Sample records for exhaust particle exposure

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

    PubMed Central

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

    1999-01-01

    OBJECTIVES: Air pollution particulates have been identified as having adverse effects on respiratory health. The present study was undertaken to further clarify the effects of diesel exhaust on bronchoalveolar cells and soluble components in normal healthy subjects. The study was also designed to evaluate whether a ceramic particle trap at the end of the tail pipe, from an idling engine, would reduce indices of airway inflammation. METHODS: The study comprised three exposures in all 10 healthy never smoking subjects; air, diluted diesel exhaust, and diluted diesel exhaust filtered with a ceramic particle trap. The exposures were given for 1 hour in randomised order about 3 weeks apart. The diesel exhaust exposure apperatus has previously been carefully developed and evaluated. Bronchoalveolar lavage was performed 24 hours after exposures and the lavage fluids from the bronchial and bronchoalveolar region were analysed for cells and soluble components. RESULTS: The particle trap reduced the mean steady state number of particles by 50%, but the concentrations of the other measured compounds were almost unchanged. It was found that diesel exhaust caused an increase in neutrophils in airway lavage, together with an adverse influence on the phagocytosis by alveolar macrophages in vitro. Furthermore, the diesel exhaust was found to be able to induce a migration of alveolar macrophages into the airspaces, together with reduction in CD3+CD25+ cells. (CD = cluster of differentiation) The use of the specific ceramic particle trap at the end of the tail pipe was not sufficient to completely abolish these effects when interacting with the exhaust from an idling vehicle. CONCLUSIONS: The current study showed that exposure to diesel exhaust may induce neutrophil and alveolar macrophage recruitment into the airways and suppress alveolar macrophage function. The particle trap did not cause significant reduction of effects induced by diesel exhaust compared with unfiltered diesel exhaust. Further studies are warranted to evaluate more efficient treatment devices to reduce adverse reactions to diesel exhaust in the airways.   PMID:10492649

  2. Effect of exposure to diesel exhaust particles on the susceptibility of the lung to infection.

    PubMed Central

    Castranova, V; Ma, J Y; Yang, H M; Antonini, J M; Butterworth, L; Barger, M W; Roberts, J; Ma, J K

    2001-01-01

    There are at least three mechanisms by which alveolar macrophages play a critical role in protecting the lung from bacterial or viral infections: production of inflammatory cytokines that recruit and activate lung phagocytes, production of antimicrobial reactive oxidant species, and production of interferon (an antiviral agent). In this article we summarize data concerning the effect of exposure to diesel exhaust particles on these alveolar macrophage functions and the role of adsorbed organic chemicals compared to the carbonaceous core in the toxicity of diesel particles. In vitro exposure of rat alveolar macrophages to diesel exhaust particles decreased the ability of lipopolysaccharide (LPS), a bacterial product] to stimulate the production of inflammatory cytokines interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-alpha). Methanol extract exhibited this potential but methanol-washed diesel particles did not. Exposure of rats to diesel exhaust particles by intratracheal instillation also decreased LPS-induced TNF-alpha and IL-1 production from alveolar macrophages. In contrast, carbon black did not exhibit this inhibitory effect. Exposure of rats to diesel exhaust particles by inhalation decreased the ability of alveolar macrophages to produce antimicrobial reactive oxidant species in response to zymosan (a fungal component). In contrast, exposure to coal dust increased zymosan-stimulated oxidant production. In vivo exposure to diesel exhaust particles but not to carbon black decreased the ability of the lungs to clear bacteria. Inhalation exposure of mice to diesel exhaust particles but not to coal dust depressed the ability of the lung to produce the antiviral agent interferon and increased viral multiplication in the lung. These results support the hypothesis that exposure to diesel exhaust particles increases the susceptibility of the lung to infection by depressing the antimicrobial potential of alveolar macrophages. This inhibitory effect appears to be due to adsorbed organic chemicals rather than the carbonaceous core of the diesel particles. PMID:11544172

  3. Diesel Exhaust Particle Exposure In Vitro Alters Monocyte Differentiation and Function

    PubMed Central

    Chaudhuri, Nazia; Jary, Hannah; Lea, Simon; Khan, Naimat; Piddock, Katie C.; Dockrell, David H.; Donaldson, Ken; Duffin, Rodger; Singh, Dave

    2012-01-01

    Air pollution by diesel exhaust particles is associated with elevated mortality and increased hospital admissions in individuals with respiratory diseases such as asthma and chronic obstructive pulmonary disease. During active inflammation monocytes are recruited to the airways and can replace resident alveolar macrophages. We therefore investigated whether chronic fourteen day exposure to low concentrations of diesel exhaust particles can alter the phenotype and function of monocytes from healthy individuals and those with chronic obstructive pulmonary disease. Monocytes were purified from the blood of healthy individuals and people with a diagnosis of chronic obstructive pulmonary disease. Monocyte-derived macrophages were generated in the presence or absence of diesel exhaust particles and their phenotypes studied through investigation of their lifespan, cytokine generation in response to Toll like receptor agonists and heat killed bacteria, and expression of surface markers. Chronic fourteen day exposure of monocyte-derived macrophages to concentrations of diesel exhaust particles >10 µg/ml caused mitochondrial and lysosomal dysfunction, and a gradual loss of cells over time both in healthy and chronic obstructive pulmonary disease individuals. Chronic exposure to lower concentrations of diesel exhaust particles impaired CXCL8 cytokine responses to lipopolysaccharide and heat killed E. coli, and this phenotype was associated with a reduction in CD14 and CD11b expression. Chronic diesel exhaust particle exposure may therefore alter both numbers and function of lung macrophages differentiating from locally recruited monocytes in the lungs of healthy people and patients with chronic obstructive pulmonary disease. PMID:23236439

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

    EPA Science Inventory

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

  5. Acute cardiac dysfunction after short-term diesel exhaust particles exposure

    Microsoft Academic Search

    Chien-Hua Huang; Lian-Yu Lin; Min-Shan Tsai; Chiung-Yuan Hsu; Huei-Wen Chen; Tzung-Dau Wang; Wei-Tien Chang; Tsun-Jen Cheng; Wen-Jone Chen

    2010-01-01

    Epidemiological studies show an association between particulate matter exposure and acute heart failure. However, underlying mechanisms remain unclear. In this study, we investigated acute cardiac hemodynamic effects and related mechanisms after 1 day exposure to diesel exhaust particles (DEPs). Male Sprague–Dawley rats were randomized and instilled with 250?g (low dose) or 500?g (high dose) of DEP or saline placebo intra-tracheally.

  6. Diesel and biodiesel exhaust particle effects on rat alveolar macrophages with in vitro exposure.

    PubMed

    Bhavaraju, Laya; Shannahan, Jonathan; William, Aaron; McCormick, Robert; McGee, John; Kodavanti, Urmila; Madden, Michael

    2014-06-01

    Combustion emissions from diesel engines emit particulate matter which deposits within the lungs. Alveolar macrophages (AMs) encounter the particles and attempt to engulf the particles. Emissions particles from diesel combustion engines have been found to contain diverse biologically active components including metals and polyaromatic hydrocarbons which cause adverse health effects. However little is known about AM response to particles from the incorporation of biodiesel. The objective of this study was to examine the toxicity in Wistar Kyoto rat AM of biodiesel blend (B20) and low sulfur petroleum diesel (PDEP) exhaust particles. Particles were independently suspended in media at a range of 1-500?gmL(-1). Results indicated B20 and PDEP initiated a dose dependent increase of inflammatory signals from AM after exposure. After 24h exposure to B20 and PDEP gene expression of cyclooxygenase-2 (COX-2) and macrophage inflammatory protein 2 (MIP-2) increased. B20 exposure resulted in elevated prostaglandin E2 (PGE2) release at lower particle concentrations compared to PDEP. B20 and PDEP demonstrated similar affinity for sequestration of PGE2 at high concentrations, suggesting detection is not impaired. Our data suggests PGE2 release from AM is dependent on the chemical composition of the particles. Particle analysis including measurements of metals and ions indicate B20 contains more of select metals than PDEP. Other particle components generally reduced by 20% with 20% incorporation of biodiesel into original diesel. This study shows AM exposure to B20 results in increased production of PGE2in vitro relative to diesel. PMID:24268344

  7. Reduction of exposure to ultrafine particles by kitchen exhaust hoods: the effects of exhaust flow rates, particle size, and burner position.

    PubMed

    Rim, Donghyun; Wallace, Lance; Nabinger, Steven; Persily, Andrew

    2012-08-15

    Cooking stoves, both gas and electric, are one of the strongest and most common sources of ultrafine particles (UFP) in homes. UFP have been shown to be associated with adverse health effects such as DNA damage and respiratory and cardiovascular diseases. This study investigates the effectiveness of kitchen exhaust hoods in reducing indoor levels of UFP emitted from a gas stove and oven. Measurements in an unoccupied manufactured house monitored size-resolved UFP (2 nm to 100 nm) concentrations from the gas stove and oven while varying range hood flow rate and burner position. The air change rate in the building was measured continuously based on the decay of a tracer gas (sulfur hexafluoride, SF(6)). The results show that range hood flow rate and burner position (front vs. rear) can have strong effects on the reduction of indoor levels of UFP released from the stove and oven, subsequently reducing occupant exposure to UFP. Higher range hood flow rates are generally more effective for UFP reduction, though the reduction varies with particle diameter. The influence of the range hood exhaust is larger for the back burner than for the front burner. The number-weighted particle reductions for range hood flow rates varying between 100 m(3)/h and 680 m(3)/h range from 31% to 94% for the front burner, from 54% to 98% for the back burner, and from 39% to 96% for the oven. PMID:22750181

  8. Effects of prenatal exposure to diesel exhaust particles on postnatal development, behavior, genotoxicity and inflammation in mice

    PubMed Central

    Hougaard, Karin S; Jensen, Keld A; Nordly, Pernille; Taxvig, Camilla; Vogel, Ulla; Saber, Anne T; Wallin, Håkan

    2008-01-01

    Background Results from epidemiological studies indicate that particulate air pollution constitutes a hazard for human health. Recent studies suggest that diesel exhaust possesses endocrine activity and therefore may affect reproductive outcome. This study in mice aimed to investigate whether exposure to diesel exhaust particles (DEP; NIST 2975) would affect gestation, postnatal development, activity, learning and memory, and biomarkers of transplacental toxicity. Pregnant mice (C57BL/6; BomTac) were exposed to 19 mg/m3 DEP (~1·106 particles/cm3; mass median diameter ? 240 nm) on gestational days 9–19, for 1 h/day. Results Gestational parameters were similar in control and diesel groups. Shortly after birth, body weights of DEP offspring were slightly lower than in controls. This difference increased during lactation, so by weaning the DEP exposed offspring weighed significantly less than the control progeny. Only slight effects of exposure were observed on cognitive function in female DEP offspring and on biomarkers of exposure to particles or genotoxic substances. Conclusion In utero exposure to DEP decreased weight gain during lactation. Cognitive function and levels of biomarkers of exposure to particles or to genotoxic substances were generally similar in exposed and control offspring. The particle size and chemical composition of the DEP and differences in exposure methods (fresh, whole exhaust versus aged, resuspended DEP) may play a significant role on the biological effects observed in this compared to other studies. PMID:18331653

  9. Diesel exhaust particle exposure causes redistribution of endothelial tube VE-cadherin.

    PubMed

    Chao, Ming-Wei; Kozlosky, John; Po, Iris P; Strickland, Pamela Ohman; Svoboda, Kathy K H; Cooper, Keith; Laumbach, Robert J; Gordon, Marion K

    2011-01-11

    Whether diesel exhaust particles (DEPs) potentially have a direct effect on capillary endothelia was examined by following the adherens junction component, vascular endothelial cell cadherin (VE-cadherin). This molecule is incorporated into endothelial adherens junctions at the cell surface, where it forms homodimeric associations with adjacent cells and contributes to the barrier function of the vasculature (Dejana et al., 2008; Venkiteswaran et al., 2002; Villasante et al., 2007). Human umbilical vein endothelial cells (HUVECs) that were pre-formed into capillary-like tube networks in vitro were exposed to DEPs for 24h. After exposure, the integrity of VE-cadherin in adherens junctions was assessed by immunofluorescence analysis, and demonstrated that increasing concentrations of DEPs caused increasing redistribution of VE-cadherin away from the cell-cell junctions toward intracellular locations. Since HUVEC tube networks are three-dimensional structures, whether particles entered the endothelial cells or tubular lumens was also examined. The data indicate that translocation of the particles does occur. The results, obtained in a setting that removes the confounding effects of inflammatory cells or blood components, suggest that if DEPs encounter alveolar capillaries in vivo, they may be able to directly affect the endothelial cell-cell junctions. PMID:20887764

  10. Controlled human exposures to diesel exhaust

    EPA Science Inventory

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

  11. EXHAUST MAIN PERSONNEL EXPOSURE CALCULATION

    SciTech Connect

    S. Su

    1999-09-29

    The purpose of this activity is to identify and determine potential radiation hazards in the service exhaust main due to a waste package leakage from an emplacement drift. This work supports the subsurface ventilation system design for the EDA II, which consists of an accessible service exhaust main for personnel, and an exhaust main for hot air flow. The objective is to provide the necessary radiation exposure calculations to determine if the service exhaust main is accessible following a waste package leak. This work includes the following items responsive to the stated purpose and objective: Calculate the limiting transient radiation exposure of personnel in the service exhaust main due to the passage of airborne radioactive material through the ventilation raise and connecting horizontal raise to the exhaust main in the event of a leaking waste package Calculate the potential exposures to maintenance workers in the service exhaust main from residual radioactive material deposited inside of the ventilation raise and connecting horizontal raise This calculation is limited to external radiation only, since the airborne and contamination sources will be contained in the ventilation raise and connecting horizontal raise.

  12. Protective Effect of Curcumin on Pulmonary and Cardiovascular Effects Induced by Repeated Exposure to Diesel Exhaust Particles in Mice

    PubMed Central

    Nemmar, Abderrahim; Subramaniyan, Deepa; Ali, Badreldin H.

    2012-01-01

    Particulate air pollution has been associated with increased risk of cardiopulmonary diseases. However, the underlying mechanisms are not fully understood. We have previously demonstrated that single dose exposure to diesel exhaust particle (DEP) causes lung inflammation and peripheral thrombotic events. Here, we exposed mice with repeated doses of DEP (15µg/animal) every 2nd day for 6 days (a total of 4 exposures), and measured several cardiopulmonary endpoints 48 h after the end of the treatments. Moreover, the potential protective effect of curcumin (the yellow pigment isolated from turmeric) on DEP-induced cardiopulmonary toxicity was assessed. DEP exposure increased macrophage and neutrophil numbers, tumor necrosis factor ? (TNF ?) in the bronchoalveolar lavage (BAL) fluid, and enhanced airway resistance to methacoline measured invasively using Flexivent. DEP also significantly increased plasma C-reactive protein (CRP) and TNF ? concentrations, systolic blood pressure (SBP) as well as the pial arteriolar thrombosis. It also significantly enhanced the plasma D-dimer and plasminogen activator inhibitor-1 (PAI-1). Pretreatment with curcumin by oral gavage (45 mg/kg) 1h before exposure to DEP significantly prevented the influx of inflammatory cells and the increase of TNF ? in BAL, and the increased airway resistance caused by DEP. Likewise, curcumin prevented the increase of SBP, CRP, TNF ?, D-dimer and PAI-1. The thrombosis was partially but significantly mitigated. In conclusion, repeated exposure to DEP induced lung and systemic inflammation characterized by TNF? release, increased SBP, and accelerated coagulation. Our findings indicate that curcumin is a potent anti-inflammatory agent that prevents the release of TNF? and protects against the pulmonary and cardiovascular effects of DEP. PMID:22745783

  13. Suppression of Cell-Mediated Immune Responses to Listeria Infection by Repeated Exposure to Diesel Exhaust Particles in Brown Norway Rats

    Microsoft Academic Search

    Xuejun J. Yin; Caroline C. Dong; Jane Y. C. Ma; James M. Antonini; Jenny R. Roberts; Charles F. Stanley; Rosana Schafer; Joseph K. H. Ma

    2004-01-01

    Diesel exhaust particles (DEP) have been shown to alter pul- monary immune responses to bacterial infection. Exposure of rats to 100 mg\\/m 3 DEP for 4 h was found to aggravate Listeria monocytogenes (Listeria) infection at 3 days postinfection, but the bacteria were largely cleared at 7 days postinfection due to the development of a strong T cell-mediated immunity. In

  14. Allergic Susceptibility Associated with Diesel Exhaust Particle Exposure: Clear as Mud

    Microsoft Academic Search

    Riccardo Polosa; Sundeep Salvi; Giuseppe U. di Maria

    2002-01-01

    Exposure to elevated levels of particulate air pollution from motor vehicles is frequently associated with increased morbidity and mortality from cardiovascular conditions, lung cancer, and nonmalignant respiratory illnesses (e.g., asthma, bronchitis, respiratory tract infections). It appears, however, that less attention has been paid to the potential role of road traffic fumes in the induction of allergic conditions. Laboratory studies in

  15. Diesel and biodiesel exhaust particle effects on rat alveolar machrophages with in vitro exposure

    EPA Science Inventory

    We conducted in vitro exposures of Wistar rat alveolar macrophages (AM) to compare and contrast the toxicity of particulate matter (PM) produced in combustion of biodiesel blend (B20) and petroleum diesel (PDEP). The PM contain detectable levels of transition metals and ions howe...

  16. 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??g 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??L 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

  17. cDNA microarray analysis of rat alveolar epithelial cells following exposure to organic extract of diesel exhaust particles.

    PubMed

    Koike, Eiko; Hirano, Seishiro; Furuyama, Akiko; Kobayashi, Takahiro

    2004-12-01

    Diesel exhaust particles (DEP) induce pulmonary diseases including asthma and chronic bronchitis. Comprehensive evaluation is required to know the mechanisms underlying the effects of air pollutants including DEP on lung diseases. Using a cDNA microarray, we examined changes in gene expression in SV40T2 cells, a rat alveolar type II epithelial cell line, following exposure to an organic extract of DEP. We identified candidate sensitive genes that were up- or down-regulated in response to DEP. The cDNA microarray analysis revealed that a 6-h exposure to the DEP extract (30 microg/ml) increased (>2-fold) the expression of 51 genes associated with drug metabolism, antioxidation, cell cycle/proliferation/apoptosis, coagulation/fibrinolysis, and expressed sequence tags (ESTs), and decreased (<0.5-fold) that of 20 genes. In the present study, heme oxygenase (HO)-1, an antioxidative enzyme, showed the maximum increase in gene expression; and type II transglutaminase (TGM-2), a regulator of coagulation, showed the most prominent decrease among the genes. We confirmed the change in the HO-1 protein level by Western blot analysis and that in the enzyme activity of TGM-2. The organic extract of DEP increased the expression of HO-1 protein and decreased the enzyme activity of TGM-2. Furthermore, these effects of DEP on either HO-1 or TGM-2 were reduced by N-acetyl-l-cysteine (NAC), thus suggesting that oxidative stress caused by this organic fraction of DEP may have induced these cellular responses. Therefore, an increase in HO-1 and a decrease in TGM-2 might be good markers of the biological response to organic compounds of airborne particulate substances. PMID:15541757

  18. 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. PMID:22754710

  19. Detailed diesel exhaust characteristics including particle surface area and lung deposited dose for better understanding of health effects in human chamber exposure studies

    NASA Astrophysics Data System (ADS)

    Wierzbicka, Aneta; Nilsson, Patrik T.; Rissler, Jenny; Sallsten, Gerd; Xu, Yiyi; Pagels, Joakim H.; Albin, Maria; Österberg, Kai; Strandberg, Bo; Eriksson, Axel; Bohgard, Mats; Bergemalm-Rynell, Kerstin; Gudmundsson, Anders

    2014-04-01

    Several diesel exhaust (DE) characteristics, comprising both particle and gas phase, recognized as important when linking with health effects, are not reported in human chamber exposure studies. In order to understand effects of DE on humans there is a need for better characterization of DE when performing exposure studies. The aim of this study was to determine and quantify detailed DE characteristics during human chamber exposure. Additionally to compare to reported DE properties in conducted human exposures. A wide battery of particle and gas phase measurement techniques have been used to provide detailed DE characteristics including the DE particles (DEP) surface area, fraction and dose deposited in the lungs, chemical composition of both particle and gas phase such as NO, NO2, CO, CO2, volatile organic compounds (including aldehydes, benzene, toluene) and polycyclic aromatic hydrocarbons (PAHs). Eyes, nose and throat irritation effects were determined. Exposure conditions with PM1 (<1 ?m) mass concentration 280 ?g m-3, number concentration 4 × 105 cm-3 and elemental to total carbon fraction of 82% were generated from a diesel vehicle at idling. When estimating the lung deposited dose it was found that using the size dependent effective density (in contrast to assuming unity density) reduced the estimated respiratory dose by 132% by mass. Accounting for agglomerated structure of DEP prevented underestimation of lung deposited dose by surface area by 37% in comparison to assuming spherical particles. Comparison of DE characteristics reported in conducted chamber exposures showed that DE properties vary to a great extent under the same DEP mass concentration and engine load. This highlights the need for detailed and standardized approach for measuring and reporting of DE properties. Eyes irritation effects, most probably caused by aldehydes in the gas phase, as well as nose irritation were observed at exposure levels below current occupational exposure limit values given for exhaust fumes. Reporting detailed DE characteristics that include DEP properties (such as mass and number concentration, size resolved information, surface area, chemical composition, lung deposited dose by number, mass and surface) and detailed gas phase including components known for their carcinogenic and irritation effect (e.g. aldehydes, benzene, PAHs) can help in determination of key parameters responsible for observed health effects and comparison of chamber exposure studies.

  20. 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 ...

  1. Apparatus for recycling collected exhaust particles

    Microsoft Academic Search

    D. F. Dolan; D. B. Kittelson; B. Y. Liu; D. Y. Pui

    1982-01-01

    The method and apparatus for controlling particulate emissions from a combustion apparatus, such as a diesel engine is disclosed. Diesel engine exhaust particles are electrically charged during the formation of the particles in the engine combustion chamber. A particle collector is used to collect the electrically charged particles on collecting structures connected to a high voltage power supply and ground.

  2. Method of recycling collected exhaust particles

    Microsoft Academic Search

    D. F. Dolan; D. B. Kittelson; B. Y. Liu; D. Y. Pui

    1982-01-01

    The method and apparatus for controlling particulate emissions from a combustion apparatus, as a diesel engine. Diesel engine exhaust particles are electrically charged during the formation of the particles in the engine combustion chamber. A particle collector is used to collect the electrically charged particles on collecting structures connected to a high voltage power supply and ground. The collecting structures

  3. Exposure to Diesel Exhaust Particle Extracts (DEPe) Impairs Some Polarization Markers and Functions of Human Macrophages through Activation of AhR and Nrf2

    PubMed Central

    Jaguin, Marie; Fardel, Olivier; Lecureur, Valérie

    2015-01-01

    Macrophages (M?), well-known to play an important role in immune response, also respond to environmental toxic chemicals such as diesel exhaust particles (DEP). Potential effects of DEPs towards M? polarization, a key hall-mark of M? physiology, remain however poorly documented. This study was therefore designed to evaluate the effects of a reference DEP extract (DEPe) on human M? polarization. Human blood monocytes-derived M? were incubated with IFN?+LPS or IL-4 to obtain M1 and M2 subtypes, respectively; a 24 h exposure of polarizing M? to 10 ?g/ml DEPe was found to impair expression of some macrophagic M1 and M2 markers, without however overall inhibition of M1 and M2 polarization processes. Notably, DEPe treatment increased the secretion of the M1 marker IL-8 and the M2 marker IL-10 in both M? subtypes, whereas it reduced lipopolysaccharide-induced IL-6 and IL-12p40 secretion in M1 M?. In M2 M?, DEPe exposure led to a reduction of CD200R expression and of CCL17, CCL18 and CCL22 secretion, associated with a lower chemotaxis of CCR4-positive cells. DEPe activated the Nrf2 and AhR pathways and induced expression of their reference target genes such as Hmox-1 and cytochrome P-4501B1 in M1 and M2 M?. Nrf2 or AhR silencing through RNA interference prevented DEPe-related down-regulation of IL-6. AhR silencing also inhibited the down-secretion of IL-12p40 and CCL18 in M1- and M2-DEPe-exposed M?, respectively. DEPs are therefore likely to alter expression of some M1 and M2 markers in an AhR- and Nrf2-dependent manner; such regulations may contribute to deleterious immune effects of atmospheric DEP. PMID:25710172

  4. 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 a real-time dosimeter to indicate when respiratory protection is advisable. PMID:11017890

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

    SciTech Connect

    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.

  6. 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...

  7. DNA damage and cytotoxicity in type II lung epithelial (A549) cell cultures after exposure to diesel exhaust and urban street particles

    Microsoft Academic Search

    Pernille Høgh Danielsen; Steffen Loft; Peter Møller

    2008-01-01

    BACKGROUND: Exposure to air pollution particles has been acknowledged to be associated with excess generation of oxidative damage to DNA in experimental model systems and humans. The use of standard reference material (SRM), such as SRM1650 and SRM2975, is advantageous because experiments can be reproduced independently, but exposure to such samples may not mimic the effects observed after exposure to

  8. 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...

  9. 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...

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

    Microsoft Academic Search

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

    2003-01-01

    ObjectivesWorkers' 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)

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

    Microsoft Academic Search

    Susan R. Woskie; Thomas J. Smith; S. Katharine Hammond; Marc B. Schenker; Eric Garshick; Frank E. Speizer

    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

  12. 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.

  13. GASOLINE VEHICLE EXHAUST PARTICLE SAMPLING STUDY

    SciTech Connect

    Kittelson, D; Watts, W; Johnson, J; Zarling, D Schauer,J Kasper, K; Baltensperger, U; Burtscher, H

    2003-08-24

    The University of Minnesota collaborated with the Paul Scherrer Institute, the University of Wisconsin (UWI) and Ricardo, Inc to physically and chemically characterize the exhaust plume from recruited gasoline spark ignition (SI) vehicles. The project objectives were: (1) Measure representative particle size distributions from a set of on-road SI vehicles and compare these data to similar data collected on a small subset of light-duty gasoline vehicles tested on a chassis dynamometer with a dilution tunnel using the Unified Drive Cycle, at both room temperature (cold start) and 0 C (cold-cold start). (2) Compare data collected from SI vehicles to similar data collected from Diesel engines during the Coordinating Research Council E-43 project. (3) Characterize on-road aerosol during mixed midweek traffic and Sunday midday periods and determine fleet-specific emission rates. (4) Characterize bulk- and size-segregated chemical composition of the particulate matter (PM) emitted in the exhaust from the gasoline vehicles. Particle number concentrations and size distributions are strongly influenced by dilution and sampling conditions. Laboratory methods were evaluated to dilute SI exhaust in a way that would produce size distributions that were similar to those measured during laboratory experiments. Size fractionated samples were collected for chemical analysis using a nano-microorifice uniform deposit impactor (nano-MOUDI). In addition, bulk samples were collected and analyzed. A mixture of low, mid and high mileage vehicles were recruited for testing during the study. Under steady highway cruise conditions a significant particle signature above background was not measured, but during hard accelerations number size distributions for the test fleet were similar to modern heavy-duty Diesel vehicles. Number emissions were much higher at high speed and during cold-cold starts. Fuel specific number emissions range from 1012 to 3 x 1016 particles/kg fuel. A simple relationship between number and mass emissions was not observed. Data were collected on-road to compare weekday with weekend air quality around the Twin Cities area. This portion of the study resulted in the development of a method to apportion the Diesel and SI contribution to on-road aerosol.

  14. BEHAVIORAL ALTERATIONS DUE TO DIESEL EXHAUST EXPOSURE

    EPA Science Inventory

    Several experiments examining the effects of diesel exhaust on the behavior of rats are reported. Animals were exposed either as adults or neonates. The spontaneous locomotor activity (SLA), measured in standard running wheel cages, of adult rats exposed for 8 h/day, 7 days/week ...

  15. 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...

  16. Relationship between particle mass and mobility for diesel exhaust particles.

    PubMed

    Park, Kihong; Cao, Feng; Kittelson, David B; McMurry, Peter H

    2003-02-01

    We used the aerosol particle mass analyzer (APM) to measure the mass of mobility-classified diesel exhaust particles. This information enabled us to determine the effective density and fractal dimension of diesel particles as a function of engine load. We found that the effective density decreases as particle size increases. TEM images showed that this occurs because particles become more highly agglomerated as size increases. Effective density and fractal dimension increased somewhat as engine load decreased. TEM images suggest that this occurs because these particles contain more condensed fuel and/or lubricating oil. Also, we observed higher effective densities when high-sulfur EPA fuel (approximately 360 ppm S) was used than for Fischer-Tropsch fuel (approximately 0 ppm S). In addition, the effective density provides the relationship between mobility and aerodynamic equivalent diameters. The relationship between these diameters enables us to intercompare, in terms of a common measure of size, mass distributions measured with the scanning mobility particle sizer (SMPS) and a MOUDI impactor without making any assumptions about particle shape or density. We show that mass distributions of diesel particles measured with the SMPS-APM are in good agreement with distributions measured with a MOUDI and a nano-MOUDI for particles larger than approximately 60 nm. However, significantly more mass and greater variation were observed by the nano-MOUDI for particles smaller than 40 nm than by the SMPS-APM. PMID:12630475

  17. 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 ...

  18. Prenatal allergen and diesel exhaust exposure and their effects on allergy in adult offspring mice

    PubMed Central

    2010-01-01

    Background Multiple studies have suggested that prenatal exposure to either allergens or air pollution may increase the risk for the development of allergic immune responses in young offspring. However, the effects of prenatal environmental exposures on adult offspring have not been well-studied. We hypothesized that combined prenatal exposure to Aspergillus fumigatus (A. fumigatus) allergen and diesel exhaust particles will be associated with altered IgE production, airway inflammation, airway hyperreactivity (AHR), and airway remodeling of adult offspring. Methods Following sensitization via the airway route to A. fumigatus and mating, pregnant BALB/c mice were exposed to additional A. fumigatus and/or diesel exhaust particles. At age 9-10 weeks, their offspring were sensitized and challenged with A. fumigatus. Results We found that adult offspring from mice that were exposed to A. fumigatus or diesel exhaust particles during pregnancy experienced decreases in IgE production. Adult offspring of mice that were exposed to both A. fumigatus and diesel exhaust particles during pregnancy experienced decreases in airway eosinophilia. Conclusion These results suggest that, in this model, allergen and/or diesel administration during pregnancy may be associated with protection from developing systemic and airway allergic immune responses in the adult offspring. PMID:20459836

  19. 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...

  20. 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...

  1. 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...

  2. Exposure to traffic exhausts and oxidative DNA damage

    PubMed Central

    Lai, C; Liou, S; Lin, H; Shih, T; Tsai, P; Chen, J; Yang, T; Jaakkola, J; Strickland, P

    2005-01-01

    Aims: To assess the relations between exposure to traffic exhausts and indicators of oxidative DNA damage among highway toll station workers. Methods: Cross-sectional study of 47 female highway toll station workers exposed to traffic exhausts and 27 female office workers as a reference group. Exposure assessment was based on average and cumulative traffic density and a biomarker of exposure, urinary 1-hydroxypyrene-glucuronide (1-OHPG). Urinary 8-hydroxydeoxyguanosine (8-OHdG) was used as a biomarker of oxidative DNA damage. Plasma nitric oxide (NO) was measured as an indicator of oxidative stress related to traffic exhaust exposure. Results: The mean concentration of urinary 8-OHdG was substantially higher among the exposed non-smokers (13.6 µg/g creatinine) compared with the reference non-smokers (7.3 µg/g creatinine; difference 6.3, 95% CI 3.0 to 9.6). The mean concentration of NO among the exposed (48.0 µmol/l) was also higher compared with the reference non-smokers (37.6 µmol/l; difference 10.4, 95% CI –0.4 to 21.2). In linear regression adjusting for confounding, a change in log(8-OHdG) was statistically significantly related to a unit change in log(1-OHPG) (ß = 0.372, 95% CI 0.081 to 0.663). Conclusions: Results indicate that exposure to traffic exhausts increases oxidative DNA damage. Urinary 8-OHdG is a promising biomarker of traffic exhaust induced oxidative stress. PMID:15778253

  3. 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...

  4. 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...

  5. Monitoring and analysis of occupational exposure to chain saw exhausts.

    PubMed

    Bünger, J; Bombosch, F; Mesecke, U; Hallier, E

    1997-10-01

    The extent of inhalation exposure to loggers from two-stroke chain saws was measured and evaluated under various conditions. Carbon monoxide, measured by personal air monitoring and determination of carboxyhemoglobin levels of the loggers, was used as an indicator of exhaust exposure. Video recordings were made to analyze the influence of varying working conditions and the individual handling of the chain saw on the amount of pollutants inhaled. The American Conference of Governmental Industrial Hygienists biological exposure index (BEI) for carboxyhemoglobin (3.5%) was exceeded during logging in heavy timber stands. When workers were paid on a piecework basis, carboxyhemoglobinemia increased to its maximum level in the first 2-3 hours of the shift and then declined. After 8 hours carboxyhemoglobin levels were 20-30% lower compared with the maximum. Increased exhaust inhalation with short-term exposures to carbon monoxide up to 400 ppm was observed in the following conditions: (1) felling operations, (2) other operations performed in a leaning of squatting position, (3) limbing in thick tops of coniferous trees, (4) working at low wind velocity, and (5) working in thick forest stands. Maximum allowable blood concentrations for carboxyhemoglobin are exceeded in chain saw operators in logging operations. Blood sampling at the end of the workday is not always suitable for determining the highest carboxyhemoglobin levels in loggers during the shift. The exposure of chain saw operators to exhaust increases under certain conditions. PMID:9342836

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

    Microsoft Academic Search

    Susan R. Woskie; Thomas J. Smith; S. Katharine Hammond; Marc B. Schenker; Eric Garshick; Frank E. Speizer

    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

  7. Variation of particle exhaust with changes in divertor magnetic balance

    NASA Astrophysics Data System (ADS)

    Petrie, T. W.; Allen, S. L.; Brooks, N. H.; Fenstermacher, M. E.; Ferron, J. R.; Greenfield, C. M.; Groth, M.; Hyatt, A. W.; Mahdavi, M. A.; Porter, G. D.; Rensink, M. E.; Schaffer, M. J.; Wade, M. R.; Watkins, J. G.

    2006-01-01

    Recent experiments on DIII-D point to the importance of two factors in determining how effectively the deuterium particle inventory in a tokamak plasma can be controlled through pumping at the divertor target(s): (1) the divertor magnetic balance, i.e. the degree to which the divertor topology is single-null or double-null (DN) and (2) the direction of the of B × ?B ion drift with respect to the X-point(s). Changes in divertor magnetic balance near the DN shape have a much stronger effect on the particle exhaust rate at the inner divertor target(s) than on the particle exhaust rate at the outer divertor target(s). The particle exhaust rate for the DN shape is strongest at the outer strike point opposite the B × ?B ion particle drift direction. Our data suggests that the presence of B × ?B and E × B ion particle drifts in the scrape-off layer and divertor(s) play an important role in the particle exhaust rates of DN and near-DN plasmas. Particle exhaust rates are shown to depend strongly on the edge (pedestal) density. These results have implications for particle control in ITER and other future tokamaks.

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

    EPA Science Inventory

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

  9. 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...

  10. 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 ?g/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 ?g/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 ?g/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-based epidemiological studies and guide future exposure assessment efforts for industrial hygiene and epidemiological studies. PMID:19277070

  11. Electrophilic and redox properties of diesel exhaust particles.

    PubMed

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

    2009-04-01

    The adverse health effects of air pollutants have been associated with their redox and electrophilic properties. Although the specific chemical species involved in these effects are not known, the characterization of their general physical and chemical properties is important to our understanding of the mechanisms by which they cause health problems. This manuscript describes results of a study examining the partition properties of these activities in aqueous and organic media. The water and dichloromethane (DCM) solubility of redox active and electrophilic constituents of seven diesel exhaust particle (DEP) samples were determined with assays developed earlier in this laboratory. The constituents exhibiting redox activity, which included both metals and nonmetal species, were associated with the particles in the aqueous suspensions. Portions of the redox active compounds were also DCM-soluble. In contrast, the electrophilic constituents included both water-soluble and DCM-soluble species. The role of quinones or quinone-like compounds in redox and electrophilic activities of the DCM-soluble constituents was assessed by reductive acetylation, a procedure that inactivates quinones. The results from this experiment indicated that most of the activities in the organic extract were associated with quinone-like substances. The partition properties of the reactive species are important in exposure assessment since the toxicokinetics of particles and solutes are quite distinct. PMID:19200952

  12. Tracking personal exposure to particulate diesel exhaust in a diesel freight terminal using organic tracer analysis

    PubMed Central

    SHEESLEY, REBECCA J.; SCHAUER, JAMES J.; GARSHICK, ERIC; LADEN, FRANCINE; SMITH, THOMAS J.; BLICHARZ, ANDREW P.; DEMINTER, JEFFREY T.

    2008-01-01

    Personal exposure to particle-phase molecular markers was measured at a trucking terminal in St Louis, MO, as part of a larger epidemiologic project aimed at assessing carbonaceous fine particulate matter (PM) exposure in this occupational setting. The integration of parallel personal exposure, ambient worksite area and ambient urban background (St Louis Supersite) measurements provided a unique opportunity to track the work-related exposure to carbonaceous fine PM in a freight terminal. The data were used to test the proposed personal exposure model in this occupational setting: Personal?exposure=urban?background+work?site?background+personal?activity To accurately assess the impact of PM emission sources, particularly motor vehicle exhaust, and organic elemental carbon (OCEC) analysis and nonpolar organic molecular marker analysis by thermal desorption-gas chromatography/mass spectrometry (TD-GCMS) were conducted on all of the PM samples. EC has been used as a tracer for diesel exhaust in urban areas, however, the emission profile for diesel exhaust is dependent upon the operating conditions of the vehicle and can vary considerably within a fleet. Hopanes, steranes, polycyclic aromatic hydrocarbons and alkanes were measured by TD-GCMS. Hopanes are source-specific organic molecular markers for lubricating oil present in motor vehicle exhaust. The concentrations of OC, EC and the organic tracers were averaged to obtain average profiles to assess differences in the personal, worksite area and urban background samples, and were also correlated individually by sample time to evaluate the exposure model presented above. Finally, a chemical mass balance model was used to apportion the motor vehicle and cigarette-smoke components of the measured OC and EC for the average personal exposure, worksite area and urban background samples. PMID:18322451

  13. 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

  14. Tracking personal exposure to particulate diesel exhaust in a diesel freight terminal using organic tracer analysis.

    PubMed

    Sheesley, Rebecca J; Schauer, James J; Garshick, Eric; Laden, Francine; Smith, Thomas J; Blicharz, Andrew P; Deminter, Jeffrey T

    2009-02-01

    Personal exposure to particle-phase molecular markers was measured at a trucking terminal in St Louis, MO, as part of a larger epidemiologic project aimed at assessing carbonaceous fine particulate matter (PM) exposure in this occupational setting. The integration of parallel personal exposure, ambient worksite area and ambient urban background (St Louis Supersite) measurements provided a unique opportunity to track the work-related exposure to carbonaceous fine PM in a freight terminal. The data were used to test the proposed personal exposure model in this occupational setting: To accurately assess the impact of PM emission sources, particularly motor vehicle exhaust, and organic elemental carbon (OCEC) analysis and nonpolar organic molecular marker analysis by thermal desorption-gas chromatography/mass spectrometry (TD-GCMS) were conducted on all of the PM samples. EC has been used as a tracer for diesel exhaust in urban areas, however, the emission profile for diesel exhaust is dependent upon the operating conditions of the vehicle and can vary considerably within a fleet. Hopanes, steranes, polycyclic aromatic hydrocarbons and alkanes were measured by TD-GCMS. Hopanes are source-specific organic molecular markers for lubricating oil present in motor vehicle exhaust. The concentrations of OC, EC and the organic tracers were averaged to obtain average profiles to assess differences in the personal, worksite area and urban background samples, and were also correlated individually by sample time to evaluate the exposure model presented above. Finally, a chemical mass balance model was used to apportion the motor vehicle and cigarette-smoke components of the measured OC and EC for the average personal exposure, worksite area and urban background samples. PMID:18322451

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

    Microsoft Academic Search

    Stefan Barath; Nicholas L Mills; Magnus Lundbäck; Håkan Törnqvist; Andrew J Lucking; Jeremy P Langrish; Stefan Söderberg; Christoffer Boman; Roger Westerholm; Jakob Löndahl; Ken Donaldson; Ian S Mudway; Thomas Sandström; David E Newby; Anders Blomberg

    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'

  16. Diesel exhaust exposure and lung cancer: a case-control study

    SciTech Connect

    Hall, N.E.L.; Wynder, E.L.

    1984-06-01

    The presence of polyaromatic hydrocarbons in the particulate phase of diesel engine exhaust has raised questions concerning potential carcinogenicity of diesel exhaust exposure. A case-control study was conducted of 502 male lung cancer cases and 502 controls without tobacco-related diseases to investigate the association of occupational diesel exhaust exposure and lung cancer. Diesel exhaust exposure was appraised by job title. The results show no association between diesel exhaust exposure and risk of lung cancer. They do, however, show the strong association between smoking and lung cancer and as such highlight the importance of smoking information in studies of occupational effect on lung cancer risk.

  17. Space shuttle exhausted aluminum oxide: A measured particle size distribution

    Microsoft Academic Search

    W. R. Cofer; G. C. Purgold; E. L. Winstead; R. A. Edahl

    1991-01-01

    Aluminum oxide (A2O3) particles were collected from the space shuttle exhaust plume immediately following the launch of STS-34 on October 18, 1989. A2O3 samples were obtained at 2.4, 3.0, 3.2, and 7.4 km in altitude. The samples were analyzed using scanning electron microscopy to develop particle size distributions. There were no indications that the particle size distribution changed as a

  18. Carbon nanotubes among diesel exhaust particles: real samples or contaminants?

    PubMed

    Jung, Heejung S; Miller, Art; Park, Kihong; Kittelson, David B

    2013-10-01

    During three separate studies involving characterization of diesel particulate matter carbon nanotubes (CNTs) were found among diesel exhaust particles sampled onto transmission electron microscopy (TEM) grids. During these studies, samples were collected from three different diesel engines at normal operating conditions with or without an iron catalyst (introduced as ferrocene) in the fuel. This paper is to report the authors' observation of CNTs among diesel exhaust particles, with the intent to stimulate awareness and further discussion regarding the formation mechanisms of CNTs during diesel combustion. PMID:24282972

  19. 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...

  20. 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...

  1. Mutagenicity of Diesel and Soy Biodiesel Exhaust Particles

    EPA Science Inventory

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

  2. Divertor particle exhaust and wall inventory on DIII-D

    SciTech Connect

    Maingi, R. [General Atomics, San Diego, CA (United States)]|[Oak Ridge Associated Universities, TN (United States); Jackson, G.L.; Mahdavi, M.A.; Schaffer, M.J. [General Atomics, San Diego, CA (United States); Wade, M.R.; Mioduszewski, P.K.; Hogan, J.T.; Klepper, C.C. [General Atomics, San Diego, CA (United States)]|[Oak Ridge National Lab., TN (United States); Haas, G. [General Atomics, San Diego, CA (United States)]|[Max Planck Inst. for Plasmaphysik, Garching (Germany)

    1995-09-01

    Many tokamaks achieve optimum plasma performance by achieving low recycling; various wall conditioning techniques including helium glow discharge cleaning (HeGDC) are routinely applied to help achieve low recycling. Many of these techniques allow strong, transient wall pumping, but they may not be effective for long-pulse tokamaks, such as the International Thermonuclear Experimental Reactor (ITER), the Tokamak Physics Experiment (TPX), Tore Supra Continu, and JT-60SU. Continuous particle exhaust using an in-situ pumping scheme may be effective for wall inventory control in such devices. Recent particle balance experiments on the Tore Supra and DIII-D tokamaks demonstrated that the wall particle inventory could be reduced during a given discharge by use of continuous particle exhaust. In this paper the authors report the first results of wall inventory control and good performance with the in-situ DIII-D cryopump, replacing the HeGDC normally applied between discharges.

  3. Divertor particle exhaust and wall inventory on DIII-D

    SciTech Connect

    Maingi, R. [Oak Ridge Associated Univ., TN (United States); Wade, M.R.; Mioduszewski, P.K. [Oak Ridge National Lab., TN (United States)

    1995-06-01

    Many tokamaks achieve optimum plasma performance by achieving low recycling; various wall conditioning techniques including helium glow discharge cleaning (HeGDC) are routinely applied to help achieve low recycling. Many of these techniques allow strong, transient wall pumping, but they may not be effective for long-pulse tokamaks, such as the International Thermonuclear Experimental Reactor (ITER), the Tokamak Physics Experiment (TPX), Tore Supra Continu, and JT-60SU. Continuous particle exhaust using an in-situ pumping scheme may be effective for wall inventory control in such devices. Recent particle balance experiments on the Tore Supra and DIII-D tokamaks demonstrated that the wall particle inventory could be reduced during a given discharge by use of continuous particle exhaust. In this paper we report the first results of wall inventory control and good performance with the in-situ DIII-D cryopump, replacing the HeGDC normally applied between discharges.

  4. Ice nucleus activity measurements of solid rocket motor exhaust particles

    NASA Technical Reports Server (NTRS)

    Keller, V. W. (compiler)

    1986-01-01

    The ice Nucleus activity of exhaust particles generated from combustion of Space Shuttle propellant in small rocket motors has been measured. The activity at -20 C was substantially lower than that of aerosols generated by unpressurized combustion of propellant samples in previous studies. The activity decays rapidly with time and is decreased further in the presence of moist air. These tests corroborate the low effectivity ice nucleus measurement results obtained in the exhaust ground cloud of the Space Shuttle. Such low ice nucleus activity implies that Space Shuttle induced inadvertent weather modification via an ice phase process is extremely unlikely.

  5. 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 ?g/m3, and 0.06-19.13 ?g/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. PMID:25411914

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

    Bradley, Jessica M; Cryar, Kipp A; El Hajj, Milad C; El Hajj, Elia C; Gardner, Jason D

    2013-10-01

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

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

    EPA Science Inventory

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

  9. 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...

  10. Sulfuric Acid and Soot Particle Formation in Aircraft Exhaust

    NASA Technical Reports Server (NTRS)

    Pueschel, Rudolf F.; Verma, S.; Ferry, G. V.; Howard, S. D.; Vay, S.; Kinne, S. A.; Baumgardner, D.; Dermott, P.; Kreidenweis, S.; Goodman, J.; Gore, Waren J. Y. (Technical Monitor)

    1997-01-01

    A combination of CN counts, Ames wire impactor size analyses and optical particle counter data in aircraft exhaust results in a continuous particle size distribution between 0.01 micrometer and 1 micrometer particle radius sampled in the exhaust of a Boeing 757 research aircraft. The two orders of magnitude size range covered by the measurements correspond to 6-7 orders of magnitude particle concentration. CN counts and small particle wire impactor data determine a nucleation mode, composed of aircraft-emitted sulfuric acid aerosol, that contributes between 62% and 85% to the total aerosol surface area and between 31% and 34% to its volume. Soot aerosol comprises 0.5% of the surface area of the sulfuric acid aerosol. Emission indices are: EIH2SO4 = 0.05 g/kgFUEL and (0.2-0.5) g/kgFUEL (for 75 ppmm and 675 ppmm fuel-S, respectively), 2.5E4particles/kgFUEL (for 75 and 675 ppmm fuel-S). The sulfur (gas) to H2SO4 (particle) conversion efficiency is between 10% and 25%.

  11. *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...

  12. 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...

  13. 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...

  14. Elemental Carbon-Based Method for Monitoring Occupational Exposures to Particulate Diesel Exhaust

    Microsoft Academic Search

    M. E. Birch; R. A. Cary

    1996-01-01

    Diesel exhaust has been classified a probable human carcinogen, and the National Institute for Occupational Safety and Health (NIOSH) has recommended that employers reduce workers' exposures. Because diesel exhaust is a chemically complex mixture containing thousands of compounds, some measure of exposure must be selected. Previously used methods involving gravimetry or analysis of the soluble organic fraction of diesel soot

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

    Microsoft Academic Search

    Yoki Mori; Sumika Murakami; Toshiyuki Sagae

    1996-01-01

    The effect of diesel exhaust particles (DEP) on the activity of catalase, an intracellular anti-oxidant, was investigated because HâOâ is a cytotoxic oxidant, and catalase released from alveolar cells is an important antioxidant in the epithelial lining fluid in the lung. DEP inhibited the activity of bovine liver catalase dose-dependently, to 25-30% of its original value. The inhibition of catalase

  16. In utero exposure to a low concentration of diesel exhaust affects spontaneous locomotor activity and monoaminergic system in male mice

    PubMed Central

    2010-01-01

    Background Epidemiological studies have suggested that suspended particulate matter (SPM) causes detrimental health effects such as respiratory and cardiovascular diseases, and that diesel exhaust particles from automobiles is a major contributor to SPM. It has been reported that neonatal and adult exposure to diesel exhaust damages the central nervous system (CNS) and induces behavioral alteration. Recently, we have focused on the effects of prenatal exposure to diesel exhaust on the CNS. In this study, we examined the effects of prenatal exposure to low concentration of diesel exhaust on behaviour and the monoaminergic neuron system. Spontaneous locomotor activity (SLA) and monoamine levels in the CNS were assessed. Methods Mice were exposed prenatally to a low concentration of diesel exhaust (171 ?g DEP/m3) for 8 hours/day on gestational days 2-16. SLA was assessed for 3 days in 4-week-old mice by analysis of the release of temperature-associated infrared rays. At 5 weeks of age, the mice were sacrificed and the brains were used for analysis by high-performance liquid chromatography (HPLC). Results and Discussion Mice exposed to a low concentration of diesel exhaust showed decreased SLA in the first 60 minutes of exposure. Over the entire test period, the mice exposed prenatally to diesel exhaust showed decreased daily SLA compared to that in control mice, and the SLA in each 3 hour period was decreased when the lights were turned on. Neurotransmitter levels, including dopamine and noradrenaline, were increased in the prefrontal cortex (PFC) in the exposure group compared to the control group. The metabolites of dopamine and noradrenaline also increased in the PFC. Neurotransmitter turnover, an index of neuronal activity, of dopamine and noradrenaline was decreased in various regions of the CNS, including the striatum, in the exposure group. The serum corticosterone level was not different between groups. The data suggest that decreased SLA in mice exposed prenatally to diesel exhaust is due to facilitated release of dopamine in the PFC. Conclusions These results indicate that exposure of mice in utero to a low concentration of diesel exhaust decreases SLA and alters the neurochemical monoamine metabolism of several regions of the brain. PMID:20331848

  17. Myocardial infarction and occupational exposure to motor exhaust: a population-based case-control study in Sweden.

    PubMed

    Ilar, Anna; Lewné, Marie; Plato, Nils; Hallqvist, Johan; Alderling, Magnus; Bigert, Carolina; Hogstedt, Christer; Gustavsson, Per

    2014-07-01

    There is a well-established association between particulate urban air pollution and cardiovascular disease, but few studies have investigated the risk associated with occupational exposure to particles from motor exhaust. This study investigated the risk of myocardial infarction (MI) after occupational exposure to motor exhaust, using elemental carbon (EC) as a marker of exposure. A population-based case-control study of first-time non-lethal MI was conducted among Swedish citizens in ages 45-70 living in Stockholm County 1992-1994, including 1,643 cases and 2,235 controls. Working histories and data on potential confounders were collected by questionnaire and medical examination. The exposure to EC was assessed through a job-exposure matrix. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated by unconditional logistic regression. We investigated various exposure metrics: intensity, cumulative exposure and years since exposure. There was an exposure-response relation between the highest average exposure intensity during the work history and the risk of MI when adjusting for smoking and alcohol drinking (p for trend 0.034), with an OR of 1.30 (95% CI 0.99-1.71) in the highest tertile of exposure compared to the unexposed. An exposure-response pattern was observed in the analysis of years since exposure cessation among formerly exposed. Additional adjustments for markers of the metabolic syndrome reduced ORs and trends to non-significant levels, although this might be an over-adjustment since the metabolic syndrome may be part of the causal pathway. Occupational exposure to motor exhaust was associated with a moderately increased risk of MI. PMID:24981789

  18. *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...

  19. 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...

  20. Implication of scavenger receptors in the interactions between diesel exhaust particles and immature or mature dendritic cells

    Microsoft Academic Search

    Solenne Taront; Audrey Dieudonné; Simon Blanchard; Pascale Jeannin; Philippe Lassalle; Yves Delneste; Philippe Gosset

    2009-01-01

    BACKGROUND: The exposure to pollutants such as diesel exhaust particles (DEP) is associated with an increased incidence of respiratory diseases. However, the mechanisms by which DEP have an effect on human health are not completely understood. In addition to their action on macrophages and airway epithelial cells, DEP also modulate the functions of dendritic cells (DC). These professional antigen-presenting cells

  1. Characterisation of lightly oxidised organic aerosol formed from the photochemical aging of diesel exhaust particles

    E-print Network

    Kroll, Jesse

    The oxidative aging of the semivolatile fraction of diesel exhaust aerosol is studied in order to better understand the influence of oxidation reactions on particle chemical composition. Exhaust is sampled from an idling ...

  2. 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 PM?.? or PM??, 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). PMID:20087407

  3. Heavy exposure to diesel exhaust linked to lung cancer death 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 evaluate cancer risk from diesel exhaust, particularly as it may relate to lung cancer, among 12,315 workers at eight non-metal mining facilities.

  4. 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 ?g/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. PMID:24705343

  5. Exhaust exposure potential from the combustion of JP-8 jet fuel in C-130 engines

    E-print Network

    Pirkle, Paul S

    2000-01-01

    of turboprop exhaust-soot-borne polycyclic aromatic hydrocarbons (PAH), elemental carbon particulate matter and carbon dioxide. Since there were no U.S. occupational exposure limits (OELs) for the first two components, working OELs were chosen by analogy...

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

    EPA Science Inventory

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

  7. INCREASED SUSCEPTIBILITY TO INFLUENZA INFECTION AFTER DIESEL EXHAUST EXPOSURE

    EPA Science Inventory

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

  8. 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...

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

    PubMed

    Morgott, David A

    2014-08-01

    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

  10. 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

  11. BIOMarkers for occupational diesel exhaust exposure monitoring (BIOMODEM)--a study in underground mining.

    PubMed

    Scheepers, P T J; Coggon, D; Knudsen, L E; Anzion, R; Autrup, H; Bogovski, S; Bos, R P; Dahmann, D; Farmer, P; Martin, E A; Micka, V; Muzyka, V; Neumann, H G; Poole, J; Schmidt-Ott, A; Seiler, F; Volf, J; Zwirner-Baier, I

    2002-08-01

    Methods for the assessment of exposures to diesel exhaust were evaluated, including various biomarkers of internal exposure and early biological effects. The impact of possible biomarkers of susceptibility was also explored. Underground workers (drivers of diesel-powered excavators) at an oil shale mine in Estonia were compared with surface workers. Personal exposures to particle-associated 1-nitropyrene (NP) were some eight times higher underground than on the surface. Underground miners were also occupationally exposed to benzene and polycyclic aromatic hydrocarbons, as indicated by excretion of urinary metabolites of benzene and pyrene. In addition, increased O(6)-alkylguanine DNA adducts were detected in the white blood cells of underground workers, suggesting higher exposure to nitroso-compounds. However, no differences between underground and surface workers were observed in the levels of other bulky DNA adducts determined by 32P-postlabelling, or in DNA damage. The study indicated that smoking, diet and residential indoor air pollution are important non-occupational factors to consider when interpreting biomonitoring results. PMID:12191893

  12. BLOOD PRESSURE RESPONSE TO CONTROLLED DIESEL EXHAUST EXPOSURE IN HUMAN SUBJECTS

    PubMed Central

    Cosselman, Kristen E.; Krishnan, Ranjini; Oron, Assaf P.; Jansen, Karen; Peretz, Alon; Sullivan, Jeffrey H.; Larson, Timothy V.; Kaufman, Joel D.

    2013-01-01

    Exposure to traffic-related air pollution is associated with risk of cardiovascular disease and mortality. We examined whether exposure to diesel exhaust increased blood pressure in human subjects. We analyzed data from 45 nonsmoking subjects, age 18–49 in double-blinded, crossover exposure studies, randomized to order. Each subject was exposed to diesel exhaust, maintained at 200 ?g/m3 of fine particulate matter, and filtered air for 120 minutes on days separated by at least two weeks. We measured blood pressure pre-exposure, at 30-minute intervals during exposure, and 3, 5, 7 and 24 hours from exposure initiation, and analyzed changes from pre-exposure values. Compared with filtered air, systolic blood pressure increased at all points measured during and after diesel exhaust exposure; the mean effect peaked between 30 and 60 minutes after exposure initiation (3.8 mmHg [95% CI: ?0.4, 8.0] and 5.1 mmHg [95% CI: 0.7, 9.5] respectively). Sex and metabolic syndrome did not modify this effect. Combining readings between 30 and 90 minutes, diesel exhaust exposure resulted in a 4.4 mmHg increase in systolic blood pressure, adjusted for participant characteristics and exposure perception (95% CI: 1.1, 7.7, p=0.0009). There was no significant effect on heart rate or diastolic pressure. Diesel exhaust inhalation was associated with a rapid, measurable increase in systolic, but not diastolic, blood pressure in young nonsmokers, independent of perception of exposure. This controlled trial in humans confirms findings from observational studies. The effect may be important on a population basis given the worldwide prevalence of exposure to traffic-related air pollution. PMID:22431582

  13. Differential effects of the particle core and organic extract of diesel exhaust particles.

    PubMed

    Totlandsdal, Annike Irene; Herseth, Jan Inge; Bølling, Anette Kocbach; Kubátová, Alena; Braun, Artur; Cochran, Richard E; Refsnes, Magne; Ovrevik, Johan; Låg, Marit

    2012-02-01

    Exposure to diesel engine exhaust particles (DEPs), representing a complex and variable mixture of components, has been associated with lung disease and induction of pro-inflammatory mediators and CYP1A1 expression. The aim of this study was to further characterise DEP-components accounting for these effects. Human bronchial epithelial cells (BEAS-2B) were exposed to either native DEPs, or corresponding methanol DEP-extract or residual DEPs, and investigated with respect to cytotoxicity and expression and release of multiple inflammation-related mediators. Both native DEPs and DEP-extract, but not residual DEPs, induced marked mRNA expression of COX-2, IL-6 and IL-8, as well as cytotoxicity and release of IL-6. However, CYP1A1 was primarily induced by the native and residual DEPs. Overall, the results of near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and gas chromatography with mass spectrometry (GC/MS) analysis of DEP-extracts indicated that the majority of the analysed PAHs and PAH-derivatives were extracted from the particles, but that certain PAH-derivatives, probably their carboxylic isomers, tended to be retained on the residual DEPs. Moreover, it appeared that certain components of the methanol extract may suppress CYP1A1 expression. These results provide insight into how different components of the complex DEP-mixture may be differently involved in DEP-induced pro-inflammatory responses and underscore the importance of identifying and clarifying the roles of active DEP-components in relation to different biological effects. PMID:22100492

  14. Toxicity of prolonged exposure to ethanol and gasoline autoengine exhaust gases

    SciTech Connect

    Massad, E.; Saldiva, P.H.; Saldiva, C.D.; Caldeira, M.P.; Cardoso, L.M.; de Morais, A.M.; Calheiros, D.F.; da Silva, R.; Boehm, G.M.

