[en] This sheet summarizes the behavior of the chemical element in the main compartments of terrestrial and aquatic ecosystems, under the following two assumptions. Isotopic discrimination is negligible, which is the case for most of the elements discussed. When the element has stable isotopes, the analogy in behavior between its stable and radioactive isotopes is implicitly accepted, bearing in mind, however, that for naturally occurring elements, the chemical form and emission medium of anthropogenic discharges are likely to involve transfer pathways and processes other than those identified for the naturally stable element. The radioactive isotope(s) designated in the heading of the data sheet correspond to radionuclides of major radioecological importance, in terms of quantities and persistence in the environment. Other isotopes, whether radioactive or stable, may also be cited. The information, which is deliberately simplified, is intended to reflect the state of knowledge on the subject at the time of updating, and to propose values for the main radioecological parameters used to estimate transfers in the environment, and more particularly within the food chain

[en] This sheet summarizes the behavior of the chemical element in the main compartments of terrestrial and aquatic ecosystems, under the following two assumptions. Isotopic discrimination is negligible, which is the case for most of the elements discussed. When the element has stable isotopes, the analogy in behavior between its stable and radioactive isotopes is implicitly accepted, bearing in mind, however, that for naturally occurring elements, the chemical form and emission medium of anthropogenic discharges are likely to involve transfer pathways and processes other than those identified for the naturally stable element. The radioactive isotope(s) designated in the heading of the data sheet correspond to radionuclides of major radioecological importance, in terms of quantities and persistence in the environment. Other isotopes, whether radioactive or stable, may also be cited. The information, which is deliberately simplified, is intended to reflect the state of knowledge on the subject at the time of updating, and to propose values for the main radioecological parameters used to estimate transfers in the environment, and more particularly within the food chain

[en] The power station of Duernrohr was the very first thermal power plant in Austria to be equipped with a denitrification and a desulfurization plant for the treatment of the total fluegas amount. More than 8 years of operation have proven that - despite some problems - the techniques (SCR and spray dryer) have a high availability and reliability. (Author)

[en] This sheet summarizes the behavior of the chemical element in the main compartments of terrestrial and aquatic ecosystems, under the following two assumptions. Isotopic discrimination is negligible, which is the case for most of the elements discussed. When the element has stable isotopes, the analogy in behavior between its stable and radioactive isotopes is implicitly accepted, bearing in mind, however, that for naturally occurring elements, the chemical form and emission medium of anthropogenic discharges are likely to involve transfer pathways and processes other than those identified for the naturally stable element. The radioactive isotope(s) designated in the heading of the data sheet correspond to radionuclides of major radioecological importance, in terms of quantities and persistence in the environment. Other isotopes, whether radioactive or stable, may also be cited. The information, which is deliberately simplified, is intended to reflect the state of knowledge on the subject at the time of updating, and to propose values for the main radioecological parameters used to estimate transfers in the environment, and more particularly within the food chain

No abstract available

[en] The need for a system of radiological protection of the environment drives regulators to urge scientists on conceptualisation of methods to demonstrate that the environment is protected against radioactive contaminants. One of the major difficulties in the implementation of ecological risk assessment for radioactive pollutants is the lack of data for wildlife chronic internal exposure to alpha or beta emitters. Situations of such chronic internal exposure at low levels are likely to cause toxic responses distinct from those observed after acute exposure at high doses because of the bioaccumulation phenomena. Biochemical mechanisms can lead to a gradual accumulation of elements present at trace level in the external medium, inducing a highly localised deposit within tissues or cells. These highly localised accumulations of radionuclides, coupling radiological and chemical toxicities, particularly for heavy elements such as actinides, may give rise to particular biological responses of a cell group, capable of causing functional or structural abnormalities at higher hierarchical levels. The assessment of these bioaccumulation phenomena investigated within the ENVIRHOM programme launched two years ago at the Institute for Radioprotection and Nuclear Safety, is primordial with regard to internal exposure to radionuclides since they increase locally both the radionuclide concentration and the biological effect of the delivered dose. Gaps of knowledge within this field constitute a strong limitation to our capability to make a reasonable risk estimate. Internal doses cannot be accurately calculated and potentially associated biological effects at any organization level remain fairly unknown. As a result, derivation of ecologically relevant and knowledge-based predicted no-effect concentrations becomes a critical issue in ERA. The scope of this paper is to illustrate the relevance of the development of a greater depth of understanding of radionuclide fate and biological effects at several hierarchical levels to support quantitative risk assessments with defined and acceptable uncertainty bounds. (Author) 15 refs

