SAR (Specific Absorption Rate)

Effects of mobile phone electromagnetic fields on an auditory order threshold task

Cinel C, Boldini A, Russo R, Fox E · 2007

Effects of 2.45 GHz microwave fields on liposomes entrapping glycoenzyme ascorbate oxidase: evidence for oligosaccharide side chain involvement.

Ramundo-Orlando A, Liberti M, Mossa G, D'Inzeo G. · 2004

Enzyme activity decreased only at 5.6 W/kg, with no response at lower SAR values. When using deglycated ascorbate oxidase without oligosaccharide chains, microwave irradiation caused no enzyme activity changes, indicating the chains are necessary for the effect. Catalytic properties of both enzyme forms were unaffected by microwave exposure in solution or in liposomes, ruling out enzyme conformational changes as a mechanism. The authors concluded that oligosaccharide chains of ascorbate oxidase are critical for microwave effects on lipid membranes.

1800 MHz radiofrequency (mobile phones, different global system for mobile communication modulations) does not affect apoptosis and heat shock protein 70 level in peripheral blood mononuclear cells from young and old donors.

Capri M et al. · 2004

Researchers studied whether prolonged in vitro exposure to 1800 MHz radiofrequency could affect human peripheral blood mononuclear cells from young and elderly donors by altering apoptosis, mitochondrial membrane potential, and heat shock protein 70 levels. Three GSM signal modulations (Basic, DTX, and Talk) were applied at specific absorption rates of 1.4 and 2.0 W kg−1. Endpoints were analyzed both with and without the apoptosis-inducing agent 2-deoxy-D-ribose. No significant difference was found between RF-exposed and sham-exposed cells for any endpoint. The 1800 MHz RF did not induce apoptosis on its own, did not alter apoptosis triggered by an agent, and did not change mitochondrial function or HSP 70 expression.

Effects of mobile phone radiation on reproduction and development in Drosophila melanogaster.

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.

Radio frequency radiation effects on protein kinase C activity in rats' brain.

Paulraj R, Behari J · 2004

Protein kinase C activity was measured in whole brain, hippocampus, and whole brain minus hippocampus after exposure. A significant decrease in enzyme level was observed in exposed rats compared to sham-exposed rats.

Glial markers and emotional memory in rats following acute cerebral radiofrequency exposures

(E) Barthélémy A et al. · 2016

Researchers exposed male Sprague Dawley rats for 15 minutes at 0, 1.5, or 6 W/kg, or for 45 minutes at 6 W/kg, to radiofrequency electromagnetic fields. Memory, emotionality, and locomotion were tested using fear conditioning, the elevated plus maze, and the open field. Long-term memory was reduced and cytosolic GFAP was increased in the hippocampus and in the olfactory bulb at 6 W/kg. No MBP or Aβ1–40 expression modification was shown. The study suggests that RF EMF-induced astrogliosis had functional consequences on memory but did not demonstrate that it was secondary to neuronal damage.

Cerebral radiofrequency exposures during adolescence: Impact on astrocytes and brain functions in healthy and pathologic rat models.

Petitdant N et al. · 2016

Researchers used rats to assess whether astrocyte reactivity, perception, and emotionality were affected by RF EMF exposures during adolescence. They also investigated if adolescent brains were more sensitive to RF EMF exposures after neurodevelopmental inflammation. Results did not show any neurobiological impairment in healthy and vulnerable RF EMF-exposed rats compared to sham-exposed controls. Data did not support the hypothesis of a specific cerebral sensitivity to RF EMF of adolescents, even after neurodevelopmental inflammation.

Do signals of a hand-held TETRA transmitter affect cognitive performance, well-being, mood or somatic complaints in healthy young men? Results of a randomized double-blind cross-over provocation study.

Sauter C et al. · 2015

Researchers conducted a double-blind cross-over study with 30 healthy young men exposed to TETRA signals at 1.5 W/kg and 6.0 W/kg and sham. Exposure lasted 2.5 hours at 385 MHz with specific absorption rates of 1.5 and 6.0 W/kg. Attention was unchanged in two of three tasks, while working memory showed significant changes in two of four subtasks. 5 out of 35 tested parameters showed significant results, four of which indicated improved performance. Mood, well-being, and subjective somatic complaints were not affected by TETRA exposure.

Do signals of a hand-held TETRA transmitter affect cognitive performance, well-being, mood or somatic complaints in healthy young men? Results of a randomized double-blind cross-over provocation study.

Sauter C et al. · 2015

German researchers exposed 30 healthy young men to TETRA radio signals (used by police and emergency services) for 2.5 hours to test effects on thinking, mood, and physical symptoms. They found no negative impacts on cognitive performance or well-being, with some participants actually showing slight improvements in certain memory tasks. The study suggests short-term exposure to TETRA signals doesn't harm mental function in healthy adults.

