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1

Health effects of exposure to diesel exhaust particles  

Microsoft Academic Search

Diesel-powered vehicles emit substantially more particles than do gasoline-powered vehicles with contemporary emission control systems. The DEP are submicron in size and readily inhaled. Approximately one-fourth of the particle mass inhaled by people is deposited in the pulmonary region, some of which is retained with a half-life of several hundred days. In animal studies, exposure to high levels of DEP

R. McClellan

1987-01-01

2

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...

3

BIOMARKERS OF DIESEL EXHAUST PARTICLES  

EPA Science Inventory

The objective of this project is to examine the detectability of some chemical components of diesel exhaust particles (DEP) in human urine following controlled human diesel exposures (IRB-approved). Ultimately, and upon validation, we propose to apply these components as biomarke...

4

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...

5

Alteration of intracellular cysteine and glutathione levels in alveolar macrophages and lymphocytes by diesel exhaust particle exposure.  

PubMed Central

The purpose of this study was to characterize the effects of diesel exhaust particles (DEP) on thiol regulation in alveolar macrophages (AM) and lymphocytes. We obtained AM and lymph node (thymic and tracheal) cells (LNC) (at different time points) from rats exposed intratracheally to DEP (5 mg/kg) or saline, and measured inflammatory markers, thiol levels, and glutathione reductase (GSH-R) activity. DEP exposure produced significant increases in neutrophils, lactate dehydrogenase, total protein, and albumin content in the lavage fluid. AM from DEP-exposed rats showed a time-dependent increase in intracellular cysteine (CYSH) and GSH. In LNC the intracellular GSH reached peak level by 24 hr, declining toward control levels by 72 hr after exposure. LNC-CYSH and AM-CYSH and GSH were increased at both 24 and 72 hr. Both Sprague-Dawley and Brown Norway rats showed similar trends of responses to DEP exposure as per measurement of the inflammatory markers and thiol changes. AM and, to a lesser degree, LNC were both active in cystine uptake. The DEP exposure stimulated GSH-R activity and increased the conversion of cystine to CYSH in both cell types. The intracellular level of GSH in DEP-exposed AM was moderately increased compared with the saline control, and was further augmented when cells were incubated with cystine. In contrast, the intracellular level of GSH in DEP-exposed LNC was significantly reduced despite the increased CYSH level and GSH-R activity when these cells were cultured for 16 hr. DEP absorbed 23-31% of CYSH, cystine, and GSH, and only 8% of glutathione disulfide when incubated in cell free media. These results indicate that DEP exposure caused lung inflammation and affected thiol levels in both AM and LNC. PMID:11940452

Al-Humadi, Nabil H; Siegel, Paul D; Lewis, Daniel M; Barger, Mark W; Ma, Jane Y C; Weissman, David N; Ma, Joseph K H

2002-01-01

6

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...

7

Anacardic acids from cashew nuts ameliorate lung damage induced by exposure to diesel exhaust particles in mice.  

PubMed

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

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

8

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

PubMed Central

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

Carvalho, Ana Laura Nicoletti; Annoni, Raquel; Torres, Larissa Helena Lobo; Durao, 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 Hilario Nascimento; Ulrich, Cornelia M.; Owen, Robert W.; Marcourakis, Tania; Trevisan, Maria Teresa Salles; Mauad, Thais

2013-01-01

9

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

EPA Science Inventory

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

10

Diesel Exhaust Exposure, Wheezing and Sneezing  

PubMed Central

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

2012-01-01

11

Generation and characterization of gasoline engine exhaust inhalation exposure atmospheres.  

PubMed

Exposure atmospheres for a rodent inhalation toxicology study were generated from the exhaust of a 4.3-L gasoline engine coupled to a dynamometer and operated on an adapted California Unified Driving Cycle. Exposure levels were maintained at three different dilution rates. One chamber at the lowest dilution had particles removed by filtration. Each exposure atmosphere was characterized for particle mass, particle number, particle size distribution, and detailed chemical speciation. The majority of the mass in the exposure atmospheres was gaseous carbon monoxide, nitrogen oxides, and volatile organics, with small amounts of particle-bound carbon/ions and metals. The atmospheres varied according to the cycle, with the largest spikes in volatile organic and inorganic species shown during the "cold start" portion of the cycle. Ammonia present from the exhaust and rodents interacted with the gasoline exhaust to form secondary inorganic particles, and an increase in exhaust resulted in higher proportions of secondary inorganics as a portion of the total particle mass. Particle size had a median of 10-20 nm by number and approximately 150 nm by mass. Volatile organics matched the composition of the fuel, with large proportions of aliphatic and aromatic hydrocarbons coupled to low amounts of oxygenated organics. A new measurement technique revealed organics reacting with nitrogen oxides have likely resulted in measurement bias in previous studies of combustion emissions. Identified and measured particle organic species accounted for about 10% of total organic particle mass and were mostly aliphatic acids and polycyclic aromatic hydrocarbons. PMID:18951232

McDonald, Jacob D; Barr, Edward B; White, Richard K; Kracko, Dean; Chow, Judith C; Zielinska, Barbara; Grosjean, Eric

2008-10-01

12

Particle exposures and infections.  

PubMed

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. Cigarette smoking, burning of biomass, dust storms, mining, agricultural work, environmental tobacco smoke (ETS), wood stoves, traffic-related emissions, gas stoves, and ambient air pollution are all particle-related exposures associated with an increased risk for respiratory infections. In addition, cigarette smoking, burning of biomass, dust storms, mining, and ETS can result in an elevated risk for tuberculosis, atypical mycobacterial infections, and meningitis. One of the mechanisms for particle-related infections includes an accumulation of iron by surface functional groups of particulate matter (PM). Since elevations in metal availability are common to every particle exposure, all PM potentially contributes to these infections. Therefore, exposures to wood stove emissions, diesel exhaust, and air pollution particles are predicted to increase the incidence and prevalence of tuberculosis, atypical mycobacterial infections, and meningitis, albeit these elevations are likely to be small and detectable only in large population studies. Since iron accumulation correlates with the presence of surface functional groups and dependent metal coordination by the PM, the risk for infection continues as long as the particle is retained. Subsequently, it is expected that the cessation of exposure will diminish, but not totally reverse, the elevated risk for infection. PMID:24488331

Ghio, A J

2014-06-01

13

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 ...

14

Prenatal and early-life exposure to high-level diesel exhaust particles leads to increased locomotor activity and repetitive behaviors in mice.  

PubMed

Abundant evidence indicates that both genetic and environmental factors contribute to the etiology of autism spectrum disorders (ASDs). However, limited knowledge is available concerning these contributing factors. An epidemiology study reported a link between increased incidence of autism and living closely to major highways, suggesting a possible role for pollutants from highway traffic. We investigated whether maternal exposure to diesel exhaust particles (DEP) negatively affects fetal development leading to autism-like phenotype in mice. Female mice and their offspring were exposed to DEP during pregnancy and nursing. Adult male offspring were then tested for behaviors reflecting the typical symptoms of ASD patients. Compared to control mice, DEP-exposed offspring exhibited higher locomotor activity, elevated levels of self-grooming in the presence of an unfamiliar mouse, and increased rearing behaviors, which may be relevant to the restricted and repetitive behaviors seen in ASD patients. However, the DEP-exposed mice did not exhibit deficits in social interactions or social communication which are the key features of ASD. These results suggest that early life exposure to DEP could have an impact on mouse development leading to observable changes in animal behaviors. Further studies are needed to reveal other environmental insults and genetic factors that would lead to animal models expressing key phenotypes of the autism spectrum disorders. PMID:23495194

Thirtamara Rajamani, Keerthi; Doherty-Lyons, Shannon; Bolden, Crystal; Willis, Daniel; Hoffman, Carol; Zelikoff, Judith; Chen, Lung-Chi; Gu, Howard

2013-08-01

15

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...

16

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

PubMed Central

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 authentic air pollution particles. This study was designed to compare the DNA oxidizing effects of authentic street particles with SRM1650 and SRM2975. The authentic street particles were collected at a traffic intensive road in Copenhagen, Denmark. Results All of the particles generated strand breaks and oxidized purines in A549 lung epithelial cells in a dose-dependent manner and there were no overt differences in their potency. The exposures also yielded dose-dependent increase of cytotoxicity (as lactate dehydrogenase release) and reduced colony forming ability with slightly stronger cytotoxicity of SRM1650 than of the other particles. In contrast, only the authentic street particles were able to generate 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in calf thymus DNA, which might be due to the much higher level of transition metals. Conclusion Authentic street particles and SRMs differ in their ability to oxidize DNA in a cell-free environment, whereas cell culture experiments indicate that the particle preparations elicit a similar alteration of the level of DNA damage and small differences in cytotoxicity. Although it cannot be ruled out that SRMs and authentic street particles might elicit different effects in animal experimental models, this study indicates that on the cellular level, SRM1650 and SRM2975 are suitable surrogate samples for the study of authentic street particles. PMID:18397523

Danielsen, Pernille H?gh; Loft, Steffen; M?ller, Peter

2008-01-01

17

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...

18

Measuring soot particles from automotive exhaust emissions  

NASA Astrophysics Data System (ADS)

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.

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

19

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...

20

Diesel exhaust particles disturb gene expression in mouse testis.  

PubMed

Inhalation of diesel exhaust particles (DEP) has been found to reduce sperm production. There is a possibility that DEP exposure elicits changes in gene expression in testis. To identify the alteration of gene expression resulting from DEP exposure, we constructed subtracted cDNA libraries from mouse testis using the suppression subtractive hybridization method. We isolated 16 candidate clones whose expression levels changed after exposure. Some of these candidates were highly similar to known testis-specific genes. Some of the clones also seemed to correlate with spermatogenesis. Northern blot analysis revealed that DEP exposure changed the expression levels of several clones in a dose-dependent manner. For example, the expression of clone R8, which was very similar to human XRRA1, increased by 2.3-fold in testis after DEP exposure. On the other hand, the expressions of long-chain acyl-CoA synthetase 6 (Acsl6) and serine/threonine kinase 35 reduced by 0.3-fold. These results indicated that some constituents of DEP alter gene expression in the testis. PMID:17295261

Mori, Tetsuya; Watanuki, Taro; Kashiwagura, Tadashi

2007-02-01

21

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 ...

22

Parental occupational exposure to engine exhausts and childhood brain tumors.  

PubMed

Childhood brain tumors (CBT) are the leading cause of cancer death in children; their risk factors are still largely unknown. Since most CBTs are diagnosed before five years of age, prenatal exposure and early postnatal factors may be involved in their etiology. We investigated the association between CBT and parental occupational exposure to engine exhausts in an Australian population-based case-control study. Parents of 306 cases and 950 controls completed detailed occupational histories. Odds ratios (OR) and 95% confidence intervals (CI) were estimated for both maternal and paternal exposure in key time periods. Increased risks were observed for maternal exposure to diesel exhaust any time before the child's birth (OR 2.03, 95% CI 1.09-3.81) and paternal exposure around the time of the child's conception (OR 1.62, 95% CI 1.12-2.34). No clear associations with other engine exhausts were found. Our results suggest that parental occupational exposure to diesel exhaust may increase the risk of CBT. PMID:23184618

Peters, Susan; Glass, Deborah C; Reid, Alison; de Klerk, Nicholas; Armstrong, Bruce K; Kellie, Stewart; Ashton, Lesley J; Milne, Elizabeth; Fritschi, Lin

2013-06-15

23

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...

24

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...

25

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...

26

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...

27

Role of Reactive Oxygen Species on Diesel Exhaust Particle-Induced Cytotoxicity in Rat Cardiac Myocytes  

Microsoft Academic Search

Exposure to air pollution containing diesel exhaust particles (DEP) is associated with an increase in mortality rate attributed to cardiovascular diseases, but the mechanisms by which DEP produces adverse cardiovascular effects at the cellular level are not elucidated. This study investigated the cytotoxic mechanisms underlying DEP-induced neonatal rat cardiac myocytes effects in vitro, focusing on the role of reactive oxygen

Yuta Okayama; Masayoshi Kuwahara; Akira K. Suzuki; Hirokazu Tsubone

2006-01-01

28

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...

29

Nasal challenge with diesel exhaust particles can induce sensitization to a neoallergen in the human mucosa  

Microsoft Academic Search

Background: Diesel exhaust particles (DEPs) increase in vivo IgE and cytokine production at the human upper respiratory mucosa, exacerbating allergic inflammation. Objective: We examined the ability of DEP exposure to lead to primary sensitization of humans by driving a de novo mucosal IgE response to a neoantigen, keyhole limpet hemocyanin (KLH). Methods: Ten atopic subjects were given an initial nasal

David Diaz-Sanchez; Marisol Penichet Garcia; Margaret Wang; Minna Jyrala; Andrew Saxon

1999-01-01

30

Occupational exposure to diesel engine exhaust: A literature review  

PubMed Central

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

Pronk, Anjoeka; Coble, Joseph; Stewart, Patricia

2010-01-01

31

Occupational exposure to diesel engine exhaust: a literature review.  

PubMed

Diesel exhaust (DE) is classified as a probable human carcinogen. Aims were to describe the major occupational uses of diesel engines and give an overview of personal DE exposure levels and determinants of exposure as reported in the published literature. Measurements representative of personal DE exposure were abstracted from the literature for the following agents: elemental carbon (EC), particulate matter (PM), carbon monoxide (CO), nitrogen oxide (NO), and nitrogen dioxide (NO(2)). Information on determinants of exposure was abstracted. In total, 3528 EC, 4166 PM, 581 CO, 322 NO, and 1404 NO(2) measurements were abstracted. From the 10,001 measurements, 32% represented exposure from on-road vehicles and 68% from off-road vehicles (30% mining, 15% railroad, and 22% others). Highest levels were reported for enclosed underground work sites in which heavy equipment is used: mining, mine maintenance, and construction (EC: 27-658 microg/m(3)). Intermediate exposure levels were generally reported for above-ground (semi-) enclosed areas in which smaller equipment was run: mechanics in a shop, emergency workers in fire stations, distribution workers at a dock, and workers loading/unloading inside a ferry (generally: EC<50 microg/m(3)). Lowest levels were reported for enclosed areas separated from the source, such as drivers and train crew, or outside, such as surface mining, parking attendants, vehicle testers, utility service workers, surface construction and airline ground personnel (EC<25 microg/m(3)). The other agents showed a similar pattern. Determinants of exposure reported for enclosed situations were ventilation and exhaust after treatment devices. Reported DE exposure levels were highest for underground mining and construction, intermediate for working in above-ground (semi-) enclosed areas and lowest for working outside or separated from the source. The presented data can be used as a basis for assessing occupational exposure in population-based epidemiological studies and guide future exposure assessment efforts for industrial hygiene and epidemiological studies. PMID:19277070

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

2009-07-01

32

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

PubMed Central

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

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

2008-01-01

33

Diesel Exhaust Particles in Lung Acutely Enhance Experimental Peripheral Thrombosis  

Microsoft Academic Search

Background—Pollution by particulates has consistently been associated with increased cardiovascular morbidity and mortality, but a plausible biological basis for this association is lacking. Methods and Results—Diesel exhaust particles (DEPs) were instilled into the trachea of hamsters, and blood platelet activation, experimental thrombosis, and lung inflammation were studied. Doses of 5 to 500 g of DEPs per animal induced neutrophil influx

Abderrahim Nemmar; Peter H. M. Hoet; David Dinsdale; Jozef Vermylen; Marc F. Hoylaerts; Benoit Nemery

2010-01-01

34

Rosmarinic acid inhibits lung injury induced by diesel exhaust particles  

Microsoft Academic Search

Epidemiological and experimental studies have suggested that diesel exhaust particles (DEP) may be involved in recent increases in lung diseases. DEP has been shown to generate reactive oxygen species. Intratracheal instillation of DEP induces lung inflammation and edema in mice. Rosmarinic acid is a naturally occurring polyphenol with antioxidative and anti-inflammatory activities. We investigated the effects of rosmarinic acid on

Chiaki Sanbongi; Hirohisa Takano; Naomi Osakabe; Naoko Sasa; Midori Natsume; Rie Yanagisawa; Ken-ichiro Inoue; Yoji Kato; Toshihiko Osawa; Toshikazu Yoshikawa

2003-01-01

35

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...

36

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...

37

Divertor Particle Exhaust and Wall Inventory on D3-D  

SciTech Connect

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 D3-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 D3-D cryopump, replacing the HeGDC normally applied between discharges.

Jackson, G.L.; Mahdavi, M.A.; Schaffer, M.J.; Maingi, R.; Wade, M.R.; Mioduszewski, P.K.

1995-06-01

38

Divertor particle exhaust and wall inventory on DIII-D  

SciTech Connect

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.

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

39

Divertor particle exhaust and wall inventory on DIII-D  

SciTech Connect

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.

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

40

*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...

41

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...

42

Exposure to diesel exhaust particulates induces cardiac dysfunction and remodeling.  

PubMed

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

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

2013-10-01

43

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...

44

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...

45

NIOSH Current Intelligence Bulletin 50 - carcinogenic effects of exposure to diesel exhaust, August 1988  

Microsoft Academic Search

The bulletin presents recent information on the potential carcinogenicity of diesel exhaust. Included are discussions of recent animal studies that confirm the relationship between cancer and exposure to whole diesel exhaust. Also discussed is epidemiological evidence that associates lung cancer with occupational exposure to diesel engine emissions. On the basis of the results of these studies, NIOSH recommends that whole-diesel

Brown-McCammon

1988-01-01

46

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

E-print Network

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 ...

Kroll, Jesse

47

*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...

48

Personal exposure to ultrafine particles.  

PubMed

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

Wallace, Lance; Ott, Wayne

2011-01-01

49

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

PubMed

A study was initiated to examine worker exposures in seven underground nonmetal mines and to examine the precision of the National Institute for Occupational Safety and Health (NIOSH) 5040 sampling and analytical method for diesel exhaust that has recently been adopted for compliance monitoring by the Mine Safety and Health Administration (MSHA). Approximately 1000 air samples using cyclones were taken on workers and in areas throughout the mines. Results indicated that worker exposures were consistently above the MSHA final limit of 160 micrograms/m3 (time-weighted average; TWA) for total carbon as determined by the NIOSH 5040 method and greater than the proposed American Conference of Governmental Industrial Hygienists TLV limit of 20 micrograms/m3 (TWA) for elemental carbon. A number of difficulties were documented when sampling for diesel exhaust using organic carbon: high and variable blank values from filters, a high variability (+/- 20%) from duplicate punches from the same sampling filter, a consistent positive interference (+26%) when open-faced monitors were sampled side-by-side with cyclones, poor correlation (r 2 = 0.38) to elemental carbon levels, and an interference from limestone that could not be adequately corrected by acid-washing of filters. The sampling and analytical precision (relative standard deviation) was approximately 11% for elemental carbon, 17% for organic carbon, and 11% for total carbon. An hypothesis is presented and supported with data that gaseous organic carbon constituents of diesel exhaust adsorb onto not only the submicron elemental carbon particles found in diesel exhaust, but also mining ore dusts. Such mining dusts are mostly nonrespirable and should not be considered equivalent to submicron diesel particulates in their potential for adverse pulmonary effects. It is recommended that size-selective sampling be employed, rather than open-faced monitoring, when using the NIOSH 5040 method. PMID:12529922

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

2002-01-01

50

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

PubMed

Children who are exposed to diesel exhaust from idling school buses are at increased risk of asthma exacerbation, decreased lung function, immunologic reactions, leukemia, and increased susceptibility to infections. Policies and initiatives that aim to protect school children from the harmful effects of exposure to diesel exhaust range from general environmental air quality standards to more specific legislation that targets diesel exhaust near school children. School nurse standards of practice specify that school nurses should attain current knowledge of environmental health concepts, implement environmental health strategies, and advocate for environmental health principles. This article provides a description of the professional responsibilities of school nurses in protecting children from harmful environmental exposures, provides an overview of legislative initiatives intended to protect school children from diesel exhaust exposure, and summarizes one school district's effort to reduce diesel exhaust exposure among school children. PMID:23850988

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

2014-04-01

51

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

PubMed

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

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

2014-05-01

52

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

PubMed Central

Background Viral infections and exposure to oxidant air pollutants are two of the most important inducers of asthma exacerbation. Our previous studies have demonstrated that exposure to diesel exhaust increases the susceptibility to influenza virus infections both in epithelial cells in vitro and in mice in vivo. Therefore, we examined whether in the setting of allergic asthma, exposure to oxidant air pollutants enhances the susceptibility to respiratory virus infections, which in turn leads to increased virus-induced exacerbation of asthma. Ovalbumin-sensitized (OVA) male C57BL/6 mice were instilled with diesel exhaust particles (DEP) or saline and 24 hours later infected with influenza A/PR/8. Animals were sacrificed 24 hours post-infection and analyzed for markers of lung injury, allergic inflammation, and pro-inflammatory cytokine production. Results Exposure to DEP or infection with influenza alone had no significant effects on markers of injury or allergic inflammation. However, OVA-sensitized mice that were exposed to DEP and subsequently infected with influenza showed increased levels of eosinophils in lung lavage and tissue. In addition Th2-type cytokines, such as IL-4 and IL-13, and markers of eosinophil chemotaxis, such as CCL11 and CCR3, were increased in OVA-sensitized mice exposed to DEP prior to infection with influenza. These mice also showed increased levels of IL-1?, but not IL-10, RANTES, and MCP-1 in lung homogenates. Conclusion These data suggest that in the setting of allergic asthma, exposure to diesel exhaust could enhance virus-induced exacerbation of allergic inflammation. PMID:19682371

Jaspers, Ilona; Sheridan, Patricia A; Zhang, Wenli; Brighton, Luisa E; Chason, Kelly D; Hua, Xiaoyang; Tilley, Stephen L

2009-01-01

53

Mutagenicity of diesel exhaust particle extracts: influence of driving cycle and environmental temperature.  

PubMed

General Motors and Volkswagen diesel passenger cars (1980 and 1981 model year) were operated on a climate controlled chassis dynomometer and the particulate portion of the exhaust was collected on high volume filters. Dichloromethane extracts of the exhaust particles (soot) collected while the cars were operated under simulated highway, urban and congested urban driving cycles were assayed for mutagenicity in Salmonella strains TA-98 and TA-100. Driving pattern did not significantly influence the mutagenic potency of the exhaust particle extracts or estimates of the amount of mutagenicity emitted from the exhaust despite large differences in particle emission rates and extractable fraction of the particles. Mutagenicity of extracts of exhaust particles collected while the vehicles were operated at test chamber temperatures of 25, 50, 75 and 100 degrees F were also very similar. The results suggest that driving pattern and environmental temperature do not significantly alter the emission of genotoxic combustion products from the exhaust. PMID:6193022

Clark, C R; Dutcher, J S; Brooks, A L; McClellan, R O; Marshall, W F; Naman, T M

1982-01-01

54

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...

55

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 ...

56

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 ...

57

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

PubMed

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

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

58

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

PubMed Central

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.

2014-01-01

59

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

PubMed

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

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

60

NIOSH Current Intelligence Bulletin 50 - carcinogenic effects of exposure to diesel exhaust, August 1988  

SciTech Connect

The bulletin presents recent information on the potential carcinogenicity of diesel exhaust. Included are discussions of recent animal studies that confirm the relationship between cancer and exposure to whole diesel exhaust. Also discussed is epidemiological evidence that associates lung cancer with occupational exposure to diesel engine emissions. On the basis of the results of these studies, NIOSH recommends that whole-diesel exhaust be regarded as a potential occupational carcinogen in conformance with the Occupational Safety and Health Administration (OSHA) cancer policy (29 CFR 1900).

Brown-McCammon, J.

1988-08-01

61

Control of Nitrous Oxide Exposure in Dental Operatories Using Local Exhaust Ventilation  

PubMed Central

An experimental portable local exhaust ventilation system was installed in three dental operatories where nitrous oxide was used routinely. Standard methods of exhaust ventilation design used in industry to control exposures to toxic airborne substances were applied to the dental operatory setting. The concentration of nitrous oxide in the dentists' breathing zones was measured before and after installation to determine the efficiency of the system in reducing occupational exposures. Results indicate that placement of the exhaust opening and exhaust air flow rate are important in determining the degree of control achieved. After the system had been installed in one operatory, peak exposures declined from over 600 parts per million (ppm) to less than 70 ppm: the time-weighted average exposure was below the NIOSH recommended level of 25 ppm. A permanently installed local exhaust ventilation system modeled after the portable one used in this pilot study may be feasible for most operatories and should not interfere with dental procedures. The results suggest that nitrous oxide exposures can be greatly reduced if dental operatories are equipped with local exhaust ventilation. ImagesFig. 4Fig. 7 PMID:3465259

Jacobs, David E.; Middendorf, Paul J.

1986-01-01

62

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

PubMed

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

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

63

Inhibition of catalase activity in vitro by diesel exhaust particles  

SciTech Connect

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

Mori, Yoki; Murakami, Sumika; Sagae, Toshiyuki [Health Sciences Univ. of Hokkaido (Japan)] [and others] [Health Sciences Univ. of Hokkaido (Japan); and others

1996-02-09

64

Diesel exhaust but not ozone increases fraction of exhaled nitric oxide in a randomized controlled experimental exposure study of healthy human subjects  

PubMed Central

Background Fraction of exhaled nitric oxide (FENO) is a promising non-invasive index of airway inflammation that may be used to assess respiratory effects of air pollution. We evaluated FENO as a measure of airway inflammation after controlled exposure to diesel exhaust or ozone. Methods Healthy volunteers were exposed to either diesel exhaust (particle concentration 300 ?g/m3) and filtered air for one hour, or ozone (300 ppb) and filtered air for 75 minutes. FENO was measured in duplicate at expiratory flow rates of 10, 50, 100 and 270 mL/s before, 6 and 24 hours after each exposure. Results Exposure to diesel exhaust increased FENO at 6 hours compared with air at expiratory flow rates of 10 mL/s (p?=?0.01) and at 50 mL/s (p?=?0.011), but FENO did not differ significantly at higher flow rates. Increases in FENO following diesel exhaust were attenuated at 24 hours. Ozone did not affect FENO at any flow rate or time point. Conclusions Exposure to diesel exhaust, but not ozone, increased FENO concentrations in healthy subjects. Differences in the induction of airway inflammation may explain divergent responses to diesel exhaust and ozone, with implications for the use of FENO as an index of exposure to air pollution. PMID:23602059

2013-01-01

65

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

PubMed Central

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

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

2013-01-01

66

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

SciTech Connect

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.

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

67

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

PubMed Central

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

Cooney, Daniel J; Hickey, Anthony J

2008-01-01

68

Interaction between soot particles and NOx during dielectric barrier discharge plasma remediation of simulated diesel exhaust  

E-print Network

of simulated diesel exhaust Rajesh Doraia) University of Illinois, Department of Chemical Engineering, 1406 from combustion effluent and from diesel exhausts in particular. Soot particles are inevitably present, a computational investigation of the effect of soot on the plasma chemistry of NOx removal in a simulated diesel

Kushner, Mark

69

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)

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.

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

2013-12-01

70

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

NASA Astrophysics Data System (ADS)

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.

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

2014-11-01

71

Exposure of mobile chipper operators to diesel exhaust.  

PubMed

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

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

2014-03-01

72

Sample characterization of automobile and forklift diesel exhaust particles and comparative pulmonary toxicity in mice.  

