Atmospheric concentrations of 7Be and 210Pb in Granada, Spain

Aerosols samples in near-surface air of Granada (Spain) were collected on a weekly basis. The seasonal ²¹⁰Pb and ⁷Be concentrations were determined during the five-year period, from October 1993 to September 1997. The elements, despite their different origin and their different distribution throughout the atmosphere, present the same seasonal variation. There was a tendency for a maximum during the summer season and a minimum during fall and/or winter. In this work, the concentration of ⁷Be and ²¹⁰Pb and meteorological data have been used in order to determine the periods of the potential radioactive pollution. This study, also, shows that the deposition of ⁷Be occurs primarily by precipitation except during the investigation periods where precipitation was scarce and irregular.This revised version was published online in November 2005 with corrections to the Cover Date.     

Atmospheric concentration of 210Pb and 7Be at Sarufutsu, Hokkaido, Japan

The atmospheric concentration of ²¹⁰Pb and ⁷Be was observed at Sarufutsu on the coast of the Sea of Okhotsuk in Hokkaido, Japan. Measurements were carried out during the period from February to August, 2001. The atmospheric concentrations of ²¹⁰Pb and ⁷Be ranged from 0.2 to 2.5 mBq/m³ and from 0.0 to 4.2 mBq/m³, respectively. The seasonal variation pattern of the atmospheric concentration of ²¹⁰Pb indicated that the air mass from Chinese Continent reached the coast of the Sea of Okhotsuk.     

Atmospheric deposition of 7Be, 40K, 137Cs and 210Pb during 1993-2001 at Tokai-mura, Japan

To evaluate the radionuclide migration from the atmosphere to the ground surface, atmospheric deposition samples were collected from 1993 to 2001 with a basin set up at Tokai-mura, Japan. Monthly samples were evaporated to dryness to obtain residual samples and measured with a Ge detector for ⁷Be, ⁴⁰K, ¹³⁷Cs and ²¹⁰Pb. According to the analysis, clear seasonal variations with spring peaks of deposition weight and deposition amounts of all the radionuclides were found. The analysis also showed that these radinuclides can be divided into two groups, each having different carrier particle sizes and, hence, different deposition processes.     

Total deposition velocities and scavenging ratios of 7Be and 210Pb at Rokkasho, Japan

The atmospheric concentrations and deposition fluxes of ⁷Be and ²¹⁰Pb were observed biweekly in Rokkasho, Japan on the Pacific Ocean coast at the northern end of Honshu Island, from March 2000 to March 2006, to clarify their regional features. Seasonal variation pattern of atmospheric ⁷Be concentrations had double peaks, and that of ²¹⁰Pb had a single peak. Deposition fluxes of ⁷Be and ²¹⁰Pb showed the same patterns. The total deposition pattern of ⁷Be was similar to that commonly seen on the Pacific Ocean side of northern Honshu Island, while the pattern of ²¹⁰Pb was similar to that commonly seen on the Japan Sea side. The lack of high spine mountains windward in Rokkasho may be the cause of this ambiguity in the winter monsoon season. Total deposition velocities and scavenging ratios of ²¹⁰Pb were similar to those of ⁷Be from spring to fall, and showed that both nuclides had a similar removal process from the atmosphere. However, the scavenging ratios of ²¹⁰Pb were slightly larger than those of ⁷Be in winter, indicating different behaviors for both nuclides in the scavenging process. The scavenging ratios of both nuclides inversely correlated with precipitation rate, and the ratios in winter were larger than in the other seasons.     

Transfer of 7Be, 210Pb and 210Po in a forest canopy of Japanese cedar

The concentrations of ⁷Be, ²¹⁰Pb and ²¹⁰Po of ca. 60 parts of a whole tree of Japanese cedar and of underlying litter and soil samples were determined for studying their transfer in a forest canopy. The results suggest that the mean residence times of ⁷Be and ²¹⁰Pb in the forest canopy were ca. 20 and 900 days, respectively, and the dry deposition rate of ⁷Be on the forest canopy was about a half of the total deposition rate.     