GFAP expression in the rat brain following sub-chronic exposure to a 900 MHz electromagnetic field signal

Ammari M et al. · 2010

This study measured glial fibrillary acidic protein (GFAP) expression in 48 rat brains to evaluate reactive astrocytosis after sub-chronic head-only exposure to a 900 MHz electromagnetic field signal. Rats were exposed either for 45 minutes per day at a SAR of 1.5 W/kg or for 15 minutes per day at a SAR of 6 W/kg, five days per week over an eight-week period. Compared to sham-treated rats, exposed rats showed an increase in GFAP levels in different brain areas, measured three and ten days after treatment.

Exposure to GSM 900 MHz electromagnetic fields affects cerebral cytochrome c oxidase activity

Ammari M, Lecomte A, Sakly M, Abdelmelek H, de-Seze R · 2008

Researchers measured cytochrome oxidase levels in rat brains using histochemical methods to evaluate regional brain metabolic activity after GSM 900 MHz signal exposure. Rats were exposed either for 45 minutes per day at a SAR of 1.5 W/Kg or for 15 minutes per day at a SAR of 6 W/Kg, over seven days. At 6 W/Kg, decreased CO activity was found in areas of the prefrontal and frontal cortex, the hippocampus, and the posterior cortex, while exposure at 1.5 W/Kg did not affect brain activity.

Effect of a chronic GSM 900 MHz exposure on glia in the rat brain

Ammari M et al. · 2008

Researchers measured GFAP expression in rat brain areas using immunocytochemistry to evaluate glial changes 10 days after chronic exposure to a GSM 900 MHz signal. Rats were exposed 5 days a week for 24 weeks at a brain-averaged SAR of 1.5 W/kg for 45 minutes per day, or at 6 W/kg for 15 minutes per day. Compared with sham or cage control animals, rats exposed at 6 W/kg had increased GFAP stained surface areas (p < 0.05), while exposure at 1.5 W/kg did not increase GFAP expression. The researchers noted that chronic exposure at 6 W/kg may induce persistent astroglia activation in the rat brain, which they described as a sign of a potential gliosis.

Effect of head-only sub-chronic and chronic exposure to 900-MHz GSM electromagnetic fields on spatial memory in rats

Ammari M et al. · 2008

French researchers exposed rats to 900 MHz cell phone radiation (the same frequency used by GSM phones) for either 8 or 24 weeks, then tested their spatial memory using a maze. The rats showed no memory problems compared to unexposed rats, even at radiation levels up to four times higher than current safety limits. This suggests that chronic cell phone radiation exposure may not impair spatial learning and memory functions in the brain.

Micronucleus frequency in erythrocytes of mice after long-term exposure to radiofrequency radiation.

Juutilainen J, Heikkinen P, Soikkeli H, Mäki-Paakkanen J. · 2007

Electromagnetic fields affect transcript levels of apoptosis-related genes in embryonic stem cell-derived neural progenitor cells.

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.

Acute exposure to 930 MHz CW electromagnetic radiation in vitro affects reactive oxygen species level in rat lymphocytes treated by iron ions.

Zmyslony M, Politanski P, Rajkowska E, Szymczak W, Jajte J. · 2004

Researchers tested whether 930 MHz continuous wave electromagnetic radiation affects reactive oxygen species (ROS) levels in rat lymphocytes. Acute exposure of 5 and 15 minutes did not affect ROS levels on its own. When iron ions were added to stimulate ROS production, the ROS level was significantly greater in exposed lymphocytes after both exposure durations.

Effects of GSM-900 microwaves on the experimental allergic encephalomyelitis (EAE) rat model of multiple sclerosis.

Anane R et al. · 2003

Researchers investigated the effects of acute GSM-900 microwave exposure on the clinical parameters of the acute EAE rat model in two independent experiments with habituated and nonhabituated rats. Female Lewis rats were divided into cage control, sham exposed, and two groups exposed at 1.5 or 6.0 W/kg local SAR averaged over the brain using a loop antenna over their heads. EAE was induced with a mixture of myelin basic protein and Mycobacterium tuberculosis. The 21-day exposure at 2 hours per day had no effect on the onset, duration, or termination of the EAE crisis.

Effects of mobile phone radiation on x-ray-induced tumorigenesis in mice.

