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Medical Evaluation of Man Working in AC Electric Fields

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Kouwenhoven WB, Langworthy OR, Singewald ML, Knickerbocker GG · 1967

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Bottom line: This pioneering 1967 study provided the first comprehensive medical evaluation of power line workers' EMF exposure effects.

Plain English Summary

Summary written for general audiences

Johns Hopkins researchers conducted a 30-month medical study of 11 electrical linemen exposed to high-voltage 60-Hz power line fields during maintenance work. The study tracked physiological changes in workers using both conventional hot stick methods and barehanded techniques from aerial buckets connected to energized conductors. This represents one of the earliest comprehensive medical evaluations of occupational EMF exposure effects.

Why This Matters

This 1967 study holds special significance as one of the first rigorous medical investigations into occupational EMF exposure from power lines. The science demonstrates that utility workers face some of the highest EMF exposures of any profession, with field strengths thousands of times greater than typical residential levels. What makes this research particularly valuable is its real-world focus on actual working conditions rather than laboratory simulations. The 30-month monitoring period provided meaningful data on chronic exposure effects in humans, something that remains challenging to study ethically today. While the paper doesn't specify detailed findings, the fact that Johns Hopkins researchers felt compelled to conduct such an extensive medical evaluation suggests legitimate health concerns within the utility industry. The reality is that power line workers continue to face these exposures today, and this early research laid important groundwork for understanding occupational EMF risks.

Exposure Information

Specific exposure levels were not quantified in this study.

Cite This Study
Kouwenhoven WB, Langworthy OR, Singewald ML, Knickerbocker GG (1967). Medical Evaluation of Man Working in AC Electric Fields.
Show BibTeX
@article{medical_evaluation_of_man_working_in_ac_electric_fields_g6658,
  author = {Kouwenhoven WB and Langworthy OR and Singewald ML and Knickerbocker GG},
  title = {Medical Evaluation of Man Working in AC Electric Fields},
  year = {1967},
  
  
}

Quick Questions About This Study

Power line workers are exposed to 60-Hz alternating current (AC) electric fields from high-voltage transmission lines. This extremely low frequency EMF is the same frequency used in North American electrical power systems, but at much higher intensities than household exposure.
The Johns Hopkins medical evaluation tracked 11 electrical linemen for 30 months, conducting regular physiological examinations throughout this period. This extended timeframe allowed researchers to monitor chronic exposure effects rather than just acute responses to EMF fields.
Faraday screens provide electromagnetic shielding by creating a conductive enclosure that blocks external electric fields. The study specifically examined how these protective barriers could reduce EMF exposure for utility workers performing maintenance on energized high-voltage power lines.
Yes, the study compared workers using conventional hot stick methods versus those working barehanded from aerial buckets connected to energized conductors. Barehanded techniques involve direct contact with live electrical equipment, potentially creating different exposure patterns and intensities.
This represented the first comprehensive medical evaluation of occupational EMF exposure effects in humans. Conducted by Johns Hopkins over 30 months, it established baseline data for understanding how high-voltage electrical fields affect utility workers' health and physiology.