Marzo 2002

WHO clarifies position on base stations and cancer

The World Health Organization (WHO) issued a press release on January 23, 2002, clarifying its position regarding the mooted relationship between mobile phone base stations and cancer. It did so because of recent press coverage of a cluster of cancers in Spain in young children. It was claimed that EMF fields emitted from mobile telephone base stations caused the cancers. The media also stated that "the World Health Organization now recognizes electromagnetic fields as a probable or possible cause of cancer".

WHO points out that this is not what they have said, and refers to their Fact Sheet 193 for further information on their position. Confusion may have arisen because the International Agency for Cancer Research, a specialized agency of WHO on cancer, has classified extremely low frequency fields as a "possible human carcinogen". The agency states that Fact Sheet 263 explains this classification, and also points out that extremely low frequency fields are very different from the fields emitted from base stations.


Fertility increase in worms after exposure to weak microwave fields

In "What's New" of July 2000 we reported on experiments by de Pomerai and colleagues using the worm C. elegans. This group from the University of Nottingham in the UK has done new experiments using this species. This time they report that prolonged exposure of worm larvae to weak microwave fields (1000 MHz) alters their growth rate, as well as the proportion of worms later maturing into egg-bearing adults. The authors believe that the observed effects are non-thermal. For further details, see "Toxicological Experiments - Other studies".

Reference: de Pomerai DL, Dawe A, Djerbid L, Allan J, et al. (2002). Growth and maturation of the nematode Caenorhabditis elegans following exposure to weak microwave fields. Enzyme and Microbial Technology 30:73-79.

Increased frequency of micronucleated cells with RF exposure (1)

A recent paper by Tice and colleagues documents studies reported earlier at the Annual meeting of the Bioelectromagnetic Society in June, 2001. The authors evaluated potential genotoxicity of a variety of radiofrequency signals on human blood cells. No evidence of DNA damage was seen after either 3 or 24 hours of exposure. However, exposure for 24 hours at SARs of 5.0 or 10.0 W/kg resulted in an increased frequency of micronucleated lymphocytes. No increase was seen with an exposure of 3 hours.

The authors conclude "under extended exposure conditions RF signals at an average SAR of 5.0 W/kg are capable of inducing chromosomal damage in human lymphocytes". The authors also point out that there is a lack of consistency in the published reports of this type of research, and make a plea for additional studies.

For further details on this and other genotoxicity studies, see "Toxicological Experiments -cancer".

Reference: Tice RR, Hook GG, Donner M, McRee DI, et al. (2002). Genotoxicity of radiofrequency signals. 1. Investigation of DNA damage and micronuclei induction in cultured human blood cells. Bioelectromagnetics 23:113-126.

Increased frequency of micronucleated cells with RF exposure (2)

Another paper in Bioelectromagnetics reported an increased frequency of micronucleated cells following exposure to RF fields. On this occasion the GSM system was used in the experiment. Human lymphocytes were exposed to 1748 MHz for 15 minutes. The maximum SAR was 5 W/kg. There were no effects on cell proliferation. The increase in micronucleated cells was seen with a phase- modulated signal, but not with a continuous wave signal. The authors of the paper caution that this is the first time this effect has been reported with phase modulated RF signals, and their results need to be confirmed.

For further details on this and other genotoxicity studies, see "Toxicological Experiments -cancer".

Reference: D'Ambrosio G, Massa R, Scarfi MR, Zeni O (2002): Cytogenetic damage in human lymphocytes following GMSK phase modulated microwave exposure. Bioelectromagnetics 23:7-13.

Swedish scientists argue about public reporting of research

In the September/October 2001 Newsletter of the Bioelectromagnetics Society, there is a reprint of an editorial that was originally published in Sweden's leading newspaper on September 3, 2001. The authors, five eminent Swedish scientists, complain about a small number of scientists who "take liberties with the truth or make statements in the media against their own better judgment". Some of the examples quoted refer to research on mobile phones. In the next issue of the Newsletter (No. 163) there is a response by scientists who, although not named in the editorial, felt that their research, and their public discussion of it, had been criticized in the editorial.

The discussion raises interesting points about the responsibility of scientists when they make statements to the media about their research.


Mobile phones and malignant melanoma of the eye

Stang and colleagues previously reported an increased risk of uveal melanoma (a rare malignant tumour of the eye) in people using devices that employ RF radiation, including mobile phones (see "What's New", February 2001).

Johansen and others now point out that in Denmark the incidence of these tumours has remained stable during the period 1943 to 1996, despite the sharp increase in the number of mobile phone subscribers. They state "our study provides no support for an association between mobile phones and ocular melanoma".

This study was an ecological study, which is a weak design when a causal relationship between factors is being examined.

Reference: Johansen C, Boice JD Jr, McLaughlin JK, Olsen JM (2002): Mobile phones and malignant melanoma of the eye. British Journal of Cancer 86:348-9.

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