Current densities measured in human models exposed to 60-Hz electric fields

Area of Science:

• Biophysics
• Electromagnetics
• Human Exposure Studies

Background:

• Understanding current densities induced in humans by external electric fields is crucial for safety assessments.
• Previous research has lacked detailed measurements across various body regions under realistic grounding conditions.

Purpose of the Study:

• To quantify current densities in homogeneous grounded human models exposed to vertical 60-Hz electric fields.
• To provide data for comparing human and animal exposure to electric fields and inform safety standards.

Main Methods:

• Validated measurement techniques using grounded hemispheres and hemispheroids.
• Exposure of human models to 10 kV/m vertical 60-Hz electric fields.
• Measurement of current densities in different body regions (chest, axillae, arms, abdomen, pelvis, legs) under varying grounding conditions.

Main Results:

• Chest current densities ranged from 125-300 nA/cm².
• Peak horizontal current density of ~400 nA/cm² observed in axillae.
• Highest measured current density was 770 nA/cm² in the lower pelvic region with one foot grounded.

Conclusions:

• Current densities vary significantly across body regions and are influenced by grounding.
• Data supports quantitative comparison of animal and human exposure to 60-Hz fields.
• Findings are applicable to safety standard development for frequencies up to 1 MHz.