116 results on '"Crilley, Leigh R."'
Search Results
102. First measurements of source apportionment of organic aerosols in the Southern Hemisphere
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Crilley, Leigh R., primary, Ayoko, Godwin A., additional, and Morawska, Lidia, additional
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- 2014
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103. Investigations of the physical and chemical properties of ambient fine particles in urban schools
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Crilley, Leigh R. and Crilley, Leigh R.
- Abstract
This thesis reports a comprehensive study on the physical and chemical properties of airborne particles in Brisbane, especially around schools. The sources and potential toxicity of the particles were identified, enabling an assessment of the contributing factors to children's exposure at school. The results from this thesis give a quantitative estimate of the range of airborne particles that children are exposed to at urban schools with different traffic conditions.
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- 2013
104. Impact of prescribed burning on urban air quality : a case study
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He, Congrong, Miljevic, Branka, Crilley, Leigh R., Morawska, Lidia, Salimi, Farhad, Ayoko, Godwin A., Barstch, E., Uhde, Erik, He, Congrong, Miljevic, Branka, Crilley, Leigh R., Morawska, Lidia, Salimi, Farhad, Ayoko, Godwin A., Barstch, E., and Uhde, Erik
- Abstract
For fuel management and/or ecological reasons prescribed burnings are conducted each year across Australia. Smoke from prescribed burnings could be the major source of air pollution in urban environment during the period of intensive prescribed burning. To investigate the impact of prescribed burning on air quality and the characteristics of prescribed burning particles, field measurements were conducted during the end period of a prescribed burning event in September 2011, Brisbane, Australia.
- Published
- 2012
105. The elemental composition and characteristics of indoor dust in Brisbane homes after the 2011 flood
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He, Congrong, Crilley, Leigh R., Ling, Xuan, Morawska, Lidia, Knibbs, Luke D., Ayoko, Godwin A., Cheung, Hing Cho, He, Congrong, Crilley, Leigh R., Ling, Xuan, Morawska, Lidia, Knibbs, Luke D., Ayoko, Godwin A., and Cheung, Hing Cho
- Abstract
Many Brisbane houses were affected by water inundation as a result of the flooding event which occurred in January 2011. The combination of waterlogged materials and large amounts of silt and organic debris in affected homes gave rise to a situation where exposures to airborne particles and dust could potentially be elevated. However, swift action to remove wet materials can help to reduce moisture and humidity in flooded houses, in an effort to improve indoor air quality in and around flooded areas. In order to gain an understanding of the effect of flooding on the concentration of inorganic elements in indoor dust, field measurements were carried out during 21 March and 3 May, 2011.
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- 2012
106. Chemical composition of outdoor airborne particles at urban schools and possible implications for the air quality in classrooms
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Crilley, Leigh R., Ayoko, Godwin A., Mazaheri, Mandana, Morawska, Lidia, Crilley, Leigh R., Ayoko, Godwin A., Mazaheri, Mandana, and Morawska, Lidia
- Abstract
Vehicle emissions are a significant source of fine particles (Dp < 2.5 µm) in an urban environment. These fine particles have been shown to have detrimental health effects, with children thought to be more susceptible. Vehicle emissions are mainly carbonaceous in nature, and carbonaceous aerosols can be defined as either elemental carbon (EC) or organic carbon (OC). EC is a soot-like material emitted from primary sources while OC fraction is a complex mixture of hundreds of organic compounds from either primary or secondary sources (Cao et al., 2006). Therefore the ratio of OC/EC can aid in the identification of source. The purpose of this paper is to use the concentration of OC and EC in fine particles to determine the levels of vehicle emissions in schools. It is expected that this will improve the understanding of the potential exposure of children in a school environment to vehicle emissions.
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- 2012
107. Indoor and outdoor particle concentrations and elemental and organic carbon at 17 primary schools
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Morawska, Lidia, Mazaheri, Mandana, Salimi, Farhad, Laiman, Rusdin, Crilley, Leigh R., Ayoko, Godwin A., Morawska, Lidia, Mazaheri, Mandana, Salimi, Farhad, Laiman, Rusdin, Crilley, Leigh R., and Ayoko, Godwin A.
- Abstract
The focus of this paper is on the measured particle number concentrations (PNC) as well as elemental and organic carbon in 17 primary schools. This study is part of the “Ultrafine Particles from Traffic Emissions and Children’s Health (UPTECH)”, which aims to determine the relationship between exposure to traffic related ultrafine (UF) particles and children’s health (http://www.ilaqh.qut.edu.au/Misc/UPTECH%20Home.htm). To achieve this, air quality and health data are being collected at 25 schools within Brisbane Metropolitan Area in Australia over two years. This paper presents the general aspects of UF particles data and preliminary results from the first 17 schools (S01 to S17), tested from Oct 2010 to Dec 2011.