PubMed Central

Two samples of diesel exhaust particles (DEPs) predominate in health effects research: an automobile-derived DEP (A-DEP) sample and the National Institute of Standards Technology standard reference material (SRM 2975) generated from a forklift engine. A-DEPs have been tested extensively for their effects on pulmonary inflammation and exacerbation of allergic asthmalike responses. In contrast, SRM 2975 has been tested thoroughly for its genotoxicity. In the present study, we combined physical and chemical analyses of both DEP samples with pulmonary toxicity testing in CD-1 mice to compare the two materials and to make associations between their physicochemical properties and their biologic effects. A-DEPs had more than 10 times the amount of extractable organic material and less than one-sixth the amount of elemental carbon compared with SRM 2975. Aspiration of 100 micro g of either DEP sample in saline produced mild acute lung injury; however, A-DEPs induced macrophage influx and activation, whereas SRM 2975 enhanced polymorphonuclear cell inflammation. A-DEPs stimulated an increase in interleukin-6 (IL-6), tumor necrosis factor alpha, macrophage inhibitory protein-2, and the TH2 cytokine IL-5, whereas SRM 2975 only induced significant levels of IL-6. Fractionated organic extracts of the same quantity of DEPs (100 micro g) did not have a discernable effect on lung responses and will require further study. The disparate results obtained highlight the need for chemical, physical, and source characterization of particle samples under investigation. Multidisciplinary toxicity testing of diesel emissions derived from a variety of generation and collection conditions is required to meaningfully assess the health hazards associated with exposures to DEPs. Key words: automobile, diesel exhaust particles, forklift, mice, pulmonary toxicity, SRM 2975. PMID:15175167

Singh, Pramila; DeMarini, David M; Dick, Colin A J; Tabor, Dennis G; Ryan, Jeff V; Linak, William P; Kobayashi, Takahiro; Gilmour, M Ian

2004-01-01

73

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

PubMed Central

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

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

2010-01-01

74

Visibility Reduction due to Jet-Exhaust Carbon Particles  

Microsoft Academic Search

Pyrolysis of hydrocarbon fuels leads to emission of free carbon in the exhaust of aircraft turbojet engines, visible as a faint dark trail. Carbon formation rises markedly when water injection is employed to augment thrust by 20-30 per cent in takeoffs under heavy loads or at high temperatures, the enhanced pyrolysis resulting from the lower combustion efficiency on such `wet

James E. McDonald

1962-01-01

75

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...

76

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...

77

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...

78

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 ...

79

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

Microsoft Academic Search

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

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

1988-01-01

80

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

Microsoft Academic Search

A case–control study of lung cancer mortality in U.S. railroad workers in jobs with and without diesel exhaust exposure is reanalyzed using a new threshold regression methodology. The study included 1256 workers who died of lung cancer and 2385 controls who died primarily of circulatory system diseases. Diesel exhaust exposure was assessed using railroad job history from the US Railroad

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

2009-01-01

81

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...

82

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

PubMed

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

Joeng, Lucky; Hayes, Amanda; Bakand, Shahnaz

2013-01-01

83

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

SciTech Connect

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.

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

1990-01-01

84

Diesel exhaust particle induction of IL17A contributes to severe asthma  

PubMed Central

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

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

85

Diesel exhaust particle-induced alterations of pulmonary phase I and phase II enzymes of rats.  

PubMed

Although diesel exhaust particles (DEP) are known to produce pulmonary disorders, the xenobiotic metabolic pathways associated with DEP detoxification and bioactivation remain unclear. In this study, the effect of acute exposure of DEP on phase I and phase II enzymes of rat lung was investigated. Intratracheal administration of DEP produced an induction of cytochrome P-450 (CYP) 1A1 enzyme protein and activity at 1 d postexposure, with the enzyme level returning to control at 5 d postexposure. On the other hand, carbon black (CB), a particle control, did not show any induction of CYP1A1 protein or enzyme activity. However, both DEP and CB significantly decreased CYP2B1 protein and enzyme activity at 1 d postexposure. The decrease in CYP2B1 enzyme protein and activity by DEP or CB treatment was observed up to 7 d postexposure. DEP and CB treatments also significantly attenuated glutathione S-transferase (GST)-pi protein at 1 d postexposure. Both DEP and CB at 35 mg/kg significantly decreased the activities of GST and catalase at 1 and 7 d postexposure. DEP, but not CB, significantly induced quinone reductase (QR) activity at 7 d postexposure. This study suggests that DEP may induce CYP1A1 and QR enzymes via a chemical effect, while the carbonaceous core may be involved in the attenuation of CYP2B1, GST, and catalase proteins and enzyme activities. PMID:12653020

Rengasamy, A; Barger, M W; Kane, E; Ma, J K H; Castranova, V; Ma, J Y C

2003-01-24

86

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

SciTech Connect

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

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); Suzuki, Akira K. [Environmental Nanotoxicology Section, Research Center for Environmental Risk, National Institute for Environmental Studies, Tsukuba, 305-8506 (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); Li, ChunMei; Taneda, Shinji [Environmental Nanotoxicology Section, Research Center for Environmental Risk, National Institute for Environmental Studies, Tsukuba, 305-8506 (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

2008-08-01

87

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

PubMed

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

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

88

Urinary hydroxy-metabolites of naphthalene, phenanthrene and pyrene as markers of exposure to diesel exhaust  

Microsoft Academic Search

Objective The objective of this study was to assess the exposure of bus-garage and waste-collection workers to polycyclic aromatic hydrocarbons (PAHs) derived from diesel exhaust by the measurement of levels of seven urinary PAH metabolites: 2-naphthol, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, 1+9-hydroxyphenanthrene, 4-hydroxyphenanthrene and 1-hydroxypyrene. Subjects and methods One urine sample from each of 46 control persons, and one pre-shift and two

Leea Kuusimäki; Yrjö Peltonen; Pertti Mutanen; Kimmo Peltonen; Kirsti Savela

2004-01-01

89

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...

90

Cardiovascular Responses of Largemouth Bass to Exhaustive Exercise and Brief Air Exposure over a Range of Water Temperatures  

Microsoft Academic Search

In this study we examined the effects of exhaustive exercise and brief air exposure on the cardiovascular function of largemouth bass Micropterus salmoides at four water temperatures (13, 17, 21, and 25°C). We used Doppler flow probes to monitor cardiac output and its components (i.e., stroke volume and heart rate) while we manually chased fish to exhaustion to simulate angling,

Steven J. Cooke; Kenneth G. Ostrand; Christopher M. Bunt; Jason F. Schreer; David H. Wahl; David P. Philipp

2003-01-01

91

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

ERIC Educational Resources Information Center

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…

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

2014-01-01

92

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

PubMed Central

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

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

2014-01-01

93

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...

94

Apparent inhibition of superoxide dismutase activity in vitro by diesel exhaust particles  

Microsoft Academic Search

The inhibitory effects of diesel exhaust particles (DEP) on superoxide dismutase (SOD) activity were examined in vitro because intratracheal administration of DEP to mice resulted in a suppression of the pulmonary enzyme activity (Sagai et al., Free Radic. Biol. Med. 14:37–47; 1993). Superoxide production, based on the reduction of cytochrome c, was suppressed considerably by the soluble fraction of mouse

Yoshito Kumagai; Junsei Taira; Masaru Sagai

1995-01-01

95

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

Microsoft Academic Search

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

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

1998-01-01

96

Biological effects of diesel exhaust particles (DEP). III. Pathogenesis of asthma like symptoms in mice  

Microsoft Academic Search

Chronic airway inflammation, mucus hypersecretion, reversible airway constriction, and bronchial hyperresponsiveness are important pathogenic features of asthma. We found that diesel exhaust particles (DEP) instilled intratracheally and repeatedly to mice (once\\/week for 16 weeks) caused marked infiltration of inflammatory cells, proliferation of goblet cells, increased mucus secretion, respiratory resistance, and airway constriction. Eosinophils in the submucosa of the proximal bronchi

Masaru Sagai; Akiko Furuyama; Takamichi Ichinose

1996-01-01

97

Enhanced nasal cytokine production in human beings after in vivo challenge with diesel exhaust particles  

Microsoft Academic Search

Background: Diesel exhaust particles (DEPs) have been implicated in the worldwide increased incidence of allergic airway disorders over the past century. They can enhance in vivo IgE production in the human upper respiratory mucosa. Objective: The study was carried out to determine whether DEPs can alter the production of cytokines by cells residing in the nasal mucosa. Methods: Eighteen hours

David Diaz-Sanchez; Albert Tsien; Adrian Casillas; Anton Robert Dotson; Andrew Saxon

1996-01-01

98

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...

99

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...

100

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 ...

101

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 ...

102

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...

103

Exposure to traffic exhaust and night cough during early childhood: the CCAAPS birth cohort.  

PubMed

Though studies have investigated the association between air pollution and respiratory health outcomes in children, few have focused on night cough. The study objective was to simultaneously evaluate family factors (i.e., race, gender, maternal and paternal asthma, and breastfeeding), health (allergen sensitization and wheezing symptoms), home factors (dog, cat, mold, endotoxin, and dust mite), and other environmental exposures (traffic exhaust and second-hand tobacco smoke) for associations with recurrent dry night cough (RNC) during early childhood. A structural equation model with repeat measures was developed assessing RNC at ages one, two, and three. The prevalence of RNC was relatively large and similar at ages, one, two, and three at 21.6%, 17.3%, and 21.1%, respectively. Children exposed to the highest tertile of traffic exhaust had an estimated 45% increase in risk of RNC compared with children less exposed (adjusted OR 1.45, 95% CI: 1.09, 1.94). Also, wheezing was associated with a 76% higher risk of RNC (adjusted OR 1.76, 95% CI: 1.36, 2.26). A protective trend for breastfeeding was found with a 27% reduction in risk associated with breastfeeding (adjusted OR 0.73, 95% CI: 0.53, 1.01). No other factors were significant. These results suggest that traffic exhaust exposure may be a risk factor for night cough in young children. PMID:19824943

Sucharew, Heidi; Ryan, Patrick H; Bernstein, David; Succop, Paul; Khurana Hershey, Gurjit K; Lockey, James; Villareal, Manuel; Reponen, Tiina; Grinshpun, Sergey; LeMasters, Grace

2010-03-01

104

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

E-print Network

Variability in Bioreactivity Linked to Changes in Size and Zeta Potential of Diesel Exhaust) nanoparticles have been used in Europe as diesel fuel additives (EnviroxTM ). We attempted to examine the effects of particles emitted from a diesel engine burning either diesel (diesel exhaust particles, DEP

Garfunkel, Eric

105

Impact of Selective Catalytic Reduction on Exhaust Particle Formation over Excess Ammonia Events.  

PubMed

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

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

2014-10-01

106

Modeling Particle Exposure in US Trucking Terminals  

PubMed Central

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 US 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: 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

Davis, ME; Smith, TJ; Laden, F; Hart, JE; Ryan, LM; Garshick, E

2007-01-01

107

The Diesel Exhaust in Miners Study: I. Overview of the Exposure Assessment Process  

PubMed Central

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

Stewart, Patricia A.; Coble, Joseph B.; Vermeulen, Roel; Schleiff, Patricia; Blair, Aaron; Lubin, Jay; Attfield, Michael; Silverman, Debra T.

2010-01-01

108

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...

109

Reactive Oxygen Species and Nitric Oxide-Mediated Lung Inflammation and Mitochondrial Dysfunction in Wild-Type and iNOS-Deficient Mice Exposed to Diesel Exhaust Particles  

Microsoft Academic Search

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

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

2009-01-01

110

Simulation of the evolution of particle size distributions in a vehicle exhaust plume with unconfined dilution by ambient air.  

PubMed

Over the past several years, numerous studies have linked ambient concentrations of particulate matter (PM) to adverse health effects, and more recent studies have identified PM size and surface area as important factors in determining the health effects of PM. This study contributes to a better understanding of the evolution of particle size distributions in exhaust plumes with unconfined dilution by ambient air. It combines computational fluid dynamics (CFD) with an aerosol dynamics model to examine the effects of different streamlines in an exhaust plume, ambient particle size distributions, and vehicle and wind speed on the particle size distribution in an exhaust plume. CFD was used to calculate the flow field and gas mixing for unconfined dilution of a vehicle exhaust plume, and the calculated dilution ratios were then used as input to the aerosol dynamics simulation. The results of the study show that vehicle speed affected the particle size distribution of an exhaust plume because increasing vehicle speed caused more rapid dilution and inhibited coagulation. Ambient particle size distributions had an effect on the smaller sized particles (approximately 10 nm range under some conditions) and larger sized particles (>2 microm) of the particle size distribution. The ambient air particle size distribution affects the larger sizes of the exhaust plume because vehicle exhaust typically contains few particles larger than 2 microm. Finally, the location of a streamline in the exhaust plume had little effect on the particle size distribution; the particle size distribution along any streamline at a distance x differed by less than 5% from the particle size distributions along any other streamline at distance x. PMID:15887887

Jiang, Pengzhi; Lignell, David O; Kelly, Kerry E; Lighty, JoAnn S; Sarofim, Adel F; Montgomery, Christopher J

2005-04-01

111

Comparison of genotoxicity of automotive exhaust particles from laboratory and environmental sources  

Microsoft Academic Search

This research (1) ranked the genotoxicity of methylene chloride extracts of laboratory and environmentally collected particles and (2) evaluated the role of collection location and sample composition on genotoxic potency. Samples of exhaust from a spark-ignition automobile, light-duty diesel automobile, and a heavy-duty diesel engine operated in a laboratory on a dynamometer were studied, as well as samples taken in

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

1984-01-01

112

Diesel Exhaust Particles Enhance Antigen-induced Airway Inflammation and Local Cytokine Expression in Mice  

Microsoft Academic Search

Previous experimental studies have suggested that nasal instillation of diesel exhaust particles (DEP) can enhance nasal IgE response and cytokine production. However, there is no experimental evi- dence for the relation of DEP to allergic asthma. We investigated the effects of DEP inoculated in- tratracheally on antigen-induced airway inflammation, local expression of cytokine proteins, and antigen-specific immunoglobulin production in mice.

HIROHISA TAKANO; TOSHIKAZU YOSHIKAWA; TAKAMICHI ICHINOSE; YUICHI MIYABARA; KOICHI IMAOKA; MASARU SAGAI

1997-01-01

113

Detection of very large ions in aircraft gas turbine engine combustor exhaust: charged small soot particles?  

Microsoft Academic Search

Small electrically charged soot particles (CSP) present in the exhaust of a jet aircraft engine combustor have been detected by a Large Ion Mass Spectrometer and quantitatively measured by an Ion Mobility Analyzer. The size and concentration measurements which took place at an aircraft gas-turbine engine combustor test-rig at the ground covered different combustor conditions (fuel flow=FF, fuel sulphur content=FSC).

S Wilhelm; H Haverkamp; A Sorokin; F Arnold

2004-01-01

114

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...

115

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...

116

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

PubMed Central

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

Kawada, Tomoyuki; Azuma, Arata

2013-01-01

117

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

PubMed Central

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

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

2012-01-01

118

Effects of exposure to nanoparticle-rich diesel exhaust on pregnancy in rats.  

PubMed

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

Li, ChunMei; Li, Xuezheng; Suzuki, Akira K; Zhang, Yonghui; Fujitani, Yuji; Nagaoka, Kentaro; Watanabe, Gen; Taya, Kazuyoshi

2013-01-01

119

Particle-Bound PAH Emission from the Exhaust of Combustion Chamber  

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

120

Bioreactivity of carbon black and diesel exhaust particles to primary Clara and type II epithelial cell cultures  

Microsoft Academic Search

OBJECTIVES: To begin to elucidate the mechanisms of particle toxicity to the lung, the bioreactivity of four carbon black (CB) and diesel exhaust particles ((DEPs), a surrogate for particulate matter of aerodynamic diameter < 10 microns (PM10), were examined with primary cultures of Clara and type II epithelial cells. METHODS: The particles were extensively characterised by surface chemistry, size, and

S. A. Murphy; K. A. BeruBe; R. J. Richards

1999-01-01

121

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

SciTech Connect

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.

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

122

Diesel Exhaust Particles Induce Cysteine Oxidation and S-Glutathionylation in House Dust Mite Induced Murine Asthma  

PubMed Central

Background Diesel exhaust particle (DEP) exposure enhances allergic inflammation and has been linked to the incidence of asthma. Oxidative stress on the thiol molecules cysteine (Cys) and glutathione (GSH) can promote inflammatory host responses. The effect of DEP on the thiol oxidation/reduction (redox) state in the asthmatic lung is unknown. Objective To determine if DEP exposure alters the Cys or GSH redox state in the asthmatic airway. Methods Bronchoalveolar lavage fluid was obtained from a house dust mite (HDM) induced murine asthma model exposed to DEP. GSH, glutathione disulfide (GSSG), Cys, cystine (CySS), and s-glutathionylated cysteine (CySSG) were determined by high pressure liquid chromatography. Results DEP co-administered with HDM, but not DEP or HDM alone, decreased total Cys, increased CySS, and increased CySSG without significantly altering GSH or GSSG. Conclusions DEP exposure promotes oxidation and S-glutathionylation of cysteine amino acids in the asthmatic airway, suggesting a novel mechanism by which DEP may enhance allergic inflammatory responses. PMID:23555996

Lee, Gerald B.; Brandt, Eric B.; Xiao, Chang; Gibson, Aaron M.; Le Cras, Timothy D.; Brown, Lou Ann S.; Fitzpatrick, Anne M.; Khurana Hershey, Gurjit K.

2013-01-01

123

Population exposure to atmospheric particles (PM) caused by emissions in Stockholm - local and regional/European scale modelling  

NASA Astrophysics Data System (ADS)

Local and regional-scale model calculations have been performed to estimate the effects of emissions in Stockholm on the population exposure to particulate matter (PM) within the city, in surrounding areas, and in the rest of Europe. The impacts of five different emission sources were investigated: Road traffic exhaust, split into Light Duty Vehicles (LDV) and Heavy Duty Vehicles (HDV), Sea Traffic, Power Plants and Residential Heating. The emissions from non-exhaust (mainly road wear due to use of studded tyres) were also treated, in addition to combustion sources. The calculated impact of the Stockholm emissions on atmospheric concentrations of particles were weighted by the population distribution and the calculated yearly average total European population exposures for the different sources are summarised below (unit: person ?g/m3). Wear particles: Road Traffic 2 520 000 Directly emitted PM: LDV-exhaust 150 000, HDV-exhaust 55 000, Sea Traffic 17 000, Power Plants 87 000, Residential Heating 178 000 - 886 000 Secondarily formed inorganic particles (nitrate, sulphate, ammonium): LDV 315 000, HDV 117 000, Sea Traffic 70 000, Power Plants 193 000, Residential Heating 26 000 - 70 000 Non-exhaust (road wear) particles dominate the total impact on PM10 exposure, contributing about 60-70% to the total exposure, due to all the studied sources in Stockholm. The calculated population exposure to the wear particles is to a very large extent (87%) occurring within the Stockholm area. The uncertainties in the emission estimates for Residential Heating using biomass (wood) are very large but it seems to be an important PM source in Stockholm. Two different estimates of the emissions were used; in the lowest estimate, which seems more realistic, the contribution to population exposure of directly emitted combustion particles from residential heating is of similar magnitude (178 000 person ?g/m3) as the contribution from road traffic exhaust (205 000 person ?g/m3). For all sources, except Sea Traffic, the total population exposure to combustion PM is much larger within Stockholm than outside; for shipping the total exposure is about as large outside the city as within. For all sources, except residential heating, the secondary inorganic aerosol (SIA) exposure is higher than the combustion particle exposure. Most of the SIA exposure occurs outside the Stockholm area.

Bergström, R.; Johansson, C.

2009-04-01

124

Health effects assessment of exposure to particles from wood  

E-print Network

AIR 27 3.1.1 Particles 27 3.1.2 PAH 29 3.2 INDOOR PENETRATION 30 3.3 EXPOSURE FROM OTHER SETTINGSHealth effects assessment of exposure to particles from wood smoke Elsa Nielsen, Marianne Dybdahl HUMAN EXPOSURE TO PARTICLES FROM WOOD SMOKE 7 HUMAN HEALTH EFFECTS 8 Human non-cancer health effects

125

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

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

126

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

PubMed

Diesel exhaust particles are the major constituent of urban carbonaceous aerosol being linked to a large range of adverse environmental and health effects. In this work, the effects of fuel reformulation, oxidation catalyst, engine type, and engine operation parameters on diesel particle emission characteristics were investigated. Particle emissions from an indirect injection (IDI) and a direct injection (DI) engine car operating under steady-state conditions with a reformulated low-sulfur, low-aromatic fuel and a standard-grade fuel were analyzed. Organic (OC) and elemental (EC) carbon fractions of the particles were quantified by a thermal-optical transmission analysis method and particle size distributions measured with a scanning mobility particle sizer (SMPS). The particle volatility characteristics were studied with a configuration that consisted of a thermal desorption unit and an SMPS. In addition, the volatility of size-selected particles was determined with a tandem differential mobility analyzer technique. The reformulated fuel was found to produce 10-40% less particulate carbon mass compared to the standard fuel. On the basis of the carbon analysis, the organic carbon contributed 27-61% to the carbon mass of the IDI engine particle emissions, depending on the fuel and engine operation parameters. The fuel reformulation reduced the particulate organic carbon emissions by 10-55%. In the particles of the DI engine, the organic carbon contributed 14-26% to the total carbon emissions, the advanced engine technology, and the oxidation catalyst, thus reducing the OC/EC ratio of particles considerably. A relatively good consistency between the particulate organic fraction quantified with the thermal optical method and the volatile fraction measured with the thermal desorption unit and SMPS was found. PMID:15180069

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

2004-05-01

127

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

Microsoft Academic Search

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

Kyle Steenland; James Deddens; Leslie Stayner

1998-01-01

128

Diesel exhaust particles impair endothelial progenitor cells, compromise endothelial integrity, reduce neoangiogenesis, and increase atherogenesis in mice.  

PubMed

The mechanisms of the harmful cardiovascular effects of small particulate matter are incompletely understood. Endothelial progenitor cells (EPCs) predict outcome of patients with vascular disease. The aim of our study was to examine the effects of diesel exhaust particles (DEP) on EPC and on the associated vascular damage in mice. C57Bl/6 mice were exposed to DEP. 2 ?g DEP/day was applicated intranasally for 3 weeks. Exposure to DEP reduced DiLDL/lectin positive EPC to 58.4 ± 5.6% (p < 0.005). Migratory capacity was reduced to 65.8 ± 3.9% (p < 0.0001). In ApoE(-/-) mice, DEP application reduced the number of EPC to 75.6 ± 6.4% (p < 0.005) and EPC migration to 58.5 ± 6.8% (p < 0.005). Neoangiogenesis was reduced to 39.5 ± 14.6% (p < 0.005). Atherogenesis was profoundly increased by DEP treatment (157.7 ± 18.1% vs. controls, p < 0.05). In cultured human EPC, DEP (0.1-100 ?g/mL) reduced migratory capacity to 25 ± 2.6% (p < 0.001). The number of colony-forming units was reduced to 8.8 ± 0.9% (p < 0.001) and production of reactive oxygen species was elevated by DEP treatment (p < 0.001). Furthermore, DEP treatment increased apoptosis of EPC (to 266 ± 62% of control, p < 0.05). In a blood-brain barrier model, DEP treatment impaired endothelial cell integrity during oxygen-glucose deprivation (p < 0.001). Diesel exhaust particles impair endothelial progenitor cell number and function in vivo and in vitro. The reduction in EPC was associated with impaired neoangiogenesis and a marked increase in atherosclerotic lesion formation. PMID:23584878

Pöss, Janine; Lorenz, Dominik; Werner, Christian; Pavlikova, Valerie; Gensch, Christoph; Speer, Thimoteus; Alessandrini, Francesca; Berezowski, Vincent; Kuntz, Mélanie; Mempel, Martin; Endres, Matthias; Böhm, Michael; Laufs, Ulrich

2013-09-01

129

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

PubMed Central

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

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; Sandstrom, Thomas; MacNee, William; Boon, Nicholas A.; Donaldson, Ken; Newby, David E.; Cassee, Flemming R.

2008-01-01

130

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

SciTech Connect

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.

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

131

Exposure to particles from laser printers operating within office workplaces.  

PubMed

While recent research has provided valuable information as to the composition of laser printer particles, their formation mechanisms, and explained why some printers are emitters while others are low emitters, questions relating to the potential exposure of office workers remained unanswered. In particular, (i) what impact does the operation of laser printers have on the background particle number concentration (PNC) of an office environment over the duration of a typical working day? (ii) What is the airborne particle exposure to office workers in the vicinity of laser printers? (iii) What influence does the office ventilation have upon the transport and concentration of particles? (iv) Is there a need to control the generation of, and/or transport of particles arising from the operation of laser printers within an office environment? (v) What instrumentation and methodology is relevant for characterizing such particles within an office location? We present experimental evidence on printer temporal and spatial PNC during the operation of 107 laser printers within open plan offices of five buildings. The 8 h time-weighted average printer particle exposure is significantly less than the 8 h time-weighted local background particle exposure, but that peak printer particle exposure can be greater than 2 orders of magnitude higher than local background particle exposure. The particle size range is predominantly ultrafine (<100 nm diameter). In addition we have established that office workers are constantly exposed to nonprinter derived particle concentrations, with up to an order of magnitude difference in such exposure among offices, and propose that such exposure be controlled along with exposure to printer derived particles. We also propose, for the first time, that peak particle reference values be calculated for each office area analogous to the criteria used in Australia and elsewhere for evaluating exposure excursion above occupational hazardous chemical exposure standards. A universal peak particle reference value of 2.0 × 10(4) particles cm(-3) has been proposed. PMID:21662984

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

2011-08-01

132

San Diego 01.05.2001 Power and Particle Exhaust in ITER Slide 1 by G. Janeschitz, et.al. _______________________________________________________________________ ITER  

E-print Network

San Diego 01.05.2001 Power and Particle Exhaust in ITER Slide 1 by G. Janeschitz, et.al. ITER. Pacher, G. Pacher, R. Tivey, M. Sugihara, JCT and HTs #12;San Diego; 01.05.2001 Power and Particle to pump #12;San Diego; 01.05.2001 Power and Particle Exhaust in ITER Slide 3 by G. Janeschitz. ITER

133

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

PubMed

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

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

2013-04-01

134

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

SciTech Connect

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.

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

135

Detection of very large ions in aircraft gas turbine engine combustor exhaust: charged small soot particles?  

NASA Astrophysics Data System (ADS)

Small electrically charged soot particles (CSP) present in the exhaust of a jet aircraft engine combustor have been detected by a Large Ion Mass Spectrometer and quantitatively measured by an Ion Mobility Analyzer. The size and concentration measurements which took place at an aircraft gas-turbine engine combustor test-rig at the ground covered different combustor conditions (fuel flow=FF, fuel sulphur content=FSC). At the high-pressure turbine stage of the engine, CSP-diameters were mostly around 6 nm and CSP-concentrations reached up to 4.8×10 7 cm -3 (positive and negative) corresponding to a CSP-emission index ECSP=2.5×10 15 CSP kg -1 fuel burnt. The ECSP increased with FF but did not increase with FSC. The latter indicates that sulphur was not a major component of the large ions. Possible CSP-sources and CSP-sinks as well as CSP-roles are discussed.

Wilhelm, S.; Haverkamp, H.; Sorokin, A.; Arnold, F.

136

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

PubMed

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

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

137

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

PubMed Central

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

Farraj, Aimen K.

2012-01-01

138

Particle exposure in a baroque church during Sunday Masses.  

PubMed

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

Polednik, Bernard

2013-10-01

139

Hard metal exposures. Part 1: Observed performance of three local exhaust ventilation systems.  

PubMed

Not every ventilation system performs as intended; much can be learned when they do not. The purpose of this study was to compare observed initial performance to expected levels for three saw-reconditioning shop ventilation systems and to characterize the changes in performance of the systems over a one-year period. These three local exhaust ventilation systems were intended to control worker exposures to cobalt, cadmium, and chromium during wet grinding, dry grinding, and welding/brazing activities. Prior to installation the authors provided some design guidance based on Industrial Ventilation, a Manual of Recommended Practice. However, the authors had limited influence on the actual installation and operation and no line authority for the systems. In apparent efforts to cut costs and to respond to other perceived needs, the installed systems deviated from the specifications used in pressure calculations in many important aspects, including adding branch ducts, use of flexible ducts, the choice of fans, and the construction of some hoods. After installation of the three systems, ventilation measurements were taken to determine if the systems met design specifications, and worker exposures were measured to determine effectiveness. The results of the latter will be published as a companion article. The deviations from design and maintenance failures may have adversely affected performance. From the beginning to the end of the study period the distribution of air flow never matched the design specifications for the systems. The observed air flows measured within the first month of installation did not match the predicated design air flows for any of the systems, probably because of the differences between the design and the installed system. Over the first year of operation, hood air flow variability was high due to inadequate cleaning of the sticky process materials which rapidly accumulated in the branch ducts. Poor distribution of air flows among branch ducts frequently produced individual hood air flows that were far below specified design levels even when the total air flow through that system was more than adequate. To experienced practitioners, it is not surprising that deviations from design recommendations and poor maintenance would be associated with poor system performance. Although commonplace, such experiences have not been documented in peer-reviewed publications to date. This publication is a first step in providing that documentation. PMID:10750277

Guffey, S E; Simcox, N; Booth, D W; Hibbard, R; Stebbins, A

2000-04-01

140

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

Microsoft Academic Search

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

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

2000-01-01

141

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...

