Assessment of Static and Extremely Low-Frequency Magnetic Fields in the Electric-Powered Trains

The engine and power supply of trains in advanced rail transit systems are electric (Alternating current (AC) or Direct current (DC)). Such systems generate magnetic fields in the range of static or extremely low frequencies. This study aimed to assess occupational exposure of train drivers to Static Magnetic Field (SMF) and Extremely Low-Frequency Magnetic Field (ELF-MF). This study was conducted in 2014 on intercity and metro trains in Tehran. Seven trains were randomly selected from intercity and metro lines. Based on the BS EN 50500:2008 method recommendations, magnetic fields were measured by the TES-1394 (ELF-MF meter) and HI-3550 (SMF meter). The exposure of drivers was assessed in accordance with of ACGIH-TLVs. The independent sample t-test, Paired samples t-test, one-way ANOVA (with LSD post hoc), and Mann–Whitney nonparametric test were used for data analysis. Mean (±SD) value of ELF-MF and SMF were measured 1.47 (±1.67) μT and <0.1 mT in the intercity AC trains, 0.45 (±0.53) μT and 0.95 (±0.07) mT in the AC trains, and 0.35 (±0.22) μT and 0.08 (±0.86) mT in the DC trains. In addition, maximum exposure to ELF-MF and SMF were 9 μT in intercity AC trains and 1 mT in DC trains, respectively. In none of the situations, exposure of train drivers to ELF-MF and SMF exceeded the ACGIH-TLVs. This does not mean that these magnetic fields are safe and harmless. Hence, the clinical and/or epidemiological study, along with an ELF-MF and SMF exposure assessment of all railway personals, can be helpful for prevention, identification, and treatment of diseases.