Volatile organic compounds (VOCs) and carbon monoxide are considered the main greenhouse gas pollutants from either automotive engines or stationary sources. The increased concentration of these pollutants in air severely affects human health and causes changes in earth climate and vegetation growth rates. Ethylene is one of the VOCs closely related with photocatalytic pollution when it reacts with nitrogen oxides in the presence of sun light to form ground-level ozone. It is also responsible for quick repining of fruits and vegetables. Carbon monoxide, on the other hand, is a poisonous gas mainly released by vehicle emissions, and when inhaled in high concentrations, it causes severe health problems related to the respiratory system leading to significant rates of deaths annually in Europe and North America. Globally, The World Health Organization (WHO) estimates that seven million people die yearly due to poor air quality-related reasons which urges current and future stringent regulations to control air pollution emissions. In the past four decades, several equipment modifications and processes have been studied for reducing these emissions. Among them is the phenomenon of Electrochemical Promotion of Catalysis (EPOC) which was first reported in the early 1980s. EPOC has been successfully shown to convert automotive, indoor and industrial air pollutants such as VOCs, CO and nitrogen oxides (NOx) to harmless gases. It involves reversible changes in the catalytic properties of catalysts deposited on solid electrolytes when a small electric current or potential is applied. More recently, it was demonstrated that EPOC can be thermally induced without any electrical polarization, in analogy to the well-known phenomenon of metal-support interaction, by using noble metal nanocatalysts supported on ionically conducting materials such as yttria-stabilized zirconia (YSZ). The objective of this research is to gain deeper understanding of the factors affecting metal-support interaction between the active metal and the support to enhance their catalytic activity for environmentally-important reaction systems; specifically, ethylene and carbon monoxide oxidation as well as hydrogen fuel purification by carbon monoxide methanation. First, the activity of platinum nanoparticles deposited on carbon black, which is a conventional support used in catalysis, is studied. The effect of particle size of four Pt/C nanoparticles synthesized using a modified reduction method for ethylene (C2H4) complete catalytic oxidation is investigated. These catalysts show high activity towards C2H4 oxidation which is found to be a strongly size-dependent reaction. Full conversion of 1000 ppm C2H4 is achieved over the smallest nanoparticles (1.5 nm) at 100oC while higher temperature 170oC is required to completely oxidize ethylene over the largest nanoparticle (6.3 nm). The second stage of this research compares the catalytic activity of platinum and ruthenium nanoparticles when deposited on ionic or mixed ionic conductive vs. non ionic conductive supports for CO and VOCs oxidation. The Pt and Ru nanoparticles are deposited on yttria-stabilized zirconia (8% Y2O3-stabilised ZrO2), cerium (IV) oxide (CeO2), samarium-doped ceria (SDC), gamma-alumina (γ-Al2O3), carbon black and on novel perovskite group Sm1-xCexFeO3 (x = 0, 1, 5) resulting in ≤ 1 wt. (weight) % of Pt and Ru on each support. It is found that the nanocatalysts deposited on ionic conductive or mixed ionic conductive supports outperformed the catalysts deposited on non ionic conductors due to strong metal-support interaction that greatly affects the electronic and catalytic properties of the catalysts. The enhanced catalytic activity towards CO and C2H4 oxidation reactions is shown by earlier catalytic activity and complete conversion, lower activation energies, greater turnover frequencies and higher intrinsic rates per active surface area. To further investigate the effect of ionic conductivity of the supports and the exchange of O2- (oxygen vacancy) between the support and the catalyst surface, complete oxidation of pollutants is studied in the absence of oxygen in the gas phase. For the first time, complete oxidation of CO and C2H4 in an oxygen-free environment at low temperatures (< 250oC) is achieved, which represents the main novel finding in this research. The idea of pollutant removal in the absence of oxygen is extended to a practical reaction for fuel cells application which is hydrogen fuel purification from CO impurities at temperatures < 100oC. Moreover, the effect of particle size, pollutant concentration, operating conditions and support nature in the absence of oxygen in the gas feed is studied. It is proposed that the metal nanoparticles and the solid electrolyte form local nano-galvanic cells at the vicinity of the three-phase boundary where the anodic reaction is CO or C2H4 oxidation and the cathodic reaction is the surface partial reduction of the support. A systematic catalyst reactivation process is suggested and the catalytic activity of these nano-catalysts is studied which can be further investigated for air pollution control applications such as in vehicle catalytic converters, indoor air quality units and power plant emissions.

