[ELF-MF occupational exposure: repeated measures on workers]. / Campi magnetici ELF ed esposizione professionale: misure ripetute della esposizione individuale in lavoratori addetti a varie mansioni.

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.

[Personal exposure to ELF magnetic fields in workers engaged in various occupations]. / Esposizione personale a campi magnetici a frequenza estremamente bassa in lavoratori addetti a varie mansioni.

Using personal dosimeters worn during two complete work-shifts, we measured occupational exposure to Extremely Low Frequency-Magnetic Fields (ELF-MF) in 290 workers employed in 56 jobs, representative of the main occupational activities in the area of Modena and Reggio Emilia (Italy). Environmental nonoccupational exposure was also monitored. In the whole sample, the mean Time-Weighted Average (TWA) exposure during work resulted 0.59 microT (SD 3.2), while the median was 0.13 microT. Exposure was lower than 1 microT in more than 90% of the workers. In one job only exposure was greater than 1 microT (job-related median TWA); in other 8 exposure was between 1 and 0.4 microT, while about 84% of the jobs presented a median TWA lower than 0.4 microT. A high variability among workers engaged in the same job resulted in various occupational tasks. Non-occupational exposure was lower than 0.4 microT in more than 98% of the examined workers. Our results show a low to moderate occupational exposure to ELF-MF in the greatest part of the workers and working activities. Also the non-occupational exposure resulted low in the large majority of the subjects. The high variability observed among workers engaged in some occupations may represent a problem in exposure evaluation. Personal monitoring is particularly useful in such a situations.