210Po Activity Concentrations Research Articles

Distribution patterns of 210Po, 210Pb and the particle export in the Taiwan Strait during the winter

210Po and 210Pb are increasingly used to constrain particle dynamics in the open oceans, however they are less used in coastal waters. Here, distributions and partitions of 210Po and 210Pb were examined in the Taiwan Strait, as well as their application to quantify particle sinking. Activity concentrations of dissolved 210Po and 210Pb (<0.6 μm) ranged from 1.21 to 7.63 dpm/(100 L) and from 1.07 to 6.33 dpm/(100 L), respectively. Activity concentrations of particulate 210Po and 210Pb varied from 1.96 to 36.74 dpm/(100 L) and from 3.11 to 38.06 dpm/(100 L). Overall, particulate 210Po and 210Pb accounted for the majority of the bulk 210Po and 210Pb. 210Po either in dissolved or particulate phases showed similar spatial patterns to 210Pb, indicating similar mechanisms for controlling the distributions of 210Po and 210Pb in the Taiwan Strait. The different fractionation coefficients indicated that particles in the Zhemin Coastal Current (ZCC) inclined to absorb 210Po prior to 210Pb while they showed an opposite effect in the Taiwan Warm Current (TWC). Based on the disequilibria between 210Po and 210Pb, the sinking fluxes of total particulate matter (TPM) were estimated to range from–0.22 to 3.84 g/(m2·d), showing an overall comparable spatial distribution to previous reported sediment accumulation rates. However, our sinking fluxes were lower than the sedimentation rates, indicating a sediment resuspension in winter and horizontal transport of particulate matter from the Taiwan Strait to the East China Sea.

210Po and 210Pb activity concentrations in Greenlandic seabirds and dose assessment

Naturally occurring radionuclides, in particular, polonium-210 (210Po), have a greater contribution than anthropogenic radionuclides to the annual effective dose received by the general public due to consumption of seafood. Knowledge of potential trophic sources and transfer of 210Po to seabird species and subsequently to the Greenlandic people is, however, still poor. Here, we assess the transfer of 210Po and 210Pb to seabirds sampled during autumn and winter 2017 and 2018 in Greenland and provide a dose assessment. The activity concentrations of 210Po in muscle and liver, respectively, ranged from 0.2 ± 0.1 Bq kg−1 w.w. in glaucous gull (Larus hyperboreus) to 21.2 ± 22.6 Bq kg−1 w.w. in thick-billed murre (Uria lomvia) and from 32.0 ± 9.4 Bq kg−1 w.w. in common eider (Somateria mollissima) to 40.5 ± 49.0 Bq kg−1 w.w. in thick-billed murre. 210Po was non-uniformly distributed in the body of thick-billed murre. Kidneys and feathers showed higher 210Po activity concentrations than heart and bone. The 210Po/210Pb activity concentration ratios are higher than unity, indicating that 210Po is preferentially taken up by seabirds compared to its progenitor 210Pb. The derived annual absorbed dose from 210Po to the whole body of thick-billed murre was 6.4 × 102 ± 3.0 × 102 μGy. The annual effective dose to the average adult and representative person in Greenland due to ingestion of 210Po in seabirds was estimated to 13.0 μSv and 57.0 μSv, respectively. This derived dose is low and poses a slight risk, and risk communication is therefore deemed unnecessary.

Modeling of 210Pb and 210Po radionuclide emissions from local power plants in central Poland.

Due to the more volatile nature of 210Po in relation to 210Pb, an imbalance of activity concentrations in high temperature combustion processes can be observed, especially in fine particulates (diameter < 0.1, 0.2 and 0.5 μm). In the atmosphere and in the soil around coal-fired power plants, 210Pb and 210Po concentrations are a combination of activities from natural and anthropogenic sources. In this study only portions of 210Po and 210Pb radionuclides resulting from energy production activities were analyzed. Due to the high mobility of fine particles, a surface area of 172 km × 140 km in central Poland was chosen for simulation. For validation of the modeling approach, three grid versions were applied: 1 km, 2 km and 4 km. Simulated results confirmed experimental-computational values of an excess of both radionuclides in the atmosphere in 2017 in the city of Lodz. Different aerosol fractions, seasons and various grids in the selected area were subjected to 36 individual simulations. The 210Po activity concentrations measured in winter and summer 2017 were 42.5 and 8.99 μBq m-3, respectively. Simulated and measured values of artificial 210Po and 210Pb activities are well correlated.

