Although a vast number of air quality investigations have been conducted on the Mpumalanga Highveld previously, there has been limited attempt to integrate available datasets from the different methods of air quality monitoring (satellite, insitu and ground-based observations) and modelling. This study compares modelled, satellite and measured data to determine the most accurate estimate of ground level sulphur dioxide (SO2) and nitrogen oxide (NOx) concentrations. The main value of the project comes from the ‘improvement’ of modelled concentration fields using measurements. Measurements only provide information on air quality at isolated places (for example monitoring stations) or at isolated times (aircraft measurements and satellite observations). Dispersion models predict concentrations continually over a wide area. However, models have inherent inaccuracies based on the assumptions made in developing the model and the variability in the input parameters supplied. These can be accounted for or are part of the inherent variability of the model results. This study assists in the refinement of modelled outputs as well as the verification of satellite data using ground-based measured data as a point of reference. In the wake of increasing governance on air pollution, industry has been compelled to account for their impacts on the environment. This study aids industry by proposing a method to quantify their impacts on the environment and possibly on human health. Three datasets from 2003 (modelled, measured and satellite) were integrated using a geographic information system in order to analyse and interrogate the data and produce an integrated set of data, maps of potentially sensitive ecosystems and maps of potential exposure to poor air quality of sensitive population groupings. The results of the study have shown that although the concentration value for the NO2 iv tropospheric column is greater than the values observed on the ground there is a good correlation between measured observations and SCIAMACHY retrievals. The sample size was too small to indicate a statistically significant bias. The results from the validation of the CALPUFF model indicate with respect to SO2 predictions that themodel is only reliable for 62% of the time within the United States Environmental Protection Agency’s model performance guideline of acceptance i.e. predictions within a factor of 2, and for NO2 the predictions are reliable for only 50% of the time. There is also no constant value by which the model under or over predicts. The cumulative distribution function graphs illustrate that the CALPUFF model predicts the highest values from the bulk of the distribution rather that the tail of the distribution where the extremes lie. This could possibly account for the large variance between measured and modelled outputs. The results of identifying areas of potential harm from SO2 emissions reveal that hotspots for high to very high risk to human health occur around all power stations. Generally the category of high risk around power stations seems to be located in areas with population agglomerations between 0-1 000 per km2 and 2001- 5000 per km2. Several high risk areas for potential harm to ecosystems from SO2 emissions can be seen on the Highveld with a large spatial extent around Kendal, Matla and Kriel power station. Approximately 871 wetlands fall within the high risk areas. The vegetation risk map indicates a high risk to several grassland and bushveld types. Model results for this study indicate no potential risk to human health from emissions of NO and subsequent conversion to NO2 in the atmosphere.

O presente trabalho avaliou a qualidade do ar de uma área central da cidade de São Carlos-SP, mais precisamente no campus 1 da Universidade de São Paulo. Nessa região há grande movimentação de pessoas e veículos, principalmente durante o horário comercial. Esta avaliação foi feita com base na determinação de um dos parâmetros utilizados para verificar a qualidade do ar, o material particulado (MP) inalável em suspensão, ou seja, partículas que possuem diâmetro aerodinâmico menor ou igual a 10 μm e podem penetrar no sistema respiratório, sendo portanto, nocivas à saúde humana. O MP foi determinado em suas frações de 2,5 e 10 μm de diâmetro (MP10 e MP2,5). Duas metodologias diferentes