No abstract available

[en] 40 rats with a body weight of 100 g received 7 semisynthetic diets with different contents of glutamic acid and one diet contained whole-egg. A L-amino acid mixture corresponding to the pattern of egg protein was the protein source of the semisynthetic diets. Glutamic acid was supplemented succesively from 0 to 58 mol-% of the total amino acid content. On the 8th day of the experimental feeding the animals were labelled by subcutaneous injection of ¹⁴C-glutamic acid. Subsequently the CO₂ and the ¹⁴CO₂ excretion were measured for 24 hours. In this period 64 to 68 % of the injected radioactivity were recovered as ¹⁴CO₂. The curve pattern of ¹⁴CO₂ excretion indicates two different processes of ¹⁴CO₂ formation. One characterizing the direct degradation of glutamic acid to CO₂ with a high rate constant and a second one with a lower rate constant characterizing the ¹⁴CO₂ formation via metabolites of glutamic acid. 77 % of the total ¹⁴CO₂ excretion in 24 hours resulted from the direct oxidation of glutamic acid and 23 % from the oxidation of intermediates. When ¹⁴CO₂ formation was measured 10 to 24 hours after injection of ¹⁴C-glutamic acid a positive correlation to the content of glutamic acid in the diet was observed. The intestinal tissue contributes considerably to the catabolization of glutamic acid, however, there seems to exist an upper limit for this capacity. (author)

[en] Male Wistar rats (of 60 g live weight) allotted in 10 groups were fed diets with gradually increasing lysine levels ranging from 1.4 to 7.4 g lysine/16 g N. Feed intake was restricted so much that the experimental animals did not change their live weights during the last 3 days of the 8-day experimental period. On the 7the experimental day, 4 animals of each group were injected, i. p. ¹⁴C-L-lysine, the ¹⁴CO₂-excretion being subsequently measured over a period of 2 hours. On the next day, 6 animals of each group were applied an i. p. injection of ¹⁵N-L-lysine, the urine being collected over the following 24-hour period to measure the ¹⁵N-frequency. Applying both labelling methods, an increased catabolisation of the amino acid was observed after the metabolically necessary lysine requirement had been covered. The methods are very sensitive and revealed, under the experimental conditions chosen, a lysine requirement coverage of about 3 g lysine/16 g N. The possibility of using also ¹⁵N-labelled compounds in the metabolism-oriented amino acid requirement determination is likely to facilitate the transfer of the methodology to farm animals would thus allow to study the amino acid requirement of man. The metabolism-oriented amino acid requirement determination will likewise allow to estimate exact amino acid requirement data under conditions that cannot be rated on the basis of productive yields. (author)

[en] Experimental rats received a subcutaneous injection of ¹⁴C of varying activity. The rats were then killed in groups within a period of from 2 mins to 30 mins after the injection. A certain amount of ¹⁴C activity was detected in the intestinal contents as early as 2 mins after the injection, both as free ¹⁴C leucine and in the TCE soluble portion of the intestinal contents (TCE = trichloroacetic acid). A comparison of the degree of labelling in the TCE soluble and the TCE precipitable fractions of the intestinal contents showed that the most likely way for free ¹⁴C leucine to get into the lumen of the intestine is via the pancreatic juice while that for protein-bound ¹⁴C leucine is through the proteins in the pancreatic gland. The degree of labelling in both fractions decreased very steeply from the first to the third third of the intestine. This may becaused either by absorption of the secreted ¹⁴C leucine or may be brought about by a delay in food passage through the intestine. (author)