Intake Of 137Cs Research Articles

Some Indicators of the 137Cs Intake in Nutrient Solution with Root Exudates of Norway Spruce (Picea abies) in a Model Experiment

This study presents the results of a model experiment with Picea abies determining the role of root exudates in the intake of radiocaesium into soil solution. It has been established that the amount of consumed 137Cs depends on the weight of the root system, with the majority of the radionuclide presumably accumulating in the primary cortex of the root; i.e., it was not redistributed further between the structural components of the plant. The amount of 137Cs entering the aerial part is approximately 2.5% of its total storage in the plant. During the experiment (7 days), 37.4–53.8% of the radionuclide accumulated in the assimilating organs were transported into pure solution with root exudates and the radiocaesium storage transported into the solution exceeded that of the roots. The movement of 137Cs in the aqueous film on the surface of the root systems have not been recorded.

Determination of radiological hazard parameters in sea snails (Rapana venosa) in the East Black Sea Coast of Turkey

The aim of this study was to determine the activity concentrations and radiological hazard parameters of 137Cs and 40K in soft tissue samples of sea snails (Rapana venosa) collected from 12 different stations in the East Black Sea coastal area of Turkey. The values in soft tissues of sea snail samples with three different sizes were between 0.31 and 1.79 Bq kg−1 for 137Cs and 163.9 and 269.4 Bq kg−1 for 40K. The mean activity concentrations of 137Cs and 40K in tissues of small-sized sea snails were determined to be higher than those of 137Cs and 40K in soft tissues of the other sizes. The determined activity concentration values were lower than the concentrations reported in similar studies. Radiological hazard parameters such as the daily intake (Dint) of 137Cs and 40K, annual committed effective dose (Eeff), and lifetime cancer risk (LCR) were calculated and compared with the international recommended values.

Agricultural aspects of radiocontamination induced by the Fukushima nuclear accident - A survey of studies by the Univ. of Tokyo Agricultural Dept. (2011-2016).

Immediately after the Fukushima nuclear power plant accident, a team of 40–50 researchers at the Graduate School of Agricultural and Life Sciences at the University of Tokyo began to analyze the behavior of radioactive materials in the fallout regions. The fallout has remained in situ and become strongly adsorbed within the soil over time. 137Cs was found to bind strongly to the fine clay, weathered biotite, and organic matter in the soil; therefore, it has not mobilized from mountainous regions, even after heavy rainfall. In farmland, the quantity of 137Cs in the soil absorbed by crop plants was small. The downward migration of 137Cs in soil is now estimated at 1–2 mm/year. The intake of 137Cs by trees occurred through the bark and not from the roots. This report summarizes the findings of research across a wide variety of agricultural specialties.

Baseline quantity of 131I, 137Cs, 134Cs and 40K in urinary excretions from Thai people and internal exposure dose

Today, sealed and unsealed radioactive materials have been used in Thailand for various purposes such as medical, agricultural and industrial applications. There is a growing trend in the use of radioactive materials. Moreover, neighboring countries are planning to construct and operate nuclear power plants. In case of nuclear power plant accidents, radioactive releases in environment and intakes into human body by inhalation and ingestion causing long term health effects. This research aims to determine the radiation baseline quantity of interested relevant radionuclides such as 131I, 137Cs, 134Cs as well as a natural radionuclide, 40K in urine samples of Thai people by gamma spectrometry. Two types of detectors (NaI and HpGe detectors) are calibrated by mixed radionuclide standards of 109Cd, 57Co, 133Ba, 54Mn, 137Cs and 60Co, (energy range from 88 to 1,331 keV). 720 urine samples are collected over a 24 hour period from Thai volunteers with the age older than 18 years old, who lived in eight locations of Thailand. To reduce the effect of geometric difference, 30 ml of urine samples are prepared for counting measurement and efficiency determination. The radiation baseline quantity of 131I, 137Cs, 134Cs and 40K in 30 ml of urine samples are 0.37±0.09, 0.63±0.13, 0.39±0.08 and 7.84±1.63 Bq, respectively. Based on the assumption of intake (50% of the intake by ingestion and 50% of the intake by inhalation), internal dose for members of public are assessed. The committed dose equivalent due to an intake of 131I, 137Cs, 134Cs and 40K are 2.36E-03±1.66-03, 1.15E-01±8.61E-02, 1.16E-01±7.77E-02, 9.44E-01±3.56E-01 mSv per year, respectively.

