Aerosol,milk and wheat flour radioactivity in Albania caused by the Chernobyl accident

Contamination of aerosols, milk and wheat flour with -nuclides, caused by the Chernobyl accident is discussed. Aerosol samples were taken in Tirana area. Milk samples were taken from all the 26 regions of our country. The variations of Cs-137, Cs-134, Ru-106 and Sb-125 radioactivity in the aerosol from May 2 to May 19, 1986 and of I-131, Te-132, Cs-134, Cs-136 and Cs-137 in cow, sheep and she-goat milks are presented. The activity of Cs-137 in wheat flour, taken in 8 regions, of the different contaminated parts of the territory, is discussed, too.     

Radionuclide ratios of90Sr/137Cs and239(240)Pu/137Cs in contaminated surface air after the Chernobyl accident in Asutria

Energy straggling in pulse height distributions of plastic scintillation counters of 4 and 10 cm in thickness was measured for 1 GeV/c pions and studied by Monte Carlo simulations. Calculated energy loss distributions are in good agreement with the experimental data and also with the prediction by the Landau straggling function.     

Dry,wet and cumulative fallout and milk contamination in Bratislava (Czecho-Slovakia) after the Chernobyl accident

The total -radioactivity of dry, wet and cumulative fallout and the radioactivity of cow milk was measured in Bratislava in the first month after the Chernobyl accident. The obtained results are in good agreement with the results of the monitoring net in Slovakia.     

Determination of131I,134Cs,137Cs in plants and cheese after Chernobyl accident in Roumania

Various samples from the south-east region of Roumania/greens, fodder, cheese/were analyzed for¹³¹I,¹³⁴Cs and¹³⁷Cs concentrations in May and July 1986 by -ray spectrometry. The concentrations are reported in nCi. kg^–1 wet weight. For greens, a considerable decrease was observed for¹³¹I/to 3.0–7.0 nCi. kg^–1/,¹³⁴Cs/to 0.5–2.0 nCi.kg^–1/ and¹³⁷Cs /to 1.0–4.0 nCi. kg^–1/ from the first half /5–15 May/ till the end of May 1986. For cheese, maximum values were measured between 5 and 15 May /sheep cottage cheese: 500–800 nCi.kg^–1 for¹³¹I, 25–50 nCi. kg^–1 for¹³⁴Cs, 40–80 nCi. kg^–1 for¹³⁷Cs/; at the beginning of July a considerable decrease /to 5–10 nCi. kg^–1 for¹³¹I, 1.2–2.0 nCi.kg^–1 for¹³⁴Cs, 2.2–3.0 nCi. kg^–1 for¹³⁷Cs/ was observed. In autumn 1986 a small increase up to 2.0–3.0 nCi. kg^–1 for¹³⁴Cs and 3.4–5.0 nCi. kg^–1 for¹³⁷Cs /in November/ was reported. The population's internal possible contamination was strongly limited by the authorities' severe control of the food-stuff.     

Determination of131I,134Cs,137Cs in grass and cheese after Chernobyl accident in Austria

Various samples from Styria /grass/ and Salzburg /cheese/ were analyzed for¹³¹I,¹³⁴Cs and¹³⁷Cs concentration during April–July 1986 by -ray spectrometry. The concentrations are reported in nCi kg^–1 wet weight. The concentration values found for¹³¹I 0.2–17.2 nCi kg^–1 /grass/, 0.1–0.5 nCi kg^–1 /cheese/, for¹³⁴Cs 1.1–6.2 nCi kg^–1 /grass/, 0.2–1.3 nCi kg^–1 /cheese/, for¹³⁷Cs 1.6–15.7 nCi kg^–1 /grass/, 0.3–2.2 nCi kg^–1 /cheese/. While radioactivity of¹³¹I,¹³⁴Cs and¹³⁷Cs in cheese samples increases from May to June, it decreases in grass samples from May to July 1986.     

Determination of137Cs and134Cs in air samples collected near Belgrade /Yugoslavia/ following the Chernobyl accident

This paper presents the results of measurements of¹³⁷Cs and¹³⁴Cs content in air sampled during May 1986. Maximum concentrations:¹³⁷Cs 2.94±0.01 Bq m^–3 and¹³⁴Cs 1.38±0.01 Bq m^–3 were registered on May 3. Several other long lived radionuclides having -energies in the region 33 keV to 1365 keV were registered in the same samples two years later. The results of measurements of the total -activity in air for the same period are also presented.     

