Assessment of intake of 210Po and 210Pb isotopes from cow's milk in Poland

Milk has been known for its nutritional properties for centuries and is often the staple of the diet in many countries. Therefore, monitoring of milk composition seems to be a relevant task as it was the purpose of this study to compare levels of ²¹⁰Po and ²¹⁰Pb in several Polish voivodeships. The methodology was based on mineralization, loss on an inorganic matrix and concentration measurement on an alpha spectrometer. The concentrations of ²¹⁰Po and ²¹⁰Pb in collected milk samples were measured using alpha spectrometry and calculations, respectively. The results showed that the lowest concentration of ²¹⁰Po is 2.8 ± 0.2 mBq l^-1 and the highest is 56.3 ± 0.7 mBq l^-1 while the ²¹⁰Pb concentrations are in the range from 2.8 ± 0.2 to 44.0 ± 1.7 mBq l^-1. The associated annual effective doses for adults jmrange from 3.5 ± 0.1 to 11.0 ± 0.2 µSv a^-1 for ²¹⁰Po and from 2.0 ± 0.1 to 5.0 ± 0.1 µSv a^-1 for ²¹⁰Pb. The lowest doses were noticed in Kuyavian-Pomeranian Voivodeship and the highest values were found in Lesser Poland Voivodeship. The results show that the annual effective dose in individual provinces is not dangerous to health. However, there are significant differences between highly and lowly industrialized voivodeships.

Determination of polonium-210 in environmental samples using diglycolamide-based cloud point extraction coupled to alpha spectrometry analysis

This study presents a novel cloud point extraction (CPE) methodology for the separation and enrichment of polonium-210 prior to alpha-spectrometric quantification in water, urine and digested samples. The extractive behaviour of diglycolamide-based ligands towards Po by CPE was determined and optimised in various acidic conditions. The extraction efficiency and selectivity of the CPE systems depend greatly on the choice of the extracting agent and acidic conditions. The thorough optimisation of those specific parameters has led to the development of a suitable cloud point extraction system for the determination of polonium-210 at ultra-trace levels compatible with alpha-spectrometry. To facilitate this coupling, a back-extraction procedure was optimised and performed on the surfactant-rich phase to enable the spontaneous deposition of polonium-210 onto a silver disk; this also avoids making the matrix transfer step mandatory due to the presence of a nitric medium. Method detection and quantification limits of 3.5 and 12 mBq L^-1, respectively, were determined by alpha spectrometry. The robustness of the proposed methodology was demonstrated by the determination of polonium ions concentration in various environmental and biological samples and solid certified reference materials.

Removal of 209Po from aquatic environment and its equilibrium and thermodynamic parameters

In this study, removal of ²⁰⁹Po from aqueous media using a natural zeolite as an adsorbent material was investigated. The adsorption experiments were performed by batch technique. The influence of specific process parameters such as initial concentration, pH of solution, contact time and temperature was studied to predict the optimum conditions for effective removing of ²¹⁰Po. Initial and equilibrium activity concentration of ²⁰⁹Po in solutions was counted by a ZnS(Ag) alpha scintillation counter. Adsorption yield of ²⁰⁹Po onto the zeolite was determined as 90 ± 2% at pH: <3 and 25 °C for 40 min of contact time. The applications of the isotherm models such as Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms were studied to evaluate adsorption characteristics of ²⁰⁹Po onto natural zeolite. Results indicated that the Dubinin-Radushkevich and Freundlich models gave a better fit to the experimental data than Langmuir isotherm models. The thermodynamic parameters such as Gibbs free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) of adsorption process were calculated. The change in entropy (ΔS^o) and enthalpy (ΔH^o) were estimated to be -0.0003 J nmol^-1 K^-1 and 0.1008 kJ nmol^-1, respectively.

