A study of iodine concentration in soils and grasses of pastures of Bryansk and Gomel regions affected by the Chernobyl accident

2021 ◽  
Author(s):  
Viсtor Berezkin ◽  
Elena Korobova ◽  
Sergey Romanov ◽  
Vladimir Baranchykov
Keyword(s):  
Thyroid Cancer ◽  
Chernobyl Accident ◽  
Local Population ◽  
Soil Layer ◽  
Iodine Content ◽  
Iodine Concentration ◽  
Mean Value ◽  
Soil Samples ◽  
Pronounced Increase ◽  
Transfer To Milk

<p>Bryansk (Russia) and Gomel (Belarus) regions were among the areas most exposed to the so-called "radioiodine impact" (<sup>131</sup>I) that occurred as a result of the Chernobyl accident in 1986. Medical examination of different groups of local population after the accident revealed a pronounced increase in thyroid cancer among children which was associated with not only <sup>131</sup>I fallout but also with a deficiency of natural iodine in these areas [1].</p><p>The aim of the research was to study iodine in vegetation and soils of different grasslands adjacent to rural settlements in the Bryansk and Gomel regions and used by local residents for grazing. The basic original data was iodine concentration in soil and plant samples collected in the affected areas of Russia and Belarus in 44 test sites.</p><p>Soil samples were collected from upper layers 0-5, 5-10 and 10-20 cm deep with the help of the soil auger, averaged vegetation samples were taken from the plots 25x25 or 50x50 cm depending upon the vegetation density. Iodine determination was performed with the help of kinetic rhodanide-nitrite technique.</p><p>The results showed insignificant difference of iodine concentration in soil samples taken from various depth and considerable variation in the content of iodine in the upper soil layer (0-5 cm) both in the Bryansk region (0.24-1.36 mg/kg, n=29) and in the Gomel region (0.23 - 5.27 mg/kg, n=15), depending upon soil type and texture.</p><p>In the Bryansk region, the highest average iodine content was observed in gray soils characteristic for its central part (mean value 0.85±0.12 mg/kg in the top 5-cm layer). In the Gomel region, the highest iodine content was observed in meliorated peat-bog soils (5.27 mg/kg, mean value equaled to 1.02±0.42 mg/kg in the top 5-cm layer).</p><p>The iodine content in the pasture vegetation ranged from 23 µg/kg to 271 µg/kg dw. Both median and mean value of iodine concentration in vegetation of upland meadows (autonomous landscapes) were significantly lower than those in lowland meadows (57 and 113 µg/kg; 67±10 and 125±16 µg/kg correspondingly).</p><p>Accounting of considerable soil ingestion by cows we hypothesize that grazing in lowland pastures with the highest stable iodine content in soils and domination of hydrophyte plant species causes higher <sup>127</sup>I consumption by cattle and transfer to milk. In case of contamination of the area by <sup>131</sup>I this can lead to a relatively lower <sup>131</sup>I transfer to milk, other conditions being equal.</p><p>The study was carried out with partial financial support by RFBR grant No. 16-55-00205 and RFBR and BRFBR, project No. 20-55-00012.</p><p>References</p><p>1. Cardis et al. 2005. Risk of thyroid cancer after exposure to 131I in childhood //Journal of National Cancer Institute, vol. 97, No 10, Pp. 724 – 732.</p><p> </p>

scholarly journals Validation of a method for in situ determination of 137Cs soil contamination density in kitchen gardens using the portable spectrometer-dosimeter MKS AT6101D

2021 ◽  
Vol 14 (2) ◽  
pp. 56-65
Author(s):  
V. P. Ramzaev ◽  
A. N. Barkovsky ◽  
A. A. Bratilova
Keyword(s):  
Soil Contamination ◽  
Chernobyl Accident ◽  
Soil Layer ◽  
Soil Samples ◽  
Ex Situ ◽  
Measuring Device ◽  
Kitchen Garden ◽  
In Situ Method ◽  
Kitchen Gardens

