137Cs, 40K, alkali–alkaline earth element and heavy metal concentrations in wild mushrooms from Turkey

In 2002, an extensive study was performed in forest sites of Izmir. This first study results led on the one hand, to quantify of ¹³⁷Cs and ⁴⁰K concentration in mushrooms collected in the Izmir region and to a first evaluation of dose in people due to the ingestion of radionuclide-contaminated mushrooms. The mushroom concentration values varied over a wide range from below detection limit to 401 ± 4 Bq kg^?1 (dry wt) for ¹³⁷Cs. The ⁴⁰K concentration values obtained for different species of mushrooms ranged from 588 ± 26 Bq kg^?1 to 2024 ± 63 Bq kg^?1 (dry wt). The annual effective dose values due to mushroom ingestion for ¹³⁷Cs are lower than the ICRP-2007’s reference level value of 1 mSv for “existing” exposure situation. Inductively coupled plasma-mass spectrometry was used to measure many alkali–alkaline earth elements and heavy metals in mushroom samples. The relationships among the concentrations of ¹³⁷Cs and the stable elements were presented and the occurrence of metals in mushrooms was evaluated.     

Accumulation of137Cs by mushrooms from Rogozno area of Poland over the period 1984–1988

The concentration of naturally occurring⁴⁰K and¹³⁷Cs from fallout were determined in various mushrooms as well as in a few samples of forest soil from the same region over the period of 1984–1988. The¹³⁷Cs content in mushrooms before the reactor accident at Chernobyl was generally below 500 Bq kg⁻¹ dry matter, except Paxillus involutus /2700 Bq kg⁻¹/. A remarkable increase of the¹³⁷Cs activity /up to ten times/ was observed in 1986. For almost all examined species this activity remained basically at the same level for the next two years. No correlation between⁴⁰K and¹³⁷Cs in mushrooms has been found.     

Current radioactivity content of wild edible mushrooms: A candidate for an environmental reference material

The paper presents the results of radiological investigation of several mushroom samples collected in the fall of 2004 in different parts of Europe. The work was performed in order to support decision making to develop and produce a certified reference material for quality assurance of radionuclide measurements in environmental samples. The levels of ¹³⁷Cs in mushrooms varied widely ranging from 0.6 to 4300 Bq/kg on dry mass basis, while those of natural ⁴⁰K were relatively constant. In one sample ⁶⁰Co of unknown origin was detected (25±2 Bq/kg dry mass), while ⁹⁰Sr concentrations were usually below the detection limit (<150 mBq/kg dry mass).     

Study of naturally occurring radioactive material (NORM) in top soil of Punjab State from the North Western part of India

The concentration levels of ²³⁸U, ²³² Th, ⁴⁰K and ¹³⁷Cs in top soils of State of Punjab located in the North Western part of India were measured using conventional low background gamma ray spectrometric setup as well as Compton suppressed gamma ray spectrometric setup. The radioactivity level of ²³⁸U and ²³²Th was found to vary between 15 Bq/kg and 27 Bq/kg and between 16 Bq/kg and 57 Bq/kg respectively. The radioactivity level of ⁴⁰K was found to vary between 266 Bq/kg and 799 Bq/kg. The mean radioactivity level of the NORM in general was found to be similar to what is expected as a result of their normal abundance.     

Linhchi mushrooms as biological monitors for137Cs pollution

Radioactivity of Linhchi mushrooms (Ganoderma Lucidum) cultivated in laboratory and production conditions has been measured in the Environmental Laboratory of Nuclear Research Institute (NRI), Dalat, Vietnam. The results showed that Linhchi mushroom has a high radioactive concentration of¹³⁷Cs, which is about 20 Bq kg^–1 fresh weight. In addition, the radioactive contents of substrata before and after cultivation were insignificant. This suggested that Linhchi mushroom should only accumulate the¹³⁷Cs radioisotope from the atmosphere, directly. Therefore, it should be considered as a bio-indicator for environmental monitoring.     

