Radioactivity in biota collected from the Basrah marine environment, Iraq.

Abstract

Since the seas are considered one of the main sources of food for humans, the food taken from them must be free of pollutants of all kinds. In this study, samples of biota and fish were collected from Iraqi marine waters, as well as from the local market, and the specific activity of natural radionuclides was measured using gamma spectroscopy with a 3 × 3 NaI(Tl) crystal. In the Iraqi marine samples, the average value of radionuclides (Ra-226, Th-232, U-238, K-40, and Raeq) was 24.89 ± 6.9, 7.34 ± 1.70, 8.39 ± 4.02, 204.3 ± 24.3, and 51.12 Bq/kg, respectively. At the same time, the values from the traditional market samples were 39.33 ± 5.5, 6.33 ± 1.2, 17.6 ± 4.4, 140.5 ± 17.8, and 53.6 ± 20 Bq/kg, respectively. There is a large discrepancy between the upper and the lower values. This results from differences in the types of samples under study, which represent the naturally occurring radioactive material (NORM) concentration in their bodies differently. That is because of many factors, including the mode of life, for some are swimming or floating, or benthic, as well as the place in which they are found in their environment, their living on shores or offshore. In addition to the differences in their nutrition, the most important factor is the nature of their body physiology in concentrating radioactive isotopes in different proportions. The health effects resulting from the activity of radionuclides present in the biota are measured using the external (Hex) and internal (Hin) hazard indices. They range from 0.04 to 2.57 and 0.1 to 2.57, respectively, and the mean is lower than the world average of 0.66. The internal (Hin) and the external risks (Hex) were greater than the acceptable limit. This is due to many factors, the most important of which are the place where they live and the way they live, as well as their physiology. We conclude from the study that the internal and external risk values exceed the acceptable limit, so it is preferable not to take it or to take it in excess.