Specific Radioactivity Research Articles

Вклад содержащих радионуклиды пищевых продуктов в формирование доз внутреннего облучения населения юго-запада Брянской области после аварии на Чернобыльской АЭС

The authors review current specific features of internal radiation doses received by people resided in 135 urban and rural settlements in six south-western districts of the Bryansk region affected by the Chernobyl accident. The residents received the average annual radiation dose > 1 mSv. The Cs-137 radioactivity contained in local agricultural and natural food was evaluated with the account of the dietary structure. Comparative analysis of long-term data on a contribution of local food contained radionuclides to the population, estimated by the average annual effective dose of internal radiation was carried out. Potatoes and pork taken from the private farms in the settlements under survey met health and hygiene standards for different levels of Cs-137 in 2022. However, there was a risk of exceeding the sanitary hygiene’s requirements for Cs-137 specific radioactivity in milk from privately-owned farms located in 89% of the settlements under survey, in 98% of beef produced in the farms and in 100% of mushrooms collected in forests near these settlements. Currently, the main dose-forming product is milk (contribution to the internal exposure dose is 60%), a smaller role in dose formation is in mushrooms (about 20%) and a minimal dose is in potatoes and meat (10% each). Over the past 20 years, the contribution of milk to the internal exposure dose has increased by 15-20%, and the contribution of mushrooms has decreased because of changes in the diet of the rural population of the Bryansk region and due to the reduction and redistribution of local products in the food basket.

NORMs distribution in the dust samples from the educational institutions of Megacity Dhaka, Bangladesh: Radiological risk assessment

This study demonstrates the specific radioactivities of primordial radionuclides in dust samples collected from educational institutions of the megacity Dhaka, Bangladesh. Elemental levels from neutron activation analysis were converted into the corresponding radioactivity. Meann=26 radioactivity abundances of 226Ra, 232Th, and 40K (NORMs: Naturally Occurring Radioactive Materials) in the dust sample were 28.6, 43.8, and 462 Bq.kg−1, respectively, where 232Th and 40K activities were relatively higher compared to the corresponding world mean values (232Th: 30 Bq.kg−1, and 40K: 400 Bq.kg−1). Alterations in NORMs abundances compared to the source materials (surface soil) were explained in terms of weathering followed by aerodynamic transportation. Calculation of usual radiological indices invokes human health hazards. Considering the higher vulnerability of school going children and juveniles towards ionizing radiations and the entrance of NOMRs-containing dust particles into the respiratory system, the estimated radiological indices only demonstrate the possible lowest risks. But in a real scenario, alpha particles from the decay series of 238U and 232Th can cause severe radiation damage to the human respiratory system.

MACROMYCETES AS BIOINDICATORS OF RADIONUCLIDE CONTAMINATION IN FOREST ECOSYSTEMS

The aim of the paper is to determine the specific activity of radionuclides in macromycetes in Ulyanovsk region forest ecosystems exposed to radiation after the Chernobyl accident.
 Materials and Methods. The fruiting bodies of macromycetes (soil and wood-destroying fungi) gathered in the radioactive contaminated territories served as the material for the research. The authors determined the specific activity of Cs-137, K-40, Ra-226, Th-232 radionuclides. The study was conducted during the growing season in the Ulyanovsk region forests (Inza and Karsun districts). For comparison, fungi samples (control) were also gathered in the Novospassky region, where the excess background radiation was not observed. Trial sites with similar forest growth conditions were selected. The specific activity of radionuclides in the fungi fruiting bodies was determined according to Guidelines 2.6.1.1194–03.
 Results. In soil fungi, the highest average Cs-137 specific activity was found in the fruiting bodies of Leccinum scabrum, K-40 and Ra-226 specific activity – in the fruiting bodies of Suillus luteus, and Th-232 specific activity – in the fruiting bodies of Macrolepiota procera.
 In wood-destroying fungi, the highest average Cs-137, K-40 and Ra-226 specific activity was observed in the fruiting bodies of Fomitopsis pinicola, and the highest Th-232 specific radioactivity – in the fruiting bodies of Coriolus versicolor. The average specific activity of all radionuclides in the mushrooms from the radioactive contamination territories (Inza and Karsun districts) was mainly higher than in the control (Novospassky district). In the studied samples of soil and wood-destroying fungi, excess radioactive concentrations were not found.
 Conclusion. Forest mycobiota can be used as a bioindicator of radioactive environmental pollution.

