Activity Concentrations Of 210Pb Research Articles

Environmental radiological risk assessment of a coal ash and slag disposal site with the use of the ERICA Tool

The aim of this study was to assess the environmental radiological risk of coal ash and slag to terrestrial wildlife. The research site used in this study was a disposal site of coal ash and slag with enhaced content of uranium decay chain radionuclides. With the use of the ERICA Tool, total dose rates to wildlife and risk of resultant radiobiological effects were estimated. As input data for the assessment, experimental activity concentrations of 238U, 226Ra and 210Pb in coal ash and slag and best estimates of activity concentrations for related daughter radionuclides and 235U decay chain were used. Where possible, the experimental data for activity concentrations of 238U, 226Ra and 210Pb in plants and related concentration ratios were used. Results were compared to background dose rates, also estimated by the Tool. The Tool's assessment data indicated internal exposure as the prevalent exposure pathway with 226Ra and 210Po as the main dose contributors. Also, the contribution of 235U decay chain to the total dose rate was not negligible since for some organisms it represented up to 11% of the total dose rate. The risk of an occurrence of radiobiological effects in plants on the coal ash and slag disposal site can be considered negligible since the estimated total dose rates were below the screening dose of 10 μGyh−1 and near the dose rates estimated for plants in the control area. However, the estimated dose rates for reference animals and Lichen & Bryophytes were above the screening dose rate for most organisms and on average 13 times higher than the estimated background dose rates. At the given dose rates, an occurrence of different radiobiological effects could not be excluded for animals in close contact with coal ash and slag such as earthworms and small burrowing mammals. A separate assessment performed on an example of reference plants showed that the use of activity concentrations in organisms as input data can result in an order of magnitude smaller estimates of dose rates in comparison to activity concentration in coal and ash as input data. Our study highlighted the need for experimental data in radiological risk assessments to mitigate the conservatism of the ERICA Tool and its tendency to overestimate dose rates.

Bioaccessibility and radioisotopes of lead in soils around a fertilizer industry in Lebanon.

The use of phosphate ore by fertilizer industries is considered a major source of soil contamination by trace metals and radionuclides. Despite its low mobility and bioavailability, lead (Pb) is among soil contaminants that pose a serious risk to human health. This study evaluates the potential impact of a fertilizer factory in North Lebanon on the total content of Pb and the activity concentration of its radioisotopes in residential, non-agricultural lands around the industry, as well as its mobility and bioaccessibility in soil samples collected at different depths. Chemical extractions by EDTA and in vitro physiologically based extraction test were used to estimate, respectively, the available and bioaccessible fractions of Pb in soils. Radioisotopes 214Pb, 212Pb and 210Pb have been analyzed by gamma spectrometry. Different physicochemical soil parameters, such as pH, carbonate content, electrical conductivity, cation exchange capacity, clay, total nitrogen and redox potential, were studied. The pseudo-total Pb varied between 12.8 and 68.5mgkg-1, while the extractable fractions were more variable, between 12 and 72% of total Pb concentration for the EDTA extracted fraction and up to 28.5% for the bioaccessible fractions. The processing of the data shows the decreases with depth in most sites of the total and available Pb and of the activity concentration of 210Pb and their positive correlations with total nitrogen. These variations and relationships with the location of studied sites show the influence of emissions from the factory or the transport of ore and by-products. The correlations between available and bioaccessible Pb on one hand, between available Pb and 210Pb on another hand, raise the question of health risk assessments taking into account the bioaccessibility of Pb and its radioisotopes.

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.

Determination of 7Be, 210Pb and 22Na Activity in Air and Rainwater samples by Gamma-ray Spectroscopy

The activity concentration of cosmogenic radionuclides in atmospheric aerosol has been used in many applications, such as air mass transport models and solar activity reconstructions. One of the most studied cosmogenic radionuclides is 7Be which is being monitored at the Nuclear Engineering Department of the National Technical University of Athens (NED- NTUA) since many years, with high accuracy and precision. Sodium-22 is another cosmogenic radionuclide met in such studies, however less reported due to its very low activity concentration, of the order of 1 μBq/m3 [1], [2] – roughly four orders of magnitude lower than that of 7Be. Besides cosmogenic radionuclides, radionuclides of terrestrial origin like the 222Rn progeny 210Pb are also used in atmospheric aerosol studies. Lead-210 serves as an ideal tracer of continental air masses because 222Rn emission from oceans and lakes is negligible (<1%) compared to land sources. However, its deposition exhibits geographic and seasonal variations depending on 226Ra content of the top soils, soil-porosity and meteorology of a particular region [3]. Values reported for 210Pb activity in the air range from 0.1 to 3.4 mBq/m3 [4]. During this research, an investigation regarding the detection of 210Pb and 22Na in atmospheric aerosol and the determination of 7Be/22Na ratio has been conducted at NED-NTUA. Sampling and analysis methods were appropriately selected to allow for the detection of all three nuclides in aerosol samples. In order to study the role of precipitation in surface air 7Be, 210Pb and 22Na activity concentration, a procedure for collecting and analyzing rainwater was also developed. From the results obtained so far it is concluded that with the sampling and analysis procedures followed, 210Pb can be easily determined with reasonable accuracy. As far as 22Na is concerned, it was concluded that it can be detected although with high uncertainty, since its activity concentration is within the limits of detection.

