31/08/2011 - August 2011 - Science Update

The following is a quick summary of another eighteen papers that have come out over the last few months related to effects of electromagnetic radiation. Some of the papers are notable papers that have been published very recently, others are papers that were published a few months ago that have not yet made it to one of the Science Updates.

The aim of this study was to evaluate an exposure assessment method that classifies apartments in three exposure categories of extremely low frequency magnetic fields (ELF-MF) based on the location of the apartment relative to the transformer room. We completed measurements in 39 apartments in 18 buildings. In each room of the apartments ELF-MF was concurrently measured with 5 to 6 EMDEX II meters for 10 min. Measured arithmetic mean ELF-MF was 0.59 µT in 8 apartments that were fully adjacent to a transformer room, either directly above the transformer or touching the transformer room wall-to-wall. In apartments that only partly touched the transformer room at corners or edges, average ELF-MF level was 0.14 µT. Average exposure in the remaining apartments was 0.10 µT. Kappa coefficient for exposure classification was 0.64 (95%-CI: 0.45-0.82) if only fully adjacent apartments were considered as highly exposed (> 0.4 µT). We found a distinct ELF-MF exposure gradient in buildings with transformer. Exposure classification based on the location of the apartment relative to the transformer room appears feasible. Such an approach considerably reduces effort for exposure assessment and may be used to eliminate selection bias in future epidemiologic studies.

The three-dimensional distribution of the specific absorption rate of energy (SAR) in phantom models was analysed to detect clusters of mobile phones producing similar spatial deposition of energy in the head. The clusters' characteristics were described from the phones external features, frequency band and communication protocol. Compliance measurements with phones in cheek and tilt positions, and on the left and right side of a physical phantom were used. Phones used the Personal Digital Cellular (PDC), Code division multiple access One (CdmaOne), Global System for Mobile Communications (GSM) and Nordic Mobile Telephony (NMT) communication systems, in the 800, 900, 1500 and 1800 MHz bands. Each phone's measurements were summarised by the half-ellipsoid in which the SAR values were above half the maximum value. Cluster analysis used the Partitioning Around Medoids algorithm. The dissimilarity measure was based on the overlap of the ellipsoids, and the Manhattan distance was used for robustness analysis. Within the 800 MHz frequency band, and in part within the 900 MHz and the 1800 MHz frequency bands, weak clustering was obtained for the handset shape (bar phone, flip with top and flip with central antennas), but only in specific positions (tilt or cheek). On measurements of 120 phones, the three-dimensional distribution of SAR in phantom models did not appear to be related to particular external phone characteristics or measurement characteristics, which could be used for refining the assessment of exposure to radiofrequency energy within the brain in epidemiological studies such as the Interphone.

Some epidemiologic studies have suggested that extremely low frequency magnetic fields might affect human health and, in particular, that the incidence of certain types of cancer might increase among individuals living or working in environments exposed to such fields. This study is part of a broad study we conducted in humans. The study presented here was designed to look for possible effects of acute exposure to 50-Hz magnetic fields (10 µT) on the interleukin 1 beta (IL-1Β), interleukin 2 (IL-2), interleukin 6 (IL-6), interleukin-1 receptor antagonist (IL-1RA), and the interleukin-2 receptor (IL-2R) production. Thirty-two young men (20-30 years old) were divided into two groups (sham-exposed or control group and exposed group) of 16 subjects each. All subjects participated in two 24-h experiments to evaluate the effects of both continuous and intermittent (1 h "off" and 1 h "on" with the field switched "on" and "off" every 15 s) exposure to linearly polarized magnetic fields. The subjects were exposed to the magnetic field from 2300 to 0800 while recumbent. Blood samples were collected during each session at 11:00, 17:00, 22:00, 01:00, 04:00, 06:00, and 08:00. Results showed that exposure to 50-Hz magnetic fields (10 µT) significantly increases IL-6 when subjects were exposed to an intermittent magnetic field. However, no effect has been observed on interleukin IL-1Β, IL-2, IL-1RA, and IL-2R. This paper has identified a significant effect on protein that is part of the human immune response. However, the magnetic field strength used (10 µT;) is considerably higher than the majority of the public will be exposed to for prolonged periods. That they did not find similar effects with the other elements of the human immune system that they assessed demonstrates the importance that cellular and mechanistic studies should focus on replicating the positive effects that have been found.

