Panagopoulos DJ, Margaritis LH. 2010. The identification of an intensity ‘window’ on the bioeffects of mobile telephony radiation. Int. J. Radiat. Biol. 86: 358–366.
An increasing number of studies have confirmed increased bioactivity associated with digital Mobile Telephony Radiation. Recent experiments conducted by the authors have revealed the existence of increased bioactivity ‘windows’ related to both GSM 900 MHz (Global System for Mobile telecommunications) and GSM 1800 MHz in which the reproduction of Drosophila melanogaster may be affected.
The objective of this study was to identify whether the recorded windows of increased bioactivity are due to the radiofrequency (RF) or extremely-low-frequency (ELF) radiation field intensities within these windows (or to any combination of them), or due to any other possible effects related to the distance from the antenna.
Three experiments were conducted using groups each consisting of 10 male and 10 female D. melanogaster. All exposures lasted 6 minutes. In the first experiment, insects were exposed to GSM 900 MHz or 1800 MHz radiation at 30 or 20 cm distances, respectively, from the antenna of a mobile phone, where the bioactivity ‘window’ appears for each type of radiation. In the second experiment, the group was exposed at 8 or 5 cm, respectively, behind a metal grid, shielding both microwave radiation and the ELF electric and magnetic fields for both types of radiation in a way that radiation and field intensities were roughly equal between the two groups. In the third experiment, a sham exposure was conducted where insects were ‘exposed’ at 10 cm distance from the mobile phone antenna with the mobile phone turned off. The effect on reproductive capacity (number of F1 pupae per maternal fly) was then compared between groups for each type of radiation.
The reproductive capacity between the two exposed groups did not differ significantly for both types of radiation, (P > 0.97 in both cases); however, the reproductive capacity of each exposed group was significantly decreased compared to the sham-exposed group (P < 10-5 in all cases).
Interpretation and Limitations
The increased bioactivity ‘window’ of digital mobile telephony radiation revealed in the study is actually more of an ‘intensity window’ and is only indirectly related with the distance from the antenna. It does not seem to be related to the wavelength (or the radiofrequency) of the radiation but is directly dependent on the intensity of the radiation/field, no matter what distance from the antenna. For both types of radiation, the reproductive capacity of insects in the second experiment was slightly lower than that of the first, although differences were within the 95% standard deviation. This may be due to the fact that the ferromagnetic metal grid shield used to diminish radiation and field intensities was more effective in the RF than in the ELF region of the electromagnetic spectrum, resulting in slightly higher values of the ELF electric and magnetic field intensities. The authors also suggest that it is unknown whether the intensity window found is related exclusively to the specific experimental animal used or if it concerns other organisms as well. Experiments with different experimental animals exposed to different intensities of mobile telephony radiation are necessary.
This study suggests that mobile telephony radiation at lower intensities might be even more bioactive than at higher ones. Since insects are found to be more resistant to radiations than mammals these results may indicate a danger for human health as well.