National Institute of Occupational Safety and Health.
Ind Health. 2011;49(3):274-9. doi: 10.2486/indhealth.ms1269.
The assessment of the occupational electromagnetic field exposure of welders is of great importance, especially in shielded-arc welding, which uses relatively high electric currents of up to several hundred amperes. In the present study, we measured the magnetic field exposure level of welders in the course of working. A 3-axis Hall magnetometer was attached to a subject's wrist in order to place the sensor probe at the closest position to the magnetic source (a cable from the current source). Data was acquired every 5 s from the beginning of the work time. The maximum exposed field was 0.35-3.35 mT (Mean ± SD: 1.55 ± 0.93 mT, N=17) and the average value per day was 0.04-0.12 mT (Mean ± SD: 0.07 ± 0.02 mT, N=17). We also conducted a finite element method-based analysis of human hand tissue for the electromagnetic field dosimetry. In addition, the magnetic field associated with grinders, an air hammer, and a drill using electromagnetic anchorage were measured; however, the magnetic fields were much lower than those generated in the welding process. These results agreed well with the results of the electromagnetic field dosimetry (1.49 mT at the wrist position), and the calculated eddy current (4.28 mA/m(2)) was much lower than the well-known guideline thresholds for electrical nerve or muscular stimulation.
评估焊工的职业电磁场暴露非常重要，特别是在使用相对较高电流（高达数百安培）的屏蔽电弧焊接中。在本研究中，我们测量了焊工在工作过程中的磁场暴露水平。将三轴霍尔磁力计附着在受试者的手腕上，以便将传感器探头放置在离磁场源（电流源的电缆）最近的位置。从工作时间开始，每 5 秒采集一次数据。最大暴露场为 0.35-3.35 mT（平均值 ± 标准差：1.55 ± 0.93 mT，N=17），每天的平均值为 0.04-0.12 mT（平均值 ± 标准差：0.07 ± 0.02 mT，N=17）。我们还进行了基于有限元方法的人体手部组织电磁场剂量分析。此外，还测量了磨床、空气锤和使用电磁锚固的钻头产生的磁场，但磁场远低于焊接过程中产生的磁场。这些结果与电磁场剂量分析结果（手腕位置为 1.49 mT）非常吻合，计算出的涡流（4.28 mA/m2）远低于已知的电神经或肌肉刺激的准则阈值。
