mayo 2002

Study finds no association between cell phone use and auditory tumours

The risk of acoustic neuroma (a rare and benign tumour of the auditory nerve) was unrelated to the frequency and duration of cell phone use, according to a recently published study. Muscat and his colleagues conducted a case-control study as part of a larger study on brain tumours (see "Research - Epidemiology" and "What's New", January 2001). They interviewed 90 patients with acoustic neuroma and 86 controls, focusing on handheld cellular telephone use and lifestyle. The risk of tumours did not increase with cell phone use and did not vary significantly by the frequency, duration, and lifetime hours of use. In patients who used cell phones the tumour occurred more often on the opposite side of the head from the side on which they used their phone.

The authors recommend that further studies should be conducted on long-term phone users. More details of this study can be found in "Research - Epidemiology".

Reference: Muscat JE, Malkin MG, Shore RE, Thompson S, et al. Handheld cellular telephone use and risk of acoustic neuroma. Neurology 2002;58:1304-1306.

Finnish study on brain tumours

Auvinen and colleagues from Helsinki have done a study on tumours of the brain and salivary glands, comparing ownership of cellular phones by tumour patients and controls. Their results were that "cellular phone use was not associated with brain tumors or salivary gland cancers overall, but there was a weak association between gliomas and analog cellular phones." The latter association was based on only 26 cases who had owned a cellular phone. The authors also state that a register-based approach has limited value because of lack of information on exposure. More details of this study can be found at "Research - Epidemiology".

Auvinen A, Hietanen M, Luukkonen R, Koskela R-S. Brain tumors and salivary gland cancers among cellular telephone users. Epidemiology 2002;13:356-359.

Microwaves fail to promote tumours in rats

In "Toxicological Experiments - cancer studies" we review studies that have looked at the effect of RF radiation on the promotion of tumours. Another study is now reported that is in agreement with the results of most other studies, which have shown no effect. Bartsch and colleagues did three experiments one year apart on rats that were given DMBA (a known carcinogen) and then exposed to RF radiation for 24 hours a day for 11 to 12 months. The radiation was the equivalent of that found 6.3 metres from a typical base station antenna of 200 W. There was no significant effect of the radiation on tumour latency (the time it takes for a tumour to develop) or on tumour incidence. There was a reduction in latency for the development of the first malignant tumour in each animal in the first experiment but not in the others. The authors have some difficulty in explaining this finding, since each experiment used similar, highly standardized conditions.

For further details, see "Toxicological Experiments - cancer studies".

Reference: Bartsch H, Bartsch C, Seebald E, Deerburg F, et al. (2002): Chronic exposure to a GSM-like signal (mobile phone) does not stimulate the development of DMBA-induced mammary tumors in rats: Results of three consecutive studies. Radiation Research 157:183-190.

- Or in mice

Another recent study also used DMBA, this time painted on the skins of ten-week-old mice, which were then exposed to 1.5 GHz (TDMA) signal for 90 minutes per day, 5 days a week, for 19 weeks. Control mice had the DMBA, but not the EMF, exposure. There were no differences in the incidence of skin tumours, or of leukaemias or lymphomas between the RF-exposed and the control mice.

This study is also summarized in more detail in " oxicological Experiments - cancer studies".

Reference: Imaida K, Kuzutani K, Wang J, Fujiwara O, et al. Lack of promotion of 7,12-dimethylbenz(a)anthracene initiated mouse skin carcinogenesis by 1.5 GHz electromagnetic near fields. Carcinogenesis 2001;11:1837-1841