Haematological studies on90Sr-90Y-toxicity

Summary Erythropoietic changes were observed, measured by⁵⁹Fe-uptake into red blood cells, and on radioiron turnover from blood plasma, at different time intervals (2–64 days) after treating adult female mice with varying activities of⁹⁰Sr-⁹⁰Y. Activities of 2.5 or 5.0 µCi radiostrontium per animal lead to a depression at time intervals of two and four days, at longer periods there was an overshoot. With activities of 0.5 or 1.0 µCi radiostrontium disturbances in the radioiron uptake are still observed, although these effects are not as pronounced as in experiments with higher burdens. In comparison with results obtained in experiments in which the plasma⁵⁹Fe-turnover was applied, even with an activity of 5 µCi radiostrontium per mouse, no deviation as against the untreated controls was detected.Dedicated to Prof. Dr. Hermann Muth, Homburg/Saar, on the occasion of his 65th birthday     

Basic features of seasonal and multi-year dynamics of Cs-137 and Sr-90 in wood

Basic features of seasonal and multiyear dynamics of accumulation of Chernobyl-derived 137Cs and 90Sr in wood are considered. Seasonal variation in the radionuclide concentration are shown to be more regular and predictable than the multiyear variation. Seasonal dynamics of 137Cs is opposite by trend to that of 90Sr. The multiyear dynamics of both 137Cs and 90Sr in the wood is variable and depends on chemical nature of individual radionuclide, type of landscape, kinetics of the radionuclide plant-available forms, and irreversible fixation of the radionuclides in the root-abundant soil layer.     

Sr-90 transfer factors for rye in podzolic soils: Dependence on soil parameters

The transfer factor (TF) for Sr-90 was studied in 10 rye fields with podzolic soils near Bremen. Values between 0.10 and 0.30 were obtained with a mean of 0.18. The TF was correlated with various soil parameters (pH, organic matter, K, Ca and P content). Negative correlations were found between TF and pH-value, Ca and P content. However, the content of organic matter in the soils was positively correlated with soil and grain activity (Bq/kg).     

90Sr-90Y biokinetics at incorporation determine the radiation burden to bone marrow

The decay characteristics of 90Sr-90Y ensure that the mother and daughter nuclides exist in radioactive equilibrium, unless they get discriminated on the basis of their chemical properties, as it happens during metabolism. Although bone is the ultimate organ of deposition, the two nuclides arrive at this target organ over different biokinetic pathways. As 90Y is not excreted, it goes through transient deposition in the liver before being secondarily deposited in bone. This leads to a temporary radioactive excess of 90Y in bone. Since the decay energy of 90Y is by a factor of about 4 higher than that of 90Sr, the initial radiation burden to the bone marrow is primarily due to 90Y. This was estimated in rats by implanting LiF thermoluminescence dosimeters (TLD) in the marrow cavity of the femur. By calibrating the TLD against a known source of 90Sr-90Y, the absorbed dose rates and cumulative doses were determined as a function of time after incorporation. Two routes of administration were employed and their influence on the radiation burden is also shown.     

Investigation on the asymmetrical induced yields in90Sr-90Y-beta-irradiated D- and L-alanines

This investigation was aimed to prove the asymmetrical interactions of polarized electrons from⁹⁰Sr-⁹⁰Y-beta-decay with D- and L-alanines. By use of ESR measurements, it was determined that the asymmetrical yields induced in⁹⁰Sr-⁹⁰Y-beta-irradiated alanines are 10% more in D-alanine than in L-alanine.     

Constraints on Miocene oceanography and climate in the Western and Central Paratethys: O-, Sr-, and Nd-isotope compositions of marine fish and mammal remains

The Paratethys evolved as a marginal sea during the Alpine–Himalayan orogeny in the Oligo-Miocene. Sediments from the northern Alpine Molasse Basin, the Vienna, and the Pannonian Basins located in the western and central part of the Paratethys thus provide unique information on regional changes in climate and oceanography during a period of active Alpine uplift. Oxygen isotope compositions of well-preserved phosphatic fossils recovered from the sediments support deposition under sub-tropical to warm-temperate climate with water temperatures of 14 to 28 °C for the Miocene. δ¹⁸O values of fossil shark teeth are similar to those reported for other Miocene marine sections and, using the best available estimates of their biostratigraphic age, show a variation until the end of the Badenian similar to that reported for composite global record. The ⁸⁷Sr/⁸⁶Sr isotope ratios of the fossils follow the global Miocene seawater trend, albeit with a much larger scatter. The deviations of ⁸⁷Sr/⁸⁶Sr in the samples from the well-constrained seawater curve are interpreted as due to local input of terrestrially-derived Sr. Contribution of local sources is also reflected in the ε_Nd values, consistent with input from ancient crystalline rocks (e.g., Bohemian Massif) and/or Mesozoic sediments with ε_Nd < ? 9. On the other hand, there is evidence for input from areas with Neogene volcanism as suggested by samples with elevated ε_Nd values > ? 7. Excluding samples showing local influence on the water column, an average ε_Nd value of ? 7.9 ± 0.5 may be inferred for the Miocene Paratethys. This value is indistinguishable from the ε_Nd value of the contemporaneous Indian Ocean, supporting a dominant role of this ocean in the Western and Central Paratethys.     

