Transfer factors of Polonium from soil to parsley and mint

Transfer factors of 210Po from soil to parsley and mint have been determined. Artificial polonium isotope (208Po) was used as a tracer to determine transfer factor of Po from soil to plant in pot experiments. Two plant growing systems were used for this study namely, an outdoor system and a sheltered system by a polyethylene tent. 208Po and 210Po were determined in soil and different parts of the studied plants (stem and leaf), using alpha spectroscopy. The results have shown that there was a clear uptake of 208Po by roots to leaves and stems of both plants. Higher values of transfer factors using the 210Po activity concentrations than the 208Po activity concentration were observed. Transfer factors of 210Po from soil to parsley varied between 20 × 10−2 and 50 × 10−2 and 22 × 10−3 and 67 × 10−3 in mint, while 208Po transfer factors varied between 4 × 10−2 and 12 × 10−2 for parsley and 10 × 10−2 and 22 × 10−2 in mint. Transfer factors of Po were higher in those plants grown in the sheltered system than in the open system; about 75% of Po was transferred from atmosphere to parsley parts using the two systems. Ratios of transferred Po from soil to mint stem and leaf in the sheltered system were higher by 2 times from those in the open system.