Dissertations / Theses on the topic 'Carbon monoxide Health aspects'

Synthesis gas (syngas), which primarily consists of carbon monoxide (CO) and hydrogen (H2), is a versatile energy carrier that can be converted to gaseous and liquid fuels or can be used for electricity production. This study was focused on MFC design improvements for performance enhancement on CO/syngas and elucidation of microbial communities, and biotransformation pathways involved in electricity production from CO/syngas in an MFC. One of the primary challenges for an efficient bioconversion of CO and syngas is the low solubility of these gaseous substrates in the aqueous phase. The first study of this thesis demonstrated the applicability of silicone membrane systems for improved CO transfer into the anodic liquid of MFCs. The incorporation of flat silicone membrane and thin wall silicone tubing into the anodic chamber of CO-fed MFCs led to improved CO transformation efficiency and correspondingly improved MFC performance. A CO transformation efficiency of 77 % and maximum power output of 18 mW/L (normalized to anodic compartment volume) was achieved for silicone membrane installed MFC. A comparably higher CO transformation efficiency of 98 % was obtained for silicone tubing installed MFC, but the high dissolved CO concentrations in the anodic liquid partially inhibited the microbial activity, thereby lowering the maximum power output to 13 mW/L. Efficient gas transfer also allowed for focusing on the process microbiology. The microbial communities and biotransformation pathways prevalent in two mesophilic CO-fed MFCs were elucidated in the second study. The identification of the microorganisms belonging to the genera Geobacter, Desulfovibrio, and Clostridium, along with the detection of acetate as the primary metabolic product in both MFCs; affirmed our hypothesis that electricity production from CO/syngas in a mesophilic MFC is primarily accomplished by a two-step process, where CO/syngas is first converted to acetate by homo-acetogenic and carboxdotrophic microorganisms, and the acetate is then utilized by CO-tolerant acetate oxidizing electricigenic microorganisms. The bioconversion of CO/syngas to electricity in an MFC was also tested at thermophilic temperature of 50°C. Silicone tubing was used for syngas delivery and the anodic design was improved to increase the microbial density. An improved volumetric power output of 33-35 mW/L and syngas conversion efficiency of 87-98 % was achieved. Also an improved Coulombic efficiency (CE) of 26 % was obtained. The analysis of the anodic microbial communities and metabolic products, along with single substrate tests where MFC was operated solely on CO or H2, revealed that similar to mesophilic MFCs electricity generation from syngas at thermophilic temperatures also occurred through syngas conversion to acetate followed by its oxidation by CO-tolerant electricigenic microorganisms. In the final study of this thesis, the applicability of a multi-electrode design containing three anodes and two cathodes to achieve high volumetric power output and CE on syngas was evaluated at several operating temperatures ranging from 37°C to 50°C. Also, the impact of different anode-cathode arrangements on power output was examined. The multi-electrode configuration considerably enhanced the system performance and provided a compact system design which could have major economic and operational implications for large scale syngas-fed MFC systems. A maximum power density of 33 mW/L and CE of 43 % was achieved at an operating temperature of 37°C. The MFC power density was greatly impacted by the anode-cathode arrangement and the highest power density was achieved in a three anode-two cathode (3A-2C) arrangement.
Composé principalement de monoxyde de carbone (CO) et d'hydrogène (H2), le gaz de synthèse est un vecteur énergétique polyvalent, qui peut être converti en un combustible liquide ou gazeux ou peut servir à la production d'électricité. La capacité du CO ou de gaz de synthèse à servir comme unique donneur d'électrons dans la production d'électricité dans une pile à combustible microbienne (PCM) ayant été récemment démontrée, la présente étude visa l'obtention d'un gain d'éfficacité de production, avec soit du CO ou du gaz de synthèse comme combustible, grâce à un aménagement amélioré de la PCM. L'étude visa aussi à élucider les communautés microbiennes et voies de biotransformation liées à la production d'électricité à partir de CO ou de gaz de synthèse dans une PCM.Un des principaux défis à une hausse d'efficacité de bioconversion de CO ou de gaz de synthèse est la faible solubilité en phase aqueuse de ces substrats gazeux. Le premier volet de ce travail démontra l'applicabilité de systèmes à membrane de silicone pour réaliser un transfert accru de CO vers l'anode liquide du PCM. L'intégration d'une membrane plane en silicone ou de tube en silicone à parois minces dans la chambre anodique d'une PCM alimentée en CO, a permis d'atteindre une éfficacité de transformation de CO accrue, et par conséquente une performance améliorée de la PCM. Une efficacité de transformation de CO de 77% et une puissance maximale de 18 mW/L furent obtenues pour une PCM équipée d'une membrane en silicone. Une efficacité de transformation de CO comparativement plus élevée (98%) fut obtenue pour une PCM équipée de tube en silicone à parois minces, mais la concentration éleve de CO dissoute dans le liquide anodique enraya en partie l'activité microbienne, baissant ainsi la puissance maximale à 13 mW/L . Un transfer gazeux efficace permetta de mettre l'accent sur le processus microbiologique. En un second volet, les communautés microbiennes et voies de biotransformation prévalentes dans deux PCM mésophiliques alimentées en CO furent élucidés. L'identification de microorganismes appartenants aux genres Geobacter, Desulfovibrio, et Clostridium, ainsi que la détection d'acétate comme principal produit métabolique dans les deux PCM, confirma notre hypothèse que la production d'électricité à partir de CO ou de gaz de synthèse dans une PCM mésophilique s'opère principalement en deux étapes: (i) le CO ou gaz de synthèse est premièrement converti en acétate par des carboxydobactéries et bactéries homoacétogéniques, puis (ii) l'acétate est oxydé par des microorganismes électrigènes tolérants au CO. Le gaz de synthèse étant principalement un gaz chaud, la bioconversion de CO ou de gaz de synthèse dans une PCM fut évalue sous des condition thermophiles à 50°C. Une puissance volumétrique accrue (33-35 mW/L) et une éfficacité de conversion de gaz de synthèse de 87-98% furent atteintes. De plus une efficacité coulombienne (EC) de 26% fut atteinte. Dans le dernier volet de cette étude, la faisabilité d'une configuration à multiples électrodes visant à permettre des PCMs consommant du gaz de synthèse à obtenir une puissance volumétrique et une EC accrue, fut évaluée à des températures de 37°C à 50°C. L'influence de la position dans laquelle les anodes et cathodes furent disposées sur la puissance générée fut évalue. Une densité de puissance maximale de 33 mW/L et une CE de 43 % furent atteintes à une température de fonctionnement de 37 °C. La densité de puissance d'une PCM fut largement influencée par la disposition et le nombre des anodes de cathodes. Un arrangement trois anodes-deux cathodes (3A-2C) offrant la plus grande puissance.