The collection of representative soil samples in the territory of settlements and subsequent measurements of the content of radionuclides in these samples under laboratory conditions (the so-called “ex situ method”) is a generally accepted technology for determining the density of soil contamination with 137Cs in the populated areas contaminated due to the Chernobyl accident. Recently, as a supplement or alternative to the ex situ method, researchers are developing field (in situ) gamma-spectrometry methods. These methods allow determining the density of soil contamination with 137Cs directly on site, without soil sampling and laboratory analysis. At the same time, the in situ methodology has several limitations, the most important of which is a lack of generally recognized metrological basis for measurements and interpretation of results. Hence, before using a particular technique and measuring device for carrying out large-scale in situ measurements, it is necessary to validate (to assess the suitability) of the selected in situ method using an established ex situ method. The aim of this study was to validate the method for determining the density of 137Cs soil contamination in kitchen gardens using the MKS AT6101D spectrometer-dosimeter in situ. The method was recently presented by a Russian-Swedish-Belarusian group of researchers in an article published in the Journal of Environmental Radioactivity (https://doi.org/10.1016/j.jenvrad.2021.106562). To validate this method, we selected 10 representative kitchen garden plots. The plots were located in six settlements of the Bryansk region in Russia. The territory of the settlements had been heavily contaminated with 137Cs as a result of the Chernobyl accident: the officially established levels of the density of soil contamination by 137Cs ranged from 111 to 511 kBq/m2 in 2017. Field gamma-ray spectra were recorded at a height of 1 m above the ground in the center of kitchen garden plots using the MKS AT6101D device. The measurement duration was in the range of 1207–1801 s (the mean value = 1383 s). Samples of soil in the kitchen gardens were taken layer by layer (with a step of 5 cm) to a depth of 20 cm using a demountable cylindrical sampler. The 137Cs content in each soil layer was determined in the laboratory using a stationary semiconductor gamma spectrometer. The values of the 137Cs contamination density of the sampled soils ranged from 77 to 548 kBq/m2. It was found that the results of the ex situ analyzes of soil samples were in a good agreement with the contamination density values obtained with the in situ method. On average, the difference between two methodologies was 7% (a maximum of 20%). The results of the study confirm that the method proposed by the international group is suitable for determining the density of soil contamination by 137Cs in kitchen gardens in remote period after the Chernobyl accident.

Bacterial influence on the formation of hematite: implications for Martian dormant life

2021 ◽  
pp. 1-15
Author(s):  
Sudeera Wickramarathna ◽  
Rohana Chandrajith ◽  
Atula Senaratne ◽  
Varun Paul ◽  
Padmanava Dash ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Soil Layer ◽  
Soil Samples ◽  
Mineral Weathering ◽  
Compositional Variation ◽  
Rrna Gene ◽  
Potential Candidate ◽  
Metabolic Processes ◽  
Extraterrestrial Life ◽  
X Ray

Abstract Previous exploration missions have revealed Mars as a potential candidate for the existence of extraterrestrial life. If life could have existed beneath the Martian subsurface, biosignatures would have been preserved in iron-rich minerals. Prior investigations of terrestrial biosignatures and metabolic processes of geological analogues would be beneficial for identifying past metabolic processes on Mars, particularly morphological and chemical signatures indicative of past life, where biological components could potentially be denatured following continued exposure to extreme conditions. The objective of the research was to find potential implications for Martian subsurface life by characterizing morphological, mineralogical and microbial signatures of hematite deposits, both hematite rock and related soil samples, collected from Highland Complex of Sri Lanka. Rock samples examined through scanning electron microscopy-energy dispersive X-ray (SEM-EDX) spectroscopy. Analysis showed globular and spherical growth layers nucleated by bacteria. EDX results showed a higher iron to oxygen ratio in nuclei colonies compared to growth layers, which indicated a compositional variation due to microbial interaction. X-ray diffraction analysis of the hematite samples revealed variations in chemical composition along the vertical soil profile, with the top surface soil layer being particularly enriched with Fe2O3, suggesting internal dissolution of hematite through weathering. Furthermore, inductively coupled plasma-mass spectrometry analyses carried out on both rock and soil samples showed a possible indication of microbially induced mineral-weathering, particularly release of trapped trace metals in the parent rock. Microbial diversity analysis using 16S rRNA gene sequencing revealed that the rock sample was dominated by Actinobacteria and Proteobacteria, specifically, members of iron-metabolizing bacterial genera, including Mycobacterium, Arthrobacter, Amycolatopsis, Nocardia and Pedomicrobium. These results suggest that morphological and biogeochemical clues derived from studying the role of bacterial activity in hematite weathering and precipitation processes can be implemented as potential comparative tools to interpret similar processes that could have occurred on early Mars.

Thyroid Cancer in Children of Ukraine after the Chernobyl Accident

2000 ◽  
Vol 24 (11) ◽  
pp. 1446-1449 ◽  
Author(s):  
Stanislav J. Rybakov ◽  
Igor V. Komissarenko ◽  
Nicolay D. Tronko ◽  
Andrey N. Kvachenyuk ◽  
Tatyana I. Bogdanova ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Chernobyl Accident ◽  
Cancer In Children

scholarly journals Assessment of Solid Mineral to Soil Radioactivity Contamination Index in Selected Mining Sites and their Radiological Risk Indices to the Public

2021 ◽  
Author(s):  
Ezekiel Oghenenyerhovwo Agbalagba ◽  
Mohammed S. Chaanda ◽  
Stephen Uloho U. Egarievwe
Keyword(s):  
Mean Value ◽  
Soil Samples ◽  
Permissible Limit ◽  
Radiation Hazard ◽  
Hazard Indices ◽  
Mean Values ◽  
Mining Sites ◽  
The Public ◽  
Risk Indices ◽  
Gamma Index

