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January 2009

Estimation of the impact of nonparticipation in case-control study suggests a reduction of about 10% in odds ratio (OR) for regular mobile phone use.

The objective of the current study was to investigate selection bias due to subjects who refused to participate in the INTERPHONE study. Those individuals who refused to participate in the full study were asked to complete a short non-respondent questionnaire. The prevalence of mobile phone use of nonparticipants obtained from the short questionnaire was used to calculate selection bias factors. Results indicate that cases and controls who did not participate reported less frequently that they were regular mobile phone users than subjects who participated in the full study questionnaire. Bias factors calculated were between 0.87 and 0.92 indicating a downward bias of approximately 10% of OR for regular mobile phone use. The authors conclude that nonparticipation information used to estimate selection bias is important to determine the size of any bias in case-control studies.

Vrijheid M, Richardson L, Armstrong BK, Auvinen A, Berg G, Carroll M, Chetrit A, Deltour I, Feychting M, Giles GG, Hours M, Iavarone I, Lagorio S, Lönn S, McBride M, Parent ME, Sadetzki S, Salminen T, Sanchez M, Schlehofer B, Schüz J, Siemiatycki J, Tynes T, Woodward A, Yamaguchi N, Cardis E. (2009). Quantifying the impact of selection bias caused by nonparticipation in a case-control study of mobile phone use. Ann Epidemiol 19(1):33-41.

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In vitro exposure to CDMA radiofrequency field signals induce reversible DNA damage caused by aphidicolin

The authors investigated DNA integrity and the effect of exposure to radiofrequency field (RF) signals from CDMA mobile phones. The in vitroexperiment was done using whole blood samples from six subjects who were exposed for 1 hour to RF signals. The combination effect of the RF signals and aphidicolin at two different concentrations (0.2 and 2.0 microg/ml) was designed to study the DNA integrity. Results of the study are that RF signals and aphidicolin (0.2 microg/ml) alone or in synergism did not produce any significant DNA damage when compared to sham exposed. Aphidicolin at 2 microg/ml concentration did produce significant DNA damage. These results indicate that the repair inhibitor aphidicolin can enhance DNA breaks at 2 microg/ml concentration and that the DNA damage could be repairable.

Tiwari R, Lakshmi NK, Surender V, Rajesh AD, Bhargava SC, Ahuja YR. (2008). Combinative exposure effect of radio frequency signals from CDMA mobile phones and aphidicolin on DNA integrity. Electromagn Biol Med 27(4):418-425.

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Clathrin-dependent endocytosis is stimulated by GSM signals

The objective of the study was to determine the mechanisms of the endocytosis stimulation. Murine melanoma cells were exposed to either Lucifer Yellow or GSM pulses (SAR 3.2 W/kg) at the same time drugs inhibiting endocytosis were administered. The results indicate that the clathrin-dependent endocytosis is stimulated by GSM signals. This suggests that the mechanism GSM signals affect are vesicles that separate from the cell membrane.

Moisescu MG, Leveque P, Verjus M-A, Kovacs E, Mir. 900 MHz modulated electromagnetic fields accelerate the clathrin-mediated endocytosis pathway. Bioelectromagnetics Ahead of print December 12, 2008 DOI 10.1002/bem.20463 

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Mobile phone radiofrequency signals may affect testicular function and structure in rabbits
The goal of the experiment was to test the effect of radiofrequency field emitted by mobile phones (800 MHz) in standby mode on testicular function and also structure. Twenty-four adult rabbits were assigned to one of three groups: (1) exposed; (2) stress control in cage; (3) ordinary controls. Exposure was giving daily for 8 hours during a period of 12 weeks. Semen analysis and sperm function were assessed by weekly tests. Results found in the experiment were: drop in semen concentration at week 6 (exposed group); motile sperm population at week 10 for exposed and stress control declined (61% and 72%, respectively); decrease in the diameter of tubules in the exposed group. Other parameters did not change significantly. The authors conclude that low intensity pulsed radiofrequency field emitted by mobile phones in the standby mode may potentially change testicular function as well as structure in adult rabbits.

Salama N, Kishimoto T, Kanayama HO. Effects of exposure to a mobile phone on testicular function and structure in adult rabbit. Int J Androl. Dec 2 2008 Ahead of print.

For more see “Research – laboratory – reproduction
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Providing subjects accurate feedback on their ability to determine exposure to mobile phone signal insufficient to change attributions or reduce symptoms.

The goal of the study was to assess whether individuals who believe they are sensitive to mobile phone radiofrequency signals and who are provided with accurate feedback on their success to indicate true from sham exposure would have an impact on their symptom level 6 months later. Participants were 69 individuals sensitive to mobile phones who were enrolled in a double-blind provocation experiment. Symptoms were evaluated with the Sensitive Soma Assessment Scale (SSAS). Subjects were then informed that mobile phone signals did not provoke any symptoms and they were also told if they were able to determine when they were exposed to mobile phone. The follow-up 6 months after the provocation study included 58 participants and results indicate that SSAS scores were not different between those who were told that they were correct (n=31) or incorrect (n=27) in their ability to feel mobile phone signals. The authors conclude that discussing other possible psychological factors that could be the cause of symptoms with electromagnetic hypersensitivity patients may be helpful for a subset of individuals.

Nieto-Hernandez R, Rubin GJ, Cleare AJ, Weinman JA, Wessely S. Can evidence change belief?  Reported mobile phone sensitivity following individual feedback of an inability to discriminate active from sham signals. J Psychosom Res 65(5):453-460. Aug 15, 2008 Ahead of print.

