Health and safety implications of exposure to electromagnetic fields in the frequency range 300 Hz to 10 MHz

Abstract

An international seminar on health effects of exposure to electromagnetic fields (EMF) in the frequency range from 300 Hz to 10 MHz (referred to as the Intermediate Frequency (IF) range) was held in Maastricht, Netherlands, on 7-8 June 1999. The seminar, organized under the International EMF Project, was sponsored jointly by the World Health Organization (WHO), the International Commission on Non-Ionizing Radiation Protection (ICNIRP), and the Government of the Netherlands. This report does not attempt to summarize all of the material presented at the conference, but focuses on sources of exposure, biophysical and dosimetric considerations pertinent to extrapolating biological data from other frequency ranges to IF and identifies potential health concerns and needs for developing exposure guidelines. This paper is based on presentations at the conference and reports of working groups consisting of the speakers and other experts. It concludes with recommendations for further research aimed at improving health risk assessments in this frequency range.

Feasibility of simultaneous intracranial EEG-fMRI in humans: A safety study

“…These parameters exceed guidelines, which deliberately lie below the level required for stimulation. It should be noted that tissue-heating also results from current flow at these frequencies but the threshold for depolarisation related effects lie well below those for significant thermal effects [27].…”

“…At RF frequencies pertinent to MRI B1-fields, the relevant medical-device current limit is 10mA root mean squared (rms) [29] although this is a default value for frequencies >100KHz and so its direct relevance in the RF frequency range of MRI systems (128Mhz at 3Tesla) is questionable [27]. Indeed this value can be contrasted with the higher contact current limits (20-45mA) derived for public exposure to RF frequency fields [53,54].…”

“…One gram of tissue will typically correspond to a volume of the order of ~1cm 3 in the human brain, which is relatively large compared to many implants and in particular those studied here; no safety limit exists for smaller masses or volumes. Temperature is simple to measure in test objects and is the direct variable corresponding to potential tissue injury from exposure to RF fields at the spatial scale of the electrode contacts [27]. The above considerations lead us to measure temperature increases over small volumes (~1mm 3 ) proximal to the implant as the best determinant of risk and for the subsequent prescription of a procedure that is likely to stay within heating limits.…”

“…Depending on their frequency and amplitude, excessive currents in tissue may cause electro-motive forces, electrolysis, depolarisation and stimulation, burning, coagulation, and vaporisation which can all lead to cell damage and ultimately cell death [25][26][27].…”

Measurements of intermediate-frequency electric and magnetic fields in households

“…However, while the range of household appliances with electrical components working in the intermediate-frequency (IF) range (300 Hz to 1 MHz) has grown significantly in recent years (e.g., induction cookers and compact fluorescent lighting), there is still only limited information available on either the typical strength of the IF fields emitted by household appliances and on the typical human exposure to IF fields at home (Gajšek et al, 2016;Litvak et al, 2002;WHO, 2005).…”