Seasonal variation in food web-based transfer factors of radiocesium in white-spotted char (Salvelinus leucomaenis) from headwater streams

The seasonal variability of food web-based transfer factors (TFweb) of radiocesium (137Cs) in white-spotted char (Salvelinus leucomaenis) was examined in the 2nd and 3rd year after the Fukushima Daiichi Nuclear Power Plant accident. Two headwater streams with similar landscape characteristics, but different amounts of fallout, were selected in Fukushima and Gunma Prefectures, Japan. The TFweb of predator–prey systems was based on the dietary contributions of prey items estimated from stable isotopes compared to their respective 137Cs activity concentrations. Char consumed more terrestrial food sources with higher contamination levels in summer than in winter based on their dietary-based 137Cs contributions. The TFweb values in Fukushima and Gunma in all seasons indicated 137Cs bioaccumulation from prey to predator. The TFweb in Gunma exhibited significant seasonal variation; the greatest values were observed in winter, while the lowest values were observed in summer. In contrast, the seasonal TFweb in Fukushima did not vary seasonally. Despite similar consumption patterns and the specific metabolic rates of char, the different seasonal patterns of TFweb at the two sites can be explained by the relative excretion rate with respect to the concentration of 137Cs consumed. 137Cs levels can remain relatively constant in the char body throughout the year in areas with high contamination, such as Fukushima, possibly because 137Cs intake overwhelms the excretion rate. Examining seasonal patterns in the transfer processes of 137Cs in white-spotted char are essential for understanding mechanisms of 137Cs accumulation in aquatic biota.

Ingestion intakes of 137Cs by the Czech population: Comparison of different approaches

Ingestion intakes of 137Cs of the Czech population were calculated in two different ways - either from the measured activity of 137Cs in components of food in combination with statistical data about consumption rates or from retention of 137Cs in the human body obtained by whole body counting or calculated from daily urinary excretion of 137Cs. Data from the time period since 1986 to 2015 are used. The daily ingestion intake was about 25 Bq d−1 in 1986 and is around 0.1 Bq d−1 at present. Both approaches of ingestion intake calculation have their advantages and disadvantages. Ingestion intake calculated from 137Cs body content was assumed to be the most accurate as it requires fewer assumptions than the calculation from food consumption. However, calculation of 137Cs intake from food consumption is an important tool for prediction doses after the release of radionuclides into environment. The best agreement exceeding the intakes from urine measurement 5 times at maximum was achieved when intakes calculated from food also included products from the natural environment. Without this, the ingestion intake could be under-predicted seriously up to 6 times, especially in the longer time after the release of 137Cs into environment. Ingestion intakes up to 11 Bq d−1 in a group of people with significant consumption of game meat containing elevated activity of 137Cs activity were included as a special case. Various groups of foodstuffs had varying effects on the total committed effective dose from 137Cs. Dose estimates for the Czech population from 137Cs ingestion intake achieved 80 μSv in 1986 and not more than 2 μSv currently and were similar to those incurred by the population of neighbouring countries.

Radioactive artificial 137Cs and natural 40K activity in 21 edible mushrooms of the genus Boletus species from SW China

This study, for the first time, presents the results of activity concentration determinations for 137Cs and 40K in a high number (21 species, 87 composite samples, and 807 fruiting bodies) of mushrooms of the genus Boletus from across Yunnan in 2011–2014 and Sichuan (Boletus tomentipes) using high-resolution high-purity germanium detector. Activity concentrations of 137Cs demonstrated some variability and range from <4.4 to 83 ± 3 Bq kg−1 dry biomass in caps and from <3.8 to 37 ± 3 Bq kg−1 dry biomass in stipes, and of 40K, respectively, from 420 ± 41 to 1300 ± 110 and from 520 ± 61 to 1300 ± 140 Bq kg−1 dry biomass. No significant variations were observed regarding 137Cs and 40K activity concentrations among the same Boletus species from different sampling sites. No activity concentrations from 134Cs were detected in any mushrooms. Internal dose rates estimated were from intake of 1 kg of mushrooms per annum for 137Cs range for species and regions from around <0.0031 to 0.047 ± 0.003 μSv, while those for 40K were from around 0.22 ± 0.04 to 1.2 ± 0.1 μSv. The overall intake of 137Cs was low since low contamination was found in Boletus species.

Chronic exposure of adult, postnatal and in utero rat models to low-dose 137Cesium: impact on circulating biomarkers.

