| 1. |
- Adeyemi, Adewale, et al.
(författare)
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Particulate Matter (PM2.5) Characterization, Air Quality Level and Origin of Air Masses in an Urban Background in Pretoria
- 2022
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Ingår i: Archives of Environmental Contamination and Toxicology. - : Springer Science and Business Media LLC. - 0090-4341 .- 1432-0703. ; 83:1, s. 77-94
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Tidskriftsartikel (refereegranskat)abstract
- Several sources have been identified as contributing to the concentration of ambient fine particulate matter, which has been associated to a variety of health issues. The chemical characteristics and sources of trace elements in PM2.5, as well as the air quality index, were investigated in this study. Twenty four-hour fine aerosol particles were collected in an urban area in Pretoria, South Africa, from April 2017 to April 2018. Eighteen trace elements were determined using an XEPOS 5 energy-dispersive X-ray fluorescence (EDXRF) spectrometer, while black and organic carbon were estimated using an optical transmissometer from the samples collected. The HYPLIT model (version 4.9) was used to estimate air mass trajectories. Health risk was calculated by comparing it to the World Health Organization's air quality index (AQI). The overall mean PM2.5 concentration of the collected sample equals 21µg/m3. Majority of PM2.5 exceedances were reported during mid-autumn and winter seasons, as compared to daily WHO guidelines and South African standards. S had the highest concentrations, greater than 1µg/m3. Ni, Se, Br and Sb showed they were extremely enriched, (EF > 10) and suggestive of anthropogenic or non crustal origin The 24-h PM, soot, BC and OC were significantly different by the geographical origin of air masses (p < 0.05). The AQI showed that 70% of the samples showed levels above the AQI range of good and healthy air. The findings include details on the concentration, composition, and potential sources of fine PM2.5, which is essential for policy formulation and mitigation strategies in South Africa’s fight against air pollution.
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| 2. |
- Adeyemi, Adewale, et al.
(författare)
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Source apportionment of fine atmospheric particles using positive matrix factorization in Pretoria, South Africa
- 2021
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Ingår i: Environmental Monitoring & Assessment. - : Springer Science and Business Media LLC. - 0167-6369 .- 1573-2959. ; 193:11
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Tidskriftsartikel (refereegranskat)abstract
- In Pretoria South Africa, we looked into the origins of fine particulate matter (PM2.5), based on one-year sampling campaign carried out between 18 April 2017 to 17 April 2018. The average PM2.5 concentration was 21.1± 15.0 µg/m3 (range 0.7 - 66.8 µg/m3), with winter being the highest and summer being the lowest. The XEPOS 5 Energy dispersive X-ray fluorescence (EDXRF) spectroscopy was used for elemental analysis, and the US EPA PMF 5.0 program was used for source apportionment. The sources identified includes fossil fuel combustion, soil dust, secondary sulphur, vehicle exhaust, road traffic, base metal/pyrometallurgical, coal burning. Coal burning and secondary sulphur were significantly higher in winter and contributed more than 50% of PM2.5 sources. The HYSPLIT model was used to calculate the air mass trajectories (version 4.9). During the one-year research cycle, five transportation clusters were established. North Limpopo (NLP), Eastern Inland (EI), Short-Indian Ocean (SIO), Long-Indian Ocean (LIO) and South Westerly-Atlantic Ocean (SWA). Local and transboundary origin accounted for 85%, while 15% were long-range transport. Due to various anthropogenic activities such as biomass burning and coal mining, NLP clusters were the key source of emissions adding to the city's PM rate. In Pretoria, the main possible source regions of PM2.5 were discovered to be NLP and EI. Effective control strategies designed at reducing secondary sulphur, coal burning, and fossil fuel combustion emissions at Southern African level and local combustion sources would be an important measure to combat the reduction of ambient PM2.5 pollution in Pretoria.
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| 3. |
- Alfeus, Anna, et al.
