Toxicity of aged gasoline exhaust particles to normal and diseased airway epithelia.

PubMed

Künzi, Lisa; Krapf, Manuel; Daher, Nancy; Dommen, Josef; Jeannet, Natalie; Schneider, Sarah; Platt, Stephen; Slowik, Jay G; Baumlin, Nathalie; Salathe, Matthias; Prévôt, André S H; Kalberer, Markus; Strähl, Christof; Dümbgen, Lutz; Sioutas, Constantinos; Baltensperger, Urs; Geiser, Marianne

2015-06-29

Particulate matter (PM) pollution is a leading cause of premature death, particularly in those with pre-existing lung disease. A causative link between particle properties and adverse health effects remains unestablished mainly due to complex and variable physico-chemical PM parameters. Controlled laboratory experiments are required. Generating atmospherically realistic aerosols and performing cell-exposure studies at relevant particle-doses are challenging. Here we examine gasoline-exhaust particle toxicity from a Euro-5 passenger car in a uniquely realistic exposure scenario, combining a smog chamber simulating atmospheric ageing, an aerosol enrichment system varying particle number concentration independent of particle chemistry, and an aerosol deposition chamber physiologically delivering particles on air-liquid interface (ALI) cultures reproducing normal and susceptible health status. Gasoline-exhaust is an important PM source with largely unknown health effects. We investigated acute responses of fully-differentiated normal, distressed (antibiotics-treated) normal, and cystic fibrosis human bronchial epithelia (HBE), and a proliferating, single-cell type bronchial epithelial cell-line (BEAS-2B). We show that a single, short-term exposure to realistic doses of atmospherically-aged gasoline-exhaust particles impairs epithelial key-defence mechanisms, rendering it more vulnerable to subsequent hazards. We establish dose-response curves at realistic particle-concentration levels. Significant differences between cell models suggest the use of fully-differentiated HBE is most appropriate in future toxicity studies.

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

Estimation of the diesel exhaust exposures of railroad workers: II. National and historical exposures.

PubMed

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

1988-01-01

The diesel exhaust exposures of railroad workers in thirteen job groups from four railroads in the United States were used to estimate U.S. national average exposures with a linear statistical model which accounts for the significant variability in exposure caused by climate, the differences among railroads and the uneven distribution of railroad workers across climatic regions. Personal measurements of respirable particulate matter, adjusted to remove the contribution of cigarette smoke particles, were used as a marker for diesel exhaust. The estimated national means of adjusted respirable particulate matter (ARP) averaged 10 micrograms/m3 lower than the simple means for each job group, reflecting the climatic differences between the northern railroads studied and the distribution of railroad workers nationally. Limited historical records, including some industrial hygiene data, were used to evaluate past diesel exhaust exposures, which were estimated to be approximately constant from the 1950's to 1983.

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...

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...

Long term exposure to environmental concentrations of diesel exhaust particles does not impact the phenotype of human bronchial epithelial cells.

PubMed

Savary, Camille C; Bellamri, Nessrine; Morzadec, Claudie; Langouët, Sophie; Lecureur, Valérie; Vernhet, Laurent

2018-06-19

Chronic exposure to diesel engine exhausts is associated with an increased risk of pulmonary diseases including lung cancer. Diesel engine exhausts contain large amounts of diesel exhaust particles (DEP) on which are adsorbed several carcinogenic compounds such as polycyclic aromatic hydrocarbons. Acute toxicity of high concentrations of DEP has been largely demonstrated in various in vitro cellular models. In contrast, the cellular and molecular impacts of low environmental concentrations of DEP on the phenotype of chronically exposed lung epithelial cells remain to be investigated. In the present study, we show that long term exposure (6 months) to 2 μg/ml (0.4 μg/cm 2 ) DEP (standard reference material 1650b) increased cytochrome P4501A mRNA levels in the human bronchial epithelial BEAS-2B cell line. However, chronic exposure to DEP did not change cell morphology, trigger epithelial-mesenchymal transition or increase anchorage-independent cell growth. Moreover, DEP increase neither the levels of reactive oxygen species or those of γ-histone H2AX, nor the expression of interleukin-6 and interleukin-8. Our results thus demonstrate that the chronic exposure to low DEP concentrations could increase cytochrome P501A gene expression in BEAS-2B cells but did not induce molecular effects related to genotoxicity, oxidative stress or inflammation. Copyright © 2018 Elsevier Ltd. All rights reserved.

Driver exposure to combustion particles in the U.S. Trucking industry.

PubMed

Davis, M E; Smith, T J; Laden, F; Hart, J E; Blicharz, A P; Reaser, P; Garshick, E

2007-11-01

A large study of combustion particle exposures for drivers of diesel-powered trucks was conducted in collaboration with an epidemiologic study of lung cancer outcomes for workers in the trucking industry. Three components of diesel exhaust combustion particles (PM(2.5), elemental carbon, and organic carbon) were measured inside the driver cabs of diesel-powered trucks from 36 different trucking terminals across the United States between 2001 and 2005. In-cab particle exposures for drivers assigned to both short and long distance trips were observed, as well as information on the smoking status of the driver, truck characteristics such as age and model, and weather conditions during the sampling session. This article summarizes these findings and describes the relationship between exhaust particles and various determinants of exposure. The results suggest that in-cab particle exposures are positively related to smoking, ambient particle concentrations, truck age, and open windows, with other significant modifying factors such as weather. This study represents the largest and most comprehensive exposure assessment of drivers in the trucking industry, encompassing a 4-year period of observations on diesel and exhaust particle exposures nationwide. The results are relevant not only to the occupational group of truck drivers being examined but also to the general population that live, commute, or work within proximity to diesel-fueled traffic or trucking terminals.

Physicochemical characterisation of combustion particles from vehicle exhaust and residential wood smoke

PubMed Central

Kocbach, Anette; Li, Yanjun; Yttri, Karl E; Cassee, Flemming R; Schwarze, Per E; Namork, Ellen

2006-01-01

Background Exposure to ambient particulate matter has been associated with a number of adverse health effects. Particle characteristics such as size, surface area and chemistry seem to influence the negative effects of particles. In this study, combustion particles from vehicle exhaust and wood smoke, currently used in biological experiments, were analysed with respect to microstructure and chemistry. Methods Vehicle exhaust particles were collected in a road tunnel during two seasons, with and without use of studded tires, whereas wood smoke was collected from a stove with single-stage combustion. Additionally, a reference diesel sample (SRM 2975) was analysed. The samples were characterised using transmission electron microscopy techniques (TEM/HRTEM, EELS and SAED). Furthermore, the elemental and organic carbon fractions were quantified using thermal optical transmission analysis and the content of selected PAHs was determined by gas chromatography-mass spectrometry. Results Carbon aggregates, consisting of tens to thousands of spherical primary particles, were the only combustion particles identified in all samples using TEM. The tunnel samples also contained mineral particles originating from road abrasion. The geometric diameters of primary carbon particles from vehicle exhaust were found to be significantly smaller (24 ± 6 nm) than for wood smoke (31 ± 7 nm). Furthermore, HRTEM showed that primary particles from both sources exhibited a turbostratic microstructure, consisting of concentric carbon layers surrounding several nuclei in vehicle exhaust or a single nucleus in wood smoke. However, no differences were detected in the graphitic character of primary particles from the two sources using SAED and EELS. The total PAH content was higher for combustion particles from wood smoke as compared to vehicle exhaust, whereas no source difference was found for the ratio of organic to total carbon. Conclusion Combustion particles from vehicle exhaust and

Diesel exhaust exposure, wheezing and sneezing.

PubMed

Bernstein, David I

2012-07-01

The rising incidence of allergic disorders in developed countries is unexplained. Exposure to traffic related air pollutants may be an important cause of wheezing and asthma in childhood. Experimental evidence from human studies suggests that diesel exhaust particles, constituents of fine particulate matter less than 2.5 microns (PM(2.5)), may act to enhance IgE mediated aeroallergen sensitization and Th2 directed cytokine responses. To date, epidemiologic investigations indicate that children living in close proximity to heavily travelled roads are more likely to be atopic and wheeze. The Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS) birth cohort study was initiated to test the hypothesis that early high exposure to traffic related air pollutants is associated with early aeroallergen sensitization and allergic respiratory phenotypes. Using an exposure cohort design, more than 700 infants born to atopic parents were recruited at age 1 living either less than 400 meters (high traffic pollutant exposure) or greater than 1,500 meters (low exposure) from a major road. Children were medically evaluated and underwent skin prick testing with aeroallergen at screening, and re-evaluated sequentially at ages 1, 2, 3, 4, and 7. In this study, both proximity and land use regression (LUR) models of traffic air pollutant exposure have been assessed. Proximity to stop and go traffic with large concentrations of bus and truck traffic predicted persistent wheezing during infancy. The LUR model estimated elemental carbon attributable to traffic (ECAT) as a proxy for diesel exhaust particulate exposure. High ECAT was significantly associated with wheezing at age 1 as well as persistent wheezing at age 3. High mold exposure predicted a well defined asthma phenotype at age 7.

Diesel Exhaust Exposure, Wheezing and Sneezing

PubMed Central

2012-01-01

The rising incidence of allergic disorders in developed countries is unexplained. Exposure to traffic related air pollutants may be an important cause of wheezing and asthma in childhood. Experimental evidence from human studies suggests that diesel exhaust particles, constituents of fine particulate matter less than 2.5 microns (PM2.5), may act to enhance IgE mediated aeroallergen sensitization and Th2 directed cytokine responses. To date, epidemiologic investigations indicate that children living in close proximity to heavily travelled roads are more likely to be atopic and wheeze. The Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS) birth cohort study was initiated to test the hypothesis that early high exposure to traffic related air pollutants is associated with early aeroallergen sensitization and allergic respiratory phenotypes. Using an exposure cohort design, more than 700 infants born to atopic parents were recruited at age 1 living either less than 400 meters (high traffic pollutant exposure) or greater than 1,500 meters (low exposure) from a major road. Children were medically evaluated and underwent skin prick testing with aeroallergen at screening, and re-evaluated sequentially at ages 1, 2, 3, 4, and 7. In this study, both proximity and land use regression (LUR) models of traffic air pollutant exposure have been assessed. Proximity to stop and go traffic with large concentrations of bus and truck traffic predicted persistent wheezing during infancy. The LUR model estimated elemental carbon attributable to traffic (ECAT) as a proxy for diesel exhaust particulate exposure. High ECAT was significantly associated with wheezing at age 1 as well as persistent wheezing at age 3. High mold exposure predicted a well defined asthma phenotype at age 7. PMID:22754710

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

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...

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...

Particle traps prevent adverse vascular and prothrombotic effects of diesel engine exhaust inhalation in men.

PubMed

Lucking, Andrew J; Lundbäck, Magnus; Barath, Stefan L; Mills, Nicholas L; Sidhu, Manjit K; Langrish, Jeremy P; Boon, Nicholas A; Pourazar, Jamshid; Badimon, Juan J; Gerlofs-Nijland, Miriam E; Cassee, Flemming R; Boman, Christoffer; Donaldson, Kenneth; Sandstrom, Thomas; Newby, David E; Blomberg, Anders

2011-04-26

In controlled human exposure studies, diesel engine exhaust inhalation impairs vascular function and enhances thrombus formation. The aim of the present study was to establish whether an exhaust particle trap could prevent these adverse cardiovascular effects in men. Nineteen healthy volunteers (mean age, 25±3 years) were exposed to filtered air and diesel exhaust in the presence or absence of a particle trap for 1 hour in a randomized, double-blind, 3-way crossover trial. Bilateral forearm blood flow and plasma fibrinolytic factors were assessed with venous occlusion plethysmography and blood sampling during intra-arterial infusion of acetylcholine, bradykinin, sodium nitroprusside, and verapamil. Ex vivo thrombus formation was determined with the use of the Badimon chamber. Compared with filtered air, diesel exhaust inhalation was associated with reduced vasodilatation and increased ex vivo thrombus formation under both low- and high-shear conditions. The particle trap markedly reduced diesel exhaust particulate number (from 150 000 to 300 000/cm(3) to 30 to 300/cm(3); P<0.001) and mass (320±10 to 7.2±2.0 μg/m(3); P<0.001), and was associated with increased vasodilatation, reduced thrombus formation, and an increase in tissue-type plasminogen activator release. Exhaust particle traps are a highly efficient method of reducing particle emissions from diesel engines. With a range of surrogate measures, the use of a particle trap prevents several adverse cardiovascular effects of exhaust inhalation in men. Given these beneficial effects on biomarkers of cardiovascular health, the widespread use of particle traps on diesel-powered vehicles may have substantial public health benefits and reduce the burden of cardiovascular disease.

[Ultrafine particle number concentration and size distribution of vehicle exhaust ultrafine particles].

PubMed

Lu, Ye-qiang; Chen, Qiu-fang; Sun, Zai; Cai, Zhi-liang; Yang, Wen-jun

2014-09-01

Ultrafine particle (UFP) number concentrations obtained from three different vehicles were measured using fast mobility particle sizer (FMPS) and automobile exhaust gas analyzer. UFP number concentration and size distribution were studied at different idle driving speeds. The results showed that at a low idle speed of 800 rmin-1 , the emission particle number concentration was the lowest and showed a increasing trend with the increase of idle speed. The majority of exhaust particles were in Nuclear mode and Aitken mode. The peak sizes were dominated by 10 nm and 50 nm. Particle number concentration showed a significantly sharp increase during the vehicle acceleration process, and was then kept stable when the speed was stable. In the range of 0. 4 m axial distance from the end of the exhaust pipe, the particle number concentration decayed rapidly after dilution, but it was not obvious in the range of 0. 4-1 m. The number concentration was larger than the background concentration. Concentration of exhaust emissions such as CO, HC and NO showed a reducing trend with the increase of idle speed,which was in contrast to the emission trend of particle number concentration.

Exposure to particles and nitrogen dioxide among taxi, bus and lorry drivers.

PubMed

Lewné, Marie; Nise, Gun; Lind, Marie-Louise; Gustavsson, Per

2006-03-01

The aims of this study have been to investigate the occurrence of systematic differences in the personal exposure to motor exhaust between different groups of taxi, bus and lorry drivers, and to study if these are influenced by the choice of exposure indicator. We used one indicator of the gaseous phase, nitrogen dioxide (NO(2)), and one of the particle phase (measured by DataRAM), of the exhausts. A total of 121 drivers were included in the study: 39 taxi drivers, 42 bus drivers and 40 lorry drivers. Personal measurements were performed during one working day. Nitrogen dioxide was measured with passive diffusive samplers and particles with Data-RAM, a logging instrument using nephelometric monitoring. The instrument measures particles between 0.1 and 10 microm in size. The average exposure to NO(2) for lorry drivers was 68 microg/m(3); for bus drivers 60 microg/m(3) and for taxi drivers 48 microg/m(3). For particles the exposure was 57 microg/m(3) for lorry drivers, 44 microg/m(3) for bus drivers and 26 microg/m(3) for taxi drivers. The result remained unchanged when exposures were adjusted for variation in urban background levels of NO(2) and particulate matter with an aerodynamic diameter <10 microm (PM(10)). Lorry drivers experienced the highest exposure and taxi drivers the lowest with bus drivers in an intermediate position, regardless of whether NO(2) or particles were used as exposure indicator. The levels of both NO(2) and particles were higher for bus drivers in the city than for them driving in the suburbs. Using diesel or petrol as a fuel for taxis had no influence on the exposure for the drivers, indicating that the taxi drivers' exposure mainly depends on exhaust from surrounding traffic.

Effects of ultrafine diesel exhaust particles on oxidative stress generation and dopamine metabolism in PC-12 cells.

PubMed

Kim, Yong-Dae; Lantz-McPeak, Susan M; Ali, Syed F; Kleinman, Michael T; Choi, Young-Sook; Kim, Heon

2014-05-01

A major constituent of urban air pollution is diesel exhaust, a complex mixture of gases, chemicals, and particles. Recent evidence suggests that exposure to air pollution can increase the risk of a fatal stroke, cause cerebrovascular damage, and induce neuroinflammation and oxidative stress that may trigger neurodegenerative diseases, such as Parkinson's disease. The specific aim of this study was to determine whether ultrafine diesel exhaust particles (DEPs), the particle component of exhaust from diesel engines, can induce oxidative stress and effect dopamine metabolism in PC-12 cells. After 24 h exposure to DEPs of 200 nm or smaller, cell viability, ROS and nitric oxide (NO(2)) generation, and levels of dopamine (DA) and its metabolites, (dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA)), were evaluated. Results indicated cell viability was not significantly changed by DEP exposure. However, ROS showed dramatic dose-dependent changes after DEP exposure (2.4 fold increase compared to control at 200 μg/mL). NO(2) levels were also dose-dependently increased after DEP exposure. Although not in a dose-dependent manner, upon DEP exposure, intracellular DA levels were increased while DOPAC and HVA levels decreased when compared to control. Results suggest that ultrafine DEPs lead to dopamine accumulation in the cytoplasm of PC-12 cells, possibly contributing to ROS formation. Further studies are warranted to elucidate this mechanism. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Health effects of exposure to diesel exhaust particles.

PubMed

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. These findings support a hypothesis that detoxification of DEP-associated organics occurs rapidly in vivo. 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. Some extracts of DEP evoke tumorigenic responses in skin-tumor bioassays, suggesting their carcinogenic potential in mammals. A number of large-scale studies have been conducted with laboratory rodents to evaluate the effects of chronic inhalation exposure to DE. An increased

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

PubMed

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.

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

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....

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.

[Exposure to nanoparticle-rich diesel exhaust affects hippocampal functions in mice].

PubMed

Win-Shwe, Tin Tin; Fujitani, Yuji; Hirano, Seishiro; Fujimaki, Hidekazu

2011-09-01

Epidemiological studies have indicated associations between day-to-day particulate air pollution and increased risks of various adverse health outcomes. Although an association between exposure to diesel exhaust particles (DEPs) and the development of pulmonary inflammation has been reported, there are limited reports on the neurotoxic effects of DEPs, particularly those of nanoparticle-rich diesel exhaust (NRDE). In this minireview, we highlighted the effects of NRDE which was generated in the National Institute for Environmental Studies, on hippocampus-dependent spatial learning ability and the expression of memory-function-related genes, neurotrophins, and proinflammatory cytokines in a mouse model.

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 ...

On the carcinogenic risk evaluation of diesel exhaust: benzene in airborne particles and alterations of heme metabolism in lymphocytes as markers of exposure.

PubMed

Muzyka, V; Veimer, S; Schmidt, N

1998-06-30

Diesel exhaust consists of a complex mixture of chemicals which contain known genotoxicants, one of which is benzene. Therefore the concentration of benzene may be used in the evaluation of full external exposure to diesel exhaust. Our attention is focused on the determination of the distribution of benzene between the gas and particulate phases in the breathing zone of bus-garage workers. Bus diesel engine exhaust was the main source of air pollution by benzene and particles. The particulate matter contained benzene in amounts comparable to those usually found for concentrations of carcinogenic polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs. A much lower concentration of benzene was associated with particulate matter in the winter than in the summer months. The level of benzene in the gas phase showed a dependence on the distance of workplace from the operating diesel motor. The study indicated that benzene associated with diesel exhaust particles (DEP) might be an important factor to consider when studying diesel exhaust exposure from air pollution sources. Since non-genotoxic effects may play an important role in the generation of tumors by genotoxic carcinogens, the level of heme synthesis was proposed as a biomarker of early health effect. Here we present the data on determination of 5-aminolevulinic acid (ALA) synthesis and heme formation in lymphocytes from a group of 45 bus-garage workers and an analogous data from a group of 25 unexposed subjects. The results indicate significant differences in ALA synthesis and heme formation between the exposed workers when compared to the non-exposed individuals. ALA was accumulated and ALA-synthase activity was increased in lymphocytes of garage workers. At the same time ferrochelatase activity was decreased and protoporphyrin contents were elevated. In addition the concentration of porphyrin associated with DNA was significantly increased. Thus, the measurement of some metabolites of heme synthesis in

Assessment of lung cell toxicity of various gasoline engine exhausts using a versatile in vitro exposure system.

PubMed

Bisig, Christoph; Comte, Pierre; Güdel, Martin; Czerwinski, Jan; Mayer, Andreas; Müller, Loretta; Petri-Fink, Alke; Rothen-Rutishauser, Barbara

2018-04-01

Adverse effect studies of gasoline exhaust are scarce, even though gasoline direct injection (GDI) vehicles can emit a high number of particles. The aim of this study was to conduct an in vitro hazard assessment of different GDI exhausts using two different cell culture models mimicking the human airway. In addition to gasoline particle filters (GPF), the effects of two lubrication oils with low and high ash content were assessed, since it is known that oils are important contributors to exhaust emissions. Complete exhausts from two gasoline driven cars (GDI1 and GDI2) were applied for 6 h (acute exposure) to a multi-cellular human lung model (16HBE14o-cell line, macrophages, and dendritic cells) and a primary human airway model (MucilAir™). GDI1 vehicle was driven unfiltered and filtered with an uncoated and a coated GPF. GDI2 vehicle was driven under four settings with different fuels: normal unleaded gasoline, 2% high and low ash oil in gasoline, and 2% high ash oil in gasoline with a GPF. GDI1 unfiltered was also used for a repeated exposure (3 times 6 h) to assess possible adverse effects. After 6 h exposure, no genes or proteins for oxidative stress or pro-inflammation were upregulated compared to the filtered air control in both cell systems, neither in GDI1 with GPFs nor in GDI2 with the different fuels. However, the repeated exposure led to a significant increase in HMOX1 and TNFa gene expression in the multi-cellular model, showing the responsiveness of the system towards gasoline engine exhaust upon prolonged exposure. The reduction of particles by GPFs is significant and no adverse effects were observed in vitro during a short-term exposure. On the other hand, more data comparing different lubrication oils and their possible adverse effects are needed. Future experiments also should, as shown here, focus on repeated exposures. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Acute diesel exhaust particle exposure increases viral titre and inflammation associated with existing influenza infection, but does not exacerbate deficits in lung function

PubMed Central

Larcombe, Alexander N.; Foong, Rachel E.; Boylen, Catherine E.; Zosky, Graeme R.

2012-01-01

Please cite this paper as: Larcombe et al. (2012) Acute diesel exhaust particle exposure increases viral titre and inflammation associated with existing influenza infection, but does not exacerbate deficits in lung function. Influenza and Other Respiratory Viruses DOI:10.1111/irv.12012. Background  Exposure to diesel exhaust particles (DEP) is thought to exacerbate many pre‐existing respiratory diseases, including asthma, bronchitis and chronic obstructive pulmonary disease, however, there is a paucity of data on whether DEP exacerbates illness due to respiratory viral infection. Objectives  To assess the physiological consequences of an acute DEP exposure during the peak of influenza‐induced illness. Methods  We exposed adult female BALB/c mice to 100 μg DEP (or control) 3·75 days after infection with 104·5 plaque forming units of influenza A/Mem71 (or control). Six hours, 24 hours and 7 days after DEP exposure we measured thoracic gas volume and lung function at functional residual capacity. Bronchoalveolar lavage fluid was taken for analyses of cellular inflammation and cytokines, and whole lungs were taken for measurement of viral titre. Results  Influenza infection resulted in significantly increased inflammation, cytokine influx and impairment to lung function. DEP exposure alone resulted in less inflammation and cytokine influx, and no impairment to lung function. Mice infected with influenza and exposed to DEP had higher viral titres and neutrophilia compared with infected mice, yet they did not have more impaired lung mechanics than mice infected with influenza alone. Conclusions  A single dose of DEP is not sufficient to physiologically exacerbate pre‐existing respiratory disease caused by influenza infection in mice. PMID:22994877

Diesel exhaust exposure and bladder cancer risk.

PubMed

Iyer, V; Harris, R E; Wynder, E L

1990-03-01

A total of 136 cases of men with urinary bladder cancer and 272 matched hospital controls were examined for potential exposure to diesel exhaust. A lifetime occupational history was obtained for all subjects in the study and assessment of exposure to diesel exhaust was based on the job titles of the subject and self-reported exposure. The risk was assessed by odds ratios, with adjustment for confounding variables, in particular cigarette smoking. There was no evidence of elevated risk in occupations with possible or probable exposure (the ORs adjusted for smoking were 1.1. and 0.9 respectively). Truck driving alone was also not associated with elevated risk (adjusted OR = 0.5). There was a weak positive crude association with any exposure, including self-reports (OR = 1.4); however after adjustment for smoking, the estimate did not retain statistical significance (OR = 1.2, 95% CI = 0.8-2.0). This study provides little to support the hypothesis of an excess of bladder cancer risk from occupational exposure to diesel exhaust.

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.

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...

Pulmonary exposure to diesel exhaust particles induces airway inflammation and cytokine expression in NC/Nga mice.

PubMed

Inoue, Ken-ichiro; Takano, Hirohisa; Yanagisawa, Rie; Ichinose, Takamichi; Shimada, Akinori; Yoshikawa, Toshikazu

2005-10-01

Although several studies have reported that diesel exhaust particles (DEP) affect cardiorespiratory health in animals and humans, the effect of DEP on animal models with spontaneous allergic disorders has been far less intensively studied. The Nc/Nga mouse is known to be a typical animal model for human atopic dermatitis (AD). In the present study, we investigated the effects of repeated pulmonary exposure to DEP on airway inflammation and cytokine expression in NC/Nga mice. The animals were randomized into two experimental groups that received vehicle or DEP by intratracheal instillation weekly for six weeks. Cellular profiles of bronchoalveolar lavage (BAL) fluid and expressions of cytokines and chemokines in both the BAL fluid and lung tissues were evaluated 24 h after the last instillation. The DEP challenge produced an increase in the numbers of total cells, neutrophils, and mononuclear cells in BAL fluid as compared to the vehicle challenge (P<0.01). DEP exposure significantly induced the lung expressions of interleukin (IL)-4, keratinocyte chemoattractant (KC), and macrophage inflammatory protein (MIP)-1alpha when compared to the vehicle challenge. These results indicate that intratracheal exposure to DEP induces the recruitment of inflammatory cells, at least partially, through the local expression of IL-4 and chemokines in NC/Nga mice.

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

Varied dose exposures to ultrafine particles in the motorcycle smoke cause kidney cell damages in male mice.

PubMed

Wardoyo, Arinto Y P; Juswono, Unggul P; Noor, Johan A E

2018-01-01

Ultrafine particles (UFPs) are one of motorcycle exhaust emissions which can penetrate the lung alveoli and deposit in the kidney. This study was aimed to investigate mice kidney cell physical damage (deformation) due to motorcycle exhaust emission exposures. The motorcycle exhaust emissions were sucked from the muffler with the rate of 33 cm 3 /s and passed through an ultrafine particle filter system before introduced into the mice exposure chamber. The dose concentration of the exhaust emissions was varied by setting the injected time of the 20s, 40s, 60s, 80s, and 100s. The mice were exposed to the smoke in the chamber for 100 s twice a day. The impact of the ultrafine particles on the kidney was observed by identifying the histological image of the kidney cell deformation using a microscope. The exposure was conducted for 10 days. The kidney observations were carried out on day 11. The results showed that there was a significant linear correlation between the total concentration of ultrafine particles deposited in the kidneys and the physical damage percentages. The increased concentrations of ultrafine particles caused larger cell deformation to the kidneys.

Particle and Power Exhaust in EAST

NASA Astrophysics Data System (ADS)

Wang, Liang; Ding, Fang; Yu, Yaowei; Gan, Kaifu; Liang, Yunfeng; Xu, Guosheng; Xiao, Bingjia; Sun, Youwen; Luo, Guangnan; Gong, Xianzu; Hu, Jiansheng; Li, Jiangang; Wan, Baonian; Maingi, Rajesh; Guo, Houyang; Garofalo, Andrea; EAST Team

2017-10-01

A total power injection up to 0.3GJ has been achieved in EAST long pulse USN operation with ITER-like water-cooling W-monoblock divertor, which has steady-state power exhaust capability of 10 MWm-2. The peak temperature of W target saturated at t = 12 s to the value T 500oC and a heat flux 3MWm-2was maintained. Great efforts to reduce heat flux and accommodate particle exhaust simultaneously have been made towards long pulse of 102s time scale. By exploiting the observation of Pfirsch-Schlüter flow direction in the SOL, the Bt direction with Bx ∇B away from the W divertor (more particles favor outer target in USN) was adopted along with optimizing the strike point location near the pumping slot, to facilitate particle and impurity exhaust with the top cryo-pump. By tailoring the 3D divertor footprint through edge magnetic topology change, the heat load was dispersed widely and thus peak heat flux and W sputtering was well controlled. Active feedback control of total radiative power with neon seeding was achieved within frad = 17-35%, exhibiting further potential for heat flux reduction with divertor and edge radiation. Other heat flux handling techniques, including quasi snowflake configuration, will also be presented.

Evolution of vehicle exhaust particles in the atmosphere.

PubMed

Canagaratna, Manjula R; Onasch, Timothy B; Wood, Ezra C; Herndon, Scott C; Jayne, John T; Cross, Eben S; Miake-Lye, Richard C; Kolb, Charles E; Worsnop, Douglas R

2010-10-01

Aerosol mass spectrometer (AMS) measurements are used to characterize the evolution of exhaust particulate matter (PM) properties near and downwind of vehicle sources. The AMS provides time-resolved chemically speciated mass loadings and mass-weighted size distributions of nonrefractory PM smaller than 1 microm (NRPM1). Source measurements of aircraft PM show that black carbon particles inhibit nucleation by serving as condensation sinks for the volatile and semi-volatile exhaust gases. Real-world source measurements of ground vehicle PM are obtained by deploying an AMS aboard a mobile laboratory. Characteristic features of the exhaust PM chemical composition and size distribution are discussed. PM mass and number concentrations are used with above-background gas-phase carbon dioxide (CO2) concentrations to calculate on-road emission factors for individual vehicles. Highly variable ratios between particle number and mass concentrations are observed for individual vehicles. NRPM1 mass emission factors measured for on-road diesel vehicles are approximately 50% lower than those from dynamometer studies. Factor analysis of AMS data (FA-AMS) is applied for the first time to map variations in exhaust PM mass downwind of a highway. In this study, above-background vehicle PM concentrations are highest close to the highway and decrease by a factor of 2 by 200 m away from the highway. Comparison with the gas-phase CO2 concentrations indicates that these vehicle PM mass gradients are largely driven by dilution. Secondary aerosol species do not show a similar gradient in absolute mass concentrations; thus, their relative contribution to total ambient PM mass concentrations increases as a function of distance from the highway. FA-AMS of single particle and ensemble data at an urban receptor site shows that condensation of these secondary aerosol species onto vehicle exhaust particles results in spatial and temporal evolution of the size and composition of vehicle exhaust PM on

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 ...

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...

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...

Penetration of diesel exhaust particles through commercially available dust half masks.

PubMed

Penconek, Agata; Drążyk, Paulina; Moskal, Arkadiusz

2013-04-01

Half masks are certified by the competent, national institutions--National Institute for Occupational Safety and Health (NIOSH) in the USA and the respective European national institutions applying common European regulations. However, certification testing is conducted with particles of NaCl, paraffin oil, or dioctyl phthalate (DOP) and at the constant flow rate, whereas particles commonly found in workplaces may differ in size, shape, and morphology from these particles. Therefore, the aim of this study was to investigate filtration efficiency of commercially available filtering facepiece half masks under the condition of exposure to diesel fumes. In this study, we focused on the particulate phase [diesel exhaust particles (DEP)] of three (petroleum diesel, ecodiesel, and biodiesel) diesel fuel combustion types. Two types of European standard-certified half masks, FFP2 and FFP - Filtering Facepiece, and three types of popular diesel fuels were tested. The study showed that the filtration efficiencies for each examined half mask and for each of diesel exhaust fumes were lower than the minimum filtration efficiency required for the standard test aerosols by the European standards. For FFP2 and FFP3 particulate half masks, standard minimum filtration efficiency is 94 and 99%, respectively, whereas 84-89% of mass of DEP from various fuels were filtered by the tested FFP2 and only 75-86% by the FFP3. The study indicated that DEP is more penetrating for these filters than the standard salt or paraffin oil test aerosols. The study also showed that the most penetrating DEP are probably in the 30- to 300-nm size range, regardless of the fuel type and the half-mask model. Finally, the pressure drops across both half masks during the 80-min tests remained below an acceptable maximum of breathing resistance-regardless of the fuel types. The respiratory system, during 40-min test exposures, may be exposed to 12-16mg of DEP if a FFP2 or FFP3 particulate half mask is used. To

Occupational exposure assessment of highway toll station workers to vehicle engine exhaust.

PubMed

Belloc-Santaliestra, Miriam; van der Haar, Rudolf; Molinero-Ruiz, Emilia

2015-01-01

Toll station workers are occupationally exposed to vehicle engine exhaust, a complex mixture of different chemical substances, including carcinogenic compounds. Therefore, a study was carried out on attendants of two highway toll stations to describe their occupational exposure to vehicle engine exhaust, based on a worst-case scenario approach. Personal sampling was conducted during the day shift for all attendants, testing for three groups of chemical substances: polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs) and aldehydes (formaldehyde and acrolein). Concentrations of total PAH, BTEX (benzene, toluene, ethylbenzene, and xylenes) and formaldehyde content varied between 97.60-336.08 ng/m3, 5.01-40.52 μg/m3, and 0.06-19.13 μg/m3, respectively. No clear relationships could be established between exposure levels and the number of vehicles. Furthermore, no differences were found between truck versus car lanes, or inside versus outside the tollbooth. Not all the detected VOCs were related to vehicle exhaust; some were consistent with the use of cleaning products. The measured concentrations were far below the established occupational exposure limits, but tended to be higher than values reported for outdoor urban environments. There are very few international studies assessing occupational exposures among toll station workers, and this is the first such study to be conducted in Spain. The results suggest that further, more detailed studies are necessary to characterize exposure properly, and ones which include other airborne pollutants, such as ultrafine particles. The comparison of the results to other similar studies was difficult, since no data related to some important exposure determinants have been provided. Therefore, it is recommended that these determinants be considered in future studies.

The Air Pollution Exposure Laboratory (APEL) for controlled human exposure to diesel exhaust and other inhalants: characterization and comparison to existing facilities.

PubMed

Birger, Nicholas; Gould, Timothy; Stewart, James; Miller, Mark R; Larson, Timothy; Carlsten, Chris

2011-03-01

The Air Pollution Exposure Laboratory (APEL) was designed for the controlled inhalation of human subjects to aged and diluted diesel exhaust (DE) to mimic "real-world" occupational and environmental conditions. An EPA Tier 3-compliant, 6.0 kW diesel generator is operated under discrete cyclic loads to simulate diesel on-road emissions. The engine accepts standard ultra-low sulfur diesel or a variety of alternative fuels (such as biodiesel) via a partitioned tank. A portion of raw exhaust is drawn into the primary dilution system and is diluted 9:1 with compressed air at standard temperature (20°C) and humidity (40%) levels. The exhaust is further diluted approximately 25:1 by high efficiency particulate air (HEPA)-filtered air (FA) and then aged for 4 min before entering the 4 × 6 × 7-foot exposure booth. An optional HEPA filter path immediately proximal to the booth can generate a particle-reduced (gas-enriched) exposure. In-booth particulate is read by a nephelometer to provide an instantaneous light scattering coefficient for closed-loop system control. A Scanning Mobility Particle Sizer and multi-stage impactor measures particle size distribution. Filter sampling allows determination of sessional average concentrations of size-fractionated and unfractionated particulate oxidative potential, elemental carbon, organic carbon and trace elements. Approximately 300 μg/m(3) PM(2.5) is routinely achievable at APEL and is well characterized in terms of oxidative potential and elemental components. APEL efficiently creates fresh DE, appropriately aged and diluted for human experimentation at safe yet realistic concentrations. Description of exposure characteristics allows comparison to other international efforts to deepen the current evidence base regarding the health effects of DE.

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...

Diesel exhaust exposure, its multi-system effects, and the effect of new technology diesel exhaust.

PubMed

Reis, Haley; Reis, Cesar; Sharip, Akbar; Reis, Wenes; Zhao, Yong; Sinclair, Ryan; Beeson, Lawrence

2018-05-01

Exposure to diesel exhaust (DE) from vehicles and industry is hazardous and affects proper function of organ systems. DE can interfere with normal physiology after acute and chronic exposure to particulate matter (PM). Exposure leads to potential systemic disease processes in the central nervous, visual, hematopoietic, respiratory, cardiovascular, and renal systems. In this review, we give an overview of the epidemiological evidence supporting the harmful effects of diesel exhaust, and the numerous animal studies conducted to investigate the specific pathophysiological mechanisms behind DE exposure. Additionally, this review includes a summary of studies that used biomarkers as an indication of biological plausibility, and also studies evaluating new technology diesel exhaust (NTDE) and its systemic effects. Lastly, this review includes new approaches to improving DE emissions, and emphasizes the importance of ongoing study in this field of environmental health. Copyright © 2018 Elsevier Ltd. All rights reserved.

Endocrine-disrupting activity of chemicals in diesel exhaust and diesel exhaust particles.

PubMed

Takeda, Ken; Tsukue, Naomi; Yoshida, Seiichi

2004-01-01

Diesel exhaust (DE) is known as the main cause of air pollution. DE is a complex mixture of particulate and vapor-phase compounds. The soluble organic fraction of the particulate materials in DE contains thousands of compounds including a variety of polycyclic aromatic hydrocarbons and heavy metals. To clarify the endocrine-disrupting activities of DE, we have reviewed the reports about the effects of DE on the reproductive and brain-nervous systems, and the endocrine-disrupting action of diesel exhaust particles (DEP). In utero exposure to low levels (0.1 mg DEP/m3) of DE from day 2 postcoitum (p.c.) until day 13 p.c. reduced the expression level of Ad4BP/SF-1 mRNA and thereby might affect the development of gonads. Low levels of DE also reduced the expression of several genes known to play key roles in gonadal development, including an enzyme necessary for testosterone synthesis. Mature male rats exposed to DE during the fetal period showed an irreversible decrease in daily sperm production due to an insufficient number of Sertoli cells. DE exposure during the fetal period influenced the brain tissue in newborn mice. In the 3 mg DEP/m3 exposure group at 10 weeks of age, a significant reduction in performance was observed in the passive avoidance learning test in both male and female mice. In addition, the fetal exposure of mice to DE affected the emotional behaviors associated with the serotonergic and dopaminergic systems in the mouse brain. In toluidine blue-stained specimens from the DE-exposed group, edema around the vessels where fluorescent granular perithelial (FGP) cells exist and degenerated granules within the FGP cytoplasm were observed; similar findings were obtained by electron microscopic examination. DEP contain many substances that stimulate Ah receptors, such as the polycyclic aromatic hydrocarbon containing benzo[a]pyrene. DEP also contain substances with estrogenic, antiestrogenic and antiandrogenic activities. The neutral substance fraction of

Exposure to ultrafine particles in asphalt work.

PubMed

Elihn, Karine; Ulvestad, Bente; Hetland, Siri; Wallen, Anna; Randem, Britt Grethe

2008-12-01

An epidemiologic study has demonstrated that asphalt workers show increased loss of lung function and an increase of biomarkers of inflammation over the asphalt paving season. The aim of this study was to investigate which possible agent(s) causes the inflammatory reaction, with emphasis on ultrafine particles. The workers' exposure to total dust, polycyclic aromatic hydrocarbons, and NO(2) was determined by personal sampling. Exposure to ultrafine particles was measured by means of particle counters and scanning mobility particle sizer mounted on a van following the paving machine. The fractions of organic and elemental carbon were determined. Asphalt paving workers were exposed to ultrafine particles with medium concentration of about 3.4 x 10(4)/cm(3). Ultrafine particles at the paving site originated mainly from asphalt paving activities and traffic exhaust; most seemed to originate from asphalt fumes. Oil mist exceeded occupational limits on some occasions. Diesel particulate matter was measured as elemental carbon, which was low, around 3 microg/m(3). NO(2) and total dust did not exceed limits. Asphalt pavers were exposed to relatively high concentrations of ultrafine particles throughout their working day, with possible adverse health effects.

Biodiesel exhaust-induced cytotoxicity and proinflammatory mediator production in human airway epithelial cells.

PubMed

Mullins, Benjamin J; Kicic, Anthony; Ling, Kak-Ming; Mead-Hunter, Ryan; Larcombe, Alexander N

2016-01-01

Increasing use of biodiesel has prompted research into the potential health effects of biodiesel exhaust exposure. Few studies directly compare the health consequences of mineral diesel, biodiesel, or blend exhaust exposures. Here, we exposed human epithelial cell cultures to diluted exhaust generated by the combustion of Australian ultralow-sulfur-diesel (ULSD), unprocessed canola oil, 100% canola biodiesel (B100), and a blend of 20% canola biodiesel mixed with 80% ULSD. The physicochemical characteristics of the exhaust were assessed and we compared cellular viability, apoptosis, and levels of interleukin (IL)-6, IL-8, and Regulated on Activation, Normal T cell Expressed and Secreted (RANTES) in exposed cultured cells. Different fuel types produced significantly different amounts of exhaust gases and different particle characteristics. All exposures resulted in significant apoptosis and loss of viability when compared with control, with an increasing proportion of biodiesel being correlated with a decrease in viability. In most cases, exposure to exhaust resulted in an increase in mediator production, with the greatest increases most often in response to B100. Exposure to pure canola oil (PCO) exhaust did not increase mediator production, but resulted in a significant decrease in IL-8 and RANTES in some cases. Our results show that canola biodiesel exhaust exposure elicits inflammation and reduces viability of human epithelial cell cultures in vitro when compared with ULSD exhaust exposure. This may be related to an increase in particle surface area and number in B100 exhaust when compared with ULSD exhaust. Exposure to PCO exhaust elicited the greatest loss of cellular viability, but virtually no inflammatory response, likely due to an overall increase in average particle size. © 2014 Wiley Periodicals, Inc.

Prolonged Pulmonary Exposure to Diesel Exhaust Particles Exacerbates Renal Oxidative Stress, Inflammation and DNA Damage in Mice with Adenine-Induced Chronic Renal Failure.

PubMed

Nemmar, Abderrahim; Karaca, Turan; Beegam, Sumaya; Yuvaraju, Priya; Yasin, Javed; Hamadi, Naserddine Kamel; Ali, Badreldin H

2016-01-01

Epidemiological evidence indicates that patients with chronic kidney diseases have increased susceptibility to adverse outcomes related to long-term exposure to particulate air pollution. However, mechanisms underlying these effects are not fully understood. Presently, we assessed the effect of prolonged exposure to diesel exhaust particles (DEP) on chronic renal failure induced by adenine (0.25% w/w in feed for 4 weeks), which is known to involve inflammation and oxidative stress. DEP (0.5m/kg) was intratracheally (i.t.) instilled every 4th day for 4 weeks (7 i.t. instillation). Four days following the last exposure to either DEP or saline (control), various renal endpoints were measured. While body weight was decreased, kidney weight increased in DEP+adenine versus saline+adenine or DEP. Water intake, urine volume, relative kidney weight were significantly increased in adenine+DEP versus DEP and adenine+saline versus saline. Plasma creatinine and urea increased and creatinine clearance decreased in adenine+DEP versus DEP and adenine+saline versus saline. Tumor necrosis factor α, lipid peroxidation and reactive oxygen species were significantly increased in adenine+DEP compared with either DEP or adenine+saline. The antioxidant calase was significantly decreased in adenine+DEP compared with either adenine+saline or DEP. Notably, renal DNA damage was significantly potentiated in adenine+DEP compared with either adenine+saline or DEP. Similarly, systolic blood pressure was increased in adenine+DEP versus adenine+saline or DEP, and in DEP versus saline. Histological evaluation revealed more collagen deposition, higher number of necrotic cell counts and dilated tubules, cast formation and collapsing glomeruli in adenine+DEP versus adenine+saline or DEP. Prolonged pulmonary exposure to diesel exhaust particles worsen renal oxidative stress, inflammation and DNA damage in mice with adenine-induced chronic renal failure. Our data provide biological plausibility that air

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

[Evaluation of the viability of BEAS-2B cells exposed to gasoline engine exhaust with different particle sizes by air-liquid interface].

PubMed

Yu, T; Zhang, X Y; Wang, Z X; Li, B; Zheng, Y X; Bin, P

2017-06-20

Objective: To evaluate the viability of gasoline engine exhaust (GEE) with different particle sizes on human lung cell line BEAS-2B in vitro by air-liquid interface (ALI) . Methods: GEE were collected with a Tedlar bag and their particulate matter (PM) number, surface and mass concentration in three kind of GEE (filtered automobile exhaust, non-filtered automobile exhaust and motorcycle exhaust without three-way catalytic converter) were measured by two type of particle size spectrometer including TSI-3321 and SMPS-3938. Five groups were included, which divided into blank control group, clean air group, filtered automobile exhaust group, non-filtered automobile exhaust group and motorcycle exhaust without three-way catalytic converter group. Except the blank control group, BEAS-2B cells, cultured on the surface of Transwells, were treated with clean air or GEE by ALI method at a flow rate of 25 ml/min, 37 ℃ for 60 min in vitro . CCK-8 cytotoxicity test kit was used to determine the cell relative viability of BEAS-2B cells. Results: In the filtered automobile exhaust, non-filtered automobile exhaust and motorcycle exhaust without three-way catalytic converter, high concentrations of fine particles can be detected, but the coarse particles only accounted for a small proportion, and the sequence of PM concentration was motorcycle exhaust without three-way catalytic converter group> non-filtered automobile exhaust group> filtered automobile exhaust group ( P <0.001) . Compared with the clean air group, the cell relative viability in the 3 GEE-exposed groups were significantly lower ( P <0.001) . Among the comparisons of GEE exposure groups with different particle size spectra, the sequence of the cell relative viability was filtered automobile exhaust group >non-filtered automobile exhaust group> motorcycle exhaust without three-way catalytic converter group ( P <0.001) . When took the clean air control group as a reference, the mean of the cell relative viability in

*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...

