Biogeochemical behavior of ²¹⁰Po in the aquatic ecosystem of the North Crimean Canal and adjacent irrigated soils

The main objectives of this study were to investigate the distribution features of the ²¹⁰Po in abiotic (water and bottom sediments) and biotic (zooplankton, mollusks, fish) components of the North Crimean Canal (NCC) aquatic ecosystem and adjacent irrigated soils as well as assessment of the doses received by water organisms from α-radiation of absorbed ²¹⁰Po. The samples were processed using standard radiochemical methods accepted in international practice. The activity of ²¹⁰Po in the samples was measured using the alpha-spectrometric OCTETE Plus complex (ORTEC-AMETEK, USA). The measurement error did not exceed 20%. Activity concentration of ²¹⁰Po in the studied objects decreased in the following rank: suspended matter (73.6 Bq/kg d.w.) > soils (32.5 Bq/kg d.w.) ≈ bottom sediments (32.1 Bq/kg d.w.) > mollusks (23.4 Bq/kg w.w.) > fish (6.4 Bq/kg w.w.). The ²¹⁰Po distribution coefficient (K_d) values in water between suspended matter and its dissolved parts varied within the 1.4 × 10⁴–1.4 × 10⁵ L/kg range. The concentration factors (CF) of ²¹⁰Po for hydrobionts of the NCC were in the range 10³–10⁴ L/kg. The calculated absorbed radiation doses from ²¹⁰Po alpha radiation for the hydrobionts of the North Crimean Canal were significantly below the recommended dose limits.