ELF-MF occupational exposure: repeated measures on workers.

The aim of our study was to estimate occupational exposure to Extremely Low Frequency-Magnetic Fields (ELF-MF). Using personal dosimeters we evaluated occupational exposure in 543 workers employed in 9 occupational settings (about 150 jobs), representative of the main occupational activities in Emilia-Romagna region. In the whole sample, the median Time-Weighted Average (TWA) exposure resulted 0.14 microT (5 degrees - 95 degrees percentiles: 0.04 - 2.50 microT); Tile production presented the highest occupational setting TWA (0.46 +/- 1.83 microT), while the lower job TWA was Stock Clerk in Tile Production and Stock Clerk in Garment Production. After 6-9 months we repeated measurement in about 10% of the original sample (about 48 subjects) to verify the resulted obtained. At repeated measurement analysis with SPSS 12.0 no variation was found compared the previous monitoring. Individual occupational exposure to ELF-MF evaluated in a relatively large group of workers engaged in the main occupational activities proved low values compared to the proposed occupational limit.