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

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

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Cell phone radiation at 6 W/kg SAR reduced brain activity in memory and decision-making regions after just one week of exposure.

Plain English Summary

Summary written for general audiences

French researchers exposed rats to cell phone radiation and measured brain enzyme activity. High-intensity exposure (6 W/kg) for 15 minutes daily reduced brain activity in memory and decision-making regions after one week. Lower exposures showed no effects, suggesting intensity matters for brain function.

Why This Matters

This study demonstrates that cell phone radiation can measurably alter brain metabolism at exposure levels well above current safety limits. The 6 W/kg SAR used here is three times higher than the 2 W/kg limit for cell phones in most countries, yet the researchers found significant changes in brain activity after just one week of brief daily exposures. What makes this particularly concerning is that the affected brain regions include the hippocampus (critical for memory formation) and prefrontal cortex (essential for decision-making and attention). The fact that these metabolic changes occurred so quickly suggests the brain is more sensitive to RF radiation than current safety standards assume. While this exposure level exceeds typical cell phone use, it's within range of what might occur during extended calls or when phones are used with poor signal strength, which forces devices to increase their power output.

Exposure Details

SAR
6 W/kg
Source/Device
900-MHz
Exposure Duration
15 min/day for over seven days

Exposure Context

This study used 6 W/kg for SAR (device absorption):

Building Biology guidelines are practitioner-based limits from real-world assessments. BioInitiative Report recommendations are based on peer-reviewed science. Check Your Exposure to compare your own measurements.

Where This Falls on the Concern Scale

Study Exposure Level in ContextStudy Exposure Level in ContextThis study: 6 W/kgExtreme Concern - 0.1 W/kgFCC Limit - 1.6 W/kgEffects observed in the Extreme Concern rangeFCC limit is 0x higher than this level
A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 900 MHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 900 MHzPower lines50/60 Hz5G mm28 GHzLogarithmic scale

Study Details

The goal of this study was conducted to measure cytochrome oxidase (CO) levels using histochemical methods in order to evaluate regional brain metabolic activity in rat brain

Exposure to a GSM 900 MHz signal for 45 min/day at a brain-averaged specific absorption rate (SAR) o...

Compared to the sham and control cage groups, rats exposed to a GSM signal at 6 W/Kg showed decrease...

Our results indicate that 6 W/Kg GSM 900 MHz microwaves may affect brain metabolism and neuronal activity in rats.

Cite This Study
Ammari M, Lecomte A, Sakly M, Abdelmelek H, de-Seze R. (2008). Exposure to GSM 900 MHz electromagnetic fields affects cerebral cytochrome c oxidase activity. Toxicology. 250(1):70-74, 2008.
Show BibTeX
@article{m_2008_exposure_to_gsm_900_812,
  author = {Ammari M and Lecomte A and Sakly M and Abdelmelek H and de-Seze R.},
  title = {Exposure to GSM 900 MHz electromagnetic fields affects cerebral cytochrome c oxidase activity.},
  year = {2008},
  
  url = {https://www.sciencedirect.com/science/article/abs/pii/S0300483X0800262X},
}

Quick Questions About This Study

Yes, French researchers found that rats exposed to 6 W/kg GSM 900 MHz radiation for 15 minutes daily showed decreased brain enzyme activity after one week. The effects occurred in memory and decision-making regions including the hippocampus and prefrontal cortex, indicating altered brain metabolism.
A 2008 study demonstrated that high-intensity GSM 900 MHz exposure (6 W/kg) significantly reduced cytochrome c oxidase activity in rat brains. This enzyme is crucial for cellular energy production, suggesting that intense cell phone radiation may impair brain cell energy metabolism.
Research shows that 15-minute daily exposure to 6 W/kg GSM radiation affects multiple brain areas including the hippocampus, prefrontal cortex, motor cortex, and visual cortex. These regions are important for memory formation, decision-making, movement control, and visual processing in rats.
No, the study found that 1.5 W/kg GSM 900 MHz exposure did not affect brain activity, while 6 W/kg exposure caused significant changes. This suggests that radiation intensity matters more than exposure duration for brain effects, with higher power levels posing greater risk.
Brain enzyme changes occurred within just one week of daily 15-minute exposures to 6 W/kg GSM 900 MHz radiation. This relatively rapid timeframe suggests that high-intensity cell phone radiation can quickly alter brain metabolism and neuronal activity in exposed animals.