Browsing by Author "Nelson, PF"

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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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    Characterisation of trace metals in atmospheric particles in the vicinity of iron and steelmaking industries in Australia
    (Elsevier, 2014-02-01) Mohiuddin, K; Strezov, V; Nelson, PF; Stelcer, E
    The aims of this work are to provide a detailed physicochemical assessment of atmospheric particles collected in the vicinity of three iron and steelmaking plants and to indicate the importance of chemical characterisation of the particles, in addition to the assessment of the particle size and concentrations. In this study, atmospheric sampling sites were selected downstream of three iron and steel processing operations in Australia and one background site in an urban area with little industrial activity. The collected particles were analysed for a range of particle size mass concentrations and detailed chemical analysis of the trace metals Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn in the corresponding particle size ranges was carried out. The PM2.5 fractions in the PM10 particles at all sampling sites ranged from 35 to 62% indicating fine particles made a significant contribution to this size fraction at these sampling sites. Similarly, PM1 to the total PM10 at all sites varied from 20 to 46% and contributed significantly to the PM10 mass loading. When compared to the background sampling site, all detected metals in the particles collected near the iron and steelmaking operations had 3.4–14 times higher concentrations of PM10, PM2.5 and PM1. Iron (Fe) was found to be the dominant metal in the particles collected in vicinity of the iron and steel processing industries contributing up to 12% of the total particle mass loading. This study suggests that the metal composition of PM10, PM2.5 and PM1 varies significantly between sites and the associated metal exposure value is considerably higher in the vicinity of iron and steel processing industries than in the urban area for the same particle concentration level. © 2013, Elsevier Ltd.
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    Mass and elemental distributions of atmospheric particles nearby blast furnace and electric arc furnace operated industrial areas in Australia
    (Elsevier, 2014-07-15) Mohiuddin, K; Strezov, V; Nelson, PF; Stelcer, E; Evans, T
    The improved understanding of mass and elemental distributions of industrial air particles is important due to their heterogeneous atmospheric behaviour and impact on human health and the environment. In this study, particles of different size ranges were collected from three sites in Australia located in the vicinity of iron and steelmaking industries and one urban background site with very little industrial influence. In order to determine the importance of the type of industrial activity on the urban atmospheric quality, the industrial sites selected in this study were in the close proximity to two blast furnace operated and one electric arc furnace based steelmaking sites. The chemical compositions of the collected air particles were analysed using the proton induced X-ray emission (PIXE) technique. This study revealed significantly higher metal concentrations in the atmospheric particles collected in the industrial sites, comparing to the background urban site, demonstrating local influence of the industrial activities to the air quality. The modality types of the particles were found to be variable between the mass and elements, and among elements in the urban and industrial areas indicating that the elemental modal distribution is as important as particle mass for particle pollution modelling. The highest elemental number distribution at all studied sites occurred with particle size of 0.1 μm. Iron was found as the main dominant metal at the industrial atmosphere in each particle size range. The industrial Fe fraction in the submicron and ultrafine size particles was estimated at up to 95% which may be released from high temperature industrial activities with the iron and steelmaking industries being one of the major contributors. Hence, these industrial elemental loadings can highly influence the atmospheric pollution at local urban and regional levels and are required to consider in the atmospheric modelling settings. © 2014, Elsevier B.V.