Содержание естественных радионуклидов 40К, 226Ra, 228Th в черноземах заповедника Каменная степь

The article discusses the results of a study of the content of natural radionuclides (40K, 226Ra, 228Th) in ordinary chernozems of the Kamennaya Steppe Reserve. The studies were carried out in soils not subject to any anthropogenic impact under the forest belt, as well as mowed and unmowed fallows. The development of nuclear energy, the widespread use of radioactive sources in industry, medicine, and agriculture has led to an increase in the content of not only artificial, but also natural radionuclides. It was revealed that the accumulation of natural radionuclides is determined by the organic matter of soils. In the chernozems under the forest belt, with the highest carbon content of organic compounds, a slightly larger amount of natural radionuclides (40K, 226Ra, 228Th) is noted. This phenomenon occurs due to selective complexation with soil organic ligands, which are enriched in the studied soils. The highest coefficient of variation is typical for 226Ra, which indicates the inhomogeneity of the activity of the radionuclide in space. 40K and 228Th are characterized by lower values. The activity of these radionuclides is more uniformly distributed in space. The obtained results are recommended to be used when conducting monitoring studies in order to prevent contamination of the soil cover with radionuclides. Keywords: CHERNOZEMS, SPECIFIC RADIOACTIVITY, NATURAL RADIONUCLIDES, POTASSIUM, RADIUM, THORIUM, KAMENNAYA STEPPE RESERVE

Design synthesis of Y-90 glass microspheres and study of their therapeutic effects on mouse liver cancer cell line Hep3B

In this article, a system for synthesizing Y-90 glass microspheres (Y-90-GM) was successfully designed in the Da Lat nuclear reactor (Vietnam), and the therapeutic effects of Y-90-GM on mice liver cancer cell line Hep3B were studied. The effects of synthesis factors, including heating time, heating temperature, gas flow rate, sample conduit length and diameter, were investigated to establish the optimal parameters. The size and shape of Y-90-GM were checked by field emission scanning electron microscope, and the radioactivity measurement was performed on a dosimeter. The results indicated that the optimal conditions for the synthesis of Y-90-GM were determined as the heating temperature of 1600 °C, heating time of 2 h, conduit length and diameter of 50 cm and 3.6 cm, and gas/oxygen flow rate of 15 mph. The Y-90-GM samples obtained at the optimal parameters have a size of 18–30 μm with a density of 3.53 g cm−3 and a specific radioactivity of 630 mCi g−1. The results of the therapeutic study on mice liver cancer cell line Hep3B showed that after two weeks of treatment with Y-90-GM (1mCi/mouse), the tumor volume was reduced by about 30.7% and after 3 consecutive treatment cycles, the liver cancer tumor was completely reduced. It was demonstrated that Y-90-GM is promising radiopharmaceuticals in the treatment of liver cancer by the radioembolization method.

Радиоактивность почв Хубсугул и Баярхонгорского аймака

The investigation has been performed at the Nuclear Research Centre National University of Mongolia. A method of determination of man- made and natural radioactivity nuclides in soil samples, using HP-Ge gamma spectrometer is discussed. Results of measurements of radionuclides in soil samples, collected from 2 different regions of Bayanhongor and Huwsgul aimag, were presented. It is determined a specific radioactivity of soil compared with world data.

Зарим хот орчмын цацраг идэвхийг гамма спектрометрээр судалсан нь

The specific radioactivity concentrations of 225Ra, 232Th, 40K and 137Cs were measured in soil samples from some city in Mongolia, using a gamma-ray spectrometer with a HpGe-detector. The background radiation of the total natural and anthropogenic radioactivity in thr studied soil was estimated.

Улаанбаатар хотын ундны усанд Rn-222-ыг тодорхойлсон тухай

The specific radioactivity of 222Rn was measured in drinking water of Ulaanbaatar city, using liquid scintillator and gamma-ray spectrometer with HpGe-detector.

Selective adsorption of Ba2+ using chemically modified alginate beads with enhanced Ba2+ affinity and its application to 131Cs production

The 131Cs radioisotope with a short half-life time and high average radiation energy can treat the cancer effectively in prostate brachytherapy. The typical 131Cs production processes have a separation step of the cesium from 131Ba to obtain a high specific radioactivity. Herein, we suggested a novel 131Cs separation method based on the Ba2+ adsorption of alginate beads. It is necessary to reduce the affinity of alginate beads to cesium ions for a high production yield. The carboxyl group of the alginate beads was replaced by a sulfonate group to reduce the cesium affinity while reinforcing their affinity to barium ions. The modified beads exhibited superior Ba2+ adsorption performances to native beads. In the fixed-bed column tests, the saturation time and adsorption capacity could be estimated with the Yoon-Nelson model in various injection flow rates and initial concentrations. In terms of the Cs elution, the modified alginate showed better performance (i.e., an elution over 88%) than the native alginate (i.e., an elution below 10%), indicating that the functional group modification was effective in reducing the affinity to cesium ions. Therefore, the separation of cesium from the barium using the modified alginate is expected to be an additional option to produce 131Cs.

