The present study investigated the core body temperature (CBT) response of free-moving adult male and female C57BL/6 mice, during and following a 2-h exposure to 1.95 GHz RF-EMF within custom-built reverberation chambers, using temperature capsules implanted within the intraperitoneal cavity and data continuously logged and transmitted via radiotelemetry postexposure. Comparing RF-EMF exposures (WBA-SAR of 1.
View Article and Find Full Text PDFThis paper describes the assessment of the electromagnetic fields produced by consumer "smart" devices used to control and monitor everyday equipment and appliances in a modern "smart" home. The assessment is based on the careful measurement of fields produced by a range of such devices in a laboratory environment configured to operate in a condition simulating high user activity. All devices included in this study operate in the 2.
View Article and Find Full Text PDFThis study considers the computationally determined thermal profile of a finely discretized, heterogeneous human body model, simulating a radiofrequency electromagnetic field (RF-EMF) worker wearing protective clothing subject to RF-EMF exposure, and subject to various environmental conditions including high ambient temperature and high humidity, with full thermoregulatory mechanisms in place. How the human body responds in various scenarios was investigated, and the information was used to consider safety limits in current international RF-EMF safety guidelines and standards. It was found that different environmental conditions had minimal impact on the magnitude of the thermal response due to RF-EMF exposure, and that the current safety factor of 10 applied in international RF-EMF safety guidelines and standards for RF-EMF workers is generally conservative, though it is only narrowly so when workers are subjected to the most adverse environmental conditions.
View Article and Find Full Text PDFBioelectromagnetics
December 2016
As the availability of Terahertz (THz) sources and their application expands, interaction with biological material needs to be well-understood. In order to accurately estimate the energy absorption pattern in skin and other tissues in the THz and far Infrared regions, values of dielectric parameters ϵ and σ are required. We present an approach for tissue water, which uses literature values of complex refractive index for pure water together with some considerations regarding the effects of dissolved salts.
View Article and Find Full Text PDFInt J Environ Res Public Health
September 2016
Mobile phone subscriptions continue to increase across the world, with the electromagnetic fields (EMF) emitted by these devices, as well as by related technologies such as Wi-Fi and smart meters, now ubiquitous. This increase in use and consequent exposure to mobile communication (MC)-related EMF has led to concern about possible health effects that could arise from this exposure. Although much research has been conducted since the introduction of these technologies, uncertainty about the impact on health remains.
View Article and Find Full Text PDFThis study considers the computationally determined thermal profile of a fully clothed, finely discretized, heterogeneous human body model, subject to the maximum allowable reference level for a 1-GHz radio frequency electromagnetic field for a worker, and also subject to adverse environmental conditions, including high humidity and high ambient temperature. An initial observation is that while electromagnetic fields at the occupational safety limit will contribute an additional thermal load to the tissues, and subsequently, cause an elevated temperature, the magnitude of this effect is far outweighed by that due to the conditions including the ambient temperature, relative humidity, and the type of clothing worn. It is envisaged that the computational modeling approach outlined in this paper will be suitably modified in future studies to evaluate the thermal response of a body at elevated metabolic rates, and for different body shapes and sizes including children and pregnant women.
View Article and Find Full Text PDFUsing numerical modeling, a worst-case scenario is considered when a person with a metallic implant is exposed to a radiofrequency (RF) electromagnetic field (EMF). An adult male standing on a conductive ground plane was exposed to a 40 MHz vertically polarized plane wave field, close to whole-body resonance where maximal induced current flows are expected in the legs. A metal plate (50-300 mm long) was attached to the tibia in the left leg.
View Article and Find Full Text PDFObjective: This study examined sensory and cognitive processing in adolescents, young adults and older adults, when exposed to 2nd (2G) and 3rd (3G) generation mobile phone signals.
Methods: Tests employed were the auditory 3-stimulus oddball and the N-back. Forty-one 13-15 year olds, forty-two 19-40 year olds and twenty 55-70 year olds were tested using a double-blind cross-over design, where each participant received Sham, 2G and 3G exposures, separated by at least 4 days.
