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Aerosol particle size distribution of atmospheric lead-210 in northern Finland.

https://arctichealth.org/en/permalink/ahliterature280887
Source
J Environ Radioact. 2017 Mar 11;172:10-14
Publication Type
Article
Date
Mar-11-2017
Author
Jussi Paatero
Alexandra Ioannidou
Jussi Ikonen
Jukka Lehto
Source
J Environ Radioact. 2017 Mar 11;172:10-14
Date
Mar-11-2017
Language
English
Publication Type
Article
Abstract
Size-segregated aerosol samples were collected with a high-volume 6-stage cascade impactor at Sodankylä, Finland, 100 km north of the Arctic Circle. The (210)Pb content of the samples were determined with radiochemical separation of in-grown (210)Po followed by alpha spectrometry. Most of the (210)Pb activity was incorporated in accumulation mode aerosol particles. The activity median aerodynamic diameter (AMAD) ranged from 0.53 µm to 0.98 µm 38-61 per cent of (210)Pb activity was found to be associated with aerosol particles smaller than 0.69 µm. A slight downward tendency of (210)Pb activity median aerodynamic diameter was observed as a function of increasing (210)Pb activity concentration. This is related to the continental origin of airborne (210)Pb on one hand, and various aerosol particle growth processes on the other hand. Also a clear tendency towards a higher (7)Be/(210)Pb activity ratio as a function of increasing aerosol particle diameter was observed. This, in turn, reflects the different origin of (210)Pb, exhalation of (222)Rn from the soil into the air, and (7)Be, formation by cosmic radiation in the upper troposphere and the stratosphere.
PubMed ID
28292593 View in PubMed
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Behaviour of radionuclides during microbially-induced mining of nickel at Talvivaara, Eastern Finland.

https://arctichealth.org/en/permalink/ahliterature276633
Source
J Environ Radioact. 2016 Jan;151 Pt 1:105-13
Publication Type
Article
Date
Jan-2016
Author
Hanna Tuovinen
Esa Pohjolainen
Janne Lempinen
Daniela Vesterbacka
David Read
Dina Solatie
Jukka Lehto
Source
J Environ Radioact. 2016 Jan;151 Pt 1:105-13
Date
Jan-2016
Language
English
Publication Type
Article
Keywords
Finland
Mining
Nickel
Radiation monitoring
Soil Pollutants, Radioactive - analysis
Abstract
The Talvivaara mine in Eastern Finland utilizes microbe-induced heap leaching to recover nickel and other valuable metals (Zn, Cu, Co) from a black schist ore. In addition to the target metals, the ore contains uranium at a concentration of 17 mg/kg, incorporated as uraninite (UO2). Uranium oxidizes from the U(IV) to U(VI) state during leaching and dissolves as the uranyl ion (UO2(2+)) in the acidic pregnant leach solution. Mobilisation of uranium has caused sufficient concern that plans have been developed for uranium recovery. The aim of this study is to generate new data leading to a better understanding of the fate of its radiotoxic daughter nuclides, primarily (226)Ra, (210)Pb and (210)Po, in the mining process. It is shown that uranium daughters mostly remain in the heaps during the leaching process and are associated with secondary minerals, including jarosite, goethite and gypsum. Thorium and progeny ((232)Th plus (228)Th, (228)Ra) are also mainly retained. High sulphate concentrations in the acidic solutions limit the solubility of radium by incorporation in the crystal lattices of precipitated secondary sulphates. Electron probe microanalysis shows that goethite in the heaps is uraniferous, resulting from the adsorption of U(VI). After recovery of target metals, the pregnant leach solution is neutralized to further remove metal contaminants and the resulting slurries stored in a bunded tailings pond. The activity concentrations of thorium, radium, lead and polonium isotopes are generally low in the pond owing to prior retention by secondary minerals in the heaps. However, (238)U activity concentrations range up to 3375 Bq/kg, which exceeds the permitted value (1000 Bq/kg) for natural radionuclides of the (238)U series.
PubMed ID
26454201 View in PubMed
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Effective half-lives of 134Cs and 137Cs in reindeer meat and in reindeer herders in Finland after the Chernobyl accident and the ensuing effective radiation doses to humans.

