Browsing by Author "Morrison, AL"

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    Airborne ultrafine particles in a Pacific Island country: characteristics, sources and implications for human exposure
    (Elsevier, 2017-09-25) Isley, CF; Nelson, PF; Taylor, MP; Mazaheri, M; Morawska, L; Atanacio, AJ; Stelcer, E; Cohen, DD; Morrison, AL
    The Pacific Islands carry a perception of having clean air, yet emissions from transport and burning activities are of concern in regard to air quality and health. Ultrafine particle number concentrations (PNCs), one of the best metrics to demonstrate combustion emissions, have not been measured either in Suva or elsewhere in the Islands. This work provides insight into PNC variation across Suva and its relationship with particle mass (PM) concentration and composition. Measurements over a short monitoring campaign provide a vignette of conditions in Suva. Ambient PNCs were monitored for 8 day at a fixed location, and mobile PNC sampling for two days. These were compared with PM concentration (TSP, PM10, PM2.5, PM1) and are discussed in relation to black carbon (BC) content and PM2.5 sources, determined from elemental concentrations; for the October 2015 period and longer-term data. Whilst Suva City PM levels remained fairly low, PM2.5 = 10–12 μg m−3, mean PNC (1.64 ± 0.02 × 104 cm−3) was high compared to global data. PNCs were greater during mobile sampling, with means of 10.3 ± 1.4 × 104 cm−3 and 3.51 ± 0.07 × 104 cm−3 when travelling by bus and taxi, respectively. Emissions from road vehicles, shipping, diesel and open burning were identified as PM sources for the October 2015 period. Transport related ultrafine particle emissions had a significant impact on microscale ambient concentrations, with PNCs near roads being 1.5 to 2 times higher than nearby outdoor locations and peak PNCs occurring during peak traffic times. Further data, particularly on transport and wet-season exposures, are required to confirm results. Understanding PNC in Suva will assist in formulating effective air emissions control strategies, potentially reducing population exposure across the Islands and in developing countries with similar emission characteristics. Suva's PNC was high in comparison to global data; high exposures were related to transport and combustion emissions, which were also identified as significant PM2.5 sources. © 2017 Elsevier Ltd.
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    Ambient air quality and indoor exposure: PM2.5 implications for health in Suva Fiji
    (Clean Air Society of Australia and New Zealand, 2018-03-01) Isley, CF; Nelson, PF; Taylor, MP; Morrison, AL; Atanacio, AJ; Stelcer, E; Cohen, DD
    Air quality data collected at urban background locations is often assumed to represent a wider urban area. Localised sources and conditions can however cause variation between different microenvironments in the same urban area. Differences in PM2.5 (particulate less than 2.5 μm) composition may also have greater implications for health outcomes than PM2.5 concentration considered alone. Samples of PM2.5 were collected for three outdoor and nine indoor microenvironments across Suva, Fiji in 2014/15. Elemental concentration data have been used to estimate source contributions to PM2.5 for each site. The 12 sites are compared to concurrent ambient measurements at a fixed monitoring site in Suva City and to ambient photometer data. The objective is to determine how well ambient measurements represent air quality across the city, including indoor environments. Surveys were used to determine how much time is spent indoors and outdoors by Suva residents to ascertain potential exposure risks. Results show that PM2.5 concentration and composition varies significantly between the different microenvironments studied. Indoor air quality was affected by both ambient air and indoor sources. Fuel used for cooking, particularly wood and kerosene, influenced indoor PM2.5 and black carbon. Given that the survey showed that people spend more time indoors than outdoors, as experienced elsewhere in the world, ambient measures of PM2.5 concentration and calculated related health risk does not accurately reflect exposures arising from city indoor microenvironments. © 2018 The Clean Air Society of Australia and New Zealand
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    PIXE analysis of MOUDI filters
    (The Clean Air Society of Australia and New Zealand, 2011-07-31) Stelcer, E; Morrison, AL; Cohen, DD; Atanacio, AJ
    This paper will present results from a series of analyses performed on 8-stage Micro Orifice Uniform Deposit Impactor (MOUDI) sampling substrates using accelerator-based Particle Induced X-ray Emission (PIXE) analyses. These experiments aimed to better understand the influence of aerosol deposition on each of the MOUDI stages on the PIXE analysis results. copyright © 2011-Clean Air Society of Australia & New Zealand