Concentration of ethylene oxide in the alveolar air of occupationally exposed workers

Ethylene oxide was tested in environmental air and in the alveolar air of 10 workers employed in a hospital sterilizer unit at hourly intervals during the work shift. Alveolar ethylene oxide concentrations (Ca) were correlated with environmental concentration (Ci) in all the workers studied (r = 0.89-0.99). The ratio between alveolar and environmental concentration (Ca/Ci) given by the slope of the regression line obtained for all the data collected was 0.24. This means that the alveolar retention of ethylene oxide, expressed as 1 - (Ca/Ci), corresponded, on average, to about 75% of the environmental concentration.     

Benzene in environmental air and human blood

To study the blood benzene levels resulting from environmental and occupational benzene exposure. Methods: Benzene in venous blood was measured in 243 nonoccupationally exposed subjects (“normal” people) and in 167 workers occupationally exposed to benzene. All exposed workers gave blood samples at the end of the work shift and on the following morning before resuming work. Blood benzene was assayed by gas chromatography (GC)-mass spectrometry. Occupational benzene exposure was monitored by environmental personal samplers and measured by GC analysis. Results: The mean occupational benzene exposure for all 167 workers studied was 186 ng/l (58 ppb; range 5–1535 ng/l, 2–500 ppb). Overall, the mean blood benzene level of all workers was 420 ng/l at the end of the shift and 287 ng/l on the morning thereafter. The blood benzene levels measured the morning after turned out to be significantly lower (t = 3.6; P < 0.0001) than those measured at the end of the shift. The mean blood benzene level of the 243 “normal” subjects was 165 ng/l, which was significantly lower than that measured in the workers on the morning thereafter (t=5.8; P < 0.0000001). The mean blood benzene concentration was significantly higher in smokers than in nonsmokers in both the general population (264 versus 123 ng/l) and in the exposed workers. In the group of nonsmoking workers, whose workplace exposure to benzene was lower than 100 ng/l, blood benzene levels were similar (210–202 ng/l) to those measured in the nonsmoking general population (165 ng/l). End-of-shift blood benzene correlated significantly with environmental exposure (y=0.91x + 251; r=0.581; n=162; P < 0.00001). Finally, there was also a significant correlation between blood benzene measured at the end of the shift and that determined on the morning thereafter (y=0.45x + 109; r=0.572; n=156; P < 0.00001). Conclusion: Nonsmoking workers occupationally exposed to benzene at environmental levels lower than 100 ng/l (mean 35 ng/l) and the nonsmoking general population exposed to ubiquitous benzene pollution have similar blood benzene concentrations. This suggests that it is impossible to distinguish between occupational and environmental exposure when the benzene level in the workplace is less than 100 ng/l. Received: 31 December 1997 / Accepted: 4 August 1998     

Nonspecific nasal responsiveness in workers occupationally exposed to respiratory irritants

The aim of the study was to establish the level of the nonspecific nasal responsiveness in a group of workers (N = 84) occupationally exposed to respiratory irritants, and to compare it with its level in healthy subjects (N = 60). Another goal was to study the effect of occupational exposure to irritants, smoking, and atopy on nonspecific nasal responsiveness. The modified method of nonspecific nasal provocation with histamine developed by van Wijk and Dieges (Clin Allerg 17:563–570, 1987) was used. The method was performed by spraying doubling concentrations of histamine (0.03–32 mg/mL), starting with saline, in a cumulative manner into each nostril. The reaction was measured by total nasal resistance (“opening” interruption technique). The result of the test was expressed as provocation concentration of histamine that caused ?75% rise of total nasal resistance compared to its value measured after saline. We found a significantly higher percentage of nasal hyperreactors and a significantly greater nonspecific nasal responsiveness among 65 exposed workers (χ² = 78.6; p < 0.001, t = ?5.48; p < 0.001, respectively) than in the group of healthy subjects. A significantly (t = 4.25; p < 0.001) increased nonspecific nasal responsiveness was observed during exposure when compared to nonspecific nasal responsiveness assessed after 2 weeks out of exposure, when tested in 19 patients. Higher smoking rate as measured by smoking category (number of cigarettes multiplied with years of smoking) was associated with the lower levels of nonspecific nasal responsiveness. Also, we failed to confirm a relation between atopy and nonspecific nasal responsiveness in a group of workers exposed to irritants. © 1993 Wiley-Liss, Inc.     