Determination of40K and137Cs concentration in selected honey samples

Seventeen honey samples collected at different sites during 1992 have been measured using the method of -spectroscopy. Measurements were performed by a low background high purity germanium spectrometer of a relative efficiency of 14.5% and an energy resolution of 1.7 keV. Using natural -ray sources to determine efficiency, it has been shown that out of 17 samples of natural honey only two (of meadow type) have specific activity of¹³⁷Cs greater than 0.5 Bq kg^–1. The remaining samples have the same¹³⁷Cs concentrations as before May, 1986. Predominant activity in all samples comes from the⁴⁰K radionuclide, indicating natural honey.     

Radiation dose assessment for137Cs from fish in the Aegean Sea before and after the Chernobyl accident

The effective doses from fish in the Aegean Sea have been calculated for the nuclide¹³⁷Cs covering the period 1975–1982. The effective dose varies between 3×10^–5 and 10×10^–5 mSv y^–1 for adults and 14×10^–5 to 56×10^–5 mSv y^–1 for children, while the cumulative effective dose for the period 1975–1982 equals to 40.86×10^–5 and 229.57×10^–5 for both adults and children of 10 y old, respectively. When compared to doses derived from the Chernobyl accident /May 1986/ it was found that the additional dose incurred by Greek individuals in May 1986 was approximately equal to the cumulative dose of 8 y contribution period /1975–1982/ for adults and to a year's contribution for children of 10 y old.     

Foliary contamination in the area of Bratislava (Czecho-Slovakia) after the Chernobyl accident

The contamination of leaves of some ornamental and fruit-tree plants (18 species), herbs (6) and early leafy vegetable (2) were assessed in the region of Bratislava and its vicinity through the first months after the Chernobyl accident. The levels of contamination showed local and temporal dependence. In October compared to its levels five months earlier, foliar contamination showed a relative 12- to 200-fold decrease of radioactivity. The effective half-life of the mixture of fission products in cumulative fallout on leaves of vegetation changed depending on time after the accident from 4 days (on day 10) to 150 days (after 2 months). The soluble fraction of radioactive contaminants on plant foliage ranged from 0.12 to 0.64.     

Comparison of food processing retention factors of 137Cs and 40K in vegetables

Removal of radiocesium from food by processing is of great concern following the accident of TEPCO’s Fukushima Daiichi Nuclear Power Plant accident. To provide more Cs removal rates, we studied the applicability of K data using edible plant samples. Values were compared for ¹³⁷Cs and ⁴⁰K of the food processing retention factors, F _r (total activity in processed food/total activity in raw food), and they were found to be close to the 1:1 line and highly correlated (R = 0.96, p < 0.001). Thus, K can be an analogue to estimate radiocesium removal rates by food processing of vegetables. Using the literature K values, we calculated the K removal rates (%), that is, (1 ? F _r) × 100, for ten vegetable types to provide potential Cs removal rates. The average percent of K removal were as follows: dried pulses, 33; fresh pulses, 15; leafy vegetables, 52; fruit vegetables, 7; flower vegetables, 44: root crops, 18; tubers, 16; ferns, 93: mushrooms, 32; and others, 30.     

Soil-to-plant transfer of 137Cs and 40K in an Atlantic blanket bog ecosystem

The transfer of ¹³⁷Cs and ⁴⁰K from soil to vegetation was studied in an Atlantic blanket bog ecosystem along the Atlantic coast of Ireland where the dominant vegetation is a mixture of Calluna vulgaris, Eriophorum vaginatum and Sphagnum mosses. The impact of soil chemistry and nutritional status of vegetation on the uptake of both radionuclides was also examined. Cesium-137 transfer factors values ranged from 1.9 to 9.6 and accumulation of ¹³⁷Cs was higher in the leaves of C. vulgaris than in the stems. Transfer factors values for ¹³⁷Cs in both C. vulgaris and E. vaginatum were similar indicating that for the vegetation studied, uptake is not dependent on plant species. The uptake of ¹³⁷Cs in bog vegetation was found to be positively correlated with the nutrient status of vegetation, in particular the secondary nutrients, calcium and magnesium. Potassium-40 transfer factors ranged from 0.9 to 13.8 and uptake was higher in E. vaginatum than in C. vulgaris, however, unlike ¹³⁷Cs, the concentrations of ⁴⁰K within the leaves and stems of C. vulgaris were similar. The concentration of both ¹³⁷Cs and ⁴⁰K found in moss samples were in general lower than those found in vascular plants.     

Distribution of137Cs,40K,238U and232Th in soils from Northern Venezuela

More than one hundred undisturbed soil samples from Northern Venezuela and the islands of Margarita and Los Roques have been analyzed for¹³⁷Cs,⁴⁰K,²³⁸U and²³²Th by -ray spectroscopy. The specimens were taken from between 5–10 cm below the earth's surface. Thus, they are valid not only for the¹³⁷Cs deposition studies but also for the estimation of the natural -ray dose from primordial radionuclides that form the terrestrial component. The concentration of⁴⁰K was directly determined from its 1461 keV -ray, while those of¹³⁷Cs,²³⁸U and²³²Th were performed using a -ray from one of their daughter radionuclides: the 661 keV -ray of^137mBa for¹³⁷Cs, the 1760 keV -ray of²¹⁴Bi for²³⁸U and the 2620 keV -ray of²⁰⁸Tl for²³²Th. Finally, the concentration values were compared with those of global estimates.     

