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Sample records for automotive diesel exhaust

  1. Promoted decomposition of NOx in automotive diesel-like exhausts by electro-catalytic honeycombs.

    PubMed

    Huang, Ta-Jen; Chiang, De-Yi; Shih, Chi; Lee, Cheng-Chin; Mao, Chih-Wei; Wang, Bo-Chung

    2015-03-17

    NO and NO2 (collectively called NOx) are major air pollutants in automotive emissions. More effective and easier treatments of NOx than those achieved by the present methods can offer better protection of human health and higher fuel efficiency that can reduce greenhouse gas emissions. However, currently commercialized technologies for automotive NOx emission control cannot effectively treat diesel-like exhausts with high NOx concentrations. Thus, exhaust gas recirculation (EGR) has been used extensively, which reduces fuel efficiency and increases particulate emission considerably. Our results show that the electro-catalytic honeycomb (ECH) promotes the decomposition of NOx to nitrogen and oxygen, without consuming reagents or other resources. NOx can be converted to nitrogen and oxygen almost completely. The ECHs are shown to effectively remove NOx from gasoline-fueled diesel-like exhausts. A very high NO concentration is preferred in the engine exhaust, especially during engine cold-start. Promoted NOx decomposition (PND) technology for real-world automotive applications is established in this study by using the ECH. With PND, EGR is no longer needed. Diesel-like engines can therefore achieve superior fuel efficiency, and all major automotive pollutants can be easily treated due to high concentration of oxygen in the diesel-like exhausts, leading to zero pollution.

  2. Automotive Fuel and Exhaust Systems.

    ERIC Educational Resources Information Center

    Irby, James F.; And Others

    Materials are provided for a 14-hour course designed to introduce the automotive mechanic to the basic operations of automotive fuel and exhaust systems incorporated on military vehicles. The four study units cover characteristics of fuels, gasoline fuel system, diesel fuel systems, and exhaust system. Each study unit begins with a general…

  3. Studies on health effects of automotive exhaust emissions. How dangerous are diesel emissions?

    PubMed

    Klingenberg, H; Winneke, H

    1990-04-01

    The following paper indicates that current results of research conducted on the effects of intentionally increased concentrations of diesel engine exhaust emissions, particularly the results of animal experiments, do not lead scientifically to final conclusions. According to the current level of knowledge, we must continue to assume that the risk of cancer, possibly due to diesel particles, is negligible, particularly under real environmental conditions. The preventive measures taken by governments are of course supported by the automotive industry, an additional research outlay, however, is necessary not only to clear up contradictions and answer new questions arising from current test results, but also to take positive, and not merely precautionary, action in the future. Due to its links to other influences on humans and plants, research conducted on the effects of motor vehicle emissions is a task that lies very much in the public interest. At the same time, the overview of concluded and ongoing research objectives presented in this paper indicates that the automotive industry is greatly committed to this issue and will meet well-justified expectations.

  4. Efficiency of automotive cabin air filters to reduce acute health effects of diesel exhaust in human subjects

    PubMed Central

    Rudell, B.; Wass, U.; Horstedt, P.; Levin, J. O.; Lindahl, R.; Rannug, U.; Sunesson, A. L.; Ostberg, Y.; Sandstrom, T.

    1999-01-01

    OBJECTIVES: To evaluate the efficiency of different automotive cabin air filters to prevent penetration of components of diesel exhaust and thereby reduce biomedical effects in human subjects. Filtered air and unfiltered diluted diesel exhaust (DDE) were used as negative and positive controls, respectively, and were compared with exposure to DDE filtered with four different filter systems. METHODS: 32 Healthy non- smoking subjects (age 21-53) participated in the study. Each subject was exposed six times for 1 hour in a specially designed exposure chamber: once to air, once to unfiltered DDE, and once to DDE filtered with the four different cabin air filters. Particle concentrations during exposure to unfiltered DDE were kept at 300 micrograms/m3. Two of the filters were particle filters. The other two were particle filters combined with active charcoal filters that might reduce certain gaseous components. Subjective symptoms were recorded and nasal airway lavage (NAL), acoustic rhinometry, and lung function measurements were performed. RESULTS: The two particle filters decreased the concentrations of diesel exhaust particles by about half, but did not reduce the intensity of symptoms induced by exhaust. The combination of active charcoal filters and a particle filter significantly reduced the symptoms and discomfort caused by the diesel exhaust. The most noticable differences in efficacy between the filters were found in the reduction of detection of an unpleasant smell from the diesel exhaust. In this respect even the two charcoal filter combinations differed significantly. The efficacy to reduce symptoms may depend on the abilities of the filters investigated to reduce certain hydrocarbons. No acute effects on NAL, rhinometry, and lung function variables were found. CONCLUSIONS: This study has shown that the use of active charcoal filters, and a particle filter, clearly reduced the intensity of symptoms induced by diesel exhaust. Complementary studies on vehicle

  5. Non-thermal plasma based technologies for the after-treatment of automotive exhaust particulates and marine diesel exhaust NOx

    SciTech Connect

    McAdams, R; Beech, P; Gillespie, R; Guy, C; Jones,S; Liddell, T; Morgan, R; Shawcross, J; Weeks, D; Hughes, D; Oesterle, J; Eberspdcher,

    2003-08-24

    The trend in environmental legislation is such that primary engine modifications will not be sufficient to meet all future emissions requirements and exhaust aftertreatment technologies will need to be employed. One potential solution that is well placed to meet those requirements is non-thermal plasma technology. This paper will describe our work with some of our partners in the development of a plasma based diesel particulate filter (DPF) and plasma assisted catalytic reduction (PACR) for NOx removal. This paper describes the development of non-thermal plasma technology for the aftertreatment of particulates from a passenger car engine and NOx from a marine diesel exhaust application.

  6. AUTOMOTIVE DIESEL MAINTENANCE. PROGRAM OUTLINE.

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    INFORMATIONAL TOPICS COVERED IN THE TEXT MATERIALS AND SELF-INSTRUCTIONAL BRANCH PROGRAMED TRAINING FILMS FOR A 2-YEAR, 55 MODULE PROGRAM IN AUTOMOTIVE DIESEL MAINTENANCE ARE GIVEN. THE 30 MODULES FOR "AUTOMOTIVE DIESEL MAINTENANCE 1" ARE AVAILABLE AS VT 005 655 - VT 005 684, AND THE 25 MODULES FOR "AUTOMOTIVE DIESEL MAINTENANCE 2" ARE AVAILABLE…

  7. AUTOMOTIVE DIESEL MAINTENANCE. PROGRAM OUTLINE.

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    INFORMATIONAL TOPICS COVERED IN THE TEXT MATERIALS AND SELF-INSTRUCTIONAL BRANCH PROGRAMED TRAINING FILMS FOR A 2-YEAR, 55 MODULE PROGRAM IN AUTOMOTIVE DIESEL MAINTENANCE ARE GIVEN. THE 30 MODULES FOR "AUTOMOTIVE DIESEL MAINTENANCE 1" ARE AVAILABLE AS VT 005 655 - VT 005 684, AND THE 25 MODULES FOR "AUTOMOTIVE DIESEL MAINTENANCE 2" ARE AVAILABLE…

  8. Diesel engine exhaust

    Integrated Risk Information System (IRIS)

    Diesel engine exhaust ; CASRN N.A . Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  9. Characterization of nitromethane emission from automotive exhaust

    NASA Astrophysics Data System (ADS)

    Sekimoto, Kanako; Inomata, Satoshi; Tanimoto, Hiroshi; Fushimi, Akihiro; Fujitani, Yuji; Sato, Kei; Yamada, Hiroyuki

    2013-12-01

    We carried out time-resolved experiments using a proton-transfer-reaction mass spectrometer and a chassis dynamometer to characterize nitromethane emission from automotive exhaust. We performed experiments under both cold-start and hot-start conditions, and determined the dependence of nitromethane emission on vehicle velocity and acceleration/deceleration as well as the effect of various types of exhaust-gas treatment system. We found that nitromethane emission was much lower from a gasoline car than from diesel trucks, probably due to the reduction function of the three-way catalyst of the gasoline car. Diesel trucks without a NOx reduction catalyst using hydrocarbons produced high emissions of nitromethane, with emission factors generally increasing with increasing acceleration at low vehicle velocities.

  10. Diesel exhaust, diesel fumes, and laryngeal cancer.

    PubMed

    Muscat, J E; Wynder, E L

    1995-03-01

    A hospital-based, case-control study of 235 male patients with laryngeal cancer and 205 male control patients was conducted to determine the effects of exposure to diesel engine exhaust and diesel fumes and the risk of laryngeal cancer. All patients were interviewed directly in the hospital with a standardized questionnaire that gathered information on smoking habits, alcohol consumption, employment history, and occupational exposures. Occupations that involve substantial exposure to diesel engine exhaust include mainly truck drivers, as well as mine workers, firefighters, and railroad workers. The odds ratio for laryngeal cancer associated with these occupations was 0.96 (95% confidence interval, 0.5 to 1.8). The odds ratio for self-reported exposure to diesel exhaust was 1.47 (95% confidence interval, 0.5 to 4.1). An elevated risk was found for self-reported exposure to diesel fumes (odds ratio, 6.4; 95% confidence interval, 1.8 to 22.6). No association was observed between jobs that entail exposure to diesel fumes, such as automobile mechanics, and the risk of laryngeal cancer. These results show that diesel engine exhaust is unrelated to laryngeal cancer risk. The different findings for self-reported diesel fumes and occupations that involve exposure to diesel fumes could reflect a recall bias.

  11. Advanced automotive diesel engine system study

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A conceptual study of an advanced automotive diesel engine is discussed. The engine concept selected for vehicle installation was a supercharged 1.4 liter, 4 cylinder spark assisted diesel of 14:1 compression ratio. A compounding unit consisting of a Lysholm compressor and expander is connected to the engine crankshaft by a belt drive. The inlet air charge is heated by the expander exhaust gas via a heat exchanger. Four levels of technology achievement on the selected engine concept were evaluated, from state-of-the-art to the ideal case. This resulted in the fuel economy increasing from 53.2 mpg to 81.7 mpg, and the 0-60 mph time decreasing from 17.6 seconds to 10.9 seconds.

  12. Advanced automotive diesel engine system study

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A conceptual study of an advanced automotive diesel engine is discussed. The engine concept selected for vehicle installation was a supercharged 1.4 liter, 4 cylinder spark assisted diesel of 14:1 compression ratio. A compounding unit consisting of a Lysholm compressor and expander is connected to the engine crankshaft by a belt drive. The inlet air charge is heated by the expander exhaust gas via a heat exchanger. Four levels of technology achievement on the selected engine concept were evaluated, from state-of-the-art to the ideal case. This resulted in the fuel economy increasing from 53.2 mpg to 81.7 mpg, and the 0-60 mph time decreasing from 17.6 seconds to 10.9 seconds.

  13. Advanced automotive diesel assessment program

    NASA Technical Reports Server (NTRS)

    Sekar, R.; Tozzi, L.

    1983-01-01

    Cummins Engine Company completed an analytical study to identify an advanced automotive (light duty) diesel (AAD) power plant for a 3,000-pound passenger car. The study resulted in the definition of a revolutionary diesel engine with several novel features. A 3,000-pound car with this engine is predicted to give 96.3, 72.2, and 78.8 MPG in highway, city, and combined highway-city driving, respectively. This compares with current diesel powered cars yielding 41.7, 35.0, and 37.7 MPG. The time for 0-60 MPH acceleration is 13.9 sec. compared to the baseline of 15.2 sec. Four technology areas were identified as crucial in bringing this concept to fruition. They are: (1) part-load preheating, (2) positive displacement compounding, (3) spark assisted diesel combustion system, and (4) piston development for adiabatic, oilless diesel engine. Marketing and planning studies indicate that an aggressive program with significant commitment could result in a production car in 10 years from the date of commencement.

  14. Controlled human exposures to diesel exhaust

    EPA Science Inventory

    Diesel exhaust (DE) is a complex mixture of gaseous and particulate compounds resulting from an incomplete combustion of diesel fuel. Controlled human exposures to DE and diesel exhaust particles (DEP) have contributed to understanding health effects. Such exposure studies of h...

  15. Controlled human exposures to diesel exhaust

    EPA Science Inventory

    Diesel exhaust (DE) is a complex mixture of gaseous and particulate compounds resulting from an incomplete combustion of diesel fuel. Controlled human exposures to DE and diesel exhaust particles (DEP) have contributed to understanding health effects. Such exposure studies of h...

  16. Diesel Exhaust in New England | US EPA

    EPA Pesticide Factsheets

    2017-04-10

    Pollution from diesel engines is a widespread problem across New England and it significantly contributes to air pollution, especially in urban areas. Diesel exhaust is made up of small particles, known as fine particulate matter.

  17. Automotive Fuel and Exhaust Systems.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    This correspondence course, originally developed for the Marine Corps, is designed to provide mechanics with an understanding of the construction, operation, malfunction, diagnosis, maintenance, and repair of the fuel and exhaust systems used in automobiles. The course contains five study units covering fundamentals of gasoline engine fuel…

  18. Generation and characterization of radiolabeled diesel exhaust.

    PubMed

    Dutcher, J S; Sun, J D; Lopez, J A; Wolf, I; Wolff, R K; McClellan, R O

    1984-07-01

    To evaluate the potential health risks associated with increased use of diesel engines, information is needed on the biological fate of inhaled diesel exhaust components. Appropriately radiolabeled exhaust produced by burning radiolabeled fuel could be used to gain this information. The purpose of this study was to characterize different radiolabeled diesel exhausts with respect to their potential use in studies of the biological fate of exhaust carbon particles and particle-associated organic compounds (particle extracts). A single-cylinder diesel engine was used to burn diesel fuel containing trace amounts of 14C-labeled hexadecane, dotriacontane, benzene, phenanthrene or benzo(a)pyrene. Greater than 98% of the 14C in all additives was converted to volatile materials upon combustion. The remainder was distributed in varying amounts between the carbon particles and particle extracts. Aromatic additives labeled carbon particles more efficiently than aliphatic additives. Column chromatography of the particle extracts showed that, in most cases, the majority of the radioactivity eluted in fractions identical to the specific fuel additive employed, suggesting that a large amount of the particle-associated organic compounds consisted of uncombusted fuel constituents. Applying an electrical load to the engine-electrical generator increased carbon particle radioactivity, but had variable effects on the amount of radioactivity in the particle extracts. 67Ga-tetramethylheptanedione was also studied as a fuel additive to label carbon particles. 67Ga was incorporated into the exhaust particles and lung deposition of particles in rats was found to be approximately 10%. However, the 67Ga-radiolabel was found to separate from the particles in vivo, making it an unsuitable radiolabel for studying the long-term lung retention of diesel exhaust carbonaceous particles.

  19. Characterization and analysis of diesel exhaust odor

    SciTech Connect

    Shala, F.J.

    1983-01-01

    An instrumental method known as the Diesel Odor Analysis System or DOAS, has been developed at A.D. Little, Inc. for measuring diesel exhaust odor. It was of interest to determine which compound or compounds in the oxygenated fraction of the exhaust were primarily responsible for the odor correlation as developed at A.D. Little, Inc. This was accomplished by observing how the measurement of the exhaust odor intensity and number of chemical constituents of the oxygenate fraction were changing with respect to the odor values as measured by the DOAS. Benzaldehyde was found to give the best correlation (R = 0.98) with odor. A quantitative relationship between exhaust odor as measured by the total intensity of aroma (TIA) and the benzaldehyde concentration (B) in ppm in the exhaust is given by: TIA = 1.11 log/sub 10/(B) + 4.10. This correlation was supported by results obtained from two other diesel engine exhaust sources. A methyl benzaldehyde isomer also yielded a good correlation (R = 0.90) with odor. Air to fuel ratio correlations were determined for the tentatively identified compounds, cinnamaldehyde (R = 0.94) and a C2-benzaldehyde isomer (R = 0.94).

  20. Characterization and analysis of diesel exhaust odor

    SciTech Connect

    Partridge, P.A.; Shala, F.J.; Cernansky, N.P.; Suffet, I.H.

    1987-04-01

    An analytical method was developed to determine which compound or compounds in the oxygenated fraction of diesel exhaust were changing in intensity and number with respect to the odor correlation between human sensory panels and diesel exhaust samples as developed at Arthur D. Little, Inc. A sample fractionation with silica Sep-Pak cartridges and gas chromatography analysis procedures were developed to analyze exhaust odor samples. By use of a chromatographic computer profiling method, correlations were developed indicating a linear relation between log (odor intensity) and log (concentration) of specific character impact peaks (which may or may not be odorous themselves). Excellent correlations were obtained with the character impact peaks identified as benzaldehyde and a methylbenzaldehyde isomer in this study. Correlation coefficients of 0.97 and 0.90, respectively, were obtained for the sample set. 17 references, 5 figures, 2 tables.

  1. Advanced Automotive Diesel Assessment Program, executive summary

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The objectives of this analytical study were: to select one advanced automotive diesel engine (AAD) concept which would increase the tank mileage of a 3,000 pound passenger car from the present 35 mpg to at least 52 mpg; to identify long term component research and development work required to bring the selected concept to fruition; and to prepare a development strategy that will bring the selected concept to a prototype testing phase. Cummins Engine Company has completed this study. The selected concept is a 4 stroke cycle, direct injection, spark assisted, advanced adiabatic diesel engine with positive displacement compounding plus expander and part load air preheating. The engine does not use a liquid coolant nor liquid lubricants. It is a 4 cylinder, in-line, 77 mm bore x 77 mm stroke, 1.434 liters displacement engine weighing 300 lb, and rated at 70 BHP at 3000 rpm. Installation dimensions are 621 mm length x 589 mm width x 479 mm height (24.4 inch x 22 inch x 18.9 inch).

  2. Advanced Automotive Diesel Assessment Program, executive summary

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The objectives of this analytical study were: to select one advanced automotive diesel engine (AAD) concept which would increase the tank mileage of a 3,000 pound passenger car from the present 35 mpg to at least 52 mpg; to identify long term component research and development work required to bring the selected concept to fruition; and to prepare a development strategy that will bring the selected concept to a prototype testing phase. Cummins Engine Company has completed this study. The selected concept is a 4 stroke cycle, direct injection, spark assisted, advanced adiabatic diesel engine with positive displacement compounding plus expander and part load air preheating. The engine does not use a liquid coolant nor liquid lubricants. It is a 4 cylinder, in-line, 77 mm bore x 77 mm stroke, 1.434 liters displacement engine weighing 300 lb, and rated at 70 BHP at 3000 rpm. Installation dimensions are 621 mm length x 589 mm width x 479 mm height (24.4 inch x 22 inch x 18.9 inch).

  3. Diesel exhaust-gas purification system

    SciTech Connect

    Doherty, B.J.

    1982-07-01

    The design of a diesel exhaust gas purification system is presented. It will provide 2000 scfm of dry, anerobic gas (essentially nitrogen) for use in air drilling operations where drill pipe corrosion is a problem, such as geothermal applications. The system is operable in the field and may be transported via highways. It will operate at ambient temperatures up to 110/sup 0/F and requires no water - diesel fuel is used to combust excess oxygen and to generate electricity for the system. Gas production costs, including capital amortization, operations, fuel and maintenance (for reasonable utilization) are about $1.50/1000 scf.

  4. Diesel injector additives for a clean exhaust

    SciTech Connect

    Herbstman, S.; Virk, K.S.

    1988-08-01

    Increased public awareness of clean air is causing closer examination of potential health problems associated with diesel exhaust particulates. Recently, the EPA published standards mandating a sixfold reduction in diesel exhaust particulates for heavy duty engines from 0.60 gm/bhp-hr in 1988-1990 to 0.10 gm/bhp-hr in 1994. NOx exhaust concentrations were also reduced. For some time now, we have been interested in ways to reduce black smoke from diesel engines since it is one of the prime contributors to exhaust particulates. One of its causes is dirty or clogged fuel injectors due to deposit buildup. During operation with dirty injectors, the spray pattern of fuel into the combustion chamber is distorted, usually resulting in a fuel-rich environment. Incomplete burning of the rich fuel mixture results in an excess of carbonaceous material which is discharged in the exhaust as black smoke. We are engaged in evaluating additives with detergency and antioxidant properties to reduce deposit buildup in the injectors. Long chain alkylamines, and other types of surfactant molecules have been reported as active in preventing deposit buildup. However, little practical information was available concerning structure-activity relationships for use in developing a commercially acceptable additive package. We decided to investigate additives which are active either as gasoline carburetor detergents or as lubricant dispersants; both categories appear to have the necessary surfactant behavior and oil solubility to satisfy our needs for a diesel injector keep clean agent. Our approach to the problem was to develop an additive package for future use in Texaco fuels to reduce black smoke.

  5. No Breathing in the Aisles: Diesel Exhaust inside School Buses.

    ERIC Educational Resources Information Center

    Solomon, Gina M.; Campbell, Todd R.; Feuer, Gail Ruderman; Masters, Julie; Samkian, Artineh; Paul, Kavita Ann

    There is evidence that diesel exhaust causes cancer and premature death, and also exacerbates asthma and other respiratory illness. Noting that the vast majority of the nation's school buses run on diesel fuel, this report details a study examining the level of diesel exhaust to which children are typically exposed as they travel to and from…

  6. Measuring soot particles from automotive exhaust emissions

    NASA Astrophysics Data System (ADS)

    Andres, Hanspeter; Lüönd, Felix; Schlatter, Jürg; Auderset, Kevin; Jordan-Gerkens, Anke; Nowak, Andreas; Ebert, Volker; Buhr, Egbert; Klein, Tobias; Tuch, Thomas; Wiedensohler, Alfred; Mamakos, Athanasios; Riccobono, Francesco; Discher, Kai; Högström, Richard; Yli-Ojanperä, Jaakko; Quincey, Paul

    2014-08-01

    The European Metrology Research Programme participating countries and the European Union jointly fund a three year project to address the need of the automotive industry for a metrological sound base for exhaust measurements. The collaborative work on particle emissions involves five European National Metrology Institutes, the Tampere University of Technology, the Joint Research Centre for Energy and Transport and the Leibniz Institute for Tropospheric Research. On one hand, a particle number and size standard for soot particles is aimed for. Eventually this will allow the partners to provide accurate and comparable calibrations of measurement instruments for the type approval of Euro 5b and Euro 6 vehicles. Calibration aerosols of combustion particles, silver and graphite proof partially suitable. Yet, a consensus choice together with instrument manufactures is pending as the aerosol choice considerably affects the number concentration measurement. Furthermore, the consortium issued consistent requirements for novel measuring instruments foreseen to replace today's opacimeters in regulatory periodic emission controls of soot and compared them with European legislative requirements. Four partners are conducting a metrological validation of prototype measurement instruments. The novel instruments base on light scattering, electrical, ionisation chamber and diffusion charging sensors and will be tested at low and high particle concentrations. Results shall allow manufacturers to further improve their instruments to comply with legal requirements.

  7. Influence of Alternative Exposure Estimates in the Diesel Exhaust Miners Study: Diesel Exhaust and Lung Cancer.

    PubMed

    Crump, Kenny S; Van Landingham, Cynthia; McClellan, Roger O

    2016-09-01

    The landmark Diesel Exhaust in Miners Study (DEMS) studied the relationship between diesel exhaust exposure (DEE) and lung cancer mortality of workers at eight nonmetal mines who were followed from beginning of dieselization of the mines (1947-1967) through December 31, 1997. The original analyses quantified DEE exposures using exposure to respirable elemental carbon (REC) to represent DEE, and CO as a surrogate for REC. However, this use of CO data, and the CO data themselves, have numerous shortcomings. We developed new estimates of REC exposures using historical data on use of diesel equipment, diesel engine horsepower (HP), mine ventilation rates, and the documented reduction in particulate matter emissions per HP in diesel engines from 1975 through 1995. These new REC estimates were applied in a conditional logistic regression of the DEMS nested case-control data very similar to the one applied in the original DEMS analyses. None of the trend slopes calculated using the new REC estimates were statistically significant (p > 0.05). Moreover, these trend slopes were smaller by roughly factors of five without control for radon exposure and factors of 12 with control for radon exposure compared to those estimated in the original DEMS analyses. Also, the 95% confidence intervals for these trend slopes had only minimal overlap with those for the slopes in the original DEMS analyses. These results underscore the uncertainty in estimates of the potency of diesel exhaust in causing lung cancer based on analysis of the DEMS data due to uncertainty in estimates of exposures to diesel exhaust.

  8. Microwave-Regenerated Diesel Exhaust Particulate Filter

    SciTech Connect

    Nixdorf, Richard D.; Green, Johney Boyd; Story, John M.; Wagner, Robert M.

    2001-03-05

    Development of a microwave-regenerated particulate filter system has evolved from bench scale work to actual diesel engine experimentation. The filter system was initially evaluated on a stationary mounted 1.2-L diesel engine and was able to remove a significant amount of carbon particles from the exhaust. The ability of the microwave energy to regenerate or clean the filter was also demonstrated on this engine under idle conditions. Based on the 1.2-L experiments, improvements to the filter design and materials were implemented and the system was re-evaluated on a vehicle equipped with a 7.3-L diesel engine. The 7.3-L engine was selected to achieve heavy filter loading in a relatively short period of time. The purpose of these experiments was to evaluate filter-loading capacity, power requirements for regeneration, and filter regeneration efficiency. A more detailed evaluation of the filter was performed on a stationary mounted 1.9-L diesel engine. The effect of exhaust flow rate, loading, transients, and regeneration on filter efficiency was evaluated with this setup. In addition, gaseous exhaust emissions were investigated with and without an oxidation catalyst on the filter cartridge during loading and regeneration. (SAE Paper SAE-2001-01-0903 © 2001 SAE International. This paper is published on this website with permission from SAE International. As a user of this website, you are permitted to view this paper on-line, download this pdf file and print one copy of this paper at no cost for your use only. The downloaded pdf file and printout of this SAE paper may not be copied, distributed or forwarded to others or for the use of others.)

  9. Diesel Engine Exhaust: Basis for Occupational Exposure Limit Value.

    PubMed

    Taxell, Piia; Santonen, Tiina

    2017-08-01

    Diesel engines are widely used in transport and power supply, making occupational exposure to diesel exhaust common. Both human and animal studies associate exposure to diesel exhaust with inflammatory lung effects, cardiovascular effects, and an increased risk of lung cancer. The International Agency for Research on Cancer has evaluated diesel exhaust as carcinogenic to humans. Yet national or regional limit values for controlling occupational exposure to diesel exhaust are rare. In recent decades, stricter emission regulations have led to diesel technologies evolving significantly, resulting in changes in exhaust emissions and composition. These changes are also expected to influence the health effects of diesel exhaust. This review provides an overview of the current knowledge on the health effects of diesel exhaust and the influence of new diesel technologies on the health risk. It discusses the relevant exposure indicators and perspectives for setting occupational exposure limit values for diesel exhaust, and outlines directions for future research. The review is based on a collaborative evaluation report by the Nordic Expert Group for Criteria Documentation of Health Risks from Chemicals and the Dutch Expert Committee on Occupational Safety. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  10. Tumorigenesis of diesel exhaust, gasoline exhaust, and related emission extracts on SENCAR mouse skin

    SciTech Connect

    Nesnow, S; Triplett, L L; Slaga, T J

    1980-01-01

    The tumorigenicity of diesel exhaust particulate emissions was examined using a sensitive mouse skin tumorigenesis model (SENCAR). The tumorigenic potency of particulate emissions from diesel, gasoline, and related emission sources was compared.

  11. Diesel engine exhaust and lung cancer: an unproven association.

    PubMed Central

    Muscat, J E; Wynder, E L

    1995-01-01

    The risk of lung cancer associated with diesel exhaust has been calculated from 14 case-control or cohort studies. We evaluated the findings from these studies to determine whether there is sufficient evidence to implicate diesel exhaust as a human lung carcinogen. Four studies found increased risks associated with long-term exposure, although two of the four studies were based on the same cohort of railroad workers. Six studies were inconclusive due to missing information on smoking habits, internal inconsistencies, or inadequate characterization of diesel exposure. Four studies found no statistically significant associations. It can be concluded that short-term exposure to diesel engine exhaust (< 20 years) does not have a causative role in human lung cancer. There is statistical but not causal evidence that long-term exposure to diesel exhaust (> 20 years) increases the risk of lung cancer for locomotive engineers, brakemen, and diesel engine mechanics. There is inconsistent evidence on the effects of long-term exposure to diesel exhaust in the trucking industry. There is no evidence for a joint effect of diesel exhaust and cigarette smoking on lung cancer risk. Using common criteria for determining causal associations, the epidemiologic evidence is insufficient to establish diesel engine exhaust as a human lung carcinogen. Images p812-a PMID:7498093

  12. Exposure to diesel exhaust linked to lung cancer in miners

    Cancer.gov

    In a study of non-metal miners in the United States, federal government scientists reported that heavy exposure to diesel exhaust increased risk of death from lung cancer. The research, all part of the Diesel Exhaust in Miners Study, was designed to evalu

  13. Diesel Exhaust in Miners Study: Q&A

    Cancer.gov

    The Diesel Exhaust in Miners Study was designed to evaluate the risk of death associated with diesel exhaust exposure, particularly as it may relate to lung cancer. The researchers observed increased risk for lung cancer death with increasing levels of ex

  14. Fumigation of Alcohol in a Light Duty Automotive Diesel Engine

    NASA Technical Reports Server (NTRS)

    Broukhiyan, E. M. H.; Lestz, S. S.

    1981-01-01

    A light-duty automotive Diesel engine was fumigated with methanol in amounts up to 35% and 50% of the total fuel energy respectively in order to determine the effect of alcohol fumigation on engine performance at various operating conditons. Engine fuel efficiency, emissions, smoke, and the occurrence of severe knock were the parameters used to evaluate performance. Raw exhaust particulate and its soluble organic extract were screened for biological activity using the Ames Salmonella typhimurium assay. Results are given for a test matrix made up of twelve steady-state operating conditions. For all conditions except the 1/4 rack (light load) condition, modest thermal efficiency gains were noted upon ethanol fumigation. Methanol showed the same increase at 3/4 and full rack (high load) conditions. However, engine roughness or the occurrence of severe knock limited the maximum amount of alcohol that could be fumigated. Brake specific nitrogen oxide concentrations were found to decrease for all ethanol conditions tested. Oxides of nitrogen emissions, on a volume basis, decreased for all alcohol conditions tested. Based on the limited particulate data analyzed, it appears that ethanol fumigation, like methanol fumigation, while lowering the mass of particulated emitted, does enhance the biological activity of that particulate.

  15. Applied Physics Modules Selected for Automotive and Diesel Technologies.

    ERIC Educational Resources Information Center

    Waring, Gene

    Designed for individualized use in an applied physics course in postsecondary vocational-technical education, this series of ten learning modules is equivalent to the content of a five-credit hour class in automotive technology or diesel technology. Almost all the modules contain technological application in the form of laboratory experiments or…

  16. Applied Physics Modules Selected for Automotive and Diesel Technologies.

    ERIC Educational Resources Information Center

    Waring, Gene

    Designed for individualized use in an applied physics course in postsecondary vocational-technical education, this series of ten learning modules is equivalent to the content of a five-credit hour class in automotive technology or diesel technology. Almost all the modules contain technological application in the form of laboratory experiments or…

  17. Evaluation of carcinogenic hazard of diesel engine exhaust needs to consider revolutionary changes in diesel technology.

    PubMed

    McClellan, Roger O; Hesterberg, Thomas W; Wall, John C

    2012-07-01

    Diesel engines, a special type of internal combustion engine, use heat of compression, rather than electric spark, to ignite hydrocarbon fuels injected into the combustion chamber. Diesel engines have high thermal efficiency and thus, high fuel efficiency. They are widely used in commerce prompting continuous improvement in diesel engines and fuels. Concern for health effects from exposure to diesel exhaust arose in the mid-1900s and stimulated development of emissions regulations and research to improve the technology and characterize potential health hazards. This included epidemiological, controlled human exposure, laboratory animal and mechanistic studies to evaluate potential hazards of whole diesel exhaust. The International Agency for Research on Cancer (1989) classified whole diesel exhaust as - "probably carcinogenic to humans". This classification stimulated even more stringent regulations for particulate matter that required further technological developments. These included improved engine control, improved fuel injection system, enhanced exhaust cooling, use of ultra low sulfur fuel, wall-flow high-efficiency exhaust particulate filters, exhaust catalysts, and crankcase ventilation filtration. The composition of New Technology Diesel Exhaust (NTDE) is qualitatively different and the concentrations of particulate constituents are more than 90% lower than for Traditional Diesel Exhaust (TDE). We recommend that future reviews of carcinogenic hazards of diesel exhaust evaluate NTDE separately from TDE.

  18. Mercaptans emissions in diesel and biodiesel exhaust

    NASA Astrophysics Data System (ADS)

    Corrêa, Sérgio Machado; Arbilla, Graciela

    Biodiesel and ethanol are fuels in clear growth and evidence, basically due to its relation with the greenhouse effect reduction. There are several works regarding regulated pollutants emissions, but there is a lack of reports in non-regulated emissions. In a previous paper (Corrêa and Arbilla, 2006) the emissions of aromatic hydrocarbons were reported and in 2007 another paper was published in 2008 focusing carbonyls emissions (Corrêa and Arbilla, 2008). In this work four mercaptans (methyl, ethyl, n-propyl and n-butyl mercaptans) were evaluated for a heavy-duty diesel engine, fueled with pure diesel (D) and biodiesel blends (v/v) of 2% (B2), 5% (B5), 10% (B10), and 20% (B20). The tests were carried using a six cylinder heavy-duty engine, typical of the Brazilian fleet of urban buses, during a real use across the city. The exhaust gases were diluted near 20 times and the mercaptans were sampled with glass fiber filters impregnated with mercuric acetate. The chemical analyses were performed by gas chromatography with mass spectrometry detection. The results indicated that the mercaptans emissions exhibit a reduction with the increase of biodiesel content, but this reduction is lower as the mercaptan molar mass increases. For B20 results the emission reduction was 18.4% for methyl mercaptan, 18.1% for ethyl mercaptan, 16.3% for n-propyl mercaptan, and 9.6% for n-butyl mercaptan.

  19. Coagulation markers in healthy human subjects exposed to diesel exhaust

    PubMed Central

    Carlsten, Chris; Kaufman, Joel D; Peretz, Alon; Trenga, Carol A; Sheppard, Lianne; Sullivan, Jeffrey H

    2008-01-01

    Background Ambient particulate matter (PM) is associated with cardiovascular morbidity and mortality. It has been proposed that PM induces a pro-thrombotic process, increasing the risk of cardiovascular events, with some support from epidemiological and laboratory-based models. Diesel exhaust is a major contributor to urban PM, and we conducted a controlled human exposure of diesel exhaust in healthy subjects. Objective To evaluate diesel exhaust exposure effects on fibrinolytic burden (D-dimer), platelet number, and endothelial injury (von Willebrand’s factor, VWF), inhibition of the fibrinolytic pathway (plasminogen activator inhibitor-1 [PAI-1]), and inflammation (C-reactive protein, CRP). Materials and Methods Randomized, crossover, double-blinded design, with 13 healthy participants exposed on three different days (≥ 2 weeks washout) to diesel exhaust at 0 (filtered air), 100μg PM2.5/m3 and 200μg PM2.5/m3. We assessed diesel exhaust-associated changes in D-dimer, VWF, PAI-1 and platelets at 3, 6 and 22 hours, and CRP at 22 hours, after exposure initiation. Results Significant changes did not occur in any primary endpoints. Among secondary endpoints, diesel exhaust (200μg PM2.5/m3) effect on PAI-1 levels at 22 hours was of borderline significance, with a 1.32-fold decrease after exposure to diesel exhaust (200μg PM2.5/m3), relative to filtered air (CI 1.00 to 1.54). Diurnal patterns in D-dimer and PAI-1 were observed. Conclusions In healthy individuals, exposure to 200μg PM2.5/m3 diesel exhaust did not affect primary pro-thrombotic endpoints. Thus, these data do not support a diesel exhaust-induced pro-thrombotic phenomenon. Replication of these studies should be carried out to ascertain whether or not they inform our mechanistic understanding of air pollution’s cardiovascular effects. PMID:17321570

  20. Bronchoalveolar inflammation after exposure to diesel exhaust: comparison between unfiltered and particle trap filtered exhaust.

    PubMed

    Rudell, B; Blomberg, A; Helleday, R; Ledin, M C; Lundbäck, B; Stjernberg, N; Hörstedt, P; Sandström, T

    1999-08-01

    Air pollution particulates have been identified as having adverse effects on respiratory health. The present study was undertaken to further clarify the effects of diesel exhaust on bronchoalveolar cells and soluble components in normal healthy subjects. The study was also designed to evaluate whether a ceramic particle trap at the end of the tail pipe, from an idling engine, would reduce indices of airway inflammation. The study comprised three exposures in all 10 healthy never smoking subjects; air, diluted diesel exhaust, and diluted diesel exhaust filtered with a ceramic particle trap. The exposures were given for 1 hour in randomised order about 3 weeks apart. The diesel exhaust exposure apperatus has previously been carefully developed and evaluated. Bronchoalveolar lavage was performed 24 hours after exposures and the lavage fluids from the bronchial and bronchoalveolar region were analysed for cells and soluble components. The particle trap reduced the mean steady state number of particles by 50%, but the concentrations of the other measured compounds were almost unchanged. It was found that diesel exhaust caused an increase in neutrophils in airway lavage, together with an adverse influence on the phagocytosis by alveolar macrophages in vitro. Furthermore, the diesel exhaust was found to be able to induce a migration of alveolar macrophages into the airspaces, together with reduction in CD3+CD25+ cells. (CD = cluster of differentiation) The use of the specific ceramic particle trap at the end of the tail pipe was not sufficient to completely abolish these effects when interacting with the exhaust from an idling vehicle. The current study showed that exposure to diesel exhaust may induce neutrophil and alveolar macrophage recruitment into the airways and suppress alveolar macrophage function. The particle trap did not cause significant reduction of effects induced by diesel exhaust compared with unfiltered diesel exhaust. Further studies are warranted to

  1. Bronchoalveolar inflammation after exposure to diesel exhaust: comparison between unfiltered and particle trap filtered exhaust

    PubMed Central

    Rudell, B.; Blomberg, A.; Helleday, R.; Ledin, M. C.; Lundback, B.; Stjernberg, N.; Horstedt, P.; Sandstrom, T.

    1999-01-01

    OBJECTIVES: Air pollution particulates have been identified as having adverse effects on respiratory health. The present study was undertaken to further clarify the effects of diesel exhaust on bronchoalveolar cells and soluble components in normal healthy subjects. The study was also designed to evaluate whether a ceramic particle trap at the end of the tail pipe, from an idling engine, would reduce indices of airway inflammation. METHODS: The study comprised three exposures in all 10 healthy never smoking subjects; air, diluted diesel exhaust, and diluted diesel exhaust filtered with a ceramic particle trap. The exposures were given for 1 hour in randomised order about 3 weeks apart. The diesel exhaust exposure apperatus has previously been carefully developed and evaluated. Bronchoalveolar lavage was performed 24 hours after exposures and the lavage fluids from the bronchial and bronchoalveolar region were analysed for cells and soluble components. RESULTS: The particle trap reduced the mean steady state number of particles by 50%, but the concentrations of the other measured compounds were almost unchanged. It was found that diesel exhaust caused an increase in neutrophils in airway lavage, together with an adverse influence on the phagocytosis by alveolar macrophages in vitro. Furthermore, the diesel exhaust was found to be able to induce a migration of alveolar macrophages into the airspaces, together with reduction in CD3+CD25+ cells. (CD = cluster of differentiation) The use of the specific ceramic particle trap at the end of the tail pipe was not sufficient to completely abolish these effects when interacting with the exhaust from an idling vehicle. CONCLUSIONS: The current study showed that exposure to diesel exhaust may induce neutrophil and alveolar macrophage recruitment into the airways and suppress alveolar macrophage function. The particle trap did not cause significant reduction of effects induced by diesel exhaust compared with unfiltered diesel

  2. Urinary mutagenic activity in workers exposed to diesel exhaust

    SciTech Connect

    Schenker, M.B.; Samuels, S.J.; Kado, N.Y. ); Hammond, S.K.; Woskie, S.R.; Smith, T.J. )

    1992-04-01

    The authors measured postshift urinary mutagenicity on a population of railroad workers with a range of diesel exhaust exposures. Postshift urinary mutagenicity was determined by a sensitive microsuspension procedure using Salmonella strain TA 98 {plus minus} S9. Number of cigarettes smoked on the study day and urinary cotinine were highly correlated with postshift urinary mutagenicity. Diesel exhaust exposure was measured over the work shift by constant-flow personal sampling pumps. The relative ranking of jobs by this adjusted respirable particle concentration (ARP) was correlated with relative contact the job groups have with operating diesel locomotives. After adjustment for cigarette smoking in multiple regressions, there was no independent association of diesel exhaust exposure, as estimated by ARP, with postshift urinary mutagenicity among smokers or nonsmokers. An important finding is the detection of baseline mutagenicity in most of the nonsmoking workers. Despite the use of individual measurements of diesel exhaust exposure, the absence of a significant association in this study may be due to the low levels of diesel exposure, the lack of a specific marker for diesel exhaust exposure, and/or urinary mutagenicity levels from diesel exposure below the limit of sensitivity for the mutagenicity assay.

  3. [Preparation of ethanol-diesel fuel blends and exhausts emission characteristics in diesel engine].

    PubMed

    Zhang, Runduo; He, Hong; Zhang, Changbin; Shi, Xiaoyan

    2003-07-01

    The technology that diesel oil is partly substituted by ethanol can reduce diesel engine exhausts emission, especially fuel soot. This research is concentrated on preparation of ethanol-diesel blend fuel and exhausts emission characteristics using diesel engine bench. Absolute ethanol can dissolve into diesel fuel at an arbitrary ratio. However, a trace of water (0.2%) addition can lead to the phase separation of blends. Organic additive synthesized during this research can develop the ability of resistance to water and maintain the stability of ethanol-diesel-trace amounts of water system. The effects of 10%, 20%, and 30% ethanol-diesel fuel blends on exhausts emission, were compared with that of diesel fuel in direct injection (DI) diesel engine. The optimum ethanol percentage for ethanol-diesel fuel blends was 20%. Using 20% ethanol-diesel fuel blend with 2% additive of the total volume, bench diesel engine showed a large amount decrease of exhaust gas, e.g. 55% of Bosch smoke number, 70% of HC emission, and 45% of CO emission at 13 kW and 1540 r/min. Without the addition of additive, the blend of ethanol produced new organic compounds such as ethanol and acetaldehyde in tail gas. However, the addition of additive obviously reduced the emission of ethanol and acetaldehyde.

  4. Embryotoxicity of irradiated and nonirradiated catalytic convertertreated automotive exhaust.

    PubMed

    Hoffman, D J; Campbell, K I

    1977-11-01

    This study was undertaken to examine the relative embryotoxicity in chick embryos of photochemically reacted and unreacted diluted automotive exhaust emissions from a system equipped with a catalytic converter. Clean air controls and H2SO4 aerosol controls equivalent in concentration to those found in the catalytic exhaust atmosphere were also studied. From day 1 through day 14 of development, continuous exposure to nonirradiated exhause resulted in decreased survival, lowered embryonic weight, a small increase in heart/body weight ratio, and altered hematocrit and serum enzyme activities (LDH and GOT). Irradiated exhaust had little effect on survival or on embryonic weight but resulted in a higher liver/body weight ratio as well as altered hematocrit and serum enzyme activities. Interactions or cumulative effects of different compositions of exhaust atmospheres may play a role in differing biological responses between unreacted and irradiated exhaust. Sulfuric acid aerosol had a minimal effect on survival and resulted in only a slight decrease in embryonic weight and serum LDH activity, with no other apparent effects. In previous studies where the catalytic converter was not used, more pronounced effects on survival, increased heart/body weigh ratio, elevated serum GPT activity, and liver discoloration were observed. Thus, the introduction of an oxidizing catalytic converter appeared to alleviate some but not all of the embryotoxic effects of automotive exhaust.

  5. Controlling automotive exhaust emissions: successes and underlying science.

    PubMed

    Twigg, Martyn V

    2005-04-15

    Photochemical reactions of vehicle exhaust pollutants were responsible for photochemical smog in many cities during the 1960s and 1970s. Engine improvements helped, but additional measures were needed to achieve legislated emissions levels. First oxidation catalysts lowered hydrocarbon and carbon monoxide, and later nitrogen oxides were reduced to nitrogen in a two-stage process. By the 1980s, exhaust gas could be kept stoichiometric and hydrocarbons, carbon monoxide and nitrogen oxides were simultaneously converted over a single 'three-way catalyst'. Today, advanced three-way catalyst systems emissions are exceptionally low. NOx control from lean-burn engines demands an additional approach because NO cannot be dissociated under lean conditions. Current lean-burn gasoline engine NOx control involves forming a nitrate phase and periodically enriching the exhaust to reduce it to nitrogen, and this is being modified for use on diesel engines. Selective catalytic reduction with ammonia is an alternative that can be very efficient, but it requires ammonia or a compound from which it can be obtained. Diesel engines produce particulate matter, and, because of health concerns, filtration processes are being introduced to control these emissions. On heavy duty diesel engines the exhaust gas temperature is high enough for NO in the exhaust to be oxidised over a catalyst to NO2 that smoothly oxidises particulate material (PM) in the filter. Passenger cars operate at lower temperatures, and it is necessary to periodically burn the PM in air at high temperatures.

  6. Diesel Exhaust Exposure Increases Susceptibility to Influenza ...

    EPA Pesticide Factsheets

    Mice were necropsied at day 1, 4, 8 and 14 post-infection and lung tissue was assessed for virus titers by TCID50, lung injury and inflammation. Lung and lymph node DC populations (CD11c+, MHCII, CD45+, CD80+ and CD86+) were identified by flow cytometry. Prior exposure to DE significantly increased viral titers in the lung at 4 and 8 days post infection in association with increased neutrophil influx and lung injury. Pro-inflammatory cytokines including IP-10, MCP-1, GM-CSF, and IL-1β, and the antiviral cytokine IFN-β were also increased at days 1, 4 and 8 post infection compared to air/flu controls. The number of DCs in the lung was not affected with previous exposure to DE, however the lymph nodes had increased number of mature DCs at 1, 4, and 8 days post infection compared to the air/flu controls. We conclude that exposure to DE prior to an influenza infection increases pulmonary inflammation, viral titers, and stimulates more DCs to migrate to the lymph nodes and mature as a consequence of the DE-enhanced influenza infection. Numerous studies have shown that diesel exhaust (DE) decreases resistance to respiratory infection and can alter the maturation and migration of dendritic cells (DCs). The purpose of this study was to evaluate the effects of DE exposure on susceptibilty to influenza infection in mice and to determine if this correlated with changes in the pulmonary DC populations. BALB/c mice were exposed to air or 0.5 mg/m3 DE from a diesel-power

  7. Diesel Exhaust Exposure Increases Susceptibility to Influenza ...

    EPA Pesticide Factsheets

    Mice were necropsied at day 1, 4, 8 and 14 post-infection and lung tissue was assessed for virus titers by TCID50, lung injury and inflammation. Lung and lymph node DC populations (CD11c+, MHCII, CD45+, CD80+ and CD86+) were identified by flow cytometry. Prior exposure to DE significantly increased viral titers in the lung at 4 and 8 days post infection in association with increased neutrophil influx and lung injury. Pro-inflammatory cytokines including IP-10, MCP-1, GM-CSF, and IL-1β, and the antiviral cytokine IFN-β were also increased at days 1, 4 and 8 post infection compared to air/flu controls. The number of DCs in the lung was not affected with previous exposure to DE, however the lymph nodes had increased number of mature DCs at 1, 4, and 8 days post infection compared to the air/flu controls. We conclude that exposure to DE prior to an influenza infection increases pulmonary inflammation, viral titers, and stimulates more DCs to migrate to the lymph nodes and mature as a consequence of the DE-enhanced influenza infection. Numerous studies have shown that diesel exhaust (DE) decreases resistance to respiratory infection and can alter the maturation and migration of dendritic cells (DCs). The purpose of this study was to evaluate the effects of DE exposure on susceptibilty to influenza infection in mice and to determine if this correlated with changes in the pulmonary DC populations. BALB/c mice were exposed to air or 0.5 mg/m3 DE from a diesel-power

  8. DIESEL EXHAUST ENHANCES INFLUENZA VIRUS INFECTIONS IN RESPIRATORY EPITHELIAL CELLS

    EPA Science Inventory

    Several factors, such as age and nutritional status can affect the susceptibility to influenza infections. Moreover, exposure to air pollutants, such as diesel exhaust (DE), has been shown to affect respiratory virus infections in rodent models. Influenza virus primarily infects ...

  9. INCREASED SUSCEPTIBILITY TO INFLUENZA INFECTION AFTER DIESEL EXHAUST EXPOSURE.

    EPA Science Inventory

    Inhaled environmental pollutants have a possible role in modulating the susceptibility of humans to respiratory infections. Diesel exhaust (DE) is a major component of urban air pollution and their effects on pulmonary infections is of great concern. Influenza infections cause ...

  10. INCREASED SUSCEPTIBILITY TO INFLUENZA INFECTION AFTER DIESEL EXHAUST EXPOSURE

    EPA Science Inventory

    Inhaled environmental pollutants have a possible role in modulating the susceptibility of humans to respiratory infections. Diesel exhaust (DE) is a major component of urban air pollution and their effects on pulmonary infections is of great concern. Influenza infections cause ...

  11. Photochemical Reaction Altered Cardiac Toxicity of Diesel Exhaust Inhalation

    EPA Science Inventory

    Rationale: Epidemiological studies have indicated an association between urban air pollution exposure and cardiovascular morbidity and mortality. The present study was designed to evaluate the cardiac effects of inhaled diesel exhaust and compared with photochemically altered d...

  12. Remote launch operations building, showing diesel exhaust (left) and intake ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Remote launch operations building, showing diesel exhaust (left) and intake (right) shafts, and tunnel entrance on the far right - Stanley R. Mickelsen Safeguard Complex, Remote Launch Operations Building, Near Service Road exit from Patrol Road, Nekoma, Cavalier County, ND

  13. Photochemical Reaction Altered Cardiac Toxicity of Diesel Exhaust Inhalation

    EPA Science Inventory

    Rationale: Epidemiological studies have indicated an association between urban air pollution exposure and cardiovascular morbidity and mortality. The present study was designed to evaluate the cardiac effects of inhaled diesel exhaust and compared with photochemically altered d...

  14. INCREASED SUSCEPTIBILITY TO INFLUENZA INFECTION AFTER DIESEL EXHAUST EXPOSURE.

    EPA Science Inventory

    Inhaled environmental pollutants have a possible role in modulating the susceptibility of humans to respiratory infections. Diesel exhaust (DE) is a major component of urban air pollution and their effects on pulmonary infections is of great concern. Influenza infections cause ...

  15. DIESEL EXHAUST ENHANCES INFLUENZA VIRUS INFECTIONS IN RESPIRATORY EPITHELIAL CELLS

    EPA Science Inventory

    Several factors, such as age and nutritional status can affect the susceptibility to influenza infections. Moreover, exposure to air pollutants, such as diesel exhaust (DE), has been shown to affect respiratory virus infections in rodent models. Influenza virus primarily infects ...

  16. INCREASED SUSCEPTIBILITY TO INFLUENZA INFECTION AFTER DIESEL EXHAUST EXPOSURE

    EPA Science Inventory

    Inhaled environmental pollutants have a possible role in modulating the susceptibility of humans to respiratory infections. Diesel exhaust (DE) is a major component of urban air pollution and their effects on pulmonary infections is of great concern. Influenza infections cause ...

  17. Capture of Heat Energy from Diesel Engine Exhaust

    SciTech Connect

    Chuen-Sen Lin

    2008-12-31

    Diesel generators produce waste heat as well as electrical power. About one-third of the fuel energy is released from the exhaust manifolds of the diesel engines and normally is not captured for useful applications. This project studied different waste heat applications that may effectively use the heat released from exhaust of Alaskan village diesel generators, selected the most desirable application, designed and fabricated a prototype for performance measurements, and evaluated the feasibility and economic impact of the selected application. Exhaust flow rate, composition, and temperature may affect the heat recovery system design and the amount of heat that is recoverable. In comparison with the other two parameters, the effect of exhaust composition may be less important due to the large air/fuel ratio for diesel engines. This project also compared heat content and qualities (i.e., temperatures) of exhaust for three types of fuel: conventional diesel, a synthetic diesel, and conventional diesel with a small amount of hydrogen. Another task of this project was the development of a computer-aided design tool for the economic analysis of selected exhaust heat recovery applications to any Alaskan village diesel generator set. The exhaust heat recovery application selected from this study was for heating. An exhaust heat recovery system was fabricated, and 350 hours of testing was conducted. Based on testing data, the exhaust heat recovery heating system showed insignificant effects on engine performance and maintenance requirements. From measurements, it was determined that the amount of heat recovered from the system was about 50% of the heat energy contained in the exhaust (heat contained in exhaust was evaluated based on environment temperature). The estimated payback time for 100% use of recovered heat would be less than 3 years at a fuel price of $3.50 per gallon, an interest rate of 10%, and an engine operation of 8 hours per day. Based on experimental data

  18. Catalysts as Sensors—A Promising Novel Approach in Automotive Exhaust Gas Aftertreatment

    PubMed Central

    Moos, Ralf

    2010-01-01

    Sensors that detect directly and in situ the status of automotive exhaust gas catalysts by monitoring the electrical properties of the catalyst coating itself are overviewed. Examples included in this review are the in-situ determination of the electrical impedance of three-way catalysts based on ceria-zirconia solutions and of lean NOx traps of earth-alkaline based coatings, as well as approaches to determine the ammonia loading in Fe-SCR-zeolites with electrical ac measurements. Even more sophisticated approaches based on interactions with electromagnetic waves are also reviewed. For that purpose, metallic stick-like antennas are inserted into the exhaust pipe. The catalyst properties are measured in a contactless manner, directly indicating the catalyst status. The radio frequency probes gauge the oxygen loading degree of three-way catalysts, the NOx-loading of lean NOx traps, and the soot loading of Diesel particulate filters. PMID:22163575

  19. Catalysts as sensors--a promising novel approach in automotive exhaust gas aftertreatment.

    PubMed

    Moos, Ralf

    2010-01-01

    Sensors that detect directly and in situ the status of automotive exhaust gas catalysts by monitoring the electrical properties of the catalyst coating itself are overviewed. Examples included in this review are the in-situ determination of the electrical impedance of three-way catalysts based on ceria-zirconia solutions and of lean NO(x) traps of earth-alkaline based coatings, as well as approaches to determine the ammonia loading in Fe-SCR-zeolites with electrical ac measurements. Even more sophisticated approaches based on interactions with electromagnetic waves are also reviewed. For that purpose, metallic stick-like antennas are inserted into the exhaust pipe. The catalyst properties are measured in a contactless manner, directly indicating the catalyst status. The radio frequency probes gauge the oxygen loading degree of three-way catalysts, the NO(x)-loading of lean NO(x) traps, and the soot loading of Diesel particulate filters.

  20. Comparison of diesel engine exhaust using chromatographic profiling techniques

    SciTech Connect

    Partridge, P.A.; Shala, F.J.; Cernansky, N.P.; Suffet, I.H. )

    1990-02-01

    An analytical method, developed for examining changes in the intensity and number of chemical compounds in the odorous fraction of diesel exhaust, has been applied to a variety of diesel engine systems. Comparisons were made using the chromatographic computer profiles of samples collected with the Diesel Odor Analysis System (DOAS) and dilution tunnel sampling systems. The different engine systems showed several areas of common peak patterns, but with distinctly different overall patterns. The benzaldehyde-odor correlation developed in a previous study worked for the engine systems tested. The differences in the overall patterns are attributed to the specific diesel fuels used and to the specific engine configurations. Samples obtained from raw and diluted (with a dilution tunnel) exhaust were compared. Diluted exhaust sample profiles were shown to contain a greater number of peaks, probably due to postcombustion reactions occurring in the dilution tunnel.

  1. Does diesel exhaust cause human lung cancer?

    PubMed

    Cox, L A

    1997-12-01

    Recent reviews of epidemiological evidence on the relation between exposure to diesel exhaust (DE) and lung cancer risk have reached conflicting conclusions, ranging from belief that there is sufficient evidence to conclude that DE is a human lung carcinogen (California EPA, 1994) to conclusions that there is inadequate evidence to support a causal association between DE and human lung cancer (Muscat and Wynder, 1995). Individual studies also conflict, with both increases and decreases in relative risks of lung cancer mortality being cited with 95% statistical confidence. On balance, reports of elevated risk outnumber reports of reduced risk. This paper reexamines the evidence linking DE exposures to lung cancer risk. After briefly reviewing animal data and biological mechanisms, it surveys the relevant epidemiological literature and examines possible explanations for the discrepancies. These explanations emphasize the distinction between statistical associations, which have been found in many studies, and causal associations, which appear not to have been established. Methodological threats to valid causal inference are identified and new approaches for controlling them are proposed using recent techniques from artificial intelligence (AI) and computational statistics. These threats have not been adequately controlled for in previous epidemiological studies. They provide plausible noncausal explanations for the reported increases in relative risks, making it impossible to infer causality between DE exposure and lung cancer risk from these studies. A key contribution is to show how recent techniques developed in the AI-and-statistics literature can help clarify the causal interpretation of complex multivariate data sets used in epidemiological risk assessments. Applied to the key study of Garshick et al. (1988), these methods show that DE concentration has no positive causal association with occupational lung cancer mortality risk.

  2. Particulate measurement issues in diesel exhausts using laser induced incandescence

    SciTech Connect

    Gupta, S. B.; Poola, R. B.; Sekar, R.

    2000-07-03

    A number of studies in the recent past have identified Laser Induced Incandescence (LII) as a versatile technique for in-flame measurement of soot concentrations. Recently, a number of researchers have focused their attention in adapting this technique to measure particulate in diesel exhausts. However the agreement with established physical sampling techniques, such as the EPA recommended filter paper collection method, was found to be less than ideal. This paper reports the efforts to adapt this technique for diesel exhaust characterization. Many of the factors affecting LII signal were identified through computer modeling. Parameters that could not be determined through such a model were determined experimentally following a parametric study. Subsequently, LII measurements were performed in the exhaust of a modified lab burner, with conditions close to that of diesel engine exhausts. Such measurements show excellent agreement with those performed using the standard filter paper collection technique.

  3. Speed control of automotive diesel engines

    NASA Astrophysics Data System (ADS)

    Outbib, Rachid; Graton, Guillaume; Dovifaaz, Xavier; Younes, Rafic

    2014-04-01

    This paper deals with Diesel engine control. More precisely, a model-based approach is considered to stabilise engine speed around a defined value. The model taken into account is nonlinear and contains explicitly the expression of fuel conversion efficiency. In general in the literature, this experimentally obtained quantity is modelled with either a polynomial or an exponential form (see for instance Younes, R. (1993). Elaboration d'un modèle de connaissance du moteur diesel avec turbocompresseur à géométrie variable en vue de l'optimisation de ses émissions. Ecole Centrale de Lyon; Omran, R., Younes, R., Champoussin, J., & Outbib, R. (2011). New indicated mean effective pressure (IMEP) model for predicting crankshaft movement. Energy Conversion and Management, 52, 3376-3382). This paper focuses on engine speed feedback stabilisation when fuel conversion efficiency is modelled with an exponential form, which is more suitable for automative applications. Simulation results are proposed to highlight the closed-loop control performances.

  4. Retention modeling of diesel exhaust particles in rats and humans.

    PubMed

    Yu, C P; Yoon, K J

    1991-05-01

    The objective of this study was to predict the lung burden in rats and humans of diesel exhaust particles from automobile emissions by means of a mathematical model. We previously developed a model to predict the deposition of diesel exhaust particles in the lungs of these species. In this study, the clearance and retention of diesel exhaust particles deposited in the lung are examined. A diesel particle is composed of a carbonaceous core (soot) and adsorbed organics. These materials can be removed from the lung after deposition by two mechanisms: (1) mechanical clearance, provided by mucociliary transport in the ciliated airways as well as macrophage phagocytosis and migration in the nonciliated airways, and (2) clearance by dissolution. To study the clearance of diesel exhaust particles from the lung, we used a compartmental model consisting of four anatomical compartments: nasopharyngeal, tracheobronchial, alveolar, and the lung-associated lymph node compartments. We also assumed a particle model made up of material components according to the characteristics of clearance: (1) a carbonaceous core of about 80 percent of particle mass, (2) slowly cleared organics of about 10 percent of particle mass, and (3) fast-cleared organics accounting for the remaining 10 percent of particle mass. The kinetic equations of the retention model were first developed for Fischer-344 rats. The transport rates of each material component of diesel exhaust particles (soot, slowly cleared organics, and fast-cleared organics) were derived using available experimental data and several mathematical approximations. The lung burden results calculated from the model showed that although the organics were cleared at nearly constant rates, the alveolar clearance rate of diesel soot decreased with increasing lung burden. This is consistent with existing experimental observations. At low lung burdens, the alveolar clearance rate of diesel soot was a constant, equal to the normal clearance rate

  5. Catalytic diesel particulate filters reduce the in vitro estrogenic activity of diesel exhaust.

    PubMed

    Wenger, Daniela; Gerecke, Andreas C; Heeb, Norbert V; Naegeli, Hanspeter; Zenobi, Renato

    2008-04-01

    An in vitro reporter gene assay based on human breast cancer T47D cells (ER-CALUX) was applied to examine the ability of diesel exhaust to induce or inhibit estrogen receptor (ER)-mediated gene expression. Exhaust from a heavy-duty diesel engine was either treated by iron- or copper/iron-catalyzed diesel particulate filters (DPFs) or studied as unfiltered exhaust. Collected samples included particle-bound and semivolatile constituents of diesel exhaust. Our findings show that all of the samples contained compounds that were able to induce ER-mediated gene expression as well as compounds that suppressed the activity of the endogenous hormone 17beta-estradiol (E2). Estrogenic activity prevailed over antiestrogenic activity. We found an overall ER-mediated activity of 1.63 +/- 0.31 ng E2 CALUX equivalents (E2-CEQs) per m(3) of unfiltered exhaust. In filtered exhaust, we measured 0.74 +/- 0.07 (iron-catalyzed DPF) and 0.55 +/- 0.09 ng E2-CEQ m(-3) (copper/iron-catalyzed DPF), corresponding to reductions in estrogenic activity of 55 and 66%, respectively. Our study demonstrates that both catalytic DPFs lowered the ER-mediated endocrine-disrupting potential of diesel exhaust.

