Effects of exposure to DAMPS and GSM signals on ornithine decarboxylase (ODC) activity: I. L-929 mouse fibroblasts

Purpose: A temporary increase in ornithine decarboxylase (ODC) activity was reported in lysed L-929 fibroblasts after exposure to the microwaves emitted by Digital Advanced Mobile Phone System (DAMPS-835 MHz, 2.5 W/kg, 8 hours). Confirmation of these data was undertaken, given the suggested potential physiopathological consequences, i.e., tumour promotion.

Materials and methods: Murine L-929 fibroblasts were exposed at various Specific Absorption rates (SAR) to (DAMPS) or Global System for Mobile communications (GSM) signals using different set-ups. Cell ODC activities were assayed using ¹⁴CO₂ generation from ¹⁴C-labeled L-ornithine.

Results: ODC activity in live L-929 cells showed no significant alteration after exposure at an SAR of 2.5 W/kg, for one hour at the end of exposure to 50 Hz-modulated DAMPS-835 using Transverse Electro-Magnetic (TEM) cells. No significant alteration in ODC activity was observed at 6 W/kg, with active fans to regulate temperature (37°C). Tests using cell lysed after exposure in another temperature-controlled set-up (waveguides) did not confirm the published studies reporting increased ODC activity in Radio-Frequency radiation (RFR)-exposed L-929 cells. In the second part of the study, no alteration of ODC activity was detected when L-929 cells were exposed to different RFR signals: 217 Hz modulated GSM-900 (wire-patch antenna) or GSM-1800 (waveguides), and lysed before ODC measurement.

Conclusion: We conclude that under our exposure conditions, DAMPS-835 and GSM signals have no influence on ODC activity in L-929 cells.