Determination Of 210Po Research Articles

Detection of Polonium-210 in Environmental, Biological and Food Samples: A Review.

Ingestion of polonium-210 from environmental media and food can cause serious health hazards (e.g., gastrointestinal symptoms, tumours, etc.) and has been a public health concern worldwide since the 2006 poisoning of Agent Litvinenko 210Po in Russia. With the development of uranium mining and applications of nuclear technology in recent decades, the radioactive hazards posed by 210Po to living organisms and the environment have become increasingly prominent. In order to strengthen the monitoring of environmental 210Po and protect both the environment and human health, a series of explorations on the methods of 210Po determination have been ongoing by researchers across the globe. However, previous reviews have focused on individual sample types and have not provided a comprehensive account of environmental, food, and biological samples that are closely related to human health. In this work, the sources, health hazards, chemical purification, and detection methods of trace 210Po in different sample types are systematically reviewed. In particular, the advantages and disadvantages of various pretreatment methods are compared, and relevant domestic and international standards are integrated, which puts forward a new direction for the subsequent establishment of rapid, simple, and efficient measurement methods.

Experimental optimization of physicochemical factors for spontaneous deposition of 210Po using newly designed deposition kit

A simple spontaneous deposition kit for 210Po determination using alpha spectrometry was newly designed, and polonium deposition characteristics under various physicochemical conditions were evaluated using it. The high-purity silver disc (99.99%) showed high deposition efficiencies of over 85.1% in the HCl concentration range of 0.01–6 M. Optimal physicochemical factors were determined to be a temperature of 90 °C, deposition time of 90 min, and the use of ascorbic acid as a reducing agent in an amount similar to that of the interfering element (Fe).

A rapid method for determination of 210Po in soil and sediments without the use of HF

A rapid method for determination of 210Po in soil and sediments without the use of HF

Determination of Natural Radionuclides (Ra-226, Po-210, Ra-228 and K-40) and Cs-137 in Fish Consumed in the City of São Paulo

The aim of the study was to determine the activity concentration of the natural radionuclides (226Ra, 210Po, 228Ra and 40K) and artificial radionuclide 137Cs in the muscle of the marine fish species most consumed in the city of São Paulo and to evaluate the annual effective dose due to the consumption of the fish. Samples were collected in the supermarket chain Extra and Carrefour and in the distribution center CEAGESP. Six fish species were selected among the most available and consumed in São Paulo city: anchovy, tuna, dogfish, croaker, hake and sardine. After the sample preparation procedures, the determination of 226Ra, 228Ra, 40K and 137Cs was carried out by gamma spectrometry and the determination of 210Po by alpha spectrometry. The results obtained for all the species studied are below the limits adopted by the Brazilian Standards for 137Cs and, therefore, their consumption offers no risk due to the ingestion of this radionuclide. The concentration obtained for the radionuclides 226Ra, 210Po, 228Ra and 137Cs in the fish samples analized are low and of the same order of magnitude as data from literature. The results obtained for the doses, for all the species studied, showed that their consumption offers no risk of exposure due to the ingestion of the analyzed radionuclides.

Determination of 210Po and 210Pb in cannabis (Cannabis sativa L.) plants and products