Carbon monoxide (CO) is an odorless, colorless, tasteless gas that binds to hemoglobin with high affinity. This property underlies the use of low doses of CO to determine hemoglobin mass (MHb) in the fields of clinical and sports medicine. However, hemoglobin bound to CO is unable to transport oxygen and exposure to high CO concentrations is a significant environmental and occupational health concern. These contrasting aspects of CO—clinically useful in low doses but potentially lethal in higher doses—mandates a need for a quantitative understanding of the temporal profiles of the uptake and distribution of CO in the human body. In this dissertation I have (i) used a mathematical model to analyze CO-rebreathing techniques used to estimate total hemoglobin mass and proposed a CO-rebreathing procedure to estimate hemoglobin mass with low errors, (ii) enhanced and validated a multicompartment model to estimate O2, CO and CO2 tensions, bicarbonate levels, pH levels, blood carboxyhemoglobin (HbCO) levels, and carboxymyoglobin (MbCO) levels in all the vascular (arterial, mixed venous and vascular subcompartments of the tissues) and tissue (brain, heart and skeletal muscle) compartments of the model in normoxia, hypoxia, CO hypoxia, hyperoxia, isocapnic hyperoxia and hyperbaric oxygen, and (iii) used this developed mathematical model to propose a treatment to improve O2 delivery and CO removal by comparing O2 and CO levels during different treatment protocols administered for otherwise-healthy CO-poisoned subjects.

Household fuel pollution from the use of low quality biomass fuels is considered as a risk factor for respiratory tract infections (RTI) in women and children. Inhalation of fuel-derived pulmonary toxins (e.g. particulate matter (PM2.5μm) , and carbon monoxide (CO) can harm the lungs of young children, due to their under-developed immune defences. In Bangladesh acute respiratory infections (ARI) are the leading cause of child mortality (< 5 years of age). This thesis aimed to examine the relationship between RTI and household fuel pollution exposure using measured pollution data and medical diagnoses. During an 18-month longitudinal health intervention in northern Bangladesh households (n=408) were interviewed (3 times) on cooking/fuel-use practices and child health. Anthropometric data (height/weight) and finger-prick blood samples for analysis of immune status (c-reactive protein, alpha-1-acidglycoprotein (AGP) and albumin) were collected (n=321 < 5 years of age). All unwell children (62.4%) were medically examined. Household pollution levels (particulate matter (PM2.5μm) and carbon monoxide (CO) were monitored for a 24-hour period (n=61). Moderate/ severe RTI was common (24.8%) (youngest child only n=213). Poor child growth (stunted: 43.8%, underweight=66.7%, wasted: 38.4%) and immunity were detected. 98% of the households used inefficient chimneyless mud stoves and low quality biomass fuels (wood, golden, dung). The measured indoor pollution levels exceeded the WHO safety thresholds (PM2.5 μm range: 85 to 3020 μg/m³ CO range: 0-16 ppm) (PM2.5 μm>25 μm/m³, CO>9ppm). Longitudinal multivariate GLM showed that cooking practices were associated with child immune status: haemoglobin levels (F= 1.555, p=NS) were significantly associated with Bihari ethnicity and a fixed stove use (F=3.718 and F=3.716, p<0.05 respectively). Elevated log₁₀-AGP levels were found (F=4.371, p<0.05) in Saidpur in households using a fixed stove (F=4.123, F=3.780, p<0.05). The patterns in child growth z-scores were due to age only (stunting: F=7.413, p<0.01, underweight F=5.787, p<0.05). Interestingly, poorer change score for weight-for-age (F=34.893, p<0.01) was associated with low age and more frequent cooking (F=6.441 and, F=6.553, p<0.05 respectively). Logistic regression (healthy vs. RTI) identified the presence of child by the stove during cooking as the sole risk factor for RTI (absent OR= 0.257, 95% CI: 0.097 - 0.676, p<0.01). Indoor cooking and the use of a fixed stove were associated with low SES. Education may help to reduce behaviours associated with high household fuel pollution exposure via the introduction of simple healthy cooking practices.

