职业接触二甲基乙酰胺工人尿中甲基乙酰胺生物限值研究

目的 研制我国职业接触二甲基乙酰胺(DMAC)工人尿中甲基乙酰胺(NMAC)的生物限值.方法 选择3家氨纶生产企业201名接触DMAC工人,应用个体采样器采集工作周末工作日的车间空气样品,用气相色谱法检测个体DMAC接触水平,同时收集当日工人班末尿样,应用气相色谱法测定尿中NMAC浓度以评价DMAC接触工人内暴露水平.通过内外剂量的回归方程、百分位数和相对内暴露(RIE)指数计算,推荐我国职业接触二甲基乙酰胺工人尿中NMAC生物接触限值.结果 201名DMAC接触工人中接触浓度符合我国DMAC接触限值133名,占66.2％,接触浓度范围在0.40～300.12mg/m3,几何平均浓度为19.4 mg/m3.工作周末班未尿中NMAC浓度范围为1.30～189.42 mg/g Cr,几何平均浓度为23.7 mg/g Cr.尿中NMAC浓度与个体DMAC外暴露浓度有相关性(F=188.872,R2=0.487,P＜0.001),回归方程为log(NMAC mg/g Cr)=0.685+0.455 log(DMAC mg/m3).以我国DMAC职业接触限值PC-TWA为20 mg/m3推算,尿中NMAC浓度为18.92 mg/g Cr.当工作场所空气中DMAC＜20 mg/m3时,90％的工人尿中NMAC水平为23.9 mg/g Cr.按RIE指数推算的尿中NMAC为19.0 mg/g Cr.结论 参考国外DMAC生物接触限值标准,建议我国DMAC生物接触限值为工作周末班未尿中NMAC 20 mg/g Cr.     

二甲基甲酰胺生物接触限值的研究

目的研究我国职业接触二甲基甲酰胺(DMF)的生物限值。方法气相色谱法检测工作场所空气中二甲基甲酰胺浓度和作业工人班末尿中甲基甲酰胺(NMF)浓度,同时研究两者的相关性。结果 DMF接触者班末尿中NMF浓度与工作场所空气中DMF浓度有密切正相关(Y=0.3389X+3.0297,r=0.9986,P0.01)。根据作业场所空气中DMF的国家职业卫生标准,按回归方程推导出职业接触DMF的生物限值。结论 DMF接触者生物接触限值推荐值:班末尿中NMF为12.0 mg/gCr。     

二硫化碳接触工人尿2-硫代噻唑烷-4-羧酸排泄规律的研究

目的　探讨二硫化碳 (CS2 )接触工人尿 2 硫代噻唑烷 4 羧酸 (TTCA)的排泄规律 ,为制定CS2 短时接触生物监测提供实验依据。方法　将受试对象分为 3组进行实验 :(1) 14名非CS2 接触者在某CS2 车间暴露 2h后收集不同时段尿液 ,分析其TTCA浓度变化 ;(2 )某CS2 车间 15名CS2 接触工人三班倒休息 4 8h后上班 ,连续收集 3d班前、班中、班末尿 ,分析其TTCA浓度变化 ;(3)收集 4 0名长期接触CS2 工人班末尿 ,分析其TTCA浓度变化与工人接触CS2 的 8h时间加权平均浓度 (PC TWA)的关系。结果　第 1组研究结果显示 ,接触CS2 4h后 (此时已停止接触 2h)尿中TTCA含量达到最高值 [(1.0 3± 0 .72 )mg/gCr];第 2组研究结果显示 ,班前尿TTCA含量极低 [(0 .37± 0 .2 8)mg/gCr],与班中尿 [上班后 4h(1.2 3± 0 .71)mg/gCr]及班末尿 [(1.31± 0 .78)mg/gCr]比较 ,差异有显著性 (P <0 .0 1) ,而班中尿TTCA值与班末尿相比 ,差异无显著性 (P >0 .0 5 ) ;第 3组研究结果显示 ,班末尿TTCA值与工人PC TWA之间有直线关系 [Y(TTCAmg/gCr) =1.16 36X(CS2 mg/m3) - 5 .4 116 ]。结论　班末尿TTCA值可作为CS2 接触工人的生物监测指标。     