    1986-08-01

    A comparative chronic inhalation exposure study was performed to investigate the potential health effects of gasoline and ethanol engine exhaust fumes. Test atmospheres of gasoline and ethanol exhaust were given to Wistar rats and Balb C mice housed in inhalation chambers for a period of 5 weeks. Gas concentration and physical parameters were continually monitored during the exposure period. Several biological parameters were assessed after the exposure including pulmonary function, mutagenicity, and hematological, biochemical, and morphological examinations. The results demonstrated that the chronic toxicity of the gasoline-fueled engine is significantly higher than that of the ethanol engine.

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

    SciTech Connect

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

    1988-04-01

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

  16. 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

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

    SciTech Connect

    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.

  18. 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. PMID:22539559

  19. 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...

  20. Diesel exhaust particles induce endothelial dysfunction in apoE{sup -/-} mice

    SciTech Connect

    Hansen, Christian S. [Department of Environmental and Occupational Health, Institute of Public Health, University of Copenhagen, Oster Farimagsgade 5, Building 5B, 2nd Floor, 1014 Copenhagen K (Denmark); Sheykhzade, Majid [Department of Pharmacology and Pharmacotherapy, Danish University of Pharmaceutical Sciences (Denmark); Moller, Peter [Department of Environmental and Occupational Health, Institute of Public Health, University of Copenhagen, Oster Farimagsgade 5, Building 5B, 2nd Floor, 1014 Copenhagen K (Denmark); Folkmann, Janne Kjaergaard [Department of Environmental and Occupational Health, Institute of Public Health, University of Copenhagen, Oster Farimagsgade 5, Building 5B, 2nd Floor, 1014 Copenhagen K (Denmark); Amtorp, Ole [Department of Pharmacology, University of Copenhagen (Denmark); Jonassen, Thomas [Department of Pharmacology, University of Copenhagen (Denmark); Loft, Steffen [Department of Environmental and Occupational Health, Institute of Public Health, University of Copenhagen, Oster Farimagsgade 5, Building 5B, 2nd Floor, 1014 Copenhagen K (Denmark)]. E-mail: s.loft@pubhealth.ku.dk

    2007-02-15

    Background: Particulate air pollution can aggravate cardiovascular disease by mechanisms suggested to involve translocation of particles to the bloodstream and impairment of endothelial function, possibly dependent on present atherosclerosis. Aim: We investigated the effects of exposure to diesel exhaust particles (DEP) in vivo and ex vivo on vasomotor functions in aorta from apoE{sup -/-} mice with slight atherosclerosis and from normal apoE{sup +/+} mice. Methods: DEP 0, 0.5 or 5 mg/kg bodyweight in saline was administered i.p. The mice were sacrificed 1 h later and aorta ring segments were mounted on wire myographs. Segments from unexposed mice were also incubated ex vivo with 0, 10 and 100 {mu}g DEP/ml before measurement of vasomotor functions. Results: Exposure to 0.5 mg/kg DEP in vivo caused a decrease in the endothelium-dependent acetylcholine elicited vasorelaxation in apoE{sup -/-} mice, whereas the response was enhanced in apoE{sup +/+} mice. No significant change was observed after administration of 5 mg/kg DEP. In vivo DEP exposure did not affect constriction induced by K{sup +} or phenylephrine. In vitro exposure to 100 {mu}g DEP/ml enhanced acetylcholine-induced relaxation and attenuated phenylephrine-induced constriction. Vasodilation induced by sodium nitroprusside was not affected by any DEP exposure. Conclusion: Exposure to DEP has acute effect on vascular functions. Endothelial dysfunction possibly due to decreased NO production as suggested by decreased acetylcholine-induced vasorelaxation and unchanged sodium nitroprusside response can be induced by DEP in vivo only in vessels of mice with some atherosclerosis.

  1. 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-? 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.

  2. Exposure of mobile chipper operators to diesel exhaust.

    PubMed

    Magagnotti, Natascia; Picchi, Gianni; Sciarra, Gianfranco; Spinelli, Raffaele

    2014-03-01

    The current boom of forest biomass is making mobile chippers increasingly popular among forest operators. This motivates concern about the potential exposure of chipper operators to noxious chemicals derived from diesel fuel combustion. The objective of this study was to determine operator exposure to BTEX (benzene, toluene, ethylbenzene, and xylenes) and polycyclic aromatic hydrocarbons (PAHs) generated from diesel combustion. This study sampled 28 mobile chipping operations in the Italian mountains, in order to determine professional exposure to BTEX and PAHs among chipper operators. IOM, Radiello®, and XAD2 samplers were used for the purpose. Operations were divided into industrial and small scale, the former based on powerful chippers with enclosed cabs and the latter on smaller machines without enclosed cabs. We could not detect any measurable exposure to BTEX, while exposure levels for PAHs were very low, especially for what concerned recognized cancer agents. That is likely related to work environment and organization because mobile chippers work in the open-air forest environment and in the presence of very few other machines. PAH concentration was significantly higher inside cabs than outside. None of the operators involved in this research was exposed to BTEX or PAHs above occupational exposure limits. PMID:24163210

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

    PubMed

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

    2008-06-01

    An idling medium-duty diesel truck operated on ultralow sulfur diesel fuel was used as an emission source to generate diesel exhaust for controlled human exposure. Repeat tests were conducted on the Federal Test Procedure using a chassis dynamometer to demonstrate the reproducibility of this vehicle as a source of diesel emissions. Exhaust was supplied to a specially constructed exposure chamber at a target concentration of 100 microg x m(-3) diesel particulate matter (DPM). Spatial variability within the chamber was negligible, whereas emission concentrations were stable, reproducible, and similar to concentrations observed on the dynamometer. Measurements of nitric oxide, nitrogen dioxide, carbon monoxide, particulate matter (PM), elemental and organic carbon, carbonyls, trace elements, and polycyclic aromatic hydrocarbons were made during exposures of both healthy and asthmatic volunteers to DPM and control conditions. The effect of the so-called "personal cloud" on total PM mass concentrations was also observed and accounted for. Conventional lung function tests in 11 volunteer subjects (7 stable asthmatic) did not demonstrate a significant change after 2-hr exposures to diesel exhaust. In summary, we demonstrated that this facility can be effectively and safely used to evaluate acute responses to diesel exhaust exposure in human volunteers. PMID:18581813

  4. Characterization of Soot Deposition and Particle Nucleation in Exhaust Gas Recirculation Coolers

    Microsoft Academic Search

    Anil Singh Bika; Alok Warey; David Long; Sandro Balestrino; Patrick Szymkowicz

    2012-01-01

    Cooled exhaust gas recirculation (EGR) is used to control engine out NOx (oxides of nitrogen) emissions from modern diesel engines by re-circulating a portion of the exhaust gases into the intake manifold of an engine after cooling it through a heat exchanger commonly referred to as an EGR cooler. However, EGR cooler fouling due to presence of soot particles and

  5. Size and critical supersaturation for condensation of jet engine exhaust particles

    Microsoft Academic Search

    Marc Pitchford; James G. Hudson; John Hallett

    1991-01-01

    In situ measurements of jet engine exhaust from a Sabreliner were made by instruments on board the NCAR Electra during a brief period of coordinated flying. Particle size distribution and critical supersaturation spectra were monitored before, during, and after the encounter with the jet exhaust plume by a condensation nucleus counter, an active scattering aerosol spectrometer probe (ASASP), and a

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

    PubMed Central

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

    2010-01-01

    We developed quantitative estimates of historical exposures to respirable elemental carbon (REC) for an epidemiologic study of mortality, including lung cancer, among diesel-exposed miners at eight non-metal mining facilities [the Diesel Exhaust in Miners Study (DEMS)]. Because there were no historical measurements of diesel exhaust (DE), historical REC (a component of DE) levels were estimated based on REC data from monitoring surveys conducted in 1998–2001 as part of the DEMS investigation. These values were adjusted for underground workers by carbon monoxide (CO) concentration trends in the mines derived from models of historical CO (another DE component) measurements and DE determinants such as engine horsepower (HP; 1 HP = 0.746 kW) and mine ventilation. CO was chosen to estimate historical changes because it was the most frequently measured DE component in our study facilities and it was found to correlate with REC exposure. Databases were constructed by facility and year with air sampling data and with information on the total rate of airflow exhausted from the underground operations in cubic feet per minute (CFM) (1 CFM = 0.0283 m3 min?1), HP of the diesel equipment in use (ADJ HP), and other possible determinants. The ADJ HP purchased after 1990 (ADJ HP1990+) was also included to account for lower emissions from newer, cleaner engines. Facility-specific CO levels, relative to those in the DEMS survey year for each year back to the start of dieselization (1947–1967 depending on facility), were predicted based on models of observed CO concentrations and log-transformed (Ln) ADJ HP/CFM and Ln(ADJ HP1990+). The resulting temporal trends in relative CO levels were then multiplied by facility/department/job-specific REC estimates derived from the DEMS surveys personal measurements to obtain historical facility/department/job/year-specific REC exposure estimates. The facility-specific temporal trends of CO levels (and thus the REC estimates) generated from these models indicated that CO concentrations had been generally greater in the past than during the 1998–2001 DEMS surveys, with the highest levels ranging from 100 to 685% greater (median: 300%). These levels generally occurred between 1970 and the early 1980s. A comparison of the CO facility-specific model predictions with CO air concentration measurements from a 1976–1977 survey external to the modeling showed that our model predictions were slightly lower than those observed (median relative difference of 29%; range across facilities: 49 to –25%). In summary, we successfully modeled past CO concentration levels using selected determinants of DE exposure to derive retrospective estimates of REC exposure. The results suggested large variations in REC exposure levels both between and within the underground operations of the facilities and over time. These REC exposure estimates were in a plausible range and were used in the investigation of exposure–response relationships in epidemiologic analyses. PMID:20876235

  7. 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 HP????(+)) 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 HP????(+)). The resulting temporal trends in relative CO levels were then multiplied by facility/department/job-specific REC estimates derived from the DEMS surveys personal measurements to obtain historical facility/department/job/year-specific REC exposure estimates. The facility-specific temporal trends of CO levels (and thus the REC estimates) generated from these models indicated that CO concentrations had been generally greater in the past than during the 1998-2001 DEMS surveys, with the highest levels ranging from 100 to 685% greater (median: 300%). These levels generally occurred between 1970 and the early 1980s. A comparison of the CO facility-specific model predictions with CO air concentration measurements from a 1976-1977 survey external to the modeling showed that our model predictions were slightly lower than those observed (median relative difference of 29%; range across facilities: 49 to -25%). In summary, we successfully modeled past CO concentration levels using selected determinants of DE exposure to derive retrospective estimates of REC exposure. The results suggested large variations in REC exposure levels both between and within the underground operations of the facilities and over time. These REC exposure estimates were in a plausible range and were used in the investigation of exposure-response relationships in epidemiologic analyses. PMID:20876235

  8. Effective Local Exhaust Ventilation for Controlling Formaldehyde Exposures during Embalming

    Microsoft Academic Search

    Michael G. Gressel; Robert T. Hughes

    1992-01-01

    Previous studies have found that formaldehyde exposures to embalmers during the embalming process exceeded current occupational health criteria and standards. There are currently just over 20,000 mortuaries in the United States, employing 75,000 people. Mortuaries, as small businesses, typically do not have access to the occupational health and safety expertise that larger companies do. Therefore, a research study was conducted

  9. 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

  10. In-vehicle Exposure to Carbon Monoxide Emissions from Vehicular Exhaust: A Critical Review

    Microsoft Academic Search

    M. El-Fadel; L. Abi-Esber

    2009-01-01

    Vehicle-induced emissions constitute a major source of air pollutants, particularly in urban areas, where heavy traffic is common occurrence. Contaminated air can flow into enclosed micro-environments, including vehicle compartments. Among various exhaust emissions, carbon monoxide (CO) was the first indicator examined in passenger compartments. This paper presents a critical review of worldwide research work conducted to characterize CO exposure inside

  11. 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...

  12. 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...

  13. 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 ...

  14. 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...

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

    Microsoft Academic Search

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

    1985-01-01

    The relationship between bladder cancer and employment in occupations involving exposure to diesel exhaust was examined using data from a hospital-based case-control study of men aged 20 to 80 years in 18 hospitals in six US cities, from January 1981 to May 1983. In this analysis, 194 cases and 582 controls were compared according to occupation, smoking history, alcohol and

  16. 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...

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

    Microsoft Academic Search

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

    2009-01-01

    ObjectiveSafety 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

  18. Exhaust particles of modern gasoline vehicles: A laboratory and an on-road study

    NASA Astrophysics Data System (ADS)

    Karjalainen, Panu; Pirjola, Liisa; Heikkilä, Juha; Lähde, Tero; Tzamkiozis, Theodoros; Ntziachristos, Leonidas; Keskinen, Jorma; Rönkkö, Topi

    2014-11-01

    Vehicle technology development and upcoming particle emission limits have increased the need for detailed analyses of particle emissions of vehicles using gasoline direct injection (GDI) techniques. In this paper the particle emission characteristics of modern GDI passenger cars were studied in a laboratory and on the road, with the focus on exhaust particle number emissions, size distributions, volatility and morphology. Both during acceleration and steady conditions the number size distribution of nonvolatile exhaust particles consisted of two modes, one with mean particle size below 30 nm and the other with mean particle size approximately 70 nm. Results indicate that both of these particles modes consisted of soot but with different morphologies. Both in laboratory and on the road, significant emissions of exhaust particles were observed also during decelerations conducted by engine braking. These particles are most likely originating from lubricant oil ash components. The semivolatile nucleation particles were observed in the laboratory experiments at high engine load conditions. Thus, in general, the study indicates that a modern gasoline vehicle can emit four distinctive types of exhaust particles. The differences in particle characteristics and formation should be taken into account in the development of emission control strategies and technologies and, on the other hand, in the assessment of the impact of particle emissions on environment and human health.

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

    PubMed Central

    Kodavanti, Urmila P.; Thomas, Ronald; Ledbetter, Allen D.; Schladweiler, Mette C.; Shannahan, Jonathan H.; Wallenborn, J. Grace; Lund, Amie K.; Campen, Matthew J.; Butler, Elizabeth O.; Gottipolu, Reddy R.; Nyska, Abraham; Richards, Judy E.; Andrews, Deborah; Jaskot, Richard H.; McKee, John; Kotha, Sainath R.; Patel, Rishi B.; Parinandi, Narasimham L.

    2011-01-01

    Background Mechanisms of cardiovascular injuries from exposure to gas and particulate air pollutants are unknown. Objective We sought to determine whether episodic exposure of rats to ozone or diesel exhaust particles (DEP) causes differential cardiovascular impairments that are exacerbated by ozone plus DEP. Methods and results Male Wistar Kyoto rats (10–12 weeks of age) were exposed to air, ozone (0.4 ppm), DEP (2.1 mg/m3), or ozone (0.38 ppm) + DEP (2.2 mg/m3) for 5 hr/day, 1 day/week for 16 weeks, or to air, ozone (0.51 or 1.0 ppm), or DEP (1.9 mg/m3) for 5 hr/day for 2 days. At the end of each exposure period, we examined pulmonary and cardiovascular biomarkers of injury. In the 16-week study, we observed mild pulmonary pathology in the ozone, DEP, and ozone + DEP exposure groups, a slight decrease in circulating lymphocytes in the ozone and DEP groups, and decreased platelets in the DEP group. After 16 weeks of exposure, mRNA biomarkers of oxidative stress (hemeoxygenase-1), thrombosis (tissue factor, plasminogen activator inhibitor-1, tissue plasminogen activator, and von Willebrand factor), vasoconstriction (endothelin-1, endothelin receptors A and B, endothelial NO synthase) and proteolysis [matrix metalloprotease (MMP)-2, MMP-3, and tissue inhibitor of matrix metalloprotease-2] were increased by DEP and/or ozone in the aorta, but not in the heart. Aortic LOX-1 (lectin-like oxidized low-density lipoprotein receptor-1) mRNA and protein increased after ozone exposure, and LOX-1 protein increased after exposure to ozone + DEP. RAGE (receptor for advanced glycation end products) mRNA increased in the ozone + DEP group. Exposure to ozone or DEP depleted cardiac mitochondrial phospholipid fatty acids (DEP > ozone). The combined effect of ozone and DEP exposure was less pronounced than exposure to either pollutant alone. Exposure to ozone or DEP for 2 days (acute) caused mild changes in the aorta. Conclusions In animals exposed to ozone or DEP alone for 16 weeks, we observed elevated biomarkers of vascular impairments in the aorta, with the loss of phospholipid fatty acids in myocardial mitochondria. We conclude that there is a possible role of oxidized lipids and protein through LOX-1 and/or RAGE signaling. PMID:20980218

  20. 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.

  1. 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??m which allows for deeper penetration into the human pulmonary system upon inhalation. The aim of this research was to elucidate the potential toxic effects of diesel exhaust on a human pulmonary-based cellular system. Validation of a dynamic direct exposure method for both laboratory (230?hp Volvo truck engine) and field (Volkswagen Passat passenger car) diesel engines, at idle mode, was implemented. Human pulmonary type II epithelial cells (A549) grown on porous membranes were exposed to unmodified diesel exhaust at a low flow rate (37.5?mL/min). In parallel, diesel emission sampling was also conducted using real-time air monitoring techniques. Induced cellular effects were assessed using a range of in vitro cytotoxicity assays (MTS, ATP, and NRU). Reduction of cell viability was observed in a time-dependent manner following 30–60?mins of exposure with NRU as the most sensitive assay. The results suggest that the dynamic direct exposure method has the potential to be implemented for both laboratory- and field-based in vitro toxicity studies of diesel exhaust emissions. PMID:23986878

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

    SciTech Connect

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

    1990-01-01

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

  3. 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. PMID:17885912

  4. The Impact of Oil Consumption Mechanisms on Diesel Exhaust Particle Size Distributions and Detailed Exhaust Chemical Composition

    SciTech Connect

    Stetter, J; Forster, N; Ghandhi, J; Foster, D

    2003-08-24

    Detailed exhaust emission data have been taken from a Cummins N-14 single cylinder research engine in which the oil consumption was varied by different engine modifications. Low sulfur fuel was used, and oil consumption was varied by modifying the intake valve stem seals, the exhaust valve stem seals, the oil control ring and combinations of these modifications. Detailed measurements of exhaust gas particle size distributions and chemical composition were made for the various oil consumption configurations for a range of engine loads and speeds. The particulate mass was measured with TEOM and traditional gravimetric filter methods. Filter data for EC/OC, sulfates and trace metals have been taken and analyzed. The trace metals in the particulate mass serve as the basis for assessing oil consumption at the different operating conditions. The data indicate that the oil consumption for the steady state testing done here was approximately an order of magnitude below oil consumption values cited in the literature. We did measure changes in the details of the chemical composition of the particulate for the different engine operating conditions, but it did not correlate with changes in the oil consumption. Furthermore, the data indicate that the particle size distribution is not strongly impacted by low level oil consumption variations observed in this work.

  5. 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...

  6. Test-methods on the test-bench: a comparison of complete exhaust and exhaust particle extracts for genotoxicity/mutagenicity assessment.

    PubMed

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

    2014-05-01

    With the growing number of new exhaust after-treatment systems, fuels and fuel additives for internal combustion engines, efficient and reliable methods for detecting exhaust genotoxicity and mutagenicity are needed to avoid the widespread application of technologies with undesirable effects toward public health. In a commonly used approach, organic extracts of particulates rather than complete exhaust is used for genotoxicity/mutagenicity assessment, which may reduce the reliability of the results. In the present study, we assessed the mutagenicity and the genotoxicity of complete diesel exhaust compared to an organic exhaust particle extract from the same diesel exhaust in a bacterial and a eukaryotic system, that is, a complex human lung cell model. Both, complete exhaust and organic extract were found to act mutagenic/genotoxic, but the amplitudes of the effects differed considerably. Furthermore, our data indicate that the nature of the mutagenicity may not be identical for complete exhaust and particle extracts. Because in addition, differences between the responses of the different biological systems were found, we suggest that a comprehensive assessment of exhaust toxicity is preferably performed with complete exhaust and with biological systems representative for the organisms and organs of interest (i.e., human lungs) and not only with the Ames test. PMID:24697289

  7. Personal Exposure to Ultrafine Particles and Oxidative DNA Damage

    PubMed Central

    Vinzents, Peter S.; Møller, Peter; Sørensen, Mette; Knudsen, Lisbeth E.; Hertel, Ole; Jensen, Finn Palmgren; Schibye, Bente; Loft, Steffen

    2005-01-01

    Exposure to ultrafine particles (UFPs) from vehicle exhaust has been related to risk of cardiovascular and pulmonary disease and cancer, even though exposure assessment is difficult. We studied personal exposure in terms of number concentrations of UFPs in the breathing zone, using portable instruments in six 18-hr periods in 15 healthy nonsmoking subjects. Exposure contrasts of outdoor pollution were achieved by bicycling in traffic for 5 days and in the laboratory for 1 day. Oxidative DNA damage was assessed as strand breaks and oxidized purines in mononuclear cells isolated from venous blood the morning after exposure measurement. Cumulated outdoor and cumulated indoor exposures to UFPs each were independent significant predictors of the level of purine oxidation in DNA but not of strand breaks. Ambient air concentrations of particulate matter with an aero-dynamic diameter of ?10 ?m (PM10), nitrous oxide, nitrogen dioxide, carbon monoxide, and/or number concentration of UFPs at urban background or busy street monitoring stations was not a significant predictor of DNA damage, although personal UFP exposure was correlated with urban background concentrations of CO and NO2, particularly during bicycling in traffic. The results indicate that biologic effects of UFPs occur at modest exposure, such as that occurring in traffic, which supports the relationship of UFPs and the adverse health effects of air pollution. PMID:16263500

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

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

  9. Autocrine ligands of the epithelial growth factor receptor mediate inflammatory responses to diesel exhaust particles

    PubMed Central

    2014-01-01

    Background Diesel exhaust is associated with cardiovascular and respiratory mortality and morbidity. Acute exposure leads to increased IL-8 expression and airway neutrophilia, however the mechanism of this response is unknown. Objectives: As cigarette smoke-induced IL-8 expression by epithelial cells involves transactivation of the epidermal growth factor receptor (EGFR), we studied the effects of diesel exhaust particles (DEP) on IL-8 release and the role of the EGFR. Methods Primary bronchial epithelial cells (PBEC) were exposed to DEPs or carbon black. IL-8 and EGFR ligand expression (transforming growth factor alpha (TGF?), heparin-binding EGF-like growth factor, and amphiregulin (AR)) were assessed by quantitative RT-PCR and ELISA. Results DEP, but not carbon black, caused a dose-dependent increase in mitogen-activated protein kinase (MAPK) activation and IL-8 expression, however above 50 ?g/ml there was an increase in cytotoxicity. At 50 ?g/ml, DEPs stimulated transcription and release of IL-8 and EGFR ligands. IL-8 release was blocked by EGFR neutralizing antibodies, an EGFR-selective tyrosine kinase inhibitor and by the metalloprotease inhibitor, GM6001, which blocks EGFR ligand shedding. Neutralizing antibodies to AR, TGF? and heparin-binding (HB)-EGF reduced DEP-induced IL-8 by >50%. Conclusion Expression of IL-8 in response to DEPs is dependent on EGFR activation and that autocrine production of EGFR ligands makes a substantial contribution to this response. Capsule Summary: This study identifies a mechanism whereby diesel particles stimulates IL-8 release from bronchial epithelial cells. This mechanism may help to explain the recruitment of neutrophils into the airways of people exposed to particulate air pollution. PMID:24555532

  10. Chronic Exposure to Plasmodium falciparum Is Associated with Phenotypic Evidence of B and T Cell Exhaustion

    PubMed Central

    Illingworth, Joseph; Butler, Noah S.; Roetynck, Sophie; Mwacharo, Jedida; Pierce, Susan K.; Bejon, Philip; Crompton, Peter D.; Marsh, Kevin

    2013-01-01

    Naturally acquired immunity to malaria develops slowly, requiring several years of repeated exposure to be effective. The cellular and molecular factors underlying this observation are only partially understood. Recent studies suggest that chronic Plasmodium falciparum exposure may induce functional exhaustion of lymphocytes, potentially impeding optimal control of infection. However, it remains unclear whether the “atypical” memory B cells (MBCs) and “exhausted” CD4 T cells described in humans exposed to endemic malaria are driven by P. falciparum per se or by other factors commonly associated with malaria, such as coinfections and malnutrition. To address this critical question we took advantage of a “natural” experiment near Kilifi, Kenya, and compared profiles of B and T cells of children living in a rural community where P. falciparum transmission is ongoing to the profiles of age-matched children living under similar conditions in a nearby community where P. falciparum transmission ceased 5 y prior to this study. We found that continuous exposure to P. falciparum drives the expansion of atypical MBCs. Persistent P. falciparum exposure was associated with an increased frequency of CD4 T cells expressing phenotypic markers of exhaustion, both programmed cell death-1 (PD-1) alone and PD-1 in combination with lymphocyte-activation gene-3 (LAG-3). This expansion of PD-1–expressing and PD-1/LAG-3–coexpressing CD4 T cells was largely confined to CD45RA+ CD4 T cells. The percentage of CD45RA+CD27+ CD4 T cells coexpressing PD-1 and LAG-3 was inversely correlated with frequencies of activated and classical MBCs. Taken together, these results suggest that P. falciparum infection per se drives the expansion of atypical MBCs and phenotypically exhausted CD4 T cells, which has been reported in other endemic areas. PMID:23264654

  11. Heavy exposure to diesel exhaust linked to lung cancer death 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 study was carried out by researchers from the National Cancer Institute (NCI), part of the National Institutes of Health, and the National Institute for Occupational Safety and Health (NIOSH), part of the Centers for Disease Control and Prevention, both parts of HHS.

  12. Diesel exhaust particle-induced airway responses are augmented in obese rats.

    PubMed

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

    2014-01-01

    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 ?, coactivator 1? 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

  13. Health risk assessment for residents exposed to atmospheric diesel exhaust particles in southern region of Taiwan

    NASA Astrophysics Data System (ADS)

    Chio, Chia-Pin; Liao, Chung-Min; Tsai, Ying-I.; Cheng, Man-Ting; Chou, Wei-Chun

    2014-03-01

    Evidence shows a strong association among air pollution, oxidative stress (OS), deoxyribonucleic acid (DNA) damage, and diseases. Recent studies indicated that the aging, human neurodegenerative diseases and cancers resulted from mitochondrial dysfunction and OS. The purpose of this study is to provide a probabilistic risk assessment model to quantify the atmospheric diesel exhaust particles (DEP)-induced pre-cancer biomarker response and cancer incidence risk for residents in south Taiwan. We conducted entirely monthly particulate matter sampling data at five sites in Kaohsiung of south Taiwan in the period 2002-2003. Three findings were found: (i) the DEP dose estimates and cancer risk quantification had heterogeneously spatiotemporal difference in south Taiwan, (ii) the pre-cancer DNA damage biomarker and cancer incidence estimates had a positive yet insignificant association, and (iii) all the estimates of cancer incidence in south Taiwan populations fell within and slight lower than the values from previous cancer epidemiological investigations. In this study, we successfully assessed the tumor incidence for residents posed by DEP exposure in south Taiwan compared with the epidemiological approach. Our approach provides a unique way for assessing human health risk for residences exposed to atmospheric DEP depending on specific combinations of local and regional conditions. Our work implicates the importance of incorporating both environmental and health risk impacts into models of air pollution exposure to guide adaptive mitigation strategies.

  14. Biophysical Assessment of Single Cell Cytotoxicity: Diesel Exhaust Particle-Treated Human Aortic Endothelial Cells

    PubMed Central

    Wu, Yangzhe; Yu, Tian; Gilbertson, Timothy A.; Zhou, Anhong; Xu, Hao; Nguyen, Kytai Truong

    2012-01-01

    Exposure to diesel exhaust particles (DEPs), a major source of traffic-related air pollution, has become a serious health concern due to its adverse influences on human health including cardiovascular and respiratory disorders. To elucidate the relationship between biophysical properties (cell topography, cytoskeleton organizations, and cell mechanics) and functions of endothelial cells exposed to DEPs, atomic force microscope (AFM) was applied to analyze the toxic effects of DEPs on a model cell line from human aortic endothelial cells (HAECs). Fluorescence microscopy and flow cytometry were also applied to further explore DEP-induced cytotoxicity in HAECs. Results revealed that DEPs could negatively impair cell viability and alter membrane nanostructures and cytoskeleton components in a dosage- and a time-dependent manner; and analyses suggested that DEPs-induced hyperpolarization in HAECs appeared in a time-dependent manner, implying DEP treatment would lead to vasodilation, which could be supported by down-regulation of cell biophysical properties (e.g., cell elasticity). These findings are consistent with the conclusion that DEP exposure triggers important biochemical and biophysical changes that would negatively impact the pathological development of cardiovascular diseases. For example, DEP intervention would be one cause of vasodilation, which will expand understanding of biophysical aspects associated with DEP cytotoxicity in HAECs. PMID:22662129

  15. Diesel exhaust particle induction of IL17A contributes to severe asthma

    PubMed Central

    Brandt, Eric B.; Kovacic, Melinda Butsch; Lee, Gerald B.; Gibson, Aaron M.; Acciani, Thomas H.; Le Cras, Timothy D.; Ryan, Patrick H.; Budelsky, Alison L.; Khurana Hershey, Gurjit K.

    2013-01-01

    Background IL-17A has been implicated in severe forms of asthma. However, the factors that promote IL-17A production during the pathogenesis of severe asthma remain undefined. Diesel exhaust particles (DEP) are a major component of traffic related air pollution and are implicated in asthma pathogenesis and exacerbation. Objective To determine the mechanism by which DEP exposure impacts asthma severity using human and mouse studies. Methods Balb/c mice were challenged with DEP +/? house dust mite extract (HDM). Airway inflammation and function, BALF cytokine levels, and flow cytometry of lung T cells were assessed. The impact of DEP exposure on frequency of asthma symptoms and serum cytokine levels was determined in children with allergic asthma. Results In mice, exposure to DEP alone did not induce asthma. DEP and HDM co-exposure markedly enhanced AHR compared to HDM alone and generated a mixed Th2 and Th17 response, including IL-13+IL-17A+ double producing T-cells. IL-17A neutralization prevented DEP-induced exacerbation of AHR. Among 235 high DEP-exposed children with allergic asthma, 32.2% had more frequent asthma symptoms over a 12 month period, compared to only 14.2% in the low DEP-exposed group (p=0.002). Additionally, high DEP-exposed children with allergic asthma had nearly six times higher serum IL-17A levels compared with low DEP-exposed children. Conclusions Expansion of Th17 cells contributes to DEP-mediated exacerbation of allergic asthma. Neutralization of IL-17A may be a useful potential therapeutic strategy to counteract the asthma promoting effects of traffic related air pollution especially in highly exposed severe allergic asthmatics. PMID:24060272

  16. 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…

  17. Diesel exhaust particles modulate vascular endothelial cell permeability: implication of ZO-1 expression.

    PubMed

    Li, Rongsong; Ning, Zhi; Cui, Jeffrey; Yu, Fei; Sioutas, Constantinos; Hsiai, Tzung

    2010-09-01

    Exposure to air pollutants increases the incidence of cardiovascular disease. Recent toxicity studies revealed that ultra-fine particles (UFP, d(p)<100-200 nm), the major portion of particulate matter (PM) by numbers in the atmosphere, induced atherosclerosis. In this study, we posited that variations in chemical composition in diesel exhausted particles (DEP) regulated endothelial cell permeability to a different extent. Human aortic endothelial cells (HAEC) were exposed to well-characterized DEP (d(p)<100 nm) emitted from a diesel engine in either idling mode (DEP1) or in urban dynamometer driving schedule (UDDS) (DEP2). Horse Radish Peroxidase-Streptavidin activity assay showed that DEP2 increased endothelial permeability to a greater extent than DEP1 (control=0.077+/-0.005, DEP1=0.175+/-0.003, DEP2=0.265+/-0.006, n=3, p<0.01). DEP2 also down-regulated tight junction protein, Zonular Occludin-1 (ZO-1), to a greater extent compared to DEP1. LDH and caspase-3 activities revealed that DEP-mediated increase in permeability was not due to direct cytotoxicity, and DEP-mediated ZO-1 down-regulation was not due to a decrease in ZO-1 mRNA. Hence, our findings suggest that DEP1 vs. DEP2 differentially influenced the extent of endothelial permeability at the post-translational level. This increase in endothelium permeability is implicated in inflammatory cell transmigration into subendothelial layers with relevance to the initiation of atherosclerosis. PMID:20576493

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

    PubMed

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

    2010-01-01

    This study was conducted to investigate the effects of engine operating conditions and exhaust aftertreatments on the mutagenicity of diesel particulate matter (DPM) collected directly in an underground mine environment. A number of after-treatment devices are currently used on diesel engines in mines, but it is critical to determine whether reductions in DPM concentrations result in a corresponding decrease in adverse health effects. An eddy-current dynamometer was used to operate naturally aspirated mechanically controlled engine at several steady-state conditions. The samples were collected when the engine was equipped with a standard muffler, a diesel oxidation catalytic converter, two types of uncatalyzed diesel particulate filter systems, and three types of disposable diesel particulate filter elements. Bacterial gene mutation activity of DPM was tested on acetone extracts using the Ames Salmonella assay. The results indicated strong correlation between engine operating conditions and mutagenic activity of DPM. When the engine was fitted with muffler, the mutagenic activity was observed for the samples collected from light-load, but not heavy-load operating conditions. When the engine was equipped with a diesel oxidation catalyst, the samples did not exhibit mutagenic activity for any of four engine operating conditions. Mutagenic activity was observed for the samples collected when the engine was retrofitted with three types of disposable filters and sintered metal diesel particulate filter and operated at light load conditions. However, those filtration systems substantially reduced the concentration-normalized mutagenic activity from the levels observed for the muffler. PMID:20711933

  19. Diesel exhaust particles suppress macrophage function and slow the pulmonary clearance of Listeria monocytogenes in rats.

    PubMed Central

    Yang, H M; Antonini, J M; Barger, M W; Butterworth, L; Roberts, B R; Ma, J K; Castranova, V; Ma, J Y

    2001-01-01

    In this study, we tested the hypothesis that exposure to diesel exhaust particles (DEP) may increase susceptibility of the host to pulmonary infection. Male Sprague-Dawley rats received a single dose of DEP (5 mg/kg), carbon black (CB, 5 mg/kg), or saline intratracheally. Three days later, the rats were inoculated intratracheally with approximately 5,000 Listeria monocytogenes and sacrificed at 3, 5, and 7 days postinfection, and we determined the number of viable Listeria in the left lobe of lungs. The remaining lungs underwent bronchoalveolar lavage (BAL) and the retrieved BAL cells were identified and counted. Luminol-dependent chemiluminescence, a measure of reactive oxygen species (ROS) formation, generated by BAL cells was monitored and the levels of nitric oxide and tumor necrosis factor (TNF)-[alpha] produced by macrophages in culture were determined. At 7 days postinfection, we excised the lung-draining lymph nodes and phenotyped the lymphocyte subpopulations. Exposure of rats to DEP, but not to CB, decreased the clearance of Listeria from the lungs. Listeria-induced generation of luminol-dependent chemiluminescence by pulmonary phagocytes decreased by exposure to DEP but not CB. Similarly, Listeria-induced production of NO by alveolar macrophages was negated at 3, 5, and 7 days after inoculation in DEP-exposed rats. In contrast, CB exposure had no effect on Listeria-induced NO production at 3 days after infection and had a substantially smaller effect than DEP at later days. Exposure to DEP or CB resulted in enlarged lung-draining lymph nodes and increased the number and percentage of CD4(+) and CD8(+) T cells. These results showed that exposure to DEP decreased the ability of macrophages to produce antimicrobial oxidants in response to Listeria, which may play a role in the increased susceptibility of rats to pulmonary infection. This DEP-induced suppression is caused partially by chemicals adsorbed onto the carbon core of DEP, because impaired macrophage function and decreased Listeria clearance were not observed following exposure to CB. PMID:11401764

  20. 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

  1. 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...

  2. 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...

  3. A comparative study on the ultrafine particle episodes induced by vehicle exhaust: A crude oil refinery and ship emissions

    NASA Astrophysics Data System (ADS)

    González, Yenny; Rodríguez, Sergio

    2013-02-01

    A study on the contribution of vehicle exhausts, ships and an oil refinery emission to the ambient air concentration of ultrafine particles (UFPs) is presented. It is based on a data set of particle number coarser than 2.5 nm (N), black carbon (BC), gaseous pollutants (NOx, SO2, CO and O3), PM2.5 and PM10 measured from 2008 to 2010 in the ambient air of Santa Cruz de Tenerife City, where a previous study found an association between hospitalizations due to heart failure and exposure to UFPs in the ambient air. The observed relationship between N, BC and gaseous pollutants allowed segregating UFP concentrations in a set of components linked to each source. It was found that vehicle exhausts contribute to the background of UFPs, whereas high UFP episodes were due to the emissions of the refinery and ships. The concentration of UFP linked to vehicle exhaust emissions maximized in the morning (07:00-09:00 GMT, 5000-25,000 cm- 3 = 25th-75th percentile), whereas those linked to ship (15,000-45,000 cm- 3) and refinery (25,000-95,000 cm- 3) emissions maximized in the 10:00-17:00 GMT period due to the effects of meteorology and photochemistry. It was found that the UFP concentrations were more sensitive to the fresh emissions of the three sources than PM2.5, which was mostly linked to aged fine particles (0.1-1 ?m) of the urban background. BC was the better tracer of vehicle exhaust emissions. It was concluded that the simultaneous monitoring of UFP, BC and PM2.5 is a suitable strategy of tracing aerosol pollutants of different nature (fresh vs. aged) and from different sources.

  4. Sulforaphane-rich broccoli sprout extract attenuates nasal allergic response to diesel exhaust particles.

    PubMed

    Heber, David; Li, Zhaoping; Garcia-Lloret, Maria; Wong, Angela M; Lee, Tsz Ying Amy; Thames, Gail; Krak, Michael; Zhang, Yanjun; Nel, Andre

    2014-01-01

    The generation of oxidative stress by ambient air pollution particles contributes to the development of allergic sensitization and asthma, as demonstrated by intranasal challenge with well-characterized diesel exhaust particle (DEP) suspensions in humans. This effect is due to the presence of redox active organic chemicals in DEP, and can be suppressed by antioxidants and inducers of phase II enzymes in animals. In this communication, we determined whether the administration of a standardized broccoli sprout extract (BSE), which contains a reproducible amount of the sulforaphane (SFN) precursor, glucoraphanin, could be used to suppress the nasal inflammatory response in human subjects challenged with 300 ?g of an aqueous DEP suspension (equivalent to daily PM exposure levels on a Los Angeles freeway). SFN is capable of inducing an antioxidant and phase II response via activation of the nuclear transcription factor (erythroid-derived 2)-like 2 (Nrf2). Previous studies have shown that 70-90% SFN delivered by BSE is absorbed, metabolized, and excreted in humans. An initial intranasal challenge with DEP in 29 human subjects was used to characterize the magnitude of the inflammatory response. Following a 4 week washout, a BSE that delivers a reproducible and standardized dose of 100 ?mol SFN in mango juice was administered daily for four days. The nasal DEP challenge was repeated and lavage fluid collected to perform white blood cell (WBC) counts. The average nasal WBC increased by 66% over the initial screening levels and by 85% over the control levels 24 hours after DEP exposure. However, total cell counts decreased by 54% when DEP challenge was preceded by daily BSE administration for 4 days (p < 0.001). Since the SFN dose in these studies is equivalent to the consumption of 100-200 g broccoli, our study demonstrates the potential preventive and therapeutic potential of broccoli or broccoli sprouts rich in glucoraphanin for reducing the impact of particulate pollution on allergic disease and asthma. PMID:24287881

  5. Susceptibility and exposure biomarkers in people exposed to PAHs from diesel exhaust.

    PubMed

    Adonis, M; Martínez, V; Riquelme, R; Ancic, P; González, G; Tapia, R; Castro, M; Lucas, D; Berthou, F; Gil, L

    2003-09-15

    Xenobiotic metabolizing enzymes, especially CYP1A1 and GSTM1, are involved in the activation and conjugation of PAHs and are controlled by polymorphic genes. PAHs released from diesel emissions in many cities of the world, especially in developing countries, contribute significantly to the toxic effects of airborne inhalable particles. We have evaluated the gene-environment interaction in Santiago of Chile, studying the contribution of CYP1A1 and GSTM1 polymorphisms on 1-OH-P urinary levels used as the PAHs exposure biomarker. The study was performed on 59 diesel exposed (38 diesel revision workers and 21 subjects working in an urban area as established street vendors) and 44 non-exposed subjects living in a rural area. The 1-OH-P urinary levels of the urban (P=0.043) and rural (P=0.040) populations showed, without considering the genotypes, significant differences between smokers and non-smokers, but no significant differences were found between smokers and non-smokers among the diesel plant workers (P=0.33). Non-smoking subjects of the diesel plants and the urban area showed similar 1-OHP levels (P=0.466) which were significantly higher than those of the subjects living in the rural area (P<0.05). When 1-OH-P levels were related with genotypes, an association was observed for the CYP1A1*2A genotype, so that the diesel-exposed workers carrying the CYP1A1*2A allele showed significantly higher 1-OH-P levels than the subjects from the rural area with the same genotype (P=0.008). On the other hand, there was no significant correlation between urinary 1-OH-P levels and GSTM1 null genotype, although higher levels of the urinary metabolite were found in individuals carrying the combined CYP1A1*2A and GSTM1 null genotype (P=0.055). These results may suggest an association between levels of the exposure biomarker 1-OH-P and presence of the CYP1A1*2A genotype, a potential genetic susceptibility biomarker which might be useful in identifying individuals at higher risk among people exposed to high PAH levels in diesel exhaust. PMID:12919719

  6. 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 measured REC exposure level by facility ranged from 40 to 384 ?g m?3 for the underground workers and from 2 to 6 ?g m?3 for the surface workers. For one prevalent underground job, ‘miner operator’, the maximum annual REC exposure estimate by facility ranged up to 685% greater than the corresponding 1998–2001 value. A comparison of the historical CO estimates from the time trend models with 1976–1977 CO measurements not used in the modeling found an overall median relative difference of 29%. Other comparisons showed similar levels of agreement. The assessment process indicated large differences in REC exposure levels over time and across the underground operations. Method evaluations indicated that the final estimates were consistent with those from alternative time trend models and demonstrated moderate to high agreement with external data. PMID:20876233

  7. A source-independent empirical correction procedure for the fast mobility and engine exhaust particle sizers

    NASA Astrophysics Data System (ADS)

    Zimmerman, Naomi; Jeong, Cheol-Heon; Wang, Jonathan M.; Ramos, Manuel; Wallace, James S.; Evans, Greg J.

    2015-01-01

    The TSI Fast Mobility Particle Sizer (FMPS) and Engine Exhaust Particle Sizer (EEPS) provide size distributions for 6-560 nm particles with a time resolution suitable for characterizing transient particle sources; however, the accuracy of these instruments can be source dependent, due to influences of particle morphology. The aim of this study was to develop a source-independent correction protocol for the FMPS and EEPS. The correction protocol consists of: (1) broadening the >80 nm size range of the distribution to account for under-sizing by the FMPS and EEPS; (2) applying an existing correction protocol in the 8-93 nm size range; and (3) dividing each size bin by the ratio of total concentration measured by the FMPS or EEPS and a water-based Condensation Particle Counter (CPC) as a surrogate scaling factor to account for particle morphology. Efficacy of the correction protocol was assessed for three sources: urban ambient air, diluted gasoline direct injection engine exhaust, and diluted diesel engine exhaust. Linear regression against a reference instrument, the Scanning Mobility Particle Sizer (SMPS), before and after applying the correction protocol demonstrated that the correction ensured agreement within 20%.

  8. Driver Exposure to Combustion Particles in the U.S. Trucking Industry

    Microsoft Academic Search

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

    2007-01-01

    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 (PM2.5, elemental carbon, and organic carbon) were measured inside the driver cabs of diesel-powered trucks from 36 different trucking terminals across the United

  9. 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 ...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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 ...

  18. Enhancement of allergic inflammation by the interaction between diesel exhaust particles and the immune system

    Microsoft Academic Search

    Andre E. Nel; David Diaz-Sanchez; David Ng; Timothy Hiura; Andrew Saxon

    1998-01-01

    There is growing evidence that fossil fuel combustion products act as adjuvants in the immune system and may lead to enhancement of allergic inflammation. Through this mechanism, particulate air pollutants may be an important contributor to the increased prevalence and morbidity of asthma and allergic rhinitis. In this communication we focus on the role of diesel exhaust particles (DEPs) in

  19. The effect of local exhaust ventilation controls on dust exposures during concrete cutting and grinding activities.

    PubMed

    Croteau, Gerry A; Guffey, Steven E; Flanagan, Mary Ellen; Seixas, Noah S

    2002-01-01

    This study assessed the effectiveness of commercially available local exhaust ventilation (LEV) systems for controlling respirable dust and crystalline silica exposures during concrete cutting and grinding activities. Work activities were performed by union-sponsored apprentices and included tuck-point grinding, surface grinding, paver block and brick cutting (masonry saw), and concrete block cutting (hand-held saw). In a randomized block design, implemented under controlled field conditions, three ventilation rates (0, 30, and 75 cfm) were tested for each tool. Each ventilation treatment was replicated three times in random order for a total of nine 15-min work sessions per study subject. With the exception of the hand-held saw, the use of LEV resulted in a significant (p < 0.05) reduction in respirable dust exposure. Mean exposure levels for the 75 cfm treatments were less than that of the 30 cfm treatments; however, differences between these two treatments were only significant for paver block cutting (p < 0.01). Although exposure reduction was significant (70-90% at the low ventilation rate and 80-95% reduction at the high ventilation rate), personal respirable dust [corrected] exposures remained very high: 1.4-2.8 x PEL (permissible exposure limit) at the low ventilation rate and 0.9-1.7 x PEL at the high ventilation rate. Exposure levels found under actual field conditions would likely be lower due to the intermittent nature of most job tasks. Despite incomplete control LEV has merit, as it would reduce the risk of workers developing disease, allow workers to use a lower level of respiratory protection, protect workers during short duration work episodes reduce exposure to nearby workers, and reduce clean-up associated dust exposures. PMID:12486779

  20. 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.

  1. 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...

  2. Impact of selective catalytic reduction on exhaust particle formation over excess ammonia events.

    PubMed

    Amanatidis, Stavros; Ntziachristos, Leonidas; Giechaskiel, Barouch; Bergmann, Alexander; Samaras, Zissis

    2014-10-01

    The introduction of selective catalytic reduction (SCR) aftertreatment to meet stringent diesel NOx emission standards around the world increases exhaust ammonia. Further to the direct air quality and health implications of ammonia, this may also lead to particle formation in the exhaust. In this study, an ammonia SCR system was examined with respect to its impact on both solid and total exhaust particle number and size distribution, downstream of a diesel particulate filter (DPF). Fuel post-injection was conducted in some tests to investigate the effect of ammonia during active DPF regeneration. On average, the post-DPF solid >23 nm and total <23 nm particle number emissions were increased by 129% (range 80-193%) and by 67% (range 26-136%), respectively, when 100 ppm ammonia level was induced downstream of the SCR catalyst. This is a typical level during ammonia overdosing, often practiced for efficient NOx control. Ammonia did not have a significant additional effect on the high particle concentrations measured during DPF regeneration. Based on species availability and formation conditions, sulfate, nitrate, and chloride salts with ammonium are possible sources of the new particles formed. Ammonia-induced particle formation corresponds to an environmental problem which is not adequately addressed by current regulations. PMID:25167537

  3. A review of cancer risk in the trucking industry, with emphasis on exposure to diesel exhaust.

    PubMed

    Boffetta, P

    2012-01-01

    Two large cohort studies of members of US unions in the trucking industries provided some evidence of an increased risk of lung cancer. However, no increased risk was reported in comparisons with an external (unexposed) population, the evidence of an association rests on the results of analyses by duration of employment, or by estimated exposure to elemental carbon. These estimates are subjects to uncertainties and potential misclassification bias. In addition, residual confounding by tobacco smoking and by other occupational exposures cannot be excluded. The hypothesis of carcinogenicity of diesel exhaust (DE) is biologically plausible; an IARC Working Group has recently concluded that the evidence is sufficient to classify DE as human carcinogen. This review of studies of truck drivers illustrates the problems of epidemiology of DE-exposed workers, and stresses the need for careful consideration to potential sources of bias and confounding. PMID:23213817

  4. Toll like receptor-3 priming alters diesel exhaust particle-induced cytokine responses in human bronchial epithelial cells.

    PubMed

    Bach, Nicolai S; Låg, Marit; Øvrevik, Johan

    2014-07-01

    Inflammation is considered central in the pathology of health effects from airborne particulate matter (PM). Preexisting inflammatory disorders, such as asthma, but also pulmonary infections, appear to be a risk factor of adverse health effects from PM exposure. Thus, to assess whether and how preexisting inflammation may sensitize lung cells toward additional proinflammatory effects of PM, human bronchial epithelial cells (BEAS-2B) were primed with the highly proinflammatory Toll-like receptor 3 (TLR3) ligand, Poly I:C, prior to exposure with diesel exhaust particles (DEP). DEP-exposure alone induced increased gene-expression of interleukin-6 (IL-6) and CXCL8 (IL-8) but did not affect expression of CCL5 (RANTES), while TLR3-priming alone induced expression of IL-6, CXCL8 and CCL5. DEP-exposure exacerbated IL-6 and CXCL8 responses in TLR3-primed cells, while TLR3-induced CCL5 was suppressed by DEP. TLR3-priming and DEP-exposure resulted in possible additive effects on p38 phosphorylation and I?B-degradation, while DEP rather suppressed ERK and JNK-activation. However, TLR3-priming elicited a considerable increase in p65-phosphorylation at serine 536 which is known to enhance the transcriptional activity of NF-?B. DEP-exposure was unable to induce p65-phosphorylation. Thus TLR3-priming may affect susceptibility toward DEP by activating both shared and complementing pathways required for optimal expression of proinflammatory genes such as IL-6 and CXCL8. The study underscores that primed "sick" cells may be more susceptible toward effects of particle-exposure and respond both stronger and differently compared to unprimed "healthy" cells. PMID:24709138

  5. CONTROLLED EXPOSURES OF HUMAN VOLUNTEERS TO DIESEL ENGINE EXHAUST: BIOMARKERS OF EXPOSURE AND HEALTH OUTCOMES

    EPA Science Inventory

    Combustion of diesel fuel contributes to ambient air pollutant fine particulate matter (PM) and gases. Fine PM exposure has been associated with increased mortality due to adverse cardiac events, and morbidity, such as increased hospitalization for asthma symptoms and lung infect...

  6. Respiratory health associated with exposure to automobile exhaust. II. Personal NO2 exposure levels according to distance from the roadside.

    PubMed

    Nakai, S; Nitta, H; Maeda, K

    1995-01-01

    We have conducted several studies to investigate the effect of automobile exhaust on respiratory symptoms. This study was designed to explore differences in personal exposure levels among residents of zones located varying distances from trunk roads with heavy traffic in Tokyo. Personal nitrogen dioxide (NO2) concentration levels for residents and NO2 concentrations inside and outside the residences of each study participant were measured during ten seasons over three years. Three residential zones were determined as follows: Zone A was 0-20 m from the roadside; Zone B was 20-150 m; and Zone C, a reference zone, was a residential district in a suburban area. Approximately fifty residents were selected as the subjects of NO2 measurements. Study participants were female, between 40 and 60 years of age, and nonsmokers. All participants used gas cooking stoves with electric ignition. Outdoor NO2 concentrations in Zone A were always the greatest among the three zones during the study periods, and those in Zone C were consistently the lowest. Personal exposure levels in Zone A were generally higher than those in the other zones, and concentrations in Zone C were the lowest during seasons when no indoor heating was used. The highest mean values for personal exposure levels in Zones A, B, and C were 63.4, 61.0, and 55.3 ppb, respectively. In analyses in which participants were stratified by heater type, the mean personal exposure levels in Zone A were the highest and the levels in Zone C were the lowest for participants without unvented heaters; differences of NO2 levels between Zones A and C ranged from 10.0 to 23.9 ppb. When there were no indoor NO2 sources except gas cooking stoves, both indoor and personal levels of NO2 were attributable primarily to motor vehicle exhaust. In contrast, the use of unvented heaters during the heating seasons could cause NO2 exposures comparable to those attributable to motor vehicles. PMID:7492902

  7. An investigation into the effect of a ceramic particle trap on the chemical mutagens in diesel exhaust

    Microsoft Academic Search

    S. T. Bagley; L. D. Dorie; D. G. Leddy; J. H. Johnson

    1987-01-01

    Diesel exhaust particles and vapor phase samples were collected from the diluted (15:1) exhaust of a 10.4 L displacement medium-duty engine (Caterpillar 3208), operated under EPA steady-state cycle Modes 4 and 5 conditions for load (50 and 75 percent, respectively) and speed (1680 rpm). Baseline (uncontrolled) emissions were compared to the exhaust modified by the use of an uncatalyzed monolithic

  8. Effects of Exposure to Nanoparticle-rich Diesel Exhaust on Pregnancy in Rats

    PubMed Central

    LI, ChunMei; LI, Xuezheng; SUZUKI, Akira K.; ZHANG, Yonghui; FUJITANI, Yuji; NAGAOKA, Kentaro; WATANABE, Gen; TAYA, Kazuyoshi

    2012-01-01

    Abstract Pollutants from burning of diesel fuel are hazardous to human health. Nanoparticles in diesel exhaust potentially have profound impact on fetal development and maternal endocrine function during pregnancy due to their ability to penetrate deeply into the body. To investigate the effects of nanoparticle-rich diesel exhaust (NR-DE) on pregnancy, pregnant rats were exposed to NR-DE, filtered diesel exhaust (F-DE) or clean air for 19 days of gestation. Relative weights of maternal liver and spleen to body weight were significantly lower in the NR-DE and F-DE groups than those in the control group. The serum concentration of maternal progesterone was significantly lower, while those of luteinizing hormone (LH) and corticosterone were significantly higher in the NR-DE and F-DE groups than those in the control group. The serum concentration of estradiol-17? was significantly higher in the F-DE group than that in the control group. The levels of cytochrome P450 side-chain cleavage enzyme, 3?-hydroxysteroid dehydrogenase and LH receptor mRNA in the corpus luteum were significantly lower in the NR-DE and F-DE groups than those in the control. In fetuses, body weight and crown-rump length were significantly greater and shorter, respectively, in both males and females in the NR-DE and F-DE groups than those in the control group. These results demonstrate that exposure of pregnant rats to NR-DE and F-DE suppresses the function of corpora lutea and stimulates the function of the adrenal cortex, suggesting a risk of spontaneous abortion associated with maternal hormonal changes. PMID:23257834

  9. Differential proinflammatory responses induced by diesel exhaust particles with contrasting PAH and metal content.

    PubMed

    Totlandsdal, Annike I; Låg, Marit; Lilleaas, Edel; Cassee, Flemming; Schwarze, Per

    2015-02-01

    Exposure to diesel engine exhaust particles (DEPs), representing a complex and variable mixture of components, has been linked with cellular production and release of several types of mediators related to pulmonary inflammation. A key challenge is to identify the specific components, which may be responsible for these effects. The aim of this study was to compare the proinflammatory potential of two DEP-samples with contrasting contents of polycyclic aromatic hydrocarbons (PAHs) and metals. The DEP-samples were compared with respect to their ability to induce cytotoxicity, expression and release of proinflammatory mediators (IL-6, IL-8), activation of mitogen-activated protein kinases (MAPKs) and expression of CYP1A1 and heme oxygenase-1 (HO-1) in human bronchial epithelial (BEAS-2B) cells. In addition, dithiothreitol and ascorbic acid assays were performed in order to examine the oxidative potential of the PM samples. The DEP-sample with the highest PAH and lowest metal content was more potent with respect to cytotoxicity and expression and release of proinflammatory mediators, CYP1A1 and HO-1 expression and MAPK activation, than the DEP-sample with lower PAH and higher metal content. The DEP-sample with the highest PAH and lowest metal content also possessed a greater oxidative potential. The present results indicate that the content of organic components may be determinant for the proinflammatory effects of DEP. The findings underscore the importance of considering the chemical composition of particulate matter-emissions, when evaluating the potential health impact and implementation of air pollution regulations. PMID:23900936

  10. Effects of diesel exhaust particles on human alveolar macrophage ability to secrete inflammatory mediators in response to lipopolysaccharide.