  6. Recent advances in investigations of toxicity of automotive exhaust.

    PubMed

    Stupfel, M

    1976-10-01

    The influence of auto exhaust on man's health is difficult to gauge considering the intricacy of human environmental urban stresses and particularly of other air polluting (industrial, domestic) emissions. Epidemiological surveys made in road tunnel employees and in traffic officers have not demonstrated specific effects and have often been complicated by cigarette smoking as a factor. Long-term animal experiments run mostly on small rodents give evidence of little effect of the pathological actions of dilutions such as those encountered in high polluted cities. However the acute toxicity of gasoline exhaust emission is well known and mostly due to carbon monoxide. Considering the different types of cycles and operating conditions of vehicles (gasoline and diesel), auto exhaust gases constitute no more a chemical entity than they show, a definite toxicity. A great number of substances that they contain (nitrogen oxides, aldehydes, antiknock additives, heavy metals, possible catalysts are highly toxic as shown by in vivo and in vitro (mutagenic) tests. Interactions of the components are for the moment ignored or poorly understood. Besides, the evolution of the physicochemical properties and natures of the auto exhaust emission in the gaseous biotope of man under determined conditions of ultraviolet irradiation, temperature, and hygrometry provoke the formation of secondary products such as oxidants and ozone. Several experiments show clearly that irradiation increases the toxicity of auto exhaust significantly. For these reasons, geographical, meteorological, and chronological (circadian and seasonal) factors should be taken into consideration, especially with regard to emission standards.

  7. Recent advances in investigations of toxicity of automotive exhaust

    PubMed Central

    Stupfel, Maurice

    1976-01-01

    The influence of auto exhaust on man's health is difficult to gauge considering the intricacy of human environmental urban stresses and particularly of other air polluting (industrial, domestic) emissions. Epidemiological surveys made in road tunnel employees and in traffic officers have not demonstrated specific effects and have often been complicated by cigarette smoking as a factor. Long-term animal experiments run mostly on small rodents give evidence of little effect of the pathological actions of dilutions such as those encountered in high polluted cities. However the acute toxicity of gasoline exhaust emission is well known and mostly due to carbon monoxide. Considering the different types of cycles and operating conditions of vehicles (gasoline and diesel), auto exhaust gases constitute no more a chemical entity than they show, a definite toxicity. A great number of substances that they contain (nitrogen oxides, aldehydes, antiknock additives, heavy metals, possible catalysts are highly toxic as shown by in vivo and in vitro (mutagenic) tests. Interactions of the components are for the moment ignored or poorly understood. Besides, the evolution of the physicochemical properties and natures of the auto exhaust emission in the gaseous biotope of man under determined conditions of ultraviolet irradiation, temperature, and hygrometry provoke the formation of secondary products such as oxidants and ozone. Several experiments show clearly that irradiation increases the toxicity of auto exhaust significantly. For these reasons, geographical, meteorological, and chronological (circadian and seasonal) factors should be taken into consideration, especially with regard to emission standards. PMID:67944

  8. Diesel Exhaust Exposure and Nasal Response to Attenuated Influenza in Normal and Allergic Volunteers

    EPA Science Inventory

    Rationale: Diesel exhaust enhances allergic inflammation, and pollutants are associated with heightened susceptibility to viral respiratory infections. The effects of combined diesel and virus exposure in humans are unknown. Objective: Test whether acute exposure to diesel modif...

  9. Diesel Exhaust Exposure and Nasal Response to Attenuated Influenza in Normal and Allergic Volunteers

    EPA Science Inventory

    Rationale: Diesel exhaust enhances allergic inflammation, and pollutants are associated with heightened susceptibility to viral respiratory infections. The effects of combined diesel and virus exposure in humans are unknown. Objective: Test whether acute exposure to diesel modif...

  10. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT II, MAINTAINING THE AIR SYSTEM--DETROIT DIESEL ENGINES.

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF THE DIESEL ENGINE AIR SYSTEM. TOPICS ARE (1) OPERATION AND FUNCTION, (2) AIR CLEANER, (3) AIR SHUT-DOWN HOUSING, (4) EXHAUST SYSTEM, (5) BLOWER, (6) TURBOCHARGER, AND (7) TROUBLE-SHOOTING TIPS ON THE AIR SYSTEM. THE MODULE CONSISTS OF A…

  11. Biological activity of particle exhaust emissions from light-duty diesel engines.

    PubMed

    Carraro, E; Locatelli, A L; Ferrero, C; Fea, E; Gilli, G

    1997-01-01

    assays were available, exhaust emission generation by biodiesel fuel seemed to yield a smaller environmental impact than that of the referenced diesel fuel. The results point out the usefulness of mutagenicity testing in the research of both newer, more efficient automotive aftertreatment devices and less polluting fuels.

  12. The Differential Oxidative Properties of Diesel Exhaust Particles

    EPA Science Inventory

    Diesel exhaust particles (DEP) accounts for a significant percentage of particulate matter (PM) released into the atmosphere and are associated with adverse pulmonary effects. Due to their extremely small size and high surface area, DEP can adsorb toxic substances, thus potentia...

  13. Are Urinary PAHs Biomarkers of Controlled Exposure to Diesel Exhaust?

    EPA Science Inventory

    Urinary polycyclic aromatic hydrocarbons (PAHs) were evaluated as possible biomarkers of exposure to diesel exhaust (DE) in two controlled-chamber studies. We report levels of 14 PAHs from 28 subjects in urine that were collected before, immediately after and the morning after ex...

  14. DIESEL EXHAUST EXPOSURE INCREASES SEVERITY OF AN ONGOING INFLUENZA INFECTION

    EPA Science Inventory

    Numerous studies have shown that air pollutants including diesel exhaust (DE) alter host defense responses, resulting in decreased resistance to respiratory infection. The purpose of this study was to evaluate the effects of DE exposure on the severity of an ongoing influenza in...

  15. EFFECTS OF DIESEL EXHAUST ON TLR3 EXPRESSION IN MICE

    EPA Science Inventory

    There are a variety of intrinsic as well as extrinsic factors, such as exposure to air pollution that can affect the pathogenesis of respiratory infections. Exposure to diesel exhaust (DE) emissions can alter host defense and immune responses and we have previously demonstrated t...

  16. MULTIDISCIPLINARY SCIENTIFIC AND ENGINEERING APPROACHES TO ASSESSING DIESEL EXHAUST TOXICITY

    EPA Science Inventory

    Based on epidemiology reports, diesel exhaust (DE) containing particulate matter (PM) may play a role in increasing cardiopulmonary mortality and morbidity, such as lung infection and asthma symptoms. DE gas-phase components may modify the PM effects. DE components vary depending...

  17. Exposure to Diesel Exhaust Enhances the Generation of Vascular Microparticles

    EPA Science Inventory

    Introduction: In the study of the health impacts of traffic-related air pollution, diesel exhaust is a pollutant of particular interest, since it is a major source of particulate matter (PM). Epidemiological studies associate exposure to ambient levels of PM with cardiovascular m...

  18. EFFECTS OF DIESEL EXHAUST ON TLR3 EXPRESSION IN MICE

    EPA Science Inventory

    There are a variety of intrinsic as well as extrinsic factors, such as exposure to air pollution that can affect the pathogenesis of respiratory infections. Exposure to diesel exhaust (DE) emissions can alter host defense and immune responses and we have previously demonstrated t...

  19. Are Urinary PAHs Biomarkers of Controlled Exposure to Diesel Exhaust?

    EPA Science Inventory

    Urinary polycyclic aromatic hydrocarbons (PAHs) were evaluated as possible biomarkers of exposure to diesel exhaust (DE) in two controlled-chamber studies. We report levels of 14 PAHs from 28 subjects in urine that were collected before, immediately after and the morning after ex...

  20. The Differential Oxidative Properties of Diesel Exhaust Particles

    EPA Science Inventory

    Diesel exhaust particles (DEP) accounts for a significant percentage of particulate matter (PM) released into the atmosphere and are associated with adverse pulmonary effects. Due to their extremely small size and high surface area, DEP can adsorb toxic substances, thus potentia...

  1. Mutagenicity of Diesel and Soy Biodiesel Exhaust Particles

    EPA Science Inventory

    Mutagenicity Of Diesel And Soy Biodiesel Exhaust Particles E Mutlua,b' SH Warrenb, PP Matthewsb, CJ Kingb, B Prestonc, MD Haysb, DG Nashb,ct, WP Linakb, MI Gilmourb, and DM DeMarinib aUniversity of North Carolina, Chapel Hill, NC bU.S. Environmental Agency, Research Triangle Pa...

  2. Effects of diesel exhaust on influenza-induced nasal inflammation

    EPA Science Inventory

    Title: Effects of Diesel Exhaust on Influenza-Induced Nasal Inflammation T L Noah, MD1,2, K Horvath, BS3, C Robinette, RN2, 0 Diaz Sanchez, PhD4 and I Jaspers, PhD1,2. 1UNC Dept. of Pediatrics, United States; 2UNC Center for Environmental Medicine, Asthma and Lung Biology, ...

  3. Effects of diesel exhaust on influenza-induced nasal inflammation

    EPA Science Inventory

    Title: Effects of Diesel Exhaust on Influenza-Induced Nasal Inflammation T L Noah, MD1,2, K Horvath, BS3, C Robinette, RN2, 0 Diaz Sanchez, PhD4 and I Jaspers, PhD1,2. 1UNC Dept. of Pediatrics, United States; 2UNC Center for Environmental Medicine, Asthma and Lung Biology, ...

  4. DIESEL EXHAUST EXPOSURE INCREASES SEVERITY OF AN ONGOING INFLUENZA INFECTION

    EPA Science Inventory

    Numerous studies have shown that air pollutants including diesel exhaust (DE) alter host defense responses, resulting in decreased resistance to respiratory infection. The purpose of this study was to evaluate the effects of DE exposure on the severity of an ongoing influenza in...

  5. MULTIDISCIPLINARY SCIENTIFIC AND ENGINEERING APPROACHES TO ASSESSING DIESEL EXHAUST TOXICITY

    EPA Science Inventory

    Based on epidemiology reports, diesel exhaust (DE) containing particulate matter (PM) may play a role in increasing cardiopulmonary mortality and morbidity, such as lung infection and asthma symptoms. DE gas-phase components may modify the PM effects. DE components vary depending...

  6. Exposure to Diesel Exhaust Enhances the Generation of Vascular Microparticles

    EPA Science Inventory

    Introduction: In the study of the health impacts of traffic-related air pollution, diesel exhaust is a pollutant of particular interest, since it is a major source of particulate matter (PM). Epidemiological studies associate exposure to ambient levels of PM with cardiovascular m...

  7. Mutagenicity of Diesel and Soy Biodiesel Exhaust Particles

    EPA Science Inventory

    Mutagenicity Of Diesel And Soy Biodiesel Exhaust Particles E Mutlua,b' SH Warrenb, PP Matthewsb, CJ Kingb, B Prestonc, MD Haysb, DG Nashb,ct, WP Linakb, MI Gilmourb, and DM DeMarinib aUniversity of North Carolina, Chapel Hill, NC bU.S. Environmental Agency, Research Triangle Pa...

  8. Diesel exhaust particles and airway inflammation

    EPA Science Inventory

    Purpose of review. Epidemiologic investigation has associated traffic-related air pollution with adverse human health outcomes. The capacity ofdiesel exhaust particles (DEP), a major emission source air pollution particle, to initiate an airway inflammation has subsequently been ...

  9. Diesel exhaust particles and airway inflammation

    EPA Science Inventory

    Purpose of review. Epidemiologic investigation has associated traffic-related air pollution with adverse human health outcomes. The capacity ofdiesel exhaust particles (DEP), a major emission source air pollution particle, to initiate an airway inflammation has subsequently been ...

  10. Diesel exhaust rapidly degrades floral odours used by honeybees.

    PubMed

    Girling, Robbie D; Lusebrink, Inka; Farthing, Emily; Newman, Tracey A; Poppy, Guy M

    2013-10-03

    Honeybees utilise floral odours when foraging for flowers; we investigated whether diesel exhaust pollution could interrupt these floral odour stimuli. A synthetic blend of eight floral chemicals, identified from oilseed rape, was exposed to diesel exhaust pollution. Within one minute of exposure the abundances of four of the chemicals were significantly lowered, with two components rendered undetectable. Honeybees were trained to recognise the full synthetic odour mix; altering the blend, by removing the two chemicals rendered undetectable, significantly reduced the ability of the trained honeybees to recognize the altered odour. Furthermore, we found that at environmentally relevant levels the mono-nitrogen oxide (NOx) fraction of the exhaust gases was a key facilitator of this odour degradation. Such changes in recognition may impact upon a honeybee's foraging efficiency and therefore the pollination services that they provide.

  11. Characterization of diesel exhaust in a chronic inhalation study.

    PubMed

    Cheng, Y S; Yeh, H C; Mauderly, J L; Mokler, B V

    1984-08-01

    We describe characterization of the exposure atmosphere in a life-span study of rats and mice exposed to chronic inhalation of diluted diesel exhaust. Diesel exhaust was generated by one of two General Motors 1980 Model, 5.7-liter V8 diesel engines connected to an eddy current dynamometer/flywheel system and operated on the Federal Test Procedure urban driving cycle. Animals were exposed 7 hours/day, 5 days/week to exhaust at particle concentrations of approximately 7000, 3500, and 350 micrograms/m3 or to clean air. Throughout the 24-month study, the mean particle mass concentration remained within 5% of the target values. Measured gas concentrations of CO, CO2, NO, NO2, and hydrocarbons were roughly proportional to the dilution ratio. A combination of a Lovelace Multijet cascade impactor followed by a parallel flow diffusion battery gave mass median diameters of 0.23 to 0.26 microns averaged over complete cycles and geometric standard deviations larger than 4. The aerosol concentration profile was associated with the operating cycle. The measured diesel particle size was similar to previously reported values of particles released to the atmosphere from the same model engine.

  12. Gravimetric Measurements of Filtering Facepiece Respirators Challenged With Diesel Exhaust.

    PubMed

    Satish, Swathi; Swanson, Jacob J; Xiao, Kai; Viner, Andrew S; Kittelson, David B; Pui, David Y H

    2017-07-01

    Elevated concentrations of diesel exhaust have been linked to adverse health effects. Filtering facepiece respirators (FFRs) are widely used as a form of respiratory protection against diesel particulate matter (DPM) in occupational settings. Previous results (Penconek A, Drążyk P, Moskal A. (2013) Penetration of diesel exhaust particles through commercially available dust half masks. Ann Occup Hyg; 57: 360-73.) have suggested that common FFRs are less efficient than would be expected for this purpose based on their certification approvals. The objective of this study was to measure the penetration of DPM through NIOSH-certified R95 and P95 electret respirators to verify this result. Gravimetric-based penetration measurements conducted using polytetrafluoroethylene (PTFE) and polypropylene (PP) filters were compared with penetration measurements made with a Scanning Mobility Particle Sizer (SMPS, TSI Inc.), which measures the particle size distribution. Gravimetric measurements using PP filters were variable compared to SMPS measurements and biased high due to adsorption of gas phase organic material. Relatively inert PTFE filters adsorbed less gas phase organic material resulting in measurements that were more accurate. To attempt to correct for artifacts associated with adsorption of gas phase organic material, primary and secondary filters were used in series upstream and downstream of the FFR. Correcting for adsorption by subtracting the secondary mass from the primary mass improved the result for both PTFE and PP filters but this correction is subject to 'equilibrium' conditions that depend on sampling time and the concentration of particles and gas phase hydrocarbons. Overall, the results demonstrate that the use of filters to determine filtration efficiency of FFRs challenged with diesel exhaust produces erroneous results due to the presence of gas phase hydrocarbons in diesel exhaust and the tendency of filters to adsorb organic material. Published by

  13. Diesel exhaust in miners study: how to understand the findings?

    PubMed Central

    2012-01-01

    The Diesel Exhaust in Miners Study (DEMS) is an outstanding epidemiological project on the association between occupational diesel exhaust exposures, measured as long-term respirable elemental carbon (REC) estimates, and lung cancer mortality in a large cohort of US miners. Two articles published recently (Attfield et al. (J Natl Cancer Inst Epub, [2012]), Silverman et al. (J Natl Cancer Inst Epub, [2012])) dsescribed the epidemiological findings. These papers are expected to have considerable impact on the evaluation of the carcinogenic potential of diesel exhaust and, furthermore, on occupational and environmental limit value discussions related to diesel motor emissions and particle exposures. DEMS found remarkable exposure-response relationships between REC exposure estimates and lung cancer mortality - conditional on a pronounced effect of surface vs. underground work on lung cancer risk. If this risk factor is ignored the estimated REC-lung cancer association is attenuated substantially. The authors relied on this risk factor in their main analyses. However, this factor “surface/underground work” remained unexplained. The factor lead the authors to introduce unusual cross-product terms of location and smoking in adjustment procedures and even caused the authors to hypothesize that high REC exposures are protective against lung cancer excess risks due to smoking. To understand the reliability of these conclusions, we should ask basic questions about the data collection process in DEMS: Did the mortality follow-up procedures suffer from errors like those that affected the NCI formaldehyde cohort study? Are the REC and/or smoking data reliable, and are these data collected/constructed in such a way that the procedures allow valid comparisons between surface and underground workers? Without clarifying the issues raised in this Commentary the Diesel Exhaust in Miners Study remains to be difficult to interpret. PMID:22676299

  14. Measurement of Gas-phase Acids in Diesel Exhaust

    NASA Astrophysics Data System (ADS)

    Wentzell, J. J.; Liggio, J.; Li, S.; Vlasenko, A. L.; Staebler, R. M.; Brook, J.; Lu, G.; Poitras, M.; Chan, T.

    2012-12-01

    Gas-phase acids were measured using chemical ionization mass spectrometry (CIMS) as part of the Diesel Engine Emission Research Experiment (DEERE). The CIMS technique, utilizing acetate ion (CH3COO-) as a reagent ion, proved to be a rapid (measurements on the order of seconds) and sensitive (several counts/pptv) method of quantifying the acid emissions. Diluted diesel exhaust measurements were made from a Constant Volume Sampling dilution tunnel using a light duty (1.9L turbocharged Volkswagen Jetta TDI) diesel engine equipped with an OEM diesel oxidation catalyst and exhaust gas recirculation, mounted on an engine dynamometer. Acids measured included isocyanic, nitrous, nitric, propionic and sum of lactic and oxalic, as well as other unidentified compounds. Complimentary measurements of CO, CO2, Total Hydrocarbon (THC), and NOx, were also performed. Several engine modes (different engine rpm and torque outputs) at steady state were examined to determine their effect on acid emissions. Emission rates with respect to NOx and fuel based emission factors were determined. Measurements of HONO fuel emission factors agree well with real-world measurements within a traffic tunnel.1 The first estimate of isocyanic acid emission factors from a diesel engine is reported, and suggests that the emission of this highly toxic compound in diesel exhaust should not be ignored. 1. Kurtenbach, R., Becker, K. H., Gomes, J. A. G., Kleffmann, J.,Lorzer, J. C., Spittler, M., Wiesen, P., Ackermann, R., Geyer, A.,and Platt, U.: Investigations of emissions and heterogeneous formation of HONO in a road traffic tunnel, Atmos. Environ., 35, 3385-3394, doi:10.1016/S1352-2310(01)00138-8, 2001.

  15. Direct Injection Compression Ignition Diesel Automotive Technology Education GATE Program

    SciTech Connect

    Anderson, Carl L

    2006-09-25

    The underlying goal of this prqject was to provide multi-disciplinary engineering training for graduate students in the area of internal combustion engines, specifically in direct injection compression ignition engines. The program was designed to educate highly qualified engineers and scientists that will seek to overcome teclmological barriers preventing the development and production of cost-effective high-efficiency vehicles for the U.S. market. Fu1iher, these highly qualified engineers and scientists will foster an educational process to train a future workforce of automotive engineering professionals who are knowledgeable about and have experience in developing and commercializing critical advanced automotive teclmologies. Eight objectives were defmed to accomplish this goal: 1. Develop an interdisciplinary internal co1nbustion engine curriculum emphasizing direct injected combustion ignited diesel engines. 2. Encourage and promote interdisciplinary interaction of the faculty. 3. Offer a Ph.D. degree in internal combustion engines based upon an interdisciplinary cuniculum. 4. Promote strong interaction with indusuy, develop a sense of responsibility with industry and pursue a self sustaining program. 5. Establish collaborative arrangements and network universities active in internal combustion engine study. 6. Further Enhance a First Class educational facility. 7. Establish 'off-campus' M.S. and Ph.D. engine programs of study at various indusuial sites. 8. Extend and Enhance the Graduate Experience.

  16. Influence of experimental pulmonary emphysema on the toxicological effects from inhaled nitrogen dioxide and diesel exhaust

    SciTech Connect

    Mauderly, J.L.; Bice, D.E.; Cheng, Y.S.; Gillett, N.A.; Henderson, R.F.; Pickrell, J.A.; Wolff, R.K. )

    1989-10-01

    This project examined the influence of preexisting, experimentally induced pulmonary emphysema on the adverse health effects in rats of chronic inhalation exposure to either nitrogen dioxide or automotive diesel-engine exhaust. Previous reports indicated that humans with chronic lung disease were among those most severely affected by episodic exposures to high concentrations of airborne toxicants. There were no previous reports comparing the effects of chronic inhalation exposure to components of automotive emissions in emphysematous and normal animals. The hypothesis tested in this project was that rats with preexisting pulmonary emphysema were more susceptible than rats with normal lungs to the adverse effects of the toxicant exposures. Young adult rats were housed continuously in inhalation exposure chambers and exposed seven hours per day, five days per week, for 24 months to nitrogen dioxide at 9.5 parts per million (ppm)2, or to diesel exhaust at 3.5 mg soot/m3, or to clean air as control animals. These concentrations were selected to produce mild, but distinct, effects in rats with normal lungs. Pulmonary emphysema was induced in one-half of the rats by intratracheal instillation of the proteolytic enzyme elastase six weeks before the toxicant exposures began. Health effects were evaluated after 12, 18, and 24 months of exposure. The measurements included respiratory function, clearance of inhaled radiolabeled particles, pulmonary immune responses to instilled antigen, biochemistry and cytology of airway fluid, total lung collagen, histopathology, lung morphometry, and lung burdens of diesel soot. The significance of influences of emphysema and toxicant exposure, and interactions between influences of the two treatments, were evaluated by analysis of variance.

  17. Experimental exposure to diesel exhaust increases arterial stiffness in man

    PubMed Central

    Lundbäck, Magnus; Mills, Nicholas L; Lucking, Andrew; Barath, Stefan; Donaldson, Ken; Newby, David E; Sandström, Thomas; Blomberg, Anders

    2009-01-01

    Introduction Exposure to air pollution is associated with increased cardiovascular morbidity, although the underlying mechanisms are unclear. Vascular dysfunction reduces arterial compliance and increases central arterial pressure and left ventricular after-load. We determined the effect of diesel exhaust exposure on arterial compliance using a validated non-invasive measure of arterial stiffness. Methods In a double-blind randomized fashion, 12 healthy volunteers were exposed to diesel exhaust (approximately 350 μg/m3) or filtered air for one hour during moderate exercise. Arterial stiffness was measured using applanation tonometry at the radial artery for pulse wave analysis (PWA), as well as at the femoral and carotid arteries for pulse wave velocity (PWV). PWA was performed 10, 20 and 30 min, and carotid-femoral PWV 40 min, post-exposure. Augmentation pressure (AP), augmentation index (AIx) and time to wave reflection (Tr) were calculated. Results Blood pressure, AP and AIx were generally low reflecting compliant arteries. In comparison to filtered air, diesel exhaust exposure induced an increase in AP of 2.5 mmHg (p = 0.02) and in AIx of 7.8% (p = 0.01), along with a 16 ms reduction in Tr (p = 0.03), 10 minutes post-exposure. Conclusion Acute exposure to diesel exhaust is associated with an immediate and transient increase in arterial stiffness. This may, in part, explain the increased risk for cardiovascular disease associated with air pollution exposure. If our findings are confirmed in larger cohorts of susceptible populations, this simple non-invasive method of assessing arterial stiffness may become a useful technique in measuring the impact of real world exposures to combustion derived-air pollution. PMID:19284640

  18. Experimental exposure to diesel exhaust increases arterial stiffness in man.

    PubMed

    Lundbäck, Magnus; Mills, Nicholas L; Lucking, Andrew; Barath, Stefan; Donaldson, Ken; Newby, David E; Sandström, Thomas; Blomberg, Anders

    2009-03-13

    Exposure to air pollution is associated with increased cardiovascular morbidity, although the underlying mechanisms are unclear. Vascular dysfunction reduces arterial compliance and increases central arterial pressure and left ventricular after-load. We determined the effect of diesel exhaust exposure on arterial compliance using a validated non-invasive measure of arterial stiffness. In a double-blind randomized fashion, 12 healthy volunteers were exposed to diesel exhaust (approximately 350 mug/m3) or filtered air for one hour during moderate exercise. Arterial stiffness was measured using applanation tonometry at the radial artery for pulse wave analysis (PWA), as well as at the femoral and carotid arteries for pulse wave velocity (PWV). PWA was performed 10, 20 and 30 min, and carotid-femoral PWV 40 min, post-exposure. Augmentation pressure (AP), augmentation index (AIx) and time to wave reflection (Tr) were calculated. Blood pressure, AP and AIx were generally low reflecting compliant arteries. In comparison to filtered air, diesel exhaust exposure induced an increase in AP of 2.5 mmHg (p = 0.02) and in AIx of 7.8% (p = 0.01), along with a 16 ms reduction in Tr (p = 0.03), 10 minutes post-exposure. Acute exposure to diesel exhaust is associated with an immediate and transient increase in arterial stiffness. This may, in part, explain the increased risk for cardiovascular disease associated with air pollution exposure. If our findings are confirmed in larger cohorts of susceptible populations, this simple non-invasive method of assessing arterial stiffness may become a useful technique in measuring the impact of real world exposures to combustion derived-air pollution.

  19. Diesel emission reduction using internal exhaust gas recirculation

    DOEpatents

    He, Xin [Denver, CO; Durrett, Russell P [Bloomfield Hills, MI

    2012-01-24

    A method for controlling combustion in a direct-injection diesel engine includes monitoring a crankshaft rotational position of a cylinder of the engine, monitoring an engine load, determining an intake stroke within the cylinder based upon the crankshaft rotational position, and when the engine load is less than a threshold engine load, opening an exhaust valve for the cylinder during a portion of the intake stroke.

  20. Lung Cancer in Railroad Workers Exposed to Diesel Exhaust

    PubMed Central

    Garshick, Eric; Laden, Francine; Hart, Jaime E.; Rosner, Bernard; Smith, Thomas J.; Dockery, Douglas W.; Speizer, Frank E.

    2004-01-01

    Diesel exhaust has been suspected to be a lung carcinogen. The assessment of this lung cancer risk has been limited by lack of studies of exposed workers followed for many years. In this study, we assessed lung cancer mortality in 54,973 U.S. railroad workers between 1959 and 1996 (38 years). By 1959, the U.S. railroad industry had largely converted from coal-fired to diesel-powered locomotives. We obtained work histories from the U.S. Railroad Retirement Board, and ascertained mortality using Railroad Retirement Board, Social Security, and Health Care Financing Administration records. Cause of death was obtained from the National Death Index and death certificates. There were 43,593 total deaths including 4,351 lung cancer deaths. Adjusting for a healthy worker survivor effect and age, railroad workers in jobs associated with operating trains had a relative risk of lung cancer mortality of 1.40 (95% confidence interval, 1.30–1.51). Lung cancer mortality did not increase with increasing years of work in these jobs. Lung cancer mortality was elevated in jobs associated with work on trains powered by diesel locomotives. Although a contribution from exposure to coal combustion products before 1959 cannot be excluded, these results suggest that exposure to diesel exhaust contributed to lung cancer mortality in this cohort. PMID:15531439

  1. CARBONYL CONTENT OF DIESEL EXHAUST FROM TWO SOURCES AND POSSIBLE IMPLICATIONS FOR CELL RESPONSES

    EPA Science Inventory

    Diesel exhaust is known to cause health effects including increases in lung inflammation and altered immunological parameters. The diesel exhausts used in our studies were collected into ice-cooled PBS from a diesel engine running at idle speed (DE2A) or at full load (DE5A). P...

  2. CARBONYL CONTENT OF DIESEL EXHAUST FROM TWO SOURCES AND POSSIBLE IMPLICATIONS FOR CELL RESPONSES

    EPA Science Inventory

    Diesel exhaust is known to cause health effects including increases in lung inflammation and altered immunological parameters. The diesel exhausts used in our studies were collected into ice-cooled PBS from a diesel engine running at idle speed (DE2A) or at full load (DE5A). P...

  3. Mutagenicity of diesel exhaust particles from an engine with differing exhaust after treatments.

    PubMed

    Shi, X-C; Keane, M J; Ong, T; Li, S-Q; Bugarski, A B

    2010-01-01

    This study was conducted to investigate the effects of engine operating conditions and exhaust aftertreatments on the mutagenicity of diesel particulate matter (DPM) collected directly in an underground mine environment. A number of after-treatment devices are currently used on diesel engines in mines, but it is critical to determine whether reductions in DPM concentrations result in a corresponding decrease in adverse health effects. An eddy-current dynamometer was used to operate naturally aspirated mechanically controlled engine at several steady-state conditions. The samples were collected when the engine was equipped with a standard muffler, a diesel oxidation catalytic converter, two types of uncatalyzed diesel particulate filter systems, and three types of disposable diesel particulate filter elements. Bacterial gene mutation activity of DPM was tested on acetone extracts using the Ames Salmonella assay. The results indicated strong correlation between engine operating conditions and mutagenic activity of DPM. When the engine was fitted with muffler, the mutagenic activity was observed for the samples collected from light-load, but not heavy-load operating conditions. When the engine was equipped with a diesel oxidation catalyst, the samples did not exhibit mutagenic activity for any of four engine operating conditions. Mutagenic activity was observed for the samples collected when the engine was retrofitted with three types of disposable filters and sintered metal diesel particulate filter and operated at light load conditions. However, those filtration systems substantially reduced the concentration-normalized mutagenic activity from the levels observed for the muffler.

  4. Determination of polycyclic aromatic hydrocarbons in diesel exhaust particulate matter and diesel fuel oil.

    PubMed

    Obuchi, A; Aoyama, H; Ohi, A; Ohuchi, H

    1984-11-16

    Clean-up procedures were developed for a method for determining the amount of polycyclic aromatic hydrocarbons (PAHs) in diesel exhaust particulate matter and in diesel fuel oils using reversed-phase high-performance liquid chromatography (HPLC). They were based mainly on the elimination of insoluble matter and aliphatic compounds that affect the performance of HPLC, from the dichloromethane extracts of particulate matter or from oils, with the aid of a disposable preparation column containing reversed-phase packings (Sep-Pak C18). Using these procedures, it is possible to detect 1 ng of benzo(a)pyrene in 30 mg of particulate matter with more than a 97% recovery or 0.5 ng in 50 microliters of oil with 91% recovery. Examples of analyses are given for particulate matter emitted from a diesel test engine and for diesel fuel oils, such as gas oil, residual oil and coal-liquefied oil.

  5. Mutagenicity of diesel exhaust soot dispersed in phospholipid surfactants

    SciTech Connect

    Wallace, W.; Keane, M.; Xing, S.; Harrison, J.; Gautam, M.; Ong, T.

    1994-06-01

    Organics extractable from respirable diesel exhaust soot particles by organic solvents have been known for some time to be direct acting frameshift mutagens in the Ames Salmonella typhimurium histidine reversion assay. Upon deposition in a pulmonary alveolus or respiratory bronchiole, respirable diesel soot particles will contact first the hypophase which is coated by and laden with surfactants. To model interactions of soot and pulmonary surfactant, the authors dispersed soots in vitro in the primary phospholipid pulmonary surfactant dipalmitoyl glycerophosphorylcholine (lecithin) (DPL) in physiological saline. They have shown that diesel soots dispersed in lecithin surfactant can express mutagenic activity, in the Ames assay system using S. typhimurium TA98, comparable to that expressed by equal amounts of soot extracted by dichloromethane/dimethylsulfoxide (DCM/DMSO). Here the authors report additional data on the same system using additional exhaust soots and also using two other phospholipids, dipalmitoyl glycerophosphoryl ethanolamine (DPPE), and dipalmitoyl phosphatidic acid (DPPA), with different ionic character hydrophilic moieties. A preliminary study of the surfactant dispersed soot in an eucaryotic cell test system also is reported.

  6. Diesel Exhaust Emissions Control for Light-Duty Vehicles

    SciTech Connect

    Mital, R.; Li, J.; Huang, S. C.; Stroia, B. J.; Yu, R. C.; Anderson, J.A.; Howden, Kenneth C.

    2003-03-01

    The objective of this paper is to present the results of diesel exhaust aftertreatment testing and analysis done under the FreedomCAR program. Nitrogen Oxides (NOx) adsorber technology was selected based on a previous investigation of various NOx aftertreatment technologies including non-thermal plasma, NOx adsorber and active lean NOx. Particulate Matter (PM) emissions were addressed by developing a catalyzed particulate filter. After various iterations of the catalyst formulation, the aftertreatment components were integrated and optimized for a light duty vehicle application. This compact exhaust aftertreatment system is dual leg and consists of a sulfur trap, NOx adsorbers, and catalyzed particulate filters (CPF). During regeneration, supplementary ARCO ECD low-sulfur diesel fuel is injected upstream of the adsorber and CPF in the exhaust. Steady state and transient emission test results with and without the exhaust aftertreatment system (EAS) are presented. Results of soot filter regeneration by injecting low-sulfur diesel fuel and slip of unregulated emissions, such as NH3, are discussed. Effects of adsorber size and bypass strategy on NOx conversion efficiency and fuel economy penalty are also presented in this paper. The results indicate that if the supplementary fuel injection is optimized, NH3 slip is negligible. During the FTP cycle, injection of low sulfur diesel fuel can create temperature exotherms high enough to regenerate a loaded CPF. With the optimized NOx adsorber regeneration strategies the fuel injection penalty can be reduced by 40 to 50%. Results for various other issues like low temperature light off, reductant optimization, exhaust sulfur management, system integration and design trade-off, are also presented and discussed in this paper. (SAE Paper SAE-2003-01-0041 © 2003 SAE International. This paper is published on this website with permission from SAE International. As a user of this website, you are permitted to view this paper on

  7. Hydrocarbon emissions speciation in diesel and biodiesel exhausts

    NASA Astrophysics Data System (ADS)

    Payri, Francisco; Bermúdez, Vicente R.; Tormos, Bernardo; Linares, Waldemar G.

    Diesel engine emissions are composed of a long list of organic compounds, ranging from C 2 to C 12+, and coming from the hydrocarbons partially oxidized in combustion or produced by pyrolisis. Many of these are considered as ozone precursors in the atmosphere, since they can interact with nitrogen oxides to produce ozone under atmospheric conditions in the presence of sunlight. In addition to problematic ozone production, Brookes, P., and Duncan, M. [1971. Carcinogenic hydrocarbons and human cells in culture. Nature.] and Heywood, J. [1988. Internal Combustion Engine Fundamentals.Mc Graw-Hill, ISBN 0-07-1000499-8.] determined that the polycyclic aromatic hydrocarbons present in exhaust gases are dangerous to human health, being highly carcinogenic. The aim of this study was to identify by means of gas chromatography the amount of each hydrocarbon species present in the exhaust gases of diesel engines operating with different biodiesel blends. The levels of reactive and non-reactive hydrocarbons present in diesel engine exhaust gases powered by different biodiesel fuel blends were also analyzed. Detailed speciation revealed a drastic change in the nature and quantity of semi-volatile compounds when biodiesel fuels are employed, the most affected being the aromatic compounds. Both aromatic and oxygenated aromatic compounds were found in biodiesel exhaust. Finally, the conservation of species for off-side analysis and the possible influence of engine operating conditions on the chemical characterization of the semi-volatile compound phase are discussed. The use of oxygenated fuel blends shows a reduction in the Engine-Out emissions of total hydrocarbons. But the potential of the hydrocarbon emissions is more dependent on the compositions of these hydrocarbons in the Engine-Out, to the quantity; a large percent of hydrocarbons existing in the exhaust, when biodiesel blends are used, are partially burned hydrocarbons, and are interesting as they have the maximum

  8. Air pollution and lung cancer: diesel exhaust, coal combustion

    SciTech Connect

    Higgins, I.T.

    1984-03-01

    It is known, that cigarette smoking is by far the most important cause of lung cancer and that about a dozen occupational exposures are also established as causes of this disease. There has been continuing uncertainty about the role of general air pollution. During the past few years, this uncertainty has been compounded with anxiety that the increasing use of diesel-powered vehicles might lead to a deterioration in air quality and, with it, an increase in the incidence of lung cancer. The purpose of this paper is to assess the current role of air pollution as a factor in lung cancer and specifically the contribution of diesel exhaust emissions to the incidence of that disease.

  9. Are urinary PAHs biomarkers of controlled exposure to diesel exhaust?

    PubMed

    Lu, Sixin S; Sobus, Jon R; Sallsten, Gerd; Albin, Maria; Pleil, Joachim D; Gudmundsson, Anders; Madden, Michael C; Strandberg, Bo; Wierzbicka, Aneta; Rappaport, Stephen M

    2014-06-01

    Urinary polycyclic aromatic hydrocarbons (PAHs) were evaluated as possible biomarkers of exposure to diesel exhaust (DE) in two controlled-chamber studies. We report levels of 14 PAHs from 28 subjects in urine that were collected before, immediately after and the morning after exposure. Using linear mixed-effects models, we tested for effects of DE exposure and several covariates (time, age, gender and urinary creatinine) on urinary PAH levels. DE exposures did not significantly alter urinary PAH levels. We conclude that urinary PAHs are not promising biomarkers of short-term exposures to DE in the range of 106-276 µg/m(3).

  10. Are urinary PAHs biomarkers of controlled exposure to diesel exhaust?

    PubMed Central

    Lu, Sixin S.; Sobus, Jon R.; Sallsten, Gerd; Albin, Maria; Pleil, Joachim D.; Gudmundsson, Anders; Madden, Michael C.; Strandberg, Bo; Wierzbicka, Aneta; Rappaport, Stephen M.

    2016-01-01

    Urinary polycyclic aromatic hydrocarbons (PAHs) were evaluated as possible biomarkers of exposure to diesel exhaust (DE) in two controlled-chamber studies. We report levels of 14 PAHs from 28 subjects in urine that were collected before, immediately after and the morning after exposure. Using linear mixed-effects models, we tested for effects of DE exposure and several covariates (time, age, gender and urinary creatinine) on urinary PAH levels. DE exposures did not significantly alter urinary PAH levels. We conclude that urinary PAHs are not promising biomarkers of short-term exposures to DE in the range of 106–276 μg/m3. PMID:24754404

  11. Chemiions and nanoparticle formation in diesel engine exhaust

    NASA Astrophysics Data System (ADS)

    Yu, Fangqun

    The nanoparticles (diameter < 50 nm) emitted by diesel engines have received increasing attention due to their potential health effects. We propose that chemiions generated during combustion play an important role in the formation of these nanoparticles. The predicted nanoparticle properties based on our chemiion theory closely match measurements in terms of total nanoparticle concentrations, and their sensitivity to fuel sulfur contents and second stage dilution conditions, while the classical homogeneous nucleation fails to explain these observed properties. Our study indicates that total number of nanoparticles formed is very sensitive to chemiion concentrations, and we propose a technique to effectively reduce vehicle nanoparticle emissions by removing ions in the exhaust.

  12. Diesel exhaust: current knowledge of adverse effects and underlying cellular mechanisms.

    PubMed

    Steiner, Sandro; Bisig, Christoph; Petri-Fink, Alke; Rothen-Rutishauser, Barbara

    2016-07-01

    Diesel engine emissions are among the most prevalent anthropogenic pollutants worldwide, and with the growing popularity of diesel-fueled engines in the private transportation sector, they are becoming increasingly widespread in densely populated urban regions. However, a large number of toxicological studies clearly show that diesel engine emissions profoundly affect human health. Thus the interest in the molecular and cellular mechanisms underlying these effects is large, especially concerning the nature of the components of diesel exhaust responsible for the effects and how they could be eliminated from the exhaust. This review describes the fundamental properties of diesel exhaust as well as the human respiratory tract and concludes that adverse health effects of diesel exhaust not only emerge from its chemical composition, but also from the interplay between its physical properties, the physiological and cellular properties, and function of the human respiratory tract. Furthermore, the primary molecular and cellular mechanisms triggered by diesel exhaust exposure, as well as the fundamentals of the methods for toxicological testing of diesel exhaust toxicity, are described. The key aspects of adverse effects induced by diesel exhaust exposure described herein will be important for regulators to support or ban certain technologies or to legitimate incentives for the development of promising new technologies such as catalytic diesel particle filters.

  13. Novel diesel exhaust filters for underground mining vehicles

    SciTech Connect

    Bickel, K.L.; Taubert, T.R.

    1995-12-31

    The U.S. Bureau of Mines (USBM) pioneered the development of disposable filters for reducing diesel particulate emissions from permissible mining machines. The USBM is now evaluating filter media that can withstand the high exhaust temperatures on nonpermissible machines. The goal of the evaluation is to find an inexpensive medium that can be cleaned or disposed of after use, and will reduce particulate emissions by 50 % or more. This report summarizes the results from screening tests of a lava rock and woven fiberglass filter media. The lava rock media exhibited low collection efficiencies, but with very low increases in exhaust back pressure. Preliminary results indicate a collection efficiency exceeding 80 % for the woven fiber media. Testing of both media is continuing.

  14. Spatial Modeling of Diesel Exhaust Markers in South Seattle

    NASA Astrophysics Data System (ADS)

    Schulte, Jill Katherine

    Background: South Park and Georgetown, two of Seattle's most diverse and affordable neighborhoods, contain the primary commercial traffic corridors from the Port of Seattle to interstates and state highways. Residents of these communities have expressed concern about exposure to diesel exhaust emitted by the large number of commercial trucks that pass through their neighborhoods. The aim of this project was to model the spatial distribution of diesel exhaust markers at a fine scale across these neighborhoods using measurements from a high-density air sampling campaign. Methods: Two-week average concentrations of two markers of diesel exhaust, 1-nitropyrene (1-NP) and light-absorbing carbon (LAC), were measured in summer and winter at 24 sites. Land-use regression models were built using spatial characteristics of sampling sites, including land use and road density. Mobile source emissions predictions from the CAL3QHCR dispersion model were included in spatial models. Light-scattering particle concentrations measured by a mobile monitoring platform that drove through the neighborhoods were also included as model covariates. Model predictions were generated using land-use regression equations for a grid of points 50m apart across the study area. Universal kriging was applied to these grid points to generate a raster surface of the gradient of predictions. Results: 1-NP concentrations ranged from 0.263 pg/m 3 to 2.51 pg/m3 in summer and 1.11 pg/m3 to 5.71 pg/m3 in winter. LAC concentrations, measured as the absorption coefficient of collected fine particles, ranged from 4.31E-06 m -1 to 7.84E-06 m-1 in summer and 6.30E-06 m -1 to 9.42E-06 m-1 in winter. The summer 1-NP model had an R2 of 0.87 and a leave-one-out cross-validated R 2 of 0.73. No prediction model of winter 1-NP was identified. The LAC models had R2 values of 0.78 and 0.79 and leave-one-out-cross-validated R2 values of 0.66 and 0.70 for August and December, respectively. Conclusions: Spatial modeling was

  15. Particulate matter in new technology diesel exhaust (NTDE) is quantitatively and qualitatively very different from that found in traditional diesel exhaust (TDE).

    PubMed

    Hesterberg, Thomas W; Long, Christopher M; Sax, Sonja N; Lapin, Charles A; McClellan, Roger O; Bunn, William B; Valberg, Peter A

    2011-09-01

    Diesel exhaust (DE) characteristic of pre-1988 engines is classified as a "probable" human carcinogen (Group 2A) by the International Agency for Research on Cancer (IARC), and the U.S. Environmental Protection Agency has classified DE as "likely to be carcinogenic to humans." These classifications were based on the large body of health effect studies conducted on DE over the past 30 or so years. However, increasingly stringent U.S. emissions standards (1988-2010) for particulate matter (PM) and nitrogen oxides (NOx) in diesel exhaust have helped stimulate major technological advances in diesel engine technology and diesel fuel/lubricant composition, resulting in the emergence of what has been termed New Technology Diesel Exhaust, or NTDE. NTDE is defined as DE from post-2006 and older retrofit diesel engines that incorporate a variety of technological advancements, including electronic controls, ultra-low-sulfur diesel fuel, oxidation catalysts, and wall-flow diesel particulate filters (DPFs). As discussed in a prior review (T. W. Hesterberg et al.; Environ. Sci. Technol. 2008, 42, 6437-6445), numerous emissions characterization studies have demonstrated marked differences in regulated and unregulated emissions between NTDE and "traditional diesel exhaust" (TDE) from pre-1988 diesel engines. Now there exist even more data demonstrating significant chemical and physical distinctions between the diesel exhaust particulate (DEP) in NTDE versus DEP from pre-2007 diesel technology, and its greater resemblance to particulate emissions from compressed natural gas (CNG) or gasoline engines. Furthermore, preliminary toxicological data suggest that the changes to the physical and chemical composition of NTDE lead to differences in biological responses between NTDE versus TDE exposure. Ongoing studies are expected to address some of the remaining data gaps in the understanding of possible NTDE health effects, but there is now sufficient evidence to conclude that health

  16. Modeling a Thermoelectric Generator Applied to Diesel Automotive Heat Recovery

    NASA Astrophysics Data System (ADS)

    Espinosa, N.; Lazard, M.; Aixala, L.; Scherrer, H.

    2010-09-01

    Thermoelectric generators (TEGs) are outstanding devices for automotive waste heat recovery. Their packaging, lack of moving parts, and direct heat to electrical conversion are the main benefits. Usually, TEGs are modeled with a constant hot-source temperature. However, energy in exhaust gases is limited, thus leading to a temperature decrease as heat is recovered. Therefore thermoelectric properties change along the TEG, affecting performance. A thermoelectric generator composed of Mg2Si/Zn4Sb3 for high temperatures followed by Bi2Te3 for low temperatures has been modeled using engineering equation solver (EES) software. The model uses the finite-difference method with a strip-fins convective heat transfer coefficient. It has been validated on a commercial module with well-known properties. The thermoelectric connection and the number of thermoelements have been addressed as well as the optimum proportion of high-temperature material for a given thermoelectric heat exchanger. TEG output power has been estimated for a typical commercial vehicle at 90°C coolant temperature.

  17. Dynamic Test Bed Analysis of Gas Energy Balance for a Diesel Exhaust System Fit with a Thermoelectric Generator

    NASA Astrophysics Data System (ADS)

    Fuc, Pawel; Lijewski, Piotr; Ziolkowski, Andrzej; Dobrzyński, Michal

    2017-02-01

    Analysis of the energy balance for an exhaust system of a diesel engine fit with an automotive thermoelectric generator (ATEG) of our own design has been carried out. A special measurement system and dedicated software were developed to measure the power generated by the modules. The research object was a 1.3-l small diesel engine with power output of 66 kW. The tests were carried out on a dynamic engine test bed that allows reproduction of an actual driving cycle expressed as a function V = f(t), simulating drivetrain (clutch, transmission) operating characteristics, vehicle geometrical parameters, and driver behavior. Measurements of exhaust gas thermodynamic parameters (temperature, pressure, and mass flow) as well as the voltage and current generated by the thermoelectric modules were performed during tests of our own design. Based on the results obtained, the flow of exhaust gas energy in the entire exhaust system was determined along with the ATEG power output. The ideal area of the exhaust system for location of the ATEG was defined to ensure the highest thermal energy recovery efficiency.

  18. Dynamic Test Bed Analysis of Gas Energy Balance for a Diesel Exhaust System Fit with a Thermoelectric Generator

    NASA Astrophysics Data System (ADS)

    Fuc, Pawel; Lijewski, Piotr; Ziolkowski, Andrzej; Dobrzyński, Michal

    2017-05-01

    Analysis of the energy balance for an exhaust system of a diesel engine fit with an automotive thermoelectric generator (ATEG) of our own design has been carried out. A special measurement system and dedicated software were developed to measure the power generated by the modules. The research object was a 1.3-l small diesel engine with power output of 66 kW. The tests were carried out on a dynamic engine test bed that allows reproduction of an actual driving cycle expressed as a function V = f( t), simulating drivetrain (clutch, transmission) operating characteristics, vehicle geometrical parameters, and driver behavior. Measurements of exhaust gas thermodynamic parameters (temperature, pressure, and mass flow) as well as the voltage and current generated by the thermoelectric modules were performed during tests of our own design. Based on the results obtained, the flow of exhaust gas energy in the entire exhaust system was determined along with the ATEG power output. The ideal area of the exhaust system for location of the ATEG was defined to ensure the highest thermal energy recovery efficiency.

  19. Thrombotic Markers in Metabolic Syndrome Subjects Exposed to Diesel Exhaust

    PubMed Central

    Carlsten, C.; Kaufman, J. D.; Trenga, C. A.; Allen, J.; Peretz, A.; Sullivan, J. H.

    2011-01-01

    Traffic-derived particulate matter (PM) is associated with cardiovascular morbidity and mortality, but the mechanism of this association is unclear. Prothrombotic processes have been linked to PM in epidemiological and animal models, but have not been consistently implicated in controlled human models. Diesel exhaust (DE) is a major contributor to PM. We conducted a controlled human exposure of DE in subjects with metabolic syndrome. The study objective was to evaluate DE exposure effects on prothrombotic markers in a population vulnerable to cardiovascular disease. A randomized, crossover, double-blinded design was used: 16 subjects with metabolic syndrome exposed on 3 different days (≥2 wk washout) to DE at 0 (filtered air, FA), 100 μg PM2.5/m3 (DE100) and 200 μg PM2.5/m3 (DE200). We assessed DE-associated changes in D-dimer, von Willebrand factor (VWF), and plasmin activator inhibitor-1 (PAI-1) at 3, 7, and 22 h after exposure initiation. A DE200-attributable decrease (1.17-fold; CI 1.04 to 1.34) in VWF was noted at 7 h. Significant changes did not occur in other primary endpoints. As previously noted with healthy subjects, strong diurnal patterns in PAI-1 were observed. Thus, in a novel study, we were unable to demonstrate a prothrombotic effect of moderate-dose diesel exhaust exposure in a population at risk for cardiovascular disease. PMID:18668408

  20. Proinflammatory Effects of Diesel Exhaust Nanoparticles on Scleroderma Skin Cells

    PubMed Central

    Mastrofrancesco, A.; Alfè, M.; Rosato, E.; Gargiulo, V.; Beatrice, C.; Di Blasio, G.; Zhang, B.; Su, D. S.; Picardo, M.; Fiorito, S.

    2014-01-01

    Autoimmune diseases are complex disorders of unknown etiology thought to result from interactions between genetic and environmental factors. We aimed to verify whether environmental pollution from diesel engine exhaust nanoparticulate (DEP) of actually operating vehicles could play a role in the development of a rare immune-mediated disease, systemic sclerosis (SSc), in which the pathogenetic role of environment has been highlighted. The effects of carbon-based nanoparticulate collected at the exhaust of newer (Euro 5) and older (Euro 4) diesel engines on SSc skin keratinocytes and fibroblasts were evaluated in vitro by assessing the mRNA expression of inflammatory cytokines (IL-1α, IL-6, IL-8, and TNF-α) and fibroblast chemical mediators (metalloproteases 2, 3, 7, 9, and 12; collagen types I and III; VEGF). DEP was shown to stimulate cytokine gene expression at a higher extent in SSc keratinocytes versus normal cells. Moreover, the mRNA gene expression of all MMPs, collagen types, and VEGF genes was significantly higher in untreated SSc fibroblasts versus controls. Euro 5 particle exposure increased the mRNA expression of MMP-2, -7, and -9 in SSc fibroblasts in a dose dependent manner and only at the highest concentration in normal cells. We suggest that environmental DEP could trigger the development of SSc acting on genetically hyperreactive cell systems. PMID:24982919

  1. Respiratory effects of diesel exhaust in salt miners

    SciTech Connect

    Gamble, J.F.; Jones, W.G.

    1983-09-01

    The respiratory health of 259 white males working at 5 salt (NaCl) mines was assessed by questionnaire, chest radiographs, and air and He-O/sup 2/ spirometry. Response variables were symptoms, pneumoconiosis, and spirometry. Predictor variables included age, height, smoking, mine, and tenure in diesel-exposed jobs. The purpose was to assess the association of response measures of respiratory health with exposure to diesel exhaust. There were only 2 cases of Grade 1 pneumoconiosis, so no further analysis was done. Comparisons within the study population showed a statistically significant dose-related association of phlegm and diesel exposure. There was a nonsignificant trend for cough and dyspnea, and no association with spirometry. Age- and smoking-adjusted rates of cough, phlegm, and dyspnea were 145, 159, and 93% of an external comparison population. Percent predicted flow rates showed statistically significant reductions, but the reductions were small and there were no dose-response relations. Percent predicted FEV1 and FVC were about 96% of predicted.

  2. The Diesel Exhaust in Miners Study: A Nested Case–Control Study of Lung Cancer and Diesel Exhaust

    PubMed Central

    Samanic, Claudine M.; Lubin, Jay H.; Blair, Aaron E.; Stewart, Patricia A.; Vermeulen, Roel; Coble, Joseph B.; Rothman, Nathaniel; Schleiff, Patricia L.; Travis, William D.; Ziegler, Regina G.; Wacholder, Sholom; Attfield, Michael D.

    2012-01-01

    Background Most studies of the association between diesel exhaust exposure and lung cancer suggest a modest, but consistent, increased risk. However, to our knowledge, no study to date has had quantitative data on historical diesel exposure coupled with adequate sample size to evaluate the exposure–response relationship between diesel exhaust and lung cancer. Our purpose was to evaluate the relationship between quantitative estimates of exposure to diesel exhaust and lung cancer mortality after adjustment for smoking and other potential confounders. Methods We conducted a nested case–control study in a cohort of 12 315 workers in eight non-metal mining facilities, which included 198 lung cancer deaths and 562 incidence density–sampled control subjects. For each case subject, we selected up to four control subjects, individually matched on mining facility, sex, race/ethnicity, and birth year (within 5 years), from all workers who were alive before the day the case subject died. We estimated diesel exhaust exposure, represented by respirable elemental carbon (REC), by job and year, for each subject, based on an extensive retrospective exposure assessment at each mining facility. We conducted both categorical and continuous regression analyses adjusted for cigarette smoking and other potential confounding variables (eg, history of employment in high-risk occupations for lung cancer and a history of respiratory disease) to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Analyses were both unlagged and lagged to exclude recent exposure such as that occurring in the 15 years directly before the date of death (case subjects)/reference date (control subjects). All statistical tests were two-sided. Results We observed statistically significant increasing trends in lung cancer risk with increasing cumulative REC and average REC intensity. Cumulative REC, lagged 15 years, yielded a statistically significant positive gradient in lung cancer risk overall

  3. Reducing Children's Exposure to School Bus Diesel Exhaust in One School District in North Carolina

    ERIC Educational Resources Information Center

    Mazer, Mary E.; Jacobson Vann, Julie C.; Lamanna, Beth F.; Davison, Jean

    2014-01-01

    Children who are exposed to diesel exhaust from idling school buses are at increased risk of asthma exacerbation, decreased lung function, immunologic reactions, leukemia, and increased susceptibility to infections. Policies and initiatives that aim to protect school children from the harmful effects of exposure to diesel exhaust range from…

  4. Effects on symptoms and lung function in humans experimentally exposed to diesel exhaust.

    PubMed

    Rudell, B; Ledin, M C; Hammarström, U; Stjernberg, N; Lundbäck, B; Sandström, T

    1996-10-01

    Diesel exhaust is a common air pollutant made up of several gases, hydrocarbons, and particles. An experimental study was carried out which was designed to evaluate if a particle trap on the tail pipe of an idling diesel engine would reduce effects on symptoms and lung function caused by the diesel exhaust, compared with exposure to unfiltered exhaust. Twelve healthy non-smoking volunteers (aged 20-37) were investigated in an exposure chamber for one hour during light work on a bicycle ergometer at 75 W. Each subject underwent three separate double blind exposures in a randomised sequence: to air and to diesel exhaust with the particle trap at the tail pipe and to unfiltered diesel exhaust. Symptoms were recorded according to the Borg scale before, every 10 minutes during, and 30 minutes after the exposure. Lung function was measured with a computerised whole body plethysmograph. The ceramic wall flow particle trap reduced the number of particles by 46%, whereas other compounds were relatively constant. It was shown that the most prominent symptoms during exposure to diesel exhaust were irritation of the eyes and nose and an unpleasant smell increasing during exposure. Both airway resistance (R(aw)) and specific airway resistance (SR(aw)) increased significantly during the exposures to diesel exhaust. Despite the 46% reduction in particle numbers by the trap effects on symptoms and lung function were not significantly attenuated. Exposure to diesel exhaust caused symptoms and bronchoconstriction which were not significantly reduced by a particle trap.

  5. Effects of diesel exhaust on lung inflammation related to bacterial endotoxin in mice.

    PubMed

    Inoue, Ken-Ichiro; Takano, Hirohisa; Yanagisawa, Rie; Sakurai, Miho; Ueki, Naoko; Yoshikawa, Toshikazu

    2006-11-01

    We have previously shown that intratracheal instillation of diesel exhaust particles enhances lung inflammation and lung expression of proinflammatory cytokines and chemokines related to bacterial endotoxin (lipopolysaccharide) in mice. The present study was designed to elucidate the effects of inhalation of diesel exhaust on lung inflammation related to lipopolysaccharide. ICR mice were exposed for 12 hr to clean air or diesel exhaust at a soot concentration of 0.3, 1.0, or 3.0 mg/m(3) after intratracheal challenge with 125 microg/kg of lipopolysaccharide. Lung inflammation and lung expression of proinflammatory chemokines such as macrophage chemoattractant protein-1 and keratinocyte chemoattractant were evaluated 24 hr after intratracheal administration. Diesel exhaust inhalation decreased lipopolysaccharide-elicited inflammatory cell recruitment into the bronchoalveolar lavage fluid as compared with clean air inhalation. Histological study demonstrated that exposure to diesel exhaust did not affect lipopolysaccharide-enhanced neutrophil recruitment into the lung parenchyma. Lipopolysaccharide instillation elevated lung expression of macrophage chemoattractant protein-1 and keratinocyte chemoattractant under clean air or diesel exhaust inhalation. However, diesel exhaust exposure did not influence but rather did suppress these levels in the presence of lipopolysaccharide. These results suggest that short-term exposure to diesel exhaust did not exacerbate lung inflammation related to bacterial endotoxin.

  6. DIESEL EXHAUST RESEARCH: WHAT HAS IT TOLD US ABOUT AMBIENT ORGANIC PM TOXICITY.

    EPA Science Inventory

    Diesel exhaust is a complex mixture of components which includes organic gaseous and particulate material. Sources of the exhaust are derived from both on road and off road engines. Use of diesel fuel continues to increase in the US and globally, though the development and use o...

  7. Reducing Children's Exposure to School Bus Diesel Exhaust in One School District in North Carolina

    ERIC Educational Resources Information Center

    Mazer, Mary E.; Jacobson Vann, Julie C.; Lamanna, Beth F.; Davison, Jean

    2014-01-01

    Children who are exposed to diesel exhaust from idling school buses are at increased risk of asthma exacerbation, decreased lung function, immunologic reactions, leukemia, and increased susceptibility to infections. Policies and initiatives that aim to protect school children from the harmful effects of exposure to diesel exhaust range from…

  8. Reduction of diesel engine exhaust noise in the petroleum mining industry. [by resonator type diffuser

    NASA Technical Reports Server (NTRS)

    Marinov, T.

    1974-01-01

    An important noise source in a drilling plant is Diesel engine exhaust. In order to reduce this noise, a reactive silencer of the derivative resonator type was proposed, calculated from the acoustic and design point of view and applied. As a result of applying such a silencer on the exhaust conduit of a Diesel engine the noise level dropped down to 18 db.

  9. DIESEL EXHAUST RESEARCH: WHAT HAS IT TOLD US ABOUT AMBIENT ORGANIC PM TOXICITY.

    EPA Science Inventory

    Diesel exhaust is a complex mixture of components which includes organic gaseous and particulate material. Sources of the exhaust are derived from both on road and off road engines. Use of diesel fuel continues to increase in the US and globally, though the development and use o...

  10. Generation and characterization of diesel exhaust in a facility for controlled human exposures

    EPA Science Inventory

    An idling medium-duty diesel truck operated on ultralow sulfur diesel fuel was used as an emission source to generate diesel exhaust for controlled human exposure. Repeat tests were conducted on the Federal Test Procedure using a chassis dynamometer to demonstrate the reproducibi...

  11. Generation and characterization of diesel exhaust in a facility for controlled human exposures

    EPA Science Inventory

    An idling medium-duty diesel truck operated on ultralow sulfur diesel fuel was used as an emission source to generate diesel exhaust for controlled human exposure. Repeat tests were conducted on the Federal Test Procedure using a chassis dynamometer to demonstrate the reproducibi...

  12. Evaluation of a disposable diesel exhaust filter for permissible mining machines

    SciTech Connect

    Ambs, J.L.; Cantrell, B.K.; Watts, W.F.; Olson, K.S.

    1994-01-01

    The US Bureau of Mines (USBM) Diesel Research Program emphasizes the development and evaluation of emission control devices to reduce exposure of miners to diesel exhaust pollutants. Studies by the USBM have shown that diesel exhaust aerosol (DEA) contributes a substantial portion of the respirable aerosol in underground coal mines using diesel equipment not equipped with emission controls. The USBM and the Donaldson Co., Inc., Minneapolis, MN, have developed a low-temperature, disposable diesel exhaust filter (DDEF) for use on permissible diesel haulage vehicles equipped with waterbath exhaust conditioners. These were evaluated in three underground mines to determine their effectiveness in reducing DEA concentrations. The DDEF reduced DEA concentrations from 70 to 90% at these mines. The usable life of the filter ranged from 10 to 32 h, depending on factors that affect DEA output, such as mine altitude, engine type, and duty-cycle. Cost per filter is approximately $40.

  13. Evaluation of a disposable diesel exhaust filter for permissible mining machines. Report of investigations/1994

    SciTech Connect

    Ambs, J.L.; Cantrell, B.K.; Watts, W.F.; Olson, K.S.