Muconic acid in urine: A reliable indicator of occupational exposure to benzene

In male subjects not occupationally exposed to benzene, the concentration of muconic acid (MA) in urine is usually below 0.5 mg/g creatinine. At ambient levels of benzene exposure (below 0.01 ppm), the mean MA level was greater in 21 smokers than in 14 nonsmokers. In 38 male subjects employed in garages and coke ovens, a statistically significant correlation was found between the airborne concentration of benzene measured with passive monitors and MA in postshift urine. The mean postshift MA concentrations corresponding to a benzene 8-hour time-weighted average exposure (TWA) of 0.5 and 1 ppm were 0.8 and 1.4 mg/g creatinine, respectively. © 1994 Wiley-Liss, Inc.     

Effect of dietary calcium on blood lead concentrations in occupationally exposed and nonexposed workers

Workers exposed to lead may benefit from a calcium-rich diet, since calcium competes with lead for intestinal absorption. We studied the effect of dietary calcium on blood lead levels. We assessed blood lead levels, dietary intake of calcium, smoking and alcohol consumption, and anthropometric and demographic data in 56 workers exposed to lead and 90 workers without such exposure. Mean intake of dietary calcium was 775 ± 370 mg/day in the nonexposed workers and 858 ± 423 mg/day in the exposed workers. Occupational lead exposure explained nearly 90% of the variance in blood lead levels of the entire cohort. Smoking and alcohol intake also showed significant associations with blood lead levels, but their combined effect was less than 2%. When the exposed and nonexposed workers were considered separately, no association was found between blood lead levels and calcium intake. The amount of calcium in the diet does not influence blood lead levels. Further studies are warranted to determine whether dietary calcium influences blood lead levels in exposed and nonexposed workers in other settings and in subjects with lower intakes of calcium. Am. J. Ind. Med. 34:512–516, 1998. © 1998 Wiley-Liss, Inc.     

Cancer risk assessment for health care workers occupationally exposed to cyclophosphamide

In the present study a cancer risk assessment of occupational exposure to cyclophosphamide (CP), a genotoxic carcinogenic antineoplastic agent, was carried out following two approaches based on (1) data from an animal study and (2) data on primary and secondary tumors in CP-treated patients. Data on the urinary excretion of CP in health care workers were used to estimate the uptake of CP, which ranged from 3.6 to 18 g/day. Based on data from an animal study, cancer risks were calculated for a health care worker with a body weight of 70 kg and a working period of 40 years, 200 days a year (linear extrapolation). The lifetime risks (70 years) of urinary bladder cancer in men and leukemias in men and women were found to be nearly the same and ranged from 95 to 600 per million. Based on the patient studies, cancer risks were calculated by multiplication of the 10-year cumulative incidence per gram of CP in patients by the estimated mean total uptake in health care workers over 10 years, 200 days a year. The risk of leukemias in women over 10 years ranged from 17 to 100 per million using the secondary tumor data (linear extrapolation). Comparable results were obtained for the risk of urinary bladder tumors and leukemias in men and women when primary tumor data were used. Thus, on an annual basis, cancer risks obtained from both the animal and the patient study were nearly the same and ranged from about 1.4 to 10 per million. In The Netherlands it is proposed that, for workers, a cancer risk per compound of one extra cancer case per million a year should be striven for (target risk) and that no risk higher than 100 per million a year (prohibitory risk) should be tolerated. From the animal and the patient study it appears that the target risk is exceeded but that the risk is still below the prohibitory risk.     

Epidemiological survey of workers exposed to inorganic germanium compounds

OBJECTIVES—To assess occupational exposure to inorganic germanium (Ge) in workers from a producing plant, and to assess the health of these workers, with a special focus on respiratory, kidney, and liver functions.
METHODS—Cross sectional study of 75 workers exposed to Ge and 79 matched referents. Exposure was characterised by measuring air and urine concentrations of the element during a typical working week, and health was assessed by a questionnaire, clinical examination, lung function testing, chest radiography, and clinical chemistry in serum and urine, including high and low molecular weight urinary proteins.
RESULTS—Airborne concentrations of Ge (inhalable fraction) ranged from 0.03 to 300 µg/m, which was reflected by increased urinary excretion of Ge (0.12-200 µg/g creatinine, after the shift at the end of the working week). Lung, liver, and haematological variables were not significantly different between referents and workers exposed to Ge. A slightly higher urinary concentration of high molecular weight proteins (albumin and transferrin) was found in workers exposed to Ge, possibly reflecting subclinical glomerular changes. No relation was found between the intensity or duration of exposure and the urinary concentration of albumin. No difference between referents and workers exposed to Ge was found for other renal variables.
CONCLUSIONS—Measurement of urinary Ge can detect occupational exposure to inorganic Ge and its compounds. It is prudent to recommend the monitoring of renal variables in workers exposed to Ge.