Automobile diesel exhaust particles induce lipid droplet formation in macrophages in vitro.

PubMed

Cao, Yi; Jantzen, Kim; Gouveia, Ana Cecilia Damiao; Skovmand, Astrid; Roursgaard, Martin; Loft, Steffen; Møller, Peter

2015-07-01

Exposure to diesel exhaust particles (DEP) has been associated with adverse cardiopulmonary health effects, which may be related to dysregulation of lipid metabolism and formation of macrophage foam cells. In this study, THP-1 derived macrophages were exposed to an automobile generated DEP (A-DEP) for 24h to study lipid droplet formation and possible mechanisms. The results show that A-DEP did not induce cytotoxicity. The production of reactive oxygen species was only significantly increased after exposure for 3h, but not 24h. Intracellular level of reduced glutathione was increased after 24h exposure. These results combined indicate an adaptive response to oxidative stress. Exposure to A-DEP was associated with significantly increased formation of lipid droplets, as well as changes in lysosomal function, assessed as reduced LysoTracker staining. In conclusion, these results indicated that exposure to A-DEP may induce formation of lipid droplets in macrophages in vitro possibly via lysosomal dysfunction. Copyright © 2015 Elsevier B.V. All rights reserved.

Chronic exposure of diesel exhaust particles induces alveolar enlargement in mice.

PubMed

Yoshizaki, Kelly; Brito, Jôse Mára; Moriya, Henrique T; Toledo, Alessandra C; Ferzilan, Sandra; Ligeiro de Oliveira, Ana Paula; Machado, Isabel D; Farsky, Sandra H P; Silva, Luiz F F; Martins, Milton A; Saldiva, Paulo H N; Mauad, Thais; Macchione, Mariangela

2015-02-07

Diesel exhaust particles (DEPs) are deposited into the respiratory tract and are thought to be a risk factor for the development of diseases of the respiratory system. In healthy individuals, the timing and mechanisms of respiratory tract injuries caused by chronic exposure to air pollution remain to be clarified. We evaluated the effects of chronic exposure to DEP at doses below those found in a typical bus corridor in Sao Paulo (150 μg/m3). Male BALB/c mice were divided into mice receiving a nasal instillation: saline (saline; n = 30) and 30 μg/10 μL of DEP (DEP; n = 30). Nasal instillations were performed five days a week, over a period of 90 days. Bronchoalveolar lavage (BAL) was performed, and the concentrations of interleukin (IL)-4, IL-10, IL-13 and interferon-gamma (INF-γ) were determined by ELISA-immunoassay. Assessment of respiratory mechanics was performed. The gene expression of Muc5ac in lung was evaluated by RT-PCR. The presence of IL-13, MAC2+ macrophages, CD3+, CD4+, CD8+ T cells and CD20+ B cells in tissues was analysed by immunohistochemistry. Bronchial thickness and the collagen/elastic fibers density were evaluated by morphometry. We measured the mean linear intercept (Lm), a measure of alveolar distension, and the mean airspace diameter (D0) and statistical distribution (D2). DEP decreased IFN-γ levels in BAL (p = 0.03), but did not significantly alter IL-4, IL-10 and IL-13 levels. MAC2+ macrophage, CD4+ T cell and CD20+ B cell numbers were not altered; however, numbers of CD3+ T cells (p ≤ 0.001) and CD8+ T cells (p ≤ 0.001) increased in the parenchyma. Although IL-13 (p = 0.008) expression decreased in the bronchiolar epithelium, Muc5ac gene expression was not altered in the lung of DEP-exposed animals. Although respiratory mechanics, elastic and collagen density were not modified, the mean linear intercept (Lm) was increased in the DEP-exposed animals (p ≤ 0.001), and the index D2 was statistically different (p = 0.038) from the

Size-Resolved Ultrafine Particle Deposition and Brownian Coagulation from Gasoline Vehicle Exhaust in an Environmental Test Chamber.

PubMed

Zhao, Yu; Wang, Fang; Zhao, Jianing

2015-10-20

Size-resolved deposition rates and Brownian coagulation of particles between 20 and 900 nm (mobility diameter) were estimated in a well-mixed environmental chamber from a gasoline vehicle exhaust with a total peak particle concentration of 10(5)-10(6) particles/cm(3) at 12.24-25.22 °C. A deposition theory with modified friction velocity and coagulation model was also employed to predict particle concentration decay. Initially during particle decay, approximately 85% or more of the particles had diameters of <100 nm. Particle deposition rates with standard deviations were highly dependent on particle size ranges, and varied from 0.012 ± 0.003 to 0.48 ± 0.02 h(-1). In the experiment, the friction velocity obtained was in the range 1.5-2.5 cm/s. The most explainable fractal dimension and Hamaker constant in coagulation model were 2.5-3 and 20 kT, respectively, and the contribution from coagulation dominated the total particle decay during the first 1 h of decay. It is considered that the modified friction velocity and best fitted fractal dimension and Hamaker constants could be further used to analyze gasoline vehicle exhaust particle dynamics and assess human exposure to vehicle particle pollutants in urban areas, tunnels, and underground parking lots.

Exposure to Inhalable, Respirable, and Ultrafine Particles in Welding Fume

PubMed Central

Pesch, Beate

2012-01-01

This investigation aims to explore determinants of exposure to particle size-specific welding fume. Area sampling of ultrafine particles (UFP) was performed at 33 worksites in parallel with the collection of respirable particles. Personal sampling of respirable and inhalable particles was carried out in the breathing zone of 241 welders. Median mass concentrations were 2.48 mg m−3 for inhalable and 1.29 mg m−3 for respirable particles when excluding 26 users of powered air-purifying respirators (PAPRs). Mass concentrations were highest when flux-cored arc welding (FCAW) with gas was applied (median of inhalable particles: 11.6 mg m−3). Measurements of particles were frequently below the limit of detection (LOD), especially inside PAPRs or during tungsten inert gas welding (TIG). However, TIG generated a high number of small particles, including UFP. We imputed measurements exposure to welding fume. Concentrations were mainly predicted by the welding process and were significantly higher when local exhaust ventilation (LEV) was inefficient or when welding was performed in confined spaces. Substitution of high-emission techniques like FCAW, efficient LEV, and using PAPRs where applicable can reduce exposure to welding fume. However, harmonizing the different exposure metrics for UFP (as particle counts) and for the respirable or inhalable fraction of the welding fume (expressed as their mass) remains challenging. PMID:22539559

Exposure to inhalable, respirable, and ultrafine particles in welding fume.

PubMed

Lehnert, Martin; Pesch, Beate; Lotz, Anne; Pelzer, Johannes; Kendzia, Benjamin; Gawrych, Katarzyna; Heinze, Evelyn; Van Gelder, Rainer; Punkenburg, Ewald; Weiss, Tobias; Mattenklott, Markus; Hahn, Jens-Uwe; Möhlmann, Carsten; Berges, Markus; Hartwig, Andrea; Brüning, Thomas

2012-07-01

This investigation aims to explore determinants of exposure to particle size-specific welding fume. Area sampling of ultrafine particles (UFP) was performed at 33 worksites in parallel with the collection of respirable particles. Personal sampling of respirable and inhalable particles was carried out in the breathing zone of 241 welders. Median mass concentrations were 2.48 mg m(-3) for inhalable and 1.29 mg m(-3) for respirable particles when excluding 26 users of powered air-purifying respirators (PAPRs). Mass concentrations were highest when flux-cored arc welding (FCAW) with gas was applied (median of inhalable particles: 11.6 mg m(-3)). Measurements of particles were frequently below the limit of detection (LOD), especially inside PAPRs or during tungsten inert gas welding (TIG). However, TIG generated a high number of small particles, including UFP. We imputed measurements exposure to welding fume. Concentrations were mainly predicted by the welding process and were significantly higher when local exhaust ventilation (LEV) was inefficient or when welding was performed in confined spaces. Substitution of high-emission techniques like FCAW, efficient LEV, and using PAPRs where applicable can reduce exposure to welding fume. However, harmonizing the different exposure metrics for UFP (as particle counts) and for the respirable or inhalable fraction of the welding fume (expressed as their mass) remains challenging.

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

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...

Exposure of miners to diesel exhaust particulates in underground nonmetal mines.

PubMed

Cohen, H J; Borak, J; Hall, T; Sirianni, G; Chemerynski, S

2002-01-01

A study was initiated to examine worker exposures in seven underground nonmetal mines and to examine the precision of the National Institute for Occupational Safety and Health (NIOSH) 5040 sampling and analytical method for diesel exhaust that has recently been adopted for compliance monitoring by the Mine Safety and Health Administration (MSHA). Approximately 1000 air samples using cyclones were taken on workers and in areas throughout the mines. Results indicated that worker exposures were consistently above the MSHA final limit of 160 micrograms/m3 (time-weighted average; TWA) for total carbon as determined by the NIOSH 5040 method and greater than the proposed American Conference of Governmental Industrial Hygienists TLV limit of 20 micrograms/m3 (TWA) for elemental carbon. A number of difficulties were documented when sampling for diesel exhaust using organic carbon: high and variable blank values from filters, a high variability (+/- 20%) from duplicate punches from the same sampling filter, a consistent positive interference (+26%) when open-faced monitors were sampled side-by-side with cyclones, poor correlation (r 2 = 0.38) to elemental carbon levels, and an interference from limestone that could not be adequately corrected by acid-washing of filters. The sampling and analytical precision (relative standard deviation) was approximately 11% for elemental carbon, 17% for organic carbon, and 11% for total carbon. An hypothesis is presented and supported with data that gaseous organic carbon constituents of diesel exhaust adsorb onto not only the submicron elemental carbon particles found in diesel exhaust, but also mining ore dusts. Such mining dusts are mostly nonrespirable and should not be considered equivalent to submicron diesel particulates in their potential for adverse pulmonary effects. It is recommended that size-selective sampling be employed, rather than open-faced monitoring, when using the NIOSH 5040 method.

*Differential injury in healthy and cytokine-treated epithelial cells exposed to diesel exhaust particles involves interaction of superoxide and nitric oxide

EPA Science Inventory

RATIONALE: Individuals with chronic pulmonary inflammation due to disease are more susceptible to the adverse health effects associated with exposure to particulate matter (PM) air pollutants, such as diesel exhaust particles (DEP). Increasing evidence suggests that these adverse...

Lung cancer and exposure to diesel exhaust among bus garage workers.

PubMed

Gustavsson, P; Plato, N; Lidström, E B; Hogstedt, C

1990-10-01

Mortality and cancer incidence was investigated among the 695 bus garage workers employed as mechanics, servicemen, or hostlers for at least six months in five bus garages in Stockholm between 1945 and 1970. The exposure to diesel exhaust and asbestos was estimated by industrial hygienists. A small excess of lung cancer mortality was found in the cohort when occupationally active men in Stockholm were used as the reference group. A case-referent study was performed within the cohort, six referents being selected for each of the 20 lung cancer cases. The lung cancer risk increased with increasing cumulative exposure to diesel exhaust, but not with cumulative asbestos exposure. The relative risk for lung cancer among the highly exposed men was 2.4 (95% CI 1.3-4.5) as compared with those with low exposure. The study indicates that exposure to diesel exhaust increases the risk for lung cancer.

Single particle mass spectral signatures from vehicle exhaust particles and the source apportionment of on-line PM2.5 by single particle aerosol mass spectrometry.

PubMed

Yang, Jian; Ma, Shexia; Gao, Bo; Li, Xiaoying; Zhang, Yanjun; Cai, Jing; Li, Mei; Yao, Ling'ai; Huang, Bo; Zheng, Mei

2017-09-01

In order to accurately apportion the many distinct types of individual particles observed, it is necessary to characterize fingerprints of individual particles emitted directly from known sources. In this study, single particle mass spectral signatures from vehicle exhaust particles in a tunnel were performed. These data were used to evaluate particle signatures in a real-world PM 2.5 apportionment study. The dominant chemical type originating from average positive and negative mass spectra for vehicle exhaust particles are EC species. Four distinct particle types describe the majority of particles emitted by vehicle exhaust particles in this tunnel. Each particle class is labeled according to the most significant chemical features in both average positive and negative mass spectral signatures, including ECOC, NaK, Metal and PAHs species. A single particle aerosol mass spectrometry (SPAMS) was also employed during the winter of 2013 in Guangzhou to determine both the size and chemical composition of individual atmospheric particles, with vacuum aerodynamic diameter (d va ) in the size range of 0.2-2μm. A total of 487,570 particles were chemically analyzed with positive and negative ion mass spectra and a large set of single particle mass spectra was collected and analyzed in order to identify the speciation. According to the typical tracer ions from different source types and classification by the ART-2a algorithm which uses source fingerprints for apportioning ambient particles, the major sources of single particles were simulated. Coal combustion, vehicle exhaust, and secondary ion were the most abundant particle sources, contributing 28.5%, 17.8%, and 18.2%, respectively. The fraction with vehicle exhaust species particles decreased slightly with particle size in the condensation mode particles. Copyright © 2017 Elsevier B.V. All rights reserved.

SUPPRESSION OF BASAL AND CYTOKINE INDUCED EXPRESSION OF ANTIGEN PRESENTATION MARKERS ON MOUSE LUNG EPITHELIAL CELLS EXPOSED TO DIESEL EXHAUST PARTICLES.

EPA Science Inventory

Diesel exhaust particles (DEP) constitute a significant component of airborne particulates in urban environment. Exposure to DEP is known to enhance susceptibility to viral and bacterial infections. We hypothesized that DEP could partially exert its effect on disease susceptibili...

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

DIESEL EXHAUST PARTICLES SUPRESS LPS-STIMULATED PRODUCTION OF PGE2 IN HUMAN ALVEOLAR MACHROPHAGES: ROLE OF P38 MAPK AND ERK PATHWAYS

EPA Science Inventory

Numerous studies have reported association between exposure to ambient levels of particulate matter (PM) and adverse health effects, which include respiratory and cardiovascular effects. Diesel exhaust particles (DEP) compose a significant fraction of PM in some areas. Alveolar m...

CULTURE CONDITIONS AFFECT HUMAN AIRWAY EPITHELIAL CELL RESPONSE TO DIESEL PARTICLE EXPOSURE IN VITRO

EPA Science Inventory

Diesel exhaust particles (DEP) are a ubiquitous ambient air contaminant that may contribute to the health effects of particulate matter inhalation. In vitro studies have shown that DEP exposure induces pro-inflammatory proteins in human airway epithelial cells (HAEC) with varying...

Thrombosis and systemic and cardiac oxidative stress and DNA damage induced by pulmonary exposure to diesel exhaust particles and the effect of nootkatone thereon.

PubMed

Nemmar, Abderrahim; Al-Salam, Suhail; Beegam, Sumaya; Yuvaraju, Priya; Ali, Badreldin H

2018-05-01

Adverse cardiovascular effects of particulate air pollution persist even at lower concentrations than those of the current air quality limit. Therefore, identification of safe and effective measures against particle-induced cardiovascular toxicity is needed. Nootkatone is a sesquiterpenoid in grapefruit with diverse bioactivities including anti-inflammatory and antioxidant effects. However, its protective effect on the cardiovascular injury induced by diesel exhaust particles (DEPs) has not been studied before. We assessed the possible protective effect of nootkatone (90 mg/kg) administered by gavage 1 h before intratracheal instillation of DEPs (30 μg/mouse). Twenty-four hours after the intratracheal administration of DEPs, various thrombotic and cardiac parameters were assessed. Nootkatone inhibited the prothrombotic effect induced by DEPs in pial arterioles and venules in vivo and platelet aggregation in whole blood in vitro. Also, nootkatone prevented the shortening of activated partial thromboplastin time and prothrombin time induced by DEPs. Nootkatone inhibited the increase of plasma concentration of fibrinogen, plasminogen activator inhibitor-1, interleukin-6, and lipid peroxidation induced by DEPs. Immunohistochemically, hearts showed an analogous increase in glutathione and nuclear factor erythroid-derived 2-like 2 expression by cardiac myocytes and endothelial cells after DEP exposure, and these effects were enhanced in mice treated with nootkatone + DEPs. Likewise, heme oxygenase-1 was increased in mice treated with nootkatone + DEPs compared with those treated with DEPs or nootkatone + saline. The DNA damage caused by DEPs was prevented by nootkatoone pretreatment. In conclusion, nootkatoone alleviates DEP-induced thrombogenicity and systemic and cardiac oxidative stress and DNA damage, at least partly, through nuclear factor erythroid-derived 2-like 2 and heme oxygenase-1 activation. NEW & NOTEWORTHY Nootkatoone, a sesquiterpenoid found in grapefruit

Modeling accumulations of particles in lung during chronic inhalation exposures that lead to impaired clearance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolff, R.K.; Griffith, W.C. Jr.; Cuddihy, R.G.

Chronic inhalation of insoluble particles of low toxicity that produce substantial lung burdens of particles, or inhalation of particles that are highly toxic to the lung, can impair clearance. This report describes model calculations of accumulations in lung of inhaled low-toxicity diesel exhaust soot and high-toxicity Ga2O3 particles. Lung burdens of diesel soot were measured periodically during a 24-mo exposure to inhaled diesel exhaust at soot concentrations of 0, 0.35, 3.5, and 7 mg m-3, 7 h d-1, 5 d wk-1. Lung burdens of Ga2O3 were measured for 1 y after a 4-wk exposure to 23 mg Ga2O3 m-3, 2more » h d-1, 5 d wk-1. Lung burdens of Ga2O3 were measured for 1 y both studies using inhaled radiolabeled tracer particles. Simulation models fit the observed lung burdens of diesel soot in rats exposed to the 3.5- and 7-mg m-3 concentrations of soot only if it was assumed that clearance remained normal for several months, then virtually stopped. Impaired clearance from high-toxicity particles occurred early after accumulations of a low burden, but that from low-toxicity particles was evident only after months of exposure, when high burdens had accumulated in lung. The impairment in clearances of Ga2O3 particles and radiolabeled tracers was similar, but the impairment in clearance of diesel soot and radiolabeled tracers differed in magnitude. This might have been related to differences in particle size and composition between the tracers and diesel soot. Particle clearance impairment should be considered both in the design of chronic exposures of laboratory animals to inhaled particles and in extrapolating the results to people.« less

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...

Mutagenicity of diesel exhaust particles and oil shale particles dispersed in lecithin surfactant.

PubMed

Wallace, W E; Keane, M J; Hill, C A; Xu, J; Ong, T M

1987-01-01

Diesel exhaust particulate material from exhaust pipe scrapings of two trucks, diluted automobile diesel exhaust particulate material collected on filters, and two oil shale ores were prepared for the Ames mutagenicity assay by dichloromethane (DCM) extraction, by dispersion into 0.85% saline, or by dispersion into dipalmitoyl lecithin (DPL) emulsion in saline. Salmonella typhimurium TA98 was used to detect frameshift mutagens in the samples. Samples of diesel soot gave positive mutagenic responses with both DCM extraction and DPL dispersion, with the DPL dispersion giving higher results in some cases. The results suggest that possible mutagens associated with inhaled particles may be dispersed or solubilized into the phospholipid component of pulmonary surfactant and become active in such a phase.

Relationship of hemoglobin to occupational exposure to motor vehicle exhaust.

PubMed

Potula, V; Hu, H

1996-01-01

To study the relationship of hemoglobin to exposure to motor vehicle exhaust. Survey. Traffic police, bus drivers, and auto-shop workers (all exposed to auto exhaust in Madras, India) and unexposed office workers. We measured levels of blood lead (by graphite furnace atomic absorption spectrophotometry), and hemoglobin. Information also was collected on age, employment duration, smoking status, alcohol ingestion, and diet type (vegetarian or nonvegetarian). Increasing exposure to motor vehicle exhaust, as reflected by job category, was significantly associated with lower levels of hemoglobin (p < 0.01). A final multivariate regression model was constructed that began with indicator variables for each job (with office workers as the reference category) and included age, duration of employment, blood lead level, alcohol ingestion, dietary type, and smoking status. After a backward-elimination procedure, employment duration as an auto-shop worker or bus driver remained as significant correlates of lower hemoglobin level and current smoking and long employment duration as significant correlates of higher hemoglobin level. Occupational exposure to automobile exhaust may be a risk factor for decreased hemoglobin level in Madras. This effect appears to be independent of blood lead level and may represent hematopoietic suppression incurred by benzene or accumulated lead burden (which is not well reflected by blood lead levels). Smoking probably increased hemoglobin level through the chronic effects of exposure to carbon monoxide. In this study, a long employment duration may have served as a proxy for better socioeconomic, and therefore, better nutritional status.

Biodiesel versus Diesel: A Pilot Study Comparing Exhaust Exposures for Employees at a Rural Municipal Facility

PubMed Central

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

2016-01-01

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 ≤2.5 µm 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. PMID:20863048

Assessment of exhaust emissions from carbon nanotube production and particle collection by sampling filters.

PubMed

Tsai, Candace Su-Jung; Hofmann, Mario; Hallock, Marilyn; Ellenbecker, Michael; Kong, Jing

2015-11-01

This study performed a workplace evaluation of emission control using available air sampling filters and characterized the emitted particles captured in filters. Characterized particles were contained in the exhaust gas released from carbon nanotube (CNT) synthesis using chemical vapor deposition (CVD). Emitted nanoparticles were collected on grids to be analyzed using transmission electron microscopy (TEM). CNT clusters in the exhaust gas were collected on filters for investigation. Three types of filters, including Nalgene surfactant-free cellulose acetate (SFCA), Pall A/E glass fiber, and Whatman QMA quartz filters, were evaluated as emission control measures, and particles deposited in the filters were characterized using scanning transmission electron microscopy (STEM) to further understand the nature of particles emitted from this CNT production. STEM analysis for collected particles on filters found that particles deposited on filter fibers had a similar morphology on all three filters, that is, hydrophobic agglomerates forming circular beaded clusters on hydrophilic filter fibers on the collecting side of the filter. CNT agglomerates were found trapped underneath the filter surface. The particle agglomerates consisted mostly of elemental carbon regardless of the shapes. Most particles were trapped in filters and no particles were found in the exhaust downstream from A/E and quartz filters, while a few nanometer-sized and submicrometer-sized individual particles and filament agglomerates were found downstream from the SFCA filter. The number concentration of particles with diameters from 5 nm to 20 µm was measured while collecting particles on grids at the exhaust piping. Total number concentration was reduced from an average of 88,500 to 700 particle/cm(3) for the lowest found for all filters used. Overall, the quartz filter showed the most consistent and highest particle reduction control, and exhaust particles containing nanotubes were successfully

Social Isolation-Induced Territorial Aggression in Male Offspring Is Enhanced by Exposure to Diesel Exhaust during Pregnancy

PubMed Central

Yokota, Satoshi; Oshio, Shigeru; Moriya, Nozomu; Takeda, Ken

2016-01-01

Diesel exhaust particles are a major component of ambient particulate matter, and concern about the health effects of exposure to ambient particulate matter is growing. Previously, we found that in utero exposure to diesel exhaust affected locomotor activity and motor coordination, but there are also indications that such exposure may contribute to increased aggression in offspring. Therefore, the aim of the present study was to test the effects of prenatal diesel exhaust exposure on social isolation-induced territorial aggression. Pregnant mice were exposed to low concentrations of diesel exhaust (DE; mass concentration of 90 μg/m3: DE group: n = 15) or clean air (control group: n = 15) for 8 h/day during gestation. Basal locomotion of male offspring was measured at 10 weeks of age. Thereafter, male offspring were individually housed for 2 weeks and subsequently assessed for aggression using the resident−intruder test at 12 weeks of age, and blood and brain tissue were collected from the male offspring on the following day for measuring serum testosterone levels and neurochemical analysis. There were no significant differences in locomotion between control and DE-exposed mice. However, DE-exposed mice showed significantly greater social isolation-induced territorial aggressive behavior than control mice. Additionally, socially-isolated DE-exposed mice expressed significantly higher concentrations of serum testosterone levels than control mice. Neurochemical analysis revealed that dopamine levels in the prefrontal cortex and nucleus accumbens were higher in socially isolated DE-exposed mice. Serotonin levels in the nucleus accumbens, amygdala, and hypothalamus were also lower in the socially isolated DE-exposed mice than in control mice. Thus, even at low doses, prenatal exposure to DE increased aggression and serum testosterone levels, and caused neurochemical changes in male socially isolated mice. These results may have serious implications for pregnant women

EFFECT OF OZONE ON DIESEL EXHAUST PARTICLE TOXICITY

EPA Science Inventory

Ambient particulate matter (PM) concentrations have been associated with mortality and morbidity. Diesel exhaust particles (DEP) are present in ambient urban air PM. Coexisting with DEP (and PM) is ozone (O(3)), which has the potential to react with some components of DEP. Some r...

Real-time and integrated measurement of potential human exposure to particle-bound polycyclic aromatic hydrocarbons (PAHs) from aircraft exhaust.

PubMed Central

Childers, J W; Witherspoon, C L; Smith, L B; Pleil, J D

2000-01-01

We used real-time monitors and low-volume air samplers to measure the potential human exposure to airborne polycyclic aromatic hydrocarbon (PAH) concentrations during various flight-related and ground-support activities of C-130H aircraft at an Air National Guard base. We used three types of photoelectric aerosol sensors (PASs) to measure real-time concentrations of particle-bound PAHs in a break room, downwind from a C-130H aircraft during a four-engine run-up test, in a maintenance hangar, in a C-130H aircraft cargo bay during cargo-drop training, downwind from aerospace ground equipment (AGE), and in a C-130H aircraft cargo bay during engine running on/off (ERO) loading and backup exercises. Two low-volume air samplers were collocated with the real-time monitors for all monitoring events except those in the break room and during in-flight activities. Total PAH concentrations in the integrated-air samples followed a general trend: downwind from two AGE units > ERO-loading exercise > four-engine run-up test > maintenance hangar during taxi and takeoff > background measurements in maintenance hangar. Each PAH profile was dominated by naphthalene, the alkyl-substituted naphthalenes, and other PAHs expected to be in the vapor phase. We also found particle-bound PAHs, such as fluoranthene, pyrene, and benzo[a]pyrene in some of the sample extracts. During flight-related exercises, total PAH concentrations in the integrated-air samples were 10-25 times higher than those commonly found in ambient air. Real-time monitor mean responses generally followed the integrated-air sample trends. These monitors provided a semiquantitative temporal profile of ambient PAH concentrations and showed that PAH concentrations can fluctuate rapidly from a baseline level < 20 to > 4,000 ng/m(3) during flight-related activities. Small handheld models of the PAS monitors exhibited potential for assessing incidental personal exposure to particle-bound PAHs in engine exhaust and for serving as

Health effects of subchronic inhalation exposure to gasoline engine exhaust.

PubMed

Reed, M D; Barrett, E G; Campen, M J; Divine, K K; Gigliotti, A P; McDonald, J D; Seagrave, J C; Mauderly, J L; Seilkop, S K; Swenberg, J A

2008-10-01

Gasoline engine emissions are a ubiquitous source of exposure to complex mixtures of particulate matter (PM) and non-PM pollutants; yet their health hazards have received little study in comparison with those of diesel emissions. As a component of the National Environmental Respiratory Center (NERC) multipollutant research program, F344 and SHR rats and A/J, C57BL/6, and BALBc mice were exposed 6 h/day, 7 days/week for 1 week to 6 months to exhaust from 1996 General Motors 4.3-L engines burning national average fuel on a simulated urban operating cycle. Exposure groups included whole exhaust diluted 1:10, 1:15, or 1:90, filtered exhaust at the 1:10 dilution, or clean air controls. Evaluations included organ weight, histopathology, hematology, serum chemistry, bronchoalveolar lavage, cardiac electrophysiology, micronuclei in circulating cells, DNA methylation and oxidative injury, clearance of Pseudomonas aeruginosa from the lung, and development of respiratory allergic responses to ovalbumin. Among the 120 outcome variables, only 20 demonstrated significant exposure effects. Several statistically significant effects appeared isolated and were not supported by related variables. The most coherent and consistent effects were those related to increased red blood cells, interpreted as likely to have resulted from exposure to 13-107 ppm carbon monoxide. Other effects supported by multiple variables included mild lung irritation and depression of oxidant production by alveolar macrophages. The lowest exposure level caused no significant effects. Because only 6 of the 20 significant effects appeared to be substantially reversed by PM filtration, the majority of effects were apparently caused by non-PM components of exhaust.

Generation and characterization of four dilutions of diesel engine exhaust for a subchronic inhalation study.

PubMed

McDonald, Jacob D; Barr, Edward B; White, Richard K; Chow, Judith C; Schauer, James J; Zielinska, Barbara; Grosjean, Eric

2004-05-01

Exposure atmospheres for a rodent inhalation toxicology study were generated from the exhaust of a 2000 Cummins ISB 5.9L diesel engine coupled to a dynamometer and operated on a slightly modified heavy-duty Federal Test Procedure cycle. Exposures were conducted to one clean air control and four diesel exhaust levels maintained at four different dilution rates (300:1, 100:1, 30:1, 10:1) that yielded particulate mass concentrations of 30, 100, 300, and 1000 microg/m3. Exposures at the four dilutions were characterized for particle mass, particle size distribution (reported elsewhere), detailed chemical speciation of gaseous, semivolatile, and particle-phase inorganic and organic compounds. Target analytes included metals, inorganic ions and gases, organic and elemental carbon, alkanes, alkenes, aromatic and aliphatic acids, aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAH), oxygenated PAH, nitrogenated PAH, isoprenoids, carbonyls, methoxyphenols, sugar derivatives, and sterols. The majority of the mass of material in the exposure atmospheres was gaseous nitrogen oxides and carbon monoxide, with lesser amounts of volatile organics and particle mass (PM) composed of carbon (approximately 90% of PM) and ions (approximately 10% of PM). Measured particle organic species accounted for about 10% of total organic particle mass and were mostly alkanes and aliphatic acids. Several of the components in the exposure atmosphere scaled in concentration with dilution but did not scale precisely with the dilution rate because of background from the rodents and scrubbed dilution air, interaction of animal derived emissions with diesel exhaust components, and day-to-day variability in the output of the engine. Rodent-derived ammonia reacted with exhaust to form secondary inorganic particles (at different rates dependent on dilution), and rodent respiration accounted for volatile organics (especially carbonyls and acids) in the same range as the diesel exhaust at the lowest

Reducing children's exposure to school bus diesel exhaust in one school district in North Carolina.

PubMed

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

2014-04-01

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 general environmental air quality standards to more specific legislation that targets diesel exhaust near school children. School nurse standards of practice specify that school nurses should attain current knowledge of environmental health concepts, implement environmental health strategies, and advocate for environmental health principles. This article provides a description of the professional responsibilities of school nurses in protecting children from harmful environmental exposures, provides an overview of legislative initiatives intended to protect school children from diesel exhaust exposure, and summarizes one school district's effort to reduce diesel exhaust exposure among school children.

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...

Anacardic Acids from Cashew Nuts Ameliorate Lung Damage Induced by Exposure to Diesel Exhaust Particles in Mice

PubMed Central

Carvalho, Ana Laura Nicoletti; Annoni, Raquel; Torres, Larissa Helena Lobo; Durão, Ana Carolina Cardoso Santos; Shimada, Ana Lucia Borges; Almeida, Francine Maria; Hebeda, Cristina Bichels; Lopes, Fernanda Degobbi Tenorio Quirino Santos; Dolhnikoff, Marisa; Martins, Milton Arruda; Silva, Luiz Fernando Ferraz; Farsky, Sandra Helena Poliselli; Saldiva, Paulo Hilário Nascimento; Ulrich, Cornelia M.; Owen, Robert W.; Marcourakis, Tania; Trevisan, Maria Teresa Salles; Mauad, Thais

2013-01-01

Anacardic acids from cashew nut shell liquid, a Brazilian natural substance, have antimicrobial and antioxidant activities and modulate immune responses and angiogenesis. As inflammatory lung diseases have been correlated to environmental pollutants exposure and no reports addressing the effects of dietary supplementation with anacardic acids on lung inflammation in vivo have been evidenced, we investigated the effects of supplementation with anacardic acids in a model of diesel exhaust particle- (DEP-) induced lung inflammation. BALB/c mice received an intranasal instillation of 50 μg of DEP for 20 days. Ten days prior to DEP instillation, animals were pretreated orally with 50, 150, or 250 mg/kg of anacardic acids or vehicle (100 μL of cashew nut oil) for 30 days. The biomarkers of inflammatory and antioxidant responses in the alveolar parenchyma, bronchoalveolar lavage fluid (BALF), and pulmonary vessels were investigated. All doses of anacardic acids ameliorated antioxidant enzyme activities and decreased vascular adhesion molecule in vessels. Animals that received 50 mg/kg of anacardic acids showed decreased levels of neutrophils and tumor necrosis factor in the lungs and BALF, respectively. In summary, we demonstrated that AAs supplementation has a potential protective role on oxidative and inflammatory mechanisms in the lungs. PMID:23533495

Bohm criterion and plasma particle/power exhaust to and recycling at the wall

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Xianzhu; Guo, Zehua

The plasma particle and power exhaust to the divertor surface drives both particle and power recycling at the surface, which in return constrains the plasma density and temperature at the target and their profile further upstream. Both particle and power exhaust fluxes are mediated by the plasma sheath next to the divertor surface. In particular, the Bohm criterion constrains the ion exit flow speed, which enters directly into the particle flux and the kinetic flow energy component of the ion power flux, and indirectly into the electron power flux through the sheath potential drop. Here we give an overview onmore » how the Bohm speed is set in a general plasma and how it enters power exhaust and power recycling at the divertor surface, and the implication on the correct implementation of sheath boundary conditions in numerical codes. The cases of ideal and non-ideal Bohm speed are distinguished as a result of the physics discussion.« less

Bohm criterion and plasma particle/power exhaust to and recycling at the wall

DOE PAGES

Tang, Xianzhu; Guo, Zehua

2017-06-07

The plasma particle and power exhaust to the divertor surface drives both particle and power recycling at the surface, which in return constrains the plasma density and temperature at the target and their profile further upstream. Both particle and power exhaust fluxes are mediated by the plasma sheath next to the divertor surface. In particular, the Bohm criterion constrains the ion exit flow speed, which enters directly into the particle flux and the kinetic flow energy component of the ion power flux, and indirectly into the electron power flux through the sheath potential drop. Here we give an overview onmore » how the Bohm speed is set in a general plasma and how it enters power exhaust and power recycling at the divertor surface, and the implication on the correct implementation of sheath boundary conditions in numerical codes. The cases of ideal and non-ideal Bohm speed are distinguished as a result of the physics discussion.« less

Lung retention and metabolic fate of inhaled benzo(a)pyrene associated with diesel exhaust particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, J.D.; Wolff, R.K.; Kanapilly, G.M.

The effect of ultrafine, insoluble, carrier particles on the lung retention and metabolic fate of inhaled PAHs was investigated with a radiolabeled model PAH, (/sup 3/H)benzo(a)pyrene (/sup 3/H-BaP). Fischer-344 rats were exposed (30 min) by nose-only inhalation to /sup 3/H-BaP adsorbed (approximately 0.1% by mass) onto diesel engine exhaust particles. The total mass concentration of these aerosols was 4-6 micrograms/liter of air with a mass median diameter of 0.14 micron. Lung clearance of the inhaled particle-associated /sup 3/H radioactivity occurred in two phases. The initially rapid clearance of this inhaled radiolabel had a half-time of less than 1 hr. Themore » second, long-term component of lung clearance had a half-time of 18 +/- 2 days and represented 50 +/- 2% of the /sup 3/H radioactivity that had initially deposited in lungs. In contrast, previous inhalation studies with a pure /sup 3/H-BaP aerosol showed that greater than 99% of the /sup 3/H radioactivity deposited in lungs was cleared within 2 hr after exposure. By HPLC analysis, the majority of diesel soot-associated /sup 3/H radioactivity retained in lungs was BaP (65-76%) with smaller amounts of BaP-phenol (13-17%) and BaP-quinone (5-18%) metabolites also being detected. No other metabolites of BaP were detected in lungs of exposed rats. Tissue distribution and excretion patterns of /sup 3/H radioactivity were qualitatively similar to previous inhalation studies with /sup 3/H-BaP coated Ga2O3 aerosols. These findings suggest that inhaled PAHs may be retained in lungs for a greater period of time when these compounds are associated with diesel engine exhaust particles. These results may have significant implications for the health risks that may be involved with human exposure to particle-associated organic pollutants.« less

Analysis of particle and vapour phase PAHs from the personal air samples of bus garage workers exposed to diesel exhaust.

PubMed

Kuusimaki, Leea; Peltonen, Kimmo; Mutanen, Pertti; Savela, Kirsti

2003-07-01

The levels of particle and vapour phase polycyclic aromatic hydrocarbons (PAHs) derived from the diesel exhaust compounds in bus garage work were measured in winter and in summer. Five personal air samples were collected from the breathing zones of 22 garage workers every other day of consecutive weeks. Control samples (n = 22) were collected from office workers in Helsinki. Fifteen PAHs in the air samples were analysed by HPLC using a fluorescence detector. Statistically significant differences were observed between total PAH levels of the exposed workers (2241 and 1245 ng/m(3)) and the control group (254 and 275 ng/m(3)) in both winter (P < 0.001) and summer (P < 0.001). Phenanthrene, pyrene, benzo[ghi]perylene and fluoranthene were the major compounds in the particle phase, and naphthalene, phenanthrene and fluorene in the vapour phase. About 98% of PAHs measured were related to the vapour phase compounds, whereas the high molecular weight PAH compounds were detected only in the particle phase. The PAH levels in the garages were twice as high (P < 0.001) in winter as in summer. Even though the exposure levels were low in the bus garages, the low level does not allow conclusions to be drawn about the possible adverse health effects due to exposure to diesel exhaust.

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

A meta-analysis of bladder cancer and diesel exhaust exposure.

PubMed

Boffetta, P; Silverman, D T

2001-01-01

The aim of this study is to review and summarize the available epidemiologic studies of bladder cancer and occupational exposure to diesel exhaust. We retrieved relevant studies and abstracted their characteristics and results. We assessed the heterogeneity of the results to decide whether to perform a fixed-effects model meta-analysis. We identified 35 relevant studies. No overall meta-analysis was performed because of heterogeneity in results. Results of railroad workers (N = 14) suggested an increased occurrence of bladder cancer, but we did not conduct a meta-analysis. The summary relative risk (RR) among truck drivers was 1.17 (95% confidence interval [CI] = 1.06-1.29, 15 studies) and that among bus drivers was 1.33 (95% CI = 1.22-1.45, 10 studies). Ten studies considered diesel exhaust exposure based on a job exposure matrix or a similar approach; the summary RR for these studies was 1.13 (95% CI = 1.00-1.27). A positive dose-response relation was suggested by 10 of the 12 studies that provided relevant information. The summary RR for high diesel exposure was 1.44 (95% CI = 1.18-1.76). There was some evidence of publication bias, however, with a lack of small studies with null or negative results. Our review suggests that exposure to diesel exhaust may increase the occurrence of bladder cancer, but the effects of misclassification, publication bias, and confounding cannot be fully taken into account.

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

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

PubMed

Bailey, Chad R; Somers, Joseph H; Steenland, Kyle

2003-01-01

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

Gene Expression Changes in the Olfactory Bulb of Mice Induced by Exposure to Diesel Exhaust Are Dependent on Animal Rearing Environment

PubMed Central

Yokota, Satoshi; Hori, Hiroshi; Umezawa, Masakazu; Kubota, Natsuko; Niki, Rikio; Yanagita, Shinya; Takeda, Ken

2013-01-01

There is an emerging concern that particulate air pollution increases the risk of cranial nerve disease onset. Small nanoparticles, mainly derived from diesel exhaust particles reach the olfactory bulb by their nasal depositions. It has been reported that diesel exhaust inhalation causes inflammation of the olfactory bulb and other brain regions. However, these toxicological studies have not evaluated animal rearing environment. We hypothesized that rearing environment can change mice phenotypes and thus might alter toxicological study results. In this study, we exposed mice to diesel exhaust inhalation at 90 µg/m3, 8 hours/day, for 28 consecutive days after rearing in a standard cage or environmental enrichment conditions. Microarray analysis found that expression levels of 112 genes were changed by diesel exhaust inhalation. Functional analysis using Gene Ontology revealed that the dysregulated genes were involved in inflammation and immune response. This result was supported by pathway analysis. Quantitative RT-PCR analysis confirmed 10 genes. Interestingly, background gene expression of the olfactory bulb of mice reared in a standard cage environment was changed by diesel exhaust inhalation, whereas there was no significant effect of diesel exhaust exposure on gene expression levels of mice reared with environmental enrichment. The results indicate for the first time that the effect of diesel exhaust exposure on gene expression of the olfactory bulb was influenced by rearing environment. Rearing environment, such as environmental enrichment, may be an important contributive factor to causation in evaluating still undefined toxic environmental substances such as diesel exhaust. PMID:23940539

Exposure assessment of diesel bus emissions.

PubMed

Yip, Maricela; Madl, Pierre; Wiegand, Aaron; Hofmann, Werner

2006-12-01

The goal of this study was to measure ultrafine particle concentrations with diameters less than 1 mum emitted by diesel buses and to assess resulting human exposure levels. The study was conducted at the Woolloongabba Busway station in Brisbane, Australia in the winter months of 2002 during which temperature inversions frequently occurred. Most buses that utilize the station are fuelled by diesel, the exhaust of which contains a significant quantity of particle matter. Passengers waiting at the station are exposed to these particles emitted from the buses. During the course of this study, passenger census was conducted, based on video surveillance, yielding person-by-person waiting time data. Furthermore, a bus census revealed accurate information about the total number of diesel versus Compressed Natural Gas (CNG) powered buses. Background (outside of the bus station) and platform measurements of ultrafine particulate number size distributions were made to determine ambient aerosol concentrations. Particle number exposure concentration ranges from 10 and 40 to 60% of bus related exhaust fumes. This changes dramatically when considering the particle mass exposure concentration, where most passengers are exposed to about 50 to 80% of exhaust fumes. The obtained data can be very significant for comparison with similar work of this type because it is shown in previous studies that exhaust emissions causes cancer in laboratory animals. It was assumed that significant differences between platform and background distributions were due to bus emissions which, combined with passenger waiting times, yielded an estimate of passenger exposure to ultrafine particles from diesel buses. From an exposure point of view, the Busway station analyzed resembles a street canyon. Although the detected exhaust particle concentration at the outbound platform is found to be in the picogram range, exposure increases with the time passengers spend on the platform along with their breathing

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.

Size-segregated emissions and metal content of vehicle-emitted particles as a function of mileage: Implications to population exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Golokhvast, Kirill S.; Chernyshev, Valery V.; Chaika, Vladimir V.

2015-10-15

The study aims at investigating the characteristics (size distribution, active surface and metal content) of particles emitted by cars as a function of mileage using a novel methodology for characterizing particulate emissions captured by Exhaust Gas Suspension (EGS). EGS was obtained by passing the exhaust gases through a container of deionized water. EGS analysis was performed using laser granulometry, electron scanning microscopy, and high resolution mass spectrometry. Implications of the differences in key features of the emitted particles on population exposure were investigated using numerical simulation for estimating size-segregated PM deposition across human respiratory tract (HRT). It was found thatmore » vehicle mileage, age and the respective emissions class have almost no effect on the size distribution of the exhaust gas particulate released into the environment; about half of the examined vehicles with low mileage were found to release particles of aerodynamic diameter above 10 μm. The exhaust gas particulate detected in the EGS of all cars can be classified into three major size classes: (1) 0.1–5 µm – soot and ash particles, metals (Au, Pt, Pd, Ir); (2) 10–30 µm – metal (Cr, Fe, Cu, Zr, Ni) and ash particles; (3) 400–1,000 µm – metal (Fe, Cr, Pb) and ash particles. Newer vehicles with low mileage are substantial sources of soot and metal particles with median diameter of 200 nm with a higher surface area (up to 89,871.16 cm{sup 2}/cm{sup 3}). These tend to deposit in the lower part of the human respiratory tract. - Highlights: • Car mileage has virtually no effect on the size of the solid particles released. • Newer diesel vehicles emit particles of lower aerodynamic diameter. • Particle active surface emitted by newer vehicles is on average 3 times higher. • Real-life emissions were translated into actual internal PM exposure.« less

Health Assessment Document for Diesel Engine Exhaust (Final 2002)

EPA Science Inventory

This assessment examined information regarding the possible health hazards associated with exposure to diesel engine exhaust (DE), which is a mixture of gases and particles.

The assessment concludes that long-term (i.e., chronic) inhalation exposure is likely to pose a l...

An efficient venturi scrubber system to remove submicron particles in exhaust gas.

PubMed

Tsai, Chuen-Jinn; Lin, Chia-Hung; Wang, Yu-Min; Hunag, Cheng-Hsiung; Li, Shou-Nan; Wu, Zong-Xue; Wang, Feng-Cai

2005-03-01

An efficient venturi scrubber system making use of heterogeneous nucleation and condensational growth of particles was designed and tested to remove fine particles from the exhaust of a local scrubber where residual SiH4 gas was abated and lots of fine SiO2 particles were generated. In front of the venturi scrubber, normal-temperature fine-water mist mixes with high-temperature exhaust gas to cool it to the saturation temperature, allowing submicron particles to grow into micron sizes. The grown particles are then scrubbed efficiently in the venturi scrubber. Test results show that the present venturi scrubber system is effective for removing submicron particles. For SiO2 particles greater than 0.1microm, the removal efficiency is greater than 80-90%, depending on particle concentration. The corresponding pressure drop is relatively low. For example, the pressure drop of the venturi scrubber is approximately 15.4 +/- 2.4 cm H2O when the liquid-to-gas ratio is 1.50 L/m3. A theoretical calculation has been conducted to simulate particle growth process and the removal efficiency of the venturi scrubber. The theoretical results agree with the experimental data reasonably well when SiO2 particle diameter is greater than 0.1 microm.