Spatial variability in Polonium-210 and Lead-210 activity concentration in New Zealand shellfish and dose assessment

The activity concentrations of Polonium-210 (210Po) and Lead-210 (210Pb) were determined in shellfish (Perna canaliculus and Paphies subtriangulata) sampled bimonthly from March 2018 to February 2019 from 14 sites around New Zealand. Activity concentrations of 210Po ranged from 4.7 ± 1.1 to 324 ± 17 Bq. kg−1 with a mean value of 57 ± 72 Bq. kg−1 (wet weight). The activity concentrations of 210Pb were lower than those for 210Po (0.1 ± 0.4 and 1.9 ± 0.4 Bq. kg−1, with a mean value of 0.7 ± 0.4 Bq. kg−1, wet weight). The calculated 210Po/210Pb activity concentration ratios were higher than unity in all samples indicating that radionuclides are not in equilibrium in shellfish and most of the 210Po was unsupported by its grandparent 210Pb. No significant difference was noted in 210Po activity concentration between different seasons, species or shellfish condition index. Significant spatial variability in 210Po activity concentration was observed with elevated 210Po activity concentration in two sampling sites: Ninety Mile Beach (mean 257 ± 47 Bq. kg−1) and Maunganui Bluff (mean 127 ± 22 Bq. kg−1). Elevated 210Po is hypothesised to be related to an increase of 210Po accumulation through diet. Individuals who consume large quantities of shellfish (10 g per day or more) from areas affected by elevated 210Po activity concentration may be exposed to an annual committed effective dose from 210Po in shellfish in excess of 1 mSv.

Assessment of 210Po and 210Pb by moss biomonitoring technique in Thrace region of Turkey

This study presents the first data of 210Po and 210Pb activity concentrations using moss species Hypnum cupressiforme from Thrace region, the northwestern part of Turkey. The moss samples were systematically collected from 40 locations in the study area. The average with standard deviation and range of 210Po and 210Pb activity concentrations were found to be 409 ± 128, 188–777 and 494 ± 183, 178–852 Bq kg−1 at dry weight, respectively. Comparatively higher radionuclide activities were found in the northeastern Thrace, probably due to 222Rn daughters attached to aerosols through high rainfall in this part of the region. A significant positive correlation was found between 210Po and 210Pb, which shows that their source and/or bioaccumulation behavior are similar. The average and range of 210Po/210Pb ratio were calculated to be 0.89 and 0.47–2.67, respectively. Those levels were calculated to be mostly lower than unity that addressed the abundance of 210Pb, probably due to predominantly inorganic particles through atmospheric deposition.

Levels of radionuclide concentrations in benthic invertebrate species from the Balearic Islands, Western Mediterranean, during 2012-2018.

Baseline levels of radionuclides in the marine environment of the Balearic Islands in Western Mediterranean have not been reported in literature. Because of their ecological role and acknowledged sensitivity to pollutants, herein, the activity concentrations of 210Po, 40K, 210Pb, 90Sr, and 234Th were measured in two types of benthic invertebrate species (mussels and sea urchins) sampled during 2012-2018. The activity concentrations of 210Po, 40K, 210Pb, and 234Th ranged from 38 ± 1 to 325 ± 11 Bq kg-1 dry weight (d.w.), 220 ± 10 to 996 ± 46 Bq kg-1 d.w., ND (lower than the limit of detection) to 55 ± 8 Bq kg-1 d.w., and ND to 70 ± 15 Bq kg-1 d.w., respectively. In all cases, no artificial 90Sr activity was detected in the collected samples. The committed effective dose to humans was calculated to be in the range of 48-640 μSv year-1.