The concentrations of polonium 210Po and radio-lead 210Pb in cannabis (Cannabis sativa L.) plants and products now legally available in Poland were determined. Limiting the delivery of radionuclides to the body is an important aspect of civil protection in many countries. Reduction in use and awareness of the risks associated with tobacco and cannabis smoking have a great impact. The 210Po and 210Pb concentrations in 44 hemps, 20 hashish and 8 hemp tea samples, as well as in 3 types of cannabis plants (highest parts of mature hemp plant Fenola, Fedora and Futura) were determined. Each of the sample names means a different type and cross of C. sativa L. Being numerous, the are recognized on the market precisely by these names. Effective doses were calculated and compared to the doses of the other combustion products, such as tobacco. In the case of hemp, the highest concentration of 210Po was found in samples of dried Sweet Carmel (34.7 ± 0.23 mBq·g−1), while the lowest in the Hemp Berry (0.57 ± 0.23 mBq·g−1). In the case of 210Pb, the highest concentration was in Strawberry Kush (2.32 ± 0.05 mBq·g−1), while the lowest in Strawberry Haze (0.19 ± 0.03 mBq·g−1). In hashish, the highest and lowest concentrations of 210Po were in Strawberry Diesel 164 ± 3 mBq·g−1 and in Mango Kush 2.5 ± 0.2 mBq·g−1. The highest and lowest concentrations in the case of 210Pb in hashish were in Pollen Hashish 45.1 ± 0.2 mBq·g−1 and in Mango Kush Hashish 0.45 ± 0.05 mBq·g−1, respectively. These radionuclides did not constitute a radioactive equilibrium (210Po/210Pb).

Improvements of 210Po determination method in thermal water samples

Determination of naturally radionuclides have been known well as an important topic in environmental study in recently. One of the most toxic radioisotope in nature, a daughter product of 238U decay chain is 210Po (polonium). The improvement and optimizations methods for determination of this attractive isotope are still presenting so far. In this paper, a new improved method was elaborated for 210Po determination in thermal water sample. In the proposed method, analytical optimization of spontaneous/auto deposition does not use Teflon cup, magnetic stirring or any preparing equipment/item only normal glass and a side of square silver. In addition, the optimization was neglected with absent of purification of polonium (Liquid-liquid extraction methods/Ion exchange chromatography/Extraction chromatographic separations). The outcome of optimal procedure were simplify, less time consuming, great reduction of costs with chemical recovery >80% and could apply for any liquid environmental samples.

Optimization of 210Po determination in soil

Abstract In recent years, naturally occurring radioactive materials (NORM) have become an important topic from the perspective of environmental protection. The list of isotopes that should be monitored in the environment is constantly growing as new amendments to international legislation are introduced. One of the often studied NORM elements is 210Po. In this study, a process of elaborating of a new method of 210Po determination in soil was presented. In the proposed method, several analytical aspects, like the influence of silica decomposition or optimization of an electrode material, were revised. The obtained procedure allows performance of complete radiochemical analysis in a single day, with the chemical efficiency of over 85% and great reduction of costs. Further, the influence of the use of phosphate fertilizers on polonium concentration in soil was also confirmed.

210Po in Paddy Soils and Rice Grains in Chau Doc, An Giang, Vietnam: Activity Concentration, Soil-to-Rice Transfer, and Health Hazard

Introduction: Soil-to-rice transfer factors (TF) are widely used to predict radionuclides' activity concentrations in rice plants. Since rice (Oryza sativa L.) is one of the most popular crops in Vietnam, the radiological risks due to 210Po contaminating rice grains and the TF must be concerned. Methods: Alpha spectrometry measured the activity concentration of 210Po in rice and soil samples collected in Chau Doc, An Giang province. TF for the uptake of 210Po from soil to rice plant has been calculated the ratio of the dry weight concentration in the plants to the dry weight concentration in the specified soil layer. Assessment of radiological risks due to ingestion of rice grains was based on estimation of the effective dose. Results: The activity concentrations of 210Po were in the ranges of 63.77 – 117.75 Bq kgdry weight-1 and 7.38 – 14.16 Bq kgdry weight-1 in soils and rice grains, respectively. Based on the radiation dose assessment, the accumulation of 210Po in rice grains was not considered for public health. The average TF values of 210Po were 0.12, 0.11, and 0.37 for grains, straws, and roots, respectively. Our TF values for rice were higher than the corresponding values found by other studies and the IAEA TRS-472 report. Conclusion: The analytical method for 210Po determination using alpha spectrometry can be applied for further studies in the field of environmental radioactivity. The measured TF values can be used to predict the radioactivity level of 210Po in rice plants cultivated in other fields in the Mekong Delta region.