    PubMed

    Mundandhara, Sailaja D; Becker, Susanne; Madden, Michael C

    2006-08-01

    Ambient particulate matter (PM) has been shown to be associated with mortality and morbidity. Diesel exhaust particles (DEP) contribute to ambient PM. Alveolar macrophages (AM) are important targets for PM effects in the lung. The effects of DEP exposure on human AM response to lipopolysachharide (LPS; from gram-negative bacteria) challenge in vitro were determined by monitoring the production of interleukin 8 (IL-8), tumor necrosis factor-alpha (TNF-alpha) and prostaglandin E(2) (PGE(2)). The roles of organic compounds and carbonaceous core of DEP in response to LPS were evaluated by comparing the DEPs effect to that of carbon black (CB), a carbonaceous particle with few adsorbed organic compounds. AMs were exposed in vitro to Standard Reference Material (SRM) DEP 2975, SRM DEP 1650, SRM 1975 (a dichloromethane extract of SRM DEP 2975) and CB particles for 24 h. DEPs induced a decreased secretion of IL-8, TNF-alpha and PGE(2) in response to a subsequent LPS stimulation. DEPs also show suppressive effect on the release of inflammatory mediators when stimulated with lipoteichoic acid, a product of gram positive bacteria. In summary, in vitro exposure of human AM to DEPs significantly suppress AM responsiveness to gram-negative and positive bacterial products, which may be a contributing factor to the impairment of pulmonary defense. PMID:16360300

  11. The role of sulfur emission in volatile particle formation in jet aircraft exhaust plumes

    Microsoft Academic Search

    B. Kärcher; D. W. Fahey

    1997-01-01

    Recent in-situ emission measurements of the Concorde in the lower stratosphere point to a surprisingly efficient conversion of fuel sulfur to H2SO4 in the exhaust plume. By means of a comprehensive model, the formation and evolution of aerosol particles and precursors are calculated in the diluting aircraft wake. The results provide strong evidence that high levels of SO3 present in

  12. MUTAGENICITY OF DIESEL-EXHAUST PARTICLE EXTRACTS COLLECTED UNDER SMOG-CHAMBER CONDITIONS USING THE 'SALMONELLA TYPHIMURIUM' TEST SYSTEM

    EPA Science Inventory

    The study was designed to detect the effect that different environmental conditions have upon diesel-exhaust organics. In this study, diesel-exhaust was injected into the Calspan smog chamber under different conditions, and the resulting particles were collected upon Pallflex gla...

  13. Condensational uptake of semivolatile organic compounds in gasoline engine exhaust onto pre-existing inorganic particles

    NASA Astrophysics Data System (ADS)

    Li, S.-M.; Liggio, J.; Graham, L.; Lu, G.; Brook, J.; Stroud, C.; Zhang, J.; Makar, P.; Moran, M. D.

    2011-10-01

    This paper presents the results of laboratory studies on the condensational uptake of gaseous organic compounds in the exhaust of a light-duty gasoline engine onto preexisting sulfate and nitrate seed particles. Significant condensation of the gaseous organic compounds in the exhaust occurs onto these inorganic particles on a time scale of 2-5 min. The amount of condensed organic mass (COM) is proportional to the seed particle mass, suggesting that the uptake is due to dissolution determined by the equilibrium partitioning between gas phase and particles, not adsorption. The amount of dissolution in unit seed mass, S, decreases as a power function with increased dilution of the exhaust, ranging from 0.23 g g-1 at a dilution ratio of 81, to 0.025 g g-1 at a dilution ratio of 2230. It increases nonlinearly with increasing concentration of the total hydrocarbons in the gas phase (THC), rising from 0.12 g g-1 to 0.26 g g-1 for a CTHC increase of 1 to 18 ?g m-3, suggesting that more organics are partitioned into the particles at higher gas phase concentrations. In terms of gas-particle partitioning, the condensational uptake of THC gases in gasoline engine exhaust can account for up to 30% of the total gas + particle THC. The organic mass spectrum of COM has the largest fragment at m/z 44, with mass ratios of mass fragments 43/44 and 57/44 at 0.59 and 2.91, much lower than those reported for gasoline engine primary organic aerosols. The mass fragment 44/total organic mass ratio of 0.097 indicates that COM contains large oxygenated components. By incorporating the present findings, regional air quality modelling results suggest that the condensational uptake of THC onto sulfate particles alone can be comparable to the primary particle mass under moderately polluted ambient conditions. These findings are important for modelling and regulating the air quality impacts of gasoline vehicular emissions.

  14. Nucleation particles in diesel exhaust: composition inferred from in situ mass spectrometric analysis.

    PubMed

    Schneider, J; Hock, N; Weimer, S; Borrmann, S; Kirchner, U; Vogt, R; Scheer, V

    2005-08-15

    Mass spectrometric measurements of size and composition of diesel exhaust particles have been performed under various conditions: chassis dynamometer tests, field measurements near a German motorway, and individual car chasing. Nucleation particles consisting of volatile sulfate and organic material could be detected both at the chassis dynamometer test facility and during individual car chasing. We found evidence that if nucleation occurs, sulfuric acid/water is the nucleating agent. Low-volatile organics species condense only on the preexisting sulfuric acid/water clusters. Nucleation was found to depend strongly on various parameters such as exhaust dilution conditions, fuel sulfur content, and engine load. The latter determines the fraction of the fuel sulfur that is converted to sulfuric acid. The organic compounds (volatile and low-volatile) condense only on preexisting particles, such as both sulfuric acid nucleation particles and larger accumulation mode soot particles. On the latter, sulfuric acid also condenses, if the conditions for nucleation are not given. The overall ratio of sulfate to organic (volatile and low-volatile) is also strongly dependent on the engine load. It was found that the production of nucleation particles even at high engine load can be suppressed by using low-sulfur fuel. PMID:16173576

  15. Nrf2 Is a Protective Factor against Oxidative Stresses Induced by Diesel Exhaust Particle in Allergic Asthma

    PubMed Central

    Kawada, Tomoyuki; Azuma, Arata

    2013-01-01

    Epidemiological studies have shown that air pollutants, such as diesel exhaust particle (DEP), are implicated in the increased incidence of allergic airway disorders. In vitro studies of molecular mechanisms have focused on the role of reactive oxygen species generated directly and indirectly by the exposure to DEP. Antioxidants effectively reduce the allergic inflammatory effects induced by DEP both in vitro and in vivo. On the other hand, Nrf2 is a transcription factor essential for the inducible and/or constitutive expression of phase II and antioxidant enzymes. Disruption of Nrf2 enhances susceptibility to airway inflammatory responses and exacerbation of allergic inflammation induced by DEP in mice. Host responses to DEP are regulated by a balance between antioxidants and proinflammatory responses. Nrf2 may be an important protective factor against oxidative stresses induced by DEP in airway inflammation and allergic asthma and is expected to contribute to chemoprevention against DEP health effects in susceptible individuals. PMID:23738037

  16. Capture Efficiency of Cooking-Related Fine and Ultrafine Particles by Residential Exhaust Hoods

    SciTech Connect

    Lunden, Melissa M.; Delp, William W.

    2014-06-05

    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 80percent. 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 34-38percent for low (51?68 L s-1) and 54?72percent for high (109?138 L s-1) settings. CEs for 0.3?2.0 ?m particles during front burner stir-frying were 3?11percent on low and 16?70percent 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 80percent both for burner combustion products and for cooking-related particles.

  17. 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 ?m 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. PMID:24750219

  18. Differential transcriptional regulation of IL-8 expression by human airway epithelial cells exposed to diesel exhaust particles

    SciTech Connect

    Tal, Tamara L. [Curriculum in Toxicology, University of North Carolina, Chapel Hill (United States); Simmons, Steven O. [Integrated Systems Toxicology, National Health and Environmental Effects Research Laboratory, U.S. EPA (United States); Silbajoris, Robert; Dailey, Lisa [Environmental and Public Health, National Health and Environmental Effects Research Laboratory, U.S. EPA (United States); Cho, Seung-Hyun [Air Pollution Prevention Control Division, National Risk Management Research Laboratory, U.S. EPA (United States); Research Participation Program, Oak Ridge Institute for Science and Education, Oak Ridge (United States); Ramabhadran, Ram [Curriculum in Toxicology, University of North Carolina, Chapel Hill (United States); Integrated Systems Toxicology, National Health and Environmental Effects Research Laboratory, U.S. EPA (United States); Linak, William [Air Pollution Prevention Control Division, National Risk Management Research Laboratory, U.S. EPA (United States); Reed, William; Bromberg, Philip A. [Center for Environmental Medicine, Asthma, and Lung Biology, University of North Carolina, Chapel Hill (United States); Samet, James M., E-mail: samet.james@epa.go [Curriculum in Toxicology, University of North Carolina, Chapel Hill (United States); Environmental and Public Health, National Health and Environmental Effects Research Laboratory, U.S. EPA (United States)

    2010-02-15

    Exposure to diesel exhaust particles (DEP) induces inflammatory signaling characterized by MAP kinase-mediated activation of NFkB and AP-1 in vitro and in bronchial biopsies obtained from human subjects exposed to DEP. NFkB and AP-1 activation results in the upregulation of genes involved in promoting inflammation in airway epithelial cells, a principal target of inhaled DEP. IL-8 is a proinflammatory chemokine expressed by the airway epithelium in response to environmental pollutants. The mechanism by which DEP exposure induces IL-8 expression is not well understood. In the current study, we sought to determine whether DEP with varying organic content induces IL-8 expression in lung epithelial cells, as well as, to develop a method to rapidly evaluate the upstream mechanism(s) by which DEP induces IL-8 expression. Exposure to DEP with varying organic content differentially induced IL-8 expression and IL-8 promoter activity human airway epithelial cells. Mutational analysis of the IL-8 promoter was also performed using recombinant human cell lines expressing reporters linked to the mutated promoters. Treatment with a low organic-containing DEP stimulated IL-8 expression by a mechanism that is predominantly NFkB-dependent. In contrast, exposure to high organic-containing DEP induced IL-8 expression independently of NFkB through a mechanism that requires AP-1 activity. Our study reveals that exposure to DEP of varying organic content induces proinflammatory gene expression through multiple specific mechanisms in human airway epithelial cells. The approaches used in the present study demonstrate the utility of a promoter-reporter assay ensemble for identifying transcriptional pathways activated by pollutant exposure.

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

    Microsoft Academic Search

    Kyle Steenland; James Deddens; Leslie Stayner

    1998-01-01

    Background 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

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

    PubMed Central

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

    2006-01-01

    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 US Railroad Retirement Board provided railroad assignment and work histories for 52,812 workers hired between 1939–1949, for whom we ascertained mortality 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. PMID:16841258

  1. Particle-Bound PAH Emission from the Exhaust of Combustion Chamber

    NASA Astrophysics Data System (ADS)

    Asgari Lamjiri, M.; Medrano, Y. S.; Guillaume, D. W.; Khachikian, C. S.

    2013-12-01

    Polycyclic Aromatic Hydrocarbons (PAHs) are harmful, semi-volatile organic compounds which are generated due to the incomplete combustion of organic substances. PAHs are of concern as a pollutant because some of these compounds are carcinogenic and mutagenic even at low levels. Most of the PAHs are recalcitrant and persistent in the environment. The PAHs carcinogenic potential can be increased by the adsorption onto small size particles (< 1?m) which can easily get into the bronchioles and alveoli of the lungs. PAHs associated with sub-micron particles are mostly generated from high temperature sources like combustion chambers. In this current study, the presence of 16 priority PAHs (listed by United States Environmental Protection Agency) which are attached to the particulates emitted from the exhaust of the jet engine are evaluated. The engine was operated at different swirl numbers (S; the ratio of tangential air flow to axial air flow) to investigate the effect of this parameter on the effluent of combustion chamber. The samples were collected using two instruments simultaneously: a particle analyzer and a Micro-Orifice Uniform Deposited Impactor (MOUDI). Particle analyzer was used to count the number of particles in different sizes and MOUDI was used to collect particles with respect to their size as they were emitted from the exhaust. The MOUDI's aluminum substrates were weighed before and after the experiment in order to measure the mass of particles that were collected during the sampling period. The concentration of PAHs associated with the particles was measured by extracting the particles with dichloromethane followed by analysis via gas chromatography/mass spectrometry (GC/MS). In general, lower molecular weight PAHs emitted from the exhaust of combustion chamber are mostly in gas phase while PAHs of higher molecular weight are adsorbed onto particles. Preliminary results from GC/MS confirm the presence of higher molecular weight PAHs like Benzo[a]pyrene in most of the samples. Better recirculation between air and fuel in higher swirl numbers results in better combustion. In higher swirl numbers, the temperature of the combustion process increases which leads to a more complete combustion. Another result of higher swirl number is a longer residence time which allows the organic substances in the fuel to remain in the reaction longer and also leads to a more complete combustion. The preliminary results from particle analyzer show that the abundance ratio of smaller particles to larger particles increases at higher swirl numbers. For example, at swirl 86, the abundance ratio of 0.3 micron particles to 0.7 micron particles was 400 while at swirl 0, this ratio was 35. Smaller particles have higher specific surface area which allows for more PAH adsorption. The preliminary results show that operating the jet engine at higher swirl numbers can have positive or negative effects on particle-bound PAH emissions. Higher temperature and residence time as well as better mixture of fuel and air can reduce PAH emission while generating more small size particles can increase surface available for PAH adsorption and, as a result, increases PAH emission. In future experiments, particle-bound PAHs of different swirl numbers will be compared in order to find a swirl number range which generates fewer Particle-bound PAHs.

  2. Novel object recognition ability in female mice following exposure to nanoparticle-rich diesel exhaust

    SciTech Connect

    Win-Shwe, Tin-Tin, E-mail: tin.tin.win.shwe@nies.go.jp [Center for Environmental Health Sciences, National Institute for Environmental Studies, 16?2 Onogawa, Tsukuba, Ibaraki 305?8506 (Japan)] [Center for Environmental Health Sciences, National Institute for Environmental Studies, 16?2 Onogawa, Tsukuba, Ibaraki 305?8506 (Japan); Fujimaki, Hidekazu; Fujitani, Yuji; Hirano, Seishiro [Center for Environmental Risk Research, National Institute for Environmental Studies, 16?2 Onogawa, Tsukuba, Ibaraki 305?8506 (Japan)] [Center for Environmental Risk Research, National Institute for Environmental Studies, 16?2 Onogawa, Tsukuba, Ibaraki 305?8506 (Japan)

    2012-08-01

    Recently, our laboratory reported that exposure to nanoparticle-rich diesel exhaust (NRDE) for 3 months impaired hippocampus-dependent spatial learning ability and up-regulated the expressions of memory function-related genes in the hippocampus of female mice. However, whether NRDE affects the hippocampus-dependent non-spatial learning ability and the mechanism of NRDE-induced neurotoxicity was unknown. Female BALB/c mice were exposed to clean air, middle-dose NRDE (M-NRDE, 47 ?g/m{sup 3}), high-dose NRDE (H-NRDE, 129 ?g/m{sup 3}), or filtered H-NRDE (F-DE) for 3 months. We then investigated the effect of NRDE exposure on non-spatial learning ability and the expression of genes related to glutamate neurotransmission using a novel object recognition test and a real-time RT-PCR analysis, respectively. We also examined microglia marker Iba1 immunoreactivity in the hippocampus using immunohistochemical analyses. Mice exposed to H-NRDE or F-DE could not discriminate between familiar and novel objects. The control and M-NRDE-exposed groups showed a significantly increased discrimination index, compared to the H-NRDE-exposed group. Although no significant changes in the expression levels of the NMDA receptor subunits were observed, the expression of glutamate transporter EAAT4 was decreased and that of glutamic acid decarboxylase GAD65 was increased in the hippocampus of H-NRDE-exposed mice, compared with the expression levels in control mice. We also found that microglia activation was prominent in the hippocampal area of the H-NRDE-exposed mice, compared with the other groups. These results indicated that exposure to NRDE for 3 months impaired the novel object recognition ability. The present study suggests that genes related to glutamate metabolism may be involved in the NRDE-induced neurotoxicity observed in the present mouse model. -- Highlights: ? The effects of nanoparticle-induced neurotoxicity remain unclear. ? We investigated the effect of exposure to nanoparticles on learning behavior. ? We found that exposure to nanoparticles impaired novel object recognition ability.

  3. Diesel exhaust exposure and smoking: A case-referent study of lung cancer among Swedish dock workers

    SciTech Connect

    Emmelin, A.; Nystroem, L.W.; Wall, S. (Umea Univ. (Sweden))

    1993-05-01

    We studied 50 lung cancer cases and 154 matched referents, all dock workers, for whom we obtained smoking information and employment histories. We assessed exposures from information on annual diesel fuel consumption from each of the 15 ports included. We used a smoker/nonsmoker term and three exposure variables (machine time, cumulative fuel, and exposed time with fuel consumption above a minimum cutpoint) in the analyses, with three categories for each exposure variable. Odds ratios (ORs) for medium and high exposure groups are consistently higher than reference (low), with an increasing exposure-response trend that is most marked for the exposed time variable (ORs: low = 1.0; medium = 1.6; high = 2.8). When smoking and that exposure variable are simultaneously included in the analyses, odds ratios for the medium (OR = 2.7) and high (OR = 6.8) levels of exposure increase, as does the odds ratio for smoking. Separating smokers and nonsmokers, with the low exposed nonsmokers as the common reference category, the odds ratios are 1.6 (medium) and 2.9 (high) for the nonsmokers, and 10.7 (medium) and 28.9 (high) for smokers. These results indicate an independent effect of diesel exhaust exposure and a strong interaction between smoking and diesel exhaust.

  4. Regulation of Human Hepatic Drug Transporter Activity and Expression by Diesel Exhaust Particle Extract

    PubMed Central

    Le Vee, Marc; Jouan, Elodie; Stieger, Bruno; Lecureur, Valérie; Fardel, Olivier

    2015-01-01

    Diesel exhaust particles (DEPs) are common environmental air pollutants primarily affecting the lung. DEPs or chemicals adsorbed on DEPs also exert extra-pulmonary effects, including alteration of hepatic drug detoxifying enzyme expression. The present study was designed to determine whether organic DEP extract (DEPe) may target hepatic drug transporters that contribute in a major way to drug detoxification. Using primary human hepatocytes and transporter-overexpressing cells, DEPe was first shown to strongly inhibit activities of the sinusoidal solute carrier (SLC) uptake transporters organic anion-transporting polypeptides (OATP) 1B1, 1B3 and 2B1 and of the canalicular ATP-binding cassette (ABC) efflux pump multidrug resistance-associated protein 2, with IC50 values ranging from approximately 1 to 20 ?g/mL and relevant to environmental exposure situations. By contrast, 25 ?g/mL DEPe failed to alter activities of the SLC transporter organic cation transporter (OCT) 1 and of the ABC efflux pumps P-glycoprotein and bile salt export pump (BSEP), whereas it only moderately inhibited those of sodium taurocholate co-transporting polypeptide and of breast cancer resistance protein (BCRP). Treatment by 25 ?g/mL DEPe was next demonstrated to induce expression of BCRP at both mRNA and protein level in cultured human hepatic cells, whereas it concomitantly repressed mRNA expression of various transporters, including OATP1B3, OATP2B1, OCT1 and BSEP. Such changes in transporter expression were found to be highly correlated to those caused by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a reference activator of the aryl hydrocarbon receptor (AhR) pathway. This suggests that DEPe, which is enriched in known ligands of AhR like polycyclic aromatic hydrocarbons, alters drug transporter expression via activation of the AhR cascade. Taken together, these data established human hepatic transporters as targets of organic chemicals containing in DEPs, which may contribute to their systemic effects through impairing hepatic transport of endogenous compound or drug substrates of these transporters. PMID:25803276

  5. Exposure to Concentrated Ambient Particles Does Not Affect Vascular Function in Patients with Coronary Heart Disease

    PubMed Central

    Mills, Nicholas L.; Robinson, Simon D.; Fokkens, Paul H. B.; Leseman, Daan L. A. C.; Miller, Mark R.; Anderson, David; Freney, Evelyn J.; Heal, Mathew R.; Donovan, Robert J.; Blomberg, Anders; Sandström, Thomas; MacNee, William; Boon, Nicholas A.; Donaldson, Ken; Newby, David E.; Cassee, Flemming R.

    2008-01-01

    Background Exposure to fine particulate air pollution is associated with increased cardiovascular morbidity and mortality. We previously demonstrated that exposure to dilute diesel exhaust causes vascular dysfunction in humans. Objectives We conducted a study to determine whether exposure to ambient particulate matter causes vascular dysfunction. Methods Twelve male patients with stable coronary heart disease and 12 age-matched volunteers were exposed to concentrated ambient fine and ultrafine particles (CAPs) or filtered air for 2 hr using a randomized, double-blind cross-over study design. We measured peripheral vascular vasomotor and fibrinolytic function, and inflammatory variables—including circulating leukocytes, serum C-reactive protein, and exhaled breath 8-isoprostane and nitrotyrosine—6–8 hr after both exposures. Results Particulate concentrations (mean ± SE) in the exposure chamber (190 ± 37 ?g/m3) were higher than ambient levels (31 ± 8 ?g/m3) and levels in filtered air (0.5 ± 0.4 ?g/m3; p < 0.001). Chemical analysis of CAPs identified low levels of elemental carbon. Exhaled breath 8-isoprostane concentrations increased after exposure to CAPs (16.9 ± 8.5 vs. 4.9 ± 1.2 pg/mL, p < 0.05), but markers of systemic inflammation were largely unchanged. Although there was a dose-dependent increase in blood flow and plasma tissue plasminogen activator release (p < 0.001 for all), CAPs exposure had no effect on vascular function in either group. Conclusions Despite achieving marked increases in particulate matter, exposure to CAPs—low in combustion-derived particles—did not affect vasomotor or fibrinolytic function in either middle-aged healthy volunteers or patients with coronary heart disease. These findings contrast with previous exposures to dilute diesel exhaust and highlight the importance of particle composition in determining the vascular effects of particulate matter in humans. PMID:18560524

  6. Extract of motorcycle exhaust particles induced macrophages apoptosis by calcium-dependent manner.

    PubMed

    Lee, Chen-Chen; Kang, Jaw-Jou

    2002-12-01

    Large survey and experiments have reported that environment pollutants from fossil fuel combustion would cause immune system deleterious by enhancement of allergic reaction and damage to respiratory tract. In this study, we reported that the extract of motorcycle exhaust particles (MEP) might affect the immune system by inducing cell apoptosis on macrophages. The motorcycle exhaust particles were collected from a two-stoke engine and their cytotoxic effect on macrophages was investigated. We found MEP is cytotoxic and induced apoptosis in RAW 264.7 cells, murine peritoneal macrophage, and rat alveolar macrophage. Pretreatment with mitochondria permeability transition inhibitor (cyclosporin A), intracellular (BAPTA-AM) and extracellular (EGTA) Ca(2+) chelator, and antioxidants (NAC, GSH, catalase, SOD) attenuated the MEP-induced cell apoptosis, and BAPTA-AM was the most effective one. Utilized Fura-2/AM loaded RAW 264.7 cells to directly detect the change of intracellular Ca(2+) concentration ([Ca(2+)](i)), we found that MEP could induce a sustained increase of [Ca(2+)](i). The raise of [Ca(2+)](i) induced by MEP could be completely blocked by the intracellular Ca(2+) chelator, BAPTA-AM, however, only partially inhibited by the extracellular Ca(2+) chelator, EGTA. These results suggested that both influx of extracellular Ca(2+) and release of Ca(2+) from the internal storage were involved. We also found that MEP caused a decrease of mitochondria membrane potential and an increase of oxidative stress in RAW 264.7 cells. In conclusion, we found that the particles, collected from the motorcycle exhaust, contain chemicals that will induce apoptosis of macrophage in calcium-dependent manner. PMID:12482235

  7. Pulmonary Exposure to Particles during Pregnancy Causes Increased Neonatal Asthma Susceptibility

    PubMed Central

    Fedulov, Alexey V.; Leme, Adriana; Yang, Zhiping; Dahl, Morten; Lim, Robert; Mariani, Thomas J.; Kobzik, Lester

    2008-01-01

    Maternal immune responses can promote allergy development in offspring, as shown in a model of increased susceptibility to asthma in babies of ovalbumin (OVA)-sensitized and -challenged mother mice. We investigated whether inflammatory responses to air pollution particles (diesel exhaust particles, DEP) or control “inert” titanium dioxide (TiO2) particles are enhanced during pregnancy and whether exposure to particles can cause increased neonatal susceptibility to asthma. Pregnant BALB/c mice (or nonpregnant controls) received particle suspensions intranasally at Day 14 of pregnancy. Lung inflammatory responses were evaluated 48 hours after exposure. Offspring of particle- or buffer-treated mothers were sensitized and aerosolized with OVA, followed by assays of airway hyperresponsiveness (AHR) and allergic inflammation (AI). Nonpregnant females had the expected minimal response to “inert” TiO2. In contrast, pregnant mice showed robust and persistent acute inflammation after both TiO2 and DEP. Genomic profiling identified genes differentially expressed in pregnant lungs exposed to TiO2. Neonates of mothers exposed to TiO2 (and DEP, but not PBS) developed AHR and AI, indicating that pregnancy exposure to both “inert” TiO2 and DEP caused increased asthma susceptibility in offspring. We conclude that (1) pregnancy enhances lung inflammatory responses to otherwise relatively innocuous inert particles; and (2) exposures of nonallergic pregnant females to inert or toxic environmental air particles can cause increased allergic susceptibility in offspring. PMID:17656681

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

    PubMed

    Clark, C R; Henderson, T R; Royer, R E; Brooks, A L; McClellan, R O; Marshall, W F; Naman, T M

    1982-01-01

    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%) 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. PMID:6193020

  9. 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...

  10. New method for time-resolved diesel engine exhaust particle mass measurement.

    PubMed

    Lehmann, U; Niemelä, V; Mohr, M

    2004-11-01

    The Dekati mass monitor (DMM; Dekati Ltd., Finland), a relatively new real-time mass measurement instrument, was investigated in this project. In contrast to the existing gravimetric filter method also used as a standard for regulation purposes, this instrument provides second-by-second data on mass concentration in the engine exhaust gas. The principle of the DMM is based on particle charging, inertial and electrical size classification, and electrical detection of aerosol particles. This study focuses on the instrument's practical performance. Details on calibration and the theory of operation will be published elsewhere. The exhaust emissions of two heavy-duty engines complying with the Euro III emission standard were measured on a dynamic engine test bench. We looked atthe particle number and mass emissions of the engines in different transient test cycles and steady-state conditions. The ability to follow transient test cycles and the response times of the DMM were investigated. The aerosol mass concentration measured by the DMM was compared with the mass concentration obtained by the standard gravimetric filter method with Teflon-coated glass fiber filters. The total mass concentration (integral over the whole cycle) measured by the DMM is about 20% higher than that measured by the standard gravimetric filter method. The total mass concentration from the DMM was also compared with the volume concentration calculated from the electrical low-pressure impactor (ELPI) measurements. Correlations were made with other particle measuring systems. The DMM correlates very well with the particulate mass (R2 = 0.95) and exhibits good linearity and repeatability. The response time to a well-defined change in exhaust concentration was observed to be fast and stable. The DMM was able to follow transient test cycles and provides good results on a second-by-second basis. The instrument used in this study was still under development, and there is therefore no complete scientific background reference for the DMM. This study therefore focuses more on the measurements than on the scientific background. The measurements have shown thatthe DMM is an adequate instrument for measuring the mass concentration of engine exhaust, with results comparable to those from the standard gravimetric filter method. In addition, the DMM provides real-time second-by-second data of the mass concentration during transient test cycles. PMID:15575290

  11. Particle Velocity Distributions in the Magnetotail Reconnection Exhaust: Results from Implicit PIC Simulations

    NASA Astrophysics Data System (ADS)

    Newman, D. L.; Goldman, M. V.; Lapenta, G.; Markidis, S.; Andersson, L.; Gosling, J. T.; Eastwood, J. P.

    2012-12-01

    The upcoming MMS mission will have the capability of measuring 3D electron and ion velocity distributions with unprecedented temporal resolution. The bulk of MMS observations of reconnection in Earth's magnetotail will involve crossings of the reconnection exhaust at various distances from the reconnection X-point and orientations relative to the current sheet. In anticipation of these observations, we have generated sets of fly-through diagnostics for the 3D electron and ion velocity-space distributions from 2D implicit PIC simulations of magnetotail reconnection. These fly-throughs represent traversals of the reconnection exhaust by a virtual satellite along a number of different trajectories. The regions probed include (1) the vicinity of the X-point where the particles are not yet co-moving with the embedded exhaust magnetic field, (2) further downstream, where the magnetic field is largely frozen into the plasma outflow, and (3) even further from the X-point near the interface of the reconnection exhaust with the initial high-density current-sheet plasma, associated with a pile-up of magnetic field lines. In many of the regions examined, the distributions are highly nonthermal and often agyrotropic, including examples of counterstreaming populations and other potentially unstable features. The results of the simulation studies will be applied to the interpretation of existing satellite observations. --- Research supported by NASA and NSF; Ion velocity moment Uix from center of implicit PIC simulation box (lower left). The X-point is at the left edge, with the virtual satellite position marked by a black star. Remaining frames show three orthogonal projections of the ion velocity distribution integrated over the third velocity component and averaged over a 0.5di square.

  12. 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. PMID:12782259

  13. Constraining the heterogeneous loss of O3 on soot particles with observations in jet engine exhaust plumes

    Microsoft Academic Search

    R. S. Gao; B. Kärcher; E. R. Keim; D. W. Fahey

    1998-01-01

    In situ measurements in the engine exhaust of a Concorde supersonic aircraft in the lower stratosphere are used to constrain heterogeneous reaction rates on soot particles in a plume model. Upper limit values are obtained for the product of the reactive uptake coefficients of O3 and NO2 and the mean surface area of individual soot particles using the model and

  14. Controlled human exposures to ambient pollutant particles in susceptible populations

    Microsoft Academic Search

    Yuh-Chin T Huang; Andrew J Ghio

    2009-01-01

    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 susceptible subjects, including the elderly and patients with cardiopulmonary diseases. Controlled human exposure studies have been used to confirm the causal relationship between

  15. Analysis of mid-tropospheric Space Shuttle exhausted aluminum oxide particles

    NASA Technical Reports Server (NTRS)

    Cofer, Wesley R., III; Lala, G. Garland; Wightman, James P.

    1987-01-01

    Aluminum oxide particles from the exhaust of the Space Shuttle were collected immediately after the launch of the SEPEX mission and during the descent over the altitude interval of 7.6-4.6 km. The SEM examination revealed that the particles were spherical and ranged in diameter from about 0.1 micron to 10 microns. Results from the energy dispersive analysis (by an X-ray method) and of the particle chemistry (by electron spectroscopy) confirmed that the particles were predominantly composed of aluminum and oxygen. The particle size distribution of the Al2O3 was bimodal, with one observed peak centered near 2.0 microns; the other distribution mode centered at a diameter of less than 0.3 micron, but could not be accurately located. A mass median diameter was slightly less than 2 microns. Evaluation of ice nucleation activity revealed only a small fraction (about 1 ppm) of active ice nuclei among the Al2O3 particulates.

  16. Comparative effects of inhaled diesel exhaust and ambient fine particles on inflammation, atherosclerosis, and vascular dysfunction

    PubMed Central

    Quan, Chunli; Sun, Qinghua; Lippmann, Morton; Chen, Lung-Chi

    2011-01-01

    Ambient air PM2.5 (particulate matter less than 2.5 ?m in diameter) has been associated with cardiovascular diseases (CVDs), but the underlying mechanisms affecting CVDs are unknown. The authors investigated whether subchronic inhalation of concentrated ambient PM2.5 (CAPs), whole diesel exhaust (WDE), or diesel exhaust gases (DEGs) led to exacerbation of atherosclerosis, pulmonary and systemic inflammation, and vascular dysfunction; and whether DEG interactions with CAPs alter cardiovascular effects. ApoE?/? mice were simultaneously exposed via inhalation for 5 hours/day, 4 days/week, for up to 5 months to one of five different exposure atmospheres: (1) filtered air (FA); (2) CAPs (105 ?g/m3); (3) WDE (DEP = 436 ?g/m3); (4) DEG (equivalent to gas levels in WDE group); and (5) CAPs+DEG (PM2.5: 113 ?g/m3; with DEG equivalent to WDE group). After 3 and 5 months, lung lavage fluid and blood sera were analyzed, and atherosclerotic plaques were quantified by ultrasound imaging, hematoxylin and eosin (H&E stain), and en face Sudan IV stain. Vascular functions were assessed after 5 months of exposure. The authors showed that (1) subchronic CAPs, WDE, and DEG inhalations increased serum vascular cell adhesion molecule (VCAM)-1 levels and enhanced phenylephrine (PE)-induced vasoconstriction; (2) for plaque exacerbation, CAPs > WDE > DEG = FA, thus PM components (not present in WDE) were responsible for plaque development; (3) atherosclerosis can exacerbated through mechanistic pathways other than inflammation and vascular dysfunction; and (4) although there were no significant interactions between CAPs and DEG on plaque exacerbation, it is less clear whether the effects of CAPs on vasomotor dysfunction and pulmonary/systemic inflammation were enhanced by the DEG coexposure. PMID:20462391

  17. Exposure to volatile organic compounds for individuals with occupations associated with potential exposure to motor vehicle exhaust and\\/or gasoline vapor emissions

    Microsoft Academic Search

    Wan-Kuen Jo; Ki-Berm Song

    2001-01-01

    Workers who work near volatile organic compounds (VOCs) source(s), motor vehicle exhausts and\\/or gasoline vapor emissions, are suspected to be exposed to highly-elevated VOC levels during their work-time. This study confirmed this suspicion and evaluated the work-time exposure VOCs for traffic police officers, parking garage attendants, service station attendants, roadside storekeepers and underground storekeepers, by measuring the concentrations of six

  18. 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

    2013-04-01

    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) ?g(-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. PMID:23470039

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

    SciTech Connect

    Li Chunmei [Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193 (Japan); Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509 (Japan); Taneda, Shinji [Environmental Nanotoxicology Section, Research Center for Environmental Risk, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506 (Japan); Suzuki, Akira K. [Environmental Nanotoxicology Section, Research Center for Environmental Risk, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506 (Japan)]. E-mail: suzukiak@nies.go.jp; Furuta, Chie [Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193 (Japan); Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509 (Japan); Watanabe, Gen [Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193 (Japan); Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509 (Japan); Taya, Kazuyoshi [Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193 (Japan); Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509 (Japan)

    2006-11-15

    A 4-nitrophenol (PNP) isolated from diesel exhaust particles (DEP) has been identified as a vasodilator. PNP is also a known degradation product of the insecticide parathion. We used uterotrophic and Hershberger assays to study the estrogenic and anti-androgenic activities of PNP in-vivo. In ovariectomized immature female rats injected subcutaneously with 1, 10, or 100 mg/kg PNP daily for 7 days, significant (P < 0.05) increases in uterine weight were seen in only those receiving 10 or 100 mg/kg PNP. Furthermore, in castrated immature male rats implanted with a silastic tube (length, 5 mm) containing crystalline testosterone and injected subcutaneously with 0.01, 0.1, or 1 mg/kg PNP daily for 5 days, those receiving the doses of 0.1 mg/kg showed significant (P < 0.05) weight decreases in seminal vesicles, ventral prostate, levator ani plus bulbocavernosus muscles, and glans penis. Plasma FSH and LH levels did not change in female rats but were significantly (P < 0.05) increased in male rats treated with 0.1 mg/kg PNP. These results clearly demonstrated that PNP has estrogenic and anti-androgenic activities in-vivo. Our results therefore suggest that diesel exhaust emissions and the degradation of parathion can lead to accumulation of PNP in air, water, and soil and thus could have serious deleterious effects on wildlife and human health.

  20. Whole and Particle-Free Diesel Exhausts Differentially Affect Cardiac Electrophysiology, Blood Pressure, and Autonomic Balance in Heart Failure–Prone Rats

    PubMed Central

    Farraj, Aimen K.

    2012-01-01

    Epidemiological studies strongly link short-term exposures to vehicular traffic and particulate matter (PM) air pollution with adverse cardiovascular (CV) events, especially in those with preexisting CV disease. Diesel engine exhaust is a key contributor to urban ambient PM and gaseous pollutants. To determine the role of gaseous and particulate components in diesel exhaust (DE) cardiotoxicity, we examined the effects of a 4-h inhalation of whole DE (wDE) (target PM concentration: 500 µg/m3) or particle-free filtered DE (fDE) on CV physiology and a range of markers of cardiopulmonary injury in hypertensive heart failure–prone rats. Arterial blood pressure (BP), electrocardiography, and heart rate variability (HRV), an index of autonomic balance, were monitored. Both fDE and wDE decreased BP and prolonged PR interval during exposure, with more effects from fDE, which additionally increased HRV triangular index and decreased T-wave amplitude. fDE increased QTc interval immediately after exposure, increased atrioventricular (AV) block Mobitz II arrhythmias shortly thereafter, and increased serum high-density lipoprotein 1 day later. wDE increased BP and decreased HRV root mean square of successive differences immediately postexposure. fDE and wDE decreased heart rate during the 4th hour of postexposure. Thus, DE gases slowed AV conduction and ventricular repolarization, decreased BP, increased HRV, and subsequently provoked arrhythmias, collectively suggesting parasympathetic activation; conversely, brief BP and HRV changes after exposure to particle-containing DE indicated a transient sympathetic excitation. Our findings suggest that whole- and particle-free DE differentially alter CV and autonomic physiology and may potentially increase risk through divergent pathways. PMID:22543275

  1. Particle exposure in a baroque church during Sunday Masses.

    PubMed

    Polednik, Bernard

    2013-10-01

    Particle concentrations were measured in a Baroque church during five Sunday Masses. The highest particle number and mass concentrations were observed when both candles and the incense were burned. They were respectively 16.8 and 14.3 times higher than outdoors for submicron particles. The exposure to particles experienced by the churchgoers, especially priests and church workers who participated in several Masses on that day, was considerably higher than the exposure experienced at the same time outdoors. PMID:23972742

  2. Variability in bioreactivity linked to changes in size and zeta potential of diesel exhaust particles in human immune cells.

    PubMed

    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-1?, TNF-?, IL-6, IFN-?, 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

  3. 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-1?, TNF-?, IL-6, IFN-?, 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

  4. 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

  5. A review of commuter exposure to ultrafine particles and its health effects

    NASA Astrophysics Data System (ADS)

    Knibbs, Luke D.; Cole-Hunter, Tom; Morawska, Lidia

    2011-05-01

    Ultrafine particles (UFPs, <100 nm) are produced in large quantities by vehicular combustion and are implicated in causing several adverse human health effects. Recent work has suggested that a large proportion of daily UFP exposure may occur during commuting. However, the determinants, variability and transport mode-dependence of such exposure are not well-understood. The aim of this review was to address these knowledge gaps by distilling the results of 'in-transit' UFP exposure studies performed to-date, including studies of health effects. We identified 47 exposure studies performed across 6 transport modes: automobile, bicycle, bus, ferry, rail and walking. These encompassed approximately 3000 individual trips where UFP concentrations were measured. After weighting mean UFP concentrations by the number of trips in which they were collected, we found overall mean UFP concentrations of 3.4, 4.2, 4.5, 4.7, 4.9 and 5.7 × 10 4 particles cm -3 for the bicycle, bus, automobile, rail, walking and ferry modes, respectively. The mean concentration inside automobiles travelling through tunnels was 3.0 × 10 5 particles cm -3. While the mean concentrations were indicative of general trends, we found that the determinants of exposure (meteorology, traffic parameters, route, fuel type, exhaust treatment technologies, cabin ventilation, filtration, deposition, UFP penetration) exhibited marked variability and mode-dependence, such that it is not necessarily appropriate to rank modes in order of exposure without detailed consideration of these factors. Ten in-transit health effects studies have been conducted and their results indicate that UFP exposure during commuting can elicit acute effects in both healthy and health-compromised individuals. We suggest that future work should focus on further defining the contribution of in-transit UFP exposure to total UFP exposure, exploring its specific health effects and investigating exposures in the developing world.

  6. Airborne Concentrations of PM2.5 and Diesel Exhaust Particles on Harlem Sidewalks: A Community-Based Pilot Study

    Microsoft Academic Search

    Patrick L. Kinney; Maneesha Aggarwal; Mary E. Northridge; Nicole A. H. Janssen; Peggy Shepard

    2000-01-01

    Residents of the dense urban core neighborhoods of New York City (NYC) have expressed increas- ing concern about the potential human health impacts of diesel vehicle emissions. We measured concentrations of particulate matter ? 2.5 µm in aerodynamic diameter (PM2.5) and diesel exhaust particles (DEP) on sidewalks in Harlem, NYC, and tested whether spatial variations in concentra- tions were related

  7. 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...

  8. 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...

  9. Interference of animal source ammonia with exposure chamber atmospheres containing acid particulate from automobile exhaust.

    PubMed

    Malanchuk, M; Barkley, N P; Contner, G L

    1980-08-01

    A study was designed to test the effect of animal source ammonia on some component concentrations in test atmospheres produced to measure the health effects of pollutants in the exhaust emissions of gasoline-powered engines equipped with oxidative catalyst converters. The dominantly acidic nature of the exhaust particulate phase required an evaluation of test chamber concentrations of the alkaline components contributed by the test animals. The animal population in the chamber was critical in maintaining the essential integrity of the pollutant atmosphere. Measures to minimize the production of the animal-produced interferent(s) were helpful in attenuating the interfering effect. PMID:6160191

  10. Use of proteomics to demonstrate a hierarchical oxidative stress response to diesel exhaust particle chemicals in a macrophage cell line.

    PubMed

    Xiao, Gary Guishan; Wang, Meiying; Li, Ning; Loo, Joseph A; Nel, Andre E

    2003-12-12

    Epidemiological studies demonstrate an association between short term exposure to ambient particulate matter (PM) and cardiorespiratory morbidity and mortality. Although the biological mechanisms of these adverse effects are unknown, emerging data suggest a key role for oxidative stress. Ambient PM and diesel exhaust particles (DEP) contain redox cycling organic chemicals that induce pro-oxidative and pro-inflammatory effects in the lung. These responses are suppressed by N-acetylcysteine (NAC), which directly complexes to electrophilic DEP chemicals and exert additional antioxidant effects at the cellular level. A proteomics approach was used to study DEP-induced responses in the macrophage cell line, RAW 264.7. We demonstrate that in the dose range 10-100 microg/ml, organic DEP extracts induce a progressive decline in the cellular GSH/GSSG ratio, in parallel with a linear increase in newly expressed proteins on the two-dimensional gel. Using matrix-assisted laser desorption ionization time-of-flight mass spectrometry and electrospray ionization-liquid chromatography/mass spectrometry/mass spectrometry analysis, 32 newly induced/NAC-suppressed proteins were identified. These include antioxidant enzymes (e.g. heme oxygenase-1 and catalase), pro-inflammatory components (e.g. p38MAPK and Rel A), and products of intermediary metabolism that are regulated by oxidative stress. Heme oxygenase-1 was induced at low extract dose and with minimal decline in the GSH/GSSG ratio, whereas MAP kinase activation required a higher chemical dose and incremental levels of oxidative stress. Moreover, at extract doses >50 microg/ml, there is a steep decline in cellular viability. These data suggest that DEP induce a hierarchical oxidative stress response in which some of these proteins may serve as markers for oxidative stress during PM exposures. PMID:14522998

  11. Effects of diesel exhaust particles on left ventricular function in isoproterenol-induced myocardial injury and healthy rats.

    PubMed

    Yan, Yuan-Horng; Huang, Chien-Hua; Chen, Wen-Jone; Wu, Ming-Fang; Cheng, Tsun-Jen

    2008-01-01

    The associations between ambient particulate matter with an aerodiameter less than 2.5 mu m (PM(2.5)) and congestive heart failure (CHF) have been reported. However, the underlying mechanisms remain unclear. We investigated the effect of diesel exhaust particles (DEPs) on left ventricular function in isoproterenol (ISO)-induced myocardial injury and healthy rats. Male Sprague-Dawley (SD) rats were injected with ISO or normal saline. Seven days later, both groups were further assigned to receive either DEPs or normal saline by intratracheal instillation (IT). Echocardiography was used to measure fractional shortening (FS) and left ventricular end-diastolic diameter (LVDd) 24 h before and after IT in each rat. Fractional shortening (FS) was significantly decreased in SD rats treated with ISO as compared to those treated with normal saline (p < .05, t-test). When FS and LVDd before and after treatment were compared in each rat, there was no difference for normal saline treatment in healthy or ISO groups. However, there was significantly lower FS before and after DEPs exposure in both groups (p < .05, paired t-test). When using SD rats treated with normal saline as a reference group, both SD rats treated with DEPs and ISO rats treated with normal saline had lower FS (p < .05 and .0001, respectively, t-test), while ISO rats treated with DEPs had the lowest FS (p < .0001, t-test). Echocardiographic assessment revealed that left ventricular function was impaired by acute DEPs exposure, and this LV function was further compromised in rats with preexisting ISO-induced myocardial injury. PMID:18236234

  12. 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-?g/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 ?g/m3 EC were 17, 200, and 689 per 10,000, respectively. For lifetime environmental exposure to 0.8 ?g/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: Vermeulen R, Silverman DT, Garshick E, Vlaanderen J, Portengen L, Steenland K. 2014. Exposure-response estimates for diesel engine exhaust and lung cancer mortality based on data from three occupational cohorts. Environ Health Perspect 122:172–177;?http://dx.doi.org/10.1289/ehp.1306880 PMID:24273233

  13. Metal particle emissions in the exhaust stream of diesel engines: an electron microscope study.

    PubMed

    Liati, Anthi; Schreiber, Daniel; Dimopoulos Eggenschwiler, Panayotis; Arroyo Rojas Dasilva, Yadira

    2013-12-17

    Scanning electron microscopy and transmission electron microscopy were applied to investigate the morphology, mode of occurrence and chemical composition of metal particles (diesel ash) in the exhaust stream of a small truck outfitted with a typical after-treatment system (a diesel oxidation catalyst (DOC) and a downstream diesel particulate filter (DPF)). Ash consists of Ca-Zn-P-Mg-S-Na-Al-K-phases (lube-oil related), Fe, Cr, Ni, Sn, Pb, Sn (engine wear), and Pd (DOC coating). Soot agglomerates of variable sizes (<0.5-5 ?m) are abundant upstream of the DPF and are ash-free or contain notably little attached ash. Post-DPF soot agglomerates are very few, typically large (>1-5 ?m, exceptionally 13 ?m), rarely <0.5 ?m, and contain abundant ash carried mostly from inside the DPF. The ash that reaches the atmosphere also occurs as separate aggregates ca. 0.2-2 ?m in size consisting of sintered primary phases, ca. 20-400 nm large. Insoluble particles of these sizes may harm the respiratory and cardiovascular systems. The DPF probably promotes breakout of large soot agglomerates (mostly ash-bearing) by favoring sintering. Noble metals detached from the DOC coating may reach the ambient air. Finally, very few agglomerates of Fe-oxide nanoparticles form newly from engine wear and escape into the atmosphere. PMID:24274188

  14. In Vitro Exposures in Diesel Exhaust Atmospheres: Resuspension of PM from Filters Verses Direct Deposition of PM from Air

    PubMed Central

    Lichtveld, Kim M.; Ebersviller, Seth M.; Sexton, Kenneth G.; Vizuete, William; Jaspers, Ilona; Jeffries, Harvey E.

    2012-01-01

    One of the most widely used in vitro particulate matter (PM) exposures methods is the collection of PM on filters, followed by resuspension in a liquid medium, with subsequent addition onto a cell culture. To avoid disruption of equilibria between gases and PM, we have developed a direct in vitro sampling and exposure method (DSEM) capable of PM-only exposures. We hypothesize that the separation of phases and post-treatment of filter-collected PM significantly modifies the toxicity of the PM compared to direct deposition, resulting in a distorted view of the potential PM health effects. Controlled test environments were created in a chamber that combined diesel exhaust with an urban-like mixture. The complex mixture was analyzed using both the DSEM and concurrently-collected filter samples. The DSEM showed that PM from test atmospheres produced significant inflammatory response, while the resuspension exposures at the same exposure concentration did not. Increasing the concentration of resuspended PM sixteen times was required to yield measurable IL-8 expression. Chemical analysis of the resuspended PM indicated a total absence of carbonyl compounds compared to the test atmosphere during the direct-exposures. Therefore, collection and resuspension of PM into liquid modifies its toxicity and likely leads to underestimating toxicity. PMID:22834915

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

    EPA Science Inventory

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

  16. Oxidative Stress, Inflammatory and Immune Response after Inhalation Exposure to Biodiesel Exhaust

    EPA Science Inventory

    Biodiesel (BD) is an advanced fuel produced from renewable domestic sources. The broad uses of BD in different industries including mining may lead to potential health effects. We hypothesized that the toxicity of biodiesel exhaust (BDE) is dependent at least on three major mecha...

  17. NEUROPHYSIOLOGICAL ALTERATIONS DUE TO DIESEL EXHAUST EXPOSURE DURING THE NEONATAL LIFE OF THE RAT

    EPA Science Inventory

    This study was designed to assess the effects of diesel exhaust on the development of the nervous system in rats as measurably somatosensory and visual evoked potentials (SEPs an VEPs, respectively). SEPs, elicited by 1 mamp, 0.5 msec pulses delivered to the tibial nerve at the t...

  18. INTERFERENCE OF ANIMAL SOURCE AMMONIA WITH EXPOSURE CHAMBER ATMOSPHERES CONTAINING ACID PARTICULATE FROM AUTOMOBILE EXHAUST

    EPA Science Inventory

    A study was designed to test the effect of animal source ammonia on some component concentrations in test atmospheres produced to measure the health effects of pollutants in the exhaust emissions of gasoline-powered engines equipped with oxidative catalyst converters. The dominan...

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

    PubMed

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

    1982-01-01

    The cytotoxicity of the dichloromethane extracts of diesel exhaust particles from passenger cars of different manufactures was studied in cultured chinese hamster ovary cells. While exhaust particles from diesel cars of the same make and model yielded extracts of similar cytotoxicity, those from cars of different manufactures yielded extracts with a 3-fold difference in cytotoxicity. Using data on the percentages of extractable organic chemicals and total exhaust particulate emission rates, the emission rate of cytotoxin into the environment from the different cars were calculated. Of the 3 factors that could affect the emission rate of cytotoxins (cytotoxicity of the extractable chemicals, amount of cytotoxins per particle, and particulate emission rate), the differences in particulate emission rates were found to be the predominant factors leading to the differences in the emission rate of cytotoxins. Our findings indicate the need to consider other chemical and physical data, not just the activities of the extracts, when the potential health risk due to the exhaust emissions of different automobiles are compared. PMID:6182643

  20. Controlled human exposures to ambient pollutant particles in susceptible populations

    PubMed Central

    2009-01-01

    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 susceptible subjects, including the elderly and patients with cardiopulmonary diseases. Controlled human exposure studies have been used to confirm the causal relationship between pollution particle exposure and adverse health effects. Earlier studies enrolled mostly young healthy subjects and have largely confirmed the capability of particles to cause adverse health effects shown in epidemiological studies. In the last few years, more studies involving susceptible populations have been published. These recent studies in susceptible populations, however, have shown that the adverse responses to particles appear diminished in these susceptible subjects compared to those in healthy subjects. The present paper reviewed and compared control human exposure studies to particles and sought to explain the "unexpected" response to particle exposure in these susceptible populations and make recommendations for future studies. We found that the causes for the discrepant results are likely multifactorial. Factors such as medications, the disease itself, genetic susceptibility, subject selection bias that is intrinsic to many controlled exposure studies and nonspecificity of study endpoints may explain part of the results. Future controlled exposure studies should select endpoints that are more closely related to the pathogenesis of the disease and reflect the severity of particle-induced health effects in the specific populations under investigation. Future studies should also attempt to control for medications and genetic susceptibility. Using a different study design, such as exposing subjects to filtered air and ambient levels of particles, and assessing the improvement in biological endpoints during filtered air exposure, may allow the inclusion of higher risk patients who are likely the main contributors to the increased particle-induced health effects in epidemiological studies. PMID:19630984

  1. 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...

  2. In utero and early life exposure to diesel exhaust air pollution increases adult susceptibility to heart failure in mice

    PubMed Central

    2013-01-01

    Background Fine particulate air pollution (PM2.5) is a global health concern, as exposure to PM2.5 has consistently been found to be associated with increased cardiovascular morbidity and mortality. Although adult exposure to traffic related PM2.5, which is largely derived from diesel exhaust (DE), has been associated with increased cardiac hypertrophy, there are limited investigations into the potential effect of in utero and early life exposure on adult susceptibility to heart disease. In this study, we investigate the effect of in utero and early life exposure to DE on adult susceptibility to heart failure. Methods Female C57BL/6 J mice were exposed to either filtered air (FA) or DE for 3 weeks (?300 ?g/m3 PM2.5 for 6 hours/day, 5 days/week) and then introduced to male breeders for timed matings. Female mice were exposed to either FA or DE throughout pregnancy and until offspring were 3 weeks of age. Offspring were then transferred to either FA or DE for an additional 8 weeks of exposure. At 12 weeks of age, male offspring underwent a baseline echocardiographic assessment, followed by a sham or transverse aortic constriction (TAC) surgery to induce pressure overload. Following sacrifice three weeks post surgery, ventricles were processed for histology to assess myocardial fibrosis and individual cardiomyocyte hypertrophy. mRNA from lung tissue was isolated to measure expression of inflammatory cytokines IL6 and TNF?. Results We observed that mice exposed to DE during in utero and early life development have significantly increased susceptibility to cardiac hypertrophy, systolic failure, myocardial fibrosis, and pulmonary congestion following TAC surgery compared to FA control, or adult DE exposed mice. In utero and early life DE exposure also strongly modified the inflammatory cytokine response in the adult lung. Conclusions We conclude that exposure to diesel exhaust air pollution during in utero and early life development in mice increases adult susceptibility to heart failure. The results of this study may imply that the effects of air pollution on cardiovascular disease in human populations may be strongly mediated through a ‘fetal origins’ of adult disease pathway. Further investigations on this potential pathway of disease are warranted. PMID:24279743

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

    SciTech Connect

    Bai Ni [Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC (Canada); James Hogg Research Centre, Providence Heart and Lung Institute, St. Paul's Hospital, University of British Columbia, Vancouver, BC (Canada); Kido, Takashi [James Hogg Research Centre, Providence Heart and Lung Institute, St. Paul's Hospital, University of British Columbia, Vancouver, BC (Canada); Kavanagh, Terrance J.; Kaufman, Joel D.; Rosenfeld, Michael E. [Department of Occupational and Environmental Health, University of Washington, Seattle, WA (United States); Breemen, Cornelis van [Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC (Canada); Eeden, Stephan F. van, E-mail: Stephan.vanEeden@hli.ubc.ca [James Hogg Research Centre, Providence Heart and Lung Institute, St. Paul's Hospital, University of British Columbia, Vancouver, BC (Canada)

    2011-09-01

    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 were 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 the blood vessels and heart. > DE exposure enhanced iNOS protein and mRNA expression in the aorta and heart. > iNOS activity was also increased after DE exposure. > This up-regulation of iNOS may contribute to vascular dysfunction and atherogenesis.

  4. Bioassay-directed fractionation and salmonella mutagenicity of automobile and forklift diesel exhaust particles.

    PubMed Central

    DeMarini, David M; Brooks, Lance R; Warren, Sarah H; Kobayashi, Takahiro; Gilmour, M Ian; Singh, Pramila

    2004-01-01

    Many pulmonary toxicity studies of diesel exhaust particles (DEPs) have used an automobile-generated sample (A-DEPs) whose mutagenicity has not been reported. In contrast, many mutagenicity studies of DEPs have used a forklift-generated sample (SRM 2975) that has been evaluated in only a few pulmonary toxicity studies. Therefore, we evaluated the mutagenicity of both DEPs in Salmonella coupled to a bioassay-directed fractionation. The percentage of extractable organic material (EOM) was 26.3% for A-DEPs and 2% for SRM 2975. Most of the A-EOM (~55%) eluted in the hexane fraction, reflecting the presence of alkanes and alkenes, typical of uncombusted fuel. In contrast, most of the SRM 2975 EOM (~58%) eluted in the polar methanol fraction, indicative of oxygenated and/or nitrated organics derived from combustion. Most of the direct-acting, base-substitution activity of the A-EOM eluted in the hexane/dichloromethane (DCM) fraction, but this activity eluted in the polar methanol fraction for the SRM 2975 EOM. The direct-acting frameshift mutagenicity eluted across fractions of A-EOM, whereas > 80% eluted only in the DCM fraction of SRM 2975 EOM. The A-DEPs were more mutagenic than SRM 2975 per mass of particle, having 227 times more polycyclic aromatic hydrocarbon-type and 8-45 more nitroarene-type mutagenic activity. These differences were associated with the different conditions under which the two DEP samples were generated and collected. A comprehensive understanding of the mechanisms responsible for the health effects of DEPs requires the evaluation of DEP standards for a variety of end points, and our results highlight the need for multidisciplinary studies on a variety of representative samples of DEPs. PMID:15175166

  5. An investigation into the effect of a ceramic particle trap on the chemical mutagens in diesel exhaust

    SciTech Connect

    Bagley, S.T.; Dorie, L.D.; Leddy, D.G.; Johnson, J.H. (Michigan Technological Univ., Houghton (USA))

    1987-01-01

    Diesel exhaust particles and vapor phase samples were collected from the diluted (15:1) exhaust of a 10.4 L displacement medium-duty engine (Caterpillar 3208), operated under EPA steady-state cycle Modes 4 and 5 conditions for load (50 and 75 percent, respectively) and speed (1680 rpm). Baseline (uncontrolled) emissions were compared to the exhaust modified by the use of an uncatalyzed monolithic ceramic trap (Corning). The Salmonella/microsome mutagenicity bioassay (Ames Test) was used to direct the course of chemical analyses. Total particulate matter (TPM), soluble organic fraction (SOF) (from TPM), sulfate fraction (SO4) (from TPM), and solid fraction (SOL) (from particle) were determined from dilute exhaust particles collected on 47 mm Teflon-coated woven glass fiber filters. Coincidentally, particles were collected on 508 x 508 mm Teflon-coated non-woven glass fiber filters, and vapor-phase samples were collected on XAD-2 resin. The SOF and VOC for chemical and biological characterization were obtained by Soxhlet extraction of samples with dichloromethane (DCM). Hydrocarbon mass balances were developed to evaluate the efficiency of the sampling system. Use of the ceramic traps caused no change in engine total hydrocarbon (HC) levels at Mode 4 but decreases in TPM, SOF, and NO2 were noted. In terms of HC emissions only, the percentage of SOF was significantly reduced, but the percentage of VOC was unchanged. For Mode 5, the engine HC levels were significantly reduced but the proportions of HC components, i.e. the percentage of SOF and the percentage of VOC, did not change significantly. Engine emission levels of TPM, SOF, and nitrogen dioxide were also significantly reduced at Mode 5. At both Modes 4 and 5, use of the ceramic particle traps caused an increase in the direct-acting (TA98) mutagenicity of the SOF and a decrease in the activity of the VOC.