锑及其化合物的职业接触生物限值研究

目的探讨我国锑及其化合物的职业接触生物限值。方法选择广西地区一家锑白粉(Sb2O3)加工厂和一家锑矿冶炼厂的办公室行政人员33名作为对照组;83名工作场所工人作为接触组,采集并检测空气样品和生物样品(尿样),对检测结果进行统计分析。结果两厂均存在接触组空气中锑及其化合物浓度高于对照组,差异有统计学意义(P0.01);两厂均存在接触组班末尿锑浓度高于对照组的情况,差异有统计学意义(P0.01);全体调查对象接触空气中锑及其化合物的浓度与班末尿锑浓度间存在良好的相关关系(n=116,r0.5);班末尿锑浓度经对数正态性转换后与空气中锑及其化合物浓度做直线回归分析,把职业接触限值(PC-TWA:0.5mg/m3)代入回归方程,推算出班末尿锑浓度为60或85μg/g肌酐。结论建议锑及其化合物的职业接触生物限值为班末尿锑60或85μg/g肌酐。     

职业接触苯乙烯的生物限值研究

目的：研究职业接触苯乙烯的生物限值。方法：高效液相色谱法测定苯乙烯作业工人班前、班后尿中苯乙醛酸（PGA）和苯乙醇酸（MA）的含量，监测工人8h苯乙烯的接触水平，同时研究两者的相关性。结果：尿中的PGA和MA浓度与苯乙烯的接触量有明显的剂量－反应关系。根据作业场所空气中苯乙烯的国家卫生标准，按回归方程推导出职业接触苯乙烯的生物限值。结论：对职业接触苯乙烯的生物限值提出的推荐值：工作班末MA为220mmol/mol肌酐或300mg/g肌酐，下一班前为88mmol/mol肌酐或120mg/g肌酐；PGA班末为7mmol/mol肌酐或100mg/g肌酐，下一班前为30mmol/mol肌酐或40mg/g肌酐。     

甲苯二异氰酸酯职业接触人群尿中代谢产物调查

为探讨职业环境中甲苯二异氰酸酯(TDI)水平和接触人群尿中甲苯二胺(TDA)水平的关系,为建立TDI职业接触的生物限值提供依据,选取深圳市2家企业61名作业工人作为接触组,另选取同企业的50名行政、后勤人员(不接触TDI)为对照组,采用气相色谱法测定车间空气中TDI水平以及2组人群尿中TDA水平,并对其相关关系进行分析。结果显示,接触组工人接触TDI浓度中位数为0.051 mg/m3,尿中TDA浓度中位数为0.563μmol/mol Cr;对照组人群接触TDI水平低于检出限(0.000 2 mg/m3),尿中TDA水平低于检出限(0.025μmol/mol Cr)。接触组人群班末尿中TDA的水平与工作场所空气中TDI水平呈正相关性[r=0.675,P0.05],尿中TDA水平(y赞,μmol/mol Cr)对工作场所空气中TDI浓度(x,mg/m3)的回归方程为:y赞=8.065 x+0.147(r=0.675,P0.05),按照我国现行的工作场所空气中TDI时间加权平均容许浓度(PCTWA=0.1 mg/m3)推算,接触工人班末尿中TDA水平为0.954μmol/mol Cr。提示本研究的职业接触甲苯二异氰酸酯生物标志物监测方法适用于评价作业环境接触人群的职业接触水平。     