The presence of 137Cesium (137Cs) in the environment after nuclear accidents at Chernobyl and more recently Fukushima Daiichi raises many health issues for the surrounding populations chronically exposed through the food chain. To mimic different exposure situations, we set up a male rat model of exposure by chronic ingestion of a 137Cs concentration likely to be ingested daily by residents of contaminated areas (6500 Bq.l−1) and tested contaminations lasting 9 months for adult, neonatal and fetal rats. We tested plasma and serum biochemistry to identify disturbances in general indicators (lipids, proteins, carbohydrates and electrolytes) and in biomarkers of thyroid, heart, brain, bone, kidney, liver and testis functions. Analysis of the general indicators showed increased levels of cholesterol (+26%), HDL cholesterol (+31%), phospholipids B (+15%) and phosphorus (+100%) in the postnatal group only. Thyroid, heart, brain, bone and kidney functions showed no blood changes in any model. The liver function evaluation showed changes in total bilirubin (+67%) and alkaline phosphatase (–11%) levels, but only for the rats exposed to 137Cs intake in adulthood. Large changes in 17β-estradiol (–69%) and corticosterone (+36%) levels affected steroidogenesis, but only in the adult model. This study showed that response profiles differed according to age at exposure: lipid metabolism was most radiosensitive in the postnatal model, and steroid hormone metabolism was most radiosensitive in rats exposed in adulthood. There was no evidence of deleterious effects suggesting a potential impact on fertility or procreation.

Estimation of annual effective dose from ingestion of 40K and 137Cs in foods frequently consumed in Korea

The activity concentrations of natural (40K) and anthropogenic (137Cs) radionuclides were measured in the 30 most commonly consumed foods in Korea. The average activity-concentrations of 40K and 137Cs were 67 Bq kg−1 and 46 mBq kg−1 fresh weight of food, respectively. The total annual intakes of 40K and 137Cs by humans were 14915 and 3.64 Bq year−1, respectively. The calculated mean annual effective doses from ingestion of the investigated foodstuffs were 92 µSv for 40K and 0.047 µSv for 137Cs. Our results can provide useful background information on radiation protection in Korea, and in other countries as well.

Distribution of 137Cs in the Mediterranean mussel (Mytilus galloprovincialis) in Eastern Black Sea Coast of Turkey

This study presents the results of 137Cs and 40K radionuclide concentrations in mussel (Mytilus galloprovincialis) samples collected during the period of February–November 2014 from twelve different stations within the border of the eastern Black Sea region of Turkey. Also, these radionuclide concentrations were determined in sea water and sediment samples. The activity concentrations in seawater, sediment and mussel tissue samples were between 1.12–1.69mBqL−1, 3.26–30.74 and 1.61–3.16Bqkg−1 for 137Cs and 231.41–399.49mBqL−1, 215.71–450.07 and 286.84–382.16Bqkg−1 for 40K, respectively. These values are also in accordance with the concentrations reported for similar regions. Additionally, radiological impact parameters such as daily intake of 137Cs and 40K, annual committed effective dose and carcinogenic risk due to the consumption of mussel were calculated and compared with the international data. Lifetime cancer risk values are lower than the limit of 10−3.

Retraction Note to: Biomonitoring fallout (137)Cs in resident and migratory fishes collected along the southern coast of India and assessment of dose.

The globally distributed fallout radionuclide 137Cs was monitored in 25 resident and 22 migratory fish species collected from some regions of west and east coast of southern India to establish a baseline data. The samples were collected during June 2008 to June 2009. Higher level of 137Cs was noted in planktivorous fishes and lower level in herbivores. A significant variation in 137Cs was observed between fishes with different feeding habits and different migratory pattern. Oceanodromic migratory fishes displayed higher cesium levels than other migratory types. Similarly, migratory fishes displayed higher 137Cs concentration compared to resident fishes. The overall range of 137Cs varied from 0.06 to 0.3 Bq/kg in fishes. The biological concentration varied from 55 to 250. The average external dose rate to fishes was calculated to be 2.7 × 10−7 μGy/h, while the internal dose rate varied from 8.50 × 10−6 to 5.27 × 10−5 μGy/h. The hazard quotient for fishes was found to be less than 1. The average intake of 137Cs via fishes to the public was calculated to be 3.5 Bq/year and subsequently the committed effective dose was 0.05 μSv/year. The data obtained were less than global average and comparable to those of many regions.