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Individuals reporting "electrosensitivity" have considerably worse health than either healthy individuals or people who report sensitivity to mobile phones

The objective of the study was to determine the difference between healthy controls and people who report “electrosensitivity” or EMF hypersensibility because research do not suggest EMF triggers symptoms reported by these two later groups. Participants were 52 “sensitive to mobile phones”, 19 “sensitive to mobile phones as well as electrosensitivity, and 60 healthy controls. Subjects completed a questionnaire assessing their psychological health and other symptoms. Results indicate that perceived sensitivity was associated with a greater chance of using mobile phone mostly for work (3% controls; 13% sensitive to mobile phones; 21% eletrosensitive) but also higher worries about radiation. Participants who reported being electrosensitive had worse general health for several measures compared to the other two groups. The authors conclude that professionals should be more attentive to the group who report being electrosensitive.

Rubin GJ, Cleare AJ, Wessely S. (2008). Psychological factors associated with self-reported sensitivity to mobile phones. J Psychosom Res 64(1):1-12.

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Cell phone use in Spanish adolescents and factors associated with intensive use
The authors wanted to assess cell phone use in adolescents in Madrid, Spain as well as some factors which would be associated with intensive usage. These possible factors link to intensive use include depression, social isolation, drug and alcohol use, school failure, and cell phone dependence. A total of 1,328 participants (13 to 20 years old) were included in the survey. More than 96% had their own cell phone and more than 50% took it to school. Prevalence of cell phone dependence was calculated to be 20%. Several factors were associated with intense cell phone usage: female sex, rural school location, good family economy, smoking tobacco, excessive alcohol consumption, depression, cell phone dependence, and school failure. The authors conclude that education is needed to establish appropriate cell phone use among adolescents.

Sánchez-Martínez M, Otero A. Factors Associated with Cell Phone Use in Adolescents in the Community of Madrid (Spain). Cyberpsychol Behav.  Dec 10 2008 Ahead of print.

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A new approach to simultaneously measure the radiofrequency (RF) exposure and the height of a worker’s position on TV and radio transmitting mast.

Alanko T, Hietanen M. A practical method to evaluate radiofrequency exposure of mast workers. Radiat Prot Dosimetry Dec 2 2008 Ahead of print.

An accurate assessment of RF exposure of mast workers who are at various heights in the antenna mast is not always possible. RF dosimeter measures are useful but will not provide the location of the individual on the mast. The objective of the study was to produce a practical method that can be used to monitor workers’ RF exposure on the antenna tower and to locate the corresponding heights. The new method uses a dosimeter (for RF exposure) and two barometers to determine the corresponding height of the worker. The authors note that their new method is not intended to be used for compliance to the exposure guidelines. It is to indicate locations on the mast where stricter assessments are needed.

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Study results useful to estimate the effects of choices made prior to SAR simulation

The authors used the finite-difference time-domain (FDTD) method to get data for specific absorption rate (SAR). They investigated how some pre-experimental choices such as FDTD resolution, power-loss computation and the position of material voxels would affect SAR simulation.

Uusitupa TM, Ilvonen SA, Laakso IM, and Nikoskinen KI. (2008). The effect of finite-difference time-domain resolution and power-loss computation method on SAR values in plane-wave exposure of Zubal phantom. Phys Med Biol 53:445-452.

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Development of voxel models of children to measure whole-body and tissue-averaged SAR

The authors used existing voxel model (Japanese adult) and re-arranged them to represent children of 3, 5, and 7 years. Then whole-body-averaged specific absorption rates (SARs) and tissue-averaged SARs for the child models for exposures to plane waves from 30 MHz to 3 GHz were determined and compared with results of scaled down adult models.

Nagaoka T, Kunieda E and Watanabe S. (2008). Proportion-corrected scaled voxel models for Japanese children and their application to the numerical dosimetry of specific absorption rate for frequencies from 30 MHz to 3 GHz. Phys. Med. Biol. 53:6695-6711.

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Most studies do show an increase in genetic damage in human cytogenetic studies but methodological issues prevent any conclusive results.

The review paper by Verschaeve on the cytogenetic studies in humans exposed to radiofrequency fields indicates that most of human studies do show that highly RF exposed individuals have an increase presence of genetic damage in their cells. Any conclusions can not be taken because of numerous methodological problems such as radiation dosimetry not being used. The author concludes that only large well-designed experiments will help reach a consensus.

Verschaeve L. Genetic damage in subjects exposed to radiofrequency radiation. Mutat Res. Nov 27 2008 Ahead of print.

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Meeting reports of the International Commission on Non-Ionizing Radiation Protection (ICNIRP)

Barrett JA and Swanson J. (2008). International Commission on Non-Ionizing Radiation Protection: '15 years on: Reviewing the past and looking forward' J. Radiol. Prot. 28:613-616.  

Swanson J. (2008). EMF and Health—A Global Issue. Exploring appropriate precautionary approaches.  J. Radiol. Prot. 28:613-616.  

This meeting report summarizes two ICNIRP meetings held in 2008. The first meeting took place in September in Prague, Czech Republic and reviewed the past history and accomplishments of the ICNIRP. Discussions were also held on future needs, priorities, and upcoming challenges. The second meeting in London UK, also in September 2008, wanted to encourage dialogue and understanding, and hopefully move forward important issues and controversies regarding EMF exposure. There was also a debate on exposure limits by several representatives from the established scientific agencies such as WHO, ICNIRP, and HPA. Another issue discussed during the meeting was the epidemiological evidence on mobile phones and brain tumours.

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