A model for assessing occupational exposure to extremely low‐frequency magnetic fields in fabrication rooms in the semiconductor health study

摘要

AbstractA model was created to assess occupational exposure to extremely low‐frequency MAgnetic fields (ELF‐MF) among semiconductor fabrication‐room (fab) workers. This model was based on the assumption that each subject's exposure arose from being near identifiable ELF‐MF sources or being in areas with high ELF‐MF levels. To assess ELF‐MF exposures, the model superimposed subjects' time‐activity patterns (patterns of how and where they spent their time) with measurements of MAgnetic‐field levels from devices and work areas. This model, which was validated by personal dosimetry on 192 persons in three fabs, predicted actual time‐weighted average exposures with a correlation coefficient of 0.62. The inability of the model to predict individual exposures more accurately was attributed to unforeseen sources of elevated ELF‐MF (transformers, distribution panels, sources in adjacent rooms) or to errors in subjects' judgments of time spent near devices. These unpredictable errors are intrinsic to the method used t