Soil-to-mushroom transfer of <Superscript>137</Superscript>Cs, <Superscript>40</Superscript>K,alkali–alkaline earth element and heavy metal in forest sites of Izmir,Turkey

The present work is devoted to an investigation on the soil to mushroom transfer parameters for ¹³⁷Cs and ⁴⁰K radionuclides, as well as for some stable elements and heavy metals. The results of transfer factors for ¹³⁷Cs and ⁴⁰K were within the range of 0.06–3.15 and 0.67–5.68, respectively and the most efficiently transferred radionuclide was ⁴⁰K. The TF values for ¹³⁷Cs typically conformed to a lognormal distribution, while for ⁴⁰K showed normal distribution. Statistically significant correlations between ¹³⁷Cs soil to mushroom transfer factors and agrochemical soil properties have been revealed. Although the concentration ratios varied within the species, the most efficiently transferred elements seems to have been K, followed by Rb, Zn, Cu, Cd, S, Cs and Hg.     

On variations of volumetric activity of 90Sr and 137Cs in the Baltic Sea coastal waters near the shore of Lithuania in 2005–2009

The article presents the measurement results of the volumetric activity (VA) of artificial radionuclides ⁹⁰Sr and ¹³⁷Cs in the coastal waters of the Baltic Sea near the Curonian Peninsula in 2005–2009. The annual average values for this period of time were 12 Bq/m³ (⁹⁰Sr) and 40 Bq/m³ (¹³⁷Cs). Considerable variations in the VA of the radionuclide in individual measurements compared to the average results were observed. The extreme values were 6 and 16 Bq/m³ for ⁹⁰Sr and for ¹³⁷Cs—27 and 75 Bq/m³. It is proposed to allow such variations under the influence of a variety of external factors such as hydro meteorological situations, inflowing rivers and bays, storm activity and etc. Besides, a possibility of penetration of radionuclides into the sea waters from the additional radioactive sources is not excluded.     

Levels and effects of natural radionuclides in soil samples of Garhwal Himalaya

Distribution of natural radionuclide gives significant parameter to assess the presence of gamma radioactivity and its radiological effect in our environment. Natural radionuclides are present in the form of ²²⁶Ra, ²³²Th and ⁴⁰K in soil, rocks, water, air, and building materials. Distribution of natural radionuclides depends on the type of minerals present in the soil and rocks. For this purpose gamma spectrometer is used as tool for finding the concentration of these radionuclides. The activity concentration of naturally occurring radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K in these soil samples were found to vary from of 8 ± 1 Bq/kg to 50 ± 10 Bq/kg with an average 20 Bq/kg, 7 ± 1–88 ± 16 Bq/kg with an Average 26 Bq/kg and 115 ± 18–885 ± 132 Bq/kg with an average 329 Bq/kg, respectively. In this paper, we are presenting the radiological effect due to distribution of natural radionuclide present in soil of Garhwal Himalaya.     

Proficiency test exercise on the determination of natural levels of radionuclides in mushroom reference material

The results from a proficiency test exercise for the determination of natural levels of radionuclides in mushroom reference material carried out by laboratories in six different countries are discussed. These laboratories submitted data on seven radionuclides, namely ¹³⁴Cs, ¹³⁷Cs, ⁴⁰K, ⁹⁰Sr, ²⁴¹Am, ²²⁶Ra, and ²¹⁰Po. However, only the data received for three of these radionuclides could be statistically evaluated to obtain consensus mean values and confidence intervals (at a significance level of 0.05). The contents of ¹³⁴Cs, ¹³⁷Cs and ⁴⁰K were quantified as 4.4, 2,899 and 1,136 Bq/kg, respectively.     

Transfer of 137Cs and stable Cs in soil-grass-milk pathway in Aomori, Japan

The soil-to-grass transfer factors and grass-to-milk transfer coefficients were determined for ¹³⁷Cs and stable Cs in soil, grass and milk samples collected in Aomori Prefecture, Japan. The concentrations of ¹³⁷Cs in the soil and grass samples collected from 25 sampling sites were 13±12 Bq.kg^-1 and 2.0±2.1 Bq.kg^-1 dry wt., respectively. The geometric mean of soil-to-grass transfer factor of ¹³⁷Cs was 0.13 and its 95% confidence interval was 0.017-0.98. The transfer factor of ¹³⁷Cs was higher than that of stable Cs, and they had a positive correlation. The concentration of K in the soil affected both transfer factors. The concentration of ¹³⁷Cs in milk samples collected from 16 sites was 76±43 mBq.kg^-1 fresh wt. and had a good correlation with that of stable Cs. The geometric mean of grass-to-milk transfer coefficient of ¹³⁷Cs was 0.0027, assuming that a cow's total daily intake was 20 kg of dry grass. The transfer coefficient of ¹³⁷Cs was positively correlated with that of stable Cs.     