The study of 137Cs and 90Sr sorption by natural and modified aluminosilicates in presence of humic acids

Journal of Radioanalytical and Nuclear Chemistry - The effect of humic acids (HA) on 137Cs and 90Sr uptake by natural and modified aluminosilicates was studied under the conditions of radioactively...     

Concentrations of 137Cs and 40K in wild mushrooms collected in a forest on Noto Peninsula,Japan

A variety of wild mushrooms were collected in a forest on the Noto Peninsula, Japan, to determine the concentration of ¹³⁷Cs and ⁴⁰K. The wild mushroom species belong to the orders Agaricales and Aphyllophorales. The concentration of ¹³⁷Cs varied widely (1.4–4,100 Bq/kg dry weight) in mushrooms growing in soil. On the contrary, ¹³⁷Cs concentration levels were relatively low (1.9–20 Bq/kg-dry weight) in mushrooms growing on wood. The concentration of ⁴⁰K varied widely (12–2,400 Bq/kg-dry weight) in contrast with several previous reports that suggest relatively constant ⁴⁰K levels in mushrooms. Unusually low concentrations of ⁴⁰K were observed in a few mushroom species that had very hard fruiting bodies with peculiar shapes. The mean and median of ¹³⁷Cs concentration in the present study were similar to those previously reported for Japanese mushrooms. Among the Agaricales mushrooms, Entolomataceae and Tricholomataceae families growing in soil had the highest concentration of ¹³⁷Cs. Among the Aphyllophorales mushrooms, Gomphaceae and Ramariaceae families growing in soil also had the highest ¹³⁷Cs concentrations. The concentrations of ¹³⁷Cs and stable Cs in mushroom samples were positively correlated. The concentration ratio of ¹³⁷Cs/Cs differed between Agaricales and Aphyllophorales mushrooms. The average ¹³⁷Cs/Cs ratio in mushrooms growing in soil was similar to that calculated for the top soil (<5 cm deep) alone because the mycelia of the mushrooms were mainly distributed near the surface of the soil.     

First-principles study of K and Cs adsorbed on Pd(111)

The adsorptions of K and Cs on Pd(111) were studied by the density functional calculations within the generalized gradient approximation. The site preference, bonding character, work function, and electron structure of the system were analyzed. For K and Cs adsorption, the hcp hollow site was found to be preferred for all the coverages investigated. The calculated adsorption geometries for (2 x 2) and (square root 3 x square root 3)R30 degrees phases are both in reasonable agreement with the observed results. The decrease of the work function upon the adsorption of K and Cs can be attributed to a dipole moment associated with the polarized adsorbate atom, which is characterized by depletion of the electron charge in the alkali metal layer and a charge accumulation in the interface region. Our results indicate that the bonding of alkali metal with the Pd(111) surface has a mixed ionic and metallic bond character at low coverage and a metallic bond of covalent character at high coverage.     

Uptake and release kinetics of134Cs by Goldfish (Carassius auratus) and137Cs by Zebra Fish (Brachydanio rerio) in controlled aquatic environment

The uptake and release kinetics of¹³⁴Cs by Goldfish (Carassius auratus) and¹³⁷Cs by Zebra Fish (Brachydanio rerio) from aquatic media of different ionic compositions and temperature was studied in controlled laboratory conditions. The accumulation of radiocesium in the case ofBrachydanio rerio is observed to be strongly dependent on the potassium ion concentration of the aquatic medium, but in the case ofCarassius auratus this dependence is quite weak. The biological half-lives of the cesium isotopes incorporated into the fish investigated in the present work vary from 19 to 80 days and are influenced by the temperature and the ionic composition of the aquatic medium.     

Determination of137Cs and90Sr in milk by the static method with an ion exchanger

This paper presents the method of⁹⁰Sr and¹³⁷Cs determination from 10 litres of milk. The preconcentration is made by the static method with a strong acid cation exchanger (OSTION KS).¹³⁷Cs from the eluent (8M HCl) is selectively eliminated with ammonium molybdophosphate and then the^137mBa gamma activity measured, using NaI(T1) detector.⁹⁰Sr as⁹⁰Y is determined after achievement of the radioactive equilibrium and measured by flow proportional counter. The method appears to be accurate, reproducible and permits to determine³² mBq¹³⁷Cs and 13 mBq⁹⁰Sr in the samples.