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Stress proteins are not induced in mammalian cells exposed to radiofrequency or microwave radiation.

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Cleary, SF, Cao, G, Liu, LM, Egle, PM, Shelton, KR · 1997

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RF radiation at levels up to 50 times higher than phone limits didn't trigger cellular stress responses, suggesting biological effects occur through subtler mechanisms.

Plain English Summary

Summary written for general audiences

Researchers exposed human and hamster cells to radiofrequency radiation at levels 25 to 100 times higher than typical phone use for 2 hours, then looked for signs of cellular stress. They found no evidence that RF radiation triggered the production of stress proteins - molecules cells make when damaged or threatened. This suggests that at these exposure levels, the radiation didn't cause detectable cellular stress responses.

Why This Matters

This 1997 study provides important evidence that radiofrequency radiation doesn't trigger one of the body's most fundamental protective mechanisms - the stress protein response. The researchers used SAR levels of 25-100 W/kg, which are dramatically higher than the 2 W/kg limit for cell phones. Put simply, if RF radiation at these intense levels doesn't activate cellular stress responses, it suggests the mechanism of biological harm may be more subtle than direct cellular damage. However, this study only examined one specific cellular response over a short timeframe. The absence of stress protein induction doesn't rule out other biological effects that researchers have documented, including DNA damage, oxidative stress, and membrane permeability changes. What this means for you is that while RF radiation may not trigger obvious cellular alarm bells, the science demonstrates multiple other pathways through which EMF exposure can affect biological systems.

Exposure Details

SAR
25, 100 W/kg
Source/Device
27- or 2450 MHz
Exposure Duration
2 hours

Exposure Context

This study used 25, 100 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 ContextA logarithmic scale showing exposure levels relative to Building Biology concern thresholds and regulatory limits.Study Exposure Level in ContextThis study: 25, 100 W/kgExtreme Concern0.1 W/kgFCC Limit1.6 W/kgEffects observed in the Extreme Concern range (Building Biology)FCC limit is 0x higher than this exposure level

Study Details

The induction of stress proteins in HeLa and CHO cells was investigated following a 2 h exposure to radiofrequency (RF) or microwave radiation.

Cells were exposed or sham exposed in vitro under isothermal (37 ± 0.2 °C) conditions. HeLa cells we...

Both cell types exhibited well-characterized responses to the positive control stresses. Under these...

Cite This Study
Cleary, SF, Cao, G, Liu, LM, Egle, PM, Shelton, KR (1997). Stress proteins are not induced in mammalian cells exposed to radiofrequency or microwave radiation. Bioelectromagnetics 18(7):499-505, 1997.
Show BibTeX
@article{cleary_1997_stress_proteins_are_not_907,
  author = {Cleary and SF and Cao and G and Liu and LM and Egle and PM and Shelton and KR},
  title = {Stress proteins are not induced in mammalian cells exposed to radiofrequency or microwave radiation.},
  year = {1997},
  
  url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/%28SICI%291521-186X%281997%2918%3A7%3C499%3A%3AAID-BEM5%3E3.0.CO%3B2-Y},
}

Quick Questions About This Study

Researchers exposed human and hamster cells to radiofrequency radiation at levels 25 to 100 times higher than typical phone use for 2 hours, then looked for signs of cellular stress. They found no evidence that RF radiation triggered the production of stress proteins - molecules cells make when damaged or threatened. This suggests that at these exposure levels, the radiation didn't cause detectable cellular stress responses.