Investigation into the radioactivity of various natural and anthropogenic radionuclides in marine sediments from the Sudanese coastline of the Red Sea

A total of sixty surface sediment samples were systematically obtained from ten distinct locations along the Sudanese coastline of the Red Sea during the summer season (June 2016) and the winter season (February 2017), subsequently analyzed using high-purity germanium (HPGe) gamma spectrometry. The activity concentrations of natural radionuclides (⁴⁰K, ²²⁶Ra, ²³²Th) as well as the anthropogenic radionuclide (¹³⁷Cs) were quantified. During the summer, the concentrations recorded were as follows: ⁴⁰K = 219 ± 169 Bq/kg, ²²⁶Ra = 6.94 ± 3.59 Bq/kg, ²³²Th = 6.32 ± 3.13 Bq/kg, and ¹³⁷Cs = 1.89 ± 1.15 Bq/kg. The relatively large standard deviation, particularly for ⁴⁰K, reflects spatial variability among the different sampling locations. The values recorded during the winter season exhibited a slight reduction. The highest activity levels were detected at Port Sudan Harbor, likely attributed to the influence of industrial activities and the composition of sediments. Correlations among the radionuclides suggest analogous geochemical behaviors. The radiological hazard indices, including Ra_eq and AEDE, were found to be substantially lower than global safety levels. No indications of recent anthropogenic inputs of ¹³⁷Cs were identified, supporting prior findings within the region. This study contributes updated baseline data and facilitates a comparative analysis with previous research conducted in both Sudanese and neighboring Red Sea locales.