Human detection thresholds of DC, AC, and hybrid electric fields: a double-blind study

Abstract

Overview

Amidst the global transition towards high-voltage electric systems, this study explores the human sensory thresholds for direct current (DC), alternating current (AC), and hybrid electric fields in a double-blind setup, highlighting implications for health and safety protocols.

Methods

• 203 participants were scrutinized in a specialized whole-body exposure lab.
• Exposure to DC, AC, and hybrid electric fields, including ion currents in parts of the experiments.
• Use of signal detection theory and adaptive staircase procedures for sensitivity and threshold assessment.
• Manipulation of environmental conditions such as relative humidity to study its effects on perception.

Findings

The study revealed lower detection thresholds for hybrid electric fields when compared to single field types of DC or AC. Notably:

• Ion current exposure significantly enhanced electric field perception.
• Higher humidity levels improved detection of DC fields, whereas lower humidity levels amplified AC field detection.
• 40% of participants detected electric fields at minimal hybrid levels (2 kV/m DC and 4kV/m AC).

Conclusion

This pioneering study on hybrid electric field perception aids in re-evaluating current safety and regulatory standards, suggesting that even at low exposure levels, a significant proportion of people can detect electric fields, pointing to potential health risks. Moreover, recommendations for further detailed studies and consideration of varying environmental conditions are discussed to refine safety measures in electric field exposure.