extremely low frequency magnetic flux densities measured near hospital in tehran

the ever increasing rate of power consumption has led to an increase in public exposure to extremely low frequency magnetic fields (elf-mfs) and brought severe concerns about their health effects. considering previous studies and the facts about potential health effects of these fields, the present study aimed to evaluate the elf-mf flux densities from power distribution lines near hospitals in tehran. elf-mf measurements were performed according to ieee standard procedures-std 644-1994 near the hospitals entrances using hi-3604 power frequency field strength measurement system during three different time periods (i.e. 12-3 am, 9-12 am, 6-9 pm). the results were analyzed using one-way anova test. mean, minimum, and maximum values of elf-mf flux densities were 0.165 ± 0.08 μt, 0.018 μt, 0.52 μt, respectively. there were no statistically significant differences in elf-mf flux densities neither among different hospital groups nor among different time periods. the elf-mf flux densities from power distribution lines around tehran hospitals were much less than the standards values, implying that it can be considered only in epidemiological studies. in fact, in the case of powerful sources, magnetic field intensity is declined rapidly by distance and is limited to a few meters around the sources. this subject is considered as one of the main reasons for contradictory results in previous studies. results of the present study can be used as a part of hospital patients’ exposure to quantify the total exposure levels of patients as a critical and sensitive group in tehran hospitals.