职业接触二甲苯尿中甲基马尿酸生物限值的研究

选择不同暴露水平的二甲苯接触个体,检测个体二甲苯暴露浓度,同时采集当日工人班末尿样,对尿中二甲苯的代谢产物甲基马尿酸的含量进行测定,将二甲苯的外暴露空气浓度与体内甲基马尿酸代谢量进行回归分析,结合国外限值资料,提出适合我国职业卫生现状的甲基马尿酸生物限值的建议。接触工人在空气中二甲苯浓度为0～144.21 mg/m3时,班末尿中甲基马尿酸(MHA)与空气中二甲苯浓度之间存在良好相关性,肌酐校正回归方程为y(g/g肌酐)=0.0052x(mg/m3)+0.0112,r=0.731;比重校正回归方程为y(g/L)=0.0089x(mg/m3)-0.0259,r=0.793。将我国二甲苯职业接触限值50 mg/m3分别代入回归方程,推出工作班末尿中甲基马尿酸含量为0.271 g/g肌酐和0.419 g/L。依据我国二甲苯实际接触情况,参考国外相关标准和文献,建议我国职业接触二甲苯的代谢产物尿中甲基马尿酸的生物接触限值为班末尿0.3 g/g肌酐或0.4 g/L。     

尿中苯巯基尿酸的高效液相色谱-质谱测定方法

目的 研制我国职业接触苯工人尿中苯巯基尿酸(SPMA)的生物限值.方法 在苯作业车间选择空气中苯浓度在32.5 mg/m~3以下接苯工人55人,应用个体采样器采集空气样品,用气相色谱法检测作业者个体苯接触水平,同时采集当日工人班后尿,应用高压液相色谱/质谱法(HPLC/MS)测定尿中SPMA含量以评价苯接触者的内暴露水平,内外暴露水平的比较用相对内暴露指数(RIE)加以评定.结果 接苯工人工作环境空气苯浓度范围为0.71～32.17 mg/m~3,几何平均浓度为6.98 mg/m~3,中位数为7.50 mg/m~3,尿中SPMA与个体苯暴露量存在良好的线性关系Y(μg/g Cr)=-8.625+18.367 X(mg/m~3),r=0.8035(P<0.01);将我国职业苯接触限值时间加权平均容许浓度(PC-TWA=6 mg/m~3)代入回归方程,推算工作班后尿中SPMA含量为101.58μg/g Cr.计算的RIE指数显示,接触1 mg/m~3苯可平均代谢转化为尿中SPMA 18.23 μg/g Cr,并且随接苯水平的上升其代谢转化效率呈下降趋势.结论 参考国外SPMA生物限值标准,建议我国职业接触苯生物限值班后尿中SPMA为100μg/gCr(47μmol/mol Cr).     

二氯甲烷职业接触内外暴露水平的关系研究

目的探讨职业接触二氯甲烷的生物接触限值。方法以50名职业接触二氯甲烷工人为接触组,另选择同一企业43名行政人员为对照组,检测工作场所空气中二氯甲烷水平,以及作业工人班末尿中的二氯甲烷水平,并进行两者间的相关分析,制订二氯甲烷的生物接触限值。结果班末尿中二氯甲烷水平与工作场所空气中二氯甲烷时间加权平均浓度具有相关性(决定系数为0.962,P<0.05),回归方程为y=0.001 1x+0.038 8(P<0.001)。结论劳动者职业接触二氯甲烷后尿中内暴露与外暴露之间存在剂量-效应关系,为制定我国职业接触二氯甲烷的生物限值提供了科学依据。     

职业接触汞生物限值的研制

对职业接触汞工人进行体检和尿汞检测,分析尿汞与工作场所空气中汞浓度及临床表现的关系,并参考国外职业接触汞的生物限值,提出我国职业接触汞的生物限值为尿总汞20μmol/mol Cr（35μg/g Cr）。     

