Urinary beta 2 microglobulin in the biological monitoring of cadmium workers.

Urinary beta 2 microglobulin (beta 2m) estimation has been added to an existing pre-employment and periodic medical surveillance programme for cadmium workers. Pre-employment values were measured in 203 men not occupationally exposed to cadmium. The overall geometric mean was 76 microgram/l (adjusted to specific gravity 1016): a significantly higher level of 96 microgram/l was found in the specimens stored continually at -20 degrees C after voiding, compared with 73 microgram/l in specimens that thawed during transport. Sodium azide had been added to all specimen bottles. Employees exposed to cadmium pigments at various stages of their manufacture had no evidence of raised urinary beta 2m despite exposures above 50 microgram/m3 for up to 11 years. This is believed to be due to the insolubility of the compounds. Five known cases of cadmium induced proteinuria whose exposure ceased up to 15 years ago had raised urinary beta 2m concentrations. Moderately raised concentrations were found in seven others with a history of cadmium oxide exposure and in whom proteinuria has never been detected. The place of urinary beta 2m in the health care of cadmium workers is discussed and the question of correct management of a cadmium worker with a high beta 2m is raised.     

Urinary beta 2 microglobulin in the biological monitoring of cadmium workers

Urinary beta 2 microglobulin (beta 2m) estimation has been added to an existing pre-employment and periodic medical surveillance programme for cadmium workers. Pre-employment values were measured in 203 men not occupationally exposed to cadmium. The overall geometric mean was 76 microgram/l (adjusted to specific gravity 1016): a significantly higher level of 96 microgram/l was found in the specimens stored continually at -20 degrees C after voiding, compared with 73 microgram/l in specimens that thawed during transport. Sodium azide had been added to all specimen bottles. Employees exposed to cadmium pigments at various stages of their manufacture had no evidence of raised urinary beta 2m despite exposures above 50 microgram/m3 for up to 11 years. This is believed to be due to the insolubility of the compounds. Five known cases of cadmium induced proteinuria whose exposure ceased up to 15 years ago had raised urinary beta 2m concentrations. Moderately raised concentrations were found in seven others with a history of cadmium oxide exposure and in whom proteinuria has never been detected. The place of urinary beta 2m in the health care of cadmium workers is discussed and the question of correct management of a cadmium worker with a high beta 2m is raised.     

Tremor in workers with low exposure to metallic mercury

In a fluorescent lamp production factory, a newly developed lightweight balance-tremormeter was used to measure postural tremor of the finger in 21 workers (ages 28 to 61) exposed for 0.5-19 yr to metallic mercury. In addition, tremor was measured in an indirect way by means of a "hole-tremormeter." The excretion of mercury in urine was 9-53 (average 20) mumol/mol creatinine. With increasing mercury excretion, the following parameters increased: the acceleration of the tremor, the contribution of the neuromuscular component (8-12 Hz) to the power spectrum of the acceleration, the width of the power-spectrum and the score on the hole-tremormeter. The study indicates that exposure to metallic mercury below the current TLV (50 micrograms/m3) may increase the tremor of the finger.     

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.     

估算综采工煤尘接触量的探讨

本文利用煤矿综采工作面各工种作业工人在各种工作状态下工作地点的粉尘环境浓度和持续时间,采用时间加权粉尘浓度,结合职业史及出勤率,推算各工种及每个操作工人的实际接尘量,可反映各工种受粉尘危害的严重程度,考虑较全面。结果较为合理、准确。     

Pulmonary function in workers with chronic exposure to cadmium oxide fumes

Summary Detailed pulmonary function studies were carried out on 11 workers of middle age, who had been exposed for 7 to 11 years to moderate concentrations of cadmium oxide. Minor abnormalities of lung volumes, intrapulmonary mixing and lung compliance were found in a few cases; no airway obstruction was present. The lung diffusing capacity and the blood gases were normal. The chest roentgenogram showed a normal vascular pattern at the periphery of the lung. It is concluded that emphysema was absent in the group studied.     

Assessment of the permissible exposure level to manganese in workers exposed to manganese dioxide dust.