Personal dosemeters can play an important role in epidemiological studies and in radiofrequency safety programmes. In this study, a Monte Carlo approach is used in conjunction with the finite difference time domain method to obtain distributions of the electric field strength close to a human body model in simulated realistic environments. The field is a proxy for the response of an ideal body-worn electric field dosemeter.
View Article and Find Full Text PDFThe present study was conducted to determine whether adolescents and/or the elderly are more sensitive to mobile phone (MP)-related bioeffects than young adults, and to determine this for both 2nd generation (2G) GSM, and 3rd generation (3G) W-CDMA exposures. To test this, resting alpha activity (8-12 Hz band of the electroencephalogram) was assessed because numerous studies have now reported it to be enhanced by MP exposure. Forty-one 13-15 year olds, forty-two 19-40 year olds, and twenty 55-70 year olds were tested using a double-blind crossover design, where each participant received Sham, 2G and 3G exposures, separated by at least 4 days.
View Article and Find Full Text PDFRadiat Prot Dosimetry
June 2010
This paper provides an insight into factors that can influence uncertainty in measurements at 900 MHz of electric fields close to the body for use in personal dosimetry. Computational simulations using the finite difference time domain method were used to determine the total electric field near the surface of the torso of heterogeneous (adult and child) human body models for a set of exposure scenarios that simulated both spatially constant and randomly varying incident fields. Modelling has shown that a properly responding isotropic electric field dosemeter mounted between 10 and 50 mm of the torso will on average underestimate the incident field strength by up to 6.
View Article and Find Full Text PDFEpstein-Barr virus (EBV) efficiently drives proliferation of human primary B cells in vitro, a process relevant for human diseases such as infectious mononucleosis and posttransplant lymphoproliferative disease. Human B-cell proliferation is also driven by ligands of Toll-like receptors (TLRs), notably viral or bacterial DNA containing unmethylated CpG dinucleotides, which triggers TLR9. Here we quantitatively investigated how TLR stimuli influence EBV-driven B-cell proliferation and expression of effector molecules.
View Article and Find Full Text PDFAustralas Phys Eng Sci Med
September 2008
Human provocation studies that investigate the effects of Global System for Mobiles (GSM) communication systems on the brain have focused on Radio Frequency (RF) exposure. We wish to further extend such study by investigating the effect of both RF and Extremely Low Frequency (ELF) field exposure, the latter generated by the GSM handset's battery switching. The use of a commercial handset as an exposure source for such investigations is problematic for a number of reasons and therefore a simulated exposure source, capable of producing both RF and ELF components of exposure, is desirable.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
March 2008
The integrity of data gathered by a body worn personal radiofrequency exposure meter has been investigated using computational methods. Simulations show that the distortion of the field by the body will cause measurement errors with a traditional 3-axis dipole field sensor. A modified measurement method for body worn personal exposure meters based on an array of 2-axis dipole field sensors is proposed.
View Article and Find Full Text PDFIEEE Trans Biomed Eng
October 2007
This study compared the potential for interference to medical devices from radio frequency (RF) fields radiated by GSM 900/1800-MHz, general packet radio service (GPRS) 900/1800-MHz, and wideband code division multiple access (WCDMA) 1900-MHz handsets. The study used a balanced half-wave dipole antenna, which was energized with a signal at the standard power level for each technology, and then brought towards the medical device while noting the distance at which interference became apparent. Additional testing was performed with signals that comply with the requirements of the international immunity standard to RF fields, IEC 61000-4-3.
View Article and Find Full Text PDFA cochlear implant system is a device used to enable hearing in people with severe hearing loss and consists of an internal implant and external speech processor. This study considers the effect of scattered radiofrequency fields when these persons are subject to mobile phone type exposure. A worst-case scenario is considered where the antenna is operating at nominal full power, the speech processor is situated behind the ear using a metallic hook, and the antenna is adjacent to the hook and the internal ball electrode.
View Article and Find Full Text PDFThis paper investigates the influence of EEG electrode caps on specific absorption rate (SAR) in the head from a GSM900 mobile phone (217-Hz modulation, peak power output 2 W). SAR measurements were recorded in an anthropomorphic phantom using a precision robotic system. Peak 10 g average SAR in the whole head and in just the temporal region was compared for three phantom arrangements; no cap, 64-electrode "Electro-Cap," and 64-electrode "Quick-Cap".
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