Brescia, F.; Sarti, M.; Massa, R.; Calabrese, M. L.; Sannino, A., and Scarfi, M. R. Reactive oxygen species formation is not enhanced by exposure to UMTS 1950 MHz radiation and co-exposure to ferrous ions in Jurkat cells. Bioelectromagnetics. 2009 May 27.
A lot of research has been conducted into possible biological effects of exposure to electromagnetic fields at frequencies used in the second generation mobile phones (900-1800 MHz, GSM signal). Fewer studies have been published on biological effects of UMTS signal, a digital technology of the third generation cellular system. Despite large similarities between the second and the third generation technologies, differences exist in the low frequency spectral content due to distinct modulation technique.
This study was conducted to assess cell viability and reactive oxygen species (ROS) production in human lymphoblastoid (Jurkat) cells exposed to UMTS signal alone or in combination with ferrous ions (FeSO4).
Cell cultures were exposed to 1950 MHz UMTS signal at SAR of 0.5 and 2 W/kg. ROS production was assessed with the fluorescent probe 2¢7¢ -dichlorofluorescein-diacetate for short (5 minutes - 1 hour) and long (24 hours) exposure durations. Cell viability was evaluated by applying the Neutral Red assay and the Resazurin assay after 24 hour exposure at both SAR values.
Results and interpretation
Treatments with FeSO4 induced a significant dose-dependant increase in ROS production and did not affect cell viability. There were no significant differences in ROS formation between sham and RF exposed cells or between FeSO4 treated and RF - FeSO4 co-exposed cells for any exposure conditions investigated. These results indicate that RF radiation did not alter spontaneous ROS production or FeSO4 – induced ROS production. No significant differences in cell viability among treatments were observed indicating the absence of cytotoxic effects under the exposure conditions investigated. The results of this study are in agreement with most published in vitro studies reporting no effect in several cell types evaluated with different oxidative stress parameters. The authors point out, however, that their results are not directly comparable with the results of other published studies because of the difference in the modulation techniques between the second and the third generation cellular systems. To the authors’ knowledge, there are no other studies available at this time on the induction of ROS after exposures and co-exposures to the UMTS signal.
It has been shown that exposure to 1950 MHz RF radiation with UMTS modulation does not affect cell viability or ROS formation in Jukart cells, and does not alter ROS production induced by ferrous ions.