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)。     

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。     

氯乙烯职业病危害及控制的研究进展

氯乙烯对暴露人群健康的危害是多方面的,除了氯乙烯急性中毒外,流行病学资料显示,氯乙烯主要是对肝脏、神经系统、消化系统和生殖系统等的危害,并引起肢端溶骨症。氯乙烯接触限值各国也不相同,目前,我国车间空气中氯乙烯的时间加权平均容许浓度为30mg／m3,我国2002规定的氯乙烯生物接触限值为工作周末的班末尿中三氯乙酸0．3mmol／L（50mg／L）。     

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。     

二甲基甲酰胺生物接触限值的研究

目的：探讨我国二甲基甲酰胺（DMF）的生物接触限值（BEI）。方法：实验室建立“车间空气中的DMF”、“尿中甲基甲酰胺（NMF）”气相色谱的监测方法,对浙江省某腈纶厂接触DMF作业现场进行劳动卫生学调查及车间空气中DMF浓度与班末尿中NMF含量相关性研究,动态观察职业接触者尿中NMF排泄量。结果：DMF接触者尿中NMF浓度与车间空气中的DMF浓度有密切正相关（Y＝0．296X－0．241,r＝0．984,P＝0．01）,脱离接触后尿中NMF衰减方程为Y＝3．704e^-0.323t,排出速率常数平均为－0．32/h,半排期为1．29h。当尿中NMF≥10mg/g Cr时,肝生化指标异常率为50．0％;当尿中NMF＜10mg/g Cr时,与对照组比较,肝生化指标差异显著性（P＞0．05）。结论：DMF接触者BEI：班末尿中NMF为10mg/g Cr。     

工作场所空气中硝基胍的职业接触限值研制

目的 研制工作场所空气中硝基胍的职业接触限值.方法 收集硝基胍的理化性质、毒理学资料(包括毒性、毒物动力学、毒作用机制等)、职业流行病学研究资料,在以上资料分析的基础上,按照工作场所有害因素职业接触限值研制的原则及方法,制订工作场所空气中硝基胍的职业接触限值.结果 建议将工作场所空气中硝基胍的短时间接触容许浓度定为5 mg/m3,时间加权平均容许浓度为2.5 mg/m3.结论 在进一步改进工艺,减少手工操作时间,加强工作场所通风换气情况下,工作场所空气中硝基胍的浓度可以降至建议的职业接触限值以下.     

江西省职业接触砷生物限值研制

目的研制江西省职业接触砷的生物限值。方法对接触砷危害的作业工人进行健康检查和尿砷检测,并结合国内外文献资料进行综合分析。结果对400名接触砷的职业工人进行尿砷测定,结果显示,尿总砷平均值为0．20mg／L,标准差为0．12mg／L,95％上限值为0．40mg／L。36名非职业接触人员尿总砷平均值为0．04mg／L,标准差为O．02mg／L,职业人群与非职业人群差异具有统计学意义（P〈0．01）。职业健康检查结果发现,9人出现砷斑等皮肤样病变。通过工作场所空气中砷及其化合物浓度测定,结合几例砷中毒患者的临床资料和国内外文献,经综合分析,提出江西省尿砷的职业接触限值。结论砷的生物指标较多,经综合分析,课题组认为以尿总砷作为判断指标更为科学合理,建议江西省职业接触砷的生物限值为尿总砷0．40mg／L。     

接触三硝基甲苯(TNT)工人尿中代谢产物的测定

有关三硝基甲苯（ＴＮＴ）在体内的毒代动力学及代谢产物的生物接触限值报道较少。一般认为对接触者进行生物监测是评价毒物多种途径进入人体的可靠指标［１］。目前国内处均在探索毒物在体内的接触阈限值，试图以此来代替某些毒物车间空气中最高容许浓度。为了解ＴＮＴ作...     