The prevalence of neuropsychological and respiratory symptoms, lung ventilatory parameters, neurofunctional performances (visual reaction time, eye-hand coordination, hand steadiness, audioverbal short term memory), and several biological parameters (calcium, iron, luteinising hormone (LH), follicle stimulating hormone (FSH), and prolactin concentrations in serum, blood counts, manganese (Mn) concentration in blood and in urine) were examined in a group of workers (n = 92) exposed to MnO2 dust in a dry alkaline battery factory and a matched control group (n = 101). In the battery plant, the current exposure of the workers to airborne Mn was measured with personal samplers and amounted on average (geometric mean) to 215 and 948 micrograms Mn/m3 for respirable and total dust respectively. For each worker, the lifetime integrated exposure to respirable and total airborne Mn dust was also assessed. The geometric means of the Mn concentrations in blood (MnB) and in urine (MnU) were significantly higher in the Mn exposed group than in the control group (MnB 0.81 v 0.68 microgram/100 ml; MnU 0.84 v 0.09 microgram/g creatinine). On an individual basis, MnU and MnB were not related to various external exposure parameters (duration of exposure, current exposure, or lifetime integrated exposure to airborne Mn). On a group basis, a statistically significant association was found between MnU and current Mn concentrations in air. No appreciable difference between the exposed and the control workers was found with regard to the other biological measurements (calcium, LH, FSH, and prolactin in serum). Although the erythropoietic parameters and serum iron concentration were in the normal range for both groups, there was a statistically significant trend towards lower values in the Mn exposed workers. The prevalences of reported neuropsychological and respiratory symptoms, the lung function parameters, and the audioverbal short term memory scores did not differ between the control and exposed groups. The Mn workers, however, performed the other neurofunctional tests (visual reaction time, eye-hand coordination, hand steadiness) less satisfactorily than the control workers. For these tests, the prevalences of abnormal results were related to the lifetime integrated exposure to total and respirable Mn dust. On the basis of logistic regression analysis it may be inferred that an increased risk of peripheral tremor exists when the lifetime integrated exposure to Mn dust exceeds 3575 or 730 micrograms Mn/m3 x year for total and respirable dust respectively. The results clearly support a previous proposal by the authors to decrease the current time weighted average exposure to Mn dust.     

Assessment of the permissible exposure level to manganese in workers exposed to manganese dioxide dust.

The prevalence of neuropsychological and respiratory symptoms, lung ventilatory parameters, neurofunctional performances (visual reaction time, eye-hand coordination, hand steadiness, audioverbal short term memory), and several biological parameters (calcium, iron, luteinising hormone (LH), follicle stimulating hormone (FSH), and prolactin concentrations in serum, blood counts, manganese (Mn) concentration in blood and in urine) were examined in a group of workers (n = 92) exposed to MnO2 dust in a dry alkaline battery factory and a matched control group (n = 101). In the battery plant, the current exposure of the workers to airborne Mn was measured with personal samplers and amounted on average (geometric mean) to 215 and 948 micrograms Mn/m3 for respirable and total dust respectively. For each worker, the lifetime integrated exposure to respirable and total airborne Mn dust was also assessed. The geometric means of the Mn concentrations in blood (MnB) and in urine (MnU) were significantly higher in the Mn exposed group than in the control group (MnB 0.81 v 0.68 microgram/100 ml; MnU 0.84 v 0.09 microgram/g creatinine). On an individual basis, MnU and MnB were not related to various external exposure parameters (duration of exposure, current exposure, or lifetime integrated exposure to airborne Mn). On a group basis, a statistically significant association was found between MnU and current Mn concentrations in air. No appreciable difference between the exposed and the control workers was found with regard to the other biological measurements (calcium, LH, FSH, and prolactin in serum). Although the erythropoietic parameters and serum iron concentration were in the normal range for both groups, there was a statistically significant trend towards lower values in the Mn exposed workers. The prevalences of reported neuropsychological and respiratory symptoms, the lung function parameters, and the audioverbal short term memory scores did not differ between the control and exposed groups. The Mn workers, however, performed the other neurofunctional tests (visual reaction time, eye-hand coordination, hand steadiness) less satisfactorily than the control workers. For these tests, the prevalences of abnormal results were related to the lifetime integrated exposure to total and respirable Mn dust. On the basis of logistic regression analysis it may be inferred that an increased risk of peripheral tremor exists when the lifetime integrated exposure to Mn dust exceeds 3575 or 730 micrograms Mn/m3 x year for total and respirable dust respectively. The results clearly support a previous proposal by the authors to decrease the current time weighted average exposure to Mn dust.     