foram utilizadas para determinar a concentração do material particulado em suspensão, fotometria por espalhamento de luz, através do equipamento ADR-1500 e gravimetria, através do PEM (Personal Enviromental Monitor). Os valores obtidos pelo método gravimétrico foram superiores aos resultados encontrados através da fotometria. As concentrações obtidas foram comparadas com os limites recomendados pela Organização Mundial da Saúde para o MP em suas frações de 2,5 e 10 μm, iguais respectivamente a 25 e 50 μg/m3. Além do material particulado foram obtidos dados para temperatura, umidade relativa e precipitação. As médias obtidas para as concentrações de MP10 e MP2,5, com o método gravimétrico, o qual fornece os resultados mais confiáveis, foram iguais respectivamente a 48,8 e 23,1 μg/m3, muito próximas portanto, de seus limites correspondentes. As menores concentrações obtidas para o MP10 foram, em sua maioria, verificadas em dias chuvosos, tanto através do PEM como do ADR. As concentrações de MP2,5, obtidas somente através do PEM, também apresentaram os menores valores em dias com chuva. Foi desenvolvido um modelo matemático que prevê o comportamento do MP10 durante as precipitações, evento este que se mostrou o mais importante na influência da concentração de material particulado atmosférico. / This study evaluated the air quality of a central area of the city São Carlos-SP, more precisely on the Campus 1 of the University of São Paulo. In this region there is a large movement of people and vehicles, manly during business hours. This evaluation was made based on determination of one parameter used to verify air quality, the inhalable particulate material (PM) suspended in the air, in other words, particles which have aerodynamic diameter less or equal to 10 μm and can penetrate in the respiratory system, therefore, harmful to human health. The PM was determined in its fractions from 2,5 and 10 μm of diameter (PM10 e PM2,5).). Two different methodologies were used to determinate the concentration of particulate suspended material, photometry by scattered light, using the equipment ADR-1500, and gravimetry, thru PEM (Personal Environmental Monitor). The data obtained from gravimetry were higher than the results found thru photometry. The concentrations found were compared to the limits recommended by World Health Organization for PM and its fractions of 2,5 and 10 μm, equal to 25 and 50 μg/m3. Besides PM, temperature, relative humidity and precipitation were measured. The average values for the concentrations of PM10 and PM2,5 , using gravimetry, which provide more reliable results, it were equal to 48,8 and 23,1 μg/m3, therefore really close to their corresponding limits. The lower concentrations seen for PM10 were, mostly, verified on rainy days, using PEM and ADR. The concentrations of PM2,5 , obtained just using PEM, also had the lowest values during rainy days. A mathematical model was developed to predict PM10 behavior during precipitations, this event has shown to have the most important influence on the concentration of atmospheric particulate matter.

University of Macau / Faculty of Science and Technology. / Department of Civil and Environmental Engineering

Thesis (MTech (Chemistry))--Peninsula Technikon, Cape Town, 1995 / An analytical method using Differential Pulse Anodic Stripping Voltammetry was developed for determining trace quantities of Cu, Pb, Cd and Zn in airborne particulate matter. The levels of the metallic pollutants were evaluated against meteorological data. Instrumental parameters and sample processing were optimised for determining the metals in the concentration range 1 to 40 μg/l with a percentage relative standard deviation (%RSD) less than 10%. Airborne particulate matter was decomposed by heating in a mixture of Hydrochloric and Sulphuric acids. Recovery studies were used to evaluate the digestion procedure, in the absence of a suitable reference material. The percentage recovery for the metals were between 95% and 100%. A total of 77 air samples were collected from January to December 1992, on the campus of the Peninsula Technikon. The samples were collected over 24 hour periods by filtration at a sampling rate of 20 liters per minute. The total average concentration for the metals was 25.3μg/m³. . No Cd was detected in any of the samples.

