Occupational Exposure to Extremely Low Frequency Electric Fields in Office Work

The aim of this study is to investigate occupational exposure to extremely low frequency (ELF) electric fields (EF) in office work. The background electric fields (n = 4) were 2- 25V/m and the highest electric field measured was 1000 V/m. Different devices found in the office environment were measured for EF exposure. Results included, e.g., (1) spot lamps: 400V/m and 1000V/m (from surface) and 30V/m (distance 50 cm), (2) coffee maker: 10-20V/m (from surface), (3) the transformer of a computer: 100-200V/m (from surface), (4) the alternator of a cellular phone: 40-60 V/m, (5) a UPS (uninterruptible power supply): 300V/m (from surface) and 5V/m (distance 1 m), (6) a PC table speaker: 250V/m (from surface). The measured values obtained are clearly below 10 000V/m threshold stipulated in the guidelines of ICNIRP (The International Commission on Non-ionizing Radiation Protection).