Sirav B, Seyhan N · 2009
Researchers investigated the effects of 900 and 1,800 MHz continuous-wave radio frequency radiation on blood-brain barrier permeability in rats. Twenty minutes of exposure at both frequencies increased blood-brain barrier permeability in male rats, while female rats showed no change. The researchers noted that the scientific evidence on radio frequency radiation safety or harm remains inconclusive.
Del Vecchio G et al. · 2009
Luukkonen J et al. · 2009
Researchers exposed human SH-SY5Y neuroblastoma cells to 872 MHz radiofrequency radiation at 5 W/kg for 1 hour, combined with menadione, a chemical that induces intracellular ROS production and DNA damage. Continuous-wave RF radiation increased DNA breakage compared to cells exposed only to menadione, and ROS levels were higher at 30 and 60 minutes after exposure ended. No effects of the GSM signal were seen on either ROS production or DNA damage.
Del Vecchio G et al. · 2009
Researchers studied the effects of radiofrequency electromagnetic field exposure on neuronal maturation using two in vitro models: murine SN56 cholinergic cells and rat primary cortical neurons. Cells were exposed at 1 W/kg at 900 MHz GSM modulated, and neurite emission, outgrowth, and branching were examined at multiple time points. RF-EMF exposure reduced the number of neurites in both cell systems, and this reduction correlated with increased expression of beta-thymosin mRNA.
Valbonesi P et al. · 2008
Researchers used the human trophoblast cell line HTR-8/SVneo to evaluate HSP70 and HSC70 protein and gene expression and primary DNA damage after nonthermal exposure to pulse-modulated 1817 MHz GSM-217 Hz waves for one hour at a SAR of 2 W/kg. Heat shock significantly enhanced HSP70 expression but not HSC70 expression. Exposure to high-frequency EMFs did not change HSP70 or HSC70 protein or gene expression. Hydrogen peroxide caused a significant increase in DNA strand breaks, but EMF exposure did not. Overall, no evidence was found that the exposure induced a HSP70-mediated stress response or primary DNA damage.
Prisco MG et al. · 2008
Lerchl A et al. · 2008
Researchers exposed adult male Djungarian hamsters to RF-EMF at 383, 900, and 1800 MHz for 60 days at 80 mW/kg. Pineal and serum melatonin levels and organ weights were not affected in any experiment. Body weight increased transiently up to 4% at 383 MHz, increased up to 6% non-transiently at 900 MHz, and was unchanged at 1800 MHz.
Lee JJ et al. · 2008
NIH3T3 mouse fibroblasts were exposed to 849 MHz RF radiation at average SAR values of 2 or 10 W/kg for either 1 hour or 1 hour per day for 3 days. Cellular invasion and migration were assessed using in vitro Matrigel invasion and Transwell migration assays. Cell cycle distribution was analyzed at 24 and 48 hours after exposure by flow cytometry. The study found no detectable effects on cell cycle distribution, cellular migration, or invasion at the tested SAR values.
Huang TQ et al. · 2008
Researchers exposed HEI-OC1 immortalized mouse auditory hair cells to 1763 MHz RF at 20 W/kg SAR in a CDMA chamber for 24 and 48 hours. They assessed cell cycle, DNA damage, heat shock protein expression, MAPK phosphorylation, and gene expression, finding no changes in cell cycle, DNA damage, HSP expression, or MAPK phosphorylation. Microarray analysis showed only 29 genes (0.09% of total) changed more than 1.5-fold after exposure.
Huang TQ, Lee MS, Oh E, Zhang BT, Seo JS, Park WY. · 2008
They assessed cell proliferation, cell cycle progression, DNA damage, and gene expression. RF exposure did not significantly change cell numbers, cell cycle distribution, or DNA damage levels. Genome-wide analysis found no genes changed more than two-fold, but ten genes changed 1.3- to 1.8-fold, including down-regulation of CXCR3 and IL1R2.
Hirose H et al. · 2008
Researchers continuously exposed BALB/3T3 cells to 2.1425 GHz W-CDMA RF fields at SARs of 80 and 800 mW/kg for 6 weeks. They also tested MCA-treated cells and MCA plus TPA-treated cells for tumor promotion and co-promotion effects. No significant differences in transformation frequency were found between RF-exposed groups and sham-exposed controls in any treatment condition. The results suggest that exposure to low-level RF radiation of up to 800 mW/kg does not induce cell transformation.
Franzellitti S, Valbonesi P, Contin A, Biondi C, Fabbri E. · 2008
Researchers evaluated HSP70 gene and protein expression in human trophoblast HTR-8/SVneo cells after 4 to 24 hours of exposure to 1.8 GHz continuous-wave and GSM signals. Inducible HSP70 protein expression was not modified by any exposure condition. HSP70C transcript levels increased after 24 hours of GSM-217Hz exposure and decreased after 4 and 16 hours of GSM-Talk exposure, while HSP70A, HSP70B, and HSC70 transcripts did not change.
Yilmaz F, Dasdag S, Akdag MZ, Kilinc N · 2008
Researchers investigated anti-apoptotic bcl-2 protein in rat brain and testes after whole-body exposure to 900 MHz cellular phone radiation. The results showed that 20 minutes of radiation did not alter bcl-2 protein in the brain and testes of rats. The study used two groups of eight Sprague-Dawley rats each, with the experimental group exposed to phones in speech condition for 20 minutes per day for one month and the sham group exposed to turned-off phones. The authors speculated that bcl-2 may not be involved in radiation effects on the brain and testes of rats.
