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Note: This study found no significant biological effects under its experimental conditions. We include all studies for scientific completeness.

DNA & Genetic Damage

Evaluation of the Effect of Chronic 94 GHz Exposure on Gene Expression in the Skin of Hairless Rats In Vivo

No Effects Found

Authors not listed · 2020

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Five months of intense 94 GHz exposure at twice occupational limits caused no skin gene changes in rats.

Plain English Summary

Summary written for general audiences

Researchers exposed hairless rats to 94 GHz millimeter wave radiation (the same frequency used in military crowd-control weapons) for 5 months at twice the occupational safety limit. Despite this intense chronic exposure, the radiation caused no detectable changes in skin gene expression in either young or adult rats.

Why This Matters

This study provides reassuring data about 94 GHz millimeter waves, the frequency used in military Active Denial Systems and some 5G applications. The researchers used exposure levels twice the occupational limit for humans over 5 months - far exceeding what most people would encounter from wireless devices. The fact that even this intense exposure produced no gene expression changes in skin tissue suggests these frequencies may be less biologically active than lower frequencies that penetrate deeper into the body. However, we should note this was an industry-standard 'no effect' finding that doesn't address other potential biological impacts beyond gene expression, and rat skin may respond differently than human tissue to millimeter wave exposure.

Exposure Information

A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 94 GHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 94 GHzPower lines50/60 HzCell phones~1 GHzWiFi2.4 GHz5G mm28 GHzLogarithmic scale

Specific exposure levels were not quantified in this study.

Cite This Study
Unknown (2020). Evaluation of the Effect of Chronic 94 GHz Exposure on Gene Expression in the Skin of Hairless Rats In Vivo.
Show BibTeX
@article{evaluation_of_the_effect_of_chronic_94_ghz_exposure_on_gene_expression_in_the_skin_of_hairless_rats_in_vivo_ce2805,
  author = {Unknown},
  title = {Evaluation of the Effect of Chronic 94 GHz Exposure on Gene Expression in the Skin of Hairless Rats In Vivo},
  year = {2020},
  doi = {10.1667/RR15470.1},
  
}
DOI: 10.1667/RR15470.1PubMed: 32126188

Quick Questions About This Study

No. This study found that chronic 94 GHz exposure at twice the occupational safety limit for 5 months caused no significant changes in skin gene expression in either young or adult hairless rats.
The 94 GHz frequency is used in military Active Denial Systems (crowd-control weapons), some medical devices, and certain 5G wireless communication applications. These millimeter waves are absorbed by the skin's surface layer.
The rats were exposed for 5 months total, receiving 3 hours of 94 GHz radiation exposure per day, 3 days per week at an intensity of 10 mW/cm² (twice the human occupational limit).
No. The study confirms that 94 GHz millimeter waves are absorbed and stopped by the first layer of skin, unlike lower frequency EMF that can penetrate deeper into body tissues.
No. The researchers specifically noted that the chronic 94 GHz exposure did not modify the animals' body temperature, indicating the radiation levels used did not cause significant thermal heating effects.