Dimbylow PJ, Nagaoka T, Xu XG. · 2009
The study compared foetal specific absorption rate (SAR) across three sets of pregnant female computational models. The models included a 26-week foetal model from the National Institute of Information and Communications Technology, Tokyo, and models at 13, 26, and 38 weeks from Rensselaer Polytechnic Institute. FDTD calculations were performed at a resolution of 2 mm for a plane wave with a vertically aligned electric field incident upon the body from the front, back and two sides from 20 MHz to 3 GHz under isolated conditions. The researchers compared external electric field values required to produce the ICNIRP public exposure localized restriction of 2 W kg(-1) when averaged over 10 g of the foetus with the ICNIRP reference levels.
Acar GO, Yener HM, Savrun FK, Kalkan T, Bayrak I, Enver O. · 2009
Tissue temperature around the facial nerve was measured with a four-channel Luxtron fiber optic system and rose by 0.39 K during and immediately after exposure, returning to baseline after 25 minutes. Facial nerve compound muscle action potential amplitudes decreased significantly after exposure but returned to normal at the 25-minute measurement.
Unknown authors · 2008
Researchers developed child head models based on magnetic resonance imaging and analyzed maximum SAR over 10 g in seven child and six adult heterogeneous head models. They also assessed SAR over 1 g in specific tissues for both child and adult head models. Simulations showed that maximum SAR over 10 g differed little between adults and children relative to variability, but maximum SAR in 1 g of peripheral brain tissue was about two times higher in child models aged 5–8 years than in adult models, with no difference for older children.
Nagaoka T, Kunieda E, Watanabe S · 2008
Researchers used an existing Japanese adult voxel model and three-dimensional deformation to create models representing average-size Japanese children at 3, 5, and 7 years old. The models consist of cubic voxels 2 mm on each side segmented into 51 tissues and organs. They calculated whole-body-averaged and tissue-averaged specific absorption rates for the child models exposed to plane waves from 30 MHz to 3 GHz and compared the results with scaled down adult models. They also determined the incident electric-field strength needed to produce a whole-body-averaged SAR of 0.08 W kg(-1), the ICNIRP basic restriction for general public exposure.
Dimbylow PJ, Hirata A, Nagaoka T. · 2008
The study intercompared the HPA male and female models NORMAN and NAOMI with the NICT male and female models TARO and HANAKO. Particular emphasis was placed on how dielectric properties are assigned to tissues such as skin and fat and on the consequences of different SAR calculation algorithms at higher frequencies. Whole-body SAR calculations were performed at three institutions for a vertically polarized plane wave incident on the front of the body from 30 MHz to 3 GHz under isolated conditions.
Yan JG, Agresti M, Zhang LL, Yan Y, Matloub HS. · 2008
Researchers exposed adult Sprague-Dawley rats to cell phones for 6 hours per day for 126 days and measured mRNA levels of several injury-associated proteins in the brain. The proteins evaluated included Calcium ATPase, Neural Cell Adhesion Molecule, Neural Growth Factor, and Vascular Endothelial Growth Factor. The results showed statistically significant mRNA up-regulation of these proteins in the brains of exposed rats.
Unknown authors · 2008
Researchers recorded TEOAEs in 27 healthy young adults before and after 10 minutes of real or sham GSM exposure in a double-blind design. TEOAE data were analyzed both globally using broadband analysis and with wavelet transform for time-frequency fine structure. Both analyses revealed no significant effect of exposure on TEOAEs.
Zhao TY, Zou SP, Knapp PE · 2007
Researchers exposed brain cells (neurons and astrocytes) to radiation from a working GSM cell phone for just 2 hours and found that genes involved in cell death pathways became more active. The effect occurred even when the phone was on standby mode, and neurons appeared more sensitive to the radiation than astrocytes (support cells in the brain). This suggests that even brief cell phone exposure can trigger cellular stress responses in brain tissue.
