Towards Danger of Mobile Phones in Planes, Trains, Cars and Elevators

Abstract

In his article Hondou deals with public safety considerations in daily life situations when mobile phones are used in closed rooms such as trains, cars or elevators. Hondou states that he can predict the possible exposure level in a typical train carriage using a simple formula. The results of his treatment claim that the ICNIRP exposure limits for public safety can be exceeded in daily life through the simultaneous usage of mobile phones in closed areas. It is true but trivial that in near-field and resonant exposure situations, the exposure limits are exceeded by far. For example, the incident field exposure during usage of a mobile phone can exceed the exposure limits by 10 dB or more. Therefore and in accordance with the standards, the appropriate safety considerations have to be based on the basic restrictions in the case of resonant environments and near-field exposures and not on the derived exposure limits. By straight forward worst-case estimation based on the basic restrictions, it becomes obvious that the exposure can never reach 25% of the whole-body averaged specific absorption rate (SAR) safety limits for environmental exposure (0.08W/kg), even in the case that every person present in an electromagnetically almost closed room talks on the phone (body weight > 30 kg), with all phones operating at a maximum average output power of 0.6W. Since the spatial peak SAR decreases approximately with the square of the distance, the highest local exposures are caused by the phone directly next to the user’s head (distances are usually a few millimeters), whereby each phone on the market is tested for compliance with the safety limits. The additional local absorption caused by neighboring phones is therefore much less, and therefore the safety limits for spatial peak SAR cannot be significantly exceeded. In other words, closed rooms do not impose safety issues other than those in any other location such as free space. The considerations of ref. 1 are not well posed, and the conclusions are not relevant for public health issues.