Effect of electric field and magnetic field on bioremediation
Answers
electromagnetism on organisms dates back to the end of the nineteenth century, to then intensify in the following decades after global electrification and the diffusion of telecommunication. The massive introduction into daily life of technologies that emit electric, magnetic and electromagnetic fields in an enormous range of frequencies and intensities led institutions and the scientific community to question itself about the effects on public health and the environment. Pertinent scientific literature is very vast and includes studies that vary greatly on the type of field, intensity, exposure duration, long-/short-term effects and considered biological targets (cell, tissue, organ and organism).
In contrast to the studies indicated above, the research that investigates the field effects on microorganisms is very limited. Model microorganisms, well characterised with genetic markers, were used in medical-health research to better understand the field action mechanisms. Some of these works showed how, in some situations, exposure to electromagnetic fields tends to enhance rather than reduce cell activity, with possible applicative consequences in the field of biotechnology, including biological techniques for depollution.
In order to identify full-scale conditions that are suitable and potentially applicable for use in electromagnetic fields to stimulate and accelerate bioremediation processes, this paper offers an examination of the scientific literature that is available on the effects of fields applied on microorganisms, and a critical analysis of it. In consideration of the objective of this document, aimed at environmental bioremediation, the effects of electromagnetic fields applied on cells, bacterial cells in particular, are focused on. The information obtained from the literature that was consulted is summarised in Tables 1, 2 and 3, respectively on nominal exposure to electrostatic fields/fields generated by direct current (DC), magnetic and electromagnetic currents/fields generated by alternate current (AC). The decision was made to treat electrostatic field applications (typically generated while maintaining a constant voltage between pairs of electrodes) together with fields generated by direct current because when the sources are applied to dielectric means (soil, wastewater, etc.) they produce similar effects. These effects are, in fact, so similar that even in most of the literature that was analysed, they are treated simultaneously, without any distinction between the two situations.