Atmospheric deposition of 210Po and 210Pb in Malaysian waters during haze events

Biogenic burning as forest fire phenomena occurring from April to August each year in the Sumatra and Borneo islands are major sources of biogenic uranium–thorium decay series in marine systems. 30 samples were collected during the Ekspedisi Pelayaran Saintifik Perdana 2009 cruise (EPSP 2009 cruise) between 12th June and 1st August 2009 from the Straits of Malacca to the Sulu and Sulawesi Seas to study the effect of haze and the monsoon season on the deposition rate of ²¹⁰Po and ²¹⁰Pb in Malaysian waters. All samples were spiked with 1 ml of lead [Pb(NO₃)₂; 25 mg ml^?1] and 0.05 ml of Polonium-209 tracer (26.08 dpm ml^?1). ²¹⁰Po activity was determined by auto plating onto silver foil and counting using an alpha spectrometry system (Canberra model Alpha Analyst with a silicon-surface barrier detector). Lead that was collected via electrodeposition, formed lead sulphate (PbSO₄) precipitation. This precipitate was wrapped onto plastic discs and counted for ²¹⁰Pb beta activity using a gross alpha–beta counting system (Tennelec model LB-5100 low background gas-flowing anti-coincidence alpha/beta counter) after 1 month to allow bismuth ingrowths. The range of ²¹⁰Po activities varied between 51.08 ± 15.1 and 742.08 ± 220.34 Bq/kg, whereas the activity of ²¹⁰Pb ranged from 31.10 ± 4.20 to 880.23 ± 123.86 Bq/kg and ²¹⁰Po/²¹⁰Pb ratio value varied between sampling stations from 0.19 to 13.77. The contents of ²¹⁰Po were also statistically positively correlated with the amount of total suspended particulate especially those recorded during heavy haze period events.     

Atmospheric deposition fluxes of <Superscript>7</Superscript>Be, <Superscript>210</Superscript>Pb and <Superscript>210</Superscript>Po at Xiamen,China

The atmospheric deposition fluxes of ⁷Be, ²¹⁰Pb and ²¹⁰Po at Xiamen were measured. The samples were collected from March 2004 to April 2005 and the sampling period was one month. The ⁷Be and ²¹⁰Pb activity were measured using HPGe γ-spectrometer after concentration using Fe(OH)₃ co-precipitation method. The ²¹⁰Po was counted with an α-spectrometer after the sample was digested and spontaneous plated onto a silver planchet. At Xiamen, the atmospheric deposition fluxes of ⁷Be varied between 0.11 and 2.93 Bq·m⁻²·d⁻¹ and the average was 1.64 Bq·m⁻²·d⁻¹; ²¹⁰Pb fluxes varied between 0.04 and 0.85 Bq·m⁻²·d⁻¹, and the average was 0.51 Bq·m⁻²·d⁻¹; ²¹⁰Po fluxes varied between 0.002 and 0.133 Bq·m⁻²·d⁻¹, and the average was 0.061 Bq·m⁻²·d⁻¹. There were positive correlations between the deposition fluxes of ⁷Be, ²¹⁰Pb or ²¹⁰Po and the amount of precipitation. The residence time of aerosols varied between 6.0 and 54.0 days with a mean of 27.1 days, which were calculated by ²¹⁰Po/²¹⁰Pb fluxes ratios.     

7Be and 210Pb concentrations in air in Málaga (Spain)

Measurements of ⁷Be and ²¹⁰Pb in atmospheric air (1 m above the ground) have been carried out each week over one and a half year period. The method used to determine ⁷Be and ²¹⁰Pb activities is based on the total amount of radioactive aerosols filtered from the air. The activities of ⁷Be and ²¹⁰Pb were determined by a hyper-pure germanium detector using standard gamma-spectrometry. The average weekly concentrations of ⁷Be were in the range of 1.21-12.1 mBq^.m^-3 and for ²¹⁰Pb in the range of 0.8-2.4 mBq^.m^-3. The weekly variations were discussed in relation to various meteorological factors. It can be said that our results showed a prevailing influence of weekly average temperature for ⁷Be concentration and the weight of aerosols and wind speed for ²¹⁰Pb oncentrations.     

