Health Council of the Netherlands: No need to change from SAR to time-temperature relation in electromagnetic fields exposure limits

TLDR

The Health Council of the Netherlands and other organisations assume that only induced electric current and heat generation/absorption from radiofrequency electromagnetic fields are scientifically established causal effects on human health, so exposure guidelines for 10 MHz–10 GHz are based on avoiding temperature increases above a SAR of 4 W/kg. During a 2010 workshop, the question was raised whether expressing exposure limits in terms of maximum allowable temperature increase would provide a practical advantage over SAR. In this paper, the HCN discusses the need for this, considering six points: consistency, applicability, quantification, causality, comprehensibility and acceptability. The HCN concludes that changing the dosimetric quantity is unlikely to advance the debate on non‑thermal effects from long‑duration, low‑intensity electromagnetic exposure, and therefore favours maintaining SAR‑based restrictions and reference levels expressed as SAR and in V/m or µT.

Abstract

The Health Council of the Netherlands (HCN) and other organisations hold the basic assumption that induced electric current and the generation and absorption of heat in biological material caused by radiofrequency electromagnetic fields are the only causal effects with possible adverse consequences for human health that have been scientifically established to date. Hence, the exposure guidelines for the 10 MHz-10 GHz frequency range are based on avoiding adverse effects of increased temperatures that may occur of the entire human body at a specific absorption rate (SAR) level above 4 W/kg. During the workshop on Thermal Aspects of Radio Frequency Exposure on 11-12 January 2010 in Gaithersburg, Maryland, USA, the question was raised whether there would be a practical advantage in shifting from expressing the exposure limits in SAR to expressing them in terms of a maximum allowable temperature increase. This would mean defining adverse time-temperature thresholds. In this paper, the HCN discusses the need for this, considering six points: consistency, applicability, quantification, causality, comprehensibility and acceptability. The HCN concludes that it seems unlikely that a change of dosimetric quantity will help us forward in the discussion on the scientific controversies regarding the existence or non-existence of non-thermal effects in humans following long duration, low intensity exposure to electromagnetic fields. Therefore, the HCN favours maintaining the current approach of basic restrictions and reference levels being expressed as SAR and in V/m or µT, respectively.