Hematotoxocity among Chinese workers heavily exposed to benzene

Benzene is a well-established hematotoxin. However, reports of its effects on specific blood cells have been somewhat inconsistent and the relative toxicity of benzene metabolites on peripheral blood cells in humans has not been evaluated. We compared hematologic outcomes in a cross-sectional study of 44 workers heavily exposed to benzene (median: 31 parts permillion [ppm] as an 8-hr time-weighted average [TWA] and 44 age and gender-matched unexposed controls from Shanghai, China. All hematologic parameters (total white blood cells [WBC], absolute lymphocyte count, platelets, red blood cells, and hematocrit) were decreased among exposed workers compared to controls, with the exception of the red blood cell mean corpuscular volume (MCV), which has higher among exposed subjects. In a subgroup of workers who were not exposed to more than 31 ppm benzene on any of 5 sampling days (n = 11, median 8 hr TWA = 7.6 ppm, range = 1–20 ppm), only the absolute lymphocyte count was significantly different between exposed workers (mean [sd] 1.6 [0.4] x 10³ μL) and controls (1.9 [0.4] x 10³ μL, p = 0.03). Among exposed subjects, a dose-response relationship with various measures of current benzene exposure (i.e., personal air monitoring, benzene metabolites in urine) was present only for the total WBC count, the absolute lymphocyte count, and the MCV. Correlations between benzene metabolites and hematologic parameters were generally similar, although hydroquinone was somewhat more strongly associated with a decrease in the absolute lymphocyte count, and catechol was more strongly associated with an increase in MCV. Morphologic review of peripheral blood slides demonstrated an excess of red blood cell abnormalities (i.e., stomatocytes and target cells) only in the most heavily exposed workers, with no differences in granulocyte, lymphocyte, or platelet morphology noted. Although benzene can affect all the major peripheral blood elements, our results support the use of the absolute lymphocyte count as the most sensitive indicator of benzene-induced hematotoxicity. © 1995 Wiley-Liss, Inc.     

外周血细胞形态学观察在苯接触工人健康监护和苯中毒诊断的意义

目的 探讨血细胞形态学观察对苯作业工人健康监护和早期预防苯中毒的意义。方法 常规采苯作业工人末梢或静脉血进行ＷＢＣ、ＲＢＣ和ＰＬＴ计数,测定ＨＧＢ浓度,并对ＷＢＣ、ＲＢＣ、ＰＬＴ作形态学观察。结果 在１２０名苯作业工人中共检出３５名异常工人,其中有１８名全血细胞减少;血细胞的形态学改变以中性细胞胞浆出现中毒颗粒和空泡最常见。结论 中性粒出现中毒颗粒和空泡是接触苯后血液系统的早期改变,随后是白细胞减     

Hematological Evidence of Occupational Exposure to Chemicals and Other Factors among Auto-Repair Workers in Rawalpindi,Pakistan

Objectives

Occupational exposure to aromatic solvents causes many serious health hazards to workers, especially if an ambient environment increases the exposure during routine working hours. This study was conducted on two related groups, i.e., automobile mechanics (MCs) and automobile spray painters (PNs), with an effort to analyze effects of chemical exposure on hematological parameters, keeping a focus on environmental parameters and workers’ personal behavioral characteristics that could be held responsible for increasing exposure risk.

Methods

A preliminary survey of various chemicals used in these places was done, and 78 blood samples were collected from three groups (control, n = 24; mechanics, n = 25; painters, n = 29). Demographic features of workers were recorded through a short questionnaire.

Results

Results showed that mean red blood cell (RBC) count was lower both in MCs [t(51) = 2.38, p < 0.021, r = 0.32] and in PNs [t(47) = 2.12, p < 0.03, r = 0.29], whereas mean hemoglobin (Hb) was significantly lower in MCs [t(51) = 2.5, p = 0.017, r = 0.33]. Combined data for exposed groups for smokers (SMs) versus nonsmokers (NSs) showed that SMs had a significantly lower number (RBC count: t(52) = 2.28, p < 0.027, r = 0.25; Hb count: t(52) = 2.71, p < 0.009, r = 0.30] of these parameters than NSs, even compared to the control group. Moreover, logistic regression results showed that smoking is a significant predictor of reduction in RBC and Hb counts, besides occupational exposure and work experience to a little extent among exposed workers. Mean white blood cell count [t(47) = 2.63, p < 0.01, r=0.35], mean corpuscle volume [t(47)= –2.82, p = 0.007, r = 0.29], and packed cell volume [t(47)= –2.28, p = 0.027, r = 31] were higher exclusively in painters, which could be related to exposure to benzene in addition to isocyanate.