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

Whole diesel exhaust has been classified recently as a probable carcinogen, and several genotoxicity studies have found particulate exhaust to be clearly mutagenic. Moreover, genotoxicity of diesel particulate is greatly influenced by fuel nature and type of combustion. In order to obtain an effective environmental pollution control, combustion processes using alternative fuels are being analyzed presently. The goal of this study is to determine whether the installation of exhaust after treatment-devices on two light-duty, exhaust gas recirculation (EGR) valve-equipped diesel engines (1930 cc and 2500 cc) can reduce the mutagenicity associated with particles collected during U.S.A. and European driving cycles. Another interesting object was to compare the ability of alternative biodiesel and conventional diesel fuels to reduce the mutagenic activity associated with collected particles from two light duty diesel engines (both 1930 cc) during the European driving cycle. SOF mutagenicity was assayed using the Salmonella/microsome test (TA 98 and TA 100 strains, +/- S9 fraction). In the first part of our study, the highest mutagenicity was revealed by TA98 strain without enzymatic activation, suggesting a direct-acting mutagenicity prevalence in diesel particulate. The 2500 cc engine revealed twofold mutagenic activity compared with the 1930 cc engine (both EGR valve equipped), whereas an opposite result was found in particulate matter amount. The use of a noncatalytic ceramic trap produced a decrease of particle mutagenic activity in the 2500 cc car, whereas an enhancement in the 1930 cc engine was found. The catalytic converter and the electrostatic filter installed on the 2500 cc engine yielded a light particle amount and an SOF mutagenicity decrease. A greater engine stress was obtained using European driving cycles, which caused the strongest mutagenicity/km compared with the U.S.A. cycles. In the second part of the investigation, even though a small number of

Diesel Exhaust Particles Contribute to Endothelia Apoptosis via Autophagy Pathway.

PubMed

Wang, Jhih-Syuan; Tseng, Chia-Yi; Chao, Ming-Wei

2017-03-01

Epidemiological studies suggest that an increase of PM2.5 diesel exhaust particles (DEP) in ambient air corresponds to increased myocardial infarctions and atherosclerosis. When exposed to DEP, endothelial cells exhibit increases in oxidative stress and apoptosis, but the role of autophagy in this DEP-induced cell death remains unclear. Here, we suggest that acute DEP exposure produces intracellular reactive oxygen species (ROS) leading to induction of DEP internalization, endothelial dysfunction, and pro-inflammation in an in vitro human umbilical vein endothelial cells (HUVEC) model. This study found that increases in intracellular oxidative stress and cellular internalization of DEP occurred within 2 h of exposure to DEP. After 2 h of DEP exposure, Mdm2 expression was increased, which triggered cellular autophagy after 4 h of DEP exposure and suppressed cellular senescence. Unfortunately, phagocytized DEP could not be eliminated by cellular autophagy, which led to a continuous buildup of ROS, an increased release of cytokines, and an increased expression of anchoring molecules. After 12 h of DEP exposure, HUVEC reduced Mdm2 expression leading to increased p53 expression, which triggered apoptosis and ultimately resulted in endothelial dysfunction. On the other hand, when cells lacked the ability to induce autophagy, DEP was unable to induce cell senescence and most of the cells survived with only a small percentage of the cells undergoing necrosis. The results presented in this study clearly demonstrate the role cellular autophagy plays in DEP-induced atherosclerosis. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

[Polycyclic aromatic hydrocarbons and soluble organic fraction in fine particles from solid fraction of biodiesel exhaust fumes].

PubMed

Szewczyńska, Małgorzata; Pośniak, Małgorzata

2012-01-01

This paper presents the results of investigations into the distribution of fine particles in the biodiesel exhaust fumes (bio-DEP), as well as into the content of polycyclic aromatic hydrocarbons (PAHs) and soluble organic fraction (SOF) in the study fractions. Samples of biodiesel B20 and B40 exhaust combustion fumes were generated at the model station composed of a diesel engine from Diesel TDI 2007 Volkswagen. Sioutas personal cascade impactor (SPCI) with Teflon filters and low-pressure impactor ELIPI (Dekati Low Pressure Impactor) were used for sampling diesel exhaust fine particles. The analysis of PAHs adsorbed on particulate fractions was performed by high performance liquid chromatography with fluorescence detection (HPLC/FL). For the determination of dry residue soluble organic fraction of biodiesel exhaust particles the gravimetric method was used. The combustion exhaust fumes of 100% ON contained mainly naphthalene, acenaphthalene, fluorene, phenanthrene, fluoranthene, pyrene, benzo(a)anthracene and chrysene, whilst the exhaust of B40-single PAHs of 4 and 5 rings, such as chrysene, benzo(k)fluoranthene, dibenzo (ah)anthracene and benzo(ghi)perylene. The total content of PAHs in diesel exhaust particles averaged 910 ng/m3 for 100% ON and 340 ng/m3 for B40. The concentrations of benzo(a)antarcene were at the levels of 310 ng/m3 (100% ON) and 90 ng/m3 (B40). The investigations indicated that a fraction < 025 microm represents the main component of diesel exhaust particles, regardless of the used fuel. Bioester B 100 commonly added to diesel fuel (ON) causes a reduction of the total particulates emission and thus reduces the amount of toxic substances adsorbed on their surface.

Diesel exhaust exposure among adolescents in Harlem: a community-driven study.

PubMed

Northridge, M E; Yankura, J; Kinney, P L; Santella, R M; Shepard, P; Riojas, Y; Aggarwal, M; Strickland, P

1999-07-01

This study sought individual-level data on diesel exhaust exposure and lung function among adolescents in Harlem as part of a community-driven research agenda. High school students administered in-person surveys to seventh grade students to ascertain information on demographics, asthma history, and self-reported and maternal smoking. Urine samples were assayed for 1-hydroxypyrene (1-HP), a marker of diesel exhaust exposure, and cotinine, a marker of tobacco smoke exposure. Computer-assisted spirometry was used to measure lung function. Three quarters (76%) of the participating students had detectable levels of 1-HP. Three students (13%) had an FEF25-75 of less than or equal to 80% of their predicted measurements, and 4 students (17%) had results between 80% and 90% of the predicted value, all of which are suggestive of possible lung impairment. These data suggest that most adolescents in Harlem are exposed to detectable levels of diesel exhaust, a known exacerbator and possible cause of chronic lung disorders such as asthma. Community-driven research initiatives are important for empowering communities to make needed changes to improve their environments and health.

Health effects of subchronic exposure to environmental levels of diesel exhaust.

PubMed

Reed, M D; Gigliotti, A P; McDonald, J D; Seagrave, J C; Seilkop, S K; Mauderly, J L

2004-04-01

Diesel exhaust is a public health concern and contributor to both ambient and occupational air pollution. As part of a general health assessment of multiple anthropogenic source emissions conducted by the National Environmental Respiratory Center (NERC), a series of health assays was conducted on rats and mice exposed to environmentally relevant levels of diesel exhaust. This article summarizes the study design and exposures, and reports findings on several general indicators of toxicity and carcinogenic potential. Diesel exhaust was generated from a commonly used 2000 model 5.9-L, 6-cylinder turbo diesel engine operated on a variable-load heavy-duty test cycle burning national average certification fuel. Animals were exposed to clean air (control) or four dilutions of whole emissions based on particulate matter concentration (30, 100, 300, and 1000 microg/m(3)). Male and female F344 rats and A/J mice were exposed by whole-body inhalation 6 h/day, 7 days/wk, for either 1 wk or 6 mo. Exposures were characterized in detail. Effects of exposure on clinical observations, body and organ weights, serum chemistry, hematology, histopathology, bronchoalveolar lavage, and serum clotting factors were mild. Significant exposure-related effects occurring in both male and female rats included decreases in serum cholesterol and clotting Factor VII and slight increases in serum gamma-glutamyl transferase. Several other responses met screening criteria for significant exposure effects but were not consistent between genders or exposure times and were not corroborated by related parameters. Carcinogenic potential as determined by micronucleated reticulocyte counts and proliferation of adenomas in A/J mice were unaffected by 6 mo of exposure. Parallel studies demonstrated effects on cardiac function and resistance to viral infection; however, the results reported here show few and only modest health hazards from subchronic or shorter exposures to realistic concentrations of

Tracking the pathway of diesel exhaust particles from the nose to the brain by X-ray florescence analysis

NASA Astrophysics Data System (ADS)

Matsui, Yasuto; Sakai, Nobumitsu; Tsuda, Akira; Terada, Yasuko; Takaoka, Masaki; Fujimaki, Hidekazu; Uchiyama, Iwao

2009-08-01

Studies have shown that exposure to nano-sized particles (< 50 nm) result in their translocation to the central nervous system through the olfactory nerve. Translocation commonly occurs via inhalation, ingestion and skin uptake. Little information is available on the specific pathway of cellular localization of nano-sized particles in the olfactory bulb. The nano-sized particles entrance into the postsynaptics cell is of particular interest because the mitral cell projects to the central nucleus of the amygdala and the piriform cortex. Therefore, our objective in this follow-up study has been to determine whether or not the mitral cells project nano-sized particles to the brain. Nano-sized particles in this study were generated using diesel exhaust. Lab mice were exposed for a period of 4 weeks. We employed synchrotron radiation (SPring-8, Japan) to determine the concentration levels of metal in the olfactory neuron pathway. Metal levels were assayed by mapping, using X-ray fluorescence analysis. The major metal components measured in the filter that collected the inhaled diesel exhaust particles were calcium, copper, iron, nickel and zinc. Our studies reveal an increase in the amount of nano-sized particles in the glomerular layer as well as in the neurons in the olfactory epithelium. Higher levels of nickel and iron were found in the olfactory epithelium's lamina propria mucosae in comparison to that in the control group. Higher levels of iron also were observed in the glomerular layer. Our studies do not clarify the specifics of metal adhesion and detachment. This remains to be one of the key issues requiring further clarification.

Impact of Diesel Exhaust Particles on Th2 Response in the Lung in Asthmatic Mice

PubMed Central

Inoue, Ken-ichiro; Koike, Eiko; Yanagisawa, Rie; Takano, Hirohisa

2008-01-01

Although it has been accepted that pulmonary exposure to diesel exhaust particles (DEP), representative constituents in particulate matter of mass median aerodynamic diameter < or 2.5 µm (PM2.5), exacerbates murine allergic asthma, the in vivo effects of DEP on their cellular events in the context of allergen-specific Th response have never been examined. The aim of this study is to elucidate whether in vivo repetitive exposure to DEP combined with allergen (ovalbumin) facilitate allergen-specific Th response in the lung using a simple ex vivo assay system. As a result, repetitive pulmonary exposure to DEP in vivo, if combined with allergen, amplifies ex vivo allergen-specific Th2 response in the lung compared to that to allergen alone, characterized by high levels of interleukin (IL)-4 and IL-5. The result suggests that in asthmatic subjects, DEP promote Th2-prone milieu in the lung, which additively/synergistically augment asthma pathophysiology in vivo. PMID:19015755

Pulmonary function in workers exposed to diesel exhausts: the effect of control measures.

PubMed

Ulfvarson, U; Alexandersson, R; Dahlqvist, M; Ekholm, U; Bergström, B

1991-01-01

To assess the protective effect of exhausts pipe filters or respirators on pulmonary function, 15 workers in a tunnel construction site, truck and loading machine drivers, rock workers, and others were studied. The total and respirable dust, combustible matter in respirable dust, carbon monoxide, nitrogen monoxide and nitrogen dioxide were measured for each subject during entire work shifts. The effect of the exposure on the lung function variables was measured by dynamic spirometry, carbon monoxide single breath technique, and nitrogen single breath wash-out. The exhaust pipe filtering had a protective effect, directly discernible in the drivers on vital capacity and FEV1.0 and for the whole group on FEV% and TLco. The dust respirators had no effect, probably because of the difficulties in correctly using personal protection under the circumstances in the tunnel. In the absence of a true exposure assessment, control measures for diesel exhausts can be tested by medical effect studies. Catalytic particle filters of diesel exhausts are one method of rendering the emissions less irritant, although they will not remove irritant gases. An indicator of diesel exhaust exposure should include the particle fraction of the diesel exhausts, but a discrimination between different sources of organic dust must be possible.

Occupational exposures to engine exhausts and other PAHs and breast cancer risk: A population-based case-control study.

PubMed

Rai, Rajni; Glass, Deborah C; Heyworth, Jane S; Saunders, Christobel; Fritschi, Lin

2016-06-01

Some previous studies have suggested that exposure to engine exhausts may increase risk of breast cancer. In a population-based case-control study of breast cancer in Western Australia we assessed occupational exposure to engine exhausts using questionnaires and telephone interviews. Odds Ratios (OR) and 95% Confidence Intervals (CI) were calculated using logistic regression. We found no association between risk of breast cancer and occupational exposure to diesel exhaust (OR 1.07, 95%CI: 0.81-1.41), gasoline exhaust (OR 0.98, 95%CI: 0.74-1.28), or other exhausts (OR 1.08, 95%CI: 0.29-4.08). There were also no significant dose- or duration-response relationships. This study did not find evidence supporting the association between occupational exposures to engine exhausts and breast cancer risk. Am. J. Ind. Med. 59:437-444, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Exposure to dust and particle-associated 1-nitropyrene of drivers of diesel-powered equipment in underground mining.

PubMed

Scheepers, P T J; Micka, V; Muzyka, V; Anzion, R; Dahmann, D; Poole, J; Bos, R P

2003-07-01

A field study was conducted in two mines in order to determine the most suitable strategy for ambient exposure assessment in the framework of a European study aimed at validation of biological monitoring approaches for diesel exhaust (BIOMODEM). Exposure to dust and particle-associated 1-nitropyrene (1-NP) was studied in 20 miners of black coal by the long wall method (Czech Republic) and in 20 workers in oil shale mining by the room and pillar method (Estonia). The study in the oil shale mine was extended to include 100 workers in a second phase (main study). In each mine half of the study population worked underground as drivers of diesel-powered trains (black coal) and excavators (oil shale). The other half consisted of workers occupied in various non-diesel production assignments. Exposure to diesel exhaust was studied by measurement of inhalable and respirable dust at fixed locations and by personal air sampling of respirable dust. The ratio of geometric mean inhalable to respirable dust concentration was approximately two to one. The underground/surface ratio of respirable dust concentrations measured at fixed locations and in the breathing zones of the workers was 2-fold or greater. Respirable dust was 2- to 3-fold higher in the breathing zone than at fixed sampling locations. The 1-NP content in these dust fractions was determined by gas chromatography-mass spectrometry/mass spectrometry and ranged from 0.003 to 42.2 ng/m(3) in the breathing zones of the workers. In mine dust no 1-NP was detected. In both mines 1-NP was observed to be primarily associated with respirable particles. The 1-NP concentrations were also higher underground than on the surface (2- to 3-fold in the coal mine and 10-fold or more in the oil shale mine). Concentrations of 1-NP in the breathing zones were also higher than at fixed sites (2.5-fold in the coal mine and 10-fold in the oil shale mine). For individual exposure assessment personal air sampling is preferred over air sampling

Numerical study of particle deposition and scaling in dust exhaust of cyclone separator

NASA Astrophysics Data System (ADS)

Xu, W. W.; Li, Q.; Zhao, Y. L.; Wang, J. J.; Jin, Y. H.

2016-05-01

The solid particles accumulation in the dust exhaust cone area of the cyclone separator can cause the wall wear. This undoubtedly prevents the flue gas turbine from long period and safe operation. So it is important to study the mechanism how the particles deposited and scale on dust exhaust cone area of the cyclone separator. Numerical simulations of gas-solid flow field have been carried out in a single tube in the third cyclone separator. The three-dimensionally coupled computational fluid dynamic (CFD) technology and the modified Discrete Phase Model (DPM) are adopted to model the gas-solid two-phase flow. The results show that with the increase of the operating temperature and processing capacity, the particle sticking possibility near the cone area will rise. The sticking rates will decrease when the particle diameter becomes bigger.

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

Diesel exhaust particles induce the over expression of tumor necrosis factor-alpha (TNF-alpha) gene in alvelor machrophage and failed to induce apoptosis through activation of nuclear factor-kappaB (NF-kappaB)

EPA Science Inventory

Exposure to particulate matter (PM2.5-10), including diesel exhaust particles (DEP) has been reported to induce lung injury and exacerbation of asthma and chronic obstructive pulmonary disease. Alveolar macrophages play a major role in the lung's response to inhaled particles and...

Basophil mediated pro-allergic inflammation in vehicle-emitted particles exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zakharenko, Alexander M.

Despite of the fact that engine manufacturers develop a new technology to reduce exhaust emissions, insufficient attention given to particulate emissions. However, diesel exhaust particles are a major source of air-borne pollution, contain vast amount of polycyclic aromatic hydrocarbons (PAHs) and may have deleterious effects on the immune system, resulting in the induction and enhancement of pro-allergic processes. In the current study, vehicle emitted particles (VEP) from 2 different types of cars (diesel - D and gasoline - G) and locomotive (L) were collected. Overall, 129 four-week-old, male SPF-class Kunming mice were subcutaneously instilled with either low dose 100, 250more » or high dose, 500 mg/kg VEP and 15 mice were assigned as control group. The systemic toxicity was evaluated and alterations in the percentages of the CD3, CD4, CD8, CD16, CD25 expressing cells, basophils, eosinophils and neutrophils were determined. Basophil percentages were inversely associated with the PAH content of the VEPs, however basophil sensitization was more important than cell count in VEP exposure. Thus, the effects of VEP-PAHs emerge with the activation of basophils in an allergen independent fashion. Despite the increased percentage of CD4+ T cells, a sharp decrease in basophil counts at 500 mg/kg of VEP indicates a decreased inhibitory effect of CD16+ monocytes on the proliferation of CD4+ T cell and suppressed polarization into a Th2 phenotype. Therefore, although the restrictions for vehicles emissions differ between countries, follow up studies and strict regulations are needed. - Highlights: • Basophil sensitization is more important than cell count in VEP exposure. • CD16+ cells are more effective than basophils on CD4+ T cell proliferation. • CD16+ and CD16- monocytes respond to VEP exposure in opposite directions. • CD8+ T cell proliferation is inhibited by all doses of VEPs. • Globally, more stringent standards are needed for vehicle particle emissions.« less

Exposure assessment of a cyclist to PM10 and ultrafine particles.

PubMed

Berghmans, P; Bleux, N; Int Panis, L; Mishra, V K; Torfs, R; Van Poppel, M

2009-02-01

Estimating personal exposure to air pollution is a crucial component in identifying high-risk populations and situations. It will enable policy makers to determine efficient control strategies. Cycling is again becoming a favorite mode of transport both in developing and in developed countries due to increasing traffic congestion and environmental concerns. In Europe, it is also seen as a healthy sports activity. However, due to high levels of hazardous pollutants in the present day road microenvironment the cyclist might be at a higher health risk due to higher breathing rate and proximity to the vehicular exhaust. In this paper we present estimates of the exposure of a cyclist to particles of various size fractions including ultrafine particles (UFP) in the town of Mol (Flanders, Belgium). The results indicate relatively higher UFP concentration exposure during morning office hours and moderate UFP levels during afternoon. The major sources of UFP and PM(10) were identified, which are vehicular emission and construction activities, respectively. We also present a dust mapping technique which can be a useful tool for town planners and local policy makers.

A case-control study of diesel exhaust exposure and bladder cancer.

PubMed

Wynder, E L; Dieck, G S; Hall, N E; 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 U.S. 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.

Diesel exhaust and lung cancer in the trucking industry: exposure-response analyses and risk assessment.

PubMed

Steenland, K; Deddens, J; Stayner, L

1998-09-01

Diesel exhaust is considered a probable human carcinogen by the International Agency for Research on Cancer (IARC). The epidemiologic evidence rests on studies of lung cancer among truck drivers, bus drivers, shipyard workers, and railroad workers. The general public is exposed to diesel exhaust in ambient air. Two regulatory agencies are now considering regulating levels of diesel exhaust: the California EPA (ambient levels) and the Mine Safety Health Administration (MSHA) (occupational levels). To date, there have been few quantitative exposure-response analyses of diesel and lung cancer based on human data. We conducted exposure-response analyses among workers in the trucking industry, adjusted for smoking. Diesel exhaust exposure was estimated based on a 1990 industrial hygiene survey. Past exposures were estimated assuming that they were a function of 1) the number of heavy duty trucks on the road, 2) the particulate emissions (grams/mile) of diesel engines over time, and 3) leaks from trucks' exhaust systems for long-haul drivers. Regardless of assumptions about past exposure, all analyses resulted in significant positive trends in lung cancer risk with increasing cumulative exposure. A male truck driver exposed to 5 micrograms/m3 of elemental carbon (a typical exposure in 1990, approximately five times urban background levels) would have a lifetime excess risk of lung cancer of 1-2% above a background risk of 5%. We found a lifetime excess risk ten times higher than the 1 per 1,000 excess risk allowed by OSHA in setting regulations. There are about 2.8 million truck drivers in the U.S. Our results depend on estimates about unknown past exposures, and should be viewed as exploratory. They conform reasonably well to recent estimates for diesel-exposed railroad workers done by the California EPA, although those results themselves have been disputed.

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.

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

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.

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

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

The generation of diesel exhaust particle aerosols from a bulk source in an aerodynamic size range similar to atmospheric particles

PubMed Central

Cooney, Daniel J; Hickey, Anthony J

2008-01-01

The influence of diesel exhaust particles (DEP) on the lungs and heart is currently a topic of great interest in inhalation toxicology. Epidemiological data and animal studies have implicated airborne particulate matter and DEP in increased morbidity and mortality due to a number of cardiopulmonary diseases including asthma, chronic obstructive pulmonary disorder, and lung cancer. The pathogeneses of these diseases are being studied using animal models and cell culture techniques. Real-time exposures to freshly combusted diesel fuel are complex and require significant infrastructure including engine operations, dilution air, and monitoring and control of gases. A method of generating DEP aerosols from a bulk source in an aerodynamic size range similar to atmospheric DEP would be a desirable and useful alternative. Metered dose inhaler technology was adopted to generate aerosols from suspensions of DEP in the propellant hydrofluoroalkane 134a. Inertial impaction data indicated that the particle size distributions of the generated aerosols were trimodal, with count median aerodynamic diameters less than 100 nm. Scanning electron microscopy of deposited particles showed tightly aggregated particles, as would be expected from an evaporative process. Chemical analysis indicated that there were no major changes in the mass proportion of 2 specific aromatic hydrocarbons (benzo[a]pyrene and benzo[k]fluoranthene) in the particles resulting from the aerosolization process. PMID:19337412

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...

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...

ACUTE BEHAVORIAL EFFECTS FROM EXPOSURE TO TWO-STROKE ENGINE EXHAUST

EPA Science Inventory

Benefits of changing from two-stroke to four-stroke engines (and other remedial requirements) can be evaluated (monetized) from the standpoint of acute behavioral effects of human exposure to exhaust from these engines. The monetization process depends upon estimates of the magn...

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...

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.

[Experimental study on characteristics of biodiesel exhausted particle].

PubMed

Ge, Yun-shan; He, Chao; Han, Xiu-kun; Wu, Si-jin; Lu, Xiao-ming

2007-07-01

A particle emission experiment of a direct-injection turbocharged diesel engine with biodiesel and diesel was carried out. A pump of 80 L/min and fiber glass filters with diameter of 90 mm was used to sample engine particles in exhaust pipe. The size distribution, soluble organic fraction (SOF) and 16 polycyclic aromatic hydrocarbons (PAHs) of particles were analyzed by a laser diffraction particle size analyzer and GC-MS. The results indicate that the volume weighted size distribution of biodiesel particle is single-peak and its median diameter d(0.5) and mean diameter d32 are decreased with the increasing speed. At the high speed the d32 and d(0.5) of biodiesel are larger than those of diesel, and quite the contrary at the low speed. SOF mass concentration and mass percentage of biodiesel are 12.3 - 31.5 mg/m3 and 38.2% - 58.0% respectively, which are much higher than those of diesel. The total PAHs emission concentration of biodiesel is 2.9 - 4.7 microg/m3 lower than that of diesel as much as 29.1% - 92.4%.

Petrol and diesel exhaust particles accelerate the horizontal transfer of plasmid-mediated antimicrobial resistance genes.

PubMed

Zhang, Ye; Gu, April Z; Cen, Tianyu; Li, Xiangyang; Li, Dan; Chen, Jianmin

2018-05-01

Particles exhausted from petrol and diesel consumptions are major components of urban air pollution that can be exposed to human via direct inhalation or other routes due to atmospheric deposition into water and soil. Antimicrobial resistance is one of the most serious threats to modern health care. However, how the petrol and diesel exhaust particles affect the development and spread of antimicrobial resistance genes (ARGs) in various environments remain largely unknown. This study investigated the effects and potential mechanisms of four representative petrol and diesel exhaust particles, namely 97 octane petrol, 93 octane petrol, light diesel oil, and marine heavy diesel oil, on the horizontal transfer of ARGs between two opportunistic Escherichia coli (E. coli) strains, E. coli S17-1 (donor) and E. coli K12 (recipient). The results demonstrated that these four representative types of nano-scale particles induced concentration-dependent increases in conjugative transfer rates compared with the controls. The underlying mechanisms involved in the accelerated transfer of ARGs were also identified, including the generation of intracellular reactive oxygen species (ROS) and the consequent induction of oxidative stress, SOS response, changes in cell morphology, and the altered mRNA expression of membrane protein genes and those involved in the promotion of conjugative transfer. The findings provide new evidences and mechanistic insights into the antimicrobial resistance risks posed by petrol and diesel exhaust particles, and highlight the implications and need for stringent strategies on alternative fuels to mitigate air pollution and health risks. Copyright © 2018 Elsevier Ltd. All rights reserved.

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...

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...

Particle exposures and infections

EPA Science Inventory

Particle exposures increase the risk for human infections. Particles can deposit in the nose, pharynx, larynx, trachea, bronchi, and distal lung and, accordingly, the respiratory tract is the system most frequently infected after such exposure; however, meningitis also occurs. Ci...

Characterizing oxidative flow reactor SOA production and OH radical exposure from laboratory experiments of complex mixtures (engine exhaust) and simple precursors (monoterpenes)

NASA Astrophysics Data System (ADS)

Michael Link, M. L.; Friedman, B.; Ortega, J. V.; Son, J.; Kim, J.; Park, G.; Park, T.; Kim, K.; Lee, T.; Farmer, D.

2016-12-01

Recent commercialization of the Oxidative Flow Reactor (OFR, occasionally described in the literature as a "Potential Aerosol Mass") has created the opportunity for many researchers to explore the mechanisms behind OH-driven aerosol formation on a wide range of oxidative timescales (hours to weeks) in both laboratory and field measurements. These experiments have been conducted in both laboratory and field settings, including simple (i.e. single component) and complex (multi-component) precursors. Standard practices for performing OFR experiments, and interpreting data from the measurements, are still being developed. Measurement of gas and particle phase chemistry, from oxidation products generated in the OFR, through laboratory studies on single precursors and the measurement of SOA from vehicle emissions on short atmospheric timescales represent two very different experiments in which careful experimental design is essential for exploring reaction mechanisms and SOA yields. Two parameters essential in experimental design are (1) the role of seed aerosol in controlling gas-particle partitioning and SOA yields, and (2) the accurate determination of OH exposure during any one experiment. We investigated the role of seed aerosol surface area in controlling the observed SOA yields and gas/particle composition from the OH-initiated oxidation of four monoterpenes using an aerosol chemical ionization time-of-flight mass spectrometer and scanning mobility particle sizer. While the OH exposure during laboratory experiments is simple to constrain, complex mixtures such as diesel exhaust have high estimated OH reactivity values, and thus require careful consideration. We developed methods for constraining OH radical exposure in the OFR during vehicle exhaust oxidation experiments. We observe changes in O/C ratios and highly functionalized species over the temperature gradient employed in the aerosol-CIMS measurement. We relate this observed, speciated chemistry to the

Combined exposure of diesel exhaust particles and respirable Soufrière Hills volcanic ash causes a (pro-)inflammatory response in an in vitro multicellular epithelial tissue barrier model.

PubMed

Tomašek, Ines; Horwell, Claire J; Damby, David E; Barošová, Hana; Geers, Christoph; Petri-Fink, Alke; Rothen-Rutishauser, Barbara; Clift, Martin J D

2016-12-12

There are justifiable health concerns regarding the potential adverse effects associated with human exposure to volcanic ash (VA) particles, especially when considering communities living in urban areas already exposed to heightened air pollution. The aim of this study was, therefore, to gain an imperative, first understanding of the biological impacts of respirable VA when exposed concomitantly with diesel particles. A sophisticated in vitro 3D triple cell co-culture model of the human alveolar epithelial tissue barrier was exposed to either a single or repeated dose of dry respirable VA (deposited dose of 0.26 ± 0.09 or 0.89 ± 0.29 μg/cm 2 , respectively) from Soufrière Hills volcano, Montserrat for a period of 24 h at the air-liquid interface (ALI). Subsequently, co-cultures were exposed to co-exposures of single or repeated VA and diesel exhaust particles (DEP; NIST SRM 2975; 0.02 mg/mL), a model urban pollutant, at the pseudo-ALI. The biological impact of each individual particle type was also analysed under these precise scenarios. The cytotoxic (LDH release), oxidative stress (depletion of intracellular GSH) and (pro-)inflammatory (TNF-α, IL-8 and IL-1β) responses were assessed after the particulate exposures. The impact of VA exposure upon cell morphology, as well as its interaction with the multicellular model, was visualised via confocal laser scanning microscopy (LSM) and scanning electron microscopy (SEM), respectively. The combination of respirable VA and DEP, in all scenarios, incited an heightened release of TNF-α and IL-8 as well as significant increases in IL-1β, when applied at sub-lethal doses to the co-culture compared to VA exposure alone. Notably, the augmented (pro-)inflammatory responses observed were not mediated by oxidative stress. LSM supported the quantitative assessment of cytotoxicity, with no changes in cell morphology within the barrier model evident. A direct interaction of the VA with all three cell types of

Combined exposure of diesel exhaust particles and respirable Soufrière Hills volcanic ash causes a (pro-)inflammatory response in an in vitro multicellular epithelial tissue barrier model

USGS Publications Warehouse

Tomašek, Ines; Horwell, Claire J.; Damby, David; Barošová, Hana; Geers, Christoph; Petri-Fink, Alke; Rothen-Rutishauser, Barbara; Clift, Martin J. D.

2016-01-01

BackgroundThere are justifiable health concerns regarding the potential adverse effects associated with human exposure to volcanic ash (VA) particles, especially when considering communities living in urban areas already exposed to heightened air pollution. The aim of this study was, therefore, to gain an imperative, first understanding of the biological impacts of respirable VA when exposed concomitantly with diesel particles.MethodsA sophisticated in vitro 3D triple cell co-culture model of the human alveolar epithelial tissue barrier was exposed to either a single or repeated dose of dry respirable VA (deposited dose of 0.26 ± 0.09 or 0.89 ± 0.29 μg/cm2, respectively) from Soufrière Hills volcano, Montserrat for a period of 24 h at the air-liquid interface (ALI). Subsequently, co-cultures were exposed to co-exposures of single or repeated VA and diesel exhaust particles (DEP; NIST SRM 2975; 0.02 mg/mL), a model urban pollutant, at the pseudo-ALI. The biological impact of each individual particle type was also analysed under these precise scenarios. The cytotoxic (LDH release), oxidative stress (depletion of intracellular GSH) and (pro-)inflammatory (TNF-α, IL-8 and IL-1β) responses were assessed after the particulate exposures. The impact of VA exposure upon cell morphology, as well as its interaction with the multicellular model, was visualised via confocal laser scanning microscopy (LSM) and scanning electron microscopy (SEM), respectively.ResultsThe combination of respirable VA and DEP, in all scenarios, incited an heightened release of TNF-α and IL-8 as well as significant increases in IL-1β, when applied at sub-lethal doses to the co-culture compared to VA exposure alone. Notably, the augmented (pro-)inflammatory responses observed were not mediated by oxidative stress. LSM supported the quantitative assessment of cytotoxicity, with no changes in cell morphology within the barrier model evident. A direct interaction of the VA with all

Assessment of the capacity of vehicle cabin air inlet filters to reduce diesel exhaust-induced symptoms in human volunteers

PubMed Central

2014-01-01

Background Exposure to particulate matter (PM) air pollution especially derived from traffic is associated with increases in cardiorespiratory morbidity and mortality. In this study, we evaluated the ability of novel vehicle cabin air inlet filters to reduce diesel exhaust (DE)-induced symptoms and markers of inflammation in human subjects. Methods Thirty healthy subjects participated in a randomized double-blind controlled crossover study where they were exposed to filtered air, unfiltered DE and DE filtered through two selected particle filters, one with and one without active charcoal. Exposures lasted for one hour. Symptoms were assessed before and during exposures and lung function was measured before and after each exposure, with inflammation assessed in peripheral blood five hours after exposures. In parallel, PM were collected from unfiltered and filtered DE and assessed for their capacity to drive damaging oxidation reactions in a cell-free model, or promote inflammation in A549 cells. Results The standard particle filter employed in this study reduced PM10 mass concentrations within the exposure chamber by 46%, further reduced to 74% by the inclusion of an active charcoal component. In addition use of the active charcoal filter was associated by a 75% and 50% reduction in NO2 and hydrocarbon concentrations, respectively. As expected, subjects reported more subjective symptoms after exposure to unfiltered DE compared to filtered air, which was significantly reduced by the filter with an active charcoal component. There were no significant changes in lung function after exposures. Similarly diesel exhaust did not elicit significant increases in any of the inflammatory markers examined in the peripheral blood samples 5 hour post-exposure. Whilst the filters reduced chamber particle concentrations, the oxidative activity of the particles themselves, did not change following filtration with either filter. In contrast, diesel exhaust PM passed through the

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)

Role of snow and cold environment in the fate and effects of nanoparticles and select organic pollutants from gasoline engine exhaust.

PubMed

Nazarenko, Yevgen; Kurien, Uday; Nepotchatykh, Oleg; Rangel-Alvarado, Rodrigo B; Ariya, Parisa A

2016-02-01

Exposure to vehicle exhaust can drive up to 70 % of excess lifetime cancer incidences due to air pollution in urban environments. Little is known about how exhaust-derived particles and organic pollutants, implicated in adverse health effects, are affected by freezing ambient temperatures and the presence of snow. Airborne particles and (semi)volatile organic constituents in dilute exhaust were studied in a novel low-temperature environmental chamber system containing natural urban snow under controlled cold environmental conditions. The presence of snow altered the aerosol size distributions of dilute exhaust in the 10 nm to 10 μm range and decreased the number density of the nanoparticulate (<100 nm) fraction of exhaust aerosols, yet increased the 100-150 nm fraction. Upon 1 hour exhaust exposure, the total organic carbon increased in the natural snow from 0.218 ± 0.014 to 0.539 ± 0.009 mg L(-1), and over 40 additional (semi)volatile organic compounds and a large number of exhaust-derived carbonaceous and likely organic particles were identified. The concentrations of benzene, toluene, ethylbenzene, and xylenes (BTEX) increased from near the detection limit to 52.48, 379.5, 242.7, and 238.1 μg kg(-1) (± 10 %), respectively, indicating the absorption of exhaust-derived toxic organic compounds by snow. The alteration of exhaust aerosol size distributions at freezing temperatures and in the presence of snow, accompanied by changes of the organic pollutant content in snow, has potential to alter health effects of human exposure to vehicle exhaust.

Effect of atmospheric ageing on volatility and ROS of biodiesel exhaust nano-particles

NASA Astrophysics Data System (ADS)

Pourkhesalian, A. M.; Stevanovic, S.; Rahman, M. M.; Faghihi, E. M.; Bottle, S. E.; Masri, A. R.; Brown, R. J.; Ristovski, Z. D.

2015-03-01

In the prospect of limited energy resources and climate change, effects of alternative biofuels on primary emissions are being extensively studied. Our two recent studies have shown that biodiesel fuel composition has a~significant impact on primary particulate matter emissions. It was also shown that particulate matter caused by biodiesels was substantially different from the emissions due to petroleum diesel. Emissions appeared to have higher oxidative potential with the increase in oxygen content and decrease of carbon chain length and unsaturation levels of fuel molecules. Overall, both studies concluded that chemical composition of biodiesel is more important than its physical properties in controlling exhaust particle emissions. This suggests that the atmospheric ageing processes, including secondary organic aerosol formation, of emissions from different fuels will be different as well. In this study, measurements were conducted on a modern common-rail diesel engine. To get more information on realistic properties of tested biodiesel particulate matter once they are released into the atmosphere, particulate matter was exposed to atmospheric oxidants, ozone and ultra-violet light; and the change in their properties was monitored for different biodiesel blends. Upon the exposure to oxidative agents, the chemical composition of the exhaust changes. It triggers the cascade of photochemical reactions resulting in the partitioning of semi-volatile compounds between the gas and particulate phase. In most of the cases, aging lead to the increase in volatility and oxidative potential, and the increment of change was mainly dependent on the chemical composition of fuels as the leading cause for the amount and the type of semi-volatile compounds present in the exhaust.

Atmospheric scavenging of solid rocket exhaust effluents

NASA Technical Reports Server (NTRS)

Fenton, D. L.; Purcell, R. Y.

1978-01-01

Solid propellant rocket exhaust was directly utilized to ascertain raindrop scavenging rates for hydrogen chloride. Two chambers were used to conduct the experiments; a large, rigid walled, spherical chamber stored the exhaust constituents, while the smaller chamber housing all the experiments was charged as required with rocket exhaust HCl. Surface uptake experiments demonstrated an HCl concentration dependence for distilled water. Sea water and brackish water HCl uptake was below the detection limit of the chlorine-ion analysis technique used. Plant life HCl uptake experiments were limited to corn and soybeans. Plant age effectively correlated the HCl uptake data. Metallic corrosion was not significant for single 20 minute exposures to the exhaust HCl under varying relative humidity. Characterization of the aluminum oxide particles substantiated the similarity between the constituents of the small scale rocket and the full size vehicles.

Numerical investigation of diesel exhaust particle transport and deposition in the CT-scan based lung airway

NASA Astrophysics Data System (ADS)

Islam, Mohammad S.; Saha, Suvash C.; Sauret, Emilie; Gu, Y. T.; Molla, Md Mamun

2017-06-01

Diesel exhaust particulates matter (DEPM) is a compound mixture of gasses and fine particles that contain more than 40 toxic air pollutants including benzene, formaldehyde, and nitrogen oxides. Exposure of DEPM to human lung airway during respiratory inhalation causes severe health hazards like diverse pulmonary diseases. This paper studies the DEPM transport and deposition in upper three generations of the realistic lung airways. A 3-D digital airway bifurcation model is constructed from the computerized tomography (CT) scan data of a healthy adult man. The Euler-Lagrange approach is used to solve the continuum and disperse phases of the calculation. Local averaged Navier-Stokes equations are solved to calculate the transport of the continuum phase. Lagrangian based Discrete Phase Model (DPM) is used to investigate the particle transport and deposition in the current anatomical model. The effects of size specific monodispersed particles on deposition are extensively investigated during different breathing pattern. The numerical results illustrate that particle diameter and breathing pattern have a substantial impact on particles transport and deposition in the tracheobronchial airways. The present realistic bifurcation model also depicts a new deposition hot spot which could advance the understanding of the therapeutic drug delivery system to the specific position of the respiratory airways.

Urban cyclist exposure to fine particle pollution in a rapidly growing city

NASA Astrophysics Data System (ADS)

Luce, B. W.; Barrett, T. E.; Ponette-González, A.

2017-12-01

Urban cyclists are exposed to elevated atmospheric concentrations of fine particulate matter (particles <2.5 µm or PM2.5). Major urban sources of PM2.5 include the incomplete combustion of fossil fuels from vehicle exhaust, which is emitted directly into cyclists' "breathing zone." In cities, human exposure to PM2.5 is a concern because its small size allows it to be inhaled deeper into the lungs than most particles. The aim of this research is to determine "hotspots" (locations with high PM2.5 concentrations) within the Dallas-Fort Worth Metroplex, Texas, where urban cyclists are most exposed to fine particle pollution. Recent research indicates that common exposure hotspots include traffic signals, junctions, bus stations, parking lots, and inclined streets. To identify these and other hotspots, a bicycle equipped with a low-cost, portable, battery-powered particle counter (Dylos 1700) coupled with a Trimble Geo 5T handheld Global Positioning System (GPS; ≤1 m ± resolution) will be used to map and measure particle mass concentrations along predetermined routes. Measurements will be conducted during a consecutive four-month period (Sep-Dec) during morning and evening rush hours when PM2.5 levels are generally highest, as well as during non-rush hour times to determine background concentrations. PM2.5 concentrations will be calculated from particle counts using an equation developed by Steinle et al. (2015). In addition, traffic counts will be conducted along the routes coinciding with the mobile monitoring times. We will present results on identified "hotspots" of high fine particle concentrations and PM2.5 exposure in the City of Denton, where particle pollution puts urban commuters most at risk, as well as average traffic counts from monitoring times. These data can be used to determine pollution mitigation strategies in rapidly growing urban areas.

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...

Comparison of primary and secondary particle formation from natural gas engine exhaust and of their volatility characteristics

NASA Astrophysics Data System (ADS)

Alanen, Jenni; Simonen, Pauli; Saarikoski, Sanna; Timonen, Hilkka; Kangasniemi, Oskari; Saukko, Erkka; Hillamo, Risto; Lehtoranta, Kati; Murtonen, Timo; Vesala, Hannu; Keskinen, Jorma; Rönkkö, Topi

2017-07-01

Natural gas usage in the traffic and energy production sectors is a growing trend worldwide; thus, an assessment of its effects on air quality, human health and climate is required. Engine exhaust is a source of primary particulate emissions and secondary aerosol precursors, which both contribute to air quality and can cause adverse health effects. Technologies, such as cleaner engines or fuels, that produce less primary and secondary aerosols could potentially significantly decrease atmospheric particle concentrations and their adverse effects. In this study, we used a potential aerosol mass (PAM) chamber to investigate the secondary aerosol formation potential of natural gas engine exhaust. The PAM chamber was used with a constant UV-light voltage, which resulted in relatively long equivalent atmospheric ages of 11 days at most. The studied retro-fitted natural gas engine exhaust was observed to form secondary aerosol. The mass of the total aged particles, i.e., particle mass measured downstream of the PAM chamber, was 6-268 times as high as the mass of the emitted primary exhaust particles. The secondary organic aerosol (SOA) formation potential was measured to be 9-20 mg kgfuel-1. The total aged particles mainly consisted of organic matter, nitrate, sulfate and ammonium, with the fractions depending on exhaust after-treatment and the engine parameters used. Also, the volatility, composition and concentration of the total aged particles were found to depend on the engine operating mode, catalyst temperature and catalyst type. For example, a high catalyst temperature promoted the formation of sulfate particles, whereas a low catalyst temperature promoted nitrate formation. However, in particular, the concentration of nitrate needed a long time to stabilize - more than half an hour - which complicated the conclusions but also indicates the sensitivity of nitrate measurements on experimental parameters such as emission source and system temperatures. Sulfate was

Commuter exposure to inhalable, thoracic and alveolic particles in various transportation modes in Delhi.

PubMed

Kumar, Pramod; Gupta, N C

2016-01-15

A public health concern is to understand the linkages between specific pollution sources and adverse health impacts. Commuting can be viewed as one of the significant-exposure activity in high-vehicle density areas. This paper investigates the commuter exposure to inhalable, thoracic and alveolic particles in various transportation modes in Delhi, India. Air pollution levels are significantly contributed by automobile exhaust and also in-vehicle exposure can be higher sometime than ambient levels. Motorcycle, auto rickshaw, car and bus were selected to study particles concentration along two routes in Delhi between Kashmere Gate and Dwarka. The bus and auto rickshaw were running on compressed natural gas (CNG) while the car and motorcycle were operated on gasoline fuel. Aerosol spectrometer was employed to measure inhalable, thoracic and alveolic particles during morning and evening rush hours for five weekdays. From the study, we observed that the concentration levels of these particles were greatly influenced by transportation modes. Concentrations of inhalable particles were found higher during morning in auto rickshaw (332.81 ± 90.97 μg/m(3)) while the commuter of bus exhibited higher exposure of thoracic particles (292.23 ± 110.45 μg/m(3)) and car commuters were exposed to maximum concentrations of alveolic particles (222.37 ± 26.56 μg/m(3)). We observed that in evening car commuters experienced maximum concentrations of all sizes of particles among the four commuting modes. Interestingly, motorcycle commuters were exposed to lower levels of inhalable and thoracic particles during morning and evening hours as compared to other modes of transport. The mean values were found greater than the median values for all the modes of transport suggesting that positive skewed distributions are characteristics of naturally occurring phenomenon. Copyright © 2015 Elsevier B.V. All rights reserved.

Pulmonary exposure to diesel exhaust particles enhances coagulatory disturbance with endothelial damage and systemic inflammation related to lung inflammation.

PubMed

Inoue, Ken-Ichiro; Takano, Hirohisa; Sakurai, Miho; Oda, Toshio; Tamura, Hiroshi; Yanagisawa, Rie; Shimada, Akinori; Yoshikawa, Toshikazu

2006-11-01

Pulmonary exposure to diesel exhaust particles (DEP) enhances lung inflammation related to bacterial endotoxin (lipopolysaccharide [LPS]) in mice. Severe lung inflammation can reportedly induce coagulatory abnormalities and systemic inflammation. This study examined the effects of components of DEP on lung inflammation, pulmonary permeability, coagulatory changes, systemic inflammatory response, and lung-to-systemic translocation of LPS in a murine model of lung inflammation. ICR mice were divided into six experimental groups that intratracheally received vehicle, LPS (2.5 mg/kg), organic chemicals in DEP (DEP-OC; 4 mg/kg) extracted with dicloromethane), residual carbonaceous nuclei of DEP (washed DEP: 4 mg/kg), DEP-OC + LPS, or washed DEP + LPS. Both DEP components exacerbated lung inflammation, vascular permeability, and the increased fibrinogen and E-selectin levels induced by LPS. With overall trends, the exacerbation was more prominent with washed DEP than with DEP-OC. Washed DEP + LPS significantly decreased activated protein C and antithrombin-III and elevated circulatory levels of interleukin (IL)-6, keratinocyte chemoattractant (KC), and LPS as compared with LPS alone, whereas DEP-OC + LPS elevated IL-6, KC, and LPS without significance. These results show that DEP components, especially washed DEP, amplify the effects if LPS on the respiratory system and suggest that they contribute to the adverse health effects of particulate air pollution on the sensitive populations with predisposing vascular and/or pulmonary diseases, including ischemic vascular diseases and respiratory infection.

