Radioactivity level in relation to geological substrate: dynamics of natural and artificial radionuclides on Teucrium montanum L. (Lamiaceae) habitats.

There are no results of comparative ecological studies of the radionuclide activity concentration in the plants and soil in relation to geological substrate. Presented research encompasses the comparative analysis of the concentration of four radionuclides, three natural (40K, 226Ra, 232Th) and one artificial (137Cs) in soil samples and aerial plant parts of Teucrium montanum from different natural habitats on serpentinite and calcareous geological substrate. The activity concentrations of radionuclides were measured with high purity germanium (HPGe) detector and expressed as Bq kg-1. The calculated activity concentrations of 40K, 226Ra, 232Th, and 137Cs in soil samples from serpentinite/calcareous habitats are in range 39.6-91.0/59.3-1018.8, 1.7-5.5/4.3-52.4, 2.4-10.9/5.9-72.9, and 57.2-844.9/29.6-701.5 Bq kg-1, respectively. The activity concentrations of 40K, 226Ra, 232Th, and 137Cs in plant samples are in range 152.9-445.9/228.0-521.4, n.d.-1.2/0.6-5.6, n.d./0.2-0.9, and 1.0-46.4/1.7-7.0 Bq kg-1, respectively. The obtained results showed that the quantities of 137Cs are greater in the soil and plant material from the serpentinite habitats, while quantities of 40K, 226Ra, and 232Th are greater in the soil and plant material from calcareous habitats. In general, the level of radioactivity in plants and soil depends on the type of the geological substrate. The content of radionuclides in plants is correlated with the radionuclide content in the soil. In addition to other specifics in physical and chemical properties, serpentinite habitats are characterized by an increased amount of Cs in the soil, which causes an increased amount of this radionuclide in plants such as Teucrium montanum.