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    PM2.5 and aerosol black carbon in Suva, Fiji
    (Elsevier, 2016-02-01) Isley, CF; Nelson, PF; Taylor, MP; Mani, FS; Maata, M; Atanacio, AJ; Stelcer, E; Cohen, DD
    Concentrations of particulate air pollution in Suva, Fiji, have been largely unknown and consequently, current strategies to reduce health risk from air pollution in Suva are not targeted effectively. This lack of air quality data is common across the Pacific Island Countries. A monitoring study, during 2014 and 2015, has characterised the fine particulate air quality in Suva, representing the most detailed study to date of fine aerosol air pollutants for the Pacific Islands; with sampling at City, Residential (Kinoya) and Background (Suva Point) sites. Meteorology for Suva, as it relates to pollutant dispersion for this period of time, has also been analysed. The study design enables the contribution of maritime air and the anthropogenic emissions to be carefully distinguished from each other and separately characterised. Back trajectory calculations show that a packet of air sampled at the Suva City site has typically travelled 724 km in the 24-h prior to sampling, mainly over open ocean waters; inferring that pollutants would also be rapidly transported away from Suva. For fine particulates, Suva City reported a mid-week PM2.5 of 8.6 ± 0.4 μg/m3, averaged over 13-months of gravimetric sampling. Continuous monitoring (Osiris laser photometer) suggests that some areas of Suva may experience levels exceeding the WHO PM2.5 guideline of 10 μg/m3, however, compared to other countries, Fiji's PM2.5 is low. Peak aerosol particulate levels, at all sites, were experienced at night-time, when atmospheric conditions were least favourable to dispersion of air pollutants. Suva's average ambient concentrations of black carbon in PM2.5, 2.2 ± 0.1 μg/m3, are, however, similar to those measured in much larger cities. With any given parcel of air spending only seven minutes, on average, over the land area of Suva Peninsula, these black carbon concentrations are indicative that significant combustion emissions occur within Suva. Many other communities in the Pacific Islands, as well as in Africa, Asia and South America share similar climate and similar burning practices and as such are likely to experience similar aerosol black carbon loadings. These black carbon levels indicate the need for combustion emissions, particularly those from open burning and diesel usage, to be addressed in air policy.© 2016, Elsevier Ltd.
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    Quantifying respirable crystalline silica in the ambient air of the Hunter Valley, NSW - sorting the silica from the silicon
    (The Clean Air Society of Australia and New Zealand, 2011-07-31) Morrison, AN; Nelson, PF; Stelcer, E; Cohen, DD; Haberlah, D
    Crystalline forms of silica are known to cause lung damage for which there is no effective treatment. Silicon is abundant in crustal material and silicates are the single largest mineral grouping, with silica (SiO2) being the most abundant crustal compound. Media reports of high levels of silicon in particles in the air in the vicinity of Hunter Valley open-cut coal mines have caused community anxiety and concerns about potential health impacts on local populations. An extensive sampling campaign using continuous air quality monitoring and targeted collection of particles has been carried out in an area close to mining operations. It was determined that silicon as silica was present in the ambient air, although the concentrations of crystalline silica measured suggest that it should not should cause health problems even for sensitive individuals within the general population. The results of the research should inform more rigorous discussions of air quality management plans for fine particles in the Hunter Valley and aid discussions of community concerns over the potential health impacts of coal mining.© 2011-Clean Air Society of Australia & New Zealand
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    Reducing mortality risk by targeting specific air pollution sources: Suva, Fiji
    (Elsevier, 2018-01-15) Isley, CF; Nelson, PF; Taylor, MP; Stelcer, E; Atanacio, AJ; Cohen, DD; Mani, FS; Maata, M
    Health implications of air pollution vary dependent upon pollutant sources. This work determines the value, in terms of reduced mortality, of reducing ambient particulate matter (PM2.5: effective aerodynamic diameter 2.5 μm or less) concentration due to different emission sources. Suva, a Pacific Island city with substantial input from combustion sources, is used as a case-study. Elemental concentration was determined, by ion beam analysis, for PM2.5 samples from Suva, spanning one year. Sources of PM2.5 have been quantified by positive matrix factorisation. A review of recent literature has been carried out to delineate the mortality risk associated with these sources. Risk factors have then been applied for Suva, to calculate the possible mortality reduction that may be achieved through reduction in pollutant levels. Higher risk ratios for black carbon and sulphur resulted in mortality predictions for PM2.5 from fossil fuel combustion, road vehicle emissions and waste burning that surpass predictions for these sources based on health risk of PM2.5 mass alone. Predicted mortality for Suva from fossil fuel smoke exceeds the national toll from road accidents in Fiji. The greatest benefit for Suva, in terms of reduced mortality, is likely to be accomplished by reducing emissions from fossil fuel combustion (diesel), vehicles and waste burning.© 2017 Elsevier B.V.