Eff ects of simultaneous combined exposure to CDMA and WCDMA electromagnetic fi eld on immune functions in rats

Purpose : Despite the importance of the immune system in defending the body against infection and cancer, little research on the possible eff ects of radiofrequency electromagnetic fi eld (RF-EMF) signals on immune functions exists, and, in the case of simultaneous combined exposure of RF-EMF, to the best of our knowledge no work has been done. The aim of this study was to assess the eff ect of simultaneous exposure to two types of RF-EMF signals, single code division multiple access (CDMA) and wideband code division multiple access (WCDMA) signals on the immune system of rats. Materials and methods : Male Sprague-Dawley rats were exposed to RF-EMF for 45 min/day, 5 days/week for up to 8 weeks. The whole body average specifi c absorption rate (SAR) of CDMA or WCDMA was 2.0 W/kg. Every 2 weeks after the experiment began, 20 rats were autopsied. Blood hematology, subtype population of splenocytes and cytokine production or mRNA expressions, interleukin (IL)-6, tumor necrosis factor (TNF)-α , IL-1 β , interferon (IFN)-γ and transforming growth factor (TGF)-β from the splenocytes or IL-6, TNF-α , and immunoglobulin (Ig) of IgG and IgM from blood serum, were examined. Results : The results suggest that 8-week exposure to CDMA (849 MHz) and WCDMA (1.95 GHz) RF simultaneously at 2.0 W/kg each for 45-min RF-EMF exposure (total, 4 W/kg) did not aff ect these immune parameters. Conclusions : The present experiments suggest that simultaneous combined exposure of CDMA and WCDMA with total SAR dose of 4.0 W/kg for 45 min/day for 8 weeks, which is a relatively high SAR level compared to the exposure levels for the human system recommended by International Commission on Non-Ionizing Radiation Protection (ICNIRP, 0.4W/kg for whole body exposure levels and 2.0 W/kg for local exposure levels of general public), did not have any detectable eff ects on immune function in rats.