ID Number		103
Study Type		In Vitro
Model		835 MHz (FM) exposure to cell lines and analysis of growth and morphology
Details		U87 MG cells were exposed to 835 MHz (FM) RF at 8.1 and 40 mW/cm2 for 20 minutes 3x/day for 7 days in a microwave (oven) chamber. Exposure at 8.1 mW/cm2, but not 40 mW/cm2, resulted in a decrease in proliferation. At both levels of exposure the cells flattened and spread out. In contrast, in a similar study by the same group, RBL-2H3 mast cells were exposed to 835 MHz (FM) RF at 8.1 mW/cm2 for 20 minutes 3x/day for 7 days in a microwave (oven) chamber. Exposure were reported to result in an increased proliferation and DNA synthesis, an increased actin distribution and granule secretion, and an altered cell morphology. In a related study, RBL-2H3 rat basophil leukemia cells were exposed to 2450 MHz (PW) at 12.8 to 58 W/kg (peak (1.8 msec pulse duration) or 6,746 to 30,571 W/kg (683 msec pulse duration) - average SAR = 5.8 W/kg and overall temperature rise (0.5 degrees C) was minimal. The authors report heat shock associated with the pulsed exposures and transient temperature rises which may not be captured in safety standards with 6 minute time averaging.
Findings		Effects
Status		Completed With Publication
Principal Investigator		St. Vincents Hospital, Australia - p.french@cfi.unsw.edu.au
Funding Agency		Private/Instit.
Country		AUSTRALIA
References		Laurence, JA et al. J Theoretical Biol., (1999) :- French, PW et al. Bioelectrochem. & Bioenerg., (1997) 43:13-18 Donnellan, M et al. Cell Biol. Int., (1997) 21:427-439
Comments		There was no dose-response for decreased proliferation in astrocytoma cells as exposure to 8.1 W/kg showed effects where those exposed to 40 W/kg did not. Further, a study by the same group on mast cells showed an increase in proliferation and DNA synthesis, as opposed to the decrease seen with astrocytoma cells. Also, during exposure of the astrocytoma cell line there was a clear and significant heat deposition into the flasks that was not characterized as to its uniformity and could have very well resulted in hot spots. Characterization of the “microwave oven” exposure system was inadequate, and significant artifacts may have been generated. Finally, there was no appropriate positive or heat only control in either study.