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- 2012
108. Preliminary results on the characterisation of organic aerosols in urban schools by Aerosol Mass Spectrometry
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Crilley, Leigh R., Ayoko, Godwin A., Jayaratne, Rohan, Morawska, Lidia, Crilley, Leigh R., Ayoko, Godwin A., Jayaratne, Rohan, and Morawska, Lidia
- Abstract
Vehicle emissions have been linked to detrimental health effects with children thought to be more susceptible (See e.g., Ryan et al 2005). In an urban environment a major source of organic aerosols (OA) are vehicle emissions. The ambient concentration of OA is dynamic in nature and the use of an aerosol mass spectrometer can achieve the necessary temporal resolution to capture the daily variation of OA (Jimenez et al 2009). Currently there is a limited understanding of effects of long term exposure to traffic emissions on children’s health. In the present study, we used an aerosol mass spectrometer to monitor OA and determine children’s potential exposure at school to traffic emissions.In this paper, we present the preliminary results of this investigation. The study is a part of a larger project aimed at gaining a holistic picture of the exposure of children to traffic related pollutants, known as UPTECH (www.ilaqh.qut.edu.au/Misc/ UPTECH%20Home.htm).
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- 2012
109. Aerosol mass spectrometric analysis of the chemical composition of non-refractory PM1 samples from school environments in Brisbane, Australia
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Crilley, Leigh R., primary, Ayoko, Godwin A., additional, Jayaratne, E. Rohan, additional, Salimi, Farhad, additional, and Morawska, Lidia, additional
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- 2013
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110. Spatial Variation of Particle Number Concentration in School Microscale Environments and Its Impact on Exposure Assessment
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Salimi, Farhad, primary, Mazaheri, Mandana, additional, Clifford, Sam, additional, Crilley, Leigh R., additional, Laiman, Rusdin, additional, and Morawska, Lidia, additional
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- 2013
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111. Concentration and oxidative potential of on-road particle emissions and their relationship with traffic composition: Relevance to exposure assessment
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Crilley, Leigh R., primary, Knibbs, Luke D., additional, Miljevic, Branka, additional, Cong, Xiaochun, additional, Fairfull-Smith, Kathryn E., additional, Bottle, Steve E., additional, Ristovski, Zoran D., additional, Ayoko, Godwin A., additional, and Morawska, Lidia, additional
- Published
- 2012
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112. Aerosol mass spectrometric analysis of the chemical composition of non-refractory PM1 samples from school environments in Brisbane, Australia.
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Crilley, Leigh R., Ayoko, Godwin A., Jayaratne, E. Rohan, Salimi, Farhad, and Morawska, Lidia
- Subjects
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MASS spectrometry , *ATMOSPHERIC aerosols , *PARTICULATE matter , *EMISSIONS (Air pollution) , *SCHOOL environment , *CHILDREN'S health - Abstract
Abstract: Long-term exposure to vehicle emissions has been associated with detrimental health effects. Children are amongst the most susceptible group and schools represent an environment where they can experience significant exposure to vehicle emissions. However, there are limited studies on children's exposure to vehicle emissions in schools. The aim of this study was to quantify the concentration of organic aerosol (OA) and in particular, vehicle emissions that children are exposed to during school hours. Therefore an Aerodyne compact time-of-flight aerosol mass spectrometer (TOF-AMS) was deployed at five urban schools in Brisbane, Australia. TOF-AMS enabled the chemical composition of the non-refractory (NR-PM1) to be analysed with a high temporal resolution to assess the concentration of vehicle emissions and other OA components during school hours. The organic fraction at each school comprised the majority of NR-PM1. Primary emissions were found to dominate the OA at only one school which had an O:C ratio of 0.17, due to fuel powered gardening equipment used near the TOF-AMS. A significant source of the OA at two of the schools was aged vehicle emissions from nearby highways. More oxidised OA was observed at the remaining two schools, which also recorded strong biomass burning influences. In general, the diurnal cycle of the total OA concentration varied between schools and was found to be at a minimum during school hours. The major organic component that school children were exposed to during school hours was secondary OA at all schools. Peak exposure of school children to vehicle emissions occurred during school drop-off and pick-up times. Unless a school is located near major roads, children are exposed predominately to regional secondary OA as opposed to local emissions during school hours in urban environments. [Copyright &y& Elsevier]
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- 2013
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113. Sources and contributions of wood smoke during winter in London: assessing local and regional influences
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Crilley, Leigh R., Bloss, William J., Yin, Jianxin, Beddows, David C.S., Harrison, Roy M., Allan, James D., Young, Dominque E., Flynn, Michael, Williams, Paul, Zotter, Peter, Prévôt, André S.H., Heal, Mathew R., Barlow, Janet F., Halios, Christos H., Lee, James D., Szidat, Sönke, and Mohr, Claudia
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13. Climate action ,11. Sustainability - Abstract
