Inventories and concentration profiles of 137Cs in undisturbed soils in the northeast of Buenos Aires Province, Argentina

Montes, María Luciana; Silva, Luís M. S.; Sa, Campbell; Runco, J.; Taylor, Marcela Andrea; Desimoni, J.

doi:10.1016/j.jenvrad.2012.10.003

Cited by 13 publications

(10 citation statements)

References 26 publications

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“…2a). Comparing these activities with those determined for unperturbed soils at La Plata (Montes et al 2013) and taking into account that, on average, 82 % of the stratospheric material is deposited in the hemisphere by injection (Valkovic 2000), almost all the 137 Cs findings reported here should arise from atmospheric nuclear tests carried out only in the southern hemisphere. Indeed, more than 60 atmospheric nuclear explosions were performed in the southern hemisphere at the Malden, Christmas and Marshal Islands, the Mururoa, Fangataufa and Bikini atolls and Emu and Maralinga in Australia.…”

Section: Resultsmentioning

confidence: 55%

“…The current 137 Cs activities (Table 1; Fig. 2a) are mostly lower than the average values reported for unperturbed soils (Montes et al 2013). Therefore, it must be…”

Section: Resultsmentioning

confidence: 71%

“…The resulting activity ranges for natural radionuclides are 24-45 Bq/kg for 232 Th, 16-27 Bq/kg for 226 Ra and 449-690 Bq/kg for 40 K. Figure 2a shows the box plot of activity values for each radionuclide. For comparison, the figure also displays the worldwide average activities for 232 Th, 226 Ra and 40 K given by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR 2008) and the interval of activity values observed in unperturbed soils around La Plata (considering the mean activity value of the top 10 cm of soil) (Montes et al 2012(Montes et al , 2013.…”

Section: Resultsmentioning

confidence: 99%

“…The start-up of a new nuclear power plant at Lima and the plans to build another one at the same place (Nucleoeléctrica Argentina 2014) make relevant the analysis of soil samples at Lima before the expansion of the nuclear facilities. In addition, this work contributes to complete the monitoring of surface soils at La Plata and at the surroundings of nuclear facilities in the Buenos Aires Province by comparing the current results with previous studies (Montes et al 2012(Montes et al , 2013 and determining new correlation coefficients. Figure 1a shows the studied region in Buenos Aires Province, Argentina.…”

Section: Introductionmentioning

confidence: 91%

“…In the case of Buenos Aires Province, where several nuclear facilities are located, only four works are found in literature. These are: the 137 Cs activity studies at San Pedro soils published by Bujan et al (2003), activity levels of 40 K, 232 Th, 226 Ra and 137 Cs reported for unperturbed soils at La Plata and Ezeiza (Montes et al 2012(Montes et al , 2013 and, close to the nuclear power plants and nuclear facilities at Lima, only 137 Cs soils activities (ARN 2011).…”

Section: Introductionmentioning

confidence: 99%

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Activities of 232Th, 226Ra, 40K, and 137Cs in surface soil and external dose assessment at two zones of Buenos Aires Province, Argentina

2016

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In the frame of establishing the radiological baseline of the Buenos Aires Province, Argentina, this work assesses the total outdoor external dose and the activity values of 40 K, 226 Ra, 232 Th and 137 Cs in superficial soils of La Plata and Lima cities. In the latter, the most important nuclear emplacement of the country is located. At La Plata, 49 sites were analyzed, which correspond to the green public spaces of the city while at Lima 6 sites around the nuclear power plants were studied. For La Plata, the external dose contribution and activity distribution maps of 40 K, 226 Ra, 232 Th and 137 Cs were obtained using the Kriging geo-statistical method. Activity values of 226 Ra and 232 Th resulted lower than their worldwide average ones, while the 40 K levels were higher than the corresponding one. The activity dataset was analyzed together with the activity values determined previously in unperturbed soils of the region. The Pearson correlation coefficient was recalculated , obtaining correlations more significant when all activity data were considered. No correlation between activity superficial distributions and the height above sea level or the geomorphological units was found. The activity values obtained in Lima soils lie in the range of the values determined for La Plata soils. Like in La Plata, 137 Cs activity around the nuclear facility could be associated only with the nuclear power tests. The average total external annual dose for La Plata inhabitants are in the range of 0.19 to 0.25 mSv/year, similar to those determined for Lima residents. The present work complements previous reports contributing to the establishment of the radiological baseline for soils of Buenos Aires Province, Argentina, the province with the most important nuclear activities of the country.

