To evaluate whether daily whole-body exposure of mice to 900 MHz GSM-modulated irradiation could affect spleen lymphocytes. T cells and B cells were stimulated ex vivo using specific monoclonal antibodies or lipopolysaccharides to induce cell proliferation, cytokine production and expression of activation markers.
|Mice were housed individually in transparent Perspex jigs with openings to provide air circulation. Four mice were placed in the cell (two above and two below the septum with daily clockwise rotation) with their caudal axis parallel to the direction of propagation.
|A blinded procedure was used for exposure. Sham-exposed mice experienced the same conditions except for the EMF. A control group was kept with minimal handling. A water cooling system was set up with two external metal jackets filled with circulating water fed through a thermostatic bath (20°C) and placed in contact with the bottom walls. The maximum difference between exposed and sham-exposed groups was < 0,5°C.
The number of spleen cells, the percentages of B cells and T cells, and the distribution of T cell subpopulations were not changed by irradiation. The findings did not show relevant differences in either T lymphocytes or B lymphocytes from animals exposed to an SAR of 1 or 2 W/kg and sham-exposed animals with few exceptions. After 1 week of exposure to 1 or 2 W/kg, an increase in IFN-gamma production was revealed that was not evident when the irradiation was prolonged to 2 or 4 weeks. This indicates that the immune system might have adapted to radiofrequency irradiation as it does with other stressing agents.
In conclusion, the in vivo data indicate that the T cell and B cell compartments were not substantially affected by radiofrequency irradiation and that a clinically relevant effect of the irradiation on the immune system is unlikely to occur.