Radioactivity Levels and Radiation Hazard in Sands from Cuban Beaches

Abstract

This study assesses the natural radioactivity levels of ²²⁶Ra, ²³²Th, and ⁴⁰K in sand samples from six Cuban white-sand beaches to evaluate potential radiological risks. Samples were analyzed using high-resolution gamma spectrometry after a one-month equilibrium period. Activity concentrations were determined via key gamma transitions of daughter nuclides. Results show that all measured values of activity, radium equivalent (R_aeq), absorbed dose rate (D_R), and gamma index (I_γ) are below internationally recommended safety thresholds. La Coloma beach exhibited the highest ²³²Th activity, slightly exceeding the global mean, but still within safe radiological limits. The calculated gamma index values (0.04–0.52) and dose rates (3–33 nGy·h⁻¹) confirm minimal radiological risk. This work provides a radiological baseline for Cuban beach sands and supports the need for further studies in other major resort areas across the island