基准剂量在制定镉生物接触限值中的应用

目的研究基准剂量（BMD）在制定镉生物接触限值中的应用。方法选择某冶炼厂和某锌制品厂职业接触镉的工人为接触组，当地医护人员和商业人员为对照；尿镉为接触生物标志物；β-微球蛋白（β2-MG）、尿N-乙酰-β-D-氨基葡萄糖苷酶（UNAG）和尿白蛋白（UALB）为效应生物标志物，并均用尿肌酐校正；用BMDS Version 1．3．2软件（EPA．U．S）进行BMD计算。结果按照对照组效应指标的95％上限为参考值上限，求得各效应指标的异常发生率，与尿镉均有剂量-效应关系；计算得到BMD和基准剂量的可信限低限水平（BMDL）；以UBM为效应指标的生物接触限值为5μg／g Cr，与WHO推荐值相一致；以UNAG为效应指标的生物接触限值为3μg／gCr。结论用基准剂量法可以制定镉生物接触限值；推荐使用更为敏感的效应指标UNAG来确定镉的生物接触限值。     

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）。     

Short-term occupational exposure limits: a simplified approach

Summary This paper presents a simplified proposal for setting health standards based on short-term exposure limits (STEL). It presents an alternative to the approach by the German MAC Commission: with only three instead of five categories, no fixed excursion factors, but ranges; more restrictive duration of sampling; no fixed frequencies of the number of accepted excursions per workshift.     

Occupational exposure to benzene in the shoe industry

In order to determine the possible actual exposure to benzene in the shoe industry from industrially used solvents, glues, and paints containing benzene as a nondeclared constituent, phenol in urine and benzene in blood, as indices of internal exposure to benzene, were measured in workers (N = 33). Since toluene, in contrast to benzene, is declared as a constituent in several glues, toluene in the blood of workers was also analysed. All analyses were performed using gas chromatography. Urine samples were collected on Monday morning (MI) before work and on Wednesday (WI) before and (WII) after work. Venous blood samples were taken on Wednesday only, 1/2 hour after work. There was no difference in the phenol concentrations of MI and WI, while the phenol concentration of WII was about twice as high as that in WI. In all blood samples, benzene was found, as well as toluene, which was about four times higher in comparison with benzene. A correlation (r = 0.465; p less than .01) was found between the difference in pre- and postshift phenol concentrations (WII-WI) in urine and the benzene concentrations in blood. The results presented show that a trace amount of benzene, which is often not declared as a constitutent in industrially used chemicals, could be a source of marked exposure to benzene. It can also be concluded that changes in phenol in urine (if preshift and postshift samples are taken) might be a sufficiently sensitive parameter to assess exposure to benzene even when other data concerning the presence of benzene in the working atmosphere are not available.     

职业接触定量化定义探讨

目的比较化学物职业接触限值(OEL)与环境空气污染物浓度限值,探讨职业接触定量化的界定。方法搜集中国、美国、欧洲化学物OEL与环境空气污染物浓度限值,并进行统计分析。结果共收集到30种化学物的45对OEL和环境浓度限值。OEL和环境空气污染物浓度限值几何均数分别为2.09 mg/m3和0.01 mg/m3,OEL是环境空气污染物浓度限值的200.17倍。2限值回归方程为lgy=1.182 lgx-2.36[决定系数(R2)=0.567]。2限值概率密度函数曲线交点浓度值为0.092 9 mg/m3,是OEL的1/22.45,环境空气污染物浓度限值8.93倍。当浓度取1/20 OEL时,该浓度低于对应的环境空气污染物浓度限值比例为20%。结论当工作场所化学物浓度高于OEL 1/10时,可定义为职业接触。     

Urinary,Circulating, and Tissue Biomonitoring Studies Indicate Widespread Exposure to Bisphenol A

Background

Bisphenol A (BPA) is one of the highest-volume chemicals produced worldwide, and human exposure to BPA is thought to be ubiquitous. Thus, there are concerns that the amount of BPA to which humans are exposed may cause adverse health effects. Importantly, results from a large number of biomonitoring studies are at odds with the results from two toxicokinetic studies.

Objective

We examined several possibilities for why biomonitoring and toxicokinetic studies could come to seemingly conflicting conclusions.

Data sources

We examined > 80 published human biomonitoring studies that measured BPA concentrations in human tissues, urine, blood, and other fluids, along with two toxicokinetic studies of human BPA metabolism.

Data extraction and synthesis

The > 80 biomonitoring studies examined included measurements in thousands of individuals from several different countries, and these studies overwhelmingly detected BPA in individual adults, adolescents, and children. Unconjugated BPA was routinely detected in blood (in the nanograms per milliliter range), and conjugated BPA was routinely detected in the vast majority of urine samples (also in the nanograms per milliliter range). In stark contrast, toxicokinetic studies proposed that humans are not internally exposed to BPA. Some regulatory agencies have relied solely on these toxicokinetic models in their risk assessments.

