Iron and steel plants in general are significant sources of PM10 pollution. Many studies have concluded that PM10 is harmful to human health and well being. ArcelorMittal Vanderbijlpark Works falls within the jurisdiction of the Vaal Triangle Airshed Priority Area (VTAPA) and has been given PM10 reduction targets in the Air Quality Management Plan. The aim of this study is to use dispersion modelling to determine the impact of the Vanderbijlpark Works steel plant on ambient PM10 and to assess the effectiveness of the reduction strategies with respect to PM10 The AERMOD dispersion model was chosen for the exercise because of its reliability when modelling near field dispersions on relatively flat terrain. Meteorological data was obtained from on-site stations. Emissions data was obtained from an already existing emissions inventory on site. The study modelled the PM10 baseline for 2010 and then modelled the predicted concentrations after implementation of the strategies as outlined in the VTAPA. The modeling scenarios were compared to the measured PM10 data from the fence line monitors. The following findings were made: Point sources were not significant contributors to PM10 emission. Modeling of area sources and other fugitive dust sources were found to be high and when compared to measured concentrations were found to be over predicted. It is concluded that the fugitive sources have been found to be the major source of PM10 emissions and that reduction of fugitives should feature prominently in emission reduction plans going forward. In addition, the fugitive emissions inventory needs to be refined to enhance the accuracy of the predictions.

BACKGROUND For many years, the Durban south community has raised concerns about ambient air pollution including particulate matter. The Durban South Industrial Basin (DSIB) may be high risk for exposure to significant levels ofPMI0 due to its geographic relationship with two major petroleum refineries, together with a pulp and paper manufacturing facility. While potential sources of elevated levels of PMlOin the south are industrial, the north is likely to be exposed to controlled burning of vacant fields and use ofbiomass fuels, particularly in informal settlements. Adverse health effects from particulate matter (PM) were well documented by extensive epidemiological observations by animal and human studies, following laboratory exposures. Studies across a variety of environmental settings have demonstrated a strong association between ambient air particulate matter (PMlO) and cardiopulmonary morbidity and mortality. Studies have reported that particulate matter is associated with adverse health effects resulting from inflammatory responses in the lower respiratory tract. Exposure to particulate matter may increase the risk of lung cancer. Some studies suggested that small temporal increases in ambient particulate matter are sufficient to cause health impacts. Other studies attributed strong seasonality to temperature inversions associated with temperature changes. Studies also illustrated the impact of temporal variation on PMl 0 levels across regions. OBJECTIVES The main objectives of this study were to determine and compare the levels of ambient PMIO in industry exposed and non-industry exposed communities, to determine temporal variation and to make recommendations. METHODS This study focused on determining the 24-hour ambient PMI0 levels in the Durban south community. The PMIO levels in Durban south (industry exposed) were compared with the PM10 levels in an area north of Durban (non-industry exposed). Relevant data obtained from the monitoring program of the South Durban Health Study (SDHS) was reviewed for the purposes of this study. The different techniques used to measure PMI0 are gravimetric sampling and tapered elemental oscillating microbalance (TEaM). Both methods were used to collect PMI0 data. The data comprised of quantitative and categorical variables. The dependent variable was the PM10 values and the independent variable was the sampling sites. Non-parametric tests were used to analyse the data. RESULTS PMI0 was recorded in all sites in north and south areas. The levels varied across all sites. Both the north and south areas recorded high PMI0 values at regular intervals. No particular trend was observed when the 24 hour PM10 concentration was compared against the standard. All sites recorded medians that were generally in the region of 40-S0,ug/m3. The site with the highest median (SIA,ug/m3 ) was Assegai. Briardale recorded the lowest median (34.9,ug/m3 ). Exceedances of the South African National Standard code 1929 maximum 24-hour concentrations of7S,ug/m3 were observed across all sites. Overall there were 163 (16.7 % of all samples) exceedances, and these ranged widely between the various sites, with no particular regional trend. Overall .June experienced the highest PMl 0 values. No differences in seasonal trends were observed in north and south. CONCLUSION On average the levels ofPMI0 do not exceed national or international standards. The findings did not reveal any statistical difference in exposure levels between the industry exposed and non-industry exposed areas. / Thesis (MMed.)-University of KwaZulu-Natal, Durban, 2008.

