Effects of extremely low frequency electromagnetic fields (ELF) on human beings. An electrical engineer viewpoint

Since the early seventies, potential health risks from Extremely Low Frequency (ELF) exposure (50 Hz) have been extensively treated in the literature (more than 1000 references registered by WHO1, 2007). After 30 years of worldwide research, the major epidemiological output is the possible moderate increased risk (by a factor 2) of childhood leukaemia in case of a long exposure to an ambient magnetic flux density (B-field) higher than 0.4 μT. However, this fact has not been confirmed by in vivo and/or in vitro studies. Moreover it has not been validated by any adverse health biological mechanisms neither for adults nor for children. Nobody knows precisely what happens inside the body and what could be a hazardous health effect of the ELF fields at 50 Hz. International recommendations (ICNIRP2) are currently, for general public, not to exceed a B-field of 100 μT (50 Hz) and an E-field of 5 kV/m (50 Hz). The authors are looking for a signal generated in the biological process under electric interactions. Herein, a rough overview of typical values of ELF fields will be presented followed by a brief literature survey on childhood leukaemia and ELF. The potential carcinogenic effect of ELF would be linked to electrical distur- bances in cell behaviour. The major concern linking childhood leukaemia and ELF is thus to determine the res- ponse of bone marrow cells under ELF fields. With that purpose, transmembrane potential will be targeted and linked to the E-field at that level. This paper is three-folded: First, the electric interactions between ambient ELF fields and the body are studied both qualitatively and quantitatively. Though no adverse health field threshold is defined, a minimum field level is fixed in order to discriminate inherent random noise, in agreement with NIEHS3. This is based on the fact that mechanisms become only plausible under field exposure above a certain strength. Different sources of internal E-field are analysed and classified according to their potential risk. Second, the hypothesis of contact current is detailed. Finally, key actions to undertake are highlighted. Based on the current state of the art and some authors’ own developments, this paper proposes simple low cost modifications of private electrical installations in order to annihilate the major source of potential effects of ELF. Particular emphasis is paid to the situation in Belgium as the authors are part of the BBEMG (see end note) and perform numerous measurements in Belgian residential homes.status: publishe