EN
The effects of exposure to a 900 MHz electromagnetic field (EMF) on the serum cortisol and triiodothyronine-thyroxin (T₃-T₄) levels in adult male Syrian hamsters were evaluated. Seventy two hamsters were used in three independent groups: 24 served as controls (without exposure to stress and EMF), 24 were exposed to a 900 MHz EMF for 10 d, and 24 were exposed to a 900 MHz EMF for 50 d. The exposures were performed 1 h/d to a 900 MHz EMF emitted by cellular phones. The levels of cortisol and T₃-T₄ were measured by using an immunoradiometric assay (IRMA) method. The results revealed the cortisol values of the group, which was exposed to 900 MHz EMF for 50 d, were higher than those of the other groups (P<0.01). The levels of T₃ in the control group were higher than that of the long-term exposure group (P<0.01), and levels of T₄ in the 900 MHz EMF group for the long-term and short-term exposure groups, were higher than that of the control group (P <0.01). These results indicate that a 900 MHz EMF emitted by cellular phones, especially in the case of long-term exposure, increased the serum cortisol and T₄ levels and decreased the T₃ level, and suggest that it can destroy the endocrine system in general.