3,138 Studies Reviewed. 77.4% Found Biological Effects. The Evidence is Clear.

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

Bioeffects Seen

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

View Original Abstract
Share:

Low-level microwave radiation at 0.16 mW/cm² altered brain wave patterns in the frontal region after repeated exposure cycles.

Plain English Summary

Summary written for general audiences

Estonian researchers exposed 20 volunteers to low-level microwave radiation similar to cell phones. The study found measurable changes in brain wave patterns in the frontal region after repeated exposure. Individual responses varied significantly, suggesting some people may be more sensitive to microwave effects than others.

Why This Matters

This study adds to the growing body of evidence that microwave radiation can directly influence brain activity, even at relatively low exposure levels. The power density used (0.16 mW/cm²) is well within the range of everyday exposures from cell phones and WiFi devices, making these findings particularly relevant for regular technology users. What's especially noteworthy is that the researchers found the brain effects localized to the frontal region, which differs from visual light stimulation that affected the back of the brain. The fact that effects became apparent only after repeated exposure cycles suggests that cumulative exposure may be more significant than single, brief exposures. While individual responses varied considerably, the demonstration that microwave radiation can measurably alter brain wave patterns challenges the assumption that non-thermal EMF exposures are biologically inert.

Exposure Details

Power Density
0.16 µW/m²
Source/Device
450 MHz with 7 Hz on-off modulation

Exposure Context

This study used 0.16 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 ContextA logarithmic scale showing exposure levels relative to Building Biology concern thresholds and regulatory limits.Study Exposure Level in ContextThis study: 0.16 µW/m²Extreme Concern1,000 uW/m2FCC Limit10M uW/m2Effects observed in the Slight Concern range (Building Biology)FCC limit is 62,500,000x higher than this exposure level

Study Details

This study focuses on the effect of low level microwave radiation on human EEG alpha and theta rhythms.

During the experiment, 20 healthy volunteers were exposed to a 450 MHz microwaves with 7 Hz on-off m...

The changes caused by photic as well as microwave stimulation were more regular on the alpha rhythm....

Therefore, photic and microwave exposure did not cause statistically significant changes in the EEG activity level for the whole group. For some subjects, clear tendencies of changes in microwave on-off cycles were noticeable.

Cite This Study
Hinrikus H, Parts M, Lass J, Tuulik V. (2004). Changes in human EEG caused by low level modulated microwave stimulation. Bioelectromagnetics. 25(6):431-440, 2004.
Show BibTeX
@article{h_2004_changes_in_human_eeg_1023,
  author = {Hinrikus H and Parts M and Lass J and Tuulik V.},
  title = {Changes in human EEG caused by low level modulated microwave stimulation.},
  year = {2004},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/15300729/},
}

Quick Questions About This Study

Estonian researchers exposed 20 volunteers to low-level microwave radiation similar to cell phones. The study found measurable changes in brain wave patterns in the frontal region after repeated exposure. Individual responses varied significantly, suggesting some people may be more sensitive to microwave effects than others.