A new technique is developed for examining non-climatic variations in widths of annual tree rings. For each tree core, the technique involves making an adjustment for regional climate as inferred from a regional chronology based on surrounding sites. The technique is applied to two stands in Gila County, Arizona, where air pollution is potentially a limiting factor on tree-ring growth. For the stand closer to the pollution sources, a marked decrease in tree-ring widths minus climate is evident during the period 1908 to 1920. Although this decrease coincides with a period when two smelters were operating nearby, air pollution cannot be definitively identified as the cause of the decrease in ring widths.

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Background: The International Agency for Research on Cancer has classified diesel exhaust as a carcinogen, and specific polycyclic aromatic hydrocarbons (PAHs) as probable carcinogens. Urban air pollution is one source of PAH exposure. These facts provided motivation to pursue three thesis objectives: 1) to critically review environmental inequity research in Canada and methods used in previous studies; 2) to determine associations between socio-demographic factors and residential traffic exposure; and, 3) to assess correlations between two PAH biomarkers and their relationship with a newer geographic information system (GIS) method (a proxy of PAH exposure measurement), and explore determinants of these two PAH biomarkers. Methods: The first objective was achieved through an extensive and critical literature review. The second and third objectives were achieved through conducting a cross-sectional study in Montreal where 107 female and 93 male volunteers completed a questionnaire and provided a urine sample for measurement of 1-hydroxypyrene (1-OHP) and 1-hydroxypyrene glucuronide (1-OHPG). GIS-based distance-weighted traffic density (DWTD) at participants’ residences and time- and distance-weighted traffic density (TDWTD) for all participants’ locations in the 48 hours before urine collection were calculated. Results: Participants with lower household income and unemployment/student status were more likely to be exposed to higher traffic density at their residence. DWTD was related to self-reported living within 100 meters of highway/major roads. Detection rates for the two biomarkers were over 95%, and females have higher 1-OHP and 1-OHPG levels (exp β: 1.56, 95% CI: 1.17 to 2.09; exp β: 1.49, 95% CI: 1.05 to 2.11, respectively) than males. Smoking in the 48-hour period before urine collection significantly predicted levels of biomarkers, and among non-smokers barbecued/grilled meat consumption was implicated in increases in 1-OHP. Conclusions: Those with lower household income and unemployment/student status experienced increased traffic exposure, while education, marital status and ethnicity were not associated with traffic exposure. While higher levels among females and an interaction with sex needs further study, PAH biomarkers are useful in capturing recent PAH exposure from smoking, and barbecued/grilled meat consumption. PAH biomarkers can be easily used in epidemiologic studies to assess general population exposures. / Thesis (Ph.D, Community Health & Epidemiology) -- Queen's University, 2013-07-30 10:41:50.321

Due to the spread of urbanisation and increased environmental awareness, odour has become a major problem in communities surrounding landfills. The aim of this research was to investigate odour emissions from landfills and develop a management tool that operators could use to assist in minimising the impacts of odour. The management tool would be in the form of real-time predictions of odour concentrations in the vicinity of a source. The Bisasar Road landfill in Springfield, Durban was a case study site for the research. The methodologies used in this project can be divided into three broad categories. Firstly, flow visualisation experiments were conducted on the case study site to investigate the effects of complex terrain and the results compared to predictions from a dispersion model. Secondly, source characterisation was done on-site. Sources of odour were identified using a portable odour monitor (Electronic nose). Sources of odour were then sampled using sorbent tubes and analysis done using Gas Chromatography - Mass Spectrometry. Thirdly, numerical dispersion modelling was done. Five available dispersion models were assessed and compared against one another in order to select the most suitable model for this application. A software management tool or 'Odour Management System' (OMS), was designed and implemented on a computer at the Bisasar Road landfill. Qualitative results of the flow visualisation experiments show that terrain does have an effect on a dispersing plume path for short-range predictions. Comparisons between the flow experiments and model predictions are qualitatively consistent. Quantitative results were not obtained for the emission flow rate and emission concentration of landfill gas. The chemical composition of the fresh waste gas was determined. ADMSTM(Advanced Dispersion Modelling System) was found to be the most suitable dispersion model for this application. The OMS has been installed on-site to produce odour concentration graphics every ten minutes. A fence line odour control misting system has been installed along approximately 600 metres of the landfill border based on work done as part of this project. Weather conditions and information provided by the OMS, assist in running the odour control system economically. / Thesis (M.Sc.Eng.)-University of Natal,Durban, 2002.