  6. Dependence between nonvolatile nucleation mode particle and soot number concentrations in an EGR equipped heavy-duty Diesel engine exhaust.

    PubMed

    Lähde, Tero; Rönkkö, Topi; Virtanen, Annele; Solla, Anu; Kytö, Matti; Söderström, Christer; Keskinen, Jorma

    2010-04-15

    Heavy duty diesel engine exhaust characteristics were studied with direct tailpipe sampling on an engine dynamometer. The exhaust particle size distributions, total particle mass, and gaseous emissions were measured with different load conditions without after-treatment. The measured particle size distributions were bimodal; distinctive accumulation and nucleation modes were detected for both volatile and dry particle samples. The condensing volatile compounds changed the characteristics of the nonvolatile nucleation mode while the soot/accumulation mode characteristics (concentration and diameter) were unchanged. A clear dependence between the soot and the nonvolatile nucleation mode number concentrations was detected. While the concentration of the soot mode decreased, the nonvolatile nucleation mode concentration increased. The soot mode number concentration decrease was related to soot-NOx trade-off; the decrease of the exhaust gas recirculation rate decreased soot emission and increased NOx emission. Simultaneously detected increase of the nonvolatile nucleation mode concentration may be caused by the decrease of the soot mode sink or by changed combustion characteristics. However, the total particle number concentration increased with decreasing soot mode number concentration. The proportion of the particle number concentration between the nonvolatile nucleation and soot mode followed the NO2:NO ratio linearly. While ratio NO2:NO increased the proportion of soot mode number concentration in total number concentration increased. Regardless of the mechanism that causes the balance between the soot mode and the nonvolatile nucleation mode emissions, the changes in the particle number size distribution should be taken into account while the particle mass emissions are controlled with combustion optimization. PMID:20199020

  7. EXPOSURE TO CONCENTRATED AMBIENT PARTICLES (CAPS): REVIEW

    EPA Science Inventory

    Epidemiologic studies support a participation of fine particulate matter (PM) with a diameter of 0.1 to 2.5 microm in the effects of air pollution particles on human health. The ambient fine particle concentrator is a recently developed technology that can enrich the mass of ambi...

  8. Effects of Diesel Exhaust Particles on Left Ventricular Function in Isoproterenol-Induced Myocardial Injury and Healthy Rats

    Microsoft Academic Search

    Yuan-Horng Yan; Chien-Hua Huang; Wen-Jone Chen; Ming-Fang Wu; Tsun-Jen Cheng

    2008-01-01

    The associations between ambient particulate matter with an aerodiameter less than 2.5 µm (PM2.5) and congestive heart failure (CHF) have been reported. However, the underlying mech- anisms remain unclear. We investigated the effect of diesel exhaust particles (DEPs) on left ventricular function in isoproterenol (ISO)-induced myocardial injury and healthy rats. Male Sprague-Dawley (SD) rats were injected with ISO or normal

  9. In situ observations of particles in jet aircraft exhausts and contrails for different sulfur-containing fuels

    Microsoft Academic Search

    U. Schumann; J. Ström; R. Busen; R. Baumann; K. Gierens; M. Krautstrunk; F. P. Schröder; J. Stingl

    1996-01-01

    The impact of sulfur oxides on particle formation and contrails is investigated in the exhaust plumes of a twin-engine jet aircraft. Different fuels were used with sulfur mass fractions of 170 and 5500 ppm in the fuel, one lower than average, the other above the specification limit of standard Jet-A1 fuel. During various phases of the same flight, the two

  10. 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.

  11. A comparison of sampling and analytical methods for assessing occupational exposure to diesel exhaust in a railroad work environment

    SciTech Connect

    Verma, D.K.; Shaw, L.; Julian, J.; Smolynec, K.; Wood, C.; Shaw, D.

    1999-10-01

    Methods of assessing occupational exposure to diesel exhaust were evaluated in a railroad work environment. The American Conference of Governmental Industrial Hygienists (ACGIH{reg_sign})-recommended elemental carbon and respirable combustible dust methods of sampling and analysis for assessing diesel exhaust were included in the study. A total of 215 personal and area samples were collected using both size-selective and non-size-selective samplers. The results demonstrate that the elemental carbon method is suitable for the railroad environment and the respirable combustible dust method is not. All elemental carbon concentrations measured were below the proposed ACG1H Threshold Limit Value (TLV{reg_sign}) of 0.15 mg/m{sup 3}. The concentrations of oxides of nitrogen (nitric oxide and nitrogen dioxide) were also found to be below their respective TLVs. There is no correlation between elemental carbon or respirable combustible dust and the oxides of nitrogen. The elemental carbon as fraction of total carbon is about 13%, except for onboard locomotives where it is about 24%. Comparison of elemental carbon and respirable combustible dust measurements showed consistent relationships for most sampling locations with respirable combustible dust concentrations 12 to 53 times higher than the elemental carbon levels.

  12. Shielding from solar particle event exposures in deep space

    Microsoft Academic Search

    John W Wilson; F. A Cucinotta; J. L Shinn; L. C Simonsen; R. R Dubey; W. R Jordan; T. D Jones; C. K Chang; M. Y Kim

    1999-01-01

    The physical composition and intensities of solar particle event exposures of sensitive astronaut tissues are examined under conditions approximating an astronaut in deep space. Response functions for conversion of particle fluence into dose and dose equivalent averaged over organ tissues are used to establish significant fluence levels and the expected dose and dose rates of the most important events from

  13. Personal exposure to JP-8 jet fuel vapors and exhaust at air force bases.

    PubMed

    Pleil, J D; Smith, L B; Zelnick, S D

    2000-03-01

    JP-8 jet fuel (similar to commercial/international jet A-1 fuel) is the standard military fuel for all types of vehicles, including the U.S. Air Force aircraft inventory. As such, JP-8 presents the most common chemical exposure in the Air Force, particularly for flight and ground crew personnel during preflight operations and for maintenance personnel performing routine tasks. Personal exposure at an Air Force base occurs through occupational exposure for personnel involved with fuel and aircraft handling and/or through incidental exposure, primarily through inhalation of ambient fuel vapors. Because JP-8 is less volatile than its predecessor fuel (JP-4), contact with liquid fuel on skin and clothing may result in prolonged exposure. The slowly evaporating JP-8 fuel tends to linger on exposed personnel during their interaction with their previously unexposed colleagues. To begin to assess the relative exposures, we made ambient air measurements and used recently developed methods for collecting exhaled breath in special containers. We then analyzed for certain volatile marker compounds for JP-8, as well as for some aromatic hydrocarbons (especially benzene) that are related to long-term health risks. Ambient samples were collected by using compact, battery-operated, personal whole-air samplers that have recently been developed as commercial products; breath samples were collected using our single-breath canister method that uses 1-L canisters fitted with valves and small disposable breathing tubes. We collected breath samples from various groups of Air Force personnel and found a demonstrable JP-8 exposure for all subjects, ranging from slight elevations as compared to a control cohort to > 100 [mutilpe] the control values. This work suggests that further studies should be performed on specific issues to obtain pertinent exposure data. The data can be applied to assessments of health outcomes and to recommendations for changes in the use of personal protective equipment that optimize risk reduction without undue impact on a mission. PMID:10706522

  14. Sorptive behavior of nitro-PAHs in street runoff and their potential as indicators of diesel vehicle exhaust particles.

    PubMed

    Murakami, Michio; Yamada, Junya; Kumata, Hidetoshi; Takada, Hideshige

    2008-02-15

    This is the first report to reveal the particle-water distribution of nitropolycyclic aromatic hydrocarbons (NPAHs) and to discuss their potential risks and utility as indicators of diesel vehicle exhaust particles (DEP). Time-series samples of runoff were collected from a highway, and NPAHs and polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatography-mass spectrometry (GC-MS) to study their dynamic behavior. The concentrations of total NPAHs ranged from 11 to 73 ng/L in particulate phase (>0.7 mcirom) and from 2.3 to 4.9 ng/L in dissolved phase (<0.7 microm). Like their PAH analogs, most (81-97%) NPAHs were associated with particulate matter. The organic carbon-normalized in situ partition coefficients (Koc') of NPAHs observed in runoff events (10(5.8-6.3) for 2-nitrofluoranthene and 10(5.8-6.2) for 1-nitropyrene [1-NP]) were more than 1 order of magnitude higher than those expected from their Kow, indicating great affinity for particulate matter such as soot. Concentrations of PAHs and NPAHs adjusted by potency equivalency factors and induction equivalency factors showed that the potential risks of NPAHs were smaller than those of PAHs by a factor of more than a hundred for the particulate phase and morethan fourforthe dissolved phase. Comparison of concentrations and compositions of NPAHs and PAHs among runoff, DEP, gasoline vehicle exhaust particles, boiler exhaust particles, and aerosols suggested that the ratio of 1-NP to total PAHs (1-NP/PAH) is a useful indicator of DEP for source apportionment of PAHs among traffic-related sources. Source-apportionment of PAHs in the runoff by 1-NP/PAH and methylphenanthrene/phenanthrene ratios suggested that most PAHs in the runoff except the second flush peak were derived from DEP but that other pyrogenic sources contributed to the particles at the second flush and thus to the overall runoff particles. PMID:18351085

  15. Ultrafine particles: exposure and source apportionment in 56 Danish homes.

    PubMed

    Bekö, Gabriel; Weschler, Charles J; Wierzbicka, Aneta; Karottki, Dorina Gabriela; Toftum, Jørn; Loft, Steffen; Clausen, Geo

    2013-09-17

    Particle number (PN) concentrations (10-300 nm in size) were continuously measured over a period of ~45 h in 56 residences of nonsmokers in Copenhagen, Denmark. The highest concentrations were measured when occupants were present and awake (geometric mean, GM: 22.3 × 10(3) cm(-3)), the lowest when the homes were vacant (GM: 6.1 × 10(3) cm(-3)) or the occupants were asleep (GM: 5.1 × 10(3) cm(-3)). Diary entries regarding occupancy and particle related activities were used to identify source events and apportion the daily integrated exposure among sources. Source events clearly resulted in increased PN concentrations and decreased average particle diameter. For a given event, elevated particle concentrations persisted for several hours after the emission of fresh particles ceased. The residential daily integrated PN exposure in the 56 homes ranged between 37 × 10(3) and 6.0 × 10(6) particles per cm(3)·h/day (GM: 3.3 × 10(5) cm(-3)·h/day). On average, ~90% of this exposure occurred outside of the period from midnight to 6 a.m. Source events, especially candle burning, cooking, toasting, and unknown activities, were responsible on average for ~65% of the residential integrated exposure (51% without the unknown activities). Candle burning occurred in half of the homes where, on average, it was responsible for almost 60% of the integrated exposure. PMID:23957328

  16. 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...

  17. Effects of ultrafine petrol exhaust particles on cytotoxicity, oxidative stress generation, DNA damage and inflammation in human A549 lung cells and murine RAW 264.7 macrophages.

    PubMed

    Durga, Mohan; Nathiya, Soundararajan; Rajasekar, Abbu; Devasena, Thiyagarajan

    2014-09-01

    Air pollution has persistently been the major cause of respiratory-related illness and death. Environmental pollutants such as diesel and petrol exhaust particles (PEPs) are the major contributors to urban air pollution. The aim of the present study was to characterize and investigate the in vitro cytotoxicity, oxidative stress, DNA damage and inflammation induced by PEPs. Cultured type II epithelium cells (human A549 lung cells) and alveolar macrophages (murine RAW 264.7 cells) were exposed to control, vehicle control and to different concentrations of PEPs for up to 24h. Each treatment was evaluated by cell viability, cytotoxicity, oxidative stress, DNA damage and inflammatory parameters. Overall in vitro studies demonstrated that both cell lines showed similar patterns in response to the above studies induced by petrol exhaust nanoparticles (PENPs). Vehicle control showed no changes compared with the control. In both cell lines, significant changes at the dose of 20 and 50?g/mL (A549 cell lines) and 10and 20?g/mL (macrophages) for PENPs were found. The reactive oxygen species production in both cell lines shot up in minutes, reached the maximum within an hour and came down after 4h. Hence, exposure to PENPs resulted in dose-dependent toxicity in cultured A549 cells and RAW 264.7 cells and was closely correlated to increased oxidative stress, DNA damage and inflammation. PMID:25173103

  18. PERSONAL EXPOSURE TO JP-8 JET FUEL VAPORS AND EXHAUST AT AIR FORCE BASES

    EPA Science Inventory

    JP-8 jet fuel (similar to commercial/international jet A-1 fuel) is the standard military fuel for all types of vehicles, including the U.S. Air Force aircraft inventory. As such, JP-8 presents the most common chemical exposure in the Air Force, particularly for flight and gro...

  19. Diesel exhaust exposure enhances venoconstriction via uncoupling of eNOS

    Microsoft Academic Search

    Travis L. Knuckles; Amie K. Lund; Selita N. Lucas; Matthew J. Campen

    2008-01-01

    Environmental air pollution is associated with adverse cardiovascular events, including increased hospital admissions due to heart failure and myocardial infarction. The exact mechanism(s) by which air pollution affects the heart and vasculature is currently unknown. Recent studies have found that exposure to air pollution enhances arterial vasoconstriction in humans and animal models. Work in our laboratory has shown that diesel

  20. Effects of combinations of diesel exhaust and ozone exposure on lung function in human volunteers.

    EPA Science Inventory

    Ozone (03) exposure induces changes in human lung function, typically seen as a decrease in forced expiratory volume in one sec (FEV1) and forced vital capacity (FVC). Because people are usually exposed to other ambient air pollutants simultaneously with 03, there may be interact...

  1. The Effect of In Utero Diesel Exhaust (DE) Exposure on Development of Allergic Inflammation in Offspring

    EPA Science Inventory

    Recent studies have shown that pre-term birth weights and the incidence of asthma are increased in children born from mothers who live close to heavily trafficked roads and highways. In this study we examined the effect of inhalation DE exposure by pregnant mice on the subsequen...

  2. Circulating factors induce coronary endothelial cell activation following exposure to inhaled diesel exhaust and nitrogen dioxide in humans: Evidence from a novel translational in vitro model**

    EPA Science Inventory

    The vascular toxicity of inhaled agents may be caused by soluble factors that are released into the systemic circulation. To confirm this in a straightforward manner, we obtained plasma from healthy human volunteers before and after exposure to diesel exhaust (DE) and nitrogen di...

  3. One versus five-days of exposure to varying concentrations of B100 soya biodiesel exhaust reveals a threshold concentration for increased sensitivity to aconitine-induced arrhythmia

    EPA Science Inventory

    Although biodiesel (BD) is rapidly being considered as an alternative to diesel fuel, its health effects have not been thoroughly characterized. We previously used the aconitine challenge test to demonstrate that a single exposure to petroleum diesel exhaust (DE) increases the ri...

  4. Xenobiotic Particle Exposure and Microvascular Endpoints: A Call to Arms

    PubMed Central

    Stapleton, Phoebe A.; Minarchick, Valerie C.; McCawley, Michael; Knuckles, Travis L.; Nurkiewicz, Timothy R.

    2011-01-01

    Xenobiotic particles can be considered in two genres: air pollution particulate matter and engineered nanoparticles. Particle exposures can occur in the greater environment, the workplace, and our homes. The majority of research in this field has, justifiably, focused on pulmonary reactions and outcomes. More recent investigations indicate that cardiovascular effects are capable of correlating with established mortality and morbidity epidemiological data following particle exposures. While the preliminary and general cardiovascular toxicology has been defined, the mechanisms behind these effects, specifically within the microcirculation, are largely unexplored. Therefore, the purpose of this review is several fold: first, a historical background on toxicological aspects of particle research is presented. Second, essential definitions, terminology, and techniques that may be unfamiliar to the microvascular scientist will be discussed. Third, the most current concepts and hypotheses driving cardiovascular research in this field will be reviewed. Lastly, potential future directions for the microvascular scientist will be suggested. Collectively speaking, microvascular research in the particle exposure field represents far more than a “niche”. The immediate demand for basic, translational, and clinical studies is high and diverse. Microvascular scientists at all career stages are strongly encouraged to expand their research interests to include investigations associated with particle exposures. PMID:21951337

  5. Modeling particle exposure in U.S. trucking terminals.

    PubMed

    Davis, M E; Smith, T J; Laden, F; Hart, J E; Ryan, L M; Garshick, E

    2006-07-01

    Multi-tiered sampling approaches are common in environmental and occupational exposure assessment, where exposures for a given individual are often modeled based on simultaneous measurements taken at multiple indoor and outdoor sites. The monitoring data from such studies is hierarchical by design, imposing a complex covariance structure that must be accounted for in order to obtain unbiased estimates of exposure. Statistical methods such as structural equation modeling (SEM) represent a useful alternative to simple linear regression in these cases, providing simultaneous and unbiased predictions of each level of exposure based on a set of covariates specific to the exposure setting. We test the SEM approach using data from a large exposure assessment of diesel and combustion particles in the U.S.trucking industry. The exposure assessment includes data from 36 different trucking terminals across the United States sampled between 2001 and 2005, measuring PM2.5 and its elemental carbon (EC), organic carbon (OC) components, by personal monitoring, and sampling at two indoor work locations and an outdoor "background" location. Using the SEM method, we predict the following: (1) personal exposures as a function of work-related exposure and smoking status; (2) work-related exposure as a function of terminal characteristics, indoor ventilation, job location, and background exposure conditions; and (3) background exposure conditions as a function of weather, nearby source pollution, and other regional differences across terminal sites. The primary advantage of SEMs in this setting is the ability to simultaneously predict exposures at each of the sampling locations, while accounting for the complex covariance structure among the measurements and descriptive variables. The statistically significant results and high R2 values observed from the trucking industry application supports the broader use of this approach in exposure assessment modeling. PMID:16856739

  6. 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...

  7. 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).

  8. Comparative mutagenic dose of ambient diesel engine exhaust.

    PubMed

    Valberg, P A; Watson, A Y

    1999-03-01

    Diesel engine exhaust contains carbon-based particles that can be inhaled and deposited on lung surfaces. Concern about the carcinogenic potential of diesel engine exhaust derives in part from the mutagenic activity of organics that can be extracted from exhaust particles. However, the lung cancer risk is controversial, and diesel exhaust is a candidate for further evaluation. A comparative potency approach can be used to rank the mutagenic risk of diesel exhaust with other combustion products. We compared the specific mutagenic activities of cigarette smoke condensate (CSC) and diesel exhaust particle extract (DEPE) and estimated "mutagenic dose" to the lungs. Although the specific mutagenic activities of CSC and DEPE are similar in magnitude, it is the dose reaching the lungs that is more relevant for comparing mutagenic potential. We calculated that, depending on the source of CSC and DEPE, a person would have to inhale approximately 63 to 181 mg of particulate from diesel engine exhaust to match the mutagenic dose of 1 cigarette. We also calculated that a person would have to breathe diesel exhaust (1.5 microg/m(3), estimated total personal exposure) for 6 to 16 yr to equal the mutagenic dose of 1 cigarette. Although instructive, comparative potency results should be used cautiously due to the need for simplifying assumptions. For example, the type of mutagenic assay and the source of cigarettes and diesel engine exhaust could affect dose estimates to some degree; however, the extent to which diesel particle mutagens are bioavailable would have an even greater effect on estimates of relative risk. For both cigarette smoke and diesel exhaust particles, we assumed that the organic mutagens are 100% bioavailable. In summary, our analysis showed a larger mutagenic dose-to-target-tissues in the smoke of one cigarette as compared to a year of exposure to diesel exhaust particulate at ambient levels. PMID:10380167

  9. DESIGN AND CHARACTERIZATION OF AN ISOKINETIC SAMPLING TRAIN FOR PARTICLE SIZE MEASUREMENTS USING EXHAUST GAS RECIRCULATION

    EPA Science Inventory

    A particulate sampling train has been constructed which satisfies the conflicting requirements of isokinetic sample extraction and constant flowrate through an inertial sizing device. Its design allows a variable fraction of the filtered exhaust gas to be added to the sample upst...

  10. REDUCING DIESEL NOX AND SOOT EMISSIONS VIA PARTICLE-FREE EXHAUST GAS RECIRCULATION - PHASE I

    EPA Science Inventory

    Diesel engines play an important role in the United States economy for power generation and transportation. However, NOx and soot emissions from both stationary and mobile diesel engines are a major contributor to air pollution. Many engine modifications and exhaust-after-t...

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

    EPA Science Inventory

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

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

    EPA Science Inventory

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

  13. Effects of exposure to nanoparticle-rich diesel exhaust on 8-OHdG synthesis in the mouse asthmatic lung

    PubMed Central

    TANAKA, MICHITAKA; TAKANO, HIROHISA; FUJITANI, YUJI; HIRANO, SEISHIRO; ICHINOSE, TAKAMICHI; SHIMADA, AKINORI; INOUE, KEN-ICHIRO

    2013-01-01

    It has been demonstrated that exposure to diesel exhaust (DE) is associated with the induction and exacerbation of respiratory disorders; however, the impacts of DE containing mainly nanoparticles have been less studied. We have previously demonstrated that inhalation exposure to nanoparticle-rich DE (NR-DE) exacerbated allergic pulmonary inflammation, in the context of enhanced local expression of proinflammatory molecules. However, the underlying mechanisms have not been fully elucidated. 8-Hydroxydeoxyguanosine (8-OHdG) is a marker of oxidative damage, particularly in DNA. This study examined the effects of NR-DE on 8-OHdG synthesis in the lung in the presence or absence of an allergen. Institute for Cancer Research (ICR) mice were exposed by inhalation to four different gas compositions (control air, low-concentration DE, high-concentration DE and high-concentration DE without particulate matter) for 8 weeks, in the presence or absence of repetitive intratracheal administration of ovalbumin (OVA). Thereafter, we assessed the levels of 8-OHdG synthesis and expression in the lungs by means of enzyme immunoassay (EIA) and immunohistochemistry. The EIA revealed that the level of 8-OHdG was significantly higher in the high-concentration NR-DE-exposed and allergen-sensitized/stimulated group compared with that in the control air-exposed and allergen-treated group. The immunohistochemistry results demonstrated that the level of immunoreactive 8-OHdG was higher in the NR-DE-exposed and allergen-treated lungs compared with that in the corresponding control air-exposed lungs. The results suggested that NR-DE exposure enhanced 8-OHdG formation in asthmatic lungs. This, at least in part, is involved in the NR-DE-mediated exacerbation of the allergic pathophysiology that was identified in our previous study. PMID:24137251

  14. Exhaust gas purifying device

    SciTech Connect

    Haneda, Y.; Hiraoka, S.; Sakuraya, Y.

    1980-08-19

    An exhaust gas purifying device is disclosed for removing harmful solid particles, sparks and flames contained in exhaust gas discharged from an internal combustion engine. The devices consists of a cylindrical body member connected to a muffler in an exhaust gas system of the engine. The cylindrical body member is separated into front and rear chambers by an intermediate partition plate. The front chamber includes an exhaust gas introducing hole in a front wall thereof and displaced with respect to a communicating hole formed in the central portion of the partition plate to thereby effectively remove the harmful particles at low flow rate of the exhaust gas. The rear chamber includes a swirl-generating means on the upstream side thereof and a solid particle collecting chamber on the outer periphery thereof to thereby remove the harmful particles at high flow rates of the exhaust gas.

  15. Diesel exhaust exposure enhances venoconstriction via uncoupling of eNOS

    SciTech Connect

    Knuckles, Travis L.; Lund, Amie K.; Lucas, Selita N. [Toxicology Division, Lovelace Respiratory Research Institute, Albuquerque, NM (United States); Campen, Matthew J. [Toxicology Division, Lovelace Respiratory Research Institute, Albuquerque, NM (United States)], E-mail: mcampen@lrri.org

    2008-08-01

    Environmental air pollution is associated with adverse cardiovascular events, including increased hospital admissions due to heart failure and myocardial infarction. The exact mechanism(s) by which air pollution affects the heart and vasculature is currently unknown. Recent studies have found that exposure to air pollution enhances arterial vasoconstriction in humans and animal models. Work in our laboratory has shown that diesel emissions (DE) enhance vasoconstriction of mouse coronary arteries. Thus, we hypothesized that DE could enhance vasoconstriction in arteries and veins through uncoupling of endothelial nitric oxide synthase (eNOS). To test this hypothesis, we first bubbled DE through a physiological saline solution and exposed isolated mesenteric veins. Second, we exposed animals, whole body, to DE at 350 {mu}g/m{sup 3} for 4 h, after which mesenteric arteries and veins were isolated. Results from these experiments show that saline bubbled with DE as well as inhaled DE enhances vasoconstriction in veins but not arteries. Exposure to several representative volatile organic compounds found in the DE-exposed saline did not enhance arterial constriction. L-nitro-arginine-methyl-ester (L-NAME), an eNOS inhibitor, normalized the control vessels to the DE-exposed vessels implicating an uncoupling of eNOS as a mechanism for enhanced vasoconstriction. The principal conclusions of this research are 1) veins exhibit endothelial dysfunction following in vivo and ex vivo exposures to DE, 2) veins appear to be more sensitive to DE effects than arteries, and 3) DE components most likely induce endothelial dysfunction through the uncoupling of eNOS.

  16. 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 not detectable. PMID:16265462

  17. ROS scavenging effects of organic extract of diesel exhaust particles on human neutrophil granulocytes and rat alveolar macrophages.

    PubMed

    Aam, Berit Bjugan; Fonnum, F

    2007-02-12

    Diesel exhaust particles are major constituents of ambient air pollution, and are associated with respiratory and cardiovascular diseases and lung cancer. The organic part of the particles is heterogenic and complex, and seems to be responsible for many of the adverse effects. Increased formation of ROS is often connected to the adverse effects. We have therefore investigated the effect of an organic extract of diesel exhaust particles on the reactive oxygen species (ROS) status in human neutrophil granulocytes and rat alveolar macrophages in vitro. ROS formation were studied by three different assays namely the use of DCFH-DA, lucigenin and luminol. The organic extract increased ROS assayed with DCFH-DA, but it decreased the amount of ROS in cells stimulated by PMA in all three assays. The identities of the ROS affected were further studied in cell free systems. The cell free studies confirmed that the extract had scavenging effects against superoxide, hypochlorite and to a smaller extent against peroxynitrite, but not against the hydroxyl radical and nitric oxide. ROS take part in the intracellular signalling pathways as well as in the defence against invading microorganisms, and the possible effects of interference of the redox status in the cells are discussed. PMID:17175087

  18. 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...

  19. 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...

  20. Personal Exposure to Fine Particles in Children Correlates Closely with Ambient Fine Particles

    Microsoft Academic Search

    Nicole A. H. Janssen; Gerard Hoek; Hendrik Harssema; Bert Brunekreef

    1999-01-01

    To investigate the validity of ambient fine-particle concentrations as a measure of exposure in epidemiological time-series studies, we established the association between personal and ambient concentrations, within subjects, over time. We conducted repeated measurements of personal and ambient fine-particle concentrations in 13 children who lived in Wageningen, The Netherlands. For each child separately, we related personal exposures to ambient concentrations

  1. EXACERBATION OF ATHEROSCLEROSIS FOLLOWING EXPOSURE TO VARIOUS COMBUSTION SOURCE PARTICLES

    EPA Science Inventory

    Exposure of ApoE knockout (ApoE-/-) mice to concentrated ambient particles (CAPs) has been shown to increase arterial plaque area and size. CAPs are a complex aerosol mixture consisting of wind-blown dust, emissions from the combustion of fossil fuels, and secondary tr...

  2. CARDIOVASCULAR RESPONSES TO ULTRAFINE CARBON PARTICLE EXPOSURES IN RATS

    EPA Science Inventory

    TD-02-042 (U. KODAVANTI) GPRA # 10108 Cardiovascular Responses to Ultrafine Carbon Particle Exposures in Rats. V. Harder1, B. Lentner1, A. Ziesenis1, E. Karg1, L. Ruprecht1, U. Kodavanti2, A. Stampfl3, J. Heyder1, H. Schulz1 GSF- Institute for Inhalation Biology1, I...

  3. The occurrence of polycyclic aromatic hydrocarbons and their derivatives and the proinflammatory potential of fractionated extracts of diesel exhaust and wood smoke particles.

    PubMed

    Totlandsdal, Annike I; Øvrevik, Johan; Cochran, Richard E; Herseth, Jan-Inge; Bølling, Anette Kocbach; Låg, Marit; Schwarze, Per; Lilleaas, Edel; Holme, Jørn A; Kubátová, Alena

    2014-01-01

    Exposure to combustion emissions, including diesel engine exhaust and wood smoke particles (DEPs and WSPs), has been associated with inflammatory responses. To investigate the possible role of polycyclic aromatic hydrocarbons (PAHs) and PAH-derivatives, the DEPs and WSPs methanol extracts were fractionated by solid phase extraction (SPE), and the fractions were analyzed for more than ?120 compounds. The pro-inflammatory effects of the fractionated extracts were characterized by exposure of bronchial epithelial lung cells (BEAS-2B). Both native DEPs and WSPs caused a concentration-dependent increase in IL-6 and IL-8 release and cytotoxicity. This is consistent with the finding of a rather similar total content of PAHs and PAH-derivatives. Yet, the samples differed in specific components, suggesting that different species contribute to the toxicological response in these two types of particles. The majority of the IL-6 release and cytotoxicity was induced upon exposure to the most polar (methanol) SPE fraction of extracts from both samples. In these fractions hydroxy-PAHs, carboxy-PAHs were observed along with nitro-amino-PAHs in DEP. However, the biological effects induced by the polar fractions could not be attributed only to the occurrence of PAH-derivatives. The present findings indicate a need for further characterization of organic extracts, beyond an extensive analysis of commonly suspected PAH and PAH-derivatives. Supplemental materials are available for this article. Go to the publisher's online edition of Journal of Environmental Science and Health, Part A, to view the supplemental file. PMID:24345236

  4. 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 at fixed sites. This study also suggests that particle-associated 1-NP much better reflects the ambient exposure to diesel exhaust particles than dust concentrations. Therefore, measurement of particle-associated 1-NP is preferred over measurement of dust concentrations by gravimetry, when linking ambient exposure to biomonitoring outcomes such as protein and DNA adducts and excretion of urinary metabolites of genotoxic substances. PMID:12855488

  5. 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

    2012-06-01

    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 mutagenic effects most effectively in the gas phase. Mutagenicity of particle extracts was less efficiently diminished. No significant differences of mutagenic effects were observed among the tested fuels. In conclusion, the benefits of the DOC concern regulated emissions except NO(X) as well as nonregulated emissions such as the mutagenicity of the exhaust. The reduction of mutagenicity was particularly observed in the condensates of the gas phase. This is probably due to better accessibility of gaseous mutagenic compounds during the passage of the DOC in contrast to the particle-bound mutagens. Concerning the particulate emissions DOC especially decreased ultrafine particles. PMID:22587467

  6. The role of exhaust ventilation systems in reducing occupational exposure to organic solvents in a paint manufacturing factory

    PubMed Central

    Jafari, Mohammad Javad; Karimi, Ali; Azari, Mansoor Rezazadeh

    2008-01-01

    This paper presents the successful design and implementation of several exhaust ventilation systems in a paint manufacturing factory. The ventilation systems were designed based on American Conference of Governmental Industrial Hygienists recommendations. The duct works, fans, and other parts were made and mounted by local manufacturers. The concentrations of toluene and xylene as the common solvents used in paint mixing factories were measured to evaluate the role of ventilation systems in controlling the organic solvents. Occupational exposure to toluene and xylene as the major pollutants was assessed with and without applying ventilation systems. For this purpose, samples were taken from breathing zone of exposed workers using personal samples. The samples were analyzed using Occupational Safety and Health Administration analytical method No.12. The samples were quantified using gas chromatography. The results showed that the ventilation systems successfully controlled toluene and xylene vapors in workplace, air well below the recommended threshold limit value of Iran (44.49 and 97.73 ppm, respectively). It was also discovered that benzene concentration in workplace air was higher than its allowable concentrations. This could be from solvents impurities that require more investigations. PMID:20040984

  7. The role of exhaust ventilation systems in reducing occupational exposure to organic solvents in a paint manufacturing factory.

    PubMed

    Jafari, Mohammad Javad; Karimi, Ali; Azari, Mansoor Rezazadeh

    2008-08-01

    This paper presents the successful design and implementation of several exhaust ventilation systems in a paint manufacturing factory. The ventilation systems were designed based on American Conference of Governmental Industrial Hygienists recommendations. The duct works, fans, and other parts were made and mounted by local manufacturers. The concentrations of toluene and xylene as the common solvents used in paint mixing factories were measured to evaluate the role of ventilation systems in controlling the organic solvents. Occupational exposure to toluene and xylene as the major pollutants was assessed with and without applying ventilation systems. For this purpose, samples were taken from breathing zone of exposed workers using personal samples. The samples were analyzed using Occupational Safety and Health Administration analytical method No.12. The samples were quantified using gas chromatography. The results showed that the ventilation systems successfully controlled toluene and xylene vapors in workplace, air well below the recommended threshold limit value of Iran (44.49 and 97.73 ppm, respectively). It was also discovered that benzene concentration in workplace air was higher than its allowable concentrations. This could be from solvents impurities that require more investigations. PMID:20040984

  8. 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

  9. DIESEL PARTICLE GENERATION, CHARACTERIZATION, AND DIRECT ANIMAL EXPOSURE STUDIES

    EPA Science Inventory

    Inhalation of diesel exhaust is associated with the development of asthma as well as other adverse health effects. Studies have also demonstrated that diesel exhaust induces pulmonary changes that worsen asthmatic responses to respiratory allergens. This paper describes the des...

  10. 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.

  11. Recovery from changes in the blood and nasal cavity and/or lungs of rats caused by exposure to methanol-fueled engine exhaust

    SciTech Connect

    Maejima, K.; Suzuki, T.; Numata, H.; Maekawa, A.; Nagase, S.; Ishinishi, N. (Japan Automobile Research Institute, Inc., Ibaraki (Japan))

    1993-07-01

    One group of male, pathogen-free, Fischer 344 rats was exposed to about 17-fold diluted exhaust generated by an M85 methanol-fueled engine (methanol with 15% gasoline) without catalyst for 8 h, and then the rates of recovery from the resulting increased levels of plasma formaldehyde and carboxyhemoglobin in their erythrocytes were measured. The carboxyhemoglobin level in the erythrocytes was restored within 4 h, whereas the plasma formaldehyde level was still elevated after 4 h but was restored to the normal level within 8 h. No methanol or formic acid was detected in the plasma. Another group of rats was exposed to the same dilution of exhaust for 8 h/d for 7 d, and then the recovery from histopathological damage of the nasal cavity and lungs was also examined. Hyperplasia/squamous metaplasia and erosion of the respiratory epithelium lining the nasoturbinate, maxilloturbinate, or nasal septum, and infiltration of neutrophils into the submucosa at level 1 (level of the posterior edge of the upper incisor teeth) were observed immediately after the exposure period. Lesions of the respiratory epithelium at level 2 (incisive papilla) were less than those at level 1. Slight lesions at levels 1 or 2 were still noticed 1 wk after exposure, but not 4 wk after exposure. Just after exposure, decreases of Clara cells in the terminal bronchiolus and of cilia in the bronchial/bronchiolar epithelium were also observed. Moreover, focal hypertrophy of alveolar walls and increase of macrophages were observed in parts adjacent to respiratory bronchiolus. One week after the exposure period, these changes were no longer seen. These results indicate that changes in the blood and in the nasal cavity and lungs caused by methanol-fueled engine exhaust are reversible. However, complete recovery from damage of the nasal cavity caused by 7-d exposure takes 4 wk, and recovery from elevated plasma formaldehyde and erythrocyte carboxyhemoglobin levels caused by a single 8-h exposure takes 4-8 h.

  12. 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

  13. Prediction of the Size of Aluminum-Oxide Particles in Exhaust Plumes of Solid Rocket Motors

    Microsoft Academic Search

    O. B. Kovalev

    2002-01-01

    The processes of coagulation and aerodynamic fragmentation of liquid particles of aluminum oxide in an accelerating gas flow in the Laval nozzle are analyzed. A formula obtained by an approximate analytical solution of equations of a two-phase flow is proposed to calculate the characteristic particle diameter at the nozzle exit. The limiting particle diameter in the nozzle throat calculated theoretically

  14. Differential Responses upon Inhalation Exposure to Biodiesel versus Diesel Exhaust on Oxidative Stress, Inflammatory and Immune Outcomes

    EPA Science Inventory

    Biodiesel (BD) exhaust may have reduced adverse health effects due to lower mass emissions and reduced production of hazardous compounds compared to diesel exhaust. To investigate this possibility, we compared adverse effects in lungs and liver of BALB/cJ mice after inhalation ex...

  15. Part 4. Assessment of plasma markers and cardiovascular responses in rats after chronic exposure to new-technology diesel exhaust in the ACES bioassay.

    PubMed

    Conklin, Daniel J; Kong, Maiying

    2015-01-01

    Although epidemiologic and experimental studies suggest that chronic exposure to diesel exhaust (DE*) emissions causes adverse cardiovascular effects, neither the specific components of DE nor the mechanisms by which DE exposure could induce cardiovascular dysfunction and exacerbate cardiovascular disease (CVD) are known. Because advances in new technologies have resulted in cleaner fuels and decreased engine emissions, uncertainty about the relationship between DE exposure and human cardiovascular health effects has increased. To address this ever-changing baseline of DE emissions, as part of the larger Advanced Collaborative Emissions Study (ACES) bioassay studying the health effects of 2007-compliant diesel engine emissions (new-technology diesel exhaust), we examined whether plasma markers of vascular inflammation, thrombosis, cardiovascular aging, cardiac fibrosis, and aorta morphometry were changed over 24 months in an exposure-level-, sex-, or exposure-duration-dependent manner. Many plasma markers--several recognized as human CVD risk factors--were measured in the plasma of rats exposed for up to 24 months to filtered air (the control) or DE. Few changes in plasma markers resulted from 12 months of DE exposure, but significant exposure-level-dependent increases in soluble intercellular adhesion molecule 1 (sICAM-1) and interleukin-6 (IL-6) levels, as well as decreases in total and non-high-density-lipoprotein cholesterol (non-HDL) levels in plasma, were observed in female rats after 24 months of DE exposure. These effects were not observed in male rats, and no changes in cardiac fibrosis or aorta morphometry resulting from DE exposure were observed in either sex. Collectively, the significant changes may reflect an enhanced sensitivity of the female cardiovascular system to chronic DE exposure; however, this conclusion should be interpreted within both the context and limitations of the current study. PMID:25842618

  16. Organic extract of diesel exhaust particles stimulates expression of Ia and costimulatory molecules associated with antigen presentation in rat peripheral blood monocytes but not in alveolar macrophages.

    PubMed

    Koike, Eiko; Kobayashi, Takahiro

    2005-12-15

    We hypothesized that diesel exhaust particles (DEP) induce the activation of antigen-presenting cells (APC) in lung. The present study was designed to clarify the following about DEP: (1) whether it affects the expression of Ia and B7 molecules in alveolar macrophages (AM) as a mature cell or in peripheral blood monocytes (PBM) as an immature cell, (2) if it affects the antigen-presenting (AP) activity of PBM, (3) what component of DEP is responsible for the effects, and (4) whether the effect of DEP is related to oxidative stress. DEP was extracted with methylene chloride. Cells were exposed to whole DEP, organic extract, or residual particles for 24 h. Cell-surface molecules were measured by flow cytometry. AP activity was assessed by antigen-specific T cell proliferation. Whole DEP or organic extract significantly increased the expression of Ia and B7 molecules on PBM but not on AM. No significant effect of residual particles was observed. A low concentration of organic extract also increased the AP activity of PBM. When the induction of an antioxidative enzyme was assessed, heme oxygenase-1 protein was found to be significantly increased by exposure to whole DEP, and the organic extract was more effective than the residual particles. Furthermore, the organic extract-induced expression of Ia antigen on PBM was reduced by the addition of an antioxidative agent. These results suggest that DEP may act on immature APC and enhance their AP activity and that the action contributing to oxidative stress may be mediated by organic compounds of DEP. PMID:15916789

  17. Organic extract of diesel exhaust particles stimulates expression of Ia and costimulatory molecules associated with antigen presentation in rat peripheral blood monocytes but not in alveolar macrophages

    SciTech Connect

    Koike, Eiko [Particulate Matter (PM2.5) and Diesel Exhaust Particles (DEP) Research Project, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan)]. E-mail: ekoike@nies.go.jp; Kobayashi, Takahiro [Environmental Health Sciences Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan)

    2005-12-15

    We hypothesized that diesel exhaust particles (DEP) induce the activation of antigen-presenting cells (APC) in lung. The present study was designed to clarify the following about DEP: (1) whether it affects the expression of Ia and B7 molecules in alveolar macrophages (AM) as a mature cell or in peripheral blood monocytes (PBM) as an immature cell (2) if it affects the antigen-presenting (AP) activity of PBM (3) what component of DEP is responsible for the effects, and (4) whether the effect of DEP is related to oxidative stress. DEP was extracted with methylene chloride. Cells were exposed to whole DEP, organic extract, or residual particles for 24 h. Cell-surface molecules were measured by flow cytometry. AP activity was assessed by antigen-specific T cell proliferation. Whole DEP or organic extract significantly increased the expression of Ia and B7 molecules on PBM but not on AM. No significant effect of residual particles was observed. A low concentration of organic extract also increased the AP activity of PBM. When the induction of an antioxidative enzyme was assessed, heme oxygenase-1 protein was found to be significantly increased by exposure to whole DEP, and the organic extract was more effective than the residual particles. Furthermore, the organic extract-induced expression of Ia antigen on PBM was reduced by the addition of an antioxidative agent. These results suggest that DEP may act on immature APC and enhance their AP activity and that the action contributing to oxidative stress may be mediated by organic compounds of DEP.

  18. The effects of an open and closed divertor on particle exhaust during edge-localized mode suppression by resonant magnetic perturbations in DIII-D

    SciTech Connect

    Unterberg, E. A. [Oak Ridge Institute for Science and Education (ORISE); Schmitz, O. [Forschungszentrum Julich, Julich, Germany; Evans, T.E. [General Atomics, San Diego; Maingi, Rajesh [ORNL; Brooks, N. H. [General Atomics, San Diego; Fenstermacher, M. E. [Lawrence Livermore National Laboratory (LLNL); Mordijck, S. [University of California, San Diego; Moyer, R.A. [University of California, San Diego; Orlov, D. M. [University of California, San Diego & La Jolla

    2010-01-01

    This paper compares the effects of divertor geometry on particle exhaust characteristics during the suppression of ELM using resonant magnetic perturbations (RMPs) on DIII-D. The subject is timely, particularly for ITER, because the combination of techniques to control or mitigate ELMs and control particle exhaust can provide confidence in the ability of an external pumping system to fully remove the particle exhaust. The differences between an open and closed divertor magnetic topology show a strong coupling of the perturbed strikepoint to the pumping manifold in closed divertor configurations, which can increase the particle exhaust by a factor of four. There is also an observed dependence on q(95) in this configuration, which is a common feature of RMP ELM suppression. Neutral density in both the active and non-active divertors is seen to increase during the RMP in the ISS configuration, and edge plasma conditions (i.e. n(e,sep) and midplane profile of D(alpha)) are seen to increase in the closed divertor configuration. Finally, the pumping exhaust is also shown to have a strong dependence on local measurements of the recycling flux. These observations, when taken as a whole, point to a substantial change in the plasma edge conditions, i.e. near the LCFS, throughout the poloidal cross-section of the vacuum vessel. This is coincident with the application of the RMP affecting the pumping capability of the system.

  19. DIESEL EXHAUST PARTICLES ENHANCE INFLUENZA VIRUS INFECTIVITY BY INCREASING VIRUS ATTACHMENT

    EPA Science Inventory

    Despite vaccination and antiviral therapies, influenza infections continue to cause large scale morbidity and mortality every year. Several factors, such as age and nutritional status can affect the incidence and severity of influenza infections. Moreover, exposure to air polluta...

  20. HEMATOLOGICAL AND MOLECULAR CARDIAC EFFECTS FOLLOWING PULMONARY EXPOSURE TO OIL COMBUSTION PARTICLES

    EPA Science Inventory

    Hematological and Molecular Cardiac Effects Following Pulmonary Exposure to Oil Combustion Particles K. Dreher, R. Jaskot, and J. Richards. USEPA, Research Triangle Park, NC Systemic health effects induced following pulmonary exposure to various combustion particles are...

  1. CHARACTERIZING THE SOURCES OF HUMAN EXPOSURE TO MUTAGENIC AND CARCINOGENIC CHEMICALS IN AIRBORNE FINE PARTICLES

    EPA Science Inventory

    Personal and ambient exposures to airborne fine particles, polycyclic aromatic hydrocarbons (PAH), and genotoxic activity has been studied in populations in the US, Japan, China, and the Czech Republic. Personal exposure monitors used to collect fine particles were extracted f...

  2. Isomer distribution of nitrotriphenylenes in airborne particles, diesel exhaust particles, and the products of gas-phase radical-initiated nitration of triphenylene

    NASA Astrophysics Data System (ADS)

    Kameda, Takayuki; Inazu, Koji; Hisamatsu, Yoshiharu; Takenaka, Norimichi; Bandow, Hiroshi

    The formation of mutagenic nitro-polycyclic aromatic hydrocarbons (NPAHs) 1- and 2-nitrotriphenylene (1- and 2-NTP) via gas-phase OH or NO 3 radical-initiated reactions of triphenylene was demonstrated for the first time using a flow reaction system. In contrast with the results of conventional electrophilic nitration, 2-NTP was formed in larger yield than 1-NTP, but this is consistent with the mechanism proposed for gas-phase radical-initiated nitration of PAH. In diesel exhaust particle (DEP) samples, both 1- and 2-NTP were identified and their concentrations determined, as well as 1-nitropyrene (1-NP), which is a representative combustion-derived NPAH: the mean concentrations of 1-NTP, 2-NTP, and 1-NP were 4.7, 1.9, and 32 pmol mg DEP-1, respectively. The mean 2-NTP/1-NTP, 1-NTP/1-NP, and 2-NTP/1-NP ratios in samples of airborne particles collected in a residential area in Osaka, Japan, were>1.55,<0.25, and 0.37, respectively; these values are much higher than those of the DEP samples. This finding indicates that there is another source for airborne NTPs, especially 2-NTP, apart from diesel exhaust. These results strongly suggest that airborne NTPs originate from atmospheric processes such as radical-initiated reactions of triphenylene, and this has a significant influence on the atmospheric occurrence of NTPs.

  3. Acute skin lesions due to localized ``hot particle`` radiation exposures

    SciTech Connect

    Baum, J.W.; Carsten, A.L.; Kaurin, D.G.L.; Schaefer, C.W.

    1996-06-01

    Purpose of the studies was to determine incidence and severity of lesions resulting from localized deposition of dose to the skin from small (<0.5 mm) discrete radioactive particles. Hanford mini-swine were exposed to localized doses from 0.2 to over 600 Gy (averaged over 1 cm{sup 2} at 70{mu}m depth) from isotopes having max beta particle energies from about 0.3-3 MeV. Incidence of erythema and scabs (indicating ulceration) were scored routinely for up to 71 days post-irradiation. Responses followed normal probability distributions, and thus, no true threshold could be defined. Ten and 50% incidence rates were deduced using probit analyses. Lowest dose producing 10% incidence was about 1 Gy for exposures to Yb-175 (0.5 MeV max energy) beta particles. Severity of lesions was estimated using diameters and persistence. From preliminary considerations of probability of induction, size, and persistence of acute lesions, a special limit for hot particle exposures in the range of 5-50 Gy may be reasonable, with an action level between about 1 Gy and the limit.

  4. Municipal waste incinerators: air and biological monitoring of workers for exposure to particles, metals, and organic compounds

    PubMed Central

    Maitre, A; Collot-Fertey, D; Anzivino, L; Marques, M; Hours, M; Stoklov, M

    2003-01-01

    Aims: To evaluate occupational exposure to toxic pollutants at municipal waste incinerators (MWIs). Methods: Twenty nine male subjects working near the furnaces in two MWIs, and 17 subjects not occupationally exposed to combustion generated pollutants were studied. Individual air samples were taken throughout the shift; urine samples were collected before and after. Stationary air samples were taken near potential sources of emission. Results: Occupational exposure did not result in the infringement of any occupational threshold limit value. Atmospheric exposure levels to particles and metals were 10–100 times higher in MWIs than at the control site. The main sources were cleaning operations for particles, and residue transfer and disposal operations for metals. MWI workers were not exposed to higher levels of polycyclic aromatic hydrocarbons than workers who are routinely in contact with vehicle exhaust. The air concentrations of volatile organic compounds and aldehydes were low and did not appear to pose any significant threat to human health. Only the measurement of chlorinated hydrocarbon levels would seem to be a reliable marker for the combustion of plastics. Urine metal levels were significantly higher at plant 1 than at plant 2 because of high levels of pollutants emanating from one old furnace. Conclusion: While biological monitoring is an easy way of acquiring data on long term personal exposure, air monitoring remains the only method that makes it possible to identify the primary sources of pollutant emission which need to be controlled if occupational exposure and environmental pollution are to be reduced. PMID:12883016

  5. Computational simulation of worker exposure using a particle trajectory method.

    PubMed

    Flynn, M R; Chen, M M; Kim, T; Muthedath, P

    1995-06-01

    The velocity field downstream of a worker is approximated with a discrete vortex algorithm. This information is used to calculate trajectories of massless tracer 'particles' released from a point-source of contaminant. Concentrations in the plane of this source are estimated by averaging over a number of such trajectories. Approximations include: (1) representing the worker by a two-dimensional elliptical cylinder; and (2) representing tracer gas contaminant by massless particles generated without momentum. These particles are transported by both vortex shedding and turbulent diffusion. Computer-predicted mean concentrations in the near-wake region downstream of the worker compare well with results from wind-tunnel tracer gas experiments employing a mannequin. Subsequently, the concept of a computational breathing zone is introduced, and predictions of worker exposure are made. These simulations of time-integrated breathing zone concentration also compare well with measured values. PMID:7793747

  6. DIET AS A FACTOR IN BEHAVIORAL RADIATION PROTECTION FOLLOWING EXPOSURE TO HEAVY PARTICLES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  7. Skin exposure to micro- and nano-particles can cause haemostasis in zebrafish larvae.

    PubMed

    McLeish, Jennifer A; Chico, Timothy J A; Taylor, Harriet B; Tucker, Carl; Donaldson, Ken; Brown, Simon B

    2010-04-01

    Low mass ambient exposure to airborne particles is associated with atherothrombotic events that may be a consequence of the combustion-derived nanoparticle content. There is concern also over the potential cardiovascular impact of manufactured nanoparticles. To better understand the mechanism by which toxic airborne particles can affect cardiovascular function we utilised zebrafish as a genetically tractable model. Using light and confocal fluorescence video-microscopy, we measured heart-rate and blood flow in the dorsal aorta and caudal artery of zebrafish larvae that had been exposed to a number of toxic and non-toxic microparticles and nanoparticles. Diesel exhaust particles (DEP), carboxy-charged Latex beads (carboxy-beads) and toxic alumina (Taimicron TM300), but not non-toxic alumina (Baikalox A125), were found to promote both skin and gut cell damage, increased leukocyte invasion into the epidermis, tail muscle ischaemia and haemostasis within the caudal artery of free swimming zebrafish larvae. The presence of sodium sulfite, a reducing agent, or warfarin, an anticoagulant, within the system water abrogated the effects of both toxic alumina and carboxy-beads but not DEP. Genetic manipulation of skin barrier function augmented skin damage and haemostasis, even for the non-toxic alumina. The toxic effects of carboxy-beads were still apparent after leukocyte numbers were depleted with anti-Pu.1 morpholino. We conclude that particle uptake across skin epithelium and gut mucosal barriers, or the presence of leukocytes, is not required for particle-induced haemostasis while a compromised skin barrier function accentuated tissue injury and haemostasis. PMID:20174755

  8. Enriched inorganic compounds in diesel exhaust particles induce mitogen-activated protein kinase activation, cytoskeleton instability, and cytotoxicity in human bronchial epithelial cells.

    PubMed

    Seriani, Robson; Junqueira, Mara S; Carvalho-Sousa, Claudia E; Arruda, Alessandra C T; Martinez, Diana; Alencar, Adriano M; Garippo, Ana L; Brito, Jôse Mara; Martins, Milton A; Saldiva, Paulo H N; Negri, Elnara M; Mauad, Thais; Macchione, Mariangela

    2015-04-01

    This study assessed the effects of the diesel exhaust particles on ERK and JNK MAPKs activation, cell rheology (viscoelasticity), and cytotoxicity in bronchial epithelial airway cells (BEAS-2B). Crude DEP and DEP after extraction with hexane (DEP/HEX) were utilized. The partial reduction of some DEP/HEX organics increased the biodisponibility of many metallic elements. JNK and ERK were activated simultaneously by crude DEP with no alterations in viscoelasticity of the cells. Mitochondrial activity, however, revealed a decrease through the MTT assay. DEP/HEX treatment increased viscoelasticity and cytotoxicity (membrane damage), and also activated JNK. Our data suggest that the greater bioavailability of metals could be involved in JNK activation and, consequently, in the reduction of fiber coherence and increase in the viscoelasticity and cytotoxicity of BEAS cells. The adverse findings detected after exposure to crude DEP and to DEP/HEX reflect the toxic potential of diesel compounds. Considering the fact that the cells of the respiratory epithelium are the first line of defense between the body and the environment, our data contribute to a better understanding of the pathways leading to respiratory cell injury and provide evidence for the onset of or worsening of respiratory diseases caused by inorganic compounds present in DEP. PMID:25769681

  9. INHALATION OF OZONE AND DIESEL EXHAUST PARTICLES (DEP) INDUCES ACUTE AND REVERSIBLE CARDIAC GENE EXPRESSION CHANGES

    EPA Science Inventory

    We have recently shown that episodic but not acute exposure to ozone or DEP induces vascular effects that are associated with the loss of cardiac mitochondrial phospholipid fatty acids (DEP 2.0 mg/m3 > ozone, 0.4 ppm). In this study we determined ozone and DEP-induced cardiac gen...

  10. Urinary mutagenic activity in workers exposed to diesel exhaust

    SciTech Connect

    Schenker, M.B.; Samuels, S.J.; Kado, N.Y. (Univ. of California, Davis (United States)); Hammond, S.K.; Woskie, S.R.; Smith, T.J. (Univ. of Massachusetts, Worcester (United States))

    1992-04-01

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

  11. Identification of mammalian cell genotoxins in respirable diesel exhaust particles by bioassay-directed chemical analysis.

    PubMed

    Oh, Seung-Min; Chung, Kyu-Hyuck

    2006-03-01

    A bioassay-directed chemical analysis which consists of mammalian cell bioassays (comet assay, CBMN assay and EROD-microbioassay) in conjunction with analytical measurements was performed to identify the most biologically active compounds of the diesel exhaust particulate matters (DEPs) on mutagenic activity. These bioassay systems were suitable to estimate the mammalian genotoxic potentials of pollutants present in low concentrations in limited environmental samples, as is the case with DEPEs. The results from mutagenic assay showed that the aromatic and slightly polar fraction of DEPs induced chromosomal damage and DNA breakage in a non-cytotoxic dose. It was also revealed that indirect-acting mutagens may mainly contribute to the mutagenic effect of aromatic fraction via the enzyme metabolism system. In the aromatic fraction, several indirect-acting mutagenic PAHs such as dibenzo(a,h)anthracene, chrysene, and 1,2-benzanthracene were detected by GC-MS and the complex mixture effect of this fraction was quantified in terms of its biological-TCDD equivalent concentration (bio-TEQ) which was 32.82 bio-TEQ ng/g-DEPs by EROD-microbioassay. Conclusively, we confirmed that indirect-acting mutagens contained in aromatic fraction may be important causatives of the genotoxicity of extracts of DEPs by integrating the results obtained from a mammalian cell bioassay-directed fractionation. PMID:16242274

  12. Exhaust particle characterization for lean and stoichiometric DI vehicles operating on ethanol-gasoline blends

    SciTech Connect

    Storey, John Morse [ORNL] [ORNL; Barone, Teresa L [ORNL] [ORNL; Thomas, John F [ORNL] [ORNL; Huff, Shean P [ORNL] [ORNL

    2012-01-01

    Gasoline direct injection (GDI) engines can offer better fuel economy and higher performance over their port fuel-injected (PFI) counterparts, and are now appearing in increasingly more U.S. and European vehicles. Small displacement, turbocharged GDI engines are replacing large displacement engines, particularly in light-duty trucks and sport utility vehicles, in order for manufacturers to meet the U.S. fuel economy standards for 2016. Furthermore, lean-burn GDI engines can offer even higher fuel economy than stoichiometric GDI engines and have overcome challenges associated with cost-effective aftertreatment for NOx control. Along with changes in gasoline engine technology, fuel composition may increase in ethanol content beyond the current 10% due to the recent EPA waiver allowing 15% ethanol. In addition, the Renewable Fuels Standard passed as part of the 2007 Energy Independence and Security Act (EISA) mandates the use of biofuels in upcoming years. GDI engines are of environmental concern due to their high particulate matter (PM) emissions relative to port-fuel injected (PFI) gasoline vehicles; widespread market penetration of GDI vehicles may result in additional PM from mobile sources at a time when the diesel contribution is declining. In this study, we characterized particulate emissions from a European certified lean-burn GDI vehicle operating on ethanol-gasoline blends. Particle mass and particle number concentration emissions were measured for the Federal Test Procedure urban driving cycle (FTP 75) and the more aggressive US06 driving cycle. Particle number-size distributions and organic to elemental carbon ratios (OC/EC) were measured for 30 MPH and 80 MPH steady-state operation. In addition, particle number concentration was measured during wide open throttle accelerations (WOTs) and gradual accelerations representative of the FTP 75. Fuels included certification gasoline and 10% (E10) and 20% (E20) ethanol blends from the same supplier. The particle mass emissions were approximately 3 and 7 mg/mile for the FTP75 and US06, respectively, with lower emissions for the ethanol blends. The data are compared to a previous study on a U.S.-legal stoichiometric GDI vehicle operating on the same ethanol blends. The lean-burn GDI vehicle emitted a higher number of particles, but had an overall smaller average size. Particle number per mile decreased with increasing ethanol content for the transient tests. For the 30 and 80 mph tests, particle number concentration decreased with increasing ethanol content, although the shape of the particle size distribution remained the same. Engine-out OC/EC ratios were highest for the stoichiometric GDI vehicle with E20, but tailpipe OC/EC ratios were similar for all vehicles.

