A blood cyanide distribution study in the rabbits intoxicated by oral route and by inhalation

Summary Blood cyanide concentration was determined in rabbits intoxicated orally or by inhalation. Experiments were carried out under urethane anaesthesia. In the inhalation experiments, rabbits inhaled a combustion product containing HCN via the tracheal cannula and in the oral studies animals were administered NaCN solution into the stomach. In addition to the carotid artery and jugular vein blood samples, postmortem samples were obtained from both sides of the heart and the descending vena cava.The arterial cyanide concentration in the inhalation group showed a close relationship with ventilation. After an initial rise, blood levels decreased a little, in some cases with transient apnea. At the last stage it again increased with gasping, reaching its maximal value. After ultimate apnea, the blood cyanide concentration declined. The blood cyanide values were higher in the oral group than in the inhalation group. The difference between the two groups became larger in the inferior order, the left heart blood-the right heart blood-blood in the descending vena cava. The left heart/right heart ratio of the inhalation group was significantly higher than that of the oral group (1.28 ±0.28 vs. 0.95 ±0.09). The coefficient of variation (c.v.) of the inhalation group was larger than that of the other group. Within the inhalation group, the left heart blood showed the largest c.v. values and this was probably due to redistribution of the cyanide by bloodstream after attainment of the maximal concentration.

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Bestimmung der Blutzyanidkonzentration in oral oder inhalatorisch vergifteten Kaninchen

Zusammenfassung Die Blutzyanidkonzentrationen wurden an Zyanid-vergifteten Kaninchen in Urethannarkose bestimmt. Die Kaninchen inhalierten HCN-haltige Verbrennungsgase durch die Trachealkanüle. Eine andere Gruppe von Tieren erhielt NaCN-Lösung per os. Während der Versuche wurden Blutproben aus einer katheterisierten Halsarterie gewonnen. Postmortale Blutproben wurden aus beiden Ventrikeln des Herzens und der kaudalen Hohlvene entnommen.Der arterielle Blutzyanidspiegel der ersten Gruppe zeigte eine enge Beziehung mit der Ventilation auf. Nach einer Konzentrationszunahme im Anfangsstadium nahm der Blutspiegel mit einer vorübergehenden Apnoe ab. Mit der terminalen Atembewegung stiegen die Blutspiegel und erreichten ihre maximalen Werte. Die Blutzyanidwerte verminderten sich nach endgültiger Apnoe. Der Blutspiegel der per-os-Gruppe nahm stetig unabhängig von der Ventilationsgröße zu. Die inhalatorische Gruppe hatte niedrigere Zyanidwerte als die orale Gruppe.

     

底排装置底部压力和回流区特性研究

采用标准k-ω湍流模型和有限速率化学反应燃烧模型对二维轴对称雷诺平均N-S方程进行了数值计算,分析了超声速自由来流下冷流和H₂-O₂10组分28步基元燃烧反应的底部排气近尾迹区流场特性,得到了不同排气参数下底部压力和回流区特性,与实验值相吻合。计算结果表明,在较小排气参数下添能比加质更有利于底压提高;随着排气总温的增加,最佳排气参数逐渐减小,回流区逐渐减小;回流区前滞止点位置随着排气参数、排气总温等因素变化而变化,而后滞止点位置几乎不变,但燃烧对回流区前后滞止点均产生了影响。      

On the acute toxicities of the combustion products of various fibers,with special reference to blood cyanide and Po2 values

Summary The blood cyanide and Po₂ levels in different parts of the body were determined in the rabbit exposed to HCN.After urethane anesthesia, the rabbit was made to inhale HCN gas through a tracheal cannula. In addition to pure HCN gas produced by addition of NaCN to H₂SO₄, the combustion products from PAN (polyacrylonitrile), silk and wool were used respectively. After ultimate cessation of respiration, the chest was opened and the blood samples were taken from the three places, the left and right heart (ventricles) and the descending vena cava and cyanide and Po₂ values were determined.The survival time was the shortest in PAN group among the combustion experiments. Silk group followed it. The decreasing order of the blood cyanide levels was silk, PAN, HCN and wool groups with respect to all sampling sites. There was not significant difference in cyanide levels among silk, PAN and HCN groups. The left heart showed the highest cyanide values of all the sampling places. Significant positive correlation was present between postmortem cyanide and Po₂ values. Inhalation of relatively large amount of HCN and the concomitant inability of cardiac function to maintain the systemic circulation effectively at the last stage were considered to contribute largely to the unequal distribution of cyanide with the highest level in the left heart blood.     

Occupational exposure and urological cancer

Occupational exposure is definitely a major cause of cancer. In the field of urology, the urinary bladder is the most important target. A classical cause of bladder cancer is exposure to carcinogenic aromatic amines, especially benzidine and beta-naphthylamine. Such exposures were related to work places in the chemical industry, implying production and processing of classical aromatic amines, and in the rubber industry. Occupational bladder cancer has also been observed in dyers, painters and hairdressers. Even some occupations with much lower exposures to carcinogenic aromatic amines, like coke oven workers or workers in the rubber industry after the ban on beta-naphthylamine, are at risk. In these occupations, exposure to complex mixtures of substances containing combustion products (e.g. polycyclic aromatic hydrocarbons) or nitrosamines is common. Renal cell cancer has been observed as an occupational disease in cases of very high exposure to trichloroethylene having led to narcotic or prenarcotic symptoms. Occupationally related cancers of the prostate or the testes appear currently not relevant.     