Determining exhaust fumes exposure in chainsaw operations.

PubMed

Neri, F; Foderi, C; Laschi, A; Fabiano, F; Cambi, M; Sciarra, G; Aprea, M C; Cenni, A; Marchi, E

2016-11-01

The objective of this study was to investigate the inhalation exposure of forest operators to polycyclic aromatic hydrocarbons (PAHs) and BTEX (benzene, toluene, ethylbenzene and total xylenes) contained in the exhaust fumes released from chainsaws and to suggest possible countermeasures. The study was carried out in four silvicultural treatments (coppice clearcut, conifer thinning, conifer pruning, and sanitary cut), using three types of chainsaw fuel (normal two-stroke petrol mix and two alkylate fuels). Eighty personal air samples were collected; IOM samplers combined with Amberlite XAD-2 sorbent tubes were used for collecting PAHs and Radiello ® samplers were used for BTEX. Results indicate that none of the four silvicultural treatments significantly affected the PAHs and BTEX inhalation exposure of forest workers. On the other hand, statistically significant differences were recorded in the inhalation exposure to PAHs and BTEX when using different fuel types. In particular, the inhalation exposure to PAHs and BTEX was generally one order of magnitude lower when using modern alkylate fuels as compared to the traditional oil and lead-free petrol mixture. The small, non-statistically significant differences in inhalation exposure recorded between the two alkylate fuels suggests that the two fuels might be equivalent in terms of quality. Our study indicates that while forest workers are exposed to PAHs and BTEX, the maximum values are generally well below accepted occupational exposure limits. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

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

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...

Development of an on-line exposure system to determine freshly produced diesel engine emission-induced cellular effects.

PubMed

Oostingh, Gertie J; Papaioannou, Eleni; Chasapidis, Leonidas; Akritidis, Theofylaktos; Konstandopoulos, Athanasios G; Duschl, Albert

2013-09-01

Diesel engine emission particle filters are often placed at exhaust outlets to remove particles from the exhaust. The use of filters results in the exposure to a reduced number of nanometer-sized particles, which might be more harmful than the exposure to a larger number of micrometer-sized particles. An in vitro exposure system was established to expose human alveolar epithelial cells to freshly generated exhaust. Computer simulations were used to determine the optimal flow characteristics and ensure equal exposure conditions for each well of a 6-well plate. A selective particle size sampler was used to continuously deliver diesel soot particles with different particle size distributions to cells in culture. To determine, whether the system could be used for cellular assays, alterations in cytokine production and cell viability of human alveolar A549 cells were determined after 3h on-line exposure followed by a 21-h conventional incubation period. Data indicated that complete diesel engine emission slightly affected pre-stimulated cells, but naive cells were not affected. The fractions containing large or small particles never affected the cells. The experimental set-up allowed a reliable exposure of the cells to the complete exhaust fraction or to the fractions containing either large or small diesel engine emission particles. Copyright © 2013 Elsevier Ltd. All rights reserved.

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…

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...

Removal properties of diesel exhaust particles by a dielectric barrier discharge reactor.

PubMed

Suzuki, Ken-ichiro; Takeuchi, Naomi; Madokoro, Kazuhiko; Fushimi, Chihiro; Yao, Shuiliang; Fujioka, Yuichi; Nihei, Yoshimasa

2008-02-01

The removal properties of diesel exhaust particles (DEP) were investigated using an engine exhaust particle size spectrometer (EEPS), field emission-type scanning electron microscopy (FE-SEM) and time-of-flight secondary ion mass spectrometry (TOF-SIMS). DEP were treated using a dielectric barrier discharge (DBD) reactor installed in the tail pipe of a diesel engine, and a model DBD reactor fed with DEP in the mixture of N(2) and O(2). When changing the experimental parameters of both the plasma conditions and the engine load conditions, we obtained characteristic information of DEP treated with plasma discharges from the particle diameter and the composition. In evaluating the model DBD reactor, it became clear that there were two types of plasma processes (reactions with active oxygen species to yield CO(2) and reactions with active nitrogen species to yield nitrogen containing compounds). Moreover, from the result of a TOF-SIMS analysis, the characteristic secondary ions, such as C(2)H(6)N(+), C(4)H(12)N(+), and C(10)H(20)N(2)(+), were strongly detected from the DEP surfaces during the plasma discharges. This indicates that the nitrogen contained hydrocarbons were generated by plasma reactions.

[Polycyclic aromatic hydrocarbons in ultrafine particles of diesel exhaust fumes--the use of ultrafast liquid chromatography].

PubMed

Małgorzata Szewczyńska; Małgorzata Pośniak

2014-01-01

The article presents the results of the determination of polycyclic aromatic hydrocarbons (PAHs) in the fine par ticles fraction emitted from 3 types of diesel fuels using ultra-high pressure liquid chromatography. Samples of diesel Eco, Verwa and Bio exhaust combustion fumes were generated at the model station which consisted of a diesel engine from the 2007 Diesel TDI 2.0. Personal Cascade Sioutas Impactor (IPCSI) with Teflon filters was used to collect samples of exhaust fume ultrafine particles. PAHs adsorbed on particulate fractions were analyzed by ultra-high pressure liquid chromatography with fluorescence detection (UHPLC/FL). Phenanthrene, fluoranthene, pyrene and chrysene present the highest concentration in the particulate matter emitted by an engine. The total contents of fine particles collected during engine operation on fuels Eco, Verwa and Bio were 134.2 μg/g, 183.8 μg/g and 153.4 μg/g, respectively, which makes 75%, 90% and 83% of the total PAHs, respectively. The highest content of benzo(a)pyrene determined in particles emitted during the combustion of fuels Eco and Bio was 1.5 μg/g and 1 μg/g, respectively. The study of the PAH concentration in the particles of fine fraction below 0.25 μm emitted from different fuels designed for diesel engines indicate that the exhaust gas content of carcinogens, including PAHs deposited on particulates, is still significant, regardless of the fuel. Application of ultrahigh pressure liquid chromatography with fluorescence detection for the analysis ofPAHs in the particles emitted in the fine fraction of diesel exhaust allowed to shorten the analysis time from 35 min to 8 min.

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...

Vacuum cleaner emissions as a source of indoor exposure to airborne particles and bacteria.

PubMed

Knibbs, Luke D; He, Congrong; Duchaine, Caroline; Morawska, Lidia

2012-01-03

Vacuuming can be a source of indoor exposure to biological and nonbiological aerosols, although there are few data that describe the magnitude of emissions from the vacuum cleaner itself. We therefore sought to quantify emission rates of particles and bacteria from a large group of vacuum cleaners and investigate their potential determinants, including temperature, dust bags, exhaust filters, price, and age. Emissions of particles between 0.009 and 20 μm and bacteria were measured from 21 vacuums. Ultrafine (<100 nm) particle emission rates ranged from 4.0 × 10(6) to 1.1 × 10(11) particles min(-1). Emission of 0.54-20 μm particles ranged from 4.0 × 10(4) to 1.2 × 10(9) particles min(-1). PM(2.5) emissions were between 2.4 × 10(-1) and 5.4 × 10(3) μg min(-1). Bacteria emissions ranged from 0 to 7.4 × 10(5) bacteria min(-1) and were poorly correlated with dust bag bacteria content and particle emissions. Large variability in emission of all parameters was observed across the 21 vacuums, which was largely not attributable to the range of determinant factors we assessed. Vacuum cleaner emissions contribute to indoor exposure to nonbiological and biological aerosols when vacuuming, and this may vary markedly depending on the vacuum used.

TEST OF A THEORETICAL COMMUTER EXPOSURE MODEL TO VEHICLE EXHAUST IN TRAFFIC

EPA Science Inventory

A theoretical model of commuter exposure is presented as a box or cell model with the automobile passenger compartment representing the microenvironment exposed to CO concentrations resulting from vehicle exhaust leaks and emissions from traffic. Equations which describe this sit...

Diesel Exhaust Particle-Induced Airway Responses are Augmented in Obese Rats

PubMed Central

Moon, Kuk-Young; Park, Moo-Kyun; Leikauf, George D.; Park, Choon-Sik; Jang, An-Soo

2015-01-01

Air pollutants and obesity are important factors that contribute to asthma. The aim of this study was to assess the airway responsiveness and inflammation in Otsuka-Long Evans Tokushima Fatty (OLETF) obese rats and Long Evans Tokushima-Otsuka (LETO) nonobese rats exposed to diesel exhaust particles (DEPs). Otsuka Long Evans Tokushima fatty rats and LETO rats were exposed intranasally to DEP and then challenged with aerosolized DEP on days 6 to 8. Body plethysmography, bronchoalveolar lavage (BAL), and histology were performed. Enhanced pause (Penh) was measured as an indicator of airway resistance on day 9 and samples were collected on day 10. After exposure to DEP, the OLETF group exhibited a greater increase in Penh compared to that in the LETO group. Moreover, the BAL fluid in mice showed an increase in the total and differential cell counts in the DEP-exposed OLETF group compared to that in the DEP-exposed LETO group. Histological assessment of lung tissue from each group revealed that the DEP-exposed OLETF group tended to have increased inflammatory cell infiltrations in the prebronchial area. Increased peroxisome proliferator-activated receptor γ, coactivator 1β messenger RNA was observed in the lungs of obese rats compared to that in nonobese rats following DEP exposure. These data indicate that the DEP-exposed OLETF group had increased airway responses and inflammation compared to the DEP-exposed LETO group, indicating that diesel particulates and obesity may be co-contributors to asthma. PMID:24536021

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

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 ...

Reanalysis of Diesel Engine Exhaust and Lung Cancer Mortality in the Diesel Exhaust in Miners Study Cohort Using Alternative Exposure Estimates and Radon Adjustment.

PubMed

Chang, Ellen T; Lau, Edmund C; Van Landingham, Cynthia; Crump, Kenny S; McClellan, Roger O; Moolgavkar, Suresh H

2018-06-01

The Diesel Exhaust in Miners Study (DEMS) (United States, 1947-1997) reported positive associations between diesel engine exhaust exposure, estimated as respirable elemental carbon (REC), and lung cancer mortality. This reanalysis of the DEMS cohort used an alternative estimate of REC exposure incorporating historical data on diesel equipment, engine horsepower, ventilation rates, and declines in particulate matter emissions per horsepower. Associations with cumulative REC and average REC intensity using the alternative REC estimate and other exposure estimates were generally attenuated compared with original DEMS REC estimates. Most findings were statistically nonsignificant; control for radon exposure substantially weakened associations with the original and alternative REC estimates. No association with original or alternative REC estimates was detected among miners who worked exclusively underground. Positive associations were detected among limestone workers, whereas no association with REC or radon was found among workers in the other 7 mines. The differences in results based on alternative exposure estimates, control for radon, and stratification by worker location or mine type highlight areas of uncertainty in the DEMS data.

Reanalysis of Diesel Engine Exhaust and Lung Cancer Mortality in the Diesel Exhaust in Miners Study Cohort Using Alternative Exposure Estimates and Radon Adjustment

PubMed Central

Chang, Ellen T; Lau, Edmund C; Van Landingham, Cynthia; Crump, Kenny S; McClellan, Roger O; Moolgavkar, Suresh H

2018-01-01

Abstract The Diesel Exhaust in Miners Study (DEMS) (United States, 1947–1997) reported positive associations between diesel engine exhaust exposure, estimated as respirable elemental carbon (REC), and lung cancer mortality. This reanalysis of the DEMS cohort used an alternative estimate of REC exposure incorporating historical data on diesel equipment, engine horsepower, ventilation rates, and declines in particulate matter emissions per horsepower. Associations with cumulative REC and average REC intensity using the alternative REC estimate and other exposure estimates were generally attenuated compared with original DEMS REC estimates. Most findings were statistically nonsignificant; control for radon exposure substantially weakened associations with the original and alternative REC estimates. No association with original or alternative REC estimates was detected among miners who worked exclusively underground. Positive associations were detected among limestone workers, whereas no association with REC or radon was found among workers in the other 7 mines. The differences in results based on alternative exposure estimates, control for radon, and stratification by worker location or mine type highlight areas of uncertainty in the DEMS data. PMID:29522073

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...

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...

Gender analysis of musculoskeletal disorders and emotional exhaustion: interactive effects from physical and psychosocial work exposures and engagement in domestic work.

PubMed

Ahlgren, Christina; Malmgren Olsson, Eva-Britt; Brulin, Christine

2012-01-01

The objective of this study was to assess the relationships between physical and psychosocial work exposures, engagement in domestic work and work-home imbalance in relation to symptoms of musculoskeletal disorders and emotional exhaustion in white- and blue-collar men and women. Three thousand employees from 21 companies were asked to answer a questionnaire on family structure, household and child care tasks, work exposure, work-home imbalance and symptoms of neck/shoulder disorders, low back disorders and emotional exhaustion. Women reported more musculoskeletal disorders and engagement in domestic work. Adverse at-work exposures were highest in blue-collar women. High engagement in domestic work was not separately associated with symptoms but paid work exposure factors were associated. High engagement in domestic work interacted with adverse work exposure and increased risk estimates for low back disorders and emotional exhaustion. Reported work-home imbalance was associated with neck/shoulder disorders in women and with emotional exhaustion in both women and men. The current article adds to earlier research by showing that high engagement in domestic work is not separately associated with increased symptoms, but interacts with psychosocial work exposure variables to produce emotional exhaustion in both women and men and low back disorders in women.

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...

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 ...

A case-control study relating railroad worker mortality to diesel exhaust exposure using a threshold regression model.

PubMed

Lee, Mei-Ling Ting; Whitmore, G A; Laden, Francine; Hart, Jaime E; Garshick, Eric

2009-01-01

A case-control study of lung cancer mortality in U.S. railroad workers in jobs with and without diesel exhaust exposure is reanalyzed using a new threshold regression methodology. The study included 1256 workers who died of lung cancer and 2385 controls who died primarily of circulatory system diseases. Diesel exhaust exposure was assessed using railroad job history from the US Railroad Retirement Board and an industrial hygiene survey. Smoking habits were available from next-of-kin and potential asbestos exposure was assessed by job history review. The new analysis reassesses lung cancer mortality and examines circulatory system disease mortality. Jobs with regular exposure to diesel exhaust had a survival pattern characterized by an initial delay in mortality, followed by a rapid deterioration of health prior to death. The pattern is seen in subjects dying of lung cancer, circulatory system diseases, and other causes. The unique pattern is illustrated using a new type of Kaplan-Meier survival plot in which the time scale represents a measure of disease progression rather than calendar time. The disease progression scale accounts for a healthy-worker effect when describing the effects of cumulative exposures on mortality.

Cytokine expression in mice exposed to diesel exhaust particles by inhalation. Role of tumor necrosis factor

PubMed Central

Saber, Anne T; Jacobsen, Nicklas R; Bornholdt, Jette; Kjær, Sanna L; Dybdahl, Marianne; Risom, Lotte; Loft, Steffen; Vogel, Ulla; Wallin, Håkan

2006-01-01

Background Particulate air pollution has been associated with lung and cardiovascular disease, for which lung inflammation may be a driving mechanism. The pro-inflammatory cytokine, tumor necrosis factor (TNF) has been suggested to have a key-role in particle-induced inflammation. We studied the time course of gene expression of inflammatory markers in the lungs of wild type mice and Tnf-/- mice after exposure to diesel exhaust particles (DEPs). Mice were exposed to either a single or multiple doses of DEP by inhalation. We measured the mRNA level of the cytokines Tnf and interleukin-6 (Il-6) and the chemokines, monocyte chemoattractant protein (Mcp-1), macrophage inflammatory protein-2 (Mip-2) and keratinocyte derived chemokine (Kc) in the lung tissue at different time points after exposure. Results Tnf mRNA expression levels increased late after DEP-inhalation, whereas the expression levels of Il-6, Mcp-1 and Kc increased early. The expression of Mip-2 was independent of TNF if the dose was above a certain level. The expression levels of the cytokines Kc, Mcp-1 and Il-6, were increased in the absence of TNF. Conclusion Our data demonstrate that Tnf is not important in early DEP induced inflammation and rather exerts negative influence on Mcp-1 and Kc mRNA levels. This suggests that other signalling pathways are important, a candidate being one involving Mcp-1. PMID:16504008

Capture efficiency of cooking-related fine and ultrafine particles by residential exhaust hoods.

PubMed

Lunden, M M; Delp, W W; Singer, B C

2015-02-01

Effective exhaust hoods can mitigate the indoor air quality impacts of pollutant emissions from residential cooking. This study reports capture efficiencies (CE) measured for cooking-generated particles for scripted cooking procedures in a 121-m3 chamber with kitchenette. CEs also were measured for burner produced CO2 during cooking and separately for pots and pans containing water. The study used four exhaust hoods previously tested by Delp and Singer (Environ. Sci. Technol., 2012, 46, 6167-6173). For pan-frying a hamburger over medium heat on the back burner, CEs for particles were similar to those for burner produced CO2 and mostly above 80%. For stir-frying green beans in a wok (high heat, front burner), CEs for burner CO2 during cooking varied by hood and airflow: CEs were 34-38% for low (51-68 l/s) and 54-72% for high (109-138 l/s) settings. CEs for 0.3-2.0 μm particles during front burner stir-frying were 3-11% on low and 16-70% on high settings. Results indicate that CEs measured for burner CO2 are not predictive of CEs of cooking-generated particles under all conditions, but they may be suitable to identify devices with CEs above 80% both for burner combustion products and for cooking-related particles. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Ion exhaust distributions and reconnection location with Magnetospheric Multiscale and global MHD test particles

NASA Astrophysics Data System (ADS)

Broll, J. M.; Fuselier, S. A.; Trattner, K. J.; Steven, P. M.; Burch, J. L.; Giles, B. L.

2017-12-01

Magnetic reconnection at Earth's dayside magnetopause is an essential process in magnetospheric physics. Under southward IMF conditions, reconnection occurs along a thin ribbon across the dayside magnetopause. The location of this ribbon has been studied extensively in terms of global optimization of quantities like reconnecting field energy or magnetic shear, but with expected errors of 1-2 Earth radii these global models give limited context for cases where an observation is near the reconnection line. Building on previous results, which established the cutoff contour method for locating reconnection using in-situ velocity measurements, we examine the effects of MHD-scale waves on reconnection exhaust distributions. We use a test particle exhaust distribution propagated through a globamagnetohydrodynamics model fields and compare with Magnetospheric Multiscale observations of reconnection exhaust.

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 ...

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

Effect of atmospheric aging on volatility and reactive oxygen species of biodiesel exhaust nano-particles

NASA Astrophysics Data System (ADS)

Pourkhesalian, A. M.; Stevanovic, S.; Rahman, M. M.; Faghihi, E. M.; Bottle, S. E.; Masri, A. R.; Brown, R. J.; Ristovski, Z. D.

2015-08-01

In the prospect of limited energy resources and climate change, effects of alternative biofuels on primary emissions are being extensively studied. Our two recent studies have shown that biodiesel fuel composition has a significant impact on primary particulate matter emissions. It was also shown that particulate matter caused by biodiesels was substantially different from the emissions due to petroleum diesel. Emissions appeared to have higher oxidative potential with the increase in oxygen content and decrease of carbon chain length and unsaturation levels of fuel molecules. Overall, both studies concluded that chemical composition of biodiesel is more important than its physical properties in controlling exhaust particle emissions. This suggests that the atmospheric aging processes, including secondary organic aerosol formation, of emissions from different fuels will be different as well. In this study, measurements were conducted on a modern common-rail diesel engine. To get more information on realistic properties of tested biodiesel particulate matter once they are released into the atmosphere, particulate matter was exposed to atmospheric oxidants, ozone and ultra-violet light; and the change in their properties was monitored for different biodiesel blends. Upon the exposure to oxidative agents, the chemical composition of the exhaust changes. It triggers the cascade of photochemical reactions resulting in the partitioning of semi-volatile compounds between the gas and particulate phase. In most of the cases, aging lead to the increase in volatility and oxidative potential, and the increment of change was mainly dependent on the chemical composition of fuels as the leading cause for the amount and the type of semi-volatile compounds present in the exhaust.

Mutagenicity of diesel engine exhaust is eliminated in the gas phase by an oxidation catalyst but only slightly reduced in the particle phase.

PubMed

Westphal, Götz A; Krahl, Jürgen; Munack, Axel; Ruschel, Yvonne; Schröder, Olaf; Hallier, Ernst; Brüning, Thomas; Bünger, Jürgen

2012-06-05

Concerns about adverse health effects of diesel engine emissions prompted strong efforts to minimize this hazard, including exhaust treatment by diesel oxidation catalysts (DOC). The effectiveness of such measures is usually assessed by the analysis of the legally regulated exhaust components. In recent years additional analytical and toxicological tests were included in the test panel with the aim to fill possible analytical gaps, for example, mutagenic potency of polycyclic aromatic hydrocarbons (PAH) and their nitrated derivatives (nPAH). This investigation focuses on the effect of a DOC on health hazards from combustion of four different fuels: rapeseed methyl ester (RME), common mineral diesel fuel (DF), SHELL V-Power Diesel (V-Power), and ARAL Ultimate Diesel containing 5% RME (B5ULT). We applied the European Stationary Cycle (ESC) to a 6.4 L turbo-charged heavy load engine fulfilling the EURO III standard. The engine was operated with and without DOC. Besides regulated emissions we measured particle size and number distributions, determined the soluble and solid fractions of the particles and characterized the bacterial mutagenicity in the gas phase and the particles of the exhaust. The effectiveness of the DOC differed strongly in regard to the different exhaust constituents: Total hydrocarbons were reduced up to 90% and carbon monoxide up to 98%, whereas nitrogen oxides (NO(X)) remained almost unaffected. Total particle mass (TPM) was reduced by 50% with DOC in common petrol diesel fuel and by 30% in the other fuels. This effect was mainly due to a reduction of the soluble organic particle fraction. The DOC caused an increase of the water-soluble fraction in the exhaust of RME, V-Power, and B5ULT, as well as a pronounced increase of nitrate in all exhausts. A high proportion of ultrafine particles (10-30 nm) in RME exhaust could be ascribed to vaporizable particles. Mutagenicity of the exhaust was low compared to previous investigations. The DOC reduced

Workplace exposure and release of ultrafine particles during atmospheric plasma spraying in the ceramic industry.

PubMed

Viana, M; Fonseca, A S; Querol, X; López-Lilao, A; Carpio, P; Salmatonidis, A; Monfort, E

2017-12-01

Atmospheric plasma spraying (APS) is a frequently used technique to produce enhanced-property coatings for different materials in the ceramic industry. This work aimed to characterise and quantify the impact of APS on workplace exposure to airborne particles, with a focus on ultrafine particles (UFPs, <100nm) and nanoparticles (<50nm). Particle number, mass concentrations, alveolar lung deposited surface area concentration, and size distributions, in the range 10nm-20μm were simultaneously monitored at the emission source, in the potential worker breathing zone, and in outdoor air. Different input materials (known as feedstock) were tested: (a) micron-sized powders, and (b) suspensions containing submicron- or nano-sized particles. Results evidenced significantly high UFP concentrations (up to 3.3×10 6 /cm 3 ) inside the spraying chamber, which impacted exposure concentrations in the worker area outside the spraying chamber (up to 8.3×10 5 /cm 3 ). Environmental release of UFPs was also detected (3.9×10 5 /cm 3 , outside the exhaust tube). Engineered nanoparticle (ENP) release to workplace air was also evidenced by TEM microscopy. UFP emissions were detected during the application of both micron-sized powder and suspensions containing submicron- or nano-sized particles, thus suggesting that emissions were process- (and not material-) dependent. An effective risk prevention protocol was implemented, which resulted in a reduction of UFP exposure in the worker area. These findings demonstrate the potential risk of occupational exposure to UFPs during atmospheric plasma spraying, and raise the need for further research on UFP formation mechanisms in high-energy industrial processes. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Nucleation mode particles with a nonvolatile core in the exhaust of a heavy duty diesel vehicle.

PubMed

Rönkkö, Topi; Virtanen, Annele; Kannosto, Jonna; Keskinen, Jorma; Lappi, Maija; Pirjola, Liisa

2007-09-15

The characteristics of the nucleation mode particles of a Euro IV heavy-duty diesel vehicle exhaust were studied. The NOx and PM emissions of the vehicle were controlled through the use of cooled EGR and high-pressure fuel injection techniques; no exhaust gas after-treatment was used. Particle measurements were performed in vehicle laboratory and on road. Nucleation mode dominated the particle number size distribution in all the tested driving conditions. According to the on-road measurements, the nucleation mode was already formed after 0.7 s residence time in the atmosphere and no significant changes were observed for longer residence times. The nucleation mode was insensitive to the fuel sulfur content, dilution air temperature, and relative humidity. An increase in the dilution ratio decreased the size of the nucleation mode particles. This behavior was observed to be linked to the total hydrocarbon concentration in the diluted sample. In volatility measurements, the nucleation mode particles were observed to have a nonvolatile core with volatile species condensed on it. The results indicate that the nucleation mode particles have a nonvolatile core formed before the dilution process. The core particles have grown because of the condensation of semivolatile material, mainly hydrocarbons, during the dilution.

Basophil mediated pro-allergic inflammation in vehicle-emitted particles exposure.

PubMed

Zakharenko, Alexander M; Engin, Ayse Basak; Chernyshev, Valery V; Chaika, Vladimir V; Ugay, Sergey M; Rezaee, Ramin; Karimi, Gholamreza; Drozd, Vladimir A; Nikitina, Anna V; Solomennik, Sergey F; Kudryavkina, Olga R; Xin, Liu; Wenpeng, Yuan; Tzatzarakis, Manolis; Tsatsakis, Aristidis M; Golokhvast, Kirill S

2017-01-01

Despite of the fact that engine manufacturers develop a new technology to reduce exhaust emissions, insufficient attention given to particulate emissions. However, diesel exhaust particles are a major source of air-borne pollution, contain vast amount of polycyclic aromatic hydrocarbons (PAHs) and may have deleterious effects on the immune system, resulting in the induction and enhancement of pro-allergic processes. In the current study, vehicle emitted particles (VEP) from 2 different types of cars (diesel - D and gasoline - G) and locomotive (L) were collected. Overall, 129 four-week-old, male SPF-class Kunming mice were subcutaneously instilled with either low dose 100, 250 or high dose, 500mg/kg VEP and 15 mice were assigned as control group. The systemic toxicity was evaluated and alterations in the percentages of the CD3, CD4, CD8, CD16, CD25 expressing cells, basophils, eosinophils and neutrophils were determined. Basophil percentages were inversely associated with the PAH content of the VEPs, however basophil sensitization was more important than cell count in VEP exposure. Thus, the effects of VEP-PAHs emerge with the activation of basophils in an allergen independent fashion. Despite the increased percentage of CD4+ T cells, a sharp decrease in basophil counts at 500mg/kg of VEP indicates a decreased inhibitory effect of CD16+ monocytes on the proliferation of CD4+ T cell and suppressed polarization into a Th2 phenotype. Therefore, although the restrictions for vehicles emissions differ between countries, follow up studies and strict regulations are needed. Copyright © 2016 Elsevier Inc. All rights reserved.

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...

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

Personal exposure to ultrafine particles.

PubMed

Wallace, Lance; Ott, Wayne

2011-01-01

Personal exposure to ultrafine particles (UFP) can occur while people are cooking, driving, smoking, operating small appliances such as hair dryers, or eating out in restaurants. These exposures can often be higher than outdoor concentrations. For 3 years, portable monitors were employed in homes, cars, and restaurants. More than 300 measurement periods in several homes were documented, along with 25 h of driving two cars, and 22 visits to restaurants. Cooking on gas or electric stoves and electric toaster ovens was a major source of UFP, with peak personal exposures often exceeding 100,000 particles/cm³ and estimated emission rates in the neighborhood of 10¹² particles/min. Other common sources of high UFP exposures were cigarettes, a vented gas clothes dryer, an air popcorn popper, candles, an electric mixer, a toaster, a hair dryer, a curling iron, and a steam iron. Relatively low indoor UFP emissions were noted for a fireplace, several space heaters, and a laser printer. Driving resulted in moderate exposures averaging about 30,000 particles/cm³ in each of two cars driven on 17 trips on major highways on the East and West Coasts. Most of the restaurants visited maintained consistently high levels of 50,000-200,000 particles/cm³ for the entire length of the meal. The indoor/outdoor ratios of size-resolved UFP were much lower than for PM₂.₅ or PM₁₀, suggesting that outdoor UFP have difficulty in penetrating a home. This in turn implies that outdoor concentrations of UFP have only a moderate effect on personal exposures if indoor sources are present. A time-weighted scenario suggests that for typical suburban nonsmoker lifestyles, indoor sources provide about 47% and outdoor sources about 36% of total daily UFP exposure and in-vehicle exposures add the remainder (17%). However, the effect of one smoker in the home results in an overwhelming increase in the importance of indoor sources (77% of the total).

Damage of natural stone tablets exposed to exhaust gas under laboratory conditions

NASA Astrophysics Data System (ADS)

Farkas, Orsolya; Szabados, György; Török, Ákos

2016-04-01

Natural stone tablets were exposed to exhaust gas under laboratory conditions to assess urban stone damage. Cylindrical test specimens (3 cm in diameter) were made from travertine, non-porous limestone, porous limestone, rhyolite tuff, sandstone, andesite, granite and marble. The samples were exposed to exhaust gas that was generated from diesel engine combustion (engine type: RÁBA D10 UTSLL 160, EURO II). The operating condition of the internal combustion engine was: 1300 r/m (app 50%). The exhaust gas was diverted into a pipe system where the samples were placed perpendicular to main flow for 1, 2, 4, 8 and 10 hours, respectively. The exhaust emission was measured by using AVL particulate measurement technology; filter paper method (AVL 415). The stone samples were documented and selective parameters were measured prior to and after exhaust gas exposure. Density, volume, ultrasonic pulse velocity, mineral composition and penetration depth of emission related particulate matter were recorded. The first results indicate that after 10 hours of exposure significant amount of particulate matter deposited on the stone surface independently from the surface properties and porosity. The black soot particles uniformly covered all types of stones, making hard to differentiate the specimens.

Exposure to carcinogenic polycyclic aromatic compounds and health risk assessment for diesel-exhaust exposed workers.

PubMed

Sauvain, J-J; Vu Duc, T; Guillemin, M

2003-07-01

Workers' exposure to diesel exhaust in a bus depot, a truck repair workshop and an underground tunnel was determined by the measuring of elemental carbon (EC) and 15 carcinogenic polycyclic aromatic compounds (PACs) proposed by the US Department of Health and Human Services/National Toxicology Program (NTP). Based on these concentration data, the genotoxic PAC contribution to the diesel-exhaust particle (DEP) lung-cancer risk was calculated. Respirable particulate matter was collected during the summer and winter of 2001 (except for in the underground situation) and analysed by coulometry for EC and by GC-MS methods for PACs. The use of potency equivalence factors (PEFs) allowed the studied PAC concentrations to be expressed as benzo[a]pyrene equivalents (B[a]P(eq)). We then calculated the lung-cancer risk due to PACs and DEPs by multiplying the B[a]P(eq) and EC concentrations by the corresponding unit risk factor. The ratio of these two risks values has been considered as an estimate of the genotoxic contribution to the DEP cancer risk. For the bus depot and truck repair workshop, exposure to EC and PACs has been shown to increase by three to six times and ten times, respectively, during winter compared to summer. This increase has been attributed mainly to a decrease in ventilation during the cold. With the PEF approach, the B[a]P(eq) concentration is five-times higher than if only benzo[ a]pyrene (B[a]P) is considered. Dibenzopyrenes contribute an important part to this increase. A simple calculation based on unit risk factors indicates that the studied PAC contribution to the total lung-cancer risk attributed to DEPs is in the range of 3-13%. The 15 NTP PACs represent a small but non-negligible part of lung-cancer risk with regard to diesel exposure. From this point of view, the dibenzopyrene family are important compounds to be considered.

Mutagenicity of diesel exhaust particle extracts: influence of fuel composition in two diesel engines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clark, C.R.; Henderson, T.R.; Royer, R.E.

The influence of diesel fuel composition on mutagenicity of exhaust particle associated organic compounds has been investigated using nine fuels varying in aromatic content and distillation properties. The tests were conducted with Oldsmobile Delta-88 and Peugot 504 diesel cars operated according to the EPA Federal Test Procedure. The particulate exhaust from each test was collected on a filter, extracted in dichloromethane and the resulting extract evaluated for mutagenicity in Salmonella strain TA-100. Mutagenicity of extracts of particles collected from the Oldsmobile were highest in the higher aromatic content fuels (> 30%) but similar for intermediate (20%) and low (13%) aromaticmore » content fuels. No influence of aromaticity on mutagenicity was observed in samples collected from the Peugeot under the same conditions. Thus, fuel aromatic content may enhance the production of mutagenic combustion products at higher concentrations, but may be dependent upon engine type. A good correlation was observed between mutagenicity of the particle extracts and the initial boiling point of the fuel (r = 0.89). Gas chromatography/mass spectrometric analysis of the aromatic fraction of the fuels showed that the fuel producing the most mutagenic combustion products was highest in phenanthrene type compounds.« less

The Diesel Exhaust in Miners Study: IV. Estimating historical exposures to diesel exhaust in underground non-metal mining facilities.

PubMed

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

2010-10-01

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

Exposure to ultrafine particles and black carbon in diesel-powered commuter trains

NASA Astrophysics Data System (ADS)

Jeong, Cheol-Heon; Traub, Alison; Evans, Greg J.

2017-04-01

Ultrafine particle (UFP), black carbon (BC) and lung deposited surface area (LDSA) concentrations measured during 43 trips on diesel-powered commuter trains revealed elevated exposures under some conditions. When the passenger coaches were pulled by a locomotive, the geometric mean concentrations of UFP, LDSA, and BC were 18, 10, and 6 times higher than the exposure levels when the locomotive pushed the coaches, respectively. In addition, UFP, LDSA, and BC concentrations in pull-trains were 5, 3, and 4 times higher than concentrations measured while walking on city sidewalks, respectively. Exposure to these pollutants was most elevated in the coach located closest to the locomotive: geometric means were 126,000 # cm-3 for UFP, 249 μm2 cm-3 for LDSA, and 17,800 ng m-3 of BC; these concentrations are much higher than those previously reported for other modes of public transportation. Markedly high levels of diesel exhaust are present in passenger trains powered by diesel locomotives operated in pull-mode. Thus, it is recommended that immediate steps be taken to evaluate, and where needed, mitigate exposure in diesel-powered passenger trains, both commuter and inter-city.

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. © 2015 Society for Risk Analysis.

Changes in rat respiratory system produced by exposure to exhaust gases of combustion of glycerol.

PubMed

Serra, Daniel Silveira; Evangelista, Janaína Serra Azul Monteiro; Zin, Walter Araujo; Leal-Cardoso, José Henrique; Cavalcante, Francisco Sales Ávila

2017-08-01

The combustion of residual glycerol to generate heat in industrial processes has been suggested as a cost-effective solution for disposal of this environmental liability. Thus, we investigated the effects of exposure to the exhaust gases of glycerol combustion in the rat respiratory system. We used 2 rats groups, one exposed to the exhaust gases from glycerol combustion (Glycerol), and the other exposed to ambient air (Control). Exposure occurred 5h a day, 5days a week for 13 weeks. We observed statistically changes in all parameters of respiratory system mechanics in vivo. This results was supported by histological analysis and morphometric data, confirming narrower airways and lung parenchimal changes. Variables related to airway resistance (ΔR N ) and elastic properties of the tissue (ΔH), increased after challenge with methacholine. Finally, analysis of lung tissue micromechanics showed statistically increases in all parameters (R, E and hysteresivity). In conclusion, exhaust gases from glycerol combustion were harmful to the respiratory system. Copyright © 2017 Elsevier B.V. All rights reserved.

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...

Effects of gasoline and ethanol-gasoline exhaust exposure on human bronchial epithelial and natural killer cells in vitro.

PubMed

Roth, Michèle; Usemann, Jakob; Bisig, Christoph; Comte, Pierre; Czerwinski, Jan; Mayer, Andreas C R; Beier, Konstantin; Rothen-Rutishauser, Barbara; Latzin, Philipp; Müller, Loretta

2017-12-01

Air pollution exposure, including passenger car emissions, may cause substantial respiratory health effects and cancer death. In western countries, the majority of passenger cars are driven by gasoline fuel. Recently, new motor technologies and ethanol fuels have been introduced to the market, but potential health effects have not been thoroughly investigated. We developed and verified a coculture model composed of bronchial epithelial cells (ECs) and natural killer cells (NKs) mimicking the human airways to compare toxic effects between pure gasoline (E0) and ethanol-gasoline-blend (E85, 85% ethanol, 15% gasoline) exhaust emitted from a flexfuel gasoline car. We drove a steady state cycle, exposed ECs for 6h and added NKs. We assessed exhaust effects in ECs alone and in cocultures by RT-PCR, flow cytometry, and oxidative stress assay. We found no toxic effects after exposure to E0 or E85 compared to air controls. Comparison between E0 and E85 exposure showed a weak association for less oxidative DNA damage after E85 exposure compared to E0. Our results indicate that short-term exposure to gasoline exhaust may have no major toxic effects in ECs and NKs and that ethanol as part of fuel for gasoline cars may be favorable. Copyright © 2017 Elsevier Ltd. All rights reserved.

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/

Chemical characterization of freshly emitted particulate matter from aircraft exhaust using single particle mass spectrometry

NASA Astrophysics Data System (ADS)

Abegglen, Manuel; Brem, B. T.; Ellenrieder, M.; Durdina, L.; Rindlisbacher, T.; Wang, J.; Lohmann, U.; Sierau, B.

2016-06-01

Non-volatile aircraft engine emissions are an important anthropogenic source of soot particles in the upper troposphere and in the vicinity of airports. They influence climate and contribute to global warming. In addition, they impact air quality and thus human health and the environment. The chemical composition of non-volatile particulate matter emission from aircraft engines was investigated using single particle time-of-flight mass spectrometry. The exhaust from three different aircraft engines was sampled and analyzed. The soot particulate matter was sampled directly behind the turbine in a test cell at Zurich Airport. Single particle analyses will focus on metallic compounds. The particles analyzed herein represent a subset of the emissions composed of the largest particles with a mobility diameter >100 nm due to instrumental restrictions. A vast majority of the analyzed particles was shown to contain elemental carbon, and depending on the engine and the applied thrust the elemental carbon to total carbon ratio ranged from 83% to 99%. The detected metallic compounds were all internally mixed with the soot particles. The most abundant metals in the exhaust were Cr, Fe, Mo, Na, Ca and Al; V, Ba, Co, Cu, Ni, Pb, Mg, Mn, Si, Ti and Zr were also detected. We further investigated potential sources of the ATOFMS-detected metallic compounds using Inductively Coupled Plasma Mass Spectrometry. The potential sources considered were kerosene, engine lubrication oil and abrasion from engine wearing components. An unambiguous source apportionment was not possible because most metallic compounds were detected in several of the analyzed sources.

Investigation into pedestrian exposure to near-vehicle exhaust emissions

PubMed Central

2009-01-01

Background Inhalation of diesel particulate matter (DPM) is known to have a negative impact on human health. Consequently, there are regulations and standards that limit the maximum concentrations to which persons may be exposed and the maximum concentrations allowed in the ambient air. However, these standards consider steady exposure over large spatial and time scales. Due to the nature of many vehicle exhaust systems, pedestrians in close proximity to a vehicle's tailpipe may experience events where diesel particulate matter concentrations are high enough to cause acute health effects for brief periods of time. Methods In order to quantify these exposure events, instruments which measure specific exhaust constituent concentrations were placed near a roadway and connected to the mouth of a mannequin used as a pedestrian surrogate. By measuring concentrations at the mannequin's mouth during drive-by events with a late model diesel truck, a representative estimate of the exhaust constituent concentrations to which a pedestrian may be exposed was obtained. Typical breathing rates were then multiplied by the measured concentrations to determine the mass of pollutant inhaled. Results The average concentration of diesel particulate matter measured over the duration of a single drive-by test often exceeded the low concentrations used in human clinical studies which are known to cause acute health effects. It was also observed that higher concentrations of diesel particulate matter were measured at the height of a stroller than were measured at the mouth of a mannequin. Conclusion Diesel particulate matter concentrations during drive-by incidents easily reach or exceed the low concentrations that can cause acute health effects for brief periods of time. For the case of a particularly well-tuned late-model year vehicle, the mass of particulate matter inhaled during a drive-by incident is small compared to the mass inhaled daily at ambient conditions. On a per breath basis

Diesel Exhaust and Lung Cancer-Aftermath of Becoming an IARC Group 1 Carcinogen.

PubMed

Silverman, Debra T

2018-06-01

The International Agency for Research on Cancer reclassified diesel exhaust from Group 2A (probably carcinogenic to humans) to Group 1 (carcinogenic to humans) in 2012. Since then, reevaluation and reanalysis of 2 major studies (Diesel Exhaust in Miners Study and Trucking Industry Particle Study) that were influential to the International Agency for Research on Cancer evaluation have replicated the original findings and demonstrated the suitability of these epidemiologic data for the quantitative risk assessment needed to set safe exposure limits in occupational and outdoor ambient environments. The challenge now is to protect the workers and general populations in urban areas from the carcinogenicity of diesel exhaust.

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...

Mutagenicity of diesel exhaust particle extracts: influence of fuel composition in two diesel engines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clark, C.R.; Henderson, T.R.; Royer, R.E.

The influence of diesel fuel composition on mutagenicity of exhaust particle associated organic compounds has been investigated using nine fuels varying in aromatic content and distillation properties. The tests were conducted with Oldsmobile Delta-88 and Peugot 504 diesel cars operated according to the EPA Federal Test Procedure. The particulate exhaust from each test was collected on a filter, extracted in dichloromethane and the resulting extract evaluated for mutagenicity in Salmonella strain TA-100. Mutagenicity of extracts of particles collected from the Oldsmobile were highest in the higher aromatic content fuels (greater than 30%) but similar for intermediate (20%) and low (13%)more » aromatic content fuels. No influence of aromaticity on mutagenicity was observed in samples collected from the Peugeot under the same conditions. Thus, fuel aromatic content may enhance the production of mutagenic combustion products at higher concentrations, but may be dependent upon engine type. A good correlation was observed between mutagenicity of the particle extracts and the initial boiling point of the fuel (r . 0.89). Gas chromatography/mass spectrometric analysis of the aromatic fraction of the fuels showed that the fuel producing the most mutagenic combustion products was highest in phenanthrene type compounds.« less

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...

Lactate and pH evaluation in exhausted humans with prolonged TASER X26 exposure or continued exertion.

PubMed

Ho, Jeffrey D; Dawes, Donald M; Cole, Jon B; Hottinger, Julie C; Overton, Kenneth G; Miner, James R

2009-09-10

Safety concerns about TASER Conducted Electrical Weapon (CEW) use and media reports of deaths after exposure have been expressed. CEWs are sometimes used on exhausted subjects to end resistance. The alternative is often a continued struggle. It is unclear if CEW use is metabolically different than allowing a continued struggle. We sought to determine if CEW exposure on exhausted humans caused worsening acidosis when compared with continued exertion. This was a prospective study of human volunteers recruited during a CEW training course. Volunteers were from several different occupations and represented a wide range of ages and body mass index characteristics. Medical histories, baseline pH and lactate values were obtained. Patients were assigned to one of four groups: 2 control groups consisting of Exertion only and CEW Exposure only, and the 2 experimental groups that were Exertion plus CEW Exposure and Exertion plus additional Exertion. Blood sampling occurred after Exertion and after any CEW exposure. This was repeated every 2-min until 20 min after protocol completion. Descriptive statistics were used to compare the four groups. The experimental groups and the control groups were compared individually at each time point using Wilcoxon rank sum tests. Lactate and pH association was assessed using multiple linear regression. Forty subjects were enrolled. There were no median pH or lactate differences between CEW Exposure groups at baseline, or between Exertion protocol groups immediately after completion. The CEW Exposure only group had higher pH and lower lactate values at all time points after exposure than the Exertion only group. After completing the Exertion protocol, there was no difference in the pH or lactate values between the continued Exertion group and the CEW Exposure group at any time points. Subjects who had CEW Exposure only had higher pH and lower lactate values than subjects who completed the Exertion protocol only. CEW exposure does not appear

Chrysotile asbestos exposure associated with removal of automobile exhaust systems (ca. 1945-1975) by mechanics: results of a simulation study.