210Po and 210Pb in forest mushrooms of genus Leccinum and topsoil from northern Poland and its contribution to the radiation dose

Wild growing mushrooms are traditional food items for man and also an important source of nutrients for small and big wildlife. Nevertheless, they can be species - specifically vulnerable for contamination with heavy metals and radionuclides. We studied a less known phenomenon of accumulation of highly toxic, the alpha-radiation emitter such as ²¹⁰Po and the beta emitter ²¹⁰Pb by three Leccinum mushrooms: orange oak bolete L. aurantiacum (Bull.) Gray (previous name Leccinum aurantiacum var. quercinum Pilát), foxy bolete L. vulpinum Watling and slate bolete L. duriusculum (Schulzer ex Kalchbr.) Singer. Fungal and soil materials were collected from areas of a different geochemical composition in the northern regions of Poland. In parallel evaluated was the risk to human consumer due to possible intake of ²¹⁰Po and ²¹⁰Pb with a mushroom meal. Results showed a heterogeneous distribution of ²¹⁰Po and ²¹⁰Pb activity concentrations within caps and stipes of fruiting bodies. Overall activity concentration for whole dried fungi material ranged from 0.59 ± 0.38 to 3.2 ± 0.2 Bq ²¹⁰Po kg^-1 and from 0.45 ± 0.04 to 3.1 ± 0.2 Bq ²¹⁰Pb kg^-1. Evaluation showed that Leccinum mushrooms consumed by locals in typical quantity of 0.5 kg (dry biomass) can contribute into annual effective radiation dose at 0.90-3.81 μSv from ²¹⁰Po decay and 0.31-2.14 μSv from ²¹⁰Pb decay, which is a small portion of the annual effective radiation dose of ²¹⁰Po and ²¹⁰Pb for human inhabiting the northern regions of Poland.

Health Risk of Polonium 210 Ingestion via Drinking Water: An Experience of Malaysia

The presence of toxic polonium-210 (Po-210) in the environment is due to the decay of primordial uranium-238. Meanwhile, several studies have reported elevated Po-210 radioactivity in the rivers around the world due to both natural and anthropogenic factors. However, the primary source of Po-210 in Langat River, Malaysia might be the natural weathering of granite rock along with mining, agriculture and industrial activities. Hence, this is the first study to determine the Po-210 activity in the drinking water supply chain in the Langat River Basin to simultaneously predict the human health risks of Po-210 ingestion. Therefore, water samples were collected in 2015⁻2016 from the four stages of the water supply chain to analyze by Alpha Spectrometry. Determined Po-210 activity, along with the influence of environmental parameters such as time-series rainfall, flood incidents and water flow data (2005⁻2015), was well within the maximum limit for drinking water quality standard proposed by the Ministry of Health Malaysia and World Health Organization. Moreover, the annual effective dose of Po-210 ingestion via drinking water supply chain indicates an acceptable carcinogenic risk for the populations in the Langat Basin at 95% confidence level; however, the estimated annual effective dose at the basin is higher than in many countries. Although several studies assume the carcinogenic risk of Po-210 ingestion to humans for a long time even at low activity, however, there is no significant causal study which links Po-210 ingestion via drinking water and cancer risk of the human. Since the conventional coagulation method is unable to remove Po-210 entirely from the treated water, introducing a two-layer water filtration system at the basin can be useful to achieve SDG target 6.1 of achieving safe drinking water supplies well before 2030, which might also be significant for other countries.

Is ecological food also radioecological? - 210Po and 210Pb studies

Presented are results of a study on accumulation of naturally occurring ²¹⁰Po and ²¹⁰Pb in ecological and conventional farming food products in Poland: fruits, vegetables and cereals. The main idea behind this research was to determine the activity concentrations of ²¹⁰Po and ²¹⁰Pb in ecological and commercial food as well as calculate and compare the effective dose (radiation) connected to different origin of analyzed food products consumption. The studies showed the majority of all compared food samples contained similar ²¹⁰Po and ²¹⁰Pb activities and statistically, the consumption of organic and commercial food would give similar annual effective dose.

210Po and 210Pb bioaccumulation and possible related dose assessment in parasol mushroom (Macrolepiota procera)

Presented are results of a study on accumulation and distribution of 210Po and 210Pb in the fruitbodies of parasol mushroom (Macrolepiota procera) and risk to human consumer due to exposure from highly radiotoxic decay particles emitted by both radionuclides. Mushrooms were collected from 16 forested places in central and northern regions of Poland. Activity concentrations of 210Po and 210Pb were determined after radiochemical separation of nuclides and subsequent measurement using validated method and alpha spectrometer. Results showed on spatially heterogeneous distribution of the 210Po and 210Po activity concentrations in M. procera and two interpolation maps were prepared. Activity concentrations of nuclides in dried caps of M. procera were in the range from 3.38 ± 0.41 to 16.70 ± 0.33 Bq∙210Po ∙kg-1 and from 5.11 ± 0.21 to 13.42 ± 0.30 Bq∙210Pb ∙kg-1. Consumption of M. procera foraged in central and northern Poland should not contribute significantly to the annual effective radiation doses from 210Po and 210Pb due to amount of both nuclides accumulated by fungus in caps.