The NHS has to meet the Climate Change Act targets of an 80% reduction to their carbon emissions by 2050. Investigation into the components of the carbon footprint of mental health care is needed to understand how services can meet these targets. This thesis first seeks to understand what is known about the carbon footprint of mental health care through two systematic reviews and two national surveys. Second, existing methodologies for estimating carbon footprints are examined to assess whether an approach is available that is ‘fit for purpose’ in mental health care. The approach needs to be applied feasibly within a clinical context and the results need to be sufficiently robust to reliably inform decisions about service design. The aim of this research is to provide an approach that service providers can use to estimate the carbon footprint of services and then use the information obtained to inform service design. This thesis defines the boundaries of assessment to ensure a consistent approach. It suggests an approach to data collection that includes financial and activity data. It presents a review of the available methods for converting this data to carbon equivalents and finds a potential five-fold range associated with carbon footprint estimates of medication. The approach developed within this study is termed the combined approach. The combined approach is then evaluated using a scenario analysis, a four-year retrospective cohort analysis and a prospective care modelling analysis to assess whether it is fit for purpose according to specified criteria. It is concluded that the combined approach is fit for the purpose of assessing how the carbon footprint of a service changes over time. However, due to the use of financial data and the problems with estimating the carbon footprint of medication, this approach has significant weaknesses, which limits its wider use.

This study compared the effect of packaging method (0.4% carbon monoxide, 80% oxygen or vacuum), storage time (7, 14 and 21 days) and internal cooking temperature 49, 57, 66, 71 and 79°C) on color and thiobarbituric acid (TBA) values of top sirloin steaks and ground beef patties. Ground beef was obtained from 3 different sources (chuck, loin and trim). All samples were stored at 2°C for 7, 14 and 21 days. All raw ground beef samples stored in 0.4% carbon monoxide remained bright red throughout the 21-day storage period. The phenomenon of premature browning (appearance of cooked color at lower than normal cooking temperatures) was observed in samples stored in high oxygen. TBA values were highest for the samples stored in 80% oxygen. Internal a* redness values were lowest for samples stored in 80% oxygen. Percent myogobin denaturation (PMD) increased with increase in internal cooking temperature and was highest for the ground beef samples stored in 80% oxygen. The a* redness values were highest for raw steaks stored in 0.4% CO. Steaks stored in vacuum had a uniform purple color, but some browning was noticed on the surface of the samples by day 14. PMD and TBA values of cooked top sirloin steaks were highest for the samples stored in 80% oxygen This study confirms that high oxygen packaging promotes rancidity in ground beef and top sirloin steaks. Packaging in 0.4% carbon monoxide helps maintain a bright cherry red color in ground beef and top sirloin steaks for up to 21 days.

Climate change presents a major threat to global health and will further exacerbate the health inequalities that exist internationally. However, the provision of healthcare results in considerable greenhouse gas (GHG) emissions and is therefore contributing to climate change itself. Meanwhile, the integration of strategies to address climate change into global health efforts will realise health co-benefits. Meeting the challenging carbon reduction targets set within the NHS will require an improved understanding of the GHG emissions association with different forms of healthcare. This thesis explores the environmental impact of the provision of renal medicine services within the United Kingdom, placing a particular emphasis upon GHG emissions. The approach required, and the opportunities that exist, to reduce the environmental impact of renal medicine services are first explored through a review of the existing literature and a survey of the current practices of renal services in England, Scotland and Wales. A study, adhering to the principles of PAS2050, of the GHG emissions attributable to an individual renal service is then reported. This is the first assessment of the carbon footprint of an individual specialty service to include both direct and indirect GHG emissions. Consideration is given to how the results might inform carbon reduction strategies. Indicative carbon burdens for outpatient appointments and inpatient admissions are derived in order to facilitate future modelling of the emissions attributable to different clinical pathways of care. A second study, in which the GHG emissions attributable to different forms of an individual treatment (haemodialysis) are determined, is then presented. Finally, four case studies of good environmental practice within renal medicine, identified from the earlier literature search and survey, are presented in the context of the results of these studies.