Seasonal exposure to dust in flax processing in Egypt.

Previous evidence suggested that interruption of worker's exposure to flax dust may lead to severe symptoms of byssinosis on their return to work. In the present study, the prevalence and severity of byssinosis was studied in a sample of flax workers (n=577) who had been exposed to dust for six months each year. Byssinosis prevailed in 36.9% of them, and 32.3% of them had their FEV 1.0 sec reduced 10% at the end of the first morning work period (4 to 6 hours) of the week. Both syndromes were higher among seasonal workers than what would be predicted if they were pemanently exposed to flax dust. A hypothesis has been presented to interpret this finding.     

地质勘探行业工人粉尘暴露水平的调查

目的　确定地质勘探行业粉尘危害程度。方法　对地质勘探行业接触粉尘工种 ,采用国产个体呼吸性粉尘采样器采集、测定呼吸性粉尘浓度、总粉尘浓度和粉尘中游离二氧化硅 (FSiO2 )含量 ,并与历年接尘点的呼吸性粉尘浓度测定结果进行比较。结果　 9个省 (自治区 )地质勘探行业的765个接触矽尘作业点中 ,呼吸性粉尘浓度超标率为 47.95 % ;呼吸性粉尘浓度最高的作业和工种是从事地质勘探作业的刻槽取样工种 ,1 996～ 2 0 0 0年其呼吸性粉尘浓度为 (6 .1 5± 3 .2 1 )mg/m3;地质勘探行业工人接触的呼吸性粉尘占总粉尘的比例高 ,粉尘中FSiO2 含量高。结论　地质勘探行业某些工种呼吸性粉尘暴露水平明显高于国家卫生标准 ,尤其是刻槽取样工和凿岩工。     

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。     

Urinary excretion of cadmium, copper and zinc in workers exposed to cadmium

Changes in urinary cadmium, copper and zinc excretion in workers who had considerable exposure to cadmium oxide fumes were investigated over a 5-year period following the cessation of exposure. The 22 male subjects aged 22 to 55 had been welders on automobile parts for periods ranging from 7 months to 23 years, using silver solder which contained cadmium. They were divided into three groups according to levels of urinary cadmium in the first medical examination in 1975: 5 in the high excretion group, 11 in the moderate group, and 6 in the low group. Renal tubular dysfunctions were indicated in most workers in the high excretion group but not in the other two groups. The high and moderate groups showed a rapid decrease in the levels of urinary-excreted cadmium, with biological half-times of 1.42 and 1.21 years, respectively. Excreted cadmium levelled off in the two groups about 1.7 and 1.5 years after the last exposure. Urinary copper excretion in the high cadmium excretion group was about twice that in the moderate and low groups, the difference being statistically significant in comparison with the controls. Urinary zinc excretion was high in all subjects immediately after cessation of exposure but decreased rapidly. After three years it was found that the reduction of urinary zinc was greatest in the high cadmium group. Urinary cadmium showed significant correlations with both copper and zinc. Urinary copper showed a negative correlation with zinc excretion in the high cadmium excretion group and a significant positive correlation in the other two groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

Urinary cadmium and lead concentrations and their relation to blood pressure in a population with low exposure.