Synthesis of typical sulfonamide antibiotics with [14C]- and [13C]-labeling on the phenyl ring for use in environmental studies

BackgroundDue to their widespread use, sulfonamide antibiotics (SAs) have become ubiquitous environmental contaminants and thus a cause of public concern. However, a complete understanding of the behavior of these pollutants in complex environmental systems has been hampered by the unavailability and high cost of isotopically labeled SAs.ResultsUsing commercially available uniformly [14C]- and [13C]-labeled aniline as starting materials, we synthesized [phenyl-ring-14C]- and [phenyl-ring-13C]-labeled sulfamethoxazole (SMX), sulfamonomethoxine (SMM), and sulfadiazine (SDZ) in four-step (via the condensation of labeled N-acetylsulfanilyl chloride and aminoheterocycles) or five-step (via the condensation of labeled N-acetylsulfonamide and chloroheterocycles) reactions, with good yields (5.0–22.5% and 28.1–54.1% for [14C]- and [13C]-labeled SAs, respectively) and high purities (> 98.0%).ConclusionThe synthesis of [14C]-labeled SAs in milligram amounts enables the preparation of labeled SAs with high specific radioactivity. The efficient and feasible methods described herein can be applied to the production of a variety of [14C]- or [13C]-labeled SAs for studies on their environmental behavior, including the fate, transformation, and bioaccumulation of these antibiotics in soils and aqueous systems.

Measurement and Analysis of the Distribution of Pb-214 Lead Isotope in Baghdad Soil using Remote Sensing Techniques

The present research aims to measure concentration of lead Pb214 in soil using remote sensing and GIS, associated radiological hazards in Baghdad, Iraq. Concentration of specific radioactivity of radioactive elements was measured and analyzed naturally and artificially in 48 soil samples for separate sites from Baghdad, Iraq using crystalline spectroscopy to detect germanium. The average radioactivity concentrations of lead were found, as it was found to have varying values ​​from one site to another, as most of them exceeded the international permissible limit, as the highest concentration was recorded at 180 Bq in the sample H28 in Waziriyah district. Battery Lab (1), and the lowest concentration value is 40Bq in (H4, H15, H45) which represents (Dora Expressway, Mansour Street, Fuel Express, and Mahmoudiya Road 2).
 Remote sensing data techniques, and Global Positioning System (GPS) have been used to analyze the effect of the isotopic distribution of heavy bullets for the city of Baghdad. Using Geographic Information Systems (GIS), concentrations were measured and observed. Results of interpolation maps showed isotope of lead is concentrated in the center and west of Baghdad, and then graded with fewer values in other sites.

Нүүрсэн дэх ураны тархалтыг судалсан тухай

The specific radioactivity concentrations of 226Ra, 232Th and 40K were measured in samples of brown coal and humic acids using γ- spectrometer.

Indoor Air Radon Concentration in Premises of Public Companies and Workplaces in Latvia.

Considering the multitudes of people who spend their time working indoors in public premises and workplaces, it is worth knowing what their level of exposure is to natural radioactive radon gas, the second most widespread and dangerous carcinogen for lung cancer development after cigarette smoking. This state-level study covered most of the territory of Latvia and conducted 941 radon measurements with Radtrack2, placed for 4–6 months in the premises of public companies, educational institutions, medical care institutions, etc. The study found that 94.7% of samples did not exceed the national permissible limit (200 Bq/m3), the level at which preventive measures should be initiated. The median value of average specific radioactivity of radon in these premises was 48 Bq/m3 (Q1 and Q3 being 27 and 85 Bq/m3), which is below the average of the European region. Slightly higher concentrations were observed in well-insulated premises with plastic windows and poorer air exchange, mostly in schools (59 (36, 109) Bq/m3) and kindergartens (48 (32, 79) Bq/m3). Industrial workplaces had surprisingly low radon levels (28 (16, 55) Bq/m3) due to strict requirements for air quality and proper ventilation. Public premises and workplaces in Latvia mostly have low radon concentrations in the air, but more attention should be paid to adequate ventilation and air exchange.