Conclusions

Available data from biomonitoring studies clearly indicate that the general population is exposed to BPA and is at risk from internal exposure to unconjugated BPA. The two toxicokinetic studies that suggested human BPA exposure is negligible have significant deficiencies, are directly contradicted by hypothesis-driven studies, and are therefore not reliable for risk assessment purposes.     

Criteria for skin notation in different countries

BACKGROUND: Skin notation criteria was introduced almost 50 years ago as a qualitative indicator of a hazard related to dermal absorption at work. However, risk is not a qualitative term, but needs a quantitative measure to be useful for prevention. For this reason, some countries have developed alternative criteria for assigning skin notations to industrial chemicals. METHODS: The present analysis compares the current use of skin notations on lists of exposure limits for industrial chemicals in six countries. RESULTS: Up to one-third of industrial chemicals listed now have a skin notation. The criteria for assigning skin notation differ but cannot explain the substantial discrepancies between countries that otherwise have very comparable occupational exposure limits (OELs). CONCLUSIONS: The increasing number of chemicals with a skin notation requires a new approach to differentiating between degrees of risk. The first step will be to address the problems related to criteria for assigning skin notations, and the effect of penetration enhancers and mixtures.     

Chronic occupational exposure to organic solvents

Summary Twenty-two persons (20 men and 2 women) were examined for their external and internal exposure to the glycol ether 1-methoxypropan-2-ol (PGME) during the production, leak testing and mounting of brake-hoses. For the measurement of external exposure, personal air monitoring was the method of choice. Average concentrations of PGME of 82.2 mg/m³ (22.3 ppm), 68.6 mg/m³ (18.6 ppm) and 11.3 mg/m³ (3.1 ppm) were found in the air of the brakehose production, leak test and mounting areas, respectively. For the estimation of internal exposure to PGME, this glycol ether was measured in both urine and blood. The biological samples were taken post-shift. The highest internal exposure levels were found in the brakehose production section and in the leak test area. The average post-shift concentrations for PGME in workers in the brakehose production section were 4.6 mg/l in urine and 13.5 mg/l in blood; the corresponding figures for workers in the leak test area were 4.2 mg/l in urine and 11.0 mg/l in blood. In blood and urine samples of workers engaged in the mounting area, PGME levels were below the detection limits. The elimination kinetics of PGME were also studied in three highly exposed persons, and mean excretion half-lives of PGME of approximately 4.4 h were found. On the basis of our results we made a rough calculation of a future biological tolerance value: we would except that concentrations of 38-109 mg per litre of blood and 10–31 mg per litre of urine would correspond to the German MAK value for PGME (375 mg/m³).     

Urinary, circulating, and tissue biomonitoring studies indicate widespread exposure to bisphenol A

Bisphenol A (BPA) is one of the highest-volume chemicals produced worldwide, and human exposure to BPA is thought to be ubiquitous. Thus, there are concerns that the amount of BPA to which humans are exposed may cause adverse health effects. We examined many possibilities for why biomonitoring and toxicokinetic studies could come to seemingly conflicting conclusions. More than 80 published human biomonitoring studies that measured BPA concentrations in human tissues, urine, blood, and other fluids, along with two toxicokinetic studies of human BPA metabolism were examined. Unconjugated BPA was routinely detected in blood (in the nanograms per milliliter range), and conjugated BPA was routinely detected in the vast majority of urine samples (also in the nanograms per milliliter range). In stark contrast, toxicokinetic studies proposed that humans are not internally exposed to BPA. Available data from biomonitoring studies clearly indicate that the general population is exposed to BPA and is at risk from internal exposure to unconjugated BPA. The two toxicokinetic studies that suggested human BPA exposure is negligible have significant deficiencies, are directly contradicted by hypothesis-driven studies, and are therefore not reliable for risk assessment purposes.     

Organic acids and bases: review of toxicological studies

Organic acids and bases are among the most frequently used chemicals in the manufacturing industries. However, the toxicology of only a number of them has been fully characterized, and for fewer still have occupational exposure limits been established. This paper reviews the acute and chronic toxicity data of the organic acids and bases, and considers the mechanism by which these chemicals produce their effects. A methodology for establishing preliminary occupational exposure limits based on the physicochemical properties of these chemicals is presented. Workplace exposure limits for 20 organic acids and bases which currently have no exposure guidelines are suggested. Advice regarding appropriate medical treatment of exposure to these materials is discussed.