Vestibular schwannomas grow in the region within the brain where most of the energy by radiofrequency electromagnetic fields from using mobile phones is absorbed. The authors used 2 Danish nationwide cohort studies, one a study of all adult Danes subscribing for a mobile phone in 1995 or earlier and one on sociodemographic factors and cancer risk, and followed subjects included in both cohorts for occurrence of vestibular schwannoma up to 2006 inclusively. In this study including 2.9 million subjects, a long-term mobile phone subscription of ≥ 11 years was not related to an increased vestibular schwannoma risk in men (relative risk estimate = 0.87, 95% confidence interval: 0.52, 1.46), and no vestibular schwannoma cases among long-term subscribers occurred in women versus 1.6 expected. Vestibular schwannomas did not occur more often on the right side of the head, although the majority of Danes reported holding their mobile phone to the right ear. Vestibular schwannomas in long-term male subscribers were not of larger size than expected. Overall, no evidence was found that mobile phone use is related to the risk of vestibular schwannoma. Because of the usually slow growth of vestibular schwannoma and possible diagnostic delay, further surveillance is indicated. It would be interesting to see if this study used the same cohort as their previous cohort study, which we criticised severely due to the very low quality of data they were able to obtain: of the 620,000 people they intended to include, not only were pay-as-you-go users excluded (much more common in the 90s), but the 200,000 heaviest contract users were also unable to be identified and therefore included in the "non-user" comparison by the methodology of the study (a retrospective cohort study such as this one compares known individuals and their exposures against the base rate for the population base, normally the countries standardised incidence rate). If so, it is unlikely that this study offers a particularly useful contribution to the literature.

Objectives The relationship between electromagnetic field exposure and stillbirth has not been evaluated. We assessed associations between residential proximity to extremely low frequency power transmission lines and stillbirth across gestational age. Methods Data included singleton live births (N=514 826) and stillbirths (N=2033) for 1998-2007 in metropolitan areas of Québec, Canada. Using power transmission line maps, the distances between lines and residential six-digit postal codes (<25, 25-49.9, 50-74.9, 75-99.9, =100 m) were calculated. Generalised estimating equations were used to compute ORs and 95% CIs for distance and stillbirth, accounting for individual and area characteristics. Early preterm (<28 weeks), late preterm (28-36 weeks) and term (=37 weeks) stillbirths were examined relative to fetuses-at-risk. Results There was no association between distance and preterm stillbirth. The odds of term stillbirth for <25 m were greater compared to =100 m (OR 2.25, 95% CI 1.14 to 4.45), but no dose-response pattern was apparent. Conclusions A graded dose-response trend between distance to lines and odds of stillbirth was not found, but the likelihood of term stillbirth was elevated for residences within 25 m of power transmission lines. Residential proximity to transmission lines is unlikely to be associated with stillbirth, but more research is needed to rule out a possible link.

Pollution caused by the electromagnetic fields (EMFs) of radio frequencies (RF) generated by the telecommunication system is one of the greatest environmental problems of the twentieth century. The purpose of this research was to verify the existence of a spatial correlation between base station (BS) clusters and cases of deaths by neoplasia in the Belo Horizonte municipality, Minas Gerais state, Brazil, from 1996 to 2006 and to measure the human exposure levels to EMF where there is a major concentration of cellular telephone transmitter antennas. A descriptive spatial analysis of the BSs and the cases of death by neoplasia identified in the municipality was performed through an ecological-epidemiological approach, using georeferencing. The database employed in the survey was composed of three data banks: 1. death by neoplasia documented by the Health Municipal Department; 2. BSs documented in ANATEL ("Agência Nacional de Telecomunicações": 'Telecommunications National Agency'); and 3. census and demographic city population data obtained from official archives provided by IBGE ("Instituto Brasileiro de Geografia e Estatística": 'Brazilian Institute of Geography and Statistics'). The results show that approximately 856 BSs were installed through December 2006. Most (39.60%) of the BSs were located in the "Centro-Sul" ('Central-Southern') region of the municipality. Between 1996 and 2006, 7191 deaths by neoplasia occurred and within an area of 500m from the BS, the mortality rate was 34.76 per 10,000 inhabitants. Outside of this area, a decrease in the number of deaths by neoplasia occurred. The greatest accumulated incidence was 5.83 per 1000 in the Central-Southern region and the lowest incidence was 2.05 per 1000 in the Barreiro region. During the environmental monitoring, the largest accumulated electric field measured was 12.4V/m and the smallest was 0.4V/m. The largest density power was 40.78 µW/cm(2), and the smallest was 0.04 µW/cm(2). Whilst this study has clearly found a significant increase in death by neoplasia for those living within 500m of a mobile phone base station (unlikely to be psychosomatic or some form of nocebo effect), the ability to closely control the data is limited. Despite this, 850 base stations does generate a large amount of data, so if the exposure to the base station is not responsible for the increased deaths, it is likely to be acting as a proxy for something else (such as socioeconomic status, if the base stations are located in poorer, more densely populated regions).