Asthma is the most common chronic disease in children and the effects of air pollution exposure on asthma and respiratory health in children have been a growing concern over recent decades. Although a number of epidemiological studies have been carried out in this field, these have produced conflicting results. The aim of this study was to assess the effects of long term exposure to nitrogen dioxide (NO2) and particulate matter (PM10) on asthma prevalence and lung function in children. To achieve this, a novel exposure model was developed and evaluated, which allowed retrospective exposure assessment of children participating in a population based birth cohort study – the Manchester Asthma and Allergy Study (MAAS). MAAS is a prospective birth cohort study comprising 1185 children specifically designed to study asthma and allergies. Clinical follow up took place at ages 3, 5, 8 and 11 years. At each follow up parents completed questionnaires on asthma diagnosis and symptoms and children underwent skin prick tests for common allergens. Children’s specific airways resistance (sRaw, at ages 3, 5, 8, 11) and forced expiratory volume in one second (FEV1, at ages 5, 8, 11) were measured. At ages 5 and 11 years FEV1 was measured at baseline and after bronchodilator treatment. The exposure model developed during this study incorporated outdoor and indoor air pollution, spatio-temporal variation in air pollution and time-activity patterns of children. The model was based on the concept of microenvironmental exposure. It modelled personal exposure based on PM10 and NO2 concentrations in children’s home, school and journey microenvironments (MEs) and the length of time they spend in these MEs. Land use regression (LUR) models were used to model PM10 and NO2 concentrations in outdoor MEs. These LUR models were specifically developed for the Greater Manchester area. A novel method was used to develop the LUR models, which used the output from an air dispersion model as dependent variables in the regression analysis. Furthermore, a novel approach was used to obtain annual concentration of PM10 and NO2 from 1996 to 2010, which involved the recalibration of the LUR models for each year. A mass balance model and indoor to outdoor ratios were used to model concentrations in indoor MEs. The performance of the exposure model was evaluated through a personal monitoring study in schoolchildren attending a local secondary school. Children wore personal NO2 monitors for two consecutive days in four seasons. Parental questionnaires and time-activity diaries were used to obtain information for the exposure model and to model NO2 exposure for the same time period. The results showed good agreement between monitored and modelled NO2 concentrations (Normalised mean bias factor=-0.04). Multiple linear regression and generalised estimating equations (GEE) were used to assess the cross-sectional and longitudinal effect of modelled exposure on sRaw and FEV1 (as % predicted). Multiple logistic regression and GEE were used to assess the effect of modelled exposure on the prevalence of asthma and current wheeze.The longitudinal analyses showed significant associations between PM10 and NO2 exposure and % predicted FEV1 (PM10: B=-1.37, p=0.019; NO2: B=-0.83, p=0.003), but no association with sRaw (PM10: B=0.009, p=0.37; NO2: B=-0.007, p=0.16). The cross-sectional analyses showed no association between pollutant exposure during the summer or winter prior to age 11 and any of the lung function measures (p>0.05). Long term PM10 or NO2 exposure were not associated with asthma or current wheeze (p>0.05).This study developed and evaluated a novel air pollution exposure model for epidemiological research. The results of this study suggest a negative impact of long term exposure to NO2 and PM10 on growth in FEV1 during primary school age. However, no evidence of an association between long term exposure to NO2 and PM10 and childhood asthma was found.