PubMed

Paustenbach, Dennis J; Madl, Amy K; Donovan, Ellen; Clark, Katherine; Fehling, Kurt; Lee, Terry C

2006-03-01

For decades, asbestos-containing gaskets were used in virtually every system that involved the transport of fluids or gases. Prior to the mid-1970s, some automobile exhaust systems contained asbestos gaskets either at flanges along the exhaust pipes or at the exhaust manifolds of the engine. A limited number of automobile mufflers were lined with asbestos paper. This paper describes a simulation study that characterized personal and bystander exposures to asbestos during the removal of automobile exhaust systems (ca. 1945-1975) containing asbestos gaskets. A total of 16 pre-1974 vehicles with old or original exhaust systems were studied. Of the 16 vehicles, 12 contained asbestos gaskets in the exhaust system and two vehicles had asbestos lining inside the muffler. A total of 82 samples (23 personal, 38 bystander, and 21 indoor background) were analyzed by Phase Contrast Microscopy (PCM) and 88 samples (25 personal, 41 bystander, and 22 indoor background) by Transmission Electron Microscopy (TEM). Only seven of 25 worker samples analyzed by TEM detected asbestos fibers and 18 were below the analytical sensitivity limit (mean 0.013 f/cc, range 0.001-0.074 f/cc). Applying the ratio of asbestos fibers:total fibers (including non-asbestos) as determined by TEM to the PCM results showed an average (1 h) adjusted PCM worker exposure of 0.018 f/cc (0.002-0.04 f/cc). The average (1 h) adjusted PCM airborne concentration for bystanders was 0.008 f/cc (range 0.0008-0.015 f/cc). Assuming a mechanic can replace four automobile single exhaust systems in 1 workday, the estimated 8-h time-weighted average (TWA) for a mechanic performing this work was 0.01 f/cc. Under a scenario where a mechanic might repeatedly conduct exhaust work, these results suggest that exposures to asbestos from work with automobile exhaust systems during the 1950s through the 1970s containing asbestos gaskets were substantially below 0.1 f/cc, the current PEL for chrysotile asbestos, and quite often were

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...

Isolation and Quantitative Estimation of Diesel Exhaust and Carbon Black Particles Ingested by Lung Epithelial Cells and Alveolar Macrophages In Vitro

EPA Science Inventory

A new procedure for isolating and estimating ingested carbonaceous diesel exhaust particles (DEP) or carbon black (CB) particles by lung epithelial cells and macrophages is described. Cells were incubated with DEP or CB to examine cell-particle interaction and ingestion. After va...

Concentrations of ultrafine particles at a highway toll collection booth and exposure implications for toll collectors.

PubMed

Cheng, Yu-Hsiang; Huang, Cheng-Hsiung; Huang, Hsiao-Lin; Tsai, Chuen-Jinn

2010-12-15

Research regarding the magnitude of ultrafine particle levels at highway toll stations is limited. This study measured ambient concentrations of ultrafine particles at a highway toll station from October 30 to November 1 and November 5 to November 6, 2008. A scanning mobility particle sizer was used to measure ultrafine particle concentrations at a ticket/cash tollbooth. Levels of hourly average ultrafine particles at the tollbooth were about 3-6 times higher than those in urban backgrounds, indicating that a considerable amount of ultrafine particles are exhausted from passing vehicles. A bi-modal size distribution pattern with a dominant mode at about <6 nm and a minor mode at about 40 nm was observed at the tollbooth. The high amounts of nanoparticles in this study can be attributed to gas-to-particle reactions in fresh fumes emitted directly from vehicles. The influences of traffic volume, wind speed, and relative humidity on ultrafine particle concentrations were also determined. High ambient concentrations of ultrafine particles existed under low wind speed, low relative humidity, and high traffic volume. Although different factors account for high ambient concentrations of ultrafine particles at the tollbooth, measurements indicate that toll collectors who work close to traffic emission sources have a high exposure risk. Copyright © 2010 Elsevier B.V. All rights reserved.

Exposure to particles from laser printers operating within office workplaces.

PubMed

McGarry, Peter; Morawska, Lidia; He, Congrong; Jayaratne, Rohan; Falk, Matthew; Tran, Quang; Wang, Hao

2011-08-01

While recent research has provided valuable information as to the composition of laser printer particles, their formation mechanisms, and explained why some printers are emitters while others are low emitters, questions relating to the potential exposure of office workers remained unanswered. In particular, (i) what impact does the operation of laser printers have on the background particle number concentration (PNC) of an office environment over the duration of a typical working day? (ii) What is the airborne particle exposure to office workers in the vicinity of laser printers? (iii) What influence does the office ventilation have upon the transport and concentration of particles? (iv) Is there a need to control the generation of, and/or transport of particles arising from the operation of laser printers within an office environment? (v) What instrumentation and methodology is relevant for characterizing such particles within an office location? We present experimental evidence on printer temporal and spatial PNC during the operation of 107 laser printers within open plan offices of five buildings. The 8 h time-weighted average printer particle exposure is significantly less than the 8 h time-weighted local background particle exposure, but that peak printer particle exposure can be greater than 2 orders of magnitude higher than local background particle exposure. The particle size range is predominantly ultrafine (<100 nm diameter). In addition we have established that office workers are constantly exposed to nonprinter derived particle concentrations, with up to an order of magnitude difference in such exposure among offices, and propose that such exposure be controlled along with exposure to printer derived particles. We also propose, for the first time, that peak particle reference values be calculated for each office area analogous to the criteria used in Australia and elsewhere for evaluating exposure excursion above occupational hazardous chemical exposure

Occupational Exposure to Diesel Motor Exhaust and Lung Cancer: A Dose-Response Relationship Hidden by Asbestos Exposure Adjustment? The ICARE Study

PubMed Central

Matrat, Mireille; Guida, Florence; Cénée, Sylvie; Févotte, Joelle; Carton, Matthieu; Cyr, Diane; Menvielle, Gwenn; Paget-Bailly, Sophie; Radoï, Loredana; Schmaus, Annie; Bara, Simona; Velten, Michel; Luce, Danièle; Stücker, Isabelle; The Icare Study Group

2015-01-01

Background. In a French large population-based case-control study we investigated the dose-response relationship between lung cancer and occupational exposure to diesel motor exhaust (DME), taking into account asbestos exposure. Methods. Exposure to DME was assessed by questionnaire. Asbestos was taken into account through a global indicator of exposure to occupational carcinogens or by a specific JEM. Results. We found a crude dose response relationship with most of the indicators of DME exposure, including with the cumulative exposure index. All results were affected by adjustment for asbestos exposure. The dose response relationships between DME and lung cancer were observed among subjects never exposed to asbestos. Conclusions. Exposure to DME and to asbestos is frequently found among the same subjects, which may explain why dose-response relationships in previous studies that adjusted for asbestos exposure were inconsistent. PMID:26425123

Motorcycle exhaust particles induce airway inflammation and airway hyperresponsiveness in BALB/C mice.

PubMed

Lee, Chen-Chen; Liao, Jiunn-Wang; Kang, Jaw-Jou

2004-06-01

A number of large studies have reported that environmental pollutants from fossil fuel combustion can cause deleterious effects to the immune system, resulting in an allergic reaction leading to respiratory tract damage. In this study, we investigated the effect of motorcycle exhaust particles (MEP), a major pollutant in the Taiwan urban area, on airway inflammation and airway hyperresponsiveness in laboratory animals. BALB/c mice were instilled intratracheally (i.t.) with 1.2 mg/kg and 12 mg/kg of MEP, which was collected from two-stroke motorcycle engines. The mice were exposed 3 times i.t. with MEP, and various parameters for airway inflammation and hyperresponsiveness were sequentially analyzed. We found that MEP would induce airway and pulmonary inflammation characterized by infiltration of eosinophils, neutrophils, lymphocytes, and macrophages in bronchoalveolar lavage fluid (BALF) and inflammatory cell infiltration in lung. In addition, MEP treatment enhanced BALF interleukin-4 (IL-4), IL-5, and interferon-gamma (IFN-gamma) cytokine levels and serum IgE production. Bronchial response measured by unrestrained plethysmography with methacholine challenge showed that MEP treatment induced airway hyperresponsiveness (AHR) in BALB/c mice. The chemical components in MEP were further fractionated with organic solvents, and we found that the benzene-extracted fraction exerts a similar biological effect as seen with MEP, including airway inflammation, increased BALF IL-4, serum IgE production, and induction of AHR. In conclusion, we present evidence showing that the filter-trapped particles emitted from the unleaded-gasoline-fueled two-stroke motorcycle engine may induce proinflammatory and proallergic response profiles in the absence of exposure to allergen.

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...

Effect of 3-D magnetic fields on neutral particle fueling and exhaust in MAST

NASA Astrophysics Data System (ADS)

Flesch, Kurt; Kremeyer, Thierry; Waters, Ian; Schmitz, Oliver; Kirk, Andrew; Harrison, James

2017-10-01

The application of resonant magnetic perturbations (RMPs) is used to suppress edge localized modes but causes in many cases a density pump-out. At MAST, this particle pump out was found to be connected to an amplifying MHD plasma response. An analysis is presented on past MAST discharges to understand the effect of these RMPs on the neutral household and on changes in neutral fueling and exhaust during the pump out. A global, 0-D particle balance model was used to study the neutral dynamics and plasma confinement during shots with and without RMP application. Using the D α emission measured by filterscopes and a calibrated 1-D CCD camera, as well as S/XB coefficients determined by the edge plasma parameters, globally averaged ion confinement times were calculated. In L-mode, discharges with RMPs that caused an MHD response had a 15-20% decrease in confinement time but an increase in total recycling flux. The application of RMPs in H-mode caused either a decrease or no change in confinement, like those in L-mode, depending on the configuration of the RMPs and plasma response. A spectroscopically assisted Penning gauge is being prepared for the next campaign at MAST-U to extend this particle balance to study impurity exhaust with RMPs. This work was funded in part by the U.S. DoE under Grant DE-SC0012315.

Mass spectrometry profiling reveals altered plasma levels of monohydroxy fatty acids and related lipids in healthy humans after controlled exposure to biodiesel exhaust.

PubMed

Gouveia-Figueira, Sandra; Karimpour, Masoumeh; Bosson, Jenny A; Blomberg, Anders; Unosson, Jon; Sehlstedt, Maria; Pourazar, Jamshid; Sandström, Thomas; Behndig, Annelie F; Nording, Malin L

2018-08-14

Experimental human exposure studies are an effective tool to study adverse health effects from acute inhalation of particulate matter and other constituents of air pollution. In this randomized and double-blinded crossover study, we investigated the systemic effect on bioactive lipid metabolite levels after controlled biodiesel exhaust exposure of healthy humans and compared it to filtered air at a separate exposure occasion. Eicosanoids and other oxylipins, as well as endocannabinoids and related lipids, were quantified in plasma from 14 healthy volunteers at baseline and at three subsequent time points (2, 6, and 24 h) after 1 h exposure sessions. Protocols based on liquid chromatography (LC) coupled to tandem mass spectrometry (MS/MS) methods were developed to detect temporal changes in circulating levels after biodiesel exhaust exposure. The exhaust was generated by a diesel engine fed with an undiluted rapeseed methyl ester fuel. Among the 51 analyzed lipid metabolites, PGF 2α , 9,10-DiHOME, 9-HODE, 5-HETE, 11-HETE, 12-HETE, and DEA displayed significant responsiveness to the biodiesel exhaust exposure as opposed to filtered air. Of these, 9-HODE and 5-HETE at 24 h survived the 10% false discovery rate cutoff (p < 0.003). Hence, the majority of the responsive lipid metabolites were monohydroxy fatty acids. We conclude that it is possible to detect alterations in circulating bioactive lipid metabolites in response to biodiesel exhaust exposure using LC-MS/MS, with emphasis on metabolites with inflammation related properties and implications on cardiovascular health and disease. These observations aid future investigations on air pollution effects, especially with regard to cardiovascular outcomes. Copyright © 2018 Elsevier B.V. All rights reserved.

Exposure to Airborne Particles and Volatile Organic Compounds from Polyurethane Molding, Spray Painting, Lacquering, and Gluing in a Workshop

PubMed Central

Mølgaard, Bjarke; Viitanen, Anna-Kaisa; Kangas, Anneli; Huhtiniemi, Marika; Larsen, Søren Thor; Vanhala, Esa; Hussein, Tareq; Boor, Brandon E.; Hämeri, Kaarle; Koivisto, Antti Joonas

2015-01-01

Due to the health risk related to occupational air pollution exposure, we assessed concentrations and identified sources of particles and volatile organic compounds (VOCs) in a handcraft workshop producing fishing lures. The work processes in the site included polyurethane molding, spray painting, lacquering, and gluing. We measured total VOC (TVOC) concentrations and particle size distributions at three locations representing the various phases of the manufacturing and assembly process. The mean working-hour TVOC concentrations in three locations studied were 41, 37, and 24 ppm according to photo-ionization detector measurements. The mean working-hour particle number concentration varied between locations from 3000 to 36,000 cm−3. Analysis of temporal and spatial variations of TVOC concentrations revealed that there were at least four substantial VOC sources: spray gluing, mold-release agent spraying, continuous evaporation from various lacquer and paint containers, and either spray painting or lacquering (probably both). The mold-release agent spray was indirectly also a major source of ultrafine particles. The workers’ exposure can be reduced by improving the local exhaust ventilation at the known sources and by increasing the ventilation rate in the area with the continuous source. PMID:25849539

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...

RISK ASSESSMENT OF THE INFLAMMOGENIC AND MUTAGENIC EFFECTS OF DIESEL EXHAUST PARTICLES: A SYSTEMS BIOLOGY APPROACH

EPA Science Inventory

Diesel exhaust particulate matter (DEP) is a ubiquitous ambient air contaminant derived from mobile and stationary diesel fuel combustion. Exposure to DEP is associated with carcinogenic and immunotoxic effects in humans and experimental animals. At the cellular level, these heal...

Some Effects of Exposure to Exhaust-gas Streams on Emittance and Thermoelectric Power of Bare-wire Platinum Rhodium - Platinum Thermocouples

NASA Technical Reports Server (NTRS)

Glawe, George E; Shepard, Charles E

1954-01-01

Thermocouples were exposed to exhaust gases from the combustion of propane, 72-octane gasoline, and JP-4 fuel. Exposure increased the emissivity of the thermocouple wire, which increased its radiation error. Two methods are presented for determining the emittance of the wires. The emissivity of a clean platinum rhodium-platinum thermocouple was approximately 0.2 in the temperature range investigated, while the emittance of an exposed thermocouple coated with exhaust residue was about 0.5. The exposure caused negligible change in the thermoelectric power of the thermocouples.

Mechanisms and Implications of Air Pollution Particle Associations with Chemokines

PubMed Central

Seagrave, JeanClare

2008-01-01

Inflammation induced by inhalation of air pollutant particles has been implicated as a mechanism for the adverse health effects associated with exposure to air pollution. The inflammatory response is associated with upregulation of various pro-inflammatory cytokines and chemokines. We have previously shown that diesel exhaust particles (DEP), a significant constituent of air pollution particulate matter in many urban areas, bind and concentrate IL-8, an important human neutrophil-attracting chemokine, and that the chemokine remains biologically active. In this report, we examine possible mechanisms of this association and the effects on clearance of the chemokine. The binding appears to be the result of ionic interactions between negatively charged particles and positively charged chemokine molecules, possibly combined with intercalation into small pores in the particles. The association is not limited to diesel exhaust particles and IL-8: several other particle types also adsorb the chemokine and several other cytokines are adsorbed onto the diesel particles. However, there are wide ranges in the effectiveness of various particle types and various cytokines. Finally, male Fisher 344 rats were intratracheally instilled with chemokine alone or combined with diesel exhaust or silica particles under isofluorane anesthesia. In contrast to silica particles, which do not bind the chemokine, the presence of diesel exhaust particles, which bind the chemokine, prolonged the retention of the chemokine. PMID:18755206

Diesel exhaust causing low-dose irritant asthma with latency?

PubMed

Adewole, Femi; Moore, Vicky C; Robertson, Alastair S; Burge, P S

2009-09-01

Diesel exhaust exposure may cause acute irritant-induced asthma and potentiate allergen-induced asthma. There are no previous reports of occupational asthma due to diesel exhaust. To describe occupational asthma with latency in workers exposed to diesel exhaust in bus garages. The Shield database of occupational asthma notifications in the West Midlands, UK, was searched between 1990 and 2006 for workers where diesel exhaust exposure was thought to be the cause of the occupational asthma. Those without other confounding exposures whose occupational asthma was validated by serial peak expiratory flow (PEF) analysis using Oasys software were included. Fifteen workers were identified with occupational asthma attributed to diesel exhaust. Three had validated new-onset asthma with latency. All worked in bus garages where diesel exhaust exposure was the only likely cause of their occupational asthma. Occupational asthma was confirmed by measures of non-specific reactivity and serial measurements of PEF with Oasys scores of 2.9, 3.73 and 4 (positive score > 2.5). The known non-specific irritant effects of diesel exhaust suggest that this is an example of low-dose irritant-induced asthma and that exposures to diesel exhaust in at least some bus garages are at a sufficient level to cause this.

U.S. EPA health assessment for diesel engine exhaust: a review.

PubMed

Ris, Charles

2007-01-01

In 2002 the U.S. Environmental Protection Agency (EPA) released a Health assessment Document for Diesel Engine Exhaust. The objective of this assessment was to examine the possible health hazards associated with exposure to diesel engine exhaust (DE). The assessment concludes that long-term inhalation exposure is likely to pose a lung cancer hazard to humans as inferred from epidemiologic and certain animal studies. Estimation of cancer potency from available epidemiology studies was not attempted because of the absence of a confident cancer dose-response and animal studies were not judged appropriate for cancer potency estimation. A noncancer chronic human health hazard is inferred from rodent studies which show dose-dependent inflammation and histopathology in the rat lung. For these noncancer effects a safe exposure concentration for humans was estimated. Short-term exposures were noted to cause irritation and inflammatory symptoms of a transient nature, these being highly variable across an exposed population. The assessment also indicates that there is emerging evidence for the exacerbation of existing allergies and asthma symptoms; however, as of 2002 the data were inadequate for quantitative dose-response analysis. The assessment conclusions are based on studies that used exposures from engines built prior to the mid 1990s. More recent engines without high-efficiency particle traps would be expected to have exhaust emissions with similar characteristics. With additional cancer epidemiology studies expected in 2007-2008, and a growing body of evidence for allergenicity and cardiovascular effects, future health assessments will have an expanded health effects data base to evaluate.

Infant leukemia and paternal exposure to motor vehicle exhaust fumes.

PubMed

Vianna, N J; Kovasznay, B; Polan, A; Ju, C

1984-09-01

The children of fathers who work in gas stations, automobile or truck repair, and aircraft maintenance appear to be at increased risk for acute leukemia during their first year of life. The odds ratio was found to be about 2.5 overall, but risk appears to be greater for female offspring. A decline in sex ratio was observed for the three decades of the study, with the lowest ratio observed from 1969 through 1978. These preliminary findings suggest that exposure to one or more of the components of exhaust fumes might be of etiologic importance for this malignancy. The limitations of this investigation are discussed.

Exposure to heavy charged particles affects thermoregulation in rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kandasamy, S.B.; Hunt, W.A.; Dalton, T.K.

1994-09-01

Rats exposed to 0.1-5 Gy of heavy particles ({sup 56}Fe, {sup 40}Ar, {sup 20}Ne or {sup 4}He) showed dose-dependent changes in body temperature. Lower doses of all particles produced hyperthermia, and higher doses of {sup 20}Ne and {sup 56}Fe produced hypothermia. Of the four HZE particles, {sup 56}Fe particles were the most potent and {sup 4}He particles were the least potent in producing changes in thermoregulation. The {sup 20}Ne and {sup 40}Ar particles produced an intermediate level of change in body temperature. Significantly greater hyperthermia was produced by exposure to 1 Gy of {sup 20}Ne, {sup 40}Ar and {sup 56}Femore » particles than by exposure to 1 Gy of {sup 60}Co {gamma} rays. Pretreating rats with the cyclo-oxygenase inhibitor indomethacin attenuated the hyperthermia produced by exposure to 1 Gy of {sup 56}Fe particles, indicating that prostaglandins mediate {sup 56}Fe-particle-induced hyperthermia. The hypothermia produced by exposure to 5 Gy of {sup 56}Fe particles is mediated by histamine and can be attenuated by treatment with the antihistamines mepyramine and cimetidine. 15 refs., 4 figs.« less

Power and Particle Exhaust in Tokamaks

ScienceCinema

Dr. Wojciech Fundamenski

2018-04-19

Dr. Fundamenski provides an introduction to plasma exhaust, specifically relating to the EFDA-JET and ITER projects in Europe. Divertor heat loads, impurity seeding, and disruption experiments are outlined.

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

PubMed Central

Zhou, Haibo; Zhang, Hongtao; Horvath, Katie; Robinette, Carole; Kesic, Matthew; Meyer, Megan; Diaz-Sanchez, David; Jaspers, Ilona

2012-01-01

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. Objectives: Test whether acute exposure to diesel modifies inflammatory responses to influenza virus in normal humans and those with allergies. Methods: We conducted a double-blind, randomized, placebo-controlled study of nasal responses to live attenuated influenza virus in normal volunteers and those with allergic rhinitis exposed to diesel (100 μg/m3) or clean air for 2 hours, followed by standard dose of virus and serial nasal lavages. Endpoints were inflammatory mediators (ELISA) and virus quantity (quantitative reverse-transcriptase polymerase chain reaction). To test for exposure effect, we used multiple regression with exposure group (diesel vs. air) as the main explanatory variable and allergic status as an additional factor. Measurements and Main Results: Baseline levels of mediators did not differ among groups. For most postvirus nasal cytokine responses, there was no significant diesel effect, and no significant interaction with allergy. However, diesel was associated with significantly increased IFN-γ responses (P = 0.02), with no interaction with allergy in the regression model. Eotaxin-1 (P = 0.01), eosinophil cationic protein (P < 0.01), and influenza RNA sequences in nasal cells (P = 0.03) were significantly increased with diesel exposure, linked to allergy. Conclusions: Short-term exposure to diesel exhaust leads to increased eosinophil activation and increased virus quantity after virus inoculation in those with allergic rhinitis. This is consistent with previous literature suggesting a diesel “adjuvant” effect promoting allergic inflammation, and our data further suggest this change may be associated with reduced virus clearance. Clinical trial registered with www.clinicaltrials.gov (NCT00617110). PMID:22071326

Photothermal laser deflection, an innovative technique to measure particles in exhausts

NASA Astrophysics Data System (ADS)

Hess, Cecil F.

1993-10-01

Photothermal Laser Deflection (PLD) is an analytical technique to measure in real-time the mass concentration of particles and gaseous exhaust pollutants in a variety of combustion devices (e.g., gas turbine engines and rockets). PLD uses a pump laser to locally heat the particle or gaseous species, thus changing the refractive index of the surrounding gas to form a thermal lens. A probe laser beam travelling through the thermal lens is temporarily deflected, and the amount of deflection is proportional to the species mass concentration. The experiments and analyses conducted during phase 1 demonstrated the feasibility of PLD in measuring the mass concentration of both soot particles and NO2 at a repetition rate of 25 HZ. PLD response was linear at soot concentrations from 0.3 to 10 mg/cubic meters at NO2 concentrations from approximately 6 to 208 ppm. Strategies to measure lower concentrations have been defined and include focusing the probe beam onto the face of the bi-cell detector. The large dynamic range, fast acquisition rate, and ability to measure particulate and gaseous pollutants makes PLD superior to other available methods.

Historical estimation of diesel exhaust exposure in a cohort study of U.S. railroad workers and lung cancer.

PubMed

Laden, Francine; Hart, Jaime E; Eschenroeder, Alan; Smith, Thomas J; Garshick, Eric

2006-09-01

We have previously shown an elevated risk of lung cancer mortality in diesel exhaust exposed railroad workers. To reduce exposure misclassification, we obtained extensive historical information on diesel locomotives used by each railroad. Starting in 1945, we calculated the rate each railroad converted from steam to diesel, creating annual railroad-specific weighting factors for the probability of diesel exposure. We also estimated the average annual exposure intensity based on emission factors. The U.S. Railroad Retirement Board provided railroad assignment and work histories for 52,812 workers hired between 1939-1949, for whom we ascertained mortality from 1959-1996. Among workers hired after 1945, as diesel locomotives were introduced, the relative risk of lung cancer for any exposure was 1.77 (95% CI = 1.50-2.09), and there was evidence of an exposure-response relationship with exposure duration. Exposed workers hired before 1945 had a relative risk of 1.30 (95% CI = 1.19-1.43) for any exposure and there was no evidence of a dose response with duration. There was no evidence of increasing risk using estimated measures of intensity although the overall lung cancer risk remained elevated. In conclusion, although precise historical estimates of exposure are not available, weighting factors helped better define the exposure-response relationship of diesel exhaust with lung cancer mortality.

Effluent sampling of Scout D and Delta launch vehicle exhausts

NASA Technical Reports Server (NTRS)

Hulten, W. C.; Storey, R. W.; Gregory, G. L.; Woods, D. C.; Harris, F. S., Jr.

1974-01-01

Characterization of engine-exhaust effluents (hydrogen chloride, aluminum oxide, carbon dioxide, and carbon monoxide) has been attempted by conducting field experiments monitoring the exhaust cloud from a Scout-Algol III vehicle launch and a Delta-Thor vehicle launch. The exhaust cloud particulate size number distribution (total number of particles as a function of particle diameter), mass loading, morphology, and elemental composition have been determined within limitations. The gaseous species in the exhaust cloud have been identified. In addition to the ground-based measurements, instrumented aircraft flights through the low-altitude, stabilized-exhaust cloud provided measurements which identified CO and HCI gases and Al2O3 particles. Measurements of the initial exhaust cloud during formation and downwind at several distances have established sampling techniques which will be used for experimental verification of model predictions of effluent dispersion and fallout from exhaust clouds.

Amyotrophic lateral sclerosis and exposure to diesel exhaust in a Danish cohort.

PubMed

Dickerson, Aisha S; Hansen, Johnni; Gredal, Ole; Weisskopf, Marc G

2018-03-24

Previous studies have suggested an increased risk of amyotrophic lateral sclerosis (ALS) and other motor neuron diseases for those in occupations commonly exposed to diesel exhaust (DE). In this study, we investigated the association between occupational exposures to DE and odds of ALS. ALS cases were identified from the Danish National Patient Registry 1982 to 2013 and individually matched to 100 controls per case based on birth year and sex. Using occupational history since 1964 from the Danish Pension Fund, Cumulative DE exposures were estimated using a job exposure matrix. Associations were evaluated using conditional logistic regression analyses and stratified by sex. DE exposure at 10-year lag periods was positively associated with ALS in men ever exposed (aOR: 1.20; 95% CI: 1.05, 1.38). For men with > 50% probability of DE exposure, we observed a positive association with ALS and the highest quartile exposures during the 5-year lag period (aOR: 1.40; 95% CI: 1.11, 1.78) and 10-year lag period (aOR: 1.41; 95% CI: 1.11, 1.79). Our study suggests an association between consistently higher exposures to DE and ALS in men but not in women. These findings support those of previously reported associations between ALS and commonly DE exposed occupations.

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

Lipophilic components of diesel exhaust particles induce pro-inflammatory responses in human endothelial cells through AhR dependent pathway(s).

PubMed

Brinchmann, Bendik C; Skuland, Tonje; Rambøl, Mia H; Szoke, Krisztina; Brinchmann, Jan E; Gutleb, Arno C; Moschini, Elisa; Kubátová, Alena; Kukowski, Klara; Le Ferrec, Eric; Lagadic-Gossmann, Dominique; Schwarze, Per E; Låg, Marit; Refsnes, Magne; Øvrevik, Johan; Holme, Jørn A

2018-05-11

Exposure to traffic-derived particulate matter (PM), such as diesel exhaust particles (DEP), is a leading environmental cause of cardiovascular disease (CVD), and may contribute to endothelial dysfunction and development of atherosclerosis. It is still debated how DEP and other inhaled PM can contribute to CVD. However, organic chemicals (OC) adhered to the particle surface, are considered central to many of the biological effects. In the present study, we have explored the ability of OC from DEP to reach the endothelium and trigger pro-inflammatory reactions, a central step on the path to atherosclerosis. Exposure-relevant concentrations of DEP (0.12 μg/cm 2 ) applied on the epithelial side of an alveolar 3D tri-culture, rapidly induced pro-inflammatory and aryl hydrocarbon receptor (AhR)-regulated genes in the basolateral endothelial cells. These effects seem to be due to soluble lipophilic constituents rather than particle translocation. Extractable organic material of DEP (DEP-EOM) was next fractionated with increasing polarity, chemically characterized, and examined for direct effects on pro-inflammatory and AhR-regulated genes in human microvascular endothelial (HMEC-1) cells and primary human endothelial cells (PHEC) from four healthy donors. Exposure-relevant concentrations of lipophilic DEP-EOM (0.15 μg/cm 2 ) induced low to moderate increases in IL-1α, IL-1β, COX2 and MMP-1 gene expression, and the MMP-1 secretion was increased. By contrast, the more polar EOM had negligible effects, even at higher concentrations. Use of pharmacological inhibitors indicated that AhR and protease-activated receptor-2 (PAR-2) were central in regulation of EOM-induced gene expression. Some effects also seemed to be attributed to redox-responses, at least at the highest exposure concentrations tested. Although the most lipophilic EOM, that contained the majority of PAHs and aliphatics, had the clearest low-concentration effects, there was no straight-forward link

Nitrophenols isolated from diesel exhaust particles promote the growth of MCF-7 breast adenocarcinoma cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Furuta, Chie; Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509; Suzuki, Akira K.

2008-08-01

Diesel exhaust particles (DEPs) cause many adverse health problems, and reports indicate increased risk of breast cancer in men and women through exposure to gasoline and vehicle exhaust. However, DEPs include vast numbers of compounds, and the specific compound(s) responsible for these actions are not clear. We recently isolated two nitrophenols from DEPs-3-methyl-4-nitrophenol (4-nitro-m-cresol; PNMC) and 4-nitro-3-phenylphenol (PNMPP)-and showed that they had estrogenic and anti-androgenic activities. Here, we tried to clarify the involvement of these two nitrophenols in promoting the growth of the MCF-7 breast cancer cell line. First, comet assay was used to detect the genotoxicity of PNMC andmore » PNMPP in a CHO cell line. At all doses tested, PNMC and PNMPP showed negative genotoxicity, indicating that they had no tumor initiating activity. Next, the estrogen-responsive breast cancer cell line MCF-7 was used to assess cell proliferation. Proliferation of MCF-7 cells was stimulated by PNMC, PNMPP, and estradiol-17{beta} and the anti-estrogens 4-hydroxytamoxifen and ICI 182,780 inhibited the proliferation. To further investigate transcriptional activity through the estrogen receptor, MCF-7 cells were transfected with a receptor gene that allowed expression of luciferase enzyme under the control of the estrogen regulatory element. PNMC and PNMPP induced luciferase activity in a dose-dependent manner at submicromolar concentrations. ICI 182,780 inhibited the luciferase activity induced by PNMC and PNMPP. These results clearly indicate that PNMC and PNMPP do not show genotoxicity but act as tumor promoters in an estrogen receptor {alpha}-predominant breast cancer cell line.« less

Mass spectrometry profiling of oxylipins, endocannabinoids, and N-acylethanolamines in human lung lavage fluids reveals responsiveness of prostaglandin E2 and associated lipid metabolites to biodiesel exhaust exposure.

PubMed

Gouveia-Figueira, Sandra; Karimpour, Masoumeh; Bosson, Jenny A; Blomberg, Anders; Unosson, Jon; Pourazar, Jamshid; Sandström, Thomas; Behndig, Annelie F; Nording, Malin L

2017-04-01

The adverse effects of petrodiesel exhaust exposure on the cardiovascular and respiratory systems are well recognized. While biofuels such as rapeseed methyl ester (RME) biodiesel may have ecological advantages, the exhaust generated may cause adverse health effects. In the current study, we investigated the responses of bioactive lipid mediators in human airways after biodiesel exhaust exposure using lipidomic profiling methods. Lipid mediator levels in lung lavage were assessed following 1-h biodiesel exhaust (average particulate matter concentration, 159 μg/m 3 ) or filtered air exposure in 15 healthy individuals in a double-blinded, randomized, controlled, crossover study design. Bronchoscopy was performed 6 h post exposure and lung lavage fluids, i.e., bronchial wash (BW) and bronchoalveolar lavage (BAL), were sequentially collected. Mass spectrometry methods were used to detect a wide array of oxylipins (including eicosanoids), endocannabinoids, N-acylethanolamines, and related lipid metabolites in the collected BW and BAL samples. Six lipids in the human lung lavage samples were altered following biodiesel exhaust exposure, three from BAL samples and three from BW samples. Of these, elevated levels of PGE 2 , 12,13-DiHOME, and 13-HODE, all of which were found in BAL samples, reached Bonferroni-corrected significance. This is the first study in humans reporting responses of bioactive lipids following biodiesel exhaust exposure and the most pronounced responses were seen in the more peripheral and alveolar lung compartments, reflected by BAL collection. Since the responsiveness and diagnostic value of a subset of the studied lipid metabolites were established in lavage fluids, we conclude that our mass spectrometry profiling method is useful to assess effects of human exposure to vehicle exhaust.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kodavanti, Urmila P., E-mail: kodavanti.urmila@epa.gov; Thomas, Ronald F.; Ledbetter, Allen D.

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/daymore » 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

Emodin mitigates diesel exhaust particles-induced increase in airway resistance, inflammation and oxidative stress in mice.

PubMed

Nemmar, Abderrahim; Al-Salam, Suhail; Yuvaraju, Priya; Beegam, Sumaya; Ali, Badreldin H

2015-08-15

Clinical and experimental studies have reported that short-term exposure to particulate air pollution is associated with inflammation, oxidative stress and impairment of lung function. Emodin (1,3,8-trihydroxy-6-methylanthraquinone) has a strong antioxidant and anti-inflammatory actions. Therefore, in the present study, we evaluated the possible ameliorative effect of emodin on diesel exhaust particles (DEP)-induced impairment of lung function, inflammation and oxidative stress in mice. Mice were intratracheally instilled with DEP (20 μg/mouse) or saline (control). Emodin was administered intraperitoneally 1h before and 7h after pulmonary exposure to DEP. Twenty-four hours following DEP exposure, we evaluated airway resistance measured by forced oscillation technique, lung inflammation and oxidative stress. Emodin treatment abated the DEP-induced increase in airway resistance, and prevented the influx of neutrophils in bronchoalveolar lavage fluid. Similarly, lung histopathology confirmed the protective effect of emodin on DEP-induced lung inflammation. DEP induced a significant increase of proinflammatory cytokines in the lung including tumor necrosis factor α, interleukin 6 and interleukin 1β. The latter effect was significantly ameliorated by emodin. DEP caused a significant increase in lung lipid peroxidation, reactive oxygen species and a significant decrease of reduced glutathione concentration. These effects were significantly mitigated by emodin. We conclude that emodin significantly mitigated DEP-induced increase of airway resistance, lung inflammation and oxidative stress. Pending further pharmacological and toxicological studies, emodin may be considered a potentially useful pulmonary protective agent against particulate air pollution-induced lung toxicity. Copyright © 2015 Elsevier B.V. All rights reserved.

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.

DIESEL EXHAUST PARTICULATE (DEP)-INDUCED ACTIV ATION OF STAT3 REQUIRES ACTIVITIES OF EGFR AND SRC IN AIRWAY EPITHELIAL CELLS

EPA Science Inventory

In vivo exposure to diesel exhaust particles (DEP) elicits acute inflammatory responses in the lung characterized by inflammatory cell influx and elevated expression of mediators such as cytokines, and chemokines. Signal transducers and activators of transcription (STAT) protein...

[Organic brain damage in garage workers after long-term exposure to diesel exhaust fumes].

PubMed

Jensen, L K; Klausen, H; Elsnab, C

1989-09-04

Diesel motors are employed to an increasing extent for occupational transport and fumes from diesel driven vehicles constitute an increasing problem as regards atmospheric pollution but, in particular, they constitute a considerable risk to health for the workers exposed to diesel exhaust fumes in their daily work. In the clinic for occupational medicine, The University Hospital, Copenhagen, 14 garage workers were examined. Eleven of these had been exposed to great quantities of diesel exhaust fumes for 2 to 29 years. All 11 presented acute symptoms due to diesel exhaust fumes in the form of headache, vertigo, fatigue, irritation of mucous membranes, nausea, abdominal discomfort or diarrhoea. Seven persons had been employed for more than five years as garage workers. Six complained of failure of memory, difficulty in concentration, irritability, increased sleep requirement, psychological changes or reduced libido. Neuropsychological examination was undertaken in these six persons and in five of them organic brain damage, mainly of slight extent, was demonstrated. Diesel exhaust fumes contain many toxic substances: carbon monoxide, nitrous gases, sulphur oxides, aldehydes and hydrocarbons. It is not possible to indicate a single compound which is responsible for possible brain damage and a combination effect may well be concerned. This is a casuistic material. Only few investigations have previously been available which illustrated a possible connection between the neurotoxic effects and, in particular, brain damage. It is now considered important to emphasize that this may constitute a problem on exposure to diesel exhaust fumes.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrafine and respirable particle exposure during vehicle fire suppression.

PubMed

Evans, Douglas E; Fent, Kenneth W

2015-10-01

Vehicle fires are a common occurrence, yet few studies have reported exposures associated with burning vehicles. This article presents an assessment of firefighters' potential for ultrafine and respirable particle exposure during vehicle fire suppression training. Fires were initiated within the engine compartment and passenger cabins of three salvaged vehicles, with subsequent water suppression by fire crews. Firefighter exposures were monitored with an array of direct reading particle and air quality instruments. A flexible metallic duct and blower drew contaminants to the instrument array, positioned at a safe distance from the burning vehicles, with the duct inlet positioned at the nozzle operator's shoulder. The instruments measured the particle number, active surface area, respirable particle mass, photoelectric response, aerodynamic particle size distributions, and air quality parameters. Although vehicle fires were suppressed quickly (<10 minutes), firefighters may be exposed to short duration, high particle concentration episodes during fire suppression, which are orders of magnitude greater than the ambient background concentration. A maximum transient particle concentration of 1.21 × 10(7) particles per cm(3), 170 mg m(-3) respirable particle mass, 4700 μm(2) cm(-3) active surface area and 1400 (arbitrary units) in photoelectric response were attained throughout the series of six fires. Expressed as fifteen minute time-weighted averages, engine compartment fires averaged 5.4 × 10(4) particles per cm(3), 0.36 mg m(-3) respirable particle mass, 92 μm(2) cm(-3) active particle surface area and 29 (arbitrary units) in photoelectric response. Similarly, passenger cabin fires averaged 2.04 × 10(5) particles per cm(3), 2.7 mg m(-3) respirable particle mass, 320 μm(2) cm(-3) active particle surface area, and 34 (arbitrary units) in photoelectric response. Passenger cabin fires were a greater potential source of exposure than engine compartment fires. The

Ultrafine and respirable particle exposure during vehicle fire suppression

PubMed Central

Fent, Kenneth W.

2015-01-01

Vehicle fires are a common occurrence, yet few studies have reported exposures associated with burning vehicles. This article presents an assessment of firefighters’ potential for ultrafine and respirable particle exposure during vehicle fire suppression training. Fires were initiated within the engine compartment and passenger cabins of three salvaged vehicles, with subsequent water suppression by fire crews. Firefighter exposures were monitored with an array of direct reading particle and air quality instruments. A flexible metallic duct and blower drew contaminants to the instrument array, positioned at a safe distance from the burning vehicles, with the duct inlet positioned at the nozzle operator’s shoulder. The instruments measured the particle number, active surface area, respirable particle mass, photoelectric response, aerodynamic particle size distributions, and air quality parameters. Although vehicle fires were suppressed quickly (<10 minutes), firefighters may be exposed to short duration, high particle concentration episodes during fire suppression, which are orders of magnitude greater than the ambient background concentration. A maximum transient particle concentration of 1.21 × 107 particles per cm3, 170 mg m−3 respirable particle mass, 4700 μm2 cm−3 active surface area and 1400 (arbitrary units) in photoelectric response were attained throughout the series of six fires. Expressed as fifteen minute time-weighted averages, engine compartment fires averaged 5.4 × 104 particles per cm3, 0.36 mg m−3 respirable particle mass, 92 μm2 cm−3 active particle surface area and 29 (arbitrary units) in photoelectric response. Similarly, passenger cabin fires averaged 2.04 × 105 particles per cm3, 2.7 mg m−3 respirable particle mass, 320 μm2 cm−3 active particle surface area, and 34 (arbitrary units) in photoelectric response. Passenger cabin fires were a greater potential source of exposure than engine compartment fires. The wind direction

Diesel exhaust particle promotes tumor lung metastasis via the induction of BLT1-mediated neutrophilic lung inflammation.

PubMed

Li, Wenjing; Liu, Ting; Xiong, Yingluo; Lv, Jiaoyan; Cui, Xinyi; He, Rui

2018-06-05

BLT1, the primary functional receptor of Leukotriene B4 (LTB4), is involved in tissue inflammation by mediating leukocyte recruitment, and recently LTB4-dependent inflammation was reported to promote lung tumor growth. Exposure to diesel exhaust particle (DEP), the major component of particulate matter 2.5 (PM 2.5 ), can elicit lung inflammation, which may increase the risk of lung cancer. However, it remains unknown about the critical factors mediating DEP-induced lung inflammation and the subsequent effect on tumor metastasis. In this study, we found that DEP exposure led to acute lung inflammation, characterized by abundant infiltration of neutrophils and elevated lung levels in LTB4, as well as several pro-inflammatory cytokines and chemokines, including IL-1β, IL-6, TNF-α, CXCL1/2. Furthermore, DEP exposure promoted lung metastasis of 3LL and 4T1 cells. BLT1 blockade by its specific antagonist U75302 significantly inhibited neutrophilic lung inflammation following DEP exposure. Importantly, BLT1 blockade before the onset of inflammation significantly reduced DEP-enhanced lung metastasis, which was associated with greatly decreased infiltrating neutrophils in lungs. Interestingly, BLT1 blockade after the occurrence of lung metastases had no effect on the magnitude of lung metastasis, suggesting that inhibition of BLT1-mediated lung inflammation was insufficient to suppress established metastatic tumor. Administration of BLT2 inhibitor LY255283 fails to inhibit DEP-induced lung inflammation and tumor metastasis. Collectively, our results demonstrate that DEP exposure causes BLT1-mediated lung neutrophilic inflammation, which is critical for tumor lung metastasis, and suggest that interruption of the LTB4-BLT1 axis could be useful for preventing PM 2.5 -induced inflammation and subsequent susceptible to lung metastasis. Copyright © 2018 Elsevier Ltd. All rights reserved.

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...

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

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

Response of selected plant and insect species to simulated solid rocket exhaust mixtures and to exhaust components from solid rocket fuels

NASA Technical Reports Server (NTRS)

Heck, W. W.; Knott, W. M.; Stahel, E. P.; Ambrose, J. T.; Mccrimmon, J. N.; Engle, M.; Romanow, L. A.; Sawyer, A. G.; Tyson, J. D.

1980-01-01

The effects of solid rocket fuel (SRF) exhaust on selected plant and and insect species in the Merritt Island, Florida area was investigated in order to determine if the exhaust clouds generated by shuttle launches would adversely affect the native, plants of the Merritt Island Wildlife Refuge, the citrus production, or the beekeeping industry of the island. Conditions were simulated in greenhouse exposure chambers and field chambers constructed to model the ideal continuous stirred tank reactor. A plant exposure system was developed for dispensing and monitoring the two major chemicals in SRF exhaust, HCl and Al203, and for dispensing and monitoring SRF exhaust (controlled fuel burns). Plants native to Merritt Island, Florida were grown and used as test species. Dose-response relationships were determined for short term exposure of selected plant species to HCl, Al203, and mixtures of the two to SRF exhaust.

Protective effect of quercetin on the reproductive toxicity of 4-nitrophenol in diesel exhaust particles on male embryonic chickens.

PubMed

Mi, Yuling; Zhang, Caiqiao; Li, Chun Mei; Taneda, Shinji; Watanabe, Gen; Suzuki, Akira K; Taya, Kazuyoshi

2010-04-01

The 4-nitrophenol (PNP) in diesel exhaust particles (DEP) has been identified as a vasodilator and is a known degradation product of the insecticide parathion. In this study, the protective effect of quercetin, a potent oxygen free radical scavenger and metal chelator, against the oxidative damage of PNP on cultured testicular cells was studied in male embryonic chickens. Testicular cells from Day 18 embryos were cultured in serum-free McCoy's 5A medium and challenged with quercetin (1.0 microg/ml) alone or in combinations with PNP (10(-7)-10(-5) M) for 48 h. The oxidative damage was estimated by measuring cell viability, content of malondialdehyde (MDA), activity of superoxide dismutase (SOD) and glutathione peroxidation (GSH-Px) activity. The results showed that exposure to PNP (10(-5) M) induced condensed nuclei, vacuolated cytoplasm and a decrease in testicular cell viability and spermatogonial cell number. Exposure to PNP induced lipid peroxidation by elevation of the content of MDA. Exposure to PNP also decreased GSH-Px activity and SOD activity. However, simultaneous supplementation with quercetin restored these parameters to the same levels as the control. Consequently, PNP induced oxidative stress in spermatogonial cells, and dietary quercetin may attenuate the reproductive toxicity of PNP to restore the intracellular antioxidant system in the testicular cells of embryonic chickens.

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...

Submicron particle monitoring of paving and related road construction operations.

PubMed

Freund, Alice; Zuckerman, Norman; Baum, Lisa; Milek, Debra

2012-01-01

This study identified activities and sources that contribute to ultrafine and other submicron particle exposure that could trigger respiratory symptoms in highway repair workers. Submicron particle monitoring was conducted for paving, milling, and pothole repair operations in a major metropolitan area where several highway repair workers were identified as symptomatic for respiratory illness following exposures at the 2001 World Trade Center disaster site. Exposure assessments were conducted for eight trades involved in road construction using a TSI P-Trak portable condensation particle counter. Direct readings near the workers' breathing zones and observations of activities and potential sources were logged on 7 days on 27 workers using four different models of pavers and two types of millers. Average worker exposure levels ranged from 2 to 3 times background during paving and from 1 to 4 times background during milling. During asphalt paving, average personal exposures to submicron particulates were 25,000-60,000, 28,000-70,000, and 23,000-37,000 particles/ cm(3) for paver operators, screed operators, and rakers, respectively. Average personal exposures during milling were 19,000-111,000, 28,000-81,000, and 19,000 particles/cm(3) for the large miller operators, miller screed operators, and raker, respectively. Personal peak exposures were measured up to 467,000 and 455,000 particles/cm(3) in paving and milling, respectively. Several sources of submicron particles were identified. These included the diesel and electric fired screed heaters; engine exhaust from diesel powered construction vehicles passing by or idling; raking, dumping, and paving of asphalt; exhaust from the hotbox heater; pavement dust or fumes from milling operations, especially when the large miller started and stopped; and secondhand cigarette smoke. To reduce the potential for health effects in workers, over 40 recommendations were made to control exposures, including improved maintenance of

Characterisation of Exposure to Ultrafine Particles from Surgical Smoke by Use of a Fast Mobility Particle Sizer.