210Po secretion from sweat glands

The results of the research indicated that the ²¹⁰Po activity concentration in sweat samples was between 0.22 ± 0.03 to 2.10 ± 0.15 mBq·g^-1 d.w. The obtained results of the studies showed that smoking and eating fish led to higher activity concentrations of ²¹⁰Po in sweat in comparison to the control group. Statistical analysis of ²¹⁰Po activity concentrations in sweat samples showed significant differences between control, smoking, fish eating and age groups, while no significant differences was found for ²¹⁰Po between volunteers as far as gender is concerned.

Natural radioactivity in tap waters from the private wells in the surroundings of the former Žirovski Vrh uranium mine and the age-dependent dose assessment

Activity concentration of (238)U, (234)U, (226)Ra, (228)Ra, (210)Pb and (210)Po in tap water from selected springs and private wells in the area of the former uranium mine at Žirovski Vrh were determined. A total of 22 tap water samples were collected at consumer's houses. The results show that the activity concentrations of uranium in water samples are in range (0.17-372) and (0.22-362) mBq L(-1) for (238)U and (234)U, respectively. Radium activity concentrations are in range (0.14-16.7) and (0.9-11.7) mBq L(-1) for (226)Ra and (228)Ra, respectively. (210)Po activity concentration is in range (0.28-8.0) mBq L(-1) and can be regarded as the lowest amongst all analysed radionuclides. The range for (210)Pb is (0.5-24.6) mBq L(-1). Based on the results obtained for activity concentrations of six radionuclides, the committed effective dose for three different age groups of population were estimated. It was found that the committed effective dose was well below the recommended value of 100 μSv year(-1), ranging from 2.3 to 34.3 μSv year(-1) for adults, from 3.5 to 32.0 μSv year(-1) for children (7-12 years) and from 3.0 to 23.3 μSv year(-1) for infants.

Radiological characterization of tap waters in Croatia and the age dependent dose assessment

Activity concentrations of (234)U, (238)U, (226)Ra, (228)Ra, (210)Po and (210)Pb in tap waters, originating from various geological regions of Croatia, were determined. Activity concentrations of measured radionuclides are in general decreasing in this order: (238)U≈(234)U>(228)Ra≈(210)Pb>(226)Ra≈(210)Po. Based on the radionuclide activity concentrations average total annual internal doses for infants, children and adults, as well as contribution of each particular radionuclide to total dose, were assessed and discussed. The highest doses were calculated for infants, which makes them the most critical group of population. All values for each population group were well below the recommended reference dose level (RDL) of 0.1mSv from one year's consumption of drinking water according to European Commission recommendations from 1998. Contribution of each particular radionuclide to total doses varied among different age groups but for each group the lowest contribution was found for (226)Ra and the highest for (228)Ra.

Polonium 210Po activities in human blood of patients with ischaemic heart disease from Gdańsk in Poland

The determination of polonium ²¹⁰Po in human blood samples is presented and discussed in this paper. The human blood samples were collected from patients of Medical University of Gdańsk with ischaemic heart disease (morbus ischaemicus cordis, MIC). The polonium concentrations in analyzed human blood samples are very differentiated. ²¹⁰Po is of particular interest in public health and although is present in the environment in extremely low amounts, it is easily bioaccumulated to the human body. The study shows that the amount of ²¹⁰Po that is incorporated into the human body depends on the food habits and some difference in its levels could be observed between smokers and non-smokers.

Natural radionuclides in bottled drinking waters produced in Croatia and their contribution to radiation dose

Activity concentrations of (234)U, (238)U, (226)Ra, (228)Ra, (210)Po and (210)Pb in all Croatian bottled drinking natural spring and natural mineral water products, commercially available on the market, were determined. The samples originated from various geological regions of Croatia. Activity concentrations of measured radionuclides are in general decreasing in this order: (234)U>(238)U>(226)Ra>(228)Ra>(210)Pb>(210)Po and (226)Ra>(228)Ra>(234)U>(238)U>(210)Pb>(210)Po for natural spring and mineral waters, respectively. Based on the radionuclide activity concentrations average total annual effective ingestion doses for infants, children and adults, as well as contribution of each particular radionuclide to total dose, were assessed and discussed. The highest doses were calculated for children from 7 to 12 years of age, which makes them the most critical group of population. All values for each type of water, as well as for each population group, were well below the recommended reference dose level (RDL) of 0.1 mSv from one year's consumption of drinking water according to the European Commission recommendations from 1998. Contribution of each particular radionuclide to total doses varied among different water types and within each water type, as well as between different age groups, where the lowest contribution was found for uranium isotopes and the highest for (228)Ra.