Peyman A, Holden SJ, Watts S, Perrott R, Gabriel C · 2007
The dielectric properties of pig cerebrospinal tissues were measured in vivo and in vitro in the frequency range of 50 MHz-20 GHz. White matter and spinal cord showed significant variation as a function of animal age while no age-related variations were recorded for grey matter. The in vitro study included tissue from pigs weighing approximately 10, 50, and 250 kg to examine variation with age. Total combined measurement uncertainty was calculated at each frequency point and reported over representative frequency regions. Comparisons were made between the in vivo and in vitro data and with literature from the past decade.
Unknown authors · 2007
Researchers measured radiofrequency fields from wireless local area networks using Wi-Fi technology against background RF fields in the frequency range 75 MHz to 3 GHz. They conducted 356 measurements at 55 sites including residences, commercial spaces, healthcare and educational institutions, and other public spaces in the U.S., France, Germany, and Sweden. Measurements were taken under conditions that would result in the higher end of exposures, including close to Wi-Fi access points and at a distance of approximately 1 m from a laptop uploading and downloading large files. In all cases, measured Wi-Fi signal levels were very far below international exposure limits (IEEE C95.1-2005 and ICNIRP) and in nearly all cases far below other RF signals in the same environments.
Dimbylow P. · 2007
Researchers used finite-difference time-domain calculations to estimate SAR from 20 MHz to 3 GHz in hybrid voxel-mathematical models of the pregnant female. Mathematical models of the developing foetus at 8-, 13-, 26- and 38-week gestation were converted into voxels and combined with the reference adult female model, NAOMI at a resolution of 2 mm. The study calculated the electric field values needed to produce the ICNIRP public exposure restriction of 2 W kg(-1) when averaged over 10 g of the foetus.
Unknown authors · 2007
The paper discusses the phenomenon, mechanism, power requirement, pressure amplitude, and auditory thresholds of microwave hearing. Microwave pulse hearing involves electromagnetic waves from hundreds of MHz to tens of GHz, unlike normal hearing which uses sound pressure waves. The microwave auditory effect does not come from direct interaction with auditory nerves but from a thermoelastic wave launched by pulse absorption in soft tissues. This thermoelastic wave travels by bone conduction to the inner ear and activates cochlear receptors like normal hearing. The paper emphasizes human exposures to wireless communication fields and MRI coils.
Unknown authors · 2007
This 2007 study explains how humans and animals can actually hear microwave pulses, a phenomenon where electromagnetic waves create audible sounds inside the head. The research shows that pulsed microwaves heat tissue, creating pressure waves that travel through bone to the inner ear, where they're perceived as clicking or buzzing sounds. This finding has important implications for understanding exposure to wireless devices and MRI equipment.
Chauhan V et al. · 2007
Researchers exposed human-derived cell lines TK6, HL60, and Mono-Mac-6 to intermittent 1.9 GHz pulse-modulated RF fields for 6 hours at SARs of 0, 1, and 10 W/kg. Cell viability, apoptosis, and cell cycle kinetics were measured immediately after exposure and 18 hours later. Cytokine expression (TNFA, IL1B, IL6, IL8, IL10, IL12) was also assessed. No detectable changes in cell viability, cell cycle kinetics, apoptosis, or cytokine expression were observed in any exposed group compared to sham controls. The positive heat-shock control showed decreased viability, increased apoptosis, and a G(2)/M cell cycle block.
Chauhan V et al. · 2007
Researchers examined the effect of RF field exposure on late onset gene expression in U87MG cells after a 24 h exposure period. A human monocyte-derived cell line (MM6) was exposed to intermittent RF fields for 6 h and gene expression was assessed immediately and at 18 h postexposure. Both cell lines were exposed to 1.9 GHz pulse-modulated RF fields for 6 or 24 h at SARs of 0.1-10.0 W/kg. The study found no evidence that nonthermal RF field exposure altered gene expression in either U87MG or MM6 cells relative to nonirradiated controls. Heat shock at 43°C for 1 h altered the expression of well-characterized heat-shock proteins in both cell lines.
Zhao TY, Zou SP, Knapp PE. · 2007
Researchers exposed primary cultured neurons and astrocytes to GSM cell phone emissions at 1900 MHz for 2 hours. Neurons showed up-regulation of caspase-2, caspase-6, and Asc genes in both 'on' and 'stand-by' modes. Astrocytes showed up-regulation of the same genes only in 'on' mode and also up-regulated the Bax gene.