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Since the Industrial Revolution, human society has rapidly developed and flourished. Meanwhile, some interconnected side effects, particularly in realms of water, energy, food and environment, are tackling the sustainability of society. These grand challenges are intricately interconnected, underscoring the importance of addressing these problems through the lens of the water-energy-environment (WEE) nexus, which emphasizes the interlinkages between these sectors. For instance, the unprecedented scale of CO₂ has accumulated in the atmosphere, and it has accelerated global warming and the chained environmental problems, such as droughts and floods. This insecurity for water resources has encouraged water recycling. At the same time, a new class of anthropogenic contaminants, including pharmaceutical and personal care products (PPCP), heavy metals, herbicides or pesticides, and per-fluoroalkyl substances (PFAS), have been accumulated in natural water bodies. These contaminants are called emerging contaminants, and these can potentially cause severe problems in ecology and human health. Thus, this thesis aimed to tackle these multifaceted issues by investigating the interfacial chemistries between the natural or engineered solids and aqueous phases, particularly in the context of in-situ carbon mineralization and water remediation.To mitigate climate change, we should not only reduce CO₂ emissions but also remove the previously emitted CO₂ from the air. In-situ carbon mineralization is a critical technology to meet the agenda of carbon dioxide removal from the air (CDR) as the potential capacity and offer a thermodynamically downhill reaction to store CO₂ permanently in solid form. During the in-situ carbon mineralization, water plays a pivotal role in the interactions at Rock-H₂O-CO₂ interfaces. However, the kinetics and mechanisms of interfacial reactions in the mineral-aqueous phases with various compositions still need to be fully understood. Additionally, in-situ carbon mineralization demands substantial water usage; therefore, addressing water security become imperative. However, during the water usage and recycling process, the accumulation of ions, including heavy metals, and the spreading of organic pollutants can intensify the concerns about water security. Thus, this thesis’s objectives are to focus on a fundamental understanding of reaction kinetics and mechanisms occurring at the interested interfaces to address these challenges. At the mineral-aqueous phase for in-situ carbon mineralization, the effect of parameters, such as temperature, pH, and mineralogy has been assessed for mineral dissolution in the aqueous phase, and both basalt and peridotite were investigated. Related to the dissolution kinetics, this thesis discussed the frameworks for determining the dissolution rate, which can affect our understanding of experimental results. The dissolution studies exploring the effect of various parameters related to the in-situ carbon mineralization provided valuable insights into the reactivity of feedstock and morphological alterations that can be utilized for reactive-transportation modeling. Also, the experiment results may suggest the system boundary to engineer the geological CO₂ storage process. Also, carbonation behaviors were studied in terms of direct carbonation and nucleation. For the direct carbonation, olivine mineral and peridotite rock retrieved from a potential CO₂ storage site were tested, and the effects of parameters including pH, additives, and temperature were discussed. During the in-situ carbon mineralization, dissolved cations and dissolved CO₂ can be nucleated and precipitated on the different types of mineral surfaces. Therefore, this study investigated the interfacial interactions with different types of mineral surfaces and containing ions in the aqueous phase. These studies provide the fundamental understanding of the thermodynamics and kinetics of carbonation during in-situ carbon mineralization. Lastly, this study explored the kinetics and mechanisms of adsorption at adsorbent–emerging contaminant containing fluid interfaces in regard to water remediation and recycling. In this study, biochar from waste streams and MOFs with different modifications were used for the strategical development of adsorbents, while spectroscopic analysis methods were adopted to elucidate the mechanisms. Also, the effect of coexisting ions or reusability was discussed. Further, the results and insights from this investigation can be utilized for developing future generations of adsorbents and designing the remediation process. Consequently, through understanding the various regimes of interfaces, this study may contribute to the advancement of strategic approaches for addressing the complex challenges within the WEE nexus, particularly related to sustainable in-situ carbon mineralization.

by Luk Shiu-fai. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (p. 234-240). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web.

