Assessment of historical magnetic field dosages received by Eskom´s live line maintenance personnel

A number of epidemiological studies have indicated that exposure to magnetic fields in certain work environments has possible detrimental health effects. A limitation of most of these studies, however, is the inaccurate assessment of historical exposure to magnetic fields. This paper describes the preliminary results of a study conducted by Eskom to assess the historical magnetic field dosages received by the members of one of Eskom´s live line maintenance teams during typical working conditions. The assessment involves incorporation of magnetic field dosage measurements with the information obtained from the live line log sheets kept by the live line workers. The study indicated that the annual magnetic field dosages received by the live line workers range between 0,65 mT.h/year and 40,83 mT.h/year with a mean of 20,37 mT/year. The approach followed can effectively be applied in the design of epidemiological studies focusing on live line maintenance