  13. Investigation and optimization of particle dimensions for needle trap device as an exhaustive active sampler.

    PubMed

    Zhan, Weiqiang; Pawliszyn, Janusz

    2012-10-19

    Various needle trap devices (NTDs) with different designs have been developed during the past decade. A theoretical model on the fundamentals of the NTD was recently proposed, which employed the theory of frontal (gas-solid) chromatography to describe the sampling process. In the current work, different types of sorbent particles with different dimensions were packed into the needle as the adsorbent. The effects of particle dimensions, which would affect the packing density and consequently affect the capacity, the extraction efficiency and desorption efficiency of the NTD were experimentally investigated and the proposed theory was validated. The results demonstrated that NTDs packed with small particles possess higher extraction capacity and efficiency but much higher resistances to flow as well. The higher resistance did not necessarily result in poor desorption efficiency. The observed relationships among those physical parameters provide valuable guidance on how to design a NTD with high performance for future applications. PMID:22985526

  14. Organic extract of diesel exhaust particles stimulates expression of Ia and costimulatory molecules associated with antigen presentation in rat peripheral blood monocytes but not in alveolar macrophages

    Microsoft Academic Search

    Eiko. Koike; Takahiro Kobayashi

    2005-01-01

    We hypothesized that diesel exhaust particles (DEP) induce the activation of antigen-presenting cells (APC) in lung. The present study was designed to clarify the following about DEP: (1) whether it affects the expression of Ia and B7 molecules in alveolar macrophages (AM) as a mature cell or in peripheral blood monocytes (PBM) as an immature cell, (2) if it affects

  15. Effect of the water-soluble fraction of diesel exhaust particles on the development and protein patterns of pollen grains in bean plants (Phaseolus vulgaris L.)

    Microsoft Academic Search

    Abdolkarim Chehregani; Fariba Mohsenzadeh; Shiva Hosseini

    2011-01-01

    Excessive air pollution may adversely affect plant growth and development. The overall objective of this research was to elucidate some microscopic effects of diesel exhaust particles (DEP) on the formation, development, and structure of pollen grains and its proteins in Phaseolus vulgaris L. Bean plants were grown in experimental pots and treated with different concentrations of the water-soluble fraction of

  16. Cooperation of the inducible nitric oxide synthase and cytochrome P450 1A1 in mediating lung inflammation and mutagenicity induced by diesel exhaust particles.

    PubMed

    Zhao, Hongwen; Barger, Mark W; Ma, Joseph K H; Castranova, Vincent; Ma, Jane Y C

    2006-08-01

    Diesel exhaust particles (DEPs) have been shown to activate oxidant generation by alveolar macrophages (AMs), alter xenobiotic metabolic pathways, and modify the balance of pro-antiinflammatory cytokines. In this study we investigated the role of nitric oxide (NO) in DEP-mediated and DEP organic extract (DEPE) -mediated inflammatory responses and evaluated the interaction of inducible NO synthase (iNOS) and cytochrome P450 1A1 (CYP1A1). Male Sprague-Dawley rats were intratracheally (IT) instilled with saline, DEPs (35 mg/kg), or DEPEs (equivalent to 35 mg DEP/kg), with or without further treatment with an iNOS inhibitor, aminoguanidine (AG; 100 mg/kg), by intraperitoneal injection 30 min before and 3, 6, and 9 hr after IT exposure. At 1 day postexposure, both DEPs and DEPEs induced iNOS expression and NO production by AMs. AG significantly lowered DEP- and DEPE-induced iNOS activity but not the protein level while attenuating DEPE- but not DEP-mediated pulmonary inflammation, airway damage, and oxidant generation by AMs. DEP or DEPE exposure resulted in elevated secretion of both interleukin (IL) -12 and IL-10 by AMs. AG significantly reduced DEP- and DEPE-activated AMs in IL-12 production. In comparison, AG inhibited IL-10 production by DEPE-exposed AMs but markedly increased its production by DEP-exposed AMs, suggesting that NO differentially regulates the pro- and antiinflammatory cytokine balance in the lung. Both DEPs and DEPEs induced CYP1A1 expression. AG strongly inhibited CYP1A1 activity and lung S9 activity-dependent 2-aminoanthracene mutagenicity. These studies show that NO plays a major role in DEPE-induced lung inflammation and CYP-dependent mutagen activation but a lesser role in particulate-induced inflammatory damage. PMID:16882535

  17. Activation of nuclear factor kappa B by diesel exhaust particles in mouse epidermal cells through phosphatidylinositol 3-kinase/Akt signaling pathway.

    PubMed

    Ma, Cuiling; Wang, Jin; Luo, Jia

    2004-05-15

    Diesel exhaust particles (DEP) induce intense inflammatory and allergic immune responses. The epidermal cells receive much exposure to DEP, and are an important source of pro-inflammatory cytokines and other inflammatory mediators. Transcription factors, such as nuclear factor kappa B (NF-kappaB) and activator protein 1 (AP-1), regulate the expression of these mediators. We hypothesize that the transcription factors are target of DEP action. The current study sought to determine whether DEP-activated NF-kappaB and AP-1 in a mouse epidermal cell line, JB6 P(+) cells. Using stable transfectants of JB6 P(+) cells expressing NF-kappaB or AP-1 luciferase reporter constructs, we demonstrated that exposure to DEP at a non-cytotoxic concentration significantly enhanced the transactivation of NF-kappaB, but not AP-1. Furthermore, DEP promoted phosphorylation of Akt, a substrate of phosphatidylinositol 3-kinase (PI3K), on Ser-473 and Thr-308 in a PI3K-dependent manner, and enhanced phosphorylation of down-stream p70/p85 S6 kinases (p70/p85S6K) as well as glycogen synthase kinase-3beta (GSK-3beta). Blockage of PI3K activation eliminated DEP-stimulated NF-kappaB transactivation. Although SAPK/JNK pathway was modestly activated by DEP, it was not involved in NF-kappaB transactivation. DEP had little effect on the phosphorylation of ERKs and p38 MAPK. Thus, DEP-induced transactivation of NF-kappaB is mediated by PI3K/Akt signaling pathway. PMID:15130773

  18. Nitrophenols isolated from diesel exhaust particles regulate steroidogenic gene expression and steroid synthesis in the human H295R adrenocortical cell line

    SciTech Connect

    Furuta, Chie [Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193 (Japan); Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509 (Japan); Noda, Shiho [Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509 (Japan); Li Chunmei; Suzuki, Akira K; Taneda, Shinji [Environmental Nanotoxicology Section, Research Center for Environmental Risk, National Institute for Environmental Studies, Tsukuba (Japan); Watanabe, Gen [Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193 (Japan); Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509 (Japan); Taya, Kazuyoshi [Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193 (Japan); Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509 (Japan)], E-mail: taya@cc.tuat.ac.jp

    2008-05-15

    Studies of nitrophenols isolated from diesel exhaust particles (DEPs), 3-methyl-4-nitrophenol (PNMC) and 4-nitro-3-phenylphenol (PNMPP) have revealed that these chemicals possess estrogenic and anti-androgenic activity in vitro and in vivo and that PNMC accumulate in adrenal glands in vivo. However, the impacts of exposure to these compounds on adrenal endocrine disruption and steroidogenesis have not been investigated. To elucidate the non-receptor mediated effects of PNMC and PNMPP, we investigated the production of the steroid hormones progesterone, cortisol, testosterone, and estradiol-17{beta} and modulation of nine major enzyme genes involved in the synthesis of steroid hormones (CYP11A, CYP11B1, CYP17, CYP19, 17{beta}HSD1, 17{beta}HSD4, CYP21, 3{beta}HSD2, StAR) in human adrenal H295R cells supplied with cAMP. Exposure to 10{sup -7} to 10{sup -5} M PNMC and 1 mM 8-Br-cAMP for 48 h decreased testosterone, cortisol, and estradiol-17{beta} levels and increased progesterone secretion. At 10{sup -5} M, PNMC with 1 mM 8-Br-cAMP significantly stimulated expression of the 17{beta}HSD4 and significantly suppressed expression of 3{beta}HSD2. In comparison, 10{sup -7} to 2 x 10{sup -5} M PNMPP with 1 mM 8-Br-cAMP for 48 h decreased concentrations of estradiol-17{beta}, increased progesterone levels, but did not affect testosterone and cortisol secretion due to the significant suppression of CYP17 and the non-significant but obvious suppression of CYP19. Our results clarified steroidogenic enzymes as candidates responsible for the inhibition or stimulation for the production of steroid hormones in the steroidogenic pathway, thus providing the first experimental evidence for multiple mechanisms of disruption of endocrine pathways by these nitrophenols.

  19. Concentrated ambient ultrafine particle exposure induces cardiac change in young healthy volunteers

    EPA Science Inventory

    Exposure to ambient ultrafine particles has been associated with cardiopulmonary toxicity and mortality. Adverse effects specifically linked to ultrafine particles include loss of sympathovagal balance and altered hemostasis. To characterize the effects of ultrafine particles in ...

  20. Measurement of the light absorbing properties of diesel exhaust particles using a three-wavelength photoacoustic spectrometer

    NASA Astrophysics Data System (ADS)

    Guo, Xuesong; Nakayama, Tomoki; Yamada, Hiroyuki; Inomata, Satoshi; Tonokura, Kenichi; Matsumi, Yutaka

    2014-09-01

    Diesel-exhaust particles (DEP) are one of the main anthropogenic sources of black carbon (BC) and organic matter (OM). Understanding the optical properties of DEP, including the enhancement of light absorption by BC due to coating and light absorption by OM, is important for evaluating the climate impact of DEP. In this study, a three-wavelength photoacoustic soot spectrometer (405, 532, and 781 nm) was used to investigate the wavelength-dependent optical properties of DEP emitted from a diesel engine vehicle running on a chassis dynamometer in transient driving mode (JE-05) and at a constant speed (either idling or driving at 70 km/h). Optical properties were measured after passing the diluted exhaust through a heater, set at 20, 47, or 300 °C (transient driving mode) or between 20 and 400 °C (constant driving mode). The OM accounted for, on average, ?40 and ?35% of the total mass concentration of DEP during the transient and constant driving modes, respectively. In transient driving mode, enhancements of scattering coefficients at 20 and 47 °C, and of the mass concentration of organics, were observed during the high-speed driving period (?80 km/h) corresponding to driving on a highway. No difference was observed in the absorption coefficients between heated and unheated particles at 781 nm for either the transient (including the high-speed driving period) or constant driving modes. These results indicate a lack of enhancement due to the lensing effect, possibly because the BC was mainly mixed externally with the OM or because it was located at the edges of particles under these experimental conditions. Contributions to total light absorption at 405 nm by the OM were estimated by comparing the wavelength dependence of the absorption coefficients with and without heating. A significant contribution by light-absorbing OM (20 ± 7%) to total light absorption at 405 nm was observed during the high-speed driving period of the JE-05 mode, while the contributions were small during other periods in the JE-05 mode (0 ± 8%) and the constant driving mode (idling: 4 ± 12%; driving at 70 km/h: 0 ± 16%).

  1. Impact of a ceramic trap and manganese fuel additive on the biological activity and chemical composition of exhaust particles from diesel engines used in underground mines

    Microsoft Academic Search

    W. M. Draper; H. Hartmann; D. B. Kittelson; W. F. Watts; K. J. Baumgard

    1987-01-01

    The U.S. Bureau of Mines study examines the effect of a ceramic particle trap and a manganese fuel additive on the mutagenic activity and chemical composition of diesel exhaust particulate matter from a heavy-duty mining engine. Particles were collected by dilution tunnel sampling from a four-cylinder, Caterpillar 3304, naturally aspirated, indirect-injection engine operated at six steady-state conditions. Depending on engine

  2. Comparison of the Particle Size Distribution of Heavy-Duty Diesel Exhaust Using a Dilution Tailpipe Sampler and an In-Plume Sampler during On-Road Operation

    Microsoft Academic Search

    J. Edward Brown; Matthew J. Clayton; D. Bruce Harris; Foy G. King Jr

    2000-01-01

    Originally constructed to develop gaseous emission factors for heavy-duty diesel trucks, the U.S. Environmental Protection Agency's (EPA) On-Road Diesel Emissions Characterization Facility has been modified to incorporate particle measurement instrumentation. An electrical low-pressure impactor designed to continuously measure and record size distribution data was used to monitor the particle size distribution of heavy-duty diesel truck exhaust. For this study, which

  3. Endothelial-constitutive nitric oxide synthase exists in airways and diesel exhaust particles inhibit the effect of nitric oxide

    SciTech Connect

    Muto, Emiko; Hayashi, Toshio; Yamada, Kazuyoshi [Nagoya Univ. School of Medicine (Japan)] [and others] [Nagoya Univ. School of Medicine (Japan); and others

    1996-12-31

    Diesel exhaust particles (DEP) are an important cause of air pollution and are thought to be responsible for some respiratory ailments, but the exact mechanism is not known. We evaluated whether DEP inhibit nitric oxide (NO) synthesis in bronchi as No is present in the exhaled air and has a physiological role in the respiratory tract. Aortic rings were also examined for comparison. We observed that acetylcholine (ACh) induced contraction of the bronchi was partially attenuated by the simultaneous release of NO. When bronchial rings were incubated either with N{sup G}-methyl-L-arginine (L-NMA): an inhibitor of NO synthase (NOS) or with DEP, the contraction to ACh was abolished. The source of the NOS was the bronchial epithelium and this endothelial-constitutive NOS was demonstrated by immunohistochemistry. DEP like L-NMA inhibited the ACh induced endothelium dependent relaxation in the aortic rings. The inhibition of NO release by DEP and L-NMA from bronchial and aortic rings was also confirmed by a selective NO electrode. We conclude that inhibition of NO availability by DEP may in part be responsible for the adverse respiratory effects seen by inhalation of these particles in polluted air. 27 refs., 6 figs.

  4. Reactive oxygen species- and nitric oxide-mediated lung inflammation and mitochondrial dysfunction in wild-type and iNOS-deficient mice exposed to diesel exhaust particles.

    PubMed

    Zhao, Hongwen; Ma, Joseph K; Barger, Mark W; Mercer, Robert R; Millecchia, Lyndell; Schwegler-Berry, Diane; Castranova, Vince; Ma, Jane Y

    2009-01-01

    Pulmonary responses to diesel exhaust particles (DEP) exposure are mediated through enhanced production of reactive oxygen species (ROS) and nitric oxide (NO) by alveolar macrophages (AM). The current study examined the differential roles of ROS and NO in DEP-induced lung injury using C57B/6J wild-type (WT) and inducible NO synthase knockout (iNOS KO) mice. Mice exposed by pharyngeal aspiration to DEP or carbon black particles (CB) (35 mg/kg) showed an inflammatory profile that included neutrophil infiltration, increased lactate dehydrogenase (LDH) activity, and elevated albumin content in bronchoalveolar lavage fluid (BALF) at 1, 3, and 7 d postexposure. The organic extract of DEP (DEPE) did not induce an inflammatory response. Comparing WT to iNOS KO mice, the results show that NO enhanced DEP-induced neutrophils infiltration and plasma albumin content in BALF and upregulated the production of the pro-inflammatory cytokine interleukin 12 (IL-12) by AM. DEP-exposed AM from iNOS KO mice displayed diminished production of IL-12 and, in response to ex vivo lipopolysaccharide (LPS) challenge, decreased production of IL-12 but increased production of IL-10 when compared to cells from WT mice. DEP, CB, but not DEPE, induced DNA damage and mitochondria dysfunction in AM, however, that is independent of cellular production of NO. These results demonstrate that DEP-induced immune/inflammatory responses in mice are regulated by both ROS- and NO-mediated pathways. NO did not affect ROS-mediated mitochondrial dysfunction and DNA damage but upregulated IL-12 and provided a counterbalance to the ROS-mediated adaptive stress response that downregulates IL-12 and upregulates IL-10. PMID:19267316

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

    Microsoft Academic Search

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

    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

  6. Soot removal from exhaust gas

    Microsoft Academic Search

    1992-01-01

    This patent describes a method. It comprises producing an exhaust gas stream from a diesel engine; adding a wetting agent to a water supply; contacting the exhaust gas stream with the water from the water supply having the wetting agent in a contact zone to produce a substantially water saturated exhaust gas stream; electrically charging particles and droplets in the

  7. Shielding from Solar Particle Event Exposures in Deep Space

    NASA Technical Reports Server (NTRS)

    Wilson, John W.; Cucinotta, F. A.; Shinn, J. L.; Simonsen, L. C.; Dubey, R. R.; Jordan, W. R.; Jones, T. D.; Chang, C. K.; Kim, M. Y.

    1999-01-01

    The physical composition and intensities of solar particle event exposures or sensitive astronaut tissues are examined under conditions approximating an astronaut in deep space. Response functions for conversion of particle fluence into dose and dose equivalent averaged over organ tissue, are used to establish significant fluence levels and the expected dose and dose rates of the most important events from past observations. The BRYNTRN transport code is used to evaluate the local environment experienced by sensitive tissues and used to evaluate bioresponse models developed for use in tactical nuclear warfare. The present results will help to the biophysical aspects of such exposure in the assessment of RBE and dose rate effects and their impact on design of protection systems for the astronauts. The use of polymers as shielding material in place of an equal mass of aluminum would prowide a large safety factor without increasing the vehicle mass. This safety factor is sufficient to provide adequate protection if a factor of two larger event than has ever been observed in fact occurs during the mission.

  8. Human exposure to large solar particle events in space

    NASA Technical Reports Server (NTRS)

    Townsend, L. W.; Wilson, J. W.; Shinn, J. L.; Curtis, S. B.

    1992-01-01

    Whenever energetic solar protons produced by solar particle events traverse bulk matter, they undergo various nuclear and atomic collision processes which significantly alter the physical characteristics and biologically important properties of their transported radiation fields. These physical interactions and their effect on the resulting radiation field within matter are described within the context of a recently developed deterministic, coupled neutron-proton space radiation transport computer code (BRYNTRN). Using this computer code, estimates of human exposure in interplanetary space, behind nominal (2 g/sq cm) and storm shelter (20 g/sq cm) thicknesses of aluminum shielding, are made for the large solar proton event of August 1972. Included in these calculations are estimates of cumulative exposures to the skin, ocular lens, and bone marrow as a function of time during the event. Risk assessment in terms of absorbed dose and dose equivalent is discussed for these organs. Also presented are estimates of organ exposures for hypothetical, worst-case flare scenarios. The rate of dose equivalent accumulation places this situation in an interesting region of dose rate between the very low values of usual concern in terrestrial radiation environments and the high-dose-rate values prevalent in radiation therapy.

  9. Treadmill stress test after diesel exhaust particulate exposure reveals a time-dependent shift from parasympathetic to sympathetic dominance

    EPA Science Inventory

    Epidemiological studies suggest that particulate matter (PM) air pollution is a major trigger of acute cardiac events-including arrhythmia-especially in those with preexisting cardiac disease. Diesel exhaust (DE) contributes the majority of urban fine and ultrafine PM, and is thu...

  10. Hypotension and AV block after diesel exhaust exposure in heart failure-prone rats: role of gaseous and particulate components

    EPA Science Inventory

    Acute inhalations ofdiesel engine exhaust (DE) and fine particulate matter (PM2.5) have been demonstrated to provoke adverse cardiac events in humans with preexisting heart disease. Electrophysiologic dysfunction and autonomic imbalance are among the mechanisms widely held to und...

  11. Exposure to airborne particles and volatile organic compounds from polyurethane molding, spray painting, lacquering, and gluing in a workshop.

    PubMed

    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

  12. Soot removal from exhaust gas

    SciTech Connect

    Leonard, R.E.

    1992-06-30

    This patent describes a method. It comprises producing an exhaust gas stream from a diesel engine; adding a wetting agent to a water supply; contacting the exhaust gas stream with the water from the water supply having the wetting agent in a contact zone to produce a substantially water saturated exhaust gas stream; electrically charging particles and droplets in the water saturated exhaust gas stream in an ionizing zone; and electrostatically attracting and de-entraining soot and soot containing water droplets from the gas stream containing electrically charged particles and droplets in a collection zone to produce a substantially soot free exhaust gas stream.

  13. Current and future emission estimates of exhaust gases and particles from shipping at the largest port in Korea.

    PubMed

    Song, Sang-Keun; Shon, Zang-Ho

    2014-05-01

    The emissions of exhaust gases (NOx , SO2, VOCs, and CO2) and particles (e.g., PM) from ships traversing Busan Port in Korea were estimated over three different years (the years 2006, 2008, and 2009). This analysis was performed according to the ship operational modes ("at sea," "maneuvering," and "in port") and ship types based on an activity-based method. The ship emissions for current (base year 2009) and future scenarios (years 2020 and 2050) were also compared. The annual emissions of SO2, VOCs, PM, and CO2 were highest (9.6?×?10(3), 374, 1.2?×?10(3), and 5.6?×?10(5) ton year(-1), respectively) in 2008. In contrast, the annual NO x emissions were highest (11.7?×?10(3) ton year(-1)) in 2006 due mainly to the high NO x emission factor. The emissions of air pollutants for each ship operational mode differed considerably, with the largest emission observed in "in port" mode. In addition, the largest fraction (approximately 45-67%) of the emissions of all air pollutants during the study period was emitted from container ships. The future ship emissions of most pollutants (except for SO2 and PM) in 2020 and 2050 are estimated to be 1.4-1.8 and 4.7-6.1 times higher than those in 2009 (base year), respectively. PMID:24497306

  14. Circulating factors induce coronary endothelial cell activation following exposure to inhaled diesel exhaust and nitrogen dioxide in humans: evidence from a novel translational in vitro model.

    PubMed

    Channell, Meghan M; Paffett, Michael L; Devlin, Robert B; Madden, Michael C; Campen, Matthew J

    2012-05-01

    The vascular toxicity of inhaled agents may be caused by soluble factors that are released into the systemic circulation. To confirm this in a straightforward manner, we obtained plasma from healthy human volunteers before and after exposure to diesel exhaust (DE) and nitrogen dioxide (NO(2)). Plasma samples were obtained from human volunteers exposed to 100 ?g/m(3) DE or filtered air for 2 h. A second cohort was exposed to 500 ppb NO(2) or filtered air in an identical protocol. Primary human coronary artery endothelial cells (hCAECs) were grown to confluence and treated for 24 h with a 10 or 30% (in media) mixture of plasma obtained before, immediately post or 24 h postexposure to pollutant exposures. Messenger RNA (mRNA) was isolated from hCAECs following the incubation and probed for intracellular cell adhesion molecule (ICAM-1) and vascular cell adhesion molecule (VCAM-1) expression. ICAM-1 mRNA expression was increased by plasma obtained at both timepoints following the NO(2) exposures. VCAM-1 was significantly elevated in cells treated with plasma obtained 24 h following diesel exposure and at both timepoints following NO(2) exposure. Interleukin-8 protein was elevated in the hCAEC supernatant when cells were incubated with plasma from NO(2) exposures. These data indicate that proinflammatory circulating factors are elevated acutely following exposure to both DE and a primary component thereof, NO(2). These functional translational assays offer novel approaches to assessing the cardiovascular risk associated with air pollution exposure. PMID:22331494

  15. Circulating Factors Induce Coronary Endothelial Cell Activation Following Exposure to Inhaled Diesel Exhaust and Nitrogen Dioxide in Humans: Evidence From a Novel Translational In Vitro Model

    PubMed Central

    Channell, Meghan M.; Paffett, Michael L.; Devlin, Robert B.; Madden, Michael C.; Campen, Matthew J.

    2012-01-01

    The vascular toxicity of inhaled agents may be caused by soluble factors that are released into the systemic circulation. To confirm this in a straightforward manner, we obtained plasma from healthy human volunteers before and after exposure to diesel exhaust (DE) and nitrogen dioxide (NO2). Plasma samples were obtained from human volunteers exposed to 100 ?g/m3 DE or filtered air for 2 h. A second cohort was exposed to 500 ppb NO2 or filtered air in an identical protocol. Primary human coronary artery endothelial cells (hCAECs) were grown to confluence and treated for 24 h with a 10 or 30% (in media) mixture of plasma obtained before, immediately post or 24 h postexposure to pollutant exposures. Messenger RNA (mRNA) was isolated from hCAECs following the incubation and probed for intracellular cell adhesion molecule (ICAM-1) and vascular cell adhesion molecule (VCAM-1) expression. ICAM-1 mRNA expression was increased by plasma obtained at both timepoints following the NO2 exposures. VCAM-1 was significantly elevated in cells treated with plasma obtained 24 h following diesel exposure and at both timepoints following NO2 exposure. Interleukin-8 protein was elevated in the hCAEC supernatant when cells were incubated with plasma from NO2 exposures. These data indicate that proinflammatory circulating factors are elevated acutely following exposure to both DE and a primary component thereof, NO2. These functional translational assays offer novel approaches to assessing the cardiovascular risk associated with air pollution exposure. PMID:22331494

  16. Development of a two dimensional-high performance liquid chromatography-tandem mass spectrometry method to quantify nitro-PAHs in particulate matter and assess personal exposures to diesel exhaust

    NASA Astrophysics Data System (ADS)

    Miller-Schulze, Justin P.

    Ambient particulate matter (PM) is of concern to regulatory agencies due to its adverse impacts on public health. A significant contributor to ambient PM is diesel exhaust (as diesel particulate matter, DPM). Current methods for accurately quantifying ambient exposures to DPM are inadequate, as they employ markers that are not well-suited as specific markers for diesel exhaust or because they lack the selectivity and sensitivity to quantify the specific markers at ambient levels. To address this issue, a 2D-HPLC-MS/MS method was developed. This method exhibited novel sensitivity and selectivity for 1-nitropyrene (1NP), a specific molecular marker for diesel exhaust; in addition, this method was used to monitor two additional nitro-PAH species, 2-nitrofluoranthene and 2-nitropyrene, which are formed exclusively via secondary atmospheric reactions. This method was applied to four sets of filter samples from three different locations which were expected to represent three different classes of exposure to diesel exhaust. These locations were: Trujillo, Peru (high exposure); Shenyang, China (medium exposure); and Seattle, Washington (low exposure). The results of these analyses were congruent with what was anticipated due to existing knowledge of environmental regulations in these areas. In addition, urine samples were analyzed for urinary metabolites of 1NP in two of these groups; the Shenyang group and a Seattle group. Differences in the concentrations of 1NP metabolites were observed, although these differences were not of the same magnitude as the differences in 1NP exposures. The results of the filter analyses indicate that the 2D-HPLC-MS/MS method developed has adequate selectivity and sensitivity to detect trace levels of environmentally relevant nitro-PAH species in ambient PM samples. The results of the urine analysis indicate that while the 1NP metabolites detected may not be adequate as biomarkers of acute exposure to diesel exhaust, they may have potential as biomarkers of chronic exposure to diesel exhaust.

  17. Particle emission and exposure during nanoparticle synthesis in research laboratories.

    PubMed

    Demou, Evangelia; Stark, Wendelin J; Hellweg, Stefanie

    2009-11-01

    Real-time size, mass and number particle concentrations, and emission rates in university laboratories producing nanoparticles by scalable flame spray pyrolysis are quantified. Measurements were conducted in four laboratories using various technological set-ups and during production of particles of a range of compositions with differing physical-chemical properties, from NaCl salt, BiPO(4), CaSO(4), Bi(2)O(3), insoluble TiO(2), SiO(2), and WO(3) to composites such as Cu/ZnO, Cu/SiO(2), Cu/ZrO(2), Ta(2)O(5)/SiO(2), and Pt/Ba/Al(2)O(3). Production time ranged from 0.25 to 400 min and yields from 0.33 to 183 g. Temporal and spatial analyses of the particle concentrations were performed indicating that elevated number concentrations in the workplace can occur. Airborne submicron number concentrations increased from background levels of 2100 up to 106,000 cm(-3) during production, while the mass concentration ranged from a background of 0.009 to 0.463 mg m(-3). Maximum particle number emission rates amounted to 1.17 x 10(12) min(-1). The size distributions displayed concentration peaks mainly between 110 and 180 nm. However, changes in the operating conditions and the production of certain nanoparticles resulted in concentration peaks in the nanoparticle size range <100 nm. The effectiveness and limitations of current technology in assessing researchers' exposure to nanoparticles during production are examined, and further measures for workers' protection are proposed. PMID:19703918

  18. Exposure to wood smoke particles produces an inflammation in healthy volunteers

    EPA Science Inventory

    Background. Human exposure to wood smoke particles (WSP) is of consequence in indoor air quality, exposures from wild fires, burning ofbiomass, and air pollution. This investigation tested the postulate that healthy volunteers exposed to WSP would demonstrate pulmonary and cardio...

  19. Diesel Exhaust in Miners Study: Questions & Answers

    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 exposure to diesel exhaust.

  20. Comparison of Algorithm-based Estimates of Occupational Diesel Exhaust Exposure to Those of Multiple Independent Raters in a Population-based Case–Control Study

    PubMed Central

    Friesen, Melissa C.

    2013-01-01

    Objectives: Algorithm-based exposure assessments based on patterns in questionnaire responses and professional judgment can readily apply transparent exposure decision rules to thousands of jobs quickly. However, we need to better understand how algorithms compare to a one-by-one job review by an exposure assessor. We compared algorithm-based estimates of diesel exhaust exposure to those of three independent raters within the New England Bladder Cancer Study, a population-based case–control study, and identified conditions under which disparities occurred in the assessments of the algorithm and the raters. Methods: Occupational diesel exhaust exposure was assessed previously using an algorithm and a single rater for all 14 983 jobs reported by 2631 study participants during personal interviews conducted from 2001 to 2004. Two additional raters independently assessed a random subset of 324 jobs that were selected based on strata defined by the cross-tabulations of the algorithm and the first rater’s probability assessments for each job, oversampling their disagreements. The algorithm and each rater assessed the probability, intensity and frequency of occupational diesel exhaust exposure, as well as a confidence rating for each metric. Agreement among the raters, their aggregate rating (average of the three raters’ ratings) and the algorithm were evaluated using proportion of agreement, kappa and weighted kappa (?w). Agreement analyses on the subset used inverse probability weighting to extrapolate the subset to estimate agreement for all jobs. Classification and Regression Tree (CART) models were used to identify patterns in questionnaire responses that predicted disparities in exposure status (i.e., unexposed versus exposed) between the first rater and the algorithm-based estimates. Results: For the probability, intensity and frequency exposure metrics, moderate to moderately high agreement was observed among raters (?w = 0.50–0.76) and between the algorithm and the individual raters (?w = 0.58–0.81). For these metrics, the algorithm estimates had consistently higher agreement with the aggregate rating (?w = 0.82) than with the individual raters. For all metrics, the agreement between the algorithm and the aggregate ratings was highest for the unexposed category (90–93%) and was poor to moderate for the exposed categories (9–64%). Lower agreement was observed for jobs with a start year <1965 versus ?1965. For the confidence metrics, the agreement was poor to moderate among raters (?w = 0.17–0.45) and between the algorithm and the individual raters (?w = 0.24–0.61). CART models identified patterns in the questionnaire responses that predicted a fair-to-moderate (33–89%) proportion of the disagreements between the raters’ and the algorithm estimates. Discussion: The agreement between any two raters was similar to the agreement between an algorithm-based approach and individual raters, providing additional support for using the more efficient and transparent algorithm-based approach. CART models identified some patterns in disagreements between the first rater and the algorithm. Given the absence of a gold standard for estimating exposure, these patterns can be reviewed by a team of exposure assessors to determine whether the algorithm should be revised for future studies. PMID:23184256

  1. In Utero Exposure to Diesel Exhaust Air Pollution Promotes Adverse Intrauterine Conditions, Resulting in Weight Gain, Altered Blood Pressure, and Increased Susceptibility to Heart Failure in Adult Mice

    PubMed Central

    Weldy, Chad S.; Liu, Yonggang; Liggitt, H. Denny; Chin, Michael T.

    2014-01-01

    Exposure to fine particulate air pollution (PM2.5) is strongly associated with cardiovascular morbidity and mortality. Exposure to PM2.5 during pregnancy promotes reduced birthweight, and the associated adverse intrauterine conditions may also promote adult risk of cardiovascular disease. Here, we investigated the potential for in utero exposure to diesel exhaust (DE) air pollution, a major source of urban PM2.5, to promote adverse intrauterine conditions and influence adult susceptibility to disease. We exposed pregnant female C57Bl/6J mice to DE (?300 µg/m3 PM2.5, 6 hrs/day, 5 days/week) from embryonic day (E) 0.5 to 17.5. At E17.5 embryos were collected for gravimetric analysis and assessed for evidence of resorption. Placental tissues underwent pathological examination to assess the extent of injury, inflammatory cell infiltration, and oxidative stress. In addition, some dams that were exposed to DE were allowed to give birth to pups and raise offspring in filtered air (FA) conditions. At 10-weeks of age, body weight and blood pressure were measured. At 12-weeks of age, cardiac function was assessed by echocardiography. Susceptibility to pressure overload-induced heart failure was then determined after transverse aortic constriction surgery. We found that in utero exposure to DE increases embryo resorption, and promotes placental hemorrhage, focal necrosis, compaction of labyrinth vascular spaces, inflammatory cell infiltration and oxidative stress. In addition, we observed that in utero DE exposure increased body weight, but counterintuitively reduced blood pressure without any changes in baseline cardiac function in adult male mice. Importantly, we observed these mice to have increased susceptibility to pressure-overload induced heart failure, suggesting this in utero exposure to DE ‘reprograms’ the heart to a heightened susceptibility to failure. These observations provide important data to suggest that developmental exposure to air pollution may strongly influence adult susceptibility to cardiovascular disease. PMID:24533117

  2. Exposure to galactic cosmic radiation and solar energetic particles.

    PubMed

    O'Sullivan, D

    2007-01-01

    Several investigations of the radiation field at aircraft altitudes have been undertaken during solar cycle 23 which occurred in the period 1993-2003. The radiation field is produced by the passage of galactic cosmic rays and their nuclear reaction products as well as solar energetic particles through the Earth's atmosphere. Galactic cosmic rays reach a maximum intensity when the sun is least active and are at minimum intensity during solar maximum period. During solar maximum an increased number of coronal mass ejections and solar flares produce high energy solar particles which can also penetrate down to aircraft altitudes. It is found that the very complicated field resulting from these processes varies with altitude, latitude and stage of solar cycle. By employing several active and passive detectors, the whole range of radiation types and energies were encompassed. In-flight data was obtained with the co-operation of many airlines and NASA. The EURADOS Aircraft Crew in-flight data base was used for comparison with the predictions of various computer codes. A brief outline of some recent studies of exposure to radiation in Earth orbit will conclude this contribution. PMID:17846031

  3. ATTRIBUTION OF PARTICLE EXPOSURE AND RISK TO COMBUSTION SOURCE EMISSIONS BASED ON PERSONAL PAH EXPOSURE AND URINARY METABOLITES

    EPA Science Inventory

    Personal airborne exposures to carcinogenic particulate PAH have been significantly correlated with exposure to respirable fine particle mass (PM 2.5) in several studies. All combustion sources emit PAH, however the relative concentrations of different PAH and other organic tr...

  4. UPREGULATION OF TISSUE FACTOR IN HUMAN ENDOTHELIAL CELLS FOLLOWING ULTRAFINE PARTICLE EXPOSURE

    EPA Science Inventory

    Epidemiology studies have linked the exposure to air pollutant particles with increased cardiovascular mortality and morbidity, but the mechanisms remain unknown. In our laboratory we have tested the hypothesis that the ultrafine fraction of ambient pollutant particles would cau...

  5. UP-REGULATION OF TISSUE FACTOR IN HUMAN PULMONARY ARTERY ENDOTHELIAL CELLS AFTER ULTRAFINE PARTICLE EXPOSURE

    EPA Science Inventory

    Background: Epidemiology studies have linked exposure to pollutant particles to increased cardiovascular mortality and morbidity, but the mechanisms remain unknown. Objectives: We tested the hypothesis that the ultrafine fraction of ambient pollutant particle...

  6. Bioassay-directed fractionation and sub-fractionation for mutagenicity and chemical analysis of diesel exhaust particles.

    PubMed

    Mutlu, Esra; Warren, Sarah H; Matthews, Peggy P; King, Charly; Linak, William P; Kooter, Ingeborg M; Schmid, Judith E; Ross, Jeffrey A; Gilmour, M Ian; Demarini, David M

    2013-12-01

    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 not characterized extensively for chemical composition or sub-fractionated and tested extensively for mutagenicity. We collected a compressor-generated DEP (C-DEP) and characterized it by conducting bioassay-directed fractionation of the extractable organics in Salmonella and correlating the results by hierarchical clustering with the concentrations of 32 polycyclic aromatic hydrocarbons (PAHs). Relative to A- and N-DEP, the mutagenic potency of C-DEP was intermediate in TA100 +S9 (PAH mutagenicity) but was lowest in TA98 -S9 (nitroarene mutagenicity). More than 50% of the mass of the extractable organics of C-DEP eluted in the nonpolar Fraction 1, and only ?20% eluted in the moderately polar Fractions 2 and 3. However, most of the mutagenicity eluted in Fractions 2 and 3, similar to A-DEP but different from N-DEP. HPLC-derived mutagrams of 62 sub-fractions per fraction confirmed that most of the mutagenicity was due to moderately polar compounds. The diagnostic strains identified a strong role for PAHs, nitroarenes, aromatic amines, and oxy-PAHs in the mutagenicity of C-DEP. Hierarchical clustering confirmed the importance of oxy-PAHs but not that of nitroarenes. To our knowledge this is the first use of hierarchical clustering to correlate chemical composition with the mutagenicity of a complex mixture. The chemical analysis and mutagenicity of C-DEP described here makes C-DEP suitable for additional toxicological studies. PMID:24105890

  7. Personal exposure to airborne particles and metals: results from the Particle TEAM study in Riverside, California.

    PubMed

    Ozkaynak, H; Xue, J; Spengler, J; Wallace, L; Pellizzari, E; Jenkins, P

    1996-01-01

    The PTEAM Study was the first large-scale probability-based study of personal exposure to particles. Sponsored by the U.S. Environmental Protection Agency (EPA) and the Air Resources Board of California, it was carried out by the Research Triangle Institute (RTI) and the Harvard University School of Public Health (HSPH). HSPH designed and constructed a 4-lpm, battery-operated personal monitor for inhalable particles (PM10) that could be worn comfortably for up to 14 hours by persons from 10 to 70 years old. The monitor was worn for two consecutive 12-hour periods (day and night) during the fall of 1990 by 178 participants representing 139,000 nonsmoking residents of Riverside, California. Nearly identical monitors were employed to collect concurrent indoor and outdoor samples. The monitors were equipped with a different sampling nozzle to collect fine particles (PM2.5). Population-weighted daytime personal PM10 exposures averaged 150 +/- 9 (SE) micrograms/m3, compared to concurrent indoor and outdoor concentrations of 95 +/- 6 micrograms/m3. This suggested the existence of excess mass near the person, a "personal cloud" that appeared related to personal activities. Fourteen of 15 prevalent elements also were evaluated in the personal samples. The two major indoor sources of indoor particles were smoking and cooking; even in these homes, however, more than half of the indoor particles came from outdoors, and a substantial portion of the indoor particles were of undetermined indoor origin. Outdoor concentrations near the homes were well correlated with outdoor concentrations at the central site, supporting the idea of using the central site as an indicator of of ambient concentrations over a wider area. Indoor concentrations were only weakly correlated with outdoor concentrations, however, and personal exposures were even more poorly correlated with outdoor concentrations. Elemental profiles were obtained for environmental tobacco smoke (ETS) (major contributions from potassium and chlorine) and cooking emissions (aluminum, iron, calcium, and chlorine). These profiles can be used in future source apportionment studies. PMID:8777374

  8. Diesel exhaust particles induce CYP1A1 and pro-inflammatory responses via differential pathways in human bronchial epithelial cells

    PubMed Central

    2010-01-01

    Background Exposure to diesel engine exhaust particles (DEPs) has been associated with several adverse health outcomes in which inflammation seems to play a key role. DEPs contain a range of different inorganic and organic compounds, including polycyclic aromatic hydrocarbons (PAHs). During the metabolic activation of PAHs, CYP1A1 enzymes are known to play a critical role. In the present study we investigated the potential of a characterised sample of DEPs to induce cytotoxicity, to influence the expression of CYP1A1 and inflammation-related genes, and to activate intracellular signalling pathways, in human bronchial epithelial cells. We specifically investigated to what extent DEP-induced expression of interleukin (IL)-6, IL-8 and cyclooxygenase (COX)-2 was regulated differentially from DEP-induced expression of CYP1A1. Results The cytotoxicity of the DEPs was characterised by a marked time- and concentration-dependent increase in necrotic cells at 4 h and above 200 ?g/ml (~ 30 ?g/cm2). DEP-induced DNA-damage was only apparent at high concentrations (? 200 ?g/ml). IL-6, IL-8 and COX-2 were the three most up-regulated genes by the DEPs in a screening of 20 selected inflammation-related genes. DEP-induced expression of CYP1A1 was detected at very low concentrations (0.025 ?g/ml), compared to the expression of IL-6, IL-8 and COX-2 (50-100 ?g/ml). A CYP1A1 inhibitor (?-naphthoflavone), nearly abolished the DEP-induced expression of IL-8 and COX-2. Of the investigated mitogen-activated protein kinases (MAPKs), the DEPs induced activation of p38. A p38 inhibitor (SB202190) strongly reduced DEP-induced expression of IL-6, IL-8 and COX-2, but only moderately affected the expression of CYP1A1. The DEPs also activated the nuclear factor-?B (NF-?B) pathway, and suppression by siRNA tended to reduce the DEP-induced expression of IL-8 and COX-2, but not CYP1A1. Conclusion The present study indicates that DEPs induce both CYP1A1 and pro-inflammatory responses in vitro, but via differential intracellular pathways. DEP-induced pro-inflammatory responses seem to occur via activation of NF-?B and p38 and are facilitated by CYP1A1. However, the DEP-induced CYP1A1 response does not seem to involve NF-?B and p38 activation. Notably, the present study also indicates that expression of CYP1A1 may represent a particular sensitive biomarker of DEP-exposure. PMID:21162728

  9. 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.

  10. Species- and sex-specific responses and recovery of wild, mature pacific salmon to an exhaustive exercise and air exposure stressor.

    PubMed

    Donaldson, Michael R; Hinch, Scott G; Jeffries, Ken M; Patterson, David A; Cooke, Steven J; Farrell, Anthony P; Miller, Kristina M

    2014-03-01

    Despite the common mechanisms that underlie vertebrate responses to exhaustive exercise stress, the magnitude and the timecourse of recovery can be context-specific. Here, we examine how wild, adult male and female pink (Oncorhynchus gorbuscha) and sockeye (Oncorhynchus nerka) salmon respond to and recover from an exhaustive exercise and air exposure stressor, designed to simulate fisheries capture and handling. We follow gill tissue gene expression for genes active in cellular stress, cell maintenance, and apoptosis as well as plasma osmoregulatory, stress, and reproductive indices. The stressor initiated a major stress response as indicated by increased normalised expression of two stress-responsive genes, Transcription Factor JUNB and cytochrome C (pink salmon only). The stressor resulted in increased plasma ion cortisol, lactate, and depressed estradiol (sockeye salmon only). Gene expression and plasma variables showed a general recovery by 24h post-stressor. Species- and sex-specific patterns were observed in stress response and recovery, with pink salmon mounting a higher magnitude stress response for plasma variables and sockeye salmon exhibiting a higher and more variable gene expression profile. These results highlight species- and sex-specific responses of migrating Pacific salmon to simulated fisheries encounters, which contribute new knowledge towards understanding the consequences of fisheries capture-and-release. PMID:24607368

  11. Full Useful Life (120,000 miles) Exhaust Emission Performance of a NOx Adsorber and Diesel Particle Filter Equipped Passenger Car and Medium-duty Engine in Conjunction with Ultra Low Sulfur Fuel (Presentation)

    SciTech Connect

    Thornton, M.; Tatur, M.; Tomazic, D.; Weber, P.; Webb, C.

    2005-08-25

    Discusses the full useful life exhaust emission performance of a NOx (nitrogen oxides) adsorber and diesel particle filter equipped light-duty and medium-duty engine using ultra low sulfur diesel fuel.

  12. 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 ?m. The number as well as mass size distribution for PM 10 was observed to be bi-modal with peaks at 0.3 ?m and 4-5 ?m. The NE emissions did not show any significant trend with change in tire pressure.

  13. Application of Novel Method to Measure Endogenous VOCs in Exhaled Breath Condensate Before and After Exposure to Diesel Exhaust

    EPA Science Inventory

    Polar volatile organic compounds (PVOCs) such as aldehydes, ketones, and alcohols are byproducts of normal human metabolism and are present in exhaled breath and blood. Environmental exposures, individual activities, and disease states can perturb normal metabolic processes and ...

  14. Aconitine "challenge" test reveals a single whole-body exposure to diesel exhaust increases cardiac arrhythmia risk in hypertensive rats

    EPA Science Inventory

    Epidemiological studies demonstrate a significant association between cardiac electrical dysfunction, arrhythmias and air pollution exposure. Sensitivity to aconitine-induced arrhythmia has been used repeatedly to examine the factors that increase the risk of such cardiac electri...

  15. Inflammatory response of lung cells exposed to whole, filtered, and hydrocarbon denuded diesel exhaust.

    PubMed

    Holder, Amara L; Lucas, Donald; Goth-Goldstein, Regine; Koshland, Catherine P

    2007-11-01

    In vitro studies with the organic extracts of diesel particles have suggested that hydrocarbons such as PAH may play a role in an inflammatory response, but these have been limited by the possible artifacts introduced in the particle collection and processing. In this study, we avoid these artifacts and use an activated carbon denuder to remove hydrocarbons from the exhaust stream to investigate their role in the inflammatory response. Human bronchial epithelial cells (16HBE14o) were exposed at the air-cell interface to diluted and aged exhaust from a diesel generator operated at partial and no load conditions. When particles were removed with a filter before cell exposure, exhaust gases accounted for almost half of the response compared to the whole exhaust. Removal of gas phase and a portion of the particle phase hydrocarbons with the denuder decreased the interleukin-8 (IL-8) secretion to unexposed levels. PMID:17767946

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

    EPA Science Inventory

    CONTEXT: Exposure to air pollution can result in the onset of atrial fibrillation. CASE PRESENTATION: We present a case of a 58 year old woman who volunteered to participate in a controlled exposure to concentrated ambient particles (CAPs). Twenty minutes into the exposure, there...

  17. PERSONAL EXPOSURE TO PARTICLES IN BANSKA BYSTRICA, SLOVAKIA

    EPA Science Inventory

    Epidemiological studies have associated adverse health impacts with ambient concentrations of particulate matter (PM), though these studies have been limited in their characterization of personal exposure to PM. An exposure study of healthy nonsmoking adults and children was cond...

  18. Part 3. Assessment of genotoxicity and oxidative damage in rats after chronic exposure to new-technology diesel exhaust in the ACES bioassay.

    PubMed

    Hallberg, Lance M; Ward, Jonathan B; Hernandez, Caterina; Ameredes, Bill T; Wickliffe, Jeffrey K

    2015-01-01

    In 2001, the U.S. Environmental Protection Agency (EPA*) and the California Air Resources Board (CARB) adopted new standards for diesel fuel and emissions from heavy-duty diesel engines. By 2007, diesel engines were required to meet these new standards for particulate matter (PM), with other standards to follow. Through a combination of advanced compression-ignition engine technology, development of exhaust aftertreatment systems, and reformulated fuels, stringent standards were introduced. Before the 2007 standards were put in place by the EPA, human health effects linked to diesel exhaust (DE) exposure had been associated with diesel-fuel solvent and combustion components. In earlier research, diesel engine exhaust components were, in turn, linked to increased mutagenicity in cultures of Salmonella typhimurium and mammalian cells (Tokiwa and Ohnishi 1986). In addition, DE was shown to increase both the incidence of tumors and the induction of 8-hydroxy-deoxyguanosine (8-OHdG) adducts in rodents (Ichinose et al. 1997) and total DNA adducts in rats (Bond et al. 1990). Furthermore, DE is composed of a complex mixture of polycyclic aromatic hydrocarbons (PAHs) and particulates. One such PAH, 3-nitrobenzanthrone (3-NBA), is also found in urban air. 3-NBA has been observed to induce micronucleus formation in the DNA of human hepatoma cells (Lamy et al. 2004). The current study is part of the Advanced Collaborative Emissions Study (ACES), a multidisciplinary program carried out by the Health Effects Institute and the Coordinating Research Council. Its purpose was to determine whether recent improvements in the engineering of heavy-duty diesel engines reduce the toxicity associated with exposure to DE components. To this end, we evaluated potential genotoxicity and induction of oxidative stress in bioassays of serum and tissues from Wistar Han rats chronically exposed--for up to 24 months--to DE from a 2007-compliant diesel engine (new-technology diesel exhaust, or NTDE). Genotoxicity was measured as DNA strand breaks in lung tissue, using an alkaline-modified comet assay. As a correlate of possible DNA damage evaluated in the comet assay, concentrations of the free DNA adduct 8-OHdG were evaluated in serum by a competitive enzyme-linked immunosorbent assay (ELISA). The 8-OHdG fragment found in the serum is a specific biomarker for the repair of oxidative DNA damage. In addition, an assay for thiobarbituric acid reactive substances (TBARS) was used to assess oxidative stress and damage in the form of lipid peroxidation in the hippocampus region of the brains of the DE-exposed animals. These endpoints were evaluated at 1, 3, 12, and 24 months of exposure to DE or to a control atmosphere (filtered air). At the concentrations of DE evaluated, there were no significant effects of exposure in male or female rats after 1, 3, 12, or 24 months in any measure of DNA damage in the comet assay (%DNA in tail, tail length, tail moment, or olive moment). The comparison of exposure groups versus control and the comparison of groups by sex for 1 and 3 months of exposure showed no significant differences in serum 8-OHdG concentrations (P > 0.05). The concentrations of 8-OHdG in all exposure groups at 3 months were higher than those in exposure groups at any other time point (P < 0.05). Looking at the levels of 8-OHdG in serum in the 12-month and 24-month groups, we saw a significant difference from control in the 12-month group at the mid and high levels (P < 0.05), as well as some other scattered changes. Sex differences were noted in the 12-month high-level group (P < 0.05). However, these differences did not follow an exposure-dependent pattern. All other comparisons were not significant (P > 0.05). Hippocampal concentrations of TBARs, measured as malondialdehyde (MDA), showed some small and scattered changes in groups exposed to different levels of DE and at different time points, but we did not consider these to be exposure-related. We concluded that exposure to DE in these rats did not produce any significant increase in o

  19. Airborne concentrations of PM(2.5) and diesel exhaust particles on Harlem sidewalks: a community-based pilot study.

    PubMed Central

    Kinney, P L; Aggarwal, M; Northridge, M E; Janssen, N A; Shepard, P

    2000-01-01

    Residents of the dense urban core neighborhoods of New York City (NYC) have expressed increasing concern about the potential human health impacts of diesel vehicle emissions. We measured concentrations of particulate matter [less than/equal to] 2.5 micro in aerodynamic diameter (PM(2.5)) and diesel exhaust particles (DEP) on sidewalks in Harlem, NYC, and tested whether spatial variations in concentrations were related to local diesel traffic density. Eight-hour (1000-1800 hr) air samples for PM(2.5 )and elemental carbon (EC) were collected for 5 days in July 1996 on sidewalks adjacent to four geographically distinct Harlem intersections. Samples were taken using portable monitors worn by study staff. Simultaneous traffic counts for diesel trucks, buses, cars, and pedestrians were carried out at each intersection on [Greater/equal to] 2 of the 5 sampling days. Eight-hour diesel vehicle counts ranged from 61 to 2,467 across the four sites. Mean concentrations of PM(2.5) exhibited only modest site-to-site variation (37-47 microg/m(3)), reflecting the importance of broader regional sources of PM(2.5). In contrast, EC concentrations varied 4-fold across sites (from 1.5 to 6 microg/m(3)), and were associated with bus and truck counts on adjacent streets and, at one site, with the presence of a bus depot. A high correlation (r = 0.95) was observed between EC concentrations measured analytically and a blackness measurement based on PM(2.5) filter reflectance, suggesting the utility of the latter as a surrogate measure of DEP in future community-based studies. These results show that local diesel sources in Harlem create spatial variations in sidewalk concentrations of DEP. The study also demonstrates the feasibility of a new paradigm for community-based research involving full and active partnership between academic scientists and community-based organizations. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:10706526

  20. Influence of physical and chemical characteristics of diesel fuels and exhaust emissions on biological effects of particle extracts: a multivariate statistical analysis of ten diesel fuels.

    PubMed

    Sjögren, M; Li, H; Banner, C; Rafter, J; Westerholm, R; Rannug, U

    1996-01-01

    The emission of diesel exhaust particulates is associated with potentially severe biological effects, e.g., cancer. The aim of the present study was to apply multivariate statistical methods to identify factors that affect the biological potency of these exhausts. Ten diesel fuels were analyzed regarding physical and chemical characteristics. Particulate exhaust emissions were sampled after combustion of these fuels on two makes of heavy duty diesel engines. Particle extracts were chemically analyzed and tested for mutagenicity in the Ames test. Also, the potency of the extracts to competitively inhibit the binding of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to the Ah receptor was assessed. Relationships between fuel characteristics and biological effects of the extracts were studied, using partial least squares regression (PLS). The most influential chemical fuel parameters included the contents of sulfur, certain polycyclic aromatic compounds (PAC), and naphthenes. Density and flash point were positively correlated with genotoxic potency. Cetane number and upper distillation curve points were negatively correlated with both mutagenicity and Ah receptor affinity. Between 61% and 70% of the biological response data could be explained by the measured chemical and physical factors of the fuels. By PLS modeling of extract data versus the biological response data, 66% of the genotoxicity could be explained, by 41% of the chemical variation. The most important variables, associated with both mutagenicity and Ah receptor affinity, included 1-nitropyrene, particle bound nitrate, indeno[1,2,3-cd]pyrene, and emitted mass of particles. S9-requiring mutagenicity was highly correlated with certain PAC, whereas S9-independent mutagenicity was better correlated with nitrates and 1-nitropyrene. The emission of sulfates also showed a correlation both with the emission of particles and with the biological effects. The results indicate that fuels with biologically less hazardous potentials should have high cetane number and contain less PAC and sulfur. The results also indicate that engine factors affect the formation and emission of nitrated PAC. PMID:8924591

  1. Prediction of frequency and exposure level of solar particle events.

    PubMed

    Kim, Myung-Hee Y; Hayat, Matthew J; Feiveson, Alan H; Cucinotta, Francis A

    2009-07-01

    For future space missions outside of the Earth's magnetic field, the risk of radiation exposure from solar particle events (SPEs) during extra-vehicular activities (EVAs) or in lightly shielded vehicles is a major concern when designing radiation protection including determining sufficient shielding requirements for astronauts and hardware. While the expected frequency of SPEs is strongly influenced by solar modulation, SPE occurrences themselves are chaotic in nature. We report on a probabilistic modeling approach, where a cumulative expected occurrence curve of SPEs for a typical solar cycle was formed from a non-homogeneous Poisson process model fitted to a database of proton fluence measurements of SPEs that occurred during the past 5 solar cycles (19-23) and those of large SPEs identified from impulsive nitrate enhancements in polar ice. From the fitted model, we then estimated the expected frequency of SPEs at any given proton fluence threshold with energy >30 MeV (Phi(30)) during a defined space mission period. Analytic energy spectra of 34 large SPEs observed in the space era were fitted over broad energy ranges extending to GeV, and subsequently used to calculate the distribution of mGy equivalent (mGy-Eq) dose for a typical blood-forming organ (BFO) inside a spacecraft as a function of total Phi(30) fluence. This distribution was combined with a simulation of SPE events using the Poisson model to estimate the probability of the BFO dose exceeding the NASA 30-d limit of 250 mGy-Eq per 30 d. These results will be useful in implementing probabilistic risk assessment approaches at NASA and guidelines for protection systems for astronauts on future space exploration missions. PMID:19509510

  2. Reducing silica and dust exposures in construction during use of powered concrete-cutting hand tools: efficacy of local exhaust ventilation on hammer drills.

