Ecological risk assessment for a former radium production site in Komi Republic, Russia

Extensive human activities in both nuclear and non-nuclear industries resulted in large number of areas polluted by technologically enhanced naturally occurring radioactive material all over the world. Protection of non-human biota inhabiting those areas from the effects of ionizing radiation has become an important issue in radiological protection. The Vodny site in Komi Republic of Russia is one of the longest radiologically exposed sites in Europe. Twenty-five years of radium production from groundwater and uranium ore, has resulted in contamination of this area with radionuclides and heavy metals. Measurements on Ge-detector, ICP-MS and sequential extraction were used to estimate radionuclide concentrations in the samples collected at the site. Calculation of doses that might be received by biota was performed using the ERICA Tool. Activity concentrations of Ra-226 in the soil samples were ranging from 164 to 11400 Bq/kg soil (dw). The highest estimated doses were observed in lichens and bryophytes (334 μGy/h) followed by soil invertebrates, flying insects and detrivorous invertebrates (150 μGy/h). Internal dose from Ra-226 was the main contributor to the total dose to all reference organisms. Mass concentrations of uranium in the soil samples ranged from 0,43 to 18 mg/kg soil (dw) and did not exceed predicted no-effect concentrations. There was no sufficient data to assess bioavailability of radionuclides in soil samples