Biological Interactions and Potential Health Effects of Extremely-Low-Frequency Magnetic Fields From Power Lines and Other Common Sources

Abstract

Various different effects of ELF magnetic fields have been reported to occur at the cellular, tissue, and animal levels. Certain effects, such as the induction of magnetophosphenes in the visual system, have been established through replication in several laboratories. Many other effects, however, have not been independently verified or, in some cases, replication efforts have led to conflicting results. A substantial amount of experimental evidence indicates that the effects of ELF magnetic fields on cellular biochemistry, structure, and function can be related to the induced current density, with a majority of the reported effects occurring at current density levels in excess of 10 mA/m2. These effects, therefore, occur at induced current-density levels that exceed the endogenous currents normally present in living tissues. From this perspective, it is extremely difficult to interpret the results of recent epidemiological studies that have reported a correlation between cancer incidence and exposure to 50-Hz or 60-Hz magnetic fields with very low flux densities. The levels of current density induced in tissue by occupational or residential exposure to these fields are, in nearly all circumstances, significantly lower than the levels found in laboratory studies to produce measurable perturbations in biological functions. There is a clear need for additional epidemiological research to clarify whether exposure to ELF magnetic fields is, in fact, causally linked to cancer risk. Laboratory animal studies conducted under controlled conditions are also needed to determine whether ELF magnetic fields can initiate or promote tumors. In addition, more studies of both a theoretical and experimental nature are needed to elucidate the molecular and cellular mechanisms through which low-intensity magnetic fields can influence living systems. A growing body of evidence indicates that cell membranes play a key role in the transduction and amplification of ELF field signals. Elucidation of the physical and biochemical pathways that mediate these transmembrane signaling events will represent a major advance in our understanding of the molecular basis of magnetic field effects of biological systems.

Mortalidade por câncer em trabalhadores de companhia geradora de eletricidade do Estado de São Paulo, Brasil

“…Embora não tenha sido ainda demonstrado, de maneira inequívoca, o mecanismo de ação através do qual os CEM exerceriam seu papel no processo de carcinogênese, estudos experimentais têm evidenciado que eles não exercem um efeito direto sobre o DNA, ao contrário do que acontece com diversos agentes iniciadores; parece, assim, mais provável que seu efeito ocorra de outra maneira, por exemplo, na fase de promoção tumoral 19,69,70,78 . A possibilidade de uma ação promotora dos CEM de 50-60 Hz implica considerar a importância da presença de outros fatores carcinógenos potenciais no ambiente de trabalho dos eletricitários, uma vez que um agente promotor atua de forma seqüencial, após a exposição a um iniciador 7 .…”

Effects of Renewable Energy Production and Infrastructure on Wildlife

“…2004 ). Moreover, as a consequence of electric transmission, power lines generate strong electromagnetic fi elds, UV discharges and acoustic pollution which can affect animal health and behavior (Phernie et al 2000 ;Tyler et al 2014 ) and have also been identifi ed as causes of wildfi res (Tenforde 1992 ;Haas et al 2005 ).…”

The effects of extremely low frequency magnetic fields on mutation induction in mice

“…Similarly, Focke et al (2010) has provided direct experimental evidence ruling out ELF electric fields as a possible carcinogen or contributing factor. The emphasis of experimental investigations has therefore been placed on determining the potential adverse health effects linked to exposure to the ELF-MF component exclusively (Tenforde, 1992).…”

“…Additionally, the geomagnetic field is known to fluctuate as a result of lunar and seasonal variations (Barnes & Greenebaum, 2007). Similarly, time-varying magnetic fields in the ELF range are also present throughout the atmosphere as a product of solar and lunar effects on ion currents in the upper atmosphere (Tenforde, 1992). There is, however, also a continuous global presence of extremely low-frequency electromagnetic waves within the geomagnetic field as a result of a number of very low-intensity signals called Schumann resonances.…”