    PubMed

    Shepherd, S; Woskie, S R; Holcroft, C; Ellenbecker, M

    2009-01-01

    Concrete cutting in construction is a major source of exposure to respirable crystalline silica. To reduce exposures, local exhaust ventilation (LEV) may be integrated into the hand tools used in concrete cutting. Volunteers from the New England Laborers Training Center participated in a field study focused on the use of LEV on concrete-cutting hammer drills. A randomized block design field experiment employing four workers measured the efficacy of four hood-vacuum source combinations compared with no LEV in reducing dust and silica exposures. Using four-stage personal cascade impactors (Marple 294) to measure dust exposure, a total of 18 personal samples were collected. Reductions of over 80% in all three biologically relevant size fractions of dust (inhalable, thoracic, and respirable) were obtained by using any combination of hood and vacuum source. This study found that respirable dust concentrations were reduced from 3.77 mg/m(3) to a range of 0.242 to 0.370 mg/m(3); thoracic dust concentrations from 12.5 mg/m(3) to a range of 0.774 to 1.23 mg/m(3); and inhalable dust concentration from 47.2 mg/m(3) to a range of 2.13 to 6.09 mg/m(3). Silica concentrations were reduced from 0.308 mg/m(3) to a range of 0.006 to 0.028 mg/m(3) in the respirable size fraction, from 0.821 mg/m(3) to a range of 0.043 to 0.090 mg/m(3) in the thoracic size fraction, and from 2.71 mg/m(3) to a range of 0.124 to 0.403 mg/m(3) in the inhalable size fraction. Reductions in dust concentrations while using the four LEV systems were not statistically significantly different from each other. PMID:19005968

  3. Circulating factors induce coronary endothelial ceIl activation foIlowing exposure to inhaled diesel exhaust and nitrogen dioxide in humans :Evidence from a novel translational in vitro model

    EPA Science Inventory

    The vascular toxicity of inhaled agents may be caused by soluble factors that are released into the systemic circulation. To confirm this in a straightforward manner, we obtained plasma from healthy human volunteers before and after exposure to diesel exhaust (DE) and nitrogen di...

  4. 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.

  5. FINE PARTICLE EXPOSURE IS ASSOCIATED WITH ALTERED VENTRICULAR REPOLARIZATION

    EPA Science Inventory

    Exposure to fine airborne particulate matter (PM2.5) has previously been associated with cardiac events, especially in older people with cardiovascular disease and in diabetics. This study examined the cardiac effects of short-term exposures to ambient PM2.5 in a prospective pane...

  6. Pedestrian Exposure to Size-Resolved Particles in Milan

    Microsoft Academic Search

    Giovanni Lonati; Senem Ozgen; Giovanna Ripamonti; Stefano Cernuschi; Michele Giugliano

    2011-01-01

    Measurement campaigns for airborne particles along a pedestrian route in the city center of Milan were performed by means of a portable instrument consisting of an optical particle counter and a global positioning system (GPS) signal receiver. Based on the size-resolved particle number concentration data and on proper density factors experimentally determined for Milan urban area, the mass concentrations were

  7. On-road and laboratory investigations on non-exhaust ultrafine particles from the interaction between the tire and road pavement under braking conditions

    NASA Astrophysics Data System (ADS)

    Kwak, Jihyun; Lee, Sunyoup; Lee, Seokhwan

    2014-11-01

    We investigated the physical and chemical characteristics of non-exhaust ultrafine particles from on-road driving and laboratory measurements using a mobile sampling vehicle. The on-road driving and laboratory measurements during constant speed conditions revealed no enhancement of ultrafine particles. Under braking events, the total number concentrations of tire particles (TPs) sampled 90 mm above the road surface was 6 times higher with broader mode diameters when compared to 40 mm above the road surface. In contrast to braking events, under cornering conditions, the total number concentrations of TPs sampled 40 mm above the road surface were 50 times higher relative to 90 mm above the road surface. From the morphological and elemental analyses, it is likely that the ultrafine particles generated from the interaction between the tire and the road surface under braking conditions might originated from sulfur-containing materials or anti-oxidants which are contained in TPs, and/or graphite and solid lubricants which are mainly present in brake particles (BPs). However, Zn which was a distinguishing elemental marker of tire wear particles didn't show in EDS spectra. Further research would be required as to the exact emission source of ultrafine particles.

  8. 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.

  9. MicroRNA Expression in Response to Controlled Exposure to Diesel Exhaust: Attenuation by the Antioxidant N-Acetylcysteine in a Randomized Crossover Study

    PubMed Central

    Yamamoto, Masatsugu; Singh, Amrit; Sava, Francesco; Pui, Mandy; Tebbutt, Scott J.

    2013-01-01

    Background: Adverse health effects associated with diesel exhaust (DE) are thought to be mediated in part by oxidative stress, but the detailed mechanisms are largely unknown. MicroRNAs (miRNAs) regulate gene expression post-transcriptionally and may respond to exposures such as DE. Objectives: We profiled peripheral blood cellular miRNAs in participants with mild asthma who were exposed to controlled DE with and without antioxidant supplementation. Methods: Thirteen participants with asthma underwent controlled inhalation of filtered air and DE in a double-blinded, randomized crossover study of three conditions: a) DE plus placebo (DEP), b) filtered air plus placebo (FAP), or c) DE with N-acetylcysteine supplementation (DEN). Total cellular RNA was extracted from blood drawn before exposure and 6 hr after exposure for miRNA profiling by the NanoString nCounter assay. MiRNAs significantly associated with DEP exposure and a predicted target [nuclear factor (erythroid-derived 2)-like 2 (NRF2)] as well as antioxidant enzyme genes were assessed by reverse transcription–quantitative polymerase chain reaction (RT-qPCR) for validation, and we also assessed the ability of N-acetylcysteine supplementation to block the effect of DE on these specific miRNAs. 8-hydroxy-2´-deoxyguanosine (8-OHdG) was measured in plasma as a systemic oxidative stress marker. Results: Expression of miR-21, miR-30e, miR-215, and miR-144 was significantly associated with DEP. The change in miR-144 was validated by RT-qPCR. NRF2 and its downstream antioxidant genes [glutamate cysteine ligase catalytic subunit (GCLC) and NAD(P)H:quinone oxidoreductase 1 (NQO1)] were negatively associated with miR-144 levels. Increases in miR-144 and miR-21 were associated with plasma 8-hydroxydeoxyguanosine 8-OHdG level and were blunted by antioxidant (i.e, DEN). Conclusions: Systemic miRNAs with plausible biological function are altered by acute moderate-dose DE exposure. Oxidative stress appears to mediate DE-associated changes in miR-144. PMID:23584289

  10. 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 cabin air filters may result in further diminishing the biomedical effects of diesel exhaust in subjects exposed in traffic and workplaces.   PMID:10450238

  11. 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...

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

    SciTech Connect

    Mauderly, J.L.; Bice, D.E.; Cheng, Y.S.; Gillett, N.A.; Griffith, W.C.; Henderson, R.F.; Pickrell, J.A.; Wolff, R.K. (Inhalation Toxicology Research Institute, Albuquerque, NM (USA))

    1990-05-01

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

  13. 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...

  14. EXPOSURE RELATIONSHIP OF PERSONAL EXPOSURE OF HIGH-RISK SUBPOPULATIONS TO AMBIENT CONCENTRATIONS OF FINE PARTICLES.

    EPA Science Inventory

    An association has been demonstrated between ambient particulate matter (PM 2.5 and PM 10) concentrations and human morbidity/mortality. However, little is known regarding the most important sources of PM exposure, interpersonal and intrapersonal variability in exposure, and the...

  15. Exhaust Fine Particle and Nitrogen Oxide Emissions from Individual Heavy-Duty Trucks at the Port of Oakland

    NASA Astrophysics Data System (ADS)

    Dallmann, T. R.; Harley, R. A.; Kirchstetter, T.

    2010-12-01

    Heavy-duty (HD) diesel trucks are a source of nitrogen oxide (NOx) emissions as well as primary fine particulate matter (PM2.5) that includes black carbon (BC) as a major component. Heavy-duty trucks contribute significantly to elevated levels of diesel particulate matter found near highways and in communities surrounding major freight-handling facilities. To reduce the air quality impact of diesel engine emissions, the California Air Resources Board has adopted new rules requiring the retrofit or replacement of in-use HD trucks. These rules take effect during 2010 at ports and railyards, and apply to all trucks operating in California by 2014. This study involves on-road measurements of PM2.5, BC, and NOx emission factor distributions from individual HD trucks driving into the Port of Oakland in the San Francisco Bay area. Measurements of exhaust plumes from individual trucks were made using a mobile laboratory equipped with fast time response (1 Hz) PM2.5, BC, NOx, and carbon dioxide (CO2) sensors. The mobile laboratory was stationed on an overpass above an arterial roadway that connects the Port to a nearby highway (I-880). The air sampling inlet was thereby located above the vertical exhaust pipes of HD diesel trucks passing by on the arterial roadway below. Fuel-specific PM2.5, BC, and NOx emission factors for individual trucks were calculated using a carbon balance method in which concentrations of these species in an exhaust plume are normalized to CO2 concentrations. Initial field sampling was conducted in November, 2009 prior to the implementation of new emission rules. Additional emission measurements were made at the same location during June 2010 and emission factor distributions and averages will be compared.

  16. Dietary modulation of the effects of exposure to 56FE particles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 and other age-related diseases, due to increases in oxidative stress. However, there are signif...

  17. TOTAL HUMAN EXPOSURE MODEL (THEM) FOR RESPIRABLE SUSPENDED PARTICLES (RSP)

    EPA Science Inventory

    A Total Human Exposure Model (THEM) has been developed that calculates 24-hour profiles using real human activity patterns and indoor air models derived from actual measurements of pollutants. HEM was designed for implementation on personal computers. urrently, the model uses the...

  18. Analysis results of micron-sized particles captured by space material exposure experiment

    NASA Astrophysics Data System (ADS)

    Kimoto, Yugo

    Space material exposure experiments were performed on the International Space Station (ISS) using the Micro-Particles Capturer and the Space Environment Exposure Device (MPAC&SEED) developed by the Japan Aerospace Exploration Agency (JAXA). MPAC is a passive experiment designed to evaluate the dust (micrometeoroid and space debris) environment and to capture particle residues for subsequent chemical analysis. We found many unexpected micron-sized particles that did not make impact with hypervelocity. The diameter of these particles is in the order of micrometers. It is difficult to analyze these particles because they are too small to handle from aerogels. Also, their colorless and transparent nature prevents us from handling them after extraction. In final paper, I present the analysis results of this micron-sized particles

  19. Protective effects of pulmonary epithelial lining fluid on oxidative stress and DNA single-strand breaks caused by ultrafine carbon black, ferrous sulphate and organic extract of diesel exhaust particles.

    PubMed

    Chuang, Hsiao-Chi; Cheng, Yi-Ling; Lei, Yu-Chen; Chang, Hui-Hsien; Cheng, Tsun-Jen

    2013-02-01

    Pulmonary epithelial lining fluid (ELF) is the first substance to make contact with inhaled particulate matter (PM) and interacts chemically with PM components. The objective of this study was to determine the role of ELF in oxidative stress, DNA damage and the production of proinflammatory cytokines following physicochemical exposure to PM. Ultrafine carbon black (ufCB, 15 nm; a model carbonaceous core), ferrous sulphate (FeSO(4); a model transition metal) and a diesel exhaust particle (DEP) extract (a model organic compound) were used to examine the acellular oxidative potential of synthetic ELF and non-ELF systems. We compared the effects of exposure to ufCB, FeSO(4) and DEP extract on human alveolar epithelial Type II (A549) cells to determine the levels of oxidative stress, DNA single-strand breaks and interleukin-8 (IL-8) production in ELF and non-ELF systems. The effects of ufCB and FeSO(4) on the acellular oxidative potential, cellular oxidative stress and DNA single-strand breakage were mitigated significantly by the addition of ELF, whereas there was no decrease following treatment with the DEP extract. There was no significant effect on IL-8 production following exposure to samples that were suspended in ELF/non-ELF systems. The results of the present study indicate that ELF plays an important role in the initial defence against PM in the pulmonary environment. Experimental components, such as ufCB and FeSO(4), induced the production of oxidative stress and led to DNA single-strand breaks, which were moderately prevented by the addition of ELF. These findings suggest that ELF plays a protective role against PM-driven oxidative stress and DNA damage. PMID:23261976

  20. Impact of a ceramic trap and manganese fuel additive on the biological activity and chemical composition of exhaust particles from diesel engines used in underground mines

    SciTech Connect

    Draper, W.M.; Hartmann, H.; Kittelson, D.B.; Watts, W.F.; Baumgard, K.J.

    1987-01-01

    The U.S. Bureau of Mines study examines the effect of a ceramic particle trap and a manganese fuel additive on the mutagenic activity and chemical composition of diesel exhaust particulate matter from a heavy-duty mining engine. Particles were collected by dilution tunnel sampling from a four-cylinder, Caterpillar 3304, naturally aspirated, indirect-injection engine operated at six steady-state conditions. Depending on engine load and speed, the ceramic particle trap reduced the following emissions: particulate matter, 80 to 94 pct; soluble organic fraction (SOF), 83 to 95 pct; 1-nitropyrene, 94 to 96 pct; and SOF mutagenicity, 72 pct (cycle-weighted average). When the Mn fuel additive was used without a ceramic particle trap, the total cycle mutagenic activity emitted increased seven-fold, in part due to elevated emissions of 1-nitropyrne. When used with the trap at the recommended concentration the Mn additive lowers the trap regenerations temperature by 65{sup 0}C, SOF removal efficiency from 86 to 62 pct, and removal efficiency for mutagenic substances from 72 to 43 pct.

  1. ECG Parameters and Exposure to Carbon Ultrafine Particles in Young Healthy Subjects

    PubMed Central

    Zareba, Wojciech; Couderc, Jean Philippe; Oberdörster, Günter; Chalupa, David; Cox, Christopher; Huang, Li-Shan; Peters, Annette; Utell, Mark J.; Frampton, Mark W.

    2010-01-01

    The mechanisms underlying the association between air pollution and cardiovascular morbidity and mortality are unknown. This study aimed to determine whether controlled exposure to elemental carbon ultrafine particles (UFP) affects electrocardiogram (ECG) parameters describing heart rate variability; repolarization duration, morphology, and variability; and changes in the ST segment. Two separate controlled studies (12 subjects each) were performed using a crossover design, in which each subject was exposed to filtered air and carbon UFP for 2 hours. The first protocol involved 2 exposures to air and 10 µg/m3 (~ 2 × 106 particles/cm3, count median diameter ~25 nm, geometric standard deviation ~1.6), at rest. The second protocol included 3 exposures to air, 10, and 25 µg/m3 UFP (~ 7 × 106 particles/cm3), with repeated exercise. Each subject underwent a continuous digital 12-lead ECG Holter recording to analyze the above ECG parameters. Repeated measures analysis of variance (ANOVA) was used to compare tested parameters between exposures. The observed responses to UFP exposure were small and generally not significant, although there were trends indicating an increase in parasympathetic tone, which is most likely also responsible for trends toward ST elevation, blunted QTc shortening, and increased variability of T-wave complexity after exposure to UFP. Recovery from exercise showed a blunted response of the parasympathetic system after exposure to UFP in comparison to air exposure. In conclusion, transient exposure to 10–25 µg/m3 ultrafine carbon particles does not cause marked changes in ECG-derived parameters in young healthy subjects. However, trends are observed indicating that some subjects might be susceptible to air pollution, with a response involving autonomic modulation of the heart and repolarization of the ventricular myocardium. PMID:18991063

  2. In-cabin commuter exposure to ultrafine particles on Los Angeles freeways.

    PubMed

    Zhu, Yifang; Eiguren-Fernandez, Arantzazu; Hinds, William C; Miguel, Antonio H

    2007-04-01

    Worldwide people are exposed to toxic ultrafine particles (UFP, with diameters (dp) less than 100 nm) and nanoparticles (NP, dp < 50 nm) under a variety of circumstances. To date, very limited information is available on human exposure to freshly emitted UFP and NP while traveling on major roads and freeways. We report in-cabin and outdoor measurements of particle number concentration and size distributions while driving three vehicles on Los Angeles freeways. Particle number concentrations and size distributions were measured under different vehicle ventilation settings. When the circulation fan was set to on, with substantial external air intake, outside changes in particle counts caused corresponding in-cabin changes approximately 30-60 s later, indicating an maximal air exchange rate of about 120-60 h(-1). Maximum in-cabin protection (approximately 85%) was obtained when both fan and recirculation were on. In-cabin and outdoor particle size distributions in the 7.9-217 nm range were observed to be mostly bimodal, with the primary peak occurring at 10-30 nm and the secondary at 50-70 nm. The vehicle's manufacture-installed particle filter offered an in-cabin protection of about 50% for particles in the 7-40 nm size range and 20-30% for particles in the 40 to approximately 200 nm size range. For an hour daily commute exposure, the in-vehicle microenvironment contributes approximately 10-50% of people's daily exposure to UFP from traffic. PMID:17438754

  3. Sociodemographic descriptors of personal exposure to fine particles (PM2.5) in EXPOLIS Helsinki.

    PubMed

    Rotko, T; Koistinen, K; Hänninen, O; Jantunen, M

    2000-01-01

    Demographic and socioeconomic differences between population sub-groups were analyzed, as a component of the EXPOLIS (Air Pollution Exposure Distributions Within Adult Urban Populations in Europe) Helsinki study, to explain variation in personal exposures to fine particles (PM2.5). Two-hundred one individuals were randomly selected among 25--55-year-old inhabitants of Helsinki Metropolitan area. Personal exposure samples and residential indoor, residential outdoor and workplace indoor microenvironment measurements of PM2.5 were collected between October 1996 and December 1997. Variation in PM2.5 personal exposures, between sociodemographic sub-groups, was best described by differences in occupational status, education and age. Lower occupational status, less educated and young participants had greater exposures than upper occupational status, more educated and older participants. Different workplace concentrations explained most of the socioeconomic differences, and personal day and night exposures and concentrations in home (but not workplace or outdoor concentrations) caused the PM2.5 exposure differences between age groups. Men had higher exposures and much larger exposure differences between the sociodemographic groups than women. No gender, socioeconomic or age differences were observed in home outdoor concentrations between groups. Exposure to tobacco smoke did not seem to create new differences between the sociodemographic groups; instead, it amplified the existing differences. PMID:10981732

  4. Exposure for ultrafine carbon particles at levels below detectable pulmonary inflammation affects cardiovascular performance in spontaneously hypertensive rats*

    EPA Science Inventory

    Rationale: Exposure to particulate matter is a risk factor for cardiopulmonary disease but the related molecular mechanisms are poorly understood. Previously we studied cardiovascular responses in healthy WKY rats following inhalation exposure to ultrafine carbon particles (UfCPs...

  5. NEUROTROPHINS OPERATE AT DIFFERENT LEVELS OF THE RESPIRATORY TRACT IN RESPONSES OF ALLERGIC MICE TO DIESEL EXHAUST PARTICLES (DEP)

    EPA Science Inventory

    Neurotrophins including NGF, NT-3, and BDNF are linked to allergic responses. Treatment with anti-p75 (pan-neurotrophin receptor) prevents the increase in airflow obstruction caused by exposure to DEP in ovalbumin (OVA)-allergic mice (Toxicol Sci 84(S1):91, 2005). Our present goa...

  6. Ultrafine particle emission of waste incinerators and comparison to the exposure of urban citizens.

    PubMed

    Buonanno, Giorgio; Morawska, Lidia

    2015-03-01

    On the basis of the growing interest on the impact of airborne particles on human exposure as well as the strong debate in Western countries on the emissions of waste incinerators, this work reviewed existing literature to: (i) show the emission factors of ultrafine particles (particles with a diameter less than 100nm) of waste incinerators; and (ii) assess the contribution of waste incinerators in terms of ultrafine particles to exposure and dose of people living in the surrounding areas of the plants in order to estimate eventual risks. The review identified only a limited number of studies measuring ultrafine particle emissions, and in general they report low particle number concentrations at the stack (the median value was equal to 5.5×10(3)partcm(-3)), in most cases higher than the outdoor background value. The lowest emissions were achieved by utilization of the bag-house filter which has an overall number-based filtration efficiency higher than 99%. Referring to reference case, the corresponding emission factor is equal to 9.1×10(12)partmin(-1), that is lower than one single high-duty vehicle. Since the higher particle number concentrations found in the most contributing microenvironments to the exposure (indoor home, transportation, urban outdoor), the contribution of the waste incinerators to the daily dose can be considered as negligible. PMID:24726660

  7. Exposure and dose assessment to particle components among an elderly population

    NASA Astrophysics Data System (ADS)

    Almeida-Silva, M.; Almeida, S. M.; Pegas, P. N.; Nunes, T.; Alves, C. A.; Wolterbeek, H. T.

    2015-02-01

    People spend the majority of their time indoors and the composition and toxicity of indoor particles is very complex and present significant differences comparing with outdoor aerosols. Consequently, ambient particles cannot represent a real exposure. The aim of this work was to determine the daily exposure and the daily inhaled dose to particle components of elders living in Elderly Care Centers. A questionnaire was applied to 193 institutionalized elders in order to achieve their daily time pattern and to define the micro-environments where PM10 and its components (carbonaceous components and trace elements) were assessed. Daily exposure was calculated by integrating the elder's time spend in each micro-environment and the concentration of the pollutants for the period of interest. This parameter, together with the inhalation rate and the standard body weight, were used to calculate the daily inhaled dose. PM10 daily exposure and daily inhaled dose ranged between 11 - 16 ?g m-3 and 20 × 10-3 - 28 × 10-3 ?g kg-1, respectively. This work not only allowed a fully quantification of the magnitude of the elders exposure, but also showed that the assessment of the integrated exposure to PM components is determinant to accomplish the dose inhaled by elders living in ECCs.

  8. Dose profiles through the dermis for on and off-skin hot particle exposures

    E-print Network

    Shaw, Kimberly Rochelle

    1993-01-01

    DOSE PROFILES THROUGH THE DERMIS FOR ON AND OFF-SKIN HOT PARTICLE EXPOSURES A Thesis by KIM6ERLY ROCHELLE SHAW Submitted to the Office of Graduate Studies of Texas AIIrM University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE August 1993 Major Subject: Health Physics DOSE PROFILES THROUGH THE DERMIS FOR ON AND OFF-SKIN HOT PARTICLE EXPOSURES A Thesis by KIMBERLY ROCHELLE SHAW Submitted to Texas A&M University in partial fulfillment...

  9. The exposure to coarse, fine and ultrafine particle emissions from concrete mixing, drilling and cutting activities.

    PubMed

    Azarmi, Farhad; Kumar, Prashant; Mulheron, Mike

    2014-08-30

    Building activities generate coarse (PM10?10?m), fine (PM2.5?2.5?m) and ultrafine particles (<100nm) making it necessary to understand both the exposure levels of operatives on site and the dispersion of ultrafine particles into the surrounding environment. This study investigates the release of particulate matter, including ultrafine particles, during the mixing of fresh concrete (incorporating Portland cement with Ground Granulated Blastfurnace Slag, GGBS or Pulverised Fuel Ash, PFA) and the subsequent drilling and cutting of hardened concrete. Particles were measured in the 5-10,000nm size range using a GRIMM particle spectrometer and a fast response differential mobility spectrometer (DMS50). The mass concentrations of PM2.5-10 fraction contributed ?52-64% of total mass released. The ultrafine particles dominated the total particle number concentrations (PNCs); being 74, 82, 95 and 97% for mixing with GGBS, mixing with PFA, drilling and cutting, respectively. Peak values measured during the drilling and cutting activities were 4 and 14 times the background. Equivalent emission factors were calculated and the total respiratory deposition dose rates for PNCs for drilling and cutting were 32.97±9.41×10(8)min(-1) and 88.25±58.82×10(8)min(-1). These are a step towards establishing number and mass emission inventories for particle exposure during construction activities. PMID:25068443

  10. Exposure to ultrafine and fine particles and noise during cycling and driving in 11 Dutch cities

    NASA Astrophysics Data System (ADS)

    Boogaard, Hanna; Borgman, Frank; Kamminga, Jaap; Hoek, Gerard

    Recent studies have suggested that exposures during traffic participation may be associated with adverse health effects. Traffic participation involves relatively short but high exposures. Potentially relevant exposures include ultrafine particles, fine particles (PM 2.5) and noise. Simultaneously, detailed real time exposure of particle number concentration (PNC), PM 2.5 and noise has been measured while driving and cycling 12 predefined routes of approximately 10-20 min duration. Sampling took place in eleven medium-sized Dutch cities on eleven weekdays in August till October 2006. To investigate variability in cyclists exposure, we systematically collected information on meteorology, GPS coordinates, type of road, traffic intensity, passing vehicles and mopeds while cycling. The overall mean PNC of car drivers was 5% higher than the mean PNC of cyclists. The overall mean concentration of PM 2.5 in the car was 11% higher than during cycling. Slightly higher 1-min peak concentrations were measured in the car (PNC 14%; PM 2.5 29% for 95-percentiles). Shorter duration peaks of PNC were higher during cycling (43% for 99-percentile of 1-s averages). Peaks in PNC typically last for less than 10 s. A large variability of exposure was found within and between routes. Factors that significantly predicted PNC variability during cycling were: passing vehicles (mopeds, cars), waiting for traffic lights, passing different types of (large) intersections and bicycle lanes and bike paths close to motorized traffic. No relation was found between PM 2.5 and those predictor variables. The correlation between PNC and noise was moderate (median 0.34). PM 2.5 had very low correlations with PNC and noise. PNC and PM 2.5 exposure of car drivers was slightly higher than that of cyclists. PNC was largely uncorrelated with PM 2.5 and reflected local traffic variables more than PM 2.5. Different factors were associated with high PNC and high noise exposures.

  11. Assessment of Two Portable Real-Time Particle Monitors Used in Nanomaterial Workplace Exposure Evaluations

    PubMed Central

    Liu, Yuewei; Beaucham, Catherine C.; Pearce, Terri A.; Zhuang, Ziqing

    2014-01-01

    Background Nanoparticle emission assessment technique was developed to semi-quantitatively evaluate nanomaterial exposures and employs a combination of filter based samples and portable real-time particle monitors, including a condensation particle counter (CPC) and an optical particle counter (OPC), to detect nanomaterial releases. This laboratory study evaluated the results from CPC and OPC simultaneously measuring a polydisperse aerosol to assess their variability and accuracy. Methods and Results Two CPCs and two OPCs were used to evaluate a polydisperse sodium chloride aerosol within an enclosed chamber. The measurement results for number concentration versus time were compared between paired particle monitors of the same type, and to results from the Scanning Mobility Particle Spectrometer (SMPS) which was widely used to measure concentration of size-specific particles. According to analyses by using the Bland-Altman method, the CPCs displayed a constant mean percent difference of ?3.8% (95% agreement limits: ?9.1 to 1.6%; range of 95% agreement limit: 10.7%) with the chamber particle concentration below its dynamic upper limit (100,000 particles per cubic centimeter). The mean percent difference increased from ?3.4% to ?12.0% (range of 95% agreement limits: 7.1%) with increasing particle concentrations that were above the dynamic upper limit. The OPC results showed the percent difference within 15% for measurements in particles with size ranges of 300 to 500 and 500 to 1000 regardless of the particle concentration. Compared with SMPS measurements, the CPC gave a mean percent difference of 22.9% (95% agreement limits: 10.5% to 35.2%); whereas the measurements from OPC were not comparable. Conclusions This study demonstrated that CPC and OPC are useful for measuring nanoparticle exposures but the results from an individual monitor should be interpreted based upon the instrument's technical parameters. Future research should challenge these monitors with particles of different sizes, shapes, or composition, to determine measurement comparability and accuracy across various workplace nanomaterials. PMID:25148239

  12. Effects of exposure to heavy particles and aging on object recognition memory in rats

    NASA Astrophysics Data System (ADS)

    Rabin, Bernard; Joseph, James; Shukitt-Hale, Barbara; Carrihill-Knoll, Kirsty; Shannahan, Ryan; Hering, Kathleen

    Exposure to HZE particles produces changes in neurocognitive performance. These changes, including deficits in spatial learning and memory, object recognition memory and operant responding, are also observed in the aged organism. As such, it has been proposed that exposure to heavy particles produces "accelerated aging". Because aging is an ongoing process, it is possible that there would be an interaction between the effects of exposure and the effects of aging, such that doses of HZE particles that do not affect the performance of younger organisms will affect the performance of organisms as they age. The present experiments were designed to test the hypothesis that young rats that had been exposed to HZE particles would show a progressive deterioration in object recognition memory as a function of the age of testing. Rats were exposed to 12 C, 28 S or 48 Ti particles at the N.A.S.A. Space Radiation Laboratory at Brookhaven National Laboratory. Following irradiation the rats were shipped to UMBC for behavioral testing. HZE particle-induced changes in object recognition memory were tested using a standard procedure: rats were placed in an open field and allowed to interact with two identical objects for up to 30 sec; twenty-four hrs later the rats were again placed in the open field, this time containing one familiar and one novel object. Non-irradiated control animals spent significantly more time with the novel object than with the familiar object. In contrast, the rats that been exposed to heavy particles spent equal amounts of time with both the novel and familiar object. The lowest dose of HZE particles which produced a disruption of object recognition memory was determined three months and eleven months following exposure. The threshold dose needed to disrupt object recognition memory three months following irradiation varied as a function of the specific particle and energy. When tested eleven months following irradiation, doses of HZE particles that did not did not affect the performance of the younger rats did affect the performance of the older rats. For all particles the dose of radiation which produced a disruption of object recognition memory was lower when the rats were tested eleven months following irradiation than when the rats were tested 3 months following exposure.

  13. Part 1. Biologic responses in rats and mice to subchronic inhalation of diesel exhaust from U.S. 2007-compliant engines: report on 1-, 3-, and 12-month exposures in the ACES bioassay.

    PubMed

    Mcdonald, Jacob D; Doyle-Eisele, Melanie; Gigliotti, Andrew; Miller, Rodney A; Seilkop, Steve; Mauderly, Joe L; Seagrave, JeanClare; Chow, Judith; Zielinska, Barbara

    2012-09-01

    The Health Effects Institute and its partners conceived and funded a program to characterize the emissions from heavy-duty diesel engines compliant with the 2007 and 2010 on-road emissions standards in the United States and to evaluate indicators of lung toxicity in rats and mice exposed repeatedly to diesel exhaust (DE*) from 2007-compliant engines. The preliminary hypothesis of this Advanced Collaborative Emissions Study (ACES) was that 2007-compliant on-road diesel emissions ". . . will not cause an increase in tumor formation or substantial toxic effects in rats and mice at the highest concentration of exhaust that can be used . . . although some biological effects may occur." This hypothesis is being tested at the Lovelace Respiratory Research Institute (LRRI) by exposing rats by chronic inhalation as a carcinogenicity bioassay, measuring indicators of pulmonary toxicity in rats after 1, 3, 12, and 24-30 months of exposure (final time point depends on the survival of animals), and measuring similar indicators of pulmonary toxicity in mice after 1 and 3 months of exposure. This report provides results of exposures through 3 months in rats and mice. Emissions from a 2007-compliant, 500-horsepower-class engine and aftertreatment system operated on a variable-duty cycle were used to generate the animal inhalation test atmospheres. Four treatment groups were exposed to one of three concentrations (dilutions) of exhaust combined with crankcase emissions, or to clean air as a negative control. Dilutions of exhaust were set to yield average integrated concentrations of 4.2, 0.8, and 0.1 ppm nitrogen dioxide (NO2). Exposure atmospheres were analyzed by daily measurements of key components and periodic detailed physical-chemical characterizations. Exposures were conducted 16 hr/dy (overnight), 5 dy/wk. Rats were evaluated for hematology, serum chemistry, bronchoalveolar lavage (BAL), lung cell proliferation, and histopathology after 1 month of exposure, and the same indicators plus pulmonary function after 3 months. Mice were evaluated for BAL, lung cell proliferation, and respiratory tract histopathology after 1 month of exposure, and the same indicators plus hematology and serum chemistry after 3 months. Samples from both species were collected for ancillary studies performed by investigators who were not at LRRI and were funded separately. Exposures were accomplished as planned, with average integrated exposure concentrations within 20% of the target dilutions. The major components were the gaseous inorganic compounds, nitrogen monoxide (NO), NO2, and carbon monoxide (CO). Minor components included low concentrations of diesel particulate matter (DPM) and volatile and semivolatile organic compounds (VOCs and SVOCs). There were no exposure-related differences in mortality or clinically evident morbidity. Among the more than 100 biologic response variables evaluated, the majority showed no significant difference from control as a result of exposure to DE. There was evidence of early lung changes in the rats, accompanied by a number of statistically significant increases in inflammatory and oxidative stress indicators, and some evidence of subtle changes in pulmonary function. In general, statistically significant effects were observed only at the highest exposure level. The mice did not have the same responses as the rats, but did have small but statistically significant increases in lavage neutrophils and the cytokine IL-6 at 1 month (but not at 3 months). These findings suggest that the rats were more sensitive than mice to the subchronic exposures. PMID:23156840

  14. Protective effects of pulmonary epithelial lining fluid on oxidative stress and DNA single-strand breaks caused by ultrafine carbon black, ferrous sulphate and organic extract of diesel exhaust particles

    SciTech Connect

    Chuang, Hsiao-Chi [School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei, Taiwan (China) [School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Division of Pulmonary Medicine, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan (China); Cheng, Yi-Ling; Lei, Yu-Chen [Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan (China)] [Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan (China); Chang, Hui-Hsien [Institute of Environmental Health, College of Public Health, National Taiwan University, Taipei, Taiwan (China)] [Institute of Environmental Health, College of Public Health, National Taiwan University, Taipei, Taiwan (China); Cheng, Tsun-Jen, E-mail: tcheng@ntu.edu.tw [Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan (China) [Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan (China); Department of Public Health, College of Public Health, National Taiwan University, Taipei, Taiwan (China)

    2013-02-01

    Pulmonary epithelial lining fluid (ELF) is the first substance to make contact with inhaled particulate matter (PM) and interacts chemically with PM components. The objective of this study was to determine the role of ELF in oxidative stress, DNA damage and the production of proinflammatory cytokines following physicochemical exposure to PM. Ultrafine carbon black (ufCB, 15 nm; a model carbonaceous core), ferrous sulphate (FeSO{sub 4}; a model transition metal) and a diesel exhaust particle (DEP) extract (a model organic compound) were used to examine the acellular oxidative potential of synthetic ELF and non-ELF systems. We compared the effects of exposure to ufCB, FeSO{sub 4} and DEP extract on human alveolar epithelial Type II (A549) cells to determine the levels of oxidative stress, DNA single-strand breaks and interleukin-8 (IL-8) production in ELF and non-ELF systems. The effects of ufCB and FeSO{sub 4} on the acellular oxidative potential, cellular oxidative stress and DNA single-strand breakage were mitigated significantly by the addition of ELF, whereas there was no decrease following treatment with the DEP extract. There was no significant effect on IL-8 production following exposure to samples that were suspended in ELF/non-ELF systems. The results of the present study indicate that ELF plays an important role in the initial defence against PM in the pulmonary environment. Experimental components, such as ufCB and FeSO{sub 4}, induced the production of oxidative stress and led to DNA single-strand breaks, which were moderately prevented by the addition of ELF. These findings suggest that ELF plays a protective role against PM-driven oxidative stress and DNA damage. -- Highlights: ? To determine the role of ELF in ROS, DNA damage and IL-8 after exposure to PM. ? ufCB, FeSO{sub 4} and DEP extract were used to examine the protective effects of ELF. ? PM-driven oxidative stress and DNA single-strand breakage were mitigated by ELF. ? The findings suggest that ELF has a protective role against PM. ? The synthetic ELF system could reduce the use of animals in PM-driven ROS testing.

  15. Interaction between age and exposure to 56Fe particles on behavior and neurochemistry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous research has shown that exposure to HZE particles, which will be encountered on long-term space missions, can adversely affect the ability of rats to perform a variety of behavioral tasks. This outcome has implications for an astronaut's ability to successfully complete requirements associ...

  16. Cognitive effects of partial and whole body exposures to 160 particles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When rats and mice are exposed to HZE particles at the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory to simulate the effect of exposure to space radiation on cognitive performance, there may be differences in the amount of tissue that is irradiated: some experimenters irra...

  17. PARTICLE TOTAL EXPOSURE ASSESSMENT METHODOLOGY (PTEAM): RIVERSIDE, CALIFORNIA PILOT STUDY - VOLUME I

    EPA Science Inventory

    The goal of this study was to estimate the frequency distribution of exposure of an urban population to inhalable particles (less than 10 micrometers in diameter). Probability sampling design was used to select 178 nonsmoking residents aged 10 or above in Riverside, CA. Each pers...

  18. Exposure to concentrated coarse air pollution particles causes mild cardiopulmonary effects in young healthy adults

    EPA Science Inventory

    Rationale: There is ample epidemiological and toxicological evidence that exposure to fme air pollution particles (PM2.5), which are primarily derived from combustion processes, can result in increased mortality and morbidity. There is less certainty as to the contribution of coa...

  19. Analysis of Exposure-Dose Variation of Inhaled Particles in Adult Subjects.

    EPA Science Inventory

    Although internal dose is a key factor for determining the health risk of inhaled pollutant particles, available dose information is largely limited to young healthy adults under a few typical exposure conditions. Extrapolation of the limited dose information to different populat...

  20. RESPIRABLE PARTICLES AND MISTS IN MOUSE PULMONARY INFECTIVITY MODEL. EFFECT OF CHRONIC OR INTERMITTENT EXPOSURE

    EPA Science Inventory

    The effects of respirable-sized sulfuric acid mist or mixtures containing acid mist and carbon particles (A-C) on the susceptibility to bacterial and viral respiratory infection were studied in mice and hamsters. Both species showed mortalities upon single 3-hour exposure to 600 ...

  1. Particle Exhaust and Scrape-off Layer Conditions During RMPs in Deuterium and Helium Discharges on DIII-D

    NASA Astrophysics Data System (ADS)

    Unterberg, E. A.; Evans, T. E.; Canik, J. M.; Schmitz, O.; Maingi, R.; Brooks, N. H.

    2009-11-01

    The complete suppression of ELMs in a tokamak using the resonant component of a 3D magnetic perturbing field (RMP) has been demonstrated on DIII-D at ITER similar pedestal-?e^* and cross-sectional shapes. Recent analysis using global particle balance and measurements of the D? poloidal distribution show that the wall inventory can be strongly affected by changing the average triangularity of the plasma. Further investigations using vacuum field-line tracing identified a bifurcation in edge plasma conditions and divertor pumping due to a difference in the perturbed separatrix in the two configurations and an apparent increase in the scrape-off layer neutral density. Comparisons with helium discharges will also be made. These results support a goal of understanding the role of particle sources and sinks during the RMP and demonstrate ELM suppression without significant wall pumping, a feature that is essential in long-pulse reactors with saturated walls.

  2. MURINE PULMONARY MACROPHAGE EXPRESSION AND PRODUCTION OF TNFA AND MIP-2 AFTER EXPOSURE TO DIESEL EXHAUST PARTICLES (DEP) AND EXTRACTS

    EPA Science Inventory

    DEP constitute an important fraction of particulate air pollution and have been shown to cause inflammation of the airways. The aim of this study was to investigate the inflammatory cytokine response of alveolar macrophages exposed to DEP and DEP-extracts. A murine alveolar macr...

  3. Assessment of cigarette smoke particle deposition within the Vitrocell® exposure module using quartz crystal microbalances

    PubMed Central

    2013-01-01

    Background Cigarette smoking is a cause of a variety of serious diseases, and to understand the toxicological impact of tobacco smoke in vitro, whole smoke exposure systems can be used. One of the main challenges of the different whole smoke exposure systems that are commercially available is that they dilute and deliver smoke in different ways, limiting/restricting the cross-comparison of biological responses. This is where dosimetry – dose quantification – can play a key role in data comparison. Quartz crystal microbalance (QCM) technology has been put forward as one such tool to quantify smoke particle deposition in vitro, in real-time. Results Using four identical QCMs, installed into the Vitrocell® mammalian 6/4 CF Stainless exposure module, we were able to quantify deposited smoke particle deposition, generated and diluted by a Vitrocell® VC 10 Smoking Robot. At diluting airflows 0.5-4.0 L/min and vacuum flow rate 5 ml/min/well through the exposure module, mean particle deposition was in the range 8.65?±?1.51 ?g/cm2-0.72?±?0.13 ?g/cm2. Additionally, the effect of varying vacuum flow rate on particle deposition was assessed from 5 ml/min/well - 100 ml/min/well. Mean deposited mass for all four airflows tested per vacuum decreased as vacuum rate was increased: mean deposition was 3.79, 2.75, 1.56 and 1.09 ?g/cm2 at vacuum rates of 5, 10, 50 and 100 ml/min/well respectively. Conclusions QCMs within the Vitrocell® exposure module have demonstrated applicability at defining particle dose ranges at various experimental conditions. This tool will prove useful for users of the Vitrocell® system for dose–response determination and QC purposes. PMID:23497606

  4. Behavioral and neurochemical abnormalities after exposure to low doses of high-energy iron particles

    SciTech Connect

    Hunt, W.A.; Joseph, J.A.; Rabin, B.M.

    1989-01-01

    Exposure of rats to high-energy iron particles (600 MeV/amu) has been found to alter behavior after doses as low as 10 rads. The performance of a task that measures upper body strength was significantly degraded after irradiation. In addition, an impairment in the regulation of dopamine release in the caudate nucleus (a motor center in the brain), lasting at least 6 months, was also found and correlated with the performance deficits. A general indication of behavioral toxicity and an index of nausea and emesis, the conditioned taste aversion, was also evident. The sensitivity to iron particles was 10-600 times greater than to gamma photons. These results suggest that behavioral and neurobiological damage may be a consequence of exposure to low doses of heavy particles and that this possibility should be extensively studied.

  5. Real-time characterization of particle-bound polycyclic aromatic hydrocarbons in ambient aerosols and from motor-vehicle exhaust

    NASA Astrophysics Data System (ADS)

    Polidori, A.; Hu, S.; Biswas, S.; Delfino, R. J.; Sioutas, C.

    2008-03-01

    A photo-electric aerosol sensor, a diffusion charger, an Aethalometer, and a continuous particle counter were used along with other real-time instruments to characterize the particle-bound polycyclic aromatic hydrocarbon (p-PAH) content, and the physical/chemical characteristics of aerosols collected a) in Wilmington (CA) near the Los Angeles port and close to 2 major freeways, and b) at a dynamometer testing facility in downtown Los Angeles (CA), where 3 diesel trucks were tested. In Wilmington, the p-PAH, surface area, particle number, and "black" carbon concentrations were 4-8 times higher at 09:00-11:00 a.m. than between 17:00 and 18:00 p.m., suggesting that during rush hour traffic people living in that area are exposed to a higher number of diesel combustion particles enriched in p-PAH coatings. Dynamometer tests revealed that the p-PAH emissions from the "baseline" truck (no catalytic converter) were up to 200 times higher than those from the 2 vehicles equipped with advanced emission control technologies, and increased when the truck was accelerating. In Wilmington, integrated filter samples were collected and analyzed to determine the concentrations of the most abundant p-PAHs. A correlation between the total p-PAH concentration (?g/m3) and the measured photo-electric aerosol sensor signal (fA) was also established. Estimated ambient p-PAH concentrations (Average=0.64 ng/m3; Standard deviation=0.46 ng/m3 were in good agreement with those reported in previous studies conducted in Los Angeles during a similar time period. Finally, we calculated the approximate theoretical lifetime (70 years per 24-h/day) lung-cancer risk in the Wilmington area due to inhalation of multi-component p-PAHs and "black" carbon. Our results indicate that the lung-cancer risk is highest during rush hour traffic and lowest in the afternoon, and that the genotoxic risk of the considered p-PAHs does not seem to contribute to a significant part of the total lung-cancer risk attributable to "black" carbon.

  6. Real-time characterization of particle-bound polycyclic aromatic hydrocarbons in ambient aerosols and from motor-vehicle exhaust

    NASA Astrophysics Data System (ADS)

    Polidori, A.; Hu, S.; Biswas, S.; Delfino, R. J.; Sioutas, C.

    2007-12-01

    A photo-electric aerosol sensor, a diffusion charger, an Aethalometer, and a continuous particle counter were used along with other real-time instruments to characterize the particle-bound polycyclic aromatic hydrocarbon (p-PAH) content, and the physical/chemical characteristics of aerosols collected a) in Wilmington (CA) near the Los Angeles port and close to 2 major freeways, and b) at a dynamometer testing facility in downtown Los Angeles (CA), where 3 diesel trucks were tested. In Wilmington, the p-PAH, surface area, particle number, and "black" carbon concentrations were 4-8 times higher at 09:00-11:00 a.m. than between 17:00 and 18:00 p.m., suggesting that during rush hour traffic people living in that area are exposed to a higher number of diesel combustion particles enriched in p-PAH coatings. Dynamometer tests revealed that the p-PAH emissions from the "baseline" truck (no catalytic converted) were up to 200 times higher than those from the 2 vehicles equipped with advanced emission control technologies, and increased when the truck was accelerating. In Wilmington, integrated filter samples were collected and analyzed to determine the concentrations of the most abundant p-PAHs. A correlation between the total p-PAH concentration (?g/m3) and the measured photo-electric aerosol sensor signal (fA) was also established. Estimated ambient p-PAH concentrations (Average = 0.64 ng/m3; Standard deviation = 0.46 ng/m3) were in good agreement with those reported in previous studies conducted in Los Angeles during a similar time period. Finally, we calculated the approximate theoretical lifetime (70 years per 24-h/day) lung-cancer risk in the Wilmington area due to inhalation of multi-component p-PAHs and "black" carbon. Our results indicate that the lung-cancer risk is highest during rush hour traffic and lowest in the afternoon, and that the genotoxic risk of the considered p-PAHs does not seem to contribute to a significant part of the total lung-cancer risk attributable to "black" carbon.

  7. Indoor exposure to radiation in the case of an outdoorrelease

    SciTech Connect

    Price, Phillip N.; Jayaraman, Buvana

    2006-06-01

    This report quantifies the effectiveness of ''sheltering in place'' in a commercial building in the event of an outdoor radiological release. The indoor exposure to airborne particles is calculated by solving the mass balance equation that accounts for the loss of particles due to deposition, filtration and exhaust. Quantitative estimates of shelter-inplace effectiveness are provided for typical commercial buildings.

  8. IN VIVO EVIDENCE OF FREE RADICAL FORMATION IN THE RAT LUNG AFTER EXPOSURE TO AN EMISSION SOURCE AIR POLLUTION PARTICLE

    EPA Science Inventory

    Exposure to air pollution particles can be associated with increased human morbidity and mortality. The mechanism(s) of lung injury remains unknown. We tested the hypothesis that lung exposure to oil fly ash (an emission source air pollution particle) causes in vivo free radical ...

  9. 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...

  10. Combination acoustical muffler and exhaust converter

    SciTech Connect

    Nitz, A.E.

    1982-11-30

    A combination acoustical muffler and exhaust converter for use with internal combustion engines, comprising an elongated hollow cylinder adapted to be connected to a source of exhaust gas, screen means positioned at a plurality of longitudinally spaced locations within said cylinder for partitioning the cylinder into a plurality of chambers arranged in series flow relation with each other and with respect to the flow of exhaust gas through said cylinder, the screens having a silencing action on said exhaust gas, magnet means in one of said chambers for exerting a magnetic pressure on the gas passing therethrough to serve to separate ferrous particles from the exhaust gas stream, a packing material of mineral material, such as mineral wool, in another of said chambers for condensing moisture in said exhaust gas and for removing hydrocarbon therefrom, and a material such as a ceramic material of an extremely fine porous nature, in still another of said chambers for removing carbon monoxide from said exhaust gas.

  11. Lung Cancer and Vehicle Exhaust in Trucking Industry Workers

    Microsoft Academic Search

    Eric Garshick; Francine Laden; Jaime E. Hart; Bernard Rosner; Mary E. Davis; Ellen A. Eisen; Thomas J. Smith

    2008-01-01

    Background: An elevated risk of lung cancer in truck drivers has been attributed to diesel exhaust exposure. Interpretation of these studies specifically implicating diesel exhaust as a carcinogen has been limited because of limited exposure measurements and lack of work records relating job title to exposure-related job duties. Objectives: We established a large retrospective cohort of trucking company workers to

  12. Analysing the causes of chronic cough: relation to diesel exhaust, ozone, nitrogen oxides, sulphur oxides and other environmental factors

    Microsoft Academic Search

    Beatrix Groneberg-Kloft; Thomas Kraus; Anke van Mark; Ulrich Wagner; Axel Fischer

    2006-01-01

    Air pollution remains a leading cause of many respiratory diseases including chronic cough. Although episodes of incidental, dramatic air pollution are relatively rare, current levels of exposure of pollutants in industrialized and developing countries such as total articles, diesel exhaust particles and common cigarette smoke may be responsible for the development of chronic cough both in children and adults. The

  13. A Novel System to Generate WTC Dust Particles for Inhalation Exposures

    PubMed Central

    Vaughan, Joshua M.; Garrett, Brittany; Prophete, Colette; Horton, Lori; Sisco, Maureen; Soukup, Joleen M.; Zelikoff, Judith; Ghio, Andrew; Peltier, Richard E.; Asgharian, Bahman; Chen, Lung-Chi; Cohen, Mitchell D.

    2014-01-01

    First Responders (FR) present at Ground Zero within the first 72-hr after the WTC (World Trade Center) collapse have progressively exhibited significant respiratory injury. The majority (>96%) of WTC dusts were >10 ?m and no studies have examined potential health effects of this size fraction. This study sought to develop a system to generate and deliver supercoarse (10–53 ?m) WTC particles to a rat model in a manner that mimicked FR exposure scenarios. A modified Fishing Line generator was integrated onto an intratracheal inhalation (ITIH) system that allowed for a bypassing of the nasal passages so as to mimic FR exposures. Dust concentrations were measured gravimetrically; particle size distribution was measured via elutriation. Results indicate that the system could produce dusts with 23 ?m MMAD at levels up to ? 1200 mg/m3. To validate system utility, F344 rats were exposed for 2-hr to ?100 mg WTC dust/m3. Exposed rats had significantly increased lung weight and levels of select tracer metals 1-hr post-exposure. Using this system, it is now possible to conduct relevant inhalation exposures to determine adverse WTC dusts impacts on the respiratory system. Furthermore, this novel integrated Fishing Line-ITIH system could potentially be used in the analyses of a wide spectrum of other dusts/pollutants of sizes previously untested or delivered to the lungs in ways that did not reflect realistic exposure scenarios. PMID:24220216

  14. A novel system to generate WTC dust particles for inhalation exposures.

    PubMed

    Vaughan, Joshua M; Garrett, Brittany J; Prophete, Colette; Horton, Lori; Sisco, Maureen; Soukup, Joleen M; Zelikoff, Judith T; Ghio, Andrew; Peltier, Richard E; Asgharian, Bahman; Chen, Lung-Chi; Cohen, Mitchell D

    2014-01-01

    First responders (FRs) present at Ground Zero within the critical first 72?h after the World Trade Center (WTC) collapse have progressively exhibited significant respiratory injury. The majority (>96%) of WTC dusts were >10??m and no studies have examined potential health effects of this size fraction. This study sought to develop a system to generate and deliver supercoarse (10-53??m) WTC particles to a rat model in a manner that mimicked FR exposure scenarios. A modified Fishing Line generator was integrated onto an intratracheal inhalation (ITIH) system that allowed for a bypassing of the nasal passages so as to mimic FR exposures. Dust concentrations were measured gravimetrically; particle size distribution was measured via elutriation. Results indicate that the system could produce dusts with 23??m mass median aerodynamic diameter (MMAD) at levels up to ?1200?mg/m(3). To validate system utility, F344 rats were exposed for 2?h to ?100?mg WTC dust/m(3). Exposed rats had significantly increased lung weight and levels of select tracer metals 1?h after exposure. Using this system, it is now possible to conduct relevant inhalation exposures to determine adverse WTC dusts impacts on the respiratory system. Furthermore, this novel integrated Fishing Line-ITIH system could potentially be used in the analyses of a wide spectrum of other dusts/pollutants of sizes previously untested or delivered to the lungs in ways that did not reflect realistic exposure scenarios. PMID:24220216

  15. Rat lung inflammatory responses after in vivo and in vitro exposure to various stone particles.

    PubMed

    Becher, R; Hetland, R B; Refsnes, M; Dahl, J E; Dahlman, H J; Schwarze, P E

    2001-09-01

    Rat lung alveolar macrophages and type 2 cells were exposed for 20 h in vitro to various stone particles with differing contents of metals and minerals (a type of mylonite, gabbro, feldspar, and quartz). The capability to induce the release of the inflammatory cytokines interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-alpha), and macrophage inflammatory protein-2 (MIP-2) was investigated. We found marked differences in potency between the various particles, with mylonite being most potent overall, followed by gabbro, and with feldspar and quartz having an approximately similar order of lower potency. The results also demonstrated differences in cytokine release pattern between the two cell types. For all particle types including quartz, type 2 cells showed the most marked increase in MIP-2 and IL-6 secretion, whereas the largest increase in TNF-alpha release was observed in macrophages. To investigate possible correlations between in vitro and in vivo inflammatory responses, rats were instilled with the same types of particles and bronchoalveolar lavage (BAL) fluid was collected after 20 h. The results demonstrated a correlation between the in vitro cytokine responses and the number of neutrophilic cells in the BAL fluid. The BAL fluid also showed a strong MIP-2 response to mylonite. However, this was the only particle type to give a significant cytokine response in the BAL fluid. We further examined whether a similar graded inflammatory response would be continued in type 2 cells and alveolar macrophages isolated from the exposed animals. Again a differential cytokine release pattern was observed between type 2 cells and macrophages, although the order of potency between particle types was altered. In conclusion, various stone particles caused differential inflammatory responses after both in vitro and in vivo exposure, with mylonite being the most potent stone particle. The results suggest the alveolar type 2 cell to be an important participant in the inflammatory response following exposure to particles. PMID:11498806

  16. Reassessment of data used in setting exposure limits for hot particles

    SciTech Connect

    Baum, J.W.; Kaurin, D.G.

    1991-05-01

    A critical review and a reassessment of data reviewed in NCRP Report 106 on effects of hot particles'' on the skin of pigs, monkeys, and humans were made. Our analysis of the data of Forbes and Mikhail on effects from activated UC{sub 2} particles, ranging in diameter from 144 {mu}m to 328 {mu}m, led to the formulation of a new model for prediction of both the threshold for acute ulceration and for ulcer diameter. A dose of 27 Gy at a depth of 1.33 mm in tissue in this model will result in an acute ulcer with a diameter determined by the radius over which this dose (at 1.33-mm depth) extends. Application of the model to the Forbes-Mikhail data yielded a threshold'' (5% probability) of 6 {times} 10{sup 9} beta particles from a point source on skin of mixed fission product beta particles, or about 10{sup 10} beta particles from Sr--Y-90, since few of the Sr-90 beta particles reach this depth. The data of Hopewell et al. for their 1 mm Sr-Y-90 exposures were also analyzed with the above model and yielded a predicted threshold of 2 {times} 10{sup 10} Sr-Y-90 beta particles for a point source on skin. Dosimetry values were employed in this latter analysis that are 3.3 times higher than previously reported for this source. An alternate interpretation of the Forbes and Mikhail data, derived from linear plots of the data, is that the threshold depends strongly on particle size with the smaller particles yielding a much lower threshold and smaller minimum size ulcer. Additional animal exposures are planned to distinguish between the above explanations. 17 refs., 3 figs., 3 tabs.

  17. Variability in onset of ECG changes indicative of ischemia after exposure to whole vs filtered diesel exhaust in hypertensive rats. Insight on mechanism?

    EPA Science Inventory

    Diesel exhaust (DE) is a complex mixture of gases including C02, O2, N02, CO, aldehydes, benzene, and polycyclic aromatic hydrocarbons (PAHs) as well as highly respirable particulate matter. DE is a significant component of fine particulate matter (PM2.5) air pollution, which its...

