Bioaccumulation of natural radio-nuclides in aquatic, riparian and terrestrial animals along Suez-Azzafrana coastline, Egypt: insights from RESRAD-BIOTA

Abstract

Purpose The protection of endogenous species is one of the important ecological issues in which all the World Environmental Agreements are searching for. The purpose of the study is to calculate the bioaccumulation impacts of some natural radio-nuclides as: Ra-226, K-40 and Th-232 in the selected Egyptian Endogenous Aquatic Red Sea Fusileer fish, Red sea Riparian Turtle and the Red sea Terrestrial Lizard by using RESAD BIOTA version 1.8. Material and methods Ten water and sediments samples were collected from different 10 sites, along the inshore of the Egyptian Suez bay beach till El-Zafarna coastal region, as these samples were taken from subsurface (20 cm–1 m). The radioactivity concentrations of some natural radioactivity radionuclides as; 226Ra, 232Th and 40K, which were measured, using gamma-ray spectrometer based on high-purity germanium (HPGe) detector of 40% relative efficiency. Results The results of the study showed that the radioactivity of some selected natural radionuclides in the selected 10 sites of Suez costal samples were arranged as: K-40 > Th-232 > Ra-226, as this was related to the characteristics of soil and rock precipitation in this zone besides the industrial activates along the selected coastal line zone of Suez bay till Al-Zafrana. On the other hand, it was observed that all the calculated Biota contamination Guide (BCG) values of the selected Egyptian endangerous species (Aquatic, Riparian and terrestrial) animals in the 10 selected sites samples were below the recommended (BCG), as the result, no radioactivity increment being detected at these selected sites. On the other hand, the BCG values of Ra-226 in both water and sediment samples for the selected Egyptian endangerous Aquatic Sea Fusileer Fish were higher than the recommended BCG values in water, while were comply with BGC values of the sediment, while in case of Egyptian endangerous Red Sea Turtle’s BCG values were comply with the recommended BCGs in water while were higher than the recommended BCGs values of sediment. In case of the selected Egyptian endangerous terrestrial Lizard its BCG values of Ra-226 were higher than the recommended BCGs in both water and sediment media. While in case of Th-232 it was observed that the BCG values of selected endangerous Red Sea Fusileer Fish were higher than the recommended BCGs in both water and sediment and also the BCG values of selected endangerous Riparian Turtle were also higher than the recommended BCGs of both water and sediment, these results may increase the suitability of the selected Egyptian endangerous Marine, Riparian and Terrestrial species to the different radiological risks. The results showed also the decrement of the radioactivity values of the measured radionuclides in the internal tissue of the Egyptian selected endangerous Red Sea Lizard (Uromastyx aegyptia) than both the selected endangerous Red Sea Turtle and Red Sea Fish species, support the reptiles, which are cold blood animals, and is less affected by gamma radiation than other terrestrial animals.