Renal tubular function of workers exposed to low levels of cadmium.

Cadmium induced renal tubular effects were examined in 65 female workers in a factory manufacturing nickel cadmium batteries. Urinary beta 2-microglobulin (beta 2m), urinary N-acetyl-D-glucosaminidase activity (NAG), and serum creatinine and serum urea concentrations were used to assess the renal effects. Of the four measures, only urinary NAG and urinary beta 2m showed a strong positive correlation with blood cadmium concentrations (r = 0.49 and 0.43 respectively); NAG showed a weaker correlation with urinary cadmium concentrations (r = 0.35). Urinary beta 2m has weak correlation with urinary cadmium (r = 0.04). Only urinary NAG showed a significant deterioration in renal function among the exposed group. NAG detects the largest proportion of abnormalities among the exposed group. Abnormal urinary beta 2m is detected in only 15.4% of the workers, half of whom have blood cadmium above 10 micrograms/l. The proportion of abnormalities detected by urinary NAG differs significantly from the proportion of abnormalities detected by urinary beta 2m (p less than 0.01). The age adjusted mean urinary NAG excretion showed a significant rise with urinary cadmium of above 3 micrograms/g creatinine. Urinary beta 2m failed to show any significant rise. With blood cadmium concentrations, the age adjusted mean urinary NAG excretion showed a rise from 1 microgram/l of blood cadmium followed by a plateau between blood cadmium concentrations of 3-10 micrograms/l. No significant rise in mean urinary excretion in beta 2m was seen until blood cadmium concentrations exceeded 10 micrograms/l.     

镉砷接触工人肾功能损伤研究

目的　探讨镉、砷对作业工人肾功能的联合作用。方法　以我国中南某厂镉、砷作业工人 114名为本研究的职业接触对象。以尿镉 (UCd)、尿砷 (UAs)作为接触标志物 ,尿 β2 微球蛋白(Uβ2 MG)、尿白蛋白 (UALB)、尿N 乙酰 β D 氨基葡萄糖苷酶 (UNAG)作为镉、砷致肾小管和肾小球损害的效应标志物。结果　UCd、UAs水平与Uβ2 MG、UALB、UNAG水平间均为正相关 ,具有明显的剂量-效应关系 (P <0 .0 5 ,P <0 .0 1)。结论　镉、砷对作业工人肾脏功能的联合作用主要表现为相加作用。     

Pulmonary function in workers exposed to low levels of fuel-oil ash

Previously, we reported significant lung function changes after exposure to fuel-oil ash during a boiler overhaul in which median PM10 and vanadium concentrations were 2.9 mg/m3 and 11.9 micrograms/m3, respectively. In this study, we examined prospectively 18 boilermakers involved in the short-term, partial overhaul of a large, oil-fired boiler where occupational exposures to PM10 and metals were relatively low. Vanadium and PM10 exposure levels were measured before and during boiler work. For PM10, median exposure before and during boiler work was 0.5 and 0.6 mg/m3, respectively. For vanadium, median exposure before and during boiler work was 1.0 and 12.7 micrograms/m3, respectively, comparable with the results of our previous study. Spirometric (PFT) testing was done three times: first day on the job (PFT1), end of overhaul (PFT2), and 2 weeks post-overhaul (PFT3). Spirometry results were analyzed using repeated measures analysis of variance. No significant differences were found. Boilermakers working on a short-term overhaul of an oil-fired boiler exhibited no significant change in any lung function parameter comparing pre-, during, and 2 weeks post-exposure. The comparatively low levels of exposure to PM10 and vanadium observed during boiler work, the short duration of the overhaul, and the healthy worker effect are possible explanations for these results.     

镉作业工人的肾脏功能变化

对镉作业工人的肾脏损害进行了探讨,结果表明尿镉低于临界值（5.05μg/gCr),尿中β2-MG、AKP、LDH已显著高于对照组;尿镉高于临界值,尿中β2-MG、AKP、LDH、γ-GT、NAG均升高,建议将β2-MG、AKP、LDH联合应用作为镉作业工人早期检测指标。     

Assessment of renal function in workers previously exposed to cadmium

Cadmium induced renal effects were examined in 60 workers (58 men, 2 women) previously exposed to cadmium. Tubular damage in the form of beta 2-microglobulinuria was found in 40%, and urinary albumin and orosomucoid increased significantly with increasing urinary cadmium and increasing relative clearance of beta 2-microglobulin. It is suggested that increased albumin excretion is secondary to the tubular damage. In no case was typical glomerular proteinuria found that could be related to cadmium. Histories of renal stones were more common among the workers with high urinary cadmium concentrations. The glomerular filtration rate was measured in 17 of the workers who had pronounced tubular dysfunction. The average glomerular filtration rate for these men was less than the age adjusted predicted value (mean = 84%). Furthermore, there was a significant (p less than 0.05) correlation (r = -0.47) between tubular reabsorption loss and a decreased glomerular filtration rate.     

