Thesis (M.S.)--University of Wisconsin-Madison, 1990. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (p. 105-110).

Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. Includes bibliographical references (leaves 226-244). Available also in a digital version from Dissertation Abstracts.

Thesis (M. Sc.)--Athens Technological Institute, 1963. / Bibliography: p. 168-169.

Thesis (I.M.E.S.)--Baylor University, 2009. / Includes bibliographical references (p. 45-48).

Over the last several years studies have shown that the quality of indoor air may be worse than outdoor air. People spend as much as 90% of their time indoors, therefor, the associated health risk due to indoor air pollution may be greater than the risk due to outdoor air pollution. Building designs have altered dramatically over the last two decades resulted in "tighter" buildings that rely on sophisticated mechanical systems to provide for the quantity of air required throughout the building. These changes over the years could result in an increased number of complaints received regarding Sick Building Syndrome symptoms. The World Health Organization (WHO) estimates that up to 30% of office buildings world-wide may have significant problems regarding poor indoor air quality (IAQ). This study involves a literature study of the major indoor air pollutants regarding the source of the pollutant, the associated health effects, the measuring techniques available and the results of previous studies conducted on the specific pollutant. Measurements will be taken in two sealed buildings, one an old and the other a new building to identify the major pollutants. A questionnaire was compiled specifically for building occupants and completed by the occupants of both buildings. From the results obtained a step-by-step method for solving indoor air quality (IAQ) problems was proposed. The method was applied and evaluated in a case study of a problem building where indoor air quality related problems were experienced. The results of the study revealed that the major indoor air pollutants are present in old as well as new buildings. The study also revealed that some office workers might be more susceptible than others to the medical reactions cause to human beings by these pollutants. Some concentrations are higher in new buildings than in old buildings. The responses from the questionnaire was evaluated against the results obtained from the measurement study. The step-by-step method in the case study provided a more systematic approach at solving IAQ problems at buildings. Solving indoor air quality problems is a very practical issue and does not necessarily require an investment of expensive high technology equipment, but might merely require a practical approach. Environmental Health Officers can play a major role in providing expert advice when scrutinizing building plans. Environmental Health Officers should empower themselves with the knowledge to do inspections or investigations in office buildings by using the step-by-step method for investigating indoor air quality problems. By addressing indoor air quality problems in buildings, the workers in healthy buildings can increase their productivity with lasting effects on a company’s bottom line.

Dans les hôpitaux, les bioaérosols en suspension dans l’air peuvent contenir des cellules bactériennes ou fongiques provenant des patients, des visiteurs, du personnel et de l’environnement extérieur. Les centrales de traitement de l’air (CTA) sont des unités permettant de filtrer, de conditionner et d’assurer une bonne qualité de l’air aux occupants et sont présentes dans certains hôpitaux. Dans la littérature, il n’y a pas de consensus sur le choix des échantillonneurs d’air et les méthodes d’analyse lorsqu’on désire évaluer la qualité de l’air qui est traité dans ces centrales. Le principal défi consiste à éviter la perturbation des soins aux patients lors de l’échantillonnage de l’air dans les CTA. Le présent projet a permis de développer un protocole permettant l’échantillonnage des bioaérosols dans les CTA en utilisant des cannes d’échantillonnage sans perturber les activités qui se déroulent dans l’hôpital. L’objectif de cette étude longitudinale était d’analyser la qualité microbiologique de l’air lors de dix campagnes s’échelonnant sur une période d’un an. Les résultats de cette étude ont démontré que les saisons affectaient significativement les concentrations de microorganismes cultivables et totaux dans l’air intérieur et extérieur d’un hôpital, mais l’effet saisonnier n’influençait pas les concentrations de particules. Le traitement de l’air réalisé avec plusieurs filtres s’est avéré efficace afin de réduire les charges microbiennes et les particules. L'utilisation des méthodes de séquençage Sanger pour l’identification des colonies isolées et de séquençage à haut débit de gènes universels a permis d'obtenir un aperçu de la diversité des espèces bactériennes et fongiques et de valider l’utilisation de marqueurs d’air biologiques. Ce projet a permis d’élaborer des méthodes d’échantillonnage en air dynamique et à haut débit. Il permettra de proposer une stratégie assurant le suivi à long terme de la qualité de l’air à l'intérieur d’un hôpital sans perturber les activités qui s’y déroulent. / Air contains bioaerosols, which are airborne particles of biological origin, including bacterial or fungal cells. Bioaerosols in hospitals may contain microorganisms from patients, visitors, staff, and the outdoor environment. Air treatment units (ATU) are present in certain hospitals and aim to ensure the best air quality for occupants. The literature is scarce when it comes to the choice of air samplers and the method of analyses to assess the air quality in these ATUs. The main challenge is to avoid disruption of patient care during air sampling. The present project developed a protocol allowing the sampling of bioaerosols in ATU using sampling rods and, therefore, without disturbing the activities taking place in the hospital. The objective of this longitudinal study was to analyze the microbiological quality of the air during ten campaigns over one year. The results of this study demonstrated that the seasons significantly affect the concentrations of culturable and total microorganisms in the indoor and outdoor air of a hospital. Airborne particle concentrations were not affected by these seasonal changes. Air treatment with several filters was proven to be effective in reducing microbial loads and particles. The use of Sanger sequencing to identify isolated colonies and next-generation sequencing methods provided insight into the diversity of bacterial and fungal species. This project developed high-velocity dynamic air sampling methods. The study proposes a strategy ensuring long-term monitoring of air quality inside a hospital without disturbing the activities that are taking place inside and to validate the use of biological markers for contaminants in the air in a normal situation.