https://arctichealth.org/en/permalink/ahliterature135732
Source
Health Phys. 2011 May;100(5):468-81
Publication Type
Article
Date
May-2011
Author
Ari-Pekka Leppänen
Maarit Muikku
Timo Jaakkola
Jukka Lehto
Tua Rahola
Kristina Rissanen
Michael Tillander
Author Affiliation
Radiation and Nuclear Safety Authority-STUK, Louhikkotie 28, FIN-96500 Rovaniemi, Finland. ari.leppanen@stuk.fi
Source
Health Phys. 2011 May;100(5):468-81
Date
May-2011
Language
English
Publication Type
Article
Keywords
Animals
Body Burden
Cesium radioisotopes - pharmacokinetics
Chernobyl Nuclear Accident
Female
Finland
Food chain
Half-Life
Humans
Male
Meat - analysis
Radiation Dosage
Radioactive fallout
Reindeer - metabolism
Abstract
Monitoring of 137Cs in reindeer herders and in reindeer meat in Finnish Lapland began in the early 1960s and has continued until today. The monitoring of 137Cs in reindeer herders and in reindeer meat in the Halla area began after the Chernobyl accident. In this study, reindeer herders together with reindeer meat samples were monitored for gamma-emitting radionuclides from two separate areas in the Finnish reindeer management area, Northern Finland and the Halla area. The effective half-lives determined for 137Cs in reindeer meat were from 3.0 ± 1.7 to 5.1 ± 0.5 y. For 134Cs, the observed effective half-lives in reindeer meat were from 1.3 ± 0.2 to 1.5 ± 0.1 y. The effective half-lives among male and female reindeer herders in Northern Finland were 5.5 ± 1.3 and 4.4 ± 0.9 y, respectively, for the body-burden of 137Cs. In the Halla reindeer herding cooperative, located to the south of Finnish Lapland in the province of Kuusamo, the effective half-lives in the reindeer herders were shorter, about 1-2 y. The 134Cs × 137Cs-1 ratios decreased more rapidly in reindeer meat and also in humans in the Halla area than in Northern Finland. This implies faster removal of Chernobyl-derived cesium from the reindeer-man food chain in the Halla area. The contribution of Chernobyl fallout (percent) in reindeer meat was 70% and 80% in the Paistunturi and Ivalo cooperatives, respectively, and 50% and 80% in the western and eastern part of Halla cooperative, respectively. In humans, the contribution of Chernobyl fallout to 137Cs in whole-body content was 60% in Northern Finland and 80% in the Halla area. The mean committed effective doses of Cs for reindeer herders in Finnish Lapland decreased from 0.36 mSv y-1 in 1987 to 0.053 mSv y-1 in 2005.
PubMed ID
21451316 View in PubMed
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Sorption and speciation of selenium in boreal forest soil.

https://arctichealth.org/en/permalink/ahliterature282812
Source
J Environ Radioact. 2016 Nov;164:220-231
Publication Type
Article
Date
Nov-2016
Author
Mervi Söderlund
Juhani Virkanen
Stellan Holgersson
Jukka Lehto
Source
J Environ Radioact. 2016 Nov;164:220-231
Date
Nov-2016
Language
English
Publication Type
Article
Keywords
Adsorption
Finland
Selenic Acid
Selenious Acid
Selenium - analysis - chemistry
Soil - chemistry
Soil Pollutants - analysis - chemistry
Taiga
Abstract
Sorption and speciation of selenium in the initial chemical forms of selenite and selenate were investigated in batch experiments on humus and mineral soil samples taken from a 4-m deep boreal forest soil excavator pit on Olkiluoto Island, on the Baltic Sea coast in southwestern Finland. The HPLC-ICP-MS technique was used to monitor any possible transformations in the selenium liquid phase speciation and to determine the concentrations of selenite and selenate in the samples for calculation of the mass distribution coefficient, Kd, for both species. Both SeO3(2-) and SeO4(2-) proved to be resistant forms in the prevailing soil conditions and no changes in selenium liquid phase speciation were seen in the sorption experiments in spite of variations in the initial selenium species, incubation time or conditions, pH, temperature or microbial activity. Selenite sorption on the mineral soil increased with time in aerobic conditions whilst the opposite trend was seen for the anaerobic soil samples. Selenite retention correlated with the contents of organic matter and weakly crystalline oxides of aluminum and iron, solution pH and the specific surface area. Selenate exhibited poorer sorption on soil than selenite and on average the Kd values were 27-times lower. Mineral soil was more efficient in retaining selenite and selenate than humus, implicating the possible importance of weakly crystalline aluminum and iron oxides for the retention of oxyanions in Olkiluoto soil. Sterilization of the soil samples decreased the retention of selenite, thus implying some involvement of soil microbes in the sorption processes or a change in sample composition, but it produced no effect for selenate. There was no sorption of selenite by quartz, potassium feldspar, hornblende or muscovite. Biotite showed the best retentive properties for selenite in the model soil solution at about pH 8, followed by hematite, plagioclase and chlorite. The Kd values for these minerals were 18, 14, 8 and 7 L/kg, respectively. It is proposed that selenite sorption is affected by the structural Fe(II) in biotite, which is capable of inducing the reduction of SeO3(2-) to Se(0). Selenite probably forms a surface complex with Fe(III) atoms on the surface of hematite, thus explaining its retention on this mineral. None of the minerals retained selenate to any extent.
PubMed ID
27521902 View in PubMed
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