Urinary excretion of phenols as an indicator of occupational exposure in the coke-plant industry

Objective: In the present study the relationship between the level of exposure to o-cresol and of 2,4- +2,5-, 3,4-, and 3,5-xylenols and the urinary excretion of their metabolites was examined. The mixed exposure to phenolic derivatives of exposed workers during their work shift was monitored by personal air sampling of the breathing-zone air and by measurements of phenol, o-cresol, and xylenol isomer concentrations in shift-end urine. Methods: The study subjects were 76 men working at a coke plant who were 22–58 years old and 34 nonexposed subjects. Concentrations of phenolic compounds were determined in the breathing-zone air during the work shift, whereas concentrations of phenol, cresol, and xylenol isomers were measured in urine collected after the work shift. Concentrations of phenols in air and urine were determined by gas chromatography with flame-ionization detection. Urine samples were extracted after acid hydrolysis of glucuronides and sulfates by solid-phase extraction. The gas chromatography-mass spectrometry method was applied to identify metabolites in urine samples. Results: The time-weighted average concentrations of phenol, cresol, and xylenol isomers detected in breathing-zone air showed that the exposure level of the workers was relatively low. The geometric mean values were as follows: 0.26 mg/m³ for phenol, 0.09 mg/m³ for o-cresol, 0.13 mg/m³ for p- and m-cresol, and 0.02–0.04 mg/m³ for xylenols at the tar-distillation process. Corresponding urinary concentrations were 10.39, 0.53, and 0.25–0.88 mg/g creatinine for phenol, o-cresol, and xylenol isomers, respectively. The correlation coefficients between the o-cresol and 2,4-, 2,5-, 3,4-, and 3,5-xylenol concentrations measured in urine and in the breathing-zone air were statistically significant, varying in the range of 0.54–0.74 for xylenol isomers and being 0.69 for o-cresol. Conclusion: We have found that the presence of o-cresol and xylenol isomers in urine can be used as a biomarker for phenol exposure. Analysis performed on workers at the tar-distillation process showed that they were exposed to relatively low concentrations of phenolic compounds. Received: 15 October 1996 / Accepted: 5 May 1997     

Measured exposures by personal monitoring for respirable suspended particles and environmental tobacco smoke of housewives and office workers resident in Bremen, Germany

Objective : Exposures to respirable suspended particles (RSP) and environmental tobacco smoke (ETS) were assessed in Bremen, Germany, as part of a European air quality study. The range and level of personal exposures were assessed for housewives and office workers. Design : Nonsmokers were randomly selected from a representative sample of the population of Bremen. Housewives were recruited into one group primarily for assessment of exposures in the home and office workers, into a second group for assessment of the contribution of the workplace to overall exposure. Methods : A total of 190 subjects collected air samples from areas close to their breathing zone by wearing personal monitors for 24 h. Samples collected were analysed for RSP, ultraviolet-absorbing particulate matter (UVPM), fluorescing particulate matter (FPM), solanesol-related particulate matter (SolPM), nicotine and 3-ethenylpyridine (3-EP). Saliva cotinine levels for all subjects were also established. Results : Overall the levels found were quite low, with the majority of results being below the limit of quantification. Workers both living and working with smokers were exposed to the highest 24-h median quantities of RSP (789 μg) and ETS particles (128 μg) measured by FPM. The highest nicotine levels, based on median 24-h time-weighted average concentrations, were experienced by office workers working with smokers (0.69 μg m⁻³). These workers were also found to have␣the highest median cotinine levels (1.6 ng ml⁻¹). Conclusions: The most highly exposed workers, both living and working with smokers, would potentially inhale over 20 cigarette equivalents (CE) per annum as based on the upper decile levels. Housewives living with smokers could inhale up to 11 CE per annum as based on the upper decile levels. Locations outside the workplace, including the home, contribute most to overall RSP and ETS particle exposure. Consideration should be given to extending the personal monitoring period in cities where levels appear to be quite low. Received: 9 May 1997 / Accepted: 17 October 1997     

Normal liver function in women in the general Japanese population subjected to environmental exposure to cadmium at various levels

