Methods, results and dose consequences of 106Ru detection in the environment in Budapest, Hungary.

Abstract From late September to early October of 2017, the majority of European networks involved in environmental radiological monitoring – including the environmental monitoring system of the KFKI Campus in Budapest – detected 106Ru isotope of artificial origin in the atmosphere. The reported values higher than the minimum detectable activity (MDA) concentrations were in the range of 0.8 μBq/m3 – 145 mBq/m3. Based on the results of environmental measurements and the available meteorological data, assessments were made to analyze concentration levels of 106Ru activity and to help understand the behavior of radioruthenium in various environmental media. Evaluation of the daily variation of activity levels indicated a maximum of 4 day-long residence time of 106Ru contamination presence in ground level air in Budapest. An average 106Ru activity concentration of 25.6 ± 1.4 mBq/m3 have been observed for the estimated residence time of 106Ru in the air. Deposition of 106Ru was dominantly influenced by rainfall, the major contributor wet deposition which led to an average of 11.3 ± 1.3 Bq/m2 deposition on the ground surface prior to plume passage. Graphical abstract Image 1 Highlights • 106Ru was detected solely in the atmosphere over Europe in the fall of 2017. • Measurement of low-activity, pure β-emitter 106Ru required advanced methods. • 106Ru was detectable in air, deposition, grass, transfer between the elements was shown. • Temporal variation of 106Ru activity indicated short residence time of the plume. • Effective dose in residence time was <0.2 μSv from major contribution of inhalation. [ABSTRACT FROM AUTHOR]