Radiological risk assessment of natural radionuclides in the marine ecosystem of the northwest Mediterranean Sea

Abstract

Purpose: This study aimed to assess the radiological risk of natural radionuclides (²²⁶Ra, ²³²Th, and ⁴⁰K) to marine ecosystem biota.

Materials and methods: The study site in this was the Mediterranean Sea, Cyprus. With the use of the RESRAD-BIOTA (RESidual RADioactivity BIOTA) code, the tissue concentration, external and internal dose rate of aquatic animals and riparian animals were estimated.

Results: The total tissue concentrations of the aquatic animals and riparian animals were simulated at 1.14 × 10⁶ Bq/kg (water media) to 0 Bq/kg (sediment media), and 1.33 × 10⁶ Bq/kg (water media) to 9.79 × 10¹ Bq/kg (sediment media), respectively. The total dose rate for aquatic animals and riparian animals was ranged from 1.94 × 10^-2 to 0 Gray per day (Gy/d) and 1.46 × 10^-2 to 7.40 × 10^-7 Gy/d, respectively.

Conclusions: Based on the risk assessment of this study, there is no significant impact due to organisms' exposure to natural radioactivity. Although, further consideration of the exposure levels is required due to the potential effects of protracted low-level ionizing radiation.

Keywords: RESRAD-BIOTA; Radiological risk; marine ecosystem; sediment; tissue concentrations.