Effects of static electromagnetic fields on chick embryo pineal gland development

The effects of static electromagnetic fields on the development of the chic k embryo pineal gland were studied. A total of 144 fertilized White Leghorn eggs were sacrificed after 5, 10 and 15 days of incubation. The stage of d evelopment was determined in all embryos using the Hamburger and Hamilton m ethod [J Morphol 49: 88-92, 1951]. The various morphometric parameters (dia meter and distance of the pineal gland and its lumen) were measured on seri al 7-mu m-thick sections. The data were obtained in a morphometer and proce ssed statistically. The intensities of the static electromagnetic fields we re 18 and 36 mT. Control and exposed embryos were equally distributed and r andomly assigned. After 5 days of incubation, 25% of embryos exposed to a s tatic electromagnetic field of 18 mT had a more advanced stage of developme nt than controls and embryos exposed to 36 mT. On the 10th and 15th day, em bryos exposed to either 18 or 36 mT tended to be more developed than contro ls. In the morphometric study, results were similar for the controls and ex posed embryos after 5 and 10 days of incubation. However, the values of the 15-day-old embryos exposed to static magnetic fields were lower than the v alues of the controls (p > 0.01). These differences were more pronounced in the embryos exposed to 36 mT. These results seem to indicate that static e lectromagnetic fields affect the development and growth of embryos unequall y, and that their action can depend not only on the intensity of the static electromagnetic field, but also on the length of exposure and the organ wh ich is developing. It may be interesting to use these data in ultrastructur al and physiological studies.