Radiological impact assessment and dose distribution pattern in gorgan bay, Northern Iran

In this study, the specific activity of radionuclides was measured using a high purity germanium detector (HPGe) and the distribution pattern of radiological parameters and hazard indicators was plotted using Surfer and GIS software. Sediment samples were collected from the Gaz River in the mountains of Golestan province, and the central and southern part of Gorgan Bay. In the samples, the average values of specific activity of Ra-226, Th-232, K-40 and Cs-137 are 17.61, 35.91, 398.65 and 4.01 Bqkg(- 1), respectively. The highest concentration of K-40 is in the sediments of the outlet of the Gaz River, which may be due to the use of potassium fertilizers for agricultural activities in this area. The concentration of Cs-137 activity in the Bay sediment is higher than other sediments, also due to the high mobility and lightness of Cs-137, higher concentration of this radionuclide is in the quiet parts in the middle of the bay. In Gorgan Bay, the maximum of radiological parameters is in the estuary of Gaz River and in line with the water flow, the maximum level of these parameters tends to northwest. Mean radiological indices such as Ra-eq, Dose, AED(out), ELCRout and AGDE estimated as 99.67 Bqkg(- 1), 45.82 nGy/h, 0.056 mSvy(- 1), 0.197 x 10(- 3) and 329.72 mu Svy(- 1), respectively which they were all within the allowable range and not threaten the health of residents.

Automated summary

In this study, the specific activity of radionuclides in sediments from the Gaz River and Gorgan Bay was measured using a high purity germanium detector. The distribution pattern of radiological parameters and hazard indicators was plotted using Surfer and GIS software. The results showed that the highest concentration of K-40 was found in the sediments of the Gaz River outlet, possibly due to the use of potassium fertilizers. The concentration of Cs-137 activity in the Bay sediment was higher than in other sediments, attributed to its high mobility and lightness. The maximum radiological parameters were observed in the estuary of the Gaz River in Gorgan Bay, with the highest levels tending towards the northwest. The mean radiological indices were within the allowable range and did not pose a threat to the health of residents.