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Orientador: Simone Andréa Pozza / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia / Made available in DSpace on 2018-08-27T15:07:05Z (GMT). No. of bitstreams: 1 Souza_ArianeFernandaEvangelistade_M.pdf: 5058138 bytes, checksum: 6dbc9aed485db6ed52dfa0e502c4a3b5 (MD5) Previous issue date: 2015 / Resumo: Devido aos problemas respiratórios e cardíacos associados ao material particulado (MP) na atmosfera, analisar a concentração e a composição química das Partículas Totais em Suspensão (PTS) e do Particulado Inalável (MP10) é relevante para verificar a qualidade do ar de um local. O objetivo deste trabalho foi determinar a composição química das PTS e do MP10, bem como conhecer as possíveis fontes destes metais por análise estatística em uma região da cidade de Limeira-SP. O monitoramento de MP foi realizado com Amostradores de Grande Volume (AGV-PTSeAGV-MP10), instalados na estação de monitoramento da Faculdade de Tecnologia/UNICAMP. As coletas foram realizadas de março de 2013 a agosto de 2014, a cada seis dias por 24 h, utilizando-se filtros de fibra de vidro. Dentre as variáveis meteorológicas estudadas, temperatura e umidade foram as que mais influenciaram nos dois MP, os resultados mostraram que quando houve o aumento, as concentrações dos particulados diminuíram. Para determinação química, a técnica escolhida foi Espectrometria de Emissão Atômica com Plasma Indutivamente Acoplado-(ICP-OES), devido a sua efetividade, alta sensibilidade e por determinar vários elementos em poucos segundos. Foram analisados dez metais de interesse, Cd, Ca, Cr, Cu, Fe, Mg, Mn, Na, Pb e Zn, dos quais Cd, Cr, Pb e Zn não foram quantificados em nenhuma das amostras estudadas. Para ambos os particulados, Ca, Fe e Na (5,08 ug/m³, 3,98 ug/m³, 13,28 ug/m³ respectivamente para as PTS e 2,94 ug/m³, 1,96 ug/m³ e 7,80 ug/m³ respectivamente para o MP10) foram encontrados em maiores concentrações. Pela Análise de Componentes Principais (ACP) e Análise de Cluster (AC), a principal fonte dos metais nas PTS é o solo, e no MP10, podem ser solo e ressuspensão de poeiras do tráfego veicular / Abstract: Due to respiratory and cardiac problems associated with particulate matter (PM) in the atmosphere, analyze the concentration and the chemical composition of Total Suspended Particles (TSP) and Particulate Inhalable (PM10) is relevant to check the air quality of a site. The objective of this study was to determine the chemical composition of TSP and PM10, and know the possible sources of these metals by statistical analysis in a region of the city of Limeira, Brazil. The monitoring was carried out with PM Samplers High Volume (Hi-Vol-TSP and Hi-Vol-PM10), installed at the monitoring station of the Faculty of Technology / UNICAMP. The samples were collected from March 2013 to August 2014, every six days for 24 h, using glass fiber filters. Among the meteorological variables, temperature and humidity were the most affected in both PM, the results showed that when there was an increase, the concentrations of particulates decreased. For chemical determination, the chosen technique was Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), for its efficiency, high sensitivity, and determine various elements in a few seconds. Were analyzed ten metals of interest, Cd, Ca, Cr, Cu , Fe, Mg, Mn, Na, Zn and Pb, including Cd, Cr, Pb and Zn were not quantified in any of the samples. For both particulates, Ca, Fe and Na (5, ugm³, 3,98 ug/m³, 13,28 ug/m³ respectively for the TSP and 2,94 ug/m³, 1,96 ug/m³ and 7,80 ug/m³ respectively for PM10) were found in higher concentrations. By Principal Component Analysis (PCA) and cluster analysis (CA), the main source of metals in TSP is the soil, and the PM10 can be ground and resuspension of dust from vehicular traffic / Mestrado / Tecnologia e Inovação / Mestra em Tecnologia

Children are a highly susceptible population to the effects of air pollution. To establish a current baseline of child respiratory health and associated risk factors in the Highveld Priority Area, a quantitative questionnaire was carried out among parents or guardians of children aged between 9 and 11 years in Witbank and Middelburg. Key health outcomes of interest were asthma and upper and lower respiratory tract complications. Air quality data were obtained for Witbank and Middelburg and compared with recently gazetted National Standards to establish potential risks. The prevalence of health outcomes and associated risk factors, such as indoor fossil fuel burning and parental smoking were considered and key risk factors identified. A unique method for the analysis of poor quality responses was introduced in order to derive the most meaning from the data. The study findings showed the air quality to be of concern particularly in Witbank; however, it also showed a similarity between the air quality in both towns. The health outcome with the highest prevalence was hay fever (occurring in the previous 6 months) with 31.7%. The use of non-electric heating sources, parental smoking and mould in the house were risk factors of most concern for respiratory health. During bivariate analysis mould was found to be associated with a number of health outcomes, most notably having bronchitis, with a crude OR of 4.74. An adjusted odds ratio of 4.05 was found for smoking in the house and having bronchitis. An adjusted OR of 6.32 was found for using gas or paraffin and having episodes of wheezing. These results may be used to direct future research studies as well as assist air quality management practices in the area. Finally, a technique to handle contradictions in questionnaire responses was developed to maximise use of data collected for application in under-resourced research environments. Copyright 2011, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Albers, PN 2011, Baseline assessment of child respiratory health in the Highveld Priority Area, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-02172012-162359 / > C12/4/230/gm / Dissertation (MSc)--University of Pretoria, 2011. / School of Health Systems and Public Health (SHSPH) / Unrestricted