急性一氧化碳中毒的胸部X线表现(附7例报告)

目的 探讨燃气热水器致急性一氧化碳中毒柿部X线表现。方法对7例急性一氧化碳中毒病人于中毒后30min-4h内进行胸部X线检查分析总结。结果7例病人中表现为急性肺泡性肺水肿改变3例；表现为肺纹理增粗、紊乱．模糊3例；心肺膈未见病变1例。结论 急性一氧化碳中霉致肺部改变，以肺泡性肺水肿改变为主，胸部X线检查可为临床治疗提供有价值的诊治依据。     

Acute toxicity of the combustion products from various kinds of fibers

Summary Acute toxicity of the combustion products from various fibers was evaluated in animal experiments. The materials used were cotton, gauze, acetate, rayon, polyester (PE), polychlal (PC), polyvinylidene chloride (PVDC), silk, wool, polyacrylonitrile (PAN), and modacryle (MA). Rats, mice, and rabbits were exposed to gases released from these materials, heated with an electric heater. In experiments with rabbits animals inhaled gases through a tracheal cannula under urethane narcosis. As indices for toxicity, the time at which animals were impaired severely, was used in rat experiments while the death time was used in experiments with rabbits and mice. The concentrations of O₂ and CO in the exposure room were determined continously, blood COHb and cyanide values were also estimated.Gases from fibers containing nitrogen impaired severely and killed the animals earlier than any other materials. Blood analyses revealed the presence of high values of cyanide in PAN, MA, and silk experiments. HCN was considered to be responsible for the high toxicity of gases from these materials. In the case of wool, despite of high toxicity of its combustion products, blood cyanide and COHb values were not very high.Gases from cotton, gauze, and rayon impaired severely and killed the animals relatively early in the exposure period. Toxicity of combution products from these materials was attributable to CO on the basis of gas and blood analyses. Acute toxicity of PE and acetate gases, being less than that of cotton, gauze, rayon under the present experimental conditions, was explained mainly by CO.Neither severe impairment nor death occurred during exposure in PC and PVDC experiments.

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Zusammenfassung In Tierversuchen wurde die akut toxische Wirkung von Gasen untersucht, die bei der Verbrennung von Fasermaterial entstehen. Es wurden hierzu folgende Materialien verwendet: Leinen, Gaze, Azetat, Kunstseide, Polyester (PE), Polychlal (PC), Polyvinylidanchlorid (PVDC), Seide, Wolle, Polyacrylonitril (PAN) and Modacryl (MA). Ratten, Mäuse und Kaninchen wurden den Gasen ausgesetzt, die durch Erhitzen der betreffenden Fasern oder der Kombination von zwei Faserarten entwickelt wurden. Bei den Versuchen mit Kaninchen inhalierten die mit Urethan narkotisierten Tiere die Gase durch eine Tracheal-kanüle. Als Kriterien für die Toxizität des jeweiligen Gases wurde bei Ratten die Zeit gewertet, bis zu der schwere Beeinträchtigungen im Verhalten (Vergiftungserscheinungen) beobachtet wurden. Bei Mäusen und Kaninchen wurde die Zeit bis zum Eintritt des Todes gemessen. In der Kammer, in der die Tiere den Gasen ausgesetzt wurden, wurde fortlaufend die Sauerstoff und CO-Konzentration gemessen, bei den Tieren CO-Hämoglobin und die Cyanid-Konzentration im Blut.Stickstoff-haltige Fasern vergifteten und töteten die Tiere durch die entwickelten Gase früher als andere Materialien. Blutanalysen ergaben relativ hohe Cyanidwerte bei Versuchen mit PAN, MA und Seide, HCN wird daher die hohe Toxizität dieser Gase zugeschrieben. Bei Wolle, deren Verbrennungsgase ebenfalls sehr toxisch sind, wurden jedoch nicht sehr hohe Cyanid- und COHb-Werte gemessen.Die Verbrennungsgase aus Leinen, Gaze und Kunstseide führten relativ schnell zu schweren Vergiftungserscheinungen und Tod der Versuchstiere, wobei die Toxizität in erster Linie auf das gebildete CO zurückzuführen ist, wie dies Gas- und Blutanalysen ergaben. Auch die Toxizität der Gase von PE und Azetat, die zwar geringer ist als die erstgenannten, beruht auf der Entstehung von CO.Weder Vergiftungserscheinungen noch Todesfälle ließen sich im Fall von PC und PVDC beobachten.

