effects of mobile phone exposure on brain metabolism
A study conducted by Dr Nora Volkow from the US National Institutes of Health has been published in the Journal of the American Medical Association.
The study reports effects of mobile phone exposure on brain metabolism (a marker of activity) and the authors conclude:
'...50-minute cell phone exposure was associated with increased brain glucose metabolism in the regio closest to the antenna. This finding is of unknown clinical significance.'
UK Government National Health Service Review
The UK NHS has reviewed the study and provides the following conclusion:
This experiment appears to have been carefully conducted. The study found a small significant difference in glucose metabolism in the area of the brain near the antenna of an active mobile phone. There are several points to note about the results that may affect their interpretation, some of which the researchers mention:
- The increase in glucose metabolism is proportionately small (2.4/33.3 μmol/100 g per minute or 7% as the papers quote). Any increased activity in the brain cells due to thinking, for example, could have led to this difference, and the wide confidence interval suggests that the difference in metabolism could have been as low as 0.67/33.3 μmol/100 g per minute or 2%.
- The study does not investigate whether mobile phones cause cancer or, as the researchers say, whether this small increase in brain activity has any detrimental effect.
- It is possible that the participants could tell if the phone was on or off or receiving a call even if they were set to silent. For example, the phone that was turned on may have been warmer. This was not tested or reported by the researchers. This is important because knowing whether the phone was making a call could have influenced the underlying brain activity.
Overall, this study provides useful additional information about the effects of phone use in experimental conditions. The effect observed was small and the researchers clearly state that they do not know the clinical significance of their findings. Further research is needed to clarify if this effect is real, and if so whether increasing the activity of brain cells in this way leads to any long-term harmful effects.