Franko Alenka, Budihna Metka V, Dodic-Fikfak Metoda
Ljubljana University Medical Centre, Clinical Institute of Occupational Medicine, Poljanski nasip 58, 1000 Ljubljana, Slovenia.
Ann Occup Hyg. 2005 Aug;49(6):521-7. doi: 10.1093/annhyg/mei022. Epub 2005 Jun 17.
The kidneys are one of the main target organs for elemental mercury (Hg(0)). The influence of Hg(0) on kidneys has been extensively studied but the long-term effects on this organ have not yet been determined with certainty. The basic aim of this research was to study the effects of a long-term exposure to Hg(0) vapours on the renal function in miners in the post-exposure period.
The population studied comprised 53 miners (33 active and 20 retired) from the Idrija Mercury Mine as the exposed miners group and 53 unexposed workers as the control group. On the basis of mine exposure records (air and biological monitoring), the environmental and biological indicators of the past exposure to Hg(0) were calculated for each miner. Kidney function was determined in both groups, i.e. in the exposed miners as well as in the controls. Glomerular kidney function was evaluated by a quantitative analysis of albumin and IgG in urine. Tubular kidney function, however, was determined by a quantitative analysis of alpha(1)-microglobulin in urine and by the enzymatic activity of N-acetyl-beta-d-glucosaminidase (NAG).
The mean exposure time in miners was 15 years. The total number of cycles of exposure ranged from 13 to 119. The mean annual time-weighted exposure was 0.29 mg m(-3) and the mean integrated exposure intensity (IEI) was 1413 mg m(-3)-h. Throughout the period of exposure the average urine mercury concentration in miners was 68.24 microg l(-1) and the average sum of peak urine mercury concentrations was 3901 microg l(-1). Albumin, IgG and alpha(1)-microglobulin in urine were significantly elevated in the exposed miners compared with the unexposed controls (t = 2.17, P = 0.03; t = 2.81, P < 0.01; and t = 2.07, P = 0.04). No significant differences were found in the urine NAG activity when the exposed miners and the unexposed workers were compared. Among the indicators of renal function only alpha(1)-microglobulin in the urine correlated significantly with the IEI (r = 0.73; P <or= 0.01) and with the sum of peak mercury urine concentrations (r = 0.67; P <or= 0.01) in the group of miners who still worked, while no significant correlations were found between these parameters in the group of the retired miners.
The results of the differences in albumin, IgG and alpha(1)-microglobulin concentrations in urine between the exposed miners and unexposed controls suggest that a long-term occupational exposure to Hg(0) could cause renal dysfunction. A high correlation between alpha(1)-microglobulin in urine and the IEI as well as between alpha(1)-microglobulin in urine and the sum of peak urine mercury concentrations in the group of active but no longer exposed miners indicates that a long-term occupational exposure to Hg(0) may cause a non-permanent tubular dysfunction.
肾脏是元素汞（Hg(0)）的主要靶器官之一。Hg(0)对肾脏的影响已得到广泛研究，但对该器官的长期影响尚未确定。本研究的基本目的是研究长期暴露于Hg(0)蒸气对矿工暴露后时期肾功能的影响。
研究人群包括来自伊德里亚汞矿的53名矿工（33名在职和20名退休）作为暴露矿工组，以及53名未暴露工人作为对照组。根据矿井暴露记录（空气和生物监测），计算每名矿工过去暴露于Hg(0)的环境和生物指标。两组均测定肾功能，即暴露矿工组和对照组。通过对尿液中白蛋白和IgG的定量分析评估肾小球肾功能。然而，肾小管功能通过对尿液中α(1)-微球蛋白的定量分析和N-乙酰-β-D-葡萄糖苷酶（NAG）的酶活性来确定。
矿工的平均暴露时间为15年。暴露周期总数为13至119个。平均年度时间加权暴露为0.29 mg m(-3)，平均综合暴露强度（IEI）为1413 mg m(-3)-h。在整个暴露期间，矿工尿液中汞的平均浓度为68.24 μg l(-1)，尿液汞峰值浓度总和平均为3901 μg l(-1)。与未暴露对照组相比，暴露矿工尿液中的白蛋白、IgG和α(1)-微球蛋白显著升高（t = 2.17，P = 0.03；t = 2.81，P < 0.01；t = 2.07，P = 0.04）。比较暴露矿工和未暴露工人时，尿液NAG活性未发现显著差异。在肾功能指标中，仅仍在工作的矿工组尿液中的α(1)-微球蛋白与IEI显著相关（r = 0.73；P ≤ 0.01），与尿液汞峰值浓度总和显著相关（r = 0.67；P ≤ 0.01），而在退休矿工组中这些参数之间未发现显著相关性。
暴露矿工与未暴露对照组尿液中白蛋白、IgG和α(1)-微球蛋白浓度差异的结果表明，长期职业暴露于Hg(0)可能导致肾功能障碍。在职但不再暴露的矿工组中，尿液α(1)-微球蛋白与IEI以及尿液α(1)-微球蛋白与尿液汞峰值浓度总和之间的高度相关性表明，长期职业暴露于Hg(0)可能导致非永久性肾小管功能障碍。
