Radionuclides in the adriatic sea and related dose-rate assessment for marine biota

Non-corresponding contaminants in marine surface sediments as a factor of ARGs spread in the Sea of Azov

The present study aims to analyze the level and total toxicity of the most common pollutants in surface sediments and assess their impact on the occurrence of antibiotic resistance genes (ARGs) in the Sea of Azov. Biotesting using the whole-cell bacterial lux-biosensors showed high integral toxicity of surface sediments and the presence of genotoxicants and substances that cause oxidative stress and protein damage. Using cluster analysis, it was shown that the distribution of pollutants in the Sea of Azov depends on the type of surface sediments. The relative abundance and distribution of 14 ARGs in surface sediments were shown. Principle component analyses results suggest that non-corresponding contaminants do not exert direct influence on the ARGs abundance in the surface sediments of the Sea of Azov. Thus, the need to investigate the significance of non-corresponding pollutants in the selection and distribution of ARGs in the aquatic environment remains a pressing problem.

The anthropogenic radiotoxic element of 137Cs accumulate to biota in the Mediterranean Sea

The abundance of ¹³⁷Cs radionuclide in the Mediterranean Sea has limited study despite its environmental effects in seafood chains. For this purpose, the activity concentration of ¹³⁷Cs in sediment and seawater have been determined using a high-resolution HPGe gamma-spectrometry system. The average activity concentrations in sediment and water were 14.16 Bq kg^-1 and 1.74 mBq L^-1, respectively. The results were used as input data of ERICA Tool modelling software to assess marine organisms' accumulation and dose. The highest and lowest accumulate activity concentration values were observed in birds (9.24E-01 Bq kg^-1) and the Vascular plant (1.37E-02 Bq kg¹), respectively. The total dose rate value was ranged between 1.94E-06 μGy h^-1 (Phytoplankton) to 4.70E-03 μGy h^-1 (Polychaete worm). The total dose rates of ¹³⁷Cs to the selected organisms were all <0.001 μGy h^-1, and there is no significant risk to marine biota in the study area.

Mobile underwater in situ gamma-ray spectroscopy to localize groundwater emanation from pockmarks in the Eckernförde bay, Germany

Eckernförde Bay in the Baltic Sea is well-known for the pockmarks areas which are located in the centre and off the southern shore-line of the bay emanating groundwater in a non-continuous but episodic way. Mobile underwater in situ gamma-ray spectroscopy is exploited proving that both ²¹⁴Bi and ⁴⁰K are efficient radiotracers for localization of seepage areas whenever either sediment is in mixture with the emanating fluid or resuspension of surface sediment occurs as a side effect of the fluid emanation.

Occurrence of 210Po in marine macroalgae inhabiting a coastal nuclear zone, southeast coast of India

The activity concentration of ²¹⁰Po in 26 species of marine macroalgae found along coast near to a nuclear installation in southeast coast of India was studied. Phaeophytes were found to accumulate the maximum ²¹⁰Po concentration and chlorophytes the minimum. The average ²¹⁰Po activity concentration values in the three groups were 6.2 ± 2.5 Bq kg^-1 (Chlorophyta), 14.4 ± 5.2 Bq kg^-1 (Phaeophyta) and 11.3 ± 3.9 Bq kg^-1 (Rhodophyta). A statistically significant variation in accumulation was found between groups (p < 0.05). The un-weighted dose rate to these algae due to ²¹⁰Po was calculated to be well below the benchmark dose limit of 10 μGy h^-1.