Bioelectromagnetics 28:122 ^ 129 (2007) Electromagnetic Fields Produced by GSM Cellular Phones and Heart Rate Variability Marta Parazzini, 1 * Paolo Ravazzani, 1 Gabriella Tognola, 1 Gyo« rgy Thuro¤ czy, 2 Ferenc B. Molnar, 2 Alessio Sacchettini, 3 Gianluca Ardesi, 3 and Luca Tommaso Mainardi 3 1 Istituto di Ingegneria Biomedica ISIB, Consiglio Nazionale delle Ricerche, Piazza Leonardo daVinci, Milano, Italy 2 Department of Non-Ionizing Radiation, National Research Institute for Radiobiology and Radiohygiene NIRR, Budapest, Anna u.5, Hungary 3 Dipartimento di Bioingegneria, Politecnico di Milano, Piazza Leonardo daVinci, Milano, Italy In this study, 26 healthy young volunteers were submitted to 900 MHz (2 W) GSM cellular phone exposure and to sham exposure in separate sessions. The study was designed to assess cardiac regulatory mechanism in different autonomic nervous system (ANS) states during exposure to low- intensity EMF. Rest-to-stand protocol was applied to evaluate ANS in quiet condition (rest, vagal prevalence) and after a sympathetic activation (stand). The procedure is conducted twice in a double- blind design: once with a genuine EMF exposure and once with a sham exposure (at least 24 h apart). During each session three-leads electrocardiograms were recorded and RR series extracted off-line. Time domain and frequency domain HRV parameters were calculated in every phase of the protocol and during different exposures. The analysis of the data show there was no statistically significant effect due to EMF exposure both on main (i.e., RR mean) and most of the other HRV parameters. A weak interaction between some HRV parameters (i.e., SDNN, TINN, and triangular index in time domain and LF power in frequency domain analysis) and RF exposure was observed and this effect seems to be gathered around the sympathetic response to stand. Bioelectromagnetics 28:122–129, 2007. ß 2006 Wiley-Liss, Inc. Key words: human studies; EMF exposure; ECG; rest-to-stand; time domain analysis; frequency domain analysis INTRODUCTION The last decade has witnessed a worldwide ex- plosion in the use of cellular phones. This has been accompanied by public concerns about the potential adverse health effects from using cellular phones and from living and working near base stations [Indepen- dent Expert Group on Mobile Phones, 2004]. Up until now, there is still a limited knowledge on potential effects (adverse or not) of GSM cellular phones on the control of cardiovascular functions and in particular on autonomic nervous system (ANS) activity controlling heart rate (HR). The relatively few studies assessed the influence of radio frequency electro- magnetic fields (RF EMFs) on cardiovascular functions during either sleep [Mann et al., 1998; Huber et al., 2003] or awaking conditions [Braune et al., 1998, 2002; Tahvanainen et al., 2004], but the results are con- troversial. Even if HR was not affected when subjects were exposed during sleep [Mann et al., 1998; Huber et al., 2003], more contradictory results are obtained in awaking conditions: some studies evidenced a slight augmented sympathetic tone revealed by blood pres- sure (BP) increase associated with exposure [Braune et al., 1998]; others [Braune et al., 2002; Tahvanainen et al., 2004] could not confirm these findings. In the mentioned studies, assessment of cardiovascular func- tions had been obtained by simple metrics based on computation of HR and BP mean values. However, more sophisticated indexes can be employed to test ANS activity [Task Force, 1996]. They are based on the analysis of the beat-to-beat fluctuations of the RR ß 2006 Wiley-Liss, Inc. —————— *Correspondence to: Dr. Marta Parazzini, Istituto di Ingegneria Biomedica ISIB, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, 20133 Milano, Italy. E-mail: marta.parazzini@polimi.it Received for review 10 January 2006; Final revision received 20 July 2006 DOI 10.1002/bem.20275 Published online 26 September 2006 in Wiley InterScience (www.interscience.wiley.com).