Cellular studies and interaction mechanisms of extremely low frequency fields

Publisher Website
Google Scholar
Abstract
Worldwide interest in the biological effects of ELF (extremely low frequency, E) or the magnetic (B) field, or if combinations of staticBand time‐varyingBfields represent an exposure metric for the cell. This question relates directly to understanding fundamental interaction mechanisms and to the development of a rationale for ELF dose threshold guidelines. The weight of experimental evidence indicates that an inducedEfield according to Faraday's law of induction during magnetic field exposures elicits cellular effects. AnE‐field‐mediated interaction has interesting consequences for microdosimetry at the cellular level and is mechanistically consistent with an interaction at the cell surface, since theEfield does not penetrate beyond the cell membrane. Recently, several studies have suggested that an ELFBfield by itself or in combination with a staticBfield may elicit cellular effects. Thus in addition toE‐field‐mediated effects, other interaction mechanisms as yet not fully understood may operate at the cellular level; this complexity is in contrast to the case for ionizing radiation. In addition to the question of an exposure field metric, the biological state of the target cell is important in ELF interactions. Biological factors such as cell type, cell cycle, cell activation, age of donor animal, passage number of cell line, presence of specific growth/mitogenic factors, temperature, shape, and cell density/packing during exposures have been shown to play a role in mediating ELF interactions with cells. Most recently, reports of single‐cell studies usher in a new direction for research that can be termed microbioelectromagnetics. Single‐cell digital microscopy introduces a new approach to answer the above questions with potential for real‐time microdosimetry and bioeffects limited only by the spatial resolution of state‐of‐the‐art microscopy, which is approximately 0.1 /μm. Digital imaging microscopy should therefore permit the quantitative assessment of spatial and temporal features of ELF field interactions within living single cells.