Objectives: Whereas it is well established that environmental exposure to cadmium (Cd) may induce kidney dysfunction, less attention has been paid to the possible disturbance of liver function by Cd exposure. The possibility that liver function is adversely affected by current levels of environmental exposure to Cd as investigated in women in the general population in Japan, where the background level of exposure to Cd is known to be high. Methods: From 1991 to 1997, 24-h food duplicate, peripheral blood and morning spot urine samples were collected from 607 non-smoking and non-habitually drinking women (age range 19–78 years) at 30 survey sites (with no known environmental pollution from heavy metals) throughout Japan. Liver function parameters in serum were examined by conventional methods. After wet-ashing, the food duplicate, blood and urine samples were analyzed for Cd intake via food (Cd-F), Cd in blood (Cd-B), and Cd in urine (Cd-U) by inductively-coupled plasma mass spectrometry. Results: The geometric mean values for Cd-F, Cd-B, and Cd-U were 24.7 (27.1) μg/day, 1.76 (2.07) μg/l, and 3.94 (4.61) μg/g creatinine (values in parentheses for 41- to 60 year-old women), respectively. It as found that the three parameters of ALP, ALT, and AST activity were positively and significantly related to the age of the subjects (whereas no association as detected in cases of γ-GTP, LAP, and albumin). Accordingly, a further analysis as made with 367 women selected by age (41–60 years; about 60% of the total population). Essentially, no Cd dose-dependent changes in liver function parameters were observed in the selected population of this narrower age range. Conclusions: Overall, it seemed prudent to conclude that liver function as not disturbed by the current environmental exposure to Cd in Japan. Received: 16 March 1999 / Accepted: 17 July 1999     

Effects of exposure to carbon disulfide (CS2) on electrocardiographic features of ischemic heart disease among viscose rayon factory workers

The objective of the study was to evaluate viscose plant workers for electrocardiographic manifestations resulting from exposure to carbon disulfide (CS₂). A total of 162 workers (118 in an exposure group and 44 in a reference group) were evaluated using a health questionnaire, physical check-up, biochemical analysis of blood samples and electrocardiograms (ECG). The exposure group consisted of workers in the following areas: viscose manufacturing, cellophane processing, ripening, and filament spinning. Reference group workers were from the administrative office, rolling area, pulp processing, and testing office. Only slight differences were found in the biochemical analyses of the two groups, with the exception of sodium (Na) levels. Personal and area sampling results were found to have a high variation due to different locations within the plant and a wide range of manufacturing processes. Highest CS₂ concentrations were found in the ripening area (54.60 ppm) and the filament spinning area (19.60 ppm). Using a multiple logistic regression model to control variables (age, gender, body mass index, duration of employment, cholesterol, smoking, and alcohol), we found a relative risk for ECG abnormalities 4.18 times significantly higher for the exposure group. The authors feel that the installation of an adequate ventilation system could greatly reduce the risk of workers developing CS₂-induced cardiovascular abnormalities. Received: 29 August 1995 / Accepted: 17 January 1997     

铅、镉、砷污染地区人群免疫功能检测分析

目的探讨铅锌矿矿区铅镉砷混合接触对不同暴露人群机体免疫状况的影响。方法选择铅锌矿矿区矿工、矿区居民和无污染地区居民3组人群共96人作为研究对象,对3组人群所处环境中的铅、镉、砷含量,人体血液和尿液的铅、镉、砷含量以及人体免疫学指标进行分析。结果矿工组血中铅、镉、砷含量几何均数分别为216.57,5.04,58.65μg/L,矿区居民组血中铅、镉、砷含量几何均数分别为143.62,2.42,33.24μg/L,均高于对照人群,几何均数分别为81.54,1.18,11.50μg/L(P<0.01)。3组人群尿液中的各种毒物差异有统计学意义(P<0.01)。矿工和矿区居民的免疫功能相对于对照组均有不同程度的下降(P<0.01)。结论接触铅、镉和砷的矿区矿工和居民免疫功能受到了不同程度的损害。     