Renal function in dry cleaning workers exposed to perchloroethylene

Perchloroethylene (PCE) is a widely used dry cleaning and degreasing solvent. Although there is evidence in animals and humans for renal effects at extremely high doses, there are few studies of its potential renal toxicity at typical occupational concentrations. This study reports on the relationship of PCE in breath and estimates of chronic exposure with the urinary ratios of total urinary protein, albumin, and n-acetyl-glucosaminidase (NAG) to creatinine in dry cleaning workers exposed to PCE. Regression models including one or more exposure variables, demographic variables, mean arterial blood pressure (MAP), and the presence of diseases affecting kidney function were examined. Urine samples, breath samples, exposure histories, and medical histories were obtained from 192 dry cleaning workers. The results failed to demonstrate any consistent relationship between exposure and renal outcome variables. However, protein/creatinine and albumin/creatinine were significantly, although weakly and positively, associated with MAP; NAG/creatinine was weakly but significantly positively associated with age; mean NAG/creatinine was also higher in non-whites. The reasons why an association between exposure and renal outcome was not found are discussed.     

Urinary protein excretion in workers exposed to low doses of cadmium

Conclusions There was evidence of mild renal dysfunction in three of the cadmium-exposed individuals out of the total of 39. However, in none of them did we find a fully developed tubular proteinuria in which moderate increases of total proteinuria, increased lysozymuria and beta-2 microglobulinuria, and excretion of low molecular weight proteins by SDS-PAGE would also be found.Out of the four parameters determined, only one patient had three of them in the abnormal range, but this patient showed predominant elimination of high molecular weight proteins, compatible with glomerular damage, an unexpected finding in cadmium poisoning. Renal dysfunction was detected in one control subject who had increased total protein classified as tubular. There were two abnormal SDS-PAGE patterns found in the control group in which the other parameters measured were normal as was the case in the cadmium exposed patients.     

Renal function of workers with low-level cadmium exposure

The influence of occupational exposure to cadmium on renal function was examined in 27 male cadmium workers from plants with second-degree usage of cadmium. The levels of cadmium in the blood and urine and various protein concentrations in the urine and serum were determined. The urinary levels of beta 2-microglobulin, retinol-binding protein, and N-acetyl-beta-D-glucosaminidase were statistically significantly increased in workers with urinary cadmium levels above 50 nmol/l. SDS-PAGE electrophoresis with silver staining is probably a sensitive indicator of the early effects of cadmium on protein excretion. The currently recommended biological exposure limits may have to be lowered.     

Assessment of renal function in workers previously exposed to cadmium.

Cadmium induced renal effects were examined in 60 workers (58 men, 2 women) previously exposed to cadmium. Tubular damage in the form of beta 2-microglobulinuria was found in 40%, and urinary albumin and orosomucoid increased significantly with increasing urinary cadmium and increasing relative clearance of beta 2-microglobulin. It is suggested that increased albumin excretion is secondary to the tubular damage. In no case was typical glomerular proteinuria found that could be related to cadmium. Histories of renal stones were more common among the workers with high urinary cadmium concentrations. The glomerular filtration rate was measured in 17 of the workers who had pronounced tubular dysfunction. The average glomerular filtration rate for these men was less than the age adjusted predicted value (mean = 84%). Furthermore, there was a significant (p less than 0.05) correlation (r = -0.47) between tubular reabsorption loss and a decreased glomerular filtration rate.     

Ventilatory function in workers exposed to low levels of toluene diisocyanate: a six-month follow-up

Peters, John M., Murphy, Raymond L. H., and Ferris, Benjamin, G., Jr. (1969).Brit. J. industr. Med.,26, 115-120. Ventilatory function in workers exposed to low levels of toluene diisocyanate: a six-month follow-up. Thirty-four workers exposed to toluene diisocyanate during production of polyurethane foam were examined with a respiratory questionnaire and tests of ventilatory capacity. The tests of pulmonary function were conducted on Monday morning and afternoon and on Tuesday morning and afternoon. Twenty-eight of these 34 workers had been examined with the same tests six months earlier. On Monday a mean change in the one-second forced expiratory volume (F.E.V._1·0) of –0·16 l. occurred that did not return to the baseline value (Monday a.m.) on Tuesday morning. A statistically significant decrease in all the measurements of ventilatory capacity except the forced vital capacity occurred over the six months in the 28 workers. The F.E.V._1·0 fell an average of 0·14 l. and flow rates at 75%, 50%, 25%, and 10% of vital capacity also decreased significantly. There was a highly significant correlation coefficient (r = 0·72) between one-day changes in F.E.V._1·0 (measured six months earlier) and six-month changes in F.E.V._1·0. Workers with respiratory symptoms (cough and/or phlegm) demonstrated greater falls in F.E.V._1·0 than did asymptomatic workers.

