TITLE
RADIOLOGICAL PROFILE OF PUBLIC DRINKING WATER FOUNTAINS IN NIKOLAEVKA, BULGARIA
AUTHOR(S)
Daniela Toneva*, Desislava Dimitrova, Iva Vasileva
ABSTRACT
This study provides a detailed radiological characterization of groundwater from public fountains in Nikolaevka, Varna Region (Bulgaria), using high-sensitivity γ-spectrometric analysis. Samples collected in July 2025 were analyzed for natural radionuclides (Ra-226, Pb-210, K-40, U-235, Th-234, Bi-214) and anthropogenic isotopes (Cs-137, Cd-109). Moderately elevated Ra-226 (4.5–6.0 Bq kg⁻¹) and Pb-210 (5.1–6.4 Bq kg⁻¹) activities indicate a natural origin from uranium-bearing sedimentary formations. The estimated annual effective dose from direct consumption remains below the WHO guideline of 0.1 mSv yr⁻¹, though cumulative exposure, particularly to Ra-226 and Pb-210, may pose a long-term risk under exclusive water use. Slight but consistent differences between public drinking-water fountains reflect lithological and hydrogeological heterogeneity within the aquifer system. These results highlight the need for systematic monitoring and targeted management of unregulated water sources to ensure safe water supply in rural communities.
DOI
How to cite this article:
Daniela Toneva*, Desislava Dimitrova, Iva Vasileva, RADIOLOGICAL PROFILE OF PUBLIC DRINKING WATER FOUNTAINS IN NIKOLAEVKA, BULGARIA, UNITECH – SELECTED PAPERS - 2025