Does Your Mobile Phone Fry Your Brain?
It is no secret that mobiles phones are #1 device that everybody uses in the daily routine. Having started to become popular in the early 2000s, they are now considered as a standard tool in people’s pockets. Most phone talks are made with them which, in time, raised a question in the concerned person’s mind. Are they harmful? Specifically, for the brain. Findings on various experiments were shared by many experts regarding this question and since that is highly related to human health, it became not only an intellectual bio-medical investigation, but it is now also a sociological issue.
Some claimed that the human body is transparent to those RF signals, so it is unable to cause any kind of serious harm where other annoyed people said ‘not that simple.’ There are still ongoing researches about the issue, mostly about SAR values. Yet, here is a simple case study to present some rough ideas about how to approach to that kind of matter.
The study focuses on the mobile phones as insulators and examines the thermal effects (i.e temperature change) on the human brain. SAR value is beyond the scope and estimations on the brain is made by deriving some approximate coefficients from well-respected papers. In other words, the temperature measurements were performed on the epidermis and temperature transfer to the brain is just estimated, making the outcomes just approximations. A tissue mimicking home-made phantom is manufactured in order to compare the temperature values.
The methodology is simple: Measure the temperature on the epidermis with 5-minutes interval during the 30-minutes conversation time at 900 MHz GSM band. The initial value is recorded at the zeroth minute. The infrared thermometer used during the process is with a 0.5% error rate and the ambience is 20.5 Celcius. Here are the results:

We can pay attention to the human model only, here is a graphic that displays the thermal change through the conduction.

Finally, we can retrieve the minimum and maximum temperature values reached during the experimental process along with the change (delta) and specifically the ‘expected change estimation’ — which was just a rough approximation made without performing a real analysis (i.e heat transfer computations)

here we see our expectations of thermal change in terms of temperature on brain cortex, it might seem as very insignificant change at first glance especially when noting the fact that around 3.5–4 Celcius of change is considered as critical. However, it was also reported that the hypothalamus, in charge of deciding the thermal behaviour, is likely to alter the thermal regulatory behaviour after a change of 0.2 Celcius. Despite around 0.2 Celcius degree not being displayed on the table, there are some relatively close forecasted values . So, there is no harm in taking simple precautions which can be summarised as follows:
- Do not use fake/replica phones
- Wear your earphones
- Prevent your infants to make long phone calls, since their skull may not be thick enough to form a sufficient and effective blockage.
