MRI Machine EMF Research

.[Effect of 1.8 GHz radiofrequency electromagnetic fields on the expression of microtubule associated protein 2 in rat neurons]

Zhao R, Zhang SZ, Yao GD, Lu DQ, Jiang H, Xu ZP · 2006

Effects of 1.8GHz radiofrequency field on DNA damage and expression of heat shock protein 70 in human lens epithelial cells

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.

Effects of 1.8GHz radiofrequency field on DNA damage and expression of heat shock protein 70 in human lens epithelial cells.

Lixia S et al. · 2006

Researchers exposed human eye lens cells to cell phone radiation at different power levels for 2 hours. Higher exposures caused temporary DNA damage and triggered cellular stress responses, suggesting that phone radiation can affect eye cells even without heating tissue.

Integration of differences in EEG analysis reveals changes in human EEG caused by microwave.

Bachmann M et al. · 2006

Researchers applied three different EEG analysis methods to detect changes caused by microwave exposure in healthy volunteers. Volunteers were exposed to 450 MHz microwave radiation modulated at several different frequencies, with a field power density of 0.16 mW/cm2 at the scalp. Statistically significant changes in EEG rhythms energy and dynamics were found in between 12% and 30% of subjects.

Investigation of co-genotoxic effects of radiofrequency electromagnetic fields in vivo.

Verschaeve L et al. · 2006

Researchers investigated combined genotoxic effects of 900 MHz radiofrequency fields and the drinking water mutagen MX in female rats over two years. MX induced DNA damage in rat brain but not in blood or liver cells. Co-exposure to RF fields and MX did not significantly increase DNA damage in blood, liver, or brain compared to MX alone. The study used alkaline comet assay and micronucleus tests on samples taken at multiple time points.

Is the brain influenced by a phone call? An EEG study of resting wakefulness.

Curcio G et al. · 2005

Researchers recorded resting EEG from 20 healthy subjects to study the effect of mobile phone EMF on waking brain activity. Subjects were randomly assigned to two groups and exposed double-blind to a 902.40 MHz signal modulated at 217 Hz with 0.25 W average power before or during EEG recording. Real exposure influenced alpha band spectral power in some bins compared to baseline and sham, with a greater effect when the EMF was on during recording. The authors concluded that pulsed high-frequency EMF can affect normal brain functioning, but no health effect conclusions were drawn.

Thermophysiological responses of human volunteers to whole body RF exposure at 220 MHz.

Adair ER et al. · 2005

Researchers measured thermoregulatory responses in six adult volunteers during 45-minute whole-body exposures to 220 MHz radio frequency energy at three power densities and three ambient temperatures. Esophageal temperature showed small changes of no more than 0.35 °C and never exceeded 37.3 °C under any test condition. Vigorous sweating occurred at PD = 12 and 15 mW/cm(2), with sweating levels higher than those observed for equivalent PD at 100 MHz. The researchers concluded that exposed subjects thermoregulate efficiently through increased heat loss responses, particularly sweating.

Non-linear analysis of the electroencephalogram for detecting effects of low-level electromagnetic fields.

Bachmann M, Kalda J, Lass J, Tuulik V, Säkki M, Hinrikus H. · 2005

Researchers exposed 23 healthy volunteers to a 450 MHz microwave field with 7 Hz frequency on-off modulation, with a field power density of 0.16 mW cm(-2) at the scalp. The study compared traditional spectral analysis and a new non-linear method called analysis of the length distribution of low-variability periods to detect EEG changes from microwave exposure. The non-linear method detected a significant effect in six exposed subjects, while spectral analysis found a significant result for only one subject.

An investigation of the effects of TETRA RF fields on intracellular calcium in neurones and cardiac myocytes.

Green AC et al. · 2005

Intracellular calcium concentration ([Ca(2 +) ](i)) was measured in cultured rat cerebellar granule cells and cardiac myocytes during exposure to TETRA fields (380.8875 MHz pulse modulated at 17.6 Hz, 25% duty cycle). Granule cells exposed at specific absorption rates (SARs) of 5, 10, 20, 50 or 400 mW x kg(-1) showed no significant changes in resting [Ca(2 +) ](i). Exposure to TETRA (50 or 400 mW x kg(-1)) had no significant effect on either the rate or amplitude of spontaneous Ca(2 +) transients in cardiac myocytes. Overall, these results showed no evidence of any consistent or biologically relevant effect of TETRA fields on [Ca(2 + )](i) in granule cells and cardiac myocytes at any of the SAR tested.

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.

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

Nikolova T et al. · 2005

German researchers exposed developing brain cells to both power line frequencies (50 Hz) and cell phone frequencies (1.71 GHz) for 6 hours to study genetic effects. They found that both types of electromagnetic fields triggered changes in genes that control cell death and DNA damage responses, though the cells themselves appeared to function normally afterward. This suggests that EMF exposure can activate cellular stress responses even when no obvious harm is visible.

Effects of electromagnetic field emitted by cellular phones on the EEG during an auditory memory task: a double blind replication study.

Krause CM et al. · 2004

Researchers conducted a double-blind study in which subjects performed a memory task with and without exposure to a digital 902 MHz field. All eight significant EEG changes from the earlier study were not significant in this replication. The effect of EMF on incorrect answers was inconsistent, with a significant increase in errors observed in this study but not in the earlier one.

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.

Changes in human EEG caused by low level modulated microwave stimulation.