142

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

PubMed

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

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

2013-12-17

143

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

NASA Astrophysics Data System (ADS)

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.

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

2011-05-01

144

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...

145

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...

146

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...

147

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...

148

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

PubMed Central

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

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

2013-01-01

149

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...

150

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...

151

Perinatal exposure to diesel exhaust affects gene expression in mouse cerebrum  

Microsoft Academic Search

Many environmental toxins alter reproductive function and affect the central nervous system (CNS). Gonadal steroid hormones\\u000a cause differentiation of neurons and affect brain function and behavior during the perinatal period, and the CNS is thought\\u000a to be particularly susceptible to toxic insult during this period. It was, therefore, hypothesized that inhalation of diesel\\u000a exhaust (DE) during the fetal or suckling

Naomi Tsukue; Manabu Watanabe; Takayuki Kumamoto; Hirohisa Takano; Ken Takeda

2009-01-01

152

Protein Kinase C-? Mediates Lung Injury Induced by Diesel Exhaust Particles  

PubMed Central

Recently, we reported that diesel exhaust particles (DEPs) disrupt tight junctions (TJs) in alveolar epithelial cells (AECs) via an increase in reactive oxygen species (ROS). In this study, we investigated the role of protein kinase C (PKC)–? activation in DEP-induced lung injury. C57/bl6 mice were instilled intratracheally with 50 ?l of saline containing 100 ?g of DEPs or titanium dioxide (TiO2). Twenty-four hours later, bronchoalveolar lavage was performed to assess neutrophil counts and protein concentrations. In addition, in vitro experiments were performed in primary rat and human AECs exposed to DEPs (50 ?g/cm2) for 3 hours. Transepithelial electrical conductance was measured, and TJ protein association was analyzed by immunoprecipitation. To determine whether the overexpression of antioxidants prevented DEP-induced lung injury, AECs and mice were infected with adenoviruses containing catalase and manganese superoxide dismutase (MnSOD) plasmids. In vivo, the overexpression of catalase and MnSOD prevented DEP-induced neutrophil recruitment. The inhibition of PKC-? activation also prevented DEP-induced neutrophil recruitment in vivo. In vitro, DEPs activated PKC-? in AECs, but not in alveolar macrophages. Using a specific myristolated PKC-? pseudosubstrate pepetide (PKC-? ps), we showed that PKC-? mediated the DEP-induced dissociation of occludin and zonula occludin–1 (ZO1) in rat and human AECs. In addition, the overexpression of constitutively active PKC-? induced the dissociation of occludin and ZO1 in AECs. DEP-induced TJ disruption occurs via PKC-?. TJ disruption seems to be in part responsible for DEP-induced lung injury. PMID:23221045

Caraballo, Juan C.; Borcherding, Jennifer; Thorne, Peter S.

2013-01-01

153

Air pollution & the brain: Subchronic diesel exhaust exposure causes neuroinflammation and elevates early markers of neurodegenerative disease  

PubMed Central

Background Increasing evidence links diverse forms of air pollution to neuroinflammation and neuropathology in both human and animal models, but the effects of long-term exposures are poorly understood. Objective We explored the central nervous system consequences of subchronic exposure to diesel exhaust (DE) and addressed the minimum levels necessary to elicit neuroinflammation and markers of early neuropathology. Methods Male Fischer 344 rats were exposed to DE (992, 311, 100, 35 and 0 ?g PM/m3) by inhalation over 6 months. Results DE exposure resulted in elevated levels of TNF? at high concentrations in all regions tested, with the exception of the cerebellum. The midbrain region was the most sensitive, where exposures as low as 100 ?g PM/m3 significantly increased brain TNF? levels. However, this sensitivity to DE was not conferred to all markers of neuroinflammation, as the midbrain showed no increase in IL-6 expression at any concentration tested, an increase in IL-1? at only high concentrations, and a decrease in MIP-1? expression, supporting that compensatory mechanisms may occur with subchronic exposure. A?42 levels were the highest in the frontal lobe of mice exposed to 992 ?g PM/m3 and tau [pS199] levels were elevated at the higher DE concentrations (992 and 311 ?g PM/m3) in both the temporal lobe and frontal lobe, indicating that proteins linked to preclinical Alzheimer's disease were affected. ? Synuclein levels were elevated in the midbrain in response to the 992 ?g PM/m3 exposure, supporting that air pollution may be associated with early Parkinson's disease-like pathology. Conclusions Together, the data support that the midbrain may be more sensitive to the neuroinflammatory effects of subchronic air pollution exposure. However, the DE-induced elevation of proteins associated with neurodegenerative diseases was limited to only the higher exposures, suggesting that air pollution-induced neuroinflammation may precede preclinical markers of neurodegenerative disease in the midbrain. PMID:21864400

2011-01-01

154

Commuter exposure to respirable particles inside buses and by bicycle.  

PubMed

The exposure of bus commuters and a cyclist to respirable particles in the city of Manchester has been evaluated, using personal sampling pumps installed in the cabs of the vehicles and carried by the cyclist. These have provided an estimate of the average exposure of commuters using bus services and cycling in a congested European city. PMID:10535138

Gee, I L; Raper, D W

1999-09-01

155

Shielding from solar particle event exposures in deep space  

Microsoft Academic Search

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

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

156

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

SciTech Connect

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.

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

157

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

PubMed Central

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

2013-01-01

158

Health effects of diesel exhaust. A contemporary air pollution issue.  

PubMed

Extracts of diesel exhaust particles are mutagenic in bacterial and mammalian cell assays; they contain hundreds of identifiable organic compounds, some of which are known mutagens and carcinogens. The particles are readily respired and about 20% to 30% of them are deposited in the pulmonary region, where they are retained for long periods. At low diesel exhaust concentrations, typical of those likely for human exposure, particle deposition and clearance rates are essentially normal and particle concentrations in the pulmonary region are expected to remain quite low. At very high concentrations of diesel exhaust, clearance processes may be overwhelmed and lung burdens of particles may continue to increase over long periods. Evidence from laboratory animals suggests that pulmonary injury and reduced respiratory function would occur in humans at these high concentrations. Epidemiologic data and laboratory studies appear to indicate that the human lung cancer risk from exposure to diesel exhaust would be quite low, even if use of diesel vehicles increased substantially. PMID:2414766

McClellan, R O; Mauderly, J L; Jones, R K; Cuddihy, R G

1985-11-01

159

Human visual response to nuclear particle exposures  

NASA Technical Reports Server (NTRS)

Experiments with accelerated helium ions were performed in an effort to localize the site of initial radiation interactions in the eye that lead to light flash observations by astronauts during spaceflight. The character and efficiency of helium ion induction of visual sensations depended on the state of dark adaptation of the retina; also, the same events were seen with different efficiencies and details when particle flux density changed. It was concluded that fast particles cause interactions in the retina, particularly in the receptor layer, and thus give rise to the sensations of light flashes, streaks, and supernovae.

Tobias, C. A.; Budinger, T. F.; Lyman, J. T.

1972-01-01

160

Evaluation and recommendations for reduction of a silica dust exposure  

E-print Network

particle sizing method were used to quantify exposure. Exposures that might exceed control levels were found to exist. In addition, work practices that increased worker exposure were identified. The local exhaust system in place was not controlling the dust...

Gruben, Raymond L

2012-06-07

161

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

PubMed

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

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

2013-09-17

162

The effect of diesel exhaust exposure on blood-brain barrier integrity and function in a murine model.  

PubMed

Epidemiological studies indicate that exposure to diesel exhaust (DE) is associated with vascular-based disorders. To investigate the effect of DE on blood-brain barrier (BBB) function and integrity, 8-week-old BALB/c mice were randomized to DE in a cyclical treatment regimen over a 2-week period. Functional integrity of BBB was determined by considering brain parenchymal abundance of IgG within the hippocampal formation and cortex at 6?h and 24?h intervals following final exposure treatment. Neurovascular inflammation was expressed as the abundance of glial fibrillar acidic protein. Two doses of DE were studied and compared to air-only treated mice. Mice exposed to DE had substantially greater abundance of parenchymal IgG compared to control mice not exposed to DE. Increased parenchymal glial fibrillar acidic protein at 24?h post-DE exposure suggested heightened neurovascular inflammation. Our findings are proof-of-concept that inhalation of DE can compromise BBB function and support the broader contention that DE exposure may contribute to neurovascular disease risk. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24477878

Heidari Nejad, Sayeh; Takechi, Ryusuke; Mullins, Benjamin J; Giles, Corey; Larcombe, Alexander N; Bertolatti, Dean; Rumchev, Krassi; Dhaliwal, Satvinder; Mamo, John

2015-01-01

163

Lung Particle Overload: Implications for Occupational Exposures to Particles  

Microsoft Academic Search

Chronic pulmonary inflammation, pulmonary fibrosis, and even lung tumors developed in a number of chronic inhalation studies in rats with highly insoluble nonfibrous particles of low cytotoxicity. Concerns were expressed that these responses are due to excessive particulate lung burdens, and the term \\

G. Oberdorster

1995-01-01

164

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

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

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

2014-09-01

165

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

PubMed

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

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

2000-03-01

166

Xenobiotic Particle Exposure and Microvascular Endpoints: A Call to Arms  

PubMed Central

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

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

2011-01-01

167

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...

168

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...

169

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...

170

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...

171

Residential indoor and outdoor coarse particles and associated endotoxin exposures  

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

172

Pedestrian exposure to size-resolved particles in Milan.  

PubMed

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 calculated in terms of particulate matter with aerodynamic diameters < or =10 microm (PM10), < or =2.5 pm (PM2.5), and < or =1 microm (PM1). Besides directly measuring the personal exposure to PM throughout the route, the measurement campaigns pointed out small spatial and temporal variations of the concentration ranges in the different urban microenvironments visited along the route as well as very peculiar features of the particles levels in the underground subway. These findings suggested that the personal exposure of pedestrians in the city center could be estimated by simply taking into account the exposure at the open air and in the subway. The comparison between measured and calculated exposures according to the microenvironment-based estimation results in reasonable accordance, even though the estimations tend to slightly underestimate (12%) the actual measured exposure. PMID:22168110

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

2011-11-01

173

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...

174

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...

175

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...

176

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

E-print Network

to assess exposure potential. Airborne concentrations of soot-borne PAH were compared with a working OEL of 0.2 mg/m³, elemental carbon particulate matter with 0.05 mg/m³ and carbon dioxide with 5,000 parts per million (volumetric) all on an 8-hour time...

Pirkle, Paul S

2012-06-07

177

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...

178

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...

179

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

Microsoft Academic Search

The objective of this study was to assess the relationships between physical and psychosocial work exposures, engagement in domestic work and work-home imbalance in relation to symptoms of musculoskeletal disorders and emotional exhaustion in white- and blue-collar men and women. Three thousand employees from 21 companies were asked to answer a questionnaire on family structure, household and child care tasks,

Christina Ahlgren; Eva-Britt Malmgren Olsson; Christine Brulin

2012-01-01

180

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

PubMed

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

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

181

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...

182

Carbonaceous particles and stone damage in a laboratory exposure system  

Microsoft Academic Search

The interaction between carbonaceous particles and stones used in historic buildings and monuments was investigated in a laboratory exposure system. Simulation experiments were carried out in a flow chamber where temperature, relative humidity, and SO2 concentration were controlled. Samples of carbonate stones (Carrara marble, Travertine, and Trani stone) were exposed for 150 days in air with 3 ppm of SO2

C. Sabbioni; G. Zappia; G. Gobbi

1996-01-01

183

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...

184

Diesel exhaust exposure enhances venoconstriction via uncoupling of eNOS  

SciTech Connect

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.

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

185

Development of indigenous local exhaust ventilation system: reduction of welders exposure to welding fumes.  

PubMed

Two (portable and mobile) local exhaust ventilation (LEV) units were developed in collaboration with the Rural Technology Institute, Gandhinagar, India. Basically, each unit consists of three parts comprising an electric motor, a blower and a fume hood. In both units the motor is fixed in a rectangular iron frame in a foot-mount position and equipped compactly with a blower, which in turn is connected to a fume hood through a flexible hosepipe. The portable unit is light in weight (50 kg) and has a cone shaped metallic fume hood. The mobile unit, on the other hand, differs from the portable model with respect to its weight (150 kg), size, RPM, voltage requirement, hood shape and size, and has a motor enclosure. The efficiency of the portable and mobile units on trial bases was tested by measuring the manganese concentration as a reference metal in welding fumes generated by electric arc welding. The concentration of manganese (mean +/- SD) was 0.218 +/- 0.06 microg/m3 in the general environment. In the workplace area where joining of metal objects by welding was done, the concentration of manganese was found to be 0.63 +/- 0.09 and 3.75 +/- 0.56 microg/m3 at a distance of 5 m and 2 m away from the site of operation, respectively. In the breathing zone it was 22.16 +/- 20.90 microg/m3 which was reduced to 8.25 +/- 4.5 microg /m3 after application of a portable LEV showing about 63% removal of the manganese concentration from the breathing zone of the welder. In another experiment conducted with a mobile LEV unit for heavy-duty work, the concentration of manganese in the breathing zone without operating the mobile LEV was 70.06 +/- 37.38 microg /m3 but was lowered to 8.29 +/- 1.76 microg /m3 after operating the mobile LEV. This indicated an average removal of manganese content by about 88% from the breathing zone of the welder. In both the experiments locations of sample collection were similar. PMID:15308834

Zaidi, Shakeel; Sathawara, Natvarbhai; Kumar, Sunil; Gandhi, Sumitra; Parmar, Chimanlal; Saiyed, Habibullah

2004-07-01

186

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

PubMed

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

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

2003-07-01

187

Acute effects of diesel exhaust particles and cisplatin on oxidative stress in cultured human kidney (HEK 293) cells, and the influence of curcumin thereon.  

PubMed

Particulate air pollution with particle diameters less than 2.5?m contribute to respiratory and extra-respiratory morbidity and mortality. We have recently reported the first in vivo experimental evidence that Diesel exhaust particles (DEP) in the lung aggravated the renal, pulmonary, and systemic effects of cisplatin (CP)-induced acute renal failure in rats. This in vitro study sought to determine whether and to what extent does DEP exposure exacerbate the effects of CP-induced oxidative stress in human embryonic kidney (HEK-293) cells, and to examine if these effects could be mitigated/prevented with curcumin (the yellow pigment isolated from turmeric). Cells viability, cysteine uptake and oxidative stress indices [glutathione (GSH), total antioxidant capacity (TAC), and the activities of antioxidant enzymes (catalase; glutathione peroxidase; superoxide dismutase)] were evaluated in all study groups. DEP aggravated the CP- induced HEK-293 cells toxicity, as evidenced by decreasing cell viability and by inducing oxidative stress (GSH depletion, TAC impairment, and antioxidant enzymes inhibition). DEP, but not CP, significantly reduced cysteine uptake. Curcumin prevented the observed DEP and CP-induced cellular insults. These findings suggest that DEP augmented the CP-induced toxicity in HEK-293 cells. Curcumin exhibited a strong potential for protection against DEP and CP-induced cytotoxicity. PMID:24113306

Waly, Mostafa I; Ali, Badreldin H; Nemmar, Abderrahim

2013-12-01

188

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...

189

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...

190

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

PubMed Central

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

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

2008-01-01

191

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)

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.

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

192

Atmospheric scavenging of solid rocket exhaust effluents  

NASA Technical Reports Server (NTRS)

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.

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

1978-01-01

193

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

PubMed Central

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

Rudell, B; Ledin, M C; Hammarstrom, U; Stjernberg, N; Lundback, B; Sandstrom, T

1996-01-01

194

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...

195

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

SciTech Connect

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.

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

1996-06-01

196

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...

197

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...

198

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...

199

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

PubMed

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

Oh, Seung-Min; Chung, Kyu-Hyuck

2006-03-01

200

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

SciTech Connect

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.

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

2012-01-01

201

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

PubMed Central

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

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

2003-01-01

202

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

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

Abdolkarim Chehregani; Fariba Mohsenzadeh; Shiva Hosseini

2011-01-01

203

The Effect of Diesel Exhaust Particles on Cell Function and Release of Inflammatory Mediators from Human Bronchial Epithelial Cells In Vitro  

Microsoft Academic Search

Animal studies have reported that diesel exhaust particles (DEP), which constitute an important fraction of particulate air pollution, lead to inflammation and\\/or damage of the airways. To investigate the mecha- nisms underlying DEP-induced airway disease in humans, we have cultured human bronchial epithelial cells (HBEC) from surgically obtained bronchial explants and investigated the effects of purified DEP on the permeability

Hasan Bayram; Jagdish L. Devalia; Raymond J. Sapsford; Takayuki Ohtoshi; Yuichi Miyabara; Masaru Sagai; Robert J. Davies

204

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

NASA Astrophysics Data System (ADS)

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%).

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

2014-09-01

205

The simulation of condensation removal of a heavy metal from exhaust gases onto sorbent particles.  

PubMed

A numerical model BAEROSOL for solving the general dynamic equation (GDE) of aerosols is presented. The goal was to model the capture of volatilized metals by sorbents under incinerator-like conditions. The model is based on algorithms presented by Jacobson and Turco [Aerosol Science and Technology 22 (1995) 73]. A hybrid size bin was used to model growth and formation of particles from the continuum phase and the coagulation of existing particles. Condensation and evaporation growth were calculated in a moving size bin approach, where coagulation and nucleation was modeled in the fixed size bin model of the hybrid grid. To account for the thermodynamic equilibrium in the gas phase, a thermodynamic equilibrium code CET89 was implemented. The particle size distribution (PSD) calculated with the model was then compared to analytical solutions provided for growth, coagulation and both combined. Finally, experimental findings by Rodriguez and Hall [Waste Management 21 (2001) 589-607] were compared to the PSD predicted by the developed model and the applicability of the model under incineration conditions is discussed. PMID:12909090

Rodriguez, Alexander; Hall, Matthew J

2003-01-01

206

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

SciTech Connect

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.

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

207

Enhanced human IgE production results from exposure to the aromatic hydrocarbons from diesel exhaust: Direct effects on B-cell IgE production  

Microsoft Academic Search

Epidemiologic and experimental studies suggest that air pollution, and particularly diesel exhaust particles (DEPs) may play a role in the increasing prevalence and severity of airway allergic disease. We show that the extract of polyaromatic hydrocarbons (PAHs) from DEPs (PAH-DEP) enhances human IgE production from purified B cells. Interleukin-4 plus CD40 monoclonal antibody–stimulated IgE production was enhanced 20% to 360%

Hiroshi Takenaka; Ke Zhang; David Diaz-Sanchez; Albert Tsien; Andrew Saxon

1995-01-01

208

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 ...

209

Shielding from Solar Particle Event Exposures in Deep Space  

NASA Technical Reports Server (NTRS)

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.

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

210

Rat inhalation test with particles from biomass combustion and biomass co-firing exhaust  

NASA Astrophysics Data System (ADS)

The health effects of 6 different fly ash samples from biomass combustion plants (bark, wood chips, waste wood, and straw), and co-firing plants (coal, co-firing of coal and sawdust) were investigated in a 28-day nose-only inhalation study with Wistar WU rats. Respirable fractions of carbon black (Printex 90) and of titanium dioxide (Bayertitan T) were used as reference materials for positive and negative controls. The exposure was done 6 hours per day, 5 days per week at an aerosol concentration of 16 mg/m3. The MMAD of all fly ash samples and reference materials in the inhalation unit were in the range from 1.5 to 3 ?m. The investigations focused predominantly on the analysis of inflammatory effects in the lungs of rats using bronchoalveolar lavage (BAL) and histopathology. Different parameters (percentage of polymorphonuclear neutrophils (PMN), interleukin-8 and interstitial inflammatory cell infiltration in the lung tissue) indicating inflammatory effects in the lung, showed a statistically significant increase in the groups exposed to carbon black (positive control), C1 (coal) and C1+BM4 (co-firing of coal and sawdust) fly ashes. Additionally, for the same groups a statistically significant increase of cell proliferation in the lung epithelium was detected. No significant effects were detected in the animal groups exposed to BM1 (bark), BM2 (wood chips), BM3 (waste wood), BM6 (straw) or titanium dioxide.

Bellmann, B.; Creutzenberg, O.; Ernst, H.; Muhle, H.

2009-02-01

211

Exposure to wear particles generated from studded tires and pavement induces inflammatory cytokine release from human macrophages.  

PubMed

Health risks associated with exposure to airborne particulate matter (PM) have been shown epidemiologically as well as experimentally, pointing to both respiratory and cardiovascular effects. Lately, wear particles generated from traffic have been recognized to be a major contributing source to the overall particle load, especially in the Nordic countries were studded tires are used. In this work, we investigated the inflammatory effect of PM10 generated from the wear of studded tires on two different types of pavement. As comparison, we also investigated PM10 from a traffic-intensive street, a subway station, and diesel exhaust particles (DEP). Human monocyte-derived macrophages, nasal epithelial cells (RPMI 2650), and bronchial epithelial cells (BEAS-2B) were exposed to the different types of particles, and the secretion of IL-6, IL-8, IL-10, and TNF-alpha into the culture medium was measured. The results show a significant release of cytokines from macrophages after exposure for all types of particles. When particles generated from asphalt/granite pavement were compared to asphalt/quartzite pavement, the granite pavement had a significantly higher capacity to induce the release of cytokines. The granite pavement particles induced cytokine release at the same magnitude as the street particles did, which was higher than what particles from both a subway station and DEP did. Exposure of epithelial cells to PM10 resulted in a significant increase of TNF-alpha secreted from BEAS-2B cells for all types of particles used (DEP was not tested), and the highest levels were induced by subway particles. None of the particle types were able to evoke detectable cytokine release from RPMI 2650 cells. The results indicate that PM10 generated by the wear of studded tires on the street surface is a large contributor to the cytokine-releasing ability of particles in traffic-intensive areas and that the type of pavement used is important for the level of this contribution. Furthermore, the airway inflammatory potential of wear particles from tires and pavement might be of a greater magnitude than that of DEP. PMID:16608163

Lindbom, John; Gustafsson, Mats; Blomqvist, Göran; Dahl, Andreas; Gudmundsson, Anders; Swietlicki, Erik; Ljungman, Anders G

2006-04-01

212

Human exposure to large solar particle events in space  

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

213

Human exposure to large solar particle events in space  

NASA Astrophysics Data System (ADS)

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/cm2) and storm shelter (20 g/cm2) 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.

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

214

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

PubMed

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

Song, Sang-Keun; Shon, Zang-Ho

2014-05-01

215

Assessing Bicyclist and Pedestrian Exposure to Ultrafine Particles: Passive1 Shielding with Noise Barriers2  

E-print Network

to traffic-related air pollutants, including ultrafine23 particles (UFP, particulate matter with aerodynamicAssessing Bicyclist and Pedestrian Exposure to Ultrafine Particles: Passive1 Shielding with Noise exposure to2 ultrafine particles (UFP), particulate matter with aerodynamic diameter less than 0.1 µm

Bertini, Robert L.

216

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...

217

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...

218

Diesel Exhaust Particles Activate the Matrix-Metalloproteinase-1 Gene in Human Bronchial Epithelia in a ?-Arrestin-Dependent Manner via Activation of RAS  

PubMed Central

Background Diesel exhaust particles (DEPs) are globally relevant air pollutants that exert a detrimental human health impact. However, mechanisms of damage by DEP exposure to human respiratory health and human susceptibility factors are only partially known. Matrix metalloproteinase-1 (MMP-1) has been implied as an (etio)pathogenic factor in human lung and airway diseases such as emphysema, chronic obstructive pulmonary disease, chronic asthma, tuberculosis, and bronchial carcinoma and has been reported to be regulated by DEPs. Objective We elucidated the molecular mechanisms of DEPs’ up-regulation of MMP-1. Methods/Results Using permanent and primary human bronchial epithelial (HBE) cells at air–liquid interface, we show that DEPs activate the human MMP-1 gene via RAS and subsequent activation of RAF-MEK-ERK1/2 mitogen-activated protein kinase signaling, which can be scaffolded by ?-arrestins. Short interfering RNA mediated ?-arrestin1/2 knockout eliminated formation, subsequent nuclear trafficking of phosphorylated ERK1/2, and resulting MMP-1 transcriptional activation. Transcriptional regulation of the human MMP-1 promoter was strongly influenced by the presence of the –1607GG polymorphism, present in 60–80% of humans, which led to striking up-regulation of MMP-1 transcriptional activation. Conclusion Our results confirm up-regulation of MMP-1 in response to DEPs in HBE and provide new mechanistic insight into how these epithelia, the first line of protection against environmental insults, up-regulate MMP-1 in response to DEP inhalation. These mechanisms include a role for the human –1607GG polymorphism as a susceptibility factor for an accentuated response, which critically depends on the ability of ?-arrestin1/2 to generate scaffolding and nuclear trafficking of phosphorylated ERK1/2. PMID:19337515

Li, Jinju; Ghio, Andrew J.; Cho, Seung-Hyun; Brinckerhoff, Constance E.; Simon, Sidney A.; Liedtke, Wolfgang

2009-01-01

219

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...

220

Diesel exhaust particles and carbon black have adjuvant activity on the local lymph node response and systemic IgE production to ovalbumin  

Microsoft Academic Search

The possible adjuvant effect of diesel exhaust particles (DEP) on the response to the model allergen ovalbumin (OA) was studied in BALB\\/c mice using the popliteal lymph node (PLN) assay. In addition to changes in PLN weight, cell numbers and cell proliferation, specific serum IgE anti-OA antibody levels were measured. OA inoculated together with DEP into one hind footpad gave

Martinus Løvik; Ann-Kristin Høgseth; Per Ivar Gaarder; Randi Hagemann; Ingvar Eide

1997-01-01

221

Different exposure of infants and adults to ultrafine particles in the urban area of Barcelona.  

PubMed

Air pollutants have been linked with a number of adverse health effects. Children are especially sensitive, particularly when they get close to the exhaust emissions of the vehicles on the street. The objective of this study was to measure the different exposure of infants and adults to ultrafine particles (UFP) as a surrogate marker of air pollution and of risk of deleterious health effects. Two different portable P-TRAK® were used to measure simultaneously exposure to UFPs at different heights, one corresponding to the height of an infant in a stroller (0.55 m) and the other one to the height of the face of an adult pedestrian (1.70 m). Measurements were taken on three different streets with high traffic density in Barcelona, in 10 consecutive days during spring, with two sampling sessions of 1 h each day, moving afoot and taking into account temperature, humidity, and wind speed. Fifty-two thousand and eight (52,008) paired values were obtained, and the results showed about 10 % higher levels of UFP concentration at 0.55 m (48,198?±?25,296 pt/cm(3)) compared to 1.70 m (43,151?±?22,517 pt/cm(3)). Differences between working and nonworking days were observed. Concentration patterns and variation by days of the week and time periods were related to traffic intensity. This study revealed that infants transported by stroller in urban areas are more exposed to air pollution than walking adults. As infants are more vulnerable and UFP have more effects on their health, measures should be taken to protect this population when it is transported in the street. PMID:25433547

Garcia-Algar, Oscar; Canchucaja, Lizzeth; d'Orazzio, Valentina; Manich, Andrea; Joya, Xavier; Vall, Oriol

2015-01-01

222

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

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

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

2012-05-01

223

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...

224

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.

225

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)

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.