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Section: Resultsmentioning

confidence: 55%

“…The current 137 Cs activities (Table 1; Fig. 2a) are mostly lower than the average values reported for unperturbed soils (Montes et al 2013). Therefore, it must be…”

Section: Resultsmentioning

confidence: 71%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 91%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Activities of 232Th, 226Ra, 40K, and 137Cs in surface soil and external dose assessment at two zones of Buenos Aires Province, Argentina

2016

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Natural and anthropogenic gamma-ray emitters and iron-bearing compounds distribution in peatlands of the southern Espinhaço mountain chain, Brazil

et al. 2019

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To help understand the dynamics of peatlands forming on the Southern Serra do Espinhaço, Brazil, the occurring natural ( 226 Ra, 232 Th, 40 K) and anthropogenic ( 137 Cs) activity of gamma-ray emitters located at three sites, namely the localities of São João da Chapada (CH), Pinheiro (PIN) and Pau de Fruta (PDF), was studied. The iron compounds were characterized by 57 Fe Mössbauer spectroscopy. Differences on natural radionuclide levels and distributions were found among the peatland sites, indicating differences on mineral composition, hydric regimes and living. Significant correlation was found only for 232 Th-226 Ra activity values (Pearson correlation coefficient of − 0.5), which is different from other South American soils, where significant positive correlations among all radionuclides were determined. In PDF and CH, the dose rate results are lower than the worldwide mean value, but in PIN, they are higher because of the relatively high 226 Ra concentration. The only anthropogenic radionuclide is 137 Cs. The convection-diffusion model fits the CH and PDF activity profiles, although the PIN profile is likely affected by other soil mechanisms as well. Mössbauer spectra reveal Fe 3+ in two different local environments and the occurrence of hematite in the upper samples of the CH site. The iron concentration decreases with depth. Contrary to soils of other regions, no significant correlation was found between iron species and the natural radioactivity. The studied peatlands exhibit clear differences between their natural and anthropogenic radionuclide distributions to those of mineral soils.

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The origin of gley colors in hydromorphic vertisols: the study case of the coastal plain of the Río de la Plata estuary

et al. 2021

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This work aims to contribute to the interpretation of soil colors; mainly to identify the pigments that generate the greenish colors in hydromorphic conditions (gley colors) in vertisols of the coastal plain of the Río de la Plata estuary. These colors are of cold hues, generally greenish (olive-gray), and occur in poorly drained soils with prolonged water accumulation. For this purpose, samples of Bssg horizons of hydromorphic vertisols from the coastal plain of the Río de la Plata estuary were analyzed using routine and chemical analyses, Mössbauer spectroscopy, determination of rocks magnetic parameters, X-ray diffraction, thermogravimetric and differential thermal analysis and petrographic-electronic microscopy. The pigments associated with the gley colors of these soils are mainly due to ferric iron content, corresponding to minerals such as ferric iron-rich smectites (nontronite/Fe-rich beidellite) and oxy-hydroxides like goethite, which colors range from green to yellow. These minerals, combined with gray or black components, e.g., manganese compounds and/or organic matter, contribute to the generation of the usual gley colors in the analyzed soils of the Pampean plain. The obtained data allows us to state that it is a mistake to assing the olive color in hydromorphic soils to the presence of ferrous iron compounds, as it is traditionally done. The oxidizing condition of iron is dominant in all the analyzed samples, integrating the composition of ferric iron-rich clay minerals and oxy-hydroxides (goethite).

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Inventories and concentration profiles of 137Cs in undisturbed soils in the northeast of Buenos Aires Province, Argentina

Cited by 13 publications

References 26 publications

Activities of 232Th, 226Ra, 40K, and 137Cs in surface soil and external dose assessment at two zones of Buenos Aires Province, Argentina

Activities of 232Th, 226Ra, 40K, and 137Cs in surface soil and external dose assessment at two zones of Buenos Aires Province, Argentina

Natural and anthropogenic gamma-ray emitters and iron-bearing compounds distribution in peatlands of the southern Espinhaço mountain chain, Brazil

The origin of gley colors in hydromorphic vertisols: the study case of the coastal plain of the Río de la Plata estuary

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