    1994-01-01

    The U.S. Bureau of Mines (USBM) Diesel Research Program emphasizes the development and evaluation of emission control devices to reduce exposure of miners to diesel exhaust pollutants. Studies by the USBM have shown that diesel exhaust aerosol (DEA) contributes a substantial portion of the respirable aerosol in underground coal mining using diesel equipment not equipped with emission controls. The USBM and the Donaldson Co., Inc., Minneapolis, MN, have developed a low-temperature, disposable diesel exhaust filter (DDEF) for use on permissible diesel haulage vehicles equipped with waterban exhaust conditioners. These were evaluated in three underground mines to determine their effectiveness in reducing DEA concentrations. The DDEF reduced DEA concentrations from 70 to 90 pct at these mines. The usable life of the filter ranged from 10 to 32 h, depending on factors that affect DEA output, such as mine altitude, engine type, and duty-cycle. Cost per filter is approximately $40.

  14. Determination of aldehydes and ketones with high atmospheric reactivity on diesel exhaust using a biofuel from animal fats

    NASA Astrophysics Data System (ADS)

    Ballesteros, R.; Monedero, E.; Guillén-Flores, J.

    2011-05-01

    Biodiesel from animal fats appears as an alternative for conventional diesel in automotive consumption. Animal fats are classified into three categories, although only one of them can be used for biodiesel production, according to regulation. Due to its novelty, researchers testing animal-fat biodiesel on diesel engines focus only on regulated emissions. In this paper, the experiments carried out analyze carbonyl compounds emissions, due to its highly atmospheric reactivity, to complete the characterization of the total emissions in this kind of biofuel. Two fuels, a reference petro-diesel and a pure animal-fat biodiesel, were tested in a 4-cylinder, direct injection, diesel engine Nissan Euro 5 M1D-Bk. Samples were collected in 4 different operating modes and 3 points along the exhaust line. The analyses of samples were made in a high performance liquid chromatography, following the method recommended by the CARB to analyze air quality. Results show, on the one hand, a significant rise in carbonyl emissions, almost three times at the mode with highest hydrocarbon emissions, when biodiesel is used. On the other hand, on average, a reduction of 90% of carbonyl emissions when exhaust gases go through the different post-treatment systems installed. Despite this reduction, specific reactivity does not decrease substantially.

  15. Identification of polycyclic aromatic hydrocarbons in unleaded petrol and diesel exhaust emission.

    PubMed

    Yadav, Vinay Kumar; Prasad, Sahdeo; Patel, Devendra K; Khan, Altaf Husain; Tripathi, Madhu; Shukla, Yogeshwer

    2010-09-01

    Inhalation of emissions from petrol and diesel exhaust particulates is associated with potentially severe biological effects. In the present study, polycyclic aromatic hydrocarbons (PAHs) were identified from smokes released by the automobile exhaust from petrol and diesel. Intensive sampling of unleaded petrol and diesel exhaust were done by using 800-cm(3) motor car and 3,455-cm(3) vehicle, respectively. The particulate phase of exhaust was collected on Whatman filter paper. Particulate matters were extracted from filter paper by using Soxhlet. PAHs were identified from particulate matter by reverse phase high performance liquid chromatography using C(18) column. A total of 14 PAHs were identified in petrol and 13 in case of diesel sample after comparing to standard samples for PAH estimation. These inhalable PAHs released from diesel and petrol exhaust are known to possess mutagenic and carcinogenic activity, which may present a potential risk for the health of inhabitants.

  16. The Effects of Diesel Exhaust Pollution on Floral Volatiles and the Consequences for Honey Bee Olfaction.

    PubMed

    Lusebrink, Inka; Girling, Robbie D; Farthing, Emily; Newman, Tracey A; Jackson, Chris W; Poppy, Guy M

    2015-10-01

    There is growing evidence of a substantial decline in pollinators within Europe and North America, most likely caused by multiple factors such as diseases, poor nutrition, habitat loss, insecticides, and environmental pollution. Diesel exhaust could be a contributing factor to this decline, since we found that diesel exhaust rapidly degrades floral volatiles, which honey bees require for flower recognition. In this study, we exposed eight of the most common floral volatiles to diesel exhaust in order to investigate whether it can affect volatile mediated plant-pollinator interaction. Exposure to diesel exhaust altered the blend of common flower volatiles significantly: myrcene was considerably reduced, β-ocimene became undetectable, and β-caryophyllene was transformed into its cis-isomer isocaryophyllene. Proboscis extension response (PER) assays showed that the alterations of the blend reduced the ability of honey bees to recognize it. The chemically reactive nitrogen oxides fraction of diesel exhaust gas was identified as capable of causing degradation of floral volatiles.

  17. Impaired vascular function after exposure to diesel exhaust generated at urban transient running conditions

    PubMed Central

    2010-01-01

    Background Traffic emissions including diesel engine exhaust are associated with increased respiratory and cardiovascular morbidity and mortality. Controlled human exposure studies have demonstrated impaired vascular function after inhalation of exhaust generated by a diesel engine under idling conditions. Objectives To assess the vascular and fibrinolytic effects of exposure to diesel exhaust generated during urban-cycle running conditions that mimic ambient 'real-world' exposures. Methods In a randomised double-blind crossover study, eighteen healthy male volunteers were exposed to diesel exhaust (approximately 250 μg/m3) or filtered air for one hour during intermittent exercise. Diesel exhaust was generated during the urban part of the standardized European Transient Cycle. Six hours post-exposure, vascular vasomotor and fibrinolytic function was assessed during venous occlusion plethysmography with intra-arterial agonist infusions. Measurements and Main Results Forearm blood flow increased in a dose-dependent manner with both endothelial-dependent (acetylcholine and bradykinin) and endothelial-independent (sodium nitroprusside and verapamil) vasodilators. Diesel exhaust exposure attenuated the vasodilatation to acetylcholine (P < 0.001), bradykinin (P < 0.05), sodium nitroprusside (P < 0.05) and verapamil (P < 0.001). In addition, the net release of tissue plasminogen activator during bradykinin infusion was impaired following diesel exhaust exposure (P < 0.05). Conclusion Exposure to diesel exhaust generated under transient running conditions, as a relevant model of urban air pollution, impairs vasomotor function and endogenous fibrinolysis in a similar way as exposure to diesel exhaust generated at idling. This indicates that adverse vascular effects of diesel exhaust inhalation occur over different running conditions with varying exhaust composition and concentrations as well as physicochemical particle properties. Importantly, exposure to diesel exhaust

  18. Comparison of the toxicity of diesel exhaust produced by bio- and fossil diesel combustion in human lung cells in vitro

    NASA Astrophysics Data System (ADS)

    Steiner, Sandro; Czerwinski, Jan; Comte, Pierre; Popovicheva, Olga; Kireeva, Elena; Müller, Loretta; Heeb, Norbert; Mayer, Andreas; Fink, Alke; Rothen-Rutishauser, Barbara

    2013-12-01

    Alternative fuels are increasingly combusted in diesel- and gasoline engines and the contribution of such exhausts to the overall air pollution is on the rise. Recent findings on the possible adverse effects of biodiesel exhaust are contradictive, at least partly resulting from the various fuel qualities, engine types and different operation conditions that were tested. However, most of the studies are biased by undesired interactions between the exhaust samples and biological culture media. We here report how complete, freshly produced exhausts from fossil diesel (B0), from a blend of 20% rapeseed-methyl ester (RME) and 80% fossil diesel (B20) and from pure rapeseed methyl ester (B100) affect a complex 3D cellular model of the human airway epithelium in vitro by exposing the cells at the air-liquid interface. The induction of pro-apoptotic and necrotic cell death, cellular morphology, oxidative stress, and pro-inflammatory responses were assessed. Compared to B0 exhaust, B20 exhaust decreased oxidative stress and pro-inflammatory responses, whereas B100 exhaust, depending on exposure duration, decreased oxidative stress but increased pro-inflammatory responses. The effects are only very weak and given the compared to fossil diesel higher ecological sustainability of biodiesel, it appears that - at least RME - can be considered a valuable alternative to pure fossil diesel.

  19. Occupational exposure to diesel engine exhaust: A literature review

    PubMed Central

    Pronk, Anjoeka; Coble, Joseph; Stewart, Patricia

    2010-01-01

    Background Diesel exhaust (DE) is classified as a probable human carcinogen. Aims were to describe the major occupational uses of diesel engines and give an overview of personal DE exposure levels and determinants of exposure as reported in the published literature. Methods Measurements representative of personal DE exposure were abstracted from the literature for the following agents: elemental carbon (EC), particulate matter (PM), carbon monoxide (CO), nitrogen oxide (NO), and nitrogen dioxide (NO2). Information on determinants of exposure was abstracted. Results In total, 3528 EC, 4166 PM, 581 CO, 322 NO, and 1404 NO2 measurements were abstracted. From the 10,001 measurements, 32% represented exposure from on-road vehicles, and 68% from off-road vehicles (30% mining, 15% railroad, and 22% other). Highest levels were reported for enclosed underground work sites where heavy equipment is used: mining, mine maintenance, and construction, (EC: 27-658 μg/m3). Intermediate exposure levels were generally reported for above ground (semi-)enclosed areas where smaller equipment was run: mechanics in a shop, emergency workers in fire stations, distribution workers at a dock, and workers loading/unloading inside a ferry (generally: EC< 50 μg/m3). Lowest levels were reported for enclosed areas separated from the source such as drivers and train crew, or outside such as surface mining, parking attendants, vehicle testers, utility service workers, surface construction and airline ground personnel (EC<25 μg/m3). The other agents showed a similar pattern. Determinants of exposure reported for enclosed situations were ventilation and exhaust after treatment devices. Conclusions Reported DE exposure levels were highest for underground mining and construction, intermediate for working in above ground (semi-)enclosed areas and lowest for working outside or separated from the source. The presented data can be used as a basis for assessing occupational exposure in population

  20. Occupational exposure to diesel engine exhaust: a literature review.

    PubMed

    Pronk, Anjoeka; Coble, Joseph; Stewart, Patricia A

    2009-07-01

    Diesel exhaust (DE) is classified as a probable human carcinogen. Aims were to describe the major occupational uses of diesel engines and give an overview of personal DE exposure levels and determinants of exposure as reported in the published literature. Measurements representative of personal DE exposure were abstracted from the literature for the following agents: elemental carbon (EC), particulate matter (PM), carbon monoxide (CO), nitrogen oxide (NO), and nitrogen dioxide (NO(2)). Information on determinants of exposure was abstracted. In total, 3528 EC, 4166 PM, 581 CO, 322 NO, and 1404 NO(2) measurements were abstracted. From the 10,001 measurements, 32% represented exposure from on-road vehicles and 68% from off-road vehicles (30% mining, 15% railroad, and 22% others). Highest levels were reported for enclosed underground work sites in which heavy equipment is used: mining, mine maintenance, and construction (EC: 27-658 microg/m(3)). Intermediate exposure levels were generally reported for above-ground (semi-) enclosed areas in which smaller equipment was run: mechanics in a shop, emergency workers in fire stations, distribution workers at a dock, and workers loading/unloading inside a ferry (generally: EC<50 microg/m(3)). Lowest levels were reported for enclosed areas separated from the source, such as drivers and train crew, or outside, such as surface mining, parking attendants, vehicle testers, utility service workers, surface construction and airline ground personnel (EC<25 microg/m(3)). The other agents showed a similar pattern. Determinants of exposure reported for enclosed situations were ventilation and exhaust after treatment devices. Reported DE exposure levels were highest for underground mining and construction, intermediate for working in above-ground (semi-) enclosed areas and lowest for working outside or separated from the source. The presented data can be used as a basis for assessing occupational exposure in population

  1. Occupational exposure to diesel engine exhaust and serum cytokine levels.

    PubMed

    Dai, Yufei; Ren, Dianzhi; Bassig, Bryan A; Vermeulen, Roel; Hu, Wei; Niu, Yong; Duan, Huawei; Ye, Meng; Meng, Tao; Xu, Jun; Bin, Ping; Shen, Meili; Yang, Jufang; Fu, Wei; Meliefste, Kees; Silverman, Debra; Rothman, Nathaniel; Lan, Qing; Zheng, Yuxin

    2017-10-12

    The International Agency for Research on Cancer has classified diesel engine exhaust (DEE) as a human lung carcinogen. Given that inflammation is suspected to be an important underlying mechanism of lung carcinogenesis, we evaluated the relationship between DEE exposure and the inflammatory response using data from a cross-sectional molecular epidemiology study of 41 diesel engine testing workers and 46 unexposed controls. Repeated personal exposure measurements of PM2.5 and other DEE constituents were taken for the diesel engine testing workers before blood collection. Serum levels of six inflammatory biomarkers including interleukin (IL)-1, IL-6, IL-8, tumor necrosis factor (TNF)-α, macrophage inflammatory protein (MIP)-1β, and monocyte chemotactic protein (MCP)-1 were analyzed in all subjects. Compared to unexposed controls, concentrations of MIP-1β were significantly reduced by ∼37% in DEE exposed workers (P < 0.001) and showed a strong decreasing trend with increasing PM2.5 concentrations in all subjects (Ptrend  < 0.001) as well as in exposed subjects only (Ptrend  = 0.001). Levels of IL-8 and MIP-1β were significantly lower in workers in the highest exposure tertile of PM2.5 (>397 µg/m(3) ) compared to unexposed controls. Further, significant inverse exposure-response relationships for IL-8 and MCP-1 were also found in relation to increasing PM2.5 levels among the DEE exposed workers. Given that IL-8, MIP-1β, and MCP-1 are chemokines that play important roles in recruitment of immunocompetent cells for immune defense and tumor cell clearance, the observed lower levels of these markers with increasing PM2.5 exposure may provide insight into the mechanism by which DEE promotes lung cancer. Environ. Mol. Mutagen., 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  2. 4-Nitrophenol, 1-nitropyrene, and 9-nitroanthracene emissions in exhaust particles from diesel vehicles with different exhaust gas treatments

    NASA Astrophysics Data System (ADS)

    Inomata, Satoshi; Fushimi, Akihiro; Sato, Kei; Fujitani, Yuji; Yamada, Hiroyuki

    2015-06-01

    The dependence of nitro-organic compound emissions in automotive exhaust particles on the type of aftertreatment used was investigated. Three diesel vehicles with different aftertreatment systems (an oxidation catalyst, vehicle-DOC; a particulate matter and NOx reduction system, vehicle-DPNR; and a urea-based selective catalytic reduction system, vehicle-SCR) and a gasoline car with a three-way catalyst were tested. Nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) and nitrophenols in the particles emitted were analyzed by thermal desorption gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry. The secondary production of nitro-organic compounds on the filters used to collect particles and the adsorption of gaseous nitro-organic compounds by the filters were evaluated. Emissions of 1-nitropyrene, 9-nitroanthracene, and 4-nitrophenol in the diesel exhaust particles were then quantified. The NOx reduction process in vehicle-DPNR appeared to remove nitro-hydrocarbons efficiently but not to remove nitro-oxygenated hydrocarbons efficiently. The nitro-PAH emission factors were lower for vehicle-DOC when it was not fitted with a catalyst than when it was fitted with a catalyst. The 4-nitrophenol emission factors were also lower for vehicle-DOC with a catalyst than vehicle-DOC without a catalyst, suggesting that the oxidation catalyst was a source of both nitro-PAHs and 4-nitrophenol. The time-resolved aerosol mass spectrometry data suggested that nitro-organic compounds are mainly produced when an engine is working under load. The presence of 4-nitrophenol in the particles was not confirmed statistically because of interference from gaseous 4-nitrophenol. Systematic errors in the estimated amounts of gaseous 1-nitropyrene and 9-nitroanthracene adsorbed onto the filters and the estimated amounts of volatile nitro-organic compounds that evaporated during sampling and during post-sampling conditioning could not be excluded. An analytical method

  3. The Diesel Exhaust in Miners Study: IV. Estimating Historical Exposures to Diesel Exhaust in Underground Non-metal Mining Facilities

    PubMed Central

    Vermeulen, Roel; Coble, Joseph B.; Lubin, Jay H.; Portengen, Lützen; Blair, Aaron; Attfield, Michael D.; Silverman, Debra T.

    2010-01-01

    We developed quantitative estimates of historical exposures to respirable elemental carbon (REC) for an epidemiologic study of mortality, including lung cancer, among diesel-exposed miners at eight non-metal mining facilities [the Diesel Exhaust in Miners Study (DEMS)]. Because there were no historical measurements of diesel exhaust (DE), historical REC (a component of DE) levels were estimated based on REC data from monitoring surveys conducted in 1998–2001 as part of the DEMS investigation. These values were adjusted for underground workers by carbon monoxide (CO) concentration trends in the mines derived from models of historical CO (another DE component) measurements and DE determinants such as engine horsepower (HP; 1 HP = 0.746 kW) and mine ventilation. CO was chosen to estimate historical changes because it was the most frequently measured DE component in our study facilities and it was found to correlate with REC exposure. Databases were constructed by facility and year with air sampling data and with information on the total rate of airflow exhausted from the underground operations in cubic feet per minute (CFM) (1 CFM = 0.0283 m3 min−1), HP of the diesel equipment in use (ADJ HP), and other possible determinants. The ADJ HP purchased after 1990 (ADJ HP1990+) was also included to account for lower emissions from newer, cleaner engines. Facility-specific CO levels, relative to those in the DEMS survey year for each year back to the start of dieselization (1947–1967 depending on facility), were predicted based on models of observed CO concentrations and log-transformed (Ln) ADJ HP/CFM and Ln(ADJ HP1990+). The resulting temporal trends in relative CO levels were then multiplied by facility/department/job-specific REC estimates derived from the DEMS surveys personal measurements to obtain historical facility/department/job/year-specific REC exposure estimates. The facility-specific temporal trends of CO levels (and thus the REC estimates) generated from

  4. Acoustic Optimization of Automotive Exhaust Heat Thermoelectric Generator

    NASA Astrophysics Data System (ADS)

    Su, C. Q.; Ye, B. Q.; Guo, X.; Hui, P.

    2012-06-01

    The potential for thermoelectric exhaust heat recovery in vehicles has been increasing with recent advances in the efficiency of thermoelectric generators (TEGs). This study analyzes the acoustic attenuation performance of exhaust-based TEGs. The acoustic characteristics of two different thermal designs of exhaust gas heat exchanger in TEGs are discussed in terms of transmission loss and acoustic insertion loss. GT-Power simulations and bench tests on a dynamometer with a high-performance production engine are carried out. Results indicate that the acoustic attenuation of TEGs could be determined and optimized. In addition, the feasibility of integration of exhaust-based TEGs and engine mufflers into the exhaust line is tested, which can help to reduce space and improve vehicle integration.

  5. [Emission characteristics of polycyclic aromatic hydrocarbons in exhaust particles from a diesel car].

    PubMed

    Tan, Pi-Qiang; Zhou, Zhou; Hu, Zhi-Yuan; Lou, Di-Ming

    2013-03-01

    The emission characteristics of polycyclic aromatic hydrocarbons (PAHs) in exhaust particles from a diesel car were studied. In the experiment, pure diesel fuel and B10 fuel with a biodiesel blend ratio of 10% were chosen. The gaseous emissions of HC, CO and NO(x) under New European Driving Cycle (NEDC) were measured, and exhaust particulate matter (PM) samples were analyzed by gas chromatography-mass spectrometry. The emission characteristics of PAHs in exhaust particles were highlighted. The results show that the emission concentrations of HC, CO, NO(x), and PM decreased when the diesel car used B10 fuel. Fluoranthene and pyrene were dominant in PAHs of PM emissions when the diesel car used pure diesel or B10 fuel. Compared to pure diesel, there was a slight increase in low-ring PAHs emissions when the diesel car used B10 fuel. On the contrary, PAHs emissions in middle and high-ring declined significantly. Besides, Benzo [ a] pyrene equivalent toxicity analysis results show that the BEQs of B10 fuel decreased by 21.6% compared to pure diesel. That means the toxicity of PAHs in exhaust particles declined when the diesel car used biodiesel fuel.

  6. Occupational monitoring of particulate diesel exhaust by NIOSH method 5040.

    PubMed

    Birch, M Eileen

    2002-06-01

    NMAM 5040 is a particulate carbon method based on a thermal-optical analysis technique. The method was evaluated and published as a method for monitoring occupational exposures to particulate diesel exhaust, but it is applicable to particulate carbon aerosols in general, and has been routinely used in both occupational and environmental settings. Both organic and elemental carbon are determined, but EC is a more selective measure of workplace diesel exposure. In previous studies, good agreement between TC results obtained by different methods has been achieved, but the OC-EC results for different methods have been quite variable. Although a reference material is not currently available to test the accuracy of different methods, previous studies indicate that purely thermal methods are subject to positive bias from organic materials that char. Charring and inadequate removal of refractory OC components during the nonoxidative mode (typically 550 degrees C in nitrogen) likely explain the positive bias of thermal methods, as well as the large variability across methods. These interferences may be negligible in some cases (e.g., samples from mines), but they present significant biases in others (e.g., urban air samples, samples containing wood or cigarette smokes). Good interlaboratory agreement was obtained in a round robin comparison between six laboratories that used NMAM 5040, which was not the case with purely thermal methods. Good agreement has also been seen in smaller-scale comparisons conducted for quality assurance purposes. Until a suitable reference material becomes available, such comparisons are recommended as part of a laboratory's QA procedures. At present, five commercial laboratories (4 in the United States and 1 in Canada) perform the 5040 analysis, and over 40 instruments are in use globally for environmental and occupational monitoring.

  7. Inhalation of diesel exhaust induces acute arterial vasocontruction in healthy volunteers

    EPA Science Inventory

    Epidemiological studies have shown an association between the incidence of adverse cardiovascular effects and exposure to ambient particulate matter (PM). Diesel exhaust particles (DE) are a major contributor to PM in urban areas. Advanced age and certain polymorphisms are among...

  8. One-Month Diesel Exhaust Inhalation Produces Hypertensive Gene Expression Phenotype in Healthy Rats

    EPA Science Inventory

    Exposure to diesel exhaust (DE) is linked to vasoconstriction, endothelial 26 dysfunction, and myocardial ischemia in compromised individuals. We hypothesized that DE 27 inhalation would cause greater inflammation, hematological alterations, and cardiac molecular 28 impairment ...

  9. Diesel exhaust worsens cardiac conduction instability in dobutamine-challenged spontaneously hypertensive rats

    EPA Science Inventory

    This study demonstrated that diesel exhaust worsened arrhythmia and cardiac function during dobutamine (simulated exercise) challenge in normotensive and hypertensive rats. The data presented here are a mathematically-derived indicator of cardiac risk, which can be used for risk ...

  10. DIESEL EXHAUST PARTICLES INDUCE ABERRANT ALVEOLAR EPITHELIAL DIRECTED CELL MOVEMENT BY DISRUPTION OF POLARITY MECHANISMS

    EPA Science Inventory

    Disruption of the respiratory epithelium contributes to the progression of a variety of respiratory diseases that are aggravated by exposure to air pollutants, specifically traffic-based pollutants such as diesel exhaust particles (DEP). Recognizing that lung repair following inj...

  11. Vascular and Cardiac Impairments in Rats Inhaling Ozone and Diesel Exhaust Particles

    EPA Science Inventory

    Background -Mechanisms of cardiovascular injuries from exposure to gas and particulate air pollutants are unknown. Objective -We hypothesized that episodic exposure of rats to ozone or diesel exhaust particles (DEP) will cause differential cardiovascular impairments, which will b...

  12. *GAS-PHASE AND PARTICULATE COMPONENTS OF DIESEL EXHAUST PRODUCE DIFFERENTIAL CARDIOPHYSIOLOGICAL IMPAIRMENTS IN HEALTHY RATS

    EPA Science Inventory

    We recently showed that inhalation exposure of normotensive Wistar Kyoto (WKY) rats to whole diesel exhaust (DE) elicited changes in cardiac gene expression pattern that broadly mimicked gene expression in non-exposed spontaneously hypertensive rats. We hypothesized that healthy ...

  13. Identification of Surrogate Measures of Diesel Exhaust Exposure in a Controlled Chamber Study

    EPA Science Inventory

    Exposure to diesel exhaust (DE) has been associated with acute cardiopulmonary and vascular responses, chronic noncancer health effects, and respiratory cancers in humans. To better understand DE exposures and eventually their related health effects, we established a controlled c...

  14. Vascular and Cardiac Impairments in Rats Inhaling Ozone and Diesel Exhaust Particles

    EPA Science Inventory

    Background -Mechanisms of cardiovascular injuries from exposure to gas and particulate air pollutants are unknown. Objective -We hypothesized that episodic exposure of rats to ozone or diesel exhaust particles (DEP) will cause differential cardiovascular impairments, which will b...

  15. *GAS-PHASE AND PARTICULATE COMPONENTS OF DIESEL EXHAUST PRODUCE DIFFERENTIAL CARDIOPHYSIOLOGICAL IMPAIRMENTS IN HEALTHY RATS

    EPA Science Inventory

    We recently showed that inhalation exposure of normotensive Wistar Kyoto (WKY) rats to whole diesel exhaust (DE) elicited changes in cardiac gene expression pattern that broadly mimicked gene expression in non-exposed spontaneously hypertensive rats. We hypothesized that healthy ...

  16. Exacerbation of allergic inflammation in mice exposed to diesel exhaust particles prior to viral infection.

    EPA Science Inventory

    Background: Viral infections and exposure to oxidant air pollutants are two ofthe most important inducers ofasthma exacerbation. Our previous studies have demonstrated that exposure to diesel exhaust increases the susceptibility to influenza virus infections both in epithelial ce...

  17. Exacerbation of allergic inflammation in mice exposed to diesel exhaust particles prior to viral infection.

    EPA Science Inventory

    Background: Viral infections and exposure to oxidant air pollutants are two ofthe most important inducers ofasthma exacerbation. Our previous studies have demonstrated that exposure to diesel exhaust increases the susceptibility to influenza virus infections both in epithelial ce...

  18. Identification of Surrogate Measures of Diesel Exhaust Exposure in a Controlled Chamber Study

    EPA Science Inventory

    Exposure to diesel exhaust (DE) has been associated with acute cardiopulmonary and vascular responses, chronic noncancer health effects, and respiratory cancers in humans. To better understand DE exposures and eventually their related health effects, we established a controlled c...

  19. Inhalation of diesel exhaust induces acute arterial vasocontruction in healthy volunteers

    EPA Science Inventory

    Epidemiological studies have shown an association between the incidence of adverse cardiovascular effects and exposure to ambient particulate matter (PM). Diesel exhaust particles (DE) are a major contributor to PM in urban areas. Advanced age and certain polymorphisms are among...

  20. DIESEL EXHAUST PARTICLES INDUCE ABERRANT ALVEOLAR EPITHELIAL DIRECTED CELL MOVEMENT BY DISRUPTION OF POLARITY MECHANISMS

    EPA Science Inventory

    Disruption of the respiratory epithelium contributes to the progression of a variety of respiratory diseases that are aggravated by exposure to air pollutants, specifically traffic-based pollutants such as diesel exhaust particles (DEP). Recognizing that lung repair following inj...

  1. Diesel exhaust worsens cardiac conduction instability in dobutamine-challenged spontaneously hypertensive rats

    EPA Science Inventory

    This study demonstrated that diesel exhaust worsened arrhythmia and cardiac function during dobutamine (simulated exercise) challenge in normotensive and hypertensive rats. The data presented here are a mathematically-derived indicator of cardiac risk, which can be used for risk ...

  2. One-Month Diesel Exhaust Inhalation Produces Hypertensive Gene Expression Phenotype in Healthy Rats

    EPA Science Inventory

    Exposure to diesel exhaust (DE) is linked to vasoconstriction, endothelial 26 dysfunction, and myocardial ischemia in compromised individuals. We hypothesized that DE 27 inhalation would cause greater inflammation, hematological alterations, and cardiac molecular 28 impairment ...

  3. Conductometric soot sensor for automotive exhausts: initial studies.

    PubMed

    Hagen, Gunter; Feistkorn, Constanze; Wiegärtner, Sven; Heinrich, Andreas; Brüggemann, Dieter; Moos, Ralf

    2010-01-01

    In order to reduce the tailpipe particulate matter emissions of Diesel engines, Diesel particulate filters (DPFs) are commonly used. Initial studies using a conductometric soot sensor to monitor their filtering efficiency, i.e., to detect a malfunction of the DPF, are presented. The sensors consist of a planar substrate equipped with electrodes on one side and with a heater on the other. It is shown that at constant speed-load points, the time until soot percolation occurs or the resistance itself are reproducible means that can be well correlated with the filtering efficiency of a DPF. It is suggested to use such a sensor setup for the detection of a DPF malfunction.

  4. Conductometric Soot Sensor for Automotive Exhausts: Initial Studies

    PubMed Central

    Hagen, Gunter; Feistkorn, Constanze; Wiegärtner, Sven; Heinrich, Andreas; Brüggemann, Dieter; Moos, Ralf

    2010-01-01

    In order to reduce the tailpipe particulate matter emissions of Diesel engines, Diesel particulate filters (DPFs) are commonly used. Initial studies using a conductometric soot sensor to monitor their filtering efficiency, i.e., to detect a malfunction of the DPF, are presented. The sensors consist of a planar substrate equipped with electrodes on one side and with a heater on the other. It is shown that at constant speed-load points, the time until soot percolation occurs or the resistance itself are reproducible means that can be well correlated with the filtering efficiency of a DPF. It is suggested to use such a sensor setup for the detection of a DPF malfunction. PMID:22294888

  5. Pretreatment with Antioxidants Augments the Acute Arterial Vasoconstriction Caused by Diesel Exhaust Inhalation.

    PubMed

    Sack, Cora S; Jansen, Karen L; Cosselman, Kristen E; Trenga, Carol A; Stapleton, Pat L; Allen, Jason; Peretz, Alon; Olives, Casey; Kaufman, Joel D

    2016-05-01

    Diesel exhaust inhalation, which is the model traffic-related air pollutant exposure, is associated with vascular dysfunction. To determine whether healthy subjects exposed to diesel exhaust exhibit acute vasoconstriction and whether this effect could be modified by the use of antioxidants or by common variants in the angiotensin II type 1 receptor (AGTR1) and other candidate genes. In a genotype-stratified, double-blind, four-way crossover study, 21 healthy adult subjects were exposed at rest in a randomized, balanced order to diesel exhaust (200 μg/m(3) particulate matter with an aerodynamic diameter ≤ 2.5 μm [PM2.5]) and filtered air, and to pretreatment with antioxidants (N-acetylcysteine and ascorbate) and placebo. Before and after each exposure, brachial artery diameter (BAd) was assessed using ultrasound. Changes in BAd were compared across pretreatment and exposure sessions. Gene-exposure interactions were evaluated in the AGTR1 A1166C polymorphism, on which recruitment was stratified, and other candidate genes, including TRPV1 and GSTM1. Compared with filtered air, exposure to diesel exhaust resulted in a significant reduction in BAd (mean, -0.09 mm, 95% confidence interval [CI], -0.01 to -0.17; P = 0.03). Pretreatment with antioxidants augmented diesel exhaust-related vasoconstriction with a mean change in BAd of -0.18 mm (95% CI, -0.28 to -0.07 mm; P = 0.001). Diesel exhaust-related vasoconstriction was primarily observed in the variant alleles of AGTR1 and TRPV1. No association was found between diesel exhaust inhalation and flow-mediated dilation. We confirmed that short-term exposure to diesel exhaust in healthy subjects is associated with acute vasoconstriction in a conductance artery and found suggestive evidence of involvement of nociception and renin-angiotensin systems in this effect. Pretreatment with an antioxidant regimen increased vasoconstriction.

  6. Effects on symptoms and lung function in humans experimentally exposed to diesel exhaust.

    PubMed Central

    Rudell, B; Ledin, M C; Hammarström, U; Stjernberg, N; Lundbäck, B; Sandström, T

    1996-01-01

    OBJECTIVES: Diesel exhaust is a common air pollutant made up of several gases, hydrocarbons, and particles. An experimental study was carried out which was designed to evaluate if a particle trap on the tail pipe of an idling diesel engine would reduce effects on symptoms and lung function caused by the diesel exhaust, compared with exposure to unfiltered exhaust. METHODS: Twelve healthy non-smoking volunteers (aged 20-37) were investigated in an exposure chamber for one hour during light work on a bicycle ergometer at 75 W. Each subject underwent three separate double blind exposures in a randomised sequence: to air and to diesel exhaust with the particle trap at the tail pipe and to unfiltered diesel exhaust. Symptoms were recorded according to the Borg scale before, every 10 minutes during, and 30 minutes after the exposure. Lung function was measured with a computerised whole body plethysmograph. RESULTS: The ceramic wall flow particle trap reduced the number of particles by 46%, whereas other compounds were relatively constant. It was shown that the most prominent symptoms during exposure to diesel exhaust were irritation of the eyes and nose and an unpleasant smell increasing during exposure. Both airway resistance (R(aw)) and specific airway resistance (SR(aw)) increased significantly during the exposures to diesel exhaust. Despite the 46% reduction in particle numbers by the trap effects on symptoms and lung function were not significantly attenuated. CONCLUSION: Exposure to diesel exhaust caused symptoms and bronchoconstriction which were not significantly reduced by a particle trap. PMID:8943829

  7. DNA adducts induced by in vitro activation of diesel and biodiesel exhaust extracts

    EPA Science Inventory

    The abstract reports the results of studies assessing the relative DNA damage potential of extracts of exhaust particles resulting from the combustion of petroleum diesel, biodiesel, and petroleum diesel-biodiesel blends. Results indicate that the commercially available B20 petr...

  8. DNA adducts induced by in vitro activation of diesel and biodiesel exhaust extracts

    EPA Science Inventory

    The abstract reports the results of studies assessing the relative DNA damage potential of extracts of exhaust particles resulting from the combustion of petroleum diesel, biodiesel, and petroleum diesel-biodiesel blends. Results indicate that the commercially available B20 petr...

  9. Inhibition of catalase activity in vitro by diesel exhaust particles.

    PubMed

    Mori, Y; Murakami, S; Sagae, T; Hayashi, H; Sakata, M; Sagai, M; Kumagai, Y

    1996-02-09

    The effect of diesel exhaust particles (DEP) on the activity of catalase, an intracellular antioxidant, was investigated because H2O2 is a cytotoxic oxidant, and catalase released from alveolar cells is an important antioxidant in the epithelial lining fluid in the lung. DEP inhibited the activity of bovine liver catalase dose-dependently, to 25-30% of its original value. The inhibition of catalase by DEP was observed only in the presence of anions such as Cl-,Br-, or thiocyanate. Other anions, such as CH3COO- or SO4-, and cations such as K+, Na+, Mg2+, or Fe2+, did not affect the activity of catalase, even in the presence of DEP extract. Catalase from guinea pig alveolar cells and catalase from red blood cells were also inhibited by DEP extracts, as was catalase from bovine liver. These results suggest that DEP taken up in the lung and located on alveolar spaces might cause cell injury by inhibiting the activity of catalase in epithelial lining fluid, enhancing the toxicity of H2O2 generated from cells in addition to that of O2- generated by the chemical reaction of DEP with oxygen.

  10. Lab-scale Lidar Sensing of Diesel Engines Exhausts

    NASA Technical Reports Server (NTRS)

    Borghese, A.

    1992-01-01

    Combustion technology and its environmental concerns are being considered with increasing attention, not only for global-scale effects, but also for toxicological implications, particularly in the lift conditions of traffic-congested areas and industrial sites. Majority combustion by-products (CO, NO(sub x)) and unburned hydrocarbons (HC), are already subject to increasingly severe regulations; however other, non-regulated minority species, mainly soot and heavy aromatic molecules, involve higher health risks, as they are suspected to be agents of serious pathologies and even mutagenic effects. This is but one of the reasons why much research work is being carried out worldwide on the physical properties of these substances. Correspondingly, the need arises to detect their presence in urban environments, with as high a sensitivity as is required by their low concentrations, proper time- and space-resolutions, and 'real-time' capabilities. Lidar techniques are excellent candidates to this purpose, although severe constraints limit their applicability, eye-safety problems and aerosol Mie scattering uncertainties above all. At CNR's Istituto Motori in Napels, a Lidar-like diagnostic system is being developed, aimed primarily at monitoring the dynamic behavior of internal combustion engines, particularly diesel exhausts, and at exploring the feasibility of a so-called 'Downtown Lidar'.

  11. Inhibition of catalase activity in vitro by diesel exhaust particles

    SciTech Connect

    Mori, Yoki; Murakami, Sumika; Sagae, Toshiyuki

    1996-02-09

    The effect of diesel exhaust particles (DEP) on the activity of catalase, an intracellular anti-oxidant, was investigated because H{sub 2}O{sub 2} is a cytotoxic oxidant, and catalase released from alveolar cells is an important antioxidant in the epithelial lining fluid in the lung. DEP inhibited the activity of bovine liver catalase dose-dependently, to 25-30% of its original value. The inhibition of catalase by DEP was observed only in the presence of anions such as Cl{sup {minus}}, Br{sup {minus}}, or thiocyanate. Other anions, such as CH{sub 3}COO{sup {minus}} or SO{sub 4}{sup {minus}}, and cations such as K{sup +}, Na{sup +}, Mg{sup 2+}, or Fe{sup 2+}, did not affect the activity of catalase, even in the presence of DEP extract. Catalase from guinea pig alveolar cells and catalase from red blood cells were also inhibited by DEP extracts, as was catalase from bovine liver. These results suggest that DEP taken up in the lung and located on alveolar spaces might cause cell injury by inhibiting the activity of catalase in epithelial lining fluid, enhancing the toxicity of H{sub 2}O{sub 2} generated from cells in addition to that of O{sub 2}{sup {minus}} generated by the chemical reaction of DEP with oxygen. 10 refs., 6 figs.

  12. Electrophilic and redox properties of diesel exhaust particles.

    PubMed

    Shinyashiki, Masaru; Eiguren-Fernandez, Arantza; Schmitz, Debra A; Di Stefano, Emma; Li, Ning; Linak, William P; Cho, Seung-Hyun; Froines, John R; Cho, Arthur K

    2009-04-01

    The adverse health effects of air pollutants have been associated with their redox and electrophilic properties. Although the specific chemical species involved in these effects are not known, the characterization of their general physical and chemical properties is important to our understanding of the mechanisms by which they cause health problems. This manuscript describes results of a study examining the partition properties of these activities in aqueous and organic media. The water and dichloromethane (DCM) solubility of redox active and electrophilic constituents of seven diesel exhaust particle (DEP) samples were determined with assays developed earlier in this laboratory. The constituents exhibiting redox activity, which included both metals and nonmetal species, were associated with the particles in the aqueous suspensions. Portions of the redox active compounds were also DCM-soluble. In contrast, the electrophilic constituents included both water-soluble and DCM-soluble species. The role of quinones or quinone-like compounds in redox and electrophilic activities of the DCM-soluble constituents was assessed by reductive acetylation, a procedure that inactivates quinones. The results from this experiment indicated that most of the activities in the organic extract were associated with quinone-like substances. The partition properties of the reactive species are important in exposure assessment since the toxicokinetics of particles and solutes are quite distinct.

  13. Lab-scale Lidar Sensing of Diesel Engines Exhausts

    NASA Technical Reports Server (NTRS)

    Borghese, A.

    1992-01-01

    Combustion technology and its environmental concerns are being considered with increasing attention, not only for global-scale effects, but also for toxicological implications, particularly in the lift conditions of traffic-congested areas and industrial sites. Majority combustion by-products (CO, NO(sub x)) and unburned hydrocarbons (HC), are already subject to increasingly severe regulations; however other, non-regulated minority species, mainly soot and heavy aromatic molecules, involve higher health risks, as they are suspected to be agents of serious pathologies and even mutagenic effects. This is but one of the reasons why much research work is being carried out worldwide on the physical properties of these substances. Correspondingly, the need arises to detect their presence in urban environments, with as high a sensitivity as is required by their low concentrations, proper time- and space-resolutions, and 'real-time' capabilities. Lidar techniques are excellent candidates to this purpose, although severe constraints limit their applicability, eye-safety problems and aerosol Mie scattering uncertainties above all. At CNR's Istituto Motori in Napels, a Lidar-like diagnostic system is being developed, aimed primarily at monitoring the dynamic behavior of internal combustion engines, particularly diesel exhausts, and at exploring the feasibility of a so-called 'Downtown Lidar'.

  14. Early Endothelial Bioactivity of Serum after Diesel Exhaust ...

    EPA Pesticide Factsheets

    Adverse cardiovascular effects of air pollution are often associated with a spike in systemic proinflammatory biomarkers, but causative linkage between circulating factors and deleterious outcomes following exposure remains elusive. Endothelial dysfunction is a consequence of systemic inflammation and precedes multiple cardiovascular pathologies. The purpose of this study was to examine the plausibility of serum-bound factors as initiators of an air pollution-induced pathologic sequelae beginning with endothelial injury, and later, cardiac dysfunction. We hypothesized that serum taken from diesel exhaust (DE)-exposed rats that develop cardiac dysfunction would alter aortic endothelial cell function in vitro. To assess cardiac function in vivo, left ventricular pressure (LVP) assessments were conducted in rats one day after a single 4 hour whole body exposure to 150 or 500 μg/m3 DE or filtered air. Rat aortic endothelial cells (RAEC) were then exposed to diluted serum (10%) collected 1 hour after exposure from a separate cohort of similarly exposed rats for measures of VCAM-1, cell viability, nitric oxide synthase (NOS) levels, and mRNA expression of key mediators of inflammation. Exposure of rats to 150 or 500 μg/m3 DE increased heart rate (HR) after exposure relative to rats exposed to filtered air, suggesting a shift towards increased sympathetic tone. LVP and HR in DE-exposed rats (500 μg/m3 DE) failed to recover to normal levels after challenge with the

  15. Development of Diesel Exhaust Aftertreatment System for Tier II Emissions

    SciTech Connect

    Yu, R. C.; Cole, A. S., Stroia, B. J.; Huang, S. C.; Howden, Kenneth C.; Chalk, Steven

    2002-06-01

    system design and analysis, critical lab/engine experiments, and ranking then selection of NOX control technologies against reliability, up-front cost, fuel economy, service interval/serviceability, and size/weight. The results of the investigations indicate that the best NOX control approach for LDV and LDT applications is a NOX adsorber system. A greater than 83% NOX reduction efficiency is required to achieve 0.07g/mile NOX Tier II vehicle-out emissions. Both active lean NOX and PACR technology are currently not capable of achieving the high conversion efficiency required for Tier II, Bin 5 emissions standards. In this paper, the NOX technology assessment and selection is first reviewed and discussed. Development of the selected NOX technology (NOX adsorber) and PM control are then discussed in more detail. Discussion includes exhaust sulfur management, further adsorber formulation development, reductant screening, diesel particulate filter development & active regeneration, and preliminary test results on the selected integrated SOX trap, NOX adsorber, and diesel particulate filter system over an FTP-75 emissions cycle, and its impact on fuel economy. Finally, the direction of future work for continued advanced aftertreatment technology development is discussed. (SAE Paper SAE-2002-01-1867 © 2002 SAE International. This paper is published on this website with permission from SAE International. As a user of this website, you are permitted to view this paper on-line, download this pdf file and print one copy of this paper at no cost for your use only. The downloaded pdf file and printout of this SAE paper may not be copied, distributed or forwarded to others or for the use of others.)

  16. Reduction in (pro-)inflammatory responses of lung cells exposed in vitro to diesel exhaust treated with a non-catalyzed diesel particle filter

    NASA Astrophysics Data System (ADS)

    Steiner, Sandro; Czerwinski, Jan; Comte, Pierre; Müller, Loretta L.; Heeb, Norbert V.; Mayer, Andreas; Petri-Fink, Alke; Rothen-Rutishauser, Barbara

    2013-12-01

    Increasingly stringent regulation of particulate matter emissions from diesel vehicles has led to the widespread use of diesel particle filters (DPFs), the effect of which on exhaust toxicity is so far poorly understood. We exposed a cellular model of the human respiratory epithelium at the air-liquid interface to non-catalyzed wall-flow DPF-filtered diesel exhaust and compared the resulting biological responses to the ones observed upon exposure to unfiltered exhaust. Filtered diesel exhaust acted highly oxidative, even though to a lesser extent than unfiltered exhaust (quantification of total reduced glutathione), and both exhaust types triggered comparable responses to oxidative stress (measurement of heme-oxygenase 1 (HMOX1) and superoxide-dismutase (SOD1) gene expression). Further, diesel exhaust filtration significantly reduced pro-inflammatory responses (measurement of tumor necrosis factor (TNF) and interleukin-8 (IL-8) gene expression and quantification of the secretion of their gene products TNF-α and IL-8). Because inflammatory processes are central to the onset of adverse respiratory health effects caused by diesel exhaust inhalation, our results imply that DPFs may make a valuable contribution to the detoxification of diesel vehicle emissions. The induction of significant oxidative stress by filtered diesel exhaust however, also implies that the non-particulate exhaust components also need to be considered for lung cell risk assessment.

  17. Enhancement of automotive exhaust heat recovery by thermoelectric devices

    SciTech Connect

    Ibrahim, Essam; Szybist, James P; Parks, II, James E

    2010-01-01

    In an effort to improve automobile fuel economy, an experimental study is undertaken to explore practical aspects of implementing thermoelectric devices for exhaust gas energy recovery. A highly instrumented apparatus consisting of a hot (exhaust gas) and a cold (coolant liquid) side rectangular ducts enclosing the thermoelectric elements has been built. Measurements of thermoelectric voltage output and flow and surface temperatures were acquired and analyzed to investigate the power generation and heat transfer properties of the apparatus. Effects of inserting aluminum wool packing material inside the hot side duct on augmentation of heat transfer from the gas stream to duct walls were studied. Data were collected for both the unpacked and packed cases to allow for detection of packing influence on flow and surface temperatures. Effects of gas and coolant inlet temperatures as well as gas flow rate on the thermoelectric power output were examined. The results indicate that thermoelectric power production is increased at higher gas inlet temperature or flow rate. However, thermoelectric power generation decreases with a higher coolant temperature as a consequence of the reduced hot-cold side temperature differential. For the hot-side duct, a large temperature gradient exists between the gas and solid surface temperature due to poor heat transfer through the gaseous medium. Adding the packing material inside the exhaust duct enhanced heat transfer and hence raised hot-side duct surface temperatures and thermoelectric power compared to the unpacked duct, particularly where the gas-to-surface temperature differential is highest. Therefore it is recommended that packing of exhaust duct becomes common practice in thermoelectric waste energy harvesting applications.

  18. Combustion-derived nanoparticulate induces the adverse vascular effects of diesel exhaust inhalation

    PubMed Central

    Mills, Nicholas L.; Miller, Mark R.; Lucking, Andrew J.; Beveridge, Jon; Flint, Laura; Boere, A. John F.; Fokkens, Paul H.; Boon, Nicholas A.; Sandstrom, Thomas; Blomberg, Anders; Duffin, Rodger; Donaldson, Ken; Hadoke, Patrick W.F.; Cassee, Flemming R.; Newby, David E.

    2011-01-01

    Aim Exposure to road traffic and air pollution may be a trigger of acute myocardial infarction, but the individual pollutants responsible for this effect have not been established. We assess the role of combustion-derived-nanoparticles in mediating the adverse cardiovascular effects of air pollution. Methods and results To determine the in vivo effects of inhalation of diesel exhaust components, 16 healthy volunteers were exposed to (i) dilute diesel exhaust, (ii) pure carbon nanoparticulate, (iii) filtered diesel exhaust, or (iv) filtered air, in a randomized double blind cross-over study. Following each exposure, forearm blood flow was measured during intra-brachial bradykinin, acetylcholine, sodium nitroprusside, and verapamil infusions. Compared with filtered air, inhalation of diesel exhaust increased systolic blood pressure (145 ± 4 vs. 133 ± 3 mmHg, P< 0.05) and attenuated vasodilatation to bradykinin (P= 0.005), acetylcholine (P= 0.008), and sodium nitroprusside (P< 0.001). Exposure to pure carbon nanoparticulate or filtered exhaust had no effect on endothelium-dependent or -independent vasodilatation. To determine the direct vascular effects of nanoparticulate, isolated rat aortic rings (n= 6–9 per group) were assessed in vitro by wire myography and exposed to diesel exhaust particulate, pure carbon nanoparticulate and vehicle. Compared with vehicle, diesel exhaust particulate (but not pure carbon nanoparticulate) attenuated both acetylcholine (P< 0.001) and sodium-nitroprusside (P= 0.019)-induced vasorelaxation. These effects were partially attributable to both soluble and insoluble components of the particulate. Conclusion Combustion-derived nanoparticulate appears to predominately mediate the adverse vascular effects of diesel exhaust inhalation. This provides a rationale for testing environmental health interventions targeted at reducing traffic-derived particulate emissions. PMID:21753226

  19. Development of naval diesel engine duty cycles for air exhaust emission environmental impact analysis. Master's thesis

    SciTech Connect

    Markle, S.P.

    1994-05-01

    A strategy for testing naval diesel engines for exhaust emissions was developed. A survey of existing international and national standard diesel engine duty cycles was conducted. All were found to be inadequate for testing and certification of engine exhaust emissions from naval diesel powered ships. Naval ship data covering 11,500 hours of engine operation of four U.S. Navy LSD 41 Class amphibious ships was analyzed to develop a 27 point class operating profile. A procedure combining ship hull form characteristics, ship propulsion plant parameters, and ship operating profile was detailed to derive an 11-Mode duty cycle representative for testing LSD 41 Class propulsion diesel engines. A similar procedure was followed for ship service diesel engines. Comparisons with industry accepted duty cycles were conducted using exhaust emission contour plots for the Colt-Pielstick PC-4B diesel engines. Results showed the 11-Mode LSD 41 Class Duty Cycle best predicted ship propulsion engine emissions compared to the 27 point operating profile propeller curve. The procedure was applied to T-AO 187 Class with similar results. The application of civilian industry standards to measure naval diesel ship propulsion engine exhaust emissions was found to be inadequate. Engine exhaust flow chemistry post turbocharger was investigated using the SANDIA Lab computer tool CHEMKIN. Results showed oxidation and reduction reactions within exhaust gases are quenched in the exhaust stack. Since the exhaust stream in the stack is unreactive, emission sampling may be performed where most convenient. A proposed emission measurement scheme for LSD 41 Class ships was presented.

  20. Combustion-derived nanoparticulate induces the adverse vascular effects of diesel exhaust inhalation.

    PubMed

    Mills, Nicholas L; Miller, Mark R; Lucking, Andrew J; Beveridge, Jon; Flint, Laura; Boere, A John F; Fokkens, Paul H; Boon, Nicholas A; Sandstrom, Thomas; Blomberg, Anders; Duffin, Rodger; Donaldson, Ken; Hadoke, Patrick W F; Cassee, Flemming R; Newby, David E

    2011-11-01

    Exposure to road traffic and air pollution may be a trigger of acute myocardial infarction, but the individual pollutants responsible for this effect have not been established. We assess the role of combustion-derived-nanoparticles in mediating the adverse cardiovascular effects of air pollution. To determine the in vivo effects of inhalation of diesel exhaust components, 16 healthy volunteers were exposed to (i) dilute diesel exhaust, (ii) pure carbon nanoparticulate, (iii) filtered diesel exhaust, or (iv) filtered air, in a randomized double blind cross-over study. Following each exposure, forearm blood flow was measured during intra-brachial bradykinin, acetylcholine, sodium nitroprusside, and verapamil infusions. Compared with filtered air, inhalation of diesel exhaust increased systolic blood pressure (145 ± 4 vs. 133 ± 3 mmHg, P< 0.05) and attenuated vasodilatation to bradykinin (P= 0.005), acetylcholine (P= 0.008), and sodium nitroprusside (P< 0.001). Exposure to pure carbon nanoparticulate or filtered exhaust had no effect on endothelium-dependent or -independent vasodilatation. To determine the direct vascular effects of nanoparticulate, isolated rat aortic rings (n= 6-9 per group) were assessed in vitro by wire myography and exposed to diesel exhaust particulate, pure carbon nanoparticulate and vehicle. Compared with vehicle, diesel exhaust particulate (but not pure carbon nanoparticulate) attenuated both acetylcholine (P< 0.001) and sodium-nitroprusside (P= 0.019)-induced vasorelaxation. These effects were partially attributable to both soluble and insoluble components of the particulate. Combustion-derived nanoparticulate appears to predominately mediate the adverse vascular effects of diesel exhaust inhalation. This provides a rationale for testing environmental health interventions targeted at reducing traffic-derived particulate emissions.

  1. AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT I, UNDERSTANDING MECHANICAL CLUTCHES.

    ERIC Educational Resources Information Center

    Minnesota State Dept. of Education, St. Paul. Div. of Vocational and Technical Education.

    ONE OF A 25-MODULE COURSE DESIGNED TO UPGRADE THE JOB SKILLS AND TECHNICAL KNOWLEDGE OF DIESEL MAINENANCE MECHANICS THIS MATERIAL WAS DEVELOPED BY INDUSTRIAL TRAINING AND SUBJECT-MATTER SPECIALISTS AND TESTED IN INDUSTRIAL TRAINING SITUATIONS. THE PURPOSE OF THIS FIRST UNIT IS TO DEVELOP AN UNDERSTANDING OF COMPONENTS, OPERATION, AND ADJUSTMENTS…

  2. AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT XX, TROUBLESHOOTING ELECTRICAL SYSTEMS.

    ERIC Educational Resources Information Center

    Minnesota State Dept. of Education, St. Paul. Div. of Vocational and Technical Education.

    THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO ACQUAINT THE TRAINEE WITH TROUBLESHOOTING PROCEDURES FOR DIESEL ENGINE ELECTRICAL SYSTEMS. TOPICS ARE (1) TROUBLESHOOTING ELECTRICAL SYSTEMS (INTRODUCTION), (2) TOOLS AND INSTRUMENTS FOR TROUBLESHOOTING, (3) THE BATTERY, (4) PERIODIC BATTERY SERVICING, (5) THE DC CHARGING SYSTEM, (6) PERIODIC…

  3. AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT XIV, UNDERSTANDING DC GENERATOR PRINCIPLES.

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATING PRINCIPLES OF DIRECT CURRENT GENERATORS USED ON DIESEL POWERED EQUIPMENT. TOPICS ARE (1) WHAT IS A GENERATOR AND ITS USE, (2) SHUNT GENERATOR PRINCIPLES, (3) POWER AND RATINGS OF A GENERATOR, (4) ARMATURE REACTION, (5) WHAT IS POLARITY, (6) TWO GENERATOR…

  4. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT IX, ENGINE COMPONENTS.

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE CONSTRUCTION, FUNCTION, AND MAINTENANCE OF DIESEL ENGINE CRANKSHAFTS, CAMSHAFTS, AND ASSOCIATED BEARINGS. TOPICS ARE SHAFTS AND BEARINGS, CAMSHAFTS, BEARINGS AND THEIR MAINTENANCE, AND DETECTING FAILURE. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL BRANCH PROGRAMED…

  5. AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT II, MECHANICAL TRANSMISSIONS.

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF MECHANICAL TRANSMISSIONS USED ON DIESEL POWERED VEHICLES. TOPICS ARE (1) PURPOSE OF TRANSMISSIONS, (2) RATIO DIFFERENCE, (3) CONSTANT MESH TRANSMISSIONS, (4) FOUR-SPEED TRUCK TRANSMISSION POWER FLOW, AND (5) TRANSMISSION TROUBLESHOOTING.…

  6. AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT XIX, LEARNING ABOUT CRANKING MOTORS.

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATING PRINCIPLES OF CRANKING MOTORS USED ON DIESEL POWERED EQUIPMENT, TOPICS ARE (1) CRANKING MOTORS. (2) MOTOR PINCIPLES, (3) CRANKING MOTOR CIRCUITS, (4) TYPES OF CRANKING MOTOR DRIVES, AND (5) CRANKING MOTOR SOLENOID CIRCUITS. THE MODULE CONSISTS OF A…

  7. Evaluation of Diesel Exhaust Continuous Monitors in Controlled Environmental Conditions

    PubMed Central

    Yu, Chang Ho; Patton, Allison P.; Zhang, Andrew; Fanac, Zhi-Hua (Tina); Weisel, Clifford P.; Lioy, Paul J.

    2015-01-01

    Diesel exhaust (DE) contains a variety of toxic air pollutants, including diesel particulate matter (DPM) and gaseous contaminants (e.g., carbon monoxide (CO)). DPM is dominated by fine (PM2.5) and ultrafine particles (UFP), and can be representatively determined by its thermal-optical refractory as elemental carbon (EC) or light-absorbing characteristics as black carbon (BC). The currently accepted reference method for sampling and analysis of occupational exposure to DPM is the National Institute for Occupational Safety and Health (NIOSH) Method 5040. However, this method cannot provide in-situ short-term measurements of DPM. Thus, real-time monitors are gaining attention to better examine DE exposures in occupational settings. However, real-time monitors are subject to changing environmental conditions. Field measurements have reported interferences in optical sensors and subsequent real-time readings, under conditions of high humidity and abrupt temperature changes. To begin dealing with these issues, we completed a controlled study to evaluate five real-time monitors: Airtec real-time DPM/EC Monitor, TSI SidePak Personal Aerosol Monitor AM510 (PM2.5), TSI Condensation Particle Counter 3007, microAeth AE51 BC Aethalometer, and Langan T15n CO Measurer. Tests were conducted under different temperatures (55, 70, and 80 °F), relative humidity (10, 40, and 80%), and DPM concentrations (50 and 200 µg/m3) in a controlled exposure facility. The 2-hour averaged EC measurements from the Airtec instrument showed relatively good agreement with NIOSH Method 5040 (R2=0.84; slope=1.17±0.06; N=27) and reported ~17% higher EC concentrations than the NIOSH reference method. Temperature, relative humidity, and DPM levels did not significantly affect relative differences in 2-hour averaged EC concentrations obtained by the Airtec instrument versus the NIOSH method (p<0.05). Multiple linear regression analyses, based on 1-min averaged data, suggested combined effects of up to 5

  8. Generation and characterization of diesel exhaust in a facility for controlled human exposures.

    PubMed

    Sawant, Aniket A; Cocker, David R; Miller, J Wayne; Taliaferro, Tony; Diaz-Sanchez, David; Linn, William S; Clark, Kenneth W; Gong, Henry

    2008-06-01

    An idling medium-duty diesel truck operated on ultralow sulfur diesel fuel was used as an emission source to generate diesel exhaust for controlled human exposure. Repeat tests were conducted on the Federal Test Procedure using a chassis dynamometer to demonstrate the reproducibility of this vehicle as a source of diesel emissions. Exhaust was supplied to a specially constructed exposure chamber at a target concentration of 100 microg x m(-3) diesel particulate matter (DPM). Spatial variability within the chamber was negligible, whereas emission concentrations were stable, reproducible, and similar to concentrations observed on the dynamometer. Measurements of nitric oxide, nitrogen dioxide, carbon monoxide, particulate matter (PM), elemental and organic carbon, carbonyls, trace elements, and polycyclic aromatic hydrocarbons were made during exposures of both healthy and asthmatic volunteers to DPM and control conditions. The effect of the so-called "personal cloud" on total PM mass concentrations was also observed and accounted for. Conventional lung function tests in 11 volunteer subjects (7 stable asthmatic) did not demonstrate a significant change after 2-hr exposures to diesel exhaust. In summary, we demonstrated that this facility can be effectively and safely used to evaluate acute responses to diesel exhaust exposure in human volunteers.

  9. Peribronchiolar fibrosis in lungs of cats chronically exposed to diesel exhaust

    SciTech Connect

    Hyde, D.M.; Plopper, C.G.; Weir, A.J.; Murnane, R.D.; Warren, D.L.; Last, J.A.; Pepelko, W.E.

    1985-02-01

    This study reports the quantitative changes in the pulmonary proximal acinar region following chronic exposure to diesel exhaust and following an additional 6 months in clean air. Cats (13 months of age) from a minimum disease colony were exposed to clean air (eight cats for 27 months and nine cats for 33 months), diesel exhaust for 8 hours/day, 7 days/week (nine cats for 27 months), or diesel exhaust for 27 months followed by 6 months in clean air (10 cats). Morphologic and morphometric evaluation using light microscopy and scanning and transmission electron microscopy revealed two major exposure-related lesions in proximal acinar regions of lungs of cats: peribronchiolar fibrosis associated with significant increases in lymphocytes, fibroblasts, and interstitial macrophages containing diesel particulate-like inclusions and bronchiolar epithelial metaplasia associated with the presence of ciliated and basal cells and alveolar macrophages containing diesel particulate-like inclusions. Peribronchiolar fibrosis was greater at the end of the 6 months in clean air following exposure, whereas the bronchiolar epithelial metaplasia was most severe at the end of exposure. Following an additional 6 months in clean air the epithelium more closely resembled the control epithelial cell population. The labeling index of terminal bronchiolar epithelium was significantly increased at the end of exposure but was not significantly different from controls or exposed cats following an additional 6 months in clean air. The ultrastructural appearance of epithelial cells remained relatively unchanged following diesel exhaust exposure with the exception of diesel particulate-like inclusions.

  10. Sulfur driven nucleation mode formation in diesel exhaust under transient driving conditions.

    PubMed

    Karjalainen, Panu; Rönkkö, Topi; Pirjola, Liisa; Heikkilä, Juha; Happonen, Matti; Arnold, Frank; Rothe, Dieter; Bielaczyc, Piotr; Keskinen, Jorma

    2014-02-18

    Sulfur driven diesel exhaust nucleation particle formation processes were studied in an aerosol laboratory, on engine dynamometers, and on the road. All test engines were equipped with a combination of a diesel oxidation catalyst (DOC) and a partial diesel particulate filter (pDPF). At steady operating conditions, the formation of semivolatile nucleation particles directly depended on SO2 conversion in the catalyst. The nucleation particle emission was most significant after a rapid increase in engine load and exhaust gas temperature. Results indicate that the nucleation particle formation at transient driving conditions does not require compounds such as hydrocarbons or sulfated hydrocarbons, however, it cannot be explained only by the nucleation of sulfuric acid. A real-world exhaust study with a heavy duty diesel truck showed that the nucleation particle formation occurs even with ultralow sulfur diesel fuel, even at downhill driving conditions, and that nucleation particles can contribute 60% of total particle number emissions. In general, due to sulfur storage and release within the exhaust aftertreatment systems and transients in driving, emissions of nucleation particles can even be the dominant part of modern diesel vehicle exhaust particulate number emissions.