Mortality and cancer incidence among a population previously exposed to environmental cadmium

Objectives: This paper evaluates the associations of previous exposure to environmental cadmium (Cd) and renal function with total mortality and cancer incidence. Methods: The study population comprised 275 residents (aged 40–92 years at baseline) in a Cd-polluted area located on Tsushima Island, Nagasaki, Japan. In the study area, the dietary intake of Cd decreased because the soil of the Cd-polluted rice fields was replaced with new soil between 1980 and 1983. The mortality rate from 1982 to 1997 and cancer incidence from 1985 to 1996 were investigated. Standardized mortality and incidence ratios (SMR and SIR) were calculated by using regional reference rates. The associations of renal function and urinary Cd levels with total mortality and cancer incidence were evaluated with Cox regression models. Results: The SMR for all subjects, and those with a urinary β₂-microglobulin (U-β₂M) concentration ≥1,000 μg/g creatinine (Cr) and <1,000 μg/g Cr was estimated at 90 [95% confidence interval (CI) 73–109], 138 (95% CI 101–183) and 66 (95% CI 49–87), respectively. After adjustment for age and other potential confounders, in men, serum β₂M (S-β₂M) (≥2.3 mg/l) and in women, serum Cr (≥1.2 mg/100 ml), relative clearance of β₂M (≥1%) and U-β₂M (≥1,000 μg/g Cr), were associated with a significantly increased risk of mortality, with hazard ratios exceeding 2.0. After further adjustment for log(U-β₂M), the rate ratio of deaths associated with, in men, increased S-β₂M was 2.53 (95% CI 0.97–6.65) and, in women, increased serum Cr (S-Cr) concentrations was 2.75 (95% CI 1.24–6.14). Urinary Cd concentrations (≥10 μg/g Cr) were not significantly associated with mortality. The overall SIR of all malignant neoplasms was 71 (95% CI 44–107). Conclusions: These findings suggest that renal tubule dysfunction and a reduced glomerular filtration rate are predictors of mortality among persons previously exposed to environmental Cd. However, the results also suggest that overall mortality rates in Cd-polluted areas are not necessarily increased, because of the low mortality among those with no, or only slight, signs of low-molecular weight proteinuria. Overall cancer incidence may not be increased among residents in Cd-polluted areas. Received: 6 July 2000 / Accepted: 9 December 2000     

Relationship of lead and cadmium to essential elements in hair, teeth, and nails of environmentally exposed people

The aim of this investigation was to evaluate the environmental exposure to Pb and Cd during 1990-1997 of inhabitants of Katowice District, which is an area of high environmental exposure to lead and cadmium, as well as exposure to Fe, Zn, Cu, Mn, Ni, Cr, Ca, Na, and K, on the basis of concentrations in hair, teeth, and nails. This investigation was to explain if accumulation of Pb and Cd can affect the concentration of such essential metals as Fe, Zn, Cu, and Ca. Inhabitants of the Beskid area constituted a control group. Analysis of the aforementioned elements was carried out on 624 hair samples, 785-tooth- samples, and 338 nail samples taking into consideration sex, age (<15, 16-30, >30 years), and type of teeth (incisor, canine, molar, premolar). Concentrations of elements in the media investigated were determined using atomic absorption spectroscopy. The results were calculated using the Statistica program. The major statistical analysis focuses on determining analysis of variance by MANOVA/ANOVA, Rao R (P<0.05), Spjotvolla-Stoline'a test, and cluster analysis (1-Pearson r). The investigation revealed that among the media investigated, Pb concentration in hair is an environmental marker of exposure to this metal in the human organism and depends on sex and age. It was also observed that an increase in Pb concentration in hair causes a decrease in Fe and Ca concentrations and changes the ratios of essential metals: Fe/Cu, Fe/Zn, and Ca/Zn. It is concluded that not only in blood but also in the hair, lead significantly influences Ca and Fe. Analysis of nail samples of people living in Katowice District indicated that an increasing concentration of Pb decreases concentrations of copper and zinc. Increased accumulation of such metals as Ni, Cr, and Mn in teeth was observed for samples taken from inhabitants of Katowice District.     

