Further round-robin tests to improve the comparability between laboratories of the measurement of carbon in diesel soot and in environmental samples

Objectives: An informal European coordination group organized two round-robin tests on filters collected from environmental, workplace and diluted diesel emissions. Previous inter-laboratory comparisons have shown that experimental samples give reasonably good results in terms of the dispersion around the mean, from all the participating laboratories. However, there were significant differences between the laboratories owing to a narrow distribution of the results within a single laboratory. In order to gain a better understanding of the differences obtained between the laboratories, it was decided to carry out more round-robin tests and to investigate further the possible factors which may influence the results. Methods: The first round-robin (RRT3) was performed on six different samples (eight replicates) analyzed by ten laboratories. The range of loading was 40 to 138 μg cm⁻² of total carbon (TC). Laboratories used their own thermal procedure parameters. The second round-robin test (RRT4) was performed on three different diluted diesel emissions (two replicates) samples analyzed by 13 laboratories. The range of loading was 21 to 37 μg cm⁻² TC. Laboratories analyzed samples using imposed temperatures (500, 650 and 800 °C) and imposed duration (12 min). Results: Inter-laboratory coefficients of variation for diluted diesel emission samples were 10% for RRT3 and ranged from 6 to 19% for RRT4. The influence of the desorption temperature was clearly demonstrated and the results tended to show that a desorption temperature of 650 °C could be an acceptable compromise. The influence of the organic carbon/elemental carbon (OC/EC) ratio was shown to be insignificant with pure diesel soot samples. Conclusions: It was expected that a significant improvement would be seen in the inter-laboratory dispersion by the use of a common standardized thermal desorption program, but the objectives of these RRTs were only partly reached. This paper provides new information that will be useful in the elaboration of a standardized procedure for the European Normalisation Centre (CEN TC 137 WG2 – General requirements for measuring procedures). Received: 14 April 2000 / Accepted: 26 July 2000     

Evaluation of an exposure setup for studying effects of diesel exhaust in humans

Diesel exhaust is a common air pollutant and work exposure has been reported to cause discomfort and affect lung function. The aim of this study was to develop an experimental setup which would allow investigation of acute effects on symptoms and lung function in humans exposed to diluted diesel exhaust. Diluted diesel exhaust was fed from an idling lorry through heated tubes into an exposure chamber. During evaluations of the setup we found the size and the shape of the exhaust particles to appear unchanged during the transport from the tail pipe to the exposure chamber. The composition of the diesel exhaust expressed as the ratios CO/NO, total hydrocarbons/NO, particles/NO, NO₂/NO, and formaldehyde/NO were almost constant at different dilutions. The concentrations of NO₂ and particles in the exposure chamber showed no obvious gradients. New steady state concentrations in the exposure chamber were obtained within 5–7 min. In a separate experiment eight healthy nonsmoking subjects were exposed to diluted exhaust at a median steady state concentration of 1.6 ppm NO₂ for the duration of 1 h in the exposure chamber. All subjects experienced unpleasant smell, eye irritation, and nasal irritation. Throat irritation, headache, dizziness, nausea, tiredness, and coughing were experienced by some subjects. Lung function was not found to be affected during the exposure. The experimental setup was found to be appropriate for creating different predetermined steady state concentrations in the exposure chamber of diluted exhaust from a continuously idling vehicle. The acute symptoms reported by the subjects were relatively similar to what patients reported at different workplaces.     

The Application of a new carbon disulfide exposure test in occupational health

Summary The commonly-used iodo-azide test (IAT) for exposure to carbon disulphide is compared with two new gaschromatographic (GLC) methods.The GLC methods are consistent with each other, but not consistent with the IAT.The urine values of 23 exposed and 6 non-exposed workers were compared with the results of the IAT and the two GLC methods.The conclusion was that GLC methods are better suited for measuring in urine at low exposure for qualitative purposes.     

Exposures to diesel exhaust in the International Brotherhood of Teamsters, 1950-1990

A prior case-control study found a positive, monotonic exposure-response relationship between exposure to diesel exhaust and lung cancer among decedents of the Central States Conference of the International Brotherhood of Teamsters. In response to critiques of the Teamsters' exposure estimates by the Health Effects Institute's Diesel Epidemiology Panel, historical exposures and associated uncertainties are investigated here. Historic diesel exhaust exposures are predicted as a function of heavy-duty diesel truck emissions, increasing use of diesel engines, and occupational elemental carbon (EC) measurements taken during the late 1980s and early 1990s. EC from diesel and nondiesel sources is distinguished in light of recent studies indicating a substantial contribution of gasoline vehicles to ambient EC. Monte Carlo sampling is used to characterize exposure distributions. The methodology used in this article-a probabilistic model for historical exposure assessment-is novel.     