The main objective of this study was to investigate the application of the United States Environmental Protection Agency (US EPA) human health risk assessment framework for quantifying the adverse human health effects of exposure to inhaled kerosene pollutants in the South African context. The study was based in the informal settlement of Cato Crest in Cato Manor, Durban. This dissertation includes a theoretical review of the environment/health Relationship, the US EPA health risk assessment approach, it's history, and the health effects of kerosene combustion products. Chapter three outlines the methodology for the study, detailing how time-activity pattern data and air quality results were collected from the community of Cato Crest. Chapter four presents the results of the health risk assessments conducted for nitrogen dioxide, benzene and toluene exposure - using both local and US EPA exposure values in the health risk assessments. A critical evaluation of the US EPA human health risk assessment framework in the South African context is provided in chapter five. The results of the study revealed that a 1-hour exposure to the nitrogen dioxide concentrations measured in Cato Crest would not present any adverse health effects. A 24-hour exposure to NO2 using US EPA default exposure values provided a slight possibility of adverse health effects being experienced in sensitive individuals in some houses. 24-Hour exposure to NO2 using local exposure values could result in both sensitive individuals and even some healthy individuals experiencing adverse health effects in all houses. Potential adverse health effects include coughing, wheezing, chest tightness, broncho-constriction and increased airway resistance. Sensitive individuals include those with asthma or other respiratory diseases. Exposure to 24hour benzene concentrations (using US EPA default exposure values) is not likely to result in individuals experiencing adverse health effects. Exposure to the same benzene concentrations at local exposure times will cause potential adverse health effects in sensitive individuals. Sensitive individuals are those with respiratory ailments and blood diseases or disorders. Exposure to monitored toluene concentrations over a 24-hour period (using both US EPA default exposure values and local exposure values) is unlikely to result in adverse health effects being experienced by any individuals. The US EPA human health risk assessment framework is seen as applicable to South Africa where developed areas are concerned (as these areas are quite similar to North American populations). In areas of South Africa that are considered less developed or undeveloped, local conditions need to be substituted into health risk assessments where possible. / Thesis (M.Sc.)-University of Natal, Durban, 2001.

The oxidation of volatile organic compounds (VOCs) plays a role in both regional and global air quality through the formation of secondary organic aerosols (SOA). More than 1000TgC/yr of non-methane VOCs are emitted from biogenic sources (significantly greater than from anthropogenic sources). Despite this magnitude and potential importance for air quality, the body of knowledge around the identities, quantities and oxidation processes of these compounds is still incomplete (e.g., Goldstein & Galbally, 2007; Robinson et al., 2009). Two-dimensional gas chromatography paired with time-of-flight mass spectrometry (GC×GC/TOFMS) is a powerful analytical technique which is explored here for its role in better characterizing biogenic VOCs (BVOCs) and thus SOA precursors. This work presents measurements of BVOCs collected during two field campaigns and analyzed using GC×GC/TOFMS. The first campaign, the Bio-hydro-atmosphere Interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen - Rocky Mountain Biogenic Aerosol Study (BEACHON-RoMBAS), took place in a Ponderosa pine forest in Colorado. The second campaign, Particle Investigations at a Northern Ozarks Tower: NOx, Oxidant, Isoprene Research (PINOT NOIR) Study, was conducted in the Ozark region of Missouri. Tens to hundreds of BVOCs were quantified in each set of samples, including primary emissions, atmospheric oxidation products, stress indicators and semi-volatile leaf surface compounds. These findings highlight that there is a largely uncharacterized diversity of BVOCs in ambient samples. Our findings demonstrate that GC×GC can distinguish between compounds with the same molecular weight and similar structures, which have highly variable potentials for production of SOA (Lee et al., 2006). This work represents some of the first analysis of ambient BVOCs with this technology, which is anticipated to contribute greatly to characterization of atmospheric SOA precursors and ultimately, regional and global modeling of SOA and fine particulate matter.