The eThekwini Municipality is facing two major challenges in controlling odorous emissions by various industries in the South Durban Basin; firstly, getting industry to manage their onsite odorous emissions and, secondly regulating these odorous emissions. This study focused on the Jacobs’s Industrial Complex (JIC) which comprises various industries releasing air emissions which impact on the local air quality. The impact of these emissions is supported by the number of odour complaints reported to the eThekwini Environmental Health Department by the public. Cleaner production (CP) is an integrated approach aimed at continuously reducing environmental impacts of processes, products and services through applying preventive approaches rather than controlling and managing pollution once it has been created. This dissertation has assessed the application of CP as a concept to prevent and reduce emissions of odours by industries in the JIC that are an impacting on the environment and neighbouring communities. Three CP case studies are analysed to demonstrate the applicability of the approach. These are a CP project for drum reprocessing company based in the South Durban Basin and two waste minimisation clubs which operated from 1998 to 2000 in Durban. The key findings, outcomes, experiences and lessons learnt from these case studies underpin the recommendation of an approach that can be applied by eThekwini Municipality to incorporate CP in the scheduled trade (ST) permitting of odour producing industries. This research has applied a multi-case study design implying both qualitative and quantitative approaches. A qualitative approach was used in the detailed analyses of case studies whilst the quantitative one was applied in the graphical analyses of the odour complaints statistics for the JIC. The study concludes by drawing two major recommendations from the lessons leant. Recommendation 1: The general CP strategy that can be applied by eThekwini Municipality in regulating, promoting, enforcing, monitoring and evaluating application of CP practices among stakeholders. The recommended objectives for the general strategy include: · Enforcement of uniform regulatory standards. · Development of a policy or guidelines. · Effective compliance monitoring and enforcement. · Develop a local Cleaner Production Centre (LCPC). · Ensure co-operative governance. · Provide adequate financial resources. · Monitoring and evaluation. Recommendation 2: Strategy for incorporating CP in the ST permitting of odour producing industries. It is recommended that the ST permit holder for an odour producing industry comply with the following: · Prioritisation of odour like the other priority pollutants. · Industry to perform an audit to map odour emitting areas. · Permit holder to development a CP based odour management plan. · Investigate possible CP projects that can be undertaken to prevent and mitigate odour emissions. · Incorporate an odour management plan into a 5 year environmental improvement plan. · Develop and appropriately manage an odour complaints management system. · Set odour management performance indicators and baselines for targets and reporting. · The permit holder should include odour management performance including odour complaints management in the annual report. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2011.

The aim of this study is to quantify the social cost of air pollution in Bophelong Township. Bophelong is a dominantly Black low-income settlement located on the South-western part of the Emfuleni Local Municipality in the Vaal Triangle. In 2006 the Vaal Triangle was the first region in the country to be declared an Airshed Priority Area in terms of the National Environmental Management Act (39/2004). Economic literature reveals that there is a strong positive correlation between poverty and pollution. It is on this basis that the study provides a theoretical background to poverty and pollution. The study makes use of a Contingent valuation method to elicit respondents‘ maximum willingness to pay for the reduction of air-pollution in the area. The survey questionnaire covers three broad socio-economic categories namely, the demographic profile, labour force profile and the residents‘ attitudes towards environmental issues. The valuation part of the questionnaire makes use of an open-ended questionnaire to elicit the respondents‘ maximum willingness to pay for the reduction of air pollution in Bophelong. The mean willingness to pay for the reduction of air-pollution in Bophelong is estimated at R132 per annum. The annual social cost of air-pollution in Bophelong is calculated by multiplying the mean willingness to pay with the estimated total population. Bophelong‘s total population was estimated at 49 408. The annual social cost of pollution is thus estimated at R6 521 856. The regression analysis shows that several factors positively influence respondents‘ willingness to pay. The analysis shows that education, employment and level of income are positively correlated with the respondents‘ willingness to pay. This study indicates that there is a positive correlation between poverty and pollution. Most of the air pollution that affects the population of Bophelong is generated from domestic sources such as the burning of coal and biomass fuels for VALUING THE SOCIAL COST OF AIR-POLLUTION IN BOPHELONG TOWNSHIP heating and cooking purposes. In order to eliminate the negative impacts of air pollution on the residents of Bophelong the study recommends that authorities must begin by ameliorating the poverty situation in the area. On the main authorities must introduce measures that target domestic sources of pollution. Some of the measures that could be undertaken to reduce the impact of pollution could include: (a) encouraging residents to adopt the more cleaner top-down coal ignition method known as Basa-njengo-Magogo, (b) providing free basic electricity to poor households in the area and (c) ensuring that houses are constructed with thermal comfort in mind, as this will minimise the need for space heating particularly during winter months. / PhD (Economics), North-West University, Vaal Triangle Campus, 2013

