Marzo 2004

No increased risk of acoustic neuroma in cell phone users

A new research paper has provided further evidence that cell phone users are not at increased risk of developing acoustic neuroma, a tumour that grows on the auditory nerve (the eighth cranial nerve). The study examined 106 cases that were seen at the one centre in Copenhagen that sees all patients with this disorder in Denmark. Each case was matched with 2 controls, and the use of cell phones prior to diagnosis was examined. The relative risk of acoustic neuroma was 0.90. A relative risk of 1 or less indicates no increased risk.

Several other studies have also concluded that there is no increased risk of this tumour in cell phone users. The exception to this was a study by Hardell and colleagues in Sweden that did find an increased risk. Several reviewers have criticized the Swedish study on methodological grounds. For more, see "Research -Epidemiology".

The Danish group is the first to report findings from the international case-control study that is underway at present (see "Research Programs - IARC).

Reference: Christensen HC, Schuz J, Kosteljanetz M, Skovgard H, et al.(2004): Cellular telephone use and risk of acoustic neuroma. Am J Epidemiol 159:277-283.


Children and mobile phones (1)

The Independent Expert Group on Mobile Phones (IEGMP) in the UK, in its 2000 report, stated:

"If there are currently unrecognised adverse health effects from the use of mobile phones, children may be more vulnerable because of their developing nervous system, the greater absorption of energy in the tissues of the head, and a longer lifetime of exposure".

The Electromagnetic Fields Committee of the Health Council of the Netherlands has reviewed the scientific evidence and could not find data to back the statement of the IEGMP. The Committee concluded that
"no major changes in head development occur after the second year of life that might point at a difference in electromagnetic susceptibility between children and adults. The Health Council therefore sees no reason to recommend limiting the use of mobile phones by children".

Reference: van Rongen E, Roubos EW, van Aernsbergen LM, Brussaard G, et al. (2004): Mobile phones and children: Is precaution warranted? Bioelectromagnetics 25:142-144.


Children and mobile phones (2)

This topic is also explored in a recent publication. The authors used a computational technique to estimate the Specific Absorption Rate (SAR) in heads of different sizes. They concluded:
"higher SAR in children's brains can be expected depending on whether the thickness of their skulls and surrounding tissues actually depends on size".

Reference: Martinez-Burdalo M, Martin A, Anguiano M, Villar R (2004): Comparison of FDTD-calculated specific absorption rate in adults and children when using a mobile phone at 900 MHz and 1800 MHz. Physics in Medicine and Biology 49:345-354.


Another study on brain function

A recent study has shown that exposure to EMFs from a cell phone at 902MHz frequency was associated with a decrease in reaction time. This was more prominent in a group who had received the exposure for 45 minutes before embarking on the tests of brain function, compared to those who had the RFR exposure during performance of the tests.

Other studies have shown changes in reaction times with exposure to RFR, though the results have not been consistent. For more, see "Research - Clinical Experiments - cognitive function".

Reference: Curcio G, Ferrara M, de Gennaro L, Cristiani R, et al. (2004): Time-course of electromagnetic field effects on human performance and tympanic temperature. Neuroreport 15:161-164.


No increase in ODC activity with RFR

Ornithine decarboxylase (ODC) is an enzyme that is involved in the growth of normal and cancer cells. Several studies have shown increased ODC levels in laboratory experiments after exposure to RFR. A recent paper reports an attempt to replicate one of these studies. In contrast to the earlier study, there was no increase of ODC activity after exposure to RFR from a cell phone with a frequency of 835 MHz. If sufficient power was used to cause increased temperature in the tissues, a decrease in ODC activity, rather than an increase, was observed.

For more, see "Research - Toxicological Experiments - cancer".

Reference: Desta, A. B., Owen RD, Cress LW (2003): Non-thermal exposure to radiofrequency energy from digital wireless phones does not affect ornithine decarboxylase activity in L929 cells. Radiat.Res.160:488-491.