Thesis (MTech (Environmental Health))--Cape Peninsula University of Technology, 2010 / Air pollution is a global problem and it can also have a larger impact in developing countries like South-Africa. Mossel Bay was one of the regions in the Western-Cape that was rated to have potentially poor air quality. With above mentioned in mind, the research was done in Bayview. Bayview is a upper income suburb of Mossel-Bay. The suburb is surrounded by industrial activities that increased the possibility of a bad status of the air. This research measured the concentrations of the primary pollutants, SO2, NO2, PM10, O3 en Benzine, as well as the meteorological data for a period of one year as from the 1st October 2008 to the 30th of September 2009. The monitoring was done by using the mobile air quality monitoring station of the Western Cape Department of Environmental Affairs and Development Planning's that was situated in Mossel Bay. The research also correlated with the human aspects of air quality control and the monitoring results. The quality of life of the Bayview residents was measured by using a structured questionnaire. The questionnaire had amongst others, obtained the symptoms of certain air quality related diseases that the 114 respondents have recorded for the responding period of air quality monitoring. Other aspects that were researched were obtaining the social status, exposure, and work exposure and health consciousness of the respondents. Air quality surveys can fail if not put in the context of the perceptions of the affected communities. Therefore the perceptions of the respondents were also tested by a structured questionnaire. Aspects of perceptions that were tested were amongst others, the visual influence of perceptions, exposure, social status and the perception of the hazard. The results of the monitoring station for the period from 1st October 2008 to 30 September 2009, were compared with the proposed standards of the National Environmental Management: Air Quality Act (Act 39 of 2004) South-African National Ambient Air Quality Standards, as well as the SANS 1929 target values for PM10. There were no exceedences of the measured pollutants against the National Air Quality Standards. The results found that the SANS 1929 standards were also not exceeded for SO2, NO2, O' and C6H6. The concentrations of PM10 equaled the SANS standards of 75pg/m3 on a few occasions. However, the SANS 1929 daily target values of 50pg/m3 were exceeded on a few occasions. Overall though, the air quality status of the research area was within the legislative conditions. Twenty six point three percent (26.3% n = 30) of the respondents did not indicate any symptoms of any air quality related illnesses during the study period.

Adverse health effects attributable to both short- and long-term exposure to air pollution have turned the focus on different microenvironments. The interior of vehicles is of relevance as road traffic emissions and re-suspension of road dust are major sources of pollutants associated with adverse health effects. Hence, the air quality inside vehicles deserves attention regarding human health. This thesis presents a new virtual methodology, using CFD, to study the distribution of fine particulate matter, PM2.5, inside a car cabin. In the CFD model, unsteady RANS and Lagrangian particle tracking were used to simulate particles entering from the exterior. In this study, a practical measurement of interior particle concentrations was also carried out as a first attempt to validate the CFD model. The objective was to find positions inside the cabin where elevated concentrations of PM2.5 are present. The results from the CFD simulations showed that significantly higher concentrations are present at head height in the front row. Due to a discrepancy in the investigated positions in the CFD model and the practical measurement, the simulation results could not be validated. Nevertheless, the simulation results in this study have provided guidelines for future measurements of interior particle concentrations.

Atmospheric concentrations of surface ozone (O3) are strongly affected by deposition to the biosphere. Deposition processes are very sensitive to turbulence, temperature, relative humidity and soil moisture deficit and are expected to respond to global climate change, with implications for both air quality (e.g. human health) and ecosystem services (e.g. crop yields). In this PhD study, the global chemistry aerosol model UKCA (United Kingdom Chemistry Aerosol model) dry deposition scheme was thoroughly investigated. Some errors in the existing implementation of the current UKCA stomatal resistance and in-canopy aerodynamic resistance terms for O3 and NOw (NO2, PAN, PPAN, MPAN) were identified and corrected (WES scheme). These model corrections led to a decrease of the total annual dry deposition of -150 Tg(O3) yr-1 (-13%) which brings UKCA more in line with multi-model inter-comparison estimates. This was associated with a large increase of surface O3 concentration