Distribution and possible dietary intake of radioactive 137Cs, 40K and 226Ra with the pantropical mushroom Macrocybe gigantea in SW China

There is scarcity of data on contamination with radiocesium (134/137Cs) of edible mushrooms from the Southwestern Asia. This study aimed to get insight into activity concentration of artificial nuclides 134/137Cs and natural 40K and 226Ra in mushrooms from Yunnan province, which is major producer in China. The specimens of pantropical mushroom Macrocybe gigantea were collected from the wild and from a farm across Yunnan land in 2012–2013 and analyzed using gamma spectrometry with hyperpure germanium coaxial detector (HPGe). M. gigantea showed low activity concentrations of 137Cs (median value for dehydrated caps was 4.5 Bq kg−1 and 5.4 Bq kg−1 for stipes) while 134Cs was not detected. Natural radionuclide 40K showed 2–3 orders of magnitude greater activity concentration compared to artificial 137Cs in M. gigantea. The activity concentrations of 226Ra from uranium and radium decay series for most of the consignments of M. gigantea examined were below the method's limit of detection. The nominal effective dose equivalent for the Yunnan people from the dietary intake of 137Cs was assessed to be below 0.01 μSv per annum on the average, and that from 40K to be below 0.1 μSv per annum. Data available for the first time on activity concentrations of 137Cs in wild-grown saprobic mushroom from this region of Asia suggest low pollution with radiocesium from fallout there. Hence, the likely health risks from intake of 137Cs from cooked M. gigantea are in practice of mushrooms absent for human consumers there. Because of abundance of mushrooms in Yunnan and high significance of the region as producer and exporter a wider study using many species is necessary to fill a gap on possible radioactive contamination and risk to mushroom consumers.

Main internal dose-forming factors for inhabitants of contaminated regions at current phase of the Chernobyl nuclear power plant accident (Kyiv region as an example)

Objective of this work is revealing of main dose forming factors of internal doses for inhabitants of contaminated regions of Kyiv region relying on the results of integral dosimetric monitoring. Three villages have been chosen for the investigation. They are: Raghivka, Zelena Poliana (Poliske district), Karpylivka (Ivankiv district). Twice a year, in May and in October those villages' residents were inspected for content of incorporated 137Cs. They were measured by direct method at the place of residence with the help of whole body counters (WBC). The principal food samples were collected for detection of 90Sr and 137Сs content. Those villages' inhabitants were interviewed about food consumption levels. Mathematical, dosimetric and radio chemical methods were used in this workResults and conclusions. The estimation of internal doses due to intake of 137Cs by ingestion of milk and potatoes are in the range 0.3-34% of doses estimated on the base of WBC data. The contribution to the dose of internal expo sure from intake of 137Cs with the milk consumption is no more than two times higher than the contribution of pota toes consumption in the case of equal consumption levels of these products. Contributions to the dose of internal exposure from intake of 90Sr with milk and potatoes consumptions are approximately similar. Consumption of mush rooms and other wild nature products by inhabitants from the inspected settlements is the main forming factor of internal dose due to 137Cs intake.

Studies on natural and anthropogenic radionuclides in sediment and biota of Mumbai Harbour Bay

Mumbai Harbour Bay (MHB) is a recipient of low level treated effluents from BARC, Trombay and its also a recipient of domestic and industrial wastes from the city of Mumbai and adjoining areas. Sediment samples were collected from various locations of MHB to determine the concentrations of naturally occurring radionuclides like 226Ra, 228Ra and 40K which varied between 4.0 and 26.0, 5.5 and 19.9, 249.6 and 557.6 Bq kg (dry) −1 respectively and are comparable to the worldwide average concentration. The mean value ratio of 228Ra/226Ra in sediment was found to be 1.4, indicating a relatively higher mobility of 238U compared to 232Th. The concentration of anthropogenic radionuclide 137Cs in sediment and biota ranged between 3.6 and 54.5 Bq kg (dry) −1 , <0.08 and 0.5 Bq kg (wet) −1 respectively. The ingestion dose to ‘General Public’ due to 137Cs intake is 0.02 μSv years−1 which is negligible compared to the internationally accepted limit of 1,000 μSv years−1 to ‘members of public’.