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Climate and weather play a significant role in patterns of air pollution occurrence and severity. An analysis of the effect of weather on pollution parameters in Hong Kong was performed. Hong Kong is one of the world's most densely populated regions and air pollution can be problematic, which is a serious public health concern. Hong Kong is impacted by Tropical Cyclones which strongly affect weather patterns. In this research, a twelve-year record (2007-2018) of tropical cyclone (TC) and pollutant concentrations (carbon monoxide, ground-level ozone, nitrogen dioxide, sulfur dioxide, and particulate matter) were analyzed to investigate the effects of TC on air quality. It is found that the occurrences of TC are strongly related to days with elevated particulate matter, sulfur dioxide and carbon monoxide concentrations (above 90th percentile), and low concentrations (below the 10th percentile) for nitrogen dioxide. In particular, the spatial location of TC with respect to Hong Kong is found to be clearly associated with high or low pollutant concentrations. When the TC is located to the North/Northeast of Hong Kong, the air quality tends to be poor because polluted air from mainland China is advected over the city. Conversely, TC located to the West resulted in good air quality by ventilating the city with relatively clean air from the ocean. / Graduate

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In everyday life, humans are exposed to toxic substances of anthropogenic origin. These substances can also be found in the ambient air and their impact poses a long-term risk for human health. Respirable particulate matter (PM) of aerodynamic diameter < 2.5 µm (PM2.5) is intensively studied, along with carcinogenic polycyclic aromatic hydrocarbons (PAHs), bound to it, such as benzo[a]pyrene (B[a]P), a reference carcinogenic PAH. Owing to small size, PM2.5 can penetrate the human body primarily via the airways and represent an increased health risk compared to larger particles. The negative health impacts of anthropogenic PM2.5, generated e.g. by fossil fuel combustion, are linked with its small size, relatively large surface, as well as with PAHs and other substances adsorbed on PM surface. PAHs, generated by an incomplete combustion of organic matter, can enter organism either via ingestion of contaminated food, water or via inhalation of polluted air. PAHs affect organisms via genotoxic, mutagenic, carcinogenic, embryotoxic and other adverse effects. One of the common denominators of these effects is oxidative stress, which is also considered to be the main mechanism of action caused by PM in the human organism. Oxidative damage induced by reactive oxygen species (ROS) may affect any cellular...

archives@tulane.edu / Gestational diabetes mellitus (GDM) increases the lifetime risk of developing type 2 diabetes mellitus (T2DM) in the mother; however, biological mechanisms remain relatively unknown, and known risk factors have shown to be incomplete. Both epidemiological and experimental research suggest that environmental exposure to particulate matter (PM2.5) may initiate and further progress chronic diseases such as T2DM. This study investigates the association between PM2.5 exposure and the risk of T2DM among women with a history of GDM. Associations between prevalent and incident T2DM with PM2.5 utilized two PM2.5 metrics: 1) annual average PM2.5 concentration and 2) annual average modeled PM2.5 exposure, calculated from daily PM2.5 concentration levels provided by the USRA/NASA Marshal Space Flight Center. Data from the Southern Community Cohort Study, who at recruitment reported a previous diagnosis of GDM, for whom T2DM, risk factor, and follow-up information were available, was provided. In total, 2403 participants were included in the analysis of prevalent T2DM, and 1036 participants were included in the analysis of incident T2DM. Associations between proximity to roadways and race with PM2.5 metrics were also conducted. Participants that live close to roadways were exposed to higher annual average PM2.5 concentrations and annual average modeled PM2.5 exposures. When stratified by race, non-Black participants were exposed to higher averages. After adjustment, a significant association was observed between annual average PM2.5 concentration and incident T2DM (hazards ratio (HR)= 1.022, 95% confidence interval (CI): 1.003, 1.040). No association was observed between annual average PM2.5 concentrations and prevalent T2DM. Annual average modeled PM2.5 exposure was not associated with either prevalent or incident T2DM. Results were partly consistent with previous literature. Additional studies with a greater range of air pollution exposures, including higher levels, additional pollutants, and more tailored exposure models, are warranted to investigate hypothesized associations. / 0 / Ashley Bell