  18. Effects of airborne saline particles on vegetation in relation to variables of exposure and other factors.

    PubMed

    McCune, D C

    1991-01-01

    Saline particles are a heterogeneous group of chloride(Cl)-containing airborne materials of natural as well as anthropogenic origins. They are usually a local problem of air pollution in terms of source and dispersion, but within these areas their effects on agricultural, ornamental or natural species of plants can be of substantial practical concern. These effects include the accumulation of Cl, the production of foliar lesions, and changes in the plant's levels of mineral nutrients and metabolites, physiological processes, and growth and reproduction. Some quantitative exposure-effect relationships have been formulated for foliar Cl, foliar lesions, and changes in growth and yield. These relationships are sensitive to various factors, such as flux, duration and frequency of exposure, species and stage of development of the plant, size and chemical composition of the particle, and light, temperature, relative humidity and precipitation during or after exposure. The interactions of these factors affect the response of the plant to saline particles by determining three major sets of processes: collection and retention of particles by the foliage; penetration of material from superficial deposits into the foliar tissue; translocation of absorbed Cl (or other ionic components) and susceptibility of tissue to it within the leaf. PMID:15092060

  19. Use of mechanistic data in assessing human risks from exposure to particles.

    PubMed Central

    McClellan, R O

    1997-01-01

    The ultimate goal of toxicologic investigations of both natural and man-made fibrous and nonfibrous particles is to provide essential input for the assessment of potential human risks from exposure to these materials. The development of risk assessment procedures for airborne particles has evolved over the years. The earliest assessments for naturally occurring materials used direct human observations and incorporated safety factors to arrive at allowable human exposures. More recently, there has been a need to assess the potential risk associated with production and use of certain man-made materials for which human data are not available or are inadequate. For these materials, it has been necessary to assess human risks using data obtained from studies conducted in laboratory animals and with cells or tissues. During the last several decades, it has been suggested that data on the mechanisms by which particles cause disease could be used to reduce the uncertainty in estimates of human risks of particle exposures. This article provides comments on the use of mechanistic data in the risk assessment process and suggestions for increasing the successful development and use of mechanistic data in risk assessments conducted in the future. PMID:9400751

  20. Excursion guidance criteria to guide control of peak emission and exposure to airborne engineered particles.

    PubMed

    McGarry, Peter; Morawska, Lidia; Knibbs, Luke D; Morris, Howard

    2013-01-01

    The overall aim of our research was to characterize airborne particles from selected nanotechnology processes and to utilize the data to develop and test quantitative particle concentration-based criteria that can be used to trigger an assessment of particle emission controls. We investigated particle number concentration (PNC), particle mass (PM) concentration, count median diameter (CMD), alveolar deposited surface area, elemental composition, and morphology from sampling of aerosols arising from six nanotechnology processes. These included fibrous and non-fibrous particles, including carbon nanotubes (CNTs). We adopted standard occupational hygiene principles in relation to controlling peak emission and exposures, as outlined by both Safe Work Australia, and the American Conference of Governmental Industrial Hygienists (ACGIH®). The results from the study were used to analyses peak and 30-minute averaged particle number and mass concentration values measured during the operation of the nanotechnology processes. Analysis of peak (highest value recorded) and 30-minute averaged particle number and mass concentration values revealed: Peak PNC(20-1000 nm) emitted from the nanotechnology processes were up to three orders of magnitude greater than the local background particle concentration (LBPC). Peak PNC(300-3000 nm) was up to an order of magnitude greater, and PM2.5 concentrations up to four orders of magnitude greater. For three of these nanotechnology processes, the 30-minute average particle number and mass concentrations were also significantly different from the LBPC (p-value < 0.001). We propose emission or exposure controls may need to be implemented or modified, or further assessment of the controls be undertaken, if concentrations exceed three times the LBPC, which is also used as the local particle reference value, for more than a total of 30 minutes during a workday, and/or if a single short-term measurement exceeds five times the local particle reference value. The use of these quantitative criteria, which we are terming the universal excursion guidance criteria, will account for the typical variation in LBPC and inaccuracy of instruments, while precautionary enough to highlight peaks in particle concentration likely to be associated with particle emission from the nanotechnology process. Recommendations on when to utilize local excursion guidance criteria are also provided. PMID:24116668

  1. Induction of heme oxygenase-1 expression in macrophages by diesel exhaust particle chemicals and quinones via the antioxidant-responsive element.

    PubMed

    Li, N; Venkatesan, M I; Miguel, A; Kaplan, R; Gujuluva, C; Alam, J; Nel, A

    2000-09-15

    Diesel exhaust particles (DEP) contain organic chemicals that contribute to the adverse health effects of inhaled particulate matter. Because DEP induce oxidative stress in the lung and in macrophages, effective antioxidant defenses are required. One type of defense is through the expression of the antioxidant enzyme, heme oxygenase I (HO-1). HO-1 as well as phase II detoxifying enzymes are induced via antioxidant response elements (ARE) in their promoters of that gene. We show that a crude DEP total extract, aromatic and polar DEP fractions, a benzo(a)pyrene quinone, and a phenolic antioxidant induce HO-1 expression in RAW264.7 cells in an ARE-dependent manner. N-acetyl cysteine and the flavonoid, luteolin, inhibited HO-1 protein expression. We also demonstrate that the same stimuli induce HO-1 mRNA expression in parallel with the activation of the SX2 enhancer of that gene. Mutation of the ARE core, but not the overlapping AP-1 binding sequence, disrupted SX2 activation. Finally, we show that biological agents, such as oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine, could also induce HO-1 expression via an ARE-dependent mechanism. Prior induction of HO-1 expression, using cobalt-protoporphyrin, protected RAW264.7 cells against DEP-induced toxicity. Taken together, these data show that HO-1 plays an important role in cytoprotection against redox-active DEP chemicals, including quinones. PMID:10975858

  2. Simple and sensitive method for determination of nitrated polycyclic aromatic hydrocarbons in diesel exhaust particles by gas chromatography-negative ion chemical ionisation tandem mass spectrometry.

    PubMed

    Kawanaka, Youhei; Sakamoto, Kazuhiko; Wang, Ning; Yun, Sun-Ja

    2007-09-01

    An extremely simple and sensitive method was developed for determination of nitrated polycyclic aromatic hydrocarbons (nitro-PAHs; mono-nitro-PAHs and dinitropyrenes) in diesel exhaust particles (DEPs) by gas chromatography-negative ion chemical ionisation tandem mass spectrometry (GC/NCI/MS/MS). We used two types of column in GC/NCI/MS/MS analysis. A polar column was used for determination of mono-nitro-PAHs, and a non-polar column was used for determination of dinitropyrenes and mono-nitro-PAHs except nitrofluoranthenes. The proposed method requires no clean-up procedure. The limits of detection ranged from 0.01 to 0.09 pg for all compounds tested. The applicability of the method to DEP samples was validated using diesel particulate standard reference materials (SRMs). Although DEPs contain complex matrices, all compounds could be detected easily in SRM2975 (diesel particulate matter) and SRM1975 (diesel particulate extract) without a clean-up procedure. The RSDs were less than 5% for all compounds examined. The quantitative results for SRMs exhibited good agreement with the available data in the literature. These results indicate that the proposed GC/NCI/MS/MS method is useful for determination of nitro-PAHs in DEP samples. PMID:17619018

  3. The aryl hydrocarbon receptor-mediated and genotoxic effects of fractionated extract of standard reference diesel exhaust particle material in pulmonary, liver and prostate cells.

    PubMed

    Pálková, Lenka; Vondrá?ek, Jan; Trilecová, Lenka; Ciganek, Miroslav; P?n?íková, Kate?ina; Ne?a, Ji?í; Milcová, Alena; Topinka, Jan; Machala, Miroslav

    2015-04-01

    Diesel exhaust particles (DEP) and the associated complex mixtures of organic pollutants, such as polycyclic aromatic hydrocarbons (PAHs), or their derivatives, have been suggested to exert deleterious effects on human health. We used a set of defined cellular models representing liver, lung and prostate tissues, in order to compare non-genotoxic and genotoxic effects of crude and fractionated extract of a standard reference DEP material - SRM 1650b. We focused on the aryl hydrocarbon receptor (AhR)-mediated activity, modulation of cell proliferation, formation of DNA adducts, oxidative DNA damage, and induction of DNA damage responses, including evaluation of apoptosis, and phosphorylation of p53 tumor suppressor and checkpoint kinases (Chk). Both PAHs and the polar aromatic compounds contributed to the AhR-mediated activity of DEP-associated organic pollutants. The principal identified AhR agonists included benzo[k]fluoranthene, indeno[1,2,3-c,d]pyrene, chrysene and several non-priority PAHs, including benzochrysenes and methylated PAHs. In contrast to PAHs, polar compounds contributed more significantly to overall formation of DNA adducts associated with phosphorylation of p53, Chk1 or Chk2, and partly with apoptosis. Therefore, more attention should be paid to identification of DEP-associated polar organic compounds, contributing to the AhR activation and cytotoxic/genotoxic effects of complex airborne mixtures of organic contaminants produced by diesel engines. PMID:25500124

  4. Sources of personal exposure to fine particles in Toronto, Ontario, Canada

    SciTech Connect

    David Kim; Andrea Sass-Kortsak; James T. Purdham; Robert E. Dales; Jeffrey R. Brook [University of North Carolina at Chapel Hill, Chapel Hill, NC (US). Department of Environmental Sciences and Engineering

    2005-08-01

    Individuals are exposed to particulate matter from both indoor and outdoor sources. The aim of this study was to compare the relative contributions of three sources of personal exposure to fine particles (PM2.5) by using chemical tracers. The study design incorporated repeated 24-hr personal exposure measurements of air pollution from 28 cardiac-compromised residents of Toronto, Ontario, Canada. Each study participant wore the Rupprecht & Patashnick ChemPass Personal Sampling System 1 day a week for a maximum of 10 weeks. During their individual exposure measurement days the subjects reported to have spent an average of 89% of their time indoors. Particle phase elemental carbon, sulfate, and calcium personal exposure data were used in a mixed-effects model as tracers for outdoor PM2.5 from traffic-related combustion, regional, and local crustal materials, respectively. These three sources were found to contribute 13% {+-} 10%, 17% {+-}16%, and 7% {+-} 6% of PM2.5 exposures. The remaining fraction of the personal PM2.5 is hypothesized to be predominantly related to indoor sources. For comparison, central site outdoor PM2.5 measurements for the same dates as personal measurements were used to construct a receptor model using the same three tracers. In this case, traffic-related combustion, regional, and local crustal materials were found to contribute 19% {+-} 17%, 52% {+-} 22%, and 10% {+-} 7%, respectively. The results indicate that the three outdoor PM2.5 sources considered are statistically significant contributors to personal exposure to PM2.5. The results also suggest that among the Toronto subjects, who spent a considerable amount of time indoors, exposure to outdoor PM2.5 includes a greater relative contribution from combustion sources compared with outdoor PM2.5 measurements where regional sources are the dominant contributor. 56 refs., 3 figs., 6 tabs.

  5. SIGNIFICANCE OF PARTICLE PARAMETERS IN THE EVALUATION OF EXPOSURE-DOSE RESPONSE RELATIONSHIPS OF INHALED PARTICLES

    Microsoft Academic Search

    GÜNTER OBERDÖRSTER

    1996-01-01

    Chronic rat inhalation studies have shown that a number of different panicle types can induce significant adverse effects, including impaired lung clearance, chronic pulmonary inflammation, pulmonary librosis, and lung tumors. These effects occurred when highly insoluble particles of low solubility and low cytotoxicity were inhaled in long-term studies. Inhaled concentrations ranged from a few milligrams per cubic meter up to

  6. Assessment of Inter-Individual, Geographic, and Seasonal Variability in Estimated Human Exposure to Fine Particles

    PubMed Central

    Jiao, Wan; Frey, H. Christopher; Cao, Ye

    2012-01-01

    Health effects associated with ambient fine particle (PM2.5) exposure are typically estimated based on concentration-response (C-R) functions using area-wide concentration as an exposure surrogate. Persons 65 and older are particularly susceptible to adverse effects from PM2.5 exposure. Using a stochastic microenvironmental simulation model, distributions of daily PM2.5 exposures were estimated based on ambient concentration, air exchange rate, penetration factor, deposition rate, indoor emission sources, census data, and activity diary data, and compared for selected regions and seasons. Even though the selected subpopulation spends an average of over 20 hours per day indoors, the ratio of daily average estimated exposure to ambient concentration (Ea/C) is approximately 0.5. The daily average Ea/C ratio varies by a factor of 4 to 5 over a 95% frequency range among individuals, primarily from variability in air exchange rates. The mean Ea/C varies by 6 to 36% among selected NC, TX and NYC domains, and 15 to 34% among four seasons, as a result of regional differences in housing stock and seasonal differences in air exchange rates. Variability in Ea/C is a key factor that may help explain heterogeneity in C-R functions across cities and seasons. Priorities for improving exposure estimates are discussed. PMID:23095102

  7. Assessment of the influence of media particle size on the biofiltration of odorous exhaust ventilation air from a piggery facility.

    PubMed

    Sheridan, B A; Curran, T P; Dodd, V A

    2002-09-01

    Two pilot scale biofiltration systems were constructed and installed at the University College Dublin Research Farm, Lyons Estate. Experimental units consisting of two pens in a 12 pen pig house were sealed off from other pens. Air from each pen was extracted and treated separately in two biofiltration systems. Wood chips larger than 20 mm were selected as the medium for biofiltration system 1, whereas chips of between 10 and 16 mm were used in biofiltration system 2. The moisture content of the media was maintained at 69+/-4% (w.w.b.) using a load cell method. The volumetric loading rates ranged from 769 to 1847 m3 [gas] m(-1) [medium] h(-1) over a 63-day experimental period. Both biofilters reduced odour between 88% and 95%. Ammonia removal efficiencies ranged from 64% to 92% and 69% to 93%, for biofiltration systems 1 and 2, respectively. Sulphur-containing compounds were reduced between 9-66%, and -147-51% across biofiltration systems 1 and 2. The pH of the biofilters' leachate remained between 6 and 8. Pressure drop for biofilter 2 was 16 Pa greater than that of biofilter I at the maximum volumetric loading rate of 1847 m3 [gas] m(-3) [medium] h(-1). It is recommended that a wood chip media particle size greater than 20 mm be used for large scale operation of a biofiltration system on intensive pig production facilities to reduce the development of anaerobic zones and to minimize pressure drop on the system fans. PMID:12139329

  8. Driver and passenger exposure to aerosol particles in buses and trams in Helsinki, Finland.

    PubMed

    Asmi, Eija; Antola, Matti; Yli-Tuomi, Tarja; Jantunen, Matti; Aarnio, Päivi; Mäkelä, Timo; Hillamo, Risto; Hämeri, Kaarle

    2009-04-01

    This study investigates commuter and driver exposure to aerosol particles in buses and trams in Helsinki, Finland. Particle number and PM(2.5) concentrations were determined in the cabin and the driver's compartment. In addition, the <2.5 microm black carbon concentration was measured in the driver's compartment and PM(2.5) was collected for elemental analysis in the cabin. The measurements were repeated on two generations of buses and trams including two measurement days in each vehicle type. Fine particle number and mass concentrations in the driver's compartments were only slightly increased compared to Helsinki background air. Daily average ratios of number and mass to the background varied in range 0.8-4.3 and 1.0-2.9, respectively, both being the highest in the older bus type. However, the drivers were exposed to elevated levels of black carbon, which some studies have addressed to be strongly correlated with adverse health effects. The daily average ratio of black carbon to the background varied between 2.4 and 11.4. Additionally, the black carbon concentration had spatial variation. The drivers were exposed to higher peak concentrations of black carbon in downtown area. Particle concentrations were smaller in the driver's compartment than in the cabin. The newer technology in the newer model of the tram and bus seemed to decrease driver exposure to aerosol particles. PMID:19195679

  9. Cytokine Production by Human Airway Epithelial Cells after Exposure to an Air Pollution Particle Is Metal-Dependent

    Microsoft Academic Search

    Jacqueline D. Carter; Andrew J. Ghio; James M. Samet; Robert B. Devlin

    1997-01-01

    Despite the many epidemiological studies supporting the contention that ambient air pollution particles can adversely affect human health, there is no clear agreement as to a biologically plausible mechanism which can explain the acute mortality and morbidity associated with exposure to particles less than 10 ?m in size. We tested the hypothesis that metals present in an air pollution particle

  10. Occupational Exposure to Ultrafine Particles among Airport Employees - Combining Personal Monitoring and Global Positioning System

    PubMed Central

    Møller, Karina Lauenborg; Thygesen, Lau Caspar; Schipperijn, Jasper; Loft, Steffen; Bonde, Jens Peter; Mikkelsen, Sigurd; Brauer, Charlotte

    2014-01-01

    Background Exposure to ultrafine particles (UFP) has been linked to cardiovascular and lung diseases. Combustion of jet fuel and diesel powered handling equipment emit UFP resulting in potentially high exposure levels among employees working at airports. High levels of UFP have been reported at several airports, especially on the apron, but knowledge on individual exposure profiles among different occupational groups working at an airport is lacking. Purpose The aim of this study was to compare personal exposure to UFP among five different occupational groups working at Copenhagen Airport (CPH). Method 30 employees from five different occupational groups (baggage handlers, catering drivers, cleaning staff and airside and landside security) at CPH were instructed to wear a personal monitor of particle number concentration in real time and a GPS device. The measurements were carried out on 8 days distributed over two weeks in October 2012. The overall differences between the groups were assessed using linear mixed model. Results Data showed significant differences in exposure levels among the groups when adjusted for variation within individuals and for effect of time and date (p<0.01). Baggage handlers were exposed to 7 times higher average concentrations (geometric mean, GM: 37×103 UFP/cm3, 95% CI: 25–55×103 UFP/cm3) than employees mainly working indoors (GM: 5×103 UFP/cm3, 95% CI: 2–11×103 UFP/cm3). Furthermore, catering drivers, cleaning staff and airside security were exposed to intermediate concentrations (GM: 12 to 20×103 UFP/cm3). Conclusion The study demonstrates a strong gradient of exposure to UFP in ambient air across occupational groups of airport employees. PMID:25203510

  11. Exposure to particle number, surface area and PM concentrations in pizzerias

    NASA Astrophysics Data System (ADS)

    Buonanno, G.; Morawska, L.; Stabile, L.; Viola, A.

    2010-10-01

    The aim of this work was to quantify exposure to particles emitted by wood-fired ovens in pizzerias. Overall, 15 microenvironments were chosen and analyzed in a 14-month experimental campaign. Particle number concentration and distribution were measured simultaneously using a Condensation Particle Counter (CPC), a Scanning Mobility Particle Sizer (SMPS), an Aerodynamic Particle Sizer (APS). The surface area and mass distributions and concentrations, as well as the estimation of lung deposition surface area and PM 1 were evaluated using the SMPS-APS system with dosimetric models, by taking into account the presence of aggregates on the basis of the Idealized Aggregate (IA) theory. The fraction of inhaled particles deposited in the respiratory system and different fractions of particulate matter were also measured by means of a Nanoparticle Surface Area Monitor (NSAM) and a photometer (DustTrak DRX), respectively. In this way, supplementary data were obtained during the monitoring of trends inside the pizzerias. We found that surface area and PM 1 particle concentrations in pizzerias can be very high, especially when compared to other critical microenvironments, such as the transport hubs. During pizza cooking under normal ventilation conditions, concentrations were found up to 74, 70 and 23 times higher than background levels for number, surface area and PM 1, respectively. A key parameter is the oven shape factor, defined as the ratio between the size of the face opening in respect to the diameter of the semicircular oven door, and particular attention must also be paid to hood efficiency.

  12. Lung cancer risk from exposure to alpha particles and inhalation of other pollutants in rats

    SciTech Connect

    Burns, F.J.

    1990-01-01

    The goal of these experiments is to establish a quantitative correlation between early DNA damage and cancer incidence in a way that would be helpful for assessing the carcinogenic risk of radon alone or in combination with specific indoor pollutants. Rat tracheal epithelium has been exposed in vivo to {sup 210}Po alpha particles in the presence and absence of NO{sub 2} or cigarette smoke. The major accomplishments so far are: the design and implementation of a tracheal implant to simulate radon alpha particle exposure, the measurement of DNA breaks in a small 7.0 mm segment of the trachea exposed to external x-irradiation, the measurement of the rate of repair of the x-ray induced tracheal DNA strand breaks, the measurement of DNA strand breaks following inhalation of cigarette smoke or NO{sub 2}, the measurement of tracheal DNA stand breaks following exposure to high doses {sup 210}Po alpha particle radiation, the assessment of the amount of mucous in the goblet cells and in the underlying mucous glands. So far we have been unable to detect DNA strand breaks in the tracheal epithelium as a result of exposure to NO{sub 2} cigarette smoke or {sup 210}Po alpha particles. We have developed a simple artificial' trachea consisting of rat tracheal epithelial cells growing on a basement membrane coated millipore filter. Experiments are proposed to utilize these artificial tracheas to eliminate the potential interference of increased mucous secretion and/or inflammation that can significantly affect the radiation dose from the alpha particles. 61 refs., 17 figs.

  13. Effects of diesel exposure on lung function and inflammation biomarkers from airway and peripheral blood of healthy volunteers in a chamber study

    PubMed Central

    2013-01-01

    Background Exposure to diesel exhaust causes inflammatory responses. Previous controlled exposure studies at a concentration of 300 ?g/m3 of diesel exhaust particles mainly lasted for 1 h. We prolonged the exposure period and investigated how quickly diesel exhaust can induce respiratory and systemic effects. Methods Eighteen healthy volunteers were exposed twice to diluted diesel exhaust (PM1 ~300 ?g/m3) and twice to filtered air (PM1 ~2 ?g/m3) for 3 h, seated, in a chamber with a double-blind set-up. Immediately before and after exposure, we performed a medical examination, spirometry, rhinometry, nasal lavage and blood sampling. Nasal lavage and blood samples were collected again 20 h post-exposure. Symptom scores and peak expiratory flow (PEF) were assessed before exposure, and at 15, 75, and 135 min of exposure. Results Self-rated throat irritation was higher during diesel exhaust than filtered air exposure. Clinical signs of irritation in the upper airways were also significantly more common after diesel exhaust exposure (odds ratio=3.2, p<0.01). PEF increased during filtered air, but decreased during diesel exhaust exposure, with a statistically significant difference at 75 min (+4 L/min vs. -10 L/min, p=0.005). Monocyte and total leukocyte counts in peripheral blood were higher after exposure to diesel exhaust than filtered air 20 h post-exposure, and a trend (p=0.07) towards increased serum IL-6 concentrations was also observed 20 h post-exposure. Conclusions Diesel exhaust induced acute adverse effects such as symptoms and signs of irritation, decreased PEF, inflammatory markers in healthy volunteers. The effects were first seen at 75 min of exposure. PMID:24321138

  14. Occupational exposure to airborne particles and other pollutants in an aviation base.

    PubMed

    Buonanno, Giorgio; Bernabei, Manuele; Avino, Pasquale; Stabile, Luca

    2012-11-01

    The occupational exposure to airborne particles and other pollutants in a high performance jet engine airport was investigated. Three spatial scales were considered: i) a downwind receptor site, ii) close to the airstrip, iii) personal monitoring. Particle number, surface area, mass concentrations and distributions were measured as well as inorganic and organic fractions, ionic fractions and Polycyclic Aromatic Hydrocarbons. Particle number distribution measured at a receptor site presents a mode of 80 nm and an average total concentration of 6.5 × 10(3) part. cm(-3); the chemical analysis shows that all the elements may be attributed to long-range transport from the sea. Particle number concentrations in the proximity of the airstrip show short term peaks during the working day mainly related to takeoff, landing and pre-flight operations of jet engines. Personal exposure of workers highlights a median number concentration of 2.5 × 10(4) part. cm(-3) and 1.7 × 10(4) part. cm(-3) for crew chief and hangar operator. PMID:22771354

  15. Cytochromes P4501 (CYP1): catalytic activities and inducibility by diesel exhaust particle extract and benzo[a]pyrene in intact human lung ex vivo.

    PubMed

    Iba, Michael M; Shin, Maria; Caccavale, Robert J

    2010-06-29

    Catalytic activities of CYP1A1, CYP1A2 and CYP1B1, and inducibility of the activities were studied in intact human lung samples (from 23 human subjects) ex vivo. The activities [as measured by ethoxyresorufin O-deethylase (EROD), methoxyresorufin O-demethylase (MROD), and 3-cyano-7-ethoxycoumarin O-deethylase (CECOD)] were present in the lungs and were induced by benzo[a]pyrene (B[a]P) and diesel exhaust particle extract (DEE) but with extensive inter-subject variability. All three activities were substantially inhibited (>or=75%) by the CYP1 inhibitor alpha-naphthoflavone, whereas only MROD and CECOD were substantially inhibited by the CYP1A2-preferential inhibitor fluvoxamine. None of the three activities was substantially inhibited by the CYP1B1-preferential inhibitor tetramethoxystilbene, indicating lack of involvement of CYP1B1 in the activities in the intact lung. CYP1A1 and CYP1A2 proteins were present in the lungs (by western blot analysis), also with extensive inter-subject variability, and were induced by B[a]P or DEE more extensively than by the combination of B[a]P and DEE (B[a]P+DEE). CYP1B1 was also present in the lungs and its level varied extensively between subjects. In contrast with CYP1A and CYP1A2 levels, CYP1B1 level was not significantly altered by B[a]P or DEE treatment and was diminished more extensively by treatment with B[a]P+DEE. The findings point to the potential usefulness of the intact lung for assessing in situ xenobiotic biotransformation reactions as well as the CYP1 specificity of the reactions ex vivo. The findings also suggest MROD and CECOD as potential markers of CYP1A2 activity in the intact lung. PMID:20435083

  16. Solar Flare Track Exposure Ages in Regolith Particles: A Calibration for Transmission Electron Microscope Measurements

    NASA Technical Reports Server (NTRS)

    Berger, Eve L.; Keller, Lindsay P.

    2015-01-01

    Mineral grains in lunar and asteroidal regolith samples provide a unique record of their interaction with the space environment. Space weathering effects result from multiple processes including: exposure to the solar wind, which results in ion damage and implantation effects that are preserved in the rims of grains (typically the outermost 100 nm); cosmic ray and solar flare activity, which result in track formation; and impact processes that result in the accumulation of vapor-deposited elements, impact melts and adhering grains on particle surfaces. Determining the rate at which these effects accumulate in the grains during their space exposure is critical to studies of the surface evolution of airless bodies. Solar flare energetic particles (mainly Fe-group nuclei) have a penetration depth of a few millimeters and leave a trail of ionization damage in insulating materials that is readily observable by transmission electron microscope (TEM) imaging. The density of solar flare particle tracks is used to infer the length of time an object was at or near the regolith surface (i.e., its exposure age). Track measurements by TEM methods are routine, yet track production rate calibrations have only been determined using chemical etching techniques [e.g., 1, and references therein]. We used focused ion beam-scanning electron microscope (FIB-SEM) sample preparation techniques combined with TEM imaging to determine the track density/exposure age relations for lunar rock 64455. The 64455 sample was used earlier by [2] to determine a track production rate by chemical etching of tracks in anorthite. Here, we show that combined FIB/TEM techniques provide a more accurate determination of a track production rate and also allow us to extend the calibration to solar flare tracks in olivine.

  17. Exposure to Ultrafine Particles from Ambient Air and Oxidative Stress–Induced DNA Damage

    PubMed Central

    Bräuner, Elvira Vaclavik; Forchhammer, Lykke; Møller, Peter; Simonsen, Jacob; Glasius, Marianne; Wåhlin, Peter; Raaschou-Nielsen, Ole; Loft, Steffen

    2007-01-01

    Background Particulate matter, especially ultrafine particles (UFPs), may cause health effects through generation of oxidative stress, with resulting damage to DNA and other macromolecules. Objective We investigated oxidative damage to DNA and related repair capacity in peripheral blood mononuclear cells (PBMCs) during controlled exposure to urban air particles with assignment of number concentration (NC) to four size modes with average diameters of 12, 23, 57, and 212 nm. Design Twenty-nine healthy adults participated in a randomized, two-factor cross-over study with or without biking exercise for 180 min and with exposure to particles (NC 6169-15362/cm3) or filtered air (NC 91-542/cm3) for 24 hr. Methods The levels of DNA strand breaks (SBs), oxidized purines as formamidopyrimidine DNA glycolase (FPG) sites, and activity of 7,8-dihydro-8-oxoguanine-DNA glycosylase (OGG1) in PBMCs were measured by the Comet assay. mRNA levels of OGG1, nucleoside diphosphate linked moiety X-type motif 1 (NUDT1), and heme oxygenase-1 (HO1) were determined by real-time reverse transcriptase–polymerase chain reaction. Results Exposure to UFPs for 6 and 24 hr significantly increased the levels of SBs and FPG sites, with a further insignificant increase after physical exercise. The OGG1 activity and expression of OGG1, NUDT1, and HO1 were unaltered. There was a significant dose–response relationship between NC and DNA damage, with the 57-nm mode as the major contributor to effects. Concomitant exposure to ozone, nitrogen oxides, and carbon monoxide had no influence. Conclusion Our results indicate that UFPs, especially the 57-nm soot fraction from vehicle emissions, causes systemic oxidative stress with damage to DNA and no apparent compensatory up-regulation of DNA repair within 24 hr. PMID:17687444

  18. Transmigration of titanium dioxide (TiO2) particles in rats after inhalation exposure.

    PubMed

    Lee, K P; Trochimowicz, H J; Reinhardt, C F

    1985-06-01

    Titanium dioxide (TiO2) has been used extensively in the manufacturing of white pigment and has generally been regarded as a nuisance dust in animals and man. After inhalation exposure, little is known about transmigration routes and potential toxic effects of translocated particles in other organs. In order to answer these questions, rats were exposed to TiO2 by inhalation exposure at concentrations of 0, 10, 50, and 250 mg/m3 for 2 years. A few free particles were retained in the nasal and tracheobronchial epithelium without any cellular damage, but aggregates of dust-laden macrophages (dust cells) were found in the lymphoid tissue of the submucosa. Inhaled particles were mostly engulfed by alveolar macrophages and confined sharply to the alveolar duct region at 10 and 50 mg/m3, while dust cells were scattered throughout alveoli at 250 mg/m3. A fraction of the inhaled particles was retained in the membranous pneumocytes and interstitial macrophages. A dense accumulation of dust cells was found in the perivascular and peribronchial lymphoid tissue. Some dust cells entered peribronchial lymphatics or pulmonary blood vessels and the general circulation. Dust cells in the hyperplastic peribronchial lymphoid tissue were exposed directly in the luminal surface of the airways and were subsequently eliminated via airways. Massive dust deposition was observed in the tracheobronchial lymph nodes. Dust transmigration was markedly reduced in the cervical lymph nodes, and only a trace amount of dust particles was found in the mesenteric lymph nodes. Some dust cells entered either blood or lymphatic vessels in the lymph nodes and then migrated into the general circulation. The incidence of extrapulmonary dust deposition in the liver or spleen was increased in a dose-related fashion similar to the lung dust burden. Since there was no tissue response to translocated particles in the lymph nodes, spleen, or liver, potential adverse health effects appear to be negligible. PMID:3996554

  19. INDOOR, OUTDOOR, AND PERSONAL AIR EXPOSURES TO PARTICLES, ELEMENTS, AND NICOTINE FOR 178 RESIDENTS OF RIVERSIDE, CALIFORNIA

    EPA Science Inventory

    Personal, indoor, and outdoor concentrations of inhalable particles and 15 elements were measured for a probability sample of 178 persons representing 139,000 nonsmoking residents of Riverside, California. ewly designed personal monitors were employed. ersonal exposures often exc...

  20. Linking In-Vehicle Ultrafine Particle Exposures to On-Road Concentrations

    PubMed Central

    Hudda, Neelakshi; Eckel, Sandrah P.; Knibbs, Luke D.; Sioutas, Constantinos; Delfino, Ralph J.; Fruin, Scott A.

    2013-01-01

    For traffic-related pollutants like ultrafine particles (UFP, Dp < 100 nm), a significant fraction of overall exposure occurs within or close to the transit microenvironment. Therefore, understanding exposure to these pollutants in such microenvironments is crucial to accurately assessing overall UFP exposure. The aim of this study was to develop models for predicting in-cabin UFP concentrations if roadway concentrations are known, taking into account vehicle characteristics, ventilation settings, driving conditions and air exchange rates (AER). Particle concentrations and AER were measured in 43 and 73 vehicles, respectively, under various ventilation settings and driving speeds. Multiple linear regression (MLR) and generalized estimating equation (GEE) regression models were used to identify and quantify the factors that determine inside-to-outside (I/O) UFP ratios and AERs across a full range of vehicle types and ages. AER was the most significant determinant of UFP I/O ratios, and was strongly influenced by ventilation setting (recirculation or outside air intake). Inclusion of ventilation fan speed, vehicle age or mileage, and driving speed explained greater than 79% of the variability in measured UFP I/O ratios. PMID:23888122

  1. Characterization of Exposures to Airborne Nanoscale Particles During Friction Stir Welding of Aluminum

    PubMed Central

    Pfefferkorn, Frank E.; Bello, Dhimiter; Haddad, Gilbert; Park, Ji-Young; Powell, Maria; Mccarthy, Jon; Bunker, Kristin Lee; Fehrenbacher, Axel; Jeon, Yongho; Virji, M. Abbas; Gruetzmacher, George; Hoover, Mark D.

    2010-01-01

    Friction stir welding (FSW) is considered one of the most significant developments in joining technology over the last half century. Its industrial applications are growing steadily and so are the number of workers using this technology. To date, there are no reports on airborne exposures during FSW. The objective of this study was to investigate possible emissions of nanoscale (<100 nm) and fine (<1 ?m) aerosols during FSW of two aluminum alloys in a laboratory setting and characterize their physicochemical composition. Several instruments measured size distributions (5 nm to 20 ?m) with 1-s resolution, lung deposited surface areas, and PM2.5 concentrations at the source and at the breathing zone (BZ). A wide range aerosol sampling system positioned at the BZ collected integrated samples in 12 stages (2 nm to 20 ?m) that were analyzed for several metals using inductively coupled plasma mass spectrometry. Airborne aerosol was directly collected onto several transmission electron microscope grids and the morphology and chemical composition of collected particles were characterized extensively. FSW generates high concentrations of ultrafine and submicrometer particles. The size distribution was bimodal, with maxima at ?30 and ?550 nm. The mean total particle number concentration at the 30 nm peak was relatively stable at ?4.0 × 105 particles cm?3, whereas the arithmetic mean counts at the 550 nm peak varied between 1500 and 7200 particles cm?3, depending on the test conditions. The BZ concentrations were lower than the source concentrations by 10–100 times at their respective peak maxima and showed higher variability. The daylong average metal-specific concentrations were 2.0 (Zn), 1.4 (Al), and 0.24 (Fe) ?g m?3; the estimated average peak concentrations were an order of magnitude higher. Potential for significant exposures to fine and ultrafine aerosols, particularly of Al, Fe, and Zn, during FSW may exist, especially in larger scale industrial operations. PMID:20453001

  2. Characterization of exposures to airborne nanoscale particles during friction stir welding of aluminum.

    PubMed

    Pfefferkorn, Frank E; Bello, Dhimiter; Haddad, Gilbert; Park, Ji-Young; Powell, Maria; McCarthy, Jon; Bunker, Kristin Lee; Fehrenbacher, Axel; Jeon, Yongho; Virji, M Abbas; Gruetzmacher, George; Hoover, Mark D

    2010-07-01

    Friction stir welding (FSW) is considered one of the most significant developments in joining technology over the last half century. Its industrial applications are growing steadily and so are the number of workers using this technology. To date, there are no reports on airborne exposures during FSW. The objective of this study was to investigate possible emissions of nanoscale (<100 nm) and fine (<1 microm) aerosols during FSW of two aluminum alloys in a laboratory setting and characterize their physicochemical composition. Several instruments measured size distributions (5 nm to 20 microm) with 1-s resolution, lung deposited surface areas, and PM(2.5) concentrations at the source and at the breathing zone (BZ). A wide range aerosol sampling system positioned at the BZ collected integrated samples in 12 stages (2 nm to 20 microm) that were analyzed for several metals using inductively coupled plasma mass spectrometry. Airborne aerosol was directly collected onto several transmission electron microscope grids and the morphology and chemical composition of collected particles were characterized extensively. FSW generates high concentrations of ultrafine and submicrometer particles. The size distribution was bimodal, with maxima at approximately 30 and approximately 550 nm. The mean total particle number concentration at the 30 nm peak was relatively stable at approximately 4.0 x 10(5) particles cm(-3), whereas the arithmetic mean counts at the 550 nm peak varied between 1500 and 7200 particles cm(-3), depending on the test conditions. The BZ concentrations were lower than the source concentrations by 10-100 times at their respective peak maxima and showed higher variability. The daylong average metal-specific concentrations were 2.0 (Zn), 1.4 (Al), and 0.24 (Fe) microg m(-3); the estimated average peak concentrations were an order of magnitude higher. Potential for significant exposures to fine and ultrafine aerosols, particularly of Al, Fe, and Zn, during FSW may exist, especially in larger scale industrial operations. PMID:20453001

  3. Children exposure to atmospheric particles in indoor of Lisbon primary schools

    NASA Astrophysics Data System (ADS)

    Almeida, Susana Marta; Canha, Nuno; Silva, Ana; Freitas, Maria do Carmo; Pegas, Priscilla; Alves, Célia; Evtyugina, Margarita; Pio, Casimiro Adrião

    2011-12-01

    Evidence continues to emerge showing that poor Indoor Air Quality (IAQ) can cause illness requiring absence from schools, and can cause acute health symptoms that decrease students' performance. Since children spend on average 7-11 h per weekday at school, the IAQ in classrooms is expected to play a key role in the assessment of the effects of their personal exposure to air pollution. Within this context the present study was conducted in order to fulfill three primary objectives 1) to measure the levels and the element composition of PM 2.5 and PM 2.5-10, in three primary schools placed in Lisbon, in order to assess the children exposure to these pollutants; 2) to study the relationship between indoor and outdoor atmospheric particles concentrations and 3) to investigate the sources of high aerosols concentrations in classrooms. In the studied classrooms, the concentrations of coarse particles significantly exceeded the ambient levels. Element concentrations suggested that the physical activity of students highly contributed to the re-suspension of sedimented particles. The high levels of CO 2 indicated that in these schools the ventilation was inadequate. This fact contributed to the establishment of poor IAQ.

  4. Muffler and exhaust gas purifier for internal combustion engines

    Microsoft Academic Search

    Ignoffo

    1977-01-01

    An internal combustion engine exhaust gas muffler and purifier with segmented hollow shell and removable middle segment are described. The shell has an upstream exhaust gas expansion chamber, a downstream sound-absorbing and sound-collecting chamber, and a middle, removable cartridge receiving housing. The cartridge is filled with small particles of exhaust gas purifying material. 2 claims, 9 figures.

  5. Phenomenological in-situ TEM gas exposure studies of palladium particles on MgO at room temperature

    NASA Technical Reports Server (NTRS)

    Heinemann, K.; Poppa, H.; Osaka, T.

    1983-01-01

    It has been found that very small vapor-deposited catalytically active metal particles in the 1-2 nm size range on metal oxide substrates can undergo significant changes when they are exposed to gases such as oxygen or air, or even when allowed to 'anneal' at room temperature (RT) under vacuum conditions. The present investigation is concerned with continued in-situ gas exposures of as-deposited, 1 to 2 nm size palladium particles on MgO to air, oxygen, nitrogen, hydrogen, CO, and water vapor at RT. It is found that the low-pressure exposure to various gases at RT can significantly affect small palladium particles supported on MgO surfaces. Exposure to oxygen for 3 min at 0.0002 m bar produces a considerable amount of coalescence, flattening of the particles, and some distinct crystallographic particle shapes.

  6. The toxicity of particles from combustion processes

    SciTech Connect

    Henderson, R.F.; Mauderly, J.L.

    1991-12-31

    The pulmonary toxicity of inhaled particles will depend on their size, solubility and inherent toxicity. Many combustion-derived particles, such as soot and fly ash, are of a respirable size and, being poorly soluble, are retained for prolonged periods in the lung. The acute toxicity of fly ash from coal combustion was compared to that of a known toxic particle, alpha-quartz, by exposures of rats to 35 mg/m{sup 3} of each type of particle for 7 hr/day, 5 days/wk for 4 wk. The acute pulmonary toxicity was measured by analysis of bronchoalveolar lavage fluid. One year after the exposures, fibrosis with granulomas was observed in the quartz-exposed rats, while little or no fibrosis developed in the fly-ash-exposed rats. The toxicity of soot from diesel exhaust was determined by chronic (30 mo) exposures of rats, 7 hr/day, 5 days/wk to exhaust containing 0.35, 3.5 or 7.0 mg/m{sup 3} soot. The two higher exposures caused persistent pulmonary inflammation, fibrosis and neoplasmas. Rats exposed to the lowest concentration demonstrated no toxic responses and there was no life shortening caused by any exposure. Ongoing comparative studies indicate that pure carbon black particles cause responses similar to those caused by diesel exhaust, indicating that much of the toxicity induced by the diesel soot results from the presence of the large lung burdens of carbonaceous particles.

  7. The toxicity of particles from combustion processes

    SciTech Connect

    Henderson, R.F.; Mauderly, J.L.

    1991-01-01

    The pulmonary toxicity of inhaled particles will depend on their size, solubility and inherent toxicity. Many combustion-derived particles, such as soot and fly ash, are of a respirable size and, being poorly soluble, are retained for prolonged periods in the lung. The acute toxicity of fly ash from coal combustion was compared to that of a known toxic particle, alpha-quartz, by exposures of rats to 35 mg/m{sup 3} of each type of particle for 7 hr/day, 5 days/wk for 4 wk. The acute pulmonary toxicity was measured by analysis of bronchoalveolar lavage fluid. One year after the exposures, fibrosis with granulomas was observed in the quartz-exposed rats, while little or no fibrosis developed in the fly-ash-exposed rats. The toxicity of soot from diesel exhaust was determined by chronic (30 mo) exposures of rats, 7 hr/day, 5 days/wk to exhaust containing 0.35, 3.5 or 7.0 mg/m{sup 3} soot. The two higher exposures caused persistent pulmonary inflammation, fibrosis and neoplasmas. Rats exposed to the lowest concentration demonstrated no toxic responses and there was no life shortening caused by any exposure. Ongoing comparative studies indicate that pure carbon black particles cause responses similar to those caused by diesel exhaust, indicating that much of the toxicity induced by the diesel soot results from the presence of the large lung burdens of carbonaceous particles.

  8. Health effects of acute exposure to air polllution. Part II: Healthy subjects exposed to cencentrated ambient particles

    EPA Science Inventory

    The purpose of this study was to assess the impact of short-term exposure to concentrated ambient particles (CAPs*) on lung function and on inflammatory parameters in blood and airways of healthy human subjects. Particles were concentrated from the ambient air in Chapel Hill, Nor...

  9. 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.

  10. Apparatus for soot removal from exhaust gas

    SciTech Connect

    Leonard, R.E.

    1991-04-02

    This patent describes an apparatus. It comprises a diesel engine producing an exhaust gas stream; means operatively connected to the diesel engine for receiving the exhaust gas stream and for contacting the exhaust gas stream with water to produce a substantially water saturated gas stream; means for electrically charging particles and droplets in the water saturated gas stream; and means for electrostatically attracting and de-entraining soot and soot containing water droplets from the gas stream containing electrically charged particles and droplets to produce a substantially soot free exhaust gas stream.; wherein the means for charging particles and droplets and the means for electrostatically attracting and de-entraining soot and soot containing water droplets.

  11. Cardiovascular and thermoregulatory responses of unrestrained rats exposed to filtered or unfiltered diesel exhaust.

    PubMed

    Gordon, Christopher J; Schladweiler, Mette C; Krantz, Todd; King, Charly; Kodavanti, Urmila P

    2012-04-01

    Diesel exhaust has been associated with adverse cardiovascular and pulmonary health effects. The relative contributions of the gas phase and particulate components of diesel exhaust are less well understood. We exposed telemetered Wistar-Kyoto rats to air or diesel exhaust that was either filtered (F) or unfiltered [gas-phase plus diesel exhaust particles (DEP)], containing ~1.9 mg/m³ of particulate matter for 5 h/day; 5 days/week for 4 consecutive weeks. Blood pressure (BP), core temperature (T(c)), heart rate (HR), and cardiac contractility (CC) estimated by the QA interval were monitored by radiotelemetry during exposure as well as during a 2-week period of recovery. Pulmonary injury and inflammation markers were analysed after 2-day, and 4 weeks of exposure, and 2-week recovery. Exposure to F or DEP was associated with a trend for a reduction in BP during weeks 1, 2 and 4. A reduction in HR in the DEP group was apparent during week 4. Exposure to DEP but not F was associated with significant reduction in CC over weeks 1-4. There was also a slight elevation in T(c) during DEP exposure. All telemetry parameters were normal during recovery at night and a 2-week recovery period. Neutrophilic inflammation in bronchoalveolar lavage fluid was evident after 2 days and 4 weeks of exposure to F and DEP. There were no signs of inflammation after 2-week recovery. We found a significant decrease in CC and slight reduction in BP. Exposure to DEP and F is associated with pulmonary inflammation, and mild effects on HR, BP, and T(c) but there is a marked effect of DEP on CC. PMID:22486347

  12. Liquid cooled exhaust flange

    SciTech Connect

    Woods, W.E.

    1990-04-24

    This patent describes a liquid-cooled exhaust flange for mating a liquid-jacketed exhaust conduit system to a conventional internal combustion engine turbo charger discharge port. It comprises: a generally cylindrical elongated exhaust conduit member adapted to mate in sandwiched relationship between the turbo charger housing and the liquid-jacketed exhaust conduit system; a cooling liquid-jacket housing internally and concentrically connected to the exhaust conduit member adapted to mate in fluidly communicating relationship with a flow of cooling liquid within the liquid-jacketed exhaust conduit system; the liquid-jacket housing covering a substantial portion of the external surface area of the exhaust conduit member so as to reduce the temperature of the external surface of the exhaust flange.

  13. Effect of cabin ventilation rate on ultrafine particle exposure inside automobiles.

    PubMed

    Knibbs, Luke D; de Dear, Richard J; Morawska, Lidia

    2010-05-01

    We alternately measured on-road and in-vehicle ultrafine (<100 nm) particle (UFP) concentration for 5 passenger vehicles that comprised an age range of 18 years. A range of cabin ventilation settings were assessed during 301 trips through a 4 km road tunnel in Sydney, Australia. Outdoor air flow (ventilation) rates under these settings were quantified on open roads using tracer gas techniques. Significant variability in tunnel trip average median in-cabin/on-road (I/O) UFP ratios was observed (0.08 to approximately 1.0). Based on data spanning all test automobiles and ventilation settings, a positive linear relationship was found between outdoor air flow rate and I/O ratio, with the former accounting for a substantial proportion of variation in the latter (R(2) = 0.81). UFP concentrations recorded in-cabin during tunnel travel were significantly higher than those reported by comparable studies performed on open roadways. A simple mathematical model afforded the ability to predict tunnel trip average in-cabin UFP concentrations with good accuracy. Our data indicate that under certain conditions, in-cabin UFP exposures incurred during tunnel travel may contribute significantly to daily exposure. The UFP exposure of automobile occupants appears strongly related to their choice of ventilation setting and vehicle. PMID:20369882

  14. MUTAGENICITY OF DIESEL-EXHAUST PARTICLE EXTRACT, 1-NITROPYRENE, AND 2,7-DINITROFLUORENONE IN SALMONELLA TYPHIMURIUM UNDER VARIOUS METABOLIC ACTIVATION CONDITIONS

    EPA Science Inventory

    The mutagenic activities of 1-nitropyrene, 2,7-dinitrofluorenone, and a diesel-exhaust extract were compared using the Salmonella typhimurium plate-incorporation assay. Each sample was tested with and without a 9000 x g liver homogenate (S9), both with and without an NADPH-genera...

  15. Developmental Exposure to Concentrated Ambient Particles and Preference for Immediate Reward in Mice

    PubMed Central

    Allen, Joshua L.; Conrad, Katherine; Oberdörster, Günter; Johnston, Carl J.; Sleezer, Brianna

    2012-01-01

    Background: Recent epidemiological studies indicate negative associations between a diverse group of air pollutants and cognitive functioning in children and adults, and aspects of attention deficit in children. Neuroinflammation and oxidative stress are two putative biological mechanisms by which air pollutants may adversely affect the brain. Objectives: We sought to determine whether exposure to concentrated ambient particulate matter (CAPS) during the first 2 weeks of life, alone or again in adulthood, could alter responding for delayed reward, a critical component of human decision making. Greater preference for immediate reward has been implicated as a component of several psychiatric disorders, addiction, obesity, and attention deficit. Methods: C57BL/6J mice were exposed to ultrafine particles (< 100 nm in aerodynamic diameter; CAPS) using the Harvard University Concentrated Ambient Particle System (HUCAPS) or filtered air in the postnatal period (days 4–7 and 10–13) with and without adult exposure over days 56–60. In adulthood, delay behavior was assessed using a fixed-ratio waiting-for-reward (FR wait) paradigm in which 25 responses (FR25) were required to initiate the waiting-for-reward component during which mice obtained “free” sucrose pellets with the stipulation that these “free” pellets were delivered at increasing delay intervals. Results: Coupled with increased FR response rates, mice exposed to postnatal CAPS displayed increased FR resets that reinstated short delays, indicating a preference for shorter delays, despite the added response cost of the FR25. No associated changes in locomotor activity were observed. Conclusions: Postnatal CAPS exposure produces an enhanced bias towards immediate rewards, a risk factor for several central nervous system (CNS) disorders. This enhancement does not appear to be the result of hyperactivity. The findings underscore the need for further evaluation of air pollution effects on the CNS and its potential contribution to CNS diseases and disorders. PMID:23063827

  16. 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 active charcoal combination filter appeared less inflammatory to A549 cells. Conclusions A cabin air inlet particle filter including an active charcoal component was highly effective in reducing both DE particulate and gaseous components, with reduced exhaust-induced symptoms in healthy volunteers. These data demonstrate the effectiveness of cabin filters to protect subjects travelling in vehicles from diesel exhaust emissions. PMID:24621126

  17. Ultrafine particle exposures while walking, cycling, and driving along an urban residential roadway

    NASA Astrophysics Data System (ADS)

    Quiros, David C.; Lee, Eon S.; Wang, Rui; Zhu, Yifang

    2013-07-01

    Elevated concentrations of ultrafine particles (UFPs, <0.1 ?m), which have been linked to adverse health effects, are commonly found along roadways. This study reports UFP and PM2.5 concentrations and respiratory exposures among four transportation modes on an urban residential street in Santa Monica, California while walking, cycling, and driving with windows open and windows closed (with air recirculation on). Repeated measurements were made for nine days during morning (7:30-9:30), afternoon (12:30-14:30), and evening (17:00-19:00) periods. Median UFP concentrations ranged 1-3 × 104 particles cm-3, were 70% lower in afternoon or evening periods compared to the morning, and were 60% lower when driving with windows closed than open. Median PM2.5 ranged 2-15 ?g m-3, well below the annual National Ambient Air Quality standard of 15 ?g m-3. Respiratory UFP exposure (particles inhaled trip-1) was ˜2 times higher while driving with windows open, ˜15 times higher when cycling, and ˜30 times higher walking, than driving with windows closed. During one evening session with perpendicular rather than parallel wind conditions, absolute UFP concentration was 80% higher, suggesting influence of off-roadway sources. Under parallel wind conditions, a parameter called emissions-weighted traffic volume, used to account for higher and lower emitting vehicles, was correlated with beach-site-subtracted UFP using second-order polynomial model (R2 = 0.61). Based on this model, an 83% on-roadway UFP reduction could be achieved by (1) requiring all trucks to meet California 2007 model-year engine standards, (2) reducing light-duty vehicle flows by 25%, and (3) replacing high-emitting light-duty vehicles (pre 1978) with newer 2010 fleet-average vehicles.

  18. Exposure and Toxicity Assessment of Ultrafine Particles from Nearby Traffic in Urban Air in Seoul, Korea

    PubMed Central

    Yang, Ji-Yeon; Kim, Jin-Yong; Jang, Ji-Young; Lee, Gun-Woo; Kim, Soo-Hwan; Shin, Dong-Chun

    2013-01-01

    Objectives We investigated the particle mass size distribution and chemical properties of air pollution particulate matter (PM) in the urban area and its capacity to induce cytotoxicity in human bronchial epithelial (BEAS-2B) cells. Methods To characterize the mass size distributions and chemical concentrations associated with urban PM, PM samples were collected by a 10-stage Micro-Orifice Uniform Deposit Impactor close to nearby traffic in an urban area from December 2007 to December 2009. PM samples for in vitro cytotoxicity testing were collected by a mini-volume air sampler with PM10 and PM2.5 inlets. Results The PM size distributions were bi-modal, peaking at 0.18 to 0.32 and 1.8 to 3.2 µm. The mass concentrations of the metals in fine particles (0.1 to 1.8 µm) accounted for 45.6 to 80.4% of the mass concentrations of metals in PM10. The mass proportions of fine particles of the pollutants related to traffic emission, lead (80.4%), cadmium (69.0%), and chromium (63.8%) were higher than those of other metals. Iron was the dominant transition metal in the particles, accounting for 64.3% of the PM10 mass in all the samples. We observed PM concentration-dependent cytotoxic effects on BEAS-2B cells. Conclusions We found that exposure to PM2.5 and PM10 from a nearby traffic area induced significant increases in protein expression of inflammatory cytokines (IL-6 and IL-8). The cell death rate and release of cytokines in response to the PM2.5 treatment were higher than those with PM10. The combined results support the hypothesis that ultrafine particles from vehicular sources can induce inflammatory responses related to environmental respiratory injury. PMID:23882447

  19. Development and application of a model (ExDoM) for calculating the respiratory tract dose and retention of particles under variable exposure conditions

    Microsoft Academic Search

    Victoria Aleksandropoulou; Mihalis Lazaridis

    The ExDoM is a model for calculating the human exposure and the deposition, dose, clearance, and finally retention of aerosol\\u000a particles in the respiratory tract at specific times during and after exposure, under variable exposure conditions. Specifically,\\u000a the model incorporates an exposure module which allows the user to set variable or static exposure conditions (exposure concentration,\\u000a physical exertion levels, and

  20. Health Risk Assessment of Lead Ingestion Exposure by Particle Sizes in Crumb Rubber on Artificial Turf Considering Bioavailability

    PubMed Central

    Kim, Sunduk; Yang, Ji-Yeon; Kim, Ho-Hyun; Yeo, In-Young; Shin, Dong-Chun

    2012-01-01

    Objectives The purpose of this study was to assess the risk of ingestion exposure of lead by particle sizes of crumb rubber in artificial turf filling material with consideration of bioavailability. Methods This study estimated the ingestion exposure by particle sizes (more than 250 um or less than 250 um) focusing on recyclable ethylene propylene diene monomer crumb rubber being used as artificial turf filling. Analysis on crumb rubber was conducted using body ingestion exposure estimate method in which total content test method, acid extraction method and digestion extraction method are reflected. Bioavailability which is a calibrating factor was reflected in ingestion exposure estimate method and applied in exposure assessment and risk assessment. Two methods using acid extraction and digestion extraction concentration were compared and evaluated. Results As a result of the ingestion exposure of crumb rubber material, the average lead exposure amount to the digestion extraction result among crumb rubber was calculated to be 1.56×10-4 mg/kg-day for low grade elementary school students and 4.87×10-5 mg/kg-day for middle and high school students in 250 um or less particle size, and that to the acid extraction result was higher than the digestion extraction result. Results of digestion extraction and acid extraction showed that the hazard quotient was estimated by about over 2 times more in particle size of lower than 250 um than in higher than 250 um. There was a case of an elementary school student in which the hazard quotient exceeded 0.1. Conclusions Results of this study confirm that the exposure of lead ingestion and risk level increases as the particle size of crumb rubber gets smaller. PMID:22355803

  1. 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...

  2. 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...

  3. Development of All-Solid-State Sensors for Measurement of Nitric Oxide and Ammonia Concentrations by Optical Absorption in Particle-Laden Combusion Exhaust Streams

    SciTech Connect

    Jerald A. Caton; Kalyan Annamalai

    2003-09-24

    An all-solid-state continuous-wave (cw) laser system for ultraviolet absorption measurements of the nitric oxide (NO) molecule has been developed and demonstrated. For the NO sensor, 250 nW of tunable cw ultraviolet radiation is produced by sum-frequency-mixing of 532-nm radiation from a diode-pumped Nd:YAG laser and tunable 395-nm radiation from an external cavity diode laser (ECDL). The sum-frequency-mixing process occurs in a beta-barium borate crystal. The nitric oxide absorption measurements are performed by tuning the ECDL and scanning the sum-frequency-mixed radiation over strong nitric oxide absorption lines near 226 nm. The nitric oxide sensor has been used for measurements in the exhaust of a coal-fired laboratory combustion facility. The Texas A&M University boiler burner facility is a 30 kW (100,000 Btu/hr) downward-fired furnace with a steel shell encasing ceramic insulation. Measurements of nitric oxide concentration in the exhaust stream were performed after modification of the facility for laser based NOx diagnostics. The diode-laser-based sensor measurements showed good agreement with the results from physical probe sampling of the combustion exhaust. The diode-laser-based ultraviolet absorption measurements were successful even when the beam was severely attenuated by particulate in the exhaust stream and window fouling. Single-laser-sweep measurements were demonstrated with an effective time resolution of 100 msec, limited at this time by the scan rate of our mechanically tuned ECDL system. Future planned modifications will lead to even faster response times at sensitivity levels at or below 1 ppm.

  4. EXHAUST EMISSIONS FROM A DIESEL ENGINE

    EPA Science Inventory

    Studies were performed using (1) Diesel particles collected from the undiluted exhaust of a single-cylinder engine, operated at constant speed and load, using a binary pure hydrocarbon fuel with air or gas mixture oxidizers, and (2) Diesel particles collected from the diluted exh...

  5. Effects of flame made zinc oxide particles in human lung cells - a comparison of aerosol and suspension exposures

    PubMed Central

    2012-01-01

    Background Predominantly, studies of nanoparticle (NPs) toxicology in vitro are based upon the exposure of submerged cell cultures to particle suspensions. Such an approach however, does not reflect particle inhalation. As a more realistic simulation of such a scenario, efforts were made towards direct delivery of aerosols to air-liquid-interface cultivated cell cultures by the use of aerosol exposure systems. This study aims to provide a direct comparison of the effects of zinc oxide (ZnO) NPs when delivered as either an aerosol, or in suspension to a triple cell co-culture model of the epithelial airway barrier. To ensure dose–equivalence, ZnO-deposition was determined in each exposure scenario by atomic absorption spectroscopy. Biological endpoints being investigated after 4 or 24h incubation include cytotoxicity, total reduced glutathione, induction of antioxidative genes such as heme-oxygenase 1 (HO–1) as well as the release of the (pro)-inflammatory cytokine TNF?. Results Off-gases released as by-product of flame ZnO synthesis caused a significant decrease of total reduced GSH and induced further the release of the cytokine TNF?, demonstrating the influence of the gas phase on aerosol toxicology. No direct effects could be attributed to ZnO particles. By performing suspension exposure to avoid the factor “flame-gases”, particle specific effects become apparent. Other parameters such as LDH and HO–1 were not influenced by gaseous compounds: Following aerosol exposure, LDH levels appeared elevated at both timepoints and the HO–1 transcript correlated positively with deposited ZnO-dose. Under submerged conditions, the HO–1 induction scheme deviated for 4 and 24h and increased extracellular LDH was found following 24h exposure. Conclusion In the current study, aerosol and suspension-exposure has been compared by exposing cell cultures to equivalent amounts of ZnO. Both exposure strategies differ fundamentally in their dose–response pattern. Additional differences can be found for the factor time: In the aerosol scenario, parameters tend to their maximum already after 4h of exposure, whereas under submerged conditions, effects appear most pronounced mainly after 24h. Aerosol exposure provides information about the synergistic interplay of gaseous and particulate phase of an aerosol in the context of inhalation toxicology. Exposure to suspensions represents a valuable complementary method and allows investigations on particle-associated toxicity by excluding all gas–derived effects. PMID:22901679

  6. Personal exposure to ultrafine particles: Two-level statistical modeling of background exposure and time-activity patterns during three seasons.