Distribution of 210Po and 210Pb radionuclides and their dependence on physico-chemical parameters of soil in Madikeri taluk, Coorg district, Karnataka, India

The paper deals with distribution of 210Po and 210Pb radionuclides in a vertical profile of illuviated soil, in Madikeri taluk of Coorg district, Karnataka, India. The activity concentration of 210Po and 210Pb radionuclides was determined using radioanalytical method and the dependence of these radionuclides on physico-chemical parameters of soil was also investigated through a statistical study. In all the layers of the soil in a vertical profile, the 210Po nuclides were found to be in disequilibrium with 210Pb. The frequency distribution of 210Po and 210Pb radionuclides was analysed using Kolgomorov–Smirnov test.

Accumulation of natural and anthropogenic radionuclides in body profiles of Bryidae, a subgroup of mosses.

Mosses can be used as biomonitors to monitor radionuclide deposition and heavy metal pollution in cities, forests, and grasslands. The aims of this work were to determine the activity concentrations of natural (210Po, 210Pb or 210Pbex (excess 210Pb is defined as the activity of 210Pb minus the activity of 226Ra), 7Be, 40K, 226Ra, 238U, and 232Th) and anthropogenic radionuclides (137Cs) in moss body profiles and in situ underlying soils of moss samples and to assess/determine the distribution features and accumulation of these radionuclides. Activity concentrations of radionuclides in the samples were measured using a low-background gamma spectrometer and a low-background alpha spectrometer. Consistent with their source, the studied radionuclides in the moss samples and underlying soils were divided according to the principal component analysis (PCA) results into an airborne group (210Po, 210Pb (210Pbex), 7Be, and 137Cs) and a terrestrial group (40K, 238U, 226Ra, and 232Th). The activity concentrations of 210Po and 210Pbex in moss body profiles were mainly concentrated in the stems-rhizoid parts, in which we measured some of the highest 210Po and 210Pbex levels compared to the results in the literature. 7Be mainly accumulated in the leaves-stem parts. Different positive correlations were observed between 210Po and 210Pb and between 7Be and 210Pb, which indicated that the uptake mechanisms of 210Po, 210Pb, and 7Be by moss plants were different, to some extent. 137Cs was detected only in some moss samples, and the fraction of 137Cs in the underlying soils was much lower than that in the moss, suggesting that mosses were protecting the underlying soils from further pollution. Except for 40K, the terrestrial radionuclide (238U, 226Ra, and 232Th) content in mosses was predominantly at low levels, which indicated not only the inability of mosses to use those elements for metabolic purposes but also the rather poor capability of mosses to directly mobilize, absorb, and transport elements (U, Ra, or Th) not dissolved in water.

Determination of 210Po in low-level wild bilberries reference material for quality control assurance in environmental analysis using extraction chromatography and α-particle spectroscopy

Abstract Certified reference materials (CRM) are being widely used for quality control assurance in environmental analysis. For certain CRM, the analytes and/or the range of concentrations are not be available or certified at all. The Joint Research Centre – Institute for Reference Materials and Measurements (JRC-IRMM) of the European Commission has issued a CRM of Wild Berries (IRMM-426) in order to validate radionuclide measurement methods for activity concentrations of the natural radionuclide 40K and the anthropogenic nuclides 90Sr and 137Cs, but not for 210Po. The aim of the work was to determine low-level activity concentration of 210Po in these wild berries. The activity concentration of 210Po was assessed by α-particle spectroscopy after dissolution of the sample by wet digestion and chemical isolation of Po by extraction chromatography. According to the time elapsed since sample collection, the results here shown can be useful not only for ultra low-level analysis of 210Po but also for 210Pb in the reference material.