Biological availability of 238U, 234U and 226Ra for wild berries and meadow grasses in natural ecosystems of Belarus

This work is devoted to investigation of behavior of 234U, 238U and 226Ra by determining the soil to plant transfer under different natural conditions such as forest or swamped areas and meadow lands with different soil types. The paper summarizes the data on investigation of uranium and radium uptake by wild berries and natural meadow grasses in the typical conditions of Belarus. Parameters characterizing the biological availability of 234U, 238U and 226Ra for bilberry (Vaccinium myrtillus), lingonberry (Vaccinium viti-idaea), blueberry (Vaccinium iliginosum) and cranberry (Vaccinium oxycoccus palustris) as well as for widely occurring mixed meadow vegetation, which belongs to the sedge-grass or grass-sedge associations and forbs, have been established. In the sites under investigation, the deposition levels of 238+239+240Pu were less than 0.37 kBq m−2 and 137Cs deposition ranged between less than 0.37 and 37 kBq m−2. It was found that activity concentrations of radionuclides in berries varied in the ranges of 0.037–0.11 for 234U, 0.036–0.10 for 238U and 0.11–0.43 Bq kg−1 for 226Ra, but in the mixed meadow grasses they were 0.32–4.4, 0.24–3.9 and 0.14–6.9 Bq kg−1 accordingly. The 234U/238U activity ratios were 1.02 ± 0.01 for wild berries, 1.20 ± 0.09 for underground meadow grasses and 1.02 ± 0.02 for proper soils. The concentration ratios (CRs, dry weight basis) of 234U and 238U for mixed meadow grasses were 0.036–0.42 and 0.041–0.46 respectively. The correspondent geometric means (GM) were 0.13 and 0.15 with geometric standard deviations (GSD) of 2.4. The CRs of 226Ra for meadow grasses were 0.031–1.0 with GM 0.20 and GSD 2.6. The CRs of 234U, 238U and 226Ra for wild berries ranged within 0.0018–0.008 (GM is 0.0034, GSD is 1.8), 0.0018–0.008 (GM is 0.0035, GSD is 1.8) and 0.005–0.033 (GM is 0.016, GSD is 2.1) accordingly. The highest CR values of uranium for mixed meadow grasses were found in the sites with high-moor peat and sandy soils. The lowest CRs for grasses were common to loamy and peat-gley soils. The CRs for the same berry species in the sites with sandy soils exceeded the appropriate CR values in the sites with loamy soils by factors of 3–4 for uranium and 4–6 for radium. The data obtained on radionuclide accumulation by plants were used to estimate the average annual effective doses to the population from radionuclide intake through the “soil – wild berries – man” and “soil – meadow vegetation – animal – cow milk-beef – man” trophic chains. The effective doses resulting from 234U, 238U and 226Ra intake with the wild berries for adults were estimated as 0.02–0.09 μSv y−1 (GM is 0.044, GSD is 1.6). It was established that only in the territory with 137Cs deposition of ∼1.0–1.5 kBq m−2 the doses resulting from 234U, 238U and 226Ra intake with wild berries can be comparable with corresponding doses from 137Cs. In the territories with higher levels of 137Cs deposition the doses resulting from its intake with the wild berries are usually over the summarized doses of uranium and 226Ra. The total doses for adults resulting from uranium and 226Ra intake with cow milk and beef ranged between 0.2 and 7.2 μSv y−1 (GM is 2.0; GSD is 2.9) and the doses from 226Ra usually exceeded the appropriate doses of uranium with a factor of 3–37. In the sites with 137Cs deposition less than 3.7 kBq m−2, the doses from 234U, 238U and 226Ra intake with cow milk and beef were assessing as 1.1–7.2 μSv y−1 and they were usually higher than the doses from 137Cs, which were assessing as 0.4–3.2 μSv y−1 for its deposition 2 kBq m−2. In the territory with 137Cs deposition 10–20 kBq m−2 and higher, the internal doses resulting from 137Cs intake with cow milk and beef (10–50 μSv y−1) exceeded the proper doses from natural 234U, 238U and 226Ra.

Reconstruction of Long-lived Radionuclide Intakes for Techa Riverside Residents

Radioactive contamination of the Techa River (Southern Urals, Russia) occurred from 1949-1956 due to routine and accidental releases of liquid radioactive wastes from the Mayak Production Association. The long-lived radionuclides in the releases were Sr and Cs. Contamination of the components of the Techa River system resulted in chronic external and internal exposure of about 30,000 residents of riverside villages. Data on radionuclide intake with diet are used to estimate internal dose in the Techa River Dosimetry System (TRDS), which was elaborated for the assessment of radiogenic risk for Techa Riverside residents. The Sr intake function was recently improved, taking into account the recently available archival data on radionuclide releases and in-depth analysis of the extensive data on Sr measurements in Techa Riverside residents. The main purpose of this paper is to evaluate the dietary intake of Cs by Techa Riverside residents. The Cs intake with river water used for drinking was reconstructed on the basis of the Sr intake-function and the concentration ratio Cs-to-Sr in river water. Intake via Cs transfer from floodplain soil to grass and cows' milk was evaluated for the first time. As a result, the maximal Cs intake level was indicated near the site of releases in upper-Techa River settlements (8,000-9,000 kBq). For villages located on the lower Techa River, the Cs intake was significantly less (down to 300 kBq). Cows' milk was the main source of Cs in diet in the upper-Techa River region.