(författare)
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PM2.5 in Cape Town, South Africa: Chemical characterization and source apportionment using dispersion-normalised positive matrix factorization
- 2024
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Ingår i: Atmospheric Pollution Research. - 1309-1042. ; 15:3
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Tidskriftsartikel (refereegranskat)abstract
- Understanding fine particulate matter (PM2.5) composition and sources is beneficial to improving visibility, addressing climate change, and mitigating poor air quality and related public health effects. Source apportionment techniques have been instrumental in evaluating the impact of sources and secondary processes on the ambient PM2.5 concentrations in receptor areas. Positive Matrix Factorization (PMF) is now the most commonly used tool due to its ability to provide mixture resolution based on available PM2.5 compositional data. Sampling and analysis of PM2.5 was conducted in Cape Town, South Africa from April 2017 to April 2018. The resulting data were dispersion normalized to address the modifications of the source concentrations resulting from the varying dispersion conditions and thereby permit dispersion normalized PMF (DN-PMF) to be employed. DN-PMF quantified the 6 sources as 2-stroke vehicles/galvanizing industries (16.8%); soil/road dust (12.3%); sulphate/marine diesel (3.6%), traffic (15.7%), sea salt (21.8%), and heating/biomass burning/cooking (15.7%). In addition, air mass back trajectory analysis using the Hybrid Single Particle Lagrangian Trajectory (HYSPLIT) model identified long-range transport pathways to Cape Town. The HYSPLIT results showed air masses from the Atlantic SSW (6%), Atlantic SW (24%), Indian Ocean (31%), and Atlantic WSW (39%) influence air quality. The primary sources affected by the transport clusters were heating, 2-stroke vehicles/galvanizing, road and soil dust, and traffic emissions. These results show that reducing emissions from the local sources will improve air quality.
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| 4. |
- Howlett-Downing, Chantelle, et al.
(författare)
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PM2.5 Chemical Composition and Geographical Origin of Air Masses in Pretoria, South Africa
- 2022
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Ingår i: Water, Air, and Soil Pollution. - : Springer Science and Business Media LLC. - 0049-6979 .- 1573-2932. ; 233
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Tidskriftsartikel (refereegranskat)abstract
- In Africa, there is a paucity of studies that reported on PM2.5, soot, BC, UV-PM (organic carbon) and trace element levels in rural and urban regions. PM2.5 samples were collected over 24 h and every third day during 19 April 2018 and 28 February 2020. The mean PM2.5 level was 24.1 μg.m−3 (range: 2.9–139 μg.m−3). PM2.5 levels exceeded the yearly World Health Organization (WHO) air quality guideline (5 μg.m−3). The daily WHO guideline (15 μg.m−3) was exceeded on 151 of the 228 days. The mean soot, black carbon and organic carbon levels were 1.43 m−1 × 10−5, 2.7 μg.m−3 and 2.1 μg.m−3, respectively. Twelve PM2.5-bound trace elements (Br, Ca, Cl, Cu, Fe, K, Ni, S, Si, Ti, U and Zn) were analysed. The geographical origin of air masses that passed the study site was estimated using the Hybrid Single-Particle Lagrangian Integrated Trajectory software. Four air masses were identified. The observed PM2.5, soot, BC, UV-PM and trace element levels at this urban background study site could potentially pose a significant risk to human health.
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| 5. |
- Howlett-Downing, Chantelle, et al.
(författare)
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Source Apportionment of PM2.5 and PM2.5-Bound Trace Elements in Pretoria, South Africa
- 2023
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Ingår i: ENVIRONMENTAL FORENSICS. - 1527-5922 .- 1527-5930.
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Tidskriftsartikel (refereegranskat)abstract
- Outdoor PM2.5 samples were collected for 34 months in Pretoria, South Africa from 18 April 2017 to 28 February 2020. The average total PM2.5 concentration was 23.2 +/- 17.3 mu g.m(3) (0.69-139 mu g.m(-3)), with the highest mean recorded during winter and the lowest during summer (p < 0.05). The sources were determined by means of cross referencing the US EPA PMF 5.0 program and the NOAA HYsplit model. The sources of the total PM2.5 were mining (33%), resuspended dust (24%), industry (15%), general exhaust (12%), vehicular emissions (12%) and biomass burning (4%). Sources of air pollutants are both ubiquitous and seasonal.Highlights center dot In central Pretoria, the largest contributing sources of PM2.5 are resuspended dust matrix and mining from surrounding areas;center dot A winter analysis was run where As, Se and Pb was included in the dataset, confirming biomass burning sources which were typically higher during the winter season; and center dot Air quality management policies should address both ubiquitous and seasonal sources.
