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.
Sakuma N et al. · 2006
Researchers conducted a large-scale in vitro study to test whether modulated RF fields from mobile radio base stations act as a DNA damaging agent. Human glioblastoma A172 cells and normal human IMR-90 fibroblasts were exposed to 2.1425 GHz CW and W-CDMA radiation. A172 cells were exposed to W-CDMA at SARs of 80, 250, and 800 mW/kg and CW at 80 mW/kg for 2 and 24 hours, while IMR-90 cells were exposed to both modulations at 80 mW/kg for the same periods. No significant differences in DNA strand breaks were observed between exposed groups and sham controls using alkaline comet assays. The authors concluded that low-level exposures do not act as a genotoxicant up to a SAR of 800 mW/kg.
Tuschl H, Novak W, Molla-Djafari H. · 2006
The study assessed whether GSM-modulated RF fields have adverse effects on the functional competence of human immune cells. Exposure was performed at GSM Basic 1950 MHz with an SAR of 1 mW/g in an intermittent mode of 5 minutes on and 10 minutes off for 8 hours. Researchers evaluated intracellular cytokine production, immune-relevant gene activity, and cytotoxicity of lymphokine-activated killer cells using blood from at least 15 donors per parameter. No statistically significant effects of exposure were found.
Hirose H et al. · 2006
Researchers conducted a large-scale in vitro study to test whether modulated RF fields from mobile radio base stations induce apoptosis or stress responses activating p53. Human glioblastoma A172 cells were exposed to W-CDMA radiation at SARs of 80, 250, and 800 mW/kg and CW radiation at 80 mW/kg for 24 or 48 hours, while human IMR-90 fibroblasts were exposed to both modulations at 80 mW/kg for 28 hours. No significant differences in apoptosis, phosphorylated p53 at serine 15, total p53, or downstream gene expression were found between exposed and sham-exposed cells.
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.
Miyakoshi J et al. · 2005
Researchers exposed human glioma MO54 cells to a continuous wave 1950 MHz RF field at SARs of 1, 2, and 10 W/kg for up to 2 hours. Cell growth was assessed by counting cell numbers up to 4 days after exposure. RF exposure at 2 and 10 W/kg did not affect the growth of MO54 cells. However, exposure at 10 W/kg for 1 and 2 hours significantly decreased the protein level of phosphorylated Hsp27 at serine 78.
Schmid G, Sauter C, Stepansky R, Lobentanz IS, Zeitlhofer J · 2005
Researchers exposed 58 healthy volunteers to a generic 1.97 GHz UMTS-like signal in a double-blinded crossover design. Each subject completed four clinical visual perception tests under high exposure, low exposure, and sham conditions. High exposure produced an average SAR of 0.63 W/kg (1 g) and 0.37 W/kg (10 g) in the left temporal cortex. No statistically significant differences in visual perception parameters were found between any exposure condition and sham.
Martinez-Burdalo M, Martin A, Anguiano M, Villar R · 2005
Researchers analyzed safety assessment procedures for human exposure near cellular base-station antennas at 900, 1800, and 2170 MHz. They compared distances where electromagnetic fields were below reference levels with distances where specific absorption rate (SAR) values in an exposed person were below basic restrictions according to European guidelines. A high-resolution human body model was placed in front of each antenna at different distances to compute whole-body averaged SAR and maximum 10 g averaged SAR. The finite-difference time-domain method was used for both electromagnetic field and SAR calculations.
Gandhi G, Anita · 2005
Researchers investigated DNA and chromosomal damage in peripheral blood lymphocytes of 24 mobile phone users exposed to microwave frequencies of 800-2000 MHz. DNA damage measured by comet assay showed a mean comet tail length of 26.76 ± 0.054 mm with 39.75% of cells damaged, which was highly significant compared to controls. The in vivo capillary blood micronucleus test also revealed a highly significant frequency of micronucleated cells at 0.25.
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
Monfrecola G, Moffa G, Procaccini EM. · 2003
The study assessed the effects of non-ionizing electromagnetic radiation emitted by CFs on cutaneous blood flow in 30 healthy volunteers aged 18 to 53 years. Cutaneous blood flow was measured on the ear skin with a laser Doppler He-Ne flowmeter under controlled temperature and humidity. Microflow was recorded across phases T0 through T6, including no CF contact, CF off touching the ear, CF on, CF on and receiving, then back through CF on, CF off, and no contact. During phases T1 to T5 microflow increased by 61.38% to 157.67% relative to baseline, and all these phases showed statistically significant elevations compared with baseline.
McNamee et al. · 2003
Researchers examined the effect of 24-hour continuous-wave and pulsed-wave 1.9 GHz radiofrequency fields on primary DNA damage and micronucleus induction in human leukocyte cultures. No significant differences in primary DNA damage were observed between sham controls and any exposed cultures when assessed by the alkaline comet assay immediately after exposure. Similarly, no significant differences were found in micronucleus incidence, micronucleated binucleated cells, binucleated cell frequency, or proliferation index between sham and exposed cultures.
McNamee et al. · 2003
Researchers exposed human white blood cells to 1.9 GHz radiofrequency radiation (similar to what cell phones emit) for 24 hours at power levels up to 10 watts per kilogram. They found no DNA damage or genetic changes in the cells, even after this extended exposure period at levels much higher than typical phone use.
Tice RR, Hook GG, Donner M, McRee DI, Guy AW. · 2002
DNA damage in leukocytes was assessed with the alkaline comet assay and chromosomal damage in lymphocytes with the micronucleus assay. No significant increase in DNA damage was seen after 3 or 24 hours, and no increase in micronucleated lymphocytes occurred after 3 hours. However, 24-hour exposures at 5.0 or 10.0 W/kg significantly increased micronucleated lymphocytes about fourfold, regardless of signal type, modulation, or frequency.
McNamee JP et al. · 2002
Researchers exposed human white blood cells to cell phone radiation (1.9 GHz) for 2 hours at various power levels to see if it would damage DNA or cause genetic abnormalities. They found no evidence of DNA damage or genetic changes at any exposure level tested, including levels 5 times higher than typical cell phone use. This Canadian government study suggests that short-term radiofrequency exposure may not directly harm genetic material in immune cells.
Hanada E, Hoshino Y, Oyama H, Watanabe Y, Nose Y. · 2002
Researchers tested the effect of wireless LAN communication on medical electronic equipment and the effect of electronic equipment on wireless LAN communication. They observed nine pieces of electronic equipment in operating mode while transmitting radio waves from a wireless LAN. No equipment malfunction occurred even with the access point very close to the equipment surface during data transmission. Medical equipment caused little change in wireless communication effectiveness, but electric knives and a remote patient monitor reduced the reception rate to about 60%. Wireless LAN speed was temporarily reduced only when a microwave oven was close to and facing the access point.
Unknown authors · 2002
The paper compares maximum allowable powers for cellular telephones at 835 and 1900 MHz under ANSI/IEEE, ICNIRP, and a proposed IEEE modification. It shows the ANSI/IEEE guideline is the most conservative, ICNIRP allows 2.5-3 times higher maximum radiated power, and the proposed modification allows up to 50% higher power. Peak 1 g SAR in smaller head models is up to 56% higher at 1900 MHz and up to 20% higher at 835 MHz than in larger models. Plastic ear models yield SARs up to two or more times smaller than realistic anatomic models, and a 2 mm thin shell phantom with lossy ear is proposed to match anatomic SARs within +/- 15%.
