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Asthma, a chronic respiratory disease affecting millions of people worldwide, can vary in severity depending on individual triggers such as Carbon Dioxide, Particulate Matter, dust mites, tobacco smoke, and indoor household activities such as cooking, cleaning, use of heating, and window opening, which can have a negative impact on indoor air quality (IAQ) and exacerbate asthma symptoms. Investigating the relationship between IAQ and asthma severity, a case study was conducted on five asthmatic participants from Bradford, UK. IAQ was measured using IoT indoor air quality monitoring devices. Indoor activities were recorded using a daily household activities questionnaire, and asthma severity was assessed using the Asthma Control Questionnaire (ACQ). Machine learning prediction models were used to analyse various IAQ parameters, such as particulate matter, carbon dioxide, and humidity levels, to identify the most significant predictors of asthma severity with IAQ. The study aimed to develop targeted interventions to improve IAQ and reduce the burden of asthma. Results showed that higher asthma severity scores were associated with increased indoor activity and higher levels of indoor air pollution. Some interventions were implemented to improve ventilation hours, significantly improving IAQ and reducing asthma symptoms, particularly those with more severe asthma. The findings indicate that interventions targeting IAQ, and indoor activities can effectively reduce asthma severity, with up to a 60% reduction in symptoms for asthma patients.

Portable ultrasonic humidifiers add moisture into room air, but they simultaneously add exposure risks of aerosolized metals from drinking water used as fill water. The inhalation exposure from emitted metals can be overlooked, and thus, co-exposure of inhalation and ingestion and co-exposure to multiple inorganic metals is investigated. The objectives of this work are: 1) predict airborne metal concentrations and particle sizes in four realistic room scenarios (33 m3 small or 72 m3 large, with varying ventilation rates from 0.2/hr -1.5/hr), and the investigated metals are arsenic, cadmium, chromium, copper, lead, and manganese; 2) characterize exposure doses and consequent risks for adults and 0.25, 1, 2.5, and 6 yr old children, when using identical drinking water ingested and as fill water, including inhalation of fine, respirable particles generated at the frequency of 8 hrs/day (equals 121.67 days/yr) and daily ingestion, under four realistic room scenarios. The risk assessment includes non-cancer [calculation of average daily dose (ADD) and hazard quotient (HQ)] and cancer risk evaluation; 3) quantify deposition fraction and deposited doses of multiple metals in human adult's and children's respiratory tract, using multi-path particle dosimetry (MPPD) model. Results show airborne-particle-bound metal concentrations increase proportionally with water metals, and a poorly ventilated room causes greater exposure. Ingestion ADDs are 2 magnitudes higher than inhalation ADD, at identical water metal concentrations