Effects of radiofrequency radiation on thyroid gland functions

In the present study we aimed to investigate possible functional effects of modulated Radiofrequency fields on thyroid gland using light microscopy, electron microscopy and immunohistochemical methods. Two months old male Wistar rats were exposed to 900 MHz pulse modulated Radiofrequency Radiation at an average power density of 0.424 mW/ cm² 20 min/day for three weeks. The RF signals were pulse modulated by rectangular pulses with a repetition frequency of 217 Hz and a duty cycle of 1:8 (pulse width 0.576 ms). In order to indicate thyroid endocrine distruption and estimate the degree of the pathology of the gland we analyzed structural alterations in follicular and colloidal diameter and area, colloid content of the follicles and height of the follicular epithelium. We evaluated apoptosis by assessing the activations of two important iniator (caspase-9) and effector (caspase-3) caspases that are the markers of cells undergoing apoptosis. Morphometrical analyses revealed hypothyrophy of the gland in 900 MHz modulated RF exposure group. The revealed signs of morphometrical results indicated that thyroid hormone secretion is inhibited by modulated RF radiation. In addition to the observations of structural alterations in RF exposed group, we also observed increased caspase-3 and caspase-9 activation and formation of apoptotic bodies in thyroid cells of the rats that were exposed to modulated RF fields. The overall findings indicate that whole body exposure of modulated RF Fields may cause pathological changes in thyroid gland by altering the gland structure and enhancing caspase dependent pathways to apoptosis.