CS2作业工人接触水平的时间加权平均浓度

目的 进行二硫化碳作业工人接触水平的时间加权平均浓度的研究,探讨它们的代表性,为进一步制订卫生标准提供依据。方法 采用国际通用的方法和仪器,分别用固定点采样法测定了车间空气中的二硫化碳浓度,个体采样法测定了作业工人8h的实际暴露水平及其8h工作地点分布的调查,计算出两者各自的TWA,并进行了比较。结果 粘胶作业工人工作的流动性较大,仅有75％的工作时间停留在车间内,分别在16．3％和8．3％的工作时间分布在车间内休息室和车间外面的环境。结论 固定点采样法和工人个体采样技术所获得的TWA值分别为14．87mg/m^3和22．14mg/m^3。MAC并不能反映流动性较大的工种工人的实际接触水平。     

History and results of the two inter-laboratory round robin endotoxin assay studies on cotton dust

BACKGROUND: In the US cotton industry, airborne cotton dust levels are regulated, and other countries are moving to specify safety limits for airborne endotoxins. There is concern about potential respiratory health hazards associated with agricultural and other organic dusts. In laboratories, ranking which samples have high and low levels of endotoxin is usually in good agreement between laboratories. When different laboratories assay identical samples, the levels differ. The objective of this research was to evaluate the intra- and inter-laboratory variability for 13 laboratories measuring endotoxin in cotton dust. METHOD: Two inter-laboratory round robin endotoxin assay studies were conducted using cotton dust. In the first round robin, each laboratory used their normal in-house assay method and then used a common extraction protocol. In the second round robin, a common extraction protocol and endotoxin assay kit was used. RESULTS: The intra-laboratory results had small variations but inter-laboratory results had very high variations. The inter-laboratory results using a common extraction protocol showed reduced differences. Using the same extraction protocol and endotoxin assay kit, the intra-laboratory variation was small and inter-laboratory variation was reduced but not enough for inter-laboratory agreement. Most of the laboratories were able to discern between the high and low endotoxin concentration dusts. CONCLUSIONS: Standardization has reduced the differences in results between laboratories and possibly further standardization may bring closer inter-laboratory agreement.     

柴油废气颗粒对大鼠气道反应性及免疫指标影响

目的探讨空气污染物中柴油废气课粒(diesel exhaust particle,DEP)吸入对哮喘模型大鼠的气道反应性和免疫学指标的影响。方法选择Wistar大鼠60只,随机分为对照组(A组)、模型组(B组)、实验组(C组、D组、E组、F组),每组各10只。每只大鼠染毒结束后次日处死,并测定每只大鼠气道阻力(RL)30min的变化;采用酶联免疫吸附试验(ELISA)测定血清IgE和肺组织中白介素-5(IL-5)和γ-干扰素(IFN-γ)浓度的变化。结果抗原激发后,B组的气道阻力(7.069±0.632)比A组(3.567±0.211)明显增高;E、F组的气道阻力(8.879±0.616),(11.009±0.693)比B组(7.069±0.632)明显增高(F=156.187,P<0.01);气道阻力增高与DEP吸入时间呈相关性(r=0.948,P<0.01);B组血清中IgE(25.003±1.172)的浓度较A组(20.242±2.143)明显增加(F=2.490,P<0.01);C、E组肺组织中IL-5浓度(17.078±5.235),(18.618±4.228)较B组(12.788±2.827)明显增高(F=4.263,P<0.01);而肺组织中IFN-γ浓度在各组之间比较差异均无统计学意义(F=1.193,P>0.05)。结论柴油废气颗粒吸入可加重哮喘大鼠的气道高反应性,促进血清IgE介导及肺组织中IL-5分泌增加的气道炎症反应。     

