Elemental mercury in urine from workers exposed to mercury vapor

Summary Elemental mercury (Hg°) in urine samples from workers in thermometer manufacturing factories was determined. In a factory in which the mercury level in the ambient air averaged more than 0.1 mg Hg m^–3, the Hg° concentration in the workers' urine ranged between 0.05 and 1.7 g Hg 1^–1 and constituted less than 1% of the inorganic mercury (In-Hg) in urine. Higher amounts of Hg° could be detected in urine on the day of the filling operation when thermometer blanks were filled with metallic mercury and on the following day when compared with other days. During this operation, the workers were exposed to mercury vapor levels with as much as 0.47–0.67 mg Hg m^–3. Our findings suggest that Hg° appears in urine quite rapidly after the worker's exposure to unusually high mercury levels.     

现行《职业性汞中毒诊断标准》的应用研究

目的 观察慢性汞中毒引起肾损伤的临床表现,研究新修订的GBZ 89-2007(职业性汞中毒诊断标准>的应用价值.方法 对8例慢性职业性轻度汞中毒患者的临床表现、诊断、治疗及预后进行综合分析.结果 8例慢性轻度汞中毒患者主要的临床表现如尿汞增高、神经衰弱综合征、手指震颤,可伴舌、眼睑震颤和近端肾小管功能障碍如尿低相对分子质量蛋白含量增高等与现行<职业性汞中毒诊断标准>中轻度中毒的诊断指标相符,职业性慢性汞中毒引起的肾损伤以β2-微球蛋白含量的增加为主要表现,且与接触工龄间存在剂量-效应关系,驱汞治疗后可以逆转.结论 新修订的GBZ 89-2007在临床诊断应用中具有实用价值,慢性汞中毒引起的肾损伤应引起临床医生的高度重视.

Abstract：

Objective To investigate the clinical manifestation of patients with renal injury induced by chronic mercury intoxication and the application of the diagnostic criteria of occupational mercury poisoning. Methods The clinical data of 8 patients with chronic occupational mercury intoxication were analysed and evaluated. Results All the observed clinical signs of chronic mercury intoxication correspond with the items of the diagnostic criteria of occupational mercury poisoning. The increasing β2-MG was one of the clinical manifestations of renal injury induced by chronical mercury intoxication. The renal injury obviously was dose-dependent and reversible. Conclusions The national diagnostic criteria of occupational mercury poisoning is practically valuable. The renal injury induced by chronic mercury intoxication should not be neglected.     

慢性汞中毒患者脑脊液汞含量的探讨

目的分析慢性汞中毒患者脑脊液汞含量的变化,探讨汞的神经毒性机制。方法选择9例慢性汞中毒患者作为中毒组,8例非汞接触患者为对照组,用碱性氯化亚锡还原-冷原子吸收光谱法测定24 h尿汞(U-Hg)和脑脊液汞(CSF-Hg)含量,用酸陸氯化亚锡还原-冷原子吸收光谱法测定同一天的血汞(B-Hg)含量；5例慢性汞中毒患者作驱汞前后B-Hg、U-Hg和CSF-Hg含量比较。结果中毒组B-Hg、U-Hg含量[(250．00±48．54)、(160．07±91．15)nmol/L]均明显高于对照组[(81．04±63．01)、(24．73±9．96)nmol/L],差异有统计学意义(P＜0．01)；中毒组CSF-Hg含量为(20．22±10．21) nmol/L,对照组CSF-Hg未检出。5例慢性汞中毒患者用二巯丙磺酸钠作2～3疗程驱汞治疗,B-Hg、U- HC、CSF-Hg含量治疗前分别为(258．00±48．68)、(141．02±63．74)和(22．60±7．14)nmol/L,治疗后明显下降,分别为(172．00±68．34)、(39．22±11．83)和(11．32±4．92)nmol/L,差异有统计学意义(P＜0．05或P＜0．01)。中毒组CSF-Hg含量与B-Hg含量有相关关系(P＜0．05),与U-Hg含量无相关关系(P＞0．05),但驱汞治疗后,CSF-Hg含量的下降与B-Hg、U-Hg含量下降的相关性均无统计。结论慢性汞中毒患者CSF-Hg含量随外周血汞升高而升高,但与U-Hg含量无关；而驱汞治疗后,B-Hg、U-Hg含量已正常,但CSF-Hg含量仍较高,其可能为引起慢性汞中毒患者神经行为功能改变和震颤等临床表现的基础物质。     

A Review of Events That Expose Children to Elemental Mercury in the United States

Objective

Concern for children exposed to elemental mercury prompted the Agency for Toxic Substances and Disease Registry and the Centers for Disease Control and Prevention to review the sources of elemental mercury exposures in children, describe the location and proportion of children affected, and make recommendations on how to prevent these exposures. In this review, we excluded mercury exposures from coal-burning facilities, dental amalgams, fish consumption, medical waste incinerators, or thimerosal-containing vaccines.