Cohort study among workers exposed to benzene in China: II. Exposure assessment

This report describes a retrospective exposure assessment method used in a follow-up mortality study of workers exposed to benzene. The approach quantified historical exposure to benzene in a multi-industry, multicenter cohort, involving 672 factories in 12 cities in China. Historical exposure data were collected to obtain exposure information related to 1,427 work units (departments) and 3,179 unique job titles from benzene-producing or -using factories in which written records and other data sources were evaluated. The basic unit for exposure assessment was a factory/work unit/job title combination which was considered separately during each of seven calendar-year time periods between 1949 and 1987 for a total of 18,435 exposure assignments. Historical information collected to estimate exposure included benzene monitoring data; lists of raw materials and factory products, and the percentage of benzene in each; the total amount and dates of use of benzene or benzene-containing materials; use of engineering controls and personal protective equipment; and other available exposure information. Overall, 38% (ranging from 3% for the earliest periods to 67% for the last period) of the estimates were based primarily on benzene monitoring data. In the absence of job-specific benzene monitoring data for a given calendar period, measurement results or exposure estimates for similar jobs and/or other calendar periods were used in conjunction with other exposure information to derive estimates. Estimated exposure levels are presented by industries and occupations. The highest average exposures during 1949–1987 were observed for the rubber and plastic industry (30.7 ppm), and for rubber glue applicators (52.6 ppm).     

Occupational epidemiology in the rubber industry: Implications of exposure variability

The variability of exposure has important implications for the design of occupational epidemiologic studies. To assess the influence of this variability in the rubber industry, the efficiency of different schemes for classification of exposure to particulates, cyclohexane-soluble contaminants, and solvents was assessed. Groupings based on job title, plant, factors affecting exposure, published classifications, and the International Standard Classification of Occupations of the International Labor Organization (ISCO-ILO) were compared. Statistical parameters for contrast in average exposure between groups and precision of average exposure within groups were developed to enable comparison of the efficiency of different classification schemes. Grouping of exposure to particulates and dermal exposure appeared to be less efficient than grouping of exposure to solvents. Grouping of solvent exposure using occupational title groups, existing classification schemes, and schemes based on factors affecting exposure showed comparable high resolution in exposure levels. Even the most detailed grouping schemes based on the combination of plant and occupational title group showed relatively modest resolution in particulate and dermal exposure levels. Groupings based on factors affecting exposure showed similar resolution for these exposures, but had higher precision due to having fewer groups. Application of optimal exposure grouping strategies will benefit new research on cancer among rubber workers. Eventually, this might resolve the situation in which a complete industry was included on the list of proven human carcinogens.     

Fertility and exposure to solvents among families in the Agricultural Health Study

Background

Several studies have reported associations between solvent exposure and reduced female fertility, but the evidence is inconclusive for male fertility.

Objectives

To investigate the impact of solvent exposure on subfertility among families of male licensed pesticide applicators in the Agricultural Health Study cohort.

Methods

The couples enrolled between 1993 and 1997. Cross‐sectional questionnaire information on work tasks was used to assess exposure to solvents. The data were limited to couples (wife aged less than 40 years) with an attempt at pregnancy in the last four years (n = 2112).

Results

Twenty eight per cent of the couples were defined as subfertile (not conceiving a pregnancy after at least 12 months of unprotected intercourse, regardless of whether or not a pregnancy ultimately occurred). Adjusted subfertility odds ratios (OR) for exposure to solvents were calculated with logistic regression. Female (OR 1.42, 95% CI 1.15 to 1.75) and male exposure to solvents (OR 1.21 (95% CI 0.93 to 1.57) for monthly exposure and 1.40 (95% CI 0.97 to 2.03) for daily or weekly exposure) were associated with subfertility. In farming, spouses may share or exchange jobs. To account for potential dual exposure, variables for parental exposure (either parent exposed or both parents exposed) were also defined. Both were strongly associated with subfertility (OR 1.62 (95% CI 1.20 to 2.17) and OR 2.10 (95% CI 1.22 to 3.60), respectively).

Conclusions

Solvents may impair fertility of either gender, though the evidence for female effects is stronger than for male effects.     

Polybrominated diphenyl ethers (flame retardants) in mother-infant pairs in the Southeastern U.S.