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

226

Operant responding following exposure to HZE particles and its relationship to particle energy and linear energy transfer  

NASA Astrophysics Data System (ADS)

On exploratory class missions astronauts will be exposed to a variety of heavy particles (HZE particles) which differ in terms of particle energy and particle linear energy transfer. The present experiments were designed to evaluate how these physical characteristics of different particles affect cognitive performance, specifically operant responding. Following exposure to 28Si, 48Ti, 12C and 16O particles at the NASA Space Radiation Laboratory rats were tested for their ability to respond appropriately to changes in reinforcement schedules using an operant task. The results showed that the effectiveness of different particles in disrupting cognitive performance, defined as the lowest dose that produced a performance decrement, varied as a function of the energy of the specific particle: for comparisons between different energies of the same particle ( e.g., 56Fe) the effectiveness of the particle was directly proportional to particle linear energy transfer, whereas for comparisons between different particles ( e.g., 56Fe and 16O) effectiveness was inversely proportional to particle linear energy transfer. The results are discussed in terms of the mechanisms that influence the effectiveness of different particles and energies and in terms of their implications for analyzing the possible risks to astronauts of decrements in cognitive performance following exposure to HZE particles on long-duration exploratory class missions.

Rabin, Bernard M.; Carrihill-Knoll, Kirsty L.; Shukitt-Hale, Barbara

2011-07-01

227

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

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

Friesen, Melissa C.

2013-01-01

228

Urban commuter exposure to particle matter and carbon monoxide inside an automobile.  

PubMed

In-vehicle exposures to different sizes of particles and carbon monoxide (CO) were determined while driving along a standardized route under a variety of traffic conditions in Kuopio, Finland during the 12-month period from January to December 1995. Arithmetic means of in-vehicle exposures during the morning rush hours were 5.7 parts per million (ppm) (geometric mean, GM = 3.1 ppm, geometric standard deviation, GSD = 1.7) for CO, 107 #/cm3 (GM = 75 #/cm3, GSD = 1.9) for fine particles (optical equivalent particle size range 0.3-1 micron) and 0.9 #/cm3 (GM = 0.6 #/cm3, GSD = 2.1) for coarse particles (optical equivalent particle size range 1-10 microns). Fine particles and CO behaved similarly in different weather and traffic conditions, while the behavior of coarse particles was usually different, and often opposite. The driving conditions that affected the passengers' exposures to CO and fine particles were the time of day (morning vs. afternoon) and average speed (decreasing). The meteorological parameters that affected the passengers' exposures to CO and fine particles were wind speed (decreasing) and relative humidity (increasing). Wind speed, relative humidity and driving speed all had opposite effects on the exposure levels to fine vs. coarse particles. Added exposures (due to commuting on top of the background levels) to CO and fine particles were considerably higher in the morning vs. the afternoon runs and also higher in the slower vs. the faster runs. PMID:10412672

Alm, S; Jantunen, M J; Vartiainen, M

1999-01-01

229

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...

230

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...

231

Combined particle emission reduction and heat recovery from combustion exhaust—A novel approach for small wood-fired appliances  

Microsoft Academic Search

Replacing fossil fuels by renewable sources of energy is one approach to address the problem of global warming due to anthropogenic emissions of greenhouse gases. Wood combustion can help to replace fuel oil or gas. It is advisable, however, to use modern technology for combustion and exhaust gas after-treatment in order to achieve best efficiency and avoid air quality problems

A. Messerer; V. Schmatloch; U. Pöschl; R. Niessner

2007-01-01

232

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...

233

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 ...

234

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)

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.

Kwak, Jihyun; Lee, Sunyoup; Lee, Seokhwan

2014-11-01

235

Roles of Reactive Oxygen Species and Heme Oxygenase1 in Modulation of Alveolar Macrophage-Mediated Pulmonary Immune Responses to Listeria monocytogenes by Diesel Exhaust Particles  

Microsoft Academic Search

Diesel exhaust particles (DEP) have been shown to suppress alveolar macrophage (AM)-mediated pulmonary immune responses to Listeria monocytogenes in vivo. In this study, effects ofDEP-derivedreactiveoxygenspecies(ROS)andhemeoxygenase (HO)-1 on AM-mediated immune responses to L. monocytogenes were investigated. Brown Norway rats were intratracheally inocu- latedwith100,000L.monocytogenes,andAMwereisolatedat7days post-infection.ExposuretoDEPortheirorganicextract(eDEP),but not the washed DEP (wDEP) or carbon black, increased intracel- lularROSandHO-1expressioninAM.InductionofROSandHO-1 byeDEP waspartiallyreversedbya-naphthoflavone,acytochrome P450 1A1 inhibitor, and

Xuejun J. Yin; Jane Y. C. M; James M. Antonini; Vincent Castranova; Joseph K. H. M

2004-01-01

236

Dietary modulation of the effects of exposure to 56Fe particles  

NASA Astrophysics Data System (ADS)

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.

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

237

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...

238

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

NASA Astrophysics Data System (ADS)

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.

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

239

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...

240

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...

241

Part 3. Assessment of genotoxicity and oxidative stress after exposure to diesel exhaust from U.S. 2007-compliant diesel engines: report on 1- and 3-month exposures in the ACES bioassay.  

PubMed

Human health hazards due to diesel exhaust (DE*) exposure have been associated with both solvent and combustion components. In the past, diesel engine exhaust components have been linked to increased mutagenicity in cultures of Salmonella typhimurium and mammalian cells (Tokiwa and Ohnishi 1986). In addition, DE has been shown to increase both the incidence of tumors and the induction of 8-hydroxy-deoxyguanosine adducts (8-OHdG) in ICR mice (Ichinose et al. 1997). Furthermore, DE is composed of a complex mixture of polycyclic aromatic hydrocarbons (PAHs) and particulates. One such PAH, 3-nitrobenzanthrone (3-NBA), has been identified in DE and found in urban air. 3-NBA has been observed to induce micronucleus formation in DNA of human hepatoma cells (Lamy et al. 2004). The purpose of the current research, which is part of the Advanced Collaborative Emissions Study (ACES), a multidisciplinary program being carried out by the Health Effects Institute and the Coordinating Research Council, is to determine whether improvements in the engineering of heavy-duty diesel engines reduce the oxidative stress and genotoxic risk associated with exposure to DE components. To this end, the genotoxicity and oxidative stress of DE from an improved diesel engine was evaluated in bioassays of tissues from Wistar Han rats and C57BL/6 mice exposed to DE. Genotoxicity was measured as strand breaks using an alkaline-modified comet assay. To correlate possible DNA damage found by the comet assay, measurement of DNA-adduct formation was evaluated by a competitive enzyme-linked immunosorbent assay (ELISA) to determine the levels of free 8-OHdG found in the serum of the animals exposed to DE. 8-OHdG is a specific modified base indicating an oxidative type of DNA damage to DNA nucleotides. In addition, a thiobarbituric acid reactive substances (TBARS) assay was used to assess oxidative stress and damage in the form of lipid peroxidation in the hippocampus region of the brains of DE-exposed animals. Results from the comet assay showed no significant differences in rats between the control and exposed groups (P = 0.53, low exposure; P = 0.92, medium exposure; P = 0.77, high exposure) after 1 month of DE exposure. There were no differences between sexes in the responses of rats to these exposures. Likewise, there were no significant differences found after 3 months of exposure. Similarly, no significant differences were found between the mice exposed for 1 and 3 months to DE, nor were any differences found between sexes. Measurements of 8-OHdG in both mice and rats showed no significant difference among DE exposure groups (P = 0.46, mice; P = 0.86, rats). In mice, measured 8-OHdG was lower in the 3-month group than the 1-month group. In rats, the inverse was true. In mice, no significant differences in the levels of lipid peroxidation, as measured by TBARS, were found between the controls and DE exposure groups (P = 0.92), nor were there any differences between sexes. In rats, comparisons between the control and low-exposure groups approached significance, but no significant differences were found between the other DE exposure groups. Additionally, in rats, there were no significant differences between the 1- and 3-month DE exposure groups. PMID:23156842

Hallberg, L M; Ward, J B; Hernandez, C; Ameredes, B T; Wickliffe, J K

2012-09-01

242

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

NASA Astrophysics Data System (ADS)

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.

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

2010-12-01

243

Effects of biodiesel, engine load and diesel particulate filter on nonvolatile particle number size distributions in heavy-duty diesel engine exhaust.  

PubMed

Diesel engine exhaust contains large numbers of submicrometer particles that degrade air quality and human health. This study examines the number emission characteristics of 10-1000 nm nonvolatile particles from a heavy-duty diesel engine, operating with various waste cooking oil biodiesel blends (B2, B10 and B20), engine loads (0%, 25%, 50% and 75%) and a diesel oxidation catalyst plus diesel particulate filter (DOC+DPF) under steady modes. For a given load, the total particle number concentrations (N(TOT)) decrease slightly, while the mode diameters show negligible changes with increasing biodiesel blends. For a given biodiesel blend, both the N(TOT) and mode diameters increase modestly with increasing load of above 25%. The N(TOT) at idle are highest and their size distributions are strongly affected by condensation and possible nucleation of semivolatile materials. Nonvolatile cores of diameters less than 16 nm are only observed at idle mode. The DOC+DPF shows remarkable filtration efficiency for both the core and soot particles, irrespective of the biodiesel blend and engine load under study. The N(TOT) post the DOC+DPF are comparable to typical ambient levels of ? 10(4)cm(-3). This implies that, without concurrent reductions of semivolatile materials, the formation of semivolatile nucleation mode particles post the after treatment is highly favored. PMID:22119306

Young, Li-Hao; Liou, Yi-Jyun; Cheng, Man-Ting; Lu, Jau-Huai; Yang, Hsi-Hsien; Tsai, Ying I; Wang, Lin-Chi; Chen, Chung-Bang; Lai, Jim-Shoung

2012-01-15

244

Dermal absorption of amorphous nanosilica particles after topical exposure for three days.  

PubMed

The skin penetration and cellular localization of well-dispersed amorphous nanosilica particles (nSPs) with a diameter of 70 nm was analyzed in mice. Our results suggest that after topical exposure for three days the particles penetrate the skin barrier and are transported to the lymph nodes. These findings underscore the need to examine biological effects following dermal exposure to nSPs for the development of safer use of nSPs. PMID:22957443

Hirai, T; Yoshikawa, T; Nabeshi, H; Yoshida, T; Akase, T; Yoshioka, Y; Itoh, N; Tsutsumi, Y

2012-08-01

245

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

PubMed Central

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

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

2013-01-01

246

Comparison of the Effects of Exposure to Different Particles or Energies on Behavioral Responding in Rats  

NASA Astrophysics Data System (ADS)

On exploratory class missions, astronauts will be exposed to a variety of heavy particles which differ in terms of quality and energy. Previous research has shown that exposure to 56Fe particles (1 GeV/n) can disrupt performance on taste aversion (CTA) learning and on operant responding using an ascending fixed-ratio schedule of reinforcement. How exposure to different types of particles and different energies will affect performance remains to be established. Rats were exposed to 56Fe (1 GeV/n, 5 GeV/n), 48Ti (1.2 GeV/n)) or 28Si (600 MeV/n) using the AGS or NSRL at Brookhaven National Laboratory. Three days following exposure, the rats were tested for the acquisition of an amphetamine-induced CTA. Compared to 1 GeV/n 56Fe, exposure to 5 GeV/n 56Fe particles required higher doses to disrupt the acquisition of an amphetamine-induced CTA. The dose-response curve for a 48Ti-induced disruption of CTA learning was similar to that produced by exposure to 1 GeV/n 56Fe particles, despite the difference in the LET of the two types of particles. In contrast the rats exposed to 28Si failed to show disruption of amphetamine-induced CTA learning, following exposure to 2.0-4.0 Gy. When tested on a ascending fixed-ratio operant task, the rats exposed to 5 GeV/n 56Fe, in contrast to the rats irradiated with 1 GeV/n 56Fe, did not show poorer performance than the non irradiated controls. These results show that the effects of exposure to heavy particles depend upon the specific particle, its energy, and the endpoint being tested. Supported by NASA Grants NAG9-1190 and NAG9-1529

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

247

Particle damage and exposure analysis in HPGR crushing of selected copper ores for column leaching  

Microsoft Academic Search

In mining operations, jaw and gyratory crushers are generally used for primary crushing, and cone crushers are used for secondary crushing. During the past decade, however, high-pressure grinding rolls (HPGR) are being considered due to potential processing benefits such as energy savings, improved exposure\\/liberation and particle weakening. At this time there is no detailed quantification of particle damage and downstream

Phanindra Kodali; Nikhil Dhawan; Tolga Depci; C. L. Lin; Jan D. Miller

2011-01-01

248

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

NASA Astrophysics Data System (ADS)

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

Kimoto, Yugo

249

Large-scale time-resolved digital particle image velocimetry (TR-DPIV) for measurement of high subsonic hot coaxial jet exhaust of a gas turbine engine  

NASA Astrophysics Data System (ADS)

The development of a highly configurable triple digital particle image velocimetry (DPIV) system is described, which is capable of acquiring both continuous, statistically independent measurements at up to 14 Hz and time-resolved PIV data at MHz rates. The system was used at QinetiQ's Noise Test Facility (NTF) as part of the EU-funded CoJeN programme to obtain measurements from high subsonic (Mach <= 0.9), hot (~500 °C), large (1/10th) scale coaxial jet flows at a standoff distance of ~1 m. High-resolution time-averaged velocity and turbulence data were obtained for complete coaxial engine exhaust plumes down to 4 m (20 jet diameters) from the nozzle exit in less than 1 h. In addition, the system allowed volumetric data to be obtained, enabling fast assessment of spatial alignment of nozzle configurations. Furthermore, novel six-frame time-series data-capture is demonstrated up to 330 kHz, used to calculate time-space correlations within the exhaust, allowing for study of spatio-temporal developments in the jet, associated with jet-noise production. The highly automated system provides synchronization triggers for simultaneous acquisition from different measurement systems (e.g. LDA) and is shown to be versatile, rugged, reliable and portable, operating remotely in a hostile environment. Data are presented for three operating conditions and two nozzle geometries, providing a database to be used to validate CFD models of coaxial jet flow.

Timmerman, B. H.; Skeen, A. J.; Bryanston-Cross, P. J.; Graves, M. J.

2009-07-01

250

Part 2. Assessment of genotoxicity after exposure to diesel exhaust from U.S. 2007-compliant diesel engines: report on 1- and 3-month exposures in the ACES bioassay.  

PubMed

Micronucleus (MN*) formation is a well-established endpoint in genetic toxicology; studies designed to examine MN formation in vivo have been conducted for decades. Conditions that cause double-strand breaks or disrupt the proper segregation of chromosomes during division result in an increase in MN frequency. Thus this endpoint is commonly employed in preclinical studies designed to assess the potential risks of human exposure to a myriad of chemical and physical agents, including inhaled diesel exhaust (DE). As part of the Advanced Collaborative Emissions Study (ACES) this investigation examined the potential of inhaled DE to induce chromosome damage in chronically exposed rodents. The ACES design included exposure of both rats and mice to DE derived from 2007-compliant heavy-duty engines. The exposure conditions consisted of air control and dilutions of DE resulting in three levels of exposure. At specified times, blood samples were collected, fixed, and shipped by the bioassay staff to Litron Laboratories for further processing and analysis. Significant improvements have been made to MN scoring by using objective, automated methods such as flow cytometry, which allows for the detection of micronucleated reticulocytes (MN-RET), micronucleated normochromatic erythrocytes (MN-NCE), and reticulocytes (RETs) in peripheral blood samples from mice and rats. By using a simple staining procedure coupled with rapid and efficient analysis, many more cells were examined in less time than was possible in traditional, microscopy-based MN assays. Thus, for each sample, 20,000 RETs were scored for the presence of MN. In the chronic-exposure bioassay, blood samples were obtained from independent groups of exposed animals at specific time points throughout the course of the entire study. This automated method is supported by numerous regulatory guidelines and meets the requirements for an Organization of Economic Cooperation and Development (OECD)-compliant assay for genotoxicity. Statistical approaches employed analysis of variance (ANOVA) to compare effects of sex, exposure condition, and duration, as well as their interactions. This initial assessment of MN was performed on both mouse and rat blood samples from the 1-month and 3-month exposures. The data from mice demonstrate the well established, sex-based difference in MN-RET and MN-NCE frequencies regularly observed in this species, with females exhibiting slightly lower frequencies. There were no sex-based differences observed in rats. An examination of the mean frequencies across the exposure groups and durations of exposure did not show an appreciable induction of MN at the 1- or 3-month exposures in either species. Further statistical analyses did not reveal any significant exposure-related effects. An examination of the potential genotoxic effects of DE is clearly valuable as part of a large-scale chronic-exposure bioassay. The data and observations from the 1-and 3-month exposure studies will eventually be combined with the results from the 1- and 2-year exposure studies to provide a comprehensive examination of chronic exposure to DE in a rodent model. This examination of chromosome damage serves an important role in the context of the entire ACES bioassay, which was designed to assess the safety of diesel combustion engines. PMID:23156841

Bemis, Jeffrey C; Torous, Dorothea K; Dertinger, Stephen D

2012-09-01

251

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

NASA Technical Reports Server (NTRS)

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

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

2005-01-01

252

DNA adduct formation and oxidative stress in colon and liver of Big Blue rats after dietary exposure to diesel particles.  

PubMed

Exposure to diesel exhaust particles (DEP) via the gastrointestinal route may impose risk of cancer in the colon and liver. We investigated the effects of DEP given in the diet to Big Blue rats by quantifying a panel of markers of DNA damage and repair, mutation, oxidative damage to proteins and lipids, and antioxidative defence mechanisms in colon mucosa cells, liver tissue and the blood compartment. Seven groups of rats were fed a diet with 0, 0.2, 0.8, 2, 8, 20 or 80 mg DEP/kg feed for 21 days. DEP induced a significant increase in DNA strand breaks in colon and liver. There was no effect on oxidative DNA damage (8-oxodG) in colon or liver DNA or in the urine. However, the mRNA expression of OGG1, encoding an enzyme involved in repair of 8-oxodG, was increased by DEP in both liver and colon. DNA adduct levels measured by 32P-post-labelling were elevated in colon and liver, and the expression of ERCC1 gene was affected in liver, but not in colon. In addition to these effects, DEP exposure induced apoptosis in liver. There was no significant change in mutation frequency in colon or liver. The levels of oxidative protein modifications (oxidized arginine and proline residues) were increased in liver accompanied by enhanced vitamin C levels. In plasma, we found no significant effects on oxidative damage to proteins and lipids, antioxidant enzymes or vitamin C levels. Our data indicate that gastrointestinal exposure to DEP induces DNA adducts and oxidative stress resulting in DNA strand breaks, enhanced repair capacity of oxidative base damage, apoptosis and protein oxidation in colon mucosa cells and liver. PMID:12919963

Dybdahl, Marianne; Risom, Lotte; Møller, Peter; Autrup, Herman; Wallin, Håkan; Vogel, Ulla; Bornholdt, Jette; Daneshvar, Bahram; Dragsted, Lars Ove; Weimann, Allan; Poulsen, Henrik Enghusen; Loft, Steffen

2003-11-01

253

Translocation of particles and inflammatory responses after exposure to fine particles and nanoparticles in an epithelial airway model  

PubMed Central

Background Experimental studies provide evidence that inhaled nanoparticles may translocate over the airspace epithelium and cause increased cellular inflammation. Little is known, however, about the dependence of particle size or material on translocation characteristics, inflammatory response and intracellular localization. Results Using a triple cell co-culture model of the human airway wall composed of epithelial cells, macrophages and dendritic cells we quantified the entering of fine (1 ?m) and nano-sized (0.078 ?m) polystyrene particles by laser scanning microscopy. The number distribution of particles within the cell types was significantly different between fine and nano-sized particles suggesting different translocation characteristics. Analysis of the intracellular localization of gold (0.025 ?m) and titanium dioxide (0.02–0.03 ?m) nanoparticles by energy filtering transmission electron microscopy showed differences in intracellular localization depending on particle composition. Titanium dioxide nanoparticles were detected as single particles without membranes as well as in membrane-bound agglomerations. Gold nanoparticles were found inside the cells as free particles only. The potential of the different particle types (different sizes and different materials) to induce a cellular response was determined by measurements of the tumour necrosis factor-? in the supernatants. We measured a 2–3 fold increase of tumour necrosis factor-? in the supernatants after applying 1 ?m polystyrene particles, gold nanoparticles, but not with polystyrene and titanium dioxide nanoparticles. Conclusion Quantitative laser scanning microscopy provided evidence that the translocation and entering characteristics of particles are size-dependent. Energy filtering transmission electron microscopy showed that the intracellular localization of nanoparticles depends on the particle material. Both particle size and material affect the cellular responses to particle exposure as measured by the generation of tumour necrosis factor-?. PMID:17894871

Rothen-Rutishauser, Barbara; Muhlfeld, Christian; Blank, Fabian; Musso, Claudia; Gehr, Peter

2007-01-01

254

Diesel exhaust particles increase LPS-stimulated COX2 expression and PGE2 production in human monocytes  

Microsoft Academic Search

Little is known about health effects of ultrafine particles (UFP) found in ambient air, but much of their action may be on cells of the lung, including cells of the monocyte\\/macrophage lin- eage. We have analyzed the effects of diesel ex- haust particles (DEP; SRM1650a) on human monocytes in vitro. DEP, on their own, had little effect on cyclooxygenase (COX)-2

Thomas P. J. Hofer; Ellen Bitterle; Ingrid Beck-Speier; Konrad L. Maier; Marion Frankenberger; Joachim Heyder; Loms Ziegler-Heitbrock

2004-01-01

255

A coupled road dust and surface moisture model to predict non-exhaust road traffic induced particle emissions (NORTRIP). Part 1: Road dust loading and suspension modelling  

NASA Astrophysics Data System (ADS)

Non-exhaust traffic induced emissions are a major source of particle mass in most European countries. This is particularly important in Nordic and Alpine countries where winter time road traction maintenance occurs, e.g. salting and sanding, and where studded tyres are used. In this paper, Part 1, the road dust sub-model of a coupled road dust and surface moisture model (NORTRIP) is described. The model provides a generalised process based formulation of the non-exhaust emissions, with emphasis on the contribution of road wear, suspension, surface dust loading and the effect of road surface moisture (retention of wear particles and suspended emissions). The model is intended for use as a tool for air quality managers to help study the impact of mitigation measures and policies. We present a description of the road dust sub-model and apply the model to two sites in Stockholm and Copenhagen where seven years of data with surface moisture measurements are available. For the site in Stockholm, where studded tyres are in use, the model predicts the PM10 concentrations very well with correlations (R2) in the range of R2 = 0.76-0.91 for daily mean PM10. The model also reproduces well the impact of a reduction in studded tyres at this site. For the site in Copenhagen the correlation is lower, in the range 0.44-0.51. The addition of salt is described in the model and at both sites this leads to improved correlations due to additional salt emissions. For future use of the model a number of model parameters, e.g. wear factors and suspension rates, still need to be refined. The effect of sanding on PM10 emissions is also presented but more information will be required before this can be confidently applied for management applications.

Denby, B. R.; Sundvor, I.; Johansson, C.; Pirjola, L.; Ketzel, M.; Norman, M.; Kupiainen, K.; Gustafsson, M.; Blomqvist, G.; Omstedt, G.

2013-10-01

256

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

PubMed

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

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

2007-04-01

257

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...

258

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

EPA Science Inventory

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

259

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

EPA Science Inventory

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

260

Exposure to genotoxins present in ambient air in Bangkok, Thailand — particle associated polycyclic aromatic hydrocarbons and biomarkers  

Microsoft Academic Search

Exposure to genotoxic compounds in ambient air has been studied in Bangkok, Thailand, by analysis of polycyclic aromatic hydrocarbons (PAHs) associated with particles and using different biomarkers of exposure. Eighty-nine male, non-smoking Royal Thai police officers were investigated. The police officers were divided into a high exposure group (traffic police) and low exposure (office duty). Particulate matter was collected using

Mathuros Ruchirawat; Chulabhorn Mahidol; Chanthana Tangjarukij; Sittisak Pui-ock; Ole Jensen; Ormrat Kampeerawipakorn; Jantamas Tuntaviroon; Auratai Aramphongphan; Herman Autrup

2002-01-01

261

Genotoxic effects of carbon black particles, diesel exhaust particles, and urban air particulates and their extracts on a human alveolar epithelial cell line (A549) and a human monocytic cell line (THP-1).  

PubMed

The possible genotoxicity of small particulate matter has been under investigation for the last 10 years. Diesel exhaust particles (DEP) are considered as "probably carcinogenic" (IARC group 2A) and a number of studies show genotoxic effects of urban particulate matter (UPM). Carbon black (CB) is carcinogenic in rats. In this study the cytotoxic and genotoxic potency of these three particle types was investigated by exposing human cells (A549 and THP-1 cell lines) in vitro to CB, DEP (SRM 1650, NIST), and UPM (SRM 1648, NIST) for 48 hr. Cytotoxicity was assessed using the Alamar Blue assay, whereas genotoxicity was assessed using the single-cell gel electrophoresis (comet assay). The particles were characterized with regard to their mean diameter in tissue culture medium (CB 100 nm, DEP 400 nm, UPM 2 microm), their total carbon content (CB 99%, DEP 85%, UPM 15%), and their acid-soluble metal composition (UPM > CB approximately DEP). The concentrations ranged from 16 ng/ml to 16 microg/ml for cytotoxicity tests and from 16 ng/ml to 1.6 microg/ml for genotoxicity tests. In both assays, paraquat was used as a reference chemical. The CB, DEP, and UPM particles showed no significant cytotoxicity. However, all three particles were able to cause significant DNA damage, although to a different extent in the two cell lines. The genotoxicity of washed particles and dichloromethane extracts was also investigated. In THP-1 cells CB washed particles and DEP extracts caused significant DNA damage. This difference in effect may be related to differences in size, structure, and composition of the particles. These results suggest that CB, DEP, and UPM are able to cause DNA damage and, therefore, may contribute to the causation of lung cancer. More detailed studies on influence of size, structure, and composition of the particles are needed. PMID:11246222

Don Porto Carero, A; Hoet, P H; Verschaeve, L; Schoeters, G; Nemery, B

2001-01-01

262

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...

263

Exposure to ultrafine particles and PM 2.5 in four Sydney transport modes  

NASA Astrophysics Data System (ADS)

Concentrations of ultrafine (<0.1 ?m) particles (UFPs) and PM 2.5 (<2.5 ?m) were measured whilst commuting along a similar route by train, bus, ferry and automobile in Sydney, Australia. One trip on each transport mode was undertaken during both morning and evening peak hours throughout a working week, for a total of 40 trips. Analyses comprised one-way ANOVA to compare overall (i.e. all trips combined) geometric mean concentrations of both particle fractions measured across transport modes, and assessment of both the correlation between wind speed and individual trip means of UFPs and PM 2.5, and the correlation between the two particle fractions. Overall geometric mean concentrations of UFPs and PM 2.5 ranged from 2.8 (train) to 8.4 (bus) × 10 4 particles cm -3 and 22.6 (automobile) to 29.6 (bus) ?g m -3, respectively, and a statistically significant difference ( p < 0.001) between modes was found for both particle fractions. Individual trip geometric mean concentrations were between 9.7 × 10 3 (train) and 2.2 × 10 5 (bus) particles cm -3 and 9.5 (train) to 78.7 (train) ?g m -3. Estimated commuter exposures were variable, and the highest return trip mean PM 2.5 exposure occurred in the ferry mode, whilst the highest UFP exposure occurred during bus trips. The correlation between fractions was generally poor, and in keeping with the duality of particle mass and number emissions in vehicle-dominated urban areas. Wind speed was negatively correlated with, and a generally poor determinant of, UFP and PM 2.5 concentrations, suggesting a more significant role for other factors in determining commuter exposure.

Knibbs, Luke D.; de Dear, Richard J.

2010-08-01

264

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

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.