  11. Neighborhood-Scale Spatial Models of Diesel Exhaust Concentration Profile Using 1-Nitropyrene and Other Nitroarenes

    PubMed Central

    Schulte, Jill K.; Fox, Julie R.; Oron, Assaf P.; Larson, Timothy V.; Simpson, Christopher D.; Paulsen, Michael; Beaudet, Nancy; Kaufman, Joel D.; Magzamen, Sheryl

    2016-01-01

    With emerging evidence that diesel exhaust exposure poses distinct risks to human health, the need for fine-scale models of diesel exhaust pollutants is growing. We modeled the spatial distribution of several nitrated polycyclic aromatic hydrocarbons (NPAHs) to identify fine-scale gradients in diesel exhaust pollution in two Seattle, WA neighborhoods. Our modeling approach fused land-use regression, meteorological dispersion modeling, and pollutant monitoring from both fixed and mobile platforms. We applied these modeling techniques to concentrations of 1-nitropyrene (1-NP), a highly specific diesel exhaust marker, at the neighborhood scale. We developed models of two additional nitroarenes present in secondary organic aerosol: 2-nitro-pyrene and 2-nitrofluoranthene. Summer predictors of 1-NP, including distance to railroad, truck emissions, and mobile black carbon measurements, showed a greater specificity to diesel sources than predictors of other NPAHs. Winter sampling results did not yield stable models, likely due to regional mixing of pollutants in turbulent weather conditions. The model of summer 1-NP had an R2 of 0.87 and cross-validated R2 of 0.73. The synthesis of high-density sampling and hybrid modeling was successful in predicting diesel exhaust pollution at a very fine scale and identifying clear gradients in NPAH concentrations within urban neighborhoods. PMID:26501773

  12. RESPONSES OF CULTURED HUMAN AIRWAY EPITHELIAL CELLS TREATED WITH DIESEL EXHAUST EXTRACTS WILL VARY WITH THE ENGINE

    EPA Science Inventory

    Epidemiologic evidence suggests that increased morbidity and mortality are associated with the concentrations of ambient air particulate matter (PM). Many sources contribute to the particulate fraction of ambient pollution, including diesel exhaust particulates (DEP). Diesel ex...

  13. RESPONSES OF CULTURED HUMAN AIRWAY EPITHELIAL CELLS TREATED WITH DIESEL EXHAUST EXTRACTS WILL VARY WITH THE ENGINE

    EPA Science Inventory

    Epidemiologic evidence suggests that increased morbidity and mortality are associated with the concentrations of ambient air particulate matter (PM). Many sources contribute to the particulate fraction of ambient pollution, including diesel exhaust particulates (DEP). Diesel ex...

  14. Fibrin clot structure remains unaffected in young, healthy individuals after transient exposure to diesel exhaust

    PubMed Central

    2010-01-01

    Exposure to urban particulate matter has been associated with an increased risk of cardiovascular disease and thrombosis. We studied the effects of transient exposure to diesel particles on fibrin clot structure of 16 healthy individuals (age 21- 44). The subjects were randomly exposed to diesel exhaust and filtered air on two separate occasions. Blood samples were collected before exposure, and 2 and 6 hours after exposure. There were no significant changes on clot permeability, maximum turbidity, lag time, fibre diameter, fibre density and fibrinogen level between samples taken after diesel exhaust exposure and samples taken after filtered air exposure. These data show that there are no prothrombotic changes in fibrin clot structure in young, healthy individuals exposed to diesel exhaust. PMID:20565709

  15. Factors and Trends Affecting the Identification of a Reliable Biomarker for Diesel Exhaust Exposure

    PubMed Central

    2014-01-01

    The monitoring of human exposures to diesel exhaust continues to be a vexing problem for specialists seeking information on the potential health effects of this ubiquitous combustion product. Exposure biomarkers have yielded a potential solution to this problem by providing a direct measure of an individual's contact with key components in the exhaust stream. Spurred by the advent of new, highly sensitive, analytical methods capable of detecting substances at very low levels, there have been numerous attempts at identifying a stable and specific biomarker. Despite these new techniques, there is currently no foolproof method for unambiguously separating diesel exhaust exposures from those arising from other combustion sources. Diesel exhaust is a highly complex mixture of solid, liquid, and gaseous components whose exact composition can be affected by many variables, including engine technology, fuel composition, operating conditions, and photochemical aging. These factors together with those related to exposure methodology, epidemiological necessity, and regulatory reform can have a decided impact on the success or failure of future research aimed at identifying a suitable biomarker of exposure. The objective of this review is to examine existing information on exposure biomarkers for diesel exhaust and to identify those factors and trends that have had an impact on the successful identification of metrics for both occupational and community settings. The information will provide interested parties with a template for more thoroughly understanding those factors affecting diesel exhaust emissions and for identifying those substances and research approaches holding the greatest promise for future success. PMID:25170242

  16. Influence of MTBE addition into gasoline on automotive exhaust emissions

    NASA Astrophysics Data System (ADS)

    Poulopoulos, S.; Philippopoulos, C.

    The effect of methyl-t-butyl ether (MTBE) addition into gasoline on the exhaust emissions from internal combustion engines was studied. A four-cylinder OPEL 1.6 l engine equipped with a hydraulic brake dynamometer was used in all the experiments. Fuels containing 0.0-11.0% MTBE were used in a wide range of engine operations, and the exhaust gases were analyzed for CO, HC (total unburned hydrocarbons, methane, ethylene) and MTBE, before and after their catalytic treatment by a three-way catalytic converter. The addition of MTBE into gasoline resulted in a decrease in CO and HC emissions only at high engine loading. During cold-start up of the engine, MTBE, HC, CO emissions were significant and increased with MTBE addition into fuel. At the catalytic converter outlet MTBE was detected when its concentration in fuels was greater than 8% and only as long as the catalytic converter operates at low temperatures. Methane and ethylene emissions were comparable for all fuels tested at engine outlet, but methane emissions remained almost at the same level while ethylene emissions were significantly decreased by the catalytic converter.

  17. The Australian Work Exposures Study: prevalence of occupational exposure to diesel engine exhaust.

    PubMed

    Peters, Susan; Carey, Renee N; Driscoll, Timothy R; Glass, Deborah C; Benke, Geza; Reid, Alison; Fritschi, Lin

    2015-06-01

    Diesel engines are widely used in occupational settings. Diesel exhaust has been classified as a lung carcinogen, but data on number of workers exposed to different levels of diesel exhaust are not available in Australia. The aim of this study was to estimate the current prevalence of exposure to diesel engine exhaust in Australian workplaces. A cross-sectional survey of Australian males and females (18-65 years old) in current paid employment was undertaken. Information about the respondents' current job and various demographic factors was collected in a telephone interview using the web-based tool OccIDEAS. Semi-quantitative occupational exposure levels to diesel exhaust were assigned using programmed decision rules and numbers of workers exposed in Australia in 2011 were estimated. We defined substantial exposure as exposed at a medium or high level, for at least 5h per week. Substantial occupational exposure to diesel exhaust was experienced by 13.4% of the respondents in their current job. Exposure prevalence varied across states, ranging from 6.4% in the Australian Capital Territory to 17.0% in Western Australia. Exposures occurred mainly in the agricultural, mining, transport and construction industries, and among mechanics. Men (20.4%) were more often exposed than women (4.7%). Extrapolation to the total working population indicated that 13.8% (95% confidence interval 10.0-20.4) of the 2011 Australian workforce were estimated to be substantially exposed to diesel exhaust, and 1.8% of the workers were estimated to experience high levels of exposures in their current job. About 1.2 million Australian workers were estimated to have been exposed to diesel exhaust in their workplace in 2011. This is the first study to describe the prevalence of occupational diesel exhaust exposure in Australia and will enable estimation of the number of lung cancers attributable to diesel exhaust exposure in the workplace. © The Author 2015. Published by Oxford University Press

  18. Systemic and vascular effects of circulating diesel exhaust particulate matter.

    PubMed

    Bai, Ni; van Eeden, Stephan F

    2013-11-01

    Numerous studies have found an association between transiently increased particulate matter air pollution and acute adverse cardiovascular health effects; however, the mechanisms underlying these effects are not clear. Translocation of ultra-fine ambient particulate matter has been proposed to play a key role in these acute side effects. This study was designed to determine the contribution of circulating (translocated) diesel exhaust particles (DEPs) to the systemic and vascular effects. C57 mice (10-week) received intravenous DEPs via tail vein injection. Following 1-h post-injection, inflammatory cytokines (IL-1β, IL-6 and TNF-α), peripheral blood cell counts, band cell counts, aortic endothelial function and vascular constriction were assessed. Thoracic aortae were isolated, and endothelial function was examined by measuring acetylcholine (ACh) and sodium nitroprusside (SNP)-stimulated vascular relaxation using a wire myograph. In addition, phenylephrine (PE)-stimulated vasoconstriction was also measured. The amount of DEPs deposited and trapped in tissues (the spleen, liver, lungs and heart) were quantified. Acute systemic DEP exposure caused a significant increase in TNF-α, peripheral neutrophil and band cell counts. ACh and SNP-induced relaxation were not affected by acute systemic DEP exposure, neither was PE-stimulated constriction. There was a significantly increased DEP deposition in the spleen as well as in the liver. No significantly increased DEPs were detected in the lung and heart. Here we show that circulating DEPs induce a systemic response characterized by increased TNF-α, peripheral granulocytes, but does not impact endothelial function. Our study also suggests that circulating particles are rapidly removed from the circulation and predominantly sequestered in the spleen and liver.

  19. Exposure to diesel exhaust particulates induces cardiac dysfunction and remodeling

    PubMed Central

    Bradley, Jessica M.; Cryar, Kipp A.; El Hajj, Milad C.; El Hajj, Elia C.

    2013-01-01

    Chronic exposure to diesel exhaust particulates (DEP) increases the risk of cardiovascular disease in urban residents, predisposing them to the development of several cardiovascular stresses, including myocardial infarctions, arrhythmias, thrombosis, and heart failure. DEP contain a high level of polycyclic aromatic hydrocarbons, which activate the aryl hydrocarbon receptor (AHR). We hypothesize that exposure to DEP elicits ventricular remodeling through the activation of the AHR pathway, leading to ventricular dilation and dysfunction. Male Sprague-Dawley rats were exposed by nose-only nebulization to DEP (SRM 2975, 0.2 mg/ml) or vehicle for 20 min/day × 5 wk. DEP exposure resulted in eccentric left ventricular dilation (8% increased left ventricular internal diameter at diastole and 23% decreased left ventricular posterior wall thickness at diastole vs. vehicle), as shown by echocardiograph assessment. Histological analysis using Picrosirius red staining revealed that DEP reduced cardiac interstitial collagen (23% decrease vs. vehicle). Further assessment of cardiac function using a pressure-volume catheter indicated impaired diastolic function (85% increased end-diastolic pressure and 19% decreased Tau vs. vehicle) and contractility (57 and 48% decreased end-systolic pressure-volume relationship and maximum change in pressure over time vs. end-diastolic volume compared with vehicle, respectively) in the DEP-exposed animals. Exposure to DEP significantly increased cardiac expression of AHR (19% increase vs. vehicle). In addition, DEP significantly decreased the cardiac expression of hypoxia inducible factor-1α, the competitive pathway to the AHR, and vascular endothelial growth factor, a downstream mediator of hypoxia inducible factor-1α (26 and 47% decrease vs. vehicle, respectively). These findings indicate that exposure to DEP induced left ventricular dilation by loss of collagen through an AHR-dependent mechanism. PMID:23887904

  20. Pulmonary effects of inhaled diesel exhaust in aged mice

    PubMed Central

    Sunil, Vasanthi R.; Patel, Kinal J.; Mainelis, Gediminas; Turpin, Barbara J.; Ridgely, Sherritta; Laumbach, Robert J.; Kipen, Howard M.; Nazarenko, Yevgen; Veleeparambil, Manoj; Gow, Andrew J.; Laskin, Jeffrey D.; Laskin, Debra L.

    2010-01-01

    Pulmonary morbidity and mortality resulting from exposure to fine particulate matter (PM) increases with age. The present studies analyzed potential mechanisms underlying increased susceptibility of the elderly to PM using diesel exhaust (DE) as a model. Mice (2 m and 18 m) were exposed to DE (0, 300, and 1000 μg/m3) for 3 h once (single) or 3 h/day for 3 days (repeated). Bronchoalveolar lavage fluid (BAL), serum and lung tissue were collected 0 and 24 h later. Exposure to DE resulted in structural alterations in the lungs of older but not younger mice, including patchy thickening of the alveolar septa and inflammatory cell localization in alveolar spaces. These effects were most pronounced 24 h after a single exposure to the higher dose of DE. Significant increases in BAL nitrogen oxides were also noted in older mice, as well as expression of lipocalin 24p3, an oxidative stress marker in the lung with no effects in younger mice. Following DE inhalation, expression of Tumor Necrosis Factor alpha (TNFα) was upregulated in lungs of both younger and older mice; however, this was attenuated in older animals. Whereas exposure to DE resulted in increases in lung Interleukin-6 (IL-6) expression in both older and younger mice, IL-8 increased only in older animals. In younger mice, constitutive expression of manganese superoxide dismutase (MnSOD) decreased after DE exposure, while in older mice, constitutive MnSOD was not detectable and DE had no effect on expression of this antioxidant. Taken together, these results suggest that altered generation of inflammatory mediators and MnSOD may contribute to increased susceptibility of older mice to inhaled DE. PMID:19729031

  1. Exposure to diesel exhaust emissions on board locomotives.

    PubMed

    Seshagiri, Baily

    2003-01-01

    Measurements of diesel exhaust emissions (DEEs) were taken in the cabs of leading and trailing locomotives on 48 runs, under winter and summer conditions, on 9 different routes. The cab windows were kept open during the summer runs and closed during the winter runs. The average measurement duration was 9.5 hours. There was virtually no exposure to DEEs in the lead locomotives during winter or summer and very little in the trailing locomotives during winter. The average elemental carbon (EC) concentration in the trailing units of the summer trials was greater than or equal to the proposed American Conference of Governmental Industrial Hygienists' threshold limit value/time-weighted average of 20 microg/m(3) on 26% of the runs, and was greater than or equal to 10 microg/m(3) on 63%. The concentrations of the gaseous components (nitric oxide, nitrogen dioxide, and carbon monoxide) were from 10 to 20 times below their respective threshold limit values. Mean EC concentration was 2.9 microg/m(3) (detection limit 2 microg/m(3)) during the winter runs and 17.1 microg/m(3) during summer. DEEs appeared to be fairly uniformly distributed in the trailing cabs. Configuration of the locomotives had a major impact on EC concentration, with the mean concentration being nearly three times higher in the forward-backward mode than in the forward-forward mode. Descriptive statistics such as means, medians, standard deviations, and so forth, are provided. Various types of statistical comparisons are reported. Recommendations for controlling exposure are made.

  2. Predictive models for deposition of inhaled diesel exhaust particles in humans and laboratory species

    SciTech Connect

    Yu, C.P.; Xu, G.B. )

    1987-01-01

    Mathematical and computer models of the respiratory tracts of human beings and of laboratory animals (rats, hamsters, guinea pigs) were used to estimate the deposition patterns of inhaled diesel exhaust particles from automobile emissions. Our goal was to be able to predict the relation between exposure to diesel exhaust particles and the deposition of these particles in the lungs of humans of various ages. Diesel exhaust particles are aggregates with a mass median aerodynamic diameter of approximately 0.2 micron. Their actual size depends on the conditions under which they are generated. Using an appropriate particle model, we derived mathematical expressions that describe the effects of diffusion, sedimentation, impaction, and interception on the deposition of these particles. Because of their small size, we found that most diesel exhaust particles deposited through diffusion, and that the role of the other mechanisms was minor. Anatomical models of the human lung from birth to adulthood, as well as models of the lungs of laboratory species were formulated mathematically using available morphometric data. We used these lung models, together with the corresponding ventilation conditions of each species, to calculate deposition of diesel exhaust particles in the lungs. Under normal breathing conditions, we calculated that 7 to 13 percent (depending on particle size) of inhaled diesel exhaust particles deposit in the alveolar region of the adult human lung. Although the breathing mode (nose or mouth breathing) did not appear to affect alveolar deposition, increasing the minute ventilation increased alveolar deposition significantly. The calculated deposition patterns for diesel exhaust particles in younger humans (under age 25) were similar.

  3. Effectiveness of non-noble metal based diesel oxidation catalysts on particle number emissions from diesel and biodiesel exhaust.

    PubMed

    Shukla, Pravesh Chandra; Gupta, Tarun; Labhasetwar, Nitin Kumar; Khobaragade, Rohini; Gupta, Neeraj K; Agarwal, Avinash Kumar

    2017-01-01

    Two new formulations of non-noble metal based diesel oxidation catalysts based on CoCe based mixed oxide (DOC2) and perovskite catalysts (DOC3) were prepared and retrofitted in a 4-cylinder diesel engine fueled by diesel and Karanja biodiesel blend (KB20). In this study, their effectiveness in reducing raw exhaust particulate emissions vis-à-vis a commercial diesel oxidation catalyst (DOC1) was evaluated. Emission characteristics such as particle number-size distribution, mass-size distribution, and surface area-size distribution, total particle number concentration and count mean diameter as a function of engine load at constant engine speed were evaluated. Variations in total particle number concentration as a function of engine speed were also determined. The prepared DOCs and the commercial DOC showed varying degrees of performance as a function of engine operating conditions. Overall, effectiveness of the prepared DOC's appeared to be more fuel specific. For diesel exhaust, overall performance of DOC1 was more effective compared to both prepared DOCs, with DOC2 being superior to DOC3. In case of KB20 exhaust, the overall performance of DOC2 was either more effective or nearly comparable to DOC1, while DOC3 being not so effective. This showed that the DOCs based on CoCe based mixed oxide catalysts have potential to replace commercial noble metal based DOC's, especially in engines fueled by biodiesel. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Mutagenicity of diesel exhaust particles from two fossil and two plant oil fuels.

    PubMed

    Bünger, J; Müller, M M; Krahl, J; Baum, K; Weigel, A; Hallier, E; Schulz, T G

    2000-09-01

    Particulate matter of diesel engine exhaust from four different fuels was studied for content of polynuclear aromatic compounds and mutagenic effects. Two so-called biodiesel fuels, rapeseed oil methylesters (RME) and soybean oil methylesters (SME), were compared directly with two fossil diesel fuels with the normal (DF) and a low sulfur content (LS-DF). Diesel exhaust particles were sampled on filters from the diluted and cooled exhaust of a test engine at five different speeds and loads. Filters were weighed for total particulate matter, Soxhlet extracted with dichloromethane and the content of insoluble material determined. The soluble organic fraction was analysed for polynuclear aromatic compounds. Mutagenicity was determined using the Salmonella typhimurium/mammalian microsome assay with strains TA98 and TA100. Compared with DF, the exhaust particles of LS-DF, RME and SME contained less insoluble material, which consisted mainly of the carbon cores of diesel exhaust particles. The concentrations of individual polynuclear aromatic compounds varied widely among the different exhaust extracts, but total concentrations of the compounds were approximately double for DF and SME compared with LS-DF and RME. In TA98 significant increases in mutation rates were obtained for the soluble organic fractions of all fuels for engines running at full speed (load modes A and D), but for DF revertants were 2- to 10-fold more frequent as compared with LS-DF, RME and SME. Revertant frequencies for DF and partly for LS-DF were also elevated in TA100, while RME and SME gave no significant increase in mutations. The results indicate that diesel exhaust particles from RME, SME and LS-DF contain less black carbon and total polynuclear aromatic compounds and are significantly less mutagenic in comparison with DF. A high sulfur content of the fuel and high engine speeds (rated power) and loads are associated with an increase in mutagenicity of diesel exhaust particles.

  5. Influence of preexisting pulmonary emphysema on susceptibility of rats to inhaled diesel exhaust

    SciTech Connect

    Mauderly, J.L.; Bice, D.E.; Cheng, Y.S.; Gillett, N.A.; Griffith, W.C.; Henderson, R.F.; Pickrell, J.A.; Wolff, R.K. )

    1990-05-01

    The susceptibilities of normal rats and rats with preexisting pulmonary emphysema to chronically inhaled diesel exhaust were compared. Rats were exposed 7 h/day, 5 days/wk for 24 months to diesel exhaust at 3.5 mg soot/m3, or to clean air as controls. Emphysema was induced in one-half of the rats by intratracheal instillation of elastase 6 wk before exhaust exposure. Measurements included lung burdens of diesel soot, respiratory function, bronchoalveolar lavage, clearance of radiolabeled particles, pulmonary immune responses, lung collagen, excised lung weight and volume, histopathology, and mean linear intercept of terminal air spaces. Parameters indicated by analysis of variance to exhibit significant interactions between the influences of emphysema and exhaust were examined to determine if the effects were more than additive (indicating increased susceptibility). Although 14 of 63 parameters demonstrated emphysema-exhaust interactions, none indicated increased susceptibility. Less soot accumulated in lungs of emphysematous rats than in those of nonemphysematous rats, and the reduced accumulation had a sparing effect in the emphysematous rats. The results did not support the hypothesis that emphysematous lungs are more susceptible than are normal lungs to chronic exposure to high levels of diesel exhaust. The superimposition of effects of emphysema and exhaust, however, might still warrant special concern for heavy exposures of emphysematous subjects.

  6. Exhaust emissions of DI diesel engine using unconventional fuels

    NASA Astrophysics Data System (ADS)

    Sudrajad, Agung; Ali, Ismail; Hamdan, Hazmie; Hamzah, Mohd. Herzwan

    2012-06-01

    Optimization of using waste plastic and tire disposal fuel on diesel engine were observed. The experimental project was comparison between using both of unconventional fuel and base diesel fuel. The engine experiment was conducted with YANMAR TF120 single cylinder four stroke diesel engine set-up at variable engine speed at 2100, 1900, 1700, 1500 and 1300 rpm. The data have been taken at each point of engine speed during the stabilized engine-operating regime. Measurement of emissions parameters at different engine speed conditions have generally indicated lower in emission COfor waste plastic fuel, lower NOx for tire disposal fuel and lower SOx for diesel fuel.

  7. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XX, CUMMINS DIESEL ENGINE, MAINTENANCE SUMMARY.

    ERIC Educational Resources Information Center

    Minnesota State Dept. of Education, St. Paul. Div. of Vocational and Technical Education.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO PROVIDE A SUMMARY OF THE REASONS AND PROCEDURES FOR DIESEL ENGINE MAINTENANCE. TOPICS ARE WHAT ENGINE BREAK-IN MEANS, ENGINE BREAK-IN, TORQUING BEARINGS (TEMPLATE METHOD), AND THE NEED FOR MAINTENANCE. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL BRANCH PROGRAMED TRAINING FILM "CUMMINS DIESEL ENGINE…

  8. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT VII, ENGINE TUNE-UP--DETROIT DIESEL ENGINE.

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF TUNE-UP PROCEDURES FOR DIESEL ENGINES. TOPICS ARE SCHEDULING TUNE-UPS, AND TUNE-UP PROCEDURES. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL BRANCH PROGRAMED TRAINING FILM "ENGINE TUNE-UP--DETROIT DIESEL ENGINE" AND OTHER MATERIALS. SEE VT 005 655 FOR FURTHER INFORMATION.…

  9. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT I, GENERAL INTRODUCTION TO DIESEL ENGINES.

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    ONE OF A 30-MODULE COURSE DESIGNED TO UPGRADE THE JOB SKILLS AND TECHNICAL KNOWLEDGE OF DIESEL MAINTENANCE MECHANICS, THIS MATERIAL WAS DEVELOPED BY INDUSTRIAL TRAINING AND SUBJECT-MATTER SPECIALISTS AND TESTED IN INDUSTRIAL TRAINING SITUATIONS. THE PURPOSE OF THIS FIRST UNIT IS TO PROVIDE AN INTRODUCTION TO DIESEL ENGINES BY DEVELOPING AN…

  10. Comparison of personal diesel and biodiesel exhaust exposures in an underground mine.

    PubMed

    Lutz, Eric A; Reed, Rustin J; Lee, Vivien S T; Burgess, Jefferey L

    2017-07-01

    This study aimed to compare personal exposures to diesel fuel and a biodiesel blend exhaust in an underground mine. Personal exposure monitoring was performed in a non-operational, hard rock underground mine during use of a load-haul-dump vehicle. Eight-hour time-weighted average (TWA8) exposure concentrations of ultra-low sulfur diesel and 75% biodiesel/25% diesel blend (B75) fuels were compared.  Compared to diesel, use of B75 was associated with relative percent reductions of 22 and 28% in median respirable (r) diesel particulate matter (DPM) and nitrogen dioxide and 25 and 23% increases in median total DPM and nitric oxide TWA8 exposure concentrations, respectively. Diesel was associated with a slightly greater total geometric mean mass concentration and lower mean surface area concentration.  Although further testing is needed, B75 has the potential to reduce rDPM exposures.

  11. Validation of the Dynamic Direct Exposure Method for Toxicity Testing of Diesel Exhaust In Vitro

    PubMed Central

    Hayes, Amanda; Bakand, Shahnaz

    2013-01-01

    Diesel exhaust emission is a major health concern because of the complex nature of its gaseous content (e.g., NO2, NO, CO, and CO2) and high concentration of particulate matter (PM) less than 2.5 μm which allows for deeper penetration into the human pulmonary system upon inhalation. The aim of this research was to elucidate the potential toxic effects of diesel exhaust on a human pulmonary-based cellular system. Validation of a dynamic direct exposure method for both laboratory (230 hp Volvo truck engine) and field (Volkswagen Passat passenger car) diesel engines, at idle mode, was implemented. Human pulmonary type II epithelial cells (A549) grown on porous membranes were exposed to unmodified diesel exhaust at a low flow rate (37.5 mL/min). In parallel, diesel emission sampling was also conducted using real-time air monitoring techniques. Induced cellular effects were assessed using a range of in vitro cytotoxicity assays (MTS, ATP, and NRU). Reduction of cell viability was observed in a time-dependent manner following 30–60 mins of exposure with NRU as the most sensitive assay. The results suggest that the dynamic direct exposure method has the potential to be implemented for both laboratory- and field-based in vitro toxicity studies of diesel exhaust emissions. PMID:23986878

  12. Acute changes in sputum IL-10 following underground exposure to diesel exhaust.

    PubMed

    Burgess, Jefferey L; Fleming, Joy E; Mulenga, Emmanuel M; Josyula, Arun; Hysong, Tracy A; Joggerst, Philip J; Kurzius-Spencer, Margaret; Miller, Hugh B

    2007-01-01

    Although exposure to diesel exhaust has been linked with adverse health effects, little is known about the acute effects of exposure in the underground workplace. Cross-shift spirometry and sputum induction were completed on twelve subjects associated with comminuted rock removal (mucking) operations in an underground copper mine using diesel powered and pneumatic equipment on separate days, and sputum collected on a baseline non-exposure day as well. For diesel operations, elemental carbon exposure averaged 538 +/- 512 microg/m(3) during the 1-2 hour operations. Sputum interleukin-10 decreased with diesel exhaust using one ELISA assay (3.69 v. 2.32 pg/ml, p = 0.015), but increased when measured with a different ELISA kit (0.18 v. 0.59 pg/ml, p = 0.019), consistent with an overall decline in IL-10 protein concentration but an increase in the biologically active form. Sputum interleukin-6 decreased with exposure to diesel exhaust, although this change lost statistical significance when restricted to non-smokers. There were no significant changes in spirometry, interleukins 1beta, 4, and 8, tumor necrosis factor alpha or 8-hydroxy-2'-deoxyguanosine. High levels of diesel exhaust can result in rapid changes in sputum IL-10, suggesting possible protein modification.

  13. Retrospective cohort study of lung cancer and diesel exhaust exposure in railroad workers

    SciTech Connect

    Garshick, E.; Schenker, M.B.; Munoz, A.; Segal, M.; Smith, T.J.; Woskie, S.R.; Hammond, S.K.; Speizer, F.E.

    1988-04-01

    The risk of lung cancer as a result of exposure to diesel exhaust from railroad locomotives was assessed in a cohort of 55,407 white male railroad workers 40 to 64 yr of age in 1959 who had started railroad service 10 to 20 years earlier. The cohort was traced until the end of 1980, and death certificates were obtained for 88% of 19,396 deaths; 1694 lung cancer cases were identified. Yearly railroad job from 1959 to death or retirement was available from the Railroad Retirement Board, and served as an index of diesel exhaust exposure. Directly standardized rates and a proportional hazards model were used to calculate the relative risk of lung cancer based on work in a job with diesel exhaust exposure beginning in 1959. A relative risk of 1.45 (95% CI = 1.11, 1.89) for lung cancer was obtained in the group of workers 40 to 44 yr of age in 1959, the group with the longest possible duration of diesel exposure. The cohort was selected to minimize the effect of past railroad asbestos exposure, and analysis with workers with possible asbestos exposure excluded resulted in a similarly elevated risk. Workers with 20 yr or more elapsed since 1959, the effective start of diesel exposure for the cohort, had the highest relative risk. These results taken in conjunction with other reported results support the hypothesis that occupational exposure to diesel exhaust results in a small but significantly elevated risk for lung cancer.

  14. Validation of the dynamic direct exposure method for toxicity testing of diesel exhaust in vitro.

    PubMed

    Joeng, Lucky; Hayes, Amanda; Bakand, Shahnaz

    2013-01-01

    Diesel exhaust emission is a major health concern because of the complex nature of its gaseous content (e.g., NO2, NO, CO, and CO2) and high concentration of particulate matter (PM) less than 2.5  μ m which allows for deeper penetration into the human pulmonary system upon inhalation. The aim of this research was to elucidate the potential toxic effects of diesel exhaust on a human pulmonary-based cellular system. Validation of a dynamic direct exposure method for both laboratory (230 hp Volvo truck engine) and field (Volkswagen Passat passenger car) diesel engines, at idle mode, was implemented. Human pulmonary type II epithelial cells (A549) grown on porous membranes were exposed to unmodified diesel exhaust at a low flow rate (37.5 mL/min). In parallel, diesel emission sampling was also conducted using real-time air monitoring techniques. Induced cellular effects were assessed using a range of in vitro cytotoxicity assays (MTS, ATP, and NRU). Reduction of cell viability was observed in a time-dependent manner following 30-60 mins of exposure with NRU as the most sensitive assay. The results suggest that the dynamic direct exposure method has the potential to be implemented for both laboratory- and field-based in vitro toxicity studies of diesel exhaust emissions.

  15. Lung cancer and diesel exhaust: an updated critical review of the occupational epidemiology literature

    PubMed Central

    Gamble, John F.; Nicolich, Mark J.; Boffetta, Paolo

    2012-01-01

    A recent review concluded that the evidence from epidemiology studies was indeterminate and that additional studies were required to support the diesel exhaust-lung cancer hypothesis. This updated review includes seven recent studies. Two population-based studies concluded that significant exposure-response (E-R) trends between cumulative diesel exhaust and lung cancer were unlikely to be entirely explained by bias or confounding. Those studies have quality data on life-style risk factors, but do not allow definitive conclusions because of inconsistent E-R trends, qualitative exposure estimates and exposure misclassification (insufficient latency based on job title), and selection bias from low participation rates. Non-definitive results are consistent with the larger body of population studies. An NCI/NIOSH cohort mortality and nested case-control study of non-metal miners have some surrogate-based quantitative diesel exposure estimates (including highest exposure measured as respirable elemental carbon (REC) in the workplace) and smoking histories. The authors concluded that diesel exhaust may cause lung cancer. Nonetheless, the results are non-definitive because the conclusions are based on E-R patterns where high exposures were deleted to achieve significant results, where a posteriori adjustments were made to augment results, and where inappropriate adjustments were made for the “negative confounding” effects of smoking even though current smoking was not associated with diesel exposure and therefore could not be a confounder. Three cohort studies of bus drivers and truck drivers are in effect air pollution studies without estimates of diesel exhaust exposure and so are not sufficient for assessing the lung cancer-diesel exhaust hypothesis. Results from all occupational cohort studies with quantitative estimates of exposure have limitations, including weak and inconsistent E-R associations that could be explained by bias, confounding or chance, exposure

  16. Lung cancer and diesel exhaust: an updated critical review of the occupational epidemiology literature.

    PubMed

    Gamble, John F; Nicolich, Mark J; Boffetta, Paolo

    2012-08-01

    A recent review concluded that the evidence from epidemiology studies was indeterminate and that additional studies were required to support the diesel exhaust-lung cancer hypothesis. This updated review includes seven recent studies. Two population-based studies concluded that significant exposure-response (E-R) trends between cumulative diesel exhaust and lung cancer were unlikely to be entirely explained by bias or confounding. Those studies have quality data on life-style risk factors, but do not allow definitive conclusions because of inconsistent E-R trends, qualitative exposure estimates and exposure misclassification (insufficient latency based on job title), and selection bias from low participation rates. Non-definitive results are consistent with the larger body of population studies. An NCI/NIOSH cohort mortality and nested case-control study of non-metal miners have some surrogate-based quantitative diesel exposure estimates (including highest exposure measured as respirable elemental carbon (REC) in the workplace) and smoking histories. The authors concluded that diesel exhaust may cause lung cancer. Nonetheless, the results are non-definitive because the conclusions are based on E-R patterns where high exposures were deleted to achieve significant results, where a posteriori adjustments were made to augment results, and where inappropriate adjustments were made for the "negative confounding" effects of smoking even though current smoking was not associated with diesel exposure and therefore could not be a confounder. Three cohort studies of bus drivers and truck drivers are in effect air pollution studies without estimates of diesel exhaust exposure and so are not sufficient for assessing the lung cancer-diesel exhaust hypothesis. Results from all occupational cohort studies with quantitative estimates of exposure have limitations, including weak and inconsistent E-R associations that could be explained by bias, confounding or chance, exposure

  17. Interpretation of Secondary Organic Aerosol Formation from Diesel Exhaust Photooxidation in an Environmental Chamber

    SciTech Connect

    Nakao, Shunsuke; Shrivastava, ManishKumar B.; Nguyen, Anh; Jung, Hee-Jung; Cocker, David R.

    2011-04-14

    Secondary organic aerosol (SOA) formation from diesel exhaust in a smog chamber was investigated. Particle volume measurement based on mobility diameter is shown to underestimate SOA formation from diesel exhaust due to the external void space of agglomerate particles, in which case mass-based measurement technique is necessary. Rapid determination of particle effective density as a function of particle mass was performed by an Aerosol Particle Mass analyzer – Scanning Mobility Particle Sizer (APM-SMPS) to obtain particle mass concentration and fractal dimension. Continuous aging of aerosol was observed in terms of atomic ratio (O/C), from 0.05 to 0.25 in 12 hours, underscoring the importance of multi-generational oxidation of low-volatile organic vapors emitted from diesel engine as the significant source of oxygenated SOA. Experimental conditions possibly have strong impacts on physical evolution of diesel particulates in a smog chamber. Higher particle effective densities were observed when raw exhaust was injected into a full bag as opposed to filling a bag with diluted exhaust using an ejector diluter. When longer transfer line was used for injecting diesel exhaust into the smog chamber, rapid particle coagulation was observed, leading to increasing particle volume concentration in dark while its mass concentration is decreasing.

  18. Research Approach for Aging and Evaluating Diesel Exhaust catalysts

    SciTech Connect

    Wayne, Scott

    2000-08-20

    To determine the impact of diesel fuel sulfur levels on emissions control devices that could lower emissions of oxides of nitrogen (NOX) and particulate matter (PM) from on-highway trucks and buses in the 2002-2004 model years. West Virginia University is evaluating: - Diesel Oxidation Catalysts - Lean NOX Catalysts

  19. A WEAR MODEL FOR DIESEL ENGINE EXHAUST VALVES

    SciTech Connect

    Blau, Peter Julian

    2009-11-01

    The work summarized here comprises the concluding effort of a multi-year project, funded by the U.S. Department of Energy, Office of Vehicle Technologies. It supports the development of a better understanding of advanced diesel engine designs in which enhanced power density, energy efficiency, and emissions control place increasing demands upon the durability of engine materials. Many kinds of metallic alloys are used in engines depending on the operating stresses, temperatures, and chemical environments. Exhaust valves, for example, are subjected to high temperatures and repetitive surface contacts that place demands on durability and frictional characteristics of the materials. Valves must continue to seal the combustion chamber properly for thousands of hours of cyclic engine operation and under varying operating conditions. It was the focus of this effort to understand the wear processes in the valve-seat area and to develop a model for the surface deformation and wear of that important interface. An annotated bibliography is provided to illustrate efforts to understand valve wear and to investigate the factors of engine operation that affect its severity and physical manifestation. The project for which this modeling effort was the final task, involved construction of a high-temperature repetitive impact test system as well as basic tribology studies of the combined processes of mechanical wear plus oxidation at elevated temperatures. Several publications resulted from this work, and are cited in this report. The materials selected for the experimental work were high-performance alloys based on nickel and cobalt. In some cases, engine-tested exhaust valves were made available for wear analysis and to ensure that the modes of surface damage produced in experiments were simulative of service. New, production-grade exhaust valves were also used to prepare test specimens for experimental work along with the other alloy samples. Wear analysis of valves and seats

  20. Biodiesel versus diesel: a pilot study comparing exhaust exposures for employees at a rural municipal facility.

    PubMed

    Traviss, Nora; Thelen, Brett Amy; Ingalls, Jaime Kathryn; Treadwell, Melinda Dawn

    2010-09-01

    Many organizations interested in renewable, domestic energy have switched from petroleum diesel to biodiesel blends for use in transportation and heavy-duty equipment. Although considerable evidence exists on the negative health effects of petroleum diesel exhaust exposures in occupational settings, there has been little research examining biodiesel exposures. Working collaboratively with a local municipality, concentrations of particulate matter (PM) and other air toxics were measured at a recycling facility in southwestern New Hampshire while heavy equipment operated first on petroleum diesel and then on a B20 blend (20% soy-based biodiesel/80% petroleum diesel). This pilot study used a combination of established industrial hygiene and environmental air monitoring methods to estimate occupational exposure profiles to PM and air toxics from combustion of petroleum diesel and biodiesel. Results indicate that B20 use dramatically reduces work area respirable particle, PM2.5 (PM < or = 2.5 microm in aerodynamic diameter), and formaldehyde levels compared with petroleum diesel. Some volatile organic compound concentrations were higher for petroleum diesel and others were higher for the B20 blend. Overall, this study suggests that biodiesel blends reduce worker exposure to and health risk from petroleum diesel exhaust, but additional exposure research is recommended.

  1. The impact of using biodiesel/marine gas oil blends on exhaust emissions from a stationary diesel engine.

    PubMed

    Karavalakis, G; Tzirakis, E; Mattheou, L; Stournas, S; Zannikos, F; Karonis, D

    2008-12-01

    The purpose of this work was to investigate the impact of marine gas oil (MGO)/biodiesel blends on the exhaust emissions and fuel consumption in a single cylinder, stationary, diesel engine. Three different origins of biodiesel were used as the blending feedstock with the reference MGO, at proportions of 5 and 10% by volume. Methyl esters were examined according to the automotive FAME standard EN 14214. The baseline MGO and biodiesel blends were examined according to ISO 8217:2005 specifications for the DMA category. Independently of the biodiesel used, a decrease of PM, HC, CO and CO(2) emissions was observed. Emissions of NO(x) were also lower with respect to MGO. This reduction in NO(x) may be attributed to some physicochemical properties of the fuels applied, such as the higher cetane number and the lower volatility of methyl esters. Reductions in PM for biodiesel blends were lower in the exhaust than those of the reference fuel which was attributed to the oxygen content and the near absence of sulphur and aromatics compounds in biodiesel. However, a slight increase in fuel consumption was observed for the biodiesel blends that may be tolerated due to the exhaust emissions benefits. Brake thermal efficiency was also determined. Unregulated emissions were characterized by determining the soluble organic fraction content of the particulate matter.

  2. Effects of water-emulsified fuel on a diesel engine generator's thermal efficiency and exhaust.

    PubMed

    Syu, Jin-Yuan; Chang, Yuan-Yi; Tseng, Chao-Heng; Yan, Yeou-Lih; Chang, Yu-Min; Chen, Chih-Chieh; Lin, Wen-Yinn

    2014-08-01

    Water-emulsified diesel has proven itself as a technically sufficient improvement fuel to improve diesel engine fuel combustion emissions and engine performance. However, it has seldom been used in light-duty diesel engines. Therefore, this paper focuses on an investigation into the thermal efficiency and pollution emission analysis of a light-duty diesel engine generator fueled with different water content emulsified diesel fuels (WD, including WD-0, WD-5, WD-10, and WD-15). In this study, nitric oxide, carbon monoxide, hydrocarbons, and carbon dioxide were analyzed by a vehicle emission gas analyzer and the particle size and number concentration were measured by an electrical low-pressure impactor. In addition, engine loading and fuel consumption were also measured to calculate the thermal efficiency. Measurement results suggested that water-emulsified diesel was useful to improve the thermal efficiency and the exhaust emission of a diesel engine. Obviously, the thermal efficiency was increased about 1.2 to 19.9%. In addition, water-emulsified diesel leads to a significant reduction of nitric oxide emission (less by about 18.3 to 45.4%). However the particle number concentration emission might be increased if the loading of the generator becomes lower than or equal to 1800 W. In addition, exhaust particle size distributions were shifted toward larger particles at high loading. The consequence of this research proposed that the water-emulsified diesel was useful to improve the engine performance and some of exhaust emissions, especially the NO emission reduction. Implications: The accumulated test results provide a good basis to resolve the corresponding pollutants emitted from a light-duty diesel engine generator. By measuring and analyzing transforms of exhaust pollutant from this engine generator, the effects of water-emulsified diesel fuel and loading on emission characteristics might be more clear. Understanding reduction of pollutant emissions during the use

  3. The characteristics of performance and exhaust emissions of a diesel engine using a biodiesel with antioxidants.

    PubMed

    Ryu, Kyunghyun

    2010-01-01

    The aim of this study is to investigate the effects of antioxidants on the oxidation stability of biodiesel fuel, the engine performance and the exhaust emissions of a diesel engine. Biodiesel fuel used in the study was derived from soybean oil. The results show that the efficiency of antioxidants is in the order TBHQ>PrG>BHA>BHT>alpha-tocopherol. The oxidative stability of biodiesel fuel attained the 6-h quality standard with 100 ppm TBHQ and with 300 ppm PrG in biodiesel fuel. Combustion characteristics and exhaust emissions in diesel engine were not influenced by the addition of antioxidants in biodiesel fuel. The BSFC of biodiesel fuel with antioxidants decreased more than that of biodiesel fuel without antioxidants, but no trends were observed according to the type or amount of antioxidant. Antioxidants had few effects on the exhaust emissions of a diesel engine running on biodiesel.

  4. HEALTH EFFECTS OF DIESEL EXHAUST: AN HEI PERSPECTIVE

    SciTech Connect

    Warren, Jane

    2000-08-20

    Diesel engines have many advantages, including good fuel economy, power, durability, lower emissions of some pollutants (such as carbon monoxide) and of carbon dioxide (a greenhouse gas). However, there are a number of concerns that need to be addressed: (1) emissions of nitrogen oxides (which contribute to ozone formation) and of particulate matter (PM); (2) questions about cancer and other health effects from exposure to diesel PM; and (3) as efforts to decrease emissions progress, a need to understand whether the nature and toxicity of the PM emitted has changed. This paper focuses on (1) carcinogenicity data, (2) noncancer effects, and (3) diesel as part of the complex ambient mixture of PM.

  5. Effects of inhaled diesel exhaust on immune responses after lung immunization

    SciTech Connect

    Bice, D.E.; Mauderly, J.L.; Jones, R.K.; McClellan, R.O.

    1985-12-01

    The inhalation of diesel exhaust particles and the accumulation of these particles in the lung-associated lymph nodes could alter the development of immune responses after lung immunization. To study this possibility, Fischer 344 rats and CD-1 mice were exposed to three levels of diesel exhaust (nominal concentration--7000, 3500, or 350 micrograms particles/m3). Chamber controls and exposed animals were immunized by intratracheal instillation of sheep red blood cells (SRBC) after 6, 12, 18, and 24 months of exposure. The number of anti-SRBC IgM antibody-forming cells (AFC) in the lung-associated lymph nodes and spleen was evaluated after immunization. The lung-associated lymph nodes from rats and mice exposed to the high levels of diesel exhaust were black with accumulated diesel particles, and the number of lymphoid cells was significantly elevated at each sacrifice time, while rats exposed to the medium level of diesel exhaust also had elevated numbers of cells in these tissues at 12, 18, and 24 months of exposure. The total number of AFC in the lung-associated lymph nodes was significantly elevated (p less than 0.05) in rats exposed to medium and high levels of diesel exhaust, but no significant effects were observed in exposed mice. Data expressed as AFC/10(6) lymphoid cells in rats and mice, and the level of specific IgM, IgG, or IgA antibody in rat sera were not significantly altered. We conclude that the increased cellularity, and the presence of diesel particles in the lung-associated lymph nodes, had a minimal effect on the immune and antigen filtration functions of these tissues.

  6. The effect of preheating the mixture on the operation of a bifuel multicylinder automotive diesel engine

    SciTech Connect

    Muthu, S.; Ilango, K.; Jagadeesan, T.R.; Ramalingam, K.K.; Vedamurthy, V.N.

    1980-12-01

    The growing demand coupled with high cost and uncertainity of crude oil supplies had led to an extensive search for a suitable alternative fuel which can be obtained from renewable sources. Since a major portion of fossil liquid fuels is consumed by the transportation sector, the alternative fuel reserch is mainly focussed towards fulfilling the needs of automotive engines. Of the various alternatives like methanol, ethanol and hydrogen, it is believed that ethanol has many desirable characteristics and hence considered as a potential substitute to be used as a diesel extender. The present work deals with the details of the investigation in which ethanol has been used as a bifuel in a six cylinder 120 HP automotive diesel engine. The main aim being to determine the optimum level of ethanol acceptance due to preheating the inlet air and the engine characteristics. It was found that upto a maximum of 65 percent of diesel could be replaced by ethanol at higher loads and speeds. While preheating of the air reduced the thermal efficiency at low loads, it permitted greater amount of ethanol to be inducted for the entire load range at a given speed. Use of additive to the alcohol has been found to result in higher thermal efficiency for the dual fuel operation.

  7. The masculinization of the fetus during pregnancy due to inhalation of diesel exhaust.

    PubMed Central

    Watanabe, N; Kurita, M

    2001-01-01

    This study was conducted to determine the impact of diesel exhaust inhalation on the fetus. Seventy-two pregnant rats and 18 nonpregnant rats were divided into three groups: a group exposed to total diesel engine exhaust containing 5.63 mg/m(3) particulate matter, 4.10 ppm nitrogen dioxide, and 8.10 ppm nitrogen oxide; a group exposed to filtered exhaust without particulate matter; and a group exposed to clean air. The exposure period was from day 7 until day 20 of pregnancy. In addition, 15 pregnant rats were treated with aromatase inhibitors or testosterone to clarify the process by which diesel exhaust exerts its toxicity. The anogenital distance was significantly longer in male and female fetuses from both exhaust-exposed groups than in those of the control. Differentiation of the testis, ovary, and thymus was delayed and disturbed. Maternal testosterone and progesterone levels, which increased due to pregnancy whether or not the rats were exposed, were significantly higher and lower, respectively, in the pregnant rats exposed to total exhaust and filtered exhaust. The serum adrenocorticotropic hormone (ACTH) level and urinary excretion of 17-hydroxycorticosteroids (OHCS) did not differ among the pregnant groups. These results indicate that elevated testosterone did not result from elevated maternal adrenal function. The feto-placental-ovarian unit and inhibition of aromatase activity and synthesis caused by diesel exhaust inhalation might have played an essential role in the accumulation of testosterone. Since both exhaust-exposed groups showed almost the same reactions toward the inhalation, the gaseous phase must have included the relevant toxicants. PMID:11266319

  8. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XXI, I--MAINTAINING THE AIR SYSTEM--CATERPILLAR DIESEL ENGINE, II--UNDERSTANDING REAR END SUSPENSION.

    ERIC Educational Resources Information Center

    Minnesota State Dept. of Education, St. Paul. Div. of Vocational and Technical Education.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF THE DIESEL ENGINE AIR SYSTEM AND REAR AXLE SUSPENSION USED ON DIESEL POWERED VEHICLES. TOPICS ARE (1) AIR INDUCTION AND EXHAUST SYSTEM, (2) VALVE MECHANISM, (3) TROUBLESHOOTING THE AIR SYSTEM, (4) PURPOSE OF VEHICLE SUSPENSION, (5) TANDEM…

  9. Pulmonary Effects of Inhaled Diesel Exhaust in Young and Old Mice: A Pilot Project

    PubMed Central

    Laskin, Debra L.; Mainelis, Gedi; Turpin, Barbara; Patel, Kinal J.; Sunil, Vasanthi R.

    2015-01-01

    It is well established that exposure to ambient fine particulate matter (PM) is associated with increased cardiovascular morbidity and mortality and that elderly individuals are particularly susceptible to these effects. We speculated that increased susceptibility of the elderly to PM is due to altered production of inflammatory mediators and antioxidants in the lung and pilot studies were performed to test this hypothesis. For these studies we used diesel exhaust, a major component of urban PM as a model. Animals (CB6F1 male mice; 2 m and 18 m) were exposed to air or diesel exhaust at 300 or 1000 µg/m3 for 3 h one time (single) or 3 h/day for 3 consecutive days (repeated). Bronchoalveolar lavage (BAL) fluid, serum and lung tissue were collected 0 and 24 h later. Following single or repeated diesel exhaust exposure, persistent structural alterations and inflammation were observed in the lungs of older mice. This consisted of patchy thickening of alveolar septa and an increase in the number of neutrophils and macrophages in alveolar spaces. In contrast, no major alterations in lung histology were noted in younger mice. In older, but not younger mice, significant increases in expression of the oxidative stress marker, lipocalin 24p3 were also observed. In both younger and older mice, exposure to diesel exhaust was associated with increased expression of TNFα in the lung. However, this response was attenuated in older mice. Exposure to high dose diesel exhaust resulted in significant increases in IL-6 and IL-8 mRNA expression in lungs of older animals which persisted for 24 h. Whereas IL-6 was also upregulated in younger mice after diesel exhaust exposure, no major effects were evident on expression of IL-8 mRNA. Expression of the antioxidant manganese superoxide dismutase (MnSOD) was decreased in lung tissue from younger animals after exposure to DE (single or repeated). In contrast, constitutive expression of MnSOD was not evident in lungs of older mice, and

  10. Global increases in allergic respiratory disease: the possible role of diesel exhaust particles.

    PubMed

    Peterson, B; Saxon, A

    1996-10-01

    Reading this article will enable the readers to recognize and evaluate i e potential relationship between allergic respiratory disease and polyaromatic hydrocarbons as air pollutants from industrial and automotive fuel sources. In this article we review the long-term trends in the prevalence of allergic airway diseases (rhinitis and asthma). We then examine the epidemiologic and other research data relating to the role that hydrocarbon fuel emissions may have had on allergic respiratory disease. Published literature on the relationship between specific air pollutants and trends in allergic respiratory disease were reviewed. Reports of research on pollutant effects on allergic antibody (IgE) were also studied. In both cases, the Melvyl-Medline database since 1975 was used for literature searches. Older references were identified from the bibliographies of relevant articles and books and with the help of the rare books collection at UCLA's Louis M. Darling Biomedical library. Examination of the historical record indicates that allergic rhinitis and allergic asthma have significantly increased in prevalence over the past two centuries. Although the reasons for this increase are not fully elucidated, epidemiologic data suggest that certain pollutants such as those produced from the burning of fossil fuels may have played an important role in the prevalence changes. Also important are studies showing that diesel exhaust, a prototypical fossil fuel, is able to enhance in vitro and in vivo IgE production. Increased levels of the compounds resulting from fossil fuel combustion may be partly responsible for the increased prevalence of allergic respiratory disease. If the nature of these compounds and the mechanisms by which they exacerbate allergic disease can be identified, steps can be taken to reduce the production or the impact of these allergy producing compounds.

  11. Response Characteristics of a Stable Mixed Potential Ammonia Sensor in Simulated Diesel Exhaust

    DOE PAGES

    Ramaiyan, Kannan P.; Pihl, Josh A.; Kreller, Cortney R.; ...

    2017-07-15

    A mixed potential sensor using Au and Pt dense wire electrodes embedded between tape-casted layers of 8 mol% yttria stabilized zirconia (YSZ) was tested for application toward NH3, NO, NO2, C3H6 and C3H8. In single-gas testing, the sensor exhibited the highest response toward NH3, while still exhibiting reasonably high sensitivity toward other interferent gases. We tested the sensor in a high-flow reactor at the National Transportation Research Center (NTRC) in order to simulate exhaust gas constituents and flow rates produced by lean-burn vehicles powered by Compression-Ignition Direct-Injection (CIDI), diesel engines. The sensor was characterized at 525 and 625°C for NH3,more » CO, C3H6, C3H8, and NOx in a base gas composition of 10% O2, 5% H2O, and 5% CO2 flowing at 15 slpm. The sensor exhibited fast response time equal to the response time of the system's switching valve (T90<0.6s). Furthermore, in simulations of overdosing a selective catalytic reduction (SCR) system, the sensor was able to selectively respond to 20ppm injections of NH3 slip despite the presence of the interferent gas species at combined concentrations ten times higher than that of the NH3. The laboratory sensor construct was transitioned to a pre-commercial, automotive stick sensor configuration that was demonstrated to retain the advantageous characteristics of the tape-cast device.« less

  12. Effect of some Turkish vegetable oil-diesel fuel blends on exhaust emissions

    SciTech Connect

    Ergeneman, M.; Oezaktas, T.; Cigizoglu, K.B.; Karaosmanoglu, F.; Arslan, E.

    1997-10-01

    For different types of vegetable oils of Turkish origin (sunflower, corn, soybean, and olive oil) were blended with grade No. 2-D diesel fuel at a ratio of 20/80 (v/v). The effect of the compression ratio on exhaust emissions is investigated in an American Society for Testing and Materials (ASTM)-cooperative fuel research (CFR) engine working with the mentioned fuel blends and a baseline diesel fuel. A decrease in soot, CO, CO{sub 2}, and HC emissions and an increase in NO{sub x} emissions have been observed for fuel blends compared to diesel fuel.

  13. Model studies of volatile diesel exhaust particle formation: organic vapours involved in nucleation and growth?

    NASA Astrophysics Data System (ADS)

    Pirjola, L.; Karl, M.; Rönkkö, T.; Arnold, F.

    2015-02-01

    High concentration of volatile nucleation mode particles (NUP) formed in the atmosphere during exhaust cools and dilutes have hazardous health effects and impair visibility in urban areas. Nucleation mechanisms in diesel exhaust are only poorly understood. We performed model studies using two sectional aerosol dynamics process models AEROFOR and MAFOR on the formation of particles in the exhaust of a diesel engine, equipped with an oxidative after-treatment system and running with low fuel sulphur content (FSC), under laboratory sampling conditions where the dilution system mimics real-world conditions. Different nucleation mechanisms were tested; based on the measured gaseous sulphuric acid (GSA) and non-volatile core and soot particle number concentrations of the raw exhaust, the model simulations showed that the best agreement between model predictions and measurements in terms of particle number size distribution was obtained by barrierless heteromolecular homogeneous nucleation between GSA and semi-volatile organic vapour (for example adipic acid) combined with the homogeneous nucleation of GSA alone. Major growth of the particles was predicted to occur by the same organic vapour at concentrations of (1-2) ×1012cm-3. The pre-existing core and soot mode concentrations had opposite trend on the NUP formation, and maximum NUP formation was predicted if a diesel particle filter (DPF) was used. On the other hand, NUP formation was ceased if the GSA concentration was less than 1010cm-3 which suggests, based on the measurements, the usage of biofuel to prevent volatile particles in diesel exhaust.

  14. Effect of short-term exposure to diesel exhaust particles and carboxylic acids on mitochondrial membrane disruption in airway epithelial cells

    EPA Science Inventory

    Rationale: Diesel exhaust has been shown to induce adverse pulmonary health effects; however, the underlying mechanisms for these effects are still unclear. Previous studies have imlplicated mitochondrial dysfunction in the toxicity of diesel exhaust particles (DEP). DEP contain...

  15. Effect of short-term exposure to diesel exhaust particles and carboxylic acids on mitochondrial membrane disruption in airway epithelial cells

    EPA Science Inventory

    Rationale: Diesel exhaust has been shown to induce adverse pulmonary health effects; however, the underlying mechanisms for these effects are still unclear. Previous studies have imlplicated mitochondrial dysfunction in the toxicity of diesel exhaust particles (DEP). DEP contain...

  16. A comparison of genotoxicity of automotive exhaust particles from laboratory and environmental sources.

    PubMed

    Brooks, A L; Li, A P; Dutcher, J S; Clark, C R; Rothenberg, S J; Kiyoura, R; Bechtold, W E; McClellan, R O

    1984-01-01

    This research (1) ranked the genotoxicity of methylene chloride extracts of laboratory and environmentally collected particles and (2) evaluated the role of collection location and sample composition on genotoxic potency. Samples of exhaust from a spark-ignition automobile, light-duty diesel automobile, and a heavy-duty diesel engine operated in a laboratory on a dynamometer were studied, as well as samples taken in a highway tunnel and outside the same tunnel. The tunnel samples were collected 30 m inside or 56 m outside the exit portal at times when between 70%-95% of the traffic consisted of diesel trucks. In the Ames Salmonella mutagenicity assay, each extract produced a dose-dependent increase in mutagenicity in strain TA-98 without addition of liver S-9 fraction. Extracts from two tunnel samples collected 1 yr apart, and extracts of particles collected outside the tunnel had similar mutagenic activity. The order of mutagenic activity per microgram of extract in TA-98 without S-9 from the lowest to the highest was environmental sample less than or equal to tunnel less than heavy-duty diesel less than light-duty diesel less than spark ignition. Addition of S-9 or testing in Salmonella strains resistant to the mutagenicity of nitroaromatic compounds (TA-98 NR and TA-98 1,8-DNP6) decreased the mutagenic response. With cell killing, sister chromatid exchanges, and mutations as endpoints in Chinese hamster ovary cells (CHO), the order of potency was tunnel less than light-duty less than spark-ignition samples. All three extracts induced a similar amount of mitotic delay per microgram with or without S-9. Enhanced chromosome aberration frequency was detected only in cells exposed to extracts from spark-ignition exhaust. The data indicated that genotoxic activity was detected in each particle extract, that the potency ranking was similar using different genetic endpoints, and that the magnitude of the genotoxic potency was similar.

  17. Computer modeling of wear in extrusion and forging of automotive exhaust valves

    NASA Astrophysics Data System (ADS)

    Tulsyan, R.; Shivpuri, R.

    1995-04-01

    In an automotive engine valve forging process, the billet is cold sheared, induction heated, and fed to a mechanical press for a two-stage forging operation with the first stage being extrusion. The main limiting factor in this operation is the wear of the dies during the first stage, extrusion. In this study. abrasive wear was identified as the primary mode of wear, and computer simulation was used to investigate the effect of process variables, such as press speed, initial billet temperature, and die preheat temperature upon abrasive wear. The result generated by this study should be applicable to other part geometry and not limited just to exhaust valves.

  18. AUTOMOTIVE DIESEL MAINTENANCE, UNIT V, MAINTAINING THE LUBRICATION SYSTEM--DETROIT DIESEL ENGINE.

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF THE DIESEL ENGINE LUBRICATION SYSTEM. TOPICS ARE LUBE OILS USED, MAINTENANCE OF THE LUBRICATION SYSTEM, AND CRANKCASE VENTILATION COMPONENTS. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL BRANCH PROGRAMED TRAINING FILM "BASIC ENGINE…

  19. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT X, USE OF MEASURING TOOLS IN DIESEL MAINTENANCE.

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE PRECISION MEASURING TOOLS USED IN DIESEL ENGINE MAINTENANCE. TOPICS ARE (1) LINEAR MEASURE, (2) MEASURING WITH RULES AND TAPES, (3) GETTING PRECISION WITH MICROMETERS, (4) DIAL INDICATORS, (5) TACHOMETERS, (6) TORQUE WRENCH, (7) THICKNESS (TECHER) GAGE, AND (8) VALVE…

  20. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT III, MAINTAINING THE FUEL SYSTEM--DETROIT DIESEL ENGINE.

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF THE DIESEL ENGINE FUEL SYSTEM. TOPICS ARE (1) PURPOSE OF THE FUEL SYSTEM, (2) TRACING THE FUEL FLOW, (3) MINOR COMPONENTS OF THE FUEL SYSTEM, (4) MAINTENANCE TIPS, (5) CONSTRUCTION AND FUNCTION OF THE FUEL INJECTORS, AND (6)…

  1. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT VI, MAINTAINING MECHANICAL GOVERNORS--DETROIT DIESEL ENGINES.

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF MECHANICAL GOVERNORS USED ON DIESEL ENGINES. TOPICS ARE (1) TYPES OF GOVERNORS AND ENGINE LOCATION, (2) GOVERNOR APPLICATIONS, (3) LIMITING SPEED MECHANICAL GOVERNOR, (4) VARIABLE SPEED MECHANICAL GOVERNOR, AND (5) CONSTANT SPEED…

  2. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT IV, MAINTAINING THE COOLING SYSTEM--DETROIT DIESEL ENGINES.

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF THE DIESEL ENGINE COOLING SYSTEM. TOPICS ARE PURPOSE OF THE COOLING SYSTEM, CARE MAINTENANCE OF THE COOLING SYSTEM, COOLING SYSTEM COMPONENTS, AND TROUBLESHOOTING TIPS. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL BRANCH PROGRAMED TRAINING…

  3. Combustion Performance and Exhaust Emission of DI Diesel Engine Using Various Sources of Waste Cooking Oil

    NASA Astrophysics Data System (ADS)

    Afiq, Mohd; Azuhairi, Mohd; Jazair, Wira

    2010-06-01

    In Malaysia, more than 200-tone of cooking oil are used by domestic users everyday. After frying process, about a quarter of these cooking oil was remained and drained into sewage system. This will pollutes waterways and affects the ecosystem. The use of waste cooking oil (WCO) for producing bio-diesel was considered in economical factor which current production cost of bio-diesel production is higher in Malaysia due to higher price of palm oil. Thus, the aim of this study is to investigate the most suitable source of WCO to become a main source of bio-diesel for bio-diesel production in this country. To perform this research, three type of WCO were obtained from house's kitchen, cafeteria and mamak's restaurant. In this study, prospect of these bio-diesel source was evaluated based on its combustion performance and exhaust emissions operated in diesel engine in the form of waste cooking oil methyl ester (WCOME) and have been compared with pure diesel fuel. A 0.6 liter, single-cylinder, air-cooled direct injection diesel engine was used to perform this experiment. Experiment was done at variable engine loads and constant engine speed. As the result, among three stated WCOMEs, the one collected from house's kitchen gives the best performance in term of brake specific fuel consumption (bsfc) and brake power (BP) with lowest soot emission.