The 24 hour urinary excretion of cadmium (U-Cd) and lead (U-Pb), and the excretion of beta-2- microglobulins and retinol binding protein concentration in spot urines, were determined in a random 4% sample of the population of a small Belgian town. Blood pressure and body weight were measured on two separate occasions. U-Cd averaged 2.4 nmol/24 h in 46 youths, increased with age, and was significantly higher in 57 adult men as compared with 59 women (9.3 v 7.2 nmol/24 h; p less than 0.01). U-Pb averaged 28 nmol/24 h in youths and similarly increased with age: adult men excreted more lead than women (64 v 40.0 nmol/24 h; p less than 0.001). Among men, manual workers excreted more cadmium (12.6 v 7.5 nmol/24 h; p less than 0.05) but a similar amount of lead (62 v 61 nmol/24 h) compared with office workers. After adjusting for sex and age, U-Cd and U-Pb were not related to body weight and cigarette consumption. In simple regression analysis, U-Cd was positively correlated with both systolic (r = +0.30; p less than 0.05) and diastolic (r = +0.38; p less than 0.01) blood pressure in women. After adjusting for other contributing variables, however, a weak but negative relation became apparent between systolic pressure and U-Cd in women (t = -2.21; p = 0.033) and between diastolic pressure and U-Cd in men (t = -2.04; p = 0.047). In women urinary beta-2-microglobulin was related to diastolic pressure (r-0.44; p<0.01) and after adjusting for age to both systolic (t=2.75; p=0.009) and diastolic (t=-3.07; p=0.004) pressure. In none of the sex-age groups did U-Pb and retinol binding protein contribute to the blood pressure variability.     

Effects of low level exposure to lead on neurophysiological functions among lead battery workers.

OBJECTIVES: Assessment of neurophysiological functions in workers with low level exposure to lead and evaluation of the efficacy of bone lead measurements in the prediction of effects of lead. METHODS: Exposure to lead of 60 workers from a lead battery battery factory was estimated from historical blood lead measurements and analysis of lead in the tibial and calcaneal bones with x ray fluorescence. Peripheral and central nervous system functions were assessed by measuring conduction velocities, sensory distal latencies, sensory amplitudes, and vibration thresholds as well as by quantitative measurement of the absolute and relative powers and mean frequencies of different electroencephalograph (EEG) channels. RESULTS: Sensory amplitudes, and to a smaller degree sensory or motor conduction velocities, showed a negative correlation with long term exposure to lead, most clearly with integrated blood lead concentration and exposure time. Vibration thresholds measured in the arm were related to recent exposure to lead, those measured in the leg to long term exposure. The alpha and beta activities of the EEG were more abundant in subjects with higher long term exposure to lead. Calcaneal lead content reflected short term exposure, tibial lead content reflected long term exposure. Blood lead history showed a closer relation with effects of lead than the tibial or calcaneal lead concentrations. CONCLUSIONS: Vibratory thresholds, quantitative EEG, and to a smaller extent the sensory amplitude, provide sensitive measures of effects of lead in occupationally exposed adults. Most accurate estimates of health risks induced by lead can be obtained from a good history of blood lead measurements. If such a history of blood lead concentrations is not available, analysis of bone lead may be used for the assessment of health risks.     

Nephropathy in cadmium workers: assessment of risk from airborne occupational exposure to cadmium.

To assess the quantitative relation between exposure to airborne cadmium and various markers of renal tubular and glomerular function, 45 male workers employed at a plant that recovers cadmium from industrial waste and 32 male hospital workers of similar age and geographical location were examined. Cumulative external exposure to airborne cadmium (dose) was estimated from historical air sampling data, adjusted for respirator use. Increasing cadmium dose was associated with multiple renal tubular functional abnormalities, including reduced reabsorption of beta-2-microglobulin (beta-2), retinol binding protein (RBP), calcium, and phosphate. Serum creatinine concentration also increased with cadmium dose, suggesting impaired glomerular function. Mean systolic and diastolic blood pressures were higher in the cadmium workers than in the unexposed (134 v 120 mm Hg and 80 v 73 mm Hg respectively), but only systolic blood pressure was significantly associated with cadmium dose in multivariate analyses. Cadmium dose remained the most important predictor of serum creatinine concentration after controlling for age, blood pressure, body size, and other extraneous factors. Logistic regression to model the probability (prevalence) of various renal abnormalities with increasing dose of cadmium was used. The probability of multiple tubular abnormalities and raised serum creatinine concentration increased sharply at cumulative cadmium exposures exceeding 300 mg/m3 days, corresponding to working for 4.3 years at the current permissible United States exposure limit for cadmium dust.