Dasdag S, Akdag MZ, Ulukaya E, Uzunlar AK, Ocak AR. (2009). Effect of Mobile Phone Exposure on Apoptotic Glial Cells and Status of Oxidative Stress in Rat Brain. Electromagnetic Biology and Medicine. 28:342-354.
There is a great deal of public concern that frequent use of wireless communication devices such as cellular phones has led to increased exposure to short- and long-term radiofrequencies (RF) and thus to health hazards, including cancer. Cells respond to different stressors in multiple ways, one of which is to initiate cell death to remove damaged and dysfunctional cells. A defect in this pathway could initiate the process that starts cancer cells and tumours. For example, exposure to radiation initiates a process called oxidative stress that causes an imbalance in the cell death pathway thus initiating cancer tumour growth. Antioxidant activity is believed to counteract this process and promote balance. These different pathways are investigated in this paper.
The objective of this study was to determine the effects of mobile phone exposure on brain glial cells in rats and investigate whether the cell death pathway is altered.
Three separate groups of rats were used in the study. The first group was placed in a Plexiglas carousel for 2 hours per day for 10 months and exposed to 900 MHz radiation. The second group was placed in the same Plexiglas carousel for the same period of time, but not exposed to radiation. The third group was left in their cages. Ten months later, brain cells from all groups were analyzed and compared for the number of dead brain cells, antioxidant activity, oxidative stress, and activation of different disease related biomarkers.
The researchers found that the cell death pathway differed between the three groups. There were many more dead brain cells and lower protective antioxidant activity in the two groups of rats that were not exposed to radiation. By contrast, there was higher protective activity and a greater number of brain cells in the first group of rats who were exposed to RF radiation.
Interpretation and Limitations
The results were the opposite of what the research group had expected, namely that there would be more brain cell death in exposed rats. They concluded that the radiation dose was not high enough to initiate the increased cell death normally seen by other groups. However, one possible explanation to support the notion that exposure to low levels of radiation could in fact lead to greater risk of diseases such as cancer, is that the increased number of cells in exposed rats could in turn increase the potential for propagating damaged cells. Damaged cells that are not properly eliminated through cell death pathways could transform into cancer cells. Continued research is required to investigate what mechanisms are triggered by lower doses of radiation and if these are linked to cancer as a result of decreased activity of the cell death pathway.
This study suggests that long-term exposure to RF radiation is associated with changes in brain cells of rats and that the cell death cycle is altered.