Interrelationships between cadmium, zinc and antioxidants in the liver of the rat exposed orally to relatively high doses of cadmium and zinc

Zinc (Zn) reduces cadmium (Cd)-induced toxicity in the liver although it increases Cd tissue burden in some conditions; hence, the present study is designed to study the relationships between Cd, Zn and antioxidants in the liver of rats exposed to Cd. Livers of male rats which received orally relatively high doses of Cd (200 mg Cd/L as Cd chloride or Cd (200 mg/L)+Zn (500 mg Zn as Zn chloride) during five weeks, were investigated. Cd induced an accumulation of Cd and Zn in parallel to depletion in important variables (GSH, GSH/GSSG, CuZn-SOD and GPx activities) and to elevation in others (Cd/Zn and GSSG). Cd, did not affect CuZn SOD/GPx, nor Mn-SOD in the liver. Cd accumulation, Cd/Zn, CuZn SOD activity and CuZn SOD/GPx, was increased remarkably under Zn action. Zn supply ameliorated GSH level and partially reversed the decrease in GSH/GSSG, but it did not ameliorate GPx activity. Analysis showed high correlations between Cd and the majority of the variables, while Zn was positively correlated with only GSSG. We suggest from our results that Zn has indirect ameliorative effects on Cd-induced toxicity in the liver and that the increase in Cd retention is probably the key mechanism modulating, in the case of relatively high doses of Cd, the antioxidant response during exposure to Cd and Zn.     

长期接触低浓度氨工人肝功能的改变

对长期接触低浓度氨工人血氨和血清ALT进行测定,以探讨长期接氨对肝功能的影响。结果表明长期低浓度氨接触可使肝功能出现轻微异常,脱离氨作业环境后,肝功能可逐步恢复正常。     

Indicators of cardiovascular risk among workers exposed to high intermittent levels of carbon disulphide

The effects of exposure to carbon disulphide have been studied mostly among workers in the viscous rayon industry, where the usual exposure profile has been relatively steady exposure over work shifts. We investigated 13 workers in a small chemical company who were exposed to low levels, peaking intermittently to relatively high levels in the range of 100-200 ppm at the end of the work shift, a pattern that may change the risk profile. Our investigation was part of a compliance order that was fought by the company and our access and follow-up was limited. Two workers had burns on their bodies associated with exposure to caustic. Four had elevations in total serum cholesterol, one had elevated serum triglycerides and three had elevations in fasting blood glucose--two of them were known to be diabetics before employment and one had a history of unexplained peripheral neuropathy. No consistent pattern suggestive of a defined lipoprotein abnormality was obvious but several atherogenic profiles were observed. Five had abnormalities on electrocardiogram, four of whom appeared to be among the most heavily exposed. The presence of these changes taken together in this context may suggest accelerated atherosclerotic changes. Tests of liver and kidney function were within the normal range for all workers, as was a complete blood count. Four of the workers had evidence of a bilateral reduction in hearing threshold at 4,000 Hz. A complete set of recommendations was forwarded to the employer, emphasizing further control of exposure to carbon disulphide, personal protection requirements and a cardiovascular risk reduction programme. Conditions improved in the plant following modifications introduced in response to a stop work order from the provincial government's occupational health and safety agency. However, a fire in 1998 put the company out of business and ended further follow-up or interventions. We conclude that these findings, while difficult to interpret because of the circumstances of the investigation, are compatible with an atherogenic effect of exposure to peaking levels of carbon disulphide. The observation should be tested in a larger population with fewer confounding factors and greater control over the investigation.     

Oxidative DNA damage in relation to neurotoxicity in the brain of mice exposed to arsenic at environmentally relevant levels

To clarify the association between oxidative DNA damage and the neurotoxicity of arsenic, the formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) as an index of oxidative DNA damage in the brain was examined in mice fed with drinking water containing 1 or 2 ppm arsenic, using an HPLC-electrochemical detector and immunohistochemical method. 8-OHdG levels were significantly increased in the brain of mice given arsenic and its immunoreactivity was distributed in the cerebral and cerebellar cortexes. Cerebral cortex neurons and Purkinje cells in the cerebellar cortex showed degenerative changes in accordance with the distribution of 8-OHdG immunoreactivity. The levels of arsenic in this study were lower than those reported in epidemiological studies. Thus, we conclude that environmentally relevant levels of arsenic induce pathological changes through oxidative DNA damage in the brain tissues in vivo and that cerebral and cerebellar cortex neurons seem to be the major targets of arsenic neurotoxicity.     