Data sources

We reviewed federal, state, and regional programs with information on mercury releases along with published reports of children exposed to elemental mercury in the United States. We selected all mercury-related events that were documented to expose (or potentially expose) children. We then explored event characteristics (i.e., the exposure source, location).

Data synthesis

Primary exposure locations were at home, at school, and at other locations such as industrial property not adequately remediated or medical facilities. Exposure to small spills from broken thermometers was the most common scenario; however, reports of such exposures are declining.

Discussion and conclusions

Childhood exposures to elemental mercury often result from inappropriate handling or cleanup of spilled mercury. The information reviewed suggests that most releases do not lead to demonstrable harm if the exposure period is short and the mercury is properly cleaned up.

Recommendations

Primary prevention should include health education and policy initiatives. For larger spills, better coordination among existing surveillance systems would assist in understanding the risk factors and in developing effective prevention efforts.     

Inorganic and organic mercury in blood,urine and hair in low level mercury vapour exposure

Summary Fourteen Japanese females exposed to elemantal mercury vapour of concentration; 0.001–0.019 mg Hg/m³, were examined for inorganic and organic mercury concentrations in red blood cells, plasma, urine, and hair. Examinations were conducted the times; at 0,4 and 8 months of mercury exposure. No significant change of inorganic and organic mercury in urine was observed for three examinations. Both inorganic and organic mercury in plasma, and only organic mercury in red blood cells, increased significantly after commencement of mercury work. The hair organic mercury values stayed constant. The intake of organic mercury was judged as constant from the constancy of hair mercury values, and the change of organic mercury concentrations in plasma and red blood cells must have been elicited from the intake of elemental mercury. The reason why the increase of plasma mercury values did not reflect to urine mercury values was discussed.Supported by the grant from the Japanese Ministry of Education     

Reconstruction of occupational mercury exposures at a chloralkali plant

OBJECTIVE—To reconstruct historical workplace exposure to mercury (Hg) from 1956 to 1994 at a large chloralkali factory for use in a current epidemiology study of the factory.
METHODS—All job activities of the employees were classified into one of 16 exposure categories, and the dates of changes in the processes were identified. Exposures to Hg for each job category, at each period of the plant''s operation, were then reconstructed from several data sources. A job-time period-exposure matrix was created, and the individual exposures of former workers were calculated. Data on exposure to Hg in air were compared with modelled concentrations of Hg in air and data on urinary Hg of the employees.
RESULTS—Within an exposure category, concentrations of Hg in air were fairly constant for the first 20 years of the factory''s operation, but began to increase in the late 1970s. Employees working in the cell room had the greatest exposures to Hg. The exposure estimates had significant correlations (p<0.001) with the urinary data and were well within the modelled range of concentrations of Hg in air.
CONCLUSIONS—The highest exposures occurred from 1987 until the plant closed in early 1994 with some exposure categories having time weighted average exposures to Hg greater than 140 µg/m³.


     

汞中毒对心血管疾病影响的研究进展

汞是危害人类健康的重金属之一,人体内血液汞的水平与心血管疾病(cardiovascular diseases, CVDs)的发生发展密切相关,但目前我国关于汞与CVDs之间的报告甚少。本研究将从汞对心血管系统的影响、汞通过干扰心血管线粒体钙稳态、诱导心血管线粒体功能障碍、诱导心血管的氧化应激、诱导脂质过氧化、诱导心血管内皮损伤等机制促进CVD进展进行综述。     

Take-home lead poisoning in a child from his father's occupational exposure

With the publication of revised CDC guidelines in 1991, concern about childhood lead poisoning has increased. Exposure to lead-based paint and paint dust is currently considered the major source of lead poisoning in the United States. We describe a child who had elevated BLL related to lead-contaminated clothing that the father brought home from his workplace. © 1996 Wiley-Liss, Inc.     

