A simple method for the determination of90Sr by using thin layer chromatography on silica gel or cellulose pretreated with calcium oxalate is proposed. In these conditions a complete separation between strontium and its daughter yttrium is obtained. Radioactivity of separated elements was measured by a linear multiscanner analyzer and the results were computer processed to obtain the activity of90Sr. The method has been applied to samples of water and milk subjected to a very simple extraction procedure. Under the experimental conditions used, the detection limit is about 25 mBq of deposited radioactivity, which corresponds to about 6 Bq/l.
Since April 29, 1986, the radioactive contamination resulting from the accident of the Chernobyl reactor has been measured in various kinds of matrixes, with particular regard to Northern Italy. Here we present the data obtained for137Cs from several measurements effected on milk and dairy products over the period of one year. In particular, we have studied the transfer kinetics of137Cs from forage to milk by feeding dairy cows with forage of known activity and we have evaluated the body Cs absorption by measuring the percentages of Cs eliminated with milk as well as with urine and feces. Further, the decay rate of137Cs in milk has been assessed and the results of the kinetic, analysis are reported. We have also evaluated the efficacy of various clay materials in removing Cs from milk. Here we report the results of adsorption kinetics for the grey clay which resulted the most effective material.
The Chernobyl fallout was estimated in Emilia-Romagna, a Northeastern region of Italy. Nuclide composition of airborne and the time evolution of the radioactivity were investigated. The comparison of the activity ratio of103Ru to137Cs allows to conclude that Italy was not influenced by the first release. The trend of the total activity and137Cs percentage in rain water was very similar to those of air particulates. A calculation model to estimate137Cs deposition onto the ground has been developed and validated by comparison of the calculated and experimental values for soil samples. The activity range was 2–40 kBq ·m–2.
Authors:E. Gattavecchia, D. Tonelli, A. Breccia, A. Fini, and E. Ferri
Radio TLC has been used for determining the radiochemical purity and composition of two99mTc-radiopharmaceuticals, available as kits and commonly used for diagnostic imaging. Moreover, the same technique has been applied to detect impurities which decrease the specific activity of131I-derivatized dermatan sulfate, a new potential radiopharmaceutical, and for establishing the best labeling conditions.
Authors:D. Tonelli, E. Gattavecchia, S. Ghini, C. Porrini, G. Celli, and A. Mercuri
Samples of honey, pollen and honey bees have been collected in some regions of Italy after the Chernobyl accident, and subjected to gamma spectrometry in order to assess their possible use as markers of the radioactive environmental contamination. Pollen has resulted in the best indicator, since it reflects exactly the air contamination and therefore it is suitable for obtaining a map of fallout. Also bees can be used for the purpose, even if their collection is more difficult, whereas honey gives only an indication.