Histological changes in the liver of Oreochromis mossambicus (Cichlidae) after exposure to cadmium and zinc

The toxic effects, of two heavy metals, cadmium (Cd) and zinc (Zn), on the histology of the liver of the southern African freshwater fish Oreochromis mossambicus, were investigated. The goal was to identify whether metal concentrations and exposure period influence the degree and nature of histological changes in the liver of exposed fish. Selected fish were exposed to a mixture of 5% concentrations of the LC₅₀ of cadmium and zinc and to a mixture of 10% concentrations of the LC₅₀ of cadmium and zinc, over both short- and long-term exposure periods. Similar histological changes occurred in the livers of specimens exposed to both 5% and 10% concentrations, indicating a definite toxic response to both the metal concentrations. These histological changes included hyalinization, hepatocyte vacuolation, cellular swelling, and congestion of blood vessels. The intensity of these histological changes was, however, influenced by the extent of the exposure period.     

Effect of barbiturates on the liver of rats exposed to carbon disulphide vapour

Summary Three-day pretreatment of rats with a daily dose of 80 mg/kg phenobarbital sodium i.p. and subsequent 8-hour exposure to 20 or 200 ppm CS₂, followed by a narcotic dose of 100 mg/kg hexobarbital sodium i.p., did not cause appreciable fat accumulation in the liver cells, SGOT and SGPT also remaining normal. Fat accumulation also was absent when exposure to 200 ppm CS₂ (48 hrs and 7 days, respectively) was preceded by hexobarbital treatment. By contrast, extensive accumulation of fat in the Kupffer cells as well as in the centrilobular, intermediate and acino-peripheral hepatic areas was found in phenobarbital-pretreated rats 24 hrs after oral administration of a very high CS₂ dose of 1 ml/kg in 1 ml/kg olive oil. At the same time, SGOT and the esterified fatty acids in the liver were raised. Accumulation of fat in the liver cells was less extensive in rats not having received phenobarbital pretreatment. Administration of olive oil alone remained without effect. From the results obtained it is concluded that degenerative hepatic damage (e.g. fat accumulation or necroses) is not likely to develop in individuals without hepatic disease receiving barbiturate-containing drug therapy, who at the workplace are exposed to a concentration of 20 ppm CS₂ (maximum acceptable concentration, threshold limit value), with occasional peak concentrations around 200 ppm.     

Changes in tubular dysfunction marker levels in parallel with the levels of copper,rather than cadmium,in urine of middle-aged women in non-polluted areas

OBJECTIVE: This study was initiated to investigate if and to what extent the elevations in urinary alpha(1)- and beta(2)-microglobulins (alpha(1)-MG and beta(2)-MG, respectively) are specific to Cd nephro-toxicity. METHODS: Stored urine samples, collected from 1,000 adult women in 11 prefectures all over Japan, were analysed for eight elements (Ca, Cd, Co, Cu, Mg, Mn, Ni and Zn), alpha(1)-MG, beta(2)-MG, creatinine (CR) and specific gravity (SG); the data were cited from previous publications. The levels of eight elements and two MGs were expressed as observed and after correction for CR or SG (1.016). Age, CR and SG distributed normally, whereas two MGs and eight elements distributed log-normally. The 1,000 cases were classified into quartiles (i.e., 250 cases/group) of the lowest to the highest values (Groups A to D) for each element. RESULTS: alpha(1)-MG and beta(2)-MG increased as a function of Ca, Cd and Cu when corrected for CR, and the two MGs increased in parallel only with Cd and Cu after SG correction. Prevalence of alpha(1)-MG-uria (cut-off values; 5.3 and 6.5 mg/g cr or l) and beta(2)-MG-uria (cut-off values; 300 and 400 microg/g cr or l) was elevated with increasing Ca, Cd and Cu when corrected for CR, but only with Cd and Cu when corrected for SG. Multiple regression analysis of 353 cases of 50-59 year-old women with the eight element levels as independent variables and one of the two MGs as a dependent variable showed that Cu was the most influential element, and both Cd and Zn were less influential. CONCLUSIONS: Urinary levels of alpha(1)-MG and beta(2)-MG among women with no environmental Cd exposure correlated more closely with Cu levels than Cd levels in urine. The observation suggests that sub-clinical elevation in alpha(1)-MG and beta(2)-MG is not always attributable to nephro-toxicity of Cd, and that consideration on possible effects of other elements such as Cu is necessary.     