over land in the Northern Hemisphere (NH) with values up to 12 ppb (+50%) higher on annual average. Many studies have shown that O3 stomatal uptake by vegetation, which is the pathway leading to damage, accounts for 40-60% of total deposition on average. The remaining non-stomatal deposition flux is to external foliar surfaces, and soil. A more mechanistic non-stomatal dry deposition approach along with a scheme to simulate the effect of moisture on foliar surfaces on the stomatal transport (ZHG scheme) was introduced in UKCA to study the relative contributions of O3 flux occurring to stomatal and non-stomatal pathways at the global scale, and to explore the sensitivity of simulated surface O3 and O3 deposition flux. The ZHG scheme, led to significant changes in the O3 dry deposition velocity (Vd) (+40% in the North Hemisphere over boreal forests and -30% over tropical regions on annual average). The results of this study show that the ZHG scheme significantly changes the partitioning between stomatal and non-stomatal O3 flux. The non-stomatal fraction increased throughout the year and considerably during the cooler season and in spring (with maxima values by up to 60% for C3 grass and by up to 70% for needle leaf trees). The performance of both UKCA dry deposition schemes were compared with measurements, focussing on the diurnal and seasonal variations of the dry deposition velocity terms and the partitioning of O3 fluxes between stomatal and non-stomatal sinks. Overall, both UKCA dry deposition schemes capture the diurnal variations of Vd reasonably well. However, this study highlighted difficulties in comparing large grid (~280 x 390 km at mid-latitudes) averaged modelled values with site and vegetation specific characteristics of the measured exchange processes (~1 km2) and the driving meteorological variables. These differences in scale are a large source of uncertainty in the comparison of measured and modelled O3 Vd. Off-line simulation tests conducted on the non-stomatal deposition component with the ZHG scheme demonstrated the importance of modelling some key environmental and meteorological factors accurately (e.g. relative humidity, friction velocity, leaf area index). This was found to be crucial in order to improve O3 Vd model performance as well as improving the representation of specific vegetation properties. A comparison of the modelled global surface O3 concentration against observations both in the NH and SH revealed that the model performs well in the NH using both schemes, capturing the observed surface O3 cycle and the absolute values. The ZHG scheme led to a reduction of the annual bias (up to -13.5% on average) in the NH monitoring sites considered for this study. This is associated with a decrease in O3 deposition simulated with ZHG (as much as of -20% on annual average). By contrast, the seasonal cycle and absolute values of the observed surface O3 are not well reproduced by the model across the SH monitoring sites used in this study and a larger bias was found using the ZHG scheme (60% on average) compared to WES scheme (47% on average), as a consequence of an increase in O3 deposition (as much as of +20% on annual average) calculated with ZHG. A future climate integration for the 2090s using RCP 8.5 scenario was used to investigate the response of UKCA modelled O3 to climate change. The effect of climate change (by altering only the GHG concentrations predicted with RCP 8.5) on the dry deposition sink of O3 was addressed contrasting the two non-stomatal deposition parameterizations, and ignoring the changes in land-use and anthropogenic emissions. The study showed that O3 Vd over land declines from 2000 to 2100, and most strongly over vegetated areas (up to -24% over S. America, -17% over N. America and -10% over Europe). Climate change led to an increase of surface O3 concentration over land (by up to 20%). Whilst the two schemes behave similarly, and an increase in turbulence has been identified as the main driver, the decrease in land Vd is generally stronger in ZHG. This effect is more important over N. America and Eurasia where ZHG exhibits larger differences in deposition compared to WES as a result of changing climate. The increase in surface O3 over Arctic and Antarctic regions shows the effect that changes in O3 deposition might have on the long-range transport of O3. Finally, the influence of climate change on the partitioning of the O3 deposition flux was examined. This analysis revealed that more O3 is predicted to deposit through stomatal pathways with ZHG over N. America, C. Europe and E. Asia (up to +30%) compared to WES as a result of changing climate. Given that ZHG scheme captures the influence of meteorology and changing climate on surface O3 better than WES, it was concluded that modelled surface O3 using ZHG scheme showed a larger sensitivity to a changing climate than WES. These results imply potentially important effects of climate change on tropospheric O3, degrading air quality through the later decades of this century.