  4. EFFECT OF DIESEL EXHAUST PARTICLES ON HUMAN NASAL LAVAGE CELLS AND DNA ADDUCTS

    EPA Science Inventory

    The overall aim of this study is to determine (using a nasal challenge model) the effect of diesel exhaust particles (DEP) on nasal responses including induction of inflammation, immune changes and DNA damage. We are also examining how treatment of DEP with ozone (oz-DEP)modify ...

  5. CARDIOVASCULAR AND THERMOREGULATORY RESPONSES OF UNRESTRAINED RATS EXPOSED TO FILTERED OR UNFILTERED DIESEL EXHAUST

    EPA Science Inventory

    Diesel exhaust (DE) has been associated with adverse cardiovascular and pulmonary health effects. The relative contributions of the gas-phase and particulate (PM) components of DE are less well understood. We exposed WKY rats with or without implanted radiotransmitters to air or ...

  6. Characterization of polycyclic aromatic compounds in diesel exhaust particulate extract responsible for aryl hydrocarbon receptor activity

    NASA Astrophysics Data System (ADS)

    Soontjens, Carol D.; Holmberg, Kristina; Westerholm, Roger N.; Rafter, Joseph J.

    Chemical fractions of a model diesel exhaust particulate extract, notably the fraction containing polycyclic aromatic hydrocarbons (PAH) (Fraction II), mono-nitro PAH (Fraction III), and dinitro-PAH (Fraction IV) have been shown to displace binding of 2,3,7,8-tetrachloro[1,6-[ 3H

  7. SAMPLE CHARACTERIZATION OF AUTOMOBILE AND FORKLIFT DIESEL EXHAUST PARTICLES AND COMPARATIVE PULMONARY TOXICITY IN MICE

    EPA Science Inventory


    Abstract

    Two samples of diesel exhaust particles (DEP) predominate in DEP health effects research: an automobile-source DEP (A-DEP) sample and the National Institute of Standards Technology (NIST) standard reference material (SRM 2975) generated from a forklift engine...

  8. Diesel Exhaust Modulates Ozone-induced Lung Function Decrements in Healthy Human Volunteers

    EPA Science Inventory

    The potential effects of combinations of dilute whole diesel exhaust (DE) and ozone (03), each a common component of ambient airborne pollutant mixtures, on lung function were examined. Healthy young human volunteers were exposed for 2 hr to pollutants while exercising (~50 L/min...

  9. NASAL RESPONSES IN ASTHMATIC AND NONASTHMATIC SUBJECTS FOLLOWING EXPOSURE TO DIESEL EXHAUST PARTICLES

    EPA Science Inventory

    Asthma rates have been increasing world-wide, and exposure to diesel exhaust particles may be implicated in this increase. Additionally DEP may also play a role in the increased morbidity and mortality associated with ambient airborne PM exposure. Two types of nasal responses hav...

  10. Increased Transcription of Immune and Metabolic Pathways in Naive and Allergic Mice Exposed to Diesel Exhaust

    EPA Science Inventory

    Diesel exhaust (DE) has been shown to enhance allergic sensitization in animals following high dose instillation or chronic inhalation exposure scenarios. The purpose of this study was to determine if short term exposures to diluted DE enhance allergic immune responses to antigen...

  11. EFFECTS OF DIESEL EXHAUST PARTICLES ON HUMAN ALVEOLAR MACROPHAGE RESPONSIVENESS TO LIPOPOLYSACCHARIDE

    EPA Science Inventory

    Effects of diesel exhaust particles on human alveolar macrophage responsiveness to lipopolysaccharide
    S. Mundandhara1 , S. Becker2 and M. Madden2, 1UNC Center for Environmental Medicine, Asthma, and Lung Biology, 2US EPA, NHEERL, HSD, Chapel Hill, NC, US

    Epidemiological...

  12. EFFECTS OF DIESEL EXHAUST PARTICLES ON HUMAN MACROPHAGE RESPONSIVENESS TO LIPOPOLYSACCHARIDE

    EPA Science Inventory

    EFFECTS OF DIESEL EXHAUST PARTICLES ON HUMAN MACROPHAGE RESPONSIVENESS TO LIPOPOLYSACCHARIDE
    S. Mundandhara1 and M.C. Madden2, 1UNC Center for Environmental Medicine, Asthma, and Lung Biology, 2US EPA, NHEERL, Human Studies Division, Chapel Hill, NC, USA

    Epidemiologica...

  13. EFFECT OF SHORT TERM DIESEL EXHAUST EXPOSURE ON NASAL RESPONSES TO INFLUENZA IN ALLERGIC RHINITICS.

    EPA Science Inventory

    Introduction: Recently published data suggest that diesel exhaust (DE) has special impact on allergic inflammation, suppressing Th1 and augmenting Th2 responses to allergen via oxidant stress effects on airway cells. Exposures to particulate air pollutants including DE are also a...

  14. Divergent Electrocardiographic Responses to Whole and Particle-Free Diesel Exhaust Inhalation in Spontaneously Hypertensive Rats

    EPA Science Inventory

    Diesel exhaust (DE) is a major contributor to traffic-related fine PM2.5. While inroads have been made in understanding the mechanisms of PM related health effects, DE’s complex mixture of PM, gases and volatile organics makes it difficult to determine how the constituents contri...

  15. Diesel Exhaust Activates & Primes Microglia: Air Pollution, Neuroinflammation, & Regulation of Dopaminergic Neurotoxicity

    EPA Science Inventory

    Air pollution is linked to central nervous system (CNS) disease, but the mechanisms responsible are poorly understood. Rats exposed to Diesel Exhaust (DE, 2.0,0.5, and 0 mg/m3) by inhalation over 4 weeks demonstrated elevated levels of whole brain IL-6 protein, nitrated proteins,...

  16. Application of a New Selective Noncatalytic NO Reduction System to Diesel Exhaust

    NASA Astrophysics Data System (ADS)

    Nakanishi, Yasufumi; Gong, Joon Dugk; Yoshihara, Yoshinobu; Nishiwaki, Kazuie

    The chemical gas-phase reduction process used to reduce nitric oxide (NO) in diesel engine exhaust has been applied to a high-speed, light-duty diesel engine. The chemical gas-phase reduction process involves adding methylamine (CH3NH2) in water solution to the exhaust gas as an NO reduction agent. In this study, an experimental selective noncatalytic NO reduction system designed to be used with a diesel engine was applied to evaluate this technique for practical use. The NOx reduction ratio (RNOx) of methylamine processes with and without the installation of a particulate filter was investigated. Two different mixing chambers with different volumes and residence times (0.1s and 0.17s) were also tested. Longer residence times were required to achieve a given level of NOx reduction in unfiltered exhaust, suggesting that the presence of particulate matter inhibits NO reduction. For the standard residence time (0.1s), the process achieved 64% NO reduction in unfiltered diesel exhaust, which increased to 80% NO reduction when a particle filter was fitted to the system.

  17. EFFECT OF DIESEL EXHAUST PARTICLES ON HUMAN NASAL LAVAGE CELLS AND DNA ADDUCTS

    EPA Science Inventory

    The overall aim of this study is to determine (using a nasal challenge model) the effect of diesel exhaust particles (DEP) on nasal responses including induction of inflammation, immune changes and DNA damage. We are also examining how treatment of DEP with ozone (oz-DEP)modify ...

  18. EFFECT OF DIESEL EXHAUST EXPOSURE ON MUCOSAL SENSITIZATION TO OVALBUMIN ANTIGEN.

    EPA Science Inventory

    Several studies in humans and animals have shown that diesel exhaust (DE) can act as an immunological adjuvant to increase the severity of Type I hypersensitivity immune responses. The mechanism by which DE causes these effects is unknown but thought to be associated with lung in...

  19. DNA adducts induced by in vitro activation of extracts of diesel and biodiesel exhaust particles

    EPA Science Inventory

    AbstractContext: Biodiesel and biodiesel-blend fuels offer a renewable alternative to petroleum diesel, but few data are available concerning the carcinogenic potential of biodiesel exhausts. Objectives: We compared the formation of covalent DNA adducts by the in vitro metabol...

  20. PRE-TREATMENT WITH DIESEL EXHAUST EXTRACT ALTERS INFLUENZA VIRUS REPLICATION IN LUNG EPITHELIAL CELLS

    EPA Science Inventory

    Diesel Exhaust (DE) has been demonstrated to generate inflammatory responses in the lung and modify immune responses to allergens. However, little is known about the effects of DE on common respiratory viral infections. We examined whether exposure to DE extracts (DEE) modifies i...

  1. EXPOSURE TO DIESEL EXHAUST ENHANCES THE SEVERITY OF AN ONGOING INFLUENZA INFECTION.

    EPA Science Inventory

    Numerous studies have shown that air pollutants including diesel exhaust (DE), alter host defense responses to decrease resistance to respiratory infection. The purpose of this study was to evaluate the effects of DE exposure on the severity of an ongoing influenza infection in ...

  2. EFFECTS OF DIESEL EXHAUST ON TLR3 SIGNALING IN RESPIRATORY EPITHELIAL CELLS

    EPA Science Inventory

    There are a variety of intrinsic as well as extrinsic factors, such as exposure to air pollution that can affect the pathogenesis of respiratory infections. Diesel exhaust (DE) emissions can significantly contribute to air pollution levels and exposure to DE can alter host defens...

  3. EFFECTS OF DIESEL EXHAUST ON TLR3 EXPRESSION AND SIGNALING IN MICE

    EPA Science Inventory

    There are a variety of intrinsic as well as extrinsic factors, such as exposure to air pollution that can affect the pathogenesis of respiratory infections. Exposure to diesel exhaust (DE) emissions can alter host defense and immune responses and we have previously demonstrated t...

  4. The Involvement of Superoxide and Nitric Oxide in Inflammation-Enhanced Diesel Exhaust Particle Cytotoxicity

    EPA Science Inventory

    Thirty-four million Americans have asthma, a chronic inflammatory lung disease. Although the mechanisms are unclear, epidemiologic studies show that exposure of asthmatics to air pollutants, like diesel exhaust particles (DEP), is more likely to result in adverse health effects....

  5. NASAL RESPONSES OF ASTHMATIC AND NON-ASTHMATIC VOLUNTEERS TO DIESEL EXHAUST PARTICLES

    EPA Science Inventory

    Asthma rates have been increasing world-wide, and exposure to diesel exhaust particles (DEP) may be implicated in this increase. Additionally DEP may also play a role in the increased morbidity and mortality associated with ambient airborne PM exposure. Two types of nasal respons...

  6. A NOVEL TECHNIQUE FOR QUANTITATIVE ESTIMATION OF UPTAKE OF DIESEL EXHAUST PARTICLES BY LUNG CELLS

    EPA Science Inventory

    While airborne particulates like diesel exhaust particulates (DEP) exert significant toxicological effects on lungs, quantitative estimation of accumulation of DEP inside lung cells has not been reported due to a lack of an accurate and quantitative technique for this purpose. I...

  7. Estimation of the diesel exhaust exposures of railroad workers. I. Current exposures

    SciTech Connect

    Woskie, S.R.; Smith, T.J.; Hammond, S.K.; Schenker, M.B.; Garshick, E.; Speizer, F.E.

    1988-01-01

    As a part of a series of epidemiological studies of railroad workers, measurements were made to characterize workers' exposures to diesel exhaust. Since diesel exhaust is not a single compound, an exposure marker was sought. The personal exposures to respirable particulate matter (RPM) of over 530 workers in 39 common jobs were measured in four U.S. railroads over a three-year period. Significant amounts of cigarette smoke (20-90%) were found in many of these samples. Therefore, the respirable particulate concentration, adjusted to remove the fraction of cigarette smoke (ARP), was chosen as a marker of diesel exhaust exposures. The geometric mean exposures to ARP ranged from 17 micrograms/m3 for clerks to 134 micrograms/m3 for locomotive shop workers. Significant interrailroad variations were observed in some job groups indicating that the different facilities, equipment, and work practices found among the railroads can affect a worker's exposure to diesel exhaust. Climate was also found to have a significant effect on exposure in some job groups.

  8. DIESEL EXHAUST ACTIVATES REDOX-SENSITIVE TRANSCRIPTION FACTORS AND KINASES IN HUMAN AIRWAYS

    EPA Science Inventory

    Diesel exhaust (DE) is a major component of airborne particulate matter. In previous studies we have described the acute inflammatory response of the human airway to inhaled DE. This was characterized by neutrophil, mast cell, and lymphocyte infiltration into the bronchial mucosa...

  9. Diesel Exhaust Modulates Ozone-induced Lung Function Decrements in Healthy Human Volunteers

    EPA Science Inventory

    The potential effects of combinations of dilute whole diesel exhaust (DE) and ozone (03), each a common component of ambient airborne pollutant mixtures, on lung function were examined. Healthy young human volunteers were exposed for 2 hr to pollutants while exercising (~50 L/min...

  10. Cardiovascular effects of diesel exhaust and ozone in a multi-pollutant context

    EPA Science Inventory

    The cardiovascular effects of two common pollutants, diesel exhaust (DE) and ozone (O3), were examined alone and in combination. Healthy subjects (n=15) were exposed for 2 hrs with intermittent, moderate exercise on Day 1 to 0.3 ppm O3, 300 µg/m3 DE, both O3 and DE, or fil...

  11. DECREASED PRODUCTION OF SURFACTANT PROTEINS AFTER DIESEL EXHAUST EXPOSURE INCREASES SUSCEPTIBILITY TO INFLUENZA INFECTION

    EPA Science Inventory

    Pulmonary surfactant proteins A and D (SP-A and SP-D), termed collectins, enhance the opsonization of foreign particles and pathogens by phagocytic cells. Inhaled pollutants such as diesel exhaust (DE) have a possible role in suppressing the production of surfactant proteins whic...

  12. EFFECTS OF DIESEL EXHAUST ON TLR3 EXPRESSION AND SIGNALING IN MICE

    EPA Science Inventory

    There are a variety of intrinsic as well as extrinsic factors, such as exposure to air pollution that can affect the pathogenesis of respiratory infections. Exposure to diesel exhaust (DE) emissions can alter host defense and immune responses and we have previously demonstrated t...

  13. DIESEL EXHAUST PARTICLE INDUCED GENE EXPRESSION CHANGES IN A MURINE MUCOSAL SENSITIZATION MODEL

    EPA Science Inventory

    Studies in humans and animals have shown diesel exhaust particles (DEP) can act as an immunological adjuvant to enhance the development of allergic lung disease and this effect is influenced by the chemical composition of the DEP. The adjuvancy of NIST SRM 2975 (NDEP) generated...

  14. DIESEL EXHAUST PARTICLE-INDUCED EPITHELIAL TOXICITY IS MODULATED BY UV-IRRADIATION -- NCSU

    EPA Science Inventory

    Asthma is a chronic inflammatory disorder of the airways affecting nearly 20 million individuals in the U.S alone. Asthmatic symptoms can be exacerbated by environmental insults like exposure to particulate matter (PM). Diesel exhaust particles (DEP) account for a portion of PM...

  15. Modulation of pulmonary inflammatory responses and anti-microbial defenses in mice exposed to diesel exhaust

    EPA Science Inventory

    Abstract: Diesel exhaust (DE) is a major component of urban air pollution and has been shown to increase the severity of infectious and allergic lung disease. The purpose of this study was to evaluate the effects of DE exposure on pulmonary inflammation, mediator production and ...

  16. DIESEL EXHAUST PARTICLE-INDUCED EPITHELIAL TOXICITY IS MODULATED BY UV-IRRADIATION

    EPA Science Inventory

    Asthma is a chronic inflammatory disorder of the airways affecting nearly 20 million individuals in the U.S alone. Asthmatic symptoms can be exacerbated by environmental insults like exposure to particulate matter (PM). Diesel exhaust particles (DEP) account for a significant por...

  17. Increased Transcription of Immune and Metabolic Pathways in Naive and Allergic Mice Exposed to Diesel Exhaust

    EPA Science Inventory

    Diesel exhaust (DE) has been shown to enhance allergic sensitization in animals following high dose instillation or chronic inhalation exposure scenarios. The purpose of this study was to determine if short term exposures to diluted DE enhance allergic immune responses to antigen...

  18. EFFECTS OF DIESEL EXHAUST PARTICLES ON HUMAN MACROPHAGE RESPONSIVENESS TO LIPOPOLYSACCHARIDE

    EPA Science Inventory

    EFFECTS OF DIESEL EXHAUST PARTICLES ON HUMAN MACROPHAGE RESPONSIVENESS TO LIPOPOLYSACCHARIDE
    S. Mundandhara1 and M.C. Madden2, 1UNC Center for Environmental Medicine, Asthma, and Lung Biology, 2US EPA, NHEERL, Human Studies Division, Chapel Hill, NC, USA

    Epidemiologica...

  19. DIFFERENTIAL CARDIAC SUSCEPTIBILITY OF WISTAR KYOTO (WKY) AND SPONTANEOUSLY HYPERTENSIVE RATS (SHR) TO DIESEL EXHAUST EXPOSURE

    EPA Science Inventory

    Exposure to diesel exhaust particles (DEP) is linked to increases in cardiovascular effects. This is enhanced in individuals with pre-existing disease. Animal models of cardiovascular disease are used to study this susceptibility. The heart is rich in mitochondria, which produce ...

  20. DIESEL EXHAUST PARTICLE-INDUCED EPITHELIAL TOXICITY IS MODULATED BY UV-IRRADIATION

    EPA Science Inventory

    Asthma is a chronic inflammatory disorder of the airways affecting nearly 20 million individuals in the U.S alone. Asthmatic symptoms can be exacerbated by environmental insults like exposure to particulate matter (PM). Diesel exhaust particles (DEP) account for a significant por...

  1. EFFECT OF DIESEL EXHAUST EXPOSURE ON MUCOSAL SENSITIZATION TO OVALBUMIN ANTIGEN.

    EPA Science Inventory

    Several studies in humans and animals have shown that diesel exhaust (DE) can act as an immunological adjuvant to increase the severity of Type I hypersensitivity immune responses. The mechanism by which DE causes these effects is unknown but thought to be associated with lung in...

  2. Ice-nucleating particle emissions from photochemically aged diesel and biodiesel exhaust

    NASA Astrophysics Data System (ADS)

    Schill, G. P.; Jathar, S. H.; Kodros, J. K.; Levin, E. J. T.; Galang, A. M.; Friedman, B.; Link, M. F.; Farmer, D. K.; Pierce, J. R.; Kreidenweis, S. M.; DeMott, P. J.

    2016-05-01

    Immersion-mode ice-nucleating particle (INP) concentrations from an off-road diesel engine were measured using a continuous-flow diffusion chamber at -30°C. Both petrodiesel and biodiesel were utilized, and the exhaust was aged up to 1.5 photochemically equivalent days using an oxidative flow reactor. We found that aged and unaged diesel exhaust of both fuels is not likely to contribute to atmospheric INP concentrations at mixed-phase cloud conditions. To explore this further, a new limit-of-detection parameterization for ice nucleation on diesel exhaust was developed. Using a global-chemical transport model, potential black carbon INP (INPBC) concentrations were determined using a current literature INPBC parameterization and the limit-of-detection parameterization. Model outputs indicate that the current literature parameterization likely overemphasizes INPBC concentrations, especially in the Northern Hemisphere. These results highlight the need to integrate new INPBC parameterizations into global climate models as generalized INPBC parameterizations are not valid for diesel exhaust.

  3. Diesel Exhaust Activates & Primes Microglia: Air Pollution, Neuroinflammation, & Regulation of Dopaminergic Neurotoxicity

    EPA Science Inventory

    Air pollution is linked to central nervous system (CNS) disease, but the mechanisms responsible are poorly understood. Rats exposed to Diesel Exhaust (DE, 2.0,0.5, and 0 mg/m3) by inhalation over 4 weeks demonstrated elevated levels of whole brain IL-6 protein, nitrated proteins,...

  4. Effects Of Combinations of Ozone and Diesel Exhaust Exposures On Blood, Cardiac, And Lung Endpoints

    EPA Science Inventory

    Human subjects were exposed to combinations of 300 ppb ozone (03) and 300 ug/m3 diesel exhaust (DE) to examine if synergistic effects were observed. Subjects received either filtered air (FA), 03, DE, or DE+03 on Day 1, followed by only 03 exposures on Day 2, and a follow-up on D...

  5. SAMPLE CHARACTERIZATION OF AUTOMOBILE AND FORKLIFT DIESEL EXHAUST PARTICLES AND COMPARATIVE PULMONARY TOXICITY IN MICE

    EPA Science Inventory


    Abstract

    Two samples of diesel exhaust particles (DEP) predominate in DEP health effects research: an automobile-source DEP (A-DEP) sample and the National Institute of Standards Technology (NIST) standard reference material (SRM 2975) generated from a forklift engine...

  6. NANOMETER DIESEL EXHAUST PARTICLES ARE NEUROTOXIC TO DOPAMINERGIC NEURONS THROUGH MICROGLIAL ACTIVATION.

    EPA Science Inventory

    NANOMETER DIESEL EXHAUST PARTICLES ARE NEUROTOXIC TO DOPAMINERGIC NEURONS THROUGH MICROGLIAL ACTIVATION. M.L. Block1,2, X. Wu1, P. Zhong1, G. Li1, T. Wang1, J.S. Hong1 & B.Veronesi.2
    1The Laboratory of Pharmacology and Chemistry, NIEHS, RTP, NC and 2 National Health and Envi...

  7. DIFFERENTIAL CARDIAC SUSCEPTIBILITY OF WISTAR KYOTO (WKY) AND SPONTANEOUSLY HYPERTENSIVE RATS (SHR) TO DIESEL EXHAUST EXPOSURE

    EPA Science Inventory

    Exposure to diesel exhaust particles (DEP) is linked to increases in cardiovascular effects. This is enhanced in individuals with pre-existing disease. Animal models of cardiovascular disease are used to study this susceptibility. The heart is rich in mitochondria, which produce ...

  8. The Involvement of Superoxide and Nitric Oxide in Inflammation-Enhanced Diesel Exhaust Particle Cytotoxicity

    EPA Science Inventory

    Thirty-four million Americans have asthma, a chronic inflammatory lung disease. Although the mechanisms are unclear, epidemiologic studies show that exposure of asthmatics to air pollutants, like diesel exhaust particles (DEP), is more likely to result in adverse health effects....

  9. DECREASED PRODUCTION OF SURFACTANT PROTEINS AFTER DIESEL EXHAUST EXPOSURE INCREASES SUSCEPTIBILITY TO INFLUENZA INFECTION

    EPA Science Inventory

    Pulmonary surfactant proteins A and D (SP-A and SP-D), termed collectins, enhance the opsonization of foreign particles and pathogens by phagocytic cells. Inhaled pollutants such as diesel exhaust (DE) have a possible role in suppressing the production of surfactant proteins whic...

  10. Diesel Exhaust-Induced Pulmonary and Cardiovascular Impairment: The Role of Hypertension Intervention

    EPA Science Inventory

    Background–Exposure to diesel exhaust (DE) particles and associated gases is linked to cardiovascular impairments; however the susceptibility of hypertensive individuals is less well understood. Objective–1) To determine cardiopulmonary effects of gas-phase versus whole-DE, and 2...

  11. Divergent Electrocardiographic Responses to Whole and Particle-Free Diesel Exhaust Inhalation in Spontaneously Hypertensive Rats

    EPA Science Inventory

    Diesel exhaust (DE) is a major contributor to traffic-related fine PM2.5. While inroads have been made in understanding the mechanisms of PM related health effects, DE’s complex mixture of PM, gases and volatile organics makes it difficult to determine how the constituents contri...

  12. A NOVEL TECHNIQUE FOR QUANTITATIVE ESTIMATION OF UPTAKE OF DIESEL EXHAUST PARTICLES BY LUNG CELLS

    EPA Science Inventory

    While airborne particulates like diesel exhaust particulates (DEP) exert significant toxicological effects on lungs, quantitative estimation of accumulation of DEP inside lung cells has not been reported due to a lack of an accurate and quantitative technique for this purpose. I...

  13. COMPARISON OF ON AND OFF ROAD DIESEL EXHAUST SOURCES ON THE SUSCEPTIBILITY TO AN INFLUENZA INFECTION.

    EPA Science Inventory

    Diesel exhaust (DE), a major component of urban air pollution, and its modulatory role in human susceptibility to respiratory infections is of great concern. The purpose of this study was to evaluate the effects of on- and off-road sources of DE exposure on the severity of an ...

  14. CARDIOVASCULAR AND THERMOREGULATORY RESPONSES OF UNRESTRAINED RATS EXPOSED TO FILTERED OR UNFILTERED DIESEL EXHAUST

    EPA Science Inventory

    Diesel exhaust (DE) has been associated with adverse cardiovascular and pulmonary health effects. The relative contributions of the gas-phase and particulate (PM) components of DE are less well understood. We exposed WKY rats with or without implanted radiotransmitters to air or ...

  15. COMPARISON OF ON AND OFF ROAD DIESEL EXHAUST SOURCES ON THE SUSCEPTIBILITY TO AN INFLUENZA INFECTION.

    EPA Science Inventory

    Diesel exhaust (DE), a major component of urban air pollution, and its modulatory role in human susceptibility to respiratory infections is of great concern. The purpose of this study was to evaluate the effects of on- and off-road sources of DE exposure on the severity of an ...

  16. EXPOSURE TO DIESEL EXHAUST ENHANCES THE SEVERITY OF AN ONGOING INFLUENZA INFECTION.

    EPA Science Inventory

    Numerous studies have shown that air pollutants including diesel exhaust (DE), alter host defense responses to decrease resistance to respiratory infection. The purpose of this study was to evaluate the effects of DE exposure on the severity of an ongoing influenza infection in ...

  17. Modulation of pulmonary inflammatory responses and anti-microbial defenses in mice exposed to diesel exhaust

    EPA Science Inventory

    Abstract: Diesel exhaust (DE) is a major component of urban air pollution and has been shown to increase the severity of infectious and allergic lung disease. The purpose of this study was to evaluate the effects of DE exposure on pulmonary inflammation, mediator production and ...

  18. EFFECT OF SHORT TERM DIESEL EXHAUST EXPOSURE ON NASAL RESPONSES TO INFLUENZA IN ALLERGIC RHINITICS.

    EPA Science Inventory

    Introduction: Recently published data suggest that diesel exhaust (DE) has special impact on allergic inflammation, suppressing Th1 and augmenting Th2 responses to allergen via oxidant stress effects on airway cells. Exposures to particulate air pollutants including DE are also a...

  19. Effects Of Combinations of Ozone and Diesel Exhaust Exposures On Blood, Cardiac, And Lung Endpoints

    EPA Science Inventory

    Human subjects were exposed to combinations of 300 ppb ozone (03) and 300 ug/m3 diesel exhaust (DE) to examine if synergistic effects were observed. Subjects received either filtered air (FA), 03, DE, or DE+03 on Day 1, followed by only 03 exposures on Day 2, and a follow-up on D...

  20. BIOASSAY-DIRECTED FRACTIONAL AND SALMONELLA MUTAGENICITY OF AUTOMOBILE AND FORKLIFT DIESEL EXHAUST PARTICLES

    EPA Science Inventory



    Abstract

    Many pulmonary toxicity studies of diesel exhaust particles (DEP) have used an
    automobile-generated sample (A-DEP) whose mutagenicity has not been reported. In contrast,
    rnany inutagenicity studies of DEP have used a forklift-generated sample (SRM ...

  1. NANOMETER DIESEL EXHAUST PARTICLES ARE NEUROTOXIC TO DOPAMINERGIC NEURONS THROUGH MICROGLIAL ACTIVATION.

    EPA Science Inventory

    NANOMETER DIESEL EXHAUST PARTICLES ARE NEUROTOXIC TO DOPAMINERGIC NEURONS THROUGH MICROGLIAL ACTIVATION. M.L. Block1,2, X. Wu1, P. Zhong1, G. Li1, T. Wang1, J.S. Hong1 & B.Veronesi.2
    1The Laboratory of Pharmacology and Chemistry, NIEHS, RTP, NC and 2 National Health and Envi...

  2. NASAL RESPONSES OF ASTHMATIC AND NON-ASTHMATIC VOLUNTEERS TO DIESEL EXHAUST PARTICLES

    EPA Science Inventory

    Asthma rates have been increasing world-wide, and exposure to diesel exhaust particles (DEP) may be implicated in this increase. Additionally DEP may also play a role in the increased morbidity and mortality associated with ambient airborne PM exposure. Two types of nasal respons...

  3. Markers of exposure to diesel exhaust in railroad workers. Research report

    SciTech Connect

    Schenker, M.B.; Samuels, S.J.; Kado, N.Y.; Hammond, S.K.; Smith, T.J.

    1990-01-01

    The study measured the exposure of railroad workers to diesel exhaust and environmental tobacco smoke by using personal air samples taken over two consecutive work shifts. Urine samples were collected from 87 subjects at the end of the study work shifts and were analyzed for markers of cigarette smoking (nicotine, cotinine) and for mutagenicity, using a sensitive microsuspension assay (Salmonella strain TA98 with or without S9 enzyme). Among smokers, a dose-response relationship was observed between urinary mutagenicity and the number of cigarettes smoked on the study day. After cigarette smoking was controlled for, no association was present between diesel exhaust exposure and urinary mutagenicity. Among nonsmokers, detectable concentrations of mutagens were present in the urine, but no association could be found between markers of diesel exhaust or environmental tobacco smoke and urinary mutagenicity. It was concluded that the mutagens associated with the levels of exposure to diesel exhaust or environmental tobacco smoke in the study were undetectable in the urine.

  4. DNA adducts induced by in vitro activation of extracts of diesel and biodiesel exhaust particles

    EPA Science Inventory

    AbstractContext: Biodiesel and biodiesel-blend fuels offer a renewable alternative to petroleum diesel, but few data are available concerning the carcinogenic potential of biodiesel exhausts. Objectives: We compared the formation of covalent DNA adducts by the in vitro metabol...

  5. DIESEL EXHAUST ACTIVATES REDOX-SENSITIVE TRANSCRIPTION FACTORS AND KINASES IN HUMAN AIRWAYS

    EPA Science Inventory

    Diesel exhaust (DE) is a major component of airborne particulate matter. In previous studies we have described the acute inflammatory response of the human airway to inhaled DE. This was characterized by neutrophil, mast cell, and lymphocyte infiltration into the bronchial mucosa...

  6. FACTORS THAT INFLUENCE THE RELATIVE POTENCY OF DIESEL EXHAUST PARTICLES AS ADJUVANTS IN ALLERGIC AIRWAY DISEASE

    EPA Science Inventory

    Description: Studies have shown that diesel exhaust particles (DEP) worsen respiratory diseases including allergic asthma. The adjuvant effects of DEP in the airways have been widely reported; however, the precise determinants and mechanisms of these effects are ill-defined. S...

  7. Cardiovascular effects of diesel exhaust and ozone in a multi-pollutant context

    EPA Science Inventory

    The cardiovascular effects of two common pollutants, diesel exhaust (DE) and ozone (O3), were examined alone and in combination. Healthy subjects (n=15) were exposed for 2 hrs with intermittent, moderate exercise on Day 1 to 0.3 ppm O3, 300 µg/m3 DE, both O3 and DE, or fil...

  8. EFFECTS OF DIESEL EXHAUST PARTICLES ON HUMAN ALVEOLAR MACROPHAGE RESPONSIVENESS TO LIPOPOLYSACCHARIDE

    EPA Science Inventory

    Effects of diesel exhaust particles on human alveolar macrophage responsiveness to lipopolysaccharide
    S. Mundandhara1 , S. Becker2 and M. Madden2, 1UNC Center for Environmental Medicine, Asthma, and Lung Biology, 2US EPA, NHEERL, HSD, Chapel Hill, NC, US

    Epidemiological...

  9. EFFECTS OF DIESEL EXHAUST ON TLR3 SIGNALING IN RESPIRATORY EPITHELIAL CELLS

    EPA Science Inventory

    There are a variety of intrinsic as well as extrinsic factors, such as exposure to air pollution that can affect the pathogenesis of respiratory infections. Diesel exhaust (DE) emissions can significantly contribute to air pollution levels and exposure to DE can alter host defens...

  10. PRE-TREATMENT WITH DIESEL EXHAUST EXTRACT ALTERS INFLUENZA VIRUS REPLICATION IN LUNG EPITHELIAL CELLS

    EPA Science Inventory

    Diesel Exhaust (DE) has been demonstrated to generate inflammatory responses in the lung and modify immune responses to allergens. However, little is known about the effects of DE on common respiratory viral infections. We examined whether exposure to DE extracts (DEE) modifies i...

  11. DIESEL EXHAUST PARTICLE INDUCED GENE EXPRESSION CHANGES IN A MURINE MUCOSAL SENSITIZATION MODEL

    EPA Science Inventory

    Studies in humans and animals have shown diesel exhaust particles (DEP) can act as an immunological adjuvant to enhance the development of allergic lung disease and this effect is influenced by the chemical composition of the DEP. The adjuvancy of NIST SRM 2975 (NDEP) generated...

  12. DIESEL EXHAUST PARTICLE COMPOSITION AND THE METHOD OF SONICATION INFLUENCE THE ADJUVANCY EFFECT AND TARC PRODUCTION

    EPA Science Inventory

    Numerous reports have shown diesel exhaust particles (DEP) can act as an immunological adjuvant in asthma. Recent interest has focused on thymus and activation-regulated chemokine (TARC) as an important modulator of this effect. This study evaluated the adjuvancy effects of thr...

  13. Diesel Exhaust-Induced Pulmonary and Cardiovascular Impairment: The Role of Hypertension Intervention

    EPA Science Inventory

    Background–Exposure to diesel exhaust (DE) particles and associated gases is linked to cardiovascular impairments; however the susceptibility of hypertensive individuals is less well understood. Objective–1) To determine cardiopulmonary effects of gas-phase versus whole-DE, and 2...

  14. DIESEL EXHAUST PARTICLE-INDUCED EPITHELIAL TOXICITY IS MODULATED BY UV-IRRADIATION -- NCSU

    EPA Science Inventory

    Asthma is a chronic inflammatory disorder of the airways affecting nearly 20 million individuals in the U.S alone. Asthmatic symptoms can be exacerbated by environmental insults like exposure to particulate matter (PM). Diesel exhaust particles (DEP) account for a portion of PM...

  15. NASAL RESPONSES IN ASTHMATIC AND NONASTHMATIC SUBJECTS FOLLOWING EXPOSURE TO DIESEL EXHAUST PARTICLES

    EPA Science Inventory

    Asthma rates have been increasing world-wide, and exposure to diesel exhaust particles may be implicated in this increase. Additionally DEP may also play a role in the increased morbidity and mortality associated with ambient airborne PM exposure. Two types of nasal responses hav...

  16. Alkyl polycyclic aromatic hydrocarbons emissions in diesel/biodiesel exhaust

    NASA Astrophysics Data System (ADS)

    Casal, Carina S.; Arbilla, Graciela; Corrêa, Sergio M.

    2014-10-01

    Polycyclic aromatic hydrocarbons (PAHs) are widely studied in environmental matrices, such as air, water, soil and sediment, because of their toxicity, mutagenicity and carcinogenicity. Because of these properties, the environmental agencies of developed countries have listed sixteen PAHs as priority pollutants. Few countries have limits for these compounds for ambient air, but they only limit emissions from stationary and mobile sources and occupational areas. There are several studies to specifically address the 16 priority PAHs and very little for the alkyl PAHs. These compounds are more abundant, more persistent and frequently more toxic than the non-alkylated PAHs, and the toxicity increases with the number of alkyl substitutions on the aromatic ring. In this study, a method was developed for the analysis of PAHs and alkyl PAHs by using a GC-MS and large injection volume injection coupled with program temperature vaporisation, which allows for limits of detection below 1.0 ng μL-1. Several variables were tested, such as the injection volume, injection velocity, injector initial temperature, duration of the solvent split and others. This method was evaluated in samples from particulate matter from the emissions of engines employing standard diesel, commercial diesel and biodiesel B20. Samples were collected on a dynamometer bench for a diesel engine cycle and the results ranged from 0.5 to 96.9 ng mL-1, indicating that diesel/biodiesel makes a significant contribution to the formation of PAHs and alkyl PAHs.

  17. Pretreatment with Antioxidants Augments the Acute Arterial Vasoconstriction Caused by Diesel Exhaust Inhalation

    PubMed Central

    Jansen, Karen L.; Cosselman, Kristen E.; Trenga, Carol A.; Stapleton, Pat L.; Allen, Jason; Peretz, Alon; Olives, Casey

    2016-01-01

    Rationale: Diesel exhaust inhalation, which is the model traffic-related air pollutant exposure, is associated with vascular dysfunction. Objectives: To determine whether healthy subjects exposed to diesel exhaust exhibit acute vasoconstriction and whether this effect could be modified by the use of antioxidants or by common variants in the angiotensin II type 1 receptor (AGTR1) and other candidate genes. Methods: In a genotype-stratified, double-blind, four-way crossover study, 21 healthy adult subjects were exposed at rest in a randomized, balanced order to diesel exhaust (200 μg/m3 particulate matter with an aerodynamic diameter ≤ 2.5 μm [PM2.5]) and filtered air, and to pretreatment with antioxidants (N-acetylcysteine and ascorbate) and placebo. Before and after each exposure, brachial artery diameter (BAd) was assessed using ultrasound. Changes in BAd were compared across pretreatment and exposure sessions. Gene–exposure interactions were evaluated in the AGTR1 A1166C polymorphism, on which recruitment was stratified, and other candidate genes, including TRPV1 and GSTM1. Measurements and Main Results: Compared with filtered air, exposure to diesel exhaust resulted in a significant reduction in BAd (mean, −0.09 mm, 95% confidence interval [CI], −0.01 to −0.17; P = 0.03). Pretreatment with antioxidants augmented diesel exhaust–related vasoconstriction with a mean change in BAd of −0.18 mm (95% CI, −0.28 to −0.07 mm; P = 0.001). Diesel exhaust–related vasoconstriction was primarily observed in the variant alleles of AGTR1 and TRPV1. No association was found between diesel exhaust inhalation and flow-mediated dilation. Conclusions: We confirmed that short-term exposure to diesel exhaust in healthy subjects is associated with acute vasoconstriction in a conductance artery and found suggestive evidence of involvement of nociception and renin–angiotensin systems in this effect. Pretreatment with an antioxidant regimen increased

  18. Effects of the biodiesel blend fuel on aldehyde emissions from diesel engine exhaust

    NASA Astrophysics Data System (ADS)

    Peng, Chiung-Yu; Yang, Hsi-Hsien; Lan, Cheng-Hang; Chien, Shu-Mei

    Interest in use of biodiesel fuels derived from vegetable oils or animal fats as alternative fuels for petroleum-based diesels has increased due to biodiesels having similar properties of those of diesels, and characteristics of renewability, biodegradability and potential beneficial effects on exhaust emissions. Generally, exhaust emissions of regulated pollutants are widely studied and the results favor biodiesels on CO, HC and particulate emissions; however, limited and inconsistent data are showed for unregulated pollutants, such as carbonyl compounds, which are also important indicators for evaluating available vehicle fuels. For better understanding biodiesel, this study examines the effects of the biodiesel blend fuel on aldehyde chemical emissions from diesel engine exhausts in comparison with those from the diesel fuel. Test engines (Mitsubishi 4M40-2AT1) with four cylinders, a total displacement of 2.84 L, maximum horsepower of 80.9 kW at 3700 rpm, and maximum torque of 217.6 N m at 2000 rpm, were mounted and operated on a Schenck DyNAS 335 dynamometer. Exhaust emission tests were performed several times for each fuel under the US transient cycle protocol from mileages of 0-80,000 km with an interval of 20,000 km, and two additional measurements were carried out at 40,000 and 80,000 km after maintenance, respectively. Aldehyde samples were collected from diluted exhaust by using a constant volume sampling system. Samples were extracted and analyzed by the HPLC/UV system. Dominant aldehydes of both fuels' exhausts are formaldehyde and acetaldehyde. These compounds together account for over 75% of total aldehyde emissions. Total aldehyde emissions for B20 (20% waste cooking oil biodiesel and 80% diesel) and diesel fuels are in the ranges of 15.4-26.9 mg bhp-h -1 and 21.3-28.6 mg bhp-h -1, respectively. The effects of increasing mileages and maintenance practice on aldehyde emissions are insignificant for both fuels. B20 generates slightly less emission than

  19. Predictive models for deposition of inhaled diesel exhaust particles in humans and laboratory species.

    PubMed

    Yu, C P; Xu, G B

    1987-01-01

    Mathematical and computer models of the respiratory tracts of human beings and of laboratory animals (rats, hamsters, guinea pigs) were used to estimate the deposition patterns of inhaled diesel exhaust particles from automobile emissions. The accuracy of these models was tested by comparing the calculated depositions in laboratory animals with actual laboratory data. Our goal was to be able to predict the relation between exposure to diesel exhaust particles and the deposition of these particles in the lungs of humans of various ages. Diesel exhaust particles are aggregates with a mass median aerodynamic diameter of approximately 0.2 micron. Their actual size depends on the conditions under which they are generated. Using an appropriate particle model, we derived mathematical expressions that describe the effects of diffusion, sedimentation, impaction, and interception on the deposition of these particles. Because of their small size, we found that most diesel exhaust particles deposited through diffusion, and that the role of the other mechanisms was minor. Anatomical models of the human lung from birth to adulthood, as well as models of the lungs of laboratory species were formulated mathematically using available morphometric data. We used these lung models, together with the corresponding ventilation conditions of each species, to calculate deposition of diesel exhaust particles in the lungs. Under normal breathing conditions, we calculated that 7 to 13 percent (depending on particle size) of inhaled diesel exhaust particles deposit in the alveolar region of the adult human lung. Although the breathing mode (nose or mouth breathing) did not appear to affect alveolar deposition, increasing the minute ventilation (the number of breaths per minute multiplied by the tidal volume) increased alveolar deposition significantly. The calculated deposition patterns for diesel exhaust particles in younger humans (under age 25) were similar. However, with the exception of

  20. Cytotoxicity of diesel exhaust particle extract--a comparison among five diesel passenger cars of different manufactures.

    PubMed

    Li, A P; Royer, R E; Brooks, A L; McClellan, R O

    1982-01-01

    The cytotoxicity of the dichloromethane extracts of diesel exhaust particles from passenger cars of different manufactures was studied in cultured chinese hamster ovary cells. While exhaust particles from diesel cars of the same make and model yielded extracts of similar cytotoxicity, those from cars of different manufactures yielded extracts with a 3-fold difference in cytotoxicity. Using data on the percentages of extractable organic chemicals and total exhaust particulate emission rates, the emission rate of cytotoxin into the environment from the different cars were calculated. Of the 3 factors that could affect the emission rate of cytotoxins (cytotoxicity of the extractable chemicals, amount of cytotoxins per particle, and particulate emission rate), the differences in particulate emission rates were found to be the predominant factors leading to the differences in the emission rate of cytotoxins. Our findings indicate the need to consider other chemical and physical data, not just the activities of the extracts, when the potential health risk due to the exhaust emissions of different automobiles are compared.

  1. The effects of operating conditions on particulate matter exhaust from diesel locomotive engines.

    PubMed

    Park, Duckshin; Yoon, Younghun; Kwon, Soon-Bark; Jeong, Wootae; Cho, Youngmin; Lee, Kiyoung

    2012-03-01

    Numerous reports have shown that fine particulates threaten human health. Since their health impact is associated with both mass and number concentrations, it is necessary to evaluate the emission standards for particulate mass accordingly. This study examined the particulate matter characteristics of diesel locomotive engine exhaust at various engine ratings. Diesel engine exhaust was collected via a dilution tunnel and the concentration and size distribution of fine particles were measured by a scanning mobility particle sizer. Exhaust gasses were measured simultaneously by a stack sampler. The maximum carbon monoxide emission was reached at 59% of the maximum rating, after which emissions decreased. The particle count median diameter increased with the engine rating, until a maximum was reached at 40% of the maximum rating. Most exhaust particles were nanoparticles with the nuclei mode range, a particle diameter (D(P))<50 nm. The increase in particles with the accumulation mode range, 50diesel engines mainly generate fine particles, exhaust particle mass and size distribution should be considered in emission regulations.

  2. Bithermal Low-Cycle Fatigue Evaluation of Automotive Exhaust System Alloy SS409

    NASA Technical Reports Server (NTRS)

    Lu, Gui-Ying; Behling, Mike B.; Halford, Gary R.

    2000-01-01

    This investigation provides, for the first time, cyclic strainrange-controlled, thermomechanical fatigue results for the ferritic stainless steel alloy SS409. The alloy has seen extensive application for automotive exhaust system components. The data were generated to calibrate the Total Strain Version of the Strainrange Partitioning (TS-SRP) method for eventual application to the design and durability assessment of automotive exhaust systems. The thermomechanical cyclic lifetime and cyclic stress-strain constitutive behavior for alloy SS409 were measured using bithermal tests cycling between isothermal extremes of 400 and 800 C. Lives ranged up to 10,000 cycles to failure with hold-times of 0.33 to 2.0 minutes. The bithermal fatigue behavior is compared to isothermal, strain-controlled fatigue behavior at both 400 and 800 C. Thermomechanical cycling was found to have a profound detrimental influence on the fatigue failure resistance of SS409 compared to isothermal cycling. Supplementary bithermal cyclic stress-strain constitutive tests with hold-times ranging from 40 seconds up to 1.5 hours were conducted to calibrate the TS-SRP equation for extrapolation to longer lifetime predictions. Observed thermomechanical (bithermal) fatigue lives correlated well with lives calculated using the calibrated TS-SRP equations: 70% of the bithermal fatigue data fall within a factor of 1.2 of calculated life; 85% within a factor of 1.4; and 100% within a factor of 1.8.

  3. Treatment of diesel exhaust using novel oxidation catalysts

    SciTech Connect

    Voss, K.E.; Lamper, J.K.; Farrauto, R.J.; Heck, R.M.; Rice, G.W.

    1993-12-31

    The authors have developed a flow through Diesel Oxidation Catalyst that removes 60-80% of the soluble organic fraction (SOF) from diesel truck engine particulate emissions. This unique catalyst exhibits high reduction in total particulate matter (TPM) emissions and low sulfate formation using a novel proprietary washcoat formulation with low platinum levels. This paper describes performance results from engine emissions tests for TPM, SOF, and gas phase HC and CO reduction for fresh and aged catalysts under steady state an transient operating conditions. Using a novel laboratory technique, the authors simulate adsorption and subsequent catalytic combustion of the SOF. The technique allows for the analysis of all the liquid and gaseous products produced and the overall selectivity of the catalytic reactions.

  4. Effect of AC Electrostatic Precipitator on Removal Diesel Exhaust Particles

    NASA Astrophysics Data System (ADS)

    Kawakami, Hitomi; Zukeran, Akinori; Yasumoto, Koji; Kubojima, Masaki; Ehara, Yoshiyasu; Yamamoto, Toshiaki

    Collection of low resistive particulate matter (PM) generated from automobile and marine diesel engines or diesel generators have been known to be difficult by the conventional electrostatic precipitators (ESP). The collection efficiency for two types ESPs such as conventional DC energized ESP (DC ESP) and rectangular-AC-waveform energized ESP (AC ESP) were investigated. The low resistive PMs agglomerate like a pearl-chain on the collection plate in DC ESP, so that these are detached from the collection plate by electrostatic repulsion force and wind force. The pearl-chain particles are changed the shape, which is such a spherical, by AC ESP. Therefore, the particle re-entrainment is suppressed by AC ESP.

  5. Eugenol attenuates pulmonary damage induced by diesel exhaust particles.

    PubMed

    Zin, Walter A; Silva, Ana G L S; Magalhães, Clarissa B; Carvalho, Giovanna M C; Riva, Douglas R; Lima, Crystianne C; Leal-Cardoso, Jose H; Takiya, Christina M; Valença, Samuel S; Saldiva, Paulo H N; Faffe, Débora S

    2012-03-01

    Environmentally relevant doses of inhaled diesel particles elicit pulmonary inflammation and impair lung mechanics. Eugenol, a methoxyphenol component of clove oil, presents in vitro and in vivo anti-inflammatory and antioxidant properties. Our aim was to examine a possible protective role of eugenol against lung injuries induced by diesel particles. Male BALB/c mice were divided into four groups. Mice received saline (10 μl in; CTRL group) or 15 μg of diesel particles DEP (15 μg in; DIE and DEUG groups). After 1 h, mice received saline (10 μl; CTRL and DIE groups) or eugenol (164 mg/kg; EUG and DEUG group) by gavage. Twenty-four hours after gavage, pulmonary resistive (ΔP1), viscoelastic (ΔP2) and total (ΔPtot) pressures, static elastance (Est), and viscoelastic component of elastance (ΔE) were measured. We also determined the fraction areas of normal and collapsed alveoli, amounts of polymorpho- (PMN) and mononuclear cells in lung parenchyma, apoptosis, and oxidative stress. Est, ΔP2, ΔPtot, and ΔE were significantly higher in the DIE than in the other groups. DIE also showed significantly more PMN, airspace collapse, and apoptosis than the other groups. However, no beneficial effect on lipid peroxidation was observed in DEUG group. In conclusion, eugenol avoided changes in lung mechanics, pulmonary inflammation, and alveolar collapse elicited by diesel particles. It attenuated the activation signal of caspase-3 by DEP, but apoptosis evaluated by TUNEL was avoided. Finally, it could not avoid oxidative stress as indicated by malondialdehyde.

  6. Control method for turbocharged diesel engines having exhaust gas recirculation

    DOEpatents

    Kolmanovsky, Ilya V.; Jankovic, Mrdjan J; Jankovic, Miroslava

    2000-03-14

    A method of controlling the airflow into a compression ignition engine having an EGR and a VGT. The control strategy includes the steps of generating desired EGR and VGT turbine mass flow rates as a function of the desired and measured compressor mass airflow values and exhaust manifold pressure values. The desired compressor mass airflow and exhaust manifold pressure values are generated as a function of the operator-requested fueling rate and engine speed. The EGR and VGT turbine mass flow rates are then inverted to corresponding EGR and VGT actuator positions to achieve the desired compressor mass airflow rate and exhaust manifold pressure. The control strategy also includes a method of estimating the intake manifold pressure used in generating the EGR valve and VGT turbine positions.

  7. Diesel exhaust induced pulmonary and cardiovascular impairment: The role of hypertension intervention

    SciTech Connect

    Kodavanti, Urmila P.; Thomas, Ronald F.; Ledbetter, Allen D.; Schladweiler, Mette C.; Bass, Virginia; Krantz, Q. Todd; King, Charly; Nyska, Abraham; Richards, Judy E.; Andrews, Debora; Gilmour, M. Ian

    2013-04-15

    Exposure to diesel exhaust (DE) and associated gases is linked to cardiovascular impairments; however, the susceptibility of hypertensive individuals is poorly understood. The objectives of this study were (1) to determine cardiopulmonary effects of gas-phase versus whole-DE and (2) to examine the contribution of systemic hypertension in pulmonary and cardiovascular effects. Male Wistar Kyoto (WKY) rats were treated with hydralazine to reduce blood pressure (BP) or L-NAME to increase BP. Spontaneously hypertensive (SH) rats were treated with hydralazine to reduce BP. Control and drug-pretreated rats were exposed to air, particle-filtered exhaust (gas), or whole DE (1500 μg/m{sup 3}), 4 h/day for 2 days or 5 days/week for 4 weeks. Acute and 4-week gas and DE exposures increased neutrophils and γ-glutamyl transferase (γ-GT) activity in lavage fluid of WKY and SH rats. DE (4 weeks) caused pulmonary albumin leakage and inflammation in SH rats. Two-day DE increased serum fatty acid binding protein-3 (FABP-3) in WKY. Marked increases occurred in aortic mRNA after 4-week DE in SH (eNOS, TF, tPA, TNF-α, MMP-2, RAGE, and HMGB-1). Hydralazine decreased BP in SH while L-NAME tended to increase BP in WKY; however, neither changed inflammation nor BALF γ-GT. DE-induced and baseline BALF albumin leakage was reduced by hydralazine in SH rats and increased by L-NAME in WKY rats. Hydralazine pretreatment reversed DE-induced TF, tPA, TNF-α, and MMP-2 expression but not eNOS, RAGE, and HMGB-1. ET-1 was decreased by HYD. In conclusion, antihypertensive drug treatment reduces gas and DE-induced pulmonary protein leakage and expression of vascular atherogenic markers. - Highlights: ► Acute diesel exhaust exposure induces pulmonary inflammation in healthy rats. ► In hypertensive rats diesel exhaust effects are seen only after long term exposure. ► Normalizing blood pressure reverses lung protein leakage caused by diesel exhaust. ► Normalizing blood pressure reverses

  8. Diesel Engine Services. An Instructor's Guide for a Program in Trade and Technical Education. Automotive Industries Occupations.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    Designed to prepare students to be engine mechanics working on automotive and large stationary diesel engines, this instructor's guide contains eight units arranged from simple to complex to facilitate student learning. Each contains behavioral objectives, a content outline, understandings and teaching approaches necessary to develop the content,…

  9. Diesel Engine Services. An Instructor's Guide for a Program in Trade and Technical Education. Automotive Industries Occupations.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    Designed to prepare students to be engine mechanics working on automotive and large stationary diesel engines, this instructor's guide contains eight units arranged from simple to complex to facilitate student learning. Each contains behavioral objectives, a content outline, understandings and teaching approaches necessary to develop the content,…

  10. Polycyclic aromatic hydrocarbon exhaust emissions from different reformulated diesel fuels and engine operating conditions

    NASA Astrophysics Data System (ADS)

    Borrás, Esther; Tortajada-Genaro, Luis A.; Vázquez, Monica; Zielinska, Barbara

    2009-12-01

    The study of light-duty diesel engine exhaust emissions is important due to their impact on atmospheric chemistry and air pollution. In this study, both the gas and the particulate phase of fuel exhaust were analyzed to investigate the effects of diesel reformulation and engine operating parameters. The research was focused on polycyclic aromatic hydrocarbon (PAH) compounds on particulate phase due to their high toxicity. These were analyzed using a gas chromatography-mass spectrometry (GC-MS) methodology. Although PAH profiles changed for diesel fuels with low-sulfur content and different percentages of aromatic hydrocarbons (5-25%), no significant differences for total PAH concentrations were detected. However, rape oil methyl ester biodiesel showed a greater number of PAH compounds, but in lower concentrations (close to 50%) than the reformulated diesel fuels. In addition, four engine operating conditions were evaluated, and the results showed that, during cold start, higher concentrations were observed for high molecular weight PAHs than during idling cycle and that the acceleration cycles provided higher concentrations than the steady-state conditions. Correlations between particulate PAHs and gas phase products were also observed. The emission of PAH compounds from the incomplete combustion of diesel fuel depended greatly on the source of the fuel and the driving patterns.

  11. A case-control study of lung cancer and diesel exhaust exposure in railroad workers.

    PubMed

    Garshick, E; Schenker, M B; Muñoz, A; Segal, M; Smith, T J; Woskie, S R; Hammond, S K; Speizer, F E

    1987-06-01

    A case-control study of deaths among U.S. railroad workers was conducted to test the hypothesis that lung cancer is associated with exposure to diesel exhaust. Employed and retired male workers with greater than or equal to 10 yr of service who were born on or after January 1, 1900 and who died between March 1, 1981 and February 28, 1982 were eligible. We collected 87% of the death certificates from 15,059 deaths reported to the U.S. Railroad Retirement Board (RRB). Cases of lung cancer (1,256) were matched to controls by age (+/- 2.5 yr) and date of death (+/- 31 days). Potential exposure to diesel exhaust was assigned based on an industrial hygiene evaluation of jobs and work areas. Each subject's work history was determined from a yearly job report filed by his employer with the RRB from 1959 until death or retirement. Asbestos exposure prior to 1959 was categorized by the job held in 1959, the end of the steam locomotive era, or by the last job held if retirement occurred before 1959. Smoking histories were obtained by questionnaire from next of kin. Using multiple conditional logistic regression analysis to adjust for smoking and asbestos exposure, workers 64 yr of age or younger at the time of death with work in a diesel exhaust exposed job for 20 yr had a significantly increased relative odds (odds ratio = 1.41, 95% Cl = 1.06, 1.88) of lung cancer. No effect of diesel exhaust exposure was seen in workers 65 yr of age or older because many of these men retired shortly after the transition to diesel-powered locomotives.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Comparative Study of Different Methods for Soot Sensing and Filter Monitoring in Diesel Exhausts

    PubMed Central

    Feulner, Markus; Hagen, Gunter; Hottner, Kathrin; Redel, Sabrina; Müller, Andreas; Moos, Ralf

    2017-01-01

    Due to increasingly tighter emission limits for diesel and gasoline engines, especially concerning particulate matter emissions, particulate filters are becoming indispensable devices for exhaust gas after treatment. Thereby, for an efficient engine and filter control strategy and a cost-efficient filter design, reliable technologies to determine the soot load of the filters and to measure particulate matter concentrations in the exhaust gas during vehicle operation are highly needed. In this study, different approaches for soot sensing are compared. Measurements were conducted on a dynamometer diesel engine test bench with a diesel particulate filter (DPF). The DPF was monitored by a relatively new microwave-based approach. Simultaneously, a resistive type soot sensor and a Pegasor soot sensing device as a reference system measured the soot concentration exhaust upstream of the DPF. By changing engine parameters, different engine out soot emission rates were set. It was found that the microwave-based signal may not only indicate directly the filter loading, but by a time derivative, the engine out soot emission rate can be deduced. Furthermore, by integrating the measured particulate mass in the exhaust, the soot load of the filter can be determined. In summary, all systems coincide well within certain boundaries and the filter itself can act as a soot sensor. PMID:28218700

  13. Comparative Study of Different Methods for Soot Sensing and Filter Monitoring in Diesel Exhausts.

    PubMed

    Feulner, Markus; Hagen, Gunter; Hottner, Kathrin; Redel, Sabrina; Müller, Andreas; Moos, Ralf

    2017-02-18

    Due to increasingly tighter emission limits for diesel and gasoline engines, especially concerning particulate matter emissions, particulate filters are becoming indispensable devices for exhaust gas after treatment. Thereby, for an efficient engine and filter control strategy and a cost-efficient filter design, reliable technologies to determine the soot load of the filters and to measure particulate matter concentrations in the exhaust gas during vehicle operation are highly needed. In this study, different approaches for soot sensing are compared. Measurements were conducted on a dynamometer diesel engine test bench with a diesel particulate filter (DPF). The DPF was monitored by a relatively new microwave-based approach. Simultaneously, a resistive type soot sensor and a Pegasor soot sensing device as a reference system measured the soot concentration exhaust upstream of the DPF. By changing engine parameters, different engine out soot emission rates were set. It was found that the microwave-based signal may not only indicate directly the filter loading, but by a time derivative, the engine out soot emission rate can be deduced. Furthermore, by integrating the measured particulate mass in the exhaust, the soot load of the filter can be determined. In summary, all systems coincide well within certain boundaries and the filter itself can act as a soot sensor.

  14. A critical assessment of studies on the carcinogenic potential of diesel exhaust.

    PubMed

    Hesterberg, Thomas W; Bunn, William B; Chase, Gerald R; Valberg, Peter A; Slavin, Thomas J; Lapin, Charles A; Hart, Georgia A

    2006-10-01

    After decades of research involving numerous epidemiologic studies and extensive investigations in laboratory animals, a causal relationship between diesel exhaust (DE) exposure and lung cancer has not been conclusively demonstrated. Epidemiologic studies of the transportation industry (trucking, busing, and railroad) show a small elevation in lung cancer incidence (relative risks [RRs] generally below 1.5), but a dose response for DE is lacking. The studies are also limited by a lack of quantitative concurrent exposure data and inadequate or lack of controls for potential confounders, particularly tobacco smoking. Furthermore, prior to dieselization, similar elevations in lung cancer incidence have been reported for truck drivers, and in-cab diesel particulate matter (DPM) exposures of truck drivers were comparable to ambient highway exposures. Taken together, these findings suggest that an unidentified occupational agent or lifestyle factor might be responsible for the low elevations in lung cancer reported in the transportation studies. In contrast, underground miners, many of whom experience the highest occupational DPM exposures, generally do not show elevations in lung cancer. Laboratory studies must be interpreted with caution with respect to predicting the carcinogenic potential of DE in humans. Tumors observed in rats following lifetime chronic inhalation of very high levels of DPM may be attributed to species-specific overload mechanisms that lack relevance to humans. Increased tumor incidence was not observed in other species (hamsters or mice) exposed to DPM at very high levels or in rats exposed at lower levels (

  15. Quantitation of nitro- and dinitropolycyclic aromatic hydrocarbons in diesel exhaust particulate matter

    SciTech Connect

    Draper, W.M.

    1986-01-01

    A method for routine trace analysis of nitropolycyclic aromatic hydrocarbons (nitro-PAH) in diesel exhaust particulate matter is described. Particle extracts are prefractionated by silica high pressure liquid chromatography and the appropriate band analyzed by capillary electron capture gas chromatography. With on-column injection, three dinitropyrene isomers were recovered in the range of 69-85% for fortifications of 10 ..mu..g nitro-PAH/g of soot. The high signal-to-noise ratio suggested detection limits of about 2 ..mu..g/g for these analytes. Analysis of the Bureau of Standards SRM 1650 diesel particulate sample demonstrated the methods accuracy for 1-nitropyrene determinations as well.

  16. Strength and fatigue of NT551 silicon nitride and NT551 diesel exhaust valves

    SciTech Connect

    Andrews, M.J.; Werezczak, A.A.; Kirkland, T.P.; Breder, K.

    2000-02-01

    The content of this report is excerpted from Mark Andrew's Ph.D. Thesis (Andrews, 1999), which was funded by a DOE/OTT High Temperature Materials Laboratory Graduate Fellowship. It involves the characterization of NT551 and valves fabricated with it. The motivations behind using silicon nitride (Si{sub 3}N{sub 4}) as an exhaust valve for a diesel engine are presented in this section. There are several economic factors that have encouraged the design and implementation of ceramic components for internal combustion (IC) engines. The reasons for selecting the diesel engine valve for this are also presented.

  17. Altered Nitric Oxide Bioavailability Contributes to Diesel Exhaust Inhalation‐Induced Cardiovascular Dysfunction in Man

    PubMed Central

    Langrish, Jeremy P.; Unosson, Jon; Bosson, Jenny; Barath, Stefan; Muala, Ala; Blackwell, Scott; Söderberg, Stefan; Pourazar, Jamshid; Megson, Ian L.; Treweeke, Andrew; Sandström, Thomas; Newby, David E.; Blomberg, Anders; Mills, Nicholas L.

