Radiofrequency (microwave) radiation exposure of mammalian cells during UV-induced DNA repair synthesis med./bio.

To investigate the effect of continuous wave (CW) and pulsed wave (PW) radiofrequency radiation in the microwave range on UV-induced DNA repair in normal human diploid fibroblasts.
The first question was whether, immediately after UV light irradiation, radiofrequency radiation at low power densities would interfere with at least one of the steps occuring in the DNA repair process. The second question was wether radiofrequency exposure by itself, without any UV preexposure, was capable of inducing DNA repair and the third question was whether pulsed wave radiofrequency radiation (medium temperature at constant 39°C), could affect incorporation of precursor radioactivity into cellular DNA by normal semiconservative synthesis.

• intact cell/cell culture
• MRC-5 (human diploid fibroblasts)

Radiofrequency radiation for 1 to 3 h at 37°C (continuous wave or pulsed wave) had no effect on the rate of repair replication label incorporated into preexisting UV-damaged DNA. Pulsed wave radiation, with a constant temperature of 39°C at 350- and 850 MHz during the repair period after UV damage, also had no effect. Assay for induction of repair synthesis by radiofrequency exposure alone in non-UV irradiated cells was negative for the continuous wave (350-, 850-, and 1200-MHz) and pulsed wave radiofrequency radiation at 37°C and the 350- and 850-MHz radiofrequency radiation at 39°C. Radiofrequency exposure does not induce DNA repair under these experimental conditions. No effect on incorporation of [³H]thymidine into DNA undergoing semiconservative synthesis was observed in preliminary experiments (at 39°C and pulsed wave radiofrequency radiation at the frequencies of 350-, 850-, and 1200 MHz).