All air concentrations of toluene diisocyanate measured during this study were below the threshold limit value (0·02 p.p.m.).

     

镉接触工人体内血清性激素水平的变化

目的 探讨镉接触工人体内血清性激素水平的变化及其机制。方法 选取南方某冶炼厂镉接触工人及当地健康男性为调查对象,经空气采样测定各车间空气中镉的浓度,用原子吸收分光光度法测定尿镉,并经肌酐校正作为调查对象体内镉负荷的生物标记物;同时测定工人体内性激素水平,并进行镉接触的剂量－效应评定。结果 在控制年龄等混杂因素后,血清睾酮水平随镉接触水平的增高而呈升高趋势,其中尿镉为10．9－21．9μmol/mol肌酐及＞21．9μmol/mol肌酐组的睾酮水平分别为：13．00nmol／L和11．37nmol／L,与0．0－2．2μmol/mol肌酐组的9．31nmol／L比较,差异有显著性;电解车间及尿镉＞21．9μmol/mol肌酐组人的血清黄体生成素水平分别为4．11U／T和4．32U／L,显著同于对照组的2．52U／L和尿镉0．0－2．2μmol/mol肌酐组的2．64U／L。结论 镉接触能引起工人血清性激素水平的变化。     

Biological monitoring of workers exposed to low levels of 2-butoxyethanol

Objectives: (1) To assess the value of urinary butoxyacetic acid (BAA) measurement for the monitoring of workers exposed to low concentration of 2-butoxyethanol (BE); (2) to evaluate the in vivo effect of low occupational BE exposure on the erythrocyte lineage; and (3) to test the possible influence of genetic polymorphism for cytochrome P450 2E1 (CYP 2E1) on urinary BAA excretion rate. Methods: Thirty-one male workers exposed to BE in a beverage package production plant were examined according to their external (BE) and internal (BAA) solvent exposure. The effect of this exposure on erythrocyte lineage [red blood cell numeration (RBC), hemoglobin (Hb), hematocrit (Htc), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), haptoglobin (Hp), reticulocyte numeration (Ret) and osmotic resistance (OR)], hepatic [aspartate aminotransferase (GOT), alanine aminotransferase (GPT)] and renal [plasmatic creatinine, urinary retinol binding protein (RBP)] parameters was also investigated. DNA purified from whole blood was used for CYP 2E1 genotyping. Results: Average airborne concentration of BE was 2.91 mg/m³ (0.59 ppm) with a standard deviation of 1.30 mg/m³ (0.27 ppm). There was a relatively good correlation between external and internal exposure estimated by measuring BAA in post-shift urine samples (average 10.4 mg/g creatinine; r=0.55;P=0.0012). Compared with a matched control group (n=21) exposed workers had a statistically significant decrease (3.3%;P=0.03) in Hct while MCHC was increased (2.1%;P=0.02). No significant difference was observed either in other erythroid parameters or in hepatic and renal biomarkers. One exposed individual exhibited a mutant allele with increased cytochrome P450 oxidative activity which coincided with a very low urinary BAA excretion. Conclusions: Single determination of BAA in post-shift urine samples can be used to assess exposure to low levels of BE. A slight but significant effect on erythroid parameters suggesting membrane damage was observed in exposed workers. The influence of the genetic polymorphism for CYP 2E1 deserves further investigation for the interpretation of urinary BAA measurements. Received: 6 December 1996 / Accepted: 21 February 1997     

Abnormal liver function in workers exposed to low levels of ethylene dichloride and vinyl chloride monomer

We investigated whether exposure to ethylene dichloride (EDC) and vinyl chloride monomer (VCM) resulted in increased risk of liver damage. Epidemiological information, including occupational, medical, smoking, and drinking history, was obtained by interview from 251 male workers. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyltransferase (GGT) were used as indicators of liver damage. Exposure to moderate or low levels of ECD and VCM resulted in a higher risk of developing abnormal ALT levels than did exposure to lower levels of the chemicals. Results were similar for AST. GGT was not associated with EDC or VCM exposure. Combined exposure to EDC and VCM showed a dose-response relationship in association with abnormal ALT levels. We concluded that relatively low concentrations of VCM and EDC cause liver damage.     