    2013-01-01

    Background Diesel exhaust inhalation causes cardiovascular dysfunction including impaired vascular reactivity, increased blood pressure, and arterial stiffness. We investigated the role of nitric oxide (NO) bioavailability in mediating these effects. Methods and Results In 2 randomized double‐blind crossover studies, healthy nonsmokers were exposed to diesel exhaust or filtered air. Study 1: Bilateral forearm blood flow was measured during intrabrachial infusions of acetylcholine (ACh; 5 to 20 μg/min) and sodium nitroprusside (SNP; 2 to 8 μg/min) in the presence of the NO clamp (NO synthase inhibitor NG‐monomethyl‐l‐arginine (l‐NMMA) 8 μg/min coinfused with the NO donor SNP at 90 to 540 ng/min to restore basal blood flow). Study 2: Blood pressure, arterial stiffness, and cardiac output were measured during systemic NO synthase inhibition with intravenous l‐NMMA (3 mg/kg). Following diesel exhaust inhalation, plasma nitrite concentrations were increased (68±48 versus 41±32 nmol/L; P=0.006) despite similar l‐NMMA–induced reductions in basal blood flow (−20.6±14.7% versus −21.1±14.6%; P=0.559) compared to air. In the presence of the NO clamp, ACh and SNP caused dose‐dependent vasodilatation that was not affected by diesel exhaust inhalation (P>0.05 for both). Following exposure to diesel exhaust, l‐NMMA caused a greater increase in blood pressure (P=0.048) and central arterial stiffness (P=0.007), but reductions in cardiac output and increases in systemic vascular resistance (P>0.05 for both) were similar to those seen with filtered air. Conclusions Diesel exhaust inhalation disturbs normal vascular homeostasis with enhanced NO generation unable to compensate for excess consumption. We suggest the adverse cardiovascular effects of air pollution are, in part, mediated through reduced NO bioavailability. Clinical Trial Registration URL: http://www.ClinicalTrials.gov. Unique identifiers: NCT00845767 and NCT01060930. PMID:23525434

  18. Characterizations of organic compounds in diesel exhaust particulates.

    PubMed

    Lim, Jaehyun; Lim, Cheolsoo; Kim, Sangkyun; Hong, Jihyung

    2015-08-01

    To characterize how the speed and load of a medium-duty diesel engine affected the organic compounds in diesel particle matter (PM) below 1 μm, four driving conditions were examined. At all four driving conditions, concentration of identifiable organic compounds in PM ultrafine (34-94 nm) and accumulation (94-1000 nm) modes ranged from 2.9 to 5.7 μg/m(3) and 9.5 to 16.4 μg/m(3), respectively. As a function of driving conditions, the non-oxygen-containing organics exhibited a reversed concentration trend to the oxygen-containing organics. The identified organic compounds were classified into eleven classes: alkanes, alkenes, alkynes, aromatic hydrocarbons, carboxylic acids, esters, ketones, alcohols, ethers, nitrogen-containing compounds, and sulfur-containing compounds. At all driving conditions, alkane class consistently showed the highest concentration (8.3 to 18.0 μg/m(3)) followed by carboxylic acid, esters, ketones and alcohols. Twelve polycyclic aromatic hydrocarbons (PAHs) were identified with a total concentration ranging from 37.9 to 174.8 ng/m(3). In addition, nine nitrogen-containing polycyclic aromatic compounds (NPACs) were identified with a total concentration ranging from 7.0 to 10.3 ng/m(3). The most abundant PAH (phenanthrene) and NPACs (7,8-benzoquinoline and 3-nitrophenanthrene) comprise a similar molecular (3 aromatic-ring) structure under the highest engine speed and engine load.

  19. Particulate matter, carbon emissions and elemental compositions from a diesel engine exhaust fuelled with diesel-biodiesel blends

    NASA Astrophysics Data System (ADS)

    Ashraful, A. M.; Masjuki, H. H.; Kalam, M. A.

    2015-11-01

    A comparative morphological analysis was performed on the exhaust particles emitted from a CI engine using different blending ratios of palm biodiesel at several operating conditions. It was observed from this experiment; peak particle concentration for PB10 at 1200 rpm is 1.85E + 02 and at 1500 rpm is 2.12E + 02. A slightly smaller amount of volatile material has found from the biodiesel samples compared to the diesel fuel sample. Thermogravimetric analysis (TGA) showed that the amount of volatile material in the soot from biodiesel fuels was slightly lower than that of diesel fuel. PB20 biodiesel blends reduced maximum 11.26% of volatile matter from the engine exhaust, while PB10 biodiesel blend reduced minimum 5.53% of volatile matter. On the other hand, the amount of fixed carbon from the biodiesel samples was slightly higher than diesel fuel. Analysis of carbon emissions, palm biodiesel (PB10) reduced elemental carbon (EC) was varies 0.75%-18%, respectively. Similarly, the emission reduction rate for PB20 was varies 11.36%-23.46% respectively. While, organic carbon (OC) emission rates reduced for PB20 was varied 13.7-49% respectively. Among the biodiesel blends, PB20 exhibited highest oxygen (O), sulfur (S) concentration and lowest silicon (Si) and iron (Fe) concentration. Scanning electron microscope (SEM) images for PB20 showed granular structure particulates with bigger grain sizes compared to diesel. Particle diameter increased under the 2100-2400 rpm speed condition and it was 8.70% higher compared to the low speed conditions. Finally, the results indicated that the composition and degree of unsaturation of the methyl ester present in biodiesel, play an important role in the chemical composition of particulate matter emissions.

  20. The Effect of the Diesel Cetane Number on Exhaust Emissions Characteristics by Various Additives

    NASA Astrophysics Data System (ADS)

    Lim, Yunsung; Seo, Choongyeol; Lee, Jongtae; Kang, Daeil; Kim, Jeong Soo; Kim, Hyung Jun

    This paper described the effect of the diesel cetane number on exhaust emissions characteristics according to various additives. In addition, the emission characteristics of test fuels blended with three additives (GTL, biodiesel and additive for improving CN) were analyzed and the potential for uses of these additives were evaluated in this study. To achieve this purpose, the test diesel vehicle with a two-thousand cubic centimeter displacement was used to analyze the emission characteristics according to the CN. Also, the NEDC (New European Driving Cycle) was applied as the test mode which is widely used as the test method for environmental certification of diesel vehicles. To analyze the characteristics of HAPs, the VOCs and PAHs were analyzed from the BTEX and the particulate matter, respectively. The analysis results revealed that the CO emissions show the largest reduction rate while the NOx+THC emissions are reduced at a low as the CN got higher. In the NEDC mode, the PM emissions in the EUDC mode were found to be at a lower level than those in the UDC mode. As for the VOCs and PAHs characteristics, the VOCs of the CN 58 show the lowest amounts. Also, the PAHs of diesel blended with GTL show the highest level, followed by those of diesel blended with biodiesel and diesel blended with cetane additive.

  1. Effects of gaseous sulphuric acid on diesel exhaust nanoparticle formation and characteristics.

    PubMed

    Rönkkö, Topi; Lähde, Tero; Heikkilä, Juha; Pirjola, Liisa; Bauschke, Ulrike; Arnold, Frank; Schlager, Hans; Rothe, Dieter; Yli-Ojanperä, Jaakko; Keskinen, Jorma

    2013-10-15

    Diesel exhaust gaseous sulphuric acid (GSA) concentrations and particle size distributions, concentrations, and volatility were studied at four driving conditions with a heavy duty diesel engine equipped with oxidative exhaust after-treatment. Low sulfur fuel and lubricant oil were used in the study. The concentration of the exhaust GSA was observed to vary depending on the engine driving history and load. The GSA affected the volatile particle fraction at high engine loads; higher GSA mole fraction was followed by an increase in volatile nucleation particle concentration and size as well as increase of size of particles possessing nonvolatile core. The GSA did not affect the number of nonvolatile particles. At low and medium loads, the exhaust GSA concentration was low and any GSA driven changes in particle population were not observed. Results show that during the exhaust cooling and dilution processes, besides critical in volatile nucleation particle formation, GSA can change the characteristics of all nucleation mode particles. Results show the dual nature of the nucleation mode particles so that the nucleation mode can include simultaneously volatile and nonvolatile particles, and fulfill the previous results for the nucleation mode formation, especially related to the role of GSA in formation processes.

  2. Diesel Exhaust Inhalation Increases Cardiac Output, Bradyarrhythmias, and Parasympathetic Tone in Aged Heart Failure-Prone Rats

    EPA Science Inventory

    Acute air pollutant inhalation is linked to adverse cardiac events and death, and hospitalizations for heart failure. Diesel exhaust (DE) is a major air pollutant suspected to exacerbate preexisting cardiac conditions, in part, through autonomic and electrophysiologic disturbance...

  3. Inflammatory Cytokines and White Blood Cell Counts Response to Environmental Levels of Diesel Exhaust and Ozone Inhalation Exposures

    EPA Science Inventory

    Epidemiological observations of urban inhalation exposures to diesel exhaust (DE) and ozone (O3) have shown pre-clinical cardiopulmonary responses in humans. Identifying the key biological mechanisms that initiate these health bioindicators is difficult due to variability in envi...

  4. Inhalation of Whole Diesel Exhaust but not Gas-Phase Components Affects In Vitro Platelet Aggregation in Hypertensive Rats

    EPA Science Inventory

    Rationale: Intravascular thrombosis and platelet aggregation are enhanced following exposure to diesel exhaust (DE) and other respirable particulate matter; however, the roles of endothelial and circulating mediators on platelet aggregation remain unclear. We hypothesized that ad...

  5. Concordance in Genomic Changes Between Mouse Lungs and Human Airway Epithelial Cells Exposed to Diesel Exhaust Particles

    EPA Science Inventory

    Human and animal toxicity studies have shown that exposure to diesel exhaust particles (DEP) or their constituents affect multiple biological processes including immune and inflammatory pathways, mutagenesis and in some cases carcinogenesis. This study compared genomic changes by...

  6. Inflammatory Cytokines and White Blood Cell Counts Response to Environmental Levels of Diesel Exhaust and Ozone Inhalation Exposures

    EPA Science Inventory

    Epidemiological observations of urban inhalation exposures to diesel exhaust (DE) and ozone (O3) have shown pre-clinical cardiopulmonary responses in humans. Identifying the key biological mechanisms that initiate these health bioindicators is difficult due to variability in envi...

  7. Concordance in Genomic Changes Between Mouse Lungs and Human Airway Epithelial Cells Exposed to Diesel Exhaust Particles

    EPA Science Inventory

    Human and animal toxicity studies have shown that exposure to diesel exhaust particles (DEP) or their constituents affect multiple biological processes including immune and inflammatory pathways, mutagenesis and in some cases carcinogenesis. This study compared genomic changes by...

  8. Blood Pressure Interventions Affect Acute and Four-Week Diesel Exhaust Induced Pulmonary Injury in Healthy and Hypertensive Rats

    EPA Science Inventory

    Rationale: We recently showed that inhalation exposure of normotensive Wistar Kyoto (WKY) rats to whole diesel exhaust (DE) elicits changes in cardiac gene expression that broadly mimics expression in spontaneously hypertensive (SH) rats without DE. We hypothesized that pharmacol...

  9. Inhalation of Whole Diesel Exhaust but not Gas-Phase Components Affects In Vitro Platelet Aggregation in Hypertensive Rats

    EPA Science Inventory

    Rationale: Intravascular thrombosis and platelet aggregation are enhanced following exposure to diesel exhaust (DE) and other respirable particulate matter; however, the roles of endothelial and circulating mediators on platelet aggregation remain unclear. We hypothesized that ad...

  10. Blood Pressure Interventions Affect Acute and Four-Week Diesel Exhaust Induced Pulmonary Injury in Healthy and Hypertensive Rats

    EPA Science Inventory

    Rationale: We recently showed that inhalation exposure of normotensive Wistar Kyoto (WKY) rats to whole diesel exhaust (DE) elicits changes in cardiac gene expression that broadly mimics expression in spontaneously hypertensive (SH) rats without DE. We hypothesized that pharmacol...

  11. Examination of cytokines and metals in exhaled breath condensate and lung lavage fluids after diesel exhaust exposure

    EPA Science Inventory

    Epidemiology studies link human exposure to ambient air pollution with the development and exacerbation of cardiopulmonary disease. Diesel exhaust (DE) is a significant source of ambient air pollution, and thus may contribute to adverse pulmonary health effects. Previous human re...

  12. Diesel Exhaust Inhalation Increases Cardiac Output, Bradyarrhythmias, and Parasympathetic Tone in Aged Heart Failure-Prone Rats

    EPA Science Inventory

    Acute air pollutant inhalation is linked to adverse cardiac events and death, and hospitalizations for heart failure. Diesel exhaust (DE) is a major air pollutant suspected to exacerbate preexisting cardiac conditions, in part, through autonomic and electrophysiologic disturbance...

  13. INHIBITION OF TYROSINE PHOSPHATASE ACTIVITY INITIATES RECEPTOR SIGNALING IN AIRWAY EPITHELIAL CELLS EXPOSED TO DIESEL EXHAUST PARTICLES

    EPA Science Inventory

    Exposure to particulate matter is associated with increased cardiopulmonary morbidity and mortality. Diesel exhaust particles (DEP) are a major component of PM in urban areas and may contribute to PM toxicity through a mechanism involving pulmonary inflammation. Expression of inf...

  14. Comparative Toxicity of Biodiesel Exhaust and Petroleum Diesel Exhaust Particulate Matter Using WKY Rat Alveolar Machrophages

    EPA Science Inventory

    Exposure to fine ambient particulate matter <2.5um (PM2.5) can induce airway inflammation, cardiopulmonary morbidity and mortality. Combustion of petroleum diesel and biodiesel contributes to PM2.5. Possible toxicity caused by inhalation of biodiesel emission particles (BioDEP) h...

  15. Comparative Toxicity of Biodiesel Exhaust and Petroleum Diesel Exhaust Particulate Matter Using WKY Rat Alveolar Machrophages

    EPA Science Inventory

    Exposure to fine ambient particulate matter <2.5um (PM2.5) can induce airway inflammation, cardiopulmonary morbidity and mortality. Combustion of petroleum diesel and biodiesel contributes to PM2.5. Possible toxicity caused by inhalation of biodiesel emission particles (BioDEP) h...

  16. Inhalation toxicology of automotive emissions as affected by an oxidation exhaust catalyst.

    PubMed

    Hysell, D K; Moore, W; Hinners, R; Malanchuk, M; Miller, R; Stara, J F

    1975-04-01

    Preliminary data are given on the acute inhalation toxicology of automotive emissions as affected by an oxidation exhaust catalyst. The catalyst effectively reduced CO and HC in the exhause which apparently had an effect (at least in a closed exposure system) on oxidant and NO2 levels by altering the HC/NOx ratio. There was a resultant reduction in biological effects due to the exposure. The catalyst altered the type of particulate to one which probably contained sulfuric acid as a major component. No evidence was present in these acute exposures to suggest a toxic response due to the higher sulfate emissions or possible catalyst attrition products. The effects of long-term exposure have not yet been investigated.

  17. Case-control study of diesel exhaust exposure and bladder cancer

    SciTech Connect

    Wynder, E.L.; Dieck, G.S.; Hall, N.E.L.; Lahti, H.

    1985-08-01

    The relationship between bladder cancer and employment in occupations involving exposure to diesel exhaust was examined using data from a hospital-based case-control study of men aged 20 to 80 years in 18 hospitals in six US cities, from January 1981 to May 1983. In this analysis, 194 cases and 582 controls were compared according to occupation, smoking history, alcohol and coffee consumption, and various demographic variables. No difference was found in the proportion of bladder cancer cases employed in occupations with exposure to diesel exhaust compared to controls. This relationship did not change after taking smoking habits into account. Bladder cancer cases were significantly more likely to be current smokers of cigarettes than were controls.

  18. Effects of coal dust and diesel exhaust on immune competence in rats

    SciTech Connect

    Mentnech, M.S.; Lewis, D.M.; Olenchock, S.A.; Mull, J.C.; Koller, W.A.; Lewis, T.R.

    1984-01-01

    The effects on the immune system of rats that had been exposed to a 2-mg/m/sup 3/ dose of either respirable coal dust, diesel exhaust fumes and particulates, or the combination of these were studied. Animals that were housed similarly but exposed only to filtered air served as controls. After 12 and 24 mo of exposure, the rats were tested for immunocompetency by enumerating antibody-producing cells in the spleen 4 d after immunization with sheep erythrocytes and by monitoring the proliferative response of splenic T-lymphocytes to the mitogens concanavalin A and phytohemagglutinin. The results of this study indicate that no major alterations occurred in the immunologic functions measured as a result of exposure to either coal dust, diesel exhaust fumes and particulates, or their combination.

  19. Fate of SO{sub 2} During Plasma Treatment of Diesel Engine Exhaust

    SciTech Connect

    Brusasco, R.M.; Merritt, B.T.; Vogtlin, G.E.

    1999-10-25

    Several catalytic aftertreatment technologies rely on the conversion of NO to NO{sub 2} to achieve efficient reduction of NO{sub x} and particulates in diesel engine exhaust. These technologies require low sulfur fuel because the catalyst component that is active in converting NO to NO{sub 2} is also active in converting SO{sub 2} to SO{sub 3}. A non-thermal plasma can be used for the selective partial oxidation of NO to NO{sub 2} in the gas-phase under diesel engine exhaust conditions. This paper discusses how a non-thermal plasma can efficiently oxidize NO to NO{sub 2} without oxidizing SO{sub 2} to SO{sub 3}. It is shown that the presence of hydrocarbons in the plasma is essential for enhancing the selective partial oxidation of NO and suppressing the oxidation of SO{sub 2}.

  20. On-Road Measurement of Exhaust Emission Factors for Individual Diesel Trucks

    NASA Astrophysics Data System (ADS)

    Dallmann, T. R.; DeMartini, S.; Harley, R. A.; Kirchstetter, T. W.; Wood, E. C.; Onasch, T. B.; Herndon, S. C.

    2011-12-01

    Diesel trucks are an important source of primary fine particulate matter (PM2.5) that includes black carbon (BC) as a major component. More stringent exhaust emission standards for new engines, effective starting in 2007, considerably reduce allowable emissions and have led to use of after-treatment control devices such as diesel particle filters. The state of California is also implementing programs to accelerate replacement or retrofit of older trucks. In light of these changes, measurements of emissions from in-use heavy-duty diesel trucks are timely and needed to understand the impact of new control technologies on emissions. PM2.5, BC mass, particle light absorption, and particle light extinction emission factors for hundreds of individual diesel trucks were measured in this study. Emissions were measured in July 2010 from trucks driving through the Caldecott tunnel in the San Francisco Bay area. Gas-phase emissions including nitric oxide, nitrogen dioxide, carbon monoxide, and carbon dioxide (CO2) were also measured. Pollutants were measured using air sampling inlets located directly above the vertical exhaust stacks of heavy-duty trucks driving by on the roadway below. All of these measurements were made using fast time response (1 Hz) sensors. Particle optical properties were simultaneously characterized with direct measurements of absorption (babs) and extinction (bext) coefficients. Emission factors for individual trucks were calculated using a carbon balance method in which emissions of PM2.5, BC, babs, and bext in each exhaust plume were normalized to emissions of CO2. Emission factor distributions and fleet-average values are quantified. Absorption and extinction emission factors are used to calculate the aerosol single scattering albedo and BC mass absorption efficiency for individual truck exhaust plumes.

  1. Reduction of NOx and PM in marine diesel engine exhaust gas using microwave plasma

    NASA Astrophysics Data System (ADS)

    Balachandran, W.; FInst, P.; Manivannan, N.; Beleca, R.; Abbod, M.

    2015-10-01

    Abatement of NOx and particulate matters (PM) of marine diesel exhaust gas using microwave (MW) non-thermal plasma is presented in this paper. NOx mainly consist of NO and less concentration of NO2 in a typical two stoke marine diesel engine and microwave plasma generation can completely remove NO. MW was generated using two 2kW microwave sources and a saw tooth passive electrode. Passive electrode was used to generate high electric field region within microwave environment where high energetic electrons (1-3eV) are produced for the generation of non-thermal plasma (NTP). 2kW gen-set diesel exhaust gas was used to test our pilot-scale MW plasma reactor. The experimental results show that almost 100% removal of NO is possible for the exhaust gas flow rate of 60l/s. It was also shown that MW can significantly remove soot particles (PM, 10nm to 365nm) entrained in the exhaust gas of 200kW marine diesel engine with 40% engine load and gas flow rate of 130l/s. MW without generating plasma showed reduction up to 50% reduction of PM and with the plasma up to 90% reduction. The major challenge in these experiments was that igniting the desired plasma and sustaining it with passive electrodes for longer period (10s of minutes) as it required fine tuning of electrode position, which was influenced by many factors such as gas flow rate, geometry of reactor and MW power.

  2. Quantitative Determination of PAHs in Diesel Engine Exhausts by GC-MS

    NASA Astrophysics Data System (ADS)

    Fleurat-Lessard, Paul; Pointet, Karine; Renou-Gonnord, Marie-France

    1999-07-01

    A gas chromatography-mass spectrometry (GC-MS) analytical protocol for quantitation of PAHs in diesel exhaust particles, adapted for a single laboratory period, is proposed. Gravitational chromatography is first used to isolate aromatic compounds. Then quantitative determination of PAHs (polycyclic aromatic hydrocarbons) is performed by GC-MS, using deuterated PAHs as internal standards. Results obtained by students for recovery yields and for quantitation are reproducible.

  3. Volatile nanoparticle formation and growth within a diluting diesel car exhaust.

    PubMed

    Uhrner, Ulrich; Zallinger, Michael; von Löwis, Sibylle; Vehkamäki, Hanna; Wehner, Birgit; Stratmann, Frank; Wiedensohler, Alfred

    2011-04-01

    A major source of particle number emissions is road traffic. However, scientific knowledge concerning secondary particle formation and growth of ultrafine particles within vehicle exhaust plumes is still very limited. Volatile nanoparticle formation and subsequent growth conditions were analyzed here to gain a better understanding of "real-world" dilution conditions. Coupled computational fluid dynamics and aerosol microphysics models together with measured size distributions within the exhaust plume of a diesel car were used. The impact of soot particles on nucleation, acting as a condensational sink, and the possible role of low-volatile organic components in growth were assessed. A prescribed reduction of soot particle emissions by 2 orders of magnitude (to capture the effect of a diesel particle filter) resulted in concentrations of nucleation-mode particles within the exhaust plume that were approximately 1 order of magnitude larger. Simulations for simplified sulfuric acid-water vapor gas-oil containing nucleation-mode particles show that the largest particle growth is located in a recirculation zone in the wake of the car. Growth of particles within the vehicle exhaust plume up to detectable size depends crucially on the relationship between the mass rate of gaseous precursor emissions and rapid dilution. Chassis dynamometer measurements indicate that emissions of possible hydrocarbon precursors are significantly enhanced under high engine load conditions and high engine speed. On the basis of results obtained for a diesel passenger car, the contributions from light diesel vehicles to the observed abundance of measured nucleation-mode particles near busy roads might be attributable to the impact of two different time scales: (1) a short one within the plume, marked by sufficient precursor emissions and rapid dilution; and (2) a second and comparatively long time scale resulting from the mix of different precursor sources and the impact of atmospheric

  4. A reevaluation of the literature regarding the health assessment of diesel engine exhaust.

    PubMed

    Bunn, William B; Hesterberg, Thomas W; Valberg, Peter A; Slavin, Thomas J; Hart, Georgia; Lapin, Charles A

    2004-12-15

    While the International Agency for Research on Cancer (IARC) classified diesel exhaust (DE) as a"probable"carcinogen in 1989 based primarily on"sufficient"animal data, other investigators have since concluded that the lung tumors found in the rat studies were a result of particle overloading. Subsequent health risk assessments of DE have not used the rat cancer data. The U.S. Environmental Protection Agency (EPA), in developing its 2002 Health Assessment Document (HAD) for DE, primarily considered the epidemiology studies of railroad workers and truck drivers to develop health risk assessments of DE. However, both sets of epidemiology studies have serious weaknesses that make them unsuitable for cancer risk assessment. Major shortcomings were the lack of contemporaneous measurements of exposures to DE, difficulties with exposure history reconstruction, and adequately accounting for other exposures such as gasoline exhaust and cigarette smoke. To compound these problems, there was not, and there is still not, a specific exposure marker for DE. Interestingly, in the underground mining industry, where diesel exposures are much higher than observed in railroad workers and truck drivers, there was no increase in lung cancer. These problems and concerns led the U.S. EPA to conclude that while DE was a"likely"carcinogen, a unit risk value or range of risk cannot be calculated from existing data and that the risk could be zero. In addition, the DE emissions have changed and continue to change with the implementation of new emission control technologies. The HAD recognized this fact and noted that further studies are needed to assess new diesel engine emissions. Recent chemical characterization studies on low-emitting diesel engines with catalyzed particulate filters have shown emissions rates for several chemicals of concern that are even lower than comparable compressed natural gas (CNG)-fueled engines. With lower emissions, better fire safety, and improved cost

  5. Exhaust emissions reduction from diesel engine using combined Annona-Eucalyptus oil blends and antioxidant additive

    NASA Astrophysics Data System (ADS)

    Senthil, R.; Silambarasan, R.; Pranesh, G.

    2017-03-01

    The limited resources, rising petroleum prices and depletion of fossil fuel have now become a matter of great concern. Hence, there is an urgent need for researchers to find some alternate fuels which are capable of substituting partly or wholly the higher demanded conventional diesel fuel. Lot of research work has been conducted on diesel engine using biodiesel and its blends with diesel as an alternate fuel. Very few works have been done with combination of biodiesel-Eucalypts oil without neat diesel and this leads to lots of scope in this area. The aim of the present study is to analyze the performance and emission characteristics of a single cylinder, direct injection, compression ignition engine using eucalyptus oil-biodiesel as fuel. The presence of eucalyptus oil in the blend reduces the viscosity and improves the volatility of the blends. The methyl ester of Annona oil is blended with eucalypts oil in 10, 20, 30, 40 and 50 %. The performance and emission characteristics are evaluated by operating the engine at different loads. The performance characteristics such as brake thermal efficiency, brake specific fuel consumption and exhaust gas temperature are evaluated. The emission constituents measured are Carbon monoxide (CO), unburned hydrocarbons (HC), Oxides of nitrogen (NOx) and Smoke. It is found that A50-Eu50 (50 Annona + 50 % Eucalyptus oil) blend showed better performance and reduction in exhaust emissions. But, it showed a very marginal increase in NOx emission when compared to that of diesel. Therefore, in order to reduce the NOx emission, antioxidant additive (A-tocopherol acetate) is mixed with Annona-Eucalyptus oil blends in various proportions by which NOx emission is reduced. Hence, A50-Eu50 blend can be used as an alternate fuel for diesel engine without any modifications.

  6. DNA adducts induced by in vitro activation of extracts of diesel and biodiesel exhaust particles.

    PubMed

    Ross, Jeffrey A; Nelson, Garret B; Mutlu, Esra; Warren, Sarah H; Gilmour, M Ian; DeMarini, David M

    2015-01-01

    Biodiesel and biodiesel-blend fuels offer a renewable alternative to petroleum diesel, but few data are available concerning the carcinogenic potential of biodiesel exhausts. We compared the formation of covalent DNA adducts by the in vitro metabolic activation of organic extracts of diesel-exhaust particles (DEP) from petroleum diesel and soy biodiesel and correlated DNA adduct levels and mutagenicity in Salmonella TA100. We examined two different DEP from petroleum diesel (C-DEP and B0), one from soy bean oil biodiesel (B100) and one from combustion of a blend of 20% B100 and 80% B0 (B20) for in vitro DNA adduct-forming potential under oxidative or nitroreductive conditions in the presence of calf thymus DNA as well as in vivo in Salmonella TA100. The modified DNA was hydrolyzed and analyzed by (32)P-postlabeling using either butanol extraction or nuclease P1 pre-enrichment. Multiple DNA adducts were produced with chromatographic mobilities consistent with PAH and nitro-PAH adducts. The types and quantities of DNA adducts produced by the two independent petroleum diesel DEP were similar, with both polycyclic aromatic hydrocarbon (PAH)- and nitro-PAH-derived adducts formed. Relative potencies for S9-mediated DNA adduct formation, either per mass of particulate or per MJ(th) energy consumed were B100 > B0 > B20. Soy biodiesel emissions induced DNA damage in the form of presumptive PAH and nitro-PAH DNA adducts that correlated with mutagenicity in Salmonella. B20 is the soy biodiesel used most commonly in the US, and it produced the lowest DNA adduct-emission factor, ∼50% that of petroleum diesel.

  7. Exhaust emissions reduction from diesel engine using combined Annona-Eucalyptus oil blends and antioxidant additive

    NASA Astrophysics Data System (ADS)

    Senthil, R.; Silambarasan, R.; Pranesh, G.

    2016-07-01

    The limited resources, rising petroleum prices and depletion of fossil fuel have now become a matter of great concern. Hence, there is an urgent need for researchers to find some alternate fuels which are capable of substituting partly or wholly the higher demanded conventional diesel fuel. Lot of research work has been conducted on diesel engine using biodiesel and its blends with diesel as an alternate fuel. Very few works have been done with combination of biodiesel-Eucalypts oil without neat diesel and this leads to lots of scope in this area. The aim of the present study is to analyze the performance and emission characteristics of a single cylinder, direct injection, compression ignition engine using eucalyptus oil-biodiesel as fuel. The presence of eucalyptus oil in the blend reduces the viscosity and improves the volatility of the blends. The methyl ester of Annona oil is blended with eucalypts oil in 10, 20, 30, 40 and 50 %. The performance and emission characteristics are evaluated by operating the engine at different loads. The performance characteristics such as brake thermal efficiency, brake specific fuel consumption and exhaust gas temperature are evaluated. The emission constituents measured are Carbon monoxide (CO), unburned hydrocarbons (HC), Oxides of nitrogen (NOx) and Smoke. It is found that A50-Eu50 (50 Annona + 50 % Eucalyptus oil) blend showed better performance and reduction in exhaust emissions. But, it showed a very marginal increase in NOx emission when compared to that of diesel. Therefore, in order to reduce the NOx emission, antioxidant additive (A-tocopherol acetate) is mixed with Annona-Eucalyptus oil blends in various proportions by which NOx emission is reduced. Hence, A50-Eu50 blend can be used as an alternate fuel for diesel engine without any modifications.

  8. Experimental investigation on performance and exhaust emissions of castor oil biodiesel from a diesel engine.

    PubMed

    Shojaeefard, M H; Etgahni, M M; Meisami, F; Barari, A

    2013-01-01

    Biodiesel, produced from plant and animal oils, is an important alternative to fossil fuels because, apart from dwindling supply, the latter are a major source of air pollution. In this investigation, effects of castor oil biodiesel blends have been examined on diesel engine performance and emissions. After producing castor methyl ester by the transesterification method and measuring its characteristics, the experiments were performed on a four cylinder, turbocharged, direct injection, diesel engine. Engine performance (power, torque, brake specific fuel consumption and thermal efficiency) and exhaust emissions were analysed at various engine speeds. All the tests were done under 75% full load. Furthermore, the volumetric blending ratios of biodiesel with conventional diesel fuel were set at 5, 10, 15, 20 and 30%. The results indicate that lower blends of biodiesel provide acceptable engine performance and even improve it. Meanwhile, exhaust emissions are much decreased. Finally, a 15% blend of castor oil-biodiesel was picked as the optimized blend of biodiesel-diesel. It was found that lower blends of castor biodiesel are an acceptable fuel alternative for the engine.

  9. Exhaust emissions from a diesel power generator fuelled by waste cooking oil biodiesel.

    PubMed

    Valente, Osmano Souza; Pasa, Vanya Márcia Duarte; Belchior, Carlos Rodrigues Pereira; Sodré, José Ricardo

    2012-08-01

    The exhaust emissions from a diesel power generator operating with waste cooking oil biodiesel blends have been studied. Fuel blends with 25%, 50% and 75% of biodiesel concentration in diesel oil were tested, varying engine load from 0 to 25 kW. The original engine settings for diesel oil operation were kept the same during the experiments with the biodiesel blends. The main physical-chemical characteristics of the fuel blends used were measured to help with the analysis of the emission results. The results show that the addition of biodiesel to the fuel increases oxides of nitrogen (NO(X)), carbon monoxide (CO) and hydrocarbon (HC) emissions. Carbon dioxide (CO(2)) and exhaust gas opacity were also increased with the use of biodiesel. Major increase of NO(X) was observed at low loads, while CO and HC were mainly increased at high loads. Using 50% of biodiesel in diesel oil, the average increase of CO(2), CO, HC and NO(X) throughout the load range investigated was 8.5%, 20.1%, 23.5% and 4.8%, respectively. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Markers of exposure to diesel exhaust and cigarette smoke in railroad workers

    SciTech Connect

    Hammond, S.K.; Smith, T.J.; Woskie, S.R.; Leaderer, B.P.; Bettinger, N.

    1988-10-01

    Diesel exhaust is a complex mixture of combustion gases, vapors and particles, and personal exposure can be estimated indirectly only. Quantitative estimates of exposure were developed for thirteen job groups in a large epidemiologic study of mortality among railroad workers. Three possible markers of exhaust exposure were developed. The first index was the concentration of respirable particles because this was simple and inexpensive to measure precisely. Major positive interference, however, was found from environmental tobacco smoke (ETS) and inorganic respirable particles from other emission sources. Composited job group samples were analyzed for particulate nicotine so the ETS component could be subtracted from the respirable particle concentration. This produced a second exposure index, the adjusted respirable particle concentrations. Since there are nondiesel sources of particles in some work areas, a third marker was sought. Diesel exhaust particles have a relatively high content of dichloromethane extractable matter, but inorganic particles have a low extractable content. Therefore, the air concentration of extractable mass was used as a third marker of diesel exposures. The extractable matter also was corrected for the contribution of ETS. The advantages and limitations of these three markers are of interest. In general, considerable caution should be used in the development and application of markers; their use requires detailed knowledge of the nature and sources of exposure in a given setting.

  11. Symptoms in Response to Controlled Diesel Exhaust More Closely Reflect Exposure Perception Than True Exposure

    PubMed Central

    Carlsten, Chris; Oron, Assaf P.; Curtiss, Heidi; Jarvis, Sara; Daniell, William; Kaufman, Joel D.

    2013-01-01

    Background Diesel exhaust (DE) exposures are very common, yet exposure-related symptoms haven’t been rigorously examined. Objective Describe symptomatic responses to freshly generated and diluted DE and filtered air (FA) in a controlled human exposure setting; assess whether such responses are altered by perception of exposure. Methods 43 subjects participated within three double-blind crossover experiments to order-randomized DE exposure levels (FA and DE calibrated at 100 and/or 200 micrograms/m3 particulate matter of diameter less than 2.5 microns), and completed questionnaires regarding symptoms and dose perception. Results For a given symptom cluster, the majority of those exposed to moderate concentrations of diesel exhaust do not report such symptoms. The most commonly reported symptom cluster was of the nose (29%). Blinding to exposure is generally effective. Perceived exposure, rather than true exposure, is the dominant modifier of symptom reporting. Conclusion Controlled human exposure to moderate-dose diesel exhaust is associated with a range of mild symptoms, though the majority of individuals will not experience any given symptom. Blinding to DE exposure is generally effective. Perceived DE exposure, rather than true DE exposure, is the dominant modifier of symptom reporting. PMID:24358296

  12. Diesel Engine Exhaust Initiates a Sequence of Pulmonary and Cardiovascular Effects in Rats

    PubMed Central

    Kooter, Ingeborg M.; Gerlofs-Nijland, Miriam E.; Boere, A. John F.; Leseman, Daan L. A. C.; Fokkens, Paul H. B.; Spronk, Henri M. H.; Frederix, Kim; ten Cate, Hugo; Knaapen, Ad M.; Vreman, Hendrik J.; Cassee, Flemming R.

    2010-01-01

    This study was designed to determine the sequence of events leading to cardiopulmonary effects following acute inhalation of diesel engine exhaust in rats. Rats were exposed for 2 h to diesel engine exhaust (1.9 mg/m3), and biological parameters related to antioxidant defense, inflammation, and procoagulation were examined after 4, 18, 24, 48, and 72 h. This in vivo inhalation study showed a pulmonary anti-oxidant response (an increased activity of the anti-oxidant enzymes glutathione peroxidase and superoxide dismutase and an increase in heme oxygenase-1 protein, heme oxygenase activity, and uric acid) which precedes the inflammatory response (an increase in IL-6 and TNF-α). In addition, increased plasma thrombogenicity and immediate anti-oxidant defense gene expression in aorta tissue shortly after the exposure might suggest direct translocation of diesel engine exhaust components to the vasculature but mediation by other pathways cannot be ruled out. This study therefore shows that different stages in oxidative stress are not only affected by dose increments but are also time dependent. PMID:21052503

  13. Health effects of exposure to diesel exhaust particles

    SciTech Connect

    McClellan, R.O.

    1987-01-01

    Diesel-powered vehicles emit substantially more particles than do gasoline-powered vehicles with contemporary emission control systems. The DEP are submicron in size and readily inhaled. Approximately one-fourth of the particle mass inhaled by people is deposited in the pulmonary region, some of which is retained with a half-life of several hundred days. In animal studies, exposure to high levels of DEP overwhelms the normal clearance mechanisms and results in lung burdens of DEP that exceed those predicted from observations at lower exposure concentrations. A variable amount of the mass of DEP is extractable with strong organic solvents. The extracted material contains more than a thousand individual compounds and is mutagenic in a number of bacterial and mammalian cell assays. Bioassay-directed chemical analysis of DEP had identified several hundred compounds. Many are PAHs, some of which are considered to have human carcinogenic potential. A number of nitrated compounds have been identified that account for a significant portion of the mutagenicity assayed in bacteria. The mutagenicity of the DEPE is generally reduced by addition of an S-9 cellular fraction or of serum proteins. Macrophages rapidly reduce the recoverable mutagenic activity associated with DEP. The association of benzo(a)pyrene and nitropyrene with DEP prolongs their retention in the lungs. This increased retention suggests the need to clarify the relative importance of competing mechanisms that detoxify particle-associated compounds and those that serve to enhance the retention of toxicologically important compounds. 109 references.

  14. Thermoelectric Generators for the Integration into Automotive Exhaust Systems for Passenger Cars and Commercial Vehicles

    NASA Astrophysics Data System (ADS)

    Frobenius, Fabian; Gaiser, Gerd; Rusche, Ulrich; Weller, Bernd

    2016-03-01

    A special thermoelectric generator system design and the setup of a thermoelectric generator for the integration into the exhaust line of combustion engine-driven vehicles are described. A prototype setup for passenger cars and the effects on the measured power output are shown. Measurement results using this setup show the potential and the limitations of a setup based on thermoelectric modules commercially available today. In a second step, a short outline of the detailed mathematical modeling of the thermoelectric generator and simulation studies based on this model are presented. By this means, it can be shown by which measures an improvement of the system power output can be achieved—even if today's modules are used. Furthermore, simulation studies show how the exhaust gas conditions of diesel- and Otto-engines significantly affect the requirements on thermoelectric materials as well as the potential and the design of the thermoelectric generator. In a further step, the design and the setup of a thermoelectric generator for an application in a commercial vehicle are presented. This thermoelectric generator is designed to be integrated into the exhaust aftertreatment box of the vehicle. Experimental results with this setup are performed and presented. The results show that thermoelectric generators can become an interesting technology for exhaust waste heat recovery due to the fact that they comprise non-moving parts. However, the efficiency of the modules commercially available today is still far from what is required. Hence, modules made of new materials known from laboratory samples are urgently required. With regard to future CO2 regulations, a large market opportunity for modules with a high efficiency can be expected.

  15. On-line analysis of diesel engine exhaust gases by selected ion flow tube mass spectrometry.

    PubMed

    Smith, David; Spanĕl, Patrik; Dabill, David; Cocker, John; Rajan, Bob

    2004-01-01

    Selected ion flow tube mass spectrometry (SIFT-MS) has been used to analyse on-line and in real time the exhaust gas emissions from a Caterpillar 3304 diesel engine under different conditions of load (idle and 50% of rated load) and speed (910, 1500 and 2200 rpm) using three types of fuel: an ultra-low-sulphur diesel, a rapeseed methyl ester and gas oil. SIFT-MS analyses of the alkanes, alkenes and aromatic hydrocarbons in the headspace of these fuels were also performed, but the headspace of the rapeseed methyl ester consists mainly of methanol and a compound with the molecular formula C4H8O. The exhaust gases were analysed for NO and NO2 using O2+* reagent ions and for HNO2 using H3O+ reagent ions. The following aldehydes and ketones in the exhaust gases were quantified by using the combination of H3O+ and NO+ reagent ions: formaldehyde, acetaldehyde, propenal, propanal, acetone, butanal, pentanal, butanone and pentanone. Formaldehyde, acetaldehyde and pentenal, all known respiratory irritants associated with sensitisation to asthma of workers exposed to diesel exhaust, are variously present within the range 100-2000 ppb. Hydrocarbons in the exhaust gases accessible to SIFT-MS analyses were also quantified as total concentrations of the various isomers of C3H4, C3H6, C4H6, C5H8, C5H10, C6H8, C6H10, C7H14, C6H6, C7H8, C8H10 and C9H12. 2004 John Wiley & Sons, Ltd.

  16. Model studies of volatile diesel exhaust particle formation: are organic vapours involved in nucleation and growth?

    NASA Astrophysics Data System (ADS)

    Pirjola, L.; Karl, M.; Rönkkö, T.; Arnold, F.

    2015-09-01

    A high concentration of volatile nucleation mode particles (NUP) formed in the atmosphere when the exhaust cools and dilutes has hazardous health effects and it impairs the visibility in urban areas. Nucleation mechanisms in diesel exhaust are only poorly understood. We performed model studies using two sectional aerosol dynamics process models AEROFOR and MAFOR on the formation of particles in the exhaust of a diesel engine, equipped with an oxidative after-treatment system and running with low fuel sulfur content (FSC) fuel, under laboratory sampling conditions where the dilution system mimics real-world conditions. Different nucleation mechanisms were tested. Based on the measured gaseous sulfuric acid (GSA) and non-volatile core and soot particle number concentrations of the raw exhaust, the model simulations showed that the best agreement between model predictions and measurements in terms of particle number size distribution was obtained by barrier-free heteromolecular homogeneous nucleation between the GSA and a semi-volatile organic vapour combined with the homogeneous nucleation of GSA alone. Major growth of the particles was predicted to occur due to the similar organic vapour at concentrations of (1-2) × 1012 cm-3. The pre-existing core and soot mode concentrations had an opposite trend on the NUP formation, and the maximum NUP formation was predicted if a diesel particle filter (DPF) was used. On the other hand, the model predicted that the NUP formation ceased if the GSA concentration in the raw exhaust was less than 1010 cm-3, which was the case when biofuel was used.

  17. Epidemiological-environmental study of diesel bus garage workers: chronic effects of diesel exhaust on the respiratory system

    SciTech Connect

    Gamble, J.; Jones, W.; Minshall, S.

    1987-10-01

    Two hundred and eighty-three (283) male diesel bus garage workers from four garages in two cities were examined to determine if there was excess chronic respiratory morbidity related to diesel exposure. The dependent variables were respiratory symptoms, radiographic interpretation for pneumoconiosis, and pulmonary function (FVC, FEV1, and flow rates). Independent variables included race, age, smoking, drinking, height, and tenure (as surrogate measure of exposure). Exposure-effect relationships within the study population showed no detectable associations of symptoms with tenure. There was an apparent association of pulmonary function and tenure. Seven workers (2.5%) had category 1 pneumoconiosis (three rounded opacities, two irregular opacities, and one with both rounded and irregular). The study population was also compared to a nonexposed blue-collar population. After indirect adjustment for age, race, and smoking, the study population had elevated prevalences of cough, phlegm, and wheezing, but there was no association with tenure. Dyspnea showed a dose-response trend but no apparent increase in prevalence. Mean percent predicted pulmonary function of the study population was greater than 100%, i.e., elevated above the comparison population. These data show there is an apparent effect of diesel exhaust on pulmonary function but not chest radiographs. Respiratory symptoms are high compared to blue-collar workers, but there is no relationship with tenure.

  18. Simulation and Optimization of the Heat Exchanger for Automotive Exhaust-Based Thermoelectric Generators

    NASA Astrophysics Data System (ADS)

    Su, C. Q.; Huang, C.; Deng, Y. D.; Wang, Y. P.; Chu, P. Q.; Zheng, S. J.

    2016-03-01

    In order to enhance the exhaust waste heat recovery efficiency of the automotive exhaust-based thermoelectric generator (TEG) system, a three-segment heat exchanger with folded-shaped internal structure for the TEG system is investigated in this study. As the major effect factors of the performance for the TEG system, surface temperature, and thermal uniformity of the heat exchanger are analyzed in this research, pressure drop along the heat exchanger is also considered. Based on computational fluid dynamics simulations and temperature distribution, the pressure drop along the heat exchanger is obtained. By considering variable length and thickness of folded plates in each segment of the heat exchanger, response surface methodology and optimization by a multi-objective genetic algorithm is applied for surface temperature, thermal uniformity, and pressure drop for the folded-shaped heat exchanger. An optimum design based on the optimization is proposed to improve the overall performance of the TEG system. The performance of the optimized heat exchanger in different engine conditions is discussed.

  19. Effect of Thermoelectric Modules' Topological Connection on Automotive Exhaust Heat Recovery System

    NASA Astrophysics Data System (ADS)

    Deng, Y. D.; Zheng, S. J.; Su, C. Q.; Yuan, X. H.; Yu, C. G.; Wang, Y. P.

    2016-03-01

    In automotive exhaust-based thermoelectric generators (AETEGs), a certain number of thermoelectric modules are connected in series and/or parallel to recover energy from exhaust gas, which provides a way to improve fuel efficiency of the vehicle. Because of the temperature distribution on the surfaces of heat exchanger, several types of modules are planned for use in an AETEG; however, property disparities among modules exist and wire resistance cannot be neglected in practical application, so experiments have been carried out to research effects of the two factors on the maximum output power of series and parallel connection. The performance of series and parallel connections have been characterized, and mathematic models have been built to analyze and predict the performance of each connection. Experiments and theoretical analysis reveal that parallel connection shows a better performance than series connection when large differences of Seebeck coefficient and resistivity exist. However, wire resistance will cause more significant power dissipation in parallel connection. The authors believe the research presented in this paper is the first to carry out an examination of the impact of module property disparity and wire resistance on the output power of an array of thermoelectric modules connected in series and parallel, which provides a reference for choosing module connection in AETEGs.

  20. The Diesel Exhaust in Miners Study: A Cohort Mortality Study With Emphasis on Lung Cancer

    PubMed Central

    Schleiff, Patricia L.; Lubin, Jay H.; Blair, Aaron; Stewart, Patricia A.; Vermeulen, Roel; Coble, Joseph B.; Silverman, Debra T.

    2012-01-01

    Background Current information points to an association between diesel exhaust exposure and lung cancer and other mortality outcomes, but uncertainties remain. Methods We undertook a cohort mortality study of 12 315 workers exposed to diesel exhaust at eight US non-metal mining facilities. Historical measurements and surrogate exposure data, along with study industrial hygiene measurements, were used to derive retrospective quantitative estimates of respirable elemental carbon (REC) exposure for each worker. Standardized mortality ratios and internally adjusted Cox proportional hazard models were used to evaluate REC exposure–associated risk. Analyses were both unlagged and lagged to exclude recent exposure such as that occurring in the 15 years directly before the date of death. Results Standardized mortality ratios for lung cancer (1.26, 95% confidence interval [CI] = 1.09 to 1.44), esophageal cancer (1.83, 95% CI = 1.16 to 2.75), and pneumoconiosis (12.20, 95% CI = 6.82 to 20.12) were elevated in the complete cohort compared with state-based mortality rates, but all-cause, bladder cancer, heart disease, and chronic obstructive pulmonary disease mortality were not. Differences in risk by worker location (ever-underground vs surface only) initially obscured a positive diesel exhaust exposure–response relationship with lung cancer in the complete cohort, although it became apparent after adjustment for worker location. The hazard ratios (HRs) for lung cancer mortality increased with increasing 15-year lagged cumulative REC exposure for ever-underground workers with 5 or more years of tenure to a maximum in the 640 to less than 1280 μg/m3-y category compared with the reference category (0 to <20 μg/m3-y; 30 deaths compared with eight deaths of the total of 93; HR = 5.01, 95% CI = 1.97 to 12.76) but declined at higher exposures. Average REC intensity hazard ratios rose to a plateau around 32 μg/m3. Elevated hazard ratios and evidence of exposure

  1. Porphyrin metabolism in lymphocytes of miners exposed to diesel exhaust at oil shale mine.

    PubMed

    Muzyka, V; Scheepers, P T J; Bogovski, S; Lang, I; Schmidt, N; Ryazanov, V; Veidebaum, T

    2004-04-25

    The present study was carried out on the evaluation and application of new biomarkers for populations exposed to occupational diesel exhaust at oil shale mines. Since not only genotoxic effects may play an important role in the generation of tumors, the level of porphyrin metabolism was proposed as a biomarker of diesel exhaust exposure effects. The data on determination of 5-aminolevulinic acid (ALA) synthesis and heme formation in lymphocytes from groups of 50 miners exposed to diesel exhaust and 50 unexposed surface workers of oil shale mine are presented. All workers were examined and interviewed using structured questionnaires. The levels of benzene, carbon monoxide and nitric oxides in air as well as concentrations of 1-nitropyrene and elemental carbon in particulate matter were used for evaluation of exposure to diesel exhaust in mine. The levels of ALA and protoporphyrin (PP), activities of ALA synthetase (ALA-S) and ferrochelatase (FC), as well as levels of PP associated with DNA (PP/DNA) were investigated in lymphocytes spectrophotometrically. Significant differences in activity of ALA synthesis and heme formation between exposed miners and surface workers were found (207+/-23 vs. 166+/-14 pmol/10(6) lymp./30' for ALA-S and 46.1+/-3.8 vs. 54.8+/-4.1 pmol/10(6) lymp./60' for FC activities, respectively, P<0.001). ALA-S activity was higher and ALA accumulated in lymphocytes of exposed miners. Inhibition of FC activity caused PP cellular accumulation and an increase in the PP/DNA level (P<0.05). Tobacco smoking led to the increase of ALA biosynthesis in lymphocytes of both surface and underground smokers. The comparison of data obtained for non-smokers and smokers of both groups of workers has shown a significant difference (P<0.05). The work duration of underground or surface workers did not significantly influence the investigated biochemical parameters. The determination of ALA synthesis in lymphocytes could be a useful biomonitoring index of organism

  2. Advanced Collaborative Emissions Study Auxiliary Findings on 2007-Compliant Diesel Engines: A Comparison With Diesel Exhaust Genotoxicity Effects Prior to 2007

    PubMed Central

    Hallberg, Lance M; Ward, Jonathan B; Wickliffe, Jeffrey K; Ameredes, Bill T

    2017-01-01

    Since its beginning, more than 117 years ago, the compression-ignition engine, or diesel engine, has grown to become a critically important part of industry and transportation. Public concerns over the health effects from diesel emissions have driven the growth of regulatory development, implementation, and technological advances in emission controls. In 2001, the United States Environmental Protection Agency and California Air Resources Board issued new diesel fuel and emission standards for heavy-duty engines. To meet these stringent standards, manufacturers used new emission after-treatment technology, and modified fuel formulations, to bring about reductions in particulate matter and nitrogen oxides within the exhaust. To illustrate the impact of that technological transition, a brief overview of pre-2007 diesel engine exhaust biomarkers of genotoxicity and health-related concerns is provided, to set the context for the results of our research findings, as part of the Advanced Collaborative Emissions Study (ACES), in which the effects of a 2007-compliant diesel engine were examined. In agreement with ACES findings reported in other tissues, we observed a lack of measurable 2007-compliant diesel treatment–associated DNA damage, in lung tissue (comet assay), blood serum (8-hydroxy-2′-deoxyguanosine [8-OHdG] assay), and hippocampus (lipid peroxidation assay), across diesel exhaust exposure levels. A time-dependent assessment of 8-OHdG and lipid peroxidation also suggested no differences in responses across diesel exhaust exposure levels more than 24 months of exposure. These results indicated that the 2007-compliant diesel engine reduced measurable reactive oxygen species–associated tissue derangements and suggested that the 2007 standards–based mitigation approaches were effective. PMID:28659715

  3. Advanced Collaborative Emissions Study Auxiliary Findings on 2007-Compliant Diesel Engines: A Comparison With Diesel Exhaust Genotoxicity Effects Prior to 2007.

    PubMed

    Hallberg, Lance M; Ward, Jonathan B; Wickliffe, Jeffrey K; Ameredes, Bill T

    2017-01-01

    Since its beginning, more than 117 years ago, the compression-ignition engine, or diesel engine, has grown to become a critically important part of industry and transportation. Public concerns over the health effects from diesel emissions have driven the growth of regulatory development, implementation, and technological advances in emission controls. In 2001, the United States Environmental Protection Agency and California Air Resources Board issued new diesel fuel and emission standards for heavy-duty engines. To meet these stringent standards, manufacturers used new emission after-treatment technology, and modified fuel formulations, to bring about reductions in particulate matter and nitrogen oxides within the exhaust. To illustrate the impact of that technological transition, a brief overview of pre-2007 diesel engine exhaust biomarkers of genotoxicity and health-related concerns is provided, to set the context for the results of our research findings, as part of the Advanced Collaborative Emissions Study (ACES), in which the effects of a 2007-compliant diesel engine were examined. In agreement with ACES findings reported in other tissues, we observed a lack of measurable 2007-compliant diesel treatment-associated DNA damage, in lung tissue (comet assay), blood serum (8-hydroxy-2'-deoxyguanosine [8-OHdG] assay), and hippocampus (lipid peroxidation assay), across diesel exhaust exposure levels. A time-dependent assessment of 8-OHdG and lipid peroxidation also suggested no differences in responses across diesel exhaust exposure levels more than 24 months of exposure. These results indicated that the 2007-compliant diesel engine reduced measurable reactive oxygen species-associated tissue derangements and suggested that the 2007 standards-based mitigation approaches were effective.

  4. Diesel Exhaust Exposure Assessment Among Tunnel Construction Workers-Correlations Between Nitrogen Dioxide, Respirable Elemental Carbon, and Particle Number.

    PubMed

    Hedmer, Maria; Wierzbicka, Aneta; Li, Huiqi; Albin, Maria; Tinnerberg, Håkan; Broberg, Karin

    2017-06-01

    Occupational exposure to diesel exhaust is common due the widespread use of diesel-powered combustion engines. Diesel exhaust is chemically complex and consists of thousands of compounds present as gases and particulate matter. Both nitrogen dioxide (NO2) and elemental carbon (EC) have been used as markers for diesel exhaust exposure. Currently EC is regarded as the best surrogate of diesel exhaust. The objective was to quantify the occupational exposure to diesel exhaust in underground tunnel construction work using a multi-metric approach, and to investigate the correlations between NO2, respirable EC, respirable organic carbon (OC), respirable total carbon (TC), respirable dust (RD), and particle number. Also, the use of NO2 as a proxy for diesel exhaust was evaluated, how much of the variability in the diesel exhaust exposure was attributed to within and between individual factors and if there was a difference between expert and self-administered measurements of NO2. The personal exposure to diesel exhaust was assessed by expert supervised measurements of NO2, EC, OC, TC, RD and particle number in the breathing zones of underground tunnel workers. Stationary sampling of NO2, EC, OC, TC, RD, size-fractioned mass concentration, and particle number were conducted. The personal and stationary measurements were conducted on three occasions simultaneously. The workers measured their exposure by repeated self-administered measurements of NO2. The self-administered measurements were performed twice for each worker with at least one month lag between the samplings. In the simultaneous sampling of diesel exhaust, the geometric mean (GM) concentration of NO2 and respirable EC were 72 µg m-3 (10th-90th percentile 34-140 µg m-3) and 2.6 µg m-3 (10th-90th percentile 1.6-7.3 µg m-3), respectively. The GM for OC and TC was 28 µg m-3 (10th-90th percentile 20-42 µg m-3) and 31 µg m-3 (10th-90th percentile 20-50 µg m-3), respectively. The GM for RD and particle number was

  5. Differential Responses upon Inhalation Exposure to Biodiesel versus Diesel Exhaust on Oxidative Stress, Inflammatory and Immune Outcomes

    EPA Science Inventory

    Biodiesel (BD) exhaust may have reduced adverse health effects due to lower mass emissions and reduced production of hazardous compounds compared to diesel exhaust. To investigate this possibility, we compared adverse effects in lungs and liver of BALB/cJ mice after inhalation ex...

  6. Differential Responses upon Inhalation Exposure to Biodiesel versus Diesel Exhaust on Oxidative Stress, Inflammatory and Immune Outcomes

    EPA Science Inventory

    Biodiesel (BD) exhaust may have reduced adverse health effects due to lower mass emissions and reduced production of hazardous compounds compared to diesel exhaust. To investigate this possibility, we compared adverse effects in lungs and liver of BALB/cJ mice after inhalation ex...

  7. Centriacinar alterations in lungs of cats chronically exposed to diesel exhaust

    SciTech Connect

    Plopper, C.G.; Hyde, D.M.; Weir, A.J.

    1983-10-01

    This study describes the morphologic changes in the centriacinar regions of lungs following long-term exposure of cats to diesel exhaust. Nine male cats (13 months of age) from a minimal disease colony were exposed to diesel exhaust for 8 hours/day, 7 days/week for 27 months. Eight cats were exposed to filtered air. Following exposure, the animals were killed by exsanguination and the lungs and trachea removed from the chest by thoracotomy, weighed, and fixed via tracheal cannula with glutaraldehyde/paraformaldehyde (550 mOsmoles, pH 7.4) at 30 cm of pressure. Centriacinar regions were selected from fixed tissue, the airways bisected, and complementary tissue halves processed by a large block method for high resolution light microscopy and for scanning electron microscopy. Compared with controls, diesel-exposed cats had lower fresh lung and kidney weights and lower fixed volumes of the right cranial lobe. The volume fractions of pulmonary parenchyma and nonparenchyma were unchanged. Epithelium of terminal and respiratory bronchioles in exposed cats consisted of three types of cells (ciliated, basal, and Clara cells), compared with only one type (Clara cells) in controls. Carbon-laden macrophages were found filling alveolar and interstitial spaces in exposed animals. Type 2 pneumocyte hyperplasia was present in proximal interalveolar septa. More distal alveolar ducts and the majority of the rest of the parenchyma were unchanged from controls. We concluded that exposure to diesel exhaust produces changes in both epithelial and interstitial tissue compartments and that the focus of these lesions in peripheral lung is the centriacinar region where alveolar ducts join terminal conducting airways.

  8. Primary particulate emissions and secondary organic aerosol (SOA) formation from idling diesel vehicle exhaust in China.

    PubMed

    Deng, Wei; Hu, Qihou; Liu, Tengyu; Wang, Xinming; Zhang, Yanli; Song, Wei; Sun, Yele; Bi, Xinhui; Yu, Jianzhen; Yang, Weiqiang; Huang, Xinyu; Zhang, Zhou; Huang, Zhonghui; He, Quanfu; Mellouki, Abdelwahid; George, Christian

    2017-09-01

    In China diesel vehicles dominate the primary emission of particulate matters from on-road vehicles, and they might also contribute substantially to the formation of secondary organic aerosols (SOA). In this study tailpipe exhaust of three typical in-use diesel vehicles under warm idling conditions was introduced directly into an indoor smog chamber with a 30m(3) Teflon reactor to characterize primary emissions and SOA formation during photo-oxidation. The emission factors of primary organic aerosol (POA) and black carbon (BC) for the three types of Chinese diesel vehicles ranged 0.18-0.91 and 0.15-0.51gkg-fuel(-1), respectively; and the SOA production factors ranged 0.50-1.8gkg-fuel(-1) and SOA/POA ratios ranged 0.7-3.7 with an average of 2.2. The fuel-based POA emission factors and SOA production factors from this study for idling diesel vehicle exhaust were 1-3 orders of magnitude higher than those reported in previous studies for idling gasoline vehicle exhaust. The emission factors for total particle numbers were 0.65-4.0×10(15)particleskg-fuel(-1), and particles with diameters less than 50nm dominated in total particle numbers. Traditional C2-C12 precursor non-methane hydrocarbons (NMHCs) could only explain less than 3% of the SOA formed during aging and contribution from other precursors including intermediate volatile organic compounds (IVOC) needs further investigation. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Effects of Exposure to Nanoparticle-rich Diesel Exhaust on Pregnancy in Rats

    PubMed Central

    LI, ChunMei; LI, Xuezheng; SUZUKI, Akira K.; ZHANG, Yonghui; FUJITANI, Yuji; NAGAOKA, Kentaro; WATANABE, Gen; TAYA, Kazuyoshi

    2012-01-01

    Abstract Pollutants from burning of diesel fuel are hazardous to human health. Nanoparticles in diesel exhaust potentially have profound impact on fetal development and maternal endocrine function during pregnancy due to their ability to penetrate deeply into the body. To investigate the effects of nanoparticle-rich diesel exhaust (NR-DE) on pregnancy, pregnant rats were exposed to NR-DE, filtered diesel exhaust (F-DE) or clean air for 19 days of gestation. Relative weights of maternal liver and spleen to body weight were significantly lower in the NR-DE and F-DE groups than those in the control group. The serum concentration of maternal progesterone was significantly lower, while those of luteinizing hormone (LH) and corticosterone were significantly higher in the NR-DE and F-DE groups than those in the control group. The serum concentration of estradiol-17β was significantly higher in the F-DE group than that in the control group. The levels of cytochrome P450 side-chain cleavage enzyme, 3β-hydroxysteroid dehydrogenase and LH receptor mRNA in the corpus luteum were significantly lower in the NR-DE and F-DE groups than those in the control. In fetuses, body weight and crown-rump length were significantly greater and shorter, respectively, in both males and females in the NR-DE and F-DE groups than those in the control group. These results demonstrate that exposure of pregnant rats to NR-DE and F-DE suppresses the function of corpora lutea and stimulates the function of the adrenal cortex, suggesting a risk of spontaneous abortion associated with maternal hormonal changes. PMID:23257834

  10. Particulate control for coal-fueled diesel engine exhaust

    SciTech Connect

    Smolensky, L.A.; Easom, B.H.