    PubMed

    Deffner, Veronika; Küchenhoff, Helmut; Maier, Verena; Pitz, Mike; Cyrys, Josef; Breitner, Susanne; Schneider, Alexandra; Gu, Jianwei; Geruschkat, Uta; Peters, Annette

    2014-11-19

    Personal exposure to air pollution is associated with time- and location-specific factors including indoor and outdoor air pollution, meteorology and time activities. Our investigation aims at the description and identification of factors determining personal exposure to particle number concentration (PNC) in everyday situations. Ten volunteers recorded their personal exposure to PNC and kept an activity diary in three different seasons besides stationary measurements of ambient air pollution and meteorology. Background exposure to PNC was modelled using the most predictive variables. In a second step, the effects of the activities were calculated adjusted for the background exposure. The average personal PNC level was highest in winter and was three times higher than the mean stationary PNC level while staying indoors and two times higher while staying outdoors. Personal indoor PNC levels were significantly increased during the use of candles, cooking and the occurrence of smell of food. High stationary outdoor PNC levels and low dew point temperatures were associated with increased personal outdoor PNC levels. Times spent in public transport were associated with lower personal PNC levels than other times spent in transportation. Personal PNC levels in everyday situations exhibited a large variability because of seasonal, microenvironment-specific and activity-specific influences.Journal of Exposure Science and Environmental Epidemiology advance online publication, 19 November 2014; doi:10.1038/jes.2014.73. PMID:25407347

  7. Spatial learning and memory deficits induced by exposure to iron-56-particle radiation

    NASA Technical Reports Server (NTRS)

    Shukitt-Hale, B.; Casadesus, G.; McEwen, J. J.; Rabin, B. M.; Joseph, J. A.

    2000-01-01

    It has previously been shown that exposing rats to particles of high energy and charge (HZE) disrupts the functioning of the dopaminergic system and behaviors mediated by this system, such as motor performance and an amphetamine-induced conditioned taste aversion; these adverse behavioral and neuronal effects are similar to those seen in aged animals. Because cognition declines with age, spatial learning and memory were assessed in the Morris water maze 1 month after whole-body irradiation with 1.5 Gy of 1 GeV/nucleon high-energy (56)Fe particles, to test the cognitive behavioral consequences of radiation exposure. Irradiated rats demonstrated cognitive impairment compared to the control group as seen in their increased latencies to find the hidden platform, particularly on the reversal day when the platform was moved to the opposite quadrant. Also, the irradiated group used nonspatial strategies during the probe trials (swim with no platform), i.e. less time spent in the platform quadrant, fewer crossings of and less time spent in the previous platform location, and longer latencies to the previous platform location. These findings are similar to those seen in aged rats, suggesting that an increased release of reactive oxygen species may be responsible for the induction of radiation- and age-related cognitive deficits. If these decrements in behavior also occur in humans, they may impair the ability of astronauts to perform critical tasks during long-term space travel beyond the magnetosphere.

  8. Brain signaling and behavioral responses induced by exposure to (56)Fe-particle radiation

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    Previous experiments have demonstrated that exposure to 56Fe-particle irradiation (1.5 Gy, 1 GeV) produced aging-like accelerations in neuronal and behavioral deficits. Astronauts on long-term space flights will be exposed to similar heavy-particle radiations that might have similar deleterious effects on neuronal signaling and cognitive behavior. Therefore, the present study evaluated whether radiation-induced spatial learning and memory behavioral deficits are associated with region-specific brain signaling deficits by measuring signaling molecules previously found to be essential for behavior [pre-synaptic vesicle proteins, synaptobrevin and synaptophysin, and protein kinases, calcium-dependent PRKCs (also known as PKCs) and PRKA (PRKA RIIbeta)]. The results demonstrated a significant radiation-induced increase in reference memory errors. The increases in reference memory errors were significantly negatively correlated with striatal synaptobrevin and frontal cortical synaptophysin expression. Both synaptophysin and synaptobrevin are synaptic vesicle proteins that are important in cognition. Striatal PRKA, a memory signaling molecule, was also significantly negatively correlated with reference memory errors. Overall, our findings suggest that radiation-induced pre-synaptic facilitation may contribute to some previously reported radiation-induced decrease in striatal dopamine release and for the disruption of the central dopaminergic system integrity and dopamine-mediated behavior.

  9. Spatial learning and memory deficits induced by exposure to iron-56-particle radiation.

    PubMed

    Shukitt-Hale, B; Casadesus, G; McEwen, J J; Rabin, B M; Joseph, J A

    2000-07-01

    It has previously been shown that exposing rats to particles of high energy and charge (HZE) disrupts the functioning of the dopaminergic system and behaviors mediated by this system, such as motor performance and an amphetamine-induced conditioned taste aversion; these adverse behavioral and neuronal effects are similar to those seen in aged animals. Because cognition declines with age, spatial learning and memory were assessed in the Morris water maze 1 month after whole-body irradiation with 1.5 Gy of 1 GeV/nucleon high-energy (56)Fe particles, to test the cognitive behavioral consequences of radiation exposure. Irradiated rats demonstrated cognitive impairment compared to the control group as seen in their increased latencies to find the hidden platform, particularly on the reversal day when the platform was moved to the opposite quadrant. Also, the irradiated group used nonspatial strategies during the probe trials (swim with no platform), i.e. less time spent in the platform quadrant, fewer crossings of and less time spent in the previous platform location, and longer latencies to the previous platform location. These findings are similar to those seen in aged rats, suggesting that an increased release of reactive oxygen species may be responsible for the induction of radiation- and age-related cognitive deficits. If these decrements in behavior also occur in humans, they may impair the ability of astronauts to perform critical tasks during long-term space travel beyond the magnetosphere. PMID:10856962

  10. Modeling the Prodromal Effects and Performance Reduction of Astronauts from Exposure to Large Solar Particle Events

    NASA Technical Reports Server (NTRS)

    Hu, S.; Kim, M. Y.; McClellan, G. E.; Nikjoo, H.; Cucinotta, F. A.

    2007-01-01

    In space exploration outside the Earth's geomagnetic field, radiation exposure from solar particle events (SPE) presents a health concern for astronauts, that could impair their performance and result in possibility of failure of the mission. Acute risks are especially of concern during spacewalks on the lunar surface because of the rapid onset of SPE's and science goals that involve long distances to crew habitats. Thus assessing the potential of early radiation effect under such adverse conditions is of prime importance. Here we present a biologic based mathematical model which describes the dose and time-dependent early human responses to ionizing radiation. We examine the possible early effects on crew behind various shielding materials from exposure to some historical large SPEs on the lunar and Mars surfaces. The doses and dose rates were calculated using the BRYNTRN code (Kim, M.Y, Hu, X, and Cucinotta, F.A, Effect of Shielding Materials from SPEs on the Lunar and Mars Surface, AIAA Space 2005, paper number AIAA-2005-6653, Long Beach, CA, August 30-September 1, 2005) and the hazard of the early radiation effects and performance reduction were calculated using the RIPD code (Anno, G.H, McClellan, G.E., Dore, M.A, Protracted Radiation-Induced Performance Decrement, Volume 1 Model Development,1996, Defense Nuclear Agency: Alexandria VA). Based on model assumptions we show that exposure to these historical SPEs do cause early effects to crew members and impair their performance if effective shielding and medical countermeasure tactics are not provided. The calculations show multiple occurrence of large SPEs in a short period of time significantly increase the severity of early illness, however early death from failure of the hematopoietic system is very unlikely because of the dose-rate and dose heterogeneity of SPEs. Results from these types of calculations will be a guide in design of protection systems and medical response strategy for astronauts in case of exposure to high dose irradiation during future space missions.

  11. Analyses of risks associated with radiation exposure from past major solar particle events

    SciTech Connect

    Weyland, M.D.; Atwell, W.; Cucinotta, F.A.; Wilson, J.W.; Hardy, A.C.

    1991-08-01

    Radiation exposures and cancer induction/mortality risks were investigated for several major solar particle events (SPE's). The SPE's included are: February 1956, November 1960, August 1972, October 1989, and the September, August, and October 1989 events combined. The three 1989 events were treated as one since all three could affect a single lunar or Mars mission. A baryon transport code was used to propagate particles through aluminum and tissue shield materials. A free space environment was utilized for all calculations. Results show the 30-day blood forming organs (BFO) limit of 25 rem was surpassed by all five events using 10 g/sq cm of shielding. The BFO limit is based on a depth dose of 5 cm of tissue, while a more detailed shield distribution of the BFO's was utilized. A comparison between the 5 cm depth dose and the dose found using the BFO shield distribution shows that the 5 cm depth value slightly higher than the BFO dose. The annual limit of 50 rem was exceeded by the August 1972, October 1989, and the three combined 1989 events with 5 g/sq cm of shielding. Cancer mortality risks ranged from 1.5 to 17 percent at 1 g/sq cm and 0.5 to 1.1 percent behind 10 g/sq cm of shielding for five events. These ranges correspond to those for a 45 year old male. It is shown that secondary particles comprise about 1/3 of the total risk at 10 g/sq cm of shielding. Utilizing a computerized Space Shuttle shielding model to represent a typical spacecraft configuration in free space at the August 1972 SPE, average crew doses exceeded the BFO dose limit.

  12. Analyses of risks associated with radiation exposure from past major solar particle events

    NASA Technical Reports Server (NTRS)

    Weyland, Mark D.; Atwell, William; Cucinotta, Francis A.; Wilson, John W.; Hardy, Alva C.

    1991-01-01

    Radiation exposures and cancer induction/mortality risks were investigated for several major solar particle events (SPE's). The SPE's included are: February 1956, November 1960, August 1972, October 1989, and the September, August, and October 1989 events combined. The three 1989 events were treated as one since all three could affect a single lunar or Mars mission. A baryon transport code was used to propagate particles through aluminum and tissue shield materials. A free space environment was utilized for all calculations. Results show the 30-day blood forming organs (BFO) limit of 25 rem was surpassed by all five events using 10 g/sq cm of shielding. The BFO limit is based on a depth dose of 5 cm of tissue, while a more detailed shield distribution of the BFO's was utilized. A comparison between the 5 cm depth dose and the dose found using the BFO shield distribution shows that the 5 cm depth value slightly higher than the BFO dose. The annual limit of 50 rem was exceeded by the August 1972, October 1989, and the three combined 1989 events with 5 g/sq cm of shielding. Cancer mortality risks ranged from 1.5 to 17 percent at 1 g/sq cm and 0.5 to 1.1 percent behind 10 g/sq cm of shielding for five events. These ranges correspond to those for a 45 year old male. It is shown that secondary particles comprise about 1/3 of the total risk at 10 g/sq cm of shielding. Utilizing a computerized Space Shuttle shielding model to represent a typical spacecraft configuration in free space at the August 1972 SPE, average crew doses exceeded the BFO dose limit.

  13. Health impacts due to personal exposure to fine particles caused by insulation of residential buildings in Europe

    NASA Astrophysics Data System (ADS)

    Gens, Alexandra; Hurley, J. Fintan; Tuomisto, Jouni T.; Friedrich, Rainer

    2014-02-01

    The insulation of residential buildings affects human exposure to fine particles. According to current EU guidelines, insulation is regulated for energy saving reasons. As buildings become tighter, the air exchange rate is reduced and, thus, the indoor concentration of pollutants is increased if there are significant indoor sources. While usually the effects of heat insulation and increase of the air-tightness of buildings on greenhouse gas emissions are highlighted, the negative impacts on human health due to higher indoor concentrations are not addressed. Thus, we investigated these impacts using scenarios in three European countries, i. e. Czech Republic, Switzerland and Greece. The assessment was based on modelling the human exposure to fine particles originating from sources of particles within outdoor and indoor air, including environmental tobacco smoke. Exposure response relationships were derived to link (adverse) health effects to the exposure. Furthermore, probable values for the parameters influencing the infiltration of fine particles into residential buildings were modelled. Results show that the insulation and increase of the air-tightness of residential buildings leads to an overall increase of the mean population exposure - and consequently adverse health effects - in all considered countries (ranging for health effects from 0.4% in Czech Republic to 11.8% in Greece for 100% insulated buildings) due to an accumulation of particles indoors, especially from environmental tobacco smoke. Considering only the emission reductions in outdoor air (omitting changes in infiltration parameters) leads to a decrease of adverse health effects. This study highlights the importance of ensuring a sufficient air exchange rate when insulating buildings, e. g. by prescribing heat ventilation and air conditioning systems in new buildings and information campaigns on good airing practice in renovated buildings. It also shows that assessing policy measures based on the exposure may provide different recommendations compared to an assessment based on only the outdoor air concentration.

  14. Exhaust gas purification device

    SciTech Connect

    Fujiwara, H.; Hibi, T.; Sayo, S.; Sugiura, Y.; Ueda, K.

    1980-02-19

    The exhaust gas purification device includes an exhaust manifold , a purification cylinder connected with the exhaust manifold through a first honey-comb shaped catalyst, and a second honeycomb shaped catalyst positioned at the rear portion of the purification cylinder. Each catalyst is supported by steel wool rings including coarse and dense portions of steel wool. The purification device further includes a secondary air supplying arrangement.

  15. Exhaust gas recirculation apparatus

    SciTech Connect

    Wake, J.; Matsuda, H.

    1980-01-01

    An exhaust gas recirculation passageway leads from an engine exhaust passageway to an engine induction passageway downstream of a throttle valve. A fuel control member of an injection pump moves the throttle valve in the opening direction to reduce the vacuum in the induction passageway and thereby the amount of exhaust gas recirculation only when the fuel control member is moved beyond a predetermined position in the fuel increasing direction. A stopper limits movement of the throttle valve in the closing direction.

  16. Investigation of a potential cotumorigenic effect of the dioxides of nitrogen and sulfur, and of diesel-engine exhaust, on the respiratory tract of Syrian golden hamsters

    SciTech Connect

    Heinrich, U.; Mohr, U.; Fuhst, R.; Brockmeyer, C. (Fraunhofer Institute for Toxicology and Aerosol Research, Hannover (Germany, F.R.))

    1989-05-01

    Syrian golden hamsters (480 males and 480 females) allocated into 24 groups were exposed 19 hours per day and 5 days per week for 6, 10.5, 15, or 18 months to total diesel exhaust, diesel exhaust without particles, a mixture of nitrogen dioxide (5 parts per million (ppm)2) and sulfur dioxide (10 ppm), or clean air. Two exposure groups from each test atmosphere were also treated by a single subcutaneous injection of either 3 mg or 6 mg of diethylnitrosamine/kg of body weight to evaluate an enhancing effect of diethylnitrosamine on exposure-related changes. Morphological evaluation was done by histopathology. Minor changes of the larynx and trachea were investigated by scanning electron microscopy, which showed a loss of ciliated cells in all exhaust-exposed groups. After exposure to diesel exhaust with or without particles, focal metaplasia and dysplasia of the respiratory epithelium were seen in the oldest animals by scanning electron microscopy. In the same specimens, attached mucous droplets indicated changes in mucous cells and mucous viscosity. Only the exposure to total diesel exhaust significantly increased the tumor rate in the upper respiratory tract of male hamsters treated with 6 mg of diethylnitrosamine per kg of body weight. At the lower diethylnitrosamine dose, no exposure-related effects on the tumor rates could be observed. The results from this study and from our other inhalation experiments appear to be insufficiently conclusive to demonstrate that diesel-engine exhaust should be classified as a cocarcinogen or enhancer for the test system used.

  17. Effect of oxidant concentration, exposure time, and seed particles on secondary organic aerosol chemical composition and yield

    NASA Astrophysics Data System (ADS)

    Lambe, A. T.; Chhabra, P. S.; Onasch, T. B.; Brune, W. H.; Hunter, J. F.; Kroll, J. H.; Cummings, M. J.; Brogan, J. F.; Parmar, Y.; Worsnop, D. R.; Kolb, C. E.; Davidovits, P.

    2015-03-01

    We performed a systematic intercomparison study of the chemistry and yields of secondary organic aerosol (SOA) generated from OH oxidation of a common set of gas-phase precursors in a Potential Aerosol Mass (PAM) continuous flow reactor and several environmental chambers. In the flow reactor, SOA precursors were oxidized using OH concentrations ranging from 2.0 × 108 to 2.2 × 1010 molec cm-3 over exposure times of 100 s. In the environmental chambers, precursors were oxidized using OH concentrations ranging from 2 × 106 to 2 × 107 molec cm-3 over exposure times of several hours. The OH concentration in the chamber experiments is close to that found in the atmosphere, but the integrated OH exposure in the flow reactor can simulate atmospheric exposure times of multiple days compared to chamber exposure times of only a day or so. In most cases, for a specific SOA type the most-oxidized chamber SOA and the least-oxidized flow reactor SOA have similar mass spectra, oxygen-to-carbon and hydrogen-to-carbon ratios, and carbon oxidation states at integrated OH exposures between approximately 1 × 1011 and 2 × 1011 molec cm-3 s, or about 1-2 days of equivalent atmospheric oxidation. This observation suggests that in the range of available OH exposure overlap for the flow reactor and chambers, SOA elemental composition as measured by an aerosol mass spectrometer is similar whether the precursor is exposed to low OH concentrations over long exposure times or high OH concentrations over short exposure times. This similarity in turn suggests that both in the flow reactor and in chambers, SOA chemical composition at low OH exposure is governed primarily by gas-phase OH oxidation of the precursors rather than heterogeneous oxidation of the condensed particles. In general, SOA yields measured in the flow reactor are lower than measured in chambers for the range of equivalent OH exposures that can be measured in both the flow reactor and chambers. The influence of sulfate seed particles on isoprene SOA yield measurements was examined in the flow reactor. The studies show that seed particles increase the yield of SOA produced in flow reactors by a factor of 3 to 5 and may also account in part for higher SOA yields obtained in the chambers, where seed particles are routinely used.

  18. Atherosclerosis lesion progression during inhalation exposure to environmental tobacco smoke: A comparison to concentrated ambient air fine particles exposure

    PubMed Central

    Chen, Lung Chi; Quan, Chunli; Hwang, Jing Shiang; Jin, Ximei; Li, Qiang; Zhong, Mianhua; Rajagopalan, Sanjay; Sun, Qinghua

    2011-01-01

    Environmental tobacco smoke (ETS) and ambient air fine particulate matter (PM2.5) are both complex mixtures that have important adverse effects on the cardiovascular system. Although exposures to these complex mixtures have been studied individually, direct comparisons between the two has not been performed. In this study, the authors employed a novel, noninvasive ultrasound biomicroscopy method (UBM) to assess the effects of long-term, low-concentration inhalations of side-stream smoke (SS) and concentrated ambient PM2.5 (CAPs) on plaque progression. ApoE?/? mice (n = 8/group) on high-fat chow (HFC), or normal chow (NC), were exposed to SS (PM = 450 ?g/m3) or filtered air (FA) for 6 h/day, 5 days/week, for 6 months; CAPs exposure was at 134 ?g/m3 (NC only). Mortality during the SS exposure was greater in the HFC than in the NC, and SS significantly enhanced the effects of diet. No mortality was observed in CAPs-exposed mice. At 4 and 6 months, SS produced the greatest change in plaque area in the left common carotid artery (CCA) in HFC as compared to FA or NC, but not in the brachiocephalic artery. In contrast, CAPs exposure significantly enhanced plaque areas in brachiocephalic and left CCA at 3 and 6 months of exposure. The effect of SS was comparable in magnitude to that produced by CAPs at an average PM2.5 mass concentration that was only 30% as high. In light of the employment of the same animal model, uniform inhalation exposure protocols, time schedules, a noninvasive monitoring protocol, and a parallel study design, these findings have broad applicability. PMID:20235771

  19. Amphetamine-Induced Taste Aversion Learning in Young and Old F-344 Rats Following Exposure to 56Fe Particles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exposure to 56Fe particles produces changes in dopaminergic function and in dopamine dependent behaviors, including amphetamine-induced conditioned taste aversion (CTA) learning. Because many of these changes are characteristic of the changes that accompany the aging process, the present study was ...

  20. Susceptibility of Tribolium confusum (Coleoptera: Tenebrionidae) to pyrethrin aerosol: effects of aerosol particle size, concentration, and exposure conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A series of laboratory studies were conducted to assess effect of droplet size on efficacy of pyrethrin aerosol against adults of Tribolium confusum Jacqueline DuVal, the confused flour beetle. A vertical flow aerosol exposure chamber that generated a standardized particle size diameter was used for...

  1. CONSISTENT INFLAMMATORY RESPONSE FOLLOWING EXPOSURE TO CONCENTRATED AMBIENT PARTICLES (CAPS) DURING FALL SEASON IN WISTAR-KYOTO RATS

    EPA Science Inventory

    CONSISTENT INFLAMMATORY RESPONSE FOLLOWING EXPOSURE TO CONCENTRATED AMBIENT PARTICLES (CAPs) DURING FALL SEASON IN WISTAR-KYOTO RATS. UP Kodavanti, MC Schladweiler, AD Ledbetter, LC Walsh, PS Gilmour, MI Gilmour, WP Watkinson, JP Nolan, JH Richards, D Andrews, DL Costa. US EPA...

  2. PULMONARY AND SYSTEMIC EFFECTS OF ZINC-CONTAINING EMISSION PARTICLES IN THREE RAT STRAINS: MULTIPLE EXPOSURE SCENARIOS

    EPA Science Inventory

    Abstract Pulmonary and Systemic Effects of Zinc-Containing Emission Particles in Three Rat Strains: Multiple Exposure Scenarios. Kodavanti, U. P., Schladweiler, M. C. J., Ledbetter, A. D., Hauser, R.*, Christiani, D. C.*, McGee, J., Richards, J. R., and Costa, D. L. (2002)....

  3. Persistent Endothelial Dysfunction in Humans after Diesel Exhaust Inhalation

    Microsoft Academic Search

    Hakan Tornqvist; Nicholas L. Mills; Manuel Gonzalez; Mark R. Miller; Simon D. Robinson; Ian L. Megson; William MacNee; Ken Donaldson; Stefan Soderberg; David E. Newby; Thomas Sandstrom; Anders Blomberg

    2007-01-01

    Rationale: Exposure to combustion-derived air pollution is associ- ated with an early (1-2 h) and sustained (24 h) rise in cardiovascular morbidity and mortality. We have previously demonstrated that inhalation of diesel exhaust causes an immediate (within 2 h) im- pairment of vascular and endothelial function in humans. Objectives: To investigate the vascular and systemic effects of diesel exhaust in

  4. Associations of Short-Term Particle and Noise Exposures with Markers of Cardiovascular and Respiratory Health among Highway Maintenance Workers

    PubMed Central

    Meier, Reto; Cascio, Wayne E.; Ghio, Andrew J.; Wild, Pascal; Danuser, Brigitta

    2014-01-01

    Background: Highway maintenance workers are constantly and simultaneously exposed to traffic-related particle and noise emissions, both of which have been linked to increased cardiovascular morbidity and mortality in population-based epidemiology studies. Objectives: We aimed to investigate short-term health effects related to particle and noise exposure. Methods: We monitored 18 maintenance workers, during as many as five 24-hr periods from a total of 50 observation days. We measured their exposure to fine particulate matter (diameter ? 2.5 ?m; PM2.5), ultrafine particles, and noise, and the cardiopulmonary health end points: blood pressure, proinflammatory and prothrombotic markers in the blood, lung function, and fractional exhaled nitric oxide (FeNO) measured approximately 15 hr after work. Heart rate variability was assessed during a sleep period approximately 10 hr after work. Results: PM2.5 exposure was significantly associated with C-reactive protein and serum amyloid A, and was negatively associated with tumor necrosis factor ?. None of the particle metrics were significantly associated with von Willebrand factor or tissue factor expression. PM2.5 and work noise were associated with markers of increased heart rate variability, and with increased high-frequency and low-frequency power. Systolic and diastolic blood pressure on the following morning were significantly associated with noise exposure after work, and nonsignificantly associated with PM2.5. We observed no significant associations between any of the exposures and lung function or FeNO. Conclusions: Our findings suggest that exposure to particles and noise during highway maintenance work might pose a cardiovascular health risk. Actions to reduce these exposures could lead to better health for this population of workers. Citation: Meier R, Cascio WE, Ghio AJ, Wild P, Danuser B, Riediker M. 2014. Associations of short-term particle and noise exposures with markers of cardiovascular and respiratory health among highway maintenance workers. Environ Health Perspect 122:726–732;?http://dx.doi.org/10.1289/ehp.1307100 PMID:24647077

  5. Modeling Acute Health Effects of Astronauts from Exposure to Large Solar Particle Events

    NASA Technical Reports Server (NTRS)

    Hu, Shaowen; Kim, Myung-Hee Y.; Cucinotta, Francis A.

    2011-01-01

    In space exploration outside the Earth s geomagnetic field, radiation exposure from solar particle events (SPE) presents a health concern for astronauts, that could impair their performance and result in possible failure of the mission. Acute risks are of special concern during extra-vehicular activities because of the rapid onset of SPE. However, most SPEs will not lead to acute risks but can lead to mission disruption if accurate projection methods are not available. Acute Radiation Sickness (ARS) is a group of clinical syndromes developing acutely (within several seconds to 3 days) after high dose whole-body or significant partial-body ionizing radiation exposures. The manifestation of these syndromes reflects the disturbance of physiological processes of various cellular groups damaged by radiation. Hematopoietic cells, skin, epithelium, intestine, and vascular endothelium are among the most sensitive tissues of human body to ionizing radiation. Most ARS symptoms are directly related to these tissues and other systems (nervous, endocrine, and cardiovascular, etc.) with coupled regulations. Here we report the progress in bio-mathematical models to describe the dose and time-dependent early human responses to ionizing radiation. The responses include lymphocyte depression, granulocyte modulation, fatigue and weakness syndrome, and upper gastrointestinal distress. The modest dose and dose-rates of SPEs are predicted to lead to large sparing of ARS, however detailed experimental data on a range of proton dose-rates for organ doses from 0.5 to 2 Gy is needed to validate the models. We also report on the ARRBOD code that integrates the BRYNTRN and SUMDOSE codes, which are used to estimate the SPE organ doses for astronauts under various space travel scenarios, with our models of ARS. The more recent effort is to provide easy web access to space radiation risk assessment using the ARRBOD code.

  6. Impact of smoking on in-vehicle fine particle exposure during driving

    NASA Astrophysics Data System (ADS)

    Sohn, Hongji; Lee, Kiyoung

    2010-09-01

    Indoor smoking ban in public places can reduce secondhand smoke (SHS) exposure. However, smoking in cars and homes has continued. The purpose of this study was to assess particulate matter less than 2.5 ?m (PM 2.5) concentration in moving cars with different window opening conditions. The PM 2.5 level was measured by an aerosol spectrometer inside and outside moving cars simultaneously, along with ultrafine particle (UFP) number concentration, speed, temperature and humidity inside cars. Two sport utility vehicles were used. Three different ventilation conditions were evaluated by up to 20 repeated experiments. In the pre-smoking phase, average in-vehicle PM 2.5 concentrations were 16-17 ?g m -3. Regardless of different window opening conditions, the PM 2.5 levels promptly increased when smoking occurred and decreased after cigarette was extinguished. Although only a single cigarette was smoked, the average PM 2.5 levels were 506-1307 ?g m -3 with different window opening conditions. When smoking was ceased, the average PM 2.5 levels for 15 min were several times higher than the US National Ambient Air Quality Standard of 35 ?g m -3. It took longer than 10 min to reach the level of the pre-smoking phase. Although UFP levels had a similar temporal profile of PM 2.5, the increased levels during the smoking phase were relatively small. This study demonstrated that the SHS exposure in cars with just a single cigarette being smoked could exceed the US EPA NAAQS under realistic window opening conditions. Therefore, the findings support the need for public education against smoking in cars and advocacy for a smoke-free car policy.

  7. Development of All-Solid-State Sensors for Measurement of Nitric Oxide and Ammonia Concentrations by Optical Absorption in Particle-Laden Combustion Exhaust Streams

    SciTech Connect

    Jerald A. Caton; Kalyan Annamalai; Robert P. Lucht

    2005-09-30

    An all-solid-state continuous-wave (cw) laser system for ultraviolet absorption measurements of the nitric oxide (NO) molecule has been developed and demonstrated. For the NO sensor, 250 nW of tunable cw ultraviolet radiation is produced by sum-frequency-mixing of 532-nm radiation from a diode-pumped Nd:YAG laser and tunable 395-nm radiation from an external cavity diode laser (ECDL). The sum-frequency-mixing process occurs in a beta-barium borate crystal. The nitric oxide absorption measurements are performed by tuning the ECDL and scanning the sum-frequency-mixed radiation over strong nitric oxide absorption lines near 226 nm. In Year 1 of the research, the nitric oxide sensor was used for measurements in the exhaust of a coal-fired laboratory combustion facility. The Texas A&M University boiler burner facility is a 30 kW (100,000 Btu/hr) downward-fired furnace with a steel shell encasing ceramic insulation. Measurements of nitric oxide concentration in the exhaust stream were performed after modification of the facility for laser based NOx diagnostics. The diode-laser-based ultraviolet absorption measurements were successful even when the beam was severely attenuated by particulate in the exhaust stream and window fouling. Single-laser-sweep measurements were demonstrated with an effective time resolution of 100 msec, limited at this time by the scan rate of our mechanically tuned ECDL system. In Year 2, the Toptica ECDL in the original system was replaced with a Sacher Lasers ECDL. The mode-hop-free tuning range and tuning rate of the Toptica ECDL were 25 GHz and a few Hz, respectively. The mode-hop-free tuning range and tuning rate of the Sacher Lasers ECDL were 90 GHz and a few hundred Hz, respectively. The Sacher Lasers ECDL thus allows us to scan over the entire NO absorption line and to determine the absorption baseline with increased accuracy and precision. The increased tuning rate is an advantage in that data can be acquired much more rapidly and the absorption measurements are less susceptible to the effects of transient fluctuations in the properties of the coal combustor exhaust stream. Gas cell measurements were performed using the NO sensor with the new ECDL, and a few spectra were acquired from the coal exhaust stream. However, the laser diode in the new ECDL failed during the coal combustor tests. In Year 3, however, we obtained a new GaN laser diode for our ECDL system, installed it, and completed an extensive series of measurements in the Texas A&M coal-fired laboratory combustion facility. The combustor was operated with coal and coal/biomass as fuels, with and without reburn, and with and without ammonia injection. Several different fuel equivalence ratios were investigated for each operating condition. A series of spectral simulations was performed using the HITRAN code to investigate the potential sensitivity of absorption measurements of ammonia in different spectral regions. It was concluded that ammonia absorption features in the 3000-nm spectral region would be hard to measure due to water vapor interferences. We will concentrate on the spectral region near 1530 nm, where other researchers have had some success in measuring ammonia.

  8. DEVELOPMENT OF ALL-SOLID-STATE SENSORS FOR MEASUREMENT OF NITRIC OXIDE AND AMMONIA CONCENTRATIONS BY OPTICAL ABSORPTION IN PARTICLE-LADEN COMBUSTION EXHAUST STREAMS

    SciTech Connect

    Jerald A. Caton; Kalyan Annamalai; Robert P. Lucht

    2004-09-30

    An all-solid-state continuous-wave (cw) laser system for ultraviolet absorption measurements of the nitric oxide (NO) molecule has been developed and demonstrated. For the NO sensor, 250 nW of tunable cw ultraviolet radiation is produced by sum-frequency-mixing of 532-nm radiation from a diode-pumped Nd:YAG laser and tunable 395-nm radiation from an external cavity diode laser (ECDL). The sum-frequency-mixing process occurs in a beta-barium borate crystal. The nitric oxide absorption measurements are performed by tuning the ECDL and scanning the sum-frequency-mixed radiation over strong nitric oxide absorption lines near 226 nm. In Year 1 of the research, the nitric oxide sensor was used for measurements in the exhaust of a coal-fired laboratory combustion facility. The Texas A&M University boiler burner facility is a 30 kW (100,000 Btu/hr) downward-fired furnace with a steel shell encasing ceramic insulation. Measurements of nitric oxide concentration in the exhaust stream were performed after modification of the facility for laser based NOx diagnostics. The diode-laser-based ultraviolet absorption measurements were successful even when the beam was severely attenuated by particulate in the exhaust stream and window fouling. Single-laser-sweep measurements were demonstrated with an effective time resolution of 100 msec, limited at this time by the scan rate of our mechanically tuned ECDL system. In Year 2 described in this progress report, the Toptica ECDL in the original system was replaced with a Sacher Lasers ECDL. The mode-hop-free tuning range and tuning rate of the Toptica ECDL were 25 GHz and a few Hz, respectively. The mode-hop-free tuning range and tuning rate of the Sacher Lasers ECDL were 90 GHz and a few hundred Hz, respectively. The Sacher Lasers ECDL thus allows us to scan over the entire NO absorption line and to determine the absorption baseline with increased accuracy and precision. The increased tuning rate is an advantage in that data can be acquired much more rapidly and the absorption measurements are less susceptible to the effects of transient fluctuations in the properties of the coal combustor exhaust stream. Gas cell measurements were performed using the NO sensor with the new ECDL, and a few spectra were acquired from the coal exhaust stream. However, the laser diode in the new ECDL failed during the coal combustor tests. A series of spectral simulations was performed using the HITRAN code to investigate the potential sensitivity of absorption measurements of ammonia in different spectral regions. It was concluded that ammonia absorption features in the 3000-nm spectral region would be hard to measure due to water vapor interferences.

  9. Development of All-Solid-State Sensors for Measurement of Nitric Oxide and Ammonia Concentrations by Optical Absorption in Particle-Laden Combustion Exhaust Streams

    SciTech Connect

    Jerald A. Caton; Kalyan Annamalai; Robert P. Lucht

    2006-12-31

    An all-solid-state continuous-wave (cw) laser system for ultraviolet absorption measurements of the nitric oxide (NO) molecule has been developed and demonstrated. For the NO sensor, 250 nW of tunable cw ultraviolet radiation is produced by sum-frequency-mixing of 532-nm radiation from a diode-pumped Nd:YAG laser and tunable 395-nm radiation from an external cavity diode laser (ECDL). The sum-frequency-mixing process occurs in a beta-barium borate crystal. The nitric oxide absorption measurements are performed by tuning the ECDL and scanning the sum-frequency-mixed radiation over strong nitric oxide absorption lines near 226 nm. In Year 1 of the research, the nitric oxide sensor was used for measurements in the exhaust of a coal-fired laboratory combustion facility. The Texas A&M University boiler burner facility is a 30 kW (100,000 Btu/hr) downward-fired furnace with a steel shell encasing ceramic insulation. Measurements of nitric oxide concentration in the exhaust stream were performed after modification of the facility for laser based NOx diagnostics. The diode-laser-based ultraviolet absorption measurements were successful even when the beam was severely attenuated by particulate in the exhaust stream and window fouling. Single-laser-sweep measurements were demonstrated with an effective time resolution of 100 msec, limited at this time by the scan rate of our mechanically tuned ECDL system. In Year 2, the Toptica ECDL in the original system was replaced with a Sacher Lasers ECDL. The mode-hop-free tuning range and tuning rate of the Toptica ECDL were 25 GHz and a few Hz, respectively. The mode-hop-free tuning range and tuning rate of the Sacher Lasers ECDL were 90 GHz and a few hundred Hz, respectively. The Sacher Lasers ECDL thus allows us to scan over the entire NO absorption line and to determine the absorption baseline with increased accuracy and precision. The increased tuning rate is an advantage in that data can be acquired much more rapidly and the absorption measurements are less susceptible to the effects of transient fluctuations in the properties of the coal combustor exhaust stream. Gas cell measurements were performed using the NO sensor with the new ECDL, and a few spectra were acquired from the coal exhaust stream. However, the laser diode in the new ECDL failed during the coal combustor tests. In Year 3, however, we obtained a new GaN laser diode for our ECDL system, installed it, and completed an extensive series of measurements in the Texas A&M coal-fired laboratory combustion facility. The combustor was operated with coal and coal/biomass as fuels, with and without reburn, and with and without ammonia injection. Several different fuel equivalence ratios were investigated for each operating condition.

  10. Combination exhaust-gas cleaner and muffler for an automobile engine

    Microsoft Academic Search

    N. Tokura; K. Masaki; H. Nagaisi

    1978-01-01

    A combination exhaust-gas cleaner and muffler for particular use in an exhaust system of an automotive engine is described. The system contains a catalytic converter using a granular catalyst which is responsible for emission of dust particles of oxides of base or noble metal, comprising at least one centrifugal separator for separating the dust particles from the exhaust gases by

  11. Assessment of environmental tobacco smoke and respirable suspended particle exposures for nonsmokers in Basel by personal monitoring

    NASA Astrophysics Data System (ADS)

    Phillips, K.; Howard, D. A.; Bentley, M. C.; Alván, G.

    One hundred and ninety-six randomly selected nonsmoking subjects collected air samples close to their breathing zone by wearing personal monitors for 24 h. The study was centred in Basel, Switzerland, and comprised housewives in one group, primarily for assessing exposures in the home, and office workers in a second group to assess the contribution of the workplace to overall exposure. Samples collected were analysed for respirable suspended particles (RSP), nicotine, 3-ethenylpyridine and environmental tobacco smoke (ETS) particles by using ultraviolet absorbance, fluorescence and solanesol measurements. Saliva cotinine analyses were also undertaken to confirm the nonsmoking status of the subjects. Based upon median 24 h time weighted average concentrations, office workers who live and work with smokers were exposed to 39 ?g m -3 RSP, 6.6 ?g m -3 ETS particles and 0.90 ?g m -3 nicotine. Housewives living with smokers were exposed to median concentrations of 34 ?g m -3 RSP, 1.4 ?g m -3 ETS particles and 0.60 ?g m -3 nicotine. Workplaces where smoking occurred were estimated, on average, to contribute between 34 and 46% to annual exposure of ETS particles and nicotine. Based upon 90th percentile values the most highly exposed housewives, those living with smokers, would potentially inhale 18 cigarette equivalents per year whilst the most highly exposed office workers, both living and working with smokers, might inhale 61 cigarette equivalents. The rate at which subjects misreported their nonsmoking status varied between 9.7 and 12.2%.

  12. Solid propellant exhausted aluminum oxide and hydrogen chloride - Environmental considerations

    NASA Technical Reports Server (NTRS)

    Cofer, W. R., III; Winstead, E. L.; Purgold, G. C.; Edahl, R. A.

    1993-01-01

    Measurements of gaseous hydrogen chloride (HCl) and particulate aluminum oxide (Al2O3) were made during penetrations of five Space Shuttle exhaust clouds and one static ground test firing of a shuttle booster. Instrumented aircraft were used to penetrate exhaust clouds and to measure and/or collect samples of exhaust for subsequent analyses. The focus was on the primary solid rocket motor exhaust products, HCl and Al2O3, from the Space Shuttle's solid boosters. Time-dependent behavior of HCl was determined for the exhaust clouds. Composition, morphology, surface chemistry, and particle size distributions were determined for the exhausted Al2O3. Results determined for the exhaust cloud from the static test firing were complicated by having large amounts of entrained alkaline ground debris (soil) in the lofted cloud. The entrained debris may have contributed to neutralization of in-cloud HCl.

  13. Mechanisms and implications of air pollution particle associations with chemokines

    SciTech Connect

    Seagrave, JeanClare [Lovelace Respiratory Research Institute, 2425 Ridgecrest Dr. SE, Albuquerque, NM 87108 (United States)], E-mail: jseagrav@LRRI.org

    2008-11-01

    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.

  14. 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

  15. Diesel engine exhaust oxidizer

    SciTech Connect

    Kammel, R.A.

    1992-06-16

    This patent describes a diesel engine exhaust oxidizing device. It comprises: an enclosure having an inlet for receiving diesel engine exhaust, a main flow path through the enclosure to an outlet of the enclosure, a by-ass through the enclosure, and a microprocessor control means.

  16. Duplex tab exhaust nozzle

    NASA Technical Reports Server (NTRS)

    Gutmark, Ephraim Jeff (Inventor); Martens, Steven (nmn) (Inventor)

    2012-01-01

    An exhaust nozzle includes a conical duct terminating in an annular outlet. A row of vortex generating duplex tabs are mounted in the outlet. The tabs have compound radial and circumferential aft inclination inside the outlet for generating streamwise vortices for attenuating exhaust noise while reducing performance loss.

  17. Exhaust gas recirculating apparatus

    Microsoft Academic Search

    H. Nohira; K. Kobashi

    1975-01-01

    The design is given of apparatus associated with an engine on a motor vehicle for either stopping the recirculation of exhaust gas through the engine completely or allowing it at a controlled rate, depending upon the operating condition of the engine. A regulating valve provided with a pair of diaphragms is installed in the exhaust gas recirculating circuit, and a

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

    SciTech Connect

    Kodavanti, Urmila P., E-mail: kodavanti.urmila@epa.gov [Environmental Public Health Division, National Health and Environmental Effects Research Laboratory (NHEERL), Office of Research and Development (ORD), U.S. Environmental Protection Agency - EPA, Research Triangle Park, NC 27711 (United States); Thomas, Ronald F.; Ledbetter, Allen D.; Schladweiler, Mette C.; Bass, Virginia; Krantz, Q. Todd; King, Charly [Environmental Public Health Division, National Health and Environmental Effects Research Laboratory (NHEERL), Office of Research and Development (ORD), U.S. Environmental Protection Agency - EPA, Research Triangle Park, NC 27711 (United States); Nyska, Abraham [Tel Aviv University, Tel Aviv (Israel); Richards, Judy E. [Environmental Public Health Division, National Health and Environmental Effects Research Laboratory (NHEERL), Office of Research and Development (ORD), U.S. Environmental Protection Agency - EPA, Research Triangle Park, NC 27711 (United States); Andrews, Debora [Research Core Unit, NHEERL, ORD, U.S. EPA, Research Triangle Park, NC 27711 (United States); Gilmour, M. Ian [Environmental Public Health Division, National Health and Environmental Effects Research Laboratory (NHEERL), Office of Research and Development (ORD), U.S. Environmental Protection Agency - EPA, Research Triangle Park, NC 27711 (United States)

    2013-04-15

    Exposure to diesel exhaust (DE) and associated gases is linked to cardiovascular impairments; however, the susceptibility of hypertensive individuals is poorly understood. The objectives of this study were (1) to determine cardiopulmonary effects of gas-phase versus whole-DE and (2) to examine the contribution of systemic hypertension in pulmonary and cardiovascular effects. Male Wistar Kyoto (WKY) rats were treated with hydralazine to reduce blood pressure (BP) or L-NAME to increase BP. Spontaneously hypertensive (SH) rats were treated with hydralazine to reduce BP. Control and drug-pretreated rats were exposed to air, particle-filtered exhaust (gas), or whole DE (1500 ?g/m{sup 3}), 4 h/day for 2 days or 5 days/week for 4 weeks. Acute and 4-week gas and DE exposures increased neutrophils and ?-glutamyl transferase (?-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-?, 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 ?-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-?, 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 atherogenic effects of diesel exhaust. ? Diesel exhaust and hydralazine cause similar aorta effect on vascular tone markers.

  19. 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

  20. Diesel engine exhaust and lung cancer: An unproven association

    SciTech Connect

    Muscat, J.E.; Wynder, E.L. [American Health Foundation, New York, NY (United States)

    1995-09-01

    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 association. 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 no 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. 77 refs., 1 tab.

  1. Particles Alter Diesel Exhaust Gases-Induced Hypotension, Cardiac Arrhythmia,Conduction Disturbance, and Autonomic Imbalance in Heart Failure-Prone Rats

    EPA Science Inventory

    Epidemiologic studies indicate that acute exposures to vehicular traffic and particulate matter (PM) air pollution are key causes of fatal cardiac arrhythmia, especially in those with preexisting cardiovascular disease. Researchers point to electrophysiologic dysfunction and auto...

  2. CATALYTICALLY AND NONCATALYTICALLY TREATED AUTOMOBILE EXHAUST: BIOLOGICAL EFFECTS IN RATS

    EPA Science Inventory

    Chronic exposure to catalytically treated or noncatalytically treated automobile exhaust significantly depressed the spontaneous locomotor activity (SLA) of rats. Exposure to H2SO4 alone or CO at comparable levels did not alter the SLA. Exposure to noncatalytically treated exhaus...

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

    EPA Science Inventory

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

  4. Laboratory evaluation of a prototype photochemical chamber designed to investigate the health effects of fresh and aged vehicular exhaust emissions

    PubMed Central

    Papapostolou, Vasileios; Lawrence, Joy E.; Diaz, Edgar A.; Wolfson, Jack M.; Ferguson, Stephen T.; Long, Mark S.; Godleski, John J.; Koutrakis, Petros

    2013-01-01

    Laboratory experiments simulating atmospheric aging of motor vehicle exhaust emissions were conducted using a single vehicle and a photochemical chamber. A compact automobile was used as a source of emissions. The vehicle exhaust was diluted with ambient air to achieve carbon monoxide (CO) concentrations similar to those observed in an urban highway tunnel. With the car engine idling, it is expected that the CO concentration is a reasonable surrogate for volatile organic compounds (VOCs) emissions. Varying the amount of dilution of the exhaust gas to produce different CO concentrations, allowed adjustment of the concentrations of VOCs in the chamber to optimize production of secondary organic aerosol (SOA) needed for animal toxicological exposures. Photochemical reactions in the chamber resulted in nitric oxide (NO) depletion, nitrogen dioxide (NO2) formation, ozone (O3) accumulation, and SOA formation. A stable SOA concentration of approximately 40 µg m?3 at a chamber mean residence time of 30 min was achieved. This relatively short mean residence time provided adequate chamber flow output for both particle characterization and animal exposures. The chamber was operated as a continuous flow reactor for animal toxicological tests. SOA mass generated from the car exhaust diluted with ambient air was almost entirely in the ultrafine mode. Chamber performance was improved by using different types of seed aerosol to provide a surface for condensation of semivolatile reaction products, thus increasing the yield of SOA. Toxicological studies using Sprague-Dawley rats found significant increases of in vivo chemiluminescence in lungs following exposure to SOA. PMID:21689011

  5. Laboratory evaluation of a prototype photochemical chamber designed to investigate the health effects of fresh and aged vehicular exhaust emissions.

    PubMed

    Papapostolou, Vasileios; Lawrence, Joy E; Diaz, Edgar A; Wolfson, Jack M; Ferguson, Stephen T; Long, Mark S; Godleski, John J; Koutrakis, Petros

    2011-07-01

    Laboratory experiments simulating atmospheric aging of motor vehicle exhaust emissions were conducted using a single vehicle and a photochemical chamber. A compact automobile was used as a source of emissions. The vehicle exhaust was diluted with ambient air to achieve carbon monoxide (CO) concentrations similar to those observed in an urban highway tunnel. With the car engine idling, it is expected that the CO concentration is a reasonable surrogate for volatile organic compounds (VOCs) emissions. Varying the amount of dilution of the exhaust gas to produce different CO concentrations, allowed adjustment of the concentrations of VOCs in the chamber to optimize production of secondary organic aerosol (SOA) needed for animal toxicological exposures. Photochemical reactions in the chamber resulted in nitric oxide (NO) depletion, nitrogen dioxide (NO?) formation, ozone (O?) accumulation, and SOA formation. A stable SOA concentration of approximately 40 ?g m?³ at a chamber mean residence time of 30 min was achieved. This relatively short mean residence time provided adequate chamber flow output for both particle characterization and animal exposures. The chamber was operated as a continuous flow reactor for animal toxicological tests. SOA mass generated from the car exhaust diluted with ambient air was almost entirely in the ultrafine mode. Chamber performance was improved by using different types of seed aerosol to provide a surface for condensation of semivolatile reaction products, thus increasing the yield of SOA. Toxicological studies using Sprague-Dawley rats found significant increases of in vivo chemiluminescence in lungs following exposure to SOA. PMID:21689011

  6. Space shuttle exhaust cloud properties

    NASA Technical Reports Server (NTRS)

    Anderson, B. J.; Keller, V. W.

    1983-01-01

    A data base describing the properties of the exhaust cloud produced by the launch of the Space Transportation System and the acidic fallout observed after each of the first four launches was assembled from a series of ground and aircraft based measurements made during the launches of STS 2, 3, and 4. Additional data were obtained from ground-based measurements during firings of the 6.4 percent model of the Solid Rocket Booster at the Marshall Center. Analysis indicates that the acidic fallout is produced by atomization of the deluge water spray by the rocket exhaust on the pad followed by rapid scavening of hydrogen chloride gas aluminum oxide particles from the Solid Rocket Boosters. The atomized spray is carried aloft by updrafts created by the hot exhaust and deposited down wind. Aircraft measurements in the STS-3 ground cloud showed an insignificant number of ice nuclei. Although no measurements were made in the column cloud, the possibility of inadvertent weather modification caused by the interaction of ice nuclei with natural clouds appears remote.

  7. Determining gaseous emission factors and driver's particle exposures during traffic congestion by vehicle-following measurement techniques.

    PubMed

    Tang, U Wa; Wang, Zhishi

    2006-11-01

    Vehicle gaseous emissions (NO, CO, CO2, and hydrocarbon [HC]) and driver's particle exposures (particulate matter < 1 microm [PM1], < 2.5 microm [PM2.5], and < 10 microm [PM10]) were measured using a mobile laboratory to follow a wide variety of vehicles during very heavy traffic congestion in Macao, Special Administrative Region, People's Republic of China, an urban area having one of the highest population densities in the world. The measurements were taken with high time resolution so that fluctuations in the emissions can be seen readily during vehicle acceleration, cruising, deceleration, and idling. The tests were conducted in close proximity to the vehicles, with the inlet of a five-gas analyzer mounted on the front bumper of the mobile laboratory, and the distance between the vehicles was usually within several meters. To measure the driver's particle exposures, the inlets of the particle analyzers were mounted at the height of the driver's breathing position in the mobile laboratory, with the driver's window open. A total of 178 and 113 vehicles were followed individually to determine the gaseous emission factor and the driver's particle exposures, respectively, for motorcycle, passenger car, taxi, truck, and bus. The gaseous emission factors were used to model the roadside air quality, and good correlations between the modeled and monitored CO, NO2, and nitrogen oxide (NO(x)) verified the reliability of the experiments. Compared with petrol passenger cars and petrol trucks, diesel taxies and diesel trucks emitted less CO but more NO(x). The impact of urban canyons is shown to cause a significant increase in the PM1 peak. The background concentrations contributed a significant amount of the driver's particle exposures. PMID:17117738

  8. Association between long-term exposure to traffic particles and blood pressure in the Veterans Administration Normative Aging Study

    PubMed Central

    Schwartz, Joel; Alexeeff, Stacey E; Mordukhovich, Irina; Gryparis, Alexandros; Vokonas, Pantel; Suh, Helen; Coull, Brent A

    2013-01-01

    Objectives Particulate air pollution is associated with cardiovascular events, but the mechanisms are not fully understood. The main objective was to assess the relationship between long-term exposure to traffic-related air pollution and blood pressure (BP). Methods The authors used longitudinal data from 853 elderly men participating in the Veterans Administration Normative Aging Study, followed during 1996–2008. Long-term average exposures to traffic particles were created from daily predictions of black carbon (BC) exposure at the geocoded address of each subject, using a validated spatiotemporal model based on ambient monitoring at 82 Boston-area locations. The authors examined the association of these exposures with BP using a mixed model. The authors included the following covariates: age, body mass index, smoking, alcohol, fasting glucose, creatinine clearance, use of cardiovascular medication, education, census-level poverty, day of week and season of clinical visit. Results The authors found significant positive associations between 1-year average BC exposure and both systolic and diastolic blood pressure. An IQR increase in 1-year average BC exposure (0.32 µg/m3) was associated with a 2.64 mm Hg increase in systolic blood pressure (95% CI 1.47 to 3.80) and a 2.41 mm Hg increase in diastolic blood pressure (95% CI 1.77 to 3.05). Conclusions Long-term exposure to traffic particles is associated with increased BP, which may explain part of the association with myocardial infarctions and cardiovascular deaths reported in cohort studies. PMID:22383587

  9. TiO2 atomic layer deposition on ZrO2 particles using alternating exposures of TiCl4 and H2O

    E-print Network

    George, Steven M.

    TiO2 atomic layer deposition on ZrO2 particles using alternating exposures of TiCl4 and H2O J was deposited with atomic layer control on ZrO2 particles using alternating exposures of TiCl4 and H2O chemistry in vacuum. The ZrO2 particles initially displayed vibrational modes consistent with ZrOH* surface

  10. Chemical Gas Sensors for Car Exhaust and Cabin Air Monitoring

    Microsoft Academic Search

    Eva-Lotta Kalman; Fredrik Winquist; Anders Löfvendahl; Bertil Rudell; Urban Wass

    2002-01-01

    A combination of charcoal and particle filters has pre viously been shown to reduce effectively the smell of diesel exhaust. In this paper it is shown that the smell of diesel exhaust can successfully be predicted by the con centration of total volatile organic compounds and the concentration of certain carbonyl compounds. Projection to latent structures was utilised for model

  11. Chemical Gas Sensors for Car Exhaust and Cabin Air Monitoring

    Microsoft Academic Search

    Eva-Lotta Kalman; Fredrik Winquist; Anders Löfvendahl; Bertil Rudell; Urban Wass

    2002-01-01

    A combination of charcoal and particle filters has previously been shown to reduce effectively the smell of diesel exhaust. In this paper it is shown that the smell of diesel exhaust can successfully be predicted by the concentration of total volatile organic compounds and the concentration of certain carbonyl compounds. Projection to latent structures was utilised for model building. An

  12. 30 CFR 36.25 - Engine exhaust system.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...whichever is the lesser. The system shall withstand repeated... (1) The exhaust system of the engine shall...or discharge of heated particles to a surrounding...explosions within the exhaust system, and the material...mixture shall not contain more than 0.5...

  13. 30 CFR 36.25 - Engine exhaust system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...whichever is the lesser. The system shall withstand repeated... (1) The exhaust system of the engine shall...or discharge of heated particles to a surrounding...explosions within the exhaust system, and the material...mixture shall not contain more than 0.5...

  14. 30 CFR 36.25 - Engine exhaust system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...whichever is the lesser. The system shall withstand repeated... (1) The exhaust system of the engine shall...or discharge of heated particles to a surrounding...explosions within the exhaust system, and the material...mixture shall not contain more than 0.5...

  15. 30 CFR 36.25 - Engine exhaust system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...whichever is the lesser. The system shall withstand repeated... (1) The exhaust system of the engine shall...or discharge of heated particles to a surrounding...explosions within the exhaust system, and the material...mixture shall not contain more than 0.5...

  16. 30 CFR 36.25 - Engine exhaust system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...whichever is the lesser. The system shall withstand repeated... (1) The exhaust system of the engine shall...or discharge of heated particles to a surrounding...explosions within the exhaust system, and the material...mixture shall not contain more than 0.5...

  17. Comparative modeling approaches for personal exposure to particle-associated PAH.

    PubMed

    Aquilina, Noel J; Delgado-Saborit, Juana Mari; Gauci, Adam P; Baker, Stephen; Meddings, Claire; Harrison, Roy M

    2010-12-15

    Several models for simulation of personal exposure (PE) to particle-associated polycyclic aromatic hydrocarbons (PAH) have been developed and tested. The modeling approaches include linear regression models (Model 1), time activity weighted models (Models 2 and 3), a hybrid model (Model 4), a univariate linear model (Model 5), and machine learning technique models (Model 6 and 7). The hybrid model (Model 4), which utilizes microenvironment data derived from time-activity diaries (TAD) with the implementation of add-on variables to account for external factors that might affect PE, proved to be the best regression model (R(2) for B(a)P = 0.346, p < 0.01; N = 68). This model was compared with results from two machine learning techniques, namely decision trees (Model 6) and neural networks (Model 7), which represent an innovative approach to PE modeling. The neural network model was promising in giving higher correlation coefficient results for all PAH (R(2) for B(a)P = 0.567, p < 0.01; N = 68) and good performance with the smaller test data set (R(2) for B(a)P = 0.640, p < 0.01; N = 23). Decision tree accuracies (Model 6) which assess how precisely the algorithm can determine the correct classification of a PE concentration range indicate good performance, but this is not comparable to the other models through R(2) values. Using neural networks (Model 7) showed significant improvements over the performance of hybrid Model 4 and the univariate general linear Model 5 for test samples (not used in developing the models). The worst performance was given by linear regression Models 1 to 3 based solely on home and workplace concentrations and time-activity data. PMID:21090571

  18. Effects of exposure to 56Fe particles or protons on fixed-ratio operant responding in rats

    NASA Technical Reports Server (NTRS)

    Rabin, Bernard M.; Buhler, Lynn L.; Joseph, James A.; Shukitt-Hale, Barbara; Jenkins, Daniel G.

    2002-01-01

    On long-duration trips outside of the magnetosphere, astronauts will be exposed to protons and to heavy particles which can affect their performance of required tasks. It is essential to determine the range of behaviors that might be affected by exposure to these types of radiation in order to understand the nature of behavioral deficits and to develop effective countermeasures. The present experiment examined the ability of rats to make an operant response following exposure to protons (250 MeV, 4 Gy) or 56Fe particles (1 GeV/n, 1 or 2 Gy). Following irradiation, rats were trained to press a lever in order to obtain food reinforcement. They were then placed on an ascending fixed-ratio schedule from FR-1 (each lever press rewarded with a food pellet) through FR-35 (35 lever presses required for 1 food pellet). Rats exposed to 4 Gy of protons or 1 Gy of 56Fe particles responded similarly to controls, increasing their rate of responding as the ratio increased. However, rats exposed to 2 Gy of 56Fe particles failed to increase their rate of responding at ratios greater than FR-20, indicating that rats exposed to 2 Gy of 56Fe particles cannot respond appropriately to increasing work requirements.

  19. The effects of strong temperatu