Determining the contribution of wood smoke to air pollution in large cities such as London is becoming increasingly important due to the changing nature of domestic heating in urban areas. During winter, biomass burning emissions have been identified as a major cause of exceedances of European air quality limits. The aim of this work was to quantify the contribution of biomass burning in London to concentrations of PM2.5 and determine whether local emissions or regional contributions were the main source of biomass smoke. To achieve this, a number of biomass burning chemical tracers were analysed at a site within central London and two sites in surrounding rural areas. Concentrations of levoglucosan, elemental carbon (EC), organic carbon (OC) and K+ were generally well correlated across the three sites. At all the sites, biomass burning was found to be a source of OC and EC, with the largest contribution of EC from traffic emissions, while for OC the dominant fraction included contributions from secondary organic aerosols, primary biogenic and cooking sources. Source apportionment of the EC and OC was found to give reasonable estimation of the total carbon from non-fossil and fossil fuel sources based upon comparison with estimates derived from 14C analysis. Aethalometer-derived black carbon data were also apportioned into the contributions from biomass burning and traffic and showed trends similar to those observed for EC. Mean wood smoke mass at the sites was estimated to range from 0.78 to 1.0 μg m−3 during the campaign in January–February 2012. Measurements on a 160 m tower in London suggested a similar ratio of brown to black carbon (reflecting wood burning and traffic respectively) in regional and London air. Peaks in the levoglucosan and K+ concentrations were observed to coincide with low ambient temperature, consistent with domestic heating as a major contributing local source in London. Overall, the source of biomass smoke in London was concluded to be a background regional source overlaid by contributions from local domestic burning emissions. This could have implications when considering future emission control strategies during winter and may be the focus of future work in order to better determine the contributing local sources., Atmospheric Chemistry and Physics, 15 (6), ISSN:1680-7375, ISSN:1680-7367
114. Validity and limitations of simple reaction kinetics to calculate concentrations of organic compounds from ion counts in PTR-MS
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Holzinger, Rupert, Acton, W. Joe F., Bloss, William J., Breitenlechner, Martin, Crilley, Leigh R., Dusanter, Sebastien, Gonin, Marc, Gros, Valerie, Keutsch, Frank N., Kiendler-Scharr, Astrid, Kramer, Louisa J., Krechmer, Jordan E., Languille, Baptiste, Locoge, Nadine, Lopez-Hilfiker, Felipe, Materic, Dusan, Moreno, Sergi, Nemitz, Eiko, Quelever, Lauriane L. J., Esteve, Roland Sarda, Sauvage, Stephane, Schallhart, Simon, Sommariva, Roberto, Tillmann, Ralf, Wedel, Sergej, Worton, David R., Xu, Kangming, Zaytsev, Alexander, Sub Atmospheric physics and chemistry, Marine and Atmospheric Research, INAR Physics, Polar and arctic atmospheric research (PANDA), Sub Atmospheric physics and chemistry, Marine and Atmospheric Research, University of Birmingham, Institut für Ionenphysik und Angewandte Physik - Institute for Ion Physics and Applied Physics [Innsbruck], Leopold Franzens Universität Innsbruck - University of Innsbruck, Centre for Energy and Environment (CERI EE - IMT Nord Europe), Ecole nationale supérieure Mines-Télécom Lille Douai (IMT Nord Europe), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Tofwerk AG, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Chimie Atmosphérique Expérimentale (CAE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Centre for Energy and Environment (CERI EE), Ecole nationale supérieure Mines-Télécom Lille Douai (IMT Lille Douai), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)
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Atmospheric Science ,Materials science ,010504 meteorology & atmospheric sciences ,Proton ,Hydronium ,H3O+ ,TRACE GASES ,Analytical chemistry ,010501 environmental sciences ,01 natural sciences ,114 Physical sciences ,Atmospheric Sciences ,Ion ,Chemical kinetics ,chemistry.chemical_compound ,Reaction rate constant ,RATE CONSTANTS ,Calibration ,ddc:550 ,lcsh:TA170-171 ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,CALIBRATION ,Range (particle radiation) ,lcsh:TA715-787 ,AIR ,lcsh:Earthwork. Foundations ,010401 analytical chemistry ,lcsh:Environmental engineering ,0104 chemical sciences ,Trace gas ,chemistry ,[SDU]Sciences of the Universe [physics] ,TOF-MS ,REACTION MASS-SPECTROMETRY ,SENSITIVITY - Abstract
In September 2017, we conducted a proton-transfer-reaction mass-spectrometry (PTR-MS) intercomparison campaign at the CESAR observatory, a rural site in the central Netherlands near the village of Cabauw. Nine research groups deployed a total of 11 instruments covering a wide range of instrument types and performance. We applied a new calibration method based on fast injection of a gas standard through a sample loop. This approach allows calibrations on timescales of seconds, and within a few minutes an automated sequence can be run allowing one to retrieve diagnostic parameters that indicate the performance status. We developed a method to retrieve the mass-dependent transmission from the fast calibrations, which is an essential characteristic of PTR-MS instruments, limiting the potential to calculate concentrations based on counting statistics and simple reaction kinetics in the reactor/drift tube. Our measurements show that PTR-MS instruments follow the simple reaction kinetics if operated in the standard range for pressures and temperature of the reaction chamber (i.e. 1–4 mbar, 30–120∘, respectively), as well as a reduced field strength E∕N in the range of 100–160 Td. If artefacts can be ruled out, it becomes possible to quantify the signals of uncalibrated organics with accuracies better than ±30 %. The simple reaction kinetics approach produces less accurate results at E∕N levels below 100 Td, because significant fractions of primary ions form water hydronium clusters. Deprotonation through reactive collisions of protonated organics with water molecules needs to be considered when the collision energy is a substantial fraction of the exoergicity of the proton transfer reaction and/or if protonated organics undergo many collisions with water molecules.
