Annemarie Maes

Genetic, carcinogenic and teratogenic effects of radiofrequency fields.

This paper reviews the literature data on the genetic toxicology of radiofrequency (RF) radiation. Whereas in the past most studies were devoted to microwave ovens and radar equipment, it is now mobile telecommunication that attracts most attention. Therefore we focus on mobile telephone frequencies where possible. According to a great majority of the papers, radiofrequency fields, and mobile telephone frequencies in particular, are not genotoxic: they do not induce genetic effects in vitro and in vivo, at least under non-thermal exposure conditions, and do not seem to be teratogenic or to induce cancer. Yet, some investigations gave rather alarming results that should be confirmed and completed by further experiments. Among them the investigation of synergistic effects and of possible mechanisms of action should be emphasised.

Screening of medicinal plants used in South African traditional medicine for genotoxic effects

Dichloromethane and 90% methanol extracts from 51 South African medicinal plants were evaluated for potential genotoxic effects using the bacterial Ames and VITOTOX tests with and without metabolic activation. Dichloromethane extracts from bulbs of Crinum macowanii showed mutagenicity in strain TA98 with and without metabolic activation, whereas extracts from leaves of Chaetacme aristata and foliage of Plumbago auriculata showed mutagenicity and/or toxicity. Extracts from the leaves of Catharanthus roseus and twigs of Combretum mkhzense were mutagenic with metabolic activation only. The only 90% methanol extracts that were mutagenic in strain TA98 were from the leaves of C. roseus and Ziziphus mucronata in the presence of metabolic activation. No genotoxic effects were found in strain TA100 or in the VITOTOX test.

954 MHz microwaves enhance the mutagenic properties of mitomycin C

This paper focuses on the combined effects of microwaves from mobile communication frequencies and a chemical DNA damaging agent mitomycin C (MMC). The investigation was performed in vitro by exposing whole blood samples to a 954 MHz emitting antenna from a GSM (Global System for Mobile Communication) base station, followed by lymphocyte cultivation in the presence of MMC. A highly reproducible synergistic effect was observed as based on the frequencies of sister chromatid exchanges in metaphase figures.

Cytogenetic effects of 900 MHz (GSM) microwaves on human lymphocytes

The cytogenetic effects of 900 MHz radiofrequency fields were investigated with the chromosome aberration and sister chromatid exchange frequency methods. Three different modes of exposure (continuous, pseudo-random and dummy burst) were studied for different power outputs (0, 2, 8, 15, 25, 50 W). The specific absorption rates varied between 0 and 10 W/kg. We investigated the possible effects of the 900 MHz radiation alone as well as of combined exposure to the chemical or physical mutagens mitomycin C and X-rays. Overall, no indication was found of a mutagenic, and/or co-mutagenic/synergistic effect of this kind of nonionizing radiation.

Cytogenetic effects of 50 Hz magnetic fields of different magnetic flux densities

Cytogenetic investigations were performed in human peripheral blood lymphocytes following exposure to 50 Hz magnetic fields alone or in combination with the chemical mutagen mitomycin C or with X-rays. It was found that magnetic fields up to 2500 microT did not significantly influence the chromosome aberration and sister chromatid exchange frequency. Also, the combined treatments failed to indicate the presence of any synergistic, potentiating, or antagonistic effect between the ELF magnetic fields and the mutagens. However, there were two exceptions: Cells exposed to 504 microT magnetic fields before and during cultivation displayed a statistically significant decrease in sister chromatid exchange frequency. Also, when cells were cultivated in the presence of 88.4 microT magnetic fields following X-ray exposures there was a significant increase in chromosome aberration frequency compared to X-ray exposure alone.

Lipoatrophia semicircularis: An Electromagnetic Hypothesis

The medical literature describes Lipoatrophia semicircularis (L.s.) as a rare, idiopathic condition characterized by semicircular impressions of the skin, at the front and sides of both thighs. A few years ago, L.s. was diagnosed in hundreds of people, mainly women, among the administrative personnel of two large companies in Belgium. Afterwards, other cases were reported to us in numerous other companies, also in other countries including the Netherlands, France, the United Kingdom, Germany, and Italy. L.s. is thus not as uncommon as previously thought and apparently seems to become an important job‐related illness. We investigated the occurrence and cause of Lipoatrophia semicircularis by registering all recently known cases and paying particular attention to the working conditions of the persons with L.s. Following the elaboration of a working hypothesis, a number of measures were taken inside offices in an attempt to prevent new cases and/or obtain remissions. Some measurements were also performed with regard to the electromagnetic environment of the workplaces. Lipoatrophia semicircularis occurs preferentially in administrative female personnel working in new or renovated office buildings. All afflicted persons work with computers or are at least working in the proximity of electrical devices. It soon became evident that this electric environment plays a major role in the occurrence of L.s., although other factors (e.g., inadequate sitting posture and dry ambient air) may further facilitate L.s. According to our observations, L.s. finds its origin in the electromagnetic environment of work places. It apparently occurs as a result of galvanic coupling between charged materials and the body.