Human co-exposure to mercury vapor and methylmercury in artisanal mercury mining areas, Guizhou, China

Mercury (Hg) concentrations were determined in human urine and hair samples from Gouxi (GX, n=25) and Laowuchang (LWC, n=18), Tongren, Guizhou, China, to evaluate human exposure from artisanal Hg mining. Geometric means of urinary Hg (U-Hg) were 216 and 560 μg g⁻¹ Creatinine (μg g⁻¹ Cr) for artisanal mining workers from GX and LWC, respectively, and clinical symptoms (finger tremor) were observed in three workers. The means of hair Me-Hg concentrations were 4.26 μg g⁻¹ (1.87-10.6 μg g⁻¹) and 4.55 μg g⁻¹ (2.29-9.55 μg g⁻¹) for the population in GX and LWC, respectively. Significant relationship was found between estimated rice Me-Hg intake and hair Me-Hg levels (r=0.73, p<0.001). Co-exposure to Hg vapor and Me-Hg may pose health risks for the study population.     

慢性汞中毒对凝血及纤溶系统的影响

目的探究慢性汞中毒对凝血、纤溶系统的影响及其可能的机制。方法采用病例对照及自身病例对照研究方法,采用酶联免疫吸附双抗体夹心法测定血栓调节蛋白(TM)、组织纤溶酶原激活物(t-PA)、组织纤溶酶原激活物抑制物(PAI)含量,并检测白细胞介素(IL)-13、IL-18、血管内皮细胞黏附因子(SICAM-1),采用酶化学法检测超氧化物歧化酶(SOD)活力和脂质过氧化产物(LPO)含量。结果慢性汞中毒患者治疗前TM[(2.36±0.16)ng/ml]较空白对照组[(4.36±0.24)ng/ml]明显降低,差异有统计学意义(P<0.01),经过治疗后,TM明显增高[(4.82±0.34)ng/ml],与治疗前的差异有统计学意义(P<0.05);慢性汞中毒患者t-PA[(3.44±0.34)ng/ml]较空白对照组[(4.52±0.16)ng/ml]明显降低,经过治疗后明显升高[(5.63±0.58)ng/ml],差异均有统计学意义(P<0.05);而PAI则较空白对照组明显升高,分别为(48.23±3.59)、(31.59±2.13)ng/ml,差异有统计学意义(P<0.05),治疗后与治疗前的差异无统计学意义(P>0.05)。慢性汞中毒患者SOD活力[(953.85±9.56)U/g Hb]较空白对照组[(1308.75±10.21)U/g Hb]明显降低,经过治疗后活力[(1217.95±6.29)U/g Hb]明显升高,差异均有统计学意义(P<0.05、P<0.01)。同时表现为LPO明显增加。慢性汞中毒患者IL-13、IL-18、SICAM-1较空白对照组明显升高,差异均有统计学意义(P<0.05、P<0.01),而治疗后与治疗前的差异无统计学意义(P>0.05)。结论慢性汞中毒可能导致患者TM/PC系统、t-PA/PAI系统失衡(抗凝血功能下降,纤溶系统功能抑制)而使机体处于继发性高凝血状态。     

Biological monitoring of environmental and occupational exposure to mercury

Summary Biological monitoring was used to assess mercury exposure from occupational and environmental sources in a group of chloralkali workers (n = 89) and in a control group (n = 75). In the control group, the median value for blood mercury (B-Hg) was 15 nmol/l, that for serum mercury (S-Hg) was 4 nmol/l and that for urinary mercury (U-Hg) was 1.1 nmol/mmol creatinine. Corresponding levels in the chloralkali group were 55 nmol/l, 45 nmol/l and 14.3 nmol/mmol creatinine, respectively. In the control group, there were statistically significant relationships between fish consumption and both B-Hg and S-Hg values (P < 0.001), whereas U-Hg correlated best with the individual amalgam burden (P < 0.01). In the chloralkali group, the mercury levels in blood and urine were significantly related to the type of work (P < 0.001) but not to the length of employment, to fish consumption or to the quantity of dental amalgam fillings. In both groups there were poor correlations between smoking or alcohol intake and the mercury levels in blood and urine. The results strongly suggest that fish is an important source of methylmercury exposure and that amalgam fillings are probably the most important source of inorganic mercury exposure among occupationally unexposed individuals. In the chloralkali group, mercury exposure from fish and amalgam was overshadowed by occupational exposure to inorganic mercury.     

职业接触汞生物限值的研制

对职业接触汞工人进行体检和尿汞检测,分析尿汞与工作场所空气中汞浓度及临床表现的关系,并参考国外职业接触汞的生物限值,提出我国职业接触汞的生物限值为尿总汞20μmol/mol Cr（35μg/g Cr）。     

