Physical Activity Program as a Fitness Tool for Workers Exposed to Electromagnetic Field

Electromagnetic field (EMF) exposure at low frequencies may cause some health problems. The present study was designed to test the effect of a comprehensive physical activity program on some fitness aspects of exposed workers with emphasis on cardio-autonomic control. A pre-test post-test experimental design was adopted. A representative sample of 30 workers exposed to low frequency EMF from Abou Qir electrical power station, Alexandria, were included in the study after fulfilling eligible criteria. Each one of the workers was subjected to a predesigned questionnaire including inquiries about sleep pattern subjective symptoms, and work and health satisfaction. Measurements of anthropometric indices, resting heart rate and blood pressure were done. Resting 12 lead ECG and R-R variability test during deep breathing were performed. A venous blood sample was taken for serum cholesterol and complete blood count determination. All these parameters were measured for the participants before and after implementation of a standardized physical activity program (PAP) for 12 weeks. Results revealed significant improvement of some subjective and general complaints, and work and health satisfaction (p<0.05 for all). Heart rate, systolic blood pressure and R-R variability indices showed significant favorable effect of the PAP in the direction of augmenting the protective parasympathetic tone. In conclusion, PAP for workers exposed to EMF seems to be a good tool to improve their fitness and to ameliorate some health risks, emphasizing its importance in preventive implications. INTRODUCTION Electromagnetic field (EMF) is determined by the force effect due to summation of electric and magnetic fields. It comprises a broad spectrum of non-ionizing radiation. (1,2) Extremely low frequency EMF is existing whenever electric wiring, electric 100 Bull High Inst Public Health Vol.39 No.1 [2009] motors and electric devices are found. Exposure may occur at home, at job and in electric vehicles. Workers in electric utilities and nearby power lines are at great risk. (1) the magnetic component of exposure is the suspicious part of low frequency EMF especially among electric utility workers. (3) On the other hand, high frequency EMF is another issue expressed as radiofrequency radiation which is present in many fields including mobile phones and their base stations. (4,5) Since the late part of the 20th century there is increasing interest in the health effects of low frequency EMF especially in the form of subjective complaints including neurasthenic symptoms and sleep troubles, disturbances in cardiovascular and gastrointestinal functions and transient hematologic changes. (6) There are also, some existing concerns about childhood leukemias and certain types of cancer. (7) Metabolic parameters including cholesterol may be adversely affected due to exposure to low frequency EMF. (8) Cardiovascular diseases among electric utility workers were studied. (3,9-11) Indices of magnetic field exposure were consistently related to mortality from arrhythmia. (3,11) Heart rate and heart rate variability may be affected by this exposure in a pattern suggesting the domination of sympathetic activity and imposing further cardiovascular risk. (12,13) Most of the reported health findings due to exposure to low frequency EMF seems to be related to workers' fitness and autonomic nervous control. (6) According to the latest guidelines,(14) all healthy adults aged 18-65 should be getting at least 30 minutes of moderate intensity activity five days of the week. Implementation of a physical activity program was shown to raise fitness, increase productivity and damp many health problems among workers. (15) The outcome of a physical fitness program for workers will be increased if properly designed with its different physical components by a