Conclusion

It appeared that workplace exposure may be complex due to interaction of multiple factors and PNs face much more exposure to isocyanate and aromatic solvents than MCs, which had significant effects on their hematopoiesis. Smoking enhances exposure risk manifolds, and among MCs it showed combined effects along with occupational exposure. There is a need to create awareness among these workers to adopt self-safety measures during routine tasks and also of a separate study to elucidate actual occupational exposure among them, eliminating confounding factors.     

低浓度苯作业工人健康状况及影响因素分析

目的 探讨低浓度苯接触工人的健康状况及影响因素.方法 对823名研究对象(直接接苯组253人,间接接苯组482人,对照组88人)进行健康体检,采用χ²检验比较各组卫生习惯、临床症状及白细胞降低率差异,采用logistic回归分析白细胞降低的影响因素.结果 直接接苯组经常使用防护用品人数的比例(78.3%)明显高于间接接苯组(55.2%)(P<0.05);间接接苯组和直接接苯组白细胞波动率(32.2%,40.7%)及白细胞降低率(20.5%,27.7%)均高于对照组(6.8%,0),差异有统计学意义(P<0.05);苯暴露、年龄和接苯工龄是白细胞降低的影响因素.结论 低浓度苯接触仍可能会产生血液毒性,白细胞计数是监测低浓度苯接触血液毒性的一个敏感指标.     

Utility of a routine medical surveillance program with benzene exposed workers

BACKGROUND: A medical surveillance program of benzene-exposed workers has to be established in such a way as to observe early signs of benzene-induced cytopenia, pancytopenia, or leukemia. This study evaluates the utility of routine medical survey applied to benzene-exposed workers by analyzing the hematological, immunological, and cytogenetic assay results. METHODS: The results of a previous study of hematological, immunological, and cytogenetic assays in benzene-exposed workers (up to 15 ppm) are used to discuss medical surveillance program by defining the relationship between various benzene exposure concentrations and toxic endpoints. RESULTS: Exposure to benzene concentration lower than 5 ppm does not produce any abnormal hematological measurements. For benzene cumulative exposure above 100 (ppm-years), some blood indices [mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), band neutrophils] show significant differences in comparison to the control group. The incidence of dicentric chromosomes was higher and the level of B-lymphocytes was lower even with workers exposed to 5 ppm of benzene; correlation with exposure indicators was not found. CONCLUSIONS: The results suggest that peripheral blood indices, although not sensitive enough, are still the most suitable parameters in a health surveillance program applied to benzene-exposed workers. B-lymphocytes could be a promising indicator of the benzene-induced damage. Cytogenetic tests did not prove to be suitable. Further investigation of useful screening tests for health surveillance program of benzene-exposed workers is still required.     

滕州市小型家具厂接触苯及苯系物人员血常规改变情况

目的探讨小型家具厂接触苯及苯系物对从业人员血常规的影响。方法对418名接触苯及苯系物和367名不接触苯及苯系物人员进行健康检查和血常规分析,在单因素分析的基础上,进行非条件多因素logistic分析。结果接触苯及苯系物人员白细胞减少78例(18.66%),血小板减少43例(10.29%),对照组分别为38(10.35%)、29例(7.9%),两组比较,差异有统计学意义,P0.01。结论接触苯及苯系物对从业人员血常规改变有直接作用,且与接触水平呈正相关。     

苯接触标志物尿中苯巯基尿酸的分析与评价

尿中苯巯基尿酸(SPMA)与苯接触存在良好相关性,是低浓度苯接触特异和敏感的生物标志物。SPMA可用高效液相色谱法(HPLC)、液质联谱(LC/MS)、气质联谱(GC/MS)和酶联免疫吸附试验(ELISA)等方法检测。本文详细介绍了国外检测尿SPMA的方法,评价了尿SPMA作为职业苯接触生物标志物的有效性和应用。     

Leukemia in relation to occupational exposures to benzene and other agents: a case-control study nested in a cohort of gas and electric utility workers