Kim TH et al. · 2008
Researchers used a carousel-type chamber to expose the heads of C57BL mice to 849 MHz or 1763 MHz RF radiation. Mice were irradiated intermittently at 7.8 W/kg for up to 12 months. Brain tissues collected at 6 and 12 months showed no differences in histology, cell proliferation, NeuN and GFAP expression in hippocampus and cerebellum, or cell death between exposure and control groups. Body weights did not differ among sham, 849 MHz, and 1763 MHz groups during the study.
Roux D et al. · 2008
Researchers investigated the role of extracellular ATP in plant responses to high-frequency, low-amplitude electromagnetic fields. Exposure to low-level 900 MHz EMF evoked accumulation of stress-related transcripts and affected ATP levels. ATP concentration dropped 27% after 30 minutes of exposure, and adenylate energy charge decreased by 18%. The authors discuss whether this reflects increased energy usage or a signaling function for ATP in stress physiology.
Inoue S, Motoda H, Koike Y, Kawamura K, Hiragami F, Kano Y. · 2008
Exposure to 2.45 GHz microwave irradiation at 200 W increased neurite outgrowth frequency about 10-fold compared to non-irradiated controls. The increase was prevented by adding a p38 MAPK inhibitor. Microwave treatment did not cause toxicity, unlike heat shock at 45°C.
Engelmann JC et al. · 2008
Researchers exposed Arabidopsis thaliana cell suspension cultures to a radiofrequency field protocol representing typical urban microwave exposure for 24 hours. They used Affymetrix-ATH1 whole genome microarrays to measure gene expression. Differential expression analysis revealed significant changes in transcription of 10 genes, but fold changes did not exceed 2.5. Three of the affected genes are dark-inducible, and their functions do not point to known plant responses to environmental stimuli.
Tiwari R et al. · 2008
Researchers exposed whole blood samples from six healthy men to RF signals from a CDMA mobile phone for one hour. They assessed DNA damage using the alkaline comet assay and tested combinative effects with aphidicolin at two concentrations. RF signals alone or with low-dose aphidicolin did not significantly increase DNA damage compared to sham exposure. However, univariate analysis showed significant DNA damage with combined exposure at both aphidicolin concentrations. APC alone at the higher concentration also caused significant damage, and DNA repair efficiency varied significantly in combined exposure groups.
Kim JY et al. · 2008
The study investigated clastogenicity of 835-MHz RF-EMF using alkaline comet assay and chromosomal aberration test on mammalian cells. No direct cytogenetic effect was found in the chromosomal aberration test with RF-EMF alone. The comet assay showed nearly negative results for RF-EMF alone, with a small increase in tail moment. RF-EMF showed a potentiation effect in the comet assay when combined with model clastogens.
Zeni O et al. · 2008
Rao VS et al. · 2008
The study used neuronal cells differentiated from a mouse embryonic stem cell line and a frequency-tunable applicator to examine calcium dynamics in real time. Control cells showed about five spontaneous calcium spikes per cell in 60 minutes, while exposure to 800 MHz RF radiation at 0.5 W/kg increased spikes to 15.7 per cell. The increase depended on frequency but not on SAR between 0.5 and 5 W/kg, and involved N-type calcium channels and phospholipase C enzymes. Microfilament disruption prevented the calcium spikes.
Pavicic I, Trosic I · 2008
Researchers exposed V79 cells to continuous wave frequencies of 864 MHz and 935 MHz for 1, 2, or 3 hours. Growth was significantly increased after two- and three-hour exposures to 864 MHz and after three-hour exposure to 935 MHz, measured 72 hours after irradiation. Colony-forming ability and cell viability did not significantly differ from control cells. The two fields showed similar effects on growth, colony-forming ability, and viability, with impact being time-dependent.
Palumbo R et al. · 2008
The study investigated apoptosis induction after 900 MHz GSM radiation by measuring caspase 3 activation in Jurkat cells and quiescent and proliferating human peripheral blood lymphocytes. Exposure was at 1.35 W/kg for one hour in a temperature-controlled dual wire patch cell system. Caspase 3 activity increased by 32.4% in Jurkat cells and 22% in proliferating lymphocytes 6 hours after exposure, but did not change in quiescent lymphocytes. Apoptosis and viability assessed 24 hours later were unaffected in both cell types. Cell cycle analysis of proliferating T cells also showed no differences between exposed and sham-exposed cultures.
Karinen A, Heinavaara S, Nylund R, Leszczynski D. · 2008
Researchers exposed a small area of forearm skin in 10 female volunteers to RF-EMF at a specific absorption rate of 1.3 W/kg and collected punch biopsies from exposed and non-exposed areas. Analysis identified 8 proteins that were statistically significantly affected, and two of those proteins were present in all 10 volunteers. The researchers described this as the first study showing that molecular level changes might take place in human volunteers in response to exposure to RF-EMF.
Höytö A, Luukkonen J, Juutilainen J, Naarala J. · 2008
Researchers exposed human SH-SY5Y neuroblastoma and mouse L929 fibroblast cells to 872 MHz radiofrequency radiation at a specific absorption rate of 5 W/kg, using either continuous waves or a GSM-modulated signal. Two statistically significant differences related to RF radiation were found: t-BOOH-induced lipid peroxidation was increased in SH-SY5Y cells, and menadione-induced caspase 3 activity was increased in L929 cells, but both only for the GSM-modulated signal. No other endpoints were significantly affected, and no effects were observed from RF radiation exposure alone.
