137Cs contamination over Transylvania region (Romania) after Chernobyl Nuclear Power Plant Accident

- Transylvanian (Romania) soil 137Cs concentration has an average of 8.3 ± 0.2 kBq m2.
- Values range between 0.4 ± 0.1 kBq m− 2 and 301.1 ± 3.0 kBq m− 2.
- More elevated values are measured in mountain areas (18.3 ± 0.6 kBq m− 2).
- Eastern slope exposure samples received the highest average (27.8 ± 0.5 kBq m− 2).
- Two hotspots: Iezer-Ighiel (72.7 ± 5.9 kBq m− 2) and Tulgheș (51.5 ± 0.6 kBq m− 2).

Following the radionuclide releases due to Chernobyl Nuclear Power Plant accident, various studies were completed by researchers all over the world in order to measure the surface contaminations by artificial radionuclides. The aim of this study was to evaluate 137Cs surface contamination and to create an inventory distribution for Transylvania region (Romania) after the Chernobyl event using γ spectrometric measurements on soil samples collected from 153 locations. The results were compared to measured data from the Danube Delta and Moldova Republic, as well as to 137Cs concentrations from the rest of Europe reported by literature. The 137Cs surface concentrations in soil samples ranged between 0.4 ± 0.1 kBq m− 2 and 301.1 ± 3.0 kBq m− 2, having an average of 8.3 ± 0.2 kBq m− 2, with more elevated values in the mountain areas (18.3 ± 0.6 kBq m− 2) compared to the hills and plains (2.6 ± 0.1 kBq m− 2). Taking into consideration the cardinal regions, the northern and western regions received the least amount of 137Cs (2.9 ± 0.1 kBq m− 2), while the southern part received 16.3 ± 0.6 kBq m− 2. Sampling points with eastern slope exposure received the highest average (27.8 ± 0.5 kBq m− 2), while southern, north-western and north-eastern ones received less than 8 kBq m− 2. Two hotspots are reported at Iezer-Ighiel (72.7 ± 5.9 kBq m− 2) and Tulgheș areas (51.5 ± 0.6 kBq m− 2).

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