The aim of this study was to investigate the effects induced by an exposure to a GSM signal (Global System for Mobile Communication) on brain BOLD (blood-oxygen-level dependent) response, as well as its time course while performing a Go-NoGo task. Participants were tested twice, once in presence of a "real" exposure to GSM radiofrequency signal and once under a "sham" exposure (placebo condition). BOLD response of active brain areas and reaction times (RTs) while performing the task were measured both before and after the exposure. RTs to the somatosensory task did not change as a function of exposure (real vs sham) to GSM signal. BOLD results revealed significant activations in inferior parietal lobule, insula, precentral and postcentral gyri associated with Go responses after both 'real' and 'sham' exposure, whereas no significant effects were observed in the ROI analysis. The present fMRI study did not detect any brain activity changes by mobile phones. Also RTs in a somatosensory task resulted unaffected.

Whether or not there is a relationship between use of mobile phones (analogue and digital cellulars, and cordless) and head tumour risk (brain tumours, acoustic neuromas, and salivary gland tumours) is still a matter of debate; progress requires a critical analysis of the methodological elements necessary for an impartial evaluation of contradictory studies. A close examination of the protocols and results from all case-control and cohort studies, pooled- and meta-analyses on head tumour risk for mobile phone users was carried out, and for each study the elements necessary for evaluating its reliability were identified. In addition, new meta-analyses of the literature data were undertaken. These were limited to subjects with mobile phone latency time compatible with the progression of the examined tumours, and with analysis of the laterality of head tumour localisation corresponding to the habitual laterality of mobile phone use. Blind protocols, free from errors, bias, and financial conditioning factors, give positive results that reveal a cause-effect relationship between long-term mobile phone use or latency and statistically significant increase of ipsilateral head tumour risk, with biological plausibility. Non-blind protocols, which instead are affected by errors, bias, and financial conditioning factors, give negative results with systematic underestimate of such risk. However, also in these studies a statistically significant increase in risk of ipsilateral head tumours is quite common after more than 10 years of mobile phone use or latency. The meta-analyses, our included, examining only data on ipsilateral tumours in subjects using mobile phones since or for at least 10 years, show large and statistically significant increases in risk of ipsilateral brain gliomas and acoustic neuromas. Our analysis of the literature studies and of the results from meta-analyses of the significant data alone shows an almost doubling of the risk of head tumours induced by long-term mobile phone use or latency. An interesting and detailed meta-analysis (freely available), assessing both the quality and depth of the data and methodology in a large number of existing case-control mobile phone studies. Covering both Hardell's work, and the Interphone papers, they have concluded that the better designed studies have consistently demonstrated an increased ipsilateral risk for brain tumours from extended mobile phone use, and even the more poorly designed studies also indicate an increase for greater than 10 years of use.

Standards stipulate 6-min time interval of averaging for measurements of radio-frequency electromagnetic fields to assess human exposure to non-ionising radiation. Having in mind the base stations of public land mobile systems, the time interval defined in such a way noticeably limits the number of measuring points in practical applications. In this paper, based on the results of measurements in the vicinity of a multisystem base station (Global System for Mobile Communications [GSM], Digital Communication System [DCS] and Universal Mobile Telecommunications System [UMTS]), it was shown that the measurement process can be significantly accelerated by using shorter time intervals of averaging-15 s, 30 s and 1 min. It was found that measurement results differed from the 6-min root-mean-square mean by 10.5 %, 15.9 and 19 %, respectively, while the uncertainty of the measurements was increased by 3.0 %, 3.8 and 4.4 %, respectively. Shorter time-averaging intervals would reduce the total duration of the exposure assessment survey, while not compromising too much on measurement quality.

