FACTORS INFLUENCING PERSONAL MAGNETIC-FIELD EXPOSURE - PRELIMINARY-RESULTS FOR POWER UTILITY AND OFFICE WORKERS

Epidemiological studies and laboratory research suggest that exposure to extremely low frequency ( < 300 Hz) magnetic fields is associated w ith an increase in risk of developing a number of rare diseases includ ing leukaemia. Overall the risks to health appear to be small but a mo re accurate exposure assessment technique would help evaluate the true extent of any health effects. In this pilot study we aimed to identif y and evaluate personal, work and environmental factors and their infl uence on measured exposure levels with a view to developing a method o f reconstructing exposure. Office workers and power utility workers me re studied using personal dosimeters to measure magnetic field exposur e, along with frequent observation or measurement of factors related t o exposure, Factors such as average and closest distance to source, ti me at position and current flow were combined in a series of metrics t o investigate simple models of personal exposure. The results indicate that mean and peak magnetic field exposure levels are linked to curre nt how and the average distance of a worker from the source of the mag netic field. These factors are more accurate predictors of high exposu res than they are of lower and average levels, It may be possible, wit h further work, to produce a model of exposure to magnetic fields for use in epidemiological studies, (C) 1998 British Occupational Hygiene Society, Published by Elsevier Science Ltd.