Radioactive survey of coastal water and sediments across Alexandria and Rashid coasts

Alexandria and Rashid being part of the Mediterranean Sea basin cities are concerned with the protection of the marine environment of their territorial waters and coasts. One of the major sources of pollution in the surface water and sediments is the radionuclides.The present study is devoted to reliable detection, identification and classification of the radionuclides using the gamma ray spectrometer to measure the density of the radionuclides (i.e. 238U, 232Th, 40K) along the Alexandria and Rashid beaches and try to know the sources of these radionuclides.Surface sediments and sea water samples were collected from Alexandria and Rashid coastal beaches. The results demonstrate that the main source of radiation along the Alexandria and Rashid beaches is the black sands, which is rich in radio-nuclides, supplied by the River Nile during the flooding period in the last 5000 years through the Rashid branch of the Nile. These black sands accumulate mostly on the Rashid beach. The sea waves carry part of these black sands to Alexandria beaches westward.The distribution of 40K along the Alexandria coast revealed that, the western area of Al-Max coast was poor in 40K. On the other hand, the eastern area of Alexandria was rich in 40K, there was a wide relationship between the presence of 40K in sediments and the biological density of fauna and flora in the coast. The behavior of 40K in sediments along the Alexandria coast has been detected as non-uniform correlations between the data at different stations reveal significant differences between their radiometric properties. The lower 40K values for seawater have been detected at stations receiving low saline water discharged from inland sources. The salinity affects the behavior of 40K in surface seawater. This was due to the solubility of 40K in seawater.The measured values for 238U and 232Th for seawater are very low.The continuous monitoring of the radio-nuclides is recommended to assure good environment of these beaches because they are bathing beaches of Alexandria, and an important resource as summer resort.