Subclinical effects of environmental hazardous factors on nervous and renal functions in humans

本研究的目的是阐明环境有害因素，如铅，镉，甲基汞（甲基汞），对人类的神经和肾功能的亚临床影响。(1)第一项研究是通过引入基准剂量（BMD）方法来估计铅影响工人神经运动功能的临界剂量。本文对121名铅作业工人和60名未接触铅的对照者的姿势摇摆参数进行了频谱分析比较。所有的摇摆参数，除了矢状摆动与眼睛打开，显着大于铅工人比对照组。BPb引起姿势摇摆的临界剂量为12.1-17.3 μg/dl。(2)为探讨发、趾甲、尿中总汞（THg）含量之间的关系及甲基汞摄入对肾小管功能的潜在影响，测定了发、趾甲、尿中总汞含量及尿N-乙酰氨基葡萄糖苷酶活性（NAG）和尿α1-微球蛋白（AMG） 关于我们 在59名妇女中，使用食物频率调查问卷估计每日从鱼和其他海产品中的汞摄入量。女性头发、趾甲和尿中THg含量分别为1.51±0.91（SD）μg/g、0.59±0.32 μg/g和0.86±0.66 μg/g肌酐（Cre），三者呈正相关。每日汞摄入量（9.15±7.84 μg/d）与头发、趾甲和尿液中THg水平显著相关。在女性中，NAG和AMG与每日汞摄入量以及头发、趾甲和尿液中的THg水平呈正相关;当使用多元回归分析来校正可能的混杂因素（如尿镉（0.47±0.28 μg/g Cre））时，这些关系几乎相似。总之，食用鱼类产生的甲基汞可以在一定程度上解释头发、脚趾甲和尿液中的总汞含量，部分原因是甲基汞降解成无机形式。(3)为了阐明职业性汞蒸气暴露对神经运动的影响，对27名矿工和冶炼工人以及52名未接触汞蒸气的受试者进行了手震颤和姿势摇摆的测量。尿汞平均值为228 μg/gCre，对照组为2.6 μg/gCre。总震颤强度和频率特异性震颤强度在1-6和10-14 Hz的接触工人显着大于未接触的主题，但他们没有显着相关的UHg接触工人。而两组间各体位摆动参数均无显著性差异，但多元回归分析显示，作业工人睁眼横向摆动与UHg呈正相关。这些研究结果表明，姿势摇摆和手震颤，可能会受到元素汞蒸气暴露。少

The objectives of this research were to clarify the subclinical effects of environmental hazardous factors such as lead, cadmium, and methylmercury (MeHg), on nervous and renal functions in humans. (1) The first study was carried out to estimate the critical dose of lead affecting the neuromotor function in workers by introducing the benchmark dose (BMD) approach. Postural sway parameters with spectral analysis were compared between 121 lead workers with BPb levels of 6-89 μg/dl and 60 unexposed controls. All sway parameters, except for sagittal sways with eyes open, were significantly larger in the lead workers than in the controls. The critical dose of BPb was estimated to be 12.1-17.3 μg/dl for postural sway. (2) To investigate the relations among total mercury (THg) levels in hair, toenail, and urine, together with potential effects of MeHg intake on renal tubular function, their levels, and urinary N-acetyl-glucosaminidase activity (NAG) and α1-microglobulin (AMG) were determined … More in 59 women, and estimated daily mercury intakes from fish and other seafood using a food frequency questionnaire. THg levels in the women were 1.51±0.91 (SD) μg/g in hair, 0.59±0.32 μg/g in toenail, and 0.86±0.66 μg/g creatinine (Cre) in urine ; and, there were positive correlations among them. The daily mercury intake of 9.15±7.84 μg/day was significantly correlated with THg levels in hair, toenail, and urine. Among the women, the NAG and AMG were positively correlated with both the daily mercury intake and THg levels in hair, toenail, and urine ; and, these relations were almost similar when using multiple regression analysis to adjust for possible confounders such as urinary cadmium (0.47±0.28 μg/g Cre). In conclusion, MeHg resulting from fish consumption can explain total mercury levels in hair, toenail, and urine to some degree, partly through the degradation into the inorganic form. (3) To clarify the neuromotor effects of occupational exposure to mercury vapor, hand tremor and postural sway were measured in 27 miners and smelters and 52 unexposed subjects. The means of the urinary mercury level (UHg) were 228 μg/g Cre for the exposed workers and 2.6 μg/g Cre for the unexposed subjects. Total tremor intensity and frequency-specific tremor intensities at 1-6 and 10-14 Hz were significantly larger in the exposed workers than in the unexposed subjects, but they were not significantly related to the UHg among the exposed workers. In contrast, there were no significant differences in any postural sway parameters between the above two group, but the transversal sway with eyes open was positively related to the UHg among the exposed workers in using multiple regression analysis. These findings suggest that postural sway and hand tremor, may be affected by elemental mercury vapor exposure. Less