Uptake of uranium, thorium, radium and potassium by four kinds of dominant plants grown in uranium mill tailing soils from the southern part of China

The concentrations of radionuclides in soil from uranium mill tailings in South China were analyzed. The results showed that all radionuclides in soil samples exceeded the soil background value. Through the field investigation, four kinds of dominant plants were identified. It was found that the total quantity of radionuclides in the whole plant from high to low were pokeberry, Cibotium barometz, reed and garden sorrel. We also found that Cibotium barometz had the highest transfer factor (TF) for ²³⁸U, garden sorrel had the highest TF for ²³²Th and reed had the highest TF for ²²⁶Ra and ⁴⁰K. Cibotium barometz had the highest bioconcentration factor (BF) for ²³⁸U, ²³²Th and ²²⁶Ra, and pokeberry had the highest BF for ⁴⁰K. Pokeberry had the highest phyto-remediation factor (PF) for ²³⁸U, ²³²Th, ²²⁶Ra and ⁴⁰K. On the basis of the above conclusions, pokeberry could be a candidate for phyto-remediation of radionuclide-contaminated soils. (authors)