6,486 Studies Reviewed. 85.2% of Original Studies Found Biological Effects. The Evidence is Clear.
Shield Your Body

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

Whole Body / General

Effect of immobilization and concurrent exposure to a pulse-modulated microwave field on core body temperature, plasma ACTH and corticosteroid, and brain ornithine decarboxylase, Fos and Jun mRNA.

No Effects Found

Stagg RB, Hawel LH III, Pastorian K, Cain C, Adey WR, Byus CV · 2001

View Original Abstract
Share:

Cell phone radiation at levels up to 5 W/kg produced no measurable stress responses in rats when proper experimental controls were used.

Plain English Summary

Summary written for general audiences

Researchers exposed rats to cell phone radiation at levels up to 5 W/kg (similar to older phones held directly against the head) while measuring stress hormones and brain activity markers. The study found no differences in stress responses between animals exposed to the radiation versus those that were only restrained, suggesting the radiation itself didn't cause additional stress at these exposure levels.

Why This Matters

This study provides important insights into EMF research methodology and the challenge of separating true biological effects from experimental stress. The researchers demonstrated that the physical restraint required for controlled RF exposure studies can itself trigger massive stress responses - ACTH levels increased 10-fold just from being tube-restrained. What makes this research valuable is its rigorous approach to controlling for these confounding factors, something many earlier EMF studies failed to do adequately. The exposure levels tested (up to 5 W/kg SAR) represent relatively high exposures compared to modern smartphones, which typically operate at SAR levels below 2 W/kg. While this study found no stress-related effects from RF exposure, it highlights why proper experimental controls are crucial in EMF research and why some conflicting results in the literature may stem from inadequate study design rather than true biological effects.

Exposure Details

SAR
0.16, 1.6 and 5 W/kg
Source/Device
1.6 GHz
Exposure Duration
2 hr

Where This Falls on the Concern Scale

Study Exposure Level in ContextStudy Exposure Level in ContextThis study: 0.16, 1.6 and 5 W/kgExtreme Concern - 0.1 W/kgFCC Limit - 1.6 W/kgEffects observed in the Extreme Concern range (Building Biology)FCC limit is 10 times higher than this level
A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 1.60 GHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 1.60 GHzPower lines50/60 Hz5G mm28 GHzLogarithmic scale

Study Details

Exposure of humans and rodents to radiofrequency (RF) cell phone fields has been reported to alter a number of stress- related parameters. To study this potential relationship in more detail, tube-restrained immobilized Fischer 344 rats were exposed in the near field in a dose-dependent manner to pulse-modulated (11 packets/s) digital cell phone microwave fields at 1.6 GHz in accordance with the Iridium protocol.

Core body temperatures, plasma levels of the stress-induced hormones adrenocorticotrophic hormone (A...

Core body temperature increased transiently (+/-0.3 degrees C) during the initial 30 min of loose-tu...

We conclude that the pulse-modulated digital Iridium RF field at SARs up to 5 W/kg is incapable of altering these stress-related responses. This conclusion is further supported by our use of an RF-field exposure apparatus that minimized immobilization stress; the use of conditioned/tube-trained animals and the measurement of hormonal and molecular markers after 2 h RF-field exposure when the stress-mediated effects were complete further support our conclusion.

Cite This Study
Stagg RB, Hawel LH III, Pastorian K, Cain C, Adey WR, Byus CV (2001). Effect of immobilization and concurrent exposure to a pulse-modulated microwave field on core body temperature, plasma ACTH and corticosteroid, and brain ornithine decarboxylase, Fos and Jun mRNA. Radiat Res 155(4):584-592, 2001.
Show BibTeX
@article{rb_2001_effect_of_immobilization_and_3418,
  author = {Stagg RB and Hawel LH III and Pastorian K and Cain C and Adey WR and Byus CV},
  title = {Effect of immobilization and concurrent exposure to a pulse-modulated microwave field on core body temperature, plasma ACTH and corticosteroid, and brain ornithine decarboxylase, Fos and Jun mRNA.},
  year = {2001},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/11260660/},
}
PubMed: 11260660

Cited By (45 papers)

Quick Questions About This Study

A 2001 study found that 1.6 GHz Iridium phone radiation at levels up to 5 W/kg did not cause stress hormone changes in rats. The radiation itself produced no differences in cortisol or ACTH levels compared to control animals, suggesting no additional stress response from the RF exposure.
Research testing 1.6 GHz radiation at SAR levels up to 5 W/kg found no significant effects on core body temperature in rats. Only minor temperature fluctuations (±0.3°C) occurred from physical restraint, not from the radiofrequency exposure itself during 2-hour testing periods.
A study examining pulse-modulated 1.6 GHz radiation found no changes in brain gene expression markers including Fos, Jun, and ornithine decarboxylase mRNA. Animals exposed to radiation for 2 hours showed identical brain molecular activity compared to sham-exposed controls.
Research on Iridium satellite phone frequencies (1.6 GHz) at realistic exposure levels found no harmful effects on biological stress responses. The study concluded that pulse-modulated digital RF fields at SARs up to 5 W/kg cannot alter stress-related hormonal or molecular markers.
A controlled study found that 2-hour exposure to 1.6 GHz cell phone radiation did not affect ACTH hormone levels in rats. While physical restraint caused 10-fold ACTH increases, the radiofrequency radiation itself produced no additional hormonal changes compared to sham exposure.