Heart rate variability (HRV) analysis in radio and TV broadcasting stations workers
More details
Hide details
Department of Work Physiology and Ergonomics, Nofer Institute of Occupational Medicine, Łódź, Poland
Department of Work Physiology and Ergonomics, Nofer Institute of Occupational Medicine, św. Teresy 8, 91-348, Łódź, Poland
Department of Psychological Research Methodology and Statistics, University of Łódź, Łódź, Poland
Department of Radiological Protection, Nofer Institute of Occupational Medicine, Łódź, Poland
Int J Occup Med Environ Health 2012;25(4):446–455
Objectives: The aim of the study was to assess the mechanism of cardiovascular impairments in workers exposed to UHF-VHF radio frequency electromagnetic fi elds (EMF). Materials and Methods: Heart rate variability (HRV) was analysed using 512 normal heart beats registered at rest. The analysis concerned time-domain (STD R-R) and frequencydomain (VLF, LF, HF) parameters of HRV. Fifty nine workers (group I) with low-level and 12 workers (group II) with highlevel exposure were examined. The mean age of the subjects was 47±9 years and 41±14 years, and mean exposure duration 19.1±8.8 years and 13±4 years, in groups I and II, respectively. The groups were divided according to: Emax, Edose, Emean for frequencies UHF, VHF and UHF+VHF: The control group consisted of 42 non-exposed subjects, aged 49±8 years. Statistical analysis comprised one-way analysis of variance, covariance analysis and logistic regression models. Results: In the exposed groups, the heart rate was higher than in the control one. Standard deviation of R-R intervals (STD R-R) was found to be signifi cantly (p = 0.0285) lower in group I (42.5±24.7 ms) compared to the control group (62.9±53.5 ms). The risk of lowered STD R-R was signifi cantly increased (OR = 2.37, p = 0.023) in group II. Both exposed groups presented signifi cantly higher VLF and LF values than the control group (p = 0.005 and p = 0.0025, respectively). The EMF-exposed groups were characterised by the dominance of the sympathetic system (LF/HF 1.3±0.35). Conclusions: The results indicate that exposure to radiofrequency EMF may affect the neurovegetative regulation.