Hinrikus H, Parts M, Lass J, Tuulik V. · 2004

Twenty healthy volunteers were exposed to 450 MHz microwaves with 7 Hz on-off modulation, with a field power density of 0.16 mW/cm2 at the scalp. The study focused on the effect of low level microwave radiation on human EEG alpha and theta rhythms. Microwave and photic exposure did not cause statistically significant changes in EEG activity for the whole group, though changes varied strongly from subject to subject.

Diseases of modern living: neurological changes associated with mobile phones and radiofrequency radiation in humans

Unknown authors · 2004

Case reports of peripheral neurological effects of radiofrequency radiation describe mainly disturbances of noxious sensation called dysaesthesia. Cases have arisen after exposure to much of the frequency range from low MHz to GHz. After very high intensity exposures nerves may be grossly injured; however, after lower intensity exposures which may result in dysaesthesia, ordinary nerve conduction studies demonstrate no abnormality although current perception threshold studies may. Only a small proportion of similarly exposed persons develop symptoms. Some observations are not consistent with the hypothesis that all health effects of radiofrequency radiation arise from thermal mechanisms.

Non-ionizing electromagnetic radiations, emitted by a cellular phone, modify cutaneous blood flow.

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.

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.

Responses of neurons to an amplitude-modulated microwave stimulus.

Beason RC, Semm P. · 2002

Researchers investigated the effects of a pulsed 900 MHz signal modulated at 217 Hz on avian brain neurons. The stimulation changed neural activity in more than half of the brain cells. 76% of responding cells increased their firing rates by an average of 3.5-fold. The remaining responding cells decreased their spontaneous activity rates. The authors suggested these responses indicate potential effects on humans using hand-held cellular phones.

Effects of 7 Hz-modulated 450 MHz electromagnetic radiation on human performance in visual memory tasks.

Lass L et al. · 2002

The study enrolled 100 subjects (37 female, 63 male) and randomly assigned them to an exposed group (10-20 min, 0.158 mW cm(-2)) or a sham-exposed group. The aim was to examine low-level 7 Hz-modulated 450 MHz radiation effects on human performance in visually presented neuropsychological tasks associated with attention and short-term memory. A battery of three different tests measured attention and short-term memory. The results of tasks 1 and 3 showed a significant increase in variances of errors (p<0.05) in the exposed versus the sham-exposed group. The results of task 2 indicated a significant decrease in errors (p<0.05) in the exposed group.

The excretion of 6-hydroxymelatonin sulfate in healthy young men exposed to electromagnetic fields emitted by cellular phone -- an experimental study.

Bortkiewicz A, Pilacik B, Gadzicka E, Szymczak W. · 2002

Effect of millimeter wave radiation on catalase activity.

Logani MK, Agelan A, Ziskin MC. · 2002

The study examined the effect of millimeter electromagnetic waves on catalase activity in mouse blood to understand mechanisms involved in its reduction. SKH-1 hairless mice were irradiated on their midbacks with 42.2±0.2 GHz millimeter waves at an incident power density of 31±5 mW/cm2 and a peak SAR of 622±100 W/kg. MW irradiation before or after cyclophosphamide administration did not significantly reduce the toxic effect of cyclophosphamide on catalase activity in mouse blood.

Chronic Exposure to a GSM-like Signal (Mobile Phone) Does Not Stimulate the Development of DMBA-Induced Mammary Tumors in Rats: Results of Three Consecutive Studies.

Bartsch H et al. · 2002

Researchers tested a GSM-like RF signal on mammary tumors induced by DMBA in female Sprague-Dawley rats as a model for human breast cancer. Three experiments were carried out under strictly standardized conditions using a GSM-like signal at 900 MHz pulsed at 217 Hz. The overall results showed no statistically significant effect of RF-field exposure on tumor latency, and cumulative tumor incidence was unaffected as well. The researchers concluded that low-level RF radiation does not appear to possess carcinogenic or cancer-promoting effects on DMBA-induced mammary tumors.

Influence of a radiofrequency electromagnetic field on cardiovascular and hormonal parameters of the autonomic nervous system in healthy individuals.

Braune S, Riedel A, Schulte-Monting J, Raczek J. · 2002

The study investigated the hypothesis that exposure to EMFs can increase sympathetic vasoconstrictor activity. Forty healthy young males and females underwent a single-blind, placebo-controlled protocol on two different days with randomized EMF and placebo periods. The EMF exposure was a GSM-like signal at 900 MHz, pulsed with 217 Hz, 2 W, delivered by a mobile phone on the right side of the head. Blood pressure, heart rate, cutaneous capillary perfusion, and serum levels of norepinephrine, epinephrine, cortisol, and endothelin were measured. Systolic and diastolic blood pressure increased about 5 mmHg during the protocol, but the changes were independent of EMF exposure.

Changes in the dielectric properties of rat tissue as a function of age at microwave frequencies.

Peyman A, Rezazadeh AA, Gabriel C · 2001

Researchers measured dielectric properties of ten rat tissues at six ages from 130 MHz to 10 GHz. Results showed a general decrease in dielectric properties with age. The decrease was more apparent in brain, skull, and skin tissues than in abdominal tissues. The variation was attributed to changes in water content and organic composition.

GSM phone signal does not produce subjective symptoms.

Koivisto M et al. · 2001

Researchers studied the influence of pulsed radiofrequency electromagnetic fields from digital GSM mobile phones (902 MHz, 217 Hz pulse modulation) on subjective symptoms in healthy subjects using two single-blind experiments. The results did not reveal any differences between exposure and non-exposure conditions. Exposure durations were about 60 minutes in Experiment 1 and 30 minutes in Experiment 2. Subjects rated symptoms including headache, dizziness, fatigue, itching or tingling of the skin, redness on the skin, and sensations of warmth on the skin.