الفهرس 
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Abstract
The objective of the present study was to investigate whether exposure of chicken eggs to 900 MHz continuous wave (CW) and low intensity electromagnetic radiation during the first five days of embryonic development may cause; teratogenic effect, behaviour aberrations and/or poor immune response ability. To verify such hypothesis, four series of experiments were carried out. For all the experiments, the eggs were incubated under normal conditions. The average (±SD) specific absorption rate (SAR) in the exposed eggs was determined numerically and it was calculated as high as 0.13 ± 0.02 mW/kg. The first experiment was to investigate the teratogenic effect at 5 days-old chicken embryos. Gross, head and limb embryo morphological malformations as well as anatomy anomalies (neural tube curvature) were assessed by stereoscopic examination. The exposed embryos displayed significantly higher morphological anomalies when contrasted to controls. There were also significantly increased anatomical anomalies as shown by the light and strong cases of the neural tube curvature in the exposed embryos. In total, more multiple abnormalities cases were observed in the EMF-exposed embryos. Moreover, exposed embryos exhibited significantly higher body weights when contrasted to the controls. The second series of experiments was to investigate the effect of exposure on the typical daily behaviour. The general activity as well as the feeding and drinking behaviour of 236 chicks was recorded during the first 7 days after hatching. Birds’ feeding, drinking and moving probabilities were modeled using a trivariate logistic regression with correlated random effects. Radiation resulted in higher probabilities of moving, feeding and drinking. The highest feeding and drinking activities were observed during morning times. Positive significant correlations between the probabilities of the feeding, drinking and moving were calculated. The third experiment was to investigate the effects of exposure on chickens’ later spatial learning and spatial memory. The spatial learning and memory performance were assessed by simple Y-maze tasks on 40 chicks per group aged 14-17 days. Three distinct positions were used during learning and a hidden position during the short term (directly after the last learning trial) and the long memory test (24h after the short memory trial). Survival analysis was used to compare time-to-an event i.e. latency of the various tasks among controls and exposed animals. Radiation resulted in prolonged latencies during the first trial at the first learning position and the long term-memory test. Radiation had no statistically significant effect(s) on the starting time, at the accomplishment times in the remaining two learning as well as the short memory trials. Finally, the fourth series of experiments aimed at investigating whether exposure of chicken eggs affects immune response ability of young chicken. The blood samples were collected at 1, 6 and 10 days-old from 66 chicks. Blood macrophages and heterophils were isolated and the following parameters were determined: total membrane-bound urokinase plasminogen activator (u-PA) and superoxide anion production on heterophils and microphages as well as nitric oxide production by macrophages. Data analysis showed an overall statistically significant effect of radiation on all parameters studied with lower values for the exposed eggs.