Can cytogenetics explain the possible association between exposure to extreme low-frequency magnetic fields and Alzheimer's disease?

Recently, a number of epidemiological studies have suggested that occupational as well as residential exposure to extreme low‐frequency electromagnetic fields (ELF‐EMFs) may be a risk factor for Alzheimers disease. This is not proven yet and there are no known biological mechanisms to explain this alleged association. Alzheimers disease is characterized by a number of events that have, at least partially, a genetic origin. In particular, trisomy of chromosomes 17 and 21 seems to be involved. Overall ELF‐EMFs have not been identified as genotoxic agents, but there are some papers in the scientific literature that indicate that they may enhance the effects of agents that are known to induce mutations or tumors. There are also some indications that ELF‐EMFs may induce aneuploïdy. This opens some perspectives for investigating the alleged association between ELF‐EMFs and Alzheimers. This paper reviews the possibility of a cytogenetic association between the electromagnetic fields and Alzheimers disease. Copyright

In vitro investigations related to the hypothesis that Lipoatrophia semicircularis finds its origin in electro-stimulation

Lipoatrophia semicircularis (L.s.) is an idiopathic condition characterized by semicircular impressions of the skin, usually at the front and sides of both thighs. It is characterized by atrophy of the subcutaneous adipocytes whereas the skin and muscles remain normal. L.s. was originally considered to be very rare but over the past 13 years an outburst of L.s. has been observed in companies in Belgium and later on also in companies in other countries (e.g., Spain) where several hundred individuals were diagnosed with L.s. All these subjects belonged to the administrative personnel and worked in renovated or new offices. Different hypotheses have been put forward to explain the appearance of Lipoatrophia semicircularis but the hypothesis of an ‘electric’ origin of L.s. is probably the best documented and plausible. The present study was aimed to further investigate the likelihood of this hypothesis. The alkaline comet assay was used to investigate DNA damage in cells of different origin following exposure to a (strong) electric current. It was found that adipocytes showed more DNA damage than the other cells and hence that they are more vulnerable to such a current than macrophages and white blood cells. It was also found that DNA damage is significantly induced by an electric current in the blood from L.s. subjects whereas this is not so in blood from subjects without L.s. This may indicate that L.s. subjects are more responsive to an induced electric current and supports the hypothesis of an ‘electric’ origin of L.s. Copyright

Genotoxicity investigation of ELF-magnetic fields in **Salmonella typhimurium** with the sensitive SOS-based VITOTOX test

We performed a genotoxicity investigation of extremely low-frequency (ELF) magnetic fields (MFs, 50 Hz, 100 and 500 µT, 1 and 2 h exposure) alone and in combination with known chemical mutagens using the VITOTOX test. This test is a very sensitive reporter assay of Salmonella typhimurium bacteria based on the SOS response. Our study showed that ELF-MFs do not induce SOS-based mutagenicity in S. typhimurium bacteria and do not show any synergetic effect when combined with chemical mutagens.

The Cytome Assay as a Tool to Investigate the Possible Association Between Exposure to Extremely Low Frequency Magnetic Fields and an Increased Risk for Alzheimer’s Disease

Exposure to extremely low frequency magnetic fields (ELF-MF) has been identified as one of the potential environmental risk factors for Alzheimers disease (AD). However, this is far from being established. So far there is no experimental evidence supporting this alleged association. We have performed an in vitro cytogenetic laboratory investigation to explore the plausibility of such association. Our investigation was based on possible similarities found in cells from AD patients and in cells exposed to ELF-MF. We especially found that 50  Hz ELF-MF increase the frequency of cells with (large) micronuclei and nuclear buds indicating that fields above 50 μT may induce chromosome instabilities as those found in AD patients. It should be stressed yet that results from the few published experimental studies on ELF-MF and AD are rather reassuring. Thus, our findings certainly do not prove anything. They only suggest that further investigations might be necessary.