210Po and 210Pb concentration in zooplankton of the Syrian coastal waters (eastern Mediterranean Sea)

210Po and 210Pb activity concentrations and their concentration ratio (CR) in marine zooplankton collected for the first time from the Syrian coastal waters (the eastern Mediterranean Sea) have been determined. The average activity concentrations of 210Po and 210Pb were 243±36 and 26.4±4.3 Bqkg-1 dw. The 210Po/210Pb activity ratio was found to be more than one in all zooplankton samples with an average of 9.2 (8.4 to 10), which indicates that the accumulation of 210Po in zooplankton does not come from the decay of the 210Pb only, and reflects a preferential bioaccumulation of 210Po over 210Pb. In addition, the Concentration Ratio (CR) for 210Po and 210Pb reached 104 and 103, respectively. This study will contribute to the radioecological reference database for zooplankton in the Mediterranean Sea.

Isotopes of 210Po and 210Pb in Hazel bolete (Leccinellum pseudoscabrum) \u2013 bioconcentration, distribution and related dose assessment

The hazel bolete Leccinellum pseudoscabrum (Kallenb.) Mikšík 2017 specimens and beneath soil layer (0–10 cm) have been examined on the occasion of 210Po and 210Pb activity concentrations, the nuclide bioaccumulation potential by species and distribution in fruit bodies. Mushrooms and forest soils came from six geographically distant locations in the northern and central parts of Poland. The threat to humans from 210Po and 210Pb contained in mushrooms has been also assessed. The absolute values of the 210Po radioactivity, respectively, in caps and stems of fruit bodies were in the range 0.74 ± 0.06–8.59 ± 0.36 Bq kg−1 dry biomass and from 0.81 ± 0.06–8.23 ± 0.37 Bq kg−1 dry biomass, while the values of the 210Pb radioactivity in caps and stems were in the range 0.61 ± 0.04–6.33 ± 0.22 Bq kg−1 dry biomass and 0.83 ± 0.04–4.59 ± 0.24 Bq kg−1 dry biomass, respectively. A potential related effective dose assessment showed that mushrooms L. pseudoscabrum can contribute at 0.89–10.3 μSv kg−1 db from 210Po decay and 0.42–4.37 μSv kg−1 db from 210Pb decay.

210Po in popular medicinal herbs from Poland

ABSTRACTHerbs are an important part of traditional medicine in Poland. Therefore, the aim of this study was the determination of polonium 210Po in 48 selected medicinal herb samples from the Polish market. The activity concentrations of 210Po were measured using alpha spectrometry. The activity concentration of 210Po was in the range from 0.3 ± 0.1 to 28.2 ± 0.4 Bq kg–1. The obtained results were compared with corresponding studies conducted worldwide. A higher 210Po activity concentration was observed in the above-ground part of plants. The obtained results show that the highest 210Po activity concentration was observed in evergreen plants and winter-hardy plants. Yet even infusions with 2 g of the most contaminated herbs examined were considered to be radiologically safe.

Geographical origin of bivalve molluscs in coastal areas using natural radioactivity fingerprinting and multivariate statistical analyses: Andalusian coast as case of study.

The presence of natural and artificial radionuclides in the marine environment produces the accumulation of radionuclides in bivalve molluscs consumed by humans, and therefore it could result in a radiological hazard. In this study, the activity concentrations of 210Po, 40K, 210Pb and 234Th were determined in different types of bivalve molluscs sampled during the period of May 2014-June 2015, along coastal areas from the Andalusian region (South of Spain), through alpha-particle spectrometry and low-level gamma-ray spectrometry. The activity concentrations of 210Po; 40K; 210Pb and 234Th varied between 40 ± 2 and 515 ± 9 Bq kg-1 dry weight (d.w.); 121 ± 7 and 674 ± 34 Bq kg-1 d.w.; ND (lower than limit of detection) and 73 ± 10 Bq kg-1 d.w.; and ND and 126 ± 27 Bq kg-1 d.w., respectively. The committed effective dose to humans was calculated to range from 41 to 479 μSv year-1. Both activity concentrations and dose levels were comparable to previous studies from other countries. Finally, a multivariate statistical analysis of natural radioactivity content allowed the discrimination between bivalve molluscs from Atlantic and Mediterranean coasts.

