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

Abstract 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 137 Cs and 40 K. The data show that the root-uptake of 137 Cs, as characterised by the median aggregated transfer-factor T ag , decreased significantly ( P Vaccinium myrtillus (from 0.023 to 0.007 m 2 kg −1 ) and Empetrum nigrum (from 0.015 to 0.007 m 2 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 40 K activity concentrations in these plants also decreased significantly ( P Vaccinium myrtillus (from approx. 140 to 20 Bq kg −1 dry wt.), Empetrum nigrum (from approx. 90 to 40 Bq kg −1 dry wt.), and also for Deschampsia flexuosa (from approx. 270 to 40 Bq kg −1 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 not always correspond to those of radiocesium.