الفهرس 
Biological Effects of RadiationOnly 14 pages are availabe for public view
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Abstract
In the present work, samples of soil, sediment and water were collected from territories of Rashid and Damietta branches of the River Nile. Natural radioactivity concentrations of 238U, 232Th and 40K have been evaluated for all samples by means of gamma spectrometric analysis using hyper pure Ge detector. The radioactivity levels for both soil and sediment samples were found to fall within the international recommended values. Nevertheless, a high natural background radiation zones were detected at Kafr-Elzayaat region due to the presence of a fertilizer factory and at Rashid region due to the presence of black sand deposits that are dominated there. The radiation hazards (absorbed dose rate, radium equivalent activity, the annual effective dose equivalent, hazard indices, gamma index and excess life time cancer risk) were calculated and compared with the previously reported data. High values for some of the radiation health parameters were found at Kafr-Elzayaat and Rashid regions representing a serious problem to public because they use the soil and sediment as constructing materials for their buildings.
The study was extended to include the toxic heavy elements using the atomic absorption technique. As consequences Pb, Cd, Cr, Hg and As toxic elements have been found to have values much larger than the world average values at Banha, Mansoura, Damietta, Rashid and Kafr-Elzayaat. These results indicate that health hazards due to the consumption of this water are certainly expected. As a consequence, strictly solutions and rules should be considered by both people and government.
Additionally the multi-generation studies of the present work on rats showed toxic effects of heavy metals on non-reproductive targets such as kidney, liver and brain. Also the ameliorating effect of aloe vera as a natural antioxidant product is found to be able to reduce the induced oxidative damage in hepatocytes and renal injury induced by heavy metals in male albino rats.
A total number of 100 male albino rats were used in this study. Biochemical analyses of blood demonstrated that heavy metals such as Cu, Cr and Cd induced oxidative stress in rat blood by decreasing the activities of antioxidant enzymes and protein content with an increase in liver enzymes.
Groups of heavy metals significantly elevated aspartate transaminase(AST), alanine amino transferase (ALT), alkaline phosphates (ALP),γ-glutamyl transferase (GGT), creatinine, urea, uric acid, cholinesterase, total cholesterol, triglycerides, low density lipoprotein (LDL) and malondialdehyde (MDA) with a significant decrease in total proteins, albumin, globulins, high density lipoprotein (HDL) and total antioxidant capacity compared to control group.
A highly significant change in brain acetyl cholinesterase (AChE) activity was recorded compared to the normal controls. The decreased (AChE) might be referred to the increase in lipid peroxidation inducing deformities of cellular membranes and disturb metabolic and nervous activity.
Administration of aloe vera either alone or combined with heavy metals ameliorated the hepatotoxicity and renal injury induced by heavy metals. Aloe vera improves liver function and serum lipid profile, and diminish the generation of free radicals by inducing antioxidant defense mechanism, hence, minimizing the damage of cell membranes. In addition, it has an anabolic effect. These results were observed when aloe vera was administered alone compared to control group and also in combination with heavy metals compared to heavy metal groups. Based on these promising findings, it might be anticipated that aloe vera treatment may be beneficial in the severely hepatotoxic ailments and renal injury. Consequently, aloe vera could be used as a potential antioxidant against heavy metals intoxications as it has protective role against heavy metal effects on liver, kidney and brain tissues functions.
These results are confirmed by histopathological examination of liver and kidney that showed destruction of the histology of liver and kidney. They were characterized by vascular congestion, vacillation, destruction of the seminal epithelia layers, focal necrosis of nucleus and edema. Significant alterations in toxic groups with an improvement in groups treated with a combination of aloe vera extract and toxic material.
These results, in addition to its environmental value are considered to be essential in analyzing any data in this field.