Functional state of the thyroid gland in sheep at a remote period after single administration of Sr-90, Pu-239 and their mixture

Five years after single intravenous injection of a mixture of 239Pu and 90Sr to semifine-wool sheep (7.4 kBq/kg + 185 kBq/kg) the iodine-fixing and hormone secreting functions of the thyroid gland were inhibited; where 90Sr alone was injected in the above dose inhibited was the hormone-secreting function only. Since 239Pu alone did not cause such alterations, the observed remote effect was attributed to the effect of the incorporated 90Sr.     

Radiologic follow-up and prognosis of efficiency of systemic Sr-89 Cl-2 therapy of bone metastases in prostate cancer

We evaluated possibilities of bone scintigraphy with 99mTc-methylendiphosphonate (99mTc-MDP) and magnetic resonance imaging (MRI) in follow-up and prediction of effect in patients with extensive bone metastatic disease treated with betha-emitter 89SrCl2. 24 patients with prostate cancer and extensive metastatic involvement of skeleton were referred for the study. 89SrCl2 was injected as single injection of 150 MBq (4 mCi), in eighteen from Amersham plc., England, as Metastron, in six--from Medradiopreparat, Russia). In all patients bone scintigraphy with 99mTc-MDP and MRI study of metastatic regions were performed before and in 3 months after 89SrCl2 injection. Patients treated with Metsatron were also studied in 6 months after injection. Quantitative analysis of data comprised count and anatomic dimensions of metastatic areas and calculation of indices [metastasis/intact bone] both for scintillation count of 99mTc-MDP bone scans and signal intensity of T1-weighted MRI scan. Henceforth, we conclude the data of bone scanning with 99mTc-MDP and of MRI give evidencies for significant regress of bone metastases in patients treated with 89SrCl2 besides symptomatic suppression of pain syndrome. 99mTc-MDP bone scanning is also of predictive value for the prognosis of therapeutic effect of systemic radiotherapy with 89SrCl2 in prostate cancer.     

Haematological studies on90Sr-90Y-toxicity: II. Femoral CFU-s kinetics and mitogen response of spleen cells

Summary Ferrokinetic perturbances in peripheral blood of mice treated with⁹⁰Sr-⁹⁰Y were demonstrated previously. This paper deals with the effects of⁹⁰Sr-⁹⁰Y treatment (2.5, 5, and 10 µCi/mouse), on the haemopoietic stem cell compartment and on the immune-status. The frequency and kinetics of haemopoietic stem cells in femoral marrow (determined as colony forming units in spleen, CFU-s) and their haemopoietic efficiency (as gauged by⁵⁹Fe-and¹²⁵IUdR-uptake) were estimated. The responsiveness of splenic lymphocytes of the same animals to mitogens (Con A, PHA, and LPS) were also measured. In all assays striking dose-dependent changes marked either by depressions or overshoots were observed during the first week post-incorporation. These are correlated with the pattern of deposition (primary and secondary) of the radionuclides⁹⁰Sr-⁹⁰Y. Towards the end of the period of observation and presumably thereafter, the dependence on dose disappeared and the values remained subnormal. An exception to this was the response of splenic lymphocytes to mitogens. Much higher reactivity was recorded up to the end. This higher reactivity is attributed to augmented cellular turnover, the newly recruited lymphocytes (in accord with their extreme radiosensitivity), being probably more reactive.     

Regulation of acidity of arable lands contaminated by Sr-90: analysis of cost of the averted doses of irradiation of population of Belarus

Results of researches on study of efficiency of soil acidity optimization on decrease of a collective doze from 90Sr to the population of Belarus are presented. On the basis of the "cost--benefit" analysis it is shown, that the savings for averted collective doze due to optimization of soil acidity of arable lands on cereals amount to 21-170 thousand US dollars per 1 man.-Sv depending on density of 90Sr soil contamination of districts of Belarus. It is established, that high effect on averting of collective doze 90Sr at cultivation of cereals can be expected at liming of sod-podsolic loamy sand soils with contamination density of 90Sr more than 12 kBq/m2, sand soils more than 16 kBq/m2, light loam soils more than 17 kBq/m2, at present time share of these lands in Belarus is about half from the area of the arable lands contaminated with radiostrontium - 86 thousand hectares.