Determinations of 210Pb contents in food, diet, environmental samples and estimations of internal dose due to daily intakes

210Pb in food, diet and environmental samples collected in China during the period of 2015–2017 was analyzed and discussed in this study. The activity concentrations of 210Pb were measured by gamma spectrometry, the average of which in sea food, cereal, mushroom, duplicate diet, soil, sediment, biomass ash and aerosol samples were 1.22 ± 0.69 Bq kg−1 fresh weight, 2.77 ± 0.33 Bq kg−1 fresh weight, 8.2 Bq kg−1 dry weight, 1.21 Bq kg−1 dry weight, 172 ± 44 Bq kg−1 dry weight, 87.2 ± 39.2 Bq kg−1 dry weight, 140 ± 185 Bq kg−1 and 813 ± 520 μBq m−3, respectively. The results were higher than those observed in various countries except for seafood. The annual effective dose due to mushroom, duplicate diet and aerosol were estimated. Furthermore, the transfer factor (TF) of 210Pb from soil to some species of mushroom were also considered. This study provided useful data for radiation protection of the public.

Activity concentration and annual effective dose estimation of 210Pb, 40K and 137Cs in soils of southern Algeria

Sixteen soil samples with depth ranging from 0 to 2 cm were collected from the Sahara region near the locations where in the early 1960s France conducted a series of aboveground and underground nuclear tests in the south of Algeria. The 210Pb activity concentration in soil samples ranged between 0.6 and 62 Bq kg−1, the 40K activity ranged between 77 and 300 Bq kg−1, and the 137Cs activity ranged between 0.2 and 4 Bq kg−1. The annual effective dose of 137Cs and 40K was calculated between ~ 0.3 and 7.5 and ~ 34 and 136 µSv a−1 with an average of 3.72 and 74.68 µSv a−1, respectively. At some sampling points, the annual effective dose crosses the limit proposed by International Atomic Energy Agency and other international standards. To reduce the exposure of public to high level of dose in the area, some recommendations are proposed at the end of this study.

Soil depth profile of 137Cs, 210Pb and 40K in Algeria

ABSTRACTThree soil depth profiles of 210Pb, 137Cs and 40K at different areas of Algeria were studied. The soil sampling areas are near the location where the French nuclear tests took place at 1960–1966. The two depth soil profiles were collected at Ghardaia region and the third one at Reggane region. The vertical distributions of radionuclides at the two soil depth profiles from Ghardaia region are different, probably due to the different soil composition. The soil depth profile from sandy soil show uniformity in the distribution of radionuclides without a clear maximum (peak). The soil depth profile that characterised by silty sand show a clear peak at 20–50 cm depth for all studied radioactive nuclides, while the observed activities are two times higher than the corresponding values in sandy soil samples. More specifically in Ghardaia region the 210Pb, 137Cs, 40K activity concentrations ranged between 27 and 50 Bq kg−1, 0.2 and 3 Bq kg−1 and 75 and 90 Bq kg−1 respectively in sandy soil type and between 37 and 75 Bq kg−1, 4 and 6 Bq kg−1 and 140 and 180 Bq kg−1 respectively in silty sand soil type. Finally, the third depth soil profile collected from Reggane site presents a completely different distribution of the studied radionuclides. The activity concentrations of 210Pb, 137Cs, 40K ranged between 37 and 51 Bq kg−1, 0.16 and 0.39 Bq kg−1 and 120 and 309 Bq kg−1 respectively. Three peaks in the 137Cs distribution revealed, were most probably, Chernobyl related 137Cs accounts for the surface peak, while the deeper peaks are connected to the weapons fallout.

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.