Heikkinen P et al. · 2001

Researchers evaluated the effect of low-level RF radiation on cancer development initiated by ionizing radiation in mice. Two hundred female CBA/S mice were randomized into four equal groups at 3 to 5 weeks of age, and all groups except the cage-control group were exposed to ionizing radiation followed by RF radiation for 1.5 h per day, 5 days a week for 78 weeks. One group received continuous NMT-type RF radiation at 902.5 MHz and 1.5 W/kg SAR, another received pulsed GSM-type RF radiation at 902.4 MHz and 0.35 W/kg SAR, while controls were sham-exposed. RF radiation exposures did not significantly increase the incidence of any neoplastic lesion. The researchers concluded that the results do not provide evidence for cancer promotion by RF radiation from mobile phones.

Effects of short-term radiation emitted by WCDMA mobile phones on teenagers and adults.

Choi SB, Kwon MK, Chung JW, Park JS, Chung K, Kim DW. · 2014

Two volunteer groups of 26 adults and 26 teenagers were simultaneously investigated by measuring physiological changes in heart rate, respiration rate, and heart rate variability for autonomic nervous system (ANS), eight subjective symptoms, and perception of RF-EMFs during sham and real exposure sessions. Short-term WCDMA RF-EMFs generated no significant changes in ANS, subjective symptoms, or the percentages of those who believed they were being exposed in either group.

Effects of radiation emitted by WCDMA mobile phones on electromagnetic hypersensitive subjects.

Kwon MK, Choi JY, Kim SK, Yoo TK, Kim DW. · 2012

In this double-blind study, two volunteer groups of 17 EHS and 20 non-EHS subjects were simultaneously investigated for physiological changes (heart rate, heart rate variability, and respiration rate), eight subjective symptoms, and perception of RF-EMFs during real and sham exposure sessions. Experiments were conducted using a dummy phone containing a WCDMA module (average power, 24 dBm at 1950 MHz; specific absorption rate, 1.57 W/kg) within a headset placed on the head for 32 min. WCDMA RF-EMFs generated no physiological changes or subjective symptoms in either group, and there was no evidence that EHS subjects perceived RF-EMFs better than non-EHS subjects.

EHS subjects do not perceive RF EMF emitted from smart phones better than non-EHS subjects.

Kwon MK, Kim SK, Koo JM, Choi JY, Kim DW. · 2012

The study used a double-blind design with 17 EHS and 20 non-EHS volunteers exposed to real and sham RF-EMF sessions. There was no indication that EHS subjects perceive RF-EMFs better than non-EHS subjects. Exposure used a WCDMA module at 1950 MHz with an average power of 24 dBm and a specific absorption rate of 1.57 W/kg for 32 min.

Effects of RF fields emitted from smart phones on cardio-respiratory parameters: a preliminary provocation study.

Kwon MK, Nam KC, Lee da S, Jang KH, Kim DW. · 2011

Researchers conducted a double-blind provocation study with 10 self-reported electromagnetic hypersensitivity and 10 non-hypersensitivity volunteers. Participants were exposed to WCDMA RF fields at 1950 MHz with 24 dBm output and a specific absorption rate of 1.57 W/kg for 30 minutes. The 30-minute exposure did not produce any physiological changes in either group.

Oxidative stress response in SH-SY5Y cells exposed to short-term 1800 MHz radiofrequency radiation

Marjanovic Cermak AM, Pavicic I, Trosic I · 2017

Human neuroblastoma SH-SY5Y cells were exposed to 1800 MHz radiofrequency radiation for 10, 30, and 60 minutes at an electric field strength of 30 V m-1 and a specific absorption rate of 1.6 W kg-1. Cell viability remained within normal physiological values after radiation exposure. Significantly higher ROS levels were observed at every radiation exposure time tested. After 60 minutes of exposure, the radiation caused significant lipid and protein damage. The highest glutathione concentration was detected after 10 minutes of exposure.

In vitro non-thermal oxidative stress response after 1800 MHz radiofrequency radiation.

Marjanovic Cermak AM et al. · 2017

Researchers exposed V79 fibroblast cells to 1800 MHz RF radiation for 10, 30, and 60 minutes at a specific absorption rate of 1.6 W/kg to investigate possible links between radiofrequency exposure and oxidative stress. Cell viability remained within normal physiological values regardless of exposure time. An increased level of superoxide radicals was detected after 60-minute exposure, and a significantly higher GSH level was observed immediately after 10-minute exposure, though GSH-Px activity was higher but not significant. Lipid oxidative damage in exposed cell samples was not observed.

In vitro non-thermal oxidative stress response after 1800 MHz radiofrequency radiation

Marjanovic Cermak AM et al. · 2017

Researchers exposed human cells to cell phone radiation (1800 MHz) for up to 60 minutes at typical phone power levels. The cells showed signs of oxidative stress, including increased harmful free radicals and elevated cellular defense responses, even without heating effects.