    1993-11-01

    The Core Separator is a cylindrical vessel having one tangential inlet and two outlets at the opposite end of the vessel. It contains an outlet for the clean flow and a second outlet for the recirculating flow. The solids-laden flue gas is introduced through a fan to the inlet of the Core Separator. Due to the swirling motion of the flow, solids move to the periphery as the central jet leaving the system through the central outlet is cleaned of particulates. The peripheral flow with most of the particles is exhausted to the cyclone and then recirculates back to the Core Separator by means of the fan. The processes of separation and solids collection are accomplished separately and in different components. The Core Separator cleans the flow discharged from the system and detains solids within the system If the Core Separator efficiency is high enough, particles cannot leave the system. They recirculate again and again until the cyclone finally collects them for removal. An analytical formula can be derived that defines the system performance. E = E{sub c}E{sub s}/1{minus}E{sub s}(1{minus}E{sub c}), where E, E{sub c}, and E{sub s} are the system, collector, and Core Separator partial separation efficiencies respectively. Examination of this equation shows that the system efficiency remains high even with poor performance in the collector, as long as the efficiency of the Core Separator is high. For example, if E{sub s} is 99% and E{sub c} is 30%, the system efficiency is 96.7%.

  11. COMPARATIVE STUDY ON EXHAUST EMISSIONS FROM DIESEL- AND CNG-POWERED URBAN BUSES

    SciTech Connect

    COROLLER, P; PLASSAT, G

    2003-08-24

    Couple years ago, ADEME engaged programs dedicated to the urban buses exhaust emissions studies. The measures associated with the reduction of atmospheric and noise pollution has particular importance in the sector of urban buses. In many cases, they illustrate the city's environmental image and contribute to reinforcing the attractiveness of public transport. France's fleet in service, presently put at about 14,000 units, consumes about 2 per cent of the total energy of city transport. It causes about 2 per cent of the HC emissions and from 4 to 6 per cent of the NOx emissions and particles. These vehicles typically have a long life span (about 15 years) and are relatively expensive to buy, about 150.000 euros per unit. Several technical solutions were evaluated to quantify, on a real condition cycle for buses, on one hand pollutants emissions, fuel consumption and on the other hand reliability, cost in real existing fleet. This paper presents main preliminary results on urban buses exhaust emission on two different cases: - existing Diesel buses, with fuel modifications (Diesel with low sulphur content), Diesel with water emulsion and bio-Diesel (30% oil ester in standard Diesel fuel); renovating CNG powered Euro II buses fleet, over representative driving cycles, set up by ADEME and partners. On these cycles, pollutants (regulated and unregulated) were measured as well as fuel consumption, at the beginning of a program and one year after to quantify reliability and increase/decrease of pollutants emissions. At the same time, some after-treatment technologies were tested under real conditions and several vehicles. Information such as fuel consumption, lubricant analysis, problem on the technology were following during a one year program. On the overall level, it is the combination of various action, pollution-reduction and renewal that will make it possible to meet the technological challenge of reducing emissions and fuel consumption by urban bus networks.

  12. Potential dilemma: the methods of meeting automotive exhaust emission standards of the clean air act of 1970.

    PubMed

    Piver, W T

    1974-08-01

    This review attempts to provide an overview of the interconnected industrial changes associated with compliance with the exhaust emission standards of the Clean Air Act of 1970. To understand the complex nature of air pollution problems, Federal legislation, and compliance with this legislation requires an understanding of automotive technology, petroleum refining, atmospheric chemistry and physics, economics, and public health. The endeavors of all of these different areas impinge to a greater or lesser extent on the final response to the Clean Air Act which is designed to safeguard public health. This overview begins by examining gasoline refinery practice and gasoline composition. Included in this discussion are average values for trace contaminants in gasoline, and an explanation of the function of the many gasoline additives. Next, exhaust emissions are characterized, average values of exhaust components given, and a summary of important atmospheric air pollution reactions presented. Emission control devices and sulfate emissions from these devices are described. This is followed by a complete discussion of methyl cyclopentadienyl manganese tricarbonyl, a substitute antiknock for tetraethyllead. In the event TEL is legally banned from gasoline, or removed because it poisons the catalytic muffler surface, this manganese antiknock is the most efficaous replacement. In this discussion, the adverse health effects caused by exposure to manganese oxide particulates, the possible exhaust emission products from this additive, are examined in detail. The review concludes with comments on automotive engine and gasoline composition redesign as an approach to automotive air pollution.

  13. Potential Dilemma: The Methods of Meeting Automotive Exhaust Emission Standards of the Clean Air Act of 1970

    PubMed Central

    Piver, Warren T.

    1974-01-01

    This review attempts to provide an overview of the interconnected industrial changes associated with compliance with the exhaust emission standards of the Clean Air Act of 1970. To understand the complex nature of air pollution problems, Federal legislation, and compliance with this legislation requires an understanding of automotive technology, petroleum refining, atmospheric chemistry and physics, economics, and public health. The endeavors of all of these different areas impinge to a greater or lesser extent on the final response to the Clean Air Act which is designed to safeguard public health. This overview begins by examining gasoline refinery practice and gasoline composition. Included in this discussion are average values for trace contaminants in gasoline, and an explanation of the function of the many gasoline additives. Next, exhaust emissions are characterized, average values of exhaust components given, and a summary of important atmospheric air pollution reactions presented. Emission control devices and sulfate emissions from these devices are described. This is followed by a complete discussion of methyl cyclopentadienyl manganese tricarbonyl, a substitute antiknock for tetraethyllead. In the event TEL is legally banned from gasoline, or removed because it poisons the catalytic muffler surface, this manganese antiknock is the most efficaous replacement. In this discussion, the adverse health effects caused by exposure to manganese oxide particulates, the possible exhaust emission products from this additive, are examined in detail. The review concludes with comments on automotive engine and gasoline composition redesign as an approach to automotive air pollution. PMID:4143457

  14. Effect of lubricant sulfur on the morphology and elemental composition of diesel exhaust particles.

    PubMed

    Tan, Piqiang; Li, Yuan; Shen, Hanyan

    2017-05-01

    This work investigates the effects of lubricant sulfur contents on the morphology, nanostructure, size distribution and elemental composition of diesel exhaust particle on a light-duty diesel engine. Three kinds of lubricant (LS-oil, MS-oil and HS-oil, all of which have different sulfur contents: 0.182%, 0.583% and 1.06%, respectively) were used in this study. The morphologies and nanostructures of exhaust particles were analyzed using high-resolution transmission electron microscopy (TEM). Size distributions of primary particles were determined through advanced image-processing software. Elemental compositions of exhaust particles were obtained through X-ray energy dispersive spectroscopy (EDS). Results show that as lubricant sulfur contents increase, the macroscopic structure of diesel exhaust particles turn from chain-like to a more complex agglomerate. The inner cores of the core-shell structure belonging to these primary particles change little; the shell thickness decreases, and the spacing of carbon layer gradually descends, and amorphous materials that attached onto outer carbon layer of primary particles increase. Size distributions of primary particles present a unimodal and normal distribution, and higher sulfur contents lead to larger size primary particles. The sulfur content in lubricants directly affects the chemical composition in the particles. The content of C (carbon) decreases as sulfur increases in the lubricants, while the contents of O (oxygen), S (sulfur) and trace elements (including S, Si (silicon), Fe (ferrum), P (phosphorus), Ca (calcium), Zn (zinc), Mg (magnesium), Cl (chlorine) and Ni (nickel)) all increase in particles. Copyright © 2017. Published by Elsevier B.V.

  15. Health effects research and regulation of diesel exhaust: an historical overview focused on lung cancer risk.

    PubMed

    Hesterberg, Thomas W; Long, Christopher M; Bunn, William B; Lapin, Charles A; McClellan, Roger O; Valberg, Peter A

    2012-06-01

    The mutagenicity of organic solvent extracts from diesel exhaust particulate (DEP), first noted more than 55 years ago, initiated an avalanche of diesel exhaust (DE) health effects research that now totals more than 6000 published studies. Despite an extensive body of results, scientific debate continues regarding the nature of the lung cancer risk posed by inhalation of occupational and environmental DE, with much of the debate focused on DEP. Decades of scientific scrutiny and increasingly stringent regulation have resulted in major advances in diesel engine technologies. The changed particulate matter (PM) emissions in "New Technology Diesel Exhaust (NTDE)" from today's modern low-emission, advanced-technology on-road heavy-duty diesel engines now resemble the PM emissions in contemporary gasoline engine exhaust (GEE) and compressed natural gas engine exhaust more than those in the "traditional diesel exhaust" (TDE) characteristic of older diesel engines. Even with the continued publication of epidemiologic analyses of TDE-exposed populations, this database remains characterized by findings of small increased lung cancer risks and inconsistent evidence of exposure-response trends, both within occupational cohorts and across occupational groups considered to have markedly different exposures (e.g. truckers versus railroad shopworkers versus underground miners). The recently published National Institute for Occupational Safety and Health (NIOSH)-National Cancer Institute (NCI) epidemiologic studies of miners provide some of the strongest findings to date regarding a DE-lung cancer association, but some inconsistent exposure-response findings and possible effects of bias and exposure misclassification raise questions regarding their interpretation. Laboratory animal studies are negative for lung tumors in all species, except for rats under lifetime TDE-exposure conditions with durations and concentrations that lead to "lung overload." The species specificity of the

  16. Genotoxic damage in mine workers exposed to diesel exhaust, and the effects of glutathione transferase genotypes.

    PubMed

    Knudsen, L E; Gaskell, M; Martin, E A; Poole, J; Scheepers, P T J; Jensen, A; Autrup, H; Farmer, P B

    2005-06-06

    This study was performed in an Estonian shale-oil mine with the purpose to develop and apply a number of biomarkers for occupational diesel-exhaust exposure monitoring. Increased breathing-zone exposures to exhaust from operators of diesel-powered trucks in the mine was confirmed in the environmental monitoring part of the study, showing a 7.5-fold higher exposure to particle-associated 1-nitropyrene (1-NP) in 50 underground workers compared with 42 surface workers [P.T.J. Scheepers, D. Coggon, L.E. Knudsen, R. Anzion, H. Autrup, S. Bogovski, R.P. Bos, D. Dahmann, P. Farmer, E.A. Martin, V. Micka, V. Muzyka, H.-G. Neumann, J. Poole, A. Schmidt-Ott, F. Seiler, J. Volf, I. Zwirner-Baier, Biomarkers for occupational diesel exhaust exposure monitoring (BIOMODEM)-a study in underground mining, Toxicol. Lett. 134 (2002) 305-317; P.T.J. Scheepers, V. Micka, V. Muzyka, R. Anzion, D. Dahmann, J. Poole, R.P. Bos, Exposure to dust and particle-associated 1-nitropyrene of drivers of diesel-powered equipment in underground mining, Ann. Occp. Hyg. 47 (2003) 379-388]. Analysis of DNA damage by the Comet assay on frozen blood samples was performed on the total study group and showed significantly higher levels (p=0.003) in underground workers (smokers) driving diesel-powered excavation machines (median 155 on a scale from 0 to 400, among 47 persons), compared with surface workers who smoked (median of 90, among 46 persons). The level of DNA damage in underground smokers was significantly higher (p=0.04) than in non-smokers. Samples from 2 of the 3 sampling weeks had significantly lower DNA damage compared with the third week, probably due to timely processing and freezing. These samples also showed significant differences (p<0.001) between underground workers (median 145, among 41 persons) and surface workers (median 60, among 30 persons). An HPLC method was developed for the analysis of (32)P-postlabelled 1-NP-DNA-adducts, and was applied to a sub-sample of 20 workers. No

  17. Diesel exhaust augments allergen-induced lower airway inflammation in allergic individuals: a controlled human exposure study.

    PubMed

    Carlsten, Chris; Blomberg, Anders; Pui, Mandy; Sandstrom, Thomas; Wong, Sze Wing; Alexis, Neil; Hirota, Jeremy

    2016-01-01

    Traffic-related air pollution has been shown to augment allergy and airway disease. However, the enhancement of allergenic effects by diesel exhaust in particular is unproven in vivo in the human lung, and underlying details of this apparent synergy are poorly understood. To test the hypothesis that a 2 h inhalation of diesel exhaust augments lower airway inflammation and immune cell activation following segmental allergen challenge in atopic subjects. 18 blinded atopic volunteers were exposed to filtered air or 300 µg PM(2.5)/m(3) of diesel exhaust in random fashion. 1 h post-exposure, diluent-controlled segmental allergen challenge was performed; 2 days later, samples from the challenged segments were obtained by bronchoscopic lavage. Samples were analysed for markers and modifiers of allergic inflammation (eosinophils, Th2 cytokines) and adaptive immune cell activation. Mixed effects models with ordinal contrasts compared effects of single and combined exposures on these end points. Diesel exhaust augmented the allergen-induced increase in airway eosinophils, interleukin 5 (IL-5) and eosinophil cationic protein (ECP) and the GSTT1 null genotype was significantly associated with the augmented IL-5 response. Diesel exhaust alone also augmented markers of non-allergic inflammation and monocyte chemotactic protein (MCP)-1 and suppressed activity of macrophages and myeloid dendritic cells. Inhalation of diesel exhaust at environmentally relevant concentrations augments allergen-induced allergic inflammation in the lower airways of atopic individuals and the GSTT1 genotype enhances this response. Allergic individuals are a susceptible population to the deleterious airway effects of diesel exhaust. NCT01792232. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  18. Smoking imputation and lung cancer in railroad workers exposed to diesel exhaust.

    PubMed

    Garshick, Eric; Laden, Francine; Hart, Jaime E; Smith, Thomas J; Rosner, Bernard

    2006-09-01

    An association between diesel exhaust exposure and lung cancer mortality in a large retrospective cohort study of US railroad workers has previously been reported. However, specific information regarding cigarette smoking was unavailable. Birth cohort, age, job, and cause of death specific smoking histories from a companion case-control study were used to impute smoking behavior for 39,388 railroad workers who died 1959-1996. Mortality analyses incorporated the effect of smoking on lung cancer risk. The smoking adjusted relative risk of lung cancer in railroad workers exposed to diesel exhaust compared to unexposed workers was 1.22 (95% CI = 1.12-1.32), and unadjusted for smoking the relative risk was 1.35 (95% CI = 1.24-1.46). These analyses illustrate the use of imputation in record-based occupational health studies to assess potential confounding due to smoking. In this cohort, small differences in smoking behavior between diesel exposed and unexposed workers did not explain the elevated lung cancer risk.

  19. Smoking imputation and lung cancer in railroad workers exposed to diesel exhaust

    PubMed Central

    Garshick, Eric; Laden, Francine; Hart, Jaime E; Smith, Thomas J; Rosner, Bernard

    2007-01-01

    Background An association between diesel exhaust exposure and lung cancer mortality in a large retrospective cohort study of US railroad workers has previously been reported. However, specific information regarding cigarette smoking was unavailable. Methods Birth cohort, age, job, and cause of death specific smoking histories from a companion case-control study were used to impute smoking behavior for 39,388 railroad workers who died 1959–1996. Mortality analyses incorporated the effect of smoking on lung cancer risk. Results The smoking adjusted relative risk of lung cancer in railroad workers exposed to diesel exhaust compared to unexposed workers was 1.22 (95% CI=1.12–1.32), and unadjusted for smoking the relative risk was 1.35 (95% CI=1.24–1.46). Conclusions These analyses illustrate the use of imputation in record-based occupational health studies to assess potential confounding due to smoking. In this cohort, small differences in smoking behavior between diesel exposed and unexposed workers did not explain the elevated lung cancer risk. PMID:16767725

  20. Glutathione peroxidase inhibitory assay for electrophilic pollutants in diesel exhaust and tobacco smoke

    PubMed Central

    Staimer, Norbert; Nguyen, Tran B.; Nizkorodov, Sergey A.; Delfino, Ralph J.

    2012-01-01

    We developed a rapid kinetic bioassay demonstrating the inhibition of glutathione peroxidase 1 (GPx-1) by organic electrophilic pollutants such as acrolein, crotonaldehyde, and p-benzoquinone that are frequently found as components of tobacco smoke, diesel exhaust, and other combustion sources. In a complementary approach, we applied a high-resolution proton-transfer reaction time-of-flight mass spectrometer (PTR-ToF-MS) to monitor in real-time the generation of electrophilic volatile carbonyls in cigarette smoke. The new bioassay uses the important antioxidant selenoenzyme GPx-1, immobilized to 96-well microtiter plates, as a probe. The selenocysteine bearing subunits of the enzyme's catalytic site are viewed as cysteine analogues and are vulnerable to electrophilic attack by compounds with conjugated carbonyl systems. The immobilization of GPx-1 to microtiter plate wells enabled facile removal of excess reactive inhibitory compounds after incubation with electrophilic chemicals or aqueous extracts of air samples derived from different sources. The inhibitory response of cigarette smoke and diesel exhaust particle extracts were compared to chemical standards of a group of electrophilic carbonyls and the arylating p-benzoquinone. GPx-1 activity was directly inactivated by millimolar concentrations of highly reactive electrophilic chemicals (including acrolein, glyoxal, methylglyoxal, and p-benzoquinone) and extracts of diesel and cigarette smoke. We conclude that the potential of air pollutant components to generate oxidative stress may be, in part, a result of electrophile-derived covalent modifications of enzymes involved in the cytosolic antioxidant defense. PMID:22349402

  1. Primary and Secondary Sources of Gas-Phase Organic Acids from Diesel Exhaust.

    PubMed

    Friedman, Beth; Link, Michael F; Fulgham, S Ryan; Brophy, Patrick; Galang, Abril; Brune, William H; Jathar, Shantanu H; Farmer, Delphine K

    2017-09-19

    Organic acids have primary and secondary sources in the atmosphere, impact ecosystem health, and are useful metrics for identifying gaps in organic oxidation chemistry through model-measurement comparisons. We photooxidized (OH oxidation) primary emissions from diesel and biodiesel fuel types under two engine loads in an oxidative flow reactor. formic, butyric, and propanoic acids, but not methacrylic acid, have primary and secondary sources. Emission factors for these gas-phase acids varied from 0.3-8.4 mg kg(-1) fuel. Secondary chemistry enhanced these emissions by 1.1 (load) to 4.4 (idle) × after two OH-equivalent days. The relative enhancement in secondary organic acids in idle versus loaded conditions was due to increased precursor emissions, not faster reaction rates. Increased hydrocarbon emissions in idle conditions due to less complete combustion (associated with less oxidized gas-phase molecules) correlated to higher primary organic acid emissions. The lack of correlation between organic aerosol and organic acid concentrations downstream of the flow reactor indicates that the secondary products formed on different oxidation time scales and that despite being photochemical products, organic acids are poor tracers for secondary organic aerosol formation from diesel exhaust. Ignoring secondary chemistry from diesel exhaust would lead to underestimates of both organic aerosol and gas-phase organic acids.

  2. Glutathione peroxidase inhibitory assay for electrophilic pollutants in diesel exhaust and tobacco smoke.

    PubMed

    Staimer, Norbert; Nguyen, Tran B; Nizkorodov, Sergey A; Delfino, Ralph J

    2012-04-01

    We developed a rapid kinetic bioassay demonstrating the inhibition of glutathione peroxidase 1 (GPx-1) by organic electrophilic pollutants, such as acrolein, crotonaldehyde, and p-benzoquinone, that are frequently found as components of tobacco smoke, diesel exhaust, and other combustion sources. In a complementary approach, we applied a high-resolution proton-transfer reaction time-of-flight mass spectrometer to monitor in real-time the generation of electrophilic volatile carbonyls in cigarette smoke. The new bioassay uses the important antioxidant selenoenzyme GPx-1, immobilized to 96-well microtiter plates, as a probe. The selenocysteine bearing subunits of the enzyme's catalytic site are viewed as cysteine analogues and are vulnerable to electrophilic attack by compounds with conjugated carbonyl systems. The immobilization of GPx-1 to microtiter plate wells enabled facile removal of excess reactive inhibitory compounds after incubation with electrophilic chemicals or aqueous extracts of air samples derived from different sources. The inhibitory response of cigarette smoke and diesel exhaust particle extracts were compared with chemical standards of a group of electrophilic carbonyls and the arylating p-benzoquinone. GPx-1 activity was directly inactivated by millimolar concentrations of highly reactive electrophilic chemicals (including acrolein, glyoxal, methylglyoxal, and p-benzoquinone) and extracts of diesel and cigarette smoke. We conclude that the potential of air pollutant components to generate oxidative stress may be, in part, a result of electrophile-derived covalent modifications of enzymes involved in the cytosolic antioxidant defense.

  3. A study on diffusion coefficients of diesel exhaust in a Korean coal mine

    SciTech Connect

    Lee, Changwoo

    1995-12-31

    Under drastically deteriorated situations, diesel equipment was introduced to some of local coal mines, aiming at higher productivity and better safety. To accommodate various diesel equipment in conventionally developed mines, mining system itself had to be modified; much larger trackless haulage ways were excavated. Possible health hazards of diesel not taken into account at the beginning become a serious concern and effective control measures are being searched for the purpose of this path is to study the diffusion characteristics of diesel exhaust in local coal mines. One of the parameters affecting dispersion of diesel contaminants is the coefficient of turbulent diffusion. Since CO is known to be closely correlated with other contaminants such as CO, NO, NO{sub 2}, SO{sub 2} and RCD, it was chosen as a tracer gas in a series of dispersion experiments. A large diesel passage as well as a conventional track haulage way were the sites for the experiments. Rectangular dispersion pulses were generated for 30{approximately}60 seconds and CO{sub 2} concentrations were recorded at several locations 50{approximately}190 m downwind. The diffusion coefficients calculated graphically vary between 0.10{approximately}0.48 m{sup 2}/s at both haulage ways. The results are analyzed to find any correlation with the air velocity and the distance from the disperser. Skobunov`s empirical formula is applied to the experimental data for comparison and the relationship between Reynolds number and Ex/D{sub p}/Sc{sub i}{sub 0.4} Sc{sub t}{radical}{lambda}/{lambda}{sub r} is also tested.

  4. Effects of diesel exhaust on the microbiota within a tuffaceous tunnel system

    SciTech Connect

    Haldeman, D.L.; Lagadinos, T.; Amy, P.S.; Hersman, L.; Meike, A.

    1996-08-01

    The abundance and distribution of microbiota that may be impacted by diesel and diesel exhaust were investigated from three depths into the walls and invert (floor) of U12n tunnel at Rainier Mesa, Nevada Test Site, a potential geological analog of Yucca Mountain. Enumerations included total cell counts, and numbers of aerobic heterotrophic, sulfate-reducing, nitrate-reducing, and diesel-degrading bacteria. Additionally, the disappearance of total petroleum hydrocarbons was determined in microcosms containing subsurface materials that were amended with diesel fuel. Results revealed that microbes capable of utilizing diesel and diesel combustion products were present in the subsurface in both the walls and the invert of the tunnel. The abundance of specific bacterial types in the tunnel invert, a perturbed environment, was greater than that observed in the tunnel wall. Few trends of microbial distribution either into the tunnel wall or the invert were noted with the exception of aerobic heterotrophic abundance which increased with depth into the wall and decreased with depth into the invert. No correlation between microbiota and a specific introduced chemical species have yet been determined. The potential for microbial contamination of the tunnel wall during sampling was determined to be negligible by the use of fluorescently labeled latex spheres (1{mu}m in dia.) as tracers. Results indicate that additional investigations might be needed to examine the microbiota and their possible impacts on the geology and geochemistry of the subsurface, both indigenous microbiota and those microorganisms that will likely be introduced by anthropogenic activity associated with the construction of a high-level waste repository.

  5. Response characteristics of stable mixed-potential NH3 sensors in diesel engine exhaust

    DOE PAGES

    Brosha, Eric L.; Prikhodko, Vitaly Y.; Kreller, Cortney R.; ...

    2016-10-20

    Here, a mixed-potential, electrochemical sensor platform is extended to NH3 sensing by the introduction of a new gold alloy working electrode. A planar, pre-commercial NH3 sensor utilized LANL’s controlled interface approach, and a Pd-Au alloy working electrode was tested in exhaust of a GM 1.9 L diesel engine downstream of a diesel oxidation catalyst through a slipstream arrangement. A fraction of the exhaust was pulled across the sensor with a pump at 20 L/min. In order to simulate NH3 slip inside of a full SCR emissions control system, NH3 was injected immediately upstream of the sensor using a calibrated massmore » flow controller. The sensor response quantitatively tracked the NH3 as measured via Fourier transform infrared (FTIR) analyzer. A calibration curve was obtained in the exhaust from an ammonia staircase response with the engine running at steady-state engine conditions resulting in low background concentrations of NOx and HC (<20 ppm) during calibration. Exhaust gas recirculation (EGR) switching and sweeps were used to evaluate the NH3 sensor response under different amounts of total background NOx. The calibration curve was used to directly compare the [NH3] calculated from sensor response to the gas phase composition measured via FTIR. In general, there was excellent quantitative agreement between the sensor response and the actual NH3 in the exhaust gas, and fast response time such that transients (<5 ppm) could be easily discerned from baseline. A LANL pre-commercial NOx sensor was tested simultaneously with the NH3 sensor and the extent of cross-sensitivity between the two sensors will be discussed.« less

  6. Exhaust Gas Recirculation Cooler Fouling in Diesel Applications: Fundamental Studies Deposit Properties and Microstructure

    SciTech Connect

    Storey, John Morse; Sluder, Scott; Lance, Michael J; Styles, Dan; Simko, Steve

    2013-01-01

    This paper reports on the results of experimental efforts aimed at improving the understanding of the mechanisms and conditions at play in the fouling of EGR coolers. An experimental apparatus was constructed to utilize simplified surrogate heat exchanger tubes in lieu of full-size heat exchangers. The use of these surrogate tubes allowed removal of the tubes after exposure to engine exhaust for study of the deposit layer and its properties. The exhaust used for fouling the surrogate tubes was produced using a modern medium-duty diesel engine fueled with both ultra-low sulfur diesel and biodiesel blends. At long exposure times, no significant difference in the fouling rate was observed between fuel types and HC levels. Surface coatings for the tubes were also evaluated to determine their impact on deposit growth. No surface treatment or coating produced a reduction in the fouling rate or any evidence of deposit removal. In addition, microstructural analysis of the fouling layers was performed using optical and electron microscopy in order to better understand the deposition mechanism. The experimental results are consistent with thermophoretic deposition for deposit formation, and van der Waals attraction between the deposit surface and exhaust-borne particulate.

  7. The effect of fuel composition on the mutagenicity of diesel engine exhaust.

    PubMed

    Crebelli, R; Conti, L; Crochi, B; Carere, A; Bertoli, C; Del Giacomo, N

    1995-03-01

    The effect of fuel composition on the mutagenicity of diesel engine emission was investigated. To this end, a fuel matrix comprising fuels with different contents of aromatic and naphthenic compounds was used. Extracts of the organic phase of raw exhausts obtained with different fuels were tested for mutagenicity in bacterial reversion assays. The results obtained demonstrate that the mutagenicity of diesel exhaust is largely dependent on the aromatic content of the fuel. In fact, mutagenicity was greatly reduced when the aromatic content of the fuel was lowered by hydrogen treatment. Conversely, mutagenicity was enhanced when the fuel was enriched with fractions of di- or triaromatic compounds. The addition of di- and trinaphthenic compounds only produced borderline mutagenicity. No clear relationship was observed between sulfur content of the fuel and mutagenicity of the exhaust. Assays in bacterial strains with different sensitivity to nitroaromatic compounds suggest a low contribution of the highly mutagenic dinitropyrenes to the responses observed, and a relatively greater contribution of 1-nitropyrene or other nitroaromatics processed by the same bacterial nitroreductase.

  8. Diesel exhaust, solvents, and other occupational exposures as risk factors for wheeze among farmers.

    PubMed

    Hoppin, Jane A; Umbach, David M; London, Stephanie J; Alavanja, Michael C R; Sandler, Dale P

    2004-06-15

    Farmers engage in activities that result in exposure to diesel exhaust, solvents, welding fumes, and other respiratory irritants. Using the Agricultural Health Study, a cohort of pesticide applicators in Iowa and North Carolina, we evaluated the odds of wheeze associated with nonpesticide occupational exposures. We used logistic regression models controlling for age, state, smoking, and history of asthma or atopy to evaluate odds of wheeze in the past year among the 20898 farmers who provided complete information on all covariates. Driving diesel tractors was associated with elevated odds of wheeze (odds ratio = 1.31; 95% confidence interval = 1.13, 1.52); the odds ratio for driving gasoline tractors was 1.11 (95% confidence interval = 1.02, 1.21). A duration-response relationship was observed for driving diesel tractors but not for driving gasoline tractors. Activities involving solvent exposure, including painting and use of solvents for cleaning, were associated with an increased odds of wheeze in a duration-dependent fashion. The highest odds of wheeze for farm activities were for daily painting (odds ratio = 1.82; 95% confidence interval = 0.89, 3.73), an indication of daily solvent exposure. These results add to the growing body of evidence of adverse respiratory effects of diesel exposure on the lung and suggest exposure to solvents may contribute as well.

  9. Studies of diesel engine particle emissions during transient operations using an Engine Exhaust Particle Sizer

    SciTech Connect

    Wang, Jian; Storey, John Morse; Domingo, Norberto; Huff, Shean P; Thomas, John F; West, Brian H; Lee, Doh-Won

    2006-01-01

    Diesel engine particle emissions during transient operations, including emissions during FTP transient cycles and during active regenerations of a NOx adsorber, were studied using a fast Engine Exhaust Particle Sizer (EEPS). For both fuels tested, a No. 2 certification diesel and a low sulfur diesel (BP-15), high particle concentrations and emission rates were mainly associated with heavy engine acceleration, high speed, and high torque during transient cycles. Averaged over the FTP transient cycle, the particle number concentration during tests with the certification fuel was 1.2e8/cm3, about four times the particle number concentration observed during tests using the BP-15 fuel. The effect of each engine parameter on particle emissions was studied. During tests using BP-15, the particle number emission rate was mainly controlled by the engine speed and torque, whereas for Certification fuel, the engine acceleration also had a strong effect on number emission rates. The effects of active regenerations of a diesel NOx adsorber on particle emissions were also characterized for two catalyst regeneration strategies: Delayed Extended Main (DEM) and Post 80 injection (Post80). Particle volume concentrations observed during DEM regenerations were much higher than those during Post80 regenerations, and the minimum air to fuel ratio achieved during the regenerations had little effect on particle emission for both strategies. This study provides valuable information for developing strategies that minimize the particle formation during active regenerations of NOx adsorbers.

  10. Health effects research and regulation of diesel exhaust: an historical overview focused on lung cancer risk

    PubMed Central

    Hesterberg, Thomas W.; Long, Christopher M.; Bunn, William B.; Lapin, Charles A.; McClellan, Roger O.; Valberg, Peter A.

    2012-01-01

    The mutagenicity of organic solvent extracts from diesel exhaust particulate (DEP), first noted more than 55 years ago, initiated an avalanche of diesel exhaust (DE) health effects research that now totals more than 6000 published studies. Despite an extensive body of results, scientific debate continues regarding the nature of the lung cancer risk posed by inhalation of occupational and environmental DE, with much of the debate focused on DEP. Decades of scientific scrutiny and increasingly stringent regulation have resulted in major advances in diesel engine technologies. The changed particulate matter (PM) emissions in “New Technology Diesel Exhaust (NTDE)” from today's modern low-emission, advanced-technology on-road heavy-duty diesel engines now resemble the PM emissions in contemporary gasoline engine exhaust (GEE) and compressed natural gas engine exhaust more than those in the “traditional diesel exhaust” (TDE) characteristic of older diesel engines. Even with the continued publication of epidemiologic analyses of TDE-exposed populations, this database remains characterized by findings of small increased lung cancer risks and inconsistent evidence of exposure-response trends, both within occupational cohorts and across occupational groups considered to have markedly different exposures (e.g. truckers versus railroad shopworkers versus underground miners). The recently published National Institute for Occupational Safety and Health (NIOSH)-National Cancer Institute (NCI) epidemiologic studies of miners provide some of the strongest findings to date regarding a DE-lung cancer association, but some inconsistent exposure-response findings and possible effects of bias and exposure misclassification raise questions regarding their interpretation. Laboratory animal studies are negative for lung tumors in all species, except for rats under lifetime TDE-exposure conditions with durations and concentrations that lead to'lung overload."The species specificity

  11. Investigation of Nitro-Organic Compounds in Diesel Engine Exhaust: Final Report, February 2007 - April 2008

    SciTech Connect

    Dane, J.; Voorhees, K. J.

    2010-06-01

    The National Renewable Energy Laboratory upgraded its ReFUEL engine and vehicle testing facility to speciate unregulated gas-phase emissions. To complement this capability, the laboratory contracted with the Colorado School of Mines (CSM) to study the effects of soy biodiesel fuel and a diesel particle filter (DPF) on emissions of polycyclic aromatic hydrocarbons (PAH) and nitro-polycyclic aromatic hydrocarbons (NPAH). CSM developed procedures to sample diesel particulate matter (PM) emissions from raw and diluted exhaust, with and without a DPF. They also developed improved procedures for extracting PAH and NPAH from the PM and quantifying them with a gas chromatograph-electron monochromator mass spectrometer. The study found the DPF generally reduced PAH emissions by 1 to 3 orders of magnitude. PAH conversion was lowest for B100, suggesting that PAHs were forming in the DPF. Orders of magnitude reductions were also found for NPAH emissions exiting the DPF.

  12. Impact of exhaust gas recirculation (EGR) on the oxidative reactivity of diesel engine soot

    SciTech Connect

    Al-Qurashi, Khalid; Boehman, Andre L.

    2008-12-15

    This paper expands the consideration of the factors affecting the nanostructure and oxidative reactivity of diesel soot to include the impact of exhaust gas recirculation (EGR). Past work showed that soot derived from oxygenated fuels such as biodiesel carries some surface oxygen functionality and thereby possesses higher reactivity than soot from conventional diesel fuel. In this work, results show that EGR exerts a strong influence on the physical properties of the soot which leads to enhanced oxidation rate. HRTEM images showed a dramatic difference between the burning modes of the soot generated under 0 and 20% EGR. The soot produced under 0% EGR strictly followed an external burning mode with no evidence of internal burning. In contrast, soot generated under 20% EGR exhibited dual burning modes: slow external burning and rapid internal burning. The results demonstrate clearly that highly reactive soot can be achieved by manipulating the physical properties of the soot via EGR. (author)

  13. NIOSH/NCI study of exposure to diesel exhaust in underground mines -- An industry perspective

    SciTech Connect

    Pritchard, C.J.

    1999-07-01

    In 1992, the National Institute for Occupational Safety and Health (NIOSH) initiated a study, funded by the National Cancer Institute (NCI), to evaluate the health effects, if any, involving underground miners exposure to diesel exhaust. An industry organization, the Methane Awareness Research Group (MARG) already in place to respond to gassy mine related issues, was redirected to work with diesel concerns. In 1995, NIOSH released a draft protocol and feasibility assessment, indicating its intent to initiate a study at 14 underground mines, some of which were operated by MARG members. After considerable debate on the study protocol, in-mine industrial hygiene studies were begun in December, 1997 and expected to end in early 1999.

  14. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XXX, I--CATERPILLAR DIESEL ENGINE MAINTENANCE SUMMARY, II--REIEWING FACTS ABOUT ALTERNATORS.

    ERIC Educational Resources Information Center

    Minnesota State Dept. of Education, St. Paul. Div. of Vocational and Technical Education.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO PROVIDE A SUMMARY OF DIESEL ENGINE MAINTENANCE FACTORS AND A REVIEW OF DIESEL ENGINE ALTERNATOR OPERATION. THE SEVEN SECTIONS COVER DIESEL ENGINE TROUBLESHOOTING AND THE OPERATION, TESTING, AND ADJUSTING OF ALTERNATORS. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL BRANCH PROGRAMED TRAINING FILM…

  15. In utero exposure to a low concentration of diesel exhaust affects spontaneous locomotor activity and monoaminergic system in male mice

    PubMed Central

    2010-01-01

    Background Epidemiological studies have suggested that suspended particulate matter (SPM) causes detrimental health effects such as respiratory and cardiovascular diseases, and that diesel exhaust particles from automobiles is a major contributor to SPM. It has been reported that neonatal and adult exposure to diesel exhaust damages the central nervous system (CNS) and induces behavioral alteration. Recently, we have focused on the effects of prenatal exposure to diesel exhaust on the CNS. In this study, we examined the effects of prenatal exposure to low concentration of diesel exhaust on behaviour and the monoaminergic neuron system. Spontaneous locomotor activity (SLA) and monoamine levels in the CNS were assessed. Methods Mice were exposed prenatally to a low concentration of diesel exhaust (171 μg DEP/m3) for 8 hours/day on gestational days 2-16. SLA was assessed for 3 days in 4-week-old mice by analysis of the release of temperature-associated infrared rays. At 5 weeks of age, the mice were sacrificed and the brains were used for analysis by high-performance liquid chromatography (HPLC). Results and Discussion Mice exposed to a low concentration of diesel exhaust showed decreased SLA in the first 60 minutes of exposure. Over the entire test period, the mice exposed prenatally to diesel exhaust showed decreased daily SLA compared to that in control mice, and the SLA in each 3 hour period was decreased when the lights were turned on. Neurotransmitter levels, including dopamine and noradrenaline, were increased in the prefrontal cortex (PFC) in the exposure group compared to the control group. The metabolites of dopamine and noradrenaline also increased in the PFC. Neurotransmitter turnover, an index of neuronal activity, of dopamine and noradrenaline was decreased in various regions of the CNS, including the striatum, in the exposure group. The serum corticosterone level was not different between groups. The data suggest that decreased SLA in mice exposed

  16. Brain suppression of AP-1 by inhaled diesel exhaust and reversal by cerium oxide nanoparticles.

    PubMed

    Lung, Shyang; Cassee, Flemming R; Gosens, Ilse; Campbell, Arezoo

    2014-08-01

    One of the uses of cerium oxide nanoparticles (nanoceria, CeO2) is as a diesel fuel additive to improve fuel efficiency. Gene/environment interactions are important determinants in the etiology of age-related disorders. Thus, it is possible that individuals on high-fat diet and genetic predisposition to vascular disease may be more vulnerable to the adverse health effects of particle exposure. The aim of this pilot study was to test the hypothesis that inhalation of diesel exhaust (DE) or diesel exhaust-containing cerium oxide nanoparticles (DCeE) induces stress in the brain of a susceptible animal model. Atherosclerotic prone, apolipoprotein E knockout (ApoE(-/-)) mice fed a high-fat diet, were exposed by inhalation to purified air (control), DE or DCeE. The stress-responsive transcription factor, activator protein-1 (AP-1), was significantly decreased in the cortical and subcortical fraction of the brain after DE exposure. The addition of nanoceria to the diesel fuel reversed this effect. The activation of another stress-related transcription factor (NF-κB) was not inhibited. AP-1 is composed of complexes of the Jun and/or Fos family of proteins. Exposure to DCeE caused c-Jun activation and this may be a mechanism by which addition of nanoceria to the fuel reversed the effect of DE exposure on AP-1 activation. This pilot study demonstrates that exposure to DE does impact the brain and addition of nanoceria may be protective. However, more extensive studies are necessary to determine how DE induced reduction of AP-1 activity and compensation by nanoceria impacts normal function of the brain.

  17. Proinflammatory doses of diesel exhaust in healthy subjects fail to elicit equivalent or augmented airway inflammation in subjects with asthma.

    PubMed

    Behndig, Annelie F; Larsson, Nirina; Brown, Joanna L; Stenfors, Nikolai; Helleday, Ragnberth; Duggan, Sean T; Dove, Rosamund E; Wilson, Susan J; Sandstrom, Thomas; Kelly, Frank J; Mudway, Ian S; Blomberg, Anders

    2011-01-01

    Exposure to traffic-derived air pollutants, particularly diesel emissions, has been associated with adverse health effects, predominantly in individuals with pre-existing respiratory disease. Here the hypothesis that this heightened sensitivity reflects an augmentation of the transient inflammatory response previously reported in healthy adults exposed to diesel exhaust is examined. 32 subjects with asthma (mild to moderate severity) and 23 healthy controls were exposed in a double-blinded crossover control fashion to both filtered air and diesel exhaust (100 μg/m(3) PM(10)) for 2 h. Airway inflammation was assessed by bronchoscopy 18 h postexposure. In addition, lung function, fraction of exhaled nitric oxide and bronchial reactivity to metacholine were examined in the subjects with asthma. In healthy control subjects a significant increase in submucosal neutrophils (p=0.004) was observed following the diesel challenge. Significant increases in neutrophil numbers (p=0.01), and in the concentrations of interleukin 6 (p=0.03) and myeloperoxidase (p=0.04), were also seen in bronchial wash after diesel, relative to the control air challenge. No evidence of enhanced airway inflammation was observed in the subjects with asthma following the diesel exposure. Exposure to diesel exhaust at concentrations consistent with roadside levels elicited an acute and active neutrophilic inflammation in the airways of healthy subjects. This response was absent in subjects with asthma, as was evidence supporting a worsening of allergic airway inflammation.

  18. Different occupations associated with amyotrophic lateral sclerosis: is diesel exhaust the link?

    PubMed

    Pamphlett, Roger; Rikard-Bell, Anna

    2013-01-01

    The cause of sporadic amyotrophic lateral sclerosis (SALS) remains unknown. We attempted to find out if occupational exposure to toxicants plays a part in the pathogenesis of this disease. In an Australia-wide case-control study we compared the lifetime occupations of 611 SALS and 775 control individuals. Occupations were coded using country-specific as well as international classifications. The risk of SALS for each occupation was calculated with odds ratios using logistic regression. In addition, the literature was searched for possible toxicant links between our findings and previously-reported occupational associations with SALS. Male occupations in our study that required lower skills and tasks tended to have increased risks of SALS, and conversely, those occupations that required higher skills and tasks had decreased risks of SALS. Of all the occupations, only truck drivers, where exposure to diesel exhaust is common, maintained an increased risk of SALS throughout all occupational groups. Another large case-control study has also found truck drivers to be at risk of SALS, and almost two-thirds of occupations, as well as military duties, that have previously been associated with SALS have potential exposure to diesel exhaust. In conclusion, two of the largest case-control studies of SALS have now found that truck drivers have an increased risk of SALS. Since exposure to diesel exhaust is common in truck drivers, as well as in other occupations that have been linked to SALS, exposure to this toxicant may underlie some of the occupations that are associated with SALS.

  19. Different Occupations Associated with Amyotrophic Lateral Sclerosis: Is Diesel Exhaust the Link?

    PubMed Central

    Pamphlett, Roger; Rikard-Bell, Anna

    2013-01-01

    The cause of sporadic amyotrophic lateral sclerosis (SALS) remains unknown. We attempted to find out if occupational exposure to toxicants plays a part in the pathogenesis of this disease. In an Australia-wide case-control study we compared the lifetime occupations of 611 SALS and 775 control individuals. Occupations were coded using country-specific as well as international classifications. The risk of SALS for each occupation was calculated with odds ratios using logistic regression. In addition, the literature was searched for possible toxicant links between our findings and previously-reported occupational associations with SALS. Male occupations in our study that required lower skills and tasks tended to have increased risks of SALS, and conversely, those occupations that required higher skills and tasks had decreased risks of SALS. Of all the occupations, only truck drivers, where exposure to diesel exhaust is common, maintained an increased risk of SALS throughout all occupational groups. Another large case-control study has also found truck drivers to be at risk of SALS, and almost two-thirds of occupations, as well as military duties, that have previously been associated with SALS have potential exposure to diesel exhaust. In conclusion, two of the largest case-control studies of SALS have now found that truck drivers have an increased risk of SALS. Since exposure to diesel exhaust is common in truck drivers, as well as in other occupations that have been linked to SALS, exposure to this toxicant may underlie some of the occupations that are associated with SALS. PMID:24244728

  20. Diesel exhaust particulate increases the size and complexity of lesions in atherosclerotic mice.

    PubMed

    Miller, Mark R; McLean, Steven G; Duffin, Rodger; Lawal, Akeem O; Araujo, Jesus A; Shaw, Catherine A; Mills, Nicholas L; Donaldson, Ken; Newby, David E; Hadoke, Patrick W F

    2013-12-11

    Diesel exhaust particulate (DEP), a major component of urban air pollution, has been linked to atherogenesis and precipitation of myocardial infarction. We hypothesized that DEP exposure would increase and destabilise atherosclerotic lesions in apolipoprotein E deficient (ApoE-/-) mice. ApoE-/- mice were fed a 'Western diet' (8 weeks) to induce 'complex' atherosclerotic plaques, with parallel experiments in normal chow fed wild-type mice. During the last 4 weeks of feeding, mice received twice weekly instillation (oropharyngeal aspiration) of 35 μL DEP (1 mg/mL, SRM-2975) or vehicle (saline). Atherosclerotic burden was assessed by en-face staining of the thoracic aorta and histological examination of the brachiocephalic artery. Brachiocephalic atherosclerotic plaques were larger in ApoE-/- mice treated with DEP (59 ± 10%) than in controls (32 ± 7%; P = 0.017). In addition, DEP-treated mice had more plaques per section of artery (2.4 ± 0.2 vs 1.8 ± 0.2; P = 0.048) and buried fibrous layers (1.2 ± 0.2 vs 0.4 ± 0.1; P = 0.028). These changes were associated with lung inflammation and increased antioxidant gene expression in the liver, but not with changes in endothelial function, plasma lipids or systemic inflammation. Increased atherosclerosis is caused by the particulate component of diesel exhaust producing advanced plaques with a potentially more vulnerable phenotype. These results are consistent with the suggestion that removal of the particulate component would reduce the adverse cardiovascular effects of diesel exhaust.

  1. Diesel exhaust particles and allergenicity of pollen grains of Lilium martagon.

    PubMed

    Chehregani, Abdolkarim; Kouhkan, Fatemeh

    2008-03-01

    Diesel exhaust particles are considered as the most important parts of air pollutants. Diesel exhaust particles have been shown to express both adjuvant activity for sensitization against common allergens and enhancing effects on allergic symptoms in sensitized individuals. In this research, pollen grains of Lilium martagon that are known as a non-allergic substance were collected and exposed to DEP 5 and 10 days. The allergy potency of different pollen extracts were compared by means of skin test, as well as analyses blood eosinophil numbers and IgE levels in the treated animals. Normal and DEP-exposed pollen grains were examined by scanning electron microscopy. Pollen extracts were also studied by SDS-PAGE for DEP-induced changes in protein profiles. Allergic bands were also studied and checked by using immunoblotting method. The results of the investigated allergy tests showed that DEP-exposed pollen grains are effective in inducing allergic symptoms. According to our microscopic observations, organic substances that exist in the DEP, mediate agglomeration of particles on the pollen surface. In appropriate conditions, water-soluble components of DEP may induce changes that affect the release of pollen proteins. SDS-PAGE showed protein profiles of pollen grains were changed and some new bands appeared in DEP-exposed pollen grains. Immunoblotting studies showed a new band in DEP-exposed pollen grains that react strongly with anti-IgE, but there is no allergenic band in normal pollen grains. On the other hand, diesel exhaust particles can carry pollen allergen molecules, induce new proteins (allergens), and also act as adjuvant for allergens.

  2. Exacerbation of allergic inflammation in mice exposed to diesel exhaust particles prior to viral infection

    PubMed Central

    Jaspers, Ilona; Sheridan, Patricia A; Zhang, Wenli; Brighton, Luisa E; Chason, Kelly D; Hua, Xiaoyang; Tilley, Stephen L

    2009-01-01

    Background Viral infections and exposure to oxidant air pollutants are two of the most important inducers of asthma exacerbation. Our previous studies have demonstrated that exposure to diesel exhaust increases the susceptibility to influenza virus infections both in epithelial cells in vitro and in mice in vivo. Therefore, we examined whether in the setting of allergic asthma, exposure to oxidant air pollutants enhances the susceptibility to respiratory virus infections, which in turn leads to increased virus-induced exacerbation of asthma. Ovalbumin-sensitized (OVA) male C57BL/6 mice were instilled with diesel exhaust particles (DEP) or saline and 24 hours later infected with influenza A/PR/8. Animals were sacrificed 24 hours post-infection and analyzed for markers of lung injury, allergic inflammation, and pro-inflammatory cytokine production. Results Exposure to DEP or infection with influenza alone had no significant effects on markers of injury or allergic inflammation. However, OVA-sensitized mice that were exposed to DEP and subsequently infected with influenza showed increased levels of eosinophils in lung lavage and tissue. In addition Th2-type cytokines, such as IL-4 and IL-13, and markers of eosinophil chemotaxis, such as CCL11 and CCR3, were increased in OVA-sensitized mice exposed to DEP prior to infection with influenza. These mice also showed increased levels of IL-1α, but not IL-10, RANTES, and MCP-1 in lung homogenates. Conclusion These data suggest that in the setting of allergic asthma, exposure to diesel exhaust could enhance virus-induced exacerbation of allergic inflammation. PMID:19682371

  3. Characteristics of trans, trans-2,4-decadienal and polycyclic aromatic hydrocarbons in exhaust of diesel engine fueled with biodiesel

    NASA Astrophysics Data System (ADS)

    Yang, Hsi-Hsien; Lo, Mei-Yu; Chi-Wei Lan, John; Wang, Jenn-Shye; Hsieh, Dennis P. H.

    The use of biodiesel fuel as a substitute for fossil fuel in diesel engines has received increasing attention in recent years. This study is the first to investigate and compare the characteristics of mutagenic species, trans, trans-2,4-decadienal ( tt-DDE), and polycyclic aromatic hydrocarbons (PAHs) in the diluted exhaust of diesel engines operated with diesel and biodiesel blend fuels. An engine of current design was operated on a dynamometer consistent with the US federal test procedure transient-cycle specifications. Petroleum diesel and a blend of petroleum diesel and biodiesel (B20) were tested. Exhaust sampling was carried out on diluted exhaust in a dilution tunnel with a constant-volume sampling system. Concentrations of tt-DDE and PAHs were analyzed by GC/MS. Although average PAH emission factors decreased from 1403 to 1051 μg bhp-h -1, the results show that tt-DDE is evidently generated (1.28 μg bhp-h -1) in the exhaust of diesel engine using B20 as fuel. This finding suggests that tt-DDE emission from the use of biodiesel should be taken into account in characterization and health-risk assessment. The results also show that tt-DDE is depleted in the diesel engine combustion process and the existence of tt-DDE in biodiesel is the major source of tt-DDE emission. The distribution of tt-DDE in the particulate phase is 55.3% under this study's sampling conditions. For diesel and B20, PAH phase distributions have similar trends. Lower molecular weight PAHs predominate in gaseous phase for both diesel and B20. Cold-start driving has higher tt-DDE and PAH emission factors, as well as a higher percentage of tt-DDE in particulate phase, than for warm-start driving.

  4. Mutagenicity of biodiesel or diesel exhaust particles and the effect of engine operating conditions

    PubMed Central

    Kisin, Elena R; Shi, X.C; Keane, Michael J; Bugarski, Aleksandar B; Shvedova, Anna A

    2015-01-01

    Background Changing the fuel supply from petroleum based ultra-low sulfur diesel (ULSD) to biodiesel and its blends is considered by many to be a viable option for controlling exposures to particulate material (PM). This is critical in the mining industry where approximately 28,000 underground miners are potentially exposed to relatively high concentrations of diesel particulate matter (DPM). This study was conducted to investigate the mutagenic potential of diesel engine emissions (DEE) from neat (B100) and blended (B50) soy-based fatty acid methyl ester (FAME) biodiesel in comparison with ULSD PM using different engine operating conditions and exhaust aftertreatment configurations. Methods The DPM samples were collected for engine equipped with either a standard muffler or a combination of the muffler and diesel oxidation catalytic converter (DOC) that was operated at four different steady-state modes. Bacterial gene mutation activity of DPM was tested on the organic solvent extracts using the Ames Salmonella assay. Results The results indicate that mutagenic activity of DPM was strongly affected by fuels, engine operating conditions, and exhaust aftertreatment systems. The mutagenicity was increased with the fraction of biodiesel in the fuel. While the mutagenic activity was observed in B50 and B100 samples collected from both light-and heavy-load operating conditions, the ULSD samples were mutagenic only at light-load conditions. The presence of DOC in the exhaust system resulted in the decreased mutagenicity when engine was fueled with B100 and B50 and operated at light-load conditions. This was not the case when engine was fueled with ULSD. Heavy-load operating condition in the presence of DOC resulted in a decrease of mutagenicity only when engine was fueled with B50, but not B100 or ULSD. Conclusions Therefore, the results indicate that DPM from neat or blended biodiesel has a higher mutagenic potency than that one of ULSD. Further research is needed to

  5. Mutagenicity of biodiesel or diesel exhaust particles and the effect of engine operating conditions.

    PubMed

    Kisin, Elena R; Shi, X C; Keane, Michael J; Bugarski, Aleksandar B; Shvedova, Anna A

    2013-03-01

    Changing the fuel supply from petroleum based ultra-low sulfur diesel (ULSD) to biodiesel and its blends is considered by many to be a viable option for controlling exposures to particulate material (PM). This is critical in the mining industry where approximately 28,000 underground miners are potentially exposed to relatively high concentrations of diesel particulate matter (DPM). This study was conducted to investigate the mutagenic potential of diesel engine emissions (DEE) from neat (B100) and blended (B50) soy-based fatty acid methyl ester (FAME) biodiesel in comparison with ULSD PM using different engine operating conditions and exhaust aftertreatment configurations. The DPM samples were collected for engine equipped with either a standard muffler or a combination of the muffler and diesel oxidation catalytic converter (DOC) that was operated at four different steady-state modes. Bacterial gene mutation activity of DPM was tested on the organic solvent extracts using the Ames Salmonella assay. The results indicate that mutagenic activity of DPM was strongly affected by fuels, engine operating conditions, and exhaust aftertreatment systems. The mutagenicity was increased with the fraction of biodiesel in the fuel. While the mutagenic activity was observed in B50 and B100 samples collected from both light-and heavy-load operating conditions, the ULSD samples were mutagenic only at light-load conditions. The presence of DOC in the exhaust system resulted in the decreased mutagenicity when engine was fueled with B100 and B50 and operated at light-load conditions. This was not the case when engine was fueled with ULSD. Heavy-load operating condition in the presence of DOC resulted in a decrease of mutagenicity only when engine was fueled with B50, but not B100 or ULSD. Therefore, the results indicate that DPM from neat or blended biodiesel has a higher mutagenic potency than that one of ULSD. Further research is needed to investigate the health effect of biodiesel

  6. Exposure to diesel exhaust fumes in the context of exposure to ultrafine particles.

    PubMed

    Bujak-Pietrek, Stella; Mikołajczyk, Urszula; Kamińska, Irena; Cieślak, Małgorzata; Szadkowska-Stańczyk, Irena

    2016-01-01

    Diesel exhaust fumes emission is a significant source of ultrafine particles, the size of which is expressed in nanometers. People occupationally exposed to diesel exhaust particles include mainly workers servicing vehicles with engines of this type. This article presents the analysis of measurements of ultrafine particle concentrations occurring in the bus depot premises during the work connected with everyday technical servicing of buses. The measurements were carried out in the everyday servicing (ES) room of the bus depot before, during and after the work connected with bus servicing. Determinations included: particle concentrations in terms of particle number and particle surface area, and mass concentrations of aerosol. Mean value of number concentration of 10- to 1000-nm particles increased almost 20-fold, from 7600 particles/cm3 before starting bus servicing procedures to 130 000 particles/cm3 during the bus servicing procedures in the room. During the procedures, the mean surface area concentration of particles potentially deposited in the alveolar (A) region was almost 3 times higher than that of the particles depositing in the tracheo-bronchial (TB) region: 356.46 μm2/cm3 vs. 95.97 μm2/cm3, respectively. The mass concentration of the fraction of particulate matter with aerodynamic diameter 0.02-1 μm (PM1) increased 5-fold during the analyzed procedures and was 0.042 mg/m3 before, and 0.298 mg/m3 while the procedures continued. At the time when bus servicing procedures continued in the ES room, a very high increase in all parameters of the analyzed particles was observed. The diesel exhaust particles exhibit a very high degree of fragmentation and, while their number is very high and their surface area is very large, their mass concentration is relatively low. The above findings confirm that ultrafine particles found in diesel exhaust fumes may be harmful to the health of the exposed people, and to their respiratory tract in particular. This work is

  7. Fast exhaust channel optical absorption method and apparatus to study the gas exchange in large diesel engines

    NASA Astrophysics Data System (ADS)

    Vattulainen, J.; Hernberg, R.; Hattar, C.; Gros, S.

    1998-01-01

    An optical absorption spectroscopic method and apparatus with shorter than 1 ms response time have been used to study the gas exchange processes in realistic conditions for a single cylinder of a large diesel engine. The method is based on measuring the differential line-of-sight optical uv absorption of the exhaust-gas-contained SO2 as a function of time in the exhaust port area just after the exhaust valves. The optical absorption by SO2 is determined from light transmission measurements at 280 and 340 nm performed through optical probes installed into the exhaust channel wall. The method has been applied to a continuously fired, large, medium speed production-line-type diesel engine with 990 kW rated power. The test engine was operated with standard light fuel oil (MDO Termoshell) and with light fuel oil treated with a sulfur additive {Di-Tert-Butyldisulfid [(CH3)3C]2S2}. The latter was to improve the optical absorption signals without increasing the fouling of the exhaust channel optical probes as in the case of heavier fuel oil qualities. In the reported case of a four-stroke diesel engine measurement results show that the method can provide time-resolved information of the SO2 density in the exhaust channel and thus give information on the single-cylinder gas exchange. During the inlet and exhaust valve overlap period the moment of fresh air entering into the measurement volume can be detected. If independent exhaust gas temperature and pressure data are available, the absorption measurements can readily be used for determining the burnt gas fraction in the exhaust channel. In this work the possibility of using the optical absorption measurement to determine the instaneous exhaust gas temperature was studied. Based on known fuel properties and conventional averaged SO2 measurements from the exhaust channel a known concentration of SO2 was assumed in the exhaust gas after the exhaust valves opening and before the inlet and exhaust valves overlap period

  8. Effects of injection pressure and injection timing to exhaust gas opacity for a conventional indirect diesel engine

    NASA Astrophysics Data System (ADS)

    Budiman, Agus; Majid, Akmal Irfan; Pambayun, Nirmala Adhi Yoga; Yuswono, Lilik Chaerul; Sukoco

    2016-06-01

    In relation to pollution control and environmental friendliness, the quality of exhaust gas from diesel engine needs to be considered. The influences of injection pressure and timing to exhaust gas opacity were investigated. A series of experiments were conducted in a one-cylinder conventional diesel engine with a naturally aspirated system and indirect injection. The default specification of injection pressure was 120 kg/cm2. To investigate the injection pressure, the engine speed was retained on 1000 rpm with pressure variations from 80 to 215 kg/cm2. On the other hand, the various injection timing (8, 10, 12, 16 degrees before TDC point and exact 18 degrees before TDC point) were used to determine their effects to exhaust gas opacity. In this case, the engine speed was varied from 1000 to 2400 rpm. The injector tester was used to measure injection pressure whereas the exhaust gas opacity was determined by the smoke meter. Those data were also statistically analyzed by product moment correlation. As the results, the injection pressure of diesel engine had a non-significant positive correlation to the exhaust gas opacity with r = 0.113 and p > 5 %. Injection pressure should be adjusted to the specification listed on the diesel engine as if it was too high or too low will lead to the higher opacity. Moreover, there was a significant positive correlation between injection timing and the exhaust gas opacity in all engine speeds.

  9. Diesel and biodiesel exhaust particle effects on rat alveolar macrophages with in vitro exposure.

    PubMed

    Bhavaraju, Laya; Shannahan, Jonathan; William, Aaron; McCormick, Robert; McGee, John; Kodavanti, Urmila; Madden, Michael

    2014-06-01

    Combustion emissions from diesel engines emit particulate matter which deposits within the lungs. Alveolar macrophages (AMs) encounter the particles and attempt to engulf the particles. Emissions particles from diesel combustion engines have been found to contain diverse biologically active components including metals and polyaromatic hydrocarbons which cause adverse health effects. However little is known about AM response to particles from the incorporation of biodiesel. The objective of this study was to examine the toxicity in Wistar Kyoto rat AM of biodiesel blend (B20) and low sulfur petroleum diesel (PDEP) exhaust particles. Particles were independently suspended in media at a range of 1-500μgmL(-1). Results indicated B20 and PDEP initiated a dose dependent increase of inflammatory signals from AM after exposure. After 24h exposure to B20 and PDEP gene expression of cyclooxygenase-2 (COX-2) and macrophage inflammatory protein 2 (MIP-2) increased. B20 exposure resulted in elevated prostaglandin E2 (PGE2) release at lower particle concentrations compared to PDEP. B20 and PDEP demonstrated similar affinity for sequestration of PGE2 at high concentrations, suggesting detection is not impaired. Our data suggests PGE2 release from AM is dependent on the chemical composition of the particles. Particle analysis including measurements of metals and ions indicate B20 contains more of select metals than PDEP. Other particle components generally reduced by 20% with 20% incorporation of biodiesel into original diesel. This study shows AM exposure to B20 results in increased production of PGE2in vitro relative to diesel. Published by Elsevier Ltd.

  10. Diesel and biodiesel exhaust particle effects on rat alveolar macrophages with in vitro exposure

    PubMed Central

    Bhavaraju, Laya; Shannahan, Jonathan; William, Aaron; McCormick, Robert; McGee, John; Kodavanti, Urmila; Madden, Michael

    2014-01-01

    Combustion emissions from diesel engines emit particulate matter which deposits within the lungs. Alveolar macrophages (AM) encounter the particles and attempt to engulf the particles. Emissions particles from diesel combustion engines have been found to contain diverse biologically active components including metals and polyaromatic hydrocarbons which cause adverse health effects. However little is known about AM response to particles from the incorporation of biodiesel. The objective of this study was to examine the toxicity in Wistar Kyoto rat AM of biodiesel blend (B20) and low sulfur petroleum diesel (PDEP) exhaust particles. Particles were independently suspended in media at a range of 1–500µg/mL. Results indicated B20 and PDEP initiated a dose dependent increase of inflammatory signals from AM after exposure. After 24hr exposure to B20 and PDEP gene expression of cyclooxygenase-2 (COX-2) and macrophage inflammatory protein 2 (MIP-2) increased. B20 exposure resulted in elevated prostaglandin E2 (PGE2) release at lower particle concentrations compared to PDEP. B20 and PDEP demonstrated similar affinity for sequesteration of PGE2 at high concentrations, suggesting detection is not imparied. Our data suggests PGE2 release from AM is dependent on the chemical composition of the particles. Particle analysis including measurments of metals and ions indicate B20 contains more of select metals than PDEP. Other particle components generally reduced by 20% with 20% incoporation of biodiesel into original diesel. This study shows AM exposure to B20 results in increased production of PGE2 in vitro relative to diesel. PMID:24268344

  11. Volatile organic compounds from the exhaust of light-duty diesel vehicles

    NASA Astrophysics Data System (ADS)

    Tsai, Jiun-Horng; Chang, Sheng-You; Chiang, Hung-Lung

    2012-12-01

    The exhaust gas constituents of light-duty diesel vehicles (LDDVs), including total hydrocarbon (THC), non-methane hydrocarbon (NMHC), carbon monoxide (CO), nitrogen oxide (NOx), and volatile organic compounds (VOCs) were measured by a dynamometer study following federal test procedure-75 (FTP-75) and highway fuel economy cycle. The average fuel consumption of these LDDVs was 0.126 L km-1 for FTP-75, with about 10% fuel consumption savings for highway driving. The average emission factors of NMHC, CO and NOx for light-duty vehicles were 0.158/0.132 (90% of THC), 1.395/1.138, and 1.735/1.907 g km-1 for FTP-75/Highway, respectively. Styrene, n-propylbenzene, n-undecane, o-ethyltoluene, 1,2,4-trimethylbenzene, toluene, o-xylene, isopropylbenzene, m,p-xylene, and ethylbenzene were the dominant VOCs of LDDV exhaust, and the emission factors were about 10-60 mg kg-1. In addition, formaldehyde, acetaldehyde, acetone, butyraldehyde, and m-tolualdehyde were the major carbonyl species from LDDV exhaust, and the emission factors ranged from 1 to 10 mg km-1. The ozone formation potentials of m,p-xylene, o-ethyltoluene, 1,2,4-trimethylbenzene, o-xylene, n-propylbenzene, styrene, and isoprene were >50 mg-O3 km-1. In addition, formaldehyde, acetaldehyde, and butyraldehyde revealed high ozone formation potential of carbonyl species, with values ranging from 10 to 95 mg-O3 km-1. Based on the exhaust constituents and ozone formation potential observed, diesel vehicles could be an important air pollution source for urban and industrial areas.

