Evaluation of Radioactive And Potential Poisoning Levels of Heavy Metals in Different Environmental Samples in Western Nile Delta, Egypt

Abstract

Nile Delta is the most densely populated region “~ 1600 inhabitants/km2 and one of the most fertile farming areas in the world that uses fertilizers. It's surrounded by highly arid environment industrial activities, wastewater, petrochemicals wastes, and agricultural drainage, which are considered as sources of pollution in the water, sediments, soil and plants by radionuclides and heavy metals. The present study is devoted to reliable detection, identification and investigation of the radionuclides using the gamma ray spectrometer to measure the activity of the radionuclides such as (238U, 232Th, 40K) along the west bank of Nile delta "Rosetta Branch" and try to know the sources of these radionuclides. The min. and max values are observed for every radioactive nuclide per each sample. In Plant samples the min. activities for U238, Th232, and K40 are 5.23 Bq/kg, 2.90 Bq/kg, and 52.83 Bq/kg respectively while and the max. activities are 5.54 Bq/kg, 4.71 Bq/kg, and 62.31 Bq/kg respectively. In Soil samples the min. activities for U238, Th232, and K40 are 4.40 Bq/kg, 3.87 Bq/kg, and 22.00 Bq/kg respectively while and the max. activities are 33.10 Bq/kg, 17.18 Bq/kg, and 306.86 Bq/kg respectively. In Water samples the min. activities for U238, Th232, and K40 are 0.04 Bq/kg, 0.21Bq/kg, and 7.20 Bq/kg respectively while and the max. activities are 0.68 Bq/kg, 0.61 Bq/kg, and 13.16 Bq/kg respectively. In Sediment samples the min. activities for U238, Th232, and K40 are 15.75 Bq/kg, 3.28 Bq/kg, and 144.67 Bq/kg respectively while and the max. activities are 31.55 Bq/kg, 21.55 Bq/kg, and 306.17 Bq/kg respectively. Also, in this research Neutron Activation Analysis "NAA" technique is used to investigate heavy metals and radionuclides in the intended samples. Surface sediments and Nile water, agriculture soil, and plant samples were collected along the study area starting from Al Qanter Al-Khayryya ended up at Rashid city. The results demonstrate that most of the obtained activities of radioactive nuclides are within the permissible worldwide ranges, with some clear observations as the high ratio in 232Th nearby Rashid city due to the black sands there, 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 results show that how Kafr Al-Zayyat pesticides factory harms the environment as it handles highly toxic chemical compounds and poisonous materials. Fourty major and trace elements in 8 surface soil and sediment samples collected from the Nile Delta were determined by epithermal neutron activation analysis and compared with corresponding data for the Upper Continental Crust "UCC" and North American Shale. Results showed the western Nile delta is not seriously polluted with metals from local human activity. High ratios are observed only for marine elements Cl, Br, I and Se, their mean concentrations recorded 1829.125 mg/kg, 71.15 mg/kg, 8.1 mg/kg, 262.63 mg/kg respectively in comparison to UCC mean values and this is related to the closeness to the Mediterranean Sea. High ratios of Fe in some samples nearby Ad khila city may be a result of corrosion from ships in the sea and the iron factories in Ad khaila at the Estuary of the Nile River. High ratios of Fe nearby Monouf city may be due to the industrial activities in Sadat City where 93 factories and may be due to the waste disposal or discharge in the environment. The continuous monitoring of the radio-nuclides is recommended to assure good environment of such areas.