Department of Occupational Diseases and Toxicology, Nofer Institute of Occupational Medicine, Łódź, Poland.
Int J Occup Med Environ Health. 2010;23(4):347-55. doi: 10.2478/v10001-010-0034-3.
A number of metals, especially heavy metals, exhibit neurotoxic properties. Neurological and neurophysiological studies indicate that the functions of the central (CNS) and peripheral nervous system (PNS) may be impaired under conditions of exposure to arsenic (As). The aim of the present study was to assess the effects of inorganic arsenic on the central and peripheral nervous system.
The study covered a group of 21 male workers (mean age: 41.9 yr; SD: 7.6; range: 31-55 yr) employed in a copper smelting factory. Their employment duration ranged from 5 to 33 years (mean: 18.1 yr; SD: 7.8). Arsenic concentrations in workplace air amounted to 0.01003 mg/m3 on average (SD: 0.00866). Urine arsenic concentrations ranged from 3.48 to 23.63 μg/l (mean: 11.91 μg/l; SD: 9.5). The control group consisted of 16 males non-occupationally exposed to As, matched for gender, age and work shift pattern. The evaluation of neurological effects was based on the findings of neurological examination, electroencephalography (EEG), visual evoked potentials (VEPs) and electroneurography (ENeG).
Clinical symptoms, such as sleeplessness or sleepiness, irritability, headache, painful spasms in extremity muscles, extremity paresthesia and pain, and muscular fatigue prevailed among functional disorders of the nervous system in workers chronically exposed to As. Neurological examination did not reveal any organic lesions in the CNS or PNS. In EEG records classified as abnormal, generalized changes were most common. VEP examinations revealed abnormalities in evoked response latency. Stimulation of the motor fibers of the peroneal and medial nerves resulted in a decreased amplitude of the motor potential. Stimulation of the sensory fibers of medial nerves brought about a decreased amplitude of the sensory potential and a lower conduction velocity of the sural nerves.
The findings of the study indicate that exposure to As concentrations within the threshold limit values (TLV) can induce subclinical effects on the nervous system, especially subclinical neuropathy.
许多金属，尤其是重金属，具有神经毒性。神经学和神经生理学研究表明，在暴露于砷（As）的情况下，中枢神经系统（CNS）和周围神经系统（PNS）的功能可能会受到损害。本研究旨在评估无机砷对中枢和周围神经系统的影响。
该研究涵盖了一组 21 名男性工人（平均年龄：41.9 岁；标准差：7.6；范围：31-55 岁），他们在一家铜冶炼厂工作。他们的工作年限从 5 年到 33 年不等（平均：18.1 年；标准差：7.8 年）。工作场所空气中的砷浓度平均为 0.01003 毫克/立方米（标准差：0.00866）。尿砷浓度范围为 3.48 至 23.63μg/l（平均值：11.91μg/l；标准差：9.5）。对照组由 16 名非职业性接触砷的男性组成，性别、年龄和工作班次相匹配。神经系统影响的评估基于神经系统检查、脑电图（EEG）、视觉诱发电位（VEPs）和神经电图（ENeG）的结果。
在长期接触砷的工人中，神经系统功能障碍主要表现为失眠或嗜睡、易怒、头痛、四肢肌肉疼痛性痉挛、四肢感觉异常和疼痛以及肌肉疲劳等临床症状。神经系统检查未发现中枢神经系统或周围神经系统有器质性病变。在被归类为异常的脑电图记录中，最常见的是广泛性变化。VEP 检查显示诱发电位潜伏期异常。刺激腓肠神经和内侧神经的运动纤维会导致运动电位幅度降低。刺激内侧神经的感觉纤维会导致感觉电位幅度降低和腓肠神经的感觉传导速度降低。
研究结果表明，在阈限值（TLV）内接触砷浓度可能会导致神经系统出现亚临床影响，尤其是亚临床神经病变。
