Development and validation of an in vivo pain assessment method for 28-day exposure to intermediate frequency magnetic fields

The objective of this study was to establish guidelines for evaluating the health effects of electromagnetic fields (EMFs). To achieve this, a comprehensive evaluation of EMF effects on living organisms from both engineering and biological perspectives is essential. As part of this study, we examined the impact of intermediate-frequency magnetic fields (IF-MF) exposure on peripheral nerves in mice and validated the reliability of five pain assessment methods. The engineering approach was based on our pilot study, while the biological approach involved exposing mice to IF-MF for a 28-day period and assessing neurotoxicity through the implementation of five pain tests. The von Frey test, conducted with a Dynamic Plantar Aesthesiometer, was performed at various time points during exposure. The results indicated that leg withdrawal time was shortened only in the positive control group. After conducting a series of assessments, we demonstrated that no statistically significant differences were observed among the IF-MF-exposed, sham-exposed and control groups. However, the positive control group exhibited significant variations in the four supplemental assessments. No significant differences were detected in the other three groups. These findings suggest that subacute (28-day) IF-MF exposure at 2.3 times the basic restriction for occupational exposure according to International Commission on Non-Ionizing Radiation Protection guideline does not result in peripheral neurotoxicity and that the utilized pain assessment methods used for IF-MF exposure are effective.