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

265

Variable Pulmonary Responses from Exposure to Concentrated Ambient Air Particles in a Rat Model of Bronchitis  

Microsoft Academic Search

Chronic bronchitis may be considered a risk factor in particu- late matter (PM)-induced morbidity. We hypothesized that a rat model of human bronchitis would be more susceptible to the pulmonary effects of concentrated ambient particles (CAPs) from Research Triangle Park, NC. Bronchitis was induced in male Sprague-Dawley rats (90 -100 days of age) by exposure to 200 ppm sulfur dioxide

Urmila P. Kodavanti; Rudolph Mebane; Allen Ledbetter; Todd Krantz; John McGee; Mette C. Jackson; Leon Walsh; Hassell Hilliard; Bai Yi Chen; Judy Richards; Daniel L. Costa

2000-01-01

266

USE OF METAL- AND FLUORESCEIN-TAGGED MATERIALS TO STUDY SETTLED PARTICLES EXPOSURE PATHWAYS  

EPA Science Inventory

Through the use of ten size ranges of tagged materials (Antley et. al., 2000a), inductively coupled plasma- mass spectrometry (ICP-MS) and flourometry are being used to study the movement of settled particles in the indoor environment, exposure pathways, and the collection effi...

267

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...

268

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 ...

269

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...

270

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...

271

Simulated restaurant cook exposure to emissions of PAHs, mutagenic aldehydes, and particles from frying bacon.  

PubMed

This study investigated the exposure of cooks to polycyclic aromatic hydrocarbons (PAHs), higher mutagenic aldehydes, total particles, and ultrafine particles during cooking. Experiments were performed by pan frying fresh and smoked bacon on both electric and gas stoves, and with the gas alone. Detailed analyses of PAHs were performed, with analyses of the levels of 32 different PAHs. A TSI-3939 scanning mobility particle sizer system was used to measure the ultrafine particles. The results showed that total PAHs were in the range of 270-300 ng/m(3) air. However, the smoked bacon experiment showed a somewhat different PAH pattern, whereby retene constituted about 10% of the total PAHs, which is a level similar to that of the abundant gas phase constituent phenanthrene. The reason for the elevated retene emissions is unknown. The total cancer risk, expressed as toxic equivalency factors, showed a somewhat higher risk on the electric stove (p < 0.05) compared with the gas stove. Levels of trans, trans-2,4-decadienal were between 34 and 54 ?g/m(3) air. The level of total particles was between 2.2 and 4.2 mg/m(3). Frying on a gas stove caused a statistically significant higher amount of ultrafine particles compared with frying on an electric stove. Large variations in the mobility diameter at peak particle concentration were found (74.4 nm-153.5 nm). The highest mobility diameter was found for frying on an electric stove. The gas flame itself showed a maximum production of 19.5-nm-sized particles and could not be the explanation for the difference between frying on the gas stove and frying on the electric stove. No single indicator for the exposure to cooking fume could be selected. Each compound should be measured independently to provide a comprehensive characterization of the cooking exposure. PMID:23343415

Jørgensen, Rikke Bramming; Strandberg, Bo; Sjaastad, Ann Kristin; Johansen, Arve; Svendsen, Kristin

2013-01-01

272

Foliar or root exposures to smelter particles: consequences for lead compartmentalization and speciation in plant leaves.  

PubMed

In urban areas with high fallout of airborne particles, metal uptake by plants mainly occurs by foliar pathways and can strongly impact crop quality. However, there is a lack of knowledge on metal localization and speciation in plants after pollution exposure, especially in the case of foliar uptake. In this study, two contrasting crops, lettuce (Lactuca sativa L.) and rye-grass (Lolium perenne L.), were exposed to Pb-rich particles emitted by a Pb-recycling factory via either atmospheric or soil application. Pb accumulation in plant leaves was observed for both ways of exposure. The mechanisms involved in Pb uptake were investigated using a combination of microscopic and spectroscopic techniques (electron microscopy, laser ablation, Raman microspectroscopy, and X-ray absorption spectroscopy). The results show that Pb localization and speciation are strongly influenced by the type of exposure (root or shoot pathway) and the plant species. Foliar exposure is the main pathway of uptake, involving the highest concentrations in plant tissues. Under atmospheric fallouts, Pb-rich particles were strongly adsorbed on the leaf surface of both plant species. In lettuce, stomata contained Pb-rich particles in their apertures, with some deformations of guard cells. In addition to PbO and PbSO4, chemical forms that were also observed in pristine particles, new species were identified: organic compounds (minimum 20%) and hexagonal platy crystals of PbCO3. In rye-grass, the changes in Pb speciation were even more egregious: Pb-cell wall and Pb-organic acid complexes were the major species observed. For root exposure, identified here as a minor pathway of Pb transfer compared to foliar uptake, another secondary species, pyromorphite, was identified in rye-grass leaves. Finally, combining bulk and spatially resolved spectroscopic techniques permitted both the overall speciation and the minor but possibly highly reactive lead species to be determined in order to better assess the health risks involved. PMID:24508855

Schreck, Eva; Dappe, Vincent; Sarret, Géraldine; Sobanska, Sophie; Nowak, Dorota; Nowak, Jakub; Stefaniak, El?bieta Anna; Magnin, Valérie; Ranieri, Vincent; Dumat, Camille

2014-04-01

273

Air shower simulation for WASAVIES: warning system for aviation exposure to solar energetic particles.  

PubMed

WASAVIES, a warning system for aviation exposure to solar energetic particles (SEPs), is under development by collaboration between several institutes in Japan and the USA. It is designed to deterministically forecast the SEP fluxes incident on the atmosphere within 6 h after flare onset using the latest space weather research. To immediately estimate the aircrew doses from the obtained SEP fluxes, the response functions of the particle fluxes generated by the incidence of monoenergetic protons into the atmosphere were developed by performing air shower simulations using the Particle and Heavy Ion Transport code system. The accuracy of the simulation was well verified by calculating the increase count rates of a neutron monitor during a ground-level enhancement, combining the response function with the SEP fluxes measured by the PAMELA spectrometer. The response function will be implemented in WASAVIES and used to protect aircrews from additional SEP exposure. PMID:24344351

Sato, T; Kataoka, R; Yasuda, H; Yashiro, S; Kuwabara, T; Shiota, D; Kubo, Y

2014-10-01

274

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

SciTech Connect

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.

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

1989-01-01

275

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

NASA Astrophysics Data System (ADS)

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.

Hunt, Walter A.; Joseph, James A.; Rabin, Bernard M.

276

Exposure assessment of diesel bus emissions.  

PubMed

The goal of this study was to measure ultrafine particle concentrations with diameters less than 1 mum emitted by diesel buses and to assess resulting human exposure levels. The study was conducted at the Woolloongabba Busway station in Brisbane, Australia in the winter months of 2002 during which temperature inversions frequently occurred. Most buses that utilize the station are fuelled by diesel, the exhaust of which contains a significant quantity of particle matter. Passengers waiting at the station are exposed to these particles emitted from the buses. During the course of this study, passenger census was conducted, based on video surveillance, yielding person-by-person waiting time data. Furthermore, a bus census revealed accurate information about the total number of diesel versus Compressed Natural Gas (CNG) powered buses. Background (outside of the bus station) and platform measurements of ultrafine particulate number size distributions were made to determine ambient aerosol concentrations. Particle number exposure concentration ranges from 10 and 40 to 60% of bus related exhaust fumes. This changes dramatically when considering the particle mass exposure concentration, where most passengers are exposed to about 50 to 80% of exhaust fumes. The obtained data can be very significant for comparison with similar work of this type because it is shown in previous studies that exhaust emissions causes cancer in laboratory animals. It was assumed that significant differences between platform and background distributions were due to bus emissions which, combined with passenger waiting times, yielded an estimate of passenger exposure to ultrafine particles from diesel buses. From an exposure point of view, the Busway station analyzed resembles a street canyon. Although the detected exhaust particle concentration at the outbound platform is found to be in the picogram range, exposure increases with the time passengers spend on the platform along with their breathing frequency. PMID:17159271

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

2006-12-01

277

Cognitive differences between male and female rats following exposure to 56Fe particles  

NASA Astrophysics Data System (ADS)

On exploratory class missions astronauts will be exposed to types and doses of radiation (HZE particles) that are not experienced in low earth orbit. While it is likely that the crew will consist of both male and female astronauts, there has been little research on the effects of exposure to HZE particles on cognitive performance in female subjects. While previous research has shown that exposure to HZE particles disrupts cognitive performance in male rats it remains to be established whether or not similar effects will occur with female subjects because estrogen may act as a neuroprotectant. Ovariectomized (OVX) female rats were obtained from Taconic Farms. Thirty mm segments of silastic tubing containing either 180 pg l7-estradiol/mL in sesame oil or vehicle alone were implanted subcutaneously in the neck. Three days following surgery the rats were exposed to 56Fe particles (1000 MeV/n, 0-200 cGy) at the NSRL. Following irradiation the rats were shipped to UMBC for behavioral testing. The results indicated that the pattern of decrements in cognitive performance differed between male and female rats. In addition, for female rats, there were differences in performance as a function of the presence or absence of estradiol. In the vehicle implanted subjects exposure to 56Fe particles did not affect operant responding on an ascending fixed-ratio schedule; whereas irradiation did disrupt responding in OVX animals given estradiol. These results suggest that estrogen may not be protective following exposure to HZE particles. This research was supported by Grant NNX08AM66G from NASA.

Rabin, Bernard; Shukitt-Hale, Barbara; Carrihill-Knoll, Kirsty; Luskin, Katharine; Long, Lauren; Joseph, James

278

Application of real-time particle sensors to help mitigate exposures of wildland firefighters.  

PubMed

High particulate exposures have been demonstrated to decrease lung function among firefighters. In this article, the authors demonstrated the feasibility of using small real-time particle sensors to inform wildland firefighters so they may make informed decisions on the use of personal respiratory protection. Using 1 mg/m3 as an indicator point for use of appropriately designed respiratory protection, such sensors could help prevent 16% to 74% of particulate exposure during prescribed burns when firefighters assess exposure as low or medium. Adherence to such a guideline for the use of respiratory protection would involve its deployment during 3% to 22% of individual 8-hour shifts. In addition, data-logging sensors would provide a valuable tool for tracking exposure to particulates among wildland firefighters for occupational health monitoring. PMID:16961007

Edwards, Rufus; Johnson, Michael; Dunn, Kevin H; Naeher, Luke P

2005-01-01

279

Effects of 3-methyl-4-nitrophenol in diesel exhaust particles on the regulation of reproductive function in immature female Japanese quail (Coturnix japonica).  

PubMed

In a previous study, we found that 3-methyl-4-nitrophenol (PNMC), a component of diesel exhaust particles and also a degradation product of the insecticide fenitrothion, exhibits reproductive toxicity in the adult male Japanese quail. The present study investigated the toxicity of PNMC in the female Japanese quail and its ability to influence reproduction in immature females. The quail (21-day-old) were injected intramuscularly (im) with PNMC at doses 0.1, 1 or 10 mg/kg body weight daily for 3 days. There was no significant difference in body growth between the PNMC-administered and control birds. However, the weights of the oviducts were significantly lower in the PNMC-treated birds at all doses. Furthermore, the plasma concentrations of luteinizing hormone (LH) and estradiol-17 beta were significantly decreased with 1 and 10 mg/kg of PNMC. These findings suggest that PNMC might influence the hypothalamo-pituitary-gonadal axis with decreasing in secretion of GnRH, LH and ovarian steroid hormones and subsequently disturb growth of the reproductive organs of immature female quail. This study indicates that PNMC induces reproductive toxicity at the central level and disrupts reproductive function in the immature female quail. PMID:17202750

Li, ChunMei; Takahashi, Shinji; Taneda, Shinji; Furuta, Chie; Watanabe, Gen; Suzuki, Akira K; Taya, Kazuyoshi

2007-06-01

280

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

PubMed

Exposure to ultrafine particles (UFPs) is deemed to be a major risk affecting human health. Therefore, airborne particle studies were performed in the recent years to evaluate the most critical micro-environments, as well as identifying the main UFP sources. Nonetheless, in order to properly evaluate the UFP exposure, personal monitoring is required as the only way to relate particle exposure levels to the activities performed and micro-environments visited. To this purpose, in the present work, the results of experimental analysis aimed at showing the effect of the time-activity patterns on UFP personal exposure are reported. In particular, 24 non-smoking couples (12 during winter and summer time, respectively), comprised of a man who worked full-time and a woman who was a homemaker, were analyzed using personal particle counter and GPS monitors. Each couple was investigated for a 48-h period, during which they also filled out a diary reporting the daily activities performed. Time activity patterns, particle number concentration exposure and the related dose received by the participants, in terms of particle alveolar-deposited surface area, were measured. The average exposure to particle number concentration was higher for women during both summer and winter (Summer: women 1.8 × 10(4) part. cm(-3); men 9.2 × 10(3) part. cm(-3); Winter: women 2.9 × 10(4) part. cm(-3); men 1.3 × 10(4) part. cm(-3)), which was likely due to the time spent undertaking cooking activities. Staying indoors after cooking also led to higher alveolar-deposited surface area dose for both women and men during the winter time (9.12 × 10(2) and 6.33 × 10(2) mm(2), respectively), when indoor ventilation was greatly reduced. The effect of cooking activities was also detected in terms of women's dose intensity (dose per unit time), being 8.6 and 6.6 in winter and summer, respectively. On the contrary, the highest dose intensity activity for men was time spent using transportation (2.8 in both winter and summer). PMID:24080417

Buonanno, G; Stabile, L; Morawska, L

2014-01-15

281

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 ...

282

Reassessment of data used in setting exposure limits for hot particles  

SciTech Connect

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.

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

1991-05-01

283

Exhaust gas recirculation system for internal combustion engine  

Microsoft Academic Search

In an exhaust gas recirculation system for an internal combustion engine having an intake manifold in which a throttle valve is disposed and an exhaust gas conduit provided with a particle trap for accumulatively catching particles entrained by exhaust gas discharged from the engine, a control valve apparatus which is disposed in a recirculation passage and connected to the intake

K. Dozono; Y. Hasegawa

1983-01-01

284

Using the Aerasense NanoTracer for simultaneously obtaining several ultrafine particle exposure metrics  

NASA Astrophysics Data System (ADS)

The expanding production and use of nanomaterials increases the chance of human exposure to engineered nanoparticles (NP), also referred to as ultrafine particles (UFP; <= 100 - 300 nm). This is particularly true in workplaces where they can become airborne and thereafter inhaled by workers during nanopowder processing. Considering the suspected hazard of many engineered UFPs, the general recommendation is to take measures for minimizing personal exposure while monitoring the UFP pollution for assessment and control purposes. The portable Aerasense NanoTracer accomplishes this UFP monitoring, either intermittently or in real time. This paper reviews its design and operational characteristics and elaborates on a number of application extensions and constraints. The NanoTracer's output signals enable several UFP exposure metrics to be simultaneously inferred. These include the airborne UFP number concentration and the number-averaged particle size, serving as characteristics of the pertaining UFP pollution. When non-hygroscopic particles are involved, the NanoTracer's output signals also allow an estimation of the lung-deposited UFP surface area concentration and the lung-deposited UFP mass concentration. It is thereby possible to distinguish between UFP depositions in the alveolar region, the trachea-bronchial region and the head airway region, respectively, by making use of the ICRP particle deposition model.

Marra, J.

2011-07-01

285

A Novel System to Generate WTC Dust Particles for Inhalation Exposures  

PubMed Central

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

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

286

Children exposure assessment to ultrafine particles and black carbon: The role of transport and cooking activities  

NASA Astrophysics Data System (ADS)

An accurate evaluation of the airborne particle dose-response relationship requires detailed measurements of the actual particle concentration levels that people are exposed to, in every microenvironment in which they reside. The aim of this work was to perform an exposure assessment of children in relation to two different aerosol species: ultrafine particles (UFPs) and black carbon (BC). To this purpose, personal exposure measurements, in terms of UFP and BC concentrations, were performed on 103 children aged 8-11 years (10.1 ± 1.1 years) using hand-held particle counters and aethalometers. Simultaneously, a time-activity diary and a portable GPS were used to determine the children's daily time-activity pattern and estimate their inhaled dose of UFPs and BC. The median concentration to which the study population was exposed was found to be comparable to the high levels typically detected in urban traffic microenvironments, in terms of both particle number (2.2 × 104 part. cm-3) and BC (3.8 ?g m-3) concentrations. Daily inhaled doses were also found to be relatively high and were equal to 3.35 × 1011 part. day-1 and 3.92 × 101 ?g day-1 for UFPs and BC, respectively. Cooking and using transportation were recognized as the main activities contributing to overall daily exposure, when normalized according to their corresponding time contribution for UFPs and BC, respectively. Therefore, UFPs and BC could represent tracers of children exposure to particulate pollution from indoor cooking activities and transportation microenvironments, respectively.

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

2013-11-01

287

Combination acoustical muffler and exhaust converter  

SciTech Connect

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.

Nitz, A.E.

1982-11-30

288

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

SciTech Connect

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.

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

289

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

Microsoft Academic Search

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

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

1997-01-01

290

Acute Inflammatory Responses in the Airways and Peripheral Blood After Short-Term Exposure to Diesel Exhaust in Healthy Human Volunteers  

Microsoft Academic Search

Several epidemiologic studies have demonstrated a consistent association between levels of particu- late matter (PM) in the ambient air with increases in cardiovascular and respiratory mortality and morbidity. Diesel exhaust (DE), in addition to generating other pollutants, is a major contributor to PM pollution in most places in the world. Although the epidemiologic evidence is strong, there are as yet

SUNDEEP SALVI; ANDERS BLOMBERG; BERTIL RUDELL; FRANK KELLY; THOMAS SANDSTRÖM; STEPHEN T. HOLGATE; ANTHONY FREW

1999-01-01

291

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...

292

Modeling Population Exposure to Ultrafine Particles in a Major Italian Urban Area  

PubMed Central

Average daily ultrafine particles (UFP) exposure of adult Milan subpopulations (defined on the basis of gender, and then for age, employment or educational status), in different exposure scenarios (typical working day in summer and winter) were simulated using a microenvironmental stochastic simulation model. The basic concept of this kind of model is that time-weighted average exposure is defined as the sum of partial microenvironmental exposures, which are determined by the product of UFP concentration and time spent in each microenvironment. In this work, environmental concentrations were derived from previous experimental studies that were based on microenvironmental measurements in the city of Milan by means of personal or individual monitoring, while time-activity patterns were derived from the EXPOLIS study. A significant difference was observed between the exposures experienced in winter (W: 28,415 pt/cm3) and summer (S: 19,558 pt/cm3). Furthermore, simulations showed a moderate difference between the total exposures experienced by women (S: 19,363 pt/cm3; W: 27,623 pt/cm3) and men (S: 18,806 pt/cm3; W: 27,897 pt/cm3). In addition, differences were found as a function of (I) age, (II) employment status and (III) educational level; accordingly, the highest total exposures resulted for (I) 55–59 years old people, (II) housewives and students and (III) people with higher educational level (more than 10 years of scholarity). Finally, significant differences were found between microenvironment-specific exposures. PMID:25321878

Spinazzè, Andrea; Cattaneo, Andrea; Peruzzo, Carlo; Cavallo, Domenico M.

2014-01-01

293

Modeling population exposure to ultrafine particles in a major italian urban area.  

PubMed

Average daily ultrafine particles (UFP) exposure of adult Milan subpopulations (defined on the basis of gender, and then for age, employment or educational status), in different exposure scenarios (typical working day in summer and winter) were simulated using a microenvironmental stochastic simulation model. The basic concept of this kind of model is that time-weighted average exposure is defined as the sum of partial microenvironmental exposures, which are determined by the product of UFP concentration and time spent in each microenvironment. In this work, environmental concentrations were derived from previous experimental studies that were based on microenvironmental measurements in the city of Milan by means of personal or individual monitoring, while time-activity patterns were derived from the EXPOLIS study. A significant difference was observed between the exposures experienced in winter (W: 28,415 pt/cm3) and summer (S: 19,558 pt/cm3). Furthermore, simulations showed a moderate difference between the total exposures experienced by women (S: 19,363 pt/cm3; W: 27,623 pt/cm3) and men (S: 18,806 pt/cm3; W: 27,897 pt/cm3). In addition, differences were found as a function of (I) age, (II) employment status and (III) educational level; accordingly, the highest total exposures resulted for (I) 55-59 years old people, (II) housewives and students and (III) people with higher educational level (more than 10 years of scholarity). Finally, significant differences were found between microenvironment-specific exposures. PMID:25321878

Spinazzè, Andrea; Cattaneo, Andrea; Peruzzo, Carlo; Cavallo, Domenico M

2014-01-01

294

Biological effects of alpha particle radiation exposure on human monocytic cells.  

PubMed

Radon ((222)Rn) gas produces decay progeny that emits high energy alpha (?)-particles. Epidemiological studies have shown that exposure to (222)Rn is linked with elevated risk of developing lung cancer, however clear mechanisms leading to such effects have not been delineated. Cytokines play a critical role in inflammation and their dysregulated production often contributes to disease pathogenesis. In this study, Bio-plex multiplex technology was employed to investigate modulations of 27 pro-inflammatory cytokines following exposure of human monocytic cells to 1.5 Gy of ?-particle radiation. Concurrently, DNA damage was assessed by examining the formation of phosphorylated H2A histone family X (?-H2AX) sites. Of the 27 cytokines assessed, 4 cytokines were shown to be statistically downregulated by ?2 fold relative to the untreated controls and included the interleukin (IL) family of proteins (IL-2, IL-15 and IL-17) and macrophage inflammatory protein 1 beta (MIP-1b). Interferon-inducible protein-12 (IP-12), vascular endothelial growth factor and regulated on activation normal T cell expressed and secreted (RANTES) were shown to be high expressors and upregulated. Cells irradiated with ?-particles ranging from 0.27 to 2.14 Gy showed statistically significant, dose-dependant increases in ?-H2AX formation. These data suggest that ?-particle radiation causes dysregulation in the production of a number of pro-inflammatory cytokines and results in significant DNA damage. PMID:22153871

Chauhan, Vinita; Howland, Matthew; Kutzner, Barbara; McNamee, James P; Bellier, Pascale V; Wilkins, Ruth C

2012-04-01

295

THE INFLUENCE OF HUMAN ACTIVITY PATTERNS ON PERSONAL PM EXPOSURE: A COMPARATIVE ANALYSIS OF FILTER-BASED AND CONTINUOUS PARTICLE MEASUREMENTS  

EPA Science Inventory

Particulate matter (PM) exposure data from the U.S. Environmental Protection Agency sponsored 1998 Baltimore and 1999 Fresno PM Exposure Studies were analyzed to identify important microenvironments and activities that may lead to increased particle exposure for select elderly ...

296

Growth of human bronchial epithelial cells at an air-liquid interface alters the response to particle exposure  

PubMed Central

Background We tested the hypothesis that normal human bronchial epithelial (NHBE) cells 1) grown submerged in media and 2) allowed to differentiate at air-liquid interface (ALI) demonstrate disparities in the response to particle exposure. Results Following exposure of submerged NHBE cells to ambient air pollution particle collected in Chapel Hill, NC, RNA for IL-8, IL-6, heme oxygenase 1 (HOX1) and cyclooxygenase 2 (COX2) increased. The same cells allowed to differentiate over 3, 10, and 21 days at ALI demonstrated no such changes following particle exposure. Similarly, BEAS-2B cells grown submerged in media demonstrated a significant increase in IL-8 and HOX1 RNA after exposure to NIST 1648 particle relative to the same cells exposed after growth at ALI. Subsequently, it was not possible to attribute the observed decreases in the response of NHBE cells to differentiation alone since BEAS-2B cells, which do not differentiate, showed similar changes when grown at ALI. With no exposure to particles, differentiation of NHBE cells at ALI over 3 to 21 days demonstrated significant decrements in baseline levels of RNA for the same proteins (i.e. IL-8, IL-6, HOX1, and COX2). With no exposure to particles, BEAS-2B cells grown at ALI showed comparable changes in RNA for IL-8 and HOX1. After the same particle exposure, NHBE cells grown at ALI on a transwell in 95% N2-5% CO2 and exposed to NIST 1648 particle demonstrated significantly greater changes in IL-8 and HOX1 relative to cells grown in 95% air-5% CO2. Conclusions We conclude that growth of NHBE cells at ALI is associated with a diminished biological effect following particle exposure relative to cells submerged in media. This decreased response showed an association with increased oxygen availability. PMID:23800224

2013-01-01

297

Exhaust gas recirculation system  

Microsoft Academic Search

In an exhaust gas recirculation system for internal combustion engines having a detachable gasket member between an exhaust gas recirculation valve and an exhaust pipe of the engine, the exhaust gas recirculation rate is controlled by a flow control orifice formed in the detachable gasket member. The recirculation valve can be applied to various types of engines requiring various recirculation

K. Numata; Y. Muramatu

1977-01-01

298

Exhaust gas recirculation system  

Microsoft Academic Search

An exhaust gas recirculation system for use in an internal combustion engine includes an intake manifold having a riser portion serving as a heating source for an intake mixture charge, an exhaust gas recirculation passage running from an exhaust manifold to an intake system for introducing part of exhaust gases from the former to the latter, and a temperature-responsive valve

N. Kawai; H. Yamamoto

1980-01-01

299

Exhaust gas recirculator  

Microsoft Academic Search

An exhaust gas recirculator for an internal combustion engine having an exhaust pipe, an intake manifold and a carburetor throttle valve. The exhaust gas recirculator comprises an egr passage which makes the exhaust pipe communicate with the intake manifold, an egr controlling valve and an egr valve respectively arranged in the upper and lower portions of the egr passage. The

Suda

1983-01-01

300

Some Behavioral Effects of Exposure to Low Doses of Fe-56 Particles  

NASA Technical Reports Server (NTRS)

Future missions in space (such as a mission to Mars) will involve long-term travel beyond the magnetic field of the Earth. As a result, astronauts will be exposed to radiation qualities and doses that differ from those experienced in low earth orbit, including exposure to heavy particles, such as Fe-56, which are a component of cosmic rays. Although the hazards of exposure to heavy particles are often minimized, they can affect neural functioning, and as a consequence, behavior. Unless the effects of exposure to cosmic rays can somehow be reduced, their effects on the brain throughout long duration flights could be disastrous. In the extreme case, it is possible that the effects of cosmic rays on space travelers could result in symptomatology resembling that of Alzheimer's or Parkinson's diseases or of advancing age, including significant cognitive and/or motor impairments. Because successful operations in space depend in part on the performance capabilities of astronauts, such impairments could jeopardize their ability to satisfy mission requirements, as well as have long-term consequences on the health of astronauts. As such, understanding the nature and extent of this risk may be vital to the effective performance and possibly the survival of astronauts during future missions in space.

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

1999-01-01

301

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...

302

Characterization of exposures to airborne nanoscale particles during friction stir welding of aluminum.  

PubMed

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

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

303

Assessment of ultrafine particles in Portuguese preschools: levels and exposure doses.  

PubMed

The aim of this work was to assess ultrafine particles (UFP) number concentrations in different microenvironments of Portuguese preschools and to estimate the respective exposure doses of UFP for 3-5-year-old children (in comparison with adults). UFP were sampled both indoors and outdoors in two urban (US1, US2) and one rural (RS1) preschool located in north of Portugal for 31 days. Total levels of indoor UFP were significantly higher at the urban preschools (mean of 1.82 × 10(4) and 1.32 × 10(4)  particles/cm(3) at US1 an US2, respectively) than at the rural one (1.15 × 10(4)  particles/cm(3) ). Canteens were the indoor microenvironment with the highest UFP (mean of 5.17 × 10(4) , 3.28 × 10(4) , and 4.09 × 10(4)  particles/cm(3) at US1, US2, and RS1), whereas the lowest concentrations were observed in classrooms (9.31 × 10(3) , 11.3 × 10(3) , and 7.14 × 10(3)  particles/cm(3) at US1, US2, and RS1). Mean indoor/outdoor ratios (I/O) of UFP at three preschools were lower than 1 (0.54-0.93), indicating that outdoor emissions significantly contributed to UFP indoors. Significant correlations were obtained between temperature, wind speed, relative humidity, solar radiation, and ambient UFP number concentrations. The estimated exposure doses were higher in children attending urban preschools; 3-5-year-old children were exposed to 4-6 times higher UFP doses than adults with similar daily schedules. PMID:24689947

Fonseca, J; Slezakova, K; Morais, S; Pereira, M C

2014-12-01

304

Children exposure to atmospheric particles in indoor of Lisbon primary schools  

NASA Astrophysics Data System (ADS)

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.