  12. On-road measurement of particle emission in the exhaust plume of a diesel passenger car.

    PubMed

    Vogt, Rainer; Scheer, Volker; Casati, Roberto; Benter, Thorsten

    2003-09-15

    Particle size distributions were measured under real world dilution conditions in the exhaust plume of a diesel passenger car closely followed by a mobile laboratory on a high speed test track. Under carefully controlled conditions the exhaust plume was continuously sampled and analyzed inside the mobile laboratory. Exhaust particle size distribution data were recorded together with exhaust gas concentrations, i.e., CO, CO2, and NO(x), and compared to data obtained from the same vehicle tested on a chassis dynamometer. Good agreement was found for the soot mode particles which occurred at a geometric mean diameter of approximately 50 nm and a total particle emission rate of 10(14) particles km(-1). Using 350 ppm high sulfur fuel and the standard oxidation catalyst a bimodal size distribution with a nucleation mode at 10 nm was observed at car velocities of 100 km h(-1) and 120 km h(-1), respectively. Nucleation mode particles were only present if high sulfur fuel was used with the oxidation catalyst installed. This is in agreement with prior work that these particles are of semivolatile nature and originate from the nucleation of sulfates formed inside the catalyst. Temporal effects of the occurrence of nucleation mode particles during steady-state cruising and the dynamical behavior during acceleration and deceleration were investigated.

  13. Neonatal Diesel Exhaust Particulate Exposure Does Not Predispose Mice to Adult Cardiac Hypertrophy or Heart Failure

    PubMed Central

    Liu, Yonggang; Weldy, Chad S.; Chin, Michael T.

    2016-01-01

    Background: We have previously reported that in utero and early life exposure to diesel exhaust particulates predisposes mice to adult heart failure, and that in utero exposure alone is sufficient to confer this predisposition. This follow up study addresses whether neonatal exposure alone can also confer this predisposition. Methods: Newborn male C57BL/6 mice were exposed to diesel exhaust (DE) particulates immediately after birth until weaning at 21 days of age, whereupon they were transferred to filtered air (FA) conditions. At the age of 12 weeks, transverse aortic constriction (TAC) was performed followed by weekly echocardiography for three weeks. After the last echocardiogram, mice were euthanized for organ harvest, gravimetry and histology. Results: Neonatal exposure to DE particulates did not increase susceptibility to cardiac hypertrophy or heart failure after TAC when compared to FA exposed controls (ventricular weight/body weight ratio 7.505 vs. 7.517 mg/g, p = Not Significant (NS)). The left ventricular ejection fraction after TAC was similar between groups at one week, two weeks, and three weeks after procedure. Histological analysis showed no difference in the degree of cardiac hypertrophy or fibrosis. Conclusions: Neonatal exposure to DE particulates does not predispose mice to TAC-induced cardiac hypertrophy and heart failure in adulthood, in contrast to previously published results showing susceptibility due to in utero exposure. PMID:27886143

  14. NOx diesel exhaust treatment using a pulsed corona discharge: the pulse repetition rate effect

    NASA Astrophysics Data System (ADS)

    Yankelevich, Y.; Wolf, M.; Baksht, R.; Pokryvailo, A.; Vinogradov, J.; Rivin, B.; Sher, E.

    2007-05-01

    The pulsed corona offers real promise for degradation of pollutants in gas and water streams. This paper presents a study of NOx removal from diesel exhaust. Special emphasis is laid on the investigation of the dependence of the NO removal rate and efficiency on the pulse repetition rate (PRR). A nanosecond solid state power supply (45 kV, 60 ns, up to 1 kHz) was used for driving the corona reactor. A Mitsubishi 10 kW 3-cylinder diesel-generator engine with a total volume of 1300 cm3 was used as a source of exhaust gas. At an NO removal rate of 35% the NO removal efficiency was 53 g kW-1h-1 for PRR = 500 Hz and the initial NO concentration was 375 ppm. A semi-empirical expression for the corona reactor removal efficiency related both to PRR and to the residence time is presented. The removal efficiency decreases with increasing PRR at constant flow rate or constant residence time. This expression demonstrates reasonable agreement between the calculation results and the experimental data.

  15. Chemical characterization and in vitro toxicity of diesel exhaust particulate matter generated under varying conditions

    PubMed Central

    Cox, David P.; Drury, Bertram E.; Gould, Timothy R.; Kavanagh, Terrance J.; Paulsen, Michael H.; Sheppard, Lianne; Simpson, Christopher D.; Stewart, James A.; Larson, Timothy V.; Kaufman, Joel D.

    2014-01-01

    Epidemiologic studies have linked diesel exhaust (DE) to cardiovascular and respiratory morbidity and mortality, as well as lung cancer. DE composition is known to vary with many factors, although it is unclear how this influences toxicity. We generated eight DE atmospheres by applying a 2×2×2 factorial design and altering three parameters in a controlled exposure facility: (1) engine load (27 vs 82 %), (2) particle aging (residence time ~5 s vs ~5 min prior to particle collection), and (3) oxidation (with or without ozonation during dilution). Selected exposure concentrations of both diesel exhaust particles (DEPs) and DE gases, DEP oxidative reactivity via DTT activity, and in vitro DEP toxicity in murine endothelial cells were measured for each DE atmosphere. Cell toxicity was assessed via measurement of cell proliferation (colony formation assay), cell viability (MTT assay), and wound healing (scratch assay). Differences in DE composition were observed as a function of engine load. The mean 1-nitropyrene concentration was 15 times higher and oxidative reactivity was two times higher for low engine load versus high load. There were no substantial differences in measured toxicity among the three DE exposure parameters. These results indicate that alteration of applied engine load shifts the composition and can modify the biological reactivity of DE. While engine conditions did not affect the selected in vitro toxicity measures, the change in oxidative reactivity suggests that toxicological studies with DE need to take into account engine conditions in characterizing biological effects. PMID:26539254

  16. Diesel engine exhaust and lung cancer mortality: time-related factors in exposure and risk.

    PubMed

    Moolgavkar, Suresh H; Chang, Ellen T; Luebeck, Georg; Lau, Edmund C; Watson, Heather N; Crump, Kenny S; Boffetta, Paolo; McClellan, Roger

    2015-04-01

    To develop a quantitative exposure-response relationship between concentrations and durations of inhaled diesel engine exhaust (DEE) and increases in lung cancer risks, we examined the role of temporal factors in modifying the estimated effects of exposure to DEE on lung cancer mortality and characterized risk by mine type in the Diesel Exhaust in Miners Study (DEMS) cohort, which followed 12,315 workers through December 1997. We analyzed the data using parametric functions based on concepts of multistage carcinogenesis to directly estimate the hazard functions associated with estimated exposure to a surrogate marker of DEE, respirable elemental carbon (REC). The REC-associated risk of lung cancer mortality in DEMS is driven by increased risk in only one of four mine types (limestone), with statistically significant heterogeneity by mine type and no significant exposure-response relationship after removal of the limestone mine workers. Temporal factors, such as duration of exposure, play an important role in determining the risk of lung cancer mortality following exposure to REC, and the relative risk declines after exposure to REC stops. There is evidence of effect modification of risk by attained age. The modifying impact of temporal factors and effect modification by age should be addressed in any quantitative risk assessment (QRA) of DEE. Until there is a better understanding of why the risk appears to be confined to a single mine type, data from DEMS cannot reliably be used for QRA.

  17. Heavy Duty Diesel Exhaust Particles during Engine Motoring Formed by Lube Oil Consumption.

    PubMed

    Karjalainen, Panu; Ntziachristos, Leonidas; Murtonen, Timo; Wihersaari, Hugo; Simonen, Pauli; Mylläri, Fanni; Nylund, Nils-Olof; Keskinen, Jorma; Rönkkö, Topi

    2016-11-15

    This study reports high numbers of exhaust emissions particles during engine motoring. Such particles were observed in the exhaust of two heavy duty vehicles with no diesel particle filter (DPF), driven on speed ramp tests and transient cycles. A significant fraction of these particles was nonvolatile in nature. The number-weighted size distribution peak was below 10 nm when a thermodenuder was used to remove semivolatile material, growing up to 40 nm after semivolatile species condensation. These particles were found to contribute to 9-13% of total particle number emitted over a complete driving cycle. Engine motoring particles originated from lube oil and evidence suggests that these are of heavy organic or organometallic material. Particles of similar characteristics have been observed in the core particle mode during normal fired engine operation. Their size and chemical character has implications primarily on the environmental toxicity of non-DPF diesel and, secondarily, on the performance of catalytic devices and DPFs. Lube oil formulation measures can be taken to reduce the emission of such particles.

  18. Neonatal Diesel Exhaust Particulate Exposure Does Not Predispose Mice to Adult Cardiac Hypertrophy or Heart Failure.

    PubMed

    Liu, Yonggang; Weldy, Chad S; Chin, Michael T

    2016-11-24

    Background: We have previously reported that in utero and early life exposure to diesel exhaust particulates predisposes mice to adult heart failure, and that in utero exposure alone is sufficient to confer this predisposition. This follow up study addresses whether neonatal exposure alone can also confer this predisposition. Methods: Newborn male C57BL/6 mice were exposed to diesel exhaust (DE) particulates immediately after birth until weaning at 21 days of age, whereupon they were transferred to filtered air (FA) conditions. At the age of 12 weeks, transverse aortic constriction (TAC) was performed followed by weekly echocardiography for three weeks. After the last echocardiogram, mice were euthanized for organ harvest, gravimetry and histology. Results: Neonatal exposure to DE particulates did not increase susceptibility to cardiac hypertrophy or heart failure after TAC when compared to FA exposed controls (ventricular weight/body weight ratio 7.505 vs. 7.517 mg/g, p = Not Significant (NS)). The left ventricular ejection fraction after TAC was similar between groups at one week, two weeks, and three weeks after procedure. Histological analysis showed no difference in the degree of cardiac hypertrophy or fibrosis. Conclusions: Neonatal exposure to DE particulates does not predispose mice to TAC-induced cardiac hypertrophy and heart failure in adulthood, in contrast to previously published results showing susceptibility due to in utero exposure.

  19. Chemical characterization and in vitro toxicity of diesel exhaust particulate matter generated under varying conditions.

    PubMed

    Fox, Julie Richman; Cox, David P; Drury, Bertram E; Gould, Timothy R; Kavanagh, Terrance J; Paulsen, Michael H; Sheppard, Lianne; Simpson, Christopher D; Stewart, James A; Larson, Timothy V; Kaufman, Joel D

    2015-10-01

    Epidemiologic studies have linked diesel exhaust (DE) to cardiovascular and respiratory morbidity and mortality, as well as lung cancer. DE composition is known to vary with many factors, although it is unclear how this influences toxicity. We generated eight DE atmospheres by applying a 2×2×2 factorial design and altering three parameters in a controlled exposure facility: (1) engine load (27 vs 82 %), (2) particle aging (residence time ~5 s vs ~5 min prior to particle collection), and (3) oxidation (with or without ozonation during dilution). Selected exposure concentrations of both diesel exhaust particles (DEPs) and DE gases, DEP oxidative reactivity via DTT activity, and in vitro DEP toxicity in murine endothelial cells were measured for each DE atmosphere. Cell toxicity was assessed via measurement of cell proliferation (colony formation assay), cell viability (MTT assay), and wound healing (scratch assay). Differences in DE composition were observed as a function of engine load. The mean 1-nitropyrene concentration was 15 times higher and oxidative reactivity was two times higher for low engine load versus high load. There were no substantial differences in measured toxicity among the three DE exposure parameters. These results indicate that alteration of applied engine load shifts the composition and can modify the biological reactivity of DE. While engine conditions did not affect the selected in vitro toxicity measures, the change in oxidative reactivity suggests that toxicological studies with DE need to take into account engine conditions in characterizing biological effects.

  20. Estrogenic and anti-androgenic activities of 4-nitrophenol in diesel exhaust particles

    SciTech Connect

    Li Chunmei; Taneda, Shinji; Suzuki, Akira K. . E-mail: suzukiak@nies.go.jp; Furuta, Chie; Watanabe, Gen; Taya, Kazuyoshi

    2006-11-15

    A 4-nitrophenol (PNP) isolated from diesel exhaust particles (DEP) has been identified as a vasodilator. PNP is also a known degradation product of the insecticide parathion. We used uterotrophic and Hershberger assays to study the estrogenic and anti-androgenic activities of PNP in-vivo. In ovariectomized immature female rats injected subcutaneously with 1, 10, or 100 mg/kg PNP daily for 7 days, significant (P < 0.05) increases in uterine weight were seen in only those receiving 10 or 100 mg/kg PNP. Furthermore, in castrated immature male rats implanted with a silastic tube (length, 5 mm) containing crystalline testosterone and injected subcutaneously with 0.01, 0.1, or 1 mg/kg PNP daily for 5 days, those receiving the doses of 0.1 mg/kg showed significant (P < 0.05) weight decreases in seminal vesicles, ventral prostate, levator ani plus bulbocavernosus muscles, and glans penis. Plasma FSH and LH levels did not change in female rats but were significantly (P < 0.05) increased in male rats treated with 0.1 mg/kg PNP. These results clearly demonstrated that PNP has estrogenic and anti-androgenic activities in-vivo. Our results therefore suggest that diesel exhaust emissions and the degradation of parathion can lead to accumulation of PNP in air, water, and soil and thus could have serious deleterious effects on wildlife and human health.

  1. TRPV4-Mediated Calcium Influx into Human Bronchial Epithelia upon Exposure to Diesel Exhaust Particles

    PubMed Central

    Li, Jinju; Kanju, Patrick; Patterson, Michael; Chew, Wei-Leong; Cho, Seung-Hyun; Gilmour, Ian; Oliver, Tim; Yasuda, Ryohei; Ghio, Andrew; Simon, Sidney A.; Liedtke, Wolfgang

    2011-01-01

    Background Human respiratory epithelia function in airway mucociliary clearance and barrier function and have recently been implicated in sensory functions. Objective We investigated a link between chronic obstructive pulmonary disease (COPD) pathogenesis and molecular mechanisms underlying Ca2+ influx into human airway epithelia elicited by diesel exhaust particles (DEP). Methods and Results Using primary cultures of human respiratory epithelial (HRE) cells, we determined that these cells possess proteolytic signaling machinery, whereby proteinase-activated receptor-2 (PAR-2) activates Ca2+-permeable TRPV4, which leads to activation of human respiratory disease–enhancing matrix metalloproteinase-1 (MMP-1), a signaling cascade initiated by diesel exhaust particles (DEP), a globally relevant air pollutant. Moreover, we observed ciliary expression of PAR-2, TRPV4, and phospholipase-Cβ3 in human airway epithelia and their DEP-enhanced protein–protein complex formation. We also found that the chronic obstructive pulmonary disease (COPD)–predisposing TRPV4P19S variant enhances Ca2+ influx and MMP 1 activation, providing mechanistic linkage between man-made air pollution and human airway disease. Conclusion DEP evoked protracted Ca2+ influx via TRPV4, enhanced by the COPD-predisposing human genetic polymorphism TRPV4P19S. This mechanism reprograms maladaptive inflammatory and extracellular-matrix–remodeling responses in human airways. The novel concept of air pollution–responsive ciliary signal transduction from PAR-2 to TRPV4 in human respiratory epithelia will accelerate rationally targeted therapies, possibly via the inhalatory route. PMID:21245013

  2. Using GC×GC-ToF-MS to characterise SVOC from diesel exhaust emissions

    NASA Astrophysics Data System (ADS)

    Alam, M. S.; Ramadhas, A. S.; Stark, C. P.; Liu, D.; Xu, H.; Harrison, R. M.

    2014-12-01

    Despite intensive research over the last 20 years, a number of major research questions remain concerning the sources and properties of road traffic-generated particulate matter. There are major knowledge gaps concerning the composition of primary vehicle exhaust aerosol, and its contribution to secondary organic aerosol (SOA) formation. These uncertainties relate especially to the semi-volatile component of the particles. Semi-Volatile Organic Compounds (SVOC) are compounds which partition directly between the gas and aerosol phases under ambient conditions, and include compounds with saturation concentrations roughly between 0.1 and 104 μg m-3. The SVOC in engine exhaust are typically hydrocarbons in the C15-C35 range. They are largely uncharacterised, other than the n-alkanes, because they are unresolved by traditional gas chromatography and form a large hump in the chromatogram referred to as Unresolved Complex Mixture (UCM). In this study, samples were collected from the exhaust of a diesel engine with and without abatement devices fitted. Engine exhaust was diluted with air and collected using both filter and impaction (MOUDI), to resolve total mass and size resolved mass respectively. Particle size distribution was evaluated by sampling simultaneously with a Scanning Mobility Particle Sizer (SMPS). 2D Gas-Chromatography Time-of-Flight Mass-Spectrometry (GC×GC-ToF-MS) was exploited to characterise and quantify the composition of SVOC from the exhaust emission. The SVOC was observed to contain predominantly n-alkanes, alkyl-cyclohexanes and aromatics; similar to both fresh lubricating oil and fuel. Preliminary results indicate that the contribution of diesel fuel to the exhaust SVOC composition is dominant at high speeds, and a more pronounced contribution from lubricating oil is observed at low speeds. Differences were also observed in the SVOC composition when using different fuel types, engine lubricants, starting temperatures and collecting samples with

  3. Metal nanoparticles in diesel exhaust derived by in-cylinder melting of detached engine fragments

    NASA Astrophysics Data System (ADS)

    Liati, Anthi; Pandurangi, Sushant Sunil; Boulouchos, Konstantinos; Schreiber, Daniel; Arroyo Rojas Dasilva, Yadira

    2015-01-01

    A wide range of environmental and health effects are linked to combustion-generated pollutants related to traffic. Nanoparticles, in particular, are a major concern for humans since they can be inhaled and have potentially toxic effects. The variability and sources of combustion-related nanoparticle pollutants remain inadequately investigated. Here we report the presence of ca. 5-100 nm large Fe3O4 nanoparticles, in form of agglomerates, in diesel exhaust. The mode of occurrence of these nanoparticles, in combination with their chemical composition matching that of steel indicate that they derive by melting of engine fragments in the combustion chamber and subsequent crystallization during cooling. To evaluate this hypothesis, we applied CFD simulations of material transport in the cylinder of a diesel engine, assuming detachment of steel fragments from various sites of the cylinder. The CFD results show that fragments ≤20 μm in size dislodged from the piston surface or from the fuel nozzle interior can be indeed transported to such hot areas of the combustion chamber where they can melt. The simulation results concur with the experimental observations and point out that metal nanoparticle formation by in-cylinder melting of engine fragments can occur in diesel engines. The present study proposes a hitherto neglected formation mechanism of metal nanoparticle emissions from internal combustion engines raising possible environmental and health concerns, especially in urban areas.

  4. Metal particle emissions in the exhaust stream of diesel engines: an electron microscope study.

    PubMed

    Liati, Anthi; Schreiber, Daniel; Dimopoulos Eggenschwiler, Panayotis; Arroyo Rojas Dasilva, Yadira

    2013-12-17

    Scanning electron microscopy and transmission electron microscopy were applied to investigate the morphology, mode of occurrence and chemical composition of metal particles (diesel ash) in the exhaust stream of a small truck outfitted with a typical after-treatment system (a diesel oxidation catalyst (DOC) and a downstream diesel particulate filter (DPF)). Ash consists of Ca-Zn-P-Mg-S-Na-Al-K-phases (lube-oil related), Fe, Cr, Ni, Sn, Pb, Sn (engine wear), and Pd (DOC coating). Soot agglomerates of variable sizes (<0.5-5 μm) are abundant upstream of the DPF and are ash-free or contain notably little attached ash. Post-DPF soot agglomerates are very few, typically large (>1-5 μm, exceptionally 13 μm), rarely <0.5 μm, and contain abundant ash carried mostly from inside the DPF. The ash that reaches the atmosphere also occurs as separate aggregates ca. 0.2-2 μm in size consisting of sintered primary phases, ca. 20-400 nm large. Insoluble particles of these sizes may harm the respiratory and cardiovascular systems. The DPF probably promotes breakout of large soot agglomerates (mostly ash-bearing) by favoring sintering. Noble metals detached from the DOC coating may reach the ambient air. Finally, very few agglomerates of Fe-oxide nanoparticles form newly from engine wear and escape into the atmosphere.

  5. Comparison of carbonaceous aerosols in Tokyo before and after implementation of diesel exhaust restrictions.

    PubMed

    Yamamoto, Naomichi; Muramoto, Atsushi; Yoshinaga, Jun; Shibata, Ken; Endo, Michio; Endo, Osamu; Hirabayashi, Motohiro; Tanabe, Kiyoshi; Goto, Sumio; Yoneda, Minoru; Shibata, Yasuyuki

    2007-09-15

    We compared the status of carbonaceous aerosols in Tokyo before and after the implementation of a diesel vehicle regulation intended to reduce the quantity of particulate carbon from diesel engines in one of the largest scale ever attempts at vehicle exhaust control. Radiocarbon (14C) in elemental carbon (EC) and total carbon (TC) were analyzed to identify fossil fuel carbonaceous particles emitted from diesel-powered vehicles. One-sided paired-month t-tests showed no distinct difference in the absolute concentrations of particles in terms of total mass (19.5 to 18.0 microg m(-3); p = 0.321), EC (3.6 to 3.3 microg m(-3); p = 0.272), and TC (6.3 to 6.2 microg m(-3); p = 0.418) for the finest particles (d(a) < 1.1 microm) after the implementation of the regulation. The ratios of the concentrations of the chemical constituents were, however, altered after the regulation. EC/TC was significantly decreased from 56.7% to 50.2% (p = 0.039). Although it was not statistically significant, the percentage of fossil carbon in EC also decreased (67.8% to 63.8%; p = 0.104). Since EC is predominantly of combustion origin, the observed decrease was likely due to the decrease in fossil EC emissions from diesel-powered vehicles. The decrease in EC/TC after the implementation of the regulation was also likely to have resulted from attachment to diesel vehicle exhaust systems of particulate filters as required as part of the regulation by the Tokyo Metropolitan Government. The EC/TC of fossil carbon of the finest particles decreased from 66.2% to 55.2% (p = 0.066), but EC/TC of biomass carbon did not decrease but rose slightly from 43.6% to 44.5% (p > 0.5). Thus, the relative ratios of components of carbonaceous aerosol particles, such as 14C, could provide a better understanding of the atmospheric pollution status, despite short-term fluctuations, than do measurements of absolute concentrations.

  6. Sample characterization of automobile and forklift diesel exhaust particles and comparative pulmonary toxicity in mice.

    PubMed Central

    Singh, Pramila; DeMarini, David M; Dick, Colin A J; Tabor, Dennis G; Ryan, Jeff V; Linak, William P; Kobayashi, Takahiro; Gilmour, M Ian

    2004-01-01

    Two samples of diesel exhaust particles (DEPs) predominate in health effects research: an automobile-derived DEP (A-DEP) sample and the National Institute of Standards Technology standard reference material (SRM 2975) generated from a forklift engine. A-DEPs have been tested extensively for their effects on pulmonary inflammation and exacerbation of allergic asthmalike responses. In contrast, SRM 2975 has been tested thoroughly for its genotoxicity. In the present study, we combined physical and chemical analyses of both DEP samples with pulmonary toxicity testing in CD-1 mice to compare the two materials and to make associations between their physicochemical properties and their biologic effects. A-DEPs had more than 10 times the amount of extractable organic material and less than one-sixth the amount of elemental carbon compared with SRM 2975. Aspiration of 100 micro g of either DEP sample in saline produced mild acute lung injury; however, A-DEPs induced macrophage influx and activation, whereas SRM 2975 enhanced polymorphonuclear cell inflammation. A-DEPs stimulated an increase in interleukin-6 (IL-6), tumor necrosis factor alpha, macrophage inhibitory protein-2, and the TH2 cytokine IL-5, whereas SRM 2975 only induced significant levels of IL-6. Fractionated organic extracts of the same quantity of DEPs (100 micro g) did not have a discernable effect on lung responses and will require further study. The disparate results obtained highlight the need for chemical, physical, and source characterization of particle samples under investigation. Multidisciplinary toxicity testing of diesel emissions derived from a variety of generation and collection conditions is required to meaningfully assess the health hazards associated with exposures to DEPs. Key words: automobile, diesel exhaust particles, forklift, mice, pulmonary toxicity, SRM 2975. PMID:15175167

  7. Systemic immunotoxicity in AJ mice following 6-month whole body inhalation exposure to diesel exhaust.

    PubMed

    Burchiel, Scott W; Lauer, Fredine T; McDonald, Jacob D; Reed, Matthew D

    2004-05-01

    The purpose of these studies was to determine the effects of subchronic diesel exposure on indicators of systemic immunity in mice. AJ mice were exposed daily for 6 months (6 h/day) to atmospheres containing one of four concentrations (30, 100, 300, and 1000 microg/m(3)) of diluted diesel exhaust (DE) in whole body exposure chambers. The effects of DE were compared to chamber exposure controls receiving fresh air. DE was assessed for effects on systemic immunity by measuring the proliferative response of spleen cells following stimulation with T cell (phytohemagglutinin, or PHA) or B cell (lipopolysaccharide, or LPS) mitogens. The results showed that DE at all exposure levels suppressed the proliferative response of T cells. B cell proliferation was increased at 30 microg/m(3) and was unaffected at the 100, 300, and 1000 microg/m(3) exposures. Polycyclic aromatic hydrocarbons (PAHs) are known to suppress spleen cell mitogenic responses, and it has been hypothesized by several groups that PAHs and perhaps benzo(a)pyrene (BaP)-quinones (BPQs) may be responsible for the effects of DE or diesel exhaust particles (DEP). Therefore, a second purpose of these studies was to determine the effects of in vitro BPQs on AJ mouse spleen cell mitogenic responses and compare to DE in preliminary studies. Unlike DE, BPQs were found to increase T cell proliferation. In addition, analysis of chamber atmospheres showed that there was little if any PAH and BPQs in DE. Therefore, these results demonstrate that because of the absence of BPQs in DE, they are likely not responsible for the immunosuppressive effect of DE on murine spleen cell responses.

  8. Response of pulmonary cellular defenses to the inhalation of high concentrations of diesel exhaust. [Rats

    SciTech Connect

    Strom, K.A.

    1984-01-01

    Rats were exposed to three concentrations of diluted diesel exhaust for 6 mo and 1 yr. Bronchopulmonary lavage was used to obtain the pulmonary phagocytes from the animals in order to study the response of the phagocytic defenses to the inhaled particulate. The cell counts of alveolar macrophages (AM) were proportional to the concentration of diesel exhaust particulate (DP) in the chronic exposures. AM increased in the lungs in response to the rate of DP mass entering the lungs, rather than to the total DP burden in the lung. The geometric mean volumes of AM from the exposed and control animals were approximately 1100 ..mu..m/sup 3/ at both 6 and 12 mo of exposure, although exposed cell-volume distributions skewed towards larger sizes. The AM volume distributions extended to 2000 ..mu..m/sup 3/ in both control and 250 /sup +/g DP/m/sup 3/ exposed animals and up to 5000 ..mu..m/sup 3/ in cells from animals exposed to 750 and 1500 ..mu..g DP/m/sup 3/. Polymorphonuclear leukocytes were present in the lavaged cell populations from the animals exposed to 750 and 1500 ..mu..g/m/sup 3/. In addition, at 1 yr of exposure, lymphocytes were also lavaged from animals exposed to 750 and 1500 ..mu..g DP/m/sup 3/. Protein, ..beta..-glucuronidase activity, and acid phosphatase activity were measured in the lavaged cells, and were elevated in the cells from animals exposed to 750 and 1500 ..mu..g/m/sup 3/. The buoyant density of diesel-laden AM was found to be greater than that of control AM, and overlapped with the buoyant density of the polymorphonuclear leukocytes. 42 references, 9 figures, 7 tables.

  9. Interactive effects of cerium oxide and diesel exhaust nanoparticles on inducing pulmonary fibrosis.

    PubMed

    Ma, Jane Y C; Young, Shih-Houng; Mercer, Robert R; Barger, Mark; Schwegler-Berry, Diane; Ma, Joseph K; Castranova, Vincent

    2014-07-15

    Cerium compounds have been used as a fuel-borne catalyst to lower the generation of diesel exhaust particles (DEPs), but are emitted as cerium oxide nanoparticles (CeO2) along with DEP in the diesel exhaust. The present study investigates the effects of the combined exposure to DEP and CeO2 on the pulmonary system in a rat model. Specific pathogen-free male Sprague-Dawley rats were exposed to CeO2 and/or DEP via a single intratracheal instillation and were sacrificed at various time points post-exposure. This investigation demonstrated that CeO2 induces a sustained inflammatory response, whereas DEP elicits a switch of the pulmonary immune response from Th1 to Th2. Both CeO2 and DEP activated AM and lymphocyte secretion of the proinflammatory cytokines IL-12 and IFN-γ, respectively. However, only DEP enhanced the anti-inflammatory cytokine IL-10 production in response to ex vivo LPS or Concanavalin A challenge that was not affected by the presence of CeO2, suggesting that DEP suppresses host defense capability by inducing the Th2 immunity. The micrographs of lymph nodes show that the particle clumps in DEP+CeO2 were significantly larger than CeO2 or DEP, exhibiting dense clumps continuous throughout the lymph nodes. Morphometric analysis demonstrates that the localization of collagen in the lung tissue after DEP+CeO2 reflects the combination of DEP-exposure plus CeO2-exposure. At 4 weeks post-exposure, the histological features demonstrated that CeO2 induced lung phospholipidosis and fibrosis. DEP induced lung granulomas that were not significantly affected by the presence of CeO2 in the combined exposure. Using CeO2 as diesel fuel catalyst may cause health concerns.

  10. Sample characterization of automobile and forklift diesel exhaust particles and comparative pulmonary toxicity in mice.

    PubMed

    Singh, Pramila; DeMarini, David M; Dick, Colin A J; Tabor, Dennis G; Ryan, Jeff V; Linak, William P; Kobayashi, Takahiro; Gilmour, M Ian

    2004-06-01

    Two samples of diesel exhaust particles (DEPs) predominate in health effects research: an automobile-derived DEP (A-DEP) sample and the National Institute of Standards Technology standard reference material (SRM 2975) generated from a forklift engine. A-DEPs have been tested extensively for their effects on pulmonary inflammation and exacerbation of allergic asthmalike responses. In contrast, SRM 2975 has been tested thoroughly for its genotoxicity. In the present study, we combined physical and chemical analyses of both DEP samples with pulmonary toxicity testing in CD-1 mice to compare the two materials and to make associations between their physicochemical properties and their biologic effects. A-DEPs had more than 10 times the amount of extractable organic material and less than one-sixth the amount of elemental carbon compared with SRM 2975. Aspiration of 100 micro g of either DEP sample in saline produced mild acute lung injury; however, A-DEPs induced macrophage influx and activation, whereas SRM 2975 enhanced polymorphonuclear cell inflammation. A-DEPs stimulated an increase in interleukin-6 (IL-6), tumor necrosis factor alpha, macrophage inhibitory protein-2, and the TH2 cytokine IL-5, whereas SRM 2975 only induced significant levels of IL-6. Fractionated organic extracts of the same quantity of DEPs (100 micro g) did not have a discernable effect on lung responses and will require further study. The disparate results obtained highlight the need for chemical, physical, and source characterization of particle samples under investigation. Multidisciplinary toxicity testing of diesel emissions derived from a variety of generation and collection conditions is required to meaningfully assess the health hazards associated with exposures to DEPs. Key words: automobile, diesel exhaust particles, forklift, mice, pulmonary toxicity, SRM 2975.

  11. Interactive effects of cerium oxide and diesel exhaust nanoparticles on inducing pulmonary fibrosis

    PubMed Central

    Ma, Jane Y.C.; Young, Shih-Houng; Mercer, Robert R.; Barger, Mark; Schwegler-Berry, Diane; Ma, Joseph K.; Castranova, Vincent

    2015-01-01

    Cerium compounds have been used as a fuel-borne catalyst to lower the generation of diesel exhaust particles (DEPs), but are emitted as cerium oxide nanoparticles (CeO2) along with DEP in the diesel exhaust. The present study investigates the effects of the combined exposure to DEP and CeO2 on the pulmonary system in a rat model. Specific pathogen-free male Sprague–Dawley rats were exposed to CeO2 and/or DEP via a single intratracheal instillation and were sacrificed at various time points post-exposure. This investigation demonstrated that CeO2 induces a sustained inflammatory response, whereas DEP elicits a switch of the pulmonary immune response from Th1 to Th2. Both CeO2 and DEP activated AM and lymphocyte secretion of the proinflammatory cytokines IL-12 and IFN-γ respectively. However, only DEP enhanced the anti-inflammatory cytokine IL-10 production in response to ex vivo LPS or Concanavalin A challenge that was not affected by the presence of CeO2, suggesting that DEP suppresses host defense capability by inducing the Th2 immunity. The micrographs of lymph nodes show that the particle clumps in DEP + CeO2 were significantly larger than CeO2 or DEP, exhibiting dense clumps continuous throughout the lymph nodes. Morphometric analysis demonstrates that the localization of collagen in the lung tissue after DEP + CeO2 reflects the combination of DEP-exposure plus CeO2-exposure. At 4 weeks post-exposure, the histological features demonstrated that CeO2 induced lung phospholipidosis and fibrosis. DEP induced lung granulomas that were not significantly affected by the presence of CeO2 in the combined exposure. Using CeO2 as diesel fuel catalyst may cause health concerns. PMID:24793434

  12. In vitro genotoxicity of exhaust emissions of diesel and gasoline engine vehicles operated on a unified driving cycle.

    PubMed

    Liu, Yu-Qing; Keane, Michael; Ensell, Mang; Miller, William; Kashon, Michael; Ong, Tong-man; Mauderly, Joe; Lawson, Doug; Gautam, Mridul; Zielinska, Barbara; Whitney, Kevin; Eberhardt, James; Wallace, William

    2005-01-01

    Acetone extracts of engine exhaust particulate matter (PM) and of vapor-phase semi-volatile organic compounds (SVOCs) collected from a set of 1998-2000 model year normal emitter diesel engine automobile or light trucks and from a set of 1982-1996 normal emitter gasoline engine automobiles or light trucks operated on the California Unified Driving Cycle at 22 [degree]C were assayed for in vitro genotoxic activities. Gasoline and diesel PM were comparably positive mutagens for Salmonella typhimurium strains YG1024 and YG1029 on a mass of PM extract basis with diesel higher on a mileage basis; gasoline SVOC was more active than diesel on an extracted-mass basis, with diesel SVOC more active on a mileage basis. For chromosomal damage indicated by micronucleus induction in Chinese hamster lung fibroblasts (V79 cells), diesel PM expressed about one-tenth that of gasoline PM on a mass of extract basis, but was comparably active on a mileage basis; diesel SVOC was inactive. For DNA damage in V79 cells indicated by the single cell gel electrophoresis (SCGE) assay, gasoline PM was positive while diesel PM was active at the higher doses; gasoline SVOC was active with toxicity preventing measurement at high doses, while diesel SVOC was inactive at all but the highest dose.

  13. Mutagenic and cytotoxic effects of exhaust particulate matter of biodiesel compared to fossil diesel fuel.

    PubMed

    Bünger, J; Krahl, J; Franke, H U; Munack, A; Hallier, E

    1998-07-08

    The mutagenic and cytotoxic effects of diesel engine exhaust (DEE) from a modern passenger car using rapeseed oil methyl esters (RME, biodiesel) as fuel were directly compared to DEE of diesel fuel (DF) derived from petroleum. Combustion particulate matter was collected on glass fiber filters coated with polytetrafluoroethylene (PTFE) from an exhaust dilution tunnel using three different engine test cycles on a chassis dynamometer. Filters were extracted with dichloromethane in a soxhlet apparatus for 12 h. The mutagenicity of the extracts was tested in the Salmonella typhimurium/mammalian microsome plate-incorporation assay using strains TA97a, TA98, TA100, and TA102. The toxicity to the established cell line L929 (mouse lung fibroblasts) was investigated in the neutral red assay. In the tester strains TA98 and TA100 a significant increase of mutations resulted for the particle extracts of both fuels, but for DF the revertants were significantly higher compared to RME. The highest levels of revertants were observed in tests including a cold start phase. This was probably due to incomplete combustion in the cold engine and a lower conversion rate of the cold catalytic converter. Testing with activated liver S9 fraction induced a slightly lower increase of revertants in most experiments. TA97a and TA102 showed no significant enhancement of spontaneous mutations. In the FTP-75 test cycle RME extracts showed slightly higher toxic effects to the L929 cells than DF, whereas in the other tests no significant differences were observable. These results indicate a higher mutagenic potency of DEE of DF compared to RME. This is probably due to the lower content of polycyclic aromatic compounds (PAC) in RME exhaust, although the emitted masses of RME were higher in most test procedures applied in this study.

  14. Ion beam analyses of particulate matter in exhaust gas of a ship diesel engine

    NASA Astrophysics Data System (ADS)

    Furuyama, Yuichi; Fujita, Hirotsugu; Taniike, Akira; Kitamura, Akira

    2011-12-01

    There is an urgent need to reduce emission of the particulate matter (PM) in the exhaust gas from ship diesel engines causing various health hazards and serious environmental pollution. Usually the heavy fuel oil (HFO) for ships is of low quality, and contains various kinds of impurities. Therefore, the emission of PM along with exhaust gas from ship diesel engines is one of the most serious environmental issues. However, the PM fundamental properties are not well known. Therefore, it is important to perform elemental analysis of the PM. The HFO contains sulfur with a relatively high concentration of a few percent. It is important to make quantitative measurements of sulfur in the PM, because this element is poisonous for the human body. In the present work, PM samples were collected from exhaust gas of a test engine, and RBS and PIXE analyses were applied successfully to quantitative analysis of the PM samples. The RBS analysis enabled quantitative analysis of sulfur and carbon in the collected PM, while heavier elements such as vanadium and iron were analyzed quantitatively with the PIXE analysis. It has been found that the concentration ratio of sulfur to carbon was between 0.007 and 0.012, and did not strongly depend on the output power of the engine. The S/ C ratio is approximately equal to the original composition of the HFO used in the present work, 0.01. From the known conversion ratio 0.015 of sulfur in the HFO to sulfates, the conversion ratio of carbon in the HFO to the PM is found to be 0.01-0.02 by the RBS measurements. On the other hand, the PIXE analysis revealed a vanadium enrichment of one order of magnitude in the PM.

  15. Composition and Integrity of PAHs, Nitro-PAHs, Hopanes and Steranes In Diesel Exhaust Particulate Matter

    PubMed Central

    Huang, Lei; Bohac, Stanislav V.; Chernyak, Sergei M.; Batterman, Stuart A.

    2013-01-01

    Diesel exhaust particulate matter contains many semivolatile organic compounds (SVOCs) of environmental and health significance. This study investigates the composition, emission rates, and integrity of 25 SVOCs, including polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs (NPAHs), and diesel biomarkers hopanes and steranes. Diesel engine particulate matter (PM), generated using an engine test bench, three engine conditions, and ultra-low sulfur diesel (ULSD), was collected on borosilicate glass fiber filters. Under high engine load, the PM emission rate was 0.102 g/kWh, and emission rate of ΣPAHs (10 compounds), ΣNPAHs (6 compounds), Σhopanes (2 compounds), and Σsteranes (2 compounds) were 2.52, 0.351, 0.02 ~ 2 and 1μg/kWh, respectively. Storage losses were evaluated for three cases: conditioning filters in clean air at 25 °C and 33% relative humidity (RH) for 24 h; storing filter samples (without extraction) wrapped in aluminum foil at 4 °C for up to one month; and storing filter extracts in glass vials capped with Teflon crimp seals at 4 °C for up to six months. After conditioning filters for 24 h, 30% of the more volatile PAHs were lost, but lower volatility NPAHs, hopanes and steranes showed negligible changes. Storing wrapped filters and extracts at 4 °C for up to one month did not lead to significant losses, but storing extracts for five months led to significant losses of PAHs and NPAHs; hopanes and steranes demonstrated greater integrity. These results suggest that even relatively brief filter conditioning periods, needed for gravimetric measurements of PM mass, and extended storage of filter extracts can lead to underestimates of SVOC concentrations. Thus, SVOC sampling and analysis protocols should utilize stringent criteria and performance checks to identify and limit possible biases occurring during filter and extract processing. PMID:24363468

  16. On-line measurements of gaseous nitro-organic compounds in diesel vehicle exhaust by proton-transfer-reaction mass spectrometry

    NASA Astrophysics Data System (ADS)

    Inomata, Satoshi; Tanimoto, Hiroshi; Fujitani, Yuji; Sekimoto, Kanako; Sato, Kei; Fushimi, Akihiro; Yamada, Hiroyuki; Hori, Shigeo; Kumazawa, Yasuko; Shimono, Akio; Hikida, Toshihide

    2013-07-01

    Nitro-organic compounds, some of which cause adverse health effects in humans, are emitted in diesel engine exhaust. Speciation and quantification of these nitro-organic compounds in diesel engine exhaust particles have been extensively conducted; however, investigations into the emissions of gaseous nitro-organic compounds in diesel engine exhaust have not. In the present study, the properties of gaseous nitro-organic compounds in diesel engine exhaust were investigated through time-resolved measurement with a proton-transfer-reaction mass spectrometer and a chassis dynamometer. Three diesel trucks were tested, each with a different type of exhaust-gas treatment system (i.e., aftertreatment). Among the nitro-organic compounds detected, the emission of nitromethane was commonly observed and found to be related to the emissions of carbon monoxide, benzene, and acetone. The emission of other nitro-organic compounds, such as nitrophenol, depended on the vehicle, possibly due to the type of aftertreatment installed.

  17. The characterisation of diesel exhaust particles - composition, size distribution and partitioning.

    PubMed

    Alam, Mohammed S; Zeraati-Rezaei, Soheil; Stark, Christopher P; Liang, Zhirong; Xu, Hongming; Harrison, Roy M

    2016-07-18

    A number of major research questions remain concerning the sources and properties of road traffic generated particulate matter. A full understanding of the composition of primary vehicle exhaust aerosol and its contribution to secondary organic aerosol (SOA) formation still remains elusive, and many uncertainties exist relating to the semi-volatile component of the particles. Semi-Volatile Organic Compounds (SVOCs) are compounds which partition directly between the gas and aerosol phases under ambient conditions. The SVOCs in engine exhaust are typically hydrocarbons in the C15-C35 range, and are largely uncharacterised because they are unresolved by traditional gas chromatography, forming a large hump in the chromatogram referred to as Unresolved Complex Mixture (UCM). In this study, thermal desorption coupled to comprehensive Two Dimensional Gas-Chromatography Time-of-Flight Mass-Spectrometry (TD-GC × GC-ToF-MS) was exploited to characterise and quantify the composition of SVOCs from the exhaust emission. Samples were collected from the exhaust of a diesel engine, sampling before and after a diesel oxidation catalyst (DOC), while testing at steady state conditions. Engine exhaust was diluted with air and collected using both filter and impaction (nano-MOUDI), to resolve total mass and size resolved mass respectively. Adsorption tubes were utilised to collect SVOCs in the gas phase and they were then analysed using thermal desorption, while particle size distribution was evaluated by sampling with a DMS500. The SVOCs were observed to contain predominantly n-alkanes, branched alkanes, alkyl-cycloalkanes, alkyl-benzenes, PAHs and various cyclic aromatics. Particle phase compounds identified were similar to those observed in engine lubricants, while vapour phase constituents were similar to those measured in fuels. Preliminary results are presented illustrating differences in the particle size distribution and SVOCs composition when collecting samples with and

  18. Application of hybrid evolutionary algorithms to low exhaust emission diesel engine design

    NASA Astrophysics Data System (ADS)

    Jeong, S.; Obayashi, S.; Minemura, Y.

    2008-01-01

    A hybrid evolutionary algorithm, consisting of a genetic algorithm (GA) and particle swarm optimization (PSO), is proposed. Generally, GAs maintain diverse solutions of good quality in multi-objective problems, while PSO shows fast convergence to the optimum solution. By coupling these algorithms, GA will compensate for the low diversity of PSO, while PSO will compensate for the high computational costs of GA. The hybrid algorithm was validated using standard test functions. The results showed that the hybrid algorithm has better performance than either a pure GA or pure PSO. The method was applied to an engineering design problem—the geometry of diesel engine combustion chamber reducing exhaust emissions such as NOx, soot and CO was optimized. The results demonstrated the usefulness of the present method to this engineering design problem. To identify the relation between exhaust emissions and combustion chamber geometry, data mining was performed with a self-organising map (SOM). The results indicate that the volume near the lower central part of the combustion chamber has a large effect on exhaust emissions and the optimum chamber geometry will vary depending on fuel injection angle.

  19. The diesel exhaust in miners study: I. Overview of the exposure assessment process.

    PubMed

    Stewart, Patricia A; Coble, Joseph B; Vermeulen, Roel; Schleiff, Patricia; Blair, Aaron; Lubin, Jay; Attfield, Michael; Silverman, Debra T

    2010-10-01

    This report provides an overview of the exposure assessment process for an epidemiologic study that investigated mortality, with a special focus on lung cancer, associated with diesel exhaust (DE) exposure among miners. Details of several components are provided in four other reports. A major challenge for this study was the development of quantitative estimates of historical exposures to DE. There is no single standard method for assessing the totality of DE, so respirable elemental carbon (REC), a component of DE, was selected as the primary surrogate in this study. Air monitoring surveys at seven of the eight study mining facilities were conducted between 1998 and 2001 and provided reference personal REC exposure levels and measurements for other agents and DE components in the mining environment. (The eighth facility had closed permanently prior to the surveys.) Exposure estimates were developed for mining facility/department/job/year combinations. A hierarchical grouping strategy was developed for assigning exposure levels to underground jobs [based on job titles, on the amount of time spent in various areas of the underground mine, and on similar carbon monoxide (CO, another DE component) concentrations] and to surface jobs (based on the use of, or proximity to, diesel-powered equipment). Time trends in air concentrations for underground jobs were estimated from mining facility-specific prediction models using diesel equipment horsepower, total air flow rates exhausted from the underground mines, and, because there were no historical REC measurements, historical measurements of CO. Exposures to potentially confounding agents, i.e. respirable dust, silica, radon, asbestos, and non-diesel sources of polycyclic aromatic hydrocarbons, also were assessed. Accuracy and reliability of the estimated REC exposures levels were evaluated by comparison with several smaller datasets and by development of alternative time trend models. During 1998-2001, the average

  20. The Diesel Exhaust in Miners Study: I. Overview of the Exposure Assessment Process

    PubMed Central

    Stewart, Patricia A.; Coble, Joseph B.; Vermeulen, Roel; Schleiff, Patricia; Blair, Aaron; Lubin, Jay; Attfield, Michael; Silverman, Debra T.

    2010-01-01

    This report provides an overview of the exposure assessment process for an epidemiologic study that investigated mortality, with a special focus on lung cancer, associated with diesel exhaust (DE) exposure among miners. Details of several components are provided in four other reports. A major challenge for this study was the development of quantitative estimates of historical exposures to DE. There is no single standard method for assessing the totality of DE, so respirable elemental carbon (REC), a component of DE, was selected as the primary surrogate in this study. Air monitoring surveys at seven of the eight study mining facilities were conducted between 1998 and 2001 and provided reference personal REC exposure levels and measurements for other agents and DE components in the mining environment. (The eighth facility had closed permanently prior to the surveys.) Exposure estimates were developed for mining facility/department/job/year combinations. A hierarchical grouping strategy was developed for assigning exposure levels to underground jobs [based on job titles, on the amount of time spent in various areas of the underground mine, and on similar carbon monoxide (CO, another DE component) concentrations] and to surface jobs (based on the use of, or proximity to, diesel-powered equipment). Time trends in air concentrations for underground jobs were estimated from mining facility-specific prediction models using diesel equipment horsepower, total air flow rates exhausted from the underground mines, and, because there were no historical REC measurements, historical measurements of CO. Exposures to potentially confounding agents, i.e. respirable dust, silica, radon, asbestos, and non-diesel sources of polycyclic aromatic hydrocarbons, also were assessed. Accuracy and reliability of the estimated REC exposures levels were evaluated by comparison with several smaller datasets and by development of alternative time trend models. During 1998–2001, the average

  1. Model of Heat Exchangers for Waste Heat Recovery from Diesel Engine Exhaust for Thermoelectric Power Generation

    NASA Astrophysics Data System (ADS)

    Baker, Chad; Vuppuluri, Prem; Shi, Li; Hall, Matthew

    2012-06-01

    The performance and operating characteristics of a hypothetical thermoelectric generator system designed to extract waste heat from the exhaust of a medium-duty turbocharged diesel engine were modeled. The finite-difference model consisted of two integrated submodels: a heat exchanger model and a thermoelectric device model. The heat exchanger model specified a rectangular cross-sectional geometry with liquid coolant on the cold side, and accounted for the difference between the heat transfer rate from the exhaust and that to the coolant. With the spatial variation of the thermoelectric properties accounted for, the thermoelectric device model calculated the hot-side and cold-side heat flux for the temperature boundary conditions given for the thermoelectric elements, iterating until temperature and heat flux boundary conditions satisfied the convection conditions for both exhaust and coolant, and heat transfer in the thermoelectric device. A downhill simplex method was used to optimize the parameters that affected the electrical power output, including the thermoelectric leg height, thermoelectric n-type to p-type leg area ratio, thermoelectric leg area to void area ratio, load electrical resistance, exhaust duct height, coolant duct height, fin spacing in the exhaust duct, location in the engine exhaust system, and number of flow paths within the constrained package volume. The calculation results showed that the configuration with 32 straight fins was optimal across the 30-cm-wide duct for the case of a single duct with total height of 5.5 cm. In addition, three counterflow parallel ducts or flow paths were found to be an optimum number for the given size constraint of 5.5 cm total height, and parallel ducts with counterflow were a better configuration than serpentine flow. Based on the reported thermoelectric properties of MnSi1.75 and Mg2Si0.5Sn0.5, the maximum net electrical power achieved for the three parallel flow paths in a counterflow arrangement was 1

  2. Comparative Cardiopulmonary Toxicity of exhausts from Soy-Based Biofuels and Diesel in Healthy and Hypertensive Rats

    EPA Science Inventory

    Increased use of renewable energy sources raise concerns about health effects of new emissions. We analyzed relative cardiopulmonary health effects of exhausts from (1) 100% soy biofuel (B100), (2) 20% soy biofuel + 80% low sulfur petroleum diesel (B20), and (3) 100% petroleum di...

  3. *Assessing differential transcriptional regulation of IL-8 expression by human airway epithelial cells exposed to diesel exhaust particles

    EPA Science Inventory

    Background: Exposure to Diesel Exhaust Particles (DEP) induces inflammatory signaling characterized by MAP kinase-mediated activation of NFkB and AP-l in vitro and in bronchial biopsies obtained from human subjects exposed to DEP. NFkB and AP-l activation results in the upregulat...

  4. 40 CFR 86.210-08 - Exhaust gas sampling system; Diesel-cycle vehicles not requiring particulate emissions measurements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Vehicles; Cold Temperature Test Procedures § 86.210-08 Exhaust gas sampling system; Diesel-cycle vehicles... the THC probe be free from cold spots (i.e., free from spots where the probe wall temperature is less... common sample pump is used for all analyzers and the sample line system design reflects good engineering...

  5. 40 CFR 86.210-08 - Exhaust gas sampling system; Diesel-cycle vehicles not requiring particulate emissions measurements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Vehicles; Cold Temperature Test Procedures § 86.210-08 Exhaust gas sampling system; Diesel-cycle vehicles... the THC probe be free from cold spots (i.e., free from spots where the probe wall temperature is less... common sample pump is used for all analyzers and the sample line system design reflects good engineering...

  6. Diesel Exhaust-Induced Cardiac Dysfunction Is Mediated by Sympathetic Dominance in Heart Failure-Prone Rats

    EPA Science Inventory

    Short-term exposure to vehicular emissions is associated with adverse cardiac events. Diesel exhaust (DE) may provoke cardiac events through defective co-ordination of the two main autonomic nervous system (ANS) branches. We exposed heart failure-prone rats once to DE (500 g/m3 ...

  7. Susceptibility of inflamed ariway and alveolar epithelial cells to injury induced by diesel exhaust particles of varying organic carbon content

    EPA Science Inventory

    Exposure to traffic-related ambient air pollution, such as diesel exhaust particles (DEP), is associated with adverse health outcomes, especially in individuals with preexisting inflammatory respiratory diseases. Using an analogous in vitro system to model both the healthy and a...

  8. Bioassay-Directed Fractionation and Sub-fractionation for Mutagenicity and Chemical Analysis of Diesel Exhaust Particles

    EPA Science Inventory

    Several types of diesel exhaust particles (DEPs) have been used for toxicology studies, including a high-organic automobile DEP (A-DEP) from Japan, and a low-organic forklift DEP developed by the National Institute of Standards and Technology (N-DEP). However, these DEPs were no...

  9. TRPA1 and Sympathetic Activation contribute to increased risk of triggered cardiac arrhythmias in hypertensive rats exposed to diesel exhaust

    EPA Science Inventory

    Background -Diesel exhaust (DE), which is emitted from on-and off-road sources, is a complex mixture of toxic gaseous and particulate components that results in adverse cardiovascular effects. Arrhythmias, which are often triggered in the hours and days following exposure, are on...

  10. Cardiovascular Effects Caused by Increasing Concentrations of Diesel Exhaust in Middle-Aged Healthy GSTM1 Null Human Volunteers

    EPA Science Inventory

    ABSTRACT Objectives: Epidemiological studies have shown an association between the incidence of adverse cardiovascular effects and exposure to ambient particulate matter (PM). Diesel exhaust (DE) is a major contributor to ambient PM in urban areas. This study was designed to e...

  11. Treadmill stress test after diesel exhaust particulate exposure reveals a time-dependent shift from parasympathetic to sympathetic dominance

    EPA Science Inventory

    Epidemiological studies suggest that particulate matter (PM) air pollution is a major trigger of acute cardiac events-including arrhythmia-especially in those with preexisting cardiac disease. Diesel exhaust (DE) contributes the majority of urban fine and ultrafine PM, and is thu...

  12. Diesel exhaust worsens cardiac conduction instability in dobutamine-challenged Wistar-Kyoto and spontaneously hypertensive rats

    EPA Science Inventory

    This study shows that a single exposure to diesel exhaust causes conduction instability in rats that is worse in the presence of hypertension. The RoR assessment is shown to be a valuable tool that can be used to reveal the deleterious effects of air pollution, particularly in th...

  13. Ventricular transcriptional data provide mechanistic insights into diesel exhaust induced attenuation of cardiac contractile response and blood pressure

    EPA Science Inventory

    Human exposures to near road ambient particulate matter and its major component, diesel exhaust (DE), have been associated with cardiovascular impairments however the mechanisms and the role of hypertension are not well understood. We have shown that DE exposure reduces blood pre...

  14. TRPA1 and Sympathetic Activation contribute to increased risk of triggered cardiac arrhythmias in hypertensive rats exposed to diesel exhaust

    EPA Science Inventory

    Background -Diesel exhaust (DE), which is emitted from on-and off-road sources, is a complex mixture of toxic gaseous and particulate components that results in adverse cardiovascular effects. Arrhythmias, which are often triggered in the hours and days following exposure, are on...

  15. *Assessing differential transcriptional regulation of IL-8 expression by human airway epithelial cells exposed to diesel exhaust particles

    EPA Science Inventory

    Background: Exposure to Diesel Exhaust Particles (DEP) induces inflammatory signaling characterized by MAP kinase-mediated activation of NFkB and AP-l in vitro and in bronchial biopsies obtained from human subjects exposed to DEP. NFkB and AP-l activation results in the upregulat...

  16. Diesel Exhaust-Induced Cardiac Dysfunction Is Mediated by Sympathetic Dominance in Heart Failure-Prone Rats

    EPA Science Inventory

    Short-term exposure to vehicular emissions is associated with adverse cardiac events. Diesel exhaust (DE) may provoke cardiac events through defective co-ordination of the two main autonomic nervous system (ANS) branches. We exposed heart failure-prone rats once to DE (500 g/m3 ...

  17. EFFECTS OF DIESEL EXHAUST ON PULMONARY RESPONSES DURING ALLERGIC SENSITIZATION TO AEROSOLIZED OVALBUMIN IN BALB/C MICE

    EPA Science Inventory

    Effects of Diesel Exhaust on Pulmonary Responses During Allergic Sensitization to Aerosolized Ovalbumin in BALB/c Mice. P. Singh1, M.J. Daniels1, D. Andrews1, E. Boykin1, W. P. Linak2 and M.I. Gilmour1. 1USEPA, ORD, NHEERL, RTP, NC. 2 USEPA, ORD, NRMRL, RTP, NC.

    Inhala...

  18. Treadmill stress test after diesel exhaust particulate exposure reveals a time-dependent shift from parasympathetic to sympathetic dominance

    EPA Science Inventory

    Epidemiological studies suggest that particulate matter (PM) air pollution is a major trigger of acute cardiac events-including arrhythmia-especially in those with preexisting cardiac disease. Diesel exhaust (DE) contributes the majority of urban fine and ultrafine PM, and is thu...

  19. Comparative Cardiopulmonary Toxicity of exhausts from Soy-Based Biofuels and Diesel in Healthy and Hypertensive Rats

    EPA Science Inventory

    Increased use of renewable energy sources raise concerns about health effects of new emissions. We analyzed relative cardiopulmonary health effects of exhausts from (1) 100% soy biofuel (B100), (2) 20% soy biofuel + 80% low sulfur petroleum diesel (B20), and (3) 100% petroleum di...

  20. Use of exhaled breath condensate endpoints for examination of Body Mass Index as a susceptibility factor to diesel exhaust.

    EPA Science Inventory

    High and low Body Mass Index (BMI) is a risk factor for effects (e.g., premature mortality) induced by exposure to common air pollutants such as ozone and particulate matter. Diesel exhaust contributes to particulate matter levels. We examined lung responses using the exhaled bre...

  1. Ventricular transcriptional data provide mechanistic insights into diesel exhaust induced attenuation of cardiac contractile response and blood pressure

    EPA Science Inventory

    Human exposures to near road ambient particulate matter and its major component, diesel exhaust (DE), have been associated with cardiovascular impairments however the mechanisms and the role of hypertension are not well understood. We have shown that DE exposure reduces blood pre...

  2. NANOMETER SIZE DIESEL EXHAUST PARTICLES ARE SELECTIVELY TOXIC TO DOPAMINERGIC NEURONS: THE ROLE OF MICROGLIA, PHAGOCYTOSIS, AND NADPH OXIDASE.

    EPA Science Inventory

    This manuscript describes the neurotoxic response of cultured brain cells to diesel exhaust particles (DEP). DEP produces an early production of free radicals (i.e., oxidative stress) in one CNS cell type (the microglial) and the subsequent degeneration of specific neuronal...

  3. Susceptibility of inflamed ariway and alveolar epithelial cells to injury induced by diesel exhaust particles of varying organic carbon content

    EPA Science Inventory

    Exposure to traffic-related ambient air pollution, such as diesel exhaust particles (DEP), is associated with adverse health outcomes, especially in individuals with preexisting inflammatory respiratory diseases. Using an analogous in vitro system to model both the healthy and a...

  4. Bioassay-Directed Fractionation and Sub-fractionation for Mutagenicity and Chemical Analysis of Diesel Exhaust Particles

    EPA Science Inventory

    Several types of diesel exhaust particles (DEPs) have been used for toxicology studies, including a high-organic automobile DEP (A-DEP) from Japan, and a low-organic forklift DEP developed by the National Institute of Standards and Technology (N-DEP). However, these DEPs were no...

  5. Cardiovascular Effects Caused by Increasing Concentrations of Diesel Exhaust in Middle-Aged Healthy GSTM1 Null Human Volunteers

    EPA Science Inventory

    ABSTRACT Objectives: Epidemiological studies have shown an association between the incidence of adverse cardiovascular effects and exposure to ambient particulate matter (PM). Diesel exhaust (DE) is a major contributor to ambient PM in urban areas. This study was designed to e...

  6. EFFECTS OF DIESEL EXHAUST ON PULMONARY RESPONSES DURING ALLERGIC SENSITIZATION TO AEROSOLIZED OVALBUMIN IN BALB/C MICE

    EPA Science Inventory

    Effects of Diesel Exhaust on Pulmonary Responses During Allergic Sensitization to Aerosolized Ovalbumin in BALB/c Mice. P. Singh1, M.J. Daniels1, D. Andrews1, E. Boykin1, W. P. Linak2 and M.I. Gilmour1. 1USEPA, ORD, NHEERL, RTP, NC. 2 USEPA, ORD, NRMRL, RTP, NC.

    Inhala...

  7. Use of exhaled breath condensate endpoints for examination of Body Mass Index as a susceptibility factor to diesel exhaust.

    EPA Science Inventory

    High and low Body Mass Index (BMI) is a risk factor for effects (e.g., premature mortality) induced by exposure to common air pollutants such as ozone and particulate matter. Diesel exhaust contributes to particulate matter levels. We examined lung resp