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| 6. |
- Mwase, Nandi S, et al.
(författare)
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Health Impact of Air Pollution from Shipping in the Baltic Sea: Effects of Different Spatial Resolutions in Sweden.
- 2020
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Ingår i: International journal of environmental research and public health. - : MDPI AG. - 1660-4601. ; 17:21
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Tidskriftsartikel (refereegranskat)abstract
- In 2015, stricter regulations to reduce sulfur dioxide emissions and particulate air pollution from shipping were implemented in the Baltic Sea. We investigated the effects on population exposure to particles <2.5 µm (PM2.5) from shipping and estimated related morbidity and mortality in Sweden's 21 counties at different spatial resolutions. We used a regional model to estimate exposure in Sweden and a city-scale model for Gothenburg. Effects of PM2.5 exposure on total mortality, ischemic heart disease, and stroke were estimated using exposure-response functions from the literature and combining them into disability-adjusted life years (DALYS). PM2.5 exposure from shipping in Gothenburg decreased by 7% (1.6 to 1.5 µg/m3) using the city-scale model, and 35% (0.5 to 0.3 µg/m3) using the regional model. Different population resolutions had no effects on population exposures. In the city-scale model, annual premature deaths due to shipping PM2.5 dropped from 97 with the high-sulfur scenario to 90 in the low-sulfur scenario, and in the regional model from 32 to 21. In Sweden, DALYs lost due to PM2.5 from Baltic Sea shipping decreased from approximately 5700 to 4200. In conclusion, sulfur emission restrictions for shipping had positive effects on health, but the model resolution affects estimations.
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| 7. |
- van der Westhuizen, Deidré, et al.
(författare)
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Atmospheric fine particulate matter (PM2.5) in Bloemfontein, South Africa
- 2022
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Ingår i: International Journal of Environmental Analytical Chemistry. - : Informa UK Limited. - 0306-7319 .- 1029-0397.
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Tidskriftsartikel (refereegranskat)abstract
- Indoor and outdoor pollution has become a worldwide problem; it impacts both the environment and human health. Research-driven air pollution assessment studies were done in some of the larger South African cities like Cape Town and Pretoria, but almost none in the Free State province. The purpose of the present study was to determine PM2.5 levels and its chemical components over a period of more than one year in the Free State capital, Bloemfontein. Particulate matter was collected on PFTE filters, which were then analysed gravimetrically, by smoke stain reflectometry and X-ray fluorescence. The average PM2.5 concentration for the study period was 11μg/m3, which exceeded the World Health Organization (WHO) annual guideline limit (5μg/m3), but not the annual South African National Ambient Air Quality Standard (20μg/m3). The daily WHO guideline (15μg/m3) was exceeded on 28days, but not the daily South African standard (40μg/m3). The average soot concentration was 1.2μg/m3. The five most abundant trace elements detected in the PM2.5 filter samples were K, Ca, Si, S and Fe.
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| 8. |
- van der Westhuizen, Deidre, et al.
(författare)
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Source apportionment of fine atmospheric particles in Bloemfontein, South Africa, using positive matrix factorization
- 2024
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Ingår i: ENVIRONMENTAL MONITORING AND ASSESSMENT. - 0167-6369 .- 1573-2959. ; 196:2
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Tidskriftsartikel (refereegranskat)abstract
- Air pollution is of major health and environmental concern globally and in South Africa. Studies on the sources of PM2.5 air pollution in low- and middle-income countries such as South Africa are limited. This study aimed to identify local and distant sources of PM2.5 pollution in Bloemfontein. PM2.5 samples were collected from June 16, 2020 to August 18, 2021. Trace element concentrations were determined by EDXRF spectroscopy. By use of the US EPA PMF 5.0 program, local sources were determined to be combustion/wood burning (49%), industry (22%), soil dust (10%), base metal/pyrometallurgical and traffic (9.6%) and water treatment/industry (9.4%). The HYSPLIT program was applied to determine distant PM2.5 source areas and the following clusters were identified: Mpumalanga province (52%), Northern Cape province (35%), Indian Ocean (8%) and Atlantic Ocean (6%). The majority of the air was found to come from the Mpumalanga province in the north-east, while the majority of local sources are ascribed to combustion/wood burning. Results from this study can be used to develop an Air Quality Management Plan for Bloemfontein.
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