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Adverse health effects of human exposure to particulate matter (PM) in indoor environments and the associated costs have been of interest in recent studies conducted outside Canada. It was, therefore, necessary to investigate these effects in a Canadian environment. This study investigated the effects of building construction and Heating, Ventilation, and Air Conditioning (HVAC) systems on the indoor concentration of airborne PM of outdoor origin and the related health impacts and cost savings in Ontario. Due to the complexity of the investigation, the study has been limited to the metropolitan areas of Toronto and Hamilton which represent much of the population of Ontario and a significant portion of all Canada. The main objective of the cost-benefit analysis (CBA) was to analyze and evaluate the effects of pollution in monetary equivalents. The modeling integrated the various models using the Impact Pathway Approach. The approach consisted of four steps: First, identify the sources and emissions of PM. Although the study focused on indoor environments, outdoor sources such as incomplete combustion from rush hour traffic were identified for the geographical areas of the study. Secondly, evaluate the dispersion or the concentration of PM on the site of interest. In order to achieve this goal, building modeling was first established that was applicable to Ontario. There were three homes and two commercial building scenarios: Existing homes (resExist), new homes constructed under minimum building code requirements (resBC), and under R2000 standard (resR2000); commercial buildings with 40% (school40) and 85% (school85) ASHRAE air filters. Air flow rates were calculated from building and HVAC sizing calculations. These flow rates were used to calculate input parameters for well-established mass balanced indoor PM concentration models. In addition, indoor exposure needed to account for time activity in each micro-environment in Ontario. This was accomplished by using time-weighted exposure modeling. Thirdly and lastly in the Impact Pathway Approach, evaluate the health impact and its monetary equivalent, respectively. In order to evaluate the health effects and monetary equivalents, the study considered fourteen retrofit cases which consisted of improving factors such as building construction, distribution system, and air filtration efficiency. Because input parameters were selected from data applicable to Ontario, the study provided a model setup that could be applied to future work in Canada. The study demonstrated that Canadian building construction provided significant protection from time-weighted PM exposure (Toronto, ambient vs. resExist/school40win, PM2.5 10.00 vs. 4.20 μg/m3). For this scenario, the prevented attributable number of cases (ANCs) was 721 for Toronto related to equivalent PM10. Cost savings due to building envelope protection of mortality alone much outweighed costs in investment scenario for new home construction (Toronto, $1,671 million vs. $21.6 million). Therefore, recommendations were made to invest in home construction. Similarly, the morbidity effects were very significant, especially for chronic bronchitis endpoints which were along the same magnitude as mortality for most of the cases. Similar results were obtained for Hamilton in proportion to their relative population at risk. In addition, Canadian building construction and HVAC systems showed larger time-weighted PM exposure in the summer compared to the winter conditions due to the various HVAC operating conditions such as air flow rates (Toronto, resExist/school40sum, PM2.5 5.18 μg/m3 ; resExist/school40win, PM2.5 4.20 μg/m3). Furthermore, cost savings from retrofits from existing home to forced air with air filtration were very significant. It was demonstrated that the cost savings related to reduction of equivalent PM10 exposure due to mortality alone much outweighed costs in retrofit investment scenarios (R2000, Toronto, $574 million vs. $4.96 million). Therefore, the government would be wise to promote more energy efficient homes by offering more incentive programs. Factors such as wall insulation, air flow rate changes of less than 600cfm, and HRV installation type did not played a major role. In addition, the effect of air filtration was more intense in homes compared to commercial buildings. Similarly, the impact of simultaneously retrofitting both, homes and commercial buildings, where children and adults spent most of the daily activities produced the greatest reduction of outdoor PM exposure. Installing high efficient air filtration in both homes and commercial buildings resulted in optimal reduced effects. The cost savings from the retrofit due to mortality alone much outweighed the investment scenario costs justifying the retrofit (Toronto, $470 million vs. $1.8 million). This demonstrated that PM concentration exposure reduction is a collective effort that needed to be regulated not only in ambient air level but in the work environment and in homes as well. It was identified that results were limited to model assumptions and input parameter data used. Since some of the parameters used, such as ambient PM concentrations, were average values, the results may not represent the exact actual conditions. Nevertheless, they provided a starting point since they were tailored to Ontario. Therefore, this study provided model simulation data that related to the Canadian environment having many factors in common such as weather, building construction, building systems, and government regulations. Therefore, the results are part of useful data for policy decisions as well as a starting point for future related work.

