8,700 Studies Reviewed. 87.0% Found Biological Effects. The Evidence is Clear.
Shield Your Body
Whole Body / General

SURVEYS OF ELECTROMAGNETIC FIELD INTENSITIES NEAR REPRESENTATIVE HIGHER-POWER FAA TRANSMITTING ANTENNAS

Bioeffects Seen

Ezra B. Larsen, John F. Shafer · 1977

Share:

Aviation radar systems generate EMF intensities up to 100 times higher than public safety guidelines in their direct beams.

Plain English Summary

Summary written for general audiences

The National Bureau of Standards measured electromagnetic field intensities around FAA transmitting antennas including aircraft radars, ground surveillance systems, and communication equipment. They found that direct beams from air route and airport surveillance radars exceeded 10 mW/cm² within 14-15 meters of antennas, but fields in areas accessible to personnel were generally below 1 mW/cm².

Why This Matters

This 1977 study provides crucial baseline data on EMF exposures from aviation radar systems that remain largely unchanged today. The finding that direct radar beams exceeded 10 mW/cm² is significant because this level is 100 times higher than many current safety guidelines for public exposure. While the researchers noted that high-intensity zones aren't normally accessible to personnel, this highlights how powerful these systems are and raises questions about exposures for maintenance workers and nearby communities. The science demonstrates that even decades ago, we were creating electromagnetic environments with intensities far exceeding what the human body evolved to handle. What this means for you is that aviation facilities represent some of the most intense EMF exposure sources in our environment, and understanding these levels helps put everyday exposures into perspective.

Exposure Information

Specific exposure levels were not quantified in this study.

Cite This Study
Ezra B. Larsen, John F. Shafer (1977). SURVEYS OF ELECTROMAGNETIC FIELD INTENSITIES NEAR REPRESENTATIVE HIGHER-POWER FAA TRANSMITTING ANTENNAS.
Show BibTeX
@article{surveys_of_electromagnetic_field_intensities_near_representative_higher_power_fa_g3660,
  author = {Ezra B. Larsen and John F. Shafer},
  title = {SURVEYS OF ELECTROMAGNETIC FIELD INTENSITIES NEAR REPRESENTATIVE HIGHER-POWER FAA TRANSMITTING ANTENNAS},
  year = {1977},
  
  
}

Quick Questions About This Study

Direct beams from air route surveillance radars exceeded 10 mW/cm² within 14 meters of antennas, while airport surveillance radars reached the same levels within 15 meters. Aircraft radars exceeded 10 mW/cm² at 2-7 meter distances.
While direct radar beams exceeded 10 mW/cm², EMF levels in areas accessible to personnel were generally less than 1 mW/cm². The high-intensity zones near antenna direct beams are typically restricted from public access.
Researchers measured electric fields between 0.5 and 24 GHz using commercial monitors, magnetic fields between 10 and 300 MHz, and electric fields between 100 kHz and 10 GHz using specialized NBS probes.
The radiation monitors couldn't accurately measure pulse-peak fields from radars or fields from scanning antennas, so most radar surveys involved fixed antennas. Time-averaging effects from antenna scanning would greatly reduce measured field values.
The newer ASR-8 airport surveillance radar model showed lower EMF emissions compared to other airport surveillance radars, which typically exceeded 10 mW/cm² within 15 meters of their antennas.