由於數據、模型等的尺度依賴性，尺度不匹配可能導致錯誤的結論。尤其在相互作用的地理過程研究，尺度適宜性對認知地理過程起著至關重要的作用。本文結合珠三角地區的氣象場和空氣品質過程模擬，對地理過程研究中的尺度適宜性問題進行了研究。 / 首先，基於尺度概念的定義，本文提出了地理過程研究中的四組尺度適宜性問題：多地理過程層、維度層、類型層和組成成分層。分析了其可操作級別以及評估流程和指標。 / 第二，在WRF模型中引入多解析度地形數據以研究數據與模型在氣象過程模擬的尺度適宜性。結果表明由於DEM數據與模型的尺度不適宜，可能對氣象變數的模擬帶來較大偏差。而3和30秒解析度的DEM數據與1千米解析度的模型可以較好地模擬香港地區的氣象過程。本案例有助於通過考慮尺度適宜性來提高氣象場的模擬能力。 / 第三，針對模擬模型與地理過程的尺度適宜性，應用WRF和CALMET模擬了香港地區的氣象過程。結果表明CALMET可以更好地模擬香港的氣象過程，但是WRF與CALMET模擬結果的差異在空間分佈上是異質的，即複雜地表條件的區域CALMET模擬改進明顯。多尺度模擬的結果也表明了跨尺度地理過程的相互影響，有助於多尺度地理過程模擬與認知。 / 第四，設計並研發了面向空氣品質過程的多尺度虛擬地理環境系統。本系統應用LAMP架構，支援模擬知識的管理、跨平臺及分散式平行計算，亦考慮到模擬的尺度依賴性，將有助於多尺度空氣品質過程的模擬和認知。應用該系統，對多尺度SO₂濃度過程進行模擬並分析了香港當地排放源的分擔率。較低的本地分擔率表明香港政府仍需要加強區域合作來治理空氣污染問題。 / 本論文的研究不僅加強對地理過程研究中的多尺度以及尺度適宜性問題的認知，有助於分解和研究複雜的尺度適宜性問題，研究案例和原型系統亦將會對香港和珠三角地區的空氣品質過程理解和管理作出有益貢獻。 / Although multiscale data and models are taken into account to study geography, due to their scale dependence, the scale mismatching may cause adverse results. Thus, scale compatibility is becoming crucial to decode geographic process, especially, for the interactive geographic processes. This thesis focused on scale compatibility in geographic process with a case study of multiscale meteorological and air quality simulation in Hong Kong Special Administrative Region (HKSAR) and the Pearl River Delta (PRD) region. / Firstly, based on the conceptual definition of scale, this dissertation identifies four groups of scale compatibility in geographic process research: multiple process level, dimension level, type level and component level. By illustrating the different operational levels from the abstract to operational, the author proposes a procedure to implement scale compatibility with potential criteria. / Secondly, scale compatibility in the reproduction of meteorological process is investigated between multiscale digital elevation model (DEM) data and the Weather Research and Forecasting Model (WRF). The experiments show that: DEM data with 3 and 30 arc sec resolutions are relatively more compatible with the WRF model of 1 km resolution to reproduce the meteorological field over Hong Kong; and uncertainty arising from scale mismatching between DEM data and the model may account for 38% of the variance in certain meteorological variables (e.g., temperature). This case study not only helps to improve meteorological simulations by taking the issue of scale compatibility into account, but also explains the significance and implementation of scale compatibility in geographic process research. / Thirdly, this thesis utilizes multiscale meteorological models to study the scale compatibility between dynamic models and interested geographic process. We conduct validation through three steps: daily statistics, spatial comparison and time series. The results support the idea that CALifornia METeorological model (CALMET) is more compatible to reproduce the meteorology process in Hong Kong; however, the discrepancy between the WRF and CALMET is spatially heterogeneous, with larger improvement over the area of complex topography and land use. The results also give evidence about the cross-scale interaction to interpret multi-scale geographic process. / Fourthly, applying the above findings, this dissertation presents a multiscale Virtual Geographic Environments (VGE) system to integrate geographical analysis and multiscale models in a cross-platform and parallel manner. With database system and Linux-Apache-MySQL-Perl (LAMP) architecture, users can manage and retrieve modeling concerning both data and model parameterization to help them reach a consensus on the simulation results and share modeling knowledge. Scale compatibility among data, models and analysis is also considered in the system design. Aided with high-resolved and regulable emission inventory, such multiscale system enables the practical application for various scenarios. As a case study, the VGE is applied to simulate and analyze the SO₂ concentration process and local contribution in HKSAR. / Achievements of this dissertation should greatly contribute to a better cognition of multiscale issues and scale compatibility concerning geographic process, and the VGE is expected to contribute to better understanding and management of air quality for both HKSAR and PRD. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Zhang, Chunxiao. / Thesis (Ph.D.) Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 135-157). / Abstracts also in Chinese.