Evidences of different meteorological patterns governing 7Be and 210Pb surface levels in the southern Iberian Peninsula

7Be, 210Pb and PM10 levels in surface air have been simultaneously measured at two sampling sites in the southern Iberian Peninsula for a period of two years. Each site covers one different meteorological area of the Guadalquivir valley, from the mouth (Huelva) to the middle point (Cordoba). The objective of the present study is to analyse the spatial variability of both natural radionuclides, and to identify and characterise the meteorological patterns associated with similar and different surface concentration levels in this complex region. Concentrations are similar in both sampling sites. 7Be level is in the 0.6–15.5 mBq m−3 range in Huelva and 1.2–13.3 mBq m−3 in Córdoba, 210Pb activity concentrations are between 0.04 and 2.30 mBq m−3 in Huelva, and between 0.03 and 1.2 mBq m−3 in Cordoba, and PM10 concentrations are found to be in the 5.1–81.3 μg m−3 range in Huelva, and 8.2–76.3 μg m−3 in Cordoba, respectively. A linear regression analysis indicates more regional variability for 210Pb than for 7Be between simultaneous measurements. Principal components analysis (PCA) is applied to the datasets and the results reveal that aerosol behaviour is mainly represented by two components, which explain 82% of the total variance. The analysis of surface measurements and meteorological parameters revealed that component F1 groups sampling periods in which the influence of similar meteorological conditions over the region lead to similar 7Be, 210Pb and PM10 concentration levels in both sampling sites. On the other hand, component F2 detaches the 7Be, 210Pb and PM10 concentration levels between monitoring sites, and the meteorological analysis shows how surface concentrations within this component are associated with the development of different mesoscale circulations in each part of the valley. The identification of sampling periods characterised by differences in surface concentrations and wind patterns between stations suggests that the valley could not be considered as one single unit for certain meteorological scenarios. These results evidence how the understanding of wind characteristics within a complex terrain provide some essential knowledge in the regionalization and/or optimization of monitoring networks.

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.

Chemometric methods for source apportionment of 210Pb, 210Bi and 210Po for 10 years of urban air radioactivity monitoring in Lodz city, Poland

The radionuclide activity concentrations of 210Pb and its decay products 210Bi and 210Po were measured in 271 total suspended particulate samples collected from 2008 to 2017 in the center of Lodz city, Poland. Natural and anthropogenic contributions to the observed activities of 210Pb, 210Bi and 210Po radionuclides were estimated. Corrected aerosol residence times were determined for this purpose. After the closure of one of the coal-fired power plants located in the center of the city, a substantial reduction in emission of these radionuclides was observed. For proper identification of the origins of these radionuclides, the concentrations of 4 K and 7Be as well as sulfur dioxide (SO2), and total air particulate matter were measured. Principal component analysis and cluster analysis were conducted for source apportionment of 210Pb, 210Bi and 210Po in urban air.

Absorption of the natural radioactive gas 222Rn and its progeny 210Pb by Spanish moss Tillandsia usneoides and its response to radiation

Radon is the most abundant radioactive gas in natural air and the major contributor to human exposure. However, few attempts have been made to directly measure the relationship between radon and plants. Epiphytic Tillandsia usneoides was chosen as a model to investigate whether it can absorb 222Rn and its daughter 210Pb and to determine the physiological and genetic effects of radon on plants. The results showed that T. usneoides was effective in reducing airborne radon because radon concentrations in the chamber after plant treatment decreased faster than those in the natural situation, and activity concentrations of 210Pb in the plant increased significantly with an increase in radon concentration. The changes in the parameters of genetic damage, including tail DNA, tail length, tail moment and olive tail moment in T. usneoides also increased significantly with the increase of radon concentrations, suggesting that DNA was unavoidably affected by radioactive radon. In contrast, the physiological responses of T. usneoides exposed to radon suggest that this plant can resist radon stress because there was no difference in MDA, soluble proteins and leaf relative electronic conductivity, and increasing SOD may play a role in the tolerance to oxidative stress. Therefore, parameters of genetic damage have the potential to be used as biomarkers to monitor the concentrations of airborne radon.

Plant Accumulation of Natural Radionuclides as Affected by Substrate Contaminated with Uranium-Mill Tailings

