Foot currents and ankle SARs induced by dielectric heaters.
Conover DL, Moss CE, Murray WE, Edwards RM, Cox C, Grajewski B, Werren DM, Smith JM · 1992
View Original AbstractIndustrial workers near dielectric heaters experienced ankle energy absorption rates up to 176 W/kg, vastly exceeding typical EMF safety limits.
Plain English Summary
Workers operating industrial dielectric heaters showed dangerously high electromagnetic energy absorption in their ankles. Twenty-seven percent of these heating machines created electrical currents through workers' feet exceeding safety limits, with maximum energy absorption reaching 176 watts per kilogram in ankle tissue.
Why This Matters
This occupational health study reveals a critical gap in how we assess EMF safety. While most research focuses on whole-body or brain exposure, this work demonstrates that specific body parts can experience extremely high energy absorption rates even when overall exposure seems manageable. The ankle SAR of 176 W/kg found in some workers is extraordinarily high - for context, cell phone SAR limits are typically around 1.6-2 W/kg. What makes this particularly concerning is that these workers were simply doing their jobs, standing where they normally worked near industrial heating equipment. The reality is that occupational EMF exposures often involve near-field conditions where traditional safety calculations break down, creating localized absorption hot spots that current safety standards don't adequately address.
Exposure Details
- SAR
- 5, 29,57, and 176 W/kg
- Electric Field
- 10000, 2400000 V/m
- Source/Device
- 6.5 to 65 MHz
Exposure Context
This study used 10000, 2400000 V/m for electric fields:
- 33.3Kx above the Building Biology guideline of 0.3 V/m
This study used 5, 29,57, and 176 W/kg for SAR (device absorption):
- 12.5x above the Building Biology guideline of 0.4 W/kg
Building Biology guidelines are practitioner-based limits from real-world assessments. BioInitiative Report recommendations are based on peer-reviewed science. Check Your Exposure to compare your own measurements.
Where This Falls on the Concern Scale
Study Details
The aim of this study is to investigate Foot currents and ankle SARs induced by dielectric heaters.
The determination of foot currents was based on near-field exposures in which reactive coupling domi...
Nearly 27 percent of the dielectric heaters induced foot currents that exceeded the 200-mA limit tha...
Show BibTeX
@article{dl_1992_foot_currents_and_ankle_910,
author = {Conover DL and Moss CE and Murray WE and Edwards RM and Cox C and Grajewski B and Werren DM and Smith JM},
title = {Foot currents and ankle SARs induced by dielectric heaters.},
year = {1992},
url = {https://pubmed.ncbi.nlm.nih.gov/1590810/},
}