Radioactivity in Montenegro beach sands and assessment of the corresponding environmental risk

Abstract

Activity concentrations of the naturally occurring radionuclides ²²⁶Ra, ²³²Th, ⁴⁰K and anthropogenic ¹³⁷Cs in sand samples collected from 20 renowned beaches on the Coast of Montenegro have been determined using an HPGe (high purity Ge spectrometer). The average activity concentrations were found to be 7.4, 5.2, 97.3 and 0.5 Bq kg⁻¹, respectively. For all sand samples, the radium equivalent activity has been evaluated and found to be lower than the limit of 370 Bq kg⁻¹. External and internal hazard indices were less than unity. The gonadal dose equivalent was estimated to be on average 75 μSv y⁻¹, which is about four times lower than the global average for soil (0.3 mSv y⁻¹). Calculated values of absorbed dose rates showed the range from 3.1 to 28 nGy h⁻¹, which is below the world median of average values (57 nGy h⁻¹). The effective dose rate in the range from 3.8 to 34.4 μSv y⁻¹ was significantly below the recommended limit value for the public (1 mSv y⁻¹). The highest dose rate was found for the Velika Plaza locality, which also showed heavy metal contents (As, B, Cd, Hg, Cr, Cu, Mn, Ni, Pb, Zn and Ba) significantly higher than in the sand from Jaz, a locality with one of the lowest dose rates.

Keywords:

• radioactivity
• radioactive nuclides
• sand
• gamma doses
• environmental risk
• Montenegro

Acknowledgements

The authors gratefully acknowledge the financial support of the Ministry of Science of Montenegro. They also thank the two anonymous reviewers for improving the manuscript.