Kesari KK, Behari J, Kumar S. Mutagenic response of 2.45 GHz radiation exposure on rat brain. Int. J. Radiat. Biol. 86(4): 334-343, 2010.
Increasing exposure to microwave radiation is causing public concern and anxiety. Studies have shown that frequent use of wireless telecommunication devices such as cellular phones, especially among young adults, can lead to possible harm in brain cells as evidenced by breaks in single- and double-stranded DNA. Normally such breaks are repaired, but if not, unrepaired multiple breaks in the DNA of a cell could be a precursor to disease. Exposure to radiation initiates a process called oxidative stress and increases free radicals that attack DNA and cause single- and double-strand breaks. Anti-oxidative enzymes counteract this process and keep cells healthy and in balance. This paper investigates the increase in double-strand breaks in DNA and the level of antioxidant activity.
The objective of this study was to determine the effects of microwave radiation (2.45GHz) on double-stranded DNA breaks and antioxidant activity in developing rat brains.
Two separate groups of young male Wistar rats (35 days old) were used in the study. The first group (experimental) was placed in a plexiglas cage and exposed to 2.45 GHz non-ionizing radiation for 2 hours per day for 35 days. The second group (sham-exposed) was placed in the same plexiglas cage for the same period of time but without exposure to non-ionizing radiation. After the experiment, brain tissues from both groups were compared for double-stranded DNA breaks and antioxidant activity.
The researchers found a significant increase in the quantity of double-strand breaks in the DNA of rats exposed to the microwave radiation. There was also lower protective antioxidant activity in the rats that were exposed to radiation.
Interpretation and limitations
The authors speculate that the brain cells produce free radicals due to stress induced by the non-ionizing radiation. These free radicals are not kept in check by antioxidant enzymes and thus the amount of damage DNA is significantly greater. Chronic exposure to radiation and the ensuing DNA damage could be a precursor to unhealthy cells and lead to a diseased state. However, since the authors could not measure the free radicals produced in the brain tissue, their hypothesis is speculative.
This study suggests that chronic exposure to microwave radiation emitted in the 2.45 GHz frequency may cause significant damage to the DNA of developing brains and this damage could be a precursor for tumour promotion.