The effect of exposure duration on the biological activity of mobile telephony radiation

In the present experiments we studied the effects of different durations of a single (continuous), daily exposure, ranging from 1 min up to 21 min, to the two established systems of digital mobile telephony radiation that are commonly used in Europe, viz. GSM 900 MHz (Global System for Mobile telecommunications) and DCS 1800 MHz (Digital Cellular System-referred to also as GSM 1800 MHz), on a well-tested biological model, the reproductive capacity of the insect Drosophila melanogaster. The insects were exposed to each type of radiation at an intensity of about 10 microW/cm(2), corresponding to a distance of 20 or 30 cm from the antenna of a DCS 1800 or a GSM 900 mobile phone handset, respectively. At these distances the bioactivity of mobile telephony radiation was found to be at a maximum due to the existence of a "window" of increased bioactivity around this value, as we have shown recently [1-4]. The results show that the reproductive capacity decreases almost linearly with increasing exposure duration to both GSM 900 and DCS 1800 radiation, suggesting that short-term exposures to these radiations have cumulative effects on living organisms. Additionally, our results show again that GSM 900 MHz radiation is slightly more bioactive than DCS 1800 MHz radiation, at the same exposure durations and under equal radiation intensities, as shown in our previous experiments [5].