BACKGROUND: Many occupational and environmental exposures have been implicated in the etiology of leukemia, but only a few, such as benzene, are well-established leukemogens. The risk of leukemia in a large cohort of gas and electricity utility workers with exposures to several suspected or confirmed carcinogens was investigated. METHODS: A case-control study nested within the cohort was conducted, with 72 leukemia cases identified among male workers, and 285 controls matched to the cases by year of birth. Only cases, and their matched controls, active in the company at the date of diagnosis were included. Exposure assessment was based on a job-exposure matrix (JEM) developed from expert judgment using a standardized procedure. RESULTS: The risk of leukemia was increased in workers with an estimated cumulative exposure to benzene > or = 16.8 ppm-years (OR = 3.6; 95% CI 1.1-11.7), and there was an indication of a dose-response relation (OR = 1.2; 95% CI 1.0-1.5 per 10 ppm-years increase in exposure). The link with benzene was more pronounced for acute leukemia than for chronic leukemia, but no association with a particular leukemia cell type was apparent. The risk of leukemia remained elevated for latency periods of 2, 5, or 10 years. CONCLUSIONS: From our evaluation, it could be estimated that the median TWA exposure to benzene among exposed workers was 0.16 ppm, i.e., within concentration ranges where an increased leukemia risk was usually not apparent in previous epidemiological studies. Although an increased leukemia risk may be real, it may also be related to other occupational factors not totally controlled for in the analysis, or to benzene exposures actually higher than expected.     

小儿手足口病血液学变化以及临床特征分析

目的探讨儿童手足口病血液学变化及临床特征。方法选取2010年1月～2011年12月期间某院儿科诊治的手足口病患儿127例做为观察对象(手足口病组),随机选取保健科同期进行体检的正常儿童120例作为对照样本(正常组),进行血细胞检测,并且分析临床特征。结果 (1)临床特征分析:发热占85.04%,皮疹占80.31%,疱疹占32.28%,呼吸道症状占40.95%,消化道症状者占29.92%,神经系统症状者占11.02%;(2)血液学变化:手足口病组白细胞计数、淋巴细胞、外周淋巴细胞绝对值分别为(16.03±2.87)×109/L、(36.44±16.21)%、(5.81±2.28)×%,高于正常组(7.58±2.01)×109/L、(45.52±6.35)%、(3.25±1.21)×%,比较差异有统计学意义(P﹤0.05)。结论手足口病患儿血液学变化主要表现为淋巴细胞下降,外周淋巴细胞绝对值升高,白细胞升高。     

流式细胞术检测家具企业混苯接触工人DNA损伤

目的:研究家具企业混苯作业工人外周血DNA损伤。方法:应用流式细胞术对32名混苯接触组和30名餐饮业对照组人员外周血淋巴细胞DNA损伤进行检测。结果:混苯接触组工人外周血淋巴细胞DNA损伤率和几何平均荧光强度均高于对照组(P<0.01),而不同工龄组工人DNA损伤率和几何平均荧光强度差别无统计学意义(P>0.05)。结论:职业性混苯接触可引起人外周血淋巴细胞DNA损伤,流式细胞术γH2AX分析法是一种有应用前景的检测外周血淋巴细胞DNA损伤的方法。     

Reference value and annual trend of white blood cell counts among adult Japanese population

Objectives

This study was initiated to establish the reference values (the 95 % lower limit in particular) for white blood cell (WBC) counts in peripheral blood of general Japanese population. Additional attempts were made to examine whether the reference range had changed in the past 100 years, and which factors had induced such change in WBC counts.

Methods

Data employed were WBC counts of >100 thousand apparently healthy Japanese men, collected in 2002 and in 2010, respectively. Information on smoking habits was collected simultaneously.

Results

The distribution of WBC counts was essentially normal. Arithmetic mean (AM) WBC was 6,248 cells/mm³ in 2002 and 6,162 cells/mm³ in 2010. Based on the 2010 observation, 3 × 10³ WBCs/mm³ (after rounding of the figure) was identified as the 95 % lower limit of the reference value for the population. No clear age dependency was detected. Smoking induced elevation in WBC, whereas WBC returned to the level of never smokers after quitting for 3 or more years.

Conclusions

Historical review disclosed a secular trend of decrease in WBC in the past 100 years, so that about 8 % of never-smoking men would be considered leukocytopenic according to the conventional cutoff of 4 × 10³ cells/mm³ as a screening level. Decreased smoking rates and improved general hygiene are discussed as possible factors for WBC count reduction. Thus, WBC count of 3 × 10³ cells/mm³ is recommended as the 95 % lower limit of the reference value for screening cases with reduced WBC counts.     

吸烟、白细胞计数与男性放射工作人员血清胆红素水平的关联性

目的 分析吸烟、白细胞计数与男性放射工作人员血清胆红素水平的关联性,探讨机体炎症反应在吸烟对血清胆红素水平影响中的作用机制.方法 基于某医疗机构对1320名男性放射工作人员在岗或离岗时的职业健康检查数据,利用线性回归分析方法分别分析吸烟与白细胞计数、吸烟与血清胆红素水平、白细胞计数与血清胆红素水平之间的关联性.结果 吸...     

