Dosimetric and exposure reference levels in national and international guidelines/standards for low-frequency electric & magnetic fields

Contemporary guidelines and standards on exposure to low frequency electric and magnetic fields consider- that induced currents/electric fields inside the human body (principally neural tissues) are relevant dosimetric quantities for setting protective limits against undesirable electrostimulation potentially leading to adverse effects. Additional consideration is given for surface electric charge effects such as discharges and contact currents for exposure to electric fields. These effects, with known interaction mechanisms providing sufficient basis for deriving human exposure limits, differ from effects connecting with the reported association of cancer or other illness with chronic exposure to ambient magnetic fields or proximity to electrical infrastructures The latter are considered associated with proposed- mechanisms that presently do not provide sufficient basis for deriving protective exposure limits. The International Commission on Non-Ionising Radiation Protection (ICNIRP) has published relevant guidelines in 1998 and in 2010, and the Institute of Electrical & Electronic Engineers (IEEE) has published its first standard StdC95.6 in 2002 and reaffirmed in 2007. In Australia, there was NHMRC* 'Interim guidelines on limits of exposure to 50/60Hz electric & magnetic fields' in 1989, and the Australian Radiation Protection & Nuclear Safety Agency (APPANSA) released for public consultation an ELF4 draft standard 'Exposure Limits for Electric & Magnetic Fields - ID Hz to 3 kHz' in 2006&. Its rationale is similar to the international documents with added information on precautionary approach and compliant verification. This paper reviews the historical development and presents a comparison of limits specified in the contemporary national and international standards/ guidelines. Although having a similar principal rationale, there are significant differences in specified dosimetric and exposure reference levels due to variation in available experimental data on effect thresholds, dosimetry & modelling, and in methodology for selection of safety acceptance margins. Discussion will also be given on future R&D that may help providing further data to improve these numeric differences.