Experiments were conducted to determine the photocatalytic degradation of three types of gas-phase compounds, NOX, VOCs, and chloramines, by TiO2 impregnated tiles. The oxides of nitrogen NO and NO2 (NOx) have a variety of negative impacts on human and environmental health ranging from serving as key precursors for the respiratory irritant ozone, to forming nitric acid, which is a primary component of acid rain. A flow tube reactor was designed for the experiments that allowed the UV illumination of the tiles under exposure to both NO and NO2 concentrations in simulated ambient air. The reactor was also used to assess NOx degradation for sampled ambient air. The PV values for NO and NO2 were 0.016 cm s-1 and 0.0015 cm s-1, respectively. For ambient experiments a decrease in ambient NOx of ~ 40% was observed over a period of roughly 5 days. The mean PV for NOx for ambient air was 0.016 cm s-1 and the maximum PV was .038 cm s-1. Overall, the results indicate that laboratory conditions generally simulate the efficiency of removing NOx by TiO2 impregnated tiles. Volatile organic compounds (VOC's) are formed in a variety of indoor environments, and can lead to respiratory problems (US EPA, 2010). The experiments determined the photocatalytic degradation of formaldehyde and methanol, two common VOCs, by TiO2 impregnated tiles. The same flow tube reactor used for the previous NOX experiments was used to test a standardized gas-phase concentration of formaldehyde and methanol. The extended UV illumination of the tiles resulted in a 50 % reduction in formaldehyde, and a 68% reduction in methanol. The deposition velocities (or the photocatalytic velocities, PV) were estimated for both VOC's. The PV for formaldehyde was 0.021 cm s-1, and the PV for methanol was 0.026 cm s-1. These PV values are slightly higher than the mean value determined for NO from the previous experiments which was 0.016 cm s-1. The results suggest that the TiO2 tiles could effectively reduce specific VOC levels in indoor environments. Chlorination is a widespread form of water disinfection. However, chlorine can produce unwanted disinfection byproducts when chlorine reacts with nitrogen containing compounds or other organics. The reaction of chlorine with ammonia produces one of three chloramines, (mono-, di-, and tri-chloramine). The production of chloramines compounds in indoor areas increases the likelihood of asthma in pool professionals, competitive swimmers, and children that frequently bath in indoor chlorinated swimming pools (Jacobs, 2007; Nemery, 2002; Zwiener, 2007). A modified flow tube reactor in conjunction with a standardized solution of monochloramine, NH2Cl, determined the photocatalytic reactions over the TiO2 tiles and seven concrete samples. The concrete samples included five different concrete types, and contained either 5 % or 15 % TiO2 by weight. The PV for the tiles was 0.045 cm s-1 for the tiles manufactured by TOTO Inc. The highest PV from the concrete samples was 0.054 cm s-1. Overall the commercial tiles were most efficient at reducing NH2Cl, compared to NOX and VOC compounds. However, the concrete samples had an even higher PV for NH2Cl than the tiles. The reason for this is unknown; however, distinct surface characteristics and a higher concentration of TiO2 in the concrete may have contributed to these findings.

Digitized by Kansas Correctional Industries

Matched weight polyvinyl chloride (PVC) filters are currently available for use in total dust air sampling. This paper studies the utility of employing two superimposed filters in a cassette. Cassettes containing "paired" PVC filters were employed, in the same way matched weight filters would be used, during side by side sampling studies with cassettes housing single PVC filters, to determine whether the presence of two filters in a cassette presented problems during sampling. The effects of dust type, particle breakthrough, moisture concentration, and increased pressure drop from the addition of a second filter were studied. The presence of static electricity between filter pairs was also noted. Under recommended loading conditions "paired" filters seemed to perform as well as single filters in all aspects studied. Due to large filter weight variations found within individual batches of PVC filters, randomly selected filter pairs should not be used as actual matched weight filters.

published_or_final_version / Mechanical Engineering / Master / Master of Philosophy