An attempt to evaluate dry deposition velocity of airborne210Pb in a forest ecosystem

Atmospheric concentration and total (wet plus dry) and dry deposition of²¹⁰Pb and⁷Be have been measured at our laboratory in Ishikawa Prefecture in Japan which faced the Sea of Japan during 1993–1994. At the same time inventories of excess²¹⁰Pb in soil samples were measured from a mixed pine forest. On the basis of the data obtained, an attempt was made to evaluate the dry deposition velocity as a result of the interception by the canopies of airborne²¹⁰Pb in a pine stand The dry deposition velocity of²¹⁰Pb in the pine stand was roughly estimated to be 0.9–0.8 cm/s, higher by a factor of about 10 than the value (mean: 0.12±0.09 cm/s; range: 0.06–0.28 cm/s) in the open area measured on the roof of our laboratory.     

Seasonal variation of 7Be deposition in Japan

Seasonal variations of ⁷Be deposition in regions throughout Japan (26°18'N-43°05'N, 127°54'E-141°27'E) were observed during the period of 1989-1995. The observation indicated that ⁷Be deposition peaked in spring all over Japan except in the inland central basin. However, spring peak was not always the annual maximum. Along the coastal side of the Japan Sea, especially around Hokuriku region, ⁷Be deposition was at its maximum in winter. In addition, September peak also was observed in some regions, which was presumably caused by high precipitation or blowing in of northern air stream. Variations were classified into 4 types according to meteorological factors and local geographical conditions: winter peak, double peaks (spring and September peaks), spring peak and non-peak. A correlation between ⁷Be deposition and precipitation was observed in winter.     

Temporal variation of 210Pb concentration in the urban aerosols of Shanghai,China

Journal of Radioanalytical and Nuclear Chemistry - This study monitored 210Pb levels of the atmospheric aerosol in Shanghai from January 2016 to February 2017. 210Pb levels were found to be low in...     

Determination of 210Pb, 210Bi and 210Po in natural drinking water

A new method for the radioanalytical determination of the ²²²Rn progenies ²¹⁰Pb, ²¹⁰Bi and ²¹⁰Powill be presented, which has been improved for analyses of water samples fromdifferent regions in Austria. 1–2 liter samples were taken in polyethylenebottles prefilled with conc. HNO₃ to obtain 0.2M acidic solutions,thus avoiding adsorption effects. After adding 1.6 mg of inactive lead carrier,the water sample was evaporated to dryness, converted to the chloride formand dissolved in 1M HCl.     

210Pb and210Po in tobacco-with a special focus on estimating the doses of210Po to man

Studies have been carried out on the solubility of Pu(III) oxalate by precipitation of Pu(III) oxalate from varying concentrations of HNO₃/HCl (0.5–2.0M) solutions and also by equilibrating freshly prepared Pu(III) oxalate with solutions containing varying concentrations of HNO₃/HCl, oxalic acid and ascorbic acid. Pu(III) solutions in HNO₃ and HCl media were prepared by reduction of Pu(IV) with ascorbic acid. 0.01–0.10M ascorbic acid concentration in the aqueous solution was maintained as holding reductant. The solubility of Pu(III) oxalate was found to be a minimum in 0.5M–1M HNO₃/HCl solutions containing 0.05M ascorbic acid and 0.2M excess oxalic acid in the supernatant.     

Trace elements, 210Po and 210Pb in a selection of berries on commercial sale in Italy

The occurrence of ²¹⁰Pb, ²¹⁰Po, trace elements was assessed in a selection of berries on commercial sale in Italy. Data confirmed that berries might serve as an important source of essential elements. The ²¹⁰Pb, ²¹⁰Po concentrations found were higher than the reference values reported by UNSCEAR for roots and fruits in the world. There is no risk whatsoever from the intake of toxic elements as Al, As, Cd, Pb, Ni, Hg in berriberries analyzed; it is necessary, however, continuously monitored the levels of these elements to protect consumers against potential adverse health effects especially when consumed in large quantities.

     

210Pb and 210Po radionuclides in the urban air of Lodz, Poland

The concentration of two important radionuclides: ²¹⁰Pb and its decay product ²¹⁰Po in the urban air in the center of the Polish city of Lodz were measured during the winter and spring seasons of 2008–2009. Urban airborne particulate matter was collected using two methods: an Anderson 9-stage impactor, and a high-volume aerosol sampler type ASS500 working in the frames of the aerosol sampling network in Poland, established for radionuclide monitoring. Average concentrations for 10 months sampling period for ²¹⁰Pb and ²¹⁰Po were 0.556 and 0.067 mBq/m³, respectively. However remarkable fluctuations due to meteorological condition were observed: from 0.010 to 0.431 mBq/m³ for ²¹⁰Po and from 0.167 to 1.847 mBq/m³ for ²¹⁰Pb. The highest concentrations, almost 60% of the total activities, of both radionuclides were found in the first two fine aerosol fractions with particle diameters below 0.36 μm. The aerosol residence times calculated from the ²¹⁰Po/²¹⁰Pb ratio ranged from 7 to 120 days.     

