Simkó M et al. · 2006
The study investigated Hsp70 expression and free radical release in human Mono Mac 6 cells exposed to ultrafine particles and radiofrequency electromagnetic fields. Ultrafine particle exposure increased free radical release by 40-45% above negative control, an effect stronger than heat treatment. Radiofrequency electromagnetic field exposure alone did not change free radical levels. Combined exposure to RF and ultrafine particles did not enhance the particle effect on free radicals. Heat treatment increased Hsp70 expression in a time-dependent manner, while ultrafine particles, RF fields, or their combination had no effect on Hsp70.
de Salles AA, Bulla G, Rodriguez CE. · 2006
Researchers simulated Specific Absorption Rate (SAR) in adult and child head models using the Finite Difference Time Domain method at 850 MHz and 1850 MHz. They used realistic head models with fitted electromagnetic parameters and tested microstrip and quarter-wavelength monopole antennas. The 1g-SAR for children was higher than for adults, exceeding 60% higher in the 10-year-old model. Results were compared with international recommendations.
Cooper TG, Mann SM, Khalid M, Blackwell RP. · 2006
The study assessed exposures of the general public to radio waves near 20 randomly selected GSM microcell and picocell base stations in the UK against ICNIRP guidelines. Exposures were generally in the range 0.002% to 2% of the ICNIRP general public reference level, with the greatest exposure quotient near any base station being 8.6%. Exposures close to microcell base stations were generally greater than those close to macrocell base stations.
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.
Aalto S et al. · 2006
Researchers studied the effects of a commercial mobile phone on regional cerebral blood flow in healthy humans using PET imaging. A mobile phone in operation induced a local decrease in cerebral blood flow beneath the antenna in the inferior temporal cortex and an increase in the prefrontal cortex. The study used a double-blind, counterbalanced design with 12 male subjects performing a verbal working memory task.
Oral B et al. · 2006
Researchers examined oxidative stress from a 900-MHz mobile phone and the possible protective effects of vitamins E and C on endometrial tissue in rats. Rats were divided into a sham control group, a 900-MHz EMF-exposed group (30 minutes daily for 30 days), and an EMF-exposed group treated with vitamins E and C before each exposure. Malondialdehyde, a marker of lipid peroxidation, and the proteins Bcl-2, Bax, caspase-3, and caspase-8 were measured in endometrial tissue. The EMF-exposed rats showed increased malondialdehyde levels and apoptosis, while vitamins E and C ameliorated oxidative tissue injury and apoptosis through free radical scavenging and antioxidant properties.
Hoyto A, Sihvonen AP, Alhonen L, Juutilainen J, Naarala J · 2006
Researchers investigated the effects of low-level radiofrequency radiation and elevated temperature on ornithine decarboxylase (ODC) activity in murine L929 fibroblasts. RF radiation did not affect cellular ODC activity. A slight temperature increase of 0.8-0.9 degrees C in the exposure system led to decreased ODC activity, which was verified by exposing cells to different temperatures in incubators.
Henderson SI, Bangay MJ. · 2006
Researchers measured radiofrequency signals from 60 base stations across five Australian cities at distances ranging from 50 to 500 m. All recorded exposure levels were well below the general public exposure limits of the ICNIRP guidelines and the Australian radiofrequency standard (ARPANSA RPS3). The highest level recorded from any single base station was 7.8 x 10(-3) W/m(2), which translates to 0.2% of the general public exposure limit.
Forgacs Z et al. · 2006
Researchers studied the possible effects of whole-body 1800 MHz GSM-like microwave exposure on male reproduction in mice. After repeated exposure at 0.018-0.023 W/kg SAR, an elevated serum testosterone level was measured, but no histopathological alteration could be detected in the reproductive organs. Leydig cell cultures from exposed animals did not differ from controls in their steroidogenic response.
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.
Yurekli AI et al. · 2006
Researchers used a gigahertz transverse electromagnetic (GTEM) cell to expose rats to electromagnetic fields at the GSM base transceiver station frequency of 945 MHz. The power density applied was 3.67 W/m2 (specific absorption rate = 11.3 mW/kg), which the researchers described as well below current exposure limits. MDA levels increased and GSH concentrations decreased significantly (p < 0.0001) under this exposure. There was also a less significant (p = 0.0190) increase in SOD (superoxide dismutase) activity under EM exposure.
Ozguner F, Bardak Y, Comlekci S. · 2006
Researchers compared how well melatonin and caffeic acid phenethyl ester (CAPE) protected rat retinas from oxidative stress caused by exposure to 900 MHz mobile-phone radiation. Melatonin and CAPE were administered daily for 60 days to the rats prior to their EMR exposure. Retinal levels of the oxidative stress markers NO and MDA increased in EMR-exposed rats, while both melatonin and CAPE caused a significant reduction in those levels. Antioxidant enzyme activities (SOD, GSH-Px, and CAT) decreased in EMR-exposed animals, but both treatments significantly increased those activities.