Influence of the environment in 40K concentration in Brazilian common beans

The consumption of beans constitutes an important dietary habit in many Latin American, Asian and African countries. Carioca beans and the black type stand out among the many consumed common beans in Brazil. ⁴⁰K was used as a natural radiotracer to evaluate the influence of the season growing and the bean type in the potassium content into grain. The activity concentrations of ⁴⁰K and ¹³⁷Cs were evaluated on samples of beans by γ-ray spectrometry. ¹³⁷Cs was less than 1.3 Bq kg ^?1. The highest potassium content in the grain were observed in the dry and winter seasons. The black beans showed higher potassium content than the carioca type. The potassium levels were compared with that of beans grown and consumed in other regions of the world. A method to estimate the bean consumption rates in Brazil independently of the location of the meal is proposed. The ingestion of common beans was estimated in 14.6 kg year^?1 per person. The two regions with the highest consumption are the Southeast (19.2 kg year^?1) and the Middle West (18.7 kg year^?1), whose account for about 60 % of the intake of common beans is related to consumption out home.     

The evaluation of 137Cs radioactivities in soils taken from the Babia Góra National Park

The aim of this work was to determine ¹³⁷Cs and ⁴⁰K radioactivities in soil samples taken from the Babia Góra National Park (BPN) in south Poland. The cluster analysis (CA) and principal component analysis (PCA) were used to discuss the obtained data. 10 cm thick soil cores were collected from the BPN area. Each sample was divided into three sub-samples. The samples were dried, homogenized and packed in polyethylene containers. The radioactivities of ¹³⁷Cs and ⁴⁰K were measured by means of gamma spectrometry. It was found that ¹³⁷Cs radioactivity in the whole 10 cm soil cores was in the range from 1,916 to 28,551 Bq m^?2. The radioactivity of ⁴⁰K varied from 1,642 to 25,654 Bq m^?2. Using CA it was possible to diverse the soils taking into account soil types. By use of the PCA method, it was chosen three factors which are appropriate to characterize researched parameters.     

Measurement of 137Cs in the soil in Korea by low-level background gamma-ray spectrometer

¹³⁷Cs was measured in soil samples collected in Korea from 2006 to 2008 using a low-level background gamma-ray spectrometer that was designed and developed by KRISS (Korea Research Institute of Standards and Science). The objectives of this study are to evaluate the newly developed low-level background gamma-ray spectrometer and, consequently, to provide information on the horizontal and vertical distribution of ¹³⁷Cs in Korean soil. ¹³⁷Cs concentrations in surface soil varied from 12.8 ± 0.9 to 108 ± 4 Bq kg^?1, and the vertical profiles of ¹³⁷Cs from the Nari basin in Ulleung Island in the East Sea/Sea of Japan and Seongsan Ilchulbong Peak, Jeju Island, showed a higher concentration in the surface layer that gradually decreased with depth. On the other hand, the ¹³⁷Cs concentration in soil samples collected from Bukhan Mountain National Park in Seoul showed a subsurface maximum and decreased with depth. The ¹³⁷Cs inventories in the soil column were calculated to be 1,830–4,360 Bq m^?2 with a mean of 2,770 Bq m^?2, which was the same order of magnitude as the global fallout inventories in the mid-latitude region of the Northern Hemisphere.     

