Phytoabsorption of radium-226 from technogenically contaminated soils by the example of Chamaenerion angustifolium, Lathirus pratensis and L. vernus

The absorption of radium-226 by Chamaenerion angustifolium, Lathirus pratensis and L. vernus from podzolic soil contaminated with solid radioactive dumps (site 1) and alluvial sod soil contaminated with radioactive water (site 2) has been studied. The concentration of radium was 0.18-63.4 Bq/g of ashed weight (AW) in soil of site 1 and 0.05-21.4 Bq/g of AW in soil of site 2. The univariate analysis of variance did not reveal interspecific differences in the accumulation of the radionuclide by plants. However, the content of radium in plants selected from the area with dumps was higher than in the area contaminated with radioactive waters. Thus, the concentration of radium was 1.08-11.67 and 0.64-8.86 Bq/g of AW for C. angustifolium and L. vernus growing in the site 1 and 0.04-3.35 and 0.04-3.78 Bq/g of AW for C. angustifolium and L. pratensis sampled at site 2. The content of mobile (watersoluble and exchangeable) forms of radium in the soils of both sites was significantly indistinguishable. The obtained results showed that the concentration of radium in the studied plant species depends most on its total content in the soil and, to a lesser extent, on the content of its mobile forms. Multiple regression analysis showed that the total content of radium in contaminated soils depends to the greatest extent on the content of organic matter and phosphorus in them. The content of radium mobile forms is associated with the content of organic matter, as well as exchangeable cations of calcium and magnesium. The correlation between radium content in the plants and these alkali-earth elements was not confirmed. Among the most significant factors which affected radium adsorption by plants was the content of organic matter, phosphorus, potassium, the ratio of physical sand and physical clay.