咽后壁滴注柴油机尾气颗粒物对雌性小鼠生殖功能的影响

目的 观察柴油机尾气颗粒物(DEP)亚急性暴露对雌性小鼠生殖功能的影响.方法 将168只ICR( Institute of Cancer Research)雌性小鼠按数字表法随机分为低(B)、中(C)、高(D)剂量DEP暴露组和对照组(A),每组42只,分别向B、C、D组小鼠咽后壁滴注0.8、3.0、12.0 μg/μl DEP混悬液及PBS各30μl,每3天重复滴注1次,共4次.测量小鼠体重及卵巢重量,计算卵巢重量/体重,检测卵母细胞的存活率、胚泡破裂百分率、第一极体释放百分率、受精率、线粒体DNA含量和超微结构的变化.结果 A、B、C、D组卵巢重量/体重分别为(15.4±7.3) ×10-5、(14.1±6.8) ×10-5、(8.2±0.7) ×10-5和(7.2±2.5)×10-5 (F=3.841,P＜0.05).A、B、C、D组加入精子后第48小时,卵母细胞存活率分别为64.3％、56.8％、39.5％、32.9％(x2=21.575,P＜0.05),第一极体释放率分别为75.5％、65.3％、37.0％、27.1％ (x2 =52.772,P＜0.05),2细胞胚胎率分别为27.9％、39.1％、17.6％、12.5％(x2=20.148,P＜0.05),2细胞以上胚胎率分别为45.3％、32.2％、12.5％、13.9％ (x2 =32.135,P＜0.05).A、B、C、D组卵母细胞线粒体DNA的拷贝数对数值分别为6.54±0.13、6.48±0.09、5.57±0.15和5.41±0.07(F =89.241,P＜0.05).C、D组卵母细胞许多线粒体肿胀、空泡化,A、B组卵母细胞结构无明显改变.结论 DEP具有雌性生殖毒性.亚急性DEP暴露可对卵巢及卵母细胞造成不同程度损伤,降低卵巢功能和卵母细胞受精能力.     

柴油废气颗粒对大鼠气道反应性及肺部病理改变影响

目的 探讨空气污染物中柴油废气颗粒(DEP)的吸入对哮喘模型大鼠的气道反应性和肺部病理改变的影响.方法 选择Wistar大鼠60只随机分为A组为正常对照组;B组为哮喘模型组,利用卵清白蛋白(OVA)制备哮喘模型;C、D、E、F组于第1天开始用OVA攻击(方法与B组相同),之后再给予吸入DEP各1、2、3、4周.每只大鼠均于最后一次雾化结束后次日处死,并测定每只大鼠气道阻力(RL)30 min的变化,观察支气管肺泡灌洗液(BALF)中炎症细胞的百分比和肺组织病理形态学改变,采用酶联免疫吸附试验法测定血清中总ISE的浓度变化.结果 抗原激发后B组RL比A组增高,E、F组的RL比B组明显增高,之间比较差异有统计学意义(F=156.186,P<0.01),RL的增高与DEP吸入时间呈显著正相关(r=0.948,P<0.01);血清中总IgE的浓度在B组较A组明显增加,之间比较差异有统计学意义(F=2.490,P<0.01);C、D、E、F组BALF中嗜酸性粒细胞占细胞总数的百分比(EOS%)逐渐增高,与B组比较差异有统计学意义(F=23.240,P<0.01),实验组BALF中中性粒细胞的浸润逐渐增多,E、F组BALF中的中性粒细胞数占细胞总数的百分比较B组明显增高,与之比较差异有统计学意义(F=36.329,P<0.01);肺组织病理切片中可以看到A组上皮细胞完整,气道周围未见炎症细胞的浸润,以纤毛柱状上皮细胞为主,仅有少量的杯状细胞,基底膜未见纤维化,实验组随着DEP的1、2、3、4周的吸入,逐渐出现上皮细胞的减少、中断、脱落,杯状细胞大量增生,气道周围的炎症细胞的浸润及基底膜的纤维化等改变.结论 柴油DEP的吸入可加重哮喘大鼠的气道高反应性和肺部的炎症反应.     

石家庄市非职业一氧化碳中毒气象因素分析

目的探讨气象因素对非职业一氧化碳中毒的影响,提出相关的气象防范指标。方法选用石家庄17个县市2006年、2007年冬季采暖期非职业一氧化碳中毒数据303个样本,与对应时段气象要素进行统计分析。结果12月、1月、2月是非职业一氧化碳中毒的多发季节;冬季的早晨7~10时是一氧化碳中毒多发时段,占全天中毒事件的47.2%;风速小（1到2级）、气温变化不大（±3.0℃之内）、有雾霾等气象条件下,易发生一氧化碳中毒。结论在不利于污染物扩散的气象条件下,要特别注意室内通风,谨防一氧化碳中毒。     