In this retrospective cohort from 2002 through 2007, 104,003 singleton live births in Hillsborough County, Florida were analyzed to elucidate the relationship between feto-infant morbidity outcomes and prenatal exposure to six criteria air pollutants. This study is based on three linked databases: The Florida Hospital Discharge database; The vital statistics records of singleton live births; Air Pollution meteorological data from the Environmental Protection Agency. There are six common air pollutants, particulate matter 2.5 (PM2.5), particulate matter 10 (PM10), ground-level ozone (O3), carbon monoxide (CO), nitrogen (NOx), and lead (Pb). These pollutants are harmful to human health and the environment. The primary outcomes of interest were low birth weight (LBW), preterm births, and small for gestational age (SGA). The intent of this project is to address these issues of air pollution effects and the methodology surrounding the study of air pollution. Using modeling, exposure values of the six criteria air pollutants were assigned to mothers over their period of pregnancy. To address these methodological concerns, this study utilizes the structural equation modeling, quartile groupings with dose response, and trimester groupings to evaluate the relationship between air pollution and birth outcomes of pregnant residents. Using structural equation modeling a significant B value of 0.35 indicated that exposure to the six criteria pollutant in pregnancy may have a significant relationship to all five birth outcomes if they are broken down into latent variables. Quartile data demonstrated that NOx seemed to have most significant associations with all outcomes with a dose response for SGA. PM10 and PM2.5 had some association to LBW and VLBW at high levels. PM10 demonstrated significance in the higher doses for SGA. However, the only dose response relationship that was demonstrated for PM10 and PM2.5 was in VLBW. PM10 also demonstrated a dose response with very preterm. If sub-divided into trimester data, PM10 demonstrated a significant relationship between exposures in all trimesters and LBW, VLBW, and SGA. PM2.5 demonstrated a significant relationship between exposures in all trimesters and VLBW. CO demonstrated a significant relationship in the 2nd trimester for LBW as well as for SGA. Mothers and their babies are a vulnerable population who are more susceptible to lower levels of pollution. These air pollutants can possibly have long-term effect on their children. Implantation of laws and regulations, warning system, or more strict EPA standards may be needed to adequately control the cost to our society.

Emissions from light-duty passenger vehicles represent a significant portion of total criteria pollutant emissions in the United States. Since the 1970s, emissions testing of these vehicles has been required in many major metropolitan areas, including Atlanta, GA, that were designated to be in non-attainment for one or more of the National Ambient Air Quality Standards. While emissions inspections have successfully reduced emissions by identifying and repairing high emitting vehicles, they have been increasingly inefficient as emissions control systems have become more durable and fewer vehicles are in need of repair. Currently, only about 9% of Atlanta area vehicles fail emissions inspection, but every vehicle is inspected annually. This research addresses explores ways to create a more efficient emissions testing program while continuing to use existing testing infrastructure. To achieve this objective, on road vehicle emissions data were collected as a part of the Continuous Atlanta Fleet Evaluation program sponsored the Georgia Department of Natural Resources. These remote sensing data were combined with in-program vehicle inspection data from the Atlanta Vehicle Inspection and Maintenance (I/M) program to establish the degree to which on road vehicle remote sensing could be used to enhance program efficiency. Based on this analysis, a multi-parameter model was developed to predict the probability of a particular vehicle failing an emissions inspection. The parameters found to influence the probability of failure include: vehicle characteristics, ownership history, vehicle usage, previous emission test results, and remote sensing emissions readings. This model was the foundation for a proposed emissions testing program that would create variable timing for vehicle retesting with high and low failure probability vehicles being more and less frequently, respectively, than the current annual cycle. Implementation of this program is estimated to reduce fleet emissions of 17% for carbon monoxide, 11% for hydrocarbons, and 5% for nitrogen oxides in Atlanta. These reductions would be achieved very cost-effectively at an estimated marginal cost of $149, $7,576 and $2,436 per-ton-per-year for carbon monoxide, hydrocarbons, and nitrogen oxides emissions reductions respectfully.

