General properties of the interaction between animals and ELF electric fields

Abstract

An analysis is given of the interaction between extremely low-frequency (ELF) electric fields and animals of arbitrary body shape. This analysis is based on three approximations which are valid in the ELF range: In living tissues, capacitive (displacement) currents are negligible compared to conduction currents; effects resulting from the finite velocity of propagation of electromagnetic fields are negligible; skin effect in living tissues is negligible. Major conclusions of the analysis are: (a) The electric field outside the body, the induced charge on the surface of the body, and the total current crossing any section through the body (eg, through the neck or limbs) are completely determined by the characteristics of the applied ELF electric field, the shape of the body, its location relative to ground and other conductors, and any conduction currents from the body to ground or other conductors. (b) All of the quantities in (a) can be measured using conducting animal models. (c) The magnitudes of the electric field outside the body and the induced charge density on the surface of the body are independent of frequency, in the ELF range, when the body is either insulated from or shorted to ground (and any other conductors in the system). (d) The only quantities affected by the electrical properties of the tissues comprising the body are the current density and electric field inside the body. (e) The electric field outside and inside a body will be unchanged by a scaled change in its size.

Computation of Electromagnetic Fields in Assemblages of Biological Cells Using a Modified Finite-Difference Time-Domain Scheme

“…The interaction between animals and humans exposed to extremely low frequency electric fields was investigated by Kaune and Gillis [29] and Guy et al [30] in 1981 and 1982 respectively. Their research outcomes furnish valuable analytical and experimental verification of the concept of quasistatic coupling at power-line frequencies.…”

“…In order to implement the quasi-static approximation to analyze scattering problems, the following two conditions have to be satisfied [29,30]:…”

Fundamental study on measurement of ELF electric field at biological body surfaces

“…5(d». Since in the ELF range, a biological body is considered to be a conductor and a scali ng effect in the size can be neglected [8], the above cond itions are considered to reprcsem the fi eld mcasuremem at the surface of a biological body in a uniform eleclfic field sueh as that under transmission lines.…”

Electromagnetic Field Computation for Power Transmission Lines Using Quasi-Static Sub-Gridding Finite-Difference Time-Domain Approach

“…The primary advantage of quasi-static formulation is thus reducing the long simulation time constraint. There have been some early efforts of using quasi-static idea to study the interaction between living tissues exposed to extremely low frequency (ELF) electric fields in the published literature such as [21][22][23]. The basis of their research dominantly verifies the effectiveness of quasi-static scheme at very low frequency.…”

“…An attempt to gain the scheme of using the same technique but at much higher frequencies of 900 MHz and 1800 MHz has been made by Emili et al in 2003 [28]. The theoretical method discussed by the authors in [21][22][23] has been realised in the present work to approximate the quasi-static FDTD subgridding. In …”