黑箱法与二氧化碳诱捕法蚊虫监测结果比较

目的比较黑箱法和二氧化碳（CO2）诱捕法监测蚊虫密度的差异,探讨黑箱法在蚊虫密度监测中的作用。方法在2个区7个点比较黑箱法和CO2诱捕法监测蚊虫密度、种类的差异,比较2种方法监测蚊种构成比、性别比和季节消长趋势的相关性。结果黑箱法监测蚊虫平均密度为25．63只／箱,是CO2诱捕法平均密度（7．32只／器）的3．50倍,黑箱法监测雌蚊平均密度为14．65只／箱,是CO2诱捕法平均密度（6．23只／器）的2．35倍,2种方法差异有统计学意义,密度指数无相关性;黑箱法捕获蚊种构成,淡色库蚊占捕蚊总数的94．97％,为优势蚊种;白纹伊蚊占4．97％,三带喙库蚊和中华按蚊各仅占0．03％;CO。诱捕法捕获蚊种构成,淡色库蚊占捕蚊总数的79．26％,为优势蚊种;白纹伊蚊占18．27％,三带喙库蚊和中华按蚊分别占2．10％和0．37％,2种监测方法蚊虫构成比差异有统计学意义。结论黑箱法设备简单,易操作,经济成本低,适用范围较广,比较适合淡色库蚊的监测,在淡色库蚊为优势种的地区,可使用黑箱法进行蚊虫密度监测;CO2诱捕法除适合淡色库蚊监测外,还适用于白纹伊蚊监测。     

Combined effects of carbon monoxide plus sodium nitrite or carbon tetrachloride on the sciatic motor conduction velocity of rats

Summary Combined administrations of 0.2 or 0.4 mmol sodium nitrite/kg i.p. and 1.2 mmol carbon monoxide/kg s.c., or administration of 1.2 mmol carbon monoxide/kg alone decrease the sciatic motor conduction velocity of rats to the same degree. Pretreatment of rats with 8.3 mmol carbon tetrachloride/kg per os did not influence the retardation of the nerve conduction following carbon monoxide intoxication. The results support the assumption that the carbon monoxide poisoning lead to threshold values of motor conduction velocity; the additional toxic substances examined are not able to aggravate this effect.     

沙棘油对汽车尾气颗粒物处理大鼠某些生化指标的影响

目的探讨沙棘油拮抗汽车尾气致大鼠某些生化指标改变的作用。方法40只大鼠随机分为5组,3个实验组(灌胃沙棘油干预2 d)和阳性组(气管灌注浓度为16 g/L的汽车尾气颗粒物混悬液,每只1 m l),阴性组(气管灌注生理盐水,每只1 m l)。24 h后处死动物,测定支气管肺泡灌洗液(BALF)和血清中乳酸脱氢酶(LDH)、酸性磷酸酶(ACP)活力及白蛋白、总蛋白、超氧化物歧化酶(SOD)、丙二醛(MDA)、谷胱甘肽硫转移酶(GST)变化。结果实验组与阳性组相比,BALF中的LDH、ACP和白蛋白含量明显降低,差异皆有显著性,SOD活力有升高趋势但差异无显著性,中高剂量组的GST活力升高、MDA含量降低,差异皆有显著性。血清实验组与阳性组相比,LDH和白蛋白含量没有明显变化,ACP降低、SOD和GST活力升高,差异皆有显著性。MDA含量没有明显变化。结论沙棘油对柴油机汽车尾气颗粒物致大鼠某些生化指标改变具有一定保护作用。     

二硫化碳对雄性生殖功能的影响

二硫化碳是常见的有毒有害化合物之一。本文着重介绍了二硫化碳对雄性性功能、生殖器官、性激素以及精子生成的影响。     

Biomonitoring of polycyclic aromatic compounds in the urine of mining workers occupationally exposed to diesel exhaust

Diesel exhaust is considered a probable human carcinogen by the IARC. Biomonitoring of workers occupationally exposed to diesel exhaust was performed to determine their internal burden of diesel associated aromatic compounds. Personal air sampling also allowed to determine the exposure of the miners at their work place towards several polycyclic aromatic hydrocarbons (PAH) and nitro-arenes, the latter of which are thought to be specific constituents of diesel exhaust. For biomonitoring the urine of 18 underground salt miners was collected during and after their shift for 24-hours. half of the 18 miners were smokers. The urinary levels of 1-hydroxypyrene and hydroxylated phenanthrene metabolites were determined as biomarkers of PAH exposure, whereas urinary levels of some aromatic amines were chosen to monitor exposure towards specific nitro-arenes from diesel exhaust like 1-nitropyrene and 3-nitrobenzanthrone and to monitor the human burden by these compounds from inhaled cigarette smoke. Non-smoking workers exposed to diesel exhaust excrete an average level of about 4 micrograms phenanthrene metabolites, whereas the urinary levels in smokers were up to 3-fold higher. In summary the results indicate that (i) diesel exposure led to an increase of PAH metabolism in the workers examined, most probably by an induction of cytochrome P450 (ii) smokers could be identified in accordance with earlier studies by their increased ratio of phenanthrene metabolites derived from 1,2- and 3,4-oxidation and their higher amounts of excreted 1-naphthylamine, and (iii) the excreted amounts of aromatic amines found as metabolites of the nitro-arenes were about 5- to 10-fold higher as one might expect from the levels determined by personal air sampling at the workplace of the individuals.     