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115. Extreme Concentrations of Nitric Oxide Control Daytime Oxidation and Quench Nocturnal Oxidation Chemistry in Delhi during Highly Polluted Episodes.
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Nelson BS, Bryant DJ, Alam MS, Sommariva R, Bloss WJ, Newland MJ, Drysdale WS, Vaughan AR, Acton WJF, Hewitt CN, Crilley LR, Swift SJ, Edwards PM, Lewis AC, Langford B, Nemitz E, Shivani, Gadi R, Gurjar BR, Heard DE, Whalley LK, Şahin ÜA, Beddows DCS, Hopkins JR, Lee JD, Rickard AR, and Hamilton JF
- Abstract
Delhi, India, suffers from periods of very poor air quality, but little is known about the chemical production of secondary pollutants in this highly polluted environment. During the postmonsoon period in 2018, extremely high nighttime concentrations of NO
x (NO and NO2 ) and volatile organic compounds (VOCs) were observed, with median NOx mixing ratios of ∼200 ppbV (maximum of ∼700 ppbV). A detailed chemical box model constrained to a comprehensive suite of speciated VOC and NOx measurements revealed very low nighttime concentrations of oxidants, NO3 , O3 , and OH, driven by high nighttime NO concentrations. This results in an atypical NO3 diel profile, not previously reported in other highly polluted urban environments, significantly perturbing nighttime radical oxidation chemistry. Low concentrations of oxidants and high nocturnal primary emissions coupled with a shallow boundary layer led to enhanced early morning photo-oxidation chemistry. This results in a temporal shift in peak O3 concentrations when compared to the premonsoon period (12:00 and 15:00 local time, respectively). This shift will likely have important implications on local air quality, and effective urban air quality management should consider the impacts of nighttime emission sources during the postmonsoon period., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)- Published
- 2023
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116. Analysis of organic aerosols collected on filters by Aerosol Mass Spectrometry for source identification.
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Crilley LR, Ayoko GA, and Morawska L
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- Polytetrafluoroethylene chemistry, Urbanization, Aerosols analysis, Air Pollutants analysis, Environmental Monitoring methods, Filtration methods, Mass Spectrometry methods
- Abstract
Aerosol Mass Spectrometers (AMS) are powerful tools in the analysis of the chemical composition of airborne particles, particularly organic aerosols which are gaining increasing attention. However, the advantages of AMS in providing on-line data can be outweighed by the difficulties involved in its use in field measurements at multiple sites. In contrast to the on-line measurement by AMS, a method which involves sample collection on filters followed by subsequent analysis by AMS could significantly broaden the scope of AMS application. We report the application of such an approach to field studies at multiple sites. An AMS was deployed at 5 urban schools to determine the sources of the organic aerosols at the schools directly. PM1 aerosols were also collected on filters at these and 20 other urban schools. The filters were extracted with water and the extract run through a nebulizer to generate the aerosols, which were analyzed by an AMS. The mass spectra from the samples collected on filters at the 5 schools were found to have excellent correlations with those obtained directly by AMS, with r(2) ranging from 0.89 to 0.98. Filter recoveries varied between the schools from 40 to 115%, possibly indicating that this method provides qualitative rather than quantitative information. The stability of the organic aerosols on Teflon filters was demonstrated by analysing samples stored for up to two years. Application of the procedure to the remaining 20 schools showed that secondary organic aerosols were the main source of aerosols at the majority of the schools. Overall, this procedure provides accurate representation of the mass spectra of ambient organic aerosols and could facilitate rapid data acquisition at multiple sites where AMS could not be deployed for logistical reasons., (Copyright © 2013 Elsevier B.V. All rights reserved.)
- Published
- 2013
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- View/download PDF
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