     

Firefighters' and instructors’ absorption of PAHs and benzene during training exercises

IntroductionTraining fires may constitute a major portion of some firefighters’ occupational exposures to smoke. However, the magnitude and composition of those exposures are not well understood and may vary by the type of training scenario and fuels.ObjectivesTo understand how structure fire training contributes to firefighters' and instructors’ select chemical exposures, we conducted biological monitoring during exercises involving combustion of pallet and straw and oriented strand board (OSB) or the use of simulated smoke.MethodsUrine was analyzed for metabolites of polycyclic aromatic hydrocarbons (PAHs) and breath was analyzed for volatile organic compounds (VOCs) including benzene.ResultsMedian concentrations of nearly all PAH metabolites in urine increased from pre-to 3-hr post-training for each scenario and were highest for OSB, followed by pallet and straw, and then simulated smoke. For instructors who supervised three trainings per day, median concentrations increased at each collection. A single day of OSB exercises led to a 30-fold increase in 1-hydroxypyrene for instructors, culminating in a median end-of-shift concentration 3.5-fold greater than median levels measured from firefighters in a previous controlled-residential fire study. Breath concentrations of benzene increased 2 to 7-fold immediately after the training exercises (with the exception of simulated smoke training). Exposures were highest for the OSB scenario and instructors accumulated PAHs with repeated daily exercises.ConclusionsDermal absorption likely contributed to the biological levels as the respiratory route was well protected. Training academies should consider exposure risks as well as instructional objectives when selecting training exercises.     

Changes of respiratory system in mice exposed to PM4.0 or TSP from exhaust gases of combustion of cashew nut shell

Air pollution is a topic discussed all over the world and the search for alternatives to reduce it is of great interest to many researchers. The use of alternative energy sources and biofuels seems to be the environmentally safer solution. In this work, the deleterious effects on the respiratory system of mice exposed to PM_4.0 or TSP, present in exhaust gases from the combustion of CNS were investigated, through data from respiratory system mechanics, oxidative stress, histopathology and morphometry of the parenchyma pulmonary. The results show changes in all variables of respiratory system mechanics, in oxidative stress, the histopathological analysis and lung morphometry. The results provide experimental support for epidemiological observations of association between effects on the respiratory system and exposure to PM_4.0 or TSP from CNS combustion exhaust gases, even at acute exposure. It can serve as a basis for regulation or adjustment of environmental laws that control the emissions of these gases.     

A novel approach to study the effect of cetane improver on performance,combustion and emission characteristics of a CI engine fuelled with E20 (diesel – bioethanol) blend

In this article an investigation was carried out to study the effects of cetane improver (2-Ethylhexyl nitrate) (2-EHN) on performance, combustion and emission characteristics of a constant speed, single cylinder CI engine fuelled with E20 (bioethanol (20%) – petrodiesel (80%). A cetane improver, 2-EHN was used at concentration of 1000 ppm and 2000 ppm with the test fuel (E20) and the results were compared to petrodiesel. The results showed that E20EHN1000 had 3.8% higher brake power (BP) to that of petrodiesel and the brake specific fuel consumption (BSFC) was similar with E20 and petrodiesel. E20EHN1000 showed 4.9% higher brake thermal efficiency (BTE) to petrodiesel and the volumetric efficiency (η_vol) was almost identical for all the test fuels. The trend for cylinder pressure (CP), net heat release rate (NHR), rate of pressure rises (ROPR) and mass fraction fuel burned (MFFB) of E20EHN1000 were also identical to those of E20 and petrodiesel. Except hydrocarbon (HC) emission, E20EHN1000 showed acceptable emission results to that of petrodiesel and other test fuel blends. Carbon dioxide (CO₂) and carbon monoxide (CO) emission for E20EHN1000 were comparable with petrodiesel but, the oxides of nitrogen (NO_x) emission was slightly higher than petrodiesel. However, E20EHN2000 showed poor performance due to the excess amount of 2-EHN, which shortened the ignition delay and reduced the premixed combustion phase with increased combustion duration. From the results, it is clearly unveiled that E20 with 1000 ppm of 2-EHN showed better results than E20, E20EHN2000 and petrodiesel.     

没食子酸的热解与燃烧动力学特性研究

目的对可水解鞣质的有机酸类单体没食子酸进行热解特性及燃烧特性分析,求解相关动力学参数。方法热重分析仪上,在氩气(Ar)气氛下5℃·min-1的升温速率进行没食子酸热解特性研究;模拟空气(N2∶O2=4∶1)气氛下,5℃·min-1、10℃·min-1和20℃·min-1升温速率,对没食子酸进行燃烧特性分析。结果没食子酸的热解分为失水、过渡、快速裂解、炭化四个阶段;没食子酸的燃烧分为失水、过渡、挥发分的释放、固定碳的燃烧四阶段。另外,在模拟空气气氛下,伴随升温速率的不同其燃烧起始温度、挥发分释放温度区间、热失重速率峰极值时所对应的温度及难挥发分及固定炭的燃烧的终止温度、挥发分指数、燃烧指数和动力学计算结果均不同。结论气氛及升温速率均为没食子酸热解过程的重要因素,且没食子酸热解过程符合FC方程模型,线性良好。