Power lines, as well as powered devices present in the living environment, generate in the surrounding areas electric and magnetic fields at 50 Hz. This is the frequency associated with the power generation and delivery network in Italy and in most of the world, and is part of the extremely low frequencies range (ELF, 0-300 Hz). Although the effects of ELF fields are under investigation for about 30 years with particular attention to the leukemia onset, scientific knowledge of biological effects and their relevance with respect to health risks is still unclear. The in vitro biological research, carried out at IREA, aims to find possible biological mechanisms explaining interactions between ELF fields and living organisms to give plausibility to the hypothesis of carcinogenicity of these fields.
Human peripheral lymphocyte cultures are mainly employed, which represent a good biological system for in vitro studies. They are easily obtained from venipuncture, have ubiquitous distribution in the body with continuous circulation in the lymphatic tissues, moreover laboratory protocols are well standardized. For the exposures, devices ensuring high magnetic field homogeneity, typically based on Helmholtz coils, are realized. In particular, magnetic field distributions are evaluated by means of computational and experimental measurements, to carry out controlled exposures. The exposure systems, PC-driven, are housed in cell culture incubators in order to ensure optimal conditions in biological samples in terms of temperature, carbon dioxide and humidity. Identical exposure systems but fed in such a way to generate zero magnetic field, are employed to house the control samples (sham samples) in order to exclude that the observed effects may arise from the conditions inside the exposure system instead of the magnetic field. Exposures, continuous or intermittent, are carried out by varying exposure duration, waveform and magnetic field intensity. Following exposures, cell samples are processed to evaluate biological endpoints for which biological effects have been reported, and evidence of replication in the literature already exists. The effects on DNA (genotoxic effects) have a key role since DNA damage is always present in the early stages of carcinogenesis. Classical and molecular cytogenetic techniques are employed at IREA, for the evaluation of genotoxic effects in mammalian cell cultures.