This study investigated the effects of microwave radiation on the PVN of the hypothalamus, extracted from rat brains. Expression of c-Fos was used to study the pattern of cellular activation in rats exposed once or repeatedly (ten times in 2 weeks) to 2.45 GHz radiation in a GTEM cell. The power intensities used were 3 and 12 W and the Finite Difference Time Domain calculation was used to determine the specific absorption rate (SAR). High SAR triggered an increase of the c-Fos marker 90 min or 24 h after radiation, and low SAR resulted in c-Fos counts higher than in control rats after 24 h. Repeated irradiation at 3 W increased cellular activation of PVN by more than 100% compared to animals subjected to acute irradiation and to repeated non-radiated repeated session control animals. The results suggest that PVN is sensitive to 2.45 GHz microwave radiation at non-thermal SAR levels. This interesting piece of research demonstrated that repeated irradiation from a 3W 2.45 GHz source had a stronger effect on rat brain cells than shorter exposures from a 12W source. It appears clear that, for assessing the mechanistic effects of mobile phone radiation, using the correct exposure is important - assuming that a higher exposure should generate the same effects (but quicker) may not be the case.

Extremely low-frequency magnetic fields (ELF-MFs) may affect human health because of the possible associations with leukaemia but also with cancer, cardiovascular and neurological disorders. In the present work, human SH-SY5Y neuroblastoma cells were exposed to a 50 Hz, 1 mT sinusoidal ELF-MF at three different times i.e. 5 days (T5), 10 days (T10) and 15 days (T15) and then the effects of ELF-MF on proteome expression and biological behaviour were investigated. Through comparative analysis between treated and control samples, we analyzed the proteome changes induced by ELF-MF exposure. 9 new proteins resolved in sample after a 15 day treatment, were involved in a cellular defence mechanism and/or in cellular organization and proliferation such as peroxiredoxin isoenzymes (2, 3 and 6), 3-mercaptopyruvate sulfurtransferase, actin cytoplasmatic 2, t-complex protein subunit beta, ropporin-1A and profilin-2 and spindlin-1. Our results indicated that ELF-MFs exposure altered the proliferative status and other important cell biology-related parameters, such as cell growth pattern, and cytoskeletal organization. These findings support our hypothesis that ELF radiation could trigger a shift towards a more invasive phenotype. This is another ELF paper demonstrating cellular effects - however, the exposure levels (1,000 µT) are well above public exposure levels, and the applicability of these results to human health is limited.

After measuring extremely low frequency electric and magnetic fields (ELF-EFs, ELF-MFs) and radio frequency electromagnetic fields (RF-EMFs) in 2006, a follow-up investigation was done in 2009. Overall, 130 measurements in bedrooms at identical and 83 at changed locations within the same or a neighbouring building were performed. The median of ELF-EFs decreased from 25.15 to 17.35 V m(-1) from 2006 to 2009. The median of all-night ELF-MFs from power supply decreased from 16.86 to 12.76 nT, whereas the arithmetic mean was almost unchanged (+0.1 %). No difference in the medians of all-night ELF-MFs of railway current was observed. RF-EMFs increased from 41.35 to 59.56 µW m(-2). Increases primarily occurred in the frequency ranges of Global System for Mobile 900 MHz, Universal Mobile Telecommunications System and Wireless Local Area Network. Television changeover from analogue to digital resulted in a reduction within the Ultra-high Frequency-band from 0.47 to 0.35 µW m(-2). The base stations of the recently established terrestrial trunked radio system caused a median of 0.05 µW m(-2).

The purpose of the precautionary principle is that legal requirements are to be made to safeguard against the possible health risks that have not yet been scientifically established. That a risk is not established cannot, therefore, be used as an excuse for not applying the principle. Yet, that rationale is exactly what is happening in the case of the possible health risks from exposure to electromagnetic fields (EMF). The scientists, representing both the World Health Organization and the European Commission, do not have at all the precautionary principle in mind when they report on health risks. Their starting point is instead to determine whether new research findings have been scientifically established and thus cannot be the basis for an amendment to the existing exposure limits. Uncertain indications of risk are ignored or played down. This approach is in conflict with European Union (EU) law, which requires that the degree of scientific uncertainty should be presented correctly. A thorough examination of the state of research shows many serious indications of possible health risks from exposure very far below existing limits for EMF. Case law, for other types of exposure, also shows that the precautionary principle can be applied on the basis of weaker evidence than that. Our investigation shows that the precautionary principle is not being used for its intended purpose in relation to exposure to EMF. The reason for this position is that decision-makers are being misled by inaccurate risk assessments.

