Eșmekaya MA, Seyhan N, Ömeroğlu S. Pulse modulated 900 MHz radiation induces hypothyroidism and apoptosis in thyroid cells: A light, electron microscopy and immunohistochemical study. Int. J. Radiat. Biol. Early Online: 1-11, 2010.
There has been a significant increase in the usage of mobile phones and as a result, the public is concerned that constant exposure to this type of radiation could lead to potential health hazards. The thyroid gland plays an important role in the body, regulating growth, development, and metabolism. Past studies have shown that hormones that the thyroid gland releases into the body are reduced in humans and animals after exposure to radiofrequency (RF) radiation emitted from mobile phones. This study looked at the cells in the thyroid gland to see if there are changes which could result in reduced hormone levels after RF exposure.
The objective of the study was to determine the effects of mobile phone exposure on thyroid gland cells in rats.
Three separate groups of each 10 two month old male rats were used in the study. The first group (RF-exposed) was exposed to 900 MHz pulse-modulated RF radiation 20 minutes per day for 21 days. The average specific absorption rate (SAR) for whole-body exposure in these rats was 1.35 W/kg. The second group (sham-control) was placed in the same RF exposure apparatus for the same period of time, but not exposed to any radiation. The third group (cage-control) was left in their cages without being exposed to any RF radiation. Following the exposure period, all three groups of rats were sacrificed and the thyroid gland cells were isolated and prepared by various methods for comparison between groups.
The researchers found a significant difference in thyroid gland cells which had been exposed to RF radiation. First, the cells from RF exposed group were on average smaller than the cells from the sham or cage-control groups. Second, there were more cells from the RF exposed mice which had a more components that were markers for cell death.
Interpretation and Limitations
The authors speculated that because there was a greater amount of cell death markers in the thyroid gland cells exposed to RF radiation, these cells could be dying at an enhanced rate. Also, the smaller size of the RF-exposed cells indicated that the cells were not producing the same amounts of thyroid hormone as the two control groups. However, hormone levels in the rats were not measured, therefore the authors don’t know whether hormone secretion was reduced in the exposed rats.
This study suggests that RF radiation emitted from mobile phones is associated with changes in the cells of the thyroid gland in rats.