210Po in the environment: insight into the naturally occurring polonium isotope

Polonium is rapidly emerging as an international environmental health concern primarily because of the recent rise in hydraulic fracturing (fracking). Recovery of unconventional oil and gas generates produced water containing natural radioactivity, which is increasing the radiological impact of 210Po. In this context, accurate measurements of 210Po in environmental samples is crucial because 210Po is the main contributor to the natural radiation dose received by all living organisms. However, the analytical chemistry of polonium is complicated, primarily due to its volatility. This review highlights recent analytical progress and challenges in determination of 210Po in the environmental and biological samples.

Determination of 210Po in air filters from metallurgic industry

The elevated concentration of 210Po attached to aerosol particles inside a non-ferrous metal refinery was studied. The aerosols were collected on Petrianov or glass-fiber filters and subsequently subjected to radiochemical procedure consisting of acid leaching and concentration by micro co-precipitation with manganese oxide. For the activity determination alpha spectrometry and liquid scintillation counting (LSC) were applied. The obtained results showed that usually observed polonium concentration inside the plant was lower than 78 mBq m−3, however short spikes up to 7430 ± 710 mBq m−3 (related to the specific thermal process) were also observed.

Optimization of the radiochemical procedure of 210Po determination in small amounts of sediment samples

The radioactivity of alpha emitter radioisotope 210Po can be used to determine the amount of 210Pb radionuclide. This radioisotope is commonly used in the dating of marine as well as freshwater lake sediments. In this type of research, the collected samples are small, often 1.5–3 g (wet sediments), especially if we work with sediments taken from mountain lakes. This work presents the problems found with 210Po determinations in a sample weighting 0.1 or 0.2 g. The analysis is based on the decomposition of samples, the concentration of the analyte, preparing source via spontaneous deposition on a silver discs, and alpha measurements of this source. The aim of this work was to optimize every stage of the procedure. The main assumption of the research was to minimize the weight of samples, the amounts of reagents taken for radiochemical determinations, and to eliminate hydrofluoric acid during the analytical process. The study focused on the optimization of the decomposition of sediments (microwave digestion with concentrated HCl and HNO3 acids), the adsorption of polonium on the container wall in time, and the deposition conditions. The results show that there is a possibility to determine 210Po in small amounts (0.1–0.2 g) of sediments without using hydrofluoric acid with the yield of radiochemical procedure above 90%. The procedure was checked by reference material, and good accuracy and precision were achieved.

Determination of 210Po and 210Pb depositions in lichen and soil samples collected from Köprübaşı-Manisa, Turkey

In this study, we aimed to determine the accumulations of 210Po and 210Pb in soil and lichen samples in Koprubasi. The Koprubasi district is home to the largest uranium deposits in Turkey. To date, there has been no study recorded in the literature related to 210Po and 210Pb depositions in lichens in Koprubasi. Six different lichen species (Cladonia convoluta, Parmelina tiliacea, Physcia stellaris, Pleurosticta acetabulum, Xanthoparmelia conspersa, and Xanthoria parietina) as well as soil samples were collected from seven sampling locations around Koprubasi. Lichens were used as biomonitors for 210Po and 210Pb deposition. The 210Po and 210Pb activity concentrations were measured in all the samples by alpha spectrometry. The activity concentrations in the lichen samples ranged from 64 to 577 Bq kg−1 with an average of 266 Bq kg−1 for 210Po and from 78 to 565 Bq kg−1 with an average of 333 Bq kg−1 for 210Pb. The activity ratios of 210Po/210Pb ranged from 0.80 to 1.99. In the lichen species, the mean 210Po activity values varied from 154 Bq kg−1 in Pleurosticta acetabulum to 390 Bq kg−1 in Xanthoparmelia conspersa. The range of the mean 210Pb activity was between 153 Bq kg−1 in Cladonia convoluta and 378 Bq kg−1 in Parmelina tiliacea. In the soil samples, 210Po and 210Pb activity concentrations were ranged from 14 to 1268 Bq kg−1 and from 19 to 1113 Bq kg−1, respectively. While the values of 210Po and 210Pb measured in the lichen samples are comparable with those of the literature, the results of 210Po and 210Pb in the soil taken from the uranium mine are higher than the results of the literature studies.

