Effects of whole-body exposure to 915MHz RFID on secretory functions of the thyroid system in rats

As a part of an investigation on the potential risks of radiofrequency identification (RFID) on human health, we studied whether exposure to 915MHz RFID in rats significantly affected the secretory function of the thyroid system. A reverberation chamber was used as a whole-body exposure system. Male Sprague-Dawley rats were exposed for 8h per day, 5 days per week, for a duration of 2, 4, 8, or 16 weeks. The estimated whole-body average specific absorption rate (SAR) varied from 3.2 to 4.6W/kg depending on the age/mass of the animals for the field of the 915MHz RFID reader. Plasma levels of triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone (TSH) were evaluated via enzyme-linked immunosorbent assay. Morphological changes in the thyroid gland were then analyzed. No changes in T3, T4, or TSH were observed over time between the sham- and RFID-exposed groups. We suggest that subchronic exposure to 915MHz RFID at a SAR of 4W/kg does not cause significant effects on thyroid secretory function.