Radiological statuses of Bulgarian black see shore

Full text: Introduction: In this paper own results of the radiation monitoring of the Black Sea coast - from village Shabla to village Resovo are presented. The study was carried out under a project funded by the BS ERA NET in FP7 of the European Commission, together with the project partners. Materials and Methods: Sampling was conducted in June 2012. 4 seawater samples (including depth of Varna Bay), 12 sand samples, 2 algae samples, 5 bottom sediments samples, 3 surface river water samples, 1 sea fish sample and 1 medical mud sample were examined. The samples were analyzed by gamma spectrometer for determination of the content technogenic and natural radionuclides and by radiochemical methods for defining the specific concentration of strontium- 90. A comparison between the specific activities of radionuclides in sea and river water, in the sands in sea bottom sediments in points and fractions, as well as in green and red algae. Results: The content of Cesium- 137 and Strontium -90 in the tested sea water ranged from 0.0041 (0.0007) to 0,0110 (0,0027) Bq/l and 0.00362 (0.00047) to 0,00409 (0,00049) Bq/l. The concentration of Cesium-137 in river water is ≤ 0,0012 Bq/l. The content of Potassium-40 in the sands is over a wide range from 4.9 (0.7) to 1152 (47) Bq/kg, a testament to their different origins. There is a difference in the contents of the radio-cesium into the upper and the lower fraction of the deep bottom sediment, and the various sampling points. It is clearly distinguished a selectivity of radio-cesium accumulation in red algae and they can be used for bio-indicator. Conclusion: The assessment of the radiological status of the Bulgarian Black Sea coast shows that with the exception of the beach in Vromos all investigated areas are safe from a radiological point of view. All studied coastal marine water as radiological indicators meet the quality standards set by Ordinance H-4/2012