Aromatic DNA adducts in white blood cells of coke workers

Summary White blood cell DNA adducts were measured in coke workers, local controls and countryside controls using the ³²P-postlabelling technique. The method detected aromatic adducts including those formed by polycyclic aromatic hydrocarbons (PAHs). Coke workers are heavily exposed to PAHs particularly when working at the batteries. A difference in adduct levels was noted between the coke workers at the battery as compared to other jobs. The adduct levels in the non-battery were higher than those in the countryside controls.     

某制鞋厂工人血液检查结果分析及对策

目的分析制鞋工人血液检查结果,探讨苯及苯系物对造血系统损害的特点,提出对策。方法对80名制鞋工人血液检查结果进行分析。并与对照组血液检查结果进行对照分析研究。结果苯接触组白细胞减少百分率与红细胞减少百分率、血红蛋白降低率、血小板减少百分率相比,均有统计学意义（P〈O．05）;苯接触组自细胞减少比例与正常对照组比较,同样有统计学意义（尸．=O．01）。结论苯及苯系物对粒细胞系统的抑制作用强于对红细胞系统和血小板的抑制作用,为预防和减少职业性苯中毒的发生,应加强职业健康监护和职业卫生监测监督。     

职业多环芳烃暴露人群尿中生物标志物浓度水平

多环芳烃类化学物质因为其被熟知的致癌性而一直备受关注, 近来越来越多的学者意识到单一的接触生物标志物并不能完全代表暴露者体内的暴露水平。本研究就1999年以后15年间报道的职业环境中接触多环芳烃类物质的工人尿中接触生物标志物进行综述, 重点对其浓度水平进行描述, 为职业环境中多环芳烃类化学物质暴露的生物学检测提供理论依据。     

Cross-sectional study of cardiovascular effects of carbon disulfide among Chinese workers of a viscose factory

OBJECTIVE: This cross-sectional study investigates the cardiovascular effects among Chinese workers who were occupationally exposed to carbon disulfide (CS2), and evaluates the protective value of the current Chinese Maximum Allowable Concentration (MAC) of CS2 against cardiovascular effects. METHODS: The measurements of exposure were performed by personal sampling and gas chromatography. The biological monitoring was performed by HPLC. Three hundred and sixty-seven exposed workers and 125 reference workers (never exposed to CS2,) were included in this study. The exposed workers were divided into 2 sub-groups according to their cumulative exposure indices, the cut-off point being at 100 which means 10 years exposure to the Chinese Maximum Allowable Concentration in the workplace (10 mg/m3). All subjects were examined using a self-administered questionnaire including medical and job history, clinical complaints in the previous three months, and underwent a clinical check-up and a 12 lead electrocardiography (ECG) at rest, coded according to the Minnesota code. Blood pressure (BP) was recorded and blood samples were collected for lipid measurements. RESULTS: The personal monitoring showed that the exposures levels (15.47 +/- 2.34 mg/m3) were below the Threshold Limit Value (TLV, 31 mg/m3), and most of the samples analyzed still showed higher values than the Chinese MAC (10 mg/m3). Clinical complaints and abnormal electrocardiograms were not significantly increased in exposed workers. No significant effect of CS2 on blood pressure, cholesterol, HDL and LDL cholesterol or triglycerides was found. Further studies are recommended to elucidate the mechanism of cardiac intoxication after CS2 exposure. CONCLUSION: This study showed that Chinese workers exposed to CS2 did not have more clinical complaints, nor more ECG abnormalities than controls and no adverse effects were found in their lipids at an exposure level below the current TLV. The present results indicate that differences of health effects reported worldwide are possibly due to different exposure levels. They also indicate that the current Chinese MAC (10 mg/m3) sufficiently protects workers against negative cardiovascular effects.     

单细胞凝胶电泳法检测苯作业工人淋巴细胞DNA损伤

目的 用碱性单细胞凝胶电泳技术检测苯作业工人外周血淋巴细胞DNA损伤,研究苯的遗传毒性。方法 采用碱性单细胞凝胶电泳技术。将接苯工人按累积浓度、历史平均浓度和测定当时8h时间加权平均浓度（8hTWA）分组。观察指标包括DNA断裂分级（将DNA断裂损伤细胞按其损伤程度分级）及DNA彗星尾长（彗头末端到彗尾的长度）。结果 接苯工人DNA断裂程度及DNA彗星尾长[Ig(尾长＋1）]两个参数,接苯组按累积浓度、历史平均浓度和8hTWA浓度计算,均明显高于对照组,差异有显著性（P＜0．01）,并有明显的剂量－反应关系。结论 彗星试验能够快速,敏感地检测苯引起的人类淋巴细胞DNA损伤,提示对于检测环境致癌物和致突变物可能是一有用工具。