Air pollution is a problem affecting developing and developed countries concerned about the adverse health effects associated with exposure to indoor and outdoor air pollutants. In developing countries like India, the problem, particularly domestic air pollution, is worsened by the use of unprocessed solid fuels for cooking. Other indoor environmental risk factors include the characteristics of housing conditions, household activities, and low Socio-economic status (SES). The potential irritants include nitrogen dioxide (NO[subscript]2), formaldehyde (HCHO), volatile organic compounds (VOCs), indoor smoking, and particulate matter (PM[subscript]2.5-10) and carbon monoxide (CO).Indoor air pollutants, especially those in domestic households are major problems that can contribute to respiratory symptoms and poor health in mothers and children and, in particular, those who live in poorer households in developing countries. There is consistent evidence that mothers and young children from these countries spend more than 80% of their time indoors, especially in the kitchen. Therefore, domestic air quality may be related to the increase in the prevalence of respiratory symptoms and other allergic conditions. In this context, this study established risk factors in the domestic environment that can determine the concentrations of domestic air pollutants and prevalence of respiratory symptoms in mothers and children. Cooking for a long time, keeping young children and infants in cooking areas, the inadequacy of ventilation, and the use of biomass fuels can relate to debilitating health problems, especially respiratory symptoms among poor households’ mothers and children particularly in developing countries.This study is cross-sectional and aims to determine that domestic concentrations of fine particles (PM[subscript]2.5), carbon monoxide (CO), and the socio-economic status (SES) and/or poverty levels, house and kitchen characteristics and households’ activities, may have a detrimental role in the prevalence of respiratory symptoms among mothers and children. One hundred and seventy households (N=170) with young children (n=299) under 15-years-of-age were selected randomly from the City of Tirupur in Coimbatore district, Tamil Nadu in South India. This city was chosen as it has diversity in terms of its ethnic mix, economic activities, physical characteristics and income disparities. Each participating household was visited and 170 households’ mothers were interviewed using a questionnaire. During the visits, study data was also collected in 80 households by measuring of indoor concentrations of PM[subscript]2.5, CO and the physical parameters, humidity and temperature.According to the statistical analysis, using biomass for cooking affects mothers’ and children’s respiratory symptoms. The results of this study show that median exposure to fine particles (PM[subscript]2.5) (1.18mg/m[superscript]3) exceeds the recommended WHO standards. CO concentrations did not have any significant relationship with mothers’ and children’s respiratory symptoms as mean concentrations of CO were 4.63ppm or 8.80mg/m[superscript]3. The study shows that kitchens with brick/stone walls and tile roofs are associated with reduced concentrations of PM[subscript]2.5 (p=0.033). If a kitchen has mud walls, a thatched roof and a floor of clay/mud, the indoor air has higher concentrations of PM[subscript]2.5 (p=0.014), Floors, such as cement, can lower the domestic air concentration of PM[subscript]2.5, (p=0.014). The study finds that lower concentrations of PM[subscript]2.5 were also found when windows were open (OR=0.14), (p=0.018).The study shows that there is a significant relationship between the prevalence of asthma in children in relation to CO and more than one time (OR=1.19) with p=0.021. In this study, it was shown that mothers with lower incomes had shortness of breath (p=0.003), almost six times higher than mothers with higher incomes. Children with allergies (78.9%) in the current study came from families where the mothers were employed as labourers and their children had respiratory symptoms such as coughing (p=0.001) and wheezing (p=0.002). The most (p=0.001) significant respiratory symptom of children from families who did not own house/unit or land was a cough: 56 (42.4%) as they usually live either in semi-open air or very badly constructed dwellings).High R/H (%) and T[superscript]oC also seem to have an effect on domestic concentrations of PM[subscript]2.5. As revealed by the statistical analysis, high T[superscript]oC and RH (%) were associated with significant impacts on mothers’ respiratory symptoms but did not have any significant impact on children’s respiratory symptoms. High-income households’ mothers and children were seen to have less significant respiratory symptoms than low-income households’ mothers. Evaluation of the literature also assessed the extent to which SES and/or poverty levels and house and kitchen characteristics and households’ activities affected respiratory symptoms in mothers and children.In conclusion, this study’s results further highlight the role of susceptibility risk factors for respiratory symptoms and show that domestic environmental factors contribute as risk factors for respiratory symptoms in mothers and children, especially in poor households. In order to improve domestic air quality and thus decrease the prevalence of respiratory symptoms, much more effort needs to be made. Because the air quality in the domestic environment is modifiable, there may be opportunities for intervention to reduce respiratory symptoms and this needs greater attention. Low SES and/or poverty levels may cause greater susceptibility to disease through malnutrition, access to health care, better housing and children’s and adult education.This study also provides recommendations how to reduce the prevalence of respiratory symptoms by improving households’ SES and/or poverty levels, one of the main risk factors for adverse health effects of respiratory symptoms in mothers and children from Tamil Nadu, South India. Since the quality of the domestic environment is very important, further intervention is needed to reduce respiratory symptoms in mothers and children, particularly young ones at a time when immune deviation usually occurs, regarding where they grow and spend most of their time. Finally, in order to reduce indoor air pollutants and respiratory symptoms in mothers and children, much more effort and greater attention needs to be paid to improve households’ low SES and/or poverty levels. The main goal should be sustainable development and poverty reduction that will enable people eventually to switch to clean fuels. SES was the most significant predicator of cooking fuel choice to ensure good health.