This dissertation consists of three essays in the field of environmental economics. The first chapter provides the first causal evidence that hostile activities online lead to physical violence. Given the recently documented relationship between pollution and social media, I exploit exogenous variation in local air quality as the first step to instrument for online aggression. In an event study setting, I find volatile organic compounds (VOCs) increase by 7% when refineries experience unexpected production outages. Together with higher air pollution, I find more aggressive behaviors both online and offline, as well as worse health outcomes near refineries. A one standard deviation increase in surrounding VOCs leads to 0.16 more hate crimes against Black people and 0.23 more hospital visits per thousand people each day. Second, I consider how emotional contagion spreads through social networks. On days with pollution spikes, surrounding areas see 30% more offensive and racist tweets and 12% more crimes; those geographically distant but socially networked regions also see offensive and racist tweets increase by 3% and more crimes by 4.5%. Nationally, overlooking spillovers would underestimate crime effects of pollution by 24%. My findings highlight the consequences of social media hostility and contribute to the public debate on cyberspace regulation. The second chapter, which is coauthored with Andrew Wilson, analyzes the relationship between weather and railway accidents. Rail thermal expansion and contraction are key considerations in rail design and construction; rail operators and rolling stock may likewise exhibit vulnerability to temperature changes. We quantify the sizes of these effects by leveraging a comprehensive dataset of railway malfunctions in the United States spanning 1997-2019. We find that both heat and cold cause elevated rates of railway malfunctions, with relatively larger increases in the number of incidents leading to a casualty as well as the number of injuries and deaths resulting from these incidents. We find that exposure to daily temperatures averaging over 30°C (86°F) leads to a 16% increase in the number of rail malfunctions, a 13% increase in the number of incidents leading to a casualty, and 18% and 36% increases injuries and deaths-effects net of any operational adjustments made to mitigate these effects. Further, while we also find that warmer locations exhibit a weaker relationship between heat and railway malfunctions, we find no evidence that companies are learning, year-over-year, how to reduce accidents. Finally, we note that effects of heat are strongest for derailments (versus other types of malfunctions) and freight trains (versus passenger trains). Our findings highlight the vulnerability of the railway system to the climate. The number of injuries and deaths associated with weather exposure-especially in comparison to operators' reported private costs of equipment failure-suggests a role for enhanced rail safety regulations and adaptation funding to protect critical heat-exposed infrastructure. The third chapter, which is a joint work with Douglas Almond and Muye Ru, explores the impact of federal policy rollback on methane leakage. Improvements in satellite measurement enable independent assessment of regulatory and climate policy. In August 2020, the Trump Administration lifted Obama-era requirements that oil and gas firms detect and repair methane leaks. We merge geo-identified data from the European TROPOMI (satellite instrument) to the specific locations of the US oil and gas infrastructure. Using a difference-in-differences design, we find a prompt increase in US methane emissions following the summer 2020 rollback. The number of high-methane emission events from the oil and gas sector more than doubled after the rollback relative to the coal sector, which did not experience the same regulatory rollback. While the oil and gas industry claims it faces a persistent, profit-making incentive to stem natural gas leaks and emissions, we find a large and nimble response by industry to changes in federal policy. Public policies that reduce methane externalities are critical given that global methane concentrations are rising at an increasing rate.

Seed-oil based biodiesel production particularly biodiesel production from the nonedible oil seed bearing plant - Jatropha curcas L. - is a key strategic direction outlined in the biofuels strategy of the Government of Ethiopia. The main objective underlying the strategy include substitution of imported diesel oil used in the road transport sector while at the same time contributing to the local and global greenhouse gasses (GHG) reduction efforts. In this study the environmental benefits and costs of production and use of Jatropha biodiesel in the road transport sector of Ethiopia is assessed using a life cycle analysis (LCA) methodology. The analysis focused on determining the potential environmental impacts and net non-renewable energy saving potential of biodiesel from Jatropha oil-seeds using the following metrics: (i) Net Greenhouse Gas (GHG) reduction, and (ii) Net Energy Balance (NEB) relative to diesel oil. The study shows that the net GHG emissions reduction potential of Jatropha Methyl Ester (JME) is highly influenced by the magnitude of initial carbon loss occurring in the process of conversion of different land uses to Jatropha plantation, and less so on other unit processes of JME production system analysed. The NEB of JME relative to use of diesel oil per functional unit of one GJ is less sensitive to impacts of land use change and is generally positive. Where no land use change impacts is considered, or where Jatropha is grown on lands with low carbon stock such as grasslands, substitution of diesel oil with JME in Ethiopia can provide GHG emission reduction of about 43%, and for each MJ of JME produced the nonrenewable energy requirement will be 0,38 MJ. Production of JME by converting lands with high above ground, below ground and/or soil carbon stocks such as shrub lands or well stocked forest lands will result in net loss of carbon and require ecological carbon payback time of 50 to hundreds of years. The impact of introducing and use of JME-diesel oil blends by Anbassa City Bus Services Enterprise (ACBSE) bus fleets shows that, displacement of diesel oil with JME that have positive GHG reduction potential, will also contribute to the reduction of air pollutants and improvement of ambient air quality in Addis Ababa. Two key recommendations of this research work are that to ensure environmental sustainability of biodiesel production from Jatropha seeds (i) land availability and land suitability assessment for estimating the potential available land for Jatropha (and other oil-seed bearing plants) shall be conducted, and (ii) minimum requirements on GHG reduction and NEB requirements on biodiesel shall be established. / Environmental Sciences / M. Sc. (Environmental Management)