Last month, results from a study conducted as part of the European Union's Risk Evaluation of Potential Environmental Hazards From Low Frequency Electromagnetic Field Exposure Using Sensitive in vitro Methods raised concerns that exposure to RF from cell phones could cause cancer. The National Radiological Protection Board (NRPB), in a response to the REFLEX study, said the results need to be considered in the context of existing published studies. The NRPB statement said, "It is well accepted from the totality of the available evidence that RF fields do not possess sufficient energy to cause direct damage to DNA. Many research groups worldwide have investigated the molecular and cellular effects of RF fields using in vitro cell systems."
NPRB admitted that some of the results from the REFLEX project challenge the 2003 opinion of the independent Advisory Group on Non-ionizing Radiation (AGNIR) that "although there has been a wide range of diverse exposures and biological models investigated, no consistent pattern has emerged from the cellular studies of RF exposure," and their opinion that positive findings have not been confirmed by other independent studies.
NPRB explained, "For example, genotoxic effects were observed in fibroblasts, granulosa cells and HL60 cells. In various assays, RF-exposed cells demonstrated an increase in single and double strand DNA breaks, and in micronucleus frequency; chromosomal aberrations were also seen in fibroblasts. Changes in the expression of specific genes, and alterations to proteins in human cell lines were also seen. There was no evidence that RF fields affected cell proliferation, apoptosis or immune function."
The results, according to NPRB, do indicate that certain types of exposure can cause genetic damage in certain cell types, but cautioned, "If RF fields do cause genotoxic or carcinogenic effect, a consistent pattern of responses would be expected. Similarly these responses would be expected to be consistent in different cell types exposed to the same fields." NPRB noted that the cell damage from RF exposure occurred in one cell type and not in others, that changes were observed at one field intensity and not a higher or lower intensities and that not all the responses have been consistently observed across the project.
NPRB concluded, "the REFLEX project provides some novel observations regarding the potential of RF fields to affect cellular and molecular processes in vitro. The results will no doubt stimulate further highly focused research to confirm or refute the findings."
NPFB said it would be issuing further advice on mobile phones and health early this year.
The complete European Union report, Risk Evaluation of Potential Environmental Hazards From Low Frequency Electromagnetic Field Exposure Using Sensitive in vitro Methods is available on the Internet. The study not only looked at RF exposure to GSM emissions at 1.8 GHz but at exposure to extremely low frequency electromagnetic fields (ELF/EMF) Interestingly enough, the genotoxic effect of ELF/EMF on human fibroblast was frequency dependent. The effect of exposure to a 1-mT field at frequencies of 3, 16.66, 30, 50, 300 and 550 Hz was tested. The effect clearly peaked at 50 Hz, a common power line frequency. It was also dependent on the age of the fibroblast donors--cells from older donors showed the greatest damage.
The results of the studies on cell exposure to the 1.8 GHz signal are interesting. As the NRPB statement pointed out, the effect of RF varied with the type of cell and the measurements conducted. In some cases, however, the effect of the 1.8 GHz signal on cells was clearly evident. You may be interested to know the study found that the generation of genotoxic effects from RF exposure was inhibited by ascorbic acid--vitamin C! In one study using HL-60 cells, ascorbic acid inhibited micronucleus frequency induction in cells exposed to a continuous wave 1.8 GHz signal at a SAR of 1.3 W/kg for 24 hours almost to the level of the sham-exposed cells.
Studies on DNA strand breaks in granulosa cells showed that continuous RF exposure for over 4 hours had less impact than similar exposure to intermittent, pulse modulation intermittent, or talk-modulation continuous signals. At exposure times of four hours, DNA strand breaks increased only slightly with RF exposure and not at all with continuous exposure. The SAR for these tests was 2.0 W/kg.
The report is 291 pages long and very detailed. However, if you work around RF or are interested in its effect on living cells, you may want to take a look at it.