Determination of long distance transport of Cs+, Co2+ and Zn2+ ions in vascular plants by autoradiography and gamma-spectrometry

Heavy metals and radionuclides can enter the food chain via cereals and vegetables grown in contaminated soils. In the case of microelements such as zinc, studies have not focused only to assessing its environmental risk, but also to enhancing its uptake by plants as an important growth-limiting factor. In our study, digitalized autoradiograms of whole plants of celery (Apium graveolens L.), tobacco (Nicotiana tabacum L.) and sunflower (Helianthus annuus L.) grown in hydroponic nutrient media spiked with 137CsCl, 60CoCl2 and 65ZnCl2 were used for quantitative determination of uptake, long-distance transport and distribution of Cs+, Co2+ and Zn2+ ions in plant tissues. Results from autoradiography and gammaspectrometry of plants showed, that cesium was translocated to aboveground part of the plants with the shoot-to-root ratio 1.0 : 0.6. On the contrary, cobalt and zinc were more immobilized in roots, with the shoot-to-root ratio up to 1.0 : 3.8. The highest concentration of cesium, cobalt and zinc, expressed in specific radioactivity per unit of leaf surface (Bq/cm2) was found in top, rapidly growing leaves, the lowest concentration in the oldest leaves in low position. Detection limits 3, 2 and 14 Bq/cm2 by using X-ray film
 for 137Cs, 60Co and 65Zn, respectively were obtained. These data correspond to detection limits 10.5 pg Cs+/cm2, 7.2 pg Co2+/cm2 and 785 pg Zn2+/cm2 at specific radioactivity of commercially available 137CsCl, 60CoCl2 and 65ZnCl2. Resolutions 1-2 mm was sufficient for visualization of metal uptake and distribution in roots, stalks, leaves and leaf venation. Obtained data are part of quantitative study of uptake and translocation of both low level-radioactive contamination in plants and microelements applied as fertilizers.

Interactions of Nereistoxin and Its Analogs with Vertebrate Nicotinic Acetylcholine Receptors and Molluscan ACh Binding Proteins.

Nereistoxin (NTX) is a marine toxin isolated from an annelid worm that lives along the coasts of Japan. Its insecticidal properties were discovered decades ago and this stimulated the development of a variety of insecticides such as Cartap that are readily transformed into NTX. One unusual feature of NTX is that it is a small cyclic molecule that contains a disulfide bond. In spite of its size, it acts as an antagonist at insect and mammalian nicotinic acetylcholine receptors (nAChRs). The functional importance of the disulfide bond was assessed by determining the effects of inserting a methylene group between the two sulfur atoms, creating dimethylaminodithiane (DMA-DT). We also assessed the effect of methylating the NTX and DMA-DT dimethylamino groups on binding to three vertebrate nAChRs. Radioligand receptor binding experiments were carried out using washed membranes from rat brain and fish (Torpedo) electric organ; [3H]-cytisine displacement was used to assess binding to the predominantly high affinity alpha4beta2 nAChRs and [125I]-alpha-bungarotoxin displacement was used to measure binding of NTX and analogs to the alpha7 and skeletal muscle type nAChRs. While the two quaternary nitrogen analogs, relative to their respective tertiary amines, displayed lower α4β2 nAChR binding affinities, both displayed much higher affinities for the Torpedo muscle nAChR and rat alpha7 brain receptors than their respective tertiary amine forms. The binding affinities of DMA-DT for the three nAChRs were lower than those of NTX and MeNTX. An AChBP mutant lacking the C loop disulfide bond that would potentially react with the NTX disulfide bond displayed an NTX affinity very similar to the parent AChBP. Inhibition of [3H]-epibatidine binding to the AChBPs was not affected by exposure to NTX or MeNTX for up to 24 hr prior to addition of the radioligand. Thus, the disulfide bond of NTX is not required to react with the vicinal disulfide in the AChBP C loop for inhibition of [3H]-epibatidine binding. However, a reversible disulfide interchange reaction of NTX with nAChRs might still occur, especially under reducing conditions. Labeled MeNTX, because it can be readily prepared with high specific radioactivity and possesses relatively high affinity for the nAChR-rich Torpedo nAChR, would be a useful probe to detect and identify any nereistoxin adducts.