This thesis investigates the potential for fouling in plain and augmented tubes in cooling tower applications. Three primary factors that affect fouling potential are examined: inside tube geometry, water velocity, and water quality. This paper presents a literature survey for in general precipitation fouling, particulate fouling, cooling water fouling, and fouling in enhanced tubes. This thesis also attempts to determine water qualities that are typical of those found in actual cooling towers. The water quality was determined by taking water samples from cooling towers throughout the country and chemically analyzing the samples. From this analysis, three water qualities were determined: an average fouling potential, a low fouling potential, and a severe fouling potential. These water qualities will be used in experimental determinations of fouling resistances in augmented tubes.

Doctor of Philosophy / Department of Biological & Agricultural Engineering / Ronaldo G. Maghirang / Emissions of particulate matter (PM) are an increasing concern for large open beef cattle feedlots. Research is needed to develop science-based information on PM emissions and abatement measures for mitigating those emissions. This research was conducted to (1) measure PM concentrations emitted from large cattle feedlots, (2) compare different samplers for measuring concentrations of PM with equivalent aerodynamic diameter of 10 µm or less (PM10), (3) evaluate the relative effectiveness of pen surface treatments in reducing PM10 emissions, and (4) predict PM control efficiency of vegetative barriers. Concentrations of PM with equivalent aerodynamic diameter of 2.5 µm or less (PM2.5), PM10, and total suspended particulates (TSP) upwind and downwind of two large cattle feedlots (KS1, KS2) in Kansas were measured with gravimetric samplers. The downwind and net concentrations generally decreased with increasing water content (WC) of the pen surface; for effective control of PM emissions from feedlots, it appears that pen surface WC should be at least 20% (wet basis). Three types of samplers for measuring PM10 concentrations in feedlots KS1 and KS2 were compared: Tapered Element Oscillating Microbalance™ (TEOM), high-volume (HV), and low-volume (LV) PM10 samplers. Measured PM10 concentration was generally largest with the TEOM PM10 sampler and smallest with the LV PM10 sampler. A laboratory apparatus was developed for measuring the PM10 emission potential of pen surfaces as affected by surface treatments. The apparatus was equipped with a simulated pen surface, mock cattle hooves that moved horizontally across the pen surface, and PM10 samplers that collected emitted PM10. Of the surface treatments evaluated, application of water (6.4 mm) and hay (723 g/m2) exhibited the greatest percentage reduction in PM10 emission potential (69% and 77%, respectively) compared with the untreated manure layer. Computational fluid dynamics (CFD) was applied to predict airflow and particle collection by a row of trees (2.2 m high × 1.6 m wide). Predicted particle collection efficiencies generally agreed with published data and ranged from less than 1% for 0.875-µm particles to approximately 32% for 15-µm particles.

