Objective
Samples of soil, vegetation and sheep faeces were collected at 4 farms in Ireland and analyzed for radiocaesium content. The highest radiocaesium activities (up to 3500 Bq/Kg dry weight) are found in the new shoots of Calluna vulgaris and Scirpus caespitosus and in Pteridium aquilinum. All other species have concentrations less than 1000 Bq/Kg throughout the period of sampling. Seasonal variability is most marked in Scirpus caespitosus and, for some of the graminoid species, an increasing caesium-137 to caesium-134 ratio is observed during the growing season. Soil samples collected from deep peat sites have shown that caesium-134 has already penetrated below the 30 cm horizon, indicating an annual migration rate in excess of 7 cm.
A comparison was made of radiocaesium in sheep by in vivo monitoring with activity in faeces taken from the grazing area. Greater variability observed in the radiocaesium content of faeces early in the season is attributed to animals returning to upland grazing over a period of 2 to 3 weeks. The activity in samples from a forestry area is 2 to 3 times higher from September onwards, possibly due to the consumption of fungi.
Preliminary soil water investigations have been carried out on upland organic soil sites. Generally, the radiocaesium content of soil water and channel water has been about 20 mBq.
Diet analysis of sheep compared with available vegetation in the field reveals diet selectivity and the maintenance of a constant diet over the study period in spite of seasonal change in vegetation availability. The actual radiocaesium content of the sheep faeces was measured and compared to the predicted levels and also to in vivo sheep measurements of radiocaesium. The same trends throughout the year were observed in all 3 although the predicted faeces activity was low compared with the actual situation.
Laboratory intercalibration and a comparison of soil sampling methodologies were carried out.
3 upland heath sites, known to have received relatively high inputs of Chernobyl radiocaesium, have been selected for study. Samples of soil and vegetation have been collected from all 3 sites and analyzed for radiocaesium concentrations and for a range of nutrient elements and physical characteristics. This data has been tabulated and is ready for statistical analysis.
Sampling and analyses have been performed as part of interlaboratory comparison studies on: the effect of different sampling techniques on measured concentrations of radiocaesium down soil profiles; possible bias in measured radiocaesium concentrations in soil and vegetation due to laboratory analytical technique; and the effect of different analytical methods on the measurement of physical and chemical soil characteristics. Samples have also been collected and analyzed for an assessment of radiocaesium uptake by plant species common to each country involved in the study.
A summary has been made of radionuclide concentrations measured in tissues from red deer, fox, brown hares, blue hares, black grouse and red grouse after the Chernobyl accident. A rough estimate of the worst case consumption of contaminated flesh by the local human population has also been made.
Approximately 30 heather plants have been propagated in sand ready for a transpiration experiment
Samples of milk, lamb meat, potatoes and drinking water have been collected from 3 locations in the Faroe Islands since 1962 and analyzed for strontium-90 and radiocaesium. From these 3 and another one location samples of soil, grass, milk, lamb meat and fresh water were collected in 1987, 1989 and 1991. Since 1982 (when fresh direct fallout from nuclear weapons testing had essentially ceased) the effective half life of strontium-90 from global fallout in Faroese milk has been 3.2 years and that of caesium-137 2.2 years whereas the effective half life of Chernobyl caesium-137 (1987 to 1989) was 1.2 years. In lamb meat caesium-137 from global fallout decayed with a 4.3 year half life and Chernobyl caesium-137 with a 1.2 year half life. In potatoes, caesium-137 from global fallout showed a half life of 2.8 years and Chernobyl caesium-137 showed a half life of 2.3 years. The observation of Chernobyl caesium in the Faroese environment has until now been too short to conclude that Chernobyl debris should behave differently from global fallout in the long run.
Gamma spectrometric analyses and soil sampling were carried out as part of an interlaboratory comparison study.
The effects on the uptake of caesium-137 to heather have been studied after adding potassium fertilizer to a forest ecosystem. There was a 50% decrease in the caesium-137 activity concentrations in plots where 50 kg or 250 kg potassium chloride was added per hectare. The decrease occurred within about 2 months. Without fertilizer a caesium-137 transfer factor (soil to heather) of about 0.25 to 1.0 m{2}/kg was found.
