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Brain & Nervous System

Can exposure to a terrestrial trunked radio (TETRA)-like signal cause symptoms? A randomised double-blind provocation study

No Effects Found

Authors not listed · 2010

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TETRA police radio signals didn't cause reported symptoms, but continuous 385 MHz radiation did trigger headaches in controlled testing.

Plain English Summary

Summary written for general audiences

UK researchers tested whether TETRA police radio signals (385.25 MHz pulsing at 17.6 Hz) cause symptoms in people claiming sensitivity to these frequencies. The study found that continuous wave signals caused some symptoms like headaches, but the pulsed TETRA-like signals did not produce the reported health effects.

Why This Matters

This study addresses a real-world concern about UK police radio systems and provides important evidence about electromagnetic hypersensitivity claims. The finding that continuous wave signals at 385.25 MHz caused headaches in all participants is particularly noteworthy, as this frequency falls within the range used by many communication devices. What makes this research valuable is its rigorous double-blind design and focus on a specific occupational exposure scenario.

The paradoxical finding that TETRA-like pulsed signals caused fewer symptoms than continuous waves challenges assumptions about pulsed RF being inherently more harmful. However, the 250 mW power level used in this study represents significant exposure compared to typical consumer devices. The fact that any RF signal at this frequency caused measurable symptoms in a controlled setting underscores the biological activity of these frequencies, even when the specific modulation patterns don't match user reports.

Exposure Information

A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 385.25 MHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 385.25 MHzPower lines50/60 HzWiFi2.4 GHz5G mm28 GHzLogarithmic scale

Specific exposure levels were not quantified in this study.

Cite This Study
Unknown (2010). Can exposure to a terrestrial trunked radio (TETRA)-like signal cause symptoms? A randomised double-blind provocation study.
Show BibTeX
@article{can_exposure_to_a_terrestrial_trunked_radio_tetra_like_signal_cause_symptoms_a_randomised_double_blind_provocation_study_ce1649,
  author = {Unknown},
  title = {Can exposure to a terrestrial trunked radio (TETRA)-like signal cause symptoms? A randomised double-blind provocation study},
  year = {2010},
  doi = {10.1136/oem.2010.055889},
  
}
DOI: 10.1136/oem.2010.055889PubMed: 20864469

Quick Questions About This Study

This double-blind study found that TETRA-like signals pulsing at 17.6 Hz did not cause the symptoms reported by sensitive users. However, continuous wave signals at the same 385.25 MHz frequency did increase headaches and fatigue in participants.
TETRA signals pulse at 17.6 Hz, creating intermittent bursts of radiofrequency energy. Continuous wave signals emit steady, uninterrupted radiation at the same frequency. This study found continuous waves more likely to cause symptoms than pulsed TETRA signals.
The study used 250 milliwatts of radiated power for 50-minute exposures. This represents relatively high exposure compared to typical consumer devices, making the symptom findings more significant for occupational or high-power communication scenarios.
The study tested whether participants could identify when active signals were present versus sham conditions. Results suggest people cannot reliably detect TETRA or continuous wave exposure, indicating symptoms may occur without conscious awareness of exposure.
The study found continuous 385.25 MHz radiation caused headaches in all participants, while TETRA-like pulsed signals did not. This challenges assumptions that pulsed RF is inherently more harmful than continuous wave emissions at the same frequency.