Waveform magnetic field survey in Russian DC and Swiss AC powered trains: A basis for biologically relevant exposure assessment

Abstract

Recent epidemiological studies suggest a link between transport magnetic fields (MF) and certain adverse health effects. We performed measurements in workplaces of engineers on Russian DC and Swiss AC powered (16.67 Hz) electric trains using a computer based waveform capture system with a 200 Hz sampling rate. MF in DC and AC trains show complex combinations of static and varying components. The most probable levels of quasistatic MF (0.001-0.03 Hz) were in the range 40 microT. Maximum levels of 120 microT were found in DC powered locomotives. These levels are much higher than the geomagnetic field at the site of measurements. MF encountered both in DC and AC powered rail systems showed irregular temporal variability in frequency composition and amplitude characteristics across the whole frequency range studied (0-50 Hz); however, more than 90% of the magnetic field power was concentrated in frequencies </=16.67 Hz. In AC locomotives, such as the most popular engine Re 4/4 II, the major energy falls around the fundamental frequency 16.67 Hz, with an average magnetic field intensity of about 44 microT; moreover, a significant contribution (about 15%) is due to components below the fundamental frequency. In Russian DC powered trains amplitudes of field variations sharply decrease from static to approximately 3-4 Hz fields; for higher frequencies a tendency of slow decrease is observed up to 50 Hz. For frequencies higher than 1 Hz average amplitudes of magnetic field variations are less than 1 microT; maximum levels reach tens of microtesla. At frequencies lower than 15 Hz, the average magnetic field generated by Swiss AC powered locomotives was approximately 10 times greater than fields observed in Russian DC powered trains.

Occupational Exposure of Train Drivers to Static and Extremely Low Frequency Magnetic Fields in Tehran Subway

“…However, the µT in AC locomotives. In addition, they reported SMF of 0.4 mT in DC-powered transport systems (14). These results are in line with the findings of the current study presented in Table 1.…”

“…Although in their study, the ELF-MF and SMF values were higher than those of the present research were, the amounts still did not exceed the recommended occupational limits. Moreover, Ptitsyna et al found that SMF is the major portion of the MF encountered on board Russian DC powered transport systems rather than AC locomotives (14). However, the SMF values in Ptitsyna et al and Nakagava and Koanas' research and other relevant studies were ten times the amount of the background level (30 to 60 µT (19)).…”

“…This change is progressive in acceleration mode and descending at the time of braking (2). Another study measured maximum SMF of DC train when passing substations (in the trips) (14). Moreover, Halgamuge et al reported that magnetic field strength varies with the speed of trains (4).…”

“…The most commonly reported of which include a 3-fold increased risk for chronic lymphocytic leukemia in engine drivers (7), double incidence rate of chronic and acute lymphocytic leukemia in engine drivers and conductors compared to the average Swedish male population (8), altering the urinary 6-hydroxymelatonin sulfate excretion (9), increased risk of sudden cardiac death (10), and cardiovascular mortality (11). Exposure to MF induced by electrified public transport has been the center of concern in different countries such as Malaysia (12), Russia (13,14), Italy (15), and Australia (4).…”

Mechanisms of Geomagnetic Field Influence on Gene Expression Using Influenza as a Model System: Basics of Physical Epidemiology

“…Intensity of industrial magnetic fields can amount up to 120 μT, but contribution of the industrial (artificial) magnetic fields in total average intensity of environmental magnetic field is rather small because of mutual compensation (cancellation) of industrial magnetic fields [84,85]. …”