Lixia S et al. · 2006
Researchers exposed human lens epithelial cells (hLEC) to a 1.8 GHz GSM radiofrequency field at SARs of 1, 2, and 3 W/kg for 2 hours and then measured DNA damage, Hsp70 expression, and cell proliferation. DNA breaks at 1 and 2 W/kg were not significantly different from controls at any time point, while the 3 W/kg dose showed significantly increased DNA damage only at 0 and 30 minutes after exposure. Hsp70 protein expression was significantly increased at 2 and 3 W/kg, but Hsp70 mRNA expression did not change in any group, and cell proliferation was unaffected at all doses.
Whitehead TD et al. · 2005
The study aimed to confirm a previous report that CDMA and FDMA radiation increased Fos levels as cells entered plateau phase. Fos mRNA levels were not significantly different from sham exposure at either SAR level for any signal modulation. Therefore, the earlier results could not be confirmed.
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.
Lee JS, Huang TQ, Lee JJ, Pack JK, Jang JJ, Seo JS. · 2005
Researchers exposed eight-week-old hsp70.1-deficient mice twice daily for 45 minutes with a 15-minute interval, five days a week for ten weeks at a whole-body average specific absorption rate of 0.4 W/Kg for both 849 MHz and 1763 MHz fields. They examined major tissues histopathologically, assessed cell proliferative activity immunocytochemically, measured apoptosis with a TUNEL assay, and evaluated heat shock protein expression and stress-activated kinase phosphorylation by western blot. No histopathological differences were found between sham- and RF-exposed mice, and there was no evidence of increased proliferative or apoptotic activity. Levels of HSP90, HSP70, and HSP25 showed no obvious changes, and RF exposure did not affect phosphorylation of ERK1/2, JNK1/2, or p38 MAPK.
Hata K et al. · 2005
The study aimed to clarify the effects of short-term 1439 MHz TDMA exposure on melatonin synthesis in rats. Researchers investigated 208 male and female rats with brain SAR of 7.5 W/kg and whole-body SAR of 1.9 to 2.0 W/kg. After a 12-hour light-dark cycle, serum and pineal melatonin and pineal serotonin were measured by radioimmunoassay in darkness. No significant differences in melatonin or serotonin levels were found between exposed, sham, and cage control groups.
Wallin MK, Marve T, Hakansson PK. · 2005
Researchers tested whether GPRS, UMTS, and WLAN signals interfere with life-supporting equipment in intensive care and operating rooms. UMTS and WLAN caused little interference and can be used safely in critical care areas, though direct contact with medical devices should be avoided. GPRS at 50 cm caused an older infusion pump to alarm and stop infusing and produced 10 cases of display interference. GPRS can be used safely at a distance of 1 m.
van Wyk MJ, Bingle M, Meyer FJ. · 2005
This study presents a variety of critical aspects that need to be considered when calculating SAR in a human body close to a mobile phone base station antenna. The results show that it is critical to take the disturbance effect of the human phantom (a large conductive body) on the base station antenna into account when the antenna-phantom spacing is less than 300 mm. For these small spacings, the antenna structure must be modeled in detail. The conclusion is that it is feasible to calculate, using the proposed techniques and methodology, accurate occupational compliance zones around base station antennas based on a SAR profile and basic restriction guidelines. A hybrid FEM/MoM technique is proposed as a suitable numerical method to obtain accurate results.
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.
Yariktas M et al. · 2005
Ozguner F et al. · 2005
Researchers exposed rats to 900 MHz EMR radiation for 30 minutes per day over 10 days and measured oxidative stress markers and antioxidant enzyme activities. Exposure increased MDA and NO levels and decreased SOD, CAT, and GSH-Px activities in myocardial tissue. Treatment with CAPE reversed these changes, indicating a protective effect against mobile phone-induced oxidative heart injury.
Ozguner F et al. · 2005
The study compared the protective effects of melatonin and CAPE against 900 MHz mobile phone radiation-induced renal tubular injury in rats. Exposure increased urinary NAG and renal MDA levels in rats. Both melatonin and CAPE significantly reduced these elevated markers. Melatonin also increased SOD and GSH-Px activities above control levels, while CAPE did not increase these enzymes.
Vangelova KK, Israel MS. · 2005
Researchers measured urinary 6-sulphatoxymelatonin and three stress hormones in 36 male operators working fast-rotating extended shifts under radiofrequency electromagnetic radiation. Exposure levels were high for broadcasting station operators, low for TV station operators, and very low for satellite station operators. Radiofrequency EMR had no effect on the typical diurnal pattern of 6-sulphatoxymelatonin. High-level exposure significantly increased excretion rates of cortisol, adrenaline, and noradrenaline, while low-level exposure changes were not significant. The 24-hour excretion of cortisol and noradrenaline correlated with time-weighted average exposure measures.
Nikolova T et al. · 2005
ELF-EMF significantly affected transcript levels of bcl-2, bax, and GADD45 genes but did not affect neural-specific gene mRNA levels. RF-EMF down-regulated neural-specific Nurr1 and up-regulated bax and GADD45 mRNA levels. Short-term RF-EMF exposure for 6 hours caused a transient increase in DNA double-strand breaks, while 48-hour exposure did not. No effects were observed on mitochondrial function, nuclear apoptosis, cell proliferation, or chromosomal alterations.
