Abstract

In recent years, due to the large diffusion of electric devices like cellular phones and their base station antennas, the exposure level of worldwide population to electric and magnetic fields has grown by orders of magnitude. This evidence pose the urgent problem to adequately evaluate the risks related to the wide-spread use of these technologies. In this study, utilizing a suitable irradiating transmission line chamber, the effects of 900 MHz radio fre-quency fields on DNA mutability and repair in Escherichia coli strains were investigated. The transmission line was very versatile and able to easily apply different field values. In this experiment the maximum electric and magnetic fields were 66 V/m and 260 nT, respectively, in the absence of cell plates. Slight decrease in spontaneous mutability to erythromycin and rifampicin-resistance was demon-strated in mismatch-repair proficient bacteria exposed to the radio frequency electromagnetic field (RF-EMF) during their growth on solid medium. The anti-mutagenic effect of the RF-EMF was much more im-pressive at the level of a hypermutagenic cytosine repeat, whose stability is strongly dependent on the activ-ity of the mismatch repair system. In contrast, in mismatch repair-defective background RF-EMF neither affected the general DNA mutability nor the stability of the cytosine repeat, suggesting that the anti