Derivation of soil to plant transfer factors of radiocesium in Northern Greece after the Chernobyl accident, and comparison with greenhouse experiments

Radiocesium contamination of cereals, due to the Chernobyl accident, was systematically studied in two selected experimental agricultural farms in Northern Greece for the years 1987, 1988 and 1989. Radiocesium contamination of all annual crops is very low, of the order of 1 Bq kg(-1), and appears to be, for the first 3 years after the Chernobyl accident, time independent, the differences lying within the experimental error. Transfer factors, relating radiocesium deposition to contamination of crops, are deduced from the experimental results. Results are also discussed in the framework of UNSCEAR's empirical model, and the corresponding parameters are deduced. In addition, greenhouse experiments show that the obtained Transfer Factors are independent of the initial radiocesium deposition and that radiocesium from the Chernobyl fallout behaves differently from usual experimental sources, such as (137)CsCl.     

A comparison of the rhizosphere-based method with DTPA, EDTA, CaCl2, and NaNO3 extraction methods for prediction of bioavailability of metals in soil to barley

A rhizosphere-based method was compared with DTPA, EDTA, CaCl2, and NaNO3 extraction methods for the evaluation of bioavailability of heavy metals in soil to barley. The extractable amounts of Cr, Cu, Zn and Cd analyzed by the rhizosphere-based method correlated significantly with the metal content of barley roots. The extractable metals identified by DTPA, EDTA, CaCl2 and NaNO3 methods exhibited relatively poor or no correlation with the metal content of barley roots. The stepwise multiple regression equation of the rhizosphere-based method was the simplest one, as no soil properties needed to be entered, whereas the equations for the DTPA, EDTA, CaCl2 and NaNO3 extraction methods always require those variables. The most distinct feature of the rhizosphere-based method was that the proposed method was suitable for acidic, neutral and near alkaline soils. In contrast, the other extraction methods were restricted to soil types. In summary, the rhizosphere-based method is the most robust approach for evaluation of bioavailability of metals in soil to barley.