Soil to plant uptake of fallout 137Cs by plants from boreal areas polluted by industrial emissions from smelters

To study the impact of industrial pollution on the soil-to-plant uptake of fallout-radiocesium in a boreal forest ecosystem, four study sites were selected at distances of 7, 16, 21 and 28 km from the large copper-nickel smelter at Monchegorsk on the Kola Peninsula (Russia). At each site, soil and selected plant species were sampled from five plots and analysed separately for Cs-137 and K-40, The data show that the root-uptake of Cs-137, as characterised by the median aggregated transfer-factor T-ag, decreased significantly (P < 0.05) with decreasing distance from the smelter for the plants Vaccinium myrtillus (from 0.023 to 0.007 m(2) kg(-1)) and Empetrum nigrum (from 0.015 to 0.007 m2 kg(-1)), but increased for Deschampsia flexuosa (from 0.013 to 0.031 m(2) kg(-1)). For Vaccinium vitis-idaea a significant trend for the T-ag was not observed. The median K-40 activity concentrations in these plants also decreased significantly (P < 0.001) with decreasing distance from the smelter for Vaccinium myrtillus (from approx. 140 to 20 Bq kg-l dry wt.), Empetrum nigrum (from approx. 90 to 40 Bq kg-l dry wt.), and also for Deschampsia flexuosa (from approx. 270 to 40 Bq kg-l dry wt.). For Vaccinium vitis-idaea such a continuous significant trend was not observed. The results for the Cu-Ni polluted soils thus show: (1) that the soil-to-plant transfer of radiocesium can be significantly modified; (2) that these modifications are quite specific; and (3) that modifications of the uptake of potassium do nor always correspond to those of radiocesium. (C) 1999 Elsevier Science B.V. All rights reserved.