Octubre 2004

Swedish study reports increased risk of acoustic neuroma with cell phone use

This study was part of the INTERPHONE study, an international case-control study of brain tumours, acoustic neuroma, and parotid gland tumours in relation to mobile phone use. It was population-based, and included all persons age 20 to 69 years of 3 geographical areas covered by the Cancer Registries in Stockholm, Göteborg, and Lund.
The study was carried out in 1999-2002. There were 148 cases and 604 controls. For regular use, regardless of duration, the relative risk was estimated to be 1.0. For those with at least 10 years (14 cases) since first regular use, the odds ratio (OR) was 1.9. This figure, which suggests a near-doubling of the risk for phone users, compared with non-users, was not quite statistically significant. For those with 5-9 years since first regular use, the OR was 1.1. For ipsilateral use (use of the phone on the same side as the tumour occurred) those with at least 10 years since first regular use had an OR of 3.9 (an almost four-fold increased risk). For 5-9 years the OR was 1.1.

The authors conclude:

"Our findings do not indicate an increased risk of acoustic neuroma related to short-term mobile phone use after a short latency period. However, our data suggest an increased risk of acoustic neuroma associated with mobile phone use of at least 10 years duration".

Acoustic neuroma is a rare benign tumour of the auditory nerve, and causes dizziness, hearing loss, and tinnitus (a ringing in the ears). It affects between 1 - 20 people per million population per year. There have been a number of other studies that have examined the relationship between this tumour and the use of cell phones. Most have had very few cases with long-term use of cell phones. More results are expected from the INTERPHONE study within the next year or two. For more, see "Research - Epidemiology".

Reference: Lonn S, Ahlbom A, Hall P, Feychting M. Mobile phone use and the risk of
acoustic neuroma. Epidemiology 2004;15:653-659.

No association between cell phone use and salivary gland tumours

Hardell and associates have published a series of papers on studies that examined a possible association between cell phones and brain tumours (for more, see "What's New", November '99, June '00, April and July '01, August and November '02, and April '03). They have now studied cell phone use and salivary gland tumours, and have found no association. They obtained information on 267 cases reported to Swedish cancer registries between 1994 and 2000, and compared them to 1053 controls. The authors caution that their study does not permit conclusions about long term heavy use of cell phones. For more, see "Research - Epidemiology".

Reference: Hardell L, Hallquist A, Mild KH, Carlberg M, et al. (2004): No association
between the use of cellular or cordless telephones and salivary gland tumours. Occup Environ Med 61:675-679.


IEEE Transactions publish papers on RF radiation
A recent edition of IEEE Transactions on Microwave Theory and Techniques published a number of papers dealing with research techniques used in the investigation of the effects of radiofrequency radiation. Amongst the topics discussed were dosimetry, exposure systems, and SAR measurement. Some of the papers are referenced below.

References: Gandhi OP, Kang G (2004): Inaccuracies of a plastic "pinna" SAM for SAR testing of cellular telephones against IEEE and ICNIRP safety guidelines. IEEE Transactions on Microwave Theory and Techniques 52: 2004-2012.

Stoykov NS, Jerome JW, Pierce LC, Taflove A (2004): Computational modeling evidence of a nonthermal electromagnetic interaction mechanism with living cells: Microwave nonlinearity in the cellular sodium ion channel. IEEE Transactions on Microwave Theory and Techniques 52:2040-2045.

Schuderer J, Samaras T, Oesch W, Spat D, et al. (2004): High peak SAR exposure unit with tight exposure and environmental control for in vitro experiments at 1800 MHz. IEEE Transactions on Microwave Theory and Techniques 52:2057-2066.

Schuderer J, Spat D, Samaras T, Oesch W, et al. (2004): In vitro exposure systems for RF exposures at 900 MHz. IEEE Transactions on Microwave Theory and Techniques 52:2067-2075

Leveque P, Dale C, Veyret B, Wiart J (2004): Dosimetric analysis of a 900 MHz rat head exposure system. IEEE Transactions on Microwave Theory and Techniques 52:2076-2083.


Failure to replicate EMF effect on short term memory

The authors of this study reported previously that electromagnetic fields (EMFs) emitted by a mobile phone facilitate short term memory functioning (Koivisto, 2002b). In the present study they attempted to replicate their earlier findings. However, there were some modifications: the short term memory test was slightly modified, the phone battery was quieter, the phone was attached to the head more comfortably, exposure conditions were separated by 24 hours, and additional tests of cognitive function were included. Improvements in the methodology were that the testing was performed in two independent laboratories (in Sweden and Finland) and was of a double blind design.

In this study the EMFs (from a 902 MHz phone) had no effect on the subjects' reaction times or the accuracy of their responses, compared with sham exposure.

For more, see "Research - Clinical Experiments - Cognitive function".

Reference: Haarala C, Ek M, Bjornberg L, Laine M, et al. (2004): 902 MHz mobile phone does not affect short term memory in humans. Bioelectromagnetics 25:452-456.