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Brain & Nervous System150 citations

Cognitive impairment in rats after long-term exposure to GSM-900 mobile phone radiation.

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Nittby H, Grafström G, Tian DP, Malmgren L, Brun A, Persson BR, Salford LG, Eberhardt J · 2008

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Rats exposed to cell phone radiation at levels similar to human use showed significant memory impairment after chronic exposure.

Plain English Summary

Summary written for general audiences

Swedish researchers exposed rats to cell phone radiation (GSM-900) for 2 hours weekly over more than a year, using power levels similar to what your phone emits. The exposed rats showed significantly impaired memory, specifically struggling to remember objects and when they encountered them compared to unexposed control rats. This suggests that chronic low-level cell phone radiation exposure may affect cognitive function and memory formation.

Why This Matters

This study adds important evidence to growing concerns about cell phone radiation's effects on brain function. What makes this research particularly relevant is the exposure level - the rats received SAR values of 0.6 and 60 milliwatts per kilogram, which overlap with typical cell phone emissions during calls (SAR limits are 1.6 W/kg in the US). The cognitive impairment occurred after protracted, low-level exposure rather than acute high doses, which better reflects how we actually use these devices. The reality is that this Swedish research team has consistently found neurological effects from mobile phone radiation across multiple studies, contributing to a body of evidence that regulatory agencies have been slow to acknowledge. What this means for you is that the 'safety' standards governing your phone were set based on heating effects alone, not the biological effects this study demonstrates at exposure levels your brain regularly experiences.

Exposure Details

SAR
0.0006 and 0.06 W/kg
Power Density
0.0033 and 0.00033 µW/m²
Source/Device
GSM‐900
Exposure Duration
2 hr/wk, 55 wk

Exposure Context

This study used 0.0033 and 0.00033 µW/m² for radio frequency:

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: 0.0033 and 0.00033 µW/m²Extreme Concern - 1,000 uW/m2FCC Limit - 10M uW/m2Effects observed in the No Concern rangeFCC limit is 30,303,030,303x 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

In this study we investigated in a rat model the long-term effects of protracted exposure to Global System for Mobile Communication-900 MHz (GSM-900) radiation.

Out of a total of 56 rats, 32 were exposed for 2 h each week for 55 weeks to radio-frequency electro...

In our study, GSM exposed rats had impaired memory for objects and their temporal order of presentat...

Our results suggest significantly reduced memory functions in rats after GSM microwave exposure.

Cite This Study
Nittby H, Grafström G, Tian DP, Malmgren L, Brun A, Persson BR, Salford LG, Eberhardt J (2008). Cognitive impairment in rats after long-term exposure to GSM-900 mobile phone radiation. Bioelectromagnetics. 29(3):219-232, 2008.
Show BibTeX
@article{h_2008_cognitive_impairment_in_rats_158,
  author = {Nittby H and Grafström G and Tian DP and Malmgren L and Brun A and Persson BR and Salford LG and Eberhardt J},
  title = {Cognitive impairment in rats after long-term exposure to GSM-900 mobile phone radiation.},
  year = {2008},
  doi = {10.1002/bem.20386},
  url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/bem.20386},
}
DOI: 10.1002/bem.20386

Cited By (150 papers)

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Quick Questions About This Study

Swedish researchers found that rats exposed to GSM-900 radiation for 2 hours weekly over more than a year showed significantly impaired memory compared to unexposed rats. The exposed rats struggled to remember objects and when they encountered them, suggesting chronic low-level exposure may affect cognitive function.
Rats exposed to GSM-900 radiation had impaired memory for objects and their temporal order of presentation compared to control rats. However, their ability to detect the place where objects were presented remained unaffected, indicating selective memory deficits rather than complete cognitive impairment.
The Swedish study exposed rats to GSM-900 cell phone radiation for 2 hours weekly over more than a year. This chronic, long-term exposure schedule was designed to simulate realistic human cell phone usage patterns and assess cumulative effects on memory function.
Yes, Swedish researchers used GSM-900 radiation at power levels similar to what cell phones emit and found significantly reduced memory functions in exposed rats. The study suggests that even realistic exposure levels may affect cognitive performance after long-term exposure.
The 2008 Swedish study found that rats exposed to GSM-900 radiation had significantly impaired temporal memory, struggling to remember when they encountered objects. This specific type of memory deficit suggests cell phone radiation may particularly affect time-related cognitive processing in the brain.