J. Solecki

Determination of transfer factors for 137Cs and 90Sr isotopes in soil–plant system

Studies on the determination of transfer factors (TF) for 137Cs and 90Sr isotopes from soil to plant are presented. Experiments were performed on grass from meadows of Bug river valleys and vegetables from Zwierzyniec region. The influence of potassium and calcium on the transfer factor of both isotopes is discussed.

90Sr and 137Cs radioisotopes and heavy metal concentrations in pharmaceutical herbal plants from the Lublin (Poland) region

Radioactivity of 90Sr and 137Cs in several species of herbs collected at Fajsławice and Góra Puławska located in Lublin (Poland) region was examined. Depending on the type of herb the radioactivity of strontium ranged from 0.004 to 1.808 Bq/kg dry weight whereas that from cesium varied from 0.053 to 9.853 Bq/kg. Calculated transfer factors of the radioisotopes in the plants studied revealed much stronger accumulation of strontium than cesium. Concentration of calcium and potassium in these plants has no influence on the concentration of measured radioisotopes.

Studies on soil samples mineralization conditions preceding the determination of 90Sr

Some results of the extraction of strontium and yttrium from soil samples by concentrated nitric acid are described. The concentration of Sr and Y in the solid was determined by XRF method. The results obtained allowed to elaborate the conditions of acid leaching and to propose an analytical procedure for the determination of 90Sr in samples without their total dissolution.

THE EXAMINATION OF GAMMA-EMITTER CONTAMINATION LEVEL OF THE LICHENS FROM EASTERN AND SOUTH-EASTERN POLAND, COLLECTED IN THE YEARS 1949-1996

The results of investigations of the level of contamination by γ-radioactive isotopes of lichens fromParmeliaceae family, collected in the years 1949–1996 are presented. The most important isotope, occurring in significant amount was137Cs. From the natural isotope group also40K,226Ra,210Pb,234Th and214Bi were found in few samples. Starting from 1956, the137Cs isotope is detected in all collected samples with two distinct maxima in 1963 and 1989. Taking into accunt the age of the collected lichens, their activity and the level of the radioactivity fall-out, the full correlation of the obtained results with the amount of the radioactive fall-out is observed.

Radiochemical contamination of bottom sediments of some natural and artificial lakes of Middle East Poland

An investigation of the presence of some radioactive isotopes in the bottom sediments of two lakes, Piaseczno and Masluchowskie (Middle East of Poland) has been performed. Similar measurements were done at the Zalew Zemborzycki artificial water reservoir, filled up few years after the most intensive period of atmospheric nuclear explosions. It was estimated, that the concentration of radionuclides, especially of artificial origin was much greater in natural lakes than in examined artificial one. That testifies for an accumulation of radioactive substances on the bottom of the water tanks. The confirmation of this thesis may be the fact, that 85% of137Cs detected in Zalew Zemborzycki comes from Chemobyl fallout while in natural lakes this isotope amounts only to 56–60%. Other isotopes, such as210Pb,226Ra, and224Ra were detected in significant amounts. The radioactivity of239,240Pu isotopes reaches 2.2–2.6 Bq/kg for the lakes and 0.7 for Zalew Zemborzycki. The238Pu to239,240Pu ratio suggests, that detected plutonium comes from world fallout.