镉作业工人尿低分子质量蛋白的研究

目的探索职业性慢性镉中毒性肾病的诊断指标.方法以职业接触镉工人139例(现职工人109名,已脱离镉作业工人30名)和无毒物接触史的健康成人100例为研究对象,分别测定血镉和尿镉以及尿β2-微球蛋白、视黄醇结合蛋白、α1-微球蛋白和白蛋白含量,并统计分析测定结果.结果现职工人尿β2-微球蛋白、视黄醇结合蛋白和α1-微球蛋白异常增高者分别为18、16和13例,脱镉工人分别为7、6和7例;3项指标的异常增高检出率经配对卡方检验,两两之间差异均无显著性(P＞0.05),尿视黄醇结合蛋白和α1-微球蛋白在检测镉中毒性肾损害上与尿β2-微球蛋白几乎具有相同的灵敏性.结论尿β2-微球蛋白、视黄醇结合蛋白和α1-微球蛋白均可作职业性镉中毒所引起肾功能障碍的诊断指标.     

Audiometric findings in workers exposed to low levels of styrene and noise

Audiometry and exposure measurements were conducted on workers from fiberglass and metal products manufacturing plants and a mail distribution terminal (N = 313). Workers exposed to noise and styrene had significantly worse pure-tone thresholds at 2, 3, 4, and 6 kHz when compared with noise-exposed or nonexposed workers. Age, noise exposure, and urinary mandelic acid (a biologic marker for styrene) were the variables that met the significance level criterion in the multiple logistic regression. The odds ratios for hearing loss were 1.19 for each increment of 1 year of age (95% confidence interval [CI], 1.11-1.28), 1.18 for every decibel >85 dB(A) of noise exposure (95% CI, 1.01-1.34), and 2.44 for each millimole of mandelic acid per gram of creatinine in urine (95% CI, 1.01-5.89). Our findings suggest that exposure to styrene even below recommended values had a toxic effect on the auditory system.     

Genotoxic effects in workers exposed to low levels of benzene from gasoline

To study genotoxic effects of exposure to low levels of benzene, single-strand breaks (SSB) in DNA of leukocytes and urinary levels of the oxidative DNA adduct 8-hydroxydeoxyguanosine (80HdG) were determined in 33 men occupationally exposed to benzene from gasoline and in 33 controls. The average exposure to benzene over a shift was determined by personal air sampling in the breathing zone. The 8-hr time-weighted average exposure to benzene was 0.13 ppm (mean value, range 0.003–0.6 ppm). Exposed workers had a significant increase of SSB (p = 0.04) over the shift compared with controls. Storage time of the samples seemed to affect the results. An analysis of samples with the same storage time showed a nonsignificant increase among the workers compared with controls. Urinary 80HdG increased over the shift among the exposed workers but not among the controls. The highest values among the exposed workers were seen in late evening, with a slight decrease the next morning. Multiple linear analysis adjusting for smoking habits showed a significant association between the exposure level of benzene during the shift and the increase of 80HdG in the urine over the shift among exposed workers (p = 0.02). These findings indicate a genotoxic effect in humans of benzene at relatively low exposure levels, that is, about 0.1 ppm (0.3 mg/m³). © 1996 Wiley-Liss, Inc.     

镉接触工人尿镉含量水平影响因素分析

目的分析镉接触工人尿镉含量的影响因素。方法选取深圳市3家镍-镉电池厂镉接触工人375名为接触组,另选取153名未接触镉的上岗前工人作为对照组,分析两组人群的尿镉含量水平,同时对3间镍-镉电池厂工作场所进行职业卫生学调查。结果工作场所空气中氧化镉短时间接触浓度平均为0.027 mg/m3,超标率为37.0%;接触组尿镉含量为(3.36±2.43)μmol/molCr,明显高于对照组[(2.09±1.74)μmol/molCr](P<0.01),接触组女性尿镉含量为(3.68±2.92)μmol/molCr,明显高于男性接触组[(2.76±2.21)μmol/molCr](P<0.01);高浓度组尿镉含量[(3.79±3.41)μmol/molCr]明显高于低浓度组[(2.82±2.12)μmol/molCr](P<0.01),高浓度接触组尿镉异常率(21.9%)也高于低浓度接触组(7.7%)(P<0.01);多元线性回归分析结果显示,工龄、工种(接触浓度)、年龄、性别与尿镉含量的相关系数依次为0.559、0.266、0.233和0.092(均P<0.05)。结论工龄增加、工作场所氧化镉浓度超标是尿镉增高的主要危险因素,降低氧化镉浓度至职业接触限值以下和减少接触时间是预防慢性镉中毒的关键。