EXECUTIVE SUMMARY

OBJECTIVES
A recent occupational study reported increases in myocardial risks among a cohort of USA male electric utility workers. Epidemiological data on DC-powered trains in Russia showed a 2-fold increase in the risk of coronary heart diseases in engine drivers of electric locomotives EL as compared to drivers of electric motor unit trains EMU. EMU-drivers were considerably less exposed to magnetic field (MF).
However, mechanisms through which MF might produce adverse health effects, are still unknown, so that the relevant MF characteristics are unclear.
There is evidence that the time-weighted average TWA of the MF strength might not be the best exposure metric: frequency and intensity "windows", DC fields and other MF features can be important.
The main objective of the project was to improve the quality and reliability of exposure assessment for complex "real world" MF produced by electrified trains, for which there was little or no information, with regard to health. The Project was oriented to clarify the following problems:
1. Is there an increased risk in cardiovascular diseases for engine drivers of AC (16.67 Hz) Swiss trains?
2. What are the exposure characteristics of MFs typical for drivers' workplaces in DC and AC trains?
3. Is there any biological response in humans and animals to train-like MF exposure?
4. How to quantify and assess biologically related exposure features of complex "real-world" train MF?

RESULTS

• Inline with the results on Russian engine drivers, the present study showed an increase of ~25% in myocardial infarction incidence among Swiss railway occupations in comparison to controls.

• A continuous monitoring of MF in workplaces of engine drivers was done. A data archive, containing ~70 hours of MF recordings by a waveform capture system in Swiss AC and Russian DC trains, was produced. MF exposure comparison for Swiss and Russian trains showed some consistency between power spectra, intermittency and polarization characteristics in the range 8-14 Hz. We developed a multifrequency MF pattern containing the average specific features typical for MF in EL.

• Studies on human volunteers showed a statistically significant heart rate acceleration under specific MF exposure.

• Studies on animals showed changes in biological parameters, such as non-specific immune resistibility and metabolic functions under exposure to train-like MF. For many analyzed parameters complex-spectra MFs act as a moderate stress-like factor. More significant biological response was achieved for complex-spectra 0-50 Hz MF, as compared with single frequency MF in the same frequency range.

• Epidemiological and biological results of the project formed a basis for improving the exposure assessment beyond TWA method. We present a set of techniques, algorithms and software to assess MF variability in different frequency ranges, including DC fields, polarization and intermittency.
  
  BENEFITS

• The project complemented previous studies on health-hazardous potential of ULF-ELF MF: both biological and epidemiological findings evidenced that complex-spectra transport MF could promote myocardial infarction incidence.

• The project filled the gap in knowledge on such characteristics of complex train MF as variability, frequency content, including DC component, polarization and intermittency.

• The presented set of methods, algorithms and software can be also utilized for quantifying different aspects of any other complex "real world" MF.

• Biological results provide a new experimental basis for further examination of different mechanisms of MF-biological system interaction.

• Quantification of the specific train MF features allows improving strategies for cost-effective preventive measures to diminish health-hazardous potential of MF in driver's workplaces.
  For the project realization a transnational collaboration of physicists, dosimetric and medical specialists, biologists, epidemiologists was established. NIS partners could access to previous achievements in Western laboratories, new technology and technological ideas was transferred to them; a related training activity was performed. This allowed NIS partners to perform studies in a higher qualified level. EU contract played a catalytic role: NIS Institutions received further national and international contracts.