Fields Cheryl A, Borak Jonathan, Louis Elan D
a Jonathan Borak & Company , New Haven , CT , USA.
b Department of Environmental Health Sciences, Yale School of Public Health , New Haven , CT , USA.
Crit Rev Toxicol. 2017 Nov;47(10):845-866. doi: 10.1080/10408444.2017.1342599. Epub 2017 Jul 19.
Elemental mercury (Hg) is a well-recognized neurotoxicant, but it is uncertain whether and for how long its neurotoxicity persists. Among studies that evaluated previously-exposed workers, only one examined workers during and also years after exposure had ceased. The objective of this review is to create a series of 'synthetic' longitudinal studies to address the question of persistence of Hg neurotoxicity in occupationally exposed workers. We systematically reviewed studies describing objective motor and sensory effects in previously-exposed mercury workers. Data from physical examination (PE), neurobehavioral (NB) tests, and electrophysiological studies (EPS) were extracted into structured tables and examined for their consistency and dose-relatedness and then compared with the corresponding results from studies of currently exposed workers. We identified six cohorts that described neurological findings in 1299 workers, examined an average of 4.8-30 years after the cessation of exposure. Historical group mean U levels ranged from 23 to >500 μg/L, with U levels >6000 μg/L in some individuals. Overall, few findings were significant; most were inconsistent across the previous-exposure studies, and in comparisons between studies of previously and currently exposed workers. The results of this systematic review indicate that Hg-related neurotoxic effects detectable on PE, NB testing, and EPS are substantially reversed over time. To the extent that such effects do persist, they are reported principally in workers who have had very high-dose exposures. In addition, based on the limited available data, those effects reported to persist have been described as having little or no functional significance.
元素汞（Hg）是一种公认的神经毒物，但其神经毒性是否会持续以及持续多久尚不确定。在评估既往接触汞工人的研究中，仅有一项研究对接触期间及接触停止数年后的工人进行了检查。本综述的目的是开展一系列“合成”纵向研究，以解决职业接触汞工人中汞神经毒性的持续性问题。我们系统回顾了描述既往接触汞工人客观运动和感觉效应的研究。将体格检查（PE）、神经行为（NB）测试和电生理研究（EPS）的数据提取到结构化表格中，检查其一致性和剂量相关性，然后与当前接触汞工人研究的相应结果进行比较。我们确定了六个队列，这些队列描述了1299名工人的神经学检查结果，平均在接触停止后4.8至30年进行检查。既往队列的平均尿汞水平范围为23至＞500μg/L，部分个体的尿汞水平＞6000μg/L。总体而言，几乎没有显著发现；大多数结果在既往接触研究中不一致，在既往接触和当前接触工人的研究比较中也不一致。本系统综述的结果表明，通过PE、NB测试和EPS可检测到的与汞相关的神经毒性效应会随着时间的推移而大幅逆转。就这些效应确实持续存在的程度而言，主要在高剂量接触的工人中报告。此外，根据有限的现有数据，报告持续存在的那些效应被描述为几乎没有或没有功能意义。