作业场所空气中碳纤维粉尘卫生标准的研究

本文在广泛收集已有资料的基础上，进行了必要的现场调查和实验研究，经综合分析提出了碳纤维粉尘的卫生标准。实验研究结果证实，碳纤维及其复合材料粉尘的毒性和致纤维化作用轻。现场调查结果表明，碳纤维粉尘对皮肤和眼有刺激作用．但受检查者胸片无尘肺样改变，对肺功能也无明显影响。基于我国作业场所空气中有害物质卫生标准的研制经验，参比类同污染物的最高容许浓度数值，建议作业场所空气中碳纤维粉尘的最高容许浓度为6mg／m3，时间加权平均容许浓度为3mg／m3。根据已获资料，本建议标准可考虑适用于碳纤维复合材料粉尘。可行性研究表明，碳纤维生产和复合材料加工过程中的粉尘浓度不高，通过加强防尘措施，不难达到本建议标准的要求。     

Ultrastructural alterations in the livers of golden hamsters following experimental chronic inhalation of diluted diesel exhaust emission

Summary The livers of Syrian golden hamsters were examined with the light and electron microscope using the techniques of thin sectioning and freeze-fracture following 5 months of exposure to various concentrations of diluted diesel exhaust gases.The light microscopical examination showed enlarged sinusoides with activated Kupffer's cells and slight changes in the cell nuclei.In the electron microscopical examination the most striking changes were seen in the mitochondria, which frequently showed a loss in cristae. In addition, the mitochondria exhibited pleomorphic character. The microbodies were of the same size as mitochondria. An increase in the number of lysosomes was observed especially in the tissue surrounding the narrow bile canaliculi.The various alterations corresponding to the different concentrations of exhaust gases could be seen especially well in the sinusoides, the mitochondria and the microbodies. In general the hepatocytes appeared to be moderately enlarged.The zonulae occludentes showed a more irregular outline and large maculae tight junctions were found on the lateral region of the plasmalemma of hepatocytes. The gap junctions exhibited a wide range of structural diversity. The intramembranous particles on the P fracture face of the plasmalemma of hepatocytes are aggregated.     

某化纤厂CS2废气对居民健康影响调查

本文就某化纤厂ＣＳ２废气对周围居民的健康影响调查作了报导。污染区大气主要污染物为ＣＳ２，其浓度为０．０２￣０．０７ｍｇ／ｍ＾３，超标率为６６．６７％。污染区空气中异味主要是恶臭和腐蛋味，污染区人群自学不适症状以眼鼻刺激，头痛头晕和气急为主，污染区人群注意力和记忆力较对照区人群明显为差（Ｐ〈０．０１）。１９份ＣＳ２作业工人尿ＴＴＣＡ检出率８４．２１％（１６／１９），１７份污染区居民尿ＴＴＣＡ检出率２     

汽油尾气对大鼠睾丸组织的氧化损伤和遗传毒性作用

目的探讨汽油尾气对大鼠睾丸的遗传毒性及氧化损伤作用。方法将汽油尾气的颗粒物、冷凝物和半挥发性有机物的二氯甲烷提取物以0、5.6、16.7和50.0L/kg的剂量经气管滴注染毒SD大鼠,每周一次,共4次。末次染毒24h后处死动物,测定睾丸脏器系数、睾丸组织内丙二醛(MDA)和羰基蛋白(CP)含量以及超氧化物岐化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性;并用彗星实验检测睾丸组织细胞中DNA的单链断裂水平。结果各剂量组体重增重和睾丸脏脏器系数与对照组相比差异无显著性(P>0.05);中、高剂量染毒组睾丸组织中MDA和CP含量显著升高;各剂量组SOD酶活力明显降低(P<0.05),而GSH-Px活性的下降仅在高剂量组具有显著性。在16.7L/kg和50.0L/kg组,睾丸组织细胞的拖尾率较对照组明显增加(P<0.05),但尾长的增加仅在50.0L/kg组具有统计学意义。结论汽油尾气可诱导大鼠睾丸组织生物大分子的氧化损伤和DNA单链断裂。