Simultaneous determination of 210Po and 210Pb in solid samples: A new method for 210Pb determination

A new method has been developed for determination of 210Pb and a simultaneous determination of 210Po and 210Pb was performed in solid samples. 210Po and 210Pb were sequentially leached at 250 °C with HNO3+HF, HClO4 and HCl. Twenty percent of the leaching solution was used for 210Po determination by α-spectrometry after 210Po spontaneous deposition on a silver disc from a weak HCl solution that containing hydroxylamine hydrochloride, sodium citrate and 209Po tracer. The remains of the leaching solution were used for determination of 210Pb, conducted by precipitation as PbCrO4 at about pH < 4, purification with an anion-exchange resin column, source preparation as PbSO4, and measurement with a β-counter. The procedure has been checked with the IAEA-327, a certified reference material, showing good agreement with the recommended values. The lower limits of detection for 3 g soil sample were found to be 0.17 Bq kg−1 for 210Po and 0.92 Bq kg−1 for 210Pb. A variety species of soil and sediment samples have been analysed using the procedure, showing average yields of 95.2 ± 2.6% for 210Po and 91.0 ± 8.3% for 210Pb.

Method of Polonium Source Preparation Using Tellurium Microprecipitation for Alpha Spectrometry.

A thin-layer source for the counting of polonium isotopes by alpha spectrometry can be rapidly prepared using microprecipitation with tellurium. Polonium was first coprecipitated with the reduction of tellurium by stannous chloride, followed by microfiltration onto a membrane filter for counting. This microprecipitation method is faster, cheaper, and more convenient than the traditional spontaneous deposition method, with an excellent Po recovery (>90%) under optimal conditions. The influences of several experimental parameters, including Te(IV) quantity, reaction time, and HCl molarity, were examined to determine the optimal conditions for Te microprecipitation. The decontamination factors of potential interferences from various radionuclides (Ra, Th, U, Pu, Am) for the counting of long-lived polonium isotopes (208Po, 209Po, and 210Po) were also evaluated, and the results confirmed a good selectivity on polonium by this microprecipitation method. Due to its strong resistance to high acidity up to 12 M HCl, the method would be particularly suitable for rapid determination of 210Po in acid leaching solution of solid samples.

Determination of 210Po and 210Pb in red-capped scaber (Leccinum aurantiacum): bioconcentration and possible related dose assessment.

The paper presents the studies on 210Po and 210Pb activity determination in red-capped scaber (Leccinum aurantiacum (Bulliard) Gray) collected in northern Poland. The aims of the studies were to determine 210Po and 210Pb content in analyzed mushrooms, evaluate the bioconcentration levels, and estimate possible related annual effective radiation dose to mushrooms consumers. The activities of 210Po and 210Pb in red-capped scaber were un-uniform and depended on sampling sites. But 210Po and 210Pb activity concentrations did not reflect their concentrations in topsoil. The results showed that the consumption of analyzed mushrooms should not increase significantly the total effective radiation dose from 210Po and 210Pb decay.

A modified method for the sequential determination of 210Po and 210Pb in Ca-rich material using liquid scintillation counting

This research describes methods for the sequential determination of 210Pb and 210Po activity concentrations in Ca-rich ash samples collected from oil shale-fired power plants in Estonia. The procedure involves digestion of Ca-rich ash samples in a microwave digestion system, radiochemical separation of 210Pb and 210Po and their measurements. All samples, blanks and standards were measured by liquid scintillation counting (Quantulus 1220). The method was tested using IAEA (International Atomic Energy Agency) RGU-1 and IAEA-444 reference materials. Spectral calibration/peak identification which included the optimization of α/β discrimination system (pulse shape analyser), and recovery have been made by 209Po and 210Pb standard solutions.