Almeida, Susana Marta; Canha, Nuno; Silva, Ana; Freitas, Maria do Carmo; Pegas, Priscilla; Alves, Célia; Evtyugina, Margarita; Pio, Casimiro Adrião

2011-12-01

305

Use of Nuclepore filters for ambient and workplace nanoparticle exposure assessment-Spherical particles  

NASA Astrophysics Data System (ADS)

Nuclepore filter collection with subsequent electron microscopy analysis for nanoparticles was carried out to examine the feasibility of the method to assess the nanoparticle exposure. The number distribution of nanoparticles collected on the filter surface was counted visually and converted to the distribution in the air using existing filtration models for Nuclepore filters. To search for a proper model, this paper studied the overall penetrations of three different nanoparticles (PSL, Ag and NaCl), covering a wide range of particle sizes (20-800 nm) and densities (1.05-10.5 g cm-3), through Nuclepore filters with two different pore diameters (1 and 3 ?m) and different face velocities (2-15 cm s-1). The data were compared with existing particle deposition models and modified models proposed by this study, which delivered different results because of different deposition processes considered. It was found that a parameter associated with flow condition and filter geometry (density of fluid medium, particle density, filtration face velocity, filter porosity and pore diameter) should be taken into account to verify the applicability of the models. The data of the overall penetration were in very good agreement with the properly applied models. A good agreement of filter surface collection between the validated model and the SEM analysis was obtained, indicating a correct nanoparticle number distribution in the air can be converted from the Nuclepore filter surface collection and this method can be applied for nanoparticle exposure assessment.

Chen, Sheng-Chieh; Wang, Jing; Fissan, Heinz; Pui, David Y. H.

2013-10-01

306

A 244Cm irradiator for protracted exposure of cultured Mammalian cells with alpha particles.  

PubMed

A 244Cm alpha-particle irradiator was designed and constructed for radiobiological studies where protracted exposure at a low dose rate of cultured mammalian cells is required. It allows irradiation of a cell monolayer attached to the Mylar bottom of a specially designed Petri dish of 56 mm diameter (approximately 25 cm(2) area). The irradiator is based on a 20-mm-diameter stainless steel chamber containing a 148 kBq 244Cm source. The chamber, flushed with helium gas at a pressure kept slightly above the external pressure, is inserted into a cell incubator where temperature and CO2 concentration are controlled. Spectrometric and dosimetric characterization of the irradiator was carried out by means of an ion-implanted-silicon charged-particle detector, CR39 detectors, and Monte Carlo simulations with the TRIM code. Average LET of particles incident on the cells at the center of the Petri dish was evaluated to be 120 keV microm(-1) at 59 mm from the source, and the average dose rate was 5.69 x 10 Gy s(-1), with +12% and -8% variations at the center and the edge, respectively. The irradiator has been successfully tested and used for several experiments involving 16-d exposure of human fibroblasts monolayers. PMID:16340609

Esposito, G; Belli, M; Simone, G; Sorrentino, E; Tabocchini, M A

2006-01-01

307

Respiratory toxicity of repeated exposure to particles produced by traffic and sugar cane burning.  

PubMed

We compared the toxicity of subchronic exposure to equivalent masses of particles from sugar cane burning and traffic. BALB/c mice received 3 intranasal instillations/week during 1, 2 or 4 weeks of either distilled water (C1, C2, C4) or particles (15?g) from traffic (UP1, UP2, UP4) or biomass burning (BP1, BP2, BP4). Lung mechanics, histology and oxidative stress were analyzed 24h after the last instillation. In all instances UP and BP groups presented worse pulmonary elastance, airway and tissue resistance, alveolar collapse, bronchoconstriction and macrophage influx into the lungs than controls. UP4, BP2 and BP4 presented more alveolar collapse than UP1 and BP1, respectively. UP and BP had worse bronchial and alveolar lesion scores than their controls; BP4 had greater bronchial lesion scores than UP4. Catalase was higher in UP4 and BP4 than in C4. In conclusion, biomass particles were more toxic than those from traffic after repeated exposures. PMID:24280381

Mazzoli-Rocha, Flavia; Carvalho, Giovanna M C; Lanzetti, Manuella; Valença, Samuel S; Silva, Luiz F F; Saldiva, Paulo H N; Zin, Walter A; Faffe, Débora S

2014-01-15

308

A Biopersistence Study following Exposure to Chrysotile Asbestos Alone or in Combination with Fine Particles  

PubMed Central

In designing a study to evaluate the inhalation biopersistence of a chrysotile asbestos that was used as a component of a joint-compound, a feasibility study was initiated to evaluate the short-term biopersistence of the chrysotile alone and of the chrysotile in combination witht the sanded reformulated joint-compound. Two groups of Wistar rats were exposed to either 7RF3 chrysotile (Group 2) or to 7RF3 chrysotile combined with aerosolized sanded joint-compound (Group 3). In addition, a control group was exposed to flltered-air. The chrysotile used in the Ready Mix joint compound is rapidly removed from the lung. The chrysotile alone exposure group had a clearance half-time of fibers L > 20 ?m of 2.2 days; in the chrysotile plus sanded exposure group the clearance half-time of fibers L > 20 ?m was 2.8 days. However, across all size ranges there was approximately an order of magnitude decrease in the mean number of fibers remaining in the lungs of Group 3 as compared to Group 2 despite similiar aerosol exposures. Histopathological examination showed that the chrysotile exposed lungs had the same appearance as the flltered-air controls. This study uniquely illustrates that additional concurrent exposure to an aerosol of the sanded joint-compound, with large numbers of fine-particles depositing in the lungs, accelerates the recruitment of macrophages, resulting in a tenfold decrease in the number of fibers remaining in the lung. The increased number of macrophages in the chrysotile/sanded joint exposure group was confirmed histologically, with this being the only exposure-related histological finding reported. PMID:18788018

Bernstein, D. M.; Donaldson, K.; Decker, U.; Gaering, S.; Kunzendorf, P.; Chevalier, J.; Holm, S. E.

2008-01-01

309

Phenomenological in-situ TEM gas exposure studies of palladium particles on MgO at room temperature  

NASA Technical Reports Server (NTRS)

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.

Heinemann, K.; Poppa, H.; Osaka, T.

1983-01-01

310

Neuronal stress following exposure to 56Fe particles and the effects of antioxidant-rich diets  

PubMed Central

Exposing young rats to particles of high energy and charge (HZE particles), a ground-based model for exposure to cosmic rays, enhances indices of oxidative stress and inflammation and disrupts the functioning of neuronal communication in critical regions of the brain [ 1]. These changes in neuronal function are similar to those seen in ageing [ 2, 3]. Although there is some recovery of function after exposure to 56Fe particles, particularly in changes observed 36 h following irradiation, long-term changes (75 days) have been observed, suggesting subcellular damage. Consequently, oxidative stress and inflammation induced by radiation could affect downstream events, such as changes in behavior and gene expression. Therefore, berry fruits high in antioxidant and anti-inflammatory activity, such as blueberries and strawberries, may prevent the occurrence of neurochemical and behavioral changes that occur if fed prior to radiation [ 4]. Rats were exposed to 56Fe (1000 MeV/n; 1.5 Gy) particles at the NASA Space Radiation Laboratory at Brookhaven National Laboratory; other rats served as non-irradiated controls. The animals were fed either a control or a 2% blueberry or strawberry diet 8 weeks prior to radiation. Rats were then either euthanized at 36 h (short term) or 30 days following irradiation (long term). Before and after the irradiation, the animals were housed at USDA Human Nutrition Research Center on Aging at Tufts University, Boston. The results of the experiments indicate that: (1) 56Fe exposure caused significant differential, neurochemical changes in critical regions of the brain, such as hippocampus, striatum, frontal cortex and cerebellum, particularly long term. (2) Neurochemical changes resulted in the disruption of autophagy, increased inflammation and increased oxidative stress protein markers. (3) Antioxidant-rich berry diets significantly reduced the accumulation of toxic cellular debris in critical regions of the brain, primarily at the 30 days post-irradiation time-point. (4) Susceptibility to inflammation, autophagy dysregulation, and oxidative stress were proportional to the levels of antioxidant enzymes in the respective brain regions. (5) Exposure to 56Fe radiation may cause the accumulation of disease-related proteins such as PHF-Tau, which has been implicated in the pathogenesis of Alzheimer's disease. Irradiation with 56Fe, which causes substantial build-up of toxic cellular debris in critical regions of the brain, may overwhelm the innate antioxidant enzyme defense system [ 5]. Therefore, berry diets high in antioxidants may be used to counter these damaging effects by reducing oxidative stress and inflammation, and activating neuronal housekeeping, in addition to boosting endogenous antioxidant enzymes. This paper was presented at the NASA Session at Heavy Ion in Therapy and Space Radiation Symposium 2013.

Poulose, Shibu M.; Bielinski, Donna; Carrihill-Knoll, Kirsty L.; Rabin, Bernard M.; Shukitt-Hale, Barbara

2014-01-01

311

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...

312

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

PubMed Central

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

2013-01-01

313

Long-term changes in amphetamine-induced reinforcement and aversion in rats following exposure to 56Fe particle  

NASA Technical Reports Server (NTRS)

Exposing rats to heavy particles produces alterations in the functioning of dopaminergic neurons and in the behaviors that depend upon the integrity of the dopaminergic system. Two of these dopamine-dependent behaviors include amphetamine-induced reinforcement, measure using the conditioned place preference procedure, and amphetamine-induced reinforcement, measured using the conditioned place preference procedure, and amphetamine-induced aversion, measured using the conditioned taste aversion. Previous research has shown that exposing rats to 1.0 Gy of 1GeV/n 56Fe particles produced a disruption of an amphetamine-induced taste aversion 3 days following exposure, but produced an apparent enhancement of the aversion 112 days following exposure. The present experiments were designed to provide a further evaluation of these results by examining taste aversion learning 154 days following exposure to 1.0 Gy 56Fe particles and to establish the convergent validity of the taste aversion results by looking at the effects of exposure on the establishment of an amphetamine-induced conditioned place preference 3, 7, and 16 weeks following irradiation. The taste aversion results failed to confirm the apparent enhancement of the amphetamine-induced CTA observed in the prior experiment. However, exposure to 56Fe particles prevented the acquisition of amphetamine-induced place preference at all three-time intervals. The results are interpreted as indicating that exposure to heavy particles can produce long-term changes in behavioral functioning. c2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

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

2003-01-01

314

Exposure vs toxicity levels of airborne quartz, metal and carbon particles in cast iron foundries.  

PubMed

Aerosol dust samples and quartz raw materials from different working stations in foundry plants were characterized in order to assess the health risk in this working environment. Samples were analysed by scanning and transmission electron microscopy coupled with image analysis and microanalysis, and by cathodoluminescence spectroscopy. In addition, the concentration and the solubility degree of Fe and other metals of potential health effect (Mn, Zn and Pb) in the bulk samples were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Overall, the results indicate substantial changes in quartz crystal structure and texture when passing from the raw material to the airborne dust, which include lattice defects, non-bridging oxygen hole centres and contamination of quartz grains by metal and/or graphite particles. All these aspects point towards the relevance of surface properties on reactivity. Exposure doses have been estimated based on surface area, and compared with threshold levels resulting from toxicology. The possible synergistic effects of concomitant exposure to inhalable magnetite, quartz and/or graphite particles in the same working environment have been properly remarked. PMID:23385294

Moroni, Beatrice; Viti, Cecilia; Cappelletti, David

2014-01-01

315

Pinnacles and pitfalls for source apportionment of potential health effects from airborne particle exposure.  

PubMed

Since its origins in the 1970s, source apportionment using receptor modeling has improved to a point where both the chemical mass balance and various methods of factor analysis have been applied to many urban and regional data sets to infer major sources or source classes influencing airborne particle concentrations. Recently the factors from the latter analyses have been combined with regression techniques using human health endpoints to infer source influence on health effects. This approach is attractive for air quality management when the composition of particles is known, since it provides, in principle, a means of quantifying major source influence on health consequences. The factor-based analyses have been used for both epidemiological and toxicological studies with some success. While the method is useful in many ways, it also has important limitations that include failing to identify specific sources, misidentification from comingled source factors, and inconsistency or unreasonableness of results from the same locations using different factor techniques. Examples of ambiguities evolving from these limitations are cited in this article. Ambiguity found in the literature is fostered by loosely worded terminology that does not distinguish statistically based factors from actual sources, and from health impacts inferred by single centrally located air monitors, which are assumed to represent actual exposure or dosage to airborne particles. PMID:17613081

Grahame, Thomas; Hidy, G M

2007-07-01

316

Exhaust gas recirculation system  

Microsoft Academic Search

An exhaust gas recirculation system is disclosed which includes a control valve inserted in an exhaust gas recirculation passageway for controlling the flow rate of the exhaust gases to be recirculated, a constant pressure chamber defined in the recirculation passageway upstream of the control valve, and a modulator valve with a diaphragm chamber in communication with the constant pressure chamber

S. Nakamura; H. Nohira; H. Tokuda

1980-01-01

317

Exhaust gas recirculation system  

Microsoft Academic Search

In a diesel engine having a turbocharger for feeding supercharged air to the engine, an exhaust gas recirculation passage communicates between the exhaust passage from the engine and the intake passage to a compressor of the turbocharger. A first control valve closes the exhaust gas recirculation passage when the output pressure of the air leading from the compressor is lower

Yoshiba

1982-01-01

318

Exhaust gas recirculation system  

Microsoft Academic Search

An exhaust gas recirculation system for an internal combustion engine. The internal combustion engine including at least one combustion chamber; an intake mechanism for delivering a combustible fluid mixture to the combustion chamber; an ignition system for igniting the combustible mixture; and an exhaust system for carrying exhaust fluid produced by the combustion of the combustible fluid mixture away from

Freesh

1982-01-01

319

Exhaust gas recirculation system  

Microsoft Academic Search

In response to the operation of an internal combustion engine, an input signal pressure is developed which differs from the atmospheric pressure by more than a first predetermined amount when exhaust gas recirculation is desirable. A recirculation valve then opens to permit the recirculation of exhaust gases from the exhaust passage to the intake passage of the engine. In response

1975-01-01

320

Measurements of children's exposures to particles and nitrogen dioxide in Santiago, Chile.  

PubMed

An exposure study of children (aged 10-12 years) living in Santiago, Chile, was conducted. Personal, indoor and outdoor fine and inhalable particulate matter (< 2.5 .m in diameter, PM2.5 and < 10 microm in diameter, PM10, respectively), and nitrogen dioxide (NO2) were measured during pilot (N = 8) and main (N = 20) studies, which were conducted during the winters of 1998 and 1999, respectively. For the main study, personal, indoor and outdoor 24-h samples were collected for five consecutive days. Similar mean personal, indoor and outdoor PM2.5 concentrations (69.5, 68.5 and 68.1 microg/m3, respectively) were found. However, for coarse particles (calculated as the difference between measured PM10 and PM2.5, PM2.5-10), indoor and outdoor levels (35.4 and 47.4 microg/m3) were lower than their corresponding personal exposures (76.3 microg/m3). Indoor and outdoor NO2 concentrations were comparable (35.8 and 36.9 ppb) and higher than personal exposures (25.9 ppb). Very low ambient indoor and personal O3 levels were found, which were mostly below the method's limit of detection (LOD). Outdoor particles contributed significantly to indoor concentrations, with effective penetration efficiencies of 0.61 and 0.30 for PM2.5 and PM2.5-10, respectively. Personal exposures were strongly associated with indoor and outdoor concentrations for PM2.5, but weakly associated for PM2.5-10. For NO2, weak associations were obtained for indoor-outdoor and personal-outdoor relationships. This is probably a result of the presence of gas cooking stoves in all the homes. Median I/O, P/I and P/O ratios for PM2.5 were close to unity, and for NO2 they ranged between 0.64 and 0.95. These ratios were probably due to high ambient PM2.5 and NO2 levels in Santiago, which diminished the relative contribution of indoor sources and subjects' activities to indoor and personal PM2.5 and NO2 levels. PMID:11993967

Rojas-Bracho, Leonora; Suh, Helen H; Oyola, Pedro; Koutrakis, Petros

2002-03-27

321

Amphetamine-induced taste aversion learning in young and old F-344 rats following exposure to 56Fe particles  

PubMed Central

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 designed to determine whether or not there would be an interaction between age and exposure to 56Fe particles in the disruption of an amphetamine-induced CTA. One hundred and forty F-344 male rats 2-, 7-, 12-, and 16-months old, were radiated with 56Fe particles (0.25–2.00 Gy, 1 GeV/n) at Brookhaven National Laboratory. Three days following irradiation, the rats were tested for the effects of radiation on the acquisition of a CTA produced by injection of amphetamine (3 mg/kg, i.p.). The main effect of age was to produce a significant decrease in conditioning day sucrose intake; there was no affect of age on the acquisition of the amphetamine-induced CTA. Exposing rats to 56Fe particles disrupted the acquisition of the CTA produced by injection of amphetamine only in the 2-month-old rats. These results do not support the hypothesis of an interaction between age and exposure to 56Fe particles in producing a disruption of amphetamine-induced CTA learning. As such, these results suggest that the aging produced by exposure to 56Fe particles may be endpoint specific. PMID:19424832

Carrihill-Knoll, K. L.; Shukitt-Hale, B.; Joseph, J. A.; Carey, A.

2007-01-01

322

Jet exhaust noise suppressor  

NASA Technical Reports Server (NTRS)

Noise suppression for a jet engine exhaust is provided by an annular divergent body attached to an exhaust nozzle. The smallest diameter of the divergent body is larger than the diameter of the exhaust nozzle exit to form an annular step which produces a shock wave in the exhaust as it passes the step. An annular shroud is disposed around the divergent body and causes outside air to pass through voids in the divergent body to mix with the jet exhaust gas. The divergent body includes a plurality of channels with separators between the channels.

Huff, R. G. (inventor)

1974-01-01

323

Lightweight polymeric exhaust components  

US Patent & Trademark Office Database

Disclosed is a muffler assembly including: a) polymeric housing having an interior surface and at least one opening for at least one inlet and one outlet exhaust pipe; b) at least one metal inlet exhaust pipe and at least one metal outlet exhaust pipe positioned within the openings to provide housing-exhaust pipe interfaces; c) a thermal insulating material coating the interior surface of the polymeric housing and extending through the housing-exhaust pipe interfaces; wherein the thermal insulating material seals the muffler assembly at the housing-exhaust pipe interfaces; and wherein the muffler assembly has a leak rate of 105 Liters/minute or less at 4.5 psig pressure. An optional muffler assembly has body mounting adapters attached to the inlet and outlet exhaust pipes and positioned within the openings to provide housing-body mounting adapter interfaces. Also disclosed are processes for manufacturing the muffler assemblies.

2013-08-13

324

MRT letter: Auto-fluorescence by human alveolar macrophages after in vitro exposure to air pollution particles.  

PubMed

Macrophages from smokers demonstrate an increased auto-fluorescence. Similarly, auto-fluorescence follows in vitro exposure of macrophages to cigarette smoke condensate (i.e., the particulate fraction of cigarette smoke). The composition of particles in cigarette smoke can be comparable to air pollution particles. We tested the postulate that macrophages exposed to air pollution particles could demonstrate auto-fluorescence. Healthy nonsmoking and healthy smoking volunteers (both 18-40 years of age) underwent fiberoptic bronchoscopy with bronchoalveolar lavage and alveolar macrophages isolated. Macrophages were incubated at 37 degrees C in 5% CO(2) with either PBS or 100 microg/mL particle for both 1 and 24 h. Particles included a residual oil fly ash, Mt. St. Helens volcanic ash, and ambient air particles collected from St. Louis, Missouri and Salt Lake City, Utah. At the end of incubation, 50 microL of the cell suspension was cytocentrifuged and examined at modes for viewing fluorescein isothiocyanate (FITC) and rhodamine fluorescence. Both emission source air pollution particles demonstrated FITC and rhodamine auto-fluorescence at 1 and 24 h, but the signal following incubation of the macrophages with oil fly ash appeared greater. Similarly, the ambient particles were associated with auto-fluorescence by the alveolar macrophages and this appeared to be dose-dependent. We conclude that exposure of macrophages to air pollution particles can be associated with auto-fluorescence in the FITC and rhodamine modes. PMID:19941295

Ghio, Andrew J; Sangani, Rahul G; Brighton, Luisa E; Carson, John L

2010-06-01

325

Modeling the acute health effects of astronauts from exposure to large solar particle events.  

PubMed

Radiation exposure from Solar Particle Events (SPE) presents a significant health concern for astronauts for exploration missions outside the protection of the Earth's magnetic field, which could impair their performance and result in the possibility of failure of the mission. Assessing the potential for early radiation effects under such adverse conditions is of prime importance. Here we apply a biologically based mathematical model that describes the dose- and time-dependent early human responses that constitute the prodromal syndromes to consider acute risks from SPEs. We examine the possible early effects on crews from exposure to some historically large solar events on lunar and/or Mars missions. The doses and dose rates of specific organs were calculated using the Baryon radiation transport (BRYNTRN) code and a computerized anatomical man model, while the hazard of the early radiation effects and performance reduction were calculated using the Radiation-Induced Performance Decrement (RIPD) code. Based on model assumptions we show that exposure to these historical events would cause moderate early health effects to crew members inside a typical spacecraft or during extra-vehicular activities, if effective shielding and medical countermeasure tactics were not provided. We also calculate possible even worse cases (double intensity, multiple occurrences in a short period of time, etc.) to estimate the severity, onset and duration of various types of early illness. Uncertainties in the calculation due to limited data on relative biological effectiveness and dose-rate modifying factors for protons and secondary radiation, and the identification of sensitive sites in critical organs are discussed. PMID:19276707

Hu, Shaowen; Kim, Myung-Hee Y; McClellan, Gene E; Cucinotta, Francis A

2009-04-01

326

Assessment of environmental tobacco smoke and respirable suspended particle exposures for nonsmokers in Prague using personal monitoring  

Microsoft Academic Search

Objective: Exposures to respirable suspended particles (RSP) and environmental tobacco smoke (ETS) were assessed in Prague, Czech Republic,\\u000a to determine the range and degree of personal exposure by means of personal monitoring over a 24-h period. Design: Self-reported nonsmokers were randomly selected from a representative sample of the population of Prague. Housewives were\\u000a recruited into one group, primarily for assessment

Keith Phillips; Mark C. Bentley; David A. Howard; Gunnar Alván

1998-01-01

327

Dose-controlled exposure of A549 epithelial cells at the air–liquid interface to airborne ultrafine carbonaceous particles  

Microsoft Academic Search

The geometry of commercially available perfusion chambers designed for harbouring three membrane-based cell cultures was modified for reliable and dose-controlled air–liquid interface (ALI) exposures. Confluent A549 epithelial cells grown on membranes were integrated in the chamber system and supplied with medium from the chamber bottom. Cell viability was not impaired by the conditions of ALI exposure without particles. Expression of

E. Bitterle; E. Karg; A. Schroeppel; W. G. Kreyling; A. Tippe; G. A. Ferron; O. Schmid; J. Heyder; K. L. Maier; T. Hofer

2006-01-01

328

Brain signaling and behavioral responses induced by exposure to (56)Fe-particle radiation  

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

329

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...

330

A coupled road dust and surface moisture model to predict non-exhaust road traffic induced particle emissions (NORTRIP). Part 2: Surface moisture and salt impact modelling  

NASA Astrophysics Data System (ADS)

Non-exhaust traffic induced emissions are a major source of airborne particulate matter in most European countries. This is particularly important in Nordic and Alpine countries where winter time road traction maintenance occurs, e.g. salting and sanding, and where studded tyres are used. Though the total mass generated by wear sources is a key factor in non-exhaust emissions, these emissions are also strongly controlled by surface moisture conditions. In this paper, Part 2, the road surface moisture sub-model of a coupled road dust and surface moisture model (NORTRIP) is described. We present a description of the road surface moisture part of the model and apply the coupled model to seven sites in Stockholm, Oslo, Helsinki and Copenhagen over 18 separate periods, ranging from 3.5 to 24 months. At two sites surface moisture measurements are available and the moisture sub-model is compared directly to these observations. The model predicts the frequency of wet roads well at both sites, with an average fractional bias of -2.6%. The model is found to correctly predict the hourly surface state, wet or dry, 85% of the time. From the 18 periods modelled using the coupled model an average absolute fractional bias of 15% for PM10 concentrations was found. Similarly the model predicts the 90'th daily mean percentiles of PM10 with an average absolute bias of 19% and an average correlation (R2) of 0.49. When surface moisture is not included in the modelling then this average correlation is reduced to 0.16, demonstrating the importance of the surface moisture conditions. Tests have been carried out to assess the sensitivity of the model to model parameters and input data. The model provides a useful tool for air quality management and for improving our understanding of non-exhaust traffic emissions.

Denby, B. R.; Sundvor, I.; Johansson, C.; Pirjola, L.; Ketzel, M.; Norman, M.; Kupiainen, K.; Gustafsson, M.; Blomqvist, G.; Kauhaniemi, M.; Omstedt, G.

2013-12-01

331

Analyses of risks associated with radiation exposure from past major solar particle events  

NASA Technical Reports Server (NTRS)

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.

Weyland, Mark D.; Atwell, William; Cucinotta, Francis A.; Wilson, John W.; Hardy, Alva C.

1991-01-01

332

Exhaust system combustor  

SciTech Connect

This patent describes a combustor for use in an exhaust gas system which combustor is tolerant to thermal gradients so as not to degrade the atomization of fuel therein. It comprises an exhaust duct for conveying exhaust gas therethrough having a side wall, an inlet end through which exhaust gas enters the exhaust duct, and an outlet end through which the exhaust gas exits the exhaust duct; a combustion chamber having an atomizer end and a combustion end fixedly mounted in the exhaust duct facing the outlet end of the exhaust duct; an atomizer mounted in the atomizer end of the combustion chamber for spraying atomized fuel into the combustion chamber; an air duct for conveying combustion air to the combustion chamber and extending through the side wall of the exhaust duct to the atomizer end of the combustion chamber; and a fuel conduit fixedly joined to the atomizer for conveying fuel to the atomizer, the fuel conduit having at least a portion thereof extending in the air duct, the portion also including a longitudinal compliance portion for allowing thermal expansion and contraction of the air duct and the combustion chamber relative to the fuel conduit while maintaining a constant position and alignment of the atomizer with respect to the combustion chamber.

Simmons, H.C.; Jones, R.V.

1992-04-21

333

Modeling the Prodromal Effects and Performance Reduction of Astronauts from Exposure to Large Solar Particle Events  

NASA Technical Reports Server (NTRS)

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.

Hu, S.; Kim, M. Y.; McClellan, G. E.; Nikjoo, H.; Cucinotta, F. A.

2007-01-01

334

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

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.

Jerald A. Caton; Kalyan Annamalai; Robert P. Lucht

2006-12-31

335

Seasonal assessment of environmental tobacco smoke and respirable suspended particle exposures for nonsmokers in Bremen using personal monitoring  

Microsoft Academic Search

The study was designed to determine seasonal differences in personal exposures to respirable suspended particles (RSP) and environmental tobacco smoke (ETS) for nonsmokers in Bremen, Germany. The subjects were office workers, either living and working in smoking locations or living and working in nonsmoking locations. One hundred and twenty four randomly selected nonsmoking subjects collected air samples close to their

K. Phillips; M. C. Bentley

2001-01-01

336

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...

337

Air Pollution Particles Produce Airway Wall Remodeling in Rat Tracheal Explants  

Microsoft Academic Search

There is evidence that chronic exposure to high levels of ambi- ent particulate pollutants (PM) is associated with chronic air- flow obstruction, but how this occurs is not known. We exposed rat tracheal explants to Ottawa urban air particles (ECH93) or die- sel exhaust particles. Afte r7di n airorgan culture, both types of PM increased explant procollagen and transforming growth

Jin Dai; Changshi Xie; Renaud Vincent; Andrew Churg

2003-01-01

338

Modeling Acute Health Effects of Astronauts from Exposure to Large Solar Particle Events  

NASA Technical Reports Server (NTRS)

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.