Soil technogenic radioactivity in the vicinity of the Morzhovets Lighthouse (the Morzhovets Island, Archangelsk region)

The aim of the study was to assess soil technogenic radioactivity in the vicinity of the Morzhovets Lighthouse and surrounding areas by measuring radio caesium (137Cs) specific activity. Location and time of the study. Field work was performed in the area around the Morzhovets Lighthouse (the Morzhovets Island, Archangelsk region) in summer 2022. Methods. Soil samples were collected at 26 sites from the 0-5 cm layer, of which at 12 sites soil samples were collected also from 5-10 и 10-20 cm layers. Aboveground phytomass was sampled as well. In the laboratory the soil samples were air-dried and placed in the Marinelli vessel for measuring 137Cs specific activity by gamma-spectrometry. Registration of the gamma-radiation from the measured soil sample, as well as processing of the obtained spectra were performed using the Progress-gamma software and hardware complex FVKM.412131.002-03. The energy calibration of the gamma spectrometer to control the safety of the setup parameters was carried out after each measurement using a combined control source OISN-137-1 in a Marinelli vessel. The minimal exposure time of the study sample was 3600 sec; however, the time was increased for some samples with low activity. Results. The territory of the Morzhovets Island is occupied by the lowland seaside terraced plane landscapes with tundra vegetation on the peaty podsolised illuvial humus soils, alternating with mires. Caesium specific radioactivity in the top 0-5 cm soil layer, represented by poorly decomposed peat horizon, was found to vary from 9.4 to 144.5 Bq/kg in the peaty illuvial-humus podzol (Gleyic Histic Entic Podzol) and from 12.2 to 139.4 Bq/kg in the bog peat gley soils (Fibric Histosols (Gleyic)). The radio caesium specific activity was shown to decrease sharply with soil depth, reaching the 3 Bq/kg detection limit of the gamma-spectrometer. Comparative analysis of the data showed that in the West Arctic sector 137Cs specific activity decreases from the east to the west, with increasing distance from the Novaya Zemlya, from 80.2 Bq/kg (the Novaya Zemlya Archipelago) and 80.7 Bq/kg (Bolshezemelskaya Tundra) to 19. 2 Bq/kg (the Svalbard Island). Conclusions. The 137Cs distribution in soil of the Morzhovets Island showed the persistent fixation of the element by the upper 5 cm-thick organic part of the soil profile, representing the primary biogeochemical barrier. The vegetation does not accumulate technogenic radioactivity. Overall, the 137Cs distribution in soils around the Morzhovsky Lighthouse displays a medley pattern. The maximal 137Cs specific activity values were measured both in the peaty illuvial-humus podzol and bog peat gley soils.

Development and preliminary evaluation of an integrin α2β1-targeted PET probe as a supplement and alternative of PSMA imaging for prostate cancer

An integrin α2β1-targeted PET probe (68Ga-IABtP) was developed to serve as a supplement and alternative of PSMA imaging for prostate cancer. 68Ga-IABtP was synthesized by labeling the precursor peptide with 68Ga with 93% labeling yield and 4.14 MBq/μg specific radioactivity. 68Ga-IABtP showed no specific uptake in LNCaP prostate cancer cell with low integrin α2β1 expression but significantly increased uptake in PC-3 prostate cancer cell with high integrin α2β1 expression, which could be specifically blocked by the integrin α2β1 monoclonal antibody. The efflux experiments demonstrated that 68Ga-IABtP could rapidly penetrate into PC-3 cell after cell binding, thereby prolonging the residence time in the tumor and allow enough time for probe clearance from the circulation and non-specific organs. The biodistribution study indicated that 68Ga-IABtP showed no specific accumulation in non-target organs and was quickly cleared from the kidney. The in vivo PET-CT imaging demonstrated that 68Ga-IABtP showed no specific uptake in LNCaP tumor but could specifically accumulate in the PC-3 tumor, and was rapidly cleared from spleen, intestine, kidney and liver, resulting in excellent contrast effect with low background signal and high target to non-target ratios.