Determination of 210Po in calcium supplements and the possible related dose assessment to the consumers

The aim of this pioneer study was to investigate the most popular calcium supplements as a potential additional source of polonium 210Po in human diet. The analyzed calcium pharmaceutics contained organic or inorganic calcium compounds; some from natural sources as mussels' shells, fish extracts, or sedimentary rocks. The objectives of this research were to investigate the naturally occurring 210Po activity concentrations in calcium supplements, find the correlations between 210Po concentration in medicament and calcium chemical form, and calculate the effective radiation dose connected to analyzed calcium supplement consumption.As results showed, 210Po concentrations in natural origin calcium supplements (especially sedimentary rocks) were higher than the other analyzed. Also the results of 210Po analysis obtained for inorganic forms of calcium supplements were higher. The highest 210Po activity concentrations were determined in mineral tablets made from sedimentary rocks: dolomite and chalk – 3.88 ± 0.22 and 3.36 ± 0.10 mBq g−1 respectively; while the lowest in organic calcium compounds: calcium lactate and calcium gluconate – 0.07 ± 0.02 and 0.17 ± 0.01 mBq g−1.The annual effective radiation doses from supplements intake were estimated as well. The highest annual radiation dose from 210Po taken with 1 tablet of calcium supplement per day was connected to sample made from chalk – 2.5 ± 0.07 μSv year−1, while the highest annual radiation dose from 210Po taken with 1 g of pure calcium per day was connected to dolomite – 12.7 ± 0.70 μSv year−1.

Determination of 210Po in hair of domestic animals from Poland and Norway

The aim of this study was to investigate the usefulness of hair to monitor the body content level of polonium activity, the utility of animals hair as a non-invasive indicator of exposure for natural 210Po. Among Polish dogs the highest 210Po concentrations were measured in 2 years old Shih Tzu and Bichon Maltese, small longhair males. Among Norwegian, 210Po concentrations were much higher and its highest values were measured in hair collected from 1 year old Greenland Dog and 3 years old Alaskan Malamute, also males. Mainly dogs’ gender and diet influenced the values of 210Po concentrations in analyzed samples.

An improved procedure for the determination of 210Po by alpha spectrometry in sediments samples from Danube Delta

The aim of this work is to find the optimal procedure for 210Po leaching from sediment samples. An improved method is described, the optimization consisting in a substantial reduction of leaching time. The method was tested on IAEA standard reference materials and compared with the classical procedure. The repeatability was estimated by analyzing seven duplicates of IAEA 385 Irish Sea sediment. However, the results are satisfactory only when the method is applied for sediments with high organic content. For silicates, a mixture of three acids was used for a complete digestion.

A methods assessment and recommendations for improving calculations and reducing uncertainties in the determination of 210Po and 210Pb activities in seawater

In marine systems, 210Po and 210Pb disequilibria are being increasingly used to examine oceanic particle formation and export. Here, an updated assessment of current methods for determining 210Po and 210Pb activity in marine samples is provided and includes a complete description of the vast number of calculations and uncertainties associated with Po and Pb loss, decay, and ingrowth during sample processing. First, we summarize the current methods for the determination of 210Po and 210Pb activities in dissolved and particulate seawater samples and recommend areas for improvement. Next, we detail the calculations and associated uncertainties using principles of error propagation, while also accounting for radionuclide ingrowth, decay, and recovery. A spreadsheet reporting these calculations is included as a downloadable Web Appendix. Our analysis provides insight into the contributions of the relative uncertainty for each parameter considered in the calculation of final 210Po and 210Pb activities and gives recommendations on how to obtain the most precise final values. For typical experimental conditions in open seawater, we show that our method allows calculating 210Pb activity with a relative uncertainty of about 7%. However for 210Po activities, the final relative uncertainty is more variable and depends on the 210Po/210Pb activity ratio in the initial sample and the time elapsed between sampling and sample processing. The lowest relative uncertainties on 210Po that can be obtained by this method is 6% and can only be obtained for samples with high 210Po/210Pb activity ratios (&gt;1) that were rapidly processed.