Root uptake of Cs-137 and Sr-90 by rye-grass on various soils in the CIS

Caesium-137 and Sr-90 were measured in samples of rye-grass and soil collected during 1992 from field plots at seven experimental sites in Belarus, Russia and Ukraine contaminated by fallout from the Chernobyl accident in 1986. On five soddy podsolic mineral soils, the concentration ratio (CR) (Bq kg(-1) dw rye-grass/Bq kg(-1) dry soil to 10 cm) for always exceeded that for Cs-137 but on one peaty soil, the CR for exceeded that for Sr-90. On a second peaty soil, both CRs were small and probably very similar. The CRs for Cs-137 on the miner al soils ranged from 0.05 to 0.39 and from 0.65 to 0.90 for Sr-90. On the pear soils, the ranges were 0.05 to 0.76 and 0.11 to 0.38, respectively. On the mineral soils, the lowest values of CR were found at a site still heavily contaminated with fuel particles at the time of sampling. (C) 1997 Elsevier Science Ltd.