PubMed

Ragde, Siri Fenstad; Jørgensen, Rikke Bramming; Føreland, Solveig

2016-08-01

Electrosurgery is a method based on a high frequency current used to cut tissue and coagulate small blood vessels during surgery. Surgical smoke is generated due to the heat created by electrosurgery. The carcinogenic potential of this smoke was assumed already in the 1980's and there has been a growing interest in the potential adverse health effects of exposure to the particles in surgical smoke. Surgical smoke is known to contain ultrafine particles (UFPs) but the knowledge about the exposure to UFPs produced by electrosurgery is however sparse. The aims of the study were therefore to characterise the exposure to UFPs in surgical smoke during different types of surgical procedures and on different job groups in the operating room, and to characterise the particle size distribution. Personal exposure measurements were performed on main surgeon, assistant surgeon, surgical nurse, and anaesthetic nurse during five different surgical procedures [nephrectomy, breast reduction surgery, abdominoplasty, hip replacement surgery, and transurethral resection of the prostate (TURP)]. The measurements were performed with a Fast Mobility Particle Sizer (FMPS) to assess the exposure to UPFs and to characterize the particle size distribution. Possible predictors of exposure were investigated using Linear Mixed Effect Models. The exposure to UFPs was highest during abdominoplasty arithmetic mean (AM) 3900 particles cm(-3) and lowest during hip replacement surgeries AM 400 particles cm(-3). The different job groups had similar exposure during the same types of surgical procedures. The use of electrosurgery resulted in short term high peak exposure (highest maximum peak value 272 000 particles cm(-3)) to mainly UFPs. The size distribution of particles varied between the different types of surgical procedures, where nephrectomy, hip replacement surgery, and TURP produced UFPs with a dominating mode of 9nm while breast reduction surgery and abdominoplasty produced UFPs with a

Ultrafine particle concentrations and exposures in seven residences in northern California.

PubMed

Bhangar, S; Mullen, N A; Hering, S V; Kreisberg, N M; Nazaroff, W W

2011-04-01

Human exposures to ultrafine particles (UFP) are poorly characterized given the potential associated health risks. Residences are important sites of exposure. To characterize residential exposures to UFP in some circumstances and to investigate governing factors, seven single-family houses in California were studied during 2007-2009. During multiday periods, time-resolved particle number concentrations were monitored indoors and outdoors and information was acquired concerning occupancy, source-related activities, and building operation. On average, occupants were home for 70% of their time. The geometric mean time-average residential exposure concentration for 21 study subjects was 14,500 particles per cm(3) (GSD = 1.8; arithmetic mean ± standard deviation = 17,000 ± 10,300 particles per cm(3)). The average contribution to residential exposures from indoor episodic sources was 150% of the contribution from particles of outdoor origin. Unvented natural-gas pilot lights contributed up to 19% to exposure for the two households where present. Episodic indoor source activities, most notably cooking, caused the highest peak exposures and most of the variation in exposure among houses. Owing to the importance of indoor sources and variations in the infiltration factor, residential exposure to UFP cannot be characterized by ambient measurements alone. Indoor and outdoor sources each contribute to residential ultrafine particle (UFP) concentrations and exposures. Under the conditions investigated, peak exposure concentrations indoors were associated with cooking, using candles, or the use of a furnace. Active particle removal systems can mitigate exposure by reducing the persistence of particles indoors. Eliminating the use of unvented gas pilot lights on cooking appliances could also be beneficial. The study results indicate that characterization of human exposure to UFP, an air pollutant of emerging public health concern, cannot be accomplished without a good

Characterization of diesel particles: effects of fuel reformulation, exhaust aftertreatment, and engine operation on particle carbon composition and volatility.

PubMed

Alander, Timo J A; Leskinen, Ari P; Raunemaa, Taisto M; Rantanen, Leena

2004-05-01

Diesel exhaust particles are the major constituent of urban carbonaceous aerosol being linked to a large range of adverse environmental and health effects. In this work, the effects of fuel reformulation, oxidation catalyst, engine type, and engine operation parameters on diesel particle emission characteristics were investigated. Particle emissions from an indirect injection (IDI) and a direct injection (DI) engine car operating under steady-state conditions with a reformulated low-sulfur, low-aromatic fuel and a standard-grade fuel were analyzed. Organic (OC) and elemental (EC) carbon fractions of the particles were quantified by a thermal-optical transmission analysis method and particle size distributions measured with a scanning mobility particle sizer (SMPS). The particle volatility characteristics were studied with a configuration that consisted of a thermal desorption unit and an SMPS. In addition, the volatility of size-selected particles was determined with a tandem differential mobility analyzer technique. The reformulated fuel was found to produce 10-40% less particulate carbon mass compared to the standard fuel. On the basis of the carbon analysis, the organic carbon contributed 27-61% to the carbon mass of the IDI engine particle emissions, depending on the fuel and engine operation parameters. The fuel reformulation reduced the particulate organic carbon emissions by 10-55%. In the particles of the DI engine, the organic carbon contributed 14-26% to the total carbon emissions, the advanced engine technology, and the oxidation catalyst, thus reducing the OC/EC ratio of particles considerably. A relatively good consistency between the particulate organic fraction quantified with the thermal optical method and the volatile fraction measured with the thermal desorption unit and SMPS was found.

Improved design of a tangential entry cyclone separator for separation of particles from exhaust gas of diesel engine.

PubMed

Mukhopadhyay, N

2011-01-01

An effective design of cyclone separator with tangential inlet is developed applying an equation derived from the correlation of collection efficiency with maximum pressure drop components of the cyclone, which can efficiently remove the particles around 1microm of the exhaust gas of diesel engine.

Lung cancer in heavy equipment operators and truck drivers with diesel exhaust exposure in the construction industry.

PubMed

Järvholm, B; Silverman, D

2003-07-01

Several studies indicate that truck drivers have an increased risk of lung cancer, but few studies have examined lung cancer risk in heavy equipment operators. Workers in both occupations are exposed to diesel exhaust. To examine the incidence and mortality from lung cancer among truck drivers and among drivers of heavy vehicles. A computerised register of Swedish construction workers participating in health examinations between 1971 and 1992 was used. Male truck drivers (n = 6364) and drivers of heavy construction vehicles (n = 14 364) were selected as index groups; carpenters/electricians constituted the reference group (n = 119 984). Operators of heavy construction equipment experienced no increased risk of lung cancer compared to risk among the carpenter/electrician referents (61 cases v 70.1 expected). However, a significant inverse trend risk with increasing use of cabins was apparent. Truck drivers had increased risks of cancer of the lung (61 cases v 47.3 expected) and prostate (124 cases v 99.7 expected), although only mortality for lung cancer was significantly increased. Comparisons with the general population showed similar results. Results are consistent with those of previous studies suggesting that heavy equipment operators with potential exposure to diesel exhaust may have little or no increased risk of lung cancer, although the use of cabins seemed to decrease the risk of lung cancer. The results for truck drivers are also consistent with previous reports of increased lung cancer risk among truck drivers exposed to diesel exhaust, as well as recent reports linking diesel exhaust exposure to prostate cancer.

The influence of occupational exposure to pesticides, polycyclic aromatic hydrocarbons, diesel exhaust, metal dust, metal fumes, and mineral oil on prostate cancer: a prospective cohort study.

PubMed

Boers, D; Zeegers, M P A; Swaen, G M; Kant, Ij; van den Brandt, P A

2005-08-01

To investigate the relation between exposure to pesticides, polycyclic aromatic hydrocarbons (PAHs), diesel exhaust, metal dust, metal fumes, and mineral oil in relation to prostate cancer incidence in a large prospective study. This cohort study was conducted among 58,279 men in the Netherlands. In September 1986, cohort members (55-69 years) completed a self-administered questionnaire on potential cancer risk factors, including job history. Follow up for prostate cancer incidence was established by linkage to cancer registries until December 1995 (9.3 years of follow up). The analyses included 1386 cases of prostate cancer and 2335 subcohort members. A blinded case-by-case expert exposure assessment was carried out to assign cases and subcohort members a cumulative probability of exposure for each potential carcinogenic exposure. In multivariate analyses there was a significant negative association for pesticides (RR 0.60; 95% CI 0.37 to 0.95) when comparing the highest tertile of exposure to pesticides with no exposure. No association was found for occupational exposure to PAHs (RR 0.75; 95% CI 0.42 to 1.31), diesel exhaust (RR 0.81; 95% CI 0.62 to 1.06), metal dust (RR 1.01; 95% CI 0.72 to 1.40), metal fumes (RR 1.11; 95% CI 0.80 to 1.54), or mineral oil (RR 0.99; 95% CI 0.66 to 1.48) when comparing the highest tertile of exposure with no exposure. In subgroup analysis, with respect to tumour invasiveness and morphology, null results were found for occupational exposure to pesticides, PAH, diesel exhaust, metal dust, metal fumes, and mineral oil. These results suggest a negative association between occupational exposure to pesticides and prostate cancer. For other carcinogenic exposures results suggest no association between occupational exposure to PAHs, diesel exhaust, metal dust, metal fumes, or mineral oil and prostate cancer.

New Methods for Personal Exposure Monitoring for Airborne Particles

PubMed Central

Koehler, Kirsten A.; Peters, Thomas

2016-01-01

Airborne particles have been associated with a range of adverse cardiopulmonary outcomes, which has driven its monitoring at stationary, central sites throughout the world. Individual exposures, however, can differ substantially from concentrations measured at central sites due to spatial variability across a region and sources unique to the individual, such as cooking or cleaning in homes, traffic emissions during commutes, and widely varying sources encountered at work. Personal monitoring with small, battery-powered instruments enables the measurement of an individual’s exposure as they go about their daily activities. Personal monitoring can substantially reduce exposure misclassification and improve the power to detect relationships between particulate pollution and adverse health outcomes. By partitioning exposures to known locations and sources, it may be possible to account for variable toxicity of different sources. This review outlines recent advances in the field of personal exposure assessment for particulate pollution. Advances in battery technology have improved the feasibility of 24-hour monitoring, providing the ability to more completely attribute exposures to microenvironment (e.g., work, home, commute). New metrics to evaluate the relationship between particulate matter and health are also being considered, including particle number concentration, particle composition measures, and particle oxidative load. Such metrics provide opportunities to develop more precise associations between airborne particles and health and may provide opportunities for more effective regulations. PMID:26385477

Accumulation of lipids and oxidatively damaged DNA in hepatocytes exposed to particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vesterdal, Lise K.; Danielsen, Pernille H.; Folkmann, Janne K.

Exposure to particles has been suggested to generate hepatosteatosis by oxidative stress mechanisms. We investigated lipid accumulation in cultured human hepatocytes (HepG2) and rat liver after exposure to four different carbon-based particles. HepG2 cells were exposed to particles for 3 h and subsequently incubated for another 18 h to manifest lipid accumulation. In an animal model of metabolic syndrome we investigated the association between intake of carbon black (CB, 14 nm) particles and hepatic lipid accumulation, inflammation and gene expression of Srebp-1, Fasn and Scd-1 involved in lipid synthesis. There was a concentration-dependent increase in intracellular lipid content after exposuremore » to CB in HepG2 cells, which was only observed after co-exposure to oleic/palmitic acid. Similar results were observed in HepG2 cells after exposure to diesel exhaust particles, fullerenes C{sub 60} or pristine single-walled carbon nanotubes. All four types of particles also generated oxidatively damaged DNA, assessed as formamidopyrimidine DNA glycosylase (FPG) sensitive sites, in HepG2 cells after 3 h exposure. The animal model of metabolic syndrome showed increased lipid load in the liver after one oral exposure to 6.4 mg/kg of CB in lean Zucker rats. This was not associated with increased iNOS staining in the liver, indicating that the oral CB exposure was associated with hepatic steatosis rather than steatohepatitis. The lipid accumulation did not seem to be related to increased lipogenesis because there were unaltered gene expression levels in both the HepG2 cells and rat livers. Collectively, exposure to particles is associated with oxidative stress and steatosis in hepatocytes. - Highlights: • Oral exposure to nanosized carbon black was associated with hepatosteatosis in rats. • In vitro studies included carbon black, C{sub 60}, diesel exhaust particles and SWCNTs. • Exposure to particles and free fatty acids increased lipid load in HepG2 cells. �

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.

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.

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...

Exposure to diesel exhaust up-regulates iNOS expression in ApoE knockout mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bai Ni; James Hogg Research Centre, Providence Heart and Lung Institute, St. Paul's Hospital, University of British Columbia, Vancouver, BC; Kido, Takashi

Traffic related particulate matter air pollution is a risk factor for cardiovascular events; however, the biological mechanisms are unclear. We hypothesize that diesel exhaust (DE) inhalation induces up-regulation of inducible nitric oxide synthase (iNOS), which is known to contribute to vascular dysfunction, progression of atherosclerosis and ultimately cardiovascular morbidity and mortality. Methods: ApoE knockout mice (30-week) were exposed to DE (at 200 {mu}g/m{sup 3} of particulate matter) or filtered-air (control) for 7 weeks (6 h/day, 5 days/week). iNOS expression in the blood vessels and heart was evaluated by immunohistochemistry and western blotting analysis. To examine iNOS activity, thoracic aortae weremore » mounted in a wire myograph, and vasoconstriction stimulated by phenylephrine (PE) was measured with and without the presence of the specific inhibitor for iNOS (1400 W). NF-{kappa}B (p65) activity was examined by ELISA. The mRNA expression of iNOS and NF-{kappa}B (p65) was determined by real-time PCR. Results: DE exposure significantly enhanced iNOS expression in the thoracic aorta (4-fold) and heart (1.5 fold). DE exposure significantly attenuated PE-stimulated vasoconstriction by {approx} 20%, which was partly reversed by 1400 W. The mRNA expression of iNOS and NF-{kappa}B was significantly augmented after DE exposure. NF-{kappa}B activity was enhanced 2-fold after DE inhalation, and the augmented NF-{kappa}B activity was positively correlated with iNOS expression (R{sup 2} = 0.5998). Conclusions: We show that exposure to DE increases iNOS expression and activity possibly via NF-{kappa}B-mediated pathway. We suspect that DE exposure-caused up-regulation of iNOS contributes to vascular dysfunction and atherogenesis, which could ultimately lead to urban air pollution-associated cardiovascular morbidity and mortality. - Highlights: > Exposed ApoE knockout mice (30-week) to diesel exhaust (DE) for 7 weeks. > Examine iNOS expression and activity in

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...

A numerical and experimental investigation of crystalline silica exposure control during tuck pointing.

PubMed

Heitbrink, William; Bennett, James

2006-07-01

National Institute for Occupational Safety and Health researchers investigated control measures for the removal of mortar between bricks, using a grinder. This task, "tuck pointing," is associated with crystalline silica exposures many times greater than the permissible exposure limit enforced by the Occupational Safety and Health Administration. Previous studies showed that local exhaust ventilation (LEV) of the grinding wheel through a shroud was often ineffective. Tuck pointing occurs on a scaffold. For practical purposes, this limits the size and power of the LEV system. Thus, the goal of this study was to develop a recommended flow rate for exposure control. Flow induced by the rotating grinding wheel, flow induced by the mortar particle stream, and particle momentum are potential control challenges. Computational fluid dynamic (CFD) simulation of the grinder, supported by some experimental measurements, showed the relative importance of these factors through varying parameters and tracking particles. In a simulation of the shroud and grinding wheel, with the wheel inserted to a cutting depth of 0.750 inch flush into the brick wall, -0.461 cubic feet per meter (0.461 into the exhaust takeoff) was induced by the rotating wheel. The more realistic situation of the wheel in a cut in the wall 1.25 inches deep (forming a trench circumferentially 0.500 inch below the wheel edge) induced an airflow of 8.24 cfm out of the shroud exhaust. Experimental measurements taken for validation were 7.3% lower than the CFD value. The trench effect disappeared when a stream of 10-mu m particles was launched from the grinding wheel edge, as the simulations with and without the trench had nearly identical induced flow rates, 10.8 cfm and 10.9 cfm. We thus interpreted the particle stream as more important than the wheel in inducing flow. This insight was possible because of the power of CFD, compared to intuition and classical boundary layer analysis. In this situation of no forced

Comparison of Airway Responses Induced in a Mouse Model by the Gas and Particulate Fractions of Gasoline Direct Injection Engine Exhaust.

PubMed

Maikawa, Caitlin L; Zimmerman, Naomi; Ramos, Manuel; Shah, Mittal; Wallace, James S; Pollitt, Krystal J Godri

2018-03-01

Diesel exhaust has been associated with asthma, but its response to other engine emissions is not clear. The increasing prevalence of vehicles with gasoline direct injection (GDI) engines motivated this study, and the objective was to evaluate pulmonary responses induced by acute exposure to GDI engine exhaust in an allergic asthma murine model. Mice were sensitized with an allergen to induce airway hyperresponsiveness or treated with saline (non-allergic group). Animals were challenged for 2-h to exhaust from a laboratory GDI engine operated at conditions equivalent to a highway cruise. Exhaust was filtered to assess responses induced by the particulate and gas fractions. Short-term exposure to particulate matter from GDI engine exhaust induced upregulation of genes related to polycyclic aromatic hydrocarbon (PAH) metabolism ( Cyp1b1 ) and inflammation ( TNFα ) in the lungs of non-allergic mice. High molecular weight PAHs dominated the particulate fraction of the exhaust, and this response was therefore likely attributable to the presence of these PAHs. The particle fraction of GDI engine exhaust further contributed to enhanced methacholine responsiveness in the central and peripheral tissues in animals with airway hyperresponsiveness. As GDI engines gain prevalence in the vehicle fleet, understanding the health impacts of their emissions becomes increasingly important.

Comparison of Airway Responses Induced in a Mouse Model by the Gas and Particulate Fractions of Gasoline Direct Injection Engine Exhaust

PubMed Central

Maikawa, Caitlin L.; Zimmerman, Naomi; Ramos, Manuel; Wallace, James S.; Pollitt, Krystal J. Godri

2018-01-01

Diesel exhaust has been associated with asthma, but its response to other engine emissions is not clear. The increasing prevalence of vehicles with gasoline direct injection (GDI) engines motivated this study, and the objective was to evaluate pulmonary responses induced by acute exposure to GDI engine exhaust in an allergic asthma murine model. Mice were sensitized with an allergen to induce airway hyperresponsiveness or treated with saline (non-allergic group). Animals were challenged for 2-h to exhaust from a laboratory GDI engine operated at conditions equivalent to a highway cruise. Exhaust was filtered to assess responses induced by the particulate and gas fractions. Short-term exposure to particulate matter from GDI engine exhaust induced upregulation of genes related to polycyclic aromatic hydrocarbon (PAH) metabolism (Cyp1b1) and inflammation (TNFα) in the lungs of non-allergic mice. High molecular weight PAHs dominated the particulate fraction of the exhaust, and this response was therefore likely attributable to the presence of these PAHs. The particle fraction of GDI engine exhaust further contributed to enhanced methacholine responsiveness in the central and peripheral tissues in animals with airway hyperresponsiveness. As GDI engines gain prevalence in the vehicle fleet, understanding the health impacts of their emissions becomes increasingly important. PMID:29494515

Long-term exposure to diesel engine exhaust induces primary DNA damage: a population-based study.

PubMed

Duan, Huawei; Jia, Xiaowei; Zhai, Qingfeng; Ma, Lu; Wang, Shan; Huang, Chuanfeng; Wang, Haisheng; Niu, Yong; Li, Xue; Dai, Yufei; Yu, Shanfa; Gao, Weimin; Chen, Wen; Zheng, Yuxin

2016-02-01

Diesel engine exhaust (DEE) is a ubiquitous environmental pollutant and is carcinogenic to humans. To seek early and sensitive biomarkers for prediction of adverse health effects, we analysed the components of DEE particles, and examined the genetic and oxidative damages in DEE-exposed workers. 101 male diesel engine testing workers who were constantly exposed to DEE and 106 matched controls were enrolled in the present study. The components of DEE were analysed, including fine particulate matter (PM2.5), element carbon (EC), nitrogen dioxide (NO2), sulfur dioxide (SO2) and polycyclic aromatic hydrocarbons (PAHs). Postshift urine samples were collected and analysed for 1-hydroxypyrene (1-OHP), an internal exposure marker for DEE. Levels of DNA strand breaks and oxidised purines, defined as formamidopyrimidine-DNA glycosylase (FPG) sites in leucocytes, were measured by medium throughput Comet assay. Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) was also used to determine the level of oxidative stress. We found higher levels of PM2.5, EC, NO2, SO2 and PAHs in the diesel engine testing workshop and significantly higher urinary 1-OHP concentrations in exposed subjects (p<0.001). Compared with controls, the levels of parameters in normal Comet and FPG-Comet assay were all significantly higher in DEE-exposed workers (p<0.001), and in a dose-dependent and time-dependent manner. There were no significant differences between DEE-exposed workers and controls in regard to leucocyte FPG sensitive sites and urinary 8-OHdG levels. These findings suggest that DEE exposure mainly induces DNA damage, which might be used as an early biomarker for risk assessment of DEE exposure. 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/

Atmospheric scavenging exhaust

NASA Technical Reports Server (NTRS)

Fenton, D. L.; Purcell, R. Y.

1977-01-01

Solid propellant rocket exhaust was directly utilized to ascertain raindrop scavenging rates for hydrogen chloride. The airborne HCl concentration varied from 0.2 to 10.0 ppm and the raindrop sizes tested included 0.55 mm, 1.1 mm, and 3.0 mm. Two chambers were used to conduct the experiments. A large, rigid walled, spherical chamber stored the exhaust constituents while the smaller chamber housing all the experiments was charged as required with rocket exhaust HCl. Surface uptake experiments demonstrated an HCl concentration dependence for distilled water. Sea water and brackish water HCl uptake was below the detection limit of the chlorine-ion analysis technique employed. Plant life HCl uptake experiments were limited to corn and soybeans. Plant age effectively correlated the HCl uptake data. Metallic corrosion was not significant for single 20 minute exposures to the exhaust HCl under varying relative humidity.

Diesel exhaust inhalation exposure induces pulmonary arterial hypertension in mice.

PubMed

Liu, Jing; Ye, Xiaoqing; Ji, Dapeng; Zhou, Xiaofei; Qiu, Cong; Liu, Weiping; Yu, Luyang

2018-06-01

Diesel exhaust (DE) is one of the main sources of urban air pollution. An increasing number of evidence showed the association of air pollution with cardiovascular diseases. Pulmonary arterial hypertension (PAH) is one of the most disastrous vascular diseases, which results in right ventricular failure and death. However, the relationship of DE inhalation exposure with PAH is still unknown. In this study, male adult mice were exposed by inhalation to filtered ambient air (negative control), 10% O 2 hypoxia (PAH-phenotype positive control), 350 μg/m 3 particulate matter whole DE, or the combination of DE and hypoxic condition. DE inhalation induced PAH-phenotype accompanied with increased right ventricular systolic pressure (RVSP), right ventricle hypertrophy and pulmonary arterial thickening in a mouse model. DE exposure induced the proliferation of vascular smooth muscle cells (VSMCs) and apoptosis of endothelial cells in pulmonary artery. DE inhalation exposure induced an accumulation of CD45 +  lymphocytes and CD68 +  macrophages surrounding and infiltrating pulmonary arteriole. The levels of pro-inflammatory cytokines tumor necrosis factor (TNF-α), interleukin-6 (IL-6) and IL-13 produced by T helper 17 (Th17) and Th2 cells were markedly elevated in lung tissues of mice after DE inhalation exposure. Our findings suggest DE exposure induces PAH by activating Th17-skewed and Th2-droved responses, stimulating VSMCs proliferation and inducing endothelial cell apoptosis by the production of multifunctional pro-inflammatory cytokines, especially IL-6 and TNF-α. Considering the adverse impact of air pollution on health care, it is imperative to understand air pollution-induced susceptibility of progressive cardiopulmonary disease, such as PAH, and also elucidate critical mechanistic pathways which mediate pulmonary artery vascular remodeling and may serve as targets for preventive measures. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

2018-03-01

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 PM 2.5 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 PM 2.5 concentrations in all subjects (P trend  < 0.001) as well as in exposed subjects only (P trend  = 0.001). Levels of IL-8 and MIP-1β were significantly lower in workers in the highest exposure tertile of PM 2.5 (>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 PM 2.5 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 PM 2.5 exposure may provide insight into the mechanism by which DEE promotes lung cancer. Environ. Mol. Mutagen. 59:144-150, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

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

Respiratory hazard assessment of combined exposure to complete gasoline exhaust and respirable volcanic ash in a multicellular human lung model at the air-liquid interface

USGS Publications Warehouse

Tomasek, Ines; Horwell, Claire J.; Bisig, Christoph; Damby, David; Comte, Pierre; Czerwinski, Jan; Petri-Fink, Alke; Clift, Martin J D; Drasler, Barbara; Rothen-Rutishauer, Barbara

2018-01-01

Communities resident in urban areas located near active volcanoes can experience volcanic ash exposures during, and following, an eruption, in addition to sustained exposures to high concentrations of anthropogenic air pollutants (e.g., vehicle exhaust emissions). Inhalation of anthropogenic pollution is known to cause the onset of, or exacerbate, respiratory and cardiovascular diseases. It is further postulated similar exposure to volcanic ash can also affect such disease states. Understanding of the impact of combined exposure of volcanic ash and anthropogenic pollution to human health, however, remains limited.The aim of this study was to assess the biological impact of combined exposure to respirable volcanic ash (from Soufrière Hills volcano (SHV), Montserrat and Chaitén volcano (ChV), Chile; representing different magmatic compositions and eruption styles) and freshly-generated complete exhaust from a gasoline vehicle. A multicellular human lung model (an epithelial cell-layer composed of A549 alveolar type II-like cells complemented with human blood monocyte-derived macrophages and dendritic cells cultured at the air-liquid interface) was exposed to diluted exhaust (1:10) continuously for 6 h, followed by immediate exposure to the ash as a dry powder (0.54 ± 0.19 μg/cm2 and 0.39 ± 0.09 μg/cm2 for SHV and ChV ash, respectively). After an 18 h incubation, cells were exposed again for 6 h to diluted exhaust, and a final 18 h incubation (at 37 °C and 5% CO2). Cell cultures were then assessed for cytotoxic, oxidative stress and (pro-)inflammatory responses.Results indicate that, at all tested (sub-lethal) concentrations, co-exposures with both ash samples induced no significant expression of genes associated with oxidative stress (HMOX1, NQO1) or production of (pro-)inflammatory markers (IL-1β, IL-8, TNF-α) at the gene and protein levels. In summary, considering the employed experimental conditions, combined exposure of

Respiratory hazard assessment of combined exposure to complete gasoline exhaust and respirable volcanic ash in a multicellular human lung model at the air-liquid interface.

PubMed

Tomašek, Ines; Horwell, Claire J; Bisig, Christoph; Damby, David E; Comte, Pierre; Czerwinski, Jan; Petri-Fink, Alke; Clift, Martin J D; Drasler, Barbara; Rothen-Rutishauser, Barbara

2018-07-01

Communities resident in urban areas located near active volcanoes can experience volcanic ash exposures during, and following, an eruption, in addition to sustained exposures to high concentrations of anthropogenic air pollutants (e.g., vehicle exhaust emissions). Inhalation of anthropogenic pollution is known to cause the onset of, or exacerbate, respiratory and cardiovascular diseases. It is further postulated similar exposure to volcanic ash can also affect such disease states. Understanding of the impact of combined exposure of volcanic ash and anthropogenic pollution to human health, however, remains limited. The aim of this study was to assess the biological impact of combined exposure to respirable volcanic ash (from Soufrière Hills volcano (SHV), Montserrat and Chaitén volcano (ChV), Chile; representing different magmatic compositions and eruption styles) and freshly-generated complete exhaust from a gasoline vehicle. A multicellular human lung model (an epithelial cell-layer composed of A549 alveolar type II-like cells complemented with human blood monocyte-derived macrophages and dendritic cells cultured at the air-liquid interface) was exposed to diluted exhaust (1:10) continuously for 6 h, followed by immediate exposure to the ash as a dry powder (0.54 ± 0.19 μg/cm 2 and 0.39 ± 0.09 μg/cm 2 for SHV and ChV ash, respectively). After an 18 h incubation, cells were exposed again for 6 h to diluted exhaust, and a final 18 h incubation (at 37 °C and 5% CO 2 ). Cell cultures were then assessed for cytotoxic, oxidative stress and (pro-)inflammatory responses. Results indicate that, at all tested (sub-lethal) concentrations, co-exposures with both ash samples induced no significant expression of genes associated with oxidative stress (HMOX1, NQO1) or production of (pro-)inflammatory markers (IL-1β, IL-8, TNF-α) at the gene and protein levels. In summary, considering the employed experimental conditions, combined exposure of

Traffic generated non-exhaust particulate emissions from concrete pavement: A mass and particle size study for two-wheelers and small cars

NASA Astrophysics Data System (ADS)

Aatmeeyata; Kaul, D. S.; Sharma, Mukesh

This study aimed to understand the non-exhaust (NE) emission of particles from wear of summer tire and concrete pavement, especially for two wheelers and small cars. A fully enclosed laboratory-scale model was fabricated to simulate road tire interaction with a facility to collect particles in different sizes. A road was cast using the M-45 concrete mixture and the centrifugal casting method. It was observed that emission of large particle non exhaust emission (LPNE) as well as PM 10 and PM 2.5 increased with increasing load. The LPNE was 3.5 mg tire -1 km -1 for a two wheeler and 6.4 mg tire -1 km -1 for a small car. The LPNE can lead to water pollution through water run-off from the roads. The contribution of the PM 10 and PM 2.5 was smaller compared to the LPNE particles (less than 0.1%). About 32 percent of particle mass of PM 10 was present below 1 μm. The number as well as mass size distribution for PM 10 was observed to be bi-modal with peaks at 0.3 μm and 4-5 μm. The NE emissions did not show any significant trend with change in tire pressure.

Nano-metal oxides: Exposure and engineering control assessment.

PubMed

Garcia, Alberto; Eastlake, Adrienne; Topmiller, Jennifer L; Sparks, Christopher; Martinez, Kenneth; Geraci, Charles L

2017-09-01

In January 2007, the National Institute for Occupational Safety and Health (NIOSH) conducted a field study to evaluate process specific emissions during the production of ENMs. This study was performed using the nanoparticle emission assessment technique (NEAT). During this study, it was determined that ENMs were released during production and cleaning of the process reactor. Airborne concentrations of silver, nickel, and iron were found both in the employee's personal breathing zone and area samples during reactor cleaning. At the completion of this initial survey, it was suggested that a flanged attachment be added to the local exhaust ventilation system.  NIOSH re-evaluated the facility in December 2011 to assess worker exposures following an increase in production rates. This study included a fully comprehensive emissions, exposure, and engineering control evaluation of the entire process. This study made use of the nanoparticle exposure assessment technique (NEAT 2.0). Data obtained from filter-based samples and direct reading instruments indicate that reactor cleanout increased the overall particle concentration in the immediate area. However, it does not appear that these concentrations affect areas outside of the production floor. As the distance between the reactor and the sample location increased, the observed particle number concentration decreased, creating a concentration gradient with respect to the reactor. The results of this study confirm that the flanged attachment on the local exhaust ventilation system served to decrease exposure potential.  Given the available toxicological data of the metals evaluated, caution is warranted. One should always keep in mind that occupational exposure levels were not developed specifically for nanoscale particles. With data suggesting that certain nanoparticles may be more toxic than the larger counterparts of the same material; employers should attempt to control emissions of these particles at the source

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

Particle exposure and inhaled dose during commuting in Singapore

NASA Astrophysics Data System (ADS)

Tan, Sok Huang; Roth, Matthias; Velasco, Erik

2017-12-01

Exposure concentration and inhaled dose of particles during door-to-door trips walking and using motorized transport modes (subway, bus, taxi) are evaluated along a selected route in a commercial district of Singapore. Concentrations of particles smaller than 2.5 μm in size (PM2.5), black carbon, particle-bound polycyclic aromatic hydrocarbons, number of particles, active surface area and carbon monoxide have been measured in-situ using portable instruments. Simultaneous measurements were conducted at a nearby park to capture the background concentrations. The heart rate of the participants was monitored during the measurements as a proxy of the inhalation rate used to calculate the inhaled dose of particles. All measured metrics were highest and well above background levels during walking. No significant difference was observed in the exposure concentration of PM2.5 for the three motorized transport modes, unlike for the metrics associated with ultrafine particles (UFP). The concentration of these freshly emitted particles was significantly lower on subway trips. The absence of combustion sources, use of air conditioning and screen doors at station platforms are effective measures to protect passengers' health. For other transport modes, sections of trips close to accelerating and idling vehicles, such as bus stops, traffic junctions and taxi stands, represent hotspots of particles. Reducing the waiting time at such locations will lower pollutants exposure and inhaled dose during a commute. After taking into account the effect of inhalation and travel duration when calculating dose, the health benefit of commuting by subway for this particular district of Singapore became even more evident. For example, pedestrians breathe in 2.6 and 3.2 times more PM2.5 and UFP, respectively than subway commuters. Public buses were the second best alternative. Walking emerged as the worst commuting mode in terms of particle exposure and inhaled dose.

Whole and particle-free diesel exhausts differentially affect cardiac electrophysiology, blood pressure, and autonomic balance in heart failure-prone rats

EPA Science Inventory

Epidemiologic studies strongly link short-term exposures to vehicular traffic and particulate matter (PM) air pollution with adverse cardiovascular events, especially in those with preexisting cardiovascular disease. Diesel engine exhaust (DE) is a key contributor to urban ambien...

Diesel Exhaust Exposure and the Risk of Lung Cancer—A Review of the Epidemiological Evidence

PubMed Central

Sun, Yi; Bochmann, Frank; Nold, Annette; Mattenklott, Markus

2014-01-01

To critically evaluate the association between diesel exhaust (DE) exposure and the risk of lung cancer, we conducted a systematic review of published epidemiological evidences. To comprehensively identify original studies on the association between DE exposure and the risk of lung cancer, literature searches were performed in literature databases for the period between 1970 and 2013, including bibliographies and cross-referencing. In total, 42 cohort studies and 32 case-control studies were identified in which the association between DE exposures and lung cancer was examined. In general, previous studies suffer from a series of methodological limitations, including design, exposure assessment methods and statistical analysis used. A lack of objective exposure information appears to be the main problem in interpreting epidemiological evidence. To facilitate the interpretation and comparison of previous studies, a job-exposure matrix (JEM) of DE exposures was created based on around 4,000 historical industrial measurements. The values from the JEM were considered during interpretation and comparison of previous studies. Overall, neither cohort nor case-control studies indicate a clear exposure-response relationship between DE exposure and lung cancer. Epidemiological studies published to date do not allow a valid quantification of the association between DE and lung cancer. PMID:24473109

The biological effects of subacute inhalation of diesel exhaust following addition of cerium oxide nanoparticles in atherosclerosis-prone mice.

PubMed

Cassee, Flemming R; Campbell, Arezoo; Boere, A John F; McLean, Steven G; Duffin, Rodger; Krystek, Petra; Gosens, Ilse; Miller, Mark R

2012-05-01

Cerium oxide (CeO(2)) nanoparticles improve the burning efficiency of fuel, however, little is known about health impacts of altered emissions from the vehicles. Atherosclerosis-prone apolipoprotein E knockout (ApoE(-/-)) mice were exposed by inhalation to diluted exhaust (1.7 mg/m(3), 20, 60 or 180 min, 5 day/week, for 4 weeks), from an engine using standard diesel fuel (DE) or the same diesel fuel containing 9 ppm cerium oxide nanoparticles (DCeE). Changes in hematological indices, clinical chemistry, atherosclerotic burden, tissue levels of inflammatory cytokines and pathology of the major organs were assessed. Addition of CeO(2) to fuel resulted in a reduction of the number (30%) and surface area (10%) of the particles in the exhaust, whereas the gaseous co-pollutants were increased (6-8%). There was, however, a trend towards an increased size and complexity of the atherosclerotic plaques following DE exposure, which was not evident in the DCeE group. There were no clear signs of altered hematological or pathological changes induced by either treatment. However, levels of proinflammatory cytokines were modulated in a brain region and liver following DCeE exposure. These results imply that addition of CeO(2) nanoparticles to fuel decreases the number of particles in exhaust and may reduce atherosclerotic burden associated with exposure to standard diesel fuel. From the extensive assessment of biological parameters performed, the only concerning effect of cerium addition was a slightly raised level of cytokines in a region of the central nervous system. Overall, the use of cerium as a fuel additive may be a potentially useful way to limit the health effects of vehicle exhaust. However, further testing is required to ensure that such an approach is not associated with a chronic inflammatory response which may eventually cause long-term health effects. Copyright © 2012 Elsevier Inc. All rights reserved.

Evaluation of an exposure assessment used in epidemiological studies of diesel exhaust and lung cancer in underground mines

PubMed Central

Crump, Kenny; Van Landingham, Cynthia

2012-01-01

NIOSH/NCI (National Institute of Occupational Safety and Health and National Cancer Institute) developed exposure estimates for respirable elemental carbon (REC) as a surrogate for exposure to diesel exhaust (DE) for different jobs in eight underground mines by year beginning in the 1940s—1960s when diesel equipment was first introduced into these mines. These estimates played a key role in subsequent epidemiological analyses of the potential relationship between exposure to DE and lung cancer conducted in these mines. We report here on a reanalysis of some of the data from this exposure assessment. Because samples of REC were limited primarily to 1998–2001, NIOSH/NCI used carbon monoxide (CO) as a surrogate for REC. In addition, because CO samples were limited, particularly in the earlier years, they used the ratio of diesel horsepower (HP) to the mine air exhaust rate as a surrogate for CO. There are considerable uncertainties connected with each of these surrogate-based steps. The estimates of HP appear to involve considerable uncertainty, although we had no data upon which to evaluate the magnitude of this uncertainty. A sizable percentage (45%) of the CO samples used in the HP to CO model was below the detection limit which required NIOSH/NCI to assign CO values to these samples. In their preferred REC estimates, NIOSH/NCI assumed a linear relation between C0 and REC, although they provided no credible support for that assumption. Their assumption of a stable relationship between HP and CO also is questionable, and our reanalysis found a statistically significant relationship in only one-half of the mines. We re-estimated yearly REC exposures mainly using NIOSH/NCI methods but with some important differences: (i) rather than simply assuming a linear relationship, we used data from the mines to estimate the CO—REC relationship; (ii) we used a different method for assigning values to nondetect CO measurements; and (iii) we took account of statistical

COMPARISON OF THE PARTICLE SIZE DISTRIBUTION OF HEAVY-DUTY DIESEL EXHAUST USING A DILUTION TAIL-PIPE SAMPLER AND IN-PLUME SAMPLER DURING ON-ROAD OPERATION

EPA Science Inventory

The paper compares the particle size distribution of heavy-duty diesel exhaust using a dilution tail-pipe sampler and an in-plume sampler during on-road operation. EPA's On-road Diesel Emissions Characterization Facility, modified to incorporate particle measurement instrumentat...

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

Measurement of airborne concentrations of tire and road wear particles in urban and rural areas of France, Japan, and the United States

NASA Astrophysics Data System (ADS)

Panko, Julie M.; Chu, Jennifer; Kreider, Marisa L.; Unice, Ken M.

2013-06-01

In addition to industrial facilities, fuel combustion, forest fires and dust erosion, exhaust and non-exhaust vehicle emissions are an important source of ambient air respirable particulate matter (PM10). Non-exhaust vehicle emissions are formed from wear particles of vehicle components such as brakes, clutches, chassis and tires. Although the non-exhaust particles are relatively minor contributors to the overall ambient air particulate load, reliable exposure estimates are few. In this study, a global sampling program was conducted to quantify tire and road wear particles (TRWP) in the ambient air in order to understand potential human exposures and the overall contribution of these particles to the PM10. The sampling was conducted in Europe, the United States and Japan and the sampling locations were selected to represent a variety of settings including both rural and urban core; and within each residential, commercial and recreational receptors. The air samples were analyzed using validated chemical markers for rubber polymer based on a pyrolysis technique. Results indicated that TRWP concentrations in the PM10 fraction were low with averages ranging from 0.05 to 0.70 μg m-3, representing an average PM10 contribution of 0.84%. The TRWP concentration in air was associated with traffic load and population density, but the trend was not statistically significant. Further, significant differences across days were not observed. This study provides a robust dataset to understand potential human exposures to airborne TRWP.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakao, Shunsuke; Shrivastava, ManishKumar B.; Nguyen, Anh

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,more » 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.« less

Estrogenic and anti-androgenic activities of 4-nitrophenol in diesel exhaust particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li Chunmei; Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509; Taneda, Shinji

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 withmore » 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.« less

Gluthathione-S-transferase M1 regulation of diesel exhaust particle-induced pro-inflammatory mediator expression in normal human bronchial epithelial cells

EPA Science Inventory

Diesel exhaust particles (DEP) contribute substantially to ambient particulate matter (PM) air pollution in urban areas. Inhalation of PM has been associated with increased incidence of lung disease in susceptible populations. We have demonstrated that the glutathione-S-transfera...

Gas and Particle Oxidation Products from Ozone Aging of Airborne Diesel Particles

NASA Astrophysics Data System (ADS)

Holmen, B. A.; Chen, Z.

2005-12-01

Diesel exhaust emissions contain fine particulate matter (PM2.5) composed of carbon-based particles with adsorbed compounds, including water soluble and insoluble substances. Many nonpolar organic compounds associated with diesel particulate matter (DPM) are known to be mutagenic and carcinogenic. In the presence of ozone, these DPM compounds can be transformed into polar species that are more toxic and poorly characterized. Understanding the gas and particle reaction products from DPM aging in the presence of tropospheric ozone is important for air quality, climate change and aerosol health effects. Aging experiments were conducted in a flow reactor to identify gas and particle-phase reaction products of DPM exposed to ambient levels of ozone. Diesel bus exhaust particles were collected on filters and then exposed to 0.1 - 0.5 ppm O3 for 0 to 72 h. Gaseous polar organic products formed during the aging experiments were collected on Tenax TA adsorbent coated with PFBHA derivatization agent. A thermal desorption gas chromatography mass spectrometry (TD/GC/MS) method was developed to determine gas-phase and particle-phase organic compounds. PFBHA and BSTFA derivatization agents converted polar species into less polar analogues prior to analysis. Preliminary results indicate that DPM hydrocarbons react with O3 to form many gas-phase polar products containing C=O (carbonyl) and COOH (carboxy) functional groups. Particle-phase PAH and alkane concentrations decreased significantly depending on time of exposure.

Ice nuclei from automobile exhaust and iodine vapor.

PubMed

Schaefer, V J

1966-12-23

When exposed to a trace of iodine vapor, the submicroscopic particles of lead exhausted by automobiles produce nuclei for the formation of ice crystals. Concentrations of particles exceeding 10(6) per liter can be directly sampled from the exhaust pipe of an idling motor. Concentrations of from 10(4) to 10(5) per liter have been found in rural air downwind of auto roads; the concentration at one rural site has increased by an order of magnitude in 13 years. The phenomenon may provide a method of modifying clouds, and of determining ( and monitoring) the percentage of automobile exhaust in a polluted atmosphere. It may be an important factor in inadvertent modification by man of the climate.

Modelling of aircrew radiation exposure during solar particle events

NASA Astrophysics Data System (ADS)

Al Anid, Hani Khaled

In 1990, the International Commission on Radiological Protection recognized the occupational exposure of aircrew to cosmic radiation. In Canada, a Commercial and Business Aviation Advisory Circular was issued by Transport Canada suggesting that action should be taken to manage such exposure. In anticipation of possible regulations on exposure of Canadian-based aircrew in the near future, an extensive study was carried out at the Royal Military College of Canada to measure the radiation exposure during commercial flights. The radiation exposure to aircrew is a result of a complex mixed-radiation field resulting from Galactic Cosmic Rays (GCRs) and Solar Energetic Particles (SEPs). Supernova explosions and active galactic nuclei are responsible for GCRs which consist of 90% protons, 9% alpha particles, and 1% heavy nuclei. While they have a fairly constant fluence rate, their interaction with the magnetic field of the Earth varies throughout the solar cycles, which has a period of approximately 11 years. SEPs are highly sporadic events that are associated with solar flares and coronal mass ejections. This type of exposure may be of concern to certain aircrew members, such as pregnant flight crew, for which the annual effective dose is limited to 1 mSv over the remainder of the pregnancy. The composition of SEPs is very similar to GCRs, in that they consist of mostly protons, some alpha particles and a few heavy nuclei, but with a softer energy spectrum. An additional factor when analysing SEPs is the effect of flare anisotropy. This refers to the way charged particles are transported through the Earth's magnetosphere in an anisotropic fashion. Solar flares that are fairly isotropic produce a uniform radiation exposure for areas that have similar geomagnetic shielding, while highly anisotropic events produce variable exposures at different locations on the Earth. Studies of neutron monitor count rates from detectors sharing similar geomagnetic shielding properties

Burden of lung cancer attributable to occupational diesel engine exhaust exposure in Canada.