Trichloro-compounds in the urine of humans exposed to methyl chloroform at sub-threshold levels

Summary Survey was carried out in 4 intaglio printing factories where methyl chloroform, the sole organic solvent in the entire process, was employed to remove excess ink. The medical interview and clinico-laboratory examinations revealed no dose-consistent adverse effects among the four groups of workers who had been exposed at the average concentrations of 4, 25, 28 and 53 ppm, respectively. Linear relationship was observed between environmental vapour concentrations and total trichloro-compounds levels in the urine of workers exposed. Increased levels of urinary metabolites towards the week-end, together with the biological half-life of 8.7 hrs as measured from the decrease in the urinary metabolites, suggested the storage of methyl chloroform in the body after repeated exposures. Perusal of previous reports as well as present results regarding toxic potency of methyl chloroform supports, with emphasis of possible accumulation, the German threshold of 200 ppm as a tentative value of choice for the time being.A part of this work was presented at the 46th Annual Meeting of the Japanese Association of Industrial Health, Osaka, April 6–8, 1973.     

Lysosomal responses in the digestive gland of the freshwater mussel, Dreissena polymorpha, experimentally exposed to cadmium

In order to examine the possible use of lysosomal response as a biomarker of freshwater quality, structural changes of lysosomes were measured by image analysis in the digestive gland of the zebra mussel, Dreissena polymorpha, exposed in laboratory conditions to cadmium. Mussels were exposed to the metal (10 and 200 microg/L) for 3 weeks and randomly collected after 7 and 21 days. At each treatment day, digestive tissues were excised and beta-glucuronidase activity was revealed in cryotome sections. Four stereological parameters were calculated: lysosomal volume density, lysosomal surface density, lysosomal surface to volume ratio, and lysosomal numerical density. The changes observed in this study reflected a general activation of the lysosomal system, including an increase in both the number and the size of lysosomes in the digestive gland cells of mussels exposed to cadmium. The digestive lysosomal response in zebra mussels was related to exposure time and to metal concentration, demonstrating the potential of this biomarker in freshwater biomonitoring.     

肝癌患者发病前血清中高尔基体糖蛋白73水平的回顾性动态观察

目的 探讨肝癌发病前后高尔基体糖蛋白73 (GP73)的动态水平及相关因素.方法 2007至2012年对一组乙型肝炎表面抗原(HBsAg)阳性者人群开展一年两次的周期性的筛查,统一保留血标本于生物样本库,直至肝癌发生.将肝癌发病时及发病前30个月内6个时点中,至少有3次血标本并有B超临床检查结果的39例肝癌患者列为血清GP73检测分析对象,最终获得162个标本.采用双抗体夹心ELISA法检测GP73.用stata软件作时序间分析并进行不同分组间差异的统计学检验.结果 肝癌发病时的39例患者GP73检测值为(126.77±73.73)μg/L,发病前5次GP73检测的平均值分别为(128.32±81.18)、(129.97±83.62)、(127.38±80.10)、(135.52±97.88)及(138.24 ±93.58) μg/L,差异无统计学意义(F=0.07,P=0.997).39例肝癌发病前后的GP73水平未见明显的趋势变化.162个检测样本按B超检查结果划分为不伴有肝硬化(63例次)和伴有肝硬化(99例次)两组,GP73平均水平分别为(97.16 ±51.39)、(151.20 ±91.68) μg/L,差异有统计学意义(F=18.22,P＜0.01).进一步以GP73均值(130.19 μg/L)将调查对象分为两组,不伴有肝硬化者中只有1/14的患者GP73水平高于平均值,而伴有肝硬化者(25例)中有12例的GP73水平高于平均值,差异有统计学意义(P =0.013).拟合回归模型也显示GP73与时间序列不相关(t=0.75,P=0.455),而与肝硬化相关(t=4.30,P＜0.01).结论 肝癌患者发病时及发病前30个月内的GP73水平动态变化不大.肝癌患者GP73水平的高低是由肝病背景所决定的;肝硬化可能是一个主要的影响因素或混杂因素.     