Keywords: inorganic germanium; occupational exposure; biological monitoring     

职业砷接触工人某些遗传毒性指标的变化

目的探讨职业砷接触工人某些遗传毒性指标的变化。方法选择云南某砒霜厂40人为接触组,当地无明显毒物接触史28人为对照组,检测并评价外周血淋巴细胞微核细胞率、微核率、彗星试验拖尾率和尾长,以及尿中总砷、有机砷水平。结果接触组外周血淋巴细胞微核细胞率、微核率、彗星试验拖尾率、尾长均极显著高于对照组(P<0.01)。尿中总砷、有机砷浓度也高于对照组(均低于0.02mg/L)。微核细胞率和微核率随有机砷浓度、工龄乘积增加有升高趋势(rs=0.356,P=0.024;rs=0.347,P=0.028)。结论职业性砷暴露可导致外周血淋巴细胞染色体和DNA损伤。     

铅作业工人SCL-90调查分析

目的探讨铅作业工人心理健康状况及其影响因素。方法对89名铅作业工人进行SCL-90量表评定,并与正常人群进行比较。结果铅作业工人SCL-90总分、阳性项目数、6个因子得分均显著高于对照组。躯体化症状阳性检出率25.8%,抑郁症状阳性检出率12.3%,偏执症状阳性检出率11.2%,敌对症状阳性检出率10.1%,恐怖症状阳性检出率8.9%。不同经济类型工厂、尿铅浓度、血锌原卟啉浓度与躯体化、抑郁、偏执、敌对、恐怖、人际关系敏感阳性症状检出率存在相关。结论职业性铅接触可影响工人的精神心理卫生,不同经济类型工厂对精神卫生影响不同。     

Alteration of thiol-disulfide homeostasis in workers occupationally exposed to arsenic

This study evaluates the redox state in occupationally arsenic-exposed workers (n = 71) by assessing the dynamic serum thiol-disulfide homeostasis. We determined the serum thiol-disulfide homeostasis parameters of exposed workers and controls (n = 43) using a novel automated colorimetric assay. Median urinary As and 8-isoprostane levels of exposed group were significantly higher than control group (16.40 μg/L vs 2μg/L, p < .001 and 2.28 ng/ml vs 0.54 ng/ml, p < .001, respectively). Disulfide level, disulfide/native thiol ratio, and disulfide/total thiol ratio were significantly higher in exposed group. The mean ceruloplasmine and myeloperoxidase activities of As-exposed group were significantly higher than control group (117.15 U/L vs 87.02 U/L, p = .035 and 148.53 U/L vs 97.75 U/L, p = .000, respectively). The median catalase activity did not differ in the two groups. Our findings revealed that As disrupts the thiol-disulfide homeostasis in favor of disulfide.     

职业性接触抗肿瘤药物甲氨喋呤工人的遗传损伤

目的用3个遗传终点来研究接触甲氨喋呤(MTX)工人的遗传损伤。方法外周血分别来自21名生产MTX工人和21名对照组工人。用微核试验、彗星试验、hprt基因突变试验和TCR基因突变试验对两组人群进行检测。结果工人组平均微核率(MNR)、平均微核细胞率(MCR)分别为10.10‰±0.95‰和8.05‰±0.75‰,明显高于对照组(5.48‰±0.82‰和4.38‰±0.58‰),差异有统计学意义(P<0.01)。工人组和对照组的平均尾长(MTL)分别为(1.30±0.06)、(0.07±0.01)μm,差异有统计学意义(P<0.01)。但两组平均尾相(MTM)的差异无统计学意义(P>0.05)。工人组的hprt和TCR平均突变率分别为1.00‰±0.02‰和(6.87±0.52)×10-4,明显高于对照组[0.86‰±0.01‰和(1.67±0.14)×10-4],差异有统计学意义(P<0.01)。结论生产MTX工人某种程度上存在遗传损伤。     

A study of factors influencing urinary arsenic excretion in exposed workers

This study was designed to evaluate the influence of occupational and non-occupational factors on urinary arsenic excretion in workers exposed to iAs (inorganic arsenic) in the dismantlement of a factory which once produced fertilisers. We measured iAs and its methylated metabolites in 108 urinary samples of workers exposed to iAs in July 2006. A total of 13.9% of the samples showed levels higher than the Biological Exposure Index (BEI) of 35 μg/l (mean value 23.9 μg/l). After the improvement of working conditions, in August–October 2006 we collected urinary samples from each of the 108 workers enrolled. We also administrated a questionnaire, in order to investigate the influence of occupational and non-occupational factors on the urinary arsenic excretion. A significant difference was observed in relation with seafood consumption and age stratification. We have found a significant reduction of urinary arsenic excretion between the two phases of biological monitoring, probably due to appropriate hygiene work-related interventions.     