The ambient gamma dose-rate and the inventory of fission products estimations with the soil samples collected at Canadian embassy in Tokyo during Fukushima nuclear accident

In this study, soil samples were collected at Canadian embassy in Tokyo (about 300 km from Fukushima) on 23 March and 23 May of 2011 for purposes of estimating concentrations of radionuclides in fallout, the total fallout inventory, the depth distribution of radionuclide of interest and the elevated ambient gamma dose-rate at this limited location. Some fission products and actinides were analyzed using gamma-ray spectrometry, alpha spectrometry and liquid scintillation counting. The elevated activity concentration levels of ¹³¹I, ¹³²I, ¹³⁴Cs, ¹³⁷Cs, ¹³⁶Cs, ¹³²Te, ¹²⁹mTe, ¹²⁹Te, ¹⁴⁰Ba and ¹⁴⁰La were measured by the gamma-ray spectrometer in the first sample collected on 23 March. Two months after the accident, the ¹³⁴Cs and ¹³⁷Cs became only detectable nuclides. A mass relaxation depth of 3.0 g/cm² was determined by the activities on the depth distribution of ¹³⁷Cs in a soil core. The total fallout inventory was thus calculated as 225 kBq/m² on March sampling date and 25 kBq/m² on May sampling date. The ambient gamma dose-rates in the sampling area estimated by the fallout fission products inventory and ¹³⁷Cs depth distribution ranged from 184 to 38 nGy/h. There was no detectable americium or plutonium in the soil samples by alpha spectrometry. Although ⁹⁰Sr or ⁸⁹Sr were detected supposedly as a result of this accident, it was less than the detection limit, which was about 0.4 Bq/kg in the soil samples.     

Geographical and vertical distribution of radiocesium levels in coniferous forest soils in Izmir

Preliminary picture of ¹³⁷Cs radioactivity levels in forested areas in and around Izmir is illustrated. Both activity concentrations and activity depositions of ¹³⁷Cs in soil samples were determined. Their values varied from 8.29±0.27 to 445±3.16 Bq.kg⁻¹ (d.w.) and 0.63±0.01 to 11.6±0.08 kBq.m^–2 (d.w.), respectively. It was found that while activity deposition of ¹³⁷Cs is normally distributed, activity concentration of ¹³⁷Cs is log-normally distributed in forest soils and the activity deposition is less variable than the activity concentration. Cesium-137 activities in soils increase with increasing elevation, annual average rainfall and soil organic matter.     

A simple correction method for isobaric interferences induced by lead during uranium isotope analysis using secondary ion mass spectrometry

The present study is to determine the activity concentration of radioactive nuclide in plant fertilizers used in agriculture in Iraqi Kurdistan region using high- purity germanium detector (HPGe) gamma spectrometer. The results showed that the range of activity concentrations for ²²⁶Ra, ²³²Th, ⁴⁰K and ¹³⁷Cs in chemicals and organic fertilizers are (0.1–134), (0.1–74), (1–12,000) and (0–1) Bq/kg respectively, based on the measured activities that were used to assess the radiological hazards. Radium equivalent activity in some samples exceeds the value (370 Bq/kg) which recommended by the OECD.     

Uptake of alpha and beta emitters by mushrooms collected and cultured in Spain

Almost all studies on the radioactive content of mushrooms have been centered on ¹³⁷Cs and, to a lesser extent, on ⁴⁰K. Other alpha and beta emitters have not been fully investigated and, therefore, their contribution to the dose due to consumption of mushrooms is not taken into consideration. We have studied the incorporation of several radionuclides: into mushrooms using two approaches — laboratory and natural conditions. Pleurotus eryngii was cultured under controlled laboratory conditions, and was found that ¹³⁴Cs was incorporated to a greater extent in the mushroom than the rest of radionuclides, and ²³⁹Pu at least. These results were confirmed by the uptake under natural conditions: ¹³⁷Cs > ^228,230,232Th ^234,238U ⁹⁰Sr >> ^239+240Pu. The contribution of thorium and uranium to the dose due to mushroom consumption in Spain is of the same order of magnitude as that of ¹³⁷Cs.This revised version was published online in November 2005 with corrections to the Cover Date.     

