Exposure of welders and other metal workers to ELF magnetic fields

Abstract

This study assessed exposure to extremely low frequency (ELF) magnetic fields of welders and other metal workers and compared exposure from different welding processes. Exposure to ELF magnetic fields was measured for 50 workers selected from a nationwide cohort of metal workers and 15 nonrandomly selected full‐time welders in a shipyard. The measurements were carried out with personal exposure meters during 3 days of work for the metal workers and 1 day of work for the shipyard welders. To record a large dynamic range of ELF magnetic field values, the measurements were carried out with “high/low” pairs of personal exposure meters. Additional measurements of static magnetic fields at fixed positions close to welding installations were done with a Hall‐effect fluxmeter. The total time of measurement was 1273 hours. The metal workers reported welding activity for 5.8% of the time, and the median of the work‐period mean exposure to ELF magnetic fields was 0.18 μT. DC metal inert or active gas welding (MIG/MAG) was used 80% of the time for welding, and AC manual metal arc welding (MMA) was used 10% of the time. The shipyard welders reported welding activity for 56% of the time, and the median and maximum of the workday mean exposure to ELF magnetic fields was 4.70 and 27.5 μT, respectively. For full‐shift welders the average workday mean was 21.2 μT for MMA welders and 2.3 μT for MIG/MAG welders. The average exposure during the effective time of welding was estimated to be 65 μT for the MMA welding process and 7 μT for the MIG/MAG welding process. The time of exposure above 1 μT was found to be a useful measure of the effective time of welding. Large differences in exposure to ELF magnetic fields were found between different groups of welders, depending on the welding process and effective time of welding. MMA (AC) welding caused roughly 10 times higher exposure to ELF magnetic fields compared with MIG/MAG (DC) welding. The measurements of static fields suggest that the combined exposure to static and ELF fields of MIG/MAG (DC) welders and the exposure to ELF fields of MMA (AC) welders are roughly of the same level. Bioelectromagnetics 18:470–477, 1997. © 1997 Wiley‐Liss, Inc.

Extremely low frequency magnetic fields and fertility: a follow up study of couples planning first pregnancies. The Danish First Pregnancy Planner Study Team.

“…Compared with a group of shipyard welders, who reported welding for 56% of the time during a similar monitoring programme, our participants had low exposure to ELF magnetic fields. 17 The only significant association between ELF magnetic fields and male markers of fertility was found between the proportion of measurements >1.0 µT and the fecundability. However, this finding was partly attributable to a relatively high fecundability among the men with low exposure (25.4% compared with 15.6% among non-welders in the original cohort of 430 couples).…”

“…Further details are given elsewhere. 17 For each participant the median recorded value was calculated together with the 75th percentile value and the proportion of measurements >0.2 and >1.0 µT. The median values of each summary measure are presented in table 1.…”

Exposure of workers to extremely low frequency magnetic fields during the temperature-rise test of electrotechnical equipment

“…The possible effects on human health from exposure to low-frequency EMFs are presented in [1,2]. Many academic works are dedicated to the measurement of the exposure of workers and the public to magnetic fields [3][4][5][6][7][8][9][10][11].…”

Magnetic Field Measurement in Industrial Environment

“…At the present time, only acute effects are demonstrated [6], and consequently ICNIRP suggests limits to the magnetic field intensity to be satisfied. One should note that since magnetic field is correlated with the current intensity flowing into devices or electrical machines the highest magnetic field intensity level is found in occupational environment [7], [8], [9], [10], [11], [12]. Hence, in order to protect workers by the risks deriving from exposure to electromagnetic (EM) fields, the European Community has adopted ICNIRP limits.…”

“…The Directive 2004/40/EC [13] requires, in general, the evaluation of the electromagnetic field intensity, and to search for adequate solutions if the threshold values are exceeded. The literature describes experiments concerning measurement field values in working sites [7], [8], [9], [10], [14]. From these papers one may argue that many of the interesting cases from the point of view of field intensity are found where the sources involved are inductors.…”