Abstract This study examined the radioactivity levels of soil samples within selected solid mining sites in Nigeria using high purity germanium (HpGe) detector. Sixty soil samples in all were collected from the ten solid mineral mining sites investigated and six samples were collected as control samples from non-mining environment for analyses. The results of the activity concentration values obtained for 40K, 226Ra and 232Th are 100.22 Bq kg-1, 33.15 Bq kg-1 and 77.31 Bq kg-1 respectively. The 226Ra and 40K activities were found to be within the United Nation Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) acceptable permissible limit, but the 232Th mean value was above the permissible limit of 30 Bq kg-1 for the public. In comparison, 40K, 226Ra and 232Th soil samples mean activity concentrations were higher than the control soil samples values by 48.6%, 43.7% and 62.3% respectively. The results of estimated radiation hazard indices indicate average values of 150.72 Bq kg-1, 68.40T, 83.65µSvy-1 and 454.70µSvy-1 for the Radium Equivalent (h), iDose Equivalent (AEDE) and Annual Gonadal Equivalent Dose (AGED) respectively. The mean values for External Hazard Indices (Hex, Hin), Representative Gamma index (s) and Excess Life Cancer Risk (ELCR) were 0.41, 0.50, 1.06 and 0.29 x10-3 respectively. The statistical analysis shows positive skewness.

scholarly journals People's Knowledge and Practice of Salt Iodization, as Well as the Assessment of Iodine Content in Salt in the Cumilla Region of Bangladesh

2021 ◽  
pp. 12-24
Author(s):  
Sadia Jahan ◽  
Md. Saddam Hossain ◽  
Md. Anisur Rahman Bhuiyan ◽  
Susmita Roy Lisa ◽  
Somaia Haque Chadni
Keyword(s):  
Iodine Deficiency ◽  
Rural Areas ◽  
Iodine Content ◽  
Iodine Concentration ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Salt Iodization ◽  
Knowledge And Practice ◽  
Urban And Rural Areas ◽  
And Behavior

Aim: To evaluate the household iodine content and knowledge, attitude, and behavior regarding salt iodization among the residents of Cumilla, Bangladesh. Subjects and Methods: We conducted a cross-sectional survey of 700 inhabitants in Cumilla's urban and rural areas to determine the iodine concentration of salt they consume. The participants were asked about what they know about iodine deficiency and salt iodization as well as how their salt was packaged and stored. Among them, 338 people provided a sample of salt to be tested of its iodine content by the titrimetric method. Results: 46.57% of people knew that iodization was the best way to prevent iodine deficiency while 35.14% considered salt iodization during purchasing. Most people stored salt in plastic boxes (89.7%) and closed containers (84.14%).Among all participants, only 37.14% of people were aware of the iodine requirement during pregnancy. In urban regions, the median iodine content was 36.76 ppm (OR=0.658, 95% CI, 0.469-0.925), while in rural areas, the median iodine content was 40.92 ppm (OR=1.188, 95% CI, 1.022-1.380). Iodine levels were less than 15 ppm (minimum limit) in 6.8% of samples and greater than 40 ppm (maximum limit) in 56.5%. Only 36.7% of the salt samples contained adequate iodine. Conclusion: An effective and consistent approach for controlling iodine concentration in distributed salt is required at Cumilla, Bangladesh.

Thyroid function of subjects with goitre and cretinism in an endemic goitre area of rural China after use of iodized salt

1988 ◽  
Vol 118 (3) ◽  
pp. 444-448 ◽  
Author(s):  
Xuan-Ping Pang ◽  
An Ouyang ◽  
Tian-Sue Su ◽  
Jerome M. Hershman
Keyword(s):  
Thyroid Function ◽  
Rural China ◽  
Public Health Problem ◽  
Iodine Content ◽  
Iodine Concentration ◽  
Epidemiological Survey ◽  
Iodized Salt ◽  
Endemic Goitre ◽  
Serum Thyroglobulin ◽  
Serum Free

Abstract. Endemic goitre and cretinism are still a public health problem in China. An epidemiological survey showed that about 5% of the inhabitants in Daxin village, Henan province, had goitre or cretinism after an iodized salt prevention programme had been carried out for two decades. The main food for the inhabitants of this area has an iodine content <30 nmol/kg and the water for cooking and drinking has an iodine concentration between 7–12 nmol/l. We studied thyroid function in subjects of this village. There were 42 with grade 0 goitre (males 29, females 13), 42 grade I (males 23, females 19), 27 grade II (males 9, females 18), 31 grade III (males 14, females 17) and 34 cretinism patients (males 30, females 4) diagnosed and classified according to WHO criteria. Serum T4, free T4, T3, free T3, T3 uptake, TSH and thyroglobulin were measured in these subjects. The patients with goitre or cretinism had significantly decreased serum free T4 and increased serum T3 and free T3 levels compared with those of controls. Thyroid size was positively correlated with age and serum thyroglobulin concentrations. Serum thyroglobulin was significantly increased even in the grade 0 goitre subjects. The percentages of subjects with serum free T4 < 12 nmol/l, T3 >2.5 nmol/l, free T3 >5.2 pmol/l, TSH >3.5 mU/l, T3/T4 ratio >0.03 and free T3/free T4 ratio >0.36 were significantly higher among goitre and cretinism patients than among controls. The data suggest that there is partial compensation for a marginal deficiency of iodine in the inhabitants of this village.

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