There are several reports indicating a linkage between exposures to 50-60 Hz electromagnetic fields and abnormalities in the early stages of embryonic development of chicken embryos. The present study was designed to demonstrate whether electromagnetic fields could be an environmental factor invoking histopathological and ultra-structural changes in livers of preincubated chicken embryos exposed to EMFs. Following other researchers and our previous results from different groups of Developmental Biology at the Animal Sciences, Faculty of Biological Sciences, Shahid-Beheshti University, effects of most effective intensities (1.33, 2.66, 5.52, and 7.32 mT) of electromagnetic fields (EMFs, 50 Hz ) on livers of pre-incubated white leghorn chicken embryos were investigated . 150 healthy, fresh, and fertilized eggs (55-65 gr) were divided into 6 groups of experimental(1-4, n = 30), control (n = 60), and sham (n = 50). Experimental eggs (inside coil) were exposed to 4 different intensities (1.33, 2.66, 5.52, and 7.32 mT). Sham groups were located inside same coil, with no exposure, for 24 h before incubation. Control, sham, and experimental groups (1-4) were then incubated in an incubator (38 +/- 0.5 degrees C, 60% humidity) for 17 days. At the end of this period, livers of experimental, sham, and control groups were processed for light and transmission electrom microscopes (TEM and SEM) studies. So, livers of 17-day old chicken embryos were removed by C-sections, fixed in formalin 10%, stained with H&E and reticulin, and studied under light microscope. Others were prepared for electron microscopes (TEM and SEM) investigations. Morphological observations indicated exencephalic embryos, embryos with asymmetrical faces, crossed beak, shorter upper beak, deformed hind limbs, gastroschesis, anophthalmia, and microphthalmia. H&E and reticulin stainings, TEMS, and SEMs studies indicated EMFs would create hepato-cytes with fibrotic bands, severe steatohepatitis, vacuolizations, swollen and extremely electron-dense mitochondria, reduced invisible cristae, crystalized mitochondria with degenerated cristae, myelin-like figures, macrophages engulfing adjacent cells, dentated nuclei, nuclei with irregular envelopes, degenerated hepatocytes, abnormal lipid accumulations, lipid droplets pushing hepatocytes' nuclei to the corner of the cells, abundant cellular infiltrations cellular infiltrations inside sinusoid and around central veins, disrupted reticulin plexus, and release of chromatin into cytosol,, with partially regular water layers. An elevated oxyradical generation and, subsequently, cell membrane disruptions were the reasons for electromagnetic fields inducing cell damages.

Effects of extremely low-frequency magnetic fields (ELF-MFs) on the histopathology, histomorphometry, ultrastructural changes (transmission electron microscope, TEM), apoptosis and alkaline phosphatase (ALP) activities in the spleens of preincubated white leghorn chicken embryo were investigated. Ninety fertilized eggs were divided into six groups as control (n = 15), sham (n = 15) and four experimental groups (1-4, n = 15). Eggs of experimental groups were exposed to 1.33, 2.66, 5.52 and 7.32 mTs flux intensities established in our previous published experiments and the last intensity was used for studying apoptosis and ultrastructures (TEM) of the spleens of 19-day-old chicken embryos. Eggs of control groups remained intact. Sham groups were placed inside the coil for 24 h before incubation with no exposures, then they were incubated in the same incubator (37°C, 60% humidity) for 19 days. Spleens of chicken embryos were removed, fixed in formalin (10%), and stained with H&E for histopathological and histomorphometrical surveys; TUNEL assay indicated possible change in apoptosis and TEM and biochemical studies were also carried out. Significant decreases in the sizes of the spleens of embryos of experimental groups, hyperemia, damages in spleen parenchyma, decreases in the numbers of splenic nodules, increases in the number of polymorphonuclear cells and sinusoidal spaces of spleens, significant increase in the level of ALP activities, significant increases in the numbers of apoptotic cells, deformed nuclei and swollen mitochondria were observed in experimental groups comparing with those in control and sham groups. ELF-MF created changes which could impair the immune functions.