PubMed

Kim, Joanne; Peters, Cheryl E; Arrandale, Victoria H; Labrèche, France; Ge, Calvin B; McLeod, Christopher B; Song, Chaojie; Lavoué, Jérôme; Davies, Hugh W; Nicol, Anne-Marie; Pahwa, Manisha; Demers, Paul A

2018-04-28

To estimate the population attributable fraction (PAF) and number of incident and fatal lung cancers in Canada from occupational exposure to diesel engine exhaust (DEE). DEE exposure prevalence and level estimates were used with Canadian Census and Labour Force Survey data to model the exposed population across the risk exposure period (REP, 1961-2001). Relative risks of lung cancer were calculated based on a meta-regression selected from the literature. PAFs were calculated using Levin's equation and applied to the 2011 lung cancer statistics obtained from the Canadian Cancer Registry. We estimated that 2.4% (95% CI 1.6% to 6.6%) of lung cancers in Canada are attributable to occupational DEE exposure, corresponding to approximately 560 (95% CI 380 to 1570) incident and 460 (95% CI 310 to 1270) fatal lung cancers in 2011. Overall, 1.6 million individuals alive in 2011 were occupationally exposed to DEE during the REP, 97% of whom were male. Occupations with the highest burden were underground miners, truck drivers and mechanics. Half of the attributable lung cancers occurred among workers with low exposure. This is the first study to quantify the burden of lung cancer attributable to occupational DEE exposure in Canada. Our results underscore a large potential for prevention, and a large public health impact from occupational exposure to low levels of DEE. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Dietary modulation of the effects of exposure to 56Fe particles

NASA Astrophysics Data System (ADS)

Rabin, B. M.; Joseph, J. A.; Shukitt-Hale, B.; Carey, A. N.

On exploratory missions to other planets, astronauts will be exposed to galactic cosmic rays composed of protons and heavy particles, such as 56Fe. Long-term exposure to these particles can cause cancer. However, there are significant uncertainties in the risk estimates for the probability of developing heavy particle-induced cancer, and in the amount of shielding needed to provide an adequate level of radiation protection. The results of this preliminary study, using a ground-based model for exposure to cosmic rays, show reduced tumorigenesis in rats maintained on diets containing blueberry or strawberry extract prior to exposure to 56Fe particles. Because the study was not initially designed to evaluate tumorigenesis following exposure to 56Fe particles, additional research is needed to evaluate the effectiveness of strawberry and blueberry supplementation. However, the preliminary results presented in this study suggest that diets containing antioxidant phytochemicals can provide additional radiation protection on interplanetary voyages.

Estimation of quantitative levels of diesel exhaust exposure and the health impact in the contemporary Australian mining industry.

PubMed

Peters, Susan; de Klerk, Nicholas; Reid, Alison; Fritschi, Lin; Musk, Aw Bill; Vermeulen, Roel

2017-03-01

To estimate quantitative levels of exposure to diesel exhaust expressed by elemental carbon (EC) in the contemporary mining industry and to describe the excess risk of lung cancer that may result from those levels. EC exposure has been monitored in Western Australian miners since 2003. Mixed-effects models were used to estimate EC levels for five surface and five underground occupation groups (as a fixed effect) and specific jobs within each group (as a random effect). Further fixed effects included sampling year and duration, and mineral mined. On the basis of published risk functions, we estimated excess lifetime risk of lung cancer mortality for several employment scenarios. Personal EC measurements (n=8614) were available for 146 different jobs at 124 mine sites. The mean estimated EC exposure level for surface occupations in 2011 was 14 µg/m 3 for 12 hour shifts. Levels for underground occupation groups ranged from 18 to 44 µg/m 3 . Underground diesel loader operators had the highest exposed specific job: 59 µg/m 3 . A lifetime career (45 years) as a surface worker or underground miner, experiencing exposure levels as estimated for 2011 (14 and 44 µg/m 3 EC), was associated with 5.5 and 38 extra lung cancer deaths per 1000 males, respectively. EC exposure levels in the contemporary Australian mining industry are still substantial, particularly for underground workers. The estimated excess numbers of lung cancer deaths associated with these exposures support the need for implementation of stringent occupational exposure limits for diesel exhaust. 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/.

Inhalation of diesel exhaust and allergen alters human bronchial epithelium DNA methylation.

PubMed

Clifford, Rachel L; Jones, Meaghan J; MacIsaac, Julia L; McEwen, Lisa M; Goodman, Sarah J; Mostafavi, Sara; Kobor, Michael S; Carlsten, Chris

2017-01-01

Allergic disease affects 30% to 40% of the world's population, and its development is determined by the interplay between environmental and inherited factors. Air pollution, primarily consisting of diesel exhaust emissions, has increased at a similar rate to allergic disease. Exposure to diesel exhaust may play a role in the development and progression of allergic disease, in particular allergic respiratory disease. One potential mechanism underlying the connection between air pollution and increased allergic disease incidence is DNA methylation, an epigenetic process with the capacity to integrate gene-environment interactions. We sought to investigate the effect of allergen and diesel exhaust exposure on bronchial epithelial DNA methylation. We performed a randomized crossover-controlled exposure study to allergen and diesel exhaust in humans, and measured single-site (CpG) resolution global DNA methylation in bronchial epithelial cells. Exposure to allergen alone, diesel exhaust alone, or allergen and diesel exhaust together (coexposure) led to significant changes in 7 CpG sites at 48 hours. However, when the same lung was exposed to allergen and diesel exhaust but separated by approximately 4 weeks, significant changes in more than 500 sites were observed. Furthermore, sites of differential methylation differed depending on which exposure was experienced first. Functional analysis of differentially methylated CpG sites found genes involved in transcription factor activity, protein metabolism, cell adhesion, and vascular development, among others. These findings suggest that specific exposures can prime the lung for changes in DNA methylation induced by a subsequent insult. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

The Variable Effects of Ozone and/or Diesel Particulate Inhalation Exposure on Allergic Airways Responses in Mice

EPA Science Inventory

Exposure to diesel exhaust particle matter (DEP) associated with the combustion of diesel fuel exacerbates asthma. Likewise, similar effects have been reported with exposure to the oxidizing air pollutant ozone (O₃). Since levels of both pollutants in ambient air are e...

Increased lung resistance after diesel particulate and ozone co-exposure not associated with enhanced lung inflammation in allergic mice*

EPA Science Inventory

Exposure to diesel exhaust particle matter (DEP) exacerbates asthma. Likewise, similar effects have been reported with exposure to the oxidizing air pollutant ozone (03) . Since levels of both pollutants in ambient air tend to be simultaneously elevated, we investigated the possi...

Comparative mutagenicity and genotoxicity of particles and aerosols emitted by the combustion of standard vs. rapeseed methyl ester supplemented bio-diesel fuels: impact of after treatment devices: oxidation catalyst and particulate filter.

PubMed

André, V; Barraud, C; Capron, D; Preterre, D; Keravec, V; Vendeville, C; Cazier, F; Pottier, D; Morin, J P; Sichel, F

2015-01-01

Diesel exhausts are partly responsible for the deleterious effects on human health associated with urban pollution, including cardiovascular diseases, asthma, COPD, and possibly lung cancer. Particulate fraction has been incriminated and thus largely investigated for its genotoxic properties, based on exposure conditions that are, however, not relevant for human risk assessment. In this paper, original and more realistic protocols were used to investigate the hazards induced by exhausts emitted by the combustion of standard (DF0) vs. bio-diesel fuels (DF7 and DF30) and to assess the impact of exhaust treatment devices (DOC and DPF). Mutagenicity and genotoxicity were evaluated for (1) resuspended particles ("off line" exposure that takes into account the bioavailability of adsorbed chemicals) and for (2) the whole aerosols (particles+gas phase components) under continuous flow exposure ("on line" exposure). Native particles displayed mutagenic properties associated with nitroaromatic profiles (YG1041), whereas PAHs did not seem to be involved. After DOC treatment, the mutagenicity of particles was fully abolished. In contrast, the level of particle deposition was low under continuous flow exposure, and the observed mutagenicity in TA98 and TA102 was thus attributable to the gas phase. A bactericidal effect was also observed in TA102 after DOC treatment, and a weak but significant mutagenicity persisted after DPF treatment for bio-diesel fuels. No formation of bulky DNA-adducts was observed on A549 cells exposed to diesel exhaust, even in very drastic conditions (organic extracts corresponding to 500 μg equivalent particule/mL, 48 h exposure). Taken together, these data indicate that the exhausts issued from the bio-diesel fuels supplemented with rapseed methyl ester (RME), and generated by current diesel engines equipped with after treatment devices are less mutagenic than older ones. The residual mutagenicity is linked to the gas phase and could be due to pro

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.

Characterization of particle exposure in ferrochromium and stainless steel production.

PubMed

Järvelä, Merja; Huvinen, Markku; Viitanen, Anna-Kaisa; Kanerva, Tomi; Vanhala, Esa; Uitti, Jukka; Koivisto, Antti J; Junttila, Sakari; Luukkonen, Ritva; Tuomi, Timo

2016-07-01

This study describes workers' exposure to fine and ultrafine particles in the production chain of ferrochromium and stainless steel during sintering, ferrochromium smelting, stainless steel melting, and hot and cold rolling operations. Workers' personal exposure to inhalable dust was assessed using IOM sampler with a cellulose acetate filter (AAWP, diameter 25 mm; Millipore, Bedford, MA). Filter sampling methods were used to measure particle mass concentrations in fixed locations. Particle number concentrations and size distributions were examined using an SMPS+C sequential mobile particle sizer and counter (series 5.400, Grimm Aerosol Technik, Ainring, Germany), and a hand-held condensation particle counter (CPC, model 3007, TSI Incorporated, MN). The structure and elemental composition of particles were analyzed using TEM-EDXA (TEM: JEM-1220, JEOL, Tokyo, Japan; EDXA: Noran System Six, Thermo Fisher Scientific Inc., Madison,WI). Workers' personal exposure to inhalable dust averaged 1.87, 1.40, 2.34, 0.30, and 0.17 mg m(-3) in sintering plant, ferrochromium smelter, stainless steel melting shop, hot rolling mill, and the cold rolling mill, respectively. Particle number concentrations measured using SMPS+C varied from 58 × 10(3) to 662 × 10(3) cm(-3) in the production areas, whereas concentrations measured using SMPS+C and CPC3007 in control rooms ranged from 24 × 10(3) to 243 × 10(3) cm(-3) and 5.1 × 10(3) to 97 × 10(3) cm(-3), respectively. The elemental composition and the structure of particles in different production phases varied. In the cold-rolling mill non-process particles were abundant. In other sites, chromium and iron originating from ore and recycled steel scrap were the most common elements in the particles studied. Particle mass concentrations were at the same level as that reported earlier. However, particle number measurements showed a high amount of ultrafine particles, especially in sintering, alloy smelting and melting, and tapping

Contribution of indoor-generated particles to residential exposure

NASA Astrophysics Data System (ADS)

Isaxon, C.; Gudmundsson, A.; Nordin, E. Z.; Lönnblad, L.; Dahl, A.; Wieslander, G.; Bohgard, M.; Wierzbicka, A.

2015-04-01

The majority of airborne particles in residences, when expressed as number concentrations, are generated by the residents themselves, through combustion/thermal related activities. These particles have a considerably smaller diameter than 2.5 μm and, due to the combination of their small size, chemical composition (e.g. soot) and intermittently very high concentrations, should be regarded as having potential to cause adverse health effects. In this study, time resolved airborne particle measurements were conducted for seven consecutive days in 22 randomly selected homes in the urban area of Lund in southern Sweden. The main purpose of the study was to analyze the influence of human activities on the concentration of particles in indoor air. Focus was on number concentrations of particles with diameters <300 nm generated by indoor activities, and how these contribute to the integrated daily residential exposure. Correlations between these particles and soot mass concentration in total dust were also investigated. It was found that candle burning and activities related to cooking (using a frying pan, oven, toaster, and their combinations) were the major particle sources. The frequency of occurrence of a given concentration indoors and outdoors was compared for ultrafine particles. Indoor data was sorted into non-occupancy and occupancy time, and the occupancy time was further divided into non-activity and activity influenced time. It was found that high levels (above 104 cm-3) indoors mainly occur during active periods of occupancy, while the concentration during non-activity influenced time differs very little from non-occupancy time. Total integrated daily residential exposure of ultrafine particles was calculated for 22 homes, the contribution from known activities was 66%, from unknown activities 20%, and from background/non-activity 14%. The collected data also allowed for estimates of particle source strengths for specific activities, and for some activities

The Diesel Exhaust in Miners study: a nested case-control study of lung cancer and diesel exhaust.

PubMed

Silverman, Debra T; 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

2012-06-06

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. 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. 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 (P (trend) = .001); among heavily

Effects of Diesel Engine Exhaust Origin Secondary Organic Aerosols on Novel Object Recognition Ability and Maternal Behavior in BALB/C Mice

PubMed Central

Win-Shwe, Tin-Tin; Fujitani, Yuji; Kyi-Tha-Thu, Chaw; Furuyama, Akiko; Michikawa, Takehiro; Tsukahara, Shinji; Nitta, Hiroshi; Hirano, Seishiro

2014-01-01

Epidemiological studies have reported an increased risk of cardiopulmonary and lung cancer mortality associated with increasing exposure to air pollution. Ambient particulate matter consists of primary particles emitted directly from diesel engine vehicles and secondary organic aerosols (SOAs) are formed by oxidative reaction of the ultrafine particle components of diesel exhaust (DE) in the atmosphere. However, little is known about the relationship between exposure to SOA and central nervous system functions. Recently, we have reported that an acute single intranasal instillation of SOA may induce inflammatory response in lung, but not in brain of adult mice. To clarify the whole body exposure effects of SOA on central nervous system functions, we first created inhalation chambers for diesel exhaust origin secondary organic aerosols (DE-SOAs) produced by oxidation of diesel exhaust particles caused by adding ozone. Male BALB/c mice were exposed to clean air (control), DE and DE-SOA in inhalation chambers for one or three months (5 h/day, 5 days/week) and were examined for memory function using a novel object recognition test and for memory function-related gene expressions in the hippocampus by real-time RT-PCR. Moreover, female mice exposed to DE-SOA for one month were mated and maternal behaviors and the related gene expressions in the hypothalamus examined. Novel object recognition ability and N-methyl-d-aspartate (NMDA) receptor expression in the hippocampus were affected in male mice exposed to DE-SOA. Furthermore, a tendency to decrease maternal performance and significantly decreased expression levels of estrogen receptor (ER)-α, and oxytocin receptor were found in DE-SOA exposed dams compared with the control. This is the first study of this type and our results suggest that the constituents of DE-SOA may be associated with memory function and maternal performance based on the impaired gene expressions in the hippocampus and hypothalamus, respectively

Workplace exposure to diesel and gasoline engine exhausts and the risk of colorectal cancer in Canadian men.

PubMed

Kachuri, Linda; Villeneuve, Paul J; Parent, Marie-Élise; Johnson, Kenneth C; Harris, Shelley A

2016-01-14

The International Agency for Research on Cancer (IARC) classified diesel exhaust as carcinogenic to humans (Group 1) and gasoline exhaust as a possible carcinogen (Group 2B) based studies of lung cancer, however the evidence for other sites is limited. We addressed this question by investigating exposure to diesel and gasoline emissions with respect to risk of colorectal cancer in men. We used data from a population-based case-control study with incident cases of colon (n = 931) and rectal (n = 840) cancer and 1360 controls from 7 Canadian provinces conducted in 1994-1997. Lifetime occupational history and information on other risk factors was collected. Occupational hygienists, blinded to case-control status, assigned exposures to each job for 3 dimensions: concentration, frequency, and reliability. Logistic regression was used to estimate odds ratios (OR) and their 95 % confidence intervals (CI), adjusted for age, province, use of proxy respondents, smoking, body-mass index, physical activity, intake of alcohol, processed meats, and occupational exposure to asbestos and aromatic amines. Among CRC cases, 638 (36 %) were exposed to diesel and 814 (46 %) were exposed to gasoline emissions. Relative to the unexposed, elevated risks were observed among subjects ever exposed to high concentration levels of diesel emissions for colorectal cancer (OR = 1.65, 95 % CI = 0.98-2.80) and rectal cancer (OR = 1.98, 95 % CI = 1.09-3.60), but not colon cancer. Prolonged (>10 years) exposure at high concentrations was also associated with high risks of rectal cancer (OR = 2.33 95 % CI = 0.94-5.78; p-trend = 0.02). No statistically significant associations were observed for gasoline emissions. Our findings suggest that sustained high-level exposure diesel emissions may increase the risk of rectal cancer.

Variability in Bioreactivity Linked to Changes in Size and Zeta Potential of Diesel Exhaust Particles in Human Immune Cells

PubMed Central

Sarkar, Srijata; Zhang, Lin; Subramaniam, Prasad; Lee, Ki-Bum; Garfunkel, Eric; Strickland, Pamela A. Ohman.; Mainelis, Gediminas; Lioy, Paul J.; Tetley, Teresa D.; Chung, Kian Fan; Zhang, Junfeng; Ryan, Mary; Porter, Alex; Schwander, Stephan

2014-01-01

Acting as fuel combustion catalysts to increase fuel economy, cerium dioxide (ceria, CeO2) nanoparticles have been used in Europe as diesel fuel additives (Envirox™). We attempted to examine the effects of particles emitted from a diesel engine burning either diesel (diesel exhaust particles, DEP) or diesel doped with various concentrations of CeO2 (DEP-Env) on innate immune responses in THP-1 and primary human peripheral blood mononuclear cells (PBMC). Batches of DEP and DEP-Env were obtained on three separate occasions using identical collection and extraction protocols with the aim of determining the reproducibility of particles generated at different times. However, we observed significant differences in size and surface charge (zeta potential) of the DEP and DEP-Env across the three batches. We also observed that exposure of THP-1 cells and PBMC to identical concentrations of DEP and DEP-Env from the three batches resulted in statistically significant differences in bioreactivity as determined by IL-1β, TNF-α, IL-6, IFN-γ, and IL-12p40 mRNA (by qRT-PCR) and protein expression (by ELISPOT assays). Importantly, bioreactivity was noted in very tight ranges of DEP size (60 to 120 nm) and zeta potential (−37 to −41 mV). Thus, these physical properties of DEP and DEP-Env were found to be the primary determinants of the bioreactivity measured in this study. Our findings also point to the potential risk of over- or under- estimation of expected bioreactivity effects (and by inference of public health risks) from bulk DEP use without taking into account potential batch-to-batch variations in physical (and possibly chemical) properties. PMID:24825358

Estimation of southern resident killer whale exposure to exhaust emissions from whale-watching vessels and potential adverse health effects and toxicity thresholds.

PubMed

Lachmuth, Cara L; Barrett-Lennard, Lance G; Steyn, D Q; Milsom, William K

2011-04-01

Southern resident killer whales in British Columbia and Washington are exposed to heavy vessel traffic. This study investigates their exposure to exhaust gases from whale-watching vessels by using a simple dispersion model incorporating data on whale and vessel behavior, atmospheric conditions, and output of airborne pollutants from the whale-watching fleet based on emissions data from regulatory agencies. Our findings suggest that current whale-watching guidelines are usually effective in limiting pollutant exposure to levels at or just below those at which measurable adverse health effects would be expected in killer whales. However, safe pollutant levels are exceeded under worst-case conditions and certain average-case conditions. To reduce killer whale exposure to exhaust we recommend: vessels position on the downwind side of whales, a maximum of 20 whale-watching vessels should be within 800 m at any given time, viewing periods should be limited, and current whale-watch guidelines and laws should be enforced. Copyright © 2011. Published by Elsevier Ltd.

NEUROGENIC RESPONSES OF RAT LUNG TO DIESEL EXHAUST

EPA Science Inventory

The investigators are among the first researchers to investigate neurogenic inflammation in the lungs of rats exposed to whole diesel exhaust. After exposure to both concentrations of diesel exhaust, consistently higher levels of plasma leakage and lower activity of the enz...

Investigation of the influence of humidity on the ultrasonic agglomeration of submicron particles in diesel exhausts.

PubMed

Riera-Franco de Sarabia, E; Elvira-Segura, L; González-Gómez, I; Rodríguez-Maroto, J J; Muñoz-Bueno, R; Dorronsoro-Areal, J L

2003-06-01

Removing very fine particles in the 0.01-1 micro m range generated in diesel combustion is important for air pollution abatement because of the impact such particles have on the environment. By forming larger particles, acoustic agglomeration of submicron particles is presented as a promising process for enhancing the efficiency of the current filtration systems for particle removal. Nevertheless, some authors have pointed out that acoustic agglomeration is much more efficient for larger particles than for smaller particles. This paper studies the effect of humidity on the acoustic agglomeration of diesel exhausts particles in the nanometer size range at 21 kHz. For the agglomeration tests, the experimental facility basically consists of a pilot scale plant with a diesel engine, an ultrasonic agglomeration chamber a dilution system, a nozzle atomizer, and an aerosol sampling and measuring station. The effect of the ultrasonic treatment, generated by a linear array of four high-power stepped-plate transducers on fumes at flow rates of 900 Nm(3)/h, was a small reduction in the number concentration of particles at the outlet of the chamber. However, the presence of humidity raised the agglomeration rate by decreasing the number particle concentration by up to 56%. A numerical study of the agglomeration process as a linear combination of the orthokinetic and hydrodynamic agglomeration coefficients resulting from mutual radiation pressure also found that acoustic agglomeration was enhanced by humidity. Both results confirm the benefit of using high-power ultrasound together with humidity to enhance the agglomeration of particles much smaller than 1 micro m.

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

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

The Diesel Exhaust in Miners Study: II. Exposure monitoring surveys and development of exposure groups.

PubMed

Coble, Joseph B; Stewart, Patricia A; Vermeulen, Roel; Yereb, Daniel; Stanevich, Rebecca; Blair, Aaron; Silverman, Debra T; Attfield, Michael

2010-10-01

Air monitoring surveys were conducted between 1998 and 2001 at seven non-metal mining facilities to assess exposure to respirable elemental carbon (REC), a component of diesel exhaust (DE), for an epidemiologic study of miners exposed to DE. Personal exposure measurements were taken on workers in a cross-section of jobs located underground and on the surface. Air samples taken to measure REC were also analyzed for respirable organic carbon (ROC). Concurrent measurements to assess exposure to nitric oxide (NO) and nitrogen dioxide (NO₂), two gaseous components of DE, were also taken. The REC measurements were used to develop quantitative estimates of average exposure levels by facility, department, and job title for the epidemiologic analysis. Each underground job was assigned to one of three sets of exposure groups from specific to general: (i) standardized job titles, (ii) groups of standardized job titles combined based on the percentage of time in the major underground areas, and (iii) larger groups based on similar area carbon monoxide (CO) air concentrations. Surface jobs were categorized based on their use of diesel equipment and proximity to DE. A total of 779 full-shift personal measurements were taken underground. The average REC exposure levels for underground jobs with five or more measurements ranged from 31 to 58 μg m⁻³ at the facility with the lowest average exposure levels and from 313 to 488 μg m⁻³ at the facility with the highest average exposure levels. The average REC exposure levels for surface workers ranged from 2 to 6 μg m⁻³ across the seven facilities. There was much less contrast in the ROC compared with REC exposure levels measured between surface and underground workers within each facility, as well as across the facilities. The average ROC levels underground ranged from 64 to 195 μg m⁻³, while on the surface, the average ROC levels ranged from 38 to 71 μg m⁻³ by facility, an ∼2- to 3-fold difference. The average

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

Controlled human exposures to ambient pollutant particles in susceptible populations

EPA Science Inventory

Epidemiologic studies have established an association between exposures to air pollution particles and human mortality and morbidity at concentrations of particles currently found in major metropolitan areas. The adverse effects of pollution particles are most prominent in suscep...

Exposure to wood smoke particles produces inflammation in healthy volunteers.

PubMed

Ghio, Andrew J; Soukup, Joleen M; Case, Martin; Dailey, Lisa A; Richards, Judy; Berntsen, Jon; Devlin, Robert B; Stone, Susan; Rappold, Ana

2012-03-01

Human exposure to wood smoke particles (WSP) impacts on human health through changes in indoor air quality, exposures from wild fires, burning of biomass and air pollution. This investigation tested the postulate that healthy volunteers exposed to WSP would demonstrate evidence of both pulmonary and systemic inflammation. Ten volunteers were exposed to filtered air and, 3 weeks or more later, WSP. Each exposure included alternating 15 min of exercise and 15 min of rest for a total duration of 2 h. Wood smoke was generated by heating an oak log on an electric element and then delivered to the exposure chamber. Endpoints measured in the volunteers included symptoms, pulmonary function tests, measures of heart rate variability and repolarisation, blood indices and analysis of cells and fluid obtained during bronchoalveolar lavage. Mean particle mass for the 10 exposures to air and WSP was measured using the mass of particles collected on filters and found to be below the detectable limit and 485±84 μg/m(3), respectively (mean±SD). There was no change in either symptom prevalence or pulmonary function with exposure to WSP. At 20 h after wood smoke exposure, blood tests demonstrated an increased percentage of neutrophils, and bronchial and bronchoalveolar lavage revealed a neutrophilic influx. We conclude that exposure of healthy volunteers to WSP may be associated with evidence of both systemic and pulmonary inflammation.

Role of snow in the fate of gaseous and particulate exhaust pollutants from gasoline-powered vehicles.

PubMed

Nazarenko, Yevgen; Fournier, Sébastien; Kurien, Uday; Rangel-Alvarado, Rodrigo Benjamin; Nepotchatykh, Oleg; Seers, Patrice; Ariya, Parisa A

2017-04-01

Little is known about pollution in urban snow and how aerosol and gaseous air pollutants interact with the urban snowpack. Here we investigate interactions of exhaust pollution with snow at low ambient temperature using fresh snow in a temperature-controlled chamber. A gasoline-powered engine from a modern light duty vehicle generated the exhaust and was operated in homogeneous and stratified engine regimes. We determined that, within a timescale of 30 min, snow takes up from the exhaust a large mass of organic pollutants and aerosol particles, which were observed by electron microscopy, mass spectrometry and aerosol sizers. Specifically, the concentration of total organic carbon in the exposed snow increased from 0.948 ± 0.009 to 1.828 ± 0.001 mg/L (homogeneous engine regime) and from 0.275 ± 0.005 to 0.514 ± 0.008 mg/L (stratified engine regime). The concentrations of benzene, toluene and 13 out of 16 measured polycyclic aromatic hydrocarbons (PAHs), particularly naphthalene, benz[a]anthracene, chrysene and benzo[a]pyrene in snow increased upon exposure from near the detection limit to 0.529 ± 0.058, 1.840 ± 0.200, 0.176 ± 0.020, 0.020 ± 0.005, 0.025 ± 0.005 and 0.028 ± 0.005 ng/kg, respectively, for the homogeneous regime. After contact with snow, 50-400 nm particles were present with higher relative abundance compared to the smaller nanoparticles (<50 nm), for the homogeneous regime. The lowering of temperature from 25 ± 1 °C to (-8) - (-10) ± 1 °C decreased the median mode diameter of the exhaust aerosol particles from 69 nm to 57 nm (p < 0.1) and addition of snow to 51 nm (p < 0.1) for the stratified regime, but increased it from 20 nm to 27 nm (p < 0.1) for the homogeneous regime. Future studies should focus on cycling of exhaust-derived pollutants between the atmosphere and cryosphere. The role of the effects we discovered should be evaluated as part of assessment of pollutant loads and exposures in

[Size distribution of particle and polycyclic aromatic hydrocarbons in particle emissions from simulated emission sources].

PubMed

Fu, Hai-Huan; Tian, Na; Shang, Hui-Bin; Zhang, Bin; Ye, Su-Fen; Chen, Xiao-Qiu; Wu, Shui-Ping

2014-01-01

Particles from cooking lampblack, biomass and plastics burning smoke, gasoline vehicular exhausts and gasoline generator exhausts were prepared in a resuspension test chamber and collected using a cascade MOUDI impactor. A total of 18 polycyclic aromatic hydrocarbons (PAHs) associated with particles were analyzed by GC-MS. The results showed that there were two peaks in the range of 0.44-1.0 microm and 2.5-10 microm for cooking lampblack, and only one peak in the range of 0.44-1.0 microm for straw and wood burning smoke. But there were no clear peak for plastics burning smoke. The peak for gasoline vehicular exhausts was found in the range of 2.5-10 microm due to the influence of water vapor associated with particles, while the particles from gasoline generator exhausts were mainly in the range of < or = 2.5 microm (accounting for 93% of the total mass). The peak in 2.5-10 microm was clear for cooking lampblack and gasoline vehicular exhausts. The peak in the range of 0.44-1.0 microm became more and more apparent with the increase of PAHs molecular weight. The fraction of PAH on particles less than 1.0 microm to that on the total particles increased along with PAH's molecular weight. Phenanthrene was the dominant compound for cooking lampblack and combustion smoke, while gasoline vehicular exhausts and generator exhausts were characterized with significantly high levels of naphthalene and benzo[g, h, i] perylene, respectively. The distribution of source characteristic ratios indicated that PAHs from cooking lampblack and biomass burning were close and they were different from those of vehicular exhausts and generator exhausts.

Commuter exposure to ultrafine particles in different urban locations, transportation modes and routes

NASA Astrophysics Data System (ADS)

Ragettli, Martina S.; Corradi, Elisabetta; Braun-Fahrländer, Charlotte; Schindler, Christian; de Nazelle, Audrey; Jerrett, Michael; Ducret-Stich, Regina E.; Künzli, Nino; Phuleria, Harish C.

2013-10-01

A better understanding of ultrafine particle (UFP) exposure in different urban transport microenvironments is important for epidemiological exposure assessments and for policy making. Three sub-studies were performed to characterize personal exposure to UFP concentration and average particle size distribution diameters in frequently traveled commuter microenvironments in the city of Basel, Switzerland. First, the spatial variation of sidewalk UFP exposures within urban areas and transport-specific microenvironments was explored. Second, exposure to UFP concentration and average particle size were quantified for five modes of transportation (walking, bicycle, bus, tram, car) during different times of the day and week, along the same route. Finally, the contribution of bicycle commuting along two different routes (along main roads, away from main roads) to total daily exposures was assessed by 24-h personal measurements. In general, smaller average particle sizes and higher UFP levels were measured at places and for travel modes in close proximity to traffic. Average trip UFP concentrations were higher in car (31,784 particles cm-³) and on bicycle (22,660 particles cm-³) compared to walking (19,481 particles cm-³) and public transportation (14,055-18,818 particles cm-³). Concentrations were highest for all travel modes during weekday morning rush hours, compared to other time periods. UFP concentration was lowest in bus, regardless of time period. Bicycle travel along main streets between home and work place (24 min on average) contributed 21% and 5% to total daily UFP exposure in winter and summer, respectively. Contribution of bicycle commutes to total daily UFP exposure could be reduced by half if main roads are avoided. Our results show the importance of considering commuter behavior and route choice in exposure assessment studies.

The Diesel Exhaust in Miners Study: II. Exposure Monitoring Surveys and Development of Exposure Groups

PubMed Central

Coble, Joseph B.; Stewart, Patricia A.; Vermeulen, Roel; Yereb, Daniel; Stanevich, Rebecca; Blair, Aaron; Silverman, Debra T.; Attfield, Michael

2010-01-01

Air monitoring surveys were conducted between 1998 and 2001 at seven non-metal mining facilities to assess exposure to respirable elemental carbon (REC), a component of diesel exhaust (DE), for an epidemiologic study of miners exposed to DE. Personal exposure measurements were taken on workers in a cross-section of jobs located underground and on the surface. Air samples taken to measure REC were also analyzed for respirable organic carbon (ROC). Concurrent measurements to assess exposure to nitric oxide (NO) and nitrogen dioxide (NO2), two gaseous components of DE, were also taken. The REC measurements were used to develop quantitative estimates of average exposure levels by facility, department, and job title for the epidemiologic analysis. Each underground job was assigned to one of three sets of exposure groups from specific to general: (i) standardized job titles, (ii) groups of standardized job titles combined based on the percentage of time in the major underground areas, and (iii) larger groups based on similar area carbon monoxide (CO) air concentrations. Surface jobs were categorized based on their use of diesel equipment and proximity to DE. A total of 779 full-shift personal measurements were taken underground. The average REC exposure levels for underground jobs with five or more measurements ranged from 31 to 58 μg m−3 at the facility with the lowest average exposure levels and from 313 to 488 μg m−3 at the facility with the highest average exposure levels. The average REC exposure levels for surface workers ranged from 2 to 6 μg m−3 across the seven facilities. There was much less contrast in the ROC compared with REC exposure levels measured between surface and underground workers within each facility, as well as across the facilities. The average ROC levels underground ranged from 64 to 195 μg m−3, while on the surface, the average ROC levels ranged from 38 to 71 μg m−3 by facility, an ∼2- to 3-fold difference. The average NO and

Filterable redox cycling activity: a comparison between diesel exhaust particles and secondary organic aerosol constituents.

PubMed

McWhinney, Robert D; Badali, Kaitlin; Liggio, John; Li, Shao-Meng; Abbatt, Jonathan P D

2013-04-02

The redox activity of diesel exhaust particles (DEP) collected from a light-duty diesel passenger car engine was examined using the dithiothreitol (DTT) assay. DEP was highly redox-active, causing DTT to decay at a rate of 23-61 pmol min(-1) μg(-1) of particle used in the assay, which was an order of magnitude higher than ambient coarse and fine particulate matter (PM) collected from downtown Toronto. Only 2-11% of the redox activity was in the water-soluble portion, while the remainder occurred at the black carbon surface. This is in contrast to redox-active secondary organic aerosol constituents, in which upward of 90% of the activity occurs in the water-soluble fraction. The redox activity of DEP is not extractable by moderately polar (methanol) and nonpolar (dichloromethane) organic solvents, and is hypothesized to arise from redox-active moieties contiguous with the black carbon portion of the particles. These measurements illustrate that "Filterable Redox Cycling Activity" may therefore be useful to distinguish black carbon-based oxidative capacity from water-soluble organic-based activity. The difference in chemical environment leading to redox activity highlights the need to further examine the relationship between activity in the DTT assay and toxicology measurements across particles of different origins and composition.

Sampling and analysis of aircraft engine cold start particles and demonstration of an electrostatic personal particle sampler.

PubMed

Armendariz, Alfredo; Leith, David; Boundy, Maryanne; Goodman, Randall; Smith, Les; Carlton, Gary

2003-01-01

Aircraft engines emit an aerosol plume during startup in extremely cold weather that can drift into areas occupied by flightline ground crews. This study tested a personal sampler used to assess exposure to particles in the plume under challenging field conditions. Area and personal samples were taken at two U.S. Air Force (USAF) flightlines during the winter months. Small tube-and-wire electrostatic precipitators (ESPs) were mounted on a stationary stand positioned behind the engines to sample the exhaust. Other ESPs were worn by ground crews to sample breathing zone concentrations. In addition, an aerodynamic particle sizer 3320 (APS) was used to determine the size distribution of the particles. Samples collected with the ESP were solvent extracted and analyzed with gas chromatography-mass spectrometry. Results indicated that the plume consisted of up to 75 mg/m(3) of unburned jet fuel particles. The APS showed that nearly the entire particle mass was respirable, because the plumes had mass median diameters less than 2 micro m. These tests demonstrated that the ESP could be used at cold USAF flightlines to perform exposure assessments to the cold start particles.

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

Engine-Operating Load Influences Diesel Exhaust Composition and Cardiopulmonary and Immune Responses

PubMed Central

Campen, Matthew J.; Harrod, Kevin S.; Seagrave, JeanClare; Seilkop, Steven K.; Mauderly, Joe L.

2011-01-01

Background: The composition of diesel engine exhaust (DEE) varies by engine type and condition, fuel, engine operation, and exhaust after treatment such as particle traps. DEE has been shown to increase inflammation, susceptibility to infection, and cardiovascular responses in experimentally exposed rodents and humans. Engines used in these studies have been operated at idle, at different steady-state loads, or on variable-load cycles, but exposures are often reported only as the mass concentration of particulate matter (PM), and the effects of different engine loads and the resulting differences in DEE composition are unknown. Objectives: We assessed the impacts of load-related differences in DEE composition on models of inflammation, susceptibility to infection, and cardiovascular toxicity. Methods: We assessed inflammation and susceptibility to viral infection in C57BL/6 mice and cardiovascular toxicity in APOE–/– mice after being exposed to DEE generated from a single-cylinder diesel generator operated at partial or full load. Results: At the same PM mass concentration, partial load resulted in higher proportions of particle organic carbon content and a smaller particle size than did high load. Vapor-phase hydrocarbon content was greater at partial load. Compared with high-load DEE, partial-load DEE caused greater responses in heart rate and T-wave morphology, in terms of both magnitude and rapidity of onset of effects, consistent with previous findings that systemic effects may be driven largely by the gas phase of the exposure atmospheres. However, high-load DEE caused more lung inflammation and greater susceptibility to viral infection than did partial load. Conclusions: Differences in engine load, as well as other operating variables, are important determinants of the type and magnitude of responses to inhaled DEE. PM mass concentration alone is not a sufficient basis for comparing or combining results from studies using DEE generated under different

Diesel exhaust particles up-regulate interleukin-17A expression via ROS/NF-κB in airway epithelium.

PubMed

Weng, Chih-Ming; Lee, Meng-Jung; He, Jung-Re; Chao, Ming-Wei; Wang, Chun-Hua; Kuo, Han-Pin

2018-05-01

IL-17A is implicated in many aspects of pathogenesis of severe asthma, including inducing neutrophilic inflammation, airway hyperresponsiveness, steroid insensitivity and airway remodeling. Diesel exhaust particles (DEP) emission from vehicles has been shown to expand Th17 cells to increase IL-17A release that contributes to DEP-mediated exacerbation of asthma severity. It is not known whether non-immune cells in airways may also release IL-17A in response to DEP exposure. In this study, We found IL-17A expression was upregulated in the epithelium of severe allergic asthma patients from high road traffic pollution areas compared to those in low. Furthermore, we found DEP concentration-dependently increased IL-17A synthesis and release by 122.3 ± 15.72% and 235.5 ± 18.37%, respectively in primary bronchial epithelial cells (PBEC), accompanied with increased ROS production. Pretreatment of ROS scavenger (NAC) significantly inhibited DEP-induced IL-17A mRNA expression. DEP-induced IκBα degradation can be inhibited by NAC. We also found DEP increased p65 and RelB subunits expression, and pretreatment of NF-κB inhibitor (SN50) also inhibited DEP-induced IL-17A expression. We further found DEP increased NF-κB subunit RelB recruitment to IL-17A promoter in PBEC and airway tissue of severe allergic asthma patients from high road traffic pollution areas. These results indicate DEP stimulates IL-17A expression in airway epithelium through ROS/NF-κB pathway, and provide a possible link between traffic pollution exposure and IL-17A-related responses in severe allergic asthma patients. Copyright © 2018 Elsevier Inc. All rights reserved.

Particles exposure while sitting at bus stops of hot and humid Singapore

NASA Astrophysics Data System (ADS)

Velasco, Erik; Tan, Sok Huang

2016-10-01

Transport microenvironments represent hotspots of personal exposure to airborne toxics, particularly of ultrafine particles. Thus, a large exposure may be experienced during daily commuting trips. Amongst these microenvironments, bus stops are critical because of the commuters' close proximity to fresh fumes rich in particles emitted by passing, idling and accelerating buses and motor vehicles, in general. Standing at a bus stop may represent a period of disproportionately high exposure and it is, therefore, essential to know the number, chemical composition and physical characteristics of such particles for a proper public health assessment and design of mobility strategies. On this account, a set of portable and battery operated sensors were used to evaluate a number of properties of the traffic particles to which thousands of citizens are daily exposed at bus stops of Singapore. In terms of fine particles, the exposure concentration was on average 1.5-3 times higher than the mean concentration at ambient level reported by the local authorities. On average 60% of those particles corresponded to black carbon. An important presence of particle-bound polycyclic aromatics was observed. The particle number concentration and active surface area were effective metrics to quantify ultrafine particles, as expected both showed strong correlations. The number of particles at bus stops was on average 3.5 times higher than at ambient level. The most alarming issue was probably the size of the particles. Assuming spherical particles, a median of 27 nm was estimated based on the active surface area and particle number data. Particles of this size form the nucleation mode, which is related to harmful health effects.

The biological effects of subacute inhalation of diesel exhaust following addition of cerium oxide nanoparticles in atherosclerosis-prone mice☆

PubMed Central

Cassee, Flemming R.; Campbell, Arezoo; Boere, A. John F.; McLean, Steven G.; Duffin, Rodger; Krystek, Petra; Gosens, Ilse; Miller, Mark R.

2012-01-01

Background Cerium oxide (CeO2) nanoparticles improve the burning efficiency of fuel, however, little is known about health impacts of altered emissions from the vehicles. Methods Atherosclerosis-prone apolipoprotein E knockout (ApoE−/−) mice were exposed by inhalation to diluted exhaust (1.7 mg/m3, 20, 60 or 180 min, 5 day/week, for 4 weeks), from an engine using standard diesel fuel (DE) or the same diesel fuel containing 9 ppm cerium oxide nanoparticles (DCeE). Changes in hematological indices, clinical chemistry, atherosclerotic burden, tissue levels of inflammatory cytokines and pathology of the major organs were assessed. Results Addition of CeO2 to fuel resulted in a reduction of the number (30%) and surface area (10%) of the particles in the exhaust, whereas the gaseous co-pollutants were increased (6–8%). There was, however, a trend towards an increased size and complexity of the atherosclerotic plaques following DE exposure, which was not evident in the DCeE group. There were no clear signs of altered hematological or pathological changes induced by either treatment. However, levels of proinflammatory cytokines were modulated in a brain region and liver following DCeE exposure. Conclusions These results imply that addition of CeO2 nanoparticles to fuel decreases the number of particles in exhaust and may reduce atherosclerotic burden associated with exposure to standard diesel fuel. From the extensive assessment of biological parameters performed, the only concerning effect of cerium addition was a slightly raised level of cytokines in a region of the central nervous system. Overall, the use of cerium as a fuel additive may be a potentially useful way to limit the health effects of vehicle exhaust. However, further testing is required to ensure that such an approach is not associated with a chronic inflammatory response which may eventually cause long-term health effects. PMID:22507957

Inflammation-Related Effects of Diesel Engine Exhaust Particles: Studies on Lung Cells In Vitro

PubMed Central

Schwarze, P. E.; Totlandsdal, A. I.; Låg, M.; Refsnes, M.; Holme, J. A.; Øvrevik, J.

2013-01-01

Diesel exhaust and its particles (DEP) have been under scrutiny for health effects in humans. In the development of these effects inflammation is regarded as a key process. Overall, in vitro studies report similar DEP-induced changes in markers of inflammation, including cytokines and chemokines, as studies in vivo. In vitro studies suggest that soluble extracts of DEP have the greatest impact on the expression and release of proinflammatory markers. Main DEP mediators of effects have still not been identified and are difficult to find, as fuel and engine technology developments lead to continuously altered characteristics of emissions. Involved mechanisms remain somewhat unclear. DEP extracts appear to comprise components that are able to activate various membrane and cytosolic receptors. Through interactions with receptors, ion channels, and phosphorylation enzymes, molecules in the particle extract will trigger various cell signaling pathways that may lead to the release of inflammatory markers directly or indirectly by causing cell death. In vitro studies represent a fast and convenient system which may have implications for technology development. Furthermore, knowledge regarding how particles elicit their effects may contribute to understanding of DEP-induced health effects in vivo, with possible implications for identifying susceptible groups of people and effect biomarkers. PMID:23509760

LIVE CELL IMAGING OF THE OXIDATIVE EFFECTS OF EXPOSURE TO AN ORGANIC PM COMPONENT

EPA Science Inventory

RATIONALE. Exposure to ambient particulate matter (PM) has been associated with adverse health effects, including inflammatory responses in the lung. Diesel exhaust particles (DEP) are a ubiquitous contributor of the fine and ultrafine PM burden in ambient air. Toxicological stud...

Inhalation exposure during spray application and subsequent sanding of a wood sealant containing zinc oxide nanoparticles.

PubMed

Cooper, Michael R; West, Gavin H; Burrelli, Leonard G; Dresser, Daniel; Griffin, Kelsey N; Segrave, Alan M; Perrenoud, Jon; Lippy, Bruce E

2017-07-01

Nano-enabled construction products have entered into commerce. There are concerns about the safety of manufactured nanomaterials, and exposure assessments are needed for a more complete understanding of risk. This study assessed potential inhalation exposure to ZnO nanoparticles during spray application and power sanding of a commercially available wood sealant and evaluated the effectiveness of local exhaust ventilation in reducing exposure. A tradesperson performed the spraying and sanding inside an environmentally-controlled chamber. Dust control methods during sanding were compared. Filter-based sampling, electron microscopy, and real-time particle counters provided measures of exposure. Airborne nanoparticles above background levels were detected by particle counters for all exposure scenarios. Nanoparticle number concentrations and particle size distributions were similar for sanding of treated versus untreated wood. Very few unbound nanoparticles were detected in aerosol samples via electron microscopy, rather nano-sized ZnO was contained within, or on the surface of larger airborne particles. Whether the presence of nanoscale ZnO in these aerosols affects toxicity merits further investigation. Mass-based exposure measurements were below the NIOSH Recommended Exposure Limit for Zn, although there are no established exposure limits for nanoscale ZnO. Local exhaust ventilation was effective, reducing airborne nanoparticle number concentrations by up to 92% and reducing personal exposure to total dust by at least 80% in terms of mass. Given the discrepancies between the particle count data and electron microscopy observations, the chemical identity of the airborne nanoparticles detected by the particle counters remains uncertain. Prior studies attributed the main source of nanoparticle emissions during sanding to copper nanoparticles generated from electric sander motors. Potentially contrary results are presented suggesting the sander motor may not have been

[Worker exposure to ultrafine particles during carbon black treatment].

