarusRepublichad been developed. The results of the Whole Body Counter measurements had been used for direct assessment of internal exposure dose and as the basis for developing a model. Model for the dose estimation is based on the classification of settlements according to regional characteristics of soil, which cause 137Cs in taking with locally produced foodstuff. The model is also based on regression of daily 137Cs intake on the density contamination of the soil for each region. The effect of the indirect factors on the dose forming had been taken into account: the number of inhabitants and the area of forest around the settlement. According to the developed method, there had been created a Catalog of Average Annual Effective Doses of Residents of the Belarus Republic.Исследования, проведенные за период 1990–2000 гг. в населённых пунктах Гомельской области, показали, что средние дозы внутреннего облучения населения, проживающего в населенных пунктах на территориях с близкими значениями плотности загрязнения,существенно различаются. Выявлены причины этого различия. Показано, что на формирование дозы внутреннего облучения оказывает влияние не только непосредственно радиационное загрязнение территории, но и ряд нерадиационных факторов. Подтверждена гипотеза о том, что доза внутреннего облучения каждого индивида, а также каждой семьи на кривой распределения дозы имеет своё определённое место, постоянное во времени. Эта закономерность была использована в качестве методической основы для реконструкции индивидуализированных доз облучения лиц в любой временной период. Разработана методика оценки средних годовых эффективных доз облучения жителей радиоактивно загрязненных населенных пунктов (НП) Республики Беларусь. Результаты СИЧ-измерений использованы для непосредственной оценки дозы внутреннего облучения и в качестве основы для разработки модели. Модель для оценки дозы базируется на классификации населённых пунктов по региональным особенностям почв, обусловливающих поступление 137Сs в продукты питания местного производства и произрастания, и построении регрессионных зависимостей суточного поступления от плотности загрязнения территории населенного пункта 137Сs для каждого региона. Учтено влияние косвенных факторов на формирование дозы: численности жителей и площади леса вокруг населённого пункта. По разработанной методике создан Каталог средних годовых эффективных доз облучения жителей населенных пунктов Республики Беларусь

Сalix[4]arene chalcone amides effects on myometrium mitochondria

Mitochondria are a key player in a wide range of the most important functions of the cell. Calixarenes are supramolecular compounds that have been widely used in bioorganic chemistry and biochemistry. The aim of this work was to study the effects of calix[4]arenes with two (С-1012, С-1021), three (С-1023, С-1024) and four (С-1011) chalcone amide groups on the myometrial mitochondria membranes polarization, Ca2+ concentration in the matrix of these organelles ([Ca2+]m ) and on the average hydrodynamic diameter of mitochondria. It was shown that permeabilized myometrium cells incubation with calix[4]arenes containing two or more chalcone amide groups, was accompanied by an increased level of myometrial mitochondria membranes polarization. All studied calix[4]arenes increased [Ca2+]m values in the absence and in the presence of exogenous Ca2+. The values of [Ca2+]m in the absence of exogenous Ca2+ were higher at mitochondria incubation in Mg2+-containing, than in Mg2+,ATP-containing medium. Incubation of isolated mitochondria with the studied calix[4]arenes resulted in changes of mitochondria volume: at incubation with С-1012, С-1021, C-1023 the average hydrodynamic diameter was decreased, while with С-1011 it was increased. Thus, we have shown that a short-term (5 min) incubation of mitochondria in the presence of 10 µM calix[4]arenes, which contain from two to four chalcone amide groups, increased the level of mitochondria membranes polarization, ionized Ca concentration in the matrix and had different effects on the mitochondrial volume