Presence and forms of210Pb,210Bi and210Po in ground level aerosols

A scheme of fractionation of²¹⁰Pb,²¹⁰Bi,²¹⁰Po forms present in air aerosols based on the combination of methods of radiochemical analysis and radiometric deteemination with leaching by different agents has been developed. The ratio between the²¹⁰Pb,²¹⁰Bi,²¹⁰Po present in the aerosol samples was determined experimentally. Carbonate of²¹⁰Pb, and²¹⁰Po and²¹⁰Bi forms connected with oxides prevai in the aerosol component of atmospheric air.     

Separation of the radioelements210Pb−210Bi−210Po by spontaneous deposition onto noble metals and verification by Cherenkov and liquid scintillation counting

A method for the separation of²¹⁰Pb,²¹⁰Bi and²¹⁰Po using spontaneous deposition has been developed. The²¹⁰Bi and²¹⁰Po are simultaneously removed by deposition onto nickel foil (copper and tin could also be used but less effectively) while the²¹⁰Po is separated from²¹⁰Bi, after dissolution of the nickel foil, by deposition onto silver foil. The effectiveness of each separation was evaluated by adding aliquot portions of each solution to a cocktail and counting with a liquid scintillation counter. Water was used as the medium to observe the Cherenkov count of the sample solution.     

Anthropogenic emissions of210Po,210Pb and226Ra in an estuarine environment

An extensive study on the distribution of natural radionuclides in an estuarine ecosystem located in Southwestern Spain is presented. This environment is highly affected by the wastes released by a phosphoric acid industry which uses phosphate rocks as raw material for fertilizer production. This rock has generally high concentrations of U and its daughters. The estuary is formed by two rivers, Odiel and Tinto, which have a common mouth into the Atlanic Ocean and a salt marsh (Odiel marsh) affected by the income of Odiel riverwaters. This river receives directly the liquid and part of the solid (gypsum) wastes released from the industries. Besides that, most of the phosphogypsum wastes are stored in uncovered piles at the right margin of the Tinto river. The study has concluded that the wastes from such industries are the cause of the enhanced concentrations found at the bed of both river channels as well as the enhancement found in surface soils in certain zones of the Odiel wet marshland. Indeed, the Northern marsh and the Mojarrera channel at the Odiel marsh seem to be the main sinks of the contaminant released by the phosphoric acid industry.     

Sedimentation and lateral transport of 210Pb over the East China Sea Shelf

²¹⁰Pb is an effective tracer of constraining particle transport and sedimentation in shelf regions. To reveal the spatial pattern of ²¹⁰Pb over the East China Sea (i.e. ECS) Shelf, ²¹⁰Pb in the surface sediments were examined at 11 stations, as well as ²³⁴Th and ²¹⁰Pb in the water column at four stations. Overall, the plume zone of the Yangtze River along the coastline is a source area of ²¹⁰Pb for the outer shelf, exporting 0.46 dpm cm^?2 year^?1 at least, which accounts for about 25 % of ²¹⁰Pb input into this region. In the southern ECS Shelf to the north of the Taiwan Strait, the focusing factor (f) values are higher than unity, indicating a sink area of ²¹⁰Pb. Boundary scavenging of ²¹⁰Pb contributes 0.36 dpm cm^?2 year^?1 to this sink area on the basis of a mass balance model evaluation. Lateral transport of ²¹⁰Pb to this region, quantified by ²³⁴Th and ²¹⁰Pb in the water column, varied from 3.34 to 6.39 dpm cm^?2 year^?1 with an average of 4.83 dpm cm^?2 year^?1, also supporting its sink characteristic. To the southwest of the Cheju Island, the f values were less than unity, revealing a source region of ²¹⁰Pb. The average export flux of ²¹⁰Pb from this region was 1.64 dpm cm^?2 year^?1. Therefore, ²¹⁰Pb sedimentation/settling showed significantly heterogeneous sedimentation of particulate matter over the ECS Shelf.