The biological effects of modulated radiofrequency (RF) electromagnetic fields have been a subject of debate since early publications more than 30 years ago, suggesting that relatively weak amplitude-modulated RF electromagnetic fields have specific biological effects different from the well-known thermal effects of RF energy. This discussion has been recently activated by the increasing human exposure to RF fields from wireless communication systems. Modulation is used in all wireless communication systems to enable the signal to carry information. A previous review in 1998 indicated that experimental evidence for modulation-specific effects of RF energy is weak. This article reviews recent studies (published after 1998) on the biological effects of modulated RF fields. The focus is on studies that have compared the effects of modulated and unmodulated (continuous wave) RF fields, or compared the effects of different kinds of modulations; studies that used only one type of signal are not included. While the majority of recent studies have reported no modulation-specific effects, there are a few interesting exceptions indicating that there may be specific effects from amplitude-modulated RF fields on the human central nervous system. These findings warrant follow-up studies.

The present study was carried out to find the effect of cell phone radiations on various biomolecules in the adult workers of Apis mellifera L. The results of the treated adults were analyzed and compared with the control. Radiation from the cell phone influences honey bees' behavior and physiology. There was reduced motor activity of the worker bees on the comb initially, followed by en masse migration and movement toward "talk mode" cell phone. The initial quiet period was characterized by rise in concentration of biomolecules including proteins, carbohydrates and lipids, perhaps due to stimulation of body mechanism to fight the stressful condition created by the radiations. At later stages of exposure, there was a slight decline in the concentration of biomolecules probably because the body had adapted to the stimulus. This is an interesting pilot study assessing biochemical changes to the hemolymph of worker bees. They took samples 10 minutes, 20 minutes and 40 minutes after beginning exposure to phones (of an unspecified network and model). Their findings were that concentrations of carbohydrate, protein and cholesterol all rose significantly up to 20 minutes exposure, before declining again by 40 minutes exposure. They also observed an increase in agitation and general activity between 20 and 40 minutes, and postulate that this may have increased the energy usage sufficiently to cause the decline between the latter two samples.

This paper explores physical signalling in biological communications, the so-called biophysical pathways, and especially the role of electromagnetic signalling in cell-cell interactions. The experiments were designed to evaluate whether different cell populations physically interfere when incubated in separate Petri dishes placed in close proximity. Two different cell populations, immortalized mouse fibroblasts (NIH3T3) and adult human microvascular endothelial cells (HMVECad) were selected and seeded in separate polystyrene Petri dishes. Dishes seeded with NIH3T3 were then placed on top of those seeded with HMVECad at distances of 4mm and 11mm. A black filter was placed between dishes containing the two cell populations in another experiment, to prevent transmission of electromagnetic radiation between the two. Cell number and morphology of NIH3T3 and endothelial cells were found to be modified in dishes without the black filter, suggesting that specific signals emitted by the cells were transmitted through the polystyrene wall, affecting cell proliferation rate and morphology, even though the cells were growing in separate dishes. When effects are dismissed through a lack of mechanistic plausibility, it's worth remembering that we still know very little about how electromagnetic fields interact with cells and cellular processes. This research supports some fascinating work that has been replicated around the world, in the field of ionising radiation. Known as the bystander effect, the principle is that you can affect non-irradiated cells by simply having them in close proximity to radiated cells (but both keeping them disconnected with respect to the mediums they are in, and shield to ensure no radiation enters the control sample), and the control cells can start to act as if they had been irradiated. The assumption is that there is some form of intercellular electromagnetic communication going on. If this assumption is found to be likely, then it creates a large number of possible and plausible ways for electromagnetic fields from power lines, mobile phones, base stations and wifi to interact with cellular processes, and therefore human health.

The energy absorbed from the radio-frequency fields of mobile telephones depends strongly on distance from the source. The authors' objective in this study was to evaluate whether gliomas occur preferentially in the areas of the brain having the highest radio-frequency exposure. The authors used 2 approaches: In a case-case analysis, tumor locations were compared with varying exposure levels; in a case-specular analysis, a hypothetical reference location was assigned for each glioma, and the distances from the actual and specular locations to the handset were compared. The study included 888 gliomas from 7 European countries (2000-2004), with tumor midpoints defined on a 3-dimensional grid based on radiologic images. The case-case analyses were carried out using unconditional logistic regression, whereas in the case-specular analysis, conditional logistic regression was used. In the case-case analyses, tumors were located closest to the source of exposure among never-regular and contralateral users, but not statistically significantly. In the case-specular analysis, the mean distances between exposure source and location were similar for cases and speculars. These results do not suggest that gliomas in mobile phone users are preferentially located in the parts of the brain with the highest radio-frequency fields from mobile phones.

IARC's 2B classification paper.