ОЦЕНКА ВЛИЯНИЯ РАДОНА НА РАДИАЦИОННУЮ ОБСТАНОВКУ В РЕСПУБЛИКЕ БЕЛАРУСЬ

The change in the radiation situation in the territory of Belarus has been assessed. It was shown that the radiation dose values connected with the Chernobyl accident were decreased and the relative value of the radon factor was increased. It was shown that these radiation factors have different trends in the territory of the Republic. There is a large irregular radon distribution in the territory of Belarus. The difference of the radon dose values in many regions of Belarus was more than in the absolute value of the Chernobyl caesium-137 dose. It is necessary that the radon influence on people must be taken into accountin the studies of biological and medical effects of radiation.Приводится анализ радиационной обстановки в Республике Беларусь, обусловленной чернобыльскими выпадениями и радоном. Показано, что при рассмотрении эффектов воздействия ионизирующего излучения на население следует учитывать не только чернобыльские выпадения, но и другие источники, в первую очередь, радон. Показана неравномерность распределения доз от радона по территории Беларуси, а также определяющее влияние радона на радиационную обстановку в большинстве административных районов страны, особенно за пределами территории сильного загрязнения чернобыльскими радионуклидами. Сделан вывод о необходимости обязательного учета радона при исследовании медико-биологических последствий облучения от техногенных и природных источников

THE REPUBLIC OF BELARUS RADON DANGER MAP

Radon is the major contributor to the background exposure of the population. In the world practice, the radon risk or radon potential mapping are used for the radon dose assessment.The aim of this work was a radon danger mapping of the Republic of Belarus to assess the radiation situation and determine the radon hazard critical areas.Materials and methods: The mapping is based on measured values of radon volume activity in the living rooms of different buildings on the territory of the six regions of the Republic of Belarus. We have performed more than 4000 measurements. Integral track radon radiometers based on the polymer Kodak LR-115 film were used to evaluate radon volume activity. Exposure time ranged from 90 to 120 days. The cartogram was built with using the MAPINFO software package.Results: The low levels of radon concentrations were determined in the Brest and Gomel regions, as well as in the southern districts of Minsk and south-western districts of the Mogilev region. The high levels radon concentrations were determined in some districts of the Vitebsk and Grodno regions, as well as in the north-eastern districts of the Mogilev region. About 2–5 times nonuniformity of radon distribution in settlements of the Republic was observed. The radon hazard critical areas with radon concentrations in the range of 200–400 Bq/m3 were found in some districts of the Vitebsk, Grodno and Mogilev regions.Conclusions: The radon risk map of the Republic of Belarus gives the possibility to estimate the existing radiation risk. Taking into account the low efficiency of countermeasures long after the Chernobyl accident, it is necessary to increase the level of radiation protection through the radon mitigation activities or to change the radon normative documents

EXPOSURE DOSES ASSESSMENT OF POPULATION AT LONG-TERM PERIOD AFTER THE CHERNOBYL ACCIDENT: INTERNATIONAL COLLABORATION EXPERIENCE

The study which had been conducted in the period from 1990 to 2000’s in the settlements ofGomelregion showed that the average internal exposure doses of population living in the settlements situated on territories with equal levels of contamination density were considerably different. The reasons for the difference have been revealed. It was shown that not only radiation contamination of territory but also a range of factors of non-radiation origin have influence on formation of internal exposure dose. The hypothesis has been approved that internal exposure dose of each individual and also of each family has its certain place, constant in time at a dose distribution curve. This appropriateness had been used as a methodological basis for reconstruction of subjects’ individual doses for any time period. Method for estimating the average annual effective exposure doses of inhabitants living in contaminated settlements of theBelarusRepublichad been developed. The results of the Whole Body Counter measurements had been used for direct assessment of internal exposure dose and as the basis for developing a model. Model for the dose estimation is based on the classification of settlements according to regional characteristics of soil, which cause 137Cs in taking with locally produced foodstuff. The model is also based on regression of daily 137Cs intake on the density contamination of the soil for each region. The effect of the indirect factors on the dose forming had been taken into account: the number of inhabitants and the area of forest around the settlement. According to the developed method, there had been created a Catalog of Average Annual Effective Doses of Residents of the Belarus Republic