Assessment of Natural Radioactive Elements and Health Risk Values in Imported Cocoa Samples at Some Libyan Markets

Abstract

This study investigated the presence of natural radioactive isotopes in imported cocoa samples collected from Derna, Libya, using gamma-ray spectrometry with a Sodium Iodide (NaI) detector. The analysis focused on the activity concentrations of radionuclides such as ²²⁶Ra, ²³⁸U, ²³²Th, and ⁴⁰K. The average activity concentrations were 46.96 Bq/kg (²²⁶Ra), 49.77 Bq/kg (²³⁸U), 53.57 Bq/kg (²³²Th), and 123.75 Bq/kg (⁴⁰K). Values for ²²⁶Ra, ²³⁸U, and ²³²Th exceeded the global recommended limits, while ⁴⁰K remained below the permissible limit. The absorbed dose rate (DR) ranged from 42.42 to 80.50 nGy/h, with an average of 58.27 nGy/h, lower than the global reference of 84 nGy/h. Internal and External annual effective doses were 0.29 mSv/y and 0.07 mSv/y, respectively, both within safe limits. The Excess Lifetime Cancer Risk (ELCR) averaged 0.26 × 10⁻³, slightly higher than the global recommended threshold (0.29 × 10⁻³). The Annual Gonadal Equivalent Dose (AGED) averaged 0.41 mSv/y, which is above the safety limit of 0.3 mSv/y. Hazard indices (Radium Equivalent, Gamma Index, Alpha Index, Hin, Hex) were all below international safety limits, indicating no immediate health risk.