Polybrominated diphenyl ethers (PBDEs) are commonly used flame retardants in foams, building material, electronics, and textiles. These chemicals leach into the environment, where they persist, and are found today in virtually every population worldwide. Several studies in recent years have detected the presence of PBDEs in maternal and infant samples. However, few of these studies were conducted in the U.S., and few examined paired or matched mother blood-cord blood samples. We analyzed serum from 10 mother-infant pairs for the presence of PBDEs in a patient population in the Southeastern U.S. Out of 35 measured PBDE congeners, five (BDE-28, -47, -99, -100, and -153) were present, with detection frequencies of 65–100 %. The total PBDE concentrations in maternal and infant sera were highly correlated (r² = 0.710, p = 0.0043). The levels of BDE-47, -99, and -100 and of total PBDEs were higher in the infant cord sera when compared with those in maternal sera (p < 0.017), suggesting that fetuses and neonates might have higher circulating concentrations of these potentially neurotoxic and endocrine disrupting chemicals compared with their mothers. The primary focus henceforward should be whether there are any deleterious effects from exposure to these chemicals on human health.     

Different acute effects of single-axis and multi-axis hand-arm vibration

Under laboratory conditions the effects of single-axis and multi-axis hand-arm vibration exposure on several strain parameters were tested in up to 20 male subjects. As parameters of these acute effects, the biodynamic vibration behavior of the hand-arm system, the electrical activity of the most affected muscle groups, the skin temperature, the vibration sensitivity of the fingertips, and the subjective vibration sensation were measured. When comparing simulated three-axis vibration exposure with single-axis vibration exposure, synergistic effects in the form of an increasing reaction could be found. It could be proven that the vector sum of the frequency-weighted acceleration in the three axes represents the acute effects better than does the weighted acceleration in the main axis alone. This summation has to take into account the relatively lower effects of vibration in the x- or y-direction compared with the z-direction. On the basis of the experimental results a new proposal for frequency weighting of the three different axes and an energetic summation procedure are derived. Application of this knowledge in the International Standard ISO 5349 is proposed.     

简易气体动式染毒装置的研制与应用

目的:根据实验需求,研制一种简易气体动式染毒装置.方法:染毒装置由水箱、配气箱、染毒盒和排气瓶4个部分组成.使用有机玻璃板制作箱体,利用排水法精确配气,利用重力作用和调节阀调节气流大小.结果:该装置设计简单合理,经实际使用,染毒效果良好.结论:该简易气体动式染毒装置成本低廉、制作简单、配气精确,可以重复使用,能够满足动式染毒实验需求.     

Cognitive effects of chronic exposure to lead and solvents

BACKGROUND: Occupational exposure to lead and solvents has declined steadily over the past 20 years, however, construction workers continue to be exposed to these neurotoxicants. The purpose of this study was to investigate the cognitive effects of chronic occupational exposure to lead and solvents. METHOD: Based on K-XRF of tibial bone lead and occupational history of solvent exposure, subjects were classified into four exposure groups: lead (N = 40), solvent (N = 39), lead/solvent (N = 45), and control (N = 33). All subjects completed tests to assess concentration, motor skills, memory, and mood. RESULTS: Relative to controls, the lead, solvent, and lead/solvent groups performed significantly more poorly on a test of verbal memory, while the lead and lead/solvent groups were slower than the solvent and control groups on a task of processing speed. Bone lead was a significant predictor of information processing speed and latency of response while solvent exposure was a significant predictor of verbal learning and memory. CONCLUSIONS: Bone lead was associated with slower speed of processing while exposure to lead and/or solvents reduced efficiency of verbal learning.     