Novel approach to predicting the release probability when applying the MARSSIM statistical test to a survey unit with a specific residual radioactivity distribution based on Monte Carlo simulation

For investigating whether the MARSSIM nonparametric test has sufficient statistical power when a site has a specific contamination distribution before conducting a final status survey (FSS), a novel approach was proposed to predict the release probability of the site. Five distributions were assumed: lognormal distribution, normal distribution, maximum extreme value distribution, minimum extreme value distribution, and uniform distribution. Hypothetical radioactivity populations were generated for each distribution, and Sign tests were performed to predict the release probabilities after extracting samples using Monte Carlo simulations. The designed Type I error (0.01, 0.05, and 0.1) was always satisfied for all distributions, while the designed Type II error (0.01, 0.05, and 0.1) was not always met for the uniform, maximum extreme value, and lognormal distributions. Through detailed analyses for lognormal and normal distributions which are often found for contaminants in actual environmental or soil samples, it was found that a greater statistical power was obtained from survey units with normal distribution than with lognormal distribution. This study is expected to contribute to achieving the designed decision error when the contamination distribution of a survey unit is identified, by predicting whether the survey unit passes the statistical test before undertaking the FSS according to MARSSIM.

Multivariate statistical study of technologically enhanced naturally occurring radioactive materials and radiation hazards in crude oil and petroleum products of Ma’rib refinery, Yemen

Crude oil and oil products are among the significant sources of technologically enhanced naturally occurring radioactive materials (TENORMs). Thirty-one samples of eight types of crude oil and petroleum products were collected from the Ma’rib Refinery, located in the Ma’rib Governorate, central Yemen. These samples were analyzed using a gamma-ray spectroscopy system with a high purity germanium detector (HPGe). The specific radio-activities of 40K, 232Th, and 226Ra for crude oil samples ranged 5.943–32.252, 1.711–12.646, and 2.445–15.520 Bq L−1, respectively. Oil products ranged 8.333–40.355, 1.556–12.812, and 3.014–17.024 Bq L−1. Potential environmental and health risks were assessed by calculating radiation hazard indicators of radium equivalent activity (Raeq) Bq L−1, absorbed gamma dose rate (AGDR) nGy h−1, annual effective dose rate (AEDR) mSv, external hazard index (Hex), internal hazard index (Hin), annual gonadal dose equivalent (AGDE) mSv, activity utilization index (AUI), excess lifetime cancer risk (ELCR), activity concentration index (Iy), and alpha index (Iα) that ranged 5.614–33.291, 2.636–15.589, 0.003–0.019, 0.016–0.093, 0.022–0.135, 0.018–0.106, 0.045–0.285, 0.011–0.067, 0.041–0.239, and 0.012–0.078 for crude oil and 9.453–36.067, 4.475–16.837, 0.005–0.021, 0.026–0.101, 0.037–0.147, 0.031–0.114, 0.019–0.072, 0.076–0.314, 0.069–0.258, and 0.015–0.085 for oil products. The estimated average values of these indicators were compared with global averages and were below the recommended limits. The relationship between TENORMs and radiation hazard indicators and their maximum activity contributions were determined by applying multivariate statistical methods. This study is important to provide an overview of activity concentrations of natural radionuclides in the petroleum industry of Yemen. Therefore, the results are useful for assessing the radiological hazards of petroleum products in humans.

Natural radioactivity of coal in the context of radioecological safety and rational use

Introduction. Environmental contamination with natural radioactive elements is an urgent ecological problem of the coal industry. Radiation hazard associated with natural radionuclides in coals and enclosing rock is a poorly studied problem requiring special attention. Radionuclides and their combustion products in coals, i. e. ash and slag waste and gas aerosol emissions, released into the biosphere, become the sources of pollution. Radiation monitoring is required in the course of geological prospecting, deposits development and rational use. The research aims to systematize research and analytical material on specific radioactivity of coal and their combustion products, and update the problem of radioecological safety monitoring. Methodology includes studying data on specific radioactivity of coal at various deposits, studying natural radioactivity of coal, enclosing rock and ash and slag waste, describing ash and slag waste and radon as a source of radioactive contamination, assessing potential radon hazard of mine workings, and analyzing ash composition characteristics for toxicologic estimation of ash dumps and their effect on the environment. Results. Generalized data on radionuclide concentration in coal burned at the CHP facilities, slag and fly ash are presented. Radionuclide specific concentration is much higher in ash and slag waste of coal heat power industry than in initial coal. It is caused by the radionuclide concentration in the products of coal combustion. Potential hazard of radon released from rock is revealed, and ash composition is characterised for toxicologic estimation of ash dumps. Conclusions. Uncontrolled coal combustion exacerbates the problem of radioecological safety due to radioactive aerosol emission and the formation of ash and slag waste with increased concentration of natural radionuclides. System monitoring of radioactivity level in the course of geological prospecting, mining, processing and combustion will allow reducing radionuclides entering the fuel cycle and environment.