Accumulation of 210Po in Medicinal Plants in the Environment of Mangalore, Southwest Coast of India

Systematic studies on the accumulation of210Po in 12 medicinal plants and activity concentration in associated soils have been carried out. The activity of210Po was measured using a ZnS (Ag) alpha counting system. The mean210Po activity concentration was found to be 27.8 and 8.3 Bq/kg for plant and soil, respectively. The plant-to-soil mean activity ratio of210Po was found to be 3.8. A good correlation was observed between the activity concentration of210Po in plant and soil. The absorbed gamma dose rates in the study area were also measured using a portable scintillometer and found to vary in the range of 34.8–52.2 nGy/h, with a mean value of 43.5 nGy/h. The results of these systematic investigations are presented and discussed in detail.

Is human hair a proper 210Po and 210Pb monitor of their increased activity in the human body?

The study focused on 210Po and 210Pb activity concentrations determination in human hair as well as investigation its utility as an easy and safe indicator of metal elicitation for natural 210Po and 210Pb, and finding differences in their concentrations in hair considering the age, gender, hair color or diet of people who donated the samples. Statistically analyzed results showed significant differences within age, hair color, and cigarette smoking groups. Our results showed that human hair could not be unambiguously used as 210Po and 210Pb body burden indicators.

Radioactivity of honey from northern Poland

This work shows significant variations in the values of 210Po in different analyzed Polish voivodeships. Statistical analysis of 210Po activity concentrations in honey samples showed significant differences between place of honey collecting, kind of honey and morphological structure of plants from which bees collected nectar.

On the extraction efficiency of highly radiotoxic 210Po in Polish herbal teas and possible related dose assessment

Presented are results of a study on 210Po extraction efficiency in Polish herbal teas and risk to the human consumer due to exposure from highly radiotoxic, carcinogenic decay particles emitted by 210Po. 12 most popular commercially available Polish herbal teas, as well as their infusions in tap and filtered water, were analyzed and 210Po activity concentrations were calculated. The results of 210Po activity determination in dried plants were from 2.11 ± 0.09 for milk thistle to 33.7 ± 0.4 Bq·kg−1 dry wt. for cistus what equaled 4.21 ± 0.18 for milk thistle and 43.8 ± 0.5 mBq per one teabag. The extraction efficiencies into tap water ranged from 4.93 ± 0.39 for lime to 27.4 ± 1.4% for elderberry, while for filtered water were between 7.55 ± 0.47 for lime and 20.3 ± 1.1% for elderberry. There were no statistically significant differences between both extractions and no correlation between 210Po extraction efficiency and 210Po activity in dried herbs. The studies indicated the analyzed herbal teas consumption should not contribute significantly to the annual effective radiation dose in Poland.

210Po and 210Pb in fish from northern Aegean Sea and radiation dose to fish consumers

This paper presents the activity concentrations of 210Po and 210Pb in 15 different commercial fish species collected around Gokceada Island (northern Aegean Sea) in 2016. The distribution of 210Po and 210Pb was investigated in fish tissues and significant differences (P < 0.05) in radionuclide concentrations were noted between muscle, gills, and liver in each species. 210Po activity concentrations in tissues were systematically higher than those of 210Pb and the average values of 210Po/210Pb concentration ratios were calculated at 6.6 ± 1.5, 8.4 ± 3.2, and 10.2 ± 1.6 in muscle, gills, and liver, respectively. The annual effective dose to consumers through 210Po ingestion with fish filet averaged 62 µSv year−1 (range 5.5–160 µSv year−1). This effective dose is in the range of natural radiation doses reported worldwide for humans through ingestion of sea food.

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.

Statistical analysis for the confirmation of seasonal variation of radionuclides in different environmental matrices

In the present study, 210Po and 210Pb activity was measured by using ZnS(Ag) alpha counter and using the statistical analysis to find the seasonal variation of activity concentration. The activity concentration of 210Po and 210Pb in soil and sediment of Cauvery in monsoon was measured. The seasonal variation analysis was performed using pairwise comparison test, which found that the activity concentration was higher in monsoon than pre-monsoon.