慢性湿疹589例斑贴试验结果分析

为分析职业性苯中毒工人外周血单个核细胞中T细胞受体删除DNA环(TRECs)的含量,了解苯中毒工人胸腺近期输出功能变化,采用实时荧光定量聚合酶链反应(real time PCR)和TaqMan方法检测苯中毒和健康人外周血单个核细胞中TRECs的含量。结果显示,TRECs含量苯中毒观察对象2·97±1·31、轻度苯中毒1·73±1·11、中度苯中毒2·28±1·44、重度苯中毒1·91±1·95,各组患者每1000个外周血单个核细胞中TRECs含量均明显低于健康组7·39±6·83(P<0·05),轻度和重度苯中毒组TRECs含量显著低于苯中毒观察对象组(P<0·05)。重度苯中毒组接苯时间>3的工人TRECs含量显著低于接苯时间≤3年者,苯中毒观察对象组接苯时间>5年的工人TRECs含量显著低于≤5年者(P<0·05)。提示苯中毒患者胸腺近期输出功能低下。     

Critical evaluation and review of cadmium concentrations in blood for use in occupational health according to the TRACY protocol

 Cadmium in blood (B-Cd) may be used to assess recent exposure to cadmium in the working or general environment. In a paper published elsewhere pooled reference values using meta-analysis of B-Cd values in general-population studies were calculated. In the present study tentative reference intervals were described which can be used for comparison with data from occupationally exposed groups or individuals. The selection of studies was done according to criteria as published by the international project TRACY. For this purpose, 800 publications covering the period 1983–1992 were reviewed on their suitability for establishing tentative reference intervals. From these 800 publications, four finally met the selection criteria. Most important criteria for selection were the check for contamination during sampling of the blood, the storage and pretreatment procedures, and the existence of internal and external quality control programs. Also, stratifications into sex, smoking habits and occupation were important selection criteria. It turned out that for non-smoking white-collar workers in the age range of 19–65 years, B-Cd values were below 0.8 μg/l for most areas. All other groups within this age group, e.g., white collar workers in Japan, blue-collar workers, and smokers tend to have higher B-Cd values in these sequences. Blue-collar workers not clearly exposed to Cd have higher values than white-collar workers, indicating still some minor exposure. It is not clear if this small exposure has an occupational or lifestyle (e.g., diet) origin. Geographic regions also show an influence on B-Cd levels, e.g., values in Japan are higher than elsewhere. This influence may be due to differences in diet. The conclusion will be that reference values for B-Cd in fact are area-dependent. Received: 10 June 1996/Accepted: 16 October 1996     

判别分析在铅接触者健康监护结果判定中的作用

目的：探讨判别分析在铅接触者健康监护结果判定中的应用价值。方法：对某蓄电池制造业近年的监测、体检资料进行判别分析。结果：建立函数式为F1＝0．204Zi 3.210Pi 14.855Ci-1.892和F2=0.829Zi 14.767Pi 23.681Ci-11.329。并用该函数式对所建模型资料和另一组资料进行判别分类，判别吻合率分别为97％和96％，经检验模型判定与实际结果均有非常显著的相关（P＜0．001）。结论：用所建模型对该地区铅接触者健康监护结果来判定分类是可行的，且具有广阔的应用前景。