The soil to plant transfer was also studied for lingonberry, bilberry and cloudberry. The mean transfer factors (Bq/kg dry matter per Bq/m{2}) were found to be 0.129 0.032 and 0.041 respectively. For lingonberry and bilberry the transfer factor decreased when the exchangeable potassium or pH of the soil decreased.
An assay system for studies of the caesium-137 transfer capacity for various soils from the forests has been established.
The frequencies of fruitbodies of mushrooms were found to peak in late July, beginning of August and in late September. The abundance of mushrooms will affect the levels of caesium-137 in roe deer. A mean caesium-137 transfer factor for the mushrooms is between 1.0 and 1.2 m{2}/kg.
During a trial hunting period of roe buck in May, the mean caesium-137 activity concentrations in the animals was found to be approximately 4 to 5 times lower than in those hunted in the normal period of August and September. Aggregated transfer factors (soil to roe deer) of between 0.04 and 0.2 m{2}/kg were found.
From about 250 samples of moose, an aggregated transfer factor (soil to moose) of about 0.02 m{2}/kg has been found. Sampling results indicate a very long ecological half life of caesium-137 in the forest ecosystem.
The collective dose of caesium-137 to humans in Gaule commune has been calculated as 1.5 man Sv.
Member States of the European Community have suffered fallout both as a result of nuclear weapons testing and again following the Chernobyl accident. Radiocaesium from both these sources is present in soils in measurable amounts and is available for transfer to vegetation and herbage and onwards to man. Work in progress indicates that radiocaesium of Chernobyl origin has remained available for recycling in upland ecosystems for a longer period of time than was predicted by models available at the time of the Chernobyl accident. These models were largely based on data from studies of radionuclide movement in lowland agricultural ecosystems. Current work has also shown that radiocaesium concentrations in different species from the same habitat can vary by an order of magnitude. This could be due to the physical composition of the plant, or to specific physiological factors.
The levels of radiocaesium present in upland vegetation and herbage are therefore often enhanced when compared to those grown on mineral rich lowland soils. Forest and upland ecosystems are also the natural habitat for domestic and wild animals such as sheep, red deer, moose and reindeer, and so a direct pathway into human food chains can be identified.
The mechanisms of recycling and transfer in these ecosystems are poorly understood, and the necessary data with which existing models can be revised or new models developed are not available. The research projects described in the following sections have been formulated with a view to using similar techniques to evaluate a number of different ecosystems where elevated levels of radiocaesium activity have already been identified, both in plant species and in grazing animals. Soil characteristics, plant composition, plant physiology and biological activity will all be examined and their effect on soil to plant transfers in acidic soils assessed. In addition, the seasonal variation in dietary composition of grazing animals and the subsequent effect on their radionuclide burden will be evaluated. Where appropriate, critical groups will be identified and annual dose commitments evaluated. All data collected will be made available for modelling purposes.
The proposal involves work on blanket bogs and montane peatlands (Ireland), upland heaths (UK), Northern Boreal forests (Sweden) and more extreme habitats as found in the Faeroe Islands (Denmark). A contrasting Mediterranean ecosystem grazed by sheep has recently been included in the programme.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques. See: The European Science Vocabulary.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques. See: The European Science Vocabulary.
- engineering and technology environmental engineering water treatment processes drinking water treatment processes
- natural sciences chemical sciences inorganic chemistry alkali metals
- natural sciences biological sciences microbiology mycology
- engineering and technology other engineering and technologies nuclear engineering
- medical and health sciences health sciences nutrition
You need to log in or register to use this function
Programme(s)
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Topic(s)
Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Data not available
Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Call for proposal
Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
Data not available
Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
Funding Scheme
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Coordinator
14 Dublin
Ireland
The total costs incurred by this organisation to participate in the project, including direct and indirect costs. This amount is a subset of the overall project budget.