La sclérose en plaques (SEP) est une maladie neuro-inflammatoire du système nerveux central. Les causes sont multifactorielles impliquant à la fois une prédisposition génétique et l'influence de facteurs environnementaux. Dans environ 85% des cas, les patients sont atteints de poussées correspondants à la survenue de signes neurologiques, suivis d'une phase de rémission partielle ou totale. De nombreux travaux avancent l'hypothèse selon laquelle le taux de poussées varie au gré des saisons, survenant plus fréquemment au printemps et en été. Cette fluctuation temporelle a soulevé la question de l'influence de paramètres dépendants de la saison tels que l'ensoleillement et le statut en vitamine D, le niveau de mélatonine ou encore la pollution atmosphérique. Etant donné cette variation de la pollution de l'air, nous avons cherché à explorer l'impact à court terme des particules fines (PM10), benzène (C6H6), dioxyde d'azote (NO2), monoxyde de carbone (CO) et de l'ozone troposphérique (O3), sur le risque de déclenchement de poussée, indépendamment des saisons "chaude" (1er avril au 30 septembre) et "froide" (1er octobre au 31 mars). Ce travail s'est appuyé sur les données de patients issus du réseau ville-hôpital alSacEP. Nous avons sélectionné 424 patients atteints de SEP à début rémittent et ayant connu un total de 1 783 poussées (2000-2009). Les niveaux journaliers de pollution, produits grâce au modèle physique déterministe ADMS-Urban, ont été modélisés sur une base horaire pour chaque IRIS de la communauté urbaine de Strasbourg par l'actuelle AASQUA ATMO Grand Est. De plus, une enquête individuelle menée dans le cadre de cette étude auprès de l'ensemble des patients (PT) a permis de collecter (par questionnaire téléphonique ou auto-questionnaire sur internet) des informations personnelles socio-économiques (SES) et du mode de vie pour 188 d'entre eux (PS). Enfin, le niveau SES des IRIS a été estimé à l’aide d’un indice de défaveur social - construit à partir des données du recensement de l’INSEE. Nous avons observé une influence saisonnière délétère à court terme de la pollution (3 jours précédant la poussée) sur le risque de poussée en PT, notamment de l'O3 en saison "chaude" et des PM10 et NO2 en saison "froide". Nos résultats suggèrent également que le contexte SES puisse exacerber ces associations, notamment chez les patients résidant dans les quartiers défavorisés lors d'exposition aux PM10, NO2, C6H6 et CO ("froide") et ceux résidant dans les quartiers favorisés et défavorisés lors de l'exposition à l'O3 ("chaude"). Enfin, nous avons observé chez la PS que le niveau d'éducation faible, le revenu familial moyen, la consommation de cigarette et le manque d'activité physique régulière sont les catégories SES et du mode de vie les plus associées avec le risque de poussée lors de l'exposition à la pollution de l'air. Ce travail montre la nécessité d'étudier les expositions environnementales au cours de la SEP selon une approche holistique intégrant des facteurs individuels et contextuels
Multiple sclerosis (MS) is a neuro-inflammatory disease of the central nervous system (CNS). Causes are multifactorial enrolling both genetic predisposition and influence of environmental factors. In 85% of cases, patients experience relapse corresponding to the occurrence of neurologic signs, followed by a phase of partial or total remission. Several studies put forth the hypothesis that relapses rate varies across season, mainly occurring during spring and summer. This temporal fluctuation raised the question of season-dependent parameters influence such as sunlight exposure and vitamin D, melatonin level or ambient air pollution. Considering this variation of air pollution, we explored the short-term impact of fine particles (PM10), benzene (C6H6), nitrogen dioxide (NO2), carbon monoxide (CO) and ground-level ozone (O3), on the risk of relapse triggering, separately for "cold" (i.e., October-March) and "hot" (April-September) season. This work has drawn from data of patients provided by the alSacEP network. We included 424 patients affected with remitting MS onset who experienced 1,783 relapses over the 2000-2009 period. Daily level of air pollution was modeled through ADMS-Urban software at the census block scale of the Strasbourg metropolitan area (AASQA ATMO Grand Est). Furthermore, an individual survey was conducted among all the patients (PT) in order to collect individual socioeconomic (SES) and lifestyle features. Finally, the census block SES position was estimated using a composite deprivation index - created from the INSEE census data. A short-term (3 days preceding the relapse) seasonal adverse effect was observed in PT, in particular during exposure to O3 in "hot" season and PM10 and NO2 in "cold" season. Results also suggest that the SES context might exacerbate these associations, in particular among patients who were living in deprived neighborhood with exposure to PM10, NO2, C6H6 and CO ("cold) and those who were living in most well-of and deprived places with exposure to O3 ("hot"). Finally, we observed among Ps that low education level, average family income, smoking and lack of physical activity are more associated with the risk of relapse triggering when patients were exposed to air pollution. This work shows the need to investigate environmental exposure such as air pollution along the SEP course using a holistic approach integrating individual and contextual factors

Thesis (M.Tech.: Environmental Health)-Durban Institute of Technology, 2005 1 v. : ill. ; 30 cm
South Durban is in the province of Kwazulu-Natal in South Africa and is home to two international petro-chemical refineries, a paper mill, sewage works, an international airport, a chemical tank farm with approximately 970 tanks, a number of landfill sites, an airport, various processing and manufacturing industries which are all in close proximity to residential and recreational areas. This area is known as the South Durban Industrial Basin (SDIB). Serious concerns have arisen about the potential health impacts that could arise from ambient air pollution from these industries. Learners and staff at the Settlers Primary School situated in Merebank, a suburb in the SDIB, perceived themselves to be at risk for air pollutant related health effects owing to the schools’ geographic location. The aims of this study was a) to determine the prevalence of asthma among learners from Grades 3 and 6 and staff at Settlers Primary School and b) To investigate whether outdoor air pollutant concentrations of sulphur dioxide (SO2), oxides of nitrogen (NOx), ozone (O3), total reduced sulphur (TRS), carbon monoxide (CO) and respirable particulate matter less than 10 microns (PM10) were associated with increased signs and symptoms of asthma in the study population.