Hu, Shaowen; Kim, Myung-Hee Y.; Cucinotta, Francis A.

2011-01-01

339

Impact of smoking on in-vehicle fine particle exposure during driving  

NASA Astrophysics Data System (ADS)

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.

Sohn, Hongji; Lee, Kiyoung

2010-09-01

340

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...

341

In situ studies on volatile jet exhaust particle emissions: Impact of fuel sulfur content and environmental conditions on nuclei mode aerosols  

NASA Astrophysics Data System (ADS)

In situ measurements of ultrafine aerosol particle emissions were performed at cruise altitudes behind the Deutsches Zentrum für Luft-und Raumfahrt ATTAS research jet (Rolls-Royce/Snecma M45H M501 engines) and a B737-300 aircraft (CFM International 56-3B1 engines). Measurements were made 0.15-20 s after emission as the source aircraft burned fuel with sulfur contents (FSC) of 2.6, 56, or 118mg kg-1. Particle size distributions of from 3- to 60-nm diameter were determined by using condensationnuclei-counters with varying lower size detection limits. Volatile particle concentrations in the aircraft plumes strongly increased as diameter decreased toward the sizes of large molecular clusters, illustrating that apparent particle emissions are extremely sensitive to the smallest particle size detectable by the instrument used. Environmental conditions and plume age alone could influence the number of detected ultrafine (volatile) aerosols within an order of magnitude, as well. The observed volatile particle emissions decreased nonlinearly as FSC decreased to 60mg kg-1, reaching minimum values of about 2×1017kg-1 and 2×1016kg-1 for particles >3nm and >5nm, respectively. Volatile particle emissions did not change significantly as FSCs were further reduced below 60mg kg-1. Volatile particle emissions did not differ significantly between the two studied engine types. In contrast, soot particle emissions from the modern CFM56-3B1 engines were 4-5 times less (4×1014kg-1) than from the older RR M45H M501 engines (1.8×1015kg-1). Contrail processing has been identified as an efficient sink/quenching parameter for ultrafine particles and reduces the remaining interstitial aerosol by factors of 2-10 depending on particle size. These and previously published data are consistent with volatile particle emissions of 2.4×1017kg-1 independent of environmental conditions, engine type and FSCs ranging between 2.6 and 2700mg kg-1. There are clear experimental indications that nonsulfate compounds (probably nonmethane hydrocarbons) begin to dominate the volatile particle composition as FSC decreases below ˜l00mg kg-1.

Schröder, F.; Brock, C. A.; Baumann, R.; Petzold, A.; Busen, R.; Schulte, P.; Fiebig, M.

2000-08-01

342

Mechanisms and Implications of Air Pollution Particle Associations with Chemokines  

PubMed Central

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

Seagrave, JeanClare

2008-01-01

343

Assessment of environmental tobacco smoke and respirable suspended particle exposures for nonsmokers in Basel by personal monitoring  

NASA Astrophysics Data System (ADS)

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%.

Phillips, K.; Howard, D. A.; Bentley, M. C.; Alván, G.

344

Time course of lung retention and toxicity of inhaled particles: short-term exposure to nano-Ceria.  

PubMed

Two Ceria nanomaterials (NM-211 and NM-212) were tested for inhalation toxicity and organ burdens in order to design a chronic and carcinogenicity inhalation study (OECD TG No. 453). Rats inhaled aerosol concentrations of 0.5, 5, and 25 mg/m(3) by whole-body exposure for 6 h/day on 5 consecutive days for 1 or 4 weeks with a post-exposure period of 24 or 129 days, respectively. Lungs were examined by bronchoalveolar lavage and histopathology. Inhaled Ceria is deposited in the lung and cleared with a half-time of 40 days; at aerosol concentrations higher than 0.5 mg/m(3), this clearance was impaired resulting in a half-time above 200 days (25 mg/m(3)). After 5 days, Ceria (>0.5 mg/m(3)) induced an early inflammatory reaction by increases of neutrophils in the lung which decreased with time, with sustained exposure, and also after the exposure was terminated (during the post-exposure period). The neutrophil number observed in bronchoalveolar lavage fluid (BALF) was decreasing and supplemented by mononuclear cells, especially macrophages which were visible in histopathology but not in BALF. Further progression to granulomatous inflammation was observed 4 weeks post-exposure. The surface area of the particles provided a dose metrics with the best correlation of the two Ceria's inflammatory responses; hence, the inflammation appears to be directed by the particle surface rather than mass or volume in the lung. Observing the time course of lung burden and inflammation, it appears that the dose rate of particle deposition drove an initial inflammatory reaction by neutrophils. The later phase (after 4 weeks) was dominated by mononuclear cells, especially macrophages. The progression toward the subsequent granulomatous reaction was driven by the duration and amount of the particles in the lung. The further progression of the biological response will be determined in the ongoing long-term study. PMID:25273020

Keller, Jana; Wohlleben, Wendel; Ma-Hock, Lan; Strauss, Volker; Gröters, Sibylle; Küttler, Karin; Wiench, Karin; Herden, Christiane; Oberdörster, Günter; van Ravenzwaay, Bennard; Landsiedel, Robert

2014-11-01

345

Effects of exposure to 56Fe particles on the acquisition of a conditioned place preference in rats  

NASA Technical Reports Server (NTRS)

Exposure to low doses of 56Fe particles produces changes in neural function and behavior. The present experiments were designed to examine the effects of irradiation on the acquisition of a dopamine-mediated conditioned place preference (CPP). In the CPP procedure, rats are given an injection of the dopamine agonist amphetamine in one distinctive compartment and a saline injection in a different compartment of a three-compartment apparatus. Control rats develop a preference for the amphetamine-paired compartment. In contrast, rats exposed to 1 Gy of 56Fe particles fail to develop a similar preference. The results of the experiment indicate that exposure to low doses of heavy particles can disrupt the neural mechanisms that mediate the reinforcement of behavior.

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

2001-01-01

346

Occupational exposure to ultrafine particles and polycyclic aromatic hydrocarbons from candle emissions.  

E-print Network

??Ultrafine particles (UFPs) are present in the ambient atmosphere and are generated from atmospheric gases, pollution sources, and combustion. Candles emit carbonaceous soot particles similar… (more)

Silver, David J

2005-01-01

347

Exhaust gas recirculation system  

Microsoft Academic Search

An auxiliary flow control valve is disposed in an exhaust gas recirculation passageway at a location upstream of a main flow control valve controlling the flow rate of exhaust gases recirculated into an intake system. Two conduits communicating with an intake manifold communicate with a vacuum chamber of a servo motor controlling the main flow control valve. One of the

Y. Fujikawa; Y. Nakajima; Y. Hayashi; K. Sugihara; Y. Hase

1976-01-01

348

Exhaust gas recirculation system  

Microsoft Academic Search

Apparatus for controlling exhaust gas recirculation in an internal combustion engine employs a first control valve in an exhaust gas recirculation passageway, a second control valve in an air conduit connecting the intake passage to atmosphere through selective restriction means, and a regulating valve responsive to differential vacuum intensities for actuating the control valves. The restriction means comprise a plurality

Y. Itoh; A. Totsune; H. Yamabe

1982-01-01

349

Exhaust gas recirculation system  

Microsoft Academic Search

An exhaust gas recirculation system comprises a valve assembly for controlling the recirculation of exhaust gases in such a manner as to maintain a difference between a first and second pressure at a predetermined value. The first pressure is a pressure in a zone in an air induction passage between a throttle valve therein and a flow restrictor disposed therein

Aoyama

1980-01-01

350

Exhaust gas recirculation system  

Microsoft Academic Search

An exhaust gas recirculation system for an internal combustion engine is disclosed in which an exhaust gas control valve and a pressure regulating valve is constructed as one body to facilitate the mounting of the system on the engine and to improve the response characteristic of the system. Also, the chamber of the pressure regulating valve opposite to the chamber

S. Hayashi; N. Shibata; Y. Takahara; S. Yamada

1981-01-01

351

EXHAUST GAS RECIRCULATION  

E-print Network

EXHAUST GAS RECIRCULATION (EGR) COOLER TESTING Southwest Research Institute® #12;overnment) and oxides of nitrogen (NOx). The use of exhaust gas recirculation (EGR) coolers is considered research, offers complete facilities for testing diesel engines and their emissions control systems

Chapman, Clark R.

352

Exhaust gas recirculating system  

Microsoft Academic Search

This patent describes an exhaust gas recirculating system for an internal combustion engine having an intake passage, a main throttle valve located in the intake passage, and an exhaust passage. The engine is installed in an automotive vehicle provided with a traction control system including means for sensing slippage of a drive wheel of the vehicle during acceleration, a second

H. Takahashi; T. Naganawa

1988-01-01

353

Exhaust gas recirculation system  

Microsoft Academic Search

An exhaust gas recirculation system for cleaning exhaust gas from an internal combustion engine is provided in which a variable constriction is provided between an intake pipe and a pressure control valve in operative connection to a throttle valve in the carburetor and the pressure differential across said variable constriction is maintained constant to keep off any influence of the

M. Minoura; K. Yorioka

1980-01-01

354

Diesel engine exhaust oxidizer  

SciTech Connect

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.

Kammel, R.A.

1992-06-16

355

Exhaust gas recirculating system  

Microsoft Academic Search

An internal combustion engine equipped with an exhaust gas recirculating system is described. The exhaust gas recirculating system comprises an EGR valve normally closing an EGR duct to prevent recirculation and movable by a signal vacuum applied thereto to an open position and control means operable to provide a signal vacuum. The control means includes a vacuum line connecting a

Harada

1978-01-01

356

Duplex tab exhaust nozzle  

NASA Technical Reports Server (NTRS)

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.

Gutmark, Ephraim Jeff (Inventor); Martens, Steven (nmn) (Inventor)

2012-01-01

357

Bacterial spore survival after exposure to HZE particle bombardment -implication for the lithopanspermia hypothesis.  

NASA Astrophysics Data System (ADS)

Based on their unique resistance to various space parameters, bacterial spores (mainly spores of Bacillus subtilis) are one of the model systems used for astrobiological studies. More re-cently, spores of B. subtilis have been applied for experimental research on the likelihood of interplanetary transfer of life. Since its first postulation by Arrhenius in 1903, the pansper-mia hypothesis has been revisited many-times, e.g. after the discovery of several lunar and Martian meteorites on Earth [1,2]. These information provided intriguing evidence that rocks may naturally be transferred between the terrestrial planets. The scenario of panspermia, now termed "lithopanspermia" involves three basic hypothetical steps: (i) the escape process, i.e. removal to space of biological material, which has survived being lifted from the surface to high altitudes; (ii) interim state in space, i.e., survival of the biological material over time scales comparable with interplanetary or interstellar passage; (iii) the entry process, i.e. nondestruc-tive deposition of the biological material on another planet [2]. In our research, spores of B. subtilis were used to study the effects of galactic cosmic radiation on spore survival and induced mutations. On an interplanetary journey, outside a protective magnetic field, spore-containing rocks would be exposed to bombardment by high-energy charged particle radiation from galac-tic sources and from the sun. Air-dried spore layers on three different host materials (i.e., non-porous igneous rocks (gabbro), quartz, and spacecraft analog material (aluminum)) were irradiated with accelerated heavy ions (Helium and Iron) with a LET (linear energy transfer) ˆ of 2 and 200 keV/Am, at the Heavy Ion Medical Accelerator (HIMAC) at the National In-stitute of Radiological Sciences, (NIRS), Chiba, Japan in the frame of the HIMAC research project 20B463 "Characterization of heavy ion-induced damage in Bacillus subtilis spores and their global transcriptional response during spore germination" (Moeller et al., 2008 [3]). To simulate the interplanetary journey of a meteorite, stacks of spore-samples on gabbro slides in different depths were exposed. Spore survival and the rate of the induced mutations (i.e., sporulation-deficiency (Spo-)) depended on the LET of the applied species of ions as well as on the location (and depth) of the irradiated spores in the artificial meteorite. The exposure to high LET iron ions led to a low level of spore survival and increased frequency of mutation to Spo-compared to low-energy charged particles compared to the low LET helium ions. In order to obtain insights on the role of DNA repair by nonhomologous end joining (NHEJ), homologous recombination (HR) and apurinic/apyrimidinic (AP) endonucleases in B. subtilis spore resistance to high-energy charged particles has been studied in parallel. Spores deficient in NHEJ and AP endonucleases were significantly more sensitive to HZE particle bombardment than were the HR-mutant and wild-type spores, indicating that NHEJ and AP endonucleases provide DNA break repair pathways during spore germination. ((References: [1] Arrhenius, S. 1903. Die Verbreitung des Lebens im Weltenraum. Umschau 7:481-485.; [2] Nicholson, W. L. 2009. Ancient micronauts: interplanetary transport of microbes by cosmic impacts. Trends Mi-crobiol. 17:243-250.; [3] Moeller, R., P. Setlow, G. Horneck, T. Berger, G. Reitz, P. Rettberg, A. J. Doherty, R. Okayasu, and W. L. Nicholson. 2008. Roles of the major, small, acid-soluble spore proteins and spore-specific and universal DNA repair mechanisms in resistance of Bacillus subtilis spores to ionizing radiation from X-rays and high-energy charged-particle bombardment. J. Bacteriol. 190:1134-1140.))

Moeller, Ralf; Berger, Thomas; Matthiä, Daniel; Okayasu, Ryuichi; Kitamura, H.; Reitz, Guenther

358

Electric exhaust gas recirculation valve  

Microsoft Academic Search

An electrically actuated EGR valve is described for controlling EGR gases in response to electric signals from a computer, the EGR valve comprising: a valve housing having an exhaust gas inlet port for passage of exhaust gases; an exhaust gas outlet port; an exhaust gas passage extending between; poppet valve means for selectively opening and closing exhaust gas passage, the

Akagi

1987-01-01

359

Carcinogenicity studies of diesel engine exhausts in laboratory animals: a review of past studies and a discussion of future research needs.  

PubMed

Diesel engines play a vital role in world economy, especially in transportation. Exhaust from traditional diesel engines using high-sulfur fuel contains high concentrations of respirable carbonaceous particles with absorbed organic compounds. Recognition that some of these compounds are mutagenic has raised concern for the cancer-causing potential of diesel exhaust exposure. Extensive research addressing this issue has been conducted during the last three decades. This critical review is offered to facilitate an updated assessment of the carcinogenicity of diesel exhaust and to provide a rationale for future animal research of new diesel technology. Life-span bioassays in rats, mice, and Syrian hamsters demonstrated that chronic inhalation of high concentrations of diesel exhaust caused lung tumors in rats but not in mice or Syrian hamsters. In 1989, the International Agency for Research on Cancer (IARC) characterized the rat findings as "sufficient evidence of animal carcinogenicity," and, with "limited" evidence from epidemiological studies, classified diesel exhaust Category 2A, a "probable human carcinogen." Subsequent research has shown that similar chronic high concentration exposure to particulate matter generally considered innocuous (such as carbon black and titanium dioxide) also caused lung tumors in rats. Thus, in 2002, the U.S. Environmental Protection Agency (EPA) concluded that the findings in the rats should not be used to characterize the cancer hazard or quantify the cancer risk of diesel exhaust. Concurrent with the conduct of the health effects studies, progressively more stringent standards have been promulgated for diesel exhaust particles and NOx. Engine manufacturers have responded with new technology diesel (improved engines, fuel injection, fuels, lubricants, and exhaust treatments) to meet the standards. This review concludes with an outline of research to evaluate the health effects of the new technology, research that is consistent with recommendations included in the U.S. EPA 2002 health assessment document. When this research has been completed, it will be appropriate for IARC to evaluate the potential cancer hazard of the new technology diesel. PMID:16097136

Hesterberg, Thomas W; Bunn, William B; McClellan, Roger O; Hart, Georgia A; Lapin, Charles A

2005-06-01

360

Space shuttle exhaust cloud properties  

NASA Technical Reports Server (NTRS)

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.

Anderson, B. J.; Keller, V. W.

1983-01-01

361

Exhaust-gas recirculation system  

Microsoft Academic Search

An exhaust-gas recirculation (EGR) system for an internal-combustion engine comprises an EGR valve for controlling the amount of exhaust-gas recirculation installed midway in an EGR passage that establishes communication between the intake and exhaust pipes of the engine, and an exhaust-gas transducer valve for opening and closing by the exhaust pressure of the exhaust gas an atmospheric-releasing orifice formed midway

K. Yamada; C. Niida; T. Takayama

1979-01-01

362

Effects of exposure to 56Fe particles or protons on fixed-ratio operant responding in rats  

NASA Technical Reports Server (NTRS)

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.

Rabin, Bernard M.; Buhler, Lynn L.; Joseph, James A.; Shukitt-Hale, Barbara; Jenkins, Daniel G.

2002-01-01

363

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 ...

364

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...

365

Electrophilic Components of Diesel Exhaust Particles (DEP) Activate Transient Receptor Potential Ankyrin-1 (TRPA1): A Probable Mechanism of Acute Pulmonary Toxicity for DEP  

PubMed Central

Inhalation of environmental particulate matter (PM) is correlated with adverse health effects in humans, but gene products that couple detection with cellular responses, and the specific properties of PM that target different pathways, have not been fully elucidated. TRPA1 and V1 are two cation channels expressed by sensory neurons and non-neuronal cells of the respiratory tract that have been implicated as possible mediators of PM toxicity. The goals of this research were to determine if environmental PM preferentially activated TRPA1 and to elucidate the criteria responsible for selectivity. Quantification of TRPA1 activation by 4 model PM revealed that diesel exhaust PM (DEP) and coal fly ash PM (CFA1) were TRPA1 agonists at concentrations >0.077 mg/ml. DEP was more potent and approximately 97% of the activity of DEP was recovered by serial extraction of the solid DEP with ethanol and hexane:n-butyl chloride. Modification of the electrophile/agonist binding sites on TRPA1 (C621, C641, C665 and K710) to non-nucleophilic residues reduced TRPA1 activation by DEP and abolished activation by DEP extracts as well as multiple individual electrophilic chemical components of DEP. However, responses to CFA1 and DEP solids were not affected by these mutations. Activity-guided fractionation of DEP and high resolution mass spectroscopy identified several new DEP-derived TRPA1 agonists and activation of mouse dorsal root ganglion neurons demonstrated TRPA1 is a primary target for DEP in a heterogeneous population of primary sensory nerves. It is concluded that TRPA1 is a specific target for electrophilic chemical components of DEP and proposed that activation of TRPA1 in the respiratory tract is likely to be an important mechanism for DEP pneumotoxicity. PMID:21591660

Deering-Rice, Cassandra E.; Romero, Erin G.; Shapiro, Darien; Hughen, Ronald W.; Light, Alan R.; Yost, Garold S.; Veranth, John M.; Reilly, Christopher A.

2011-01-01

366

Exposure of wildland firefighters to carbon monoxide, fine particles, and levoglucosan.  

PubMed

Wildland firefighters are occupationally exposed to elevated levels of woodsmoke. Eighteen wildland firefighters were monitored for their personal exposure to particulate matter with median aerodynamic diameter of 2.5 microns (PM2.5), levoglucosan (LG), and carbon monoxide (CO) at 30 prescribed burns at the Savannah River Site, South Carolina. Linear mixed effect models were used to investigate the effect on exposure of various factors and to examine whether the firefighters were able to qualitatively estimate their own exposures. Exposure to PM2.5 and CO was higher when firefighters performed 'holding' tasks compared with 'lighting' duties, whereas exposures to CO and LG were higher when burns were in compartments with predominantly pine vegetation (P < 0.05). Exposures to PM2.5 (64-2068 µg m(-3)) and CO (0.02-8.2 p.p.m.) fell within the ranges observed in previous studies. Some recommended shorter term exposure limits for CO were exceeded in a few instances. The very low LG:PM2.5 ratios in some samples suggest that the exposures of wildland firefighters to pollutants at prescribed burns may be substantially impacted by non-woodsmoke sources. The association of the qualitative exposure estimation of the firefighters with actual PM2.5 and CO measurements (P < 0.01) indicates that qualitative estimation may be used to assess exposure in epidemiology studies. PMID:23813888

Adetona, Olorunfemi; Simpson, Christopher D; Onstad, Gretchen; Naeher, Luke P

2013-10-01

367

Simulation of the radiation exposure in space during a large solar energetic particle event with GEANT4  

NASA Astrophysics Data System (ADS)

The radiation field in space is complex due to the various contributing sources and astronauts at the International Space Station (ISS) in low Earth orbit or beyond are exposed to significantly increased doses compared to on ground or in the lower atmosphere. The main sources of the increased radiation level are Galactic Cosmic Ray (GCR) particles, mainly fully charged ions from hydrogen to iron with energies up to hundreds of GeV per nucleon and more, trapped protons from the radiation belts with energies up to several hundreds of MeV, and solar energetic particles up to several GeV released in large eruptions on the sun related to solar x-ray flares and coronal mass ejections. While the intensities of Galactic Cosmic Rays and trapped protons are relatively stable and changing slowly over the solar cycle, solar energetic particle events last for several hours up to days and are characterized by strong increases in the particle intensity. The radiation exposure during a large particle event can be very harmful to astronauts especially during extra vehicular activities and outside the protective magnetic field of the Earth. The MATROSHKA human phantom was and is used on the International Space Station to measure the radiation exposure in and outside ISS in order to evaluate the radiation risk in low Earth orbit. A voxel-based description of the MATROSHKA phantom (NUNDO-Numerical RANDO Model) was used in the present work to numerically estimate the radiation exposure of the human body and the individual organs during a large solar particle event. The transport of primary protons following an exponential energy distribution was simulated in order to calculate the energy deposition and organ doses in the MATROSHKA phantom during such an event taking into account different amounts of shielding provided by a surrounding aluminum shell. The primary particle energy distribution used in this work follows the description of the spectrum of the solar energetic particle event in August 1972 in the energy range from 45 MeV to 1 GeV. The transport calculations of the energetic particles through the shielding and the phantom model were performed using the Monte-Carlo code GEANT4.

Matthiä, Daniel; Berger, Thomas; Puchalska, Monika; Reitz, Guenther

368

Effects of long-term exposure to ammonium sulfate particles on growth and gas exchange rates of Fagus crenata, Castanopsis sieboldii, Larix kaempferi and Cryptomeria japonica seedlings  

NASA Astrophysics Data System (ADS)

To clarify the effects of long-term exposure to ammonium sulfate (AS) particles on growth and physiological functions of forest tree species, seedlings of Fagus crenata, Castanopsis sieboldii, Larix kaempferi and Cryptomeria japonica were exposed to submicron-size AS particles during two growing seasons from 3 June 2011 to 8 October 2012. The mean sulfate concentration in PM2.5 increased during the exposure inside the chamber in 2011 and 2012 by 2.73 and 4.32 ?g SO42- m-3, respectively. No significant effects of exposure to AS particles were detected on the whole-plant dry mass of the seedlings. These results indicate that the exposure to submicrometer AS particles at the ambient level for two growing seasons did not significantly affect the growth of the seedlings. No significant effects of exposure to AS particles were found on the net photosynthetic rate in the leaves or needles of F. crenata, C. sieboldii and L. kaempferi seedlings. Also, in the previous-year needles of C. japonica seedlings, exposure to AS particles significantly reduced the net photosynthetic rate, which may be caused by the reduction in the concentration of ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco). On the contrary, in current-year needles of C. japonica seedlings, net photosynthetic rate significantly increased with exposure to AS particles, which may be the result of increases in stomatal conductance and concentrations of Rubisco and chlorophyll. Furthermore, exposure to AS particles correlated with an increase in concentrations of NH4+, free amino acid and total soluble protein, suggesting that AS particles may be deliquesced, absorbed into the leaves and metabolized into amino acid and protein. These results suggest that net photosynthesis in the needles of C. japonica is relatively sensitive to submicron-size AS particles as compared with the other three tree species.

Yamaguchi, Masahiro; Otani, Yoko; Li, Peiran; Nagao, Hiroshi; Lenggoro, I. Wuled; Ishida, Atsushi; Yazaki, Kenichi; Noguchi, Kyotaro; Nakaba, Satoshi; Yamane, Kenichi; Kuroda, Katsushi; Sano, Yuzou; Funada, Ryo; Izuta, Takeshi

2014-11-01

369

Environmental Tobacco Smoke and Respirable Suspended Particle Exposures for Non-Smokers in Beijing  

Microsoft Academic Search

The study was centred in Beijing, People's Republic of China, 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. Two hundred and fifty-three randomly selected non-smok ing subjects collected air samples near to their breathing zone by wearing per

Keith Phillips; David A. Howard; Mark C. Bentley; Gunnar Alván

1998-01-01

370

BIOLOGICAL EFFECTS OF CO-EXPOSURE TO FINE PARTICLES AND NITROGEN DIOXIDE IN HEALTHY YOUNG ADULTS  

EPA Science Inventory

Exposure to particulate matter (PM) is associated with adverse health effects. It is unclear if co-exposure to NO2, a common pollutant gas, potentiates the PM effects. Healthy young volunteers were recruited and exposed to either filtered air (FA), NO2 (0.5 ppm), concentrated Cha...

371

Synergistic effects of exposure to concentrated ambient fine pollution particles and nitrogen dioxide in humans  

EPA Science Inventory

Exposure to single pollutants such as ambient particulate matter (PM) is associated with adverse health effects. It is unclear, however, if simultaneous exposure to multiple air pollutants (e.g. PM and ozone or nitrogen dioxide), a more real world scenario, results in non-additiv...

372

BIOMAKERS OF EXPOSURE AND METABOLIC SUSCEPTIBILITY TO FINE PARTICLE AIR POLLUTION  

EPA Science Inventory

The influence of metabolic susceptibility (GSTM1 and NAT2 genotypes) on the association between personal air exposures and biomarkers of exposure, dose, and genetic damage were measured for 60 individuals in two regions exposed to ambient air in the Czech Republic. Personal mon...

373

Geomagnetic influence on aircraft radiation exposure during a solar energetic particle event in October 2003  

Microsoft Academic Search

We present initial results from the Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) model during the Halloween 2003 superstorm. The objective of NAIRAS is to produce global, real-time, data-driven predictions of ionizing radiation for archiving and assessing the biologically harmful radiation exposure levels at commercial airline altitudes. We have conducted a case study of radiation exposure during a

Christopher J. Mertens; Brian T. Kress; Michael Wiltberger; Steve R. Blattnig; Tony S. Slaba; Stanley C. Solomon; M. Engel

2010-01-01

374

The effects of delta rays on the number of particle-track traversals per cell in laboratory and space exposures  

NASA Technical Reports Server (NTRS)

It is a common practice to estimate the number of particle-track traversals per cell or cell nucleus as the product of the ion's linear energy transfer (LET) and cell area. This practice ignores the effects of track width due to the lateral extension of delta rays. We make estimates of the number of particle-track traversals per cell, which includes the effects of delta rays using radial cutoffs in the ionization density about an ion's track of 1 mGy and 1 cGy. Calculations for laboratory and space radiation exposures are discussed, and show that the LET approximation provides a large underestimate of the actual number of particle-track traversals per cell from high-charge and energy (HZE) ions. In light of the current interest in the mechanisms of radiation action, including signal transduction and cytoplasmic damage, these results should be of interest for radiobiology studies with HZE ions.