One of the most prevalent pollutants in urban cities is diesel exhaust particulate (DEP). Air pollution has been linked with increased risk of recurrent myocardial infarction (MI) and MI related death (Brook, 2008). This may be due, in part, to effects on atherosclerotic plaque stability and blood clotting tendency. Whether exposure to DEP changes the response of the heart to ischaemia, resulting in increased damage after MI is less well documented. The work described in this thesis was designed to investigate the hypothesis that pulmonary instillation of DEP would increase vulnerability of the heart to subsequent myocardial reperfusion injury secondary to activation of a systemic inflammatory response, endothelial dysfunction and triggering of transient receptor potential vanilloid 1 (TRPV1) mediated autonomic reflexes in the lung. Examination of bronchoalveolar lavage (BAL) fluid revealed pulmonary inflammation 6 h after exposure to DEP, characterised by neutrophil infiltration, raised levels of the inflammatory mediator interleukin-6 (IL-6) and an increase in alveolar permeability demonstrated by increased levels of protein in the lavage fluid. Pulmonary inflammation was largely resolved 24 h after exposure. While there was no indication of systemic inflammation at 6 h after DEP instillation, the levels of two inflammatory mediators, IL-6 and tumour necrosis factor alpha (TNFα) were increased in the plasma by 24 h after exposure. DEP had no affect on blood flow responses to the endothelium dependent dilator acetylcholine (ACh) in rat hind-limb vasculature in vivo at 6 or 24 h. In summary, while exposure of rats to DEP can induce both pulmonary and systemic inflammation, it does not modify endothelium-dependent vasodilatation. Ischaemia-reperfusion (I/R) was induced in vivo in anaesthetised rats and ex vivo in buffer perfused hearts from rats that had received DEP in vivo 6 h earlier. In both in vivo and ex vivo I/R models, infarct size (unstained by triphenyltetrazolium choride) was significantly increased in hearts from DEP-instilled rats relative to hearts from saline-instilled or non-instilled rats. Baseline oxidant stress, determined by electron paramagnetic spin resonance (EPR) in heart perfusate, was also significantly higher in perfusate of hearts from DEP-instilled rats. In summary, a single exposure of the lung to DEP leads to priming of the myocardium for I/R injury. As the results cited above illustrated, priming of hearts appeared unlikely to be due to either coronary vascular endothelial dysfunction or systemic inflammation. At 6 h post exposure, DEP was associated with increased blood pressure and myocardial hypersensitivity to ischaemia-induced arrhythmias, both suggestive of sympathetic activation. The beta 1 (β1) selective blocker metoprolol was used to investigate the role of the sympathetic nervous system (SNS) in transmitting the influence of DEP in the lung to the myocardium via β1 adrenoceptor activation. Administration of metoprolol (10 mg/kg, intraperotineal) at the time of DEP instillation into the lung was found to protect the heart from potentiation of ex vivo reperfusion injury. Metoprolol was also effective in reducing oxygen free radical generation from these hearts. The TRPV1 antagonist AMG 9810 was also used to study the role of TRPV1 receptors in mediating the priming influence of pulmonary DEP to the myocardium since activation of sensory receptors have been reported to modify sympathetic output via feedback to the central nervous system (Widdicombe et al., 2001). Coadministration of AMG 9810 (30 mg/kg) in vivo with DEP into the lung was found to prevent enhancement of ex vivo reperfusion injury associated with DEP instillation alone. Collectively these results have demonstrated that a single exposure of the lung to DEP leads to priming of the myocardium for I/R injury. Furthermore, this priming occurs via activation of a pulmonary sensory reflex that is likely to involve secondary activation of systemic β1 adrenoceptors.

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The problem of the falling under gravity suspension droplet was examined for cases where the droplet contains particles with different densities and different sizes. Cases examined include droplets composed of uniform-size particles with two different densities, of uniform-density particles of two different sizes, and of a distribution of particles of different densities. The study was conducted using both simulations based on Oseenlet particle interactions and laboratory experiments. It is observed that when the particles in the suspension droplet have different sizes and densities, an interesting segregation phenomenon occurs in which lighter/smaller particles are transported downward with the droplet and preferentially leave the droplet by entering into the droplet tail, whereas heavier/larger particles remain for longer periods of time in the droplet. When computations are performed with two particle densities or two particle sizes, a point is eventually reached where all of the lighter/smaller particles have been ejected from the droplet, and the droplet continues to fall with only the heavier/larger particles. A simple model explaining three stages of this segregation process is presented.