Orientador: Maria Stella Gonçalves Raddi / Banca: Paulo Pinto Gontijo Filho / Banca: Carlos Henrique Gomes Martins / Resumo: Os principais parâmetros de qualidade do ar de um ambiente naturalmente ventilado e outro climatizado, destinados a ocupação comum, foram analisados. As variáveis ambientais consideradas foram concentração de bactéria (UFC/m3 de ar), concentração de fungo (UFC/m3 de ar), taxa de CO2 (ppm), umidade relativa do ar (%), velocidade (Km/h), temperatura (ºC) e concentração de partículas (æg/m3 de ar). Nossos achados apontam que os parâmetros mais influenciados pela ocupação dos ambientes são taxa de CO2 e concentração de aerossóis bacterianos, porém os valores médios no ambiente ventilado foram menores que no climatizado. Em decorrência da utilização, cada vez mais freqüente, de sistemas de condicionamento do ar, esse trabalho visou colaborar com o conhecimento dos principais parâmetros de qualidade de ar em ambientes climatizados e naturalmente ventilados. Para que a boa qualidade do ar de interiores possa ser mantida, em ambientes onde a ventilação é constante, é imprescindível o controle do número de ocupantes. / Abstract: The mainly environmentals parameters of the air quality in ventilatized and climatized ambients, destinated to the common occupation, were analyzed in this research. The evaluated environmental variables were the concentration of bacteria (CFU/m3 of air), concentration of fungo (CFU/m3 of air), rate of carbon dioxide (ppm), relative air humidity (%), speed (Km/h), temperature (ºC) and concentration of particles (æg/m3 of air). The correlation among the number of people, and the other variables, obtain significance, in the two samples, for the concentration of bacterial aerosols, CO2 rate and the temperature for the climatized ambient. In the ventilated ambient only the CO2 concentration and the number of people was correlated in the two samples. / Mestre

>Magister Scientiae - MSc / Ambient air pollution is the biggest environmental threat to human health. According to the World Health Organisation (WHO), ambient air pollution kills millions of people worldwide every year. Airborne particulate matter (APM) affects more people than any other air pollutant and has been linked with various adverse health outcomes, especially fine fractions (commonly abbreviated to PM2.5). PM2.5 penetrates lung tissue to enter the cardiovascular system where it poses the greatest risk. Detailed ambient APM studies are rare in Africa. Such studies are needed to better understand the characteristics, origins and trends of particulate pollution. This study was conducted in Cape Town (the first of its kind for the area) as part of a bigger project on ambient PM2.5 and soot concentrations in South Africa. PM2.5 filter samples were collected at a fixed sampling site in the suburb of Kraaifontein from April 2017 to April 2018, yielding 121 days of data. PM2.5 mass concentration and absorption coefficient determinations were done using gravimetric analysis and smoke stain reflectometry (SSR). Mean PM2.5 concentration for the study period was 13.4 ± 8.1 μg.m-3 (range: 1.17-39.1 μg.m-3) that fell below the South African National Ambient Air Quality Standard (SA NAAQS) annual limit of 20 μg.m-3 but exceeded the WHO annual limit of 10 μg.m-3. Mean absorption coefficient for the same period was 1.38 ± 1.23 m-1.10-5 (range: 0.00-5.38 m-1.10-5) which did not exceeded any limits. Source-region analyses were performed using single, 24-hour backward trajectories and trajectory clusters derived from the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model. Six single trajectories were identified; the most frequent were trajectories Atlantic-Ocean (38.8 %) and Indian-Ocean (26.4 %). Cluster analyses yielded three to four clusters per season. Dominating clusters were Atlantic-Ocean (61.8 %) and Indian-Ocean (29.5 %) and Inland (8.50 %). Contributions by local sources (within 40 km of the sampling site) to PM mass in samples far exceeded those of distant sources through long-range transport (LRT).