Study of some immunological parameters in workers occupationally exposed to benzene

Objective: The aim of the study was to investigate the immunotoxicity of benzene exposure, to establish the correlation between the exposure biomarkers and some immunological parameters, and to assess the possible influence of confounding factors on the results of immunological assay applicable in routine medical surveillance of benzene-exposed workers. Methods: Forty-nine female workers in the shoemaking industry who were exposed to solvent mixtures and 27 nonexposed controls were examined. Workers were exposed to benzene concentrations of up to 15 ppm, and to toluene of up to 50 ppm. Results: Significant differences in the levels of benzene and toluene in blood and phenols in post-shift urine between the exposed and the control group confirmed solvent exposure. The number of B-lymphocytes (P=0.01) was lower in the shoe workers than in the controls. Significant correlation was found between the level of immunoglobulin G and benzene in the work atmosphere, while confounding factors had no impact on immunological values. Conclusion: According to these results, exposure to benzene concentration lower than 15 ppm can induce depression of the circulating B-lymphocyte level and therefore this fact could be used to develop a promising method for health surveillance of benzene-exposed workers. However, considerably more effort in the research on benzene immunotoxicity, especially in the search for suitable health surveillance methods, is still required. Received: 15 July 1999 / Accepted: 22 January 2000     

Formic acid excretion in comparison with methanol excretion in urine of workers occupationally exposed to methanol

Summary A semiautomated head-space gas chromatographic (GC) method was developed for measuring formic acid in urine. The method consists of heating 1 ml urine sample in a 20-ml air-tight vial in the presence of 1 ml sulfuric acid and 2 ml ethanol at 60°C for 30 min for ethyl esterification and air-liquid equilibrium, followed by automatic injection of 1 ml head-space air into a flame ionization detector GC. The detection limit was 1 mg/l for formic acid. The method was applied to measure formic acid in the shift-end urine samples from 88 workers exposed to methanol at 66.6 ppm (as geometric mean) and in urine samples from 149 nonexposed controls. Methanol concentrations were also determined. Regression analysis showed that urinary formic acid concentrations, as observed or corrected for either creatinine concentration or specific gravity of urine (1.016), correlated significantly with time-weighted average intensities of exposure to methanol vapor. Men excreted significantly more formic acid than women. Comparison with methanol excretion suggested, however, that urinary formic acid is less sensitive than urinary methanol as an indicator of methanol vapor exposure, primarily because the background level for formic acid (26 mg/l as arithmetic mean, or 23 mg/l as geometric mean) is more than ten times higher than the level for methanol (1.9 mg/l as arithmetic mean, or 1.7mg/l as geometric mean). After theoretical methanol exposure at infinite concentration, the urinary formic acid/methanol ratio should be about 0.4.     

Spirometric function in non-smoking workers exposed to aluminum

BACKGROUND: Exposure to aluminum (Al) causes the onset of respiratory disorders. This study is aimed at providing further information on how occupational exposure to Al affects the respiratory apparatus in healthy non-smokers, with particular attention to respiratory function. METHODS: A group of 50 male shipyard workers who were exposed to Al underwent medical examination, standard chest X-rays and spirometry in accordance with the C.E.C.A. protocol. The data were compared with those of a homogeneous group of controls, all with blood aluminum (AlB) levels below 7.5 ng/ml. Statistical analysis was performed on the following spirometric parameters: vital capacity (VC), forced vital capacity (FVC), maximum forced expiratory volume in 1 s (FEV1), and mean forced expiratory flow during mid-half of FVC (FEF(25-75%)). Environmental Al levels were also measured at the various workstations. RESULTS: Fifty male workers with an average age 31.82 +/- 5.05 years, occupational exposure of 11.81 +/- 3.71 years, presented with average AlB levels of 32.64 +/- 8.69 ng/ml. Environmental monitoring displayed Al levels higher than TLV TWA for all the workstations studied. None of the sample displayed significant pathological conditions. Statistical comparison of the spirometric parameters showed a decrease in the examined values in exposed workers. This decrease was found to be directly proportional to the AlB level. CONCLUSION: The authors conclude that Al affects respiratory function and that limit values should be reassessed.     