Christ A, Samaras T, Klingenböck A, Kuster N. · 2006
The study investigated electromagnetic near-field absorption in layered biological tissue from 30 MHz to 6000 MHz. Two effects can increase SAR in layered tissue versus homogeneous liquid: standing wave effects at larger distances depending on frequency and fat thickness, and high local skin absorption from reactive E-fields in the very close near-field. A conservative exposure estimate can be obtained by applying a multiplication factor of 1 to 3 to current dosimetric values.
Chauhan V et al. · 2006
Researchers exposed human lymphoblastoma TK6 cells to 1.9 GHz pulse-modulated RF fields at SARs of 1 and 10 W/kg. They assessed expression of proto-oncogenes FOS, JUN, and MYC using real-time RT-PCR. They also monitored transcript levels of the heat-shock proteins HSP27 and inducible HSP70. Transcript levels in RF-exposed cells showed no significant difference compared to sham-exposed cells. Positive heat-shock controls showed significant elevation of HSP27, HSP70, FOS, and JUN, and a decline in MYC mRNA.
Chauhan V et al. · 2006
Researchers exposed HL-60 and MM6 cells to intermittent 1.9 GHz pulse-modulated RF fields at SARs of 1 and 10 W/kg for 6 hours. No significant changes in gene expression were found between sham-exposed and RF-exposed groups in either cell line. Positive heat-shock controls showed significant increases in HSP27, HSP70, c-fos, and c-jun at both time points.
Hondou T et al et al. · 2006
Researchers conducted a numerical investigation using a realistic human body model and an actual elevator size to assess SAR from a mobile phone modeled as a dipole antenna at 16 mm from the head. They used finite-difference time-domain technique with a supercomputer at frequencies of 900, 1500, and 2000 MHz with 250 mW transmitting power. Results showed that peak 10-g SAR depends on passenger and antenna position, with substantial increases in whole-body average SAR and peak 10-g SAR in the elevator over free-space values. However, the maximum values met international RF safety guidelines, with whole-body average SAR at 4.4% and peak spatial-average SAR at 78% of the guideline.
Sun LX, Yao K, Jiang H, He JL, Lu DQ, Wang KJ, Li HW · 2006
Researchers exposed cultured human lens epithelial cells to 217 Hz modulated microwave radiation at four SAR levels for 2 hours. DNA single strand breaks were measured using the comet assay immediately after irradiation and at 30 and 60 minutes afterward. At the highest dose, significant DNA damage remained one hour after irradiation and cell proliferation was significantly decreased.
Qutob SS et al. · 2006
Researchers exposed U87MG glioblastoma cells to a 1.9 GHz pulse-modulated RF field for 4 hours at SARs of 0.1, 1.0, and 10.0 W/kg to assess global gene expression. No evidence was found that non-thermal RF fields affect gene expression in these cells compared to nonirradiated controls. Heat shock at 43°C for 1 hour up-regulated typical stress-responsive genes in the positive control group.
Tkalec M, Malaric K, Pevalek-Kozlina B. · 2005
Researchers evaluated duckweed growth and peroxidase activity after exposure in a Gigahertz Transversal Electromagnetic (GTEM) cell to electric fields at frequencies of 400, 900, and 1900 MHz. Plants exposed for 2 h to a 23 V/m field at 900 MHz showed significantly decreased growth compared with the control, while the same field strength at 400 MHz did not have such an effect. Peroxidase activity in exposed plants varied depending on exposure characteristics, with a significant increase of 41% found in plants exposed for 2 h to 41 V/m at 900 MHz.
Weisbrot D, Lin H, Ye L, Blank M, Goodman R. · 2003
Researchers exposed fruit flies to a discontinuous RF signal from a GSM multiband phone at 900/1,900 MHz with SAR approximately 1.4 W/kg for 10 days from egg laying through pupation. The non-thermal radiation increased offspring numbers, elevated hsp70 levels, increased SRE DNA-binding, and induced ELK-1 phosphorylation.
McNamee, J. · 2003