Cucinotta, F. A.; Nikjoo, H.; Goodhead, D. T.; Wilson, J. W. (Principal Investigator)

1998-01-01

375

Particle-size dependence on metal(loid) distributions in mine wastes: Implications for water contamination and human exposure  

USGS Publications Warehouse

The mining and processing of metal-bearing ores has resulted in contamination issues where waste materials from abandoned mines remain in piles of untreated and unconsolidated material, posing the potential for waterborne and airborne transport of toxic elements. This study presents a systematic method of particle size separation, mass distribution, and bulk chemical analysis for mine tailings and adjacent background soil samples from the Rand historic mining district, California, in order to assess particle size distribution and related trends in metal(loid) concentration as a function of particle size. Mine tailings produced through stamp milling and leaching processes were found to have both a narrower and finer particle size distribution than background samples, with significant fractions of particles available in a size range (???250 ??m) that could be incidentally ingested. In both tailings and background samples, the majority of trace metal(loid)s display an inverse relationship between concentration and particle size, resulting in higher proportions of As, Cr, Cu, Pb and Zn in finer-sized fractions which are more susceptible to both water- and wind-borne transport as well as ingestion and/or inhalation. Established regulatory screening levels for such elements may, therefore, significantly underestimate potential exposure risk if relying solely on bulk sample concentrations to guide remediation decisions. Correlations in elemental concentration trends (such as between As and Fe) indicate relationships between elements that may be relevant to their chemical speciation. ?? 2011 Elsevier Ltd.

Kim, C.S.; Wilson, K.M.; Rytuba, J.J.

2011-01-01

376

Estimates of Carrington-class solar particle event radiation exposures as a function of altitude in the atmosphere of Mars  

NASA Astrophysics Data System (ADS)

Radiation exposure estimates for crew members on the surface of Mars may vary widely because of the large variations in terrain altitude. The maximum altitude difference between the highest (top of Olympus Mons) and the lowest (bottom of the Hellas impact basin) points on Mars is about 32 km. In this work estimates of radiation exposures as a function of altitude, from the Hellas impact basin to Olympus Mons, are made for a solar particle event proton radiation environment comparable to the Carrington event of 1859. We assume that the proton energy distribution for this Carrington-type event is similar to that of the Band Function fit of the February 1956 event. In this work we use the HZETRN 2010 radiation transport code, originally developed at NASA Langley Research Center, and the Computerized Anatomical Male and Female human geometry models to estimate exposures for aluminum shield areal densities similar to those provided by a spacesuit, surface lander, and permanent habitat as a function of altitude in the Mars atmosphere. Comparisons of the predicted organ exposures with current NASA Permissible Exposure Limits (PELs) are made.

Townsend, L. W.; Anderson, J. A.; Adamczyk, A. M.; Werneth, C. M.

2013-08-01

377

Acute and fractionated exposure to high-LET (56)Fe HZE-particle radiation both result in similar long-term deficits in adult hippocampal neurogenesis.  

PubMed

Astronauts on multi-year interplanetary missions will be exposed to a low, chronic dose of high-energy, high-charge particles. Studies in rodents show acute, nonfractionated exposure to these particles causes brain changes such as fewer adult-generated hippocampal neurons and stem cells that may be detrimental to cognition and mood regulation and thus compromise mission success. However, the influence of a low, chronic dose of these particles on neurogenesis and stem cells is unknown. To examine the influence of galactic cosmic radiation on neurogenesis, adult-generated stem and progenitor cells in Nestin-CreER(T2)/R26R-YFP transgenic mice were inducibly labeled to allow fate tracking. Mice were then sham exposed or given one acute 100 cGy (56)Fe-particle exposure or five fractionated 20 cGy (56)Fe-particle exposures. Adult-generated hippocampal neurons and stem cells were quantified 24 h or 3 months later. Both acute and fractionated exposure decreased the amount of proliferating cells and immature neurons relative to sham exposure. Unexpectedly, neither acute nor fractionated exposure decreased the number of adult neural stem cells relative to sham expsoure. Our findings show that single and fractionated exposures of (56)Fe-particle irradiation are similarly detrimental to adult-generated neurons. Implications for future missions and ground-based studies in space radiation are discussed. PMID:24320054

Rivera, Phillip D; Shih, Hung-Ying; Leblanc, Junie A; Cole, Mara G; Amaral, Wellington Z; Mukherjee, Shibani; Zhang, Shichuan; Lucero, Melanie J; Decarolis, Nathan A; Chen, Benjamin P C; Eisch, Amelia J

2013-12-01

378

Exposure to 16O-particle radiation causes aging-like decrements in rats through increased oxidative stress, inflammation and loss of autophagy.  

PubMed

Exposing young rats to particles of high energy and charge (HZE particles), a ground-based model for exposure to cosmic rays, enhances indices of oxidative stress and inflammation, disrupts the functioning of neuronal communication, and alters cognitive behaviors. Even though exposure to HZE particles occurs at low fluence rates, the cumulative effects of long-term exposure result in molecular changes similar to those seen in aged animals. In the present study, we assessed markers of autophagy, a dynamic process for intracellular degradation and recycling of toxic proteins and organelles, as well as stress and inflammatory responses, in the brains of Sprague-Dawley rats irradiated at 2 months of age with 5 and 50 cGy and 1 Gy of ionizing oxygen particles ((16)O) (1000 MeV/n). Compared to nonirradiated controls, exposure to (16)O particles significantly inhibited autophagy function in the hippocampus as measured by accumulation of ubiquitin inclusion bodies such as P62/SQSTM1, autophagosome marker microtubule-associated protein 1 beta light chain 3 (MAP1B-LC3), beclin1 and proteins such as mammalian target of rapamycin (mTOR). The molecular changes measured at short (36 h) and long (75 days) intervals after (16)O-particle exposure indicate that the loss of autophagy function occurred shortly after exposure but was recovered via inhibition of mTOR. However, HZE-particle radiation caused significant sustained loss of protein kinase C alpha (PKC-?), a key G protein modulator involved in neuronal survival and functions of neuronal trophic factors. Exposure to (16)O particles also caused substantial increases in the levels of nuclear factor kappa B (NF-?B) and glial fibrillary acidic protein (GFAP), indicating glial cell activation 75 days after exposure. This is the first report to show the molecular effects of (16)O-particle radiation on oxidative stress, inflammation and loss of autophagy in the brain of young rats. PMID:21962006

Poulose, Shibu M; Bielinski, Donna F; Carrihill-Knoll, Kirsty; Rabin, Bernard M; Shukitt-Hale, Barbara

2011-12-01

379

Exhaust gas recirculator  

SciTech Connect

An exhaust gas recirculator for an internal combustion engine having an exhaust pipe, an intake manifold and a carburetor throttle valve. The exhaust gas recirculator comprises an egr passage which makes the exhaust pipe communicate with the intake manifold, an egr controlling valve and an egr valve respectively arranged in the upper and lower portions of the egr passage. The egr valve operates in association with the carburetor throttle valve for metering the flow of egr gas. The egr controlling valve is separated by a diaphragm into an egr gas chamber communicating with the egr passage between the egr controlling valve and the egr valve and a negative pressure chamber communicating with the intake manifold. The negative pressure chamber contains a compression spring, and the diaphragm is connected with a valve member through a rod upon which is disposed a stopper to serve as a different seal in place of the valve member to close off the exhaust gas passage, which valve member and stopper are constructed to be opened and closed by pressure difference between the egr gas chamber and the negative pressure chamber and by elastic force of the compression spring. The egr controlling valve functions to control the pressure difference around the egr valve to be constant.

Suda, K.

1983-01-04

380

CONCENTRATED COARSE AIR PARTICLE EXPOSURE PRODUCES MILD TOXICOLOGICAL EFFECTS IN HEALTHY VOLUNTEERS  

EPA Science Inventory

Epidemiological studies have shown that the adverse health effects of ambient particulate matter (PM) exposure to be in general more strongly associated with "fine" PM (2.5 µM) from wind-blown dust, mechanical ...

381

EVALUATION OF ULTRAFINE PARTICLES AS PART OF A HEALTH EFFECTS EXPOSURE STUDY  

EPA Science Inventory

Ambient particulate matter (PM) is a complex mixture that includes bioactive and toxic compounds of natural and anthropogenic origin. Numerous epidemiological studies have reported associations between exposure to ambient levels of PM and various indices of cardiopulmonary morbi...

382

Environmental Tobacco Smoke and Respirable Suspended Particle Exposures for Non-Smokers in Beijing  

Microsoft Academic Search

The study was centred in Beijing, People’s Republic of China, 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. Two hundred and fifty-three randomly selected non-smoking subjects collected air samples near to their breathing zone by wearing personal monitors

Keith Phillips; David A. Howard; Mark C. Bentley; Gunnar Alván

1998-01-01

383

Activation of respiratory epithelial cells by wood smoke particles persists beyond immediate exposure.  

EPA Science Inventory

The biological effect of particles on epithelial cells involves, in part, oxidant generation and a cascade of reactions culminating in inflammatory mediator release. Whether there is an immediate short-lived activation or continued persistent response of the cells to the particle...

384

CORRELATIONS OF PERSONAL EXPOSURE TO PARTICLES WITH OUTDOOR AIR MEASUREMENT: A REVIEW OF RECENT STUDIES  

EPA Science Inventory

Epidemiological studies have found a correlation between daily mortality and particle concentrations in outdoor air as measured at a central monitoring station. These studies have been the central reason for the U.S. EPA to propose new tighter particle standards. However, perso...

385

Pulmonary and systemic effects of short-term inhalation exposure to ultrafine carbon black particles  

Microsoft Academic Search

While environmental particles are associated with mortality and morbidity related to pulmonary and cardiovascular (CV) disease, the mechanisms involved in CV health effects are not known. Changes in systemic clotting factors have been associated with pulmonary inflammation. We hypothesized that inhaled ultrafine particles result in an inflammatory response which may stimulate systemic clotting factor release. Adult male Wistar rats were

Peter S Gilmour; Axel Ziesenis; E. Rona Morrison; Mark A Vickers; Ellen M Drost; Isobel Ford; Erwin Karg; Claudia Mossa; Andreas Schroeppel; George A Ferron; Joachim Heyder; Michael Greaves; William MacNee; Kenneth Donaldson

2004-01-01

386

Proinflammatory effects of diesel exhaust nanoparticles on scleroderma skin cells.  

PubMed

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

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

2014-01-01

387

Proinflammatory Effects of Diesel Exhaust Nanoparticles on Scleroderma Skin Cells  

PubMed Central

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

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

2014-01-01

388

Indoor ultrafine particle exposures and home heating systems: a cross-sectional survey of Canadian homes during the winter months.  

PubMed

Exposure to airborne particulate matter has a negative effect on respiratory health in both children and adults. Ultrafine particle (UFP) exposures are of particular concern owing to their enhanced ability to cause oxidative stress and inflammation in the lungs. In this investigation, our objective was to examine the contribution of home heating systems (electric baseboard heaters, wood stoves, forced-air oil/natural gas furnace) to indoor UFP exposures. We conducted a cross-sectional survey in 36 homes in the cities of Montréal, Québec, and Pembroke, Ontario. Real-time measures of indoor UFP concentrations were collected in each home for approximately 14 h, and an outdoor UFP measurement was collected outside each home before indoor sampling. A home-characteristic questionnaire was also administered, and air exchange rates were estimated using carbon dioxide as a tracer gas. Average UFP exposures of 21,594 cm(-3) (95% confidence interval (CI): 14,014, 29,174) and 6660 cm(-3) (95% CI: 4339, 8982) were observed for the evening (1600-2400) and overnight (2400-0800) hours, respectively. In an unadjusted comparison, overnight baseline UFP exposures were significantly greater in homes with electric baseboard heaters as compared to homes using forced-air oil or natural gas furnaces, and homes using wood stoves had significantly greater overnight baseline UFP exposures than homes using forced-air natural gas furnaces. However, in multivariate models, electric oven use (beta=12,253 cm(-3), 95% CI: 3524, 20,982), indoor relative humidity (beta=1136 cm(-3) %, 95% CI: 372, 1899), and indoor smoking (beta=18,192 cm(-3), 95% CI: 2073, 34,311) were the only significant determinants of mean indoor UFP exposure, whereas air exchange rate (beta=4351 cm(-3) h(-1), 95% CI: 1507, 7195) and each 10,000 cm(-3) increase in outdoor UFPs (beta=811 cm(-3), 95% CI: 244,1377) were the only significant determinants of overnight baseline UFP exposures. In general, our findings suggest that home heating systems are not important determinants of indoor UFP exposures. PMID:17033678

Weichenthal, Scott; Dufresne, Andre; Infante-Rivard, Claire; Joseph, Lawrence

2007-05-01

389

Exhaust gas recirculation system  

SciTech Connect

An engine exhaust gas recirculation (EGR) system is provided in which a sonic flow EGR valve is moved to open positions to establish a different constant rate of flow at each open position of the EGR valve in response to air pressure acting on a servo means secured to the valve, the air pressure force being controlled by changes in a control vacuum opposing the air pressure force and modified by an air bleed device as a function of changes in engine exhaust gas backpressure levels, to provide an EGR valve movement that varies essentially in proportion to changes in engine air flow.

Rachedi, S.H.

1983-08-30

390

Hyperventilation and exhaustion syndrome.  

PubMed

Chronic stress is among the most common diagnoses in Sweden, most commonly in the form of exhaustion syndrome (ICD-10 classification - F43.8). The majority of patients with this syndrome also have disturbed breathing (hyperventilation). The aim of this study was to investigate the association between hyperventilation and exhaustion syndrome. Thirty patients with exhaustion syndrome and 14 healthy subjects were evaluated with the Nijmegen Symptom Questionnaire (NQ). The participants completed questionnaires about exhaustion, mental state, sleep disturbance, pain and quality of life. The evaluation was repeated 4 weeks later, after half of the patients and healthy subjects had engaged in a therapy method called 'Grounding', a physical exercise inspired by African dance. The patients reported significantly higher levels of hyperventilation as compared to the healthy subjects. All patients' average score on NQ was 26.57 ± 10.98, while that of the healthy subjects was 15.14 ± 7.89 (t = -3.48, df = 42, p < 0.001). The NQ scores correlated strongly with two measures of exhaustion (Karolinska Exhaustion Scale KES r = 0.772, p < 0.01; Shirom Melamed Burnout Measure SMBM r = 0.565, p < 0.01), mental status [Hospital Anxiety and Depression Score (HADS) depression r = 0.414, p < 0.01; HADS anxiety r = 0.627, p < 0.01], sleep disturbances (r = -0.514, p < 0.01), pain (r = -.370, p < 0.05) and poor well-being (Medical Outcomes Survey Short Form 36 questionnaire- SR Health r = -0.529, p < 0.05). In the logistic regression analysis, the variance in the scores from NQ were explained to a high degree (R(2)  = 0.752) by scores in KES and HADS. The brief Grounding training contributed to a near significant reduction in hyperventilation (F = 2.521, p < 0.124) and to significant reductions in exhaustion scores and scores of depression and anxiety. The conclusion is that hyperventilation is common in exhaustion syndrome patients and that it can be reduced by systematic physical therapy such as Grounding. PMID:24134551

Ristiniemi, Heli; Perski, Aleksander; Lyskov, Eugene; Emtner, Margareta

2014-12-01

391

Intranasal exposure to amorphous nanosilica particles could activate intrinsic coagulation cascade and platelets in mice  

PubMed Central

Background Nanomaterials with particle sizes <100 nm have been already applied in various applications such as cosmetics, medicines, and foods. Therefore, ensuring the safety of nanomaterials is becoming increasingly important. Here we examined the localization and biological responses of intranasally administered amorphous nanosilica particles in mice, focusing on the coagulation system. Methods We used nanosilica particles with diameters of 30, 70, or 100 nm (nSP30, nSP70, or nSP100 respectively), and conventional microscale silica particles with diameters of 300 or 1000 nm (mSP300 or mSP1000, respectively). BALB/c mice were intranasally exposed to nSP30, nSP70, nSP100, mSP300, or mSP1000 at concentrations of 500 ?g/mouse for 7 days. After 24 hours of last administration, we performed the in vivo transmission electron microscopy analysis, hematological examination and coagulation tests. Results In vivo transmission electron microscopy analysis showed that nanosilica particles with a diameter <100 nm were absorbed through the nasal cavity and were distributed into liver and brain. Hematological examination and coagulation tests showed that platelet counts decreased and that the activated partial thromboplastin time was prolonged in nSP30 or nSP70-treated groups of mice, indicating that nanosilica particles might have activated a coagulation cascade. In addition, in in vitro activation tests of human plasma, nanosilica particles had greater potential than did conventional microscale silica particles to activate coagulation factor XII. In nanosilica-particle-treated groups, the levels of soluble CD40 ligand, and von Willebrand factor which are involved in stimulating platelets tended to slightly increase with decreasing particle size. Conclusions These results suggest that intranasally administered nanosilica particles with diameters of 30 and 70 nm could induce abnormal activation of the coagulation system through the activation of an intrinsic coagulation cascade. This study provides information to advance the development of safe and effective nanosilica particles. PMID:23958113

2013-01-01

392

Estimates of HZE particle contributions to SPE radiation exposures on interplanetary missions  

NASA Technical Reports Server (NTRS)

Estimates of radiation doses resulting from possible HZE (high energy heavy ion) components of Solar Particle Events (SPEs) are presented for crews of manned interplanetary missions. The calculations assume a model spectrum obtained by folding measured solar flare HZE particle abundances with the measured energy spectra of SPE alpha particles. These hypothetical spectra are then transported through aluminum spacecraft shielding. The results, presented as estimates of absorbed dose and dose equivalent, indicate that HZE components by themselves are not a major concern for crew protection but should be included in any overall risk assessment. The predictions are found to be sensitive to the assumed spectral hardness parameters.

Townsend, L. W.; Cucinotta, F. A.; Wilson, J. W.; Bagga, R.

1994-01-01

393

Respiratory Effects of Fine and Ultrafine Particles from Indoor Sources--A Randomized Sham-Controlled Exposure Study of Healthy Volunteers  

PubMed Central

Particulate air pollution is linked to impaired respiratory health. We analyzed particle emissions from common indoor sources (candles burning (CB), toasting bread (TB), frying sausages (FS)) and lung function in 55 healthy volunteers (mean age 33.0 years) in a randomized cross-over controlled exposure study. Lung-deposited particle surface area concentration (PSC), size-specific particle number concentration (PNC) up to 10 µm, and particle mass concentration (PMC) of PM1, PM2.5 and PM10 were determined during exposure (2 h). FEV1, FVC and MEF25%–75% was measured before, 4 h and 24 h after exposure. Wilcoxon-rank sum tests (comparing exposure scenarios) and mixed linear regression using particle concentrations and adjusting for personal characteristics, travel time and transportation means before exposure sessions were performed. While no effect was seen comparing the exposure scenarios and in the unadjusted model, inverse associations were found for PMC from CB and FS in relation to FEV1 and MEF25%–75%. with a change in 10 µg/m3 in PM2.5 from CB being associated with a change in FEV1 of ?19 mL (95%-confidence interval:?43; 5) after 4 h. PMC from TB and PNC of UFP were not associated with lung function changes, but PSC from CB was. Elevated indoor fine particles from certain sources may be associated with small decreases in lung function in healthy adults. PMID:25000149

Soppa, Vanessa J.; Schins, Roel P. F.; Hennig, Frauke; Hellack, Bryan; Quass, Ulrich; Kaminski, Heinz; Kuhlbusch, Thomas A. J.; Hoffmann, Barbara; Weinmayr, Gudrun

2014-01-01

394

Respiratory effects of fine and ultrafine particles from indoor sources--a randomized sham-controlled exposure study of healthy volunteers.  

PubMed

Particulate air pollution is linked to impaired respiratory health. We analyzed particle emissions from common indoor sources (candles burning (CB), toasting bread (TB), frying sausages (FS)) and lung function in 55 healthy volunteers (mean age 33.0 years) in a randomized cross-over controlled exposure study. Lung-deposited particle surface area concentration (PSC), size-specific particle number concentration (PNC) up to 10 µm, and particle mass concentration (PMC) of PM1, PM2.5 and PM10 were determined during exposure (2 h). FEV1, FVC and MEF25%-75% was measured before, 4 h and 24 h after exposure. Wilcoxon-rank sum tests (comparing exposure scenarios) and mixed linear regression using particle concentrations and adjusting for personal characteristics, travel time and transportation means before exposure sessions were performed. While no effect was seen comparing the exposure scenarios and in the unadjusted model, inverse associations were found for PMC from CB and FS in relation to FEV1 and MEF25%-75%. with a change in 10 µg/m3 in PM2.5 from CB being associated with a change in FEV1 of -19 mL (95%-confidence interval:-43; 5) after 4 h. PMC from TB and PNC of UFP were not associated with lung function changes, but PSC from CB was. Elevated indoor fine particles from certain sources may be associated with small decreases in lung function in healthy adults. PMID:25000149

Soppa, Vanessa J; Schins, Roel P F; Hennig, Frauke; Hellack, Bryan; Quass, Ulrich; Kaminski, Heinz; Kuhlbusch, Thomas A J; Hoffmann, Barbara; Weinmayr, Gudrun

2014-07-01

395

Interactive effects of cerium oxide and diesel exhaust nanoparticles on inducing pulmonary fibrosis.  

PubMed

Cerium compounds have been used as a fuel-borne catalyst to lower the generation of diesel exhaust particles (DEPs), but are emitted as cerium oxide nanoparticles (CeO2) along with DEP in the diesel exhaust. The present study investigates the effects of the combined exposure to DEP and CeO2 on the pulmonary system in a rat model. Specific pathogen-free male Sprague-Dawley rats were exposed to CeO2 and/or DEP via a single intratracheal instillation and were sacrificed at various time points post-exposure. This investigation demonstrated that CeO2 induces a sustained inflammatory response, whereas DEP elicits a switch of the pulmonary immune response from Th1 to Th2. Both CeO2 and DEP activated AM and lymphocyte secretion of the proinflammatory cytokines IL-12 and IFN-?, respectively. However, only DEP enhanced the anti-inflammatory cytokine IL-10 production in response to ex vivo LPS or Concanavalin A challenge that was not affected by the presence of CeO2, suggesting that DEP suppresses host defense capability by inducing the Th2 immunity. The micrographs of lymph nodes show that the particle clumps in DEP+CeO2 were significantly larger than CeO2 or DEP, exhibiting dense clumps continuous throughout the lymph nodes. Morphometric analysis demonstrates that the localization of collagen in the lung tissue after DEP+CeO2 reflects the combination of DEP-exposure plus CeO2-exposure. At 4 weeks post-exposure, the histological features demonstrated that CeO2 induced lung phospholipidosis and fibrosis. DEP induced lung granulomas that were not significantly affected by the presence of CeO2 in the combined exposure. Using CeO2 as diesel fuel catalyst may cause health concerns. PMID:24793434

Ma, Jane Y C; Young, Shih-Houng; Mercer, Robert R; Barger, Mark; Schwegler-Berry, Diane; Ma, Joseph K; Castranova, Vincent

2014-07-15

396

Beijing ambient particle exposure accelerates atherosclerosis in ApoE knockout mice by upregulating visfatin expression.  

PubMed

Ambient particulate matter (PM) exposure has been associated with atherosclerosis. However, research on the effect of real-world exposure to ambient PM in regulating visfatin expression in an animal model is very limited. The objective is to investigate whether Beijing ambient PM exposure could accelerate atherosclerosis in ApoE knockout (ApoE(-/-)) mice by upregulating visfatin expression. Forty male ApoE(-/-) mice were exposed to untreated ambient air (PM group, n = 20) or filtered air (FA group, n = 20), 24 h/day, 7 days/week, for 2 months. During the exposure, the mass concentrations of PM2.5 and PM10 in the two groups were continuously monitored. Moreover, a receptor source apportionment model was applied to apportion sources of PM2.5. At the end of the exposure, visfatin in plasma and aorta, biomarkers of inflammation, oxidative stress and lipid metabolism in blood samples, and bronchoalveolar lavage fluid (BALF) were determined, and the plaque area of the atherosclerosis lesions was quantified. PM-exposed mice were significantly higher than FA-exposed mice in terms of plasma visfatin, OxLDL, MDA, serum TC, LDL, TNF-? as well as IL-6, TNF-?, OxLDL, and MDA in BALF, while SOD and GSH-Px activities in plasma and BALF were reduced in PM-exposed mice. Pathological analysis of the aorta demonstrated that the plaque area and visfatin protein in the PM group increased significantly compared to the FA group. Our findings indicate that ambient PM exposure could accelerate atherosclerosis, which is related to visfatin upregulation, as well as the activation of inflammation and oxidative stress. PMID:24523034

Wan, Qiang; Cui, Xiaobing; Shao, Jiman; Zhou, Fenghua; Jia, Yuhua; Sun, Xuegang; Zhao, Xiaoshan; Chen, Yuyao; Diao, Jianxin; Zhang, Lei

2014-09-01

397

Ultrafine particle size distributions near freeways: Effects of differing wind directions on exposure  

PubMed Central

High ambient ultrafine particle (UFP) concentrations may play an important role in the adverse health effects associated with living near busy roadways. However, UFP size distributions change rapidly as vehicle emissions dilute and age. These size changes can influence UFP lung deposition rates and dose because deposition in the respiratory system is a strong function of particle size. Few studies to date have measured and characterized changes in near-road UFP size distributions in real-time, thus missing transient variations in size distribution due to short-term fluctuations in wind speed, direction, or particle dynamics. In this study we measured important wind direction effects on near-freeway UFP size distributions and gradients using a mobile platform with 5-s time resolution. Compared to more commonly measured perpendicular (downwind) conditions, parallel wind conditions appeared to promote formation of broader and larger size distributions of roughly one-half the particle concentration. Particles during more parallel wind conditions also changed less in size with downwind distance and the fraction of lung-deposited particle number was calculated to be 15% lower than for downwind conditions, giving a combined decrease of about 60%. In addition, a multivariate analysis of several variables found meteorology, particularly wind direction and temperature, to be important in predicting UFP concentrations within 150 m of a freeway (R2 = 0.46, p = 0.014). PMID:24415904

Kozawa, Kathleen H.; Winer, Arthur M.; Fruin, Scott A.

2013-01-01

398

Designing stainless exhaust systems  

SciTech Connect

With the ever-increasing price of automobiles, durability and reduced operating costs have become major concerns in North America, Europe, and Japan. In the US, the exhaust system was once thought of as disposable every 3--4 years, but it is now considered a nonreplaceable item for at least 5--7 years, the average time an initial owner keeps a vehicle. Through the mid-1980s, the only stainless steel on most US car exhausts was the downpipe and catalytic converter, and these were due to government warranty mandates. Today, most US passenger car exhaust systems are almost entirely stainless steel, and with the 1996 model year switch of GM light trucks, the average use of stainless alloys in US vehicles will exceed 23 kg per vehicle. The US experience with stainless has shown that certain design considerations can further increase system life and reduce manufacturing problems. Such considerations may also benefit the European situation, which has seen an increase in the use of stainless alloys in exhaust components since tighter pollution laws began taking effect in 1990.

Douthett, J.A.

1995-11-01

399

Exhaust gas reflux apparatus  

SciTech Connect

An exhaust gas reflux apparatus is described comprising: EGR regulating valve means for controlling a reflux amount of an exhaust gas which is refluxed into an intake system of an internal combustion engine; having at least two operating states; sensing means for sensing the operating state of the engine; first control means responsive to the sensing means for detecting the start of a predetermined one of the operating states of the engine, in which the temperature of the exhaust gas becomes high; timer means responsive to detection by the first control means of the start of the predetermined operating state for measuring a time delay, and time delay beginning immediately after and only in response to the detection of the start of the predetermined operating state and expiring a predetermined time interval thereafter; and second control means responsive to the timer means for controlling the EGR regulating valve means to stop the reflux of the exhaust gas immediately after expiration of the predetermined time interval.

Osada, A.

1988-01-19

400

Exhaust gas recirculation system  

Microsoft Academic Search

An engine exhaust gas recirculation (EGR) system is provided in which a sonic flow EGR valve is moved to open positions to establish a different constant rate of flow at each open position of the EGR valve in response to air pressure acting on a servo means secured to the valve, the air pressure force being controlled by changes in

Rachedi

1983-01-01

401

Exhaust gas recirculation system  

Microsoft Academic Search

The EGR control system comprises EGR control valve means including a first fluid chamber the vacuum in which increases and decreases in accordance with operating conditions of the engine whereby EGR control valve means control the recirculated amount of exhaust gases back to the engine and a second fluid chamber receiving therein a suction vacuum to thereby cause multiplication of

Aoyama

1979-01-01