DNA damage in outdoor workers occupationally exposed to environmental air pollutants

Background

Health concerns about the exposure to genotoxic and carcinogenic agents in the air are particularly significant for outdoor workers in less developed countries.

Aims

To investigate the association between personal exposure to a group of air pollutants and severity of DNA damage in outdoor workers from two Mexican cities.

Methods

DNA damage (Comet assay) and personal exposure to volatile organic compounds, PM_2.5, and ozone were investigated in 55 outdoor and indoor workers from México City and Puebla.

Results

In México City, outdoor workers had greater DNA damage, reflected by a longer tail length, than indoor workers (median 46.8 v 30.1 μm), and a greater percentage of highly damaged cells (cells with tail length ⩾41 μm); in Puebla, outdoor and indoor workers had similar DNA damage. There were more alkali labile sites in outdoor than indoor workers. The DNA damage magnitude was positively correlated with PM_2.5 and ozone exposure. Outdoor and indoor workers with ⩾60% of highly damaged cells (highly damaged workers) had significantly higher exposures to PM_2.5, ozone, and some volatile organic compounds. The main factors associated with the highly damaged workers were ozone, PM_2.5, and 1‐ethyl‐2‐methyl benzene exposure.

Conclusions

With this approach, the effects of some air pollutants could be correlated with biological endpoints from the Comet assay. It is suggested that the use of personal exposure assessment and biological endpoints evaluation could be an important tool to generate a more precise assessment of the associated potential health risks.     

职业性苯接触者的呼出苯生物接触限值研究

通过现场调查、临床体检和实验测定的“班前”呼出苯浓度与接触苯浓度之比和高、中、低苯浓度接触者的呼出苯的毒物动力学观察结果,结合工人体检的健康状况和其它生物学监测指标间的关系,并参照国外制订呼出苯生物阈限值的文献报道;根据我国现行苯的最高容许浓度(40mg/m~3),建议职业性苯接触者“班前”末端呼出气中苯的生物接触限值为0.40μg/L(0.12ppm)。     

环氧丙烷对职业接触者的毒性作用

目的 研究较低浓度环氧丙烷对职业接触人群健康的影响情况,分析不同的研究指标在环氧丙烷毒性研究和职业人群健康监护工作中的作用和意义,为保护接触工人的健康与安全、提高劳动生产率提供科学的依据。方法选择特大型企业接触环氧丙烷作业的工人为对象,分别采用传统的和现代最新的方法研究环氧丙烷对职业接触人群遗传毒性作用,同时也对接触者的一般毒性危害作了比较系统的调查。结果长期接触较低浓度环氧丙烷的作业工人,其健康受到了一定程度的危害。主要表现在中枢神经系统症状比较明显。接触组染色体畸变率、淋巴细胞微核试验没有明显改变,但姐妹染色单体互换率有明显增加,血红蛋白加合物和DNA加合物的实验结果也证实了这一点,且具有更为敏感的特性。结论环氧丙烷对接触者具有一定的遗传毒性。     

Urinary homovanillic acid and vanillylmandelic acid in workers exposed to carbon disulfide

Homovanillic acid (HVA) and vanillylmandellic acid (VMA), two end products of dopamine metabolism, were measured in 60 workers exposed to carbon disulfide (CS₂) in a rayon factory and in 48 unexposed workers. The airborne CS₂ concentrations in eight major exposure zones of the plant were measured monthly over a period of 4 years, from 1990 to 1994. In addition, the exposure concentrations and exposure history of each worker were integrated to estimate the overall lifetime exposure. Industrial hygiene data showed that the geometric mean concentrations of CS₂ in the plant ranged from 2.68 to 20.19 ppm, and more than 15% of the studied population had been repeatedly exposed to CS₂ at concentrations exceeding the ACGIH recommended time-weighted average of 10 ppm. The results showed that there was a significantly lower level and a higher proportion of CS₂ workers with decreased HVA and VMA excretion. However, there were no statistical correlations between the two dopaminergic metabolites and the mean CS₂ concentration, and years of employment. In contrast, significant dose-effect relationships were observed between these two matabolites and the integrated cumulative exposure (ICE) variable. The correlation coefficients for ICE and HVA, and ICE and VMA were -0.35 (p < 0.01) and -0.20 (p < 0.05), respectively. These data suggest that chronic exposure to CS₂ was associated with measurable reduction in catecholamine metabolite concentrations. This finding is compatible with the earlier observations in laboratory animals that CS₂ exposures interfere with neurochemical metabolism. © 1996 Wiley-Liss, Inc.