July 2003

No genotoxic effects from RF fields in human blood cells ….

Researchers from Health Canada have failed to find evidence of genotoxicity in human blood cells exposed for 24 hours to either pulsed or continuous wave RF radiation from a 1.9 GHz field. The authors comment that of the four studies assessing the effect of a 24-hour RF-field exposure on human blood cells, only one has shown an increase in micronucleated cells (a sign of chromosome damage). They suggest that the positive study may have been due to increased temperatures in the cell cultures.

Reference: McNamee JP, Bellier PV, Gajda GB, Lavallée BF, et al. (2003): No evidence for genotoxic effects from 24 hr exposure of human leukocytes to 1.9 GHz radiofrequency fields. Radiat Res 159:693-697.

… or in rats

The authors state that their study is the first large-scale investigation in rats examining a potential genotoxic effect of chronic, low-level exposure to 1.6 GHz RF radiation. Rats were exposed for 2 hours per day, five days per week, for 2 years. The incidence of micronuclei was no different in the red blood cells of exposed rats than in sham-exposed rats.
Reference: Vijayalaxmi, Sasser L, Morris JE, Wilson BW, et al. (2003): Genotoxic potential of 1.6 GHz wireless communication signal: in vivo two-year bioassay. Radiat Res 159: 558-564.

For more on these studies, see "Research - Toxicological Experiments - cancer studies".

Hands-free accessories do not increase energy absorption in the head

In the April 2000 issue of Which? Magazine, the UK Consumers' Association published a report on hands-free accessories for mobile phones. They reported that tests showed that the use of these accessories increases the deposition of radiofrequency (RF) energy in the head by up to three times compared to a mobile phone alone held close to the head.

Now a group from the Motorola Florida Research Laboratories reports the opposite - the hands-free accessories decrease the RF energy exposure in the head. They state that the UK tests "were not performed with internationally recommended methodologies for SAR measurements aimed at determining compliance with RF-radiation exposure limits". The authors point out two main deficiencies in the methodology used in the UK study. The first was the use of a model without the equivalent of the human torso. If at least some of the wire runs close to the torso, the RF exposure is significantly lower in the head because the human body attenuates the electromagnetic field along the wire. The second was the positioning of the phone 13 mm from the ear, which introduced an artificial reduction in SAR, compared to the device operating next to the ear.

Reference: Bit-Babik, G, Chou CK, Faraone A, Gessner A, et al. (2003): Estimation of the SAR in the human head and body due to radiofrequency radiation exposure from handheld mobile phones with hands-free accessories. Radiation Research 159:550-557.

Swiss report on RF health effects

Reports on the health effects of RF radiation have appeared frequently from various countries in the last few years. In addition to the reports from the Royal Society of Canada and the Independent Expert Group on Mobile Phones from the UK (see "Links"), there have been others from the Netherlands (see "What's New", April 2002) and from France and Norway ("What's New", May 2003). Now the Swiss Federal bureau for environment, forest and landscape has released a report on high frequency radiation and health by Dr Röösli of the University of Bern and Dr Rapp of the Institute for Social and Preventive Medicine at the University of Basel. Their final conclusions are that "The survey shows that no conclusive assessment of the risk to human health may be made on the basis of present scientific data". A summary in English can be found at www.umwelt-schweiz.ch/buwal/de/fachgebiete/fg_nis/news/2003-04-14-00385/index.html

CTIA announces new research programs

The Cellular Telecommunications and Internet Association (CTAI) has announced funding for Phase 2 of CRADA - the Cooperative and Development Agreement with the Food and Drug Administration of the USA. The new research will focus on epidemiology, and in particular on the best epidemiological tools for measuring exposure to RF energy from wireless phones. The two funded studies are expected to conclude by the fall of 2005. More details can be found at the CTIA web site www.wow-com.com and at www.fda.gov.cellphones.

No increase in brain tumour rates in New Zealand

A new study has found no increase in the incidence of malignant brain tumours in New Zealand since the introduction of cell phones in 1987. This includes those sites of the head and neck that hypothetically receive the highest levels of RF radiation during phone use. However, acoustic neuroma, a tumour type that has been implicated in studies by Hardell's group (see "Research - Clinical studies - Epidemiology"), was not included. The authors caution that ecological studies such as this are limited in many ways.

Reference: Cook A, Woodward A, Pearce N, Marshall C (2003): Cellular telephone use and time trends for brain, head and neck tumours. NZMJ 116:No. 117

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