Ranking of extremely low frequency magnetic fields associated with twenty-one commonly used office and household appliances in Port Harcourt, Nigeria
Common household and office appliances generate extremely low frequency (ELF) magnetic fields at frequency of 50/60 Hz. The magnitude of magnetic field intensity from twenty-one types of household and office equipment have been measured using Triaxial Magnetic Field Meter (TM-192 model). For each type of the 21 sampled equipment, magnetic field measurements were carried out for five samples, bringing the number to a total of 105. The results of the mean magnetic field intensity (Bs) ranged from 0.012 to 72.752 μT at (zero) 0 m with the light bulb ranking lowest (0.011 %) and hair clipper ranking highest (65.783 %). The results of Bs ranged from 0.001 to 10.072 μT at a distance of 0.5 m with the light bulb and electric stove ranking lowest (0.008 % ) and hair clipper ranking highest (82.992 %). The results of Bs ranged from 0.001 to 0.235 μT at a distance of 1.0 m with the light bulb, laptop, electric iron and electric stove ranking lowest (0.169 % ) and hair clipper ranking highest (39.763 %). These results fall below the specified limits of 100 μT and 500 μT (for the public and occupationally exposed persons respectively) set by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) as being capable of causing adverse health effects but above the magnetic field exposure capable of causing some level of biological risk effect to living organisms. Statistical analyses showed a correlation in the trend of Bs as there was reduction in Bs against distance for all the surveyed equipment. Efforts should always be made to minimize the extent of exposure to ELF magnetic fields as low as reasonably achievable to check possible health side-effects.