PubMed

Mikołajczyk, Urszula; Bujak-Pietrek, Stella; Szadkowska-Stańczyk, Irena

2015-01-01

The aim of the project was to assess the exposure of workers to ultrafine particles released during handling and packing of carbon black. The assessment included the results of the measurements performed in a carbon black handling plant before, during, and after work shift. The number concentration of particles within the dimension range 10-1000 nm and 10-100 nm was assayed by a condensation particle counter (CPC). The mass concentration of particles was determined by a DustTrak II DRX aerosol concentration monitor. The surface area concentration of the particles potentially deposited in the alveolar (A) and tracheo-bronchial (TB) regions was estimated by an AeroTrak 9000 nanoparticle monitor. An average mass concentration of particles during the process was 6-fold higher than that before its start, while a 3-fold increase in the average number concentration of particles within the dimension range 10-1000 nm and 10-100 nm was observed during the process. At the same time a 4-fold increase was found in the surface area concentration of the particles potentially deposited in the A and TB regions. During the process of carbon black handling and packing a significantly higher values of each of the analysed parameters, characterizing the exposure to ultrafine particles, were noted. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Exposures to nanoparticles and fibers during injection molding and recycling of carbon nanotube reinforced polycarbonate composites.

PubMed

Boonruksa, Pongsit; Bello, Dhimiter; Zhang, Jinde; Isaacs, Jacqueline A; Mead, Joey L; Woskie, Susan R

2017-07-01

In this study, the characteristics of airborne particles generated during injection molding and grinding processes of carbon nanotube reinforced polycarbonate composites (CNT-PC) were investigated. Particle number concentration, size distribution, and morphology of particles emitted from the processes were determined using real-time particle sizers and transmission electron microscopy. The air samples near the operator's breathing zone were collected on filters and analyzed using scanning electron microscope for particle morphology and respirable fiber count. Processing and grinding during recycling of CNT-PC released airborne nanoparticles (NPs) with a geometric mean (GM) particle concentration from 4.7 × 10 3 to 1.7 × 10 6 particles/cm 3 . The ratios of the GM particle concentration measured during the injection molding process with exhaust ventilation relative to background were up to 1.3 (loading), 1.9 (melting), and 1.4 (molding), and 101.4 for grinding process without exhaust ventilation, suggesting substantial NP exposures during these processes. The estimated mass concentration was in the range of 1.6-95.2 μg/m 3 . Diverse particle morphologies, including NPs, NP agglomerates, particles with embedded or protruding CNTs and fibers, were observed. No free CNTs were found during any of the investigated processes. The breathing zone respirable fiber concentration during the grinding process ranged from non-detectable to 0.13 fiber/cm 3 . No evidence was found that the emissions were affected by the number of recycling cycles. Institution of exposure controls is recommended during these processes to limit exposures to airborne NPs and CNT-containing fibers.

Residential indoor and outdoor coarse particles and associated endotoxin exposures

NASA Astrophysics Data System (ADS)

Wheeler, Amanda J.; Dobbin, Nina A.; Lyrette, Ninon; Wallace, Lance; Foto, Mark; Mallick, Ranjeeta; Kearney, Jill; Van Ryswyk, Keith; Gilbert, Nicolas L.; Harrison, Ian; Rispler, Kathleen; Héroux, Marie-Eve

2011-12-01

There is a growing body of evidence demonstrating that coarse particles (PM 10-2.5) have detrimental impacts upon health, especially for respiratory effects. There are limited data available for indoor residential exposures. Some data exist regarding the composition of this PM size fraction with emphasis on crustal elements and biological components. This study includes data from 146 homes sampled in Regina, Saskatchewan (SK) where 5-day integrated concurrent monitoring of indoor and outdoor coarse particles was conducted during the winter and summer of 2007. The coarse particle filters were subsequently analysed for endotoxin content to determine the contribution of this compound. Winter indoor geometric mean concentrations of coarse particles exceeded outdoor concentrations (3.73 μg m -3 vs 2.49 μg m -3; paired t-test p < 0.0001); however the reverse was found in summer (4.34 μg m -3 vs 8.82 μg m -3; paired t-test p < 0.0001). Linear regression indicated that winter predictors of indoor coarse particles were outdoor coarse particles, ventilation and presence of at least two or more occupants. During the summer, increased use of central air conditioning was associated with reduced coarse particles, while smoking and the presence of two or more occupants resulted in increased coarse particles. Endotoxin concentrations (EU μg -1) were lower indoors than outdoors in both seasons. Spatial variability of ambient coarse particles was assessed to determine the suitability of using a single monitoring station within a city to estimate exposure. The coefficients of variation between homes sampled simultaneously and the central monitoring station were calculated (median COV in summer = 15% and winter = 24%) and showed significant variability by week, especially during the summer months, suggesting a single site may be insufficient for characterizing exposure. Future studies should consider daily measurements per home to understand shorter term exposures and day to day

Diesel particle-induced transcriptional expression of P21 involves activation of EGFR, SRC, and STAT3

EPA Science Inventory

Exposure to diesel exhaust particles (DEP) has been associated with adverse health outcomes such as inflammation, adjuvancy, and mutagenesis. However, the molecular mechanisms by which DEP inhalation exerts these effects are still largely unknown. We previously reported that expo...

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

Strategies for setting occupational exposure limits for particles.

PubMed Central

Greim, H A; Ziegler-Skylakakis, K

1997-01-01

To set occupational exposure limits (OELs) for aerosol particles, dusts, or chemicals, one has to evaluate whether mechanistic considerations permit identification of a no observed effect level (NOEL). In the case of carcinogenic effects, this can be assumed if no genotoxicity is involved, and exposure is considered safe if it does not exceed the NOEL. If tumor induction is associated with genotoxicity, any exposure is considered to be of risk, although a NOEL may be identified in the animal or human exposure studies. This must also be assumed when no information on the carcinogenic mechanism, including genotoxicity, is available. Aerosol particles, especially fibrous dusts, which include man-made mineral fiber(s) (MMMF), present a challenge for toxicological evaluation. Many MMMF that have been investigated have induced tumors in animals and genotoxicity in vitro. Since these effects have been associated with long-thin fiber geometry and high durability in vivo, all fibers meeting such criteria are considered carcinogenic unless the opposite has been demonstrated. This approach is practicable. Investigations on fiber tumorigenicity/genotoxicity should include information on dose response, pathobiochemistry, particle clearance, and persistence of the material in the target organ. Such information will introduce quantitative aspects into the qualitative approach that has so far been used to classify fibrous dusts as carcinogens. The rationales for classifying the potential carcinogenicity of MMMF and for setting OELs used by the different European committees and regulatory agencies are described. PMID:9400750

Constraints on Exposure Ages of Lunar and Asteroidal Regolith Particles

NASA Technical Reports Server (NTRS)

Berger, Eve L.; Keller, Lindsay P

2014-01-01

Mineral grains in lunar and asteroidal regolith samples provide a unique record of their interaction with the space environment. Exposure to the solar wind results in implantation effects that are preserved in the rims of grains (typically the outermost 100 nm), while impact processes result in the accumulation of vapor-deposited elements, impact melts and adhering grains on particle surfaces. These processes are collectively referred to as space weathering. A critical element in the study of these processes is to determine the rate at which these effects accumulate in the grains during their space exposure. For small particulate samples, one can use the density of solar flare particle tracks to infer the length of time the particle was at the regolith surface (i.e., its exposure age). We have developed a new technique that enables more accurate determination of solar flare particle track densities in mineral grains <50 micron in size that utilizes focused ion beam (FIB) sample preparation combined with transmission electron microscopy (TEM) imaging. We have applied this technique to lunar soil grains from the Apollo 16 site (soil 64501) and most recently to samples from asteroid 25143 Itokawa returned by the Hayabusa mission. Our preliminary results show that the Hayabusa grains have shorter exposure ages compared to typical lunar soil grains. We will use these techniques to re-examine the track density-exposure age calibration from lunar samples reported by Blanford et al. (1975).

Personal exposure to ultrafine particles: the influence of time-activity patterns.

PubMed

Buonanno, G; Stabile, L; Morawska, L

2014-01-15

Exposure to ultrafine particles (UFPs) is deemed to be a major risk affecting human health. Therefore, airborne particle studies were performed in the recent years to evaluate the most critical micro-environments, as well as identifying the main UFP sources. Nonetheless, in order to properly evaluate the UFP exposure, personal monitoring is required as the only way to relate particle exposure levels to the activities performed and micro-environments visited. To this purpose, in the present work, the results of experimental analysis aimed at showing the effect of the time-activity patterns on UFP personal exposure are reported. In particular, 24 non-smoking couples (12 during winter and summer time, respectively), comprised of a man who worked full-time and a woman who was a homemaker, were analyzed using personal particle counter and GPS monitors. Each couple was investigated for a 48-h period, during which they also filled out a diary reporting the daily activities performed. Time activity patterns, particle number concentration exposure and the related dose received by the participants, in terms of particle alveolar-deposited surface area, were measured. The average exposure to particle number concentration was higher for women during both summer and winter (Summer: women 1.8 × 10(4) part. cm(-3); men 9.2 × 10(3) part. cm(-3); Winter: women 2.9 × 10(4) part. cm(-3); men 1.3 × 10(4) part. cm(-3)), which was likely due to the time spent undertaking cooking activities. Staying indoors after cooking also led to higher alveolar-deposited surface area dose for both women and men during the winter time (9.12 × 10(2) and 6.33 × 10(2) mm(2), respectively), when indoor ventilation was greatly reduced. The effect of cooking activities was also detected in terms of women's dose intensity (dose per unit time), being 8.6 and 6.6 in winter and summer, respectively. On the contrary, the highest dose intensity activity for men was time spent using transportation (2.8 in

Diet as a factor in behavioral radiation protection following exposure to heavy particles

NASA Technical Reports Server (NTRS)

Rabin, Bernard M.; Shukitt-Hale, Barbara; Joseph, James; Todd, Paul

2005-01-01

Major risks associated with radiation exposures on deep space missions include carcinogenesis due to heavy-particle exposure of cancer-prone tissues and performance decrements due to neurological damage produced by heavy particles. Because exposure to heavy particles can cause oxidative stress, it is possible that antioxidants can be used to mitigate these risks (and possibly some health risks of microgravity). To assess the capacity of antioxidant diets to mitigate the effects of exposure to heavy particles, rats were maintained on antioxidant diets containing 2% blueberry or strawberry extract or a control diet for 8 weeks prior to exposure to 1.5 or 2.0 Gy of accelerated iron particles at Brookhaven National Laboratory. Following irradiation rats were tested on a series of behavioral tasks: amphetamine-induced taste aversion learning, operant responding and spatial learning and memory. The results indicated that the performance of the irradiated rats maintained on the antioxidant diets was, in general, significantly better than that of the control animals, although the effectiveness of the diets ameliorating the radiation-induced deterioration in performance varied as a function of both the specific diet and the specific endpoint. In addition, animals fed antioxidant diets prior to exposure showed reduced heavy particle-induced tumorigenesis one year after exposure compared to the animals fed the control diet. These results suggest that antioxidant diets have the potential to serve as part of a system designed to provide protection to astronauts against the effects of heavy particles on exploratory missions outside the magnetic field of the earth.

Exposure to carbon monoxide, fine particle mass, and ultrafine particle number in Jakarta, Indonesia: effect of commute mode.

PubMed

Both, Adam F; Westerdahl, Dane; Fruin, Scott; Haryanto, Budi; Marshall, Julian D

2013-01-15

We measured real-time exposure to PM(2.5), ultrafine PM (particle number) and carbon monoxide (CO) for commuting workers school children, and traffic police, in Jakarta, Indonesia. In total, we measured exposures for 36 individuals covering 93 days. Commuters in private cars experienced mean (st dev) exposures of 22 (9.4) ppm CO, 91 (38) μg/m(3)PM(2.5), and 290 (150)×10(3) particles cm(-3). Mean concentrations were higher in public transport than in private cars for PM(2.5) (difference in means: 22%) and particle counts (54%), but not CO, likely reflecting in-vehicle particle losses in private cars owing to air-conditioning. However, average commute times were longer for private car commuters than public transport commuters (in our sample, 24% longer: 3.0 vs. 2.3 h per day). Commute and traffic-related exposures experienced by Jakarta residents are among the highest in the world, owing to high on-road concentrations and multi-hour commutes. Copyright © 2012 Elsevier B.V. All rights reserved.

Ultrafine particle concentrations in and around idling school buses

NASA Astrophysics Data System (ADS)

Zhang, Qunfang; Fischer, Heidi J.; Weiss, Robert E.; Zhu, Yifang

2013-04-01

Unnecessary school bus idling increases children's exposure to diesel exhaust, but to what extent children are exposed to ultrafine particles (UFPs, diameter < 100 nm) in and around idling school buses remains unclear. This study employed nine school buses and simulated five scenarios by varying emissions source, wind direction, and window position. The purpose was to investigate the impact of idling on UFP number concentration and PM2.5 mass concentration inside and near school buses. Near the school buses, total particle number concentration increased sharply from engine off to engine on under all scenarios, by a factor of up to 26. The impact of idling on UFP number concentration inside the school buses depended on wind direction and window position: wind direction was important and statistically significant while the effect of window positions depended on wind direction. Under certain scenarios, idling increased in-cabin total particle number concentrations by a factor of up to 5.8, with the significant increase occurring in the size range of 10-30 nm. No significant change of in-cabin PM2.5 mass concentration was observed due to idling, regardless of wind direction and window position, indicating that PM2.5 is not a good indicator for primary diesel exhaust particle exposure. The deposition rates based on total particle number concentration inside school bus cabins varied between 1.5 and 5.0 h-1 across nine tested buses under natural convection conditions, lower than those of passenger cars but higher than those of indoor environments.

Lack of acute phase response in the livers of mice exposed to diesel exhaust particles or carbon black by inhalation

PubMed Central

Saber, Anne T; Halappanavar, Sabina; Folkmann, Janne K; Bornholdt, Jette; Boisen, Anne Mette Z; Møller, Peter; Williams, Andrew; Yauk, Carole; Vogel, Ulla; Loft, Steffen; Wallin, Håkan

2009-01-01

Background Epidemiologic and animal studies have shown that particulate air pollution is associated with increased risk of lung and cardiovascular diseases. Although the exact mechanisms by which particles induce cardiovascular diseases are not known, studies suggest involvement of systemic acute phase responses, including C-reactive protein (CRP) and serum amyloid A (SAA) in humans. In this study we test the hypothesis that diesel exhaust particles (DEP) – or carbon black (CB)-induced lung inflammation initiates an acute phase response in the liver. Results Mice were exposed to filtered air, 20 mg/m3 DEP or CB by inhalation for 90 minutes/day for four consecutive days; we have previously shown that these mice exhibit pulmonary inflammation (Saber AT, Bornholdt J, Dybdahl M, Sharma AK, Loft S, Vogel U, Wallin H. Tumor necrosis factor is not required for particle-induced genotoxicity and pulmonary inflammation., Arch. Toxicol. 79 (2005) 177–182). As a positive control for the induction of an acute phase response, mice were exposed to 12.5 mg/kg of lipopolysaccharide (LPS) intraperitoneally. Quantitative real time RT-PCR was used to examine the hepatic mRNA expression of acute phase proteins, serum amyloid P (Sap) (the murine homologue of Crp) and Saa1 and Saa3. While significant increases in the hepatic expression of Sap, Saa1 and Saa3 were observed in response to LPS, their levels did not change in response to DEP or CB. In a comprehensive search for markers of an acute phase response, we analyzed liver tissue from these mice using high density DNA microarrays. Globally, 28 genes were found to be significantly differentially expressed in response to DEP or CB. The mRNA expression of three of the genes (serine (or cysteine) proteinase inhibitor, clade A, member 3C, apolipoprotein E and transmembrane emp24 domain containing 3) responded to both exposures. However, these changes were very subtle and were not confirmed by real time RT-PCR. Conclusion Our findings

Exhaust particle and NOx emission performance of an SCR heavy duty truck operating in real-world conditions

NASA Astrophysics Data System (ADS)

Saari, Sampo; Karjalainen, Panu; Ntziachristos, Leonidas; Pirjola, Liisa; Matilainen, Pekka; Keskinen, Jorma; Rönkkö, Topi

2016-02-01

Particle and NOx emissions of an SCR equipped HDD truck were studied in real-world driving conditions using the "Sniffer" mobile laboratory. Real-time CO2 measurement enables emission factor calculation for NOx and particles. In this study, we compared three different emission factor calculation methods and characterised their suitability for real-world chasing experiments. The particle number emission was bimodal and dominated by the nucleation mode particles (diameter below 23 nm) having emission factor up to 1 × 1015 #/kgfuel whereas emission factor for soot (diameter above 23 nm that is consistent with the PMP standard) was typically 1 × 1014 #/kgfuel. The effect of thermodenuder on the exhaust particles indicated that the nucleation particles consisted mainly of volatile compounds, but sometimes there also existed a non-volatile core. The nucleation mode particles are not controlled by current regulations in Europe. However, these particles consistently form under atmospheric dilution in the plume of the truck and constitute a health risk for the human population that is exposed to those. Average NOx emission was 3.55 g/kWh during the test, whereas the Euro IV emission limit over transient testing is 3.5 g NOx/kWh. The on-road emission performance of the vehicle was very close to the expected levels, confirming the successful operation of the SCR system of the tested vehicle. Heavy driving conditions such as uphill driving increased both the NOx and particle number emission factors whereas the emission factor for soot particle number remains rather constant.

Radon-induced lung cancer deaths may be overestimated due to failure to account for confounding by exposure to diesel engine exhaust in BEIR VI miner studies.

PubMed

Cao, Xiaodong; MacNaughton, Piers; Laurent, Jose Cedeno; Allen, Joseph G

2017-01-01

EPA reported that radon is the second leading cause of lung cancer in the United States, killing 21,100 people per year. EPA relies on the BEIR VI models, based on an evaluation of radon exposure and lung cancer risk in studies of miners. But these models did not account for co-exposure to diesel exhaust, a known human carcinogen recently classified by IARC. It is probable then that a portion of the lung cancer deaths in the miner cohorts are originally attributable to the exposure to diesel rather than radon. To re-evaluate EPA's radon attributable lung cancer estimates accounting for diesel exposure information in the miner cohorts. We used estimates of historical diesel concentrations, combined with diesel exposure-response functions, to estimate the risks of lung cancer attributable to diesel engine exhaust (DEE) exposure in the miner studies. We re-calculated the fatal lung cancer risk attributable to radon after accounting for risk from diesel and re-estimated the number of U.S. deaths associated with radon in the U.S. using EPA's methodology. Considering the probable confounding with DEE exposure and using the same estimate of baseline mortality from 1989-91 that the EPA currently uses in their calculations, we estimate that radon-induced lung cancer deaths per year are 15,600 (95% CI: 14,300, 17,000)- 19,300 (95% CI: 18,800, 20,000) in the U.S. population, a reduction of 9%-26%. The death estimates would be 12,900-15,900 using 2014 baseline vital statistics. We recommend further research on re-evaluating the health effects of exposure to radon that accounts for new information on diesel exhaust carcinogenicity in BEIR VI models, up-to-date vital statistics and new epidemiological evidence from residential studies.

Radon-induced lung cancer deaths may be overestimated due to failure to account for confounding by exposure to diesel engine exhaust in BEIR VI miner studies

PubMed Central

MacNaughton, Piers; Laurent, Jose Cedeno; Allen, Joseph G.

2017-01-01

Background EPA reported that radon is the second leading cause of lung cancer in the United States, killing 21,100 people per year. EPA relies on the BEIR VI models, based on an evaluation of radon exposure and lung cancer risk in studies of miners. But these models did not account for co-exposure to diesel exhaust, a known human carcinogen recently classified by IARC. It is probable then that a portion of the lung cancer deaths in the miner cohorts are originally attributable to the exposure to diesel rather than radon. Objective To re-evaluate EPA’s radon attributable lung cancer estimates accounting for diesel exposure information in the miner cohorts. Methods We used estimates of historical diesel concentrations, combined with diesel exposure-response functions, to estimate the risks of lung cancer attributable to diesel engine exhaust (DEE) exposure in the miner studies. We re-calculated the fatal lung cancer risk attributable to radon after accounting for risk from diesel and re-estimated the number of U.S. deaths associated with radon in the U.S. using EPA’s methodology. Results Considering the probable confounding with DEE exposure and using the same estimate of baseline mortality from 1989–91 that the EPA currently uses in their calculations, we estimate that radon-induced lung cancer deaths per year are 15,600 (95% CI: 14,300, 17,000)– 19,300 (95% CI: 18,800, 20,000) in the U.S. population, a reduction of 9%–26%. The death estimates would be 12,900–15,900 using 2014 baseline vital statistics. Conclusions We recommend further research on re-evaluating the health effects of exposure to radon that accounts for new information on diesel exhaust carcinogenicity in BEIR VI models, up-to-date vital statistics and new epidemiological evidence from residential studies. PMID:28886109

Aryl Hydrocarbon Receptor activation by diesel exhaust particles mediates epithelium-derived cytokines expression in severe allergic asthma.

PubMed

Weng, Chih-Ming; Wang, Chun-Hua; Lee, Meng-Jung; He, Jung-Re; Huang, Hsin-Yu; Chao, Ming-Wei; Chung, Kian Fan; Kuo, Han-Pin

2018-04-19

Exposure to environmental pollutants promotes Th2 cell responses. Aryl hydrocarbon receptor (AhR) activation aggravates allergic responses. Epithelium-derived thymic stromal lymphopoietin (TSLP), interleukin (IL)-25 and IL-33 are implicated in the dysregulation of Th2 immune responses in severe allergic asthma. Bronchial biopsies of 28 allergic severe asthma and 6 mild asthma subjects from highly polluted areas were analyzed for AhR nuclear translocation (NT), cytokine expression and gene activation. Cultured primary epithelial cells were stimulated with diesel exhausted particles (DEP) to determine AhR-mediated IL-33, Il-25 and TSLP synthesis and release. Primary bronchial epithelial cells exposed to DEP showed up-regulation of IL-33, IL-25 and TSLP. These effects were abolished by knock-down of AhR by siRNA. Increased AhR/ARNT binding to promoters of IL-33, IL-25, and TSLP was found using chromatin immunoprecipitation (ChIP) assay. Allergic severe asthma with high AhR NT had higher bronchial gene and protein expression of IL-33, IL-25 and TSLP. These patients derived clinical benefit from anti-IgE treatment. AhR activation by DEP mediates up-regulation of IL-33, IL-25 and TSLP with Th2 activation, potentially linking environmental pollution and allergic severe asthma. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Occupational exposure to diesel engine exhaust and alterations in lymphocyte subsets.

PubMed

Lan, Qing; Vermeulen, Roel; Dai, Yufei; Ren, Dianzhi; Hu, Wei; Duan, Huawei; Niu, Yong; Xu, Jun; Fu, Wei; Meliefste, Kees; Zhou, Baosen; Yang, Jufang; Ye, Meng; Jia, Xiaowei; Meng, Tao; Bin, Ping; Kim, Christopher; Bassig, Bryan A; Hosgood, H Dean; Silverman, Debra; Zheng, Yuxin; Rothman, Nathaniel

2015-05-01

The International Agency for Research on Cancer recently classified diesel engine exhaust (DEE) as a Group I carcinogen based largely on its association with lung cancer. However, the exposure-response relationship is still a subject of debate and the underlying mechanism by which DEE causes lung cancer in humans is not well understood. We conducted a cross-sectional molecular epidemiology study in a diesel engine truck testing facility of 54 workers exposed to a wide range of DEE (ie, elemental carbon air levels, median range: 49.7, 6.1-107.7 µg/m(3)) and 55 unexposed comparable controls. The total lymphocyte count (p=0.00044) and three of the four major lymphocyte subsets (ie, CD4+ T cells (p=0.00019), CD8+ T cells (p=0.0058) and B cells (p=0.017)) were higher in exposed versus control workers and findings were highly consistent when stratified by smoking status. In addition, there was evidence of an exposure-response relationship between elemental carbon and these end points (ptrends<0.05), and CD4+ T cell levels were significantly higher in the lowest tertile of DEE exposed workers compared to controls (p=0.012). Our results suggest that DEE exposure is associated with higher levels of cells that play a key role in the inflammatory process, which is increasingly being recognised as contributing to the aetiology of lung cancer. This study provides new insights into the underlying mechanism of DEE carcinogenicity. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Prenatal and early-life diesel exhaust exposure causes autism-like behavioral changes in mice.

PubMed

Chang, Yu-Chi; Cole, Toby B; Costa, Lucio G

2018-04-20

Escalating prevalence of autism spectrum disorders (ASD) in recent decades has triggered increasing efforts in understanding roles played by environmental risk factors as a way to address this widespread public health concern. Several epidemiological studies show associations between developmental exposure to traffic-related air pollution and increased ASD risk. In rodent models, a limited number of studies have shown that developmental exposure to ambient ultrafine particulates or diesel exhaust (DE) can result in behavioral phenotypes consistent with mild ASD. We performed a series of experiments to determine whether developmental DE exposure induces ASD-related behaviors in mice. C57Bl/6J mice were exposed from embryonic day 0 to postnatal day 21 to 250-300 μg/m 3 DE or filtered air (FA) as control. Mice exposed developmentally to DE exhibited deficits in all three of the hallmark categories of ASD behavior: reduced social interaction in the reciprocal interaction and social preference tests, increased repetitive behavior in the T-maze and marble-burying test, and reduced or altered communication as assessed by measuring isolation-induced ultrasonic vocalizations and responses to social odors. These findings demonstrate that exposure to traffic-related air pollution, in particular that associated with diesel-fuel combustion, can cause ASD-related behavioral changes in mice, and raise concern about air pollution as a contributor to the onset of ASD in humans.

Foam cell formation by particulate matter (PM) exposure: a review.

PubMed

Cao, Yi; Long, Jimin; Ji, Yuejia; Chen, Gui; Shen, Yuexin; Gong, Yu; Li, Juan

2016-11-01

Increasing evidence suggests that exposure of particulate matter (PM) from traffic vehicles, e.g., diesel exhaust particles (DEP), was associated with adverse vascular effects, e.g., acceleration of atherosclerotic plaque progression. By analogy, engineered nanoparticles (NPs) could also induce similar effects. The formation of lipid laden foam cells, derived predominately from macrophages and vascular smooth muscle cells (VSMC), is closely associated with the development of atherosclerosis and adverse vascular effects. We reviewed current studies about particle exposure-induced lipid laden foam cell formation. In vivo studies using animal models have shown that exposure of air pollution by PM promoted lipid accumulation in alveolar macrophages or foam cells in plaques, which was likely associated with pulmonary inflammation or systemic oxidative stress, but not blood lipid profile. In support of these findings, in vitro studies showed that direct exposure of cultured macrophages to DEP or NP exposure, with or without further exposure to external lipids, promoted intracellular lipid accumulation. The mechanisms remained unknown. Although a number studies found increased reactive oxygen species (ROS) or an adaptive response to oxidative stress, the exact role of oxidative stress in mediating particle-induced foam cell formation requires future research. There is currently lack of reports concerning VSMC as a source for foam cells induced by particle exposure. In the future, it is necessary to explore the role of foam cell formation in particle exposure-induced atherosclerosis development. In addition, the formation of VSMC derived foam cells by particle exposure may also need extensive studies.

Multi-cellular human bronchial models exposed to diesel exhaust particles: assessment of inflammation, oxidative stress and macrophage polarization.

PubMed

Ji, Jie; Upadhyay, Swapna; Xiong, Xiaomiao; Malmlöf, Maria; Sandström, Thomas; Gerde, Per; Palmberg, Lena

2018-05-02

Diesel exhaust particles (DEP) are a major component of outdoor air pollution. DEP mediated pulmonary effects are plausibly linked to inflammatory and oxidative stress response in which macrophages (MQ), epithelial cells and their cell-cell interaction plays a crucial role. Therefore, in this study we aimed at studying the cellular crosstalk between airway epithelial cells with MQ and MQ polarization following exposure to aerosolized DEP by assessing inflammation, oxidative stress, and MQ polarization response markers. Lung mucosa models including primary bronchial epithelial cells (PBEC) cultured at air-liquid interface (ALI) were co-cultured without (PBEC-ALI) and with MQ (PBEC-ALI/MQ). Cells were exposed to 12.7 μg/cm 2 aerosolized DEP using XposeALI ® . Control (sham) models were exposed to clean air. Cell viability was assessed. CXCL8 and IL-6 were measured in the basal medium by ELISA. The mRNA expression of inflammatory markers (CXCL8, IL6, TNFα), oxidative stress (NFKB, HMOX1, GPx) and MQ polarization markers (IL10, IL4, IL13, MRC1, MRC2 RETNLA, IL12 andIL23) were measured by qRT-PCR. The surface/mRNA expression of TLR2/TLR4 was detected by FACS and qRT-PCR. In PBEC-ALI exposure to DEP significantly increased the secretion of CXCL8, mRNA expression of inflammatory markers (CXCL8, TNFα) and oxidative stress markers (NFKB, HMOX1, GPx). However, mRNA expressions of these markers (CXCL8, IL6, NFKB, and HMOX1) were reduced in PBEC-ALI/MQ models after DEP exposure. TLR2 and TLR4 mRNA expression increased after DEP exposure in PBEC-ALI. The surface expression of TLR2 and TLR4 on PBEC was significantly reduced in sham-exposed PBEC-ALI/MQ compared to PBEC-ALI. After DEP exposure surface expression of TLR2 was increased on PBEC of PBEC-ALI/MQ, while TLR4 was decreased in both models. DEP exposure resulted in similar expression pattern of TLR2/TLR4 on MQ as in PBEC. In PBEC-ALI/MQ, DEP exposure increased the mRNA expression of anti-inflammatory M2 macrophage

Environment effects from SRB exhaust effluents: Technique development and preliminary assessment

NASA Technical Reports Server (NTRS)

Goldford, A. I.; Adelfang, S. I.; Hickey, J. S.; Smith, S. R.; Welty, R. P.; White, G. L.

1977-01-01

Techniques to determine the environmental effects from the space shuttle SRB (Solid Rocket Booster) exhaust effluents are used to perform a preliminary climatological assessment. The exhaust effluent chemistry study was performed and the exhaust effluent species were determined. A reasonable exhaust particle size distribution is constructed for use in nozzle analyses and for the deposition model. The preliminary assessment is used to identify problems that are associated with the full-scale assessment; therefore, these preliminary air quality results are used with caution in drawing conclusion regarding the environmental effects of the space shuttle exhaust effluents.

Personal exposure to ultrafine particles from PVC welding and concrete work during tunnel rehabilitation.

PubMed

Jørgensen, Rikke Bramming; Buhagen, Morten; Føreland, Solveig

2016-07-01

To investigate the exposure to number concentration of ultrafine particles and the size distribution in the breathing zone of workers during rehabilitation of a subsea tunnel. Personal exposure was measured using a TSI 3091 Fast Mobility Particle Sizer (FMPS), measuring the number concentration of submicrometre particles (including ultrafine particles) and the particle size distribution in the size range 5.6-560 nm. The measurements were performed in the breathing zone of the operators by the use of a conductive silicone tubing. Working tasks studied were operation of the slipforming machine, operations related to finishing the verge, and welding the PVC membrane. In addition, background levels were measured. Arithmetic mean values of ultrafine particles were in the range 6.26×10(5)-3.34×10(6). Vertical PVC welding gave the highest exposure. Horizontal welding was the work task with the highest maximum peak exposure, 8.1×10(7) particles/cm(3). Background concentrations of 4.0×10(4)-3.1×10(5) were found in the tunnel. The mobility diameter at peak particle concentration varied between 10.8 nm during horizontal PVC welding and during breaks and 60.4 nm while finishing the verge. PVC welding in a vertical position resulted in very high exposure of the worker to ultrafine particles compared to other types of work tasks. In evaluations of worker exposure to ultrafine particles, it seems important to distinguish between personal samples taken in the breathing zone of the worker and more stationary work area measurements. There is a need for a portable particle-sizing instrument for measurements of ultrafine particles in working environments. 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/

Biomarker as a Research Tool in Linking Exposure to Air Particles and Respiratory Health

PubMed Central

2015-01-01

Some of the environmental toxicants from air pollution include particulate matter (PM10), fine particulate matter (PM2.5), and ultrafine particles (UFP). Both short- and long-term exposure could result in various degrees of respiratory health outcomes among exposed persons, which rely on the individuals' health status. Methods. In this paper, we highlight a review of the studies that have used biomarkers to understand the association between air particles exposure and the development of respiratory problems resulting from the damage in the respiratory system. Data from previous epidemiological studies relevant to the application of biomarkers in respiratory system damage reported from exposure to air particles are also summarized. Results. Based on these analyses, the findings agree with the hypothesis that biomarkers are relevant in linking harmful air particles concentrations to increased respiratory health effects. Biomarkers are used in epidemiological studies to provide an understanding of the mechanisms that follow airborne particles exposure in the airway. However, application of biomarkers in epidemiological studies of health effects caused by air particles in both environmental and occupational health is inchoate. Conclusion. Biomarkers unravel the complexity of the connection between exposure to air particles and respiratory health. PMID:25984536

The effect of thymoquinone treatment on the combined renal and pulmonary toxicity of cisplatin and diesel exhaust particles

PubMed Central

Ali, Badreldin H; Shalaby, Asem; Manoj, Priyadarsini; Waly, Mostafa I; Yasin, Javed; Fahim, Mohamed; Nemmar, Abderrahim

2015-01-01

Particulate air pollution (PAP) exposure is associated with increased morbidity and mortality, particularly in patients with renal disease. However, there are only a few studies on the interaction between PAP and renal injury, and none on agents that may ameliorate it. We studied the interaction between cisplatin (CP) nephrotoxicity and a single exposure to diesel exhaust particle (DEP) in rats 24 h before sacrifice, and assessed the effect of co-treatment with the active ingredient in Nigella Sativa seed oil, thymoquinone (TQ) thereon. Rats were injected intraperitoneally with CP (6 mg/kg) and four days later, they were exposed intratracheally to DEP (0.5 mg/kg), and were sacrificed 24 h later. Oral TQ (20 mg/kg) was given daily throughout the experimental period. CP alone caused several physiological, biochemical, and histopathological changes that included reduced growth and creatinine clearance, and raised plasma neutrophil gelatinase-associated lipocalin (NGAL), interleukin 6 (IL-6) and C-reactive protein (CRP), creatinine and urea concentrations, and urinary N-acetyl-b-D-glucosaminidase (NAG) activities. It adversely affected several indices of oxidative damage in the kidneys, and induced renal tubular necrosis. Most of these actions were significantly potentiated in rats given both CP and DEP. TQ significantly abrogated many of the effects of CP and DEP, given alone and in combination. These results provide experimental evidence that subjects with renal diseases can be at higher risk from PAP, and that TQ, pending further pharmacological and toxicological studies, can be considered a useful agent in patients with renal diseases and exposed to PAP. PMID:25925792

Exposure To An Organic PM Component Induces Inflammatory And Adaptive Gene Expression Through Mitochondrial Oxidative Stress

EPA Science Inventory

RATIONALE. Exposure to ambient particulate matter (PM) has been associated with adverse health effects including inflammatory responses in the lung. Diesel exhaust particles (DEP) are a ubiquitous contributor to the fine and ultrafine PM burden in ambient air. Toxicological studi...

Stratospheric aircraft exhaust plume and wake chemistry studies

NASA Technical Reports Server (NTRS)

Miake-Lye, R. C.; Martinez-Sanchez, M.; Brown, R. C.; Kolb, C. E.; Worsnop, D. R.; Zahniser, M. S.; Robinson, G. N.; Rodriguez, J. M.; Ko, M. K. W.; Shia, R-L.

1992-01-01

This report documents progress to date in an ongoing study to analyze and model emissions leaving a proposed High Speed Civil Transport (HSCT) from when the exhaust gases leave the engine until they are deposited at atmospheric scales in the stratosphere. Estimates are given for the emissions, summarizing relevant earlier work (CIAP) and reviewing current propulsion research efforts. The chemical evolution and the mixing and vortical motion of the exhaust are analyzed to track the exhaust and its speciation as the emissions are mixed to atmospheric scales. The species tracked include those that could be heterogeneously reactive on the surfaces of the condensed solid water (ice) particles and on exhaust soot particle surfaces. Dispersion and reaction of chemical constituents in the far wake are studied with a Lagrangian air parcel model, in conjunction with a radiation code to calculate the net heating/cooling. Laboratory measurements of heterogeneous chemistry of aqueous sulfuric acid and nitric acid hydrates are also described. Results include the solubility of HCl in sulfuric acid which is a key parameter for modeling stratospheric processing. We also report initial results for condensation of nitric acid trihydrate from gas phase H2O and HNO3.

Exposure-Response Estimates for Diesel Engine Exhaust and Lung Cancer Mortality Based on Data from Three Occupational Cohorts

PubMed Central

Silverman, Debra T.; Garshick, Eric; Vlaanderen, Jelle; Portengen, Lützen; Steenland, Kyle

2013-01-01

Background: Diesel engine exhaust (DEE) has recently been classified as a known human carcinogen. Objective: We derived a meta-exposure–response curve (ERC) for DEE and lung cancer mortality and estimated lifetime excess risks (ELRs) of lung cancer mortality based on assumed occupational and environmental exposure scenarios. Methods: We conducted a meta-regression of lung cancer mortality and cumulative exposure to elemental carbon (EC), a proxy measure of DEE, based on relative risk (RR) estimates reported by three large occupational cohort studies (including two studies of workers in the trucking industry and one study of miners). Based on the derived risk function, we calculated ELRs for several lifetime occupational and environmental exposure scenarios and also calculated the fractions of annual lung cancer deaths attributable to DEE. Results: We estimated a lnRR of 0.00098 (95% CI: 0.00055, 0.0014) for lung cancer mortality with each 1-μg/m3-year increase in cumulative EC based on a linear meta-regression model. Corresponding lnRRs for the individual studies ranged from 0.00061 to 0.0012. Estimated numbers of excess lung cancer deaths through 80 years of age for lifetime occupational exposures of 1, 10, and 25 μg/m3 EC were 17, 200, and 689 per 10,000, respectively. For lifetime environmental exposure to 0.8 μg/m3 EC, we estimated 21 excess lung cancer deaths per 10,000. Based on broad assumptions regarding past occupational and environmental exposures, we estimated that approximately 6% of annual lung cancer deaths may be due to DEE exposure. Conclusions: Combined data from three U.S. occupational cohort studies suggest that DEE at levels common in the workplace and in outdoor air appear to pose substantial excess lifetime risks of lung cancer, above the usually acceptable limits in the United States and Europe, which are generally set at 1/1,000 and 1/100,000 based on lifetime exposure for the occupational and general population, respectively. Citation

Control of particle and power exhaust in pellet fuelled ITER DT scenarios employing integrated models

NASA Astrophysics Data System (ADS)

Wiesen, S.; Köchl, F.; Belo, P.; Kotov, V.; Loarte, A.; Parail, V.; Corrigan, G.; Garzotti, L.; Harting, D.

2017-07-01

The integrated model JINTRAC is employed to assess the dynamic density evolution of the ITER baseline scenario when fuelled by discrete pellets. The consequences on the core confinement properties, α-particle heating due to fusion and the effect on the ITER divertor operation, taking into account the material limitations on the target heat loads, are discussed within the integrated model. Using the model one can observe that stable but cyclical operational regimes can be achieved for a pellet-fuelled ITER ELMy H-mode scenario with Q  =  10 maintaining partially detached conditions in the divertor. It is shown that the level of divertor detachment is inversely correlated with the core plasma density due to α-particle heating, and thus depends on the density evolution cycle imposed by pellet ablations. The power crossing the separatrix to be dissipated depends on the enhancement of the transport in the pedestal region being linked with the pressure gradient evolution after pellet injection. The fuelling efficacy of the deposited pellet material is strongly dependent on the E  ×  B plasmoid drift. It is concluded that integrated models like JINTRAC, if validated and supported by realistic physics constraints, may help to establish suitable control schemes of particle and power exhaust in burning ITER DT-plasma scenarios.

Applicability of empirical data currently used in predicting solid propellant exhaust plumes

NASA Technical Reports Server (NTRS)

Tevepaugh, J. A.; Smith, S. D.; Penny, M. M.; Greenwood, T.; Roberts, B. B.

1977-01-01

Theoretical and experimental approaches to exhaust plume analysis are compared. A two-phase model is extended to include treatment of reacting gas chemistry, and thermodynamical modeling of the gaseous phase of the flow field is considered. The applicability of empirical data currently available to define particle drag coefficients, heat transfer coefficients, mean particle size, and particle size distributions is investigated. Experimental and analytical comparisons are presented for subscale solid rocket motors operating at three altitudes with attention to pitot total pressure and stagnation point heating rate measurements. The mathematical treatment input requirements are explained. The two-phase flow field solution adequately predicts gasdynamic properties in the inviscid portion of two-phase exhaust plumes. It is found that prediction of exhaust plume gas pressures requires an adequate model of flow field dynamics.

Combusting vegetable oils in diesel engines: the impact of unsaturated fatty acids on particle emissions and mutagenic effects of the exhaust.

PubMed

Bünger, Jürgen; Bünger, Jörn F; Krahl, Jürgen; Munack, Axel; Schröder, Olaf; Brüning, Thomas; Hallier, Ernst; Westphal, Götz A

2016-06-01

High particle emissions and strong mutagenic effects were observed after combustion of vegetable oil in diesel engines. This study tested the hypothesis that these results are affected by the amount of unsaturated or polyunsaturated fatty acids of vegetable oils. Four different vegetable oils (coconut oil, CO; linseed oil, LO; palm tree oil, PO; and rapeseed oil, RO) and common diesel fuel (DF) were combusted in a heavy-duty diesel engine. The exhausts were investigated for particle emissions and mutagenic effects in direct comparison with emissions of DF. The engine was operated using the European Stationary Cycle. Particle masses were measured gravimetrically while mutagenicity was determined using the bacterial reverse mutation assay with tester strains TA98 and TA100. Combustion of LO caused the largest amount of total particulate matter (TPM). In comparison with DF, it particularly raised the soluble organic fraction (SOF). RO presented second highest TPM and SOF, followed by CO and PO, which were scarcely above DF. RO revealed the highest number of mutations of the vegetable oils closely followed by LO. PO was less mutagenic, but still induced stronger effects than DF. While TPM and SOF were strongly correlated with the content of polyunsaturated fatty acids in the vegetable oils, mutagenicity had a significant correlation with the amount of total unsaturated fatty acids. This study supports the hypothesis that numbers of double bounds in unsaturated fatty acids of vegetable oils combusted in diesel engines influence the amount of emitted particles and the mutagenicity of the exhaust. Further investigations have to elucidate the causal relationship.

Loss and replacement of small particles on the contact surfaces of footwear during successive exposures.

PubMed

Stoney, David A; Bowen, Andrew M; Stoney, Paul L

2016-12-01

On the contact surfaces of footwear loosely, moderately and strongly held particle fractions were separated and analyzed in an effort to detect different particle signals. Three environmental exposure sites were chosen to have different, characteristic particle types (soil minerals). Shoes of two types (work boots and tennis shoes) were tested, accumulating particles by walking 250m in each environment. Some shoes were exposed to only one environment; others were exposed to all three, in one of six different sequences. Sampling methods were developed to separate particles from the contact surface of the shoe based on how tightly they were held to the sole. Loosely held particles were removed by walking on paper, moderately held particles were removed by electrostatic lifting, and the most tightly held particles were removed by moist swabbing. The resulting numbers and types of particles were determined using forensic microscopy. Particle profiles from the different fractions were compared to test the ability to objectively distinguish the order of exposure to the three environments. Without exception, the samples resulting from differential sampling are dominated by the third site in the sequential footwear exposures. No noticeable differences are seen among the differential samplings of the loosely, moderately and strongly held particles: the same overwhelming presence of the third site is seen. It is clear from these results (1) that the third (final) exposure results in the nearly complete removal of any particles from prior exposures, and (2) that under the experimental conditions loosely, moderately and strongly held particles are affected similarly, without any detectable enrichment of the earlier exposures among the more tightly held particles. These findings have significant implications for casework, demonstrating that particles on the contact surfaces of footwear are rapidly lost and replaced. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Emerging Mechanistic Targets in Lung Injury Induced by Combustion-Generated Particles

PubMed Central

Fariss, Marc W.; Gilmour, M. Ian; Reilly, Christopher A.; Liedtke, Wolfgang; Ghio, Andrew J.

2013-01-01

The mechanism for biological effect following exposure to combustion-generated particles is incompletely defined. The identification of pathways regulating the acute toxicological effects of these particles provides specific targets for therapeutic manipulation in an attempt to impact disease following exposures. Transient receptor potential (TRP) cation channels were identified as “particle sensors” in that their activation was coupled with the initiation of protective responses limiting airway deposition and inflammatory responses, which promote degradation and clearance of the particles. TRPA1, V1, V4, and M8 have a capacity to mediate adverse effects after exposure to combustion-generated particulate matter (PM); relative contributions of each depend upon particle composition, dose, and deposition. Exposure of human bronchial epithelial cells to an organic extract of diesel exhaust particle was followed by TRPV4 mediating Ca++ influx, increased RAS expression, mitogen-activated protein kinase signaling, and matrix metalloproteinase-1 activation. These novel pathways of biological effect can be targeted by compounds that specifically inhibit critical signaling reactions. In addition to TRPs and calcium biochemistry, humic-like substances (HLS) and cell/tissue iron equilibrium were identified as potential mechanistic targets in lung injury after particle exposure. In respiratory epithelial cells, iron sequestration by HLS in wood smoke particle (WSP) was associated with oxidant generation, cell signaling, transcription factor activation, and release of inflammatory mediators. Similar to WSP, cytotoxic insoluble nanosized spherical particles composed of HLS were isolated from cigarette smoke condensate. Therapies that promote bioelimination of HLS and prevent the disruption of iron homeostasis could function to reduce the harmful effects of combustion-generated PM exposure. PMID:23322347

Case report: Atrial fibrillation following exposure to ambient air pollution particles

EPA Science Inventory