Competitive biosorption of thorium and uranium by Micrococcus luteus

Lichens, sampled around Chernobyl in 1990 and in Slovenia in 1992, were analyzed for radionuclides and elements, including Cs. Data were processed by Monte Carlo aided Target Transformation Factor (MCTTFA). The resulting factors indicate environmental accumulation routes. ⁴⁰K : K and ²¹⁰Pb : Pb ratios tested the procedure, showing fully mixed ⁴⁰K and K, while for ²¹⁰Pb and Pb the expected variability in specific radioactivity was confirmed. ¹³⁷Cs showed a large factor-specific variability in ¹³⁷Cs : Cs ratios. For the 1990 data, MCTTFA singled-out ¹³⁷Cs in a separate factor, suggesting that the overall behavior of ¹³⁷Cs cannot be derived from that of Cs: source (route)-related specific radioactivity makes that all individual transport-components should be taken into account.