Experimental macroscopic dosimetry for extremely-low-frequency electric and magnetic fields

Abstract

Environmental and laboratory exposure to electric and magnetic fields (EMF) in the extremely-low-frequency range (ELF) produces electrical quantities that interact directly with the exposed biological system on a scale small compared to the size of the human body but large with respect to cellular dimensions. The purpose of this paper is to describe these macroscopic electrical quantities and their characterization through measurements on living systems and experimental models. Electric field exposure results in a total induced current, surface electric fields, internal electric fields, and internal currents. Magnetic field exposure results in internal magnetic field, internal electric fields, and internal currents. Basic properties of fields and matter determine the methods by which these quantities can be measured. Quantification or dosimetry for these parameters on a macroscopic basis can be directed to the whole body, a cross section across the body, a local surface area, or a local volume. Models of varying degrees of sophistication have been used to establish spatial distributions of external fields and internal fields and currents.

Exposure of DMBA-treated female rats in a 50-Hz, 50 μTesla magnetic field: effects on mammary tumor growth, melatonin levels, and T lymphocyte activation

“…First, as outlined above, by using a high DMBA dose and by waiting until 52 days of age to begin MF exposure we may have reduced the sensitivity of the model to detect MF-effects on mammary carcinogenesis. Second, the differences in MF-induced current are quite large between rodents and man because of size and geometry differences so that much lower flux densities than in rodents may affect biological functions in man if the interaction mechanism is based on induced currents (40). Third, there are several epidemiological studies suggesting an association between increased breast cancer risk and MF exposure at flux densities occurring at occupational and residential exposures (41)(42)(43)(44)(45)(46).…”

Effects of Weak Alternating Magnetic Fields on Nocturnal Melatonin Production and Mammary Carcinogenesis in Rats

“…Indeed, if biological effects of MFs are not caused by the M F per se but by an induced current, the rat-to-human scaling factor would be between 5 an 7, i.e. the human induced current equivalent of a 1 pT field in rats would be approximately 0.15-0.2 pT [21]. However, even this weak M F would be well in the range of elevated exposure by the epidemiological scale, especially when the reduced field exposure at night, which is the important time peri od for melatonin production, is considered [22], How ever, the induced current model is a matter of dispute.…”

Το Ηλεκτρικό Μαγνητικό Πεδίο Σε Δίκτυα Και Εγκαταστάσεις Ως Παράγων Περιβαλλοντικών Επιπτώσεων

“…Η μικροσκοπική δοσιμετρία είναι η ανάπτυξη μοντέλων που επεξεργάζονται το επαγόμενο ηλεκτρομαγνητικό περιβάλλον σε κλίμακες μεγέθους του ζωντανού κυττάρου. Η μακροσκοπική δοσιμετρία ασχολείται με δοσιμετρικές ποσότητες ανηγμένες σε όγκους ή επιφάνειες των οποίων οι διαστάσεις είναι μεγαλύτερες από αυτές των ζωντανών κυττάρων [26,[119][120][121],…”