Article review date
7 August 2026
Article publication date
27 July 2026
ARPANSA summary
This study combined advances in anatomical modelling and data from human experiments to calculate the induced electric field in human tissues from low frequency magnetic field exposure at the threshold of perception (the level where a person can feel a slight tingling on the skin). The arms of 24 subjects were positioned into a magnetic stimulation device. Participants were in control of the level of the applied stimulation and adjusted the level themselves until it was just barely perceptible, which was marked as the threshold level.
Images captured during testing were used to combine the participants’ forearms with highly featured anatomical forearm models generated from magnetic resonance images. The matched models were then used to compute the induced electric field in the participant’s forearm at the threshold of perception. The calculated average perception threshold was at an induced electric field of 32.2 V/m, with variability between subjects of 5.2 V/m.
The anatomical modelling methodology used in this study was also compared to simpler methodologies used in prior research. The authors found that the simpler methodologies underestimate the induced electric field at the perception threshold and they subsequently used this information to develop a correction coefficient (an adjustment value) for values from earlier research.
Published in
Bioelectromagnetics
Link to article
ARPANSA commentary
This study is a significant advancement in the computational methods used to determine the induced electric field in tissues at the threshold of perception in humans. In addition to increased model sophistication, a notable difference between this study and previous studies is the method used to arrive at the perception threshold. In prior research (Saritas, E. et al., 2013; Havel, W. et al., 1997), experimenters controlled the stimulus level in pre-defined steps. Allowing participants to repeatedly adjust the exposure level as in this study may lead to more accurately determined thresholds but simultaneously introduces additional psychological confounders; for example, the stimulation device would make a noise which may have made the subjects think that they perceived the exposure. A major limitation, as acknowledged by the authors, is that the forearm models used in the study did not include detailed nerve architecture, offering an avenue for further improvement in future studies.
It is important to note that exposures of the level used in this study do not occur in the everyday environment. ARPANSA has measured extremely low frequency magnetic field (ELF-EMF) exposure in Australian homes (Karipidis, K., 2014) and near electrical supply infrastructure (technical report 170). In both measurement surveys, levels were far below the limits prescribed in international guidelines and farther below the exposure used in this study.
The International Commission on Non-Ionizing Radiation Protection is currently reviewing its low frequency exposure guidelines. Studies like this one will help to inform the development of these guidelines. The limits prescribed in the exposure guidelines are set conservatively, with consideration for uncertainty in the scientific evidence and are ultimately far below the level at which adverse health effects are known to occur.