Monitoring the environmental contamination of Kara Sea and shallow bays of Novaya Zemlya

The distribution of ¹³⁷Cs and ^239,240Pu in various ecosystems of the Kara Sea as well as speciation of these radionuclides has been studied to assess their potential mobility. In bottom sediment and seawater samples collected in Abrosimov, Tsivolky, Stepovoy, and Sedov Bays and on the coast of Novaya Zemlya, the content of anthropogenic radionuclides ¹³⁷Cs and ^239,240Pu does not exceed the values typical of the offshore zone in the Kara Sea (in sea water: 1.0–3.7 Bq/m³ for ¹³⁷Cs and 50–90 mBq/m³ for ^239,240Pu; in bottom sediments: 0.5–18.3 Bq/kg for ¹³⁷Cs and 4.3–7.3 Bq/kg for ^239,240Pu). The present monitoring study is important for the development of a long-term forecast for the dynamics of environmental contamination in the shallow bays of Novaya Zemlya.     

Measurement of fallout with rain in Hiroshima and several sites in Japan from the Fukushima reactor accident

Fallout with rain from the Fukushima reactor accident was monitored for about two months in Higashi-Hiroshima City, Hiroshima, Japan, from March 20 to May 23, 2011. Gamma-ray (γ-ray) spectra measured using a low background HPGe spectrometer showed clear evidence of fission products—¹³¹I, ¹³⁷Cs, and ¹³⁴Cs. The ¹³¹I was observed on March 27 and April 8, while ¹³⁷Cs and ¹³⁴Cs were observed on March 27, April 18, and April 22. The ¹³¹I, ¹³⁷Cs, and ¹³⁴Cs activity concentrations in rainwater collected in Hiroshima reached 0.44 ± 0.09 on April 8, 0.17 ± 0.01 on April 18, and 0.15 ± 0.01 Bq/L on April 18, 2011, respectively. These activity levels were compared with global results collected from the Northern Hemisphere. Several samples of rainwater that were collected in Chiba (Kashiwa) on March 21, April 11, and May 12; Tokyo (Nerima) on March 21 and April 11; Osaka (Hirano) on April 8; Nara (Kitakatsuragi) on April 9; and Fukushima (Fukushima) on April 19, were also measured by our spectrometer and compared. Among these samples of rainwater collected at different locations in Japan, the one collected at Kashiwa City, Chiba Prefecture, on March 21 showed the highest activity concentrations of 6072 ± 1,   632 ± 4,   766 ± 3,   637 ± 1,   97.6 ± 0.8, and 752 ± 2 Bq/L for ¹³¹I,   ¹³²I,   ¹³²Te,   ¹³⁴Cs,   ¹³⁶Cs, and ¹³⁷Cs, respectively. The health risks due to these high activity levels were considered in terms of several regulations. The ratio of the activites for the isotopes ¹³¹I to ¹³⁷Cs and ¹³⁴Cs to ¹³⁷Cs were compared with the other measurements and discussed.     

Marine sediments as a radioactive pollution repository in the world

During a time period little longer than 60 years, it has been created a radioactive pollution background over the natural one, which started in 1945 and it has been growing up since then, due to several nuclear tests, minor nuclear reactors failure and four major accidents: Wind Scale, Three Mile Island, Chernobyl and Fukushima. This radioactive polluting background can be easily detected through ¹³⁷Cs fission product, which by the effect of wind, river currents and rain has been accumulated in marine sediments, mainly because sea represents about 80 % of earth’s surface. Since energy demand has been growing up with no interruption during last two centuries, and nuclear energy seems to be the largest available source, it is very likely a great expansion of nuclear energy during twenty-first century. So, this paper presents results obtained in strategic points of the two large littorals in Mexico: Gulf and Pacific Ocean, as an attempt to establish there some figure to evaluate the present radioactive pollution. An adequate figure to do it, seems to be the quotient of activity per gram of ¹³⁷Cs in marine sediments (Bq¹³⁷Cs/g), divided by activity per gram of ⁴⁰K natural radioactivity (Bq⁴⁰K/g). When this result is multiplied by 100 the percentage of polluting radioactivity (¹³⁷Cs) related to natural radioactivity (⁴⁰K) is obtained. This percentage seems to be useful to evaluate the importance of radioactive pollution from 4 points of view: a) calculate the extent of already radioactive pollution present in the seas of world; b) avoid the panic in case of nuclear accidents, c) what will be the growing up rate in the future; d) if it is possible to keep one decreasing rate at same decaying rate of ¹³⁷Cs (t_1/2 = 30.07 years), since from 1945, starting time of radioactive pollution, it has decayed only about 2.2 half lives.