To study whether 2450 MHz continuous wave high frequency electromagnetic fields could induce cancer-like changes in mouse cells, and whether these electromagnetic fields could initiate malignant or synergistic transformation.
The cells were exposed to high frequency electromagnetic fields alone and/or were treated with a known initiating chemical, methylcholanthrene (2.5 µg/ml). TPA was used as a positive control tumor promotor (5 ng/ml) that could enhance transformation frequency initiated by methylcholanthrene in multistage carcinogenesis.
Temperature controls were also performed (38, 40, 42, and 44°C).
|Exposure duration||continuous for 2 h|
|SAR||200 mW/g||maximum||calculated||-||100 W/kg, 50 W/kg, 20 W/kg, 10 W/kg and 5 W/kg|
No significant differences were revealed in the malignant transformation frequency between the controls and high frequency electromagnetic fields with or without TPA. However, the transformation frequency for irradiation at a SAR value of more than 100 W/kg with methylcholanthrene or "methylcholanthrene plus TPA" was increased compared with "methylcholanthrene alone" or "methylcholanthrene plus TPA".
On the other hand, the corresponding heat groups ("heat alone", "heat + methylcholanthrene", and "heat + methylcholanthrene + TPA") did not increase transformation compared with each control level in these cells.
The data suggest that 2450 MHz high frequency electromagnetic fields could not contribute to the initiation stage of tumor formation, but it may contribute to the promotion stage at the extremely high SAR (100 W/kg).