"Carbon monoxide releasing molecules (CORMs) are carbonyl organometallic complexes that liberate controlled amounts of carbon monoxide, which is a signalling and cytoprotective molecule important in human physiology and pathophysiology. Several studies in animals have shown that CORMs are beneficial in the treatment of cardiovascular diseases, inflammation and organ protection. Additionally, CORMs present antimicrobial properties. (...)"

D.Phil. (Geography)
The Infrared Atmospheric Sounding Interferometer (lASI), operational in polar-orbit since 2006 on the European MetOp-A satellite, is the most advanced of its kind in space. It has been designed to provide soundings of the troposphere and lower stratosphere at nadir in a spectral interval of 0.25 em" across the range 645-2 760 em". Fine spectral sampling such as this is imperative in the sounding of trace gases. Since its launch, the routine retrievals of greenhouse, species from IASI measurements have made a valuable contribution to atmospheric chemistry studies at a global scale. The main contribution of this thesis is the development of a new trace gas retrieval scheme for IASI measurements. The goal was to improve on the global operational scheme in terms of the algorithm complexity, speed of calculation and spatial resolution achieved in the final solution. This schemedirectly retrieves column integrated trace gas densities at single field-of-view (FOV) from IASI measurements within a 10% accuracy limit. The scheme is built on the Bayesian framework of probability and based on the assumption that the inversion of total column values, as apposed to gas profiles, is a near-linear problem. Performance of the retrieval scheme is demonstrated on simulated noisy measurements for carbon monoxide (CO). Being a linear solution, the scheme is'highly dependent on the accuracy of the a priori. A statistical estimate of the a priori was computed using a principal component regression analysis with 50 eigenvectors. The corresponding root-mean-square (RMS) error of the a priori was calculated to be 9.3%. In general terms, the physical retrieval improved on the a priori, and sensitivity studies were performed to demonstrate the accuracy and stability of the retrieval scheme under a numberof perturbations. A full system characterization and error analysis is additionally preformed to elicidate the nature of this complex problem. The hyperspectral IASI measurements introduce a significant correlation error in the retrieval. The Absorption Line Cluster (ALC) channel selection method was developed in this thesis, to address the correlation error explicitly. When a first neighbour correlation factor of 0.71 is assumed in the measurement error covariance for the clusters of ALC channels, then most of the correlation error is removed in the retrieval. In conclusion, the total column trace gas retrieval scheme developed here is fast, simple, intuitive, transparent and robust. These characteristics together make it highly suitable for implementation in an operational environment intended for air quality monitoring on a regional scale.

Tropospheric oxidation modulates pollution chemistry and greenhouse gas lifetimes. The hydroxyl radical (OH) is the primary oxidant and the main sink for methane, the second-most influential anthropogenic contributor to climate change. OH is produced following the photolysis of ozone, an oxidant, respiratory irritant and greenhouse gas. Trends in methane or ozone are frequently attributed to their sources, but sink-driven variability is less often considered. I investigate the influence of fluctuations in turbulent loss to the Earth’s surface, also known as deposition, on tropospheric ozone concentrations and chemistry over the relatively polluted eastern United States. I use idealized sensitivity simulations with the global chemistry-climate model AM3 to demonstrate that coherent shifts in deposition, on the order recently observed at a long-term measurement site, affect surface ozone concentrations as much as decreases in its precursor emissions have over the past decade. I conclude that a sub-regional deposition measurement network is needed to confidently attribute trends in tropospheric ozone. Next, I turn to the remote marine troposphere to evaluate two theoretical proxies for variability in the methane sink, OH, with observations from the NASA Atmospheric Tomography (ATom) aircraft campaign. The low concentration and short lifetime of OH preclude the development of a representative measurement network to track its fluctuations in space and time. This dearth of constraints has led to discrepancies in the methane lifetime across models that project atmospheric composition and climate. Observational and modeling studies suggest that few processes control OH fluctuations in relatively clean air masses, and the short OH lifetime implies that it is at steady-state (total production is equal to loss). I leverage this chemistry by evaluating a convolution of OH drivers, OH production scaled by the lifetime of OH against its sink with carbon monoxide, as a potential “steady-state” proxy. I also assess the predictive skill of formaldehyde (HCHO), an intermediate product of the methane and OH reaction. I find that both proxies broadly reflect OH on sub-hemispheric scales (2 km altitude by 20° zonal bins) relative to existing, well-mixed proxies that capture, at best, hemispheric OH variability. HCHO is produced following methane loss by reaction with OH and reflects the insolation influence on OH, while the steady-state proxy demonstrates a stronger relationship with OH and offers insight into its sensitivity to a wider array of drivers. Few components—water vapor, nitric oxide, and the photolysis rate of ozone to singlet-d atomic oxygen—dominate steady-state proxy variance in most regions of the remote troposphere, with water vapor controlling the largest spatial extent. Current satellite instruments measure water vapor directly, and other retrievals like nitrogen dioxide columns or aerosol optical depth or could be used to infer nitric acid or the rate of ozone photolysis. Thus satellite observations may be used to derive a steady-state proxy product to infer OH variability and sensitivity in the near-term. HCHO is also retrieved from satellite instruments, and an OH product using satellite-observed HCHO columns is already in development. The relatively high fluctuation frequency of HCHO or the steady-state proxy advances our insight into the connection between OH and its drivers. The observed steady-state proxy demonstrates a widespread sensitivity to water vapor along the ATom flight tracks, and I conclude that an improved and consistent representation of the water vapor distribution is a necessary step in constraining the methane lifetime across global chemistry-climate models.

