Impact assessment of radioactive contamination of the environment on population in existing exposure situations

Full text: Introduction: In the paper the existing exposure situation at Eleshnitsa - a part from of the former shutdown uranium mining industry in Bulgaria has been presented. To assess the impact on the population, stations near populated areas were investigated. The radiation parameters of air, water, bottom sediments and vegetation from this area were studied and the radiation risk for population was estimated. Materials and methods: The radiation parameters of air, water, bottom sediments and vegetation from this area are studied and the radiation risk for population was estimated using mathematical models of irradiation. Analyzed water samples from 21 observation points, including 13 of surface water and 8 of groundwater (including 6 adit and 2 piezometers) and bottom sediments samples from 10 observation points. The bottom sediments were gamma spectrometric analyzed for determination of natural radionuclides and radiochemical water samples for determination of the specific concentration of natural Uranium, Radium and determination of total alpha and beta activity. Results: Uranium - 238 and Radium - 226 in the studied bottom sediments ranged respectively from 52 to 794 Bq/kg, and from 38.5 to 211 Bq/kg. The concentration of natural Uranium in the water sample is less than 0,3 to 57,07 Bq/l, and Radium - 226 from 0.05 to 0,5 Bq/l. Ratio 238U/226Ra for bottom sediments is from 1.0 to 9.7 , and for water – from 7 to 295. The values of the ratio 238U/226Ra in water respectively Ra motility are many times higher than those in the bottom sediments. The estimated risk for use of water is approximately equal to 102. Conclusion: The factor causing the external and internal exposure of the population in uranium mining areas is liquidated with the closure of uranium mining industry in Bulgaria, but mine waters continue to determine the radiation contamination of the environment, which determines the high risk for the population in the area