Environmental concern due to plant accumulation of natural radionuclides is a major concern in uranium mining areas. To evaluate the risk associated with the transfer of radionuclides to edible plants, the uptake of 238U, 226Ra, and 210Pb by Chinese cabbage (Brassica rapa L. subsp. pekinensis (Lour.) Hanelt) grown in soils contaminated with uranium-mill tailings (UMT) was investigated. Test plants were grown under controlled conditions in substrate composed of soil and UMT in different ratios. Activity concentrations of 238U, 226Ra, and 210Pb in substrate, leaves, and roots were measured and the concentration ratios determined. Soil characteristics were determined, since they directly affect bioavailability of radionuclides. Concentration ratios of 238U, 226Ra, and 210Pb in leaves varied from 0.001 to 0.006, 0.024 to 0.172, and 0.004 to 0.011, respectively, and in roots from 0.020 to 0.126, 0.015 to 0.241, and 0.033 to 1.460, respectively. Concentrations of 238U, 226Ra, and 210Pb in leaves and roots were found to correlate with the amount of 238U, 226Ra, and 210Pb in the substrate. A higher amount of 226Ra accumulated in aboveground parts (57–877 Bq kg−1 d. m. for leaves) compared to 238U (0.6–4.7 Bq kg−1 d. m. for leaves) and 210Pb (8–53 Bq kg−1 d. m. for leaves), which were mainly stored in the roots. The relationships between the amount of radionuclides in plants and soil characteristics and their role in radionuclide uptake are discussed and critically evaluated.

Heavy metals and radioactive nuclide concentrations in mosses in Greece

ABSTRACTTerrestrial mosses obtain most of their nutrients directly from precipitation and dry deposition, and they can be used for monitoring of heavy metals and airborne radionuclide depositions. Ninety-five (95) samples of Hypnumcupressiforme Hedw., were collected in the region of Northern Greece during the end of summer 2016. Differences have been observed in the activity concentrations of 7Be, 210Pb, 137Cs and 40K between the mosses collected from ground surface, rocks, branches and near roots. No correlation between the concentrations of these radionuclides has been found. Furthermore, the concentrations of 33 elements were determined in all moss samples by using INAA technique.

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.

A study of temporal variations of 7Be and 210Pb concentrations and their correlations with rainfall and other parameters in the South West Coast of India

As a part of establishing a regional database on natural radioactivity, the atmospheric concentrations of 210Pb and 7Be were measured over a three and half year period (2014–2017) in Mangalore and Kaiga in the South West Coast of India. A total of 99 air samples, collected in the different months of the year, were analysed in this study. The mean activity concentrations of 7Be and 210Pb were found to be 5.5 ± 3.1 mBq m−3 and 1.1 ± 0.73 mBq m−3, respectively. Both the radionuclides exhibited strong seasonal variations, with maximum concentration of 7Be occurring in the summer and that of 210Pb in the winter season. The concentration of both the radionuclides was minimum in the rainy season. Higher 210Pb concentration during winter was attributed to the ingression of continental air masses due to the wind regime from the North East. The sunspot number index of the solar activity also plays an important role in the increase and decrease of 7Be concentration in the air. A clear trend of increased and lowered concentration of 7Be with lower and higher solar activity (low and high sunspot number), respectively, in accordance with the 11-year solar cycle, was observed in this study. The temporal variation of PM10 concentration was also studied and it showed maximum value in the winter and minimum in the rainy season with an average of 56.9 μg m−3. Statistically significant positive correlation was observed between the PM10 and 210Pb activity concentration, whereas a weak correlation was observed between PM10 and 7Be. This is due to the fact that 7Be is largely associated with sub-micrometer size particles, whereas PM10 is contributed by larger sizes. The dependence of the activity concentrations of 7Be and 210Pb with meteorological parameters such as rainfall, temperature, and humidity was studied through linear regression analysis. A significant correlation was observed between 7Be and 210Pb concentrations with rainfall intensity (with identical correlation coefficients), which suggested that the removal mechanisms of these two radionuclides were similar. 7Be showed a strong correlation with temperature, whereas 210Pb with humidity. A comparison of the data obtained in the present study for the South West Coast of India with the global literature values of 7Be and 210Pb in aerosols showed that the values did not reflect the well-known latitudinal dependence of the 7Be tropospheric fluxes. Overall, the study provides an improved understanding of the correlation and variability of 210Pb and 7Be concentrations in the atmosphere in the South West Coast of India.

Dependence of radon exhalation on grain size of sedimentary waste

Tailings resulted from sulphuric acid leaching process of uranium from sedimentary rocks contain high concentrations of 226Ra and its daughters, the most important of which is 222Rn. Movement of radon gas out of the tailings is strongly influenced by the physicochemical characteristics of these tailings especially their radium content and the grain size. So, the tailing samples were size fractionated into four sizes (> 250, 250–125, 125–74 and 250 and < 74 µm, the activity concentrations of 230Th, 226Ra, 214Pb, 214Bi, 210Pb, 232Th and 40K increased throughout with decreasing particle size, while that of 238U, 234U and 235U have an opposite effect. The results revealed an inverse relationship between the radon exhalation rate and size fractionation. Also, the results showed a good correlation between radium activity concentration and radon mass exhalation rate.