Climate change is regarded as the greatest threat facing the world today. The Intergovernmental Panel on Climate Change (IPCC) concluded that climate change is caused by human activities, as a result of greenhouse gases (GHGs) being emitted into the atmosphere. Scientific literature on the impact of climate change is well documented, especially for the health sector. The mission of the Gauteng Department of Health (GDoH) is to “contribute towards the reduction of the burden of diseases in all the communities in Gauteng”. Ekurhuleni Health District is part of GDoH and shares a similar mission. However, this mission is under threat due to the direct and indirect impact of climate change on the public health sector. Therefore, it is essential for Ekurhuleni Health District and Provincial Clinics to take measures to reduce their contribution to climate change in the light of improving the health of their constituent. This study estimates the carbon footprint of the employees of Ekurhuleni Health District and Provincial Clinics and determines the knowledge and perception of climate change among managers and operational employees. The methodologies of the Greenhouse Gas Protocol (GHGP) and the Department of Environmental Forestry and Rural Affairs (DEFRA) were used to quantify the carbon footprints of the employees of the Ekurhuleni Health District and Provincial Clinics. A content analysis was applied to determine the knowledge and perception of climate change. The study revealed that Scope 2, indirect emissions (electricity), accounts for 92% (35150 t CO2e) of the total carbon footprints for the period of five years, 2010-2014. Scope 1, direct emission (vehicles), is responsible for 4% (1362 t CO2e) and Scope 3, indirect emissions for ICT, for 2% (862 t CO2e), office paper 1% (181 t CO2e) and air conditioners 1% (458 t CO2e). The majority of employees demonstrated basic knowledge of climate change. However, the concept of GHGs was unfamiliar to most of the employees. In terms of perceptions of climate change, the majority of employees were concerned about the future of the planet and climate change and believed that climate change will impact their job description. The study recommends the following mitigation measures, among others, to reduce carbon footprints: (1) electrical vehicles; (2) substituting personal desktops with laptops; and (3) substituting HFC-23 air conditioner refrigerant with R410A. These recommendations have the potential to reduce the carbon emissions by 2445 t CO2e for the period of five (5) years and save R7 875 089 from fuel and power consumption. Furthermore, the District Office and Provincial Clinics can generate a revenue of R293 400 by registering for a CMD project for five years or R1 173 600 for the duration of the project (20 years).
Environmental Sciences
M. Sc. (Environmental Management)

Introduction: In Timor-Leste, anemia affects approximately 21% of reproductive age of women. The established risk factor for anemia is poor nutritional status, but recently solid fuel use in the household has emerged as a possible risk factors. The association between solid fuel and anemia has been studied in children and pregnant women, but there hasn’t been a study conducted to find the association among all reproductive age women from 15-49 years old. Aim: The objective of this study is to determine if use of solid fuels (charcoal, wood, and straw/shrubs/grass) compared to cleaner fuels (electricity, LPG. natural gas, biogas, and kerosene) associated with the increasing of the prevalence of anemia among reproductive age women (15-49 years old) in Timor-Leste. Methods: This study used data from the Timor-Leste Demographic Health Survey (TLDHS) 2009-2010. The data used was based on the individual level within household from 13 districts in Timor-Leste. Bivariable logistic regression analysis was performed to assess associations between each independent variable (type of fuels, age group, BMI group, residence, wealth index, education level and smoking behavior) and the outcome variable (anemia) and mutlivariable logistic regression model was also performed with significant covariates. Results: The association based on the type of fuels showed that the odds ratio for anemia in women using solid fuels was 1.73 (OR: 95% CI: 1.49 - 2.01) compared to the women using cleaner fuels. After adjustment for other covariates, the odds ratio for anemia in women that use solid fuels was 1.43 (95% CI: 1.29-1.64) compared to women using cleaner fuels. Discussion: Based on our study population, this study found that reproductive age women 15-49 years old in Timor-Leste who used solid fuel as a source of energy for cooking or heating activities in the household were at higher risk for anemia.