This thesis applies, evaluates and compares methods for estimating exposure to traffic-related pollution within a GIS environment. The methods were used in two contrasting case studies; Greater London and Sheffield, where they were selected on basis of data availability and resolution. The methods used in this research were CALINE3, DMRB, ADMS-Urban and ISC3 (air pollution dispersion models), kriging and co-kriging (spatial interpolation), SAVIAH (regression method) and traditional exposure indicators. Calculated estimates were validated by comparing them to monitored NO2 data. In the Sheffield case study the best methods were then used to analyse relationships between traffic-related pollution and respiratory health. Evaluation of the performance of the various methods found that none of the methods used in Greater London worked very well, although ISC3 and kriging tended to give more reliable results. In Sheffield DMR.B and SAVIAH gave the best estimates of monitored pollution levels. Traditional exposure indicators were only used in Sheffield of which ‘density of main roads within 150 metres’, ‘traffic flow within 150 metres’ and ‘HGV flow within 150 metres’ provided the most reliable estimates. In general, the quality of all exposure measures was highly dependent on the quality of input data. This is largely due to the fact that most variation of traffic-related pollution occurs close to main roads. In Greater London the quality of data was clearly inadequate. In Sheffield, where data was of a higher quality, results were better. No substantial or significant associations were found between the exposure measures and health outcome in the Sheffield case study. In Sheffield, this research also showed that passive sampling of NO2 provided a reliable measure of relative levels of air pollution across an urban area. It also showed that none of the models were able to detect raised NO2 concentrations due to accumulation of pollution from the city, as a result of wind direction. The results of this research show that, although the methods used here can help in the investigation of relationships between traffic-related pollution and health, there is a major need to improve methods for modelling exposure to air pollution. An important development could be to link different models together within a GIS environment, in order to improve the ability to use available information and exploit the different capabilities of the models. In order to detect the effects of traffic-related pollutants on chronic health, estimates are needed across large populations. Linkage of the methods applied here, would be particularly useful to model spatial and temporal variations in these types of studies

<p>The field of "perinatal programming" has increasingly implicated an adverse early-life environment in the etiology of many chronic health problems and mental disorders. The following dissertation research is based on the hypothesis that the programming of brain and behavior by an altered early-life environment is propagated by inflammatory mechanisms in the placenta and developing brain. Offspring outcomes of two different maternal environmental exposures--air pollution and a "Western diet" (both highly relevant for the modern world)--were assessed in a mouse model in order to identify mechanisms common to developmental programming more generally.</p><p>The first set of experiments characterized the long-term behavioral and metabolic consequences of prenatal air pollution exposure in adult offspring. The male offspring of diesel exhaust particle (DEP)-exposed dams were predisposed to obesity, insulin resistance, and increased anxiety following placement on a high-fat diet (HFD) in adulthood. Furthermore, DEP/HFD male offspring exhibited evidence of macrophage priming, both in microglia and peripheral macrophages. The next experiment examined whether prenatal air pollution exposure could also synergize with a simultaneous "second hit" (i.e., maternal stress) during gestation. The offspring of mothers exposed to both air pollution and stress during gestation were more anxious as adults, but only the male offspring of this group also exhibited impaired cognition, in conjunction with neuroinflammatory changes. A further experiment revealed that prenatal air pollution exposure altered microglial maturation in a TLR4- and sex-dependent manner, consistent with the previous results. However, we found limited evidence of a placental immune response to DEP, potentially due to analysis too late in gestation. </p><p>The second set of experiments characterized the enduring behavioral and metabolic consequences of maternal consumption of a "Western diet" (HFD in combination with BCAA supplementation) prior to and during gestation and lactation. The adult offspring of HFD-fed dams were more anxious in adulthood, despite being placed on a low-fat diet at weaning. Male HFD offspring were also hyperactive, whereas female HFD offspring exhibited more severe metabolic disturbances. Furthermore, there was evidence of microglial priming and peripheral macrophage priming in male HFD offspring, similar to the prenatal air pollution model. The next experiment also found evidence of altered microglial development due to maternal HFD, in conjunction with widespread, sex-specific immune gene regulation in the placenta in response to maternal diet. Moreover, maternal HFD decreased placental serotonin production, and also programmed long-term alterations in serotonergic function in the prefrontal cortex of adult HFD offspring. Taken together, these experiments define sexually dimorphic innate immune mechanisms in the placenta and developing brain that may underlie the long-term metabolic and behavioral consequences of maternal environmental exposures.</p> / Dissertation