Mashevich M, Folkman D, Kesar A, Barbul A, et al. (2003).
These authors examined whether RF exposure to human blood lymphocytes produced evidence of aneuploidy (an alteration in chromosome complement).
They exposed the blood cells to continuous wave 830 MHz radiation for 72 hours. Other samples were sham-exposed. The exposure was inhomogeneous, and in consequence the average SAR levels were in the range of 1.8-8.8 W/kg. To compare aneuploidy changes at the different levels of exposure, the samples were divided into four groups according to their average SAR level of exposure: 1.6-2.3 W/kg (n = 4); 2.6-3.5 W/kg (n = 5); 4.0-4.8 W/kg (n = 7); and 7.8-8.8 W/kg (n = 5). No significant increase in aneuploidy was seen at the first level of exposure, but there were significant increases at the other exposure levels, compared to sham-exposure. Chromosome 17 was used for the aneuploidy assessment.
The authors also exposed samples to different temperatures in the range of 34.5 - 41.0 °C for 72 hours. There was no difference in aneuploidy in the range of 34.5 - 38.5 °C, but elevation of temperature to 40 °C led to an increase in aneuploidy. The authors concluded that the changes observed in the radiation experiments were not likely to be thermal in nature since the temperature did not exceed 38 °C.
The SAR levels in this study are rather high, although the authors state that they were lower than the ICNIRP localized exposure limit for the head and neck of 10 W/kg.
Mashevich et al. hypothesize that the chromosomal changes could be related to disturbance of the function of proteins that regulate the pathway of chromosome segregation on the one hand and DNA replication on the other. They state that aneuploidy is a phenomenon known to be associated with a pre-cancerous phase, and that their experiment suggests that RF radiation exposure at a SAR value of 2.9 W/kg and above poses a risk for cancer.
Additional notes: In the December 2003 issue of Bioelectromagnetics, there is correspondence about this study. Chou and Swicord cast doubt on the authors' statement that the observed changes were due to non-thermal effects of the radiation, and the authors reply to this assertion.