Дистанционная передача сигналов лучевого поражения в межклеточном пространстве в организме у мышей с различным уровнем генетически детерминированной радиочувствительности

The search results of "bystander" signals are presented at different model of influence of IR on Balb/c and C57bl/6 mice, characterized by different levels of genetically determined sensitivity to IR influence. We used the following models of IR influence: 1) external gamma-quanta influence from small samples of nuclear fuel from the CNPP 4th power unit modified in the course of the accident in 1986, which are 99% connected with 137Cs, with the total dose of irradiation of about 5.0 Gy for 16 hours and accumulated dose of 0.290 Gy for 231 day of exposure, 2) internal intake of 137Cs with water for 40 days. It is shown that cells of different types (splenocytes, hepatocytes, bone marrow and astroglia cells) irrespective of a model of IR influence produce the factors, which failed to be identified in this research, raising the SSF levels in the DNA of non-irradiated cells. Under conditions of a single exposure to gamma-field external irradiation at a dose of about 5.0 Gy, the intensity of production of "bystander" signals is higher in the mice with the raised level of genetically determined sensitivity to RI (Balb/c). Under the same conditions of gamma-field exposure, induction of additional levels of SSF in the DNA of non-irradiated cells is detected for at least one month after IR exposure. Intraperitoneal injection of melanin in the melanin-glucan complex from fungus F. fomentarius before irradiation exposure promotes an essential decrease in the production of "bystander" signals, testifying in favor of the free radical nature of their certain part.

Research into the Factors Affecting the Uptake of 90Sr and 137Cs by Plants from Radioactively Contaminated Soils of the Southern Urals

The objective of this work was to study the factors affecting the intake of 90Sr and 137Cs by plants from soils exposed to radioactive contamination resulting from operations of the Mayak Industrial Association. Specific activities of 90Sr and 137Cs in the samples were determined by the radiochemical method. The most severe contamination by 90Sr and 137Cs of natural soils was found in forest soil cover and in the 0-5 cm soil layer. The contamination density of the area is mainly determined by activity in the soil layer 0-20 cm that contains 3-97% of 90Sr and 60-92% of 137Cs. Portions of radionuclides contained in soil (89-96% of 90Sr and 18-73% of 137Cs) can be converted into cationic use. An insignificant share of water-soluble radionuclides goes from soil to agricultural produce.

Averted Doses to Norwegian Sámi Reindeer Herders after the Chernobyl Accident

The Chernobyl fallout is an enduring challenge to reindeer husbandry in Norway, and South Sámi reindeer herders in central and southern Norway are as contaminated by (137)Cs as inhabitants close to Chernobyl. Therefore, Norwegian authorities continuously recommend to these reindeer herders the use of countermeasures to reduce their intake of (137)Cs. In this study, the authors have applied data on contamination levels in reindeer, results of dietary surveys, and whole body monitoring data in low and high contaminated areas to estimate the effectiveness of countermeasures and resulting averted doses to the reindeer herders. In the most contaminated area, the various countermeasures applied reduced radiocesium ingestion doses during 1986-2009 by about 73%, to an integrated dose of about 17 mSv. However, to comply with the recommended (137)Cs ingestion dose limit of 1 mSv y(-1), the study indicates that reindeer herders in the most contaminated areas will need to carry on with their countermeasures for another 10-15 y. Furthermore, the study indicates that whole body monitoring is an important tool to assess individual doses and countermeasure effectiveness in long-term management of a contamination situation and that such monitoring may be required to reach long-term reference levels.

Estimation of intakes of 131I, 137Cs and 134Cs after the Chernobyl accident

Activities of (131)I and (137)Cs excreted in urine from two healthy males during May 1986, when contaminated air masses from Chernobyl arrived on the territory of the Czech Republic, were determined by bioassay. The data were used to estimate the intakes and committed effective doses from these radionuclides. The results for inhalation intakes are of particular interest, in the absence of sufficient contemporary data for airborne activity. They are found to be higher than initial estimates based on air sampling.