Paul M, Hammond S K, Abdollahzadeh S
Department of Obstetrics and Gynecology, University of Massachusetts Medical Center, Worcester 01655.
Bioelectromagnetics. 1994;15(6):519-29. doi: 10.1002/bem.2250150605.
Given the current interest in potential carcinogenic and developmental effects of exposure to extremely-low-frequency electromagnetic fields, there is a need to identify cohorts of exposed female workers for future epidemiologic investigations. This study was designed to test the hypothesis that nurses working in neonatal intensive care units (NICU) may be significantly exposed to power-frequency magnetic fields. An electromagnetic field monitor was used to measure magnetic fields at distances of 5, 15, 30, and 60 cm from the surfaces of each device used in the NICU. Six female nurses assigned to the NICU (the "exposed" group) and six female nurses working in the normal newborn nursery (the "referent" group) wore EMDEX dosimeters for the entire duration of their 12 h shifts. An investigator kept a detailed log of each NICU subject's whereabouts for the first one-third of her shift. Magnetic fields at 5 cm from the front (defined by the nurses' usual work area) of the NICU devices ranged from less than 0.1 to 114 microT and in all cases decreased considerably with increasing distance. The geometric mean of the shift-time-weighted average exposure of the NICU nurses was 0.17 microT compared with 0.11 microT for the normal newborn nurses. The percentage of time when subjects were exposed to magnetic fields of 0.4 microT or greater ranged from 5.8% to 15.6% for the NICU nurses, 0.4% to 2.9% for five of the comparison group nurses, and was 9.4% for one of the normal newborn nurses with unidentified aberrantly high exposures. Log data revealed that the vast majority of observed peaks among NICU nurses occurred while subjects were in close proximity to infant bed units. We conclude that NICU nurses represent one female-intensive job sector with intermittent high exposures to ELF magnetic fields and encourage larger exposure studies of nurses in a variety of medical settings.
鉴于当前对暴露于极低频电磁场的潜在致癌和发育影响的关注，有必要确定暴露的女性工人队列，以便未来进行流行病学调查。本研究旨在检验以下假设：在新生儿重症监护病房（NICU）工作的护士可能会显著暴露于工频磁场。使用电磁场监测仪测量距离NICU中使用的每个设备表面5、15、30和60厘米处的磁场。六名被分配到NICU的女性护士（“暴露”组）和六名在正常新生儿保育室工作的女性护士（“对照”组）在其12小时轮班期间全程佩戴EMDEX剂量仪。一名调查员详细记录了每个NICU受试者在轮班前三分之一时间内的行踪。距离NICU设备前部（由护士的通常工作区域定义）5厘米处的磁场强度范围从小于0.1微特斯拉到114微特斯拉，并且在所有情况下都随着距离增加而显著降低。NICU护士轮班时间加权平均暴露的几何平均值为0.17微特斯拉，而正常新生儿护士为0.11微特斯拉。NICU护士暴露于0.4微特斯拉或更高磁场的时间百分比范围为5.8%至15.6%，对照组五名护士为从0.4%至2.9%，一名正常新生儿护士有未识别的异常高暴露，其暴露时间百分比为9.4%。日志数据显示，NICU护士中观察到的绝大多数峰值出现在受试者靠近婴儿床单元时。我们得出结论：NICU护士代表了一个女性密集型工作部门，她们会间歇性地高暴露于极低频磁场，并鼓励在各种医疗环境中对护士进行更大规模的暴露研究。