Exposure of children to lead and cadmium from a mining area of Brazil

During the past 50 years the Ribeira river valley, in the southern part of the state of S?o Paulo, Brazil, had been under the influence of the full activity of a huge lead refinery and mine working by the side of the river. The plant completely stopped all kinds of industrial activities at the end of 1995, and part of the worker population and their families still remain living nearby in small communities. The objective of the study was to assess the exposure of children to lead and cadmium in these areas, where residual environmental contamination from the past industrial activity still exists. Blood samples of 295 children aged 7 to 14 years, residing in rural and urban areas around the mine and the refinery, were collected. A questionnaire was given to gather information on food habits, leisure activities, father's past employment, current and former residential places, and other variables. Blood lead and cadmium concentrations were analyzed by graphite furnace atomic absorption spectrometry using Zeeman background correction. Cadmium values obtained in this population were mostly below established quantification limits (0.5 microg/dl). The median of blood lead level (BLL) obtained in children living close to the lead refinery was 11.25 microg/dl, and the median in other mining regions far from the refinery was 4.4 microg/dl. Logistic regression analysis was conducted to examine the independent contribution of selected variables in predicting BLL in these children. The following variables showed significant association with high BLL: residential area close to the lead refinery [odds ratio (OR)=10.38 (95% confidence interval (Cl)=4.86-23.25)], former father's occupational lead exposure [OR=4.07 (95% Cl=1.82-9.24)], and male gender [OR=2.60 (95% Cl=1.24-5.62)].     

Exposure of hairdressers to the main cosmetics used in hairdressing salons in France: A preliminary study

In recent years, more attention has been given to chemical exposure in hairdressers. This increasing interest is largely due to the various respiratory and skin symptoms observed in hairdressers. According to these symptoms, hairdressers are in contact with various sources of exposure. Particularly in France, little information is available to assess professional exposure of hairdressers. In order to gather information to assess exposure in hairdressers, 11 hairdressing salons were visited. All the salons were located in Brest City (France). Preferentially, small hairdressing salons were visited. Observations were performed to obtain salon characteristics and to record workers' practices. Calculations revealed that in the worst-case scenario, dermal professional exposure reaches 14.68 and 13.67 mg/kg/day for hair coloring and highlighting mixtures, respectively. Inhalation exposure represents 14.2 and 18.1 mg/kg/day for hair coloring and highlighting mixtures, respectively. These exposure values represent baseline values for exposure of French hairdressers working in small hairdressing salons.     

Further reduction in lead exposure in women in general populations in Japan in the 1990s, and comparison with levels in east and south-east Asia

Objective: The objective of the study was to elucidate the current level of environmental lead (Pb) exposure of women in general population in Japan, where the use of organic Pb in automobile gasoline was phased out from 1973 to reach a zero level early in the 1980s. Methods: A survey was conducted in 27 sites throughout Japan from 1991 to 1997. Five hundred and eighty-eight non-smoking women from the sites offered 24-h food duplicate, peripheral blood, and spot urine samples. Pb in food duplicates (Pb-F), blood (Pb-B), and urine (Pb-U) were analyzed by inductively-coupled plasma mass spectrometry. The results of Pb-F and Pb-B were compared with observations from a study conducted from 1977 to 1981 on 339 women at the same sites. Log-normal distribution was assumed for the evaluation of the results. Results: Geometric means (GMs) of Pb-F, Pb-B, and Pb-U in the 1991–1997 study were 9.0 μg/day, 20.2 μg/l, and 2.18 μg/g creatinine, respectively. The values for Pb-F and Pb-B were substantially lower than the values (32.8 μg/day for Pb-F and 31.7 μg/l for Pb-B) obtained in the 1977–1981 study, which were already low when compared internationally. Cd-U values in the period from 1991 to 1997 also appeared to be among the lowest in the world. Analysis for time-dependent changes in Pb-U was, however, not possible at the time of this study because no values were available for the period from 1977 to 1981. Conclusions: Substantial reductions from 1977–1981 levels in environmental Pb exposure were observed among the study populations in Japan. Current exposure levels appear to be lower than those in other parts of Asia, the USA, and Europe. Received: 16 March 1999 / Accepted: 27 August 1999