不同接触途径所致急性亚急性汞中毒的分析研究

目的 研究不同接触途径所致急性、亚急性汞中毒的临床特点。方法将33例患者按汞进入体内途径的不同分为3组,即皮肤吸收组、呼吸道吸收组和消化道吸收组,分析其临床特点。结果急性汞中毒以周身中毒症状、口腔-牙龈炎症状及胃肠道症状为著,部分病人可有皮疹、呼吸道及肾脏受累;而神经．精神症状和震颤多不明显。3种不同接触途径所致中毒其临床表现各有特点,如皮肤接触起病者,以亚急性为主,皮疹较为突出;消化道吸收者急性起病,胃肠道症状较明显;呼吸道吸收者多急性起病,呼吸系统症状较突出等。结论3种不同接触途径所致中毒有许多共同点,但又有各自特点。     

Effect of occupational mercury exposure on plasma lysosomal hydrolases

Summary The activities of three plasma lysosomal hydrolases, -galactosidase, -glucuronidase and -N-acetylglucosaminidase, were studied in 20 workers exposed to metallic mercury vapor in a chlorine alkali plant and in 10 nonexposed referents. The urinary excretion and blood levels of mercury were determined on the day of study, and the history of mercury exposure was reviewed from the records of mercury concentrations in urine and blood over periods of up to 133 months. The average levels of -N-acetylglucosaminidase and -glucuronidase were higher in the plasma of exposed workers, but the difference was not significant. No significant positive correlation was seen between lyosomal enzyme activities and cumulative long-term exposure to mercury. It is concluded that measurement of plasma lysosomal hydrolase-activities is not of great value in the biological monitoring of workers exposed to low concentrations of metallic mercury vapor.In line with published data, the concentration of mercury showed a clearcut diurnal variation in nonexposed persons, persons currently exposed and persons with a history of past exposure. The excretion rate of mercury remained constant throughout the day.     

Clinical observations in ethyl mercury chloride poisoning

Forty-one patients in the Peoples Republic of China were poisoned by ethyl mercury chloride, caused by the ingestion of rice that had been treated with the chemical. A dose-response relationship was found. Five months after the onset of the intoxication, the patients were still in poor condition. They were treated with two chelating agents, sodium dimercaptopropane sulfonate (DMPS) and sodium dimercaptosuccinate (DMS), whose effects were compared. Both agents were effective but DMPS was superior. Although urinary excretion is not the best estimate of body burden in alkyl mercury intoxication, during chelation therapy urinary mercury was an effective indicator for diagnosis and assessment of the degree of intoxication. Chelation therapy was useful as long as the urinary mercury level was elevated.     

High exposure of Chinese mercury mine workers to elemental mercury vapor and increased methylmercury levels in their hair

Objective The aim of this study was to determine the level of exposure of mercury (Hg) miners and smelter workers to elemental mercury (Hg⁰) vapor in China, who work in Hg mines without using protective equipment against Hg⁰ vapor. In addition, the level of methylmercury (MeHg) intake by the workers was estimated from the MeHg concentration in their hair. Methods Urinary total mercury (THg) and hair THg and MeHg concentrations were measured in 26 Hg miners and smelter workers (i.e., exposed group), and 48 unexposed people (unexposed group). Results The exposed group showed high geometric mean THg concentrations in urine (258 ng/ml, 226 μg/g creatinine) and hair (20.0 μg/g). The urinary THg concentration of the smelter workers in particular was extremely high (338 μg/g creatinine in urine). The highest urine THg concentration reached 4577 μg/g creatinine. THg concentrations in urine and hair showed a significant correlation in the exposed group (r=0.62), indicating the adhesion of Hg⁰ vapor to hair. However, no such significant correlation was found in the unexposed group. Hair MeHg concentration in the exposed group (1.97 μg/g) was about threefold higher than that in the unexposed group (0.60 μg/g). Conclusions This study shows that smelter workers in a Chinese Hg mine are exposed to extremely high levels of Hg⁰ vapor, and that Hg miners are exposed to higher levels of MeHg than the unexposed subjects. Further study is needed to determine the cause of the higher hair MeHg concentration in the exposed group.     

Glutathione level after long-term occupational elemental mercury exposure

Many in vitro and in vivo studies have elucidated the interaction of inorganic mercury (Hg) and glutathione. However, human studies are limited. In this study, we investigated the potential effects of remote long-term intermittent occupational elemental Hg vapour (Hg degrees ) exposure on erythrocyte glutathione levels and some antioxidative enzyme activities in ex-mercury miners in the period after exposure. The study included 49 ex-mercury miners divided into subgroups of 28 still active, Hg degrees -not-exposed miners and 21 elderly retired miners, and 41 controls, age-matched to the miners subgroup. The control workers were taken from "mercury-free works". Reduced glutathione (GSH) and oxidized disulphide glutathione (GSSG) concentrations in haemolysed erythrocytes were determined by capillary electrophoresis, while total glutathione (total GSH) and the GSH/GSSG ratio were calculated from the determined values. Catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) activities in erythrocytes were measured using commercially available reagent kits, while urine Hg (U-Hg) concentrations were determined by cold vapour atomic absorption (CVAAS). No correlation of present U-Hg levels, GSH, GSSG, and antioxidative enzymes with remote occupational biological exposure indices were found. The mean CAT activity in miners and retired miners was significantly higher (p<0.05) than in the controls. No differences in mean GPx activity among the three groups were found, whereas the mean GR activity was significantly higher (p<0.05) in miners than in retired miners. The mean concentrations of GSH (mmol/g Hb) in miners (13.03+/-3.71) were significantly higher (p<0.05) than in the control group (11.68+/-2.66). No differences in mean total GSH, GSSG levels, and GSH/GSSG ratio between miners and controls were found. A positive correlation between GSSG and present U-Hg excretion (r=0.41, p=0.001) in the whole group of ex-mercury miners was observed. The significantly lower GSH level (p<0.05) determined in the group of retired miners (9.64+/-1.45) seems to be age-related (r= -0.39, p=0.001). Thus, the moderate but significantly increased GSH level, GR and CAT activity in erythrocytes in the subgroup of miners observed in the period after exposure to Hg degrees could be an inductive and additive response to maintain the balance between GSH and antioxidative enzymes in interaction with the Hg body burden accumulated during remote occupational exposure, which does not represent a severely increased oxidative stress.     

Occupational mercury exposure and male reproductive health

This retrospective cohort study was designed to investigate the relationship of male occupational exposure to elemental mercury and several reproductive outcomes. All subjects worked at least 4 months between 1953 and 1966 at a plant that used elemental mercury; 247 white male employees who had the highest exposures were compared to 255 matched nonexposed employees. Individual exposure to mercury was estimated from urinary mercury measurement records. Information on reproductive history and potential confounding variables was obtained through personal interview with each of the employees and with a subset of their wives. No associations were demonstrated between mercury exposure and decreased fertility or increased rates of major malformations or serious childhood illnesses. After controlling for previous miscarriage history, mercury exposure was not a significant risk factor for miscarriage. Because of this study's potential problems with long-term recall, further studies of the effect of mercury on pregnancy outcome are warranted in other populations.     

Electrophysiological evidence for impairment of contrast sensitivity in mercury vapor occupational intoxication

Contrast sensitivity (CS) was evaluated in 41 former workers from a lamp manufacturing plant who were on disability retirement due to exposure to mercury and 14 age-matched controls. The CS was measured monocularly using the sweep visual evoked potential (sVEP) paradigm at 6 spatial frequencies (0.2, 0.8, 2.0, 4.0, 15.0, and 30 cpd). Statistical difference (p<0.05) was found between the controls and the patient right and left eyes for 2.0 and 4.0 cpd. According the results in those spatial frequencies the eyes were classified in best and worst. Statistical differences were found between the controls and the best eyes for 2.0 and 4.0 cpd and for 0.8, 2.0, and 4.0 cpd for their worst eyes. No correlation was found between CS results and the time of exposure (mean=8.9 yr+/-4.1), time away from the mercury source (mean=6.0 yr+/-3.9), urinary mercury level at the time of work (mean=40.6 microg/g+/-36.3) or with the mercury level at the CS measurement time (mean=1.6 microg/g+/-1.1). We show the first evidence of a permanent impairment in CS measured objectively with the sVEP. Our data complement the previous psychophysical works reporting a diffuse impairment in the CS function showing a CS reduction in the low to middle spatial frequencies. In conclusion, non-reversible CS impairment was found in occupational exposure to mercury vapor. We suggest that CS measurement should be included in studies of the mercury effects of occupational exposure.     

Identifying occupational and nonoccupational exposure to mercury in dental personnel

The objective of this study was to investigate the occupational and nonoccupational exposure to mercury (Hg) vapor in dental personnel by examining the relationships between blood mercury, urine mercury, and their ratio with air mercury. The method was performed on 50 occupational exposed and 50 unexposed controls (25 men and 25 women). The mercury concentrations in air and human biological samples were determined based on the National Institute for Occupational Safety and Health (NIOSH) method and standard method (SM) by a new mode of liquid-phase microextraction, respectively. The mean mercury concentrations in urine (μg Hg⁰/g creatinine) and blood were significantly higher than control group, respectively (19.41 ± 5.18 vs 2.15 ± 0.07 μg/g and 16.40 ± 4.97 vs 2.50 ± 0.02 μg/L) (p <.001). The relationships between mercury concentration in blood/urine ratio (r = .380) with dental office air are new indicators for assessing occupational exposure in dental personnel.