Bracken T D, Rankin R F, Senior R S, Kavet R, Geissinger L G
T. Dan Braken, Inc., Portland, Oregon, USA.
Appl Occup Environ Hyg. 2001 Mar;16(3):369-79. doi: 10.1080/10473220118938.
The purposes of the research reported here were to quantify the power-frequency magnetic-field exposures of cable splicers while they were performing tasks in energized network distribution vaults and to compare these exposures with occupational exposure guideline levels. Network vaults supply electricity to commercial and residential urban areas as well as to large buildings. Participating workers wore a personal exposure monitor at the waist, kept a simple diary to record their work location, and recorded information about the vaults and tasks performed. To capture temporal variability, a stationary meter was deployed in the vault during a task. Load current in the vault was measured. To examine temporal variability over long time periods, stationary meters were deployed in selected vaults for one month. Data were collected during 77 tasks in 69 vaults for 191 person-tasks, representing approximately 400 hours of in-vault personal exposure data. Highest exposures were observed in tasks performed near secondary conductors. Personal exposure variability arises principally from worker movement and activities in the vaults, not from load variability during a task. Maximum field during a person-task exceeded the International Committee on Non-Ionizing Radiation Protection (ICNIRP) (0.42 millitesla) and the American Conference of Governmental Industrial Hygienists (ACGIH) (1.0 millitesla) guideline levels during 14 percent and 8 percent of the person-tasks, respectively. The mean of measurements during a person-task exceeded those guideline levels during 4 percent and 2 percent of the person-tasks, respectively. A large number of person-tasks (40%) had measured fields above the ACGIH recommended limit of 0.1 millitesla for workers with pacemakers or other implanted devices. Based on the frequency and duration of their high exposures, cable splicers working in network distribution vaults are one of the most highly exposed groups in the electric utility industry. Selective assignment of work location and task could minimize the likelihood of exposures for vault workers exceeding guideline limits for wearers of pacemakers or other implanted devices. Scheduling vault tasks during off-peak hours (nights and weekends) may reduce exposures. However, even during these periods exposures in certain vaults can still exceed guideline levels.
本文所报告的研究目的是量化电缆接头工在带电的网络配电室内执行任务时所受到的工频磁场暴露，并将这些暴露与职业暴露指导水平进行比较。网络配电室为城市商业和居民区以及大型建筑供电。参与研究的工人在腰部佩戴个人暴露监测器，记录简单的日志以记录其工作地点，并记录有关配电室和所执行任务的信息。为了捕捉时间变异性，在一项任务期间在配电室内部署了一个固定测量仪。测量了配电室内的负载电流。为了研究长时间内的时间变异性，在选定的配电室内部署固定测量仪达一个月之久。在69个配电室内进行了77项任务，收集了191人次任务的数据，约代表400小时的室内个人暴露数据。在靠近二次导体处执行的任务中观察到最高暴露水平。个人暴露的变异性主要源于工人在配电室内的移动和活动，而非任务期间的负载变化。在分别14%和8%的人次任务中，人次任务期间的最大场强超过了国际非电离辐射防护委员会（ICNIRP）（0.42毫特斯拉）和美国政府工业卫生学家会议（ACGIH）（1.0毫特斯拉）的指导水平。在分别4%和2%的人次任务中，人次任务期间的测量平均值超过了这些指导水平。大量的人次任务（40%）测量到的场强高于ACGIH为佩戴起搏器或其他植入装置的工人推荐的0.1毫特斯拉的限值。基于其高暴露的频率和持续时间，在网络配电室内工作的电缆接头工是电力行业中暴露程度最高的群体之一。有选择地分配工作地点和任务可以降低配电室工人的暴露超过起搏器或其他植入装置佩戴者指导限值的可能性。在非高峰时段（夜间和周末）安排配电室任务可能会减少暴露。然而，即使在这些时段，某些配电室内的暴露仍可能超过指导水平。