Nuclides.net: a computational environment for nuclear data and applications in radioprotection and radioecology

An interactive multimedia tool, Nuclides.net, has been developed at the Institute for Transuranium Elements. The Nuclides.net "integrated environment" is a suite of computer programs ranging from a powerful user-friendly interface, which allows the user to navigate the nuclides chart and explore the properties of nuclides, to various computational modules for decay calculations, dosimetry and shielding calculations, etc. The product is particularly suitable for environmental radioprotection and radioecology. Detailed descriptions of Nuclides.net and some potential applications in radioprotection and radioecology are presented.

Determination of 210Po in environmental materials: A review of analytical methodology

Polonium-210 ((210)Po) is analysed for a variety of purposes, including for radiological impact assessment, as a tracer of environmental processes, and as an indirect measure of its progenitor lead-210 ((210)Pb). Losses of polonium may occur at temperatures above 100 degrees C, depending on conditions, requiring particular care in sample preparation and treatment. In spite of this problem, the analysis of (210)Po is relatively straightforward, due to the ease of source preparation through spontaneous auto-deposition onto metal surfaces and the uncomplicated alpha spectrum. Although several optimisation studies have been carried out, published source preparation methods remain remarkably diverse. Some areas where further study would be useful are identified.

Measurement of the 234U/238U ratio by MC-ICPMS in drinking water, hair, nails, and urine as an indicator of uranium exposure source

The isotopic ratio (234)U/(238)U in drinking water and in hair, toenail, and urine samples from 45 individuals who consumed 0.2-2775 microg d(-1) of uranium in their drinking water was determined using a multi-collector inductively coupled plasma mass spectrometer (MC-ICPMS). The U/U atom ratio in the water samples varied from 51 x 10(-6) to 252 x 10(-6) whereas in secular equilibrium (i.e., unity activity ratio) the ratio is 54.9 x 10(-6). The correlation of the (234)U/(238)U ratio between hair and nail samples was 0.98, and between hair and nails and urine the ratio was 0.91 and 0.89, respectively. The correlation of the ratio between water and the hair or nails was 0.97 but only 0.72 for water and urine, possibly due to spectral interferences. These results conclusively demonstrated that the uranium found in the bioassays can be traced to the drinking water, thus providing a direct link to the source of exposure. Hair may serve as an excellent indicator of occupational or environmental exposure to uranium and provide information regarding its source. Bioassay of hair is attractive as it is an effective bio-concentrator, samples can be easily stored, the concentration reflects an integrated value, and, finally, the measurement of the (234)U/(238)U isotopic ratio in digested hair samples by MC-ICPMS is feasible and highly informative. Hair bioassay can also be used to assess exposure to depleted uranium long after the subjects have left the area suspected of contamination.

Uranium isotopes in public drinking water and dose assessment for man in Poland

238U, 234U and 235U were determined in tap water from municipal water pipes that drew their supply from surface water or ground water in various locations in Poland. Average activity concentrations of 238U, 234U and 235U in tap water from surface water were 9.6 +/- 7.1, 12.8 +/- 9.7 and 0.41 +/- 0.31 Bq m(-3), respectively, whereas from ground water they were 4.5 +/- 6.0, 5.7 +/- 6.9 and 0.19 +/- 0.27 Bq m(-3), respectively. Activity concentrations of 234U were higher than 238U. Ratios of 234U/238U ranged from 1.07 to 2.60, indicating the lack of equilibrium between these isotopes. The average 235U/238U ratio was 0.043 +/- 0.008, being close to 0.046 for natural uranium. Average annual intake with water and food was 7.6 +/- 5.1 Bq for 238U and 9.5 +/- 6.6 Bq for 234U. Annual committed effective doses calculated from these intakes for adults were 0.34 +/- 0.23 and 0.47 +/- 0.32 microSv, respectively; 235U contributed to the total dose from the uranium isotopes by about 2%.