The effects of 884 MHz GSM wireless communication signals on headache and other symptoms: an experimental provocation study

Findings from prior studies of possible health and physiological effects from mobile phone use have been inconsistent. Exposure periods in provocation studies have been rather short and personal characteristics of the participants poorly defined. We studied the effect of radiofrequency field (RF) on self-reported symptoms and detection of fields after a prolonged exposure time and with a well defined study group including subjects reporting symptoms attributed to mobile phone use. The design was a double blind, cross-over provocation study testing a 3-h long GSM handset exposure versus sham. The study group was 71 subjects age 18-45, including 38 subjects reporting headache or vertigo in relation to mobile phone use (symptom group) and 33 non-symptomatic subjects. Symptoms were scored on a 7-point Likert scale before, after 1(1/2) and 2(3/4) h of exposure. Subjects reported their belief of actual exposure status. The results showed that headache was more commonly reported after RF exposure than sham, mainly due to an increase in the non-symptom group. Neither group could detect RF exposure better than by chance. A belief that the RF exposure had been active was associated with skin symptoms. The higher prevalence of headache in the non-symptom group towards the end of RF exposure justifies further investigation of possible physiological correlates. The current study indicates a need to better characterize study participants in mobile phone exposure studies and differences between symptom and non-symptom groups.     

Analysis of three-dimensional SAR distributions emitted by mobile phones in an epidemiological perspective

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. Bioelectromagnetics. Bioelectromagnetics 32:634–643, 2011. © 2011 Wiley Periodicals, Inc.     

Review: Weak radiofrequency radiation exposure from mobile phone radiation on plants

Aim: The aim of this article was to explore the hypothesis that non-thermal, weak, radiofrequency electromagnetic fields (RF-EMF) have an effect on living plants. Subject and methods: In this study, we performed an analysis of the data extracted from the 45 peer-reviewed scientific publications (1996–2016) describing 169 experimental observations to detect the physiological and morphological changes in plants due to the non-thermal RF-EMF effects from mobile phone radiation. Twenty-nine different species of plants were considered in this work. Results: Our analysis demonstrates that the data from a substantial amount of the studies on RF-EMFs from mobile phones show physiological and/or morphological effects (89.9%, p < 0.001). Additionally, our analysis of the results from these reported studies demonstrates that the maize, roselle, pea, fenugreek, duckweeds, tomato, onions and mungbean plants seem to be very sensitive to RF-EMFs. Our findings also suggest that plants seem to be more responsive to certain frequencies, especially the frequencies between (i) 800 and 1500 MHz (p < 0.0001), (ii) 1500 and 2400 MHz (p < 0.0001) and (iii) 3500 and 8000 MHz (p = 0.0161). Conclusion: The available literature on the effect of RF-EMFs on plants to date observed the significant trend of radiofrequency radiation influence on plants. Hence, this study provides new evidence supporting our hypothesis. Nonetheless, this endorses the need for more experiments to observe the effects of RF-EMFs, especially for the longer exposure durations, using the whole organisms. The above observation agrees with our earlier study, in that it supported that it is not a well-grounded method to characterize biological effects without considering the exposure duration. Nevertheless, none of these findings can be directly associated with human; however, on the other hand, this cannot be excluded, as it can impact the human welfare and health, either directly or indirectly, due to their complexity and varied effects (calcium metabolism, stress proteins, etc.). This study should be useful as a reference for researchers conducting epidemiological studies and the long-term experiments, using whole organisms, to observe the effects of RF-EMFs.     

Statistical analysis of personal radiofrequency electromagnetic field measurements with nondetects

Exposimeters are increasingly applied in bioelectromagnetic research to determine personal radiofrequency electromagnetic field (RF‐EMF) exposure. The main advantages of exposimeter measurements are their convenient handling for study participants and the large amount of personal exposure data, which can be obtained for several RF‐EMF sources. However, the large proportion of measurements below the detection limit is a challenge for data analysis. With the robust ROS (regression on order statistics) method, summary statistics can be calculated by fitting an assumed distribution to the observed data. We used a preliminary sample of 109 weekly exposimeter measurements from the QUALIFEX study to compare summary statistics computed by robust ROS with a naïve approach, where values below the detection limit were replaced by the value of the detection limit. For the total RF‐EMF exposure, differences between the naïve approach and the robust ROS were moderate for the 90th percentile and the arithmetic mean. However, exposure contributions from minor RF‐EMF sources were considerably overestimated with the naïve approach. This results in an underestimation of the exposure range in the population, which may bias the evaluation of potential exposure‐response associations. We conclude from our analyses that summary statistics of exposimeter data calculated by robust ROS are more reliable and more informative than estimates based on a naïve approach. Nevertheless, estimates of source‐specific medians or even lower percentiles depend on the assumed data distribution and should be considered with caution. Bioelectromagnetics. Bioelectromagnetics 29:471–478, 2008. © 2008 Wiley‐Liss, Inc.     

Focus formation of C3H/10T1/2 cells and exposure to a 836.55 MHz modulated radiofrequency field

Disruption of communication between transformed cells and normal cells is involved in tumor promotion. We have tested the hypothesis that exposures to radiofrequency (RF) fields using a form of digital modulation (TDMA) and a chemical tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA), are copromoters that enhance focus formation of transformed cells in coculture with parental C3H/10T1/2 murine fibroblasts. RF field exposures did not influence TPA's dose-dependent promotion of focus formation in coculture. Cell cultures were exposed to an 836.55 MHz TDMA-modulated field in TEM transmission line chambers, with incident energies that simulated field intensities at a user's head. Specific absorption rates (SARs) of 0.15, 1.5, and 15 μW/g were used during each digital packet, and the packet frequency was 50/s. The TEM chambers were placed in a commercial incubator at 37 °C and 95% humidity/5% CO2. The RF field exposures were in a repeating cycle, 20 min on, 20 min off, 24 h/day for 28 days. At 1.5 μW/g, TPA-induced focus formation (at 10, 30, and 50 ng/ml) was not significantly different in RF-exposed cultures compared to parallel sham-exposed cultures in ten independent experiments in terms of the number, density, and area of foci. Similarly, at 0.15 and 15.0 μW/g, in two and four experiments, respectively, RF exposure did not alter TPA-induced focus formation. The findings support a conclusion that repeated exposures to this RF field do not influence tumor promotion in vitro, based on the RF field's inability to enhance TPA-induced focus formation. Bioelectromagnetics 18:237–243, 1997 © 1997 Wiley-Liss, Inc.     

Hypersensitivity symptoms associated with exposure to cellular telephones: no causal link

The hypothesis that there exist hypersensitive persons who perceive subjective symptoms from radiofrequency (RF) fields emitted by hand held mobile phones (cellular phones) was tested using double blind provocation experiments. We also tested whether sensitive subjects are able to determine whether the phone is on or off by sensing RF fields. The study group consisted of 20 volunteers (13 women and 7 men) who reported themselves as being sensitive to cellular phones. The RF exposure sources were one analogue NMT phone (900 MHz) and two digital GSM phones (900 and 1800 MHz). The duration of a test session was 30 min, and three or four sessions were performed in random order for each subject during 1 day. The subjects were asked to report symptoms or sensations as soon as they perceived any abnormal feelings. In addition, the subjects' blood pressure, heart rate, and breathing frequency were monitored every 5 min. The results of the study indicated that various symptoms were reported, and most of them appeared in the head region. However, the number of reported symptoms was higher during sham exposure than during real exposure conditions. In addition, none of the test persons could distinguish real RF exposure from sham exposure. Hence, we conclude that adverse subjective symptoms or sensations, though unquestionably perceived by the test subjects, were not produced by cellular phones.     

No evidence of major transcriptional changes in the brain of mice exposed to 1800 MHz GSM signal

To analyze possible effects of microwaves on gene expression, mice were exposed to global system for mobile communication (GSM) 1800 MHz signal for 1 h at a whole body SAR of 1.1 W/kg. Gene expression was studied in the whole brain, where the average SAR was 0.2 W/kg, by expression microarrays containing over 22,600 probe sets. Comparison of data from sham and exposed animals showed no significant difference in gene expression modulation. However, when less stringent constraints were adopted to analyze microarray results, 75 genes were found to be modulated following exposure. Forty-two probes showed fold changes ranging from 1.5 to 2.8, whereas 33 were down-regulated from 0.67- to 0.29-fold changes, but these differences in gene expression were not confirmed by real-time PCR. Under these specific limited conditions, no consistent indication of gene expression modulation in whole mouse brain was found associated to GSM 1800 MHz exposure.     

Effect of nonionizing radiation on the purkinje cells of the rat cerebellum

In one experiment, Sprague Dawley rats (16–21 days of gestation) and their offspring were exposed to 100-MHz (CW) electromagnetic radiation at 46 mW/cm² (SAR 2.77 mW/g) for 4 h/day for 97 days. In another experiment, the pregnant rats were irradiated daily from 17 to 21 days of gestation with 2450-MHz (CW) microwaves at 10 mW/cm² (SAR 2 mW/g) for 21 h/day. In a third experiment, 6-day-old rat pups were irradiated 7 h/day for five days with 2450-MHz radiation at 10 mW/cm². Equal numbers of animals were sham irradiated in each group. Quantitative studies of Purkinje cells showed a significant and irreversible decrease in rats irradiated during fetal or fetal and early postnatal life. In animals exposed postnatally, and euthanized immediately after irradiation, significant decrease in the relative number of Purkinje cells was apparent. However, restoration apparently occurred after forty days of recovery.     

Scientific basis for the Soviet and Russian radiofrequency standards for the general public

The former Soviet Union (USSR) and the USA were the first countries to introduce standards limiting exposure to radiofrequency (RF) fields. However, the exposure limits in the USSR standards were always much lower than those in the USA and other countries. The objective of this article is to provide a history of the development of the Soviet and Russian RF standards. In addition, we summarize the scientific evidence used to develop the original USSR RF and subsequent Russian public health standards, as well as the mobile telecommunications standard published in 2003, but we do not critique them. We also describe the protective approaches used by the Soviet and Russian scientists for setting their limits. A translation of the papers of the key studies used to develop their standards is available in the online version of this publication. Bioelectromagnetics 33:623–633, 2012. © 2012 Wiley Periodicals, Inc.     

Review of possible modulation-dependent biological effects of radiofrequency fields

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 relationship between visual working memory and attention: retention of precise colour information in the absence of effects on perceptual selection

We examined the conditions under which a feature value in visual working memory (VWM) recruits visual attention to matching stimuli. Previous work has suggested that VWM supports two qualitatively different states of representation: an active state that interacts with perceptual selection and a passive (or accessory) state that does not. An alternative hypothesis is that VWM supports a single form of representation, with the precision of feature memory controlling whether or not the representation interacts with perceptual selection. The results of three experiments supported the dual-state hypothesis. We established conditions under which participants retained a relatively precise representation of a parcticular colour. If the colour was immediately task relevant, it reliably recruited attention to matching stimuli. However, if the colour was not immediately task relevant, it failed to interact with perceptual selection. Feature maintenance in VWM is not necessarily equivalent with feature-based attentional selection.     

Dosimetry in mice exposed to 1.6 GHz microwaves in a carrousel irradiator

We have developed a carrousel irradiator for mice which delivers a head‐first and near‐field radiofrequency exposure that more closely simulates cellular telephone and radio use than conventional whole body exposure systems. Mouse cadavers were placed on the carrousel irradiator and exposed with their noses 5 mm from the feedpoint of a 1.6 GHz antenna. Local measured specific absorption rates (SAR) in brain regions corresponding to the frontal cortex, medial caudate putamen, and midhippocampal areas were 2.9, 2.4, and 2.2 W/kg per watt of irradiated power, respectively. In addition, average SAR was estimated to be 3.4 W/kg per watt along the sagittal plane of the brain, 2.0 W/kg per watt along the sagittal plane of the body, and between 6.8 and 8.1 W/kg per watt at peak locations along the sagittal plane at the body surface. This detailed SAR information in mice is critical to the interpretation of biological studies of IRIDIUM exposure, and similar analysis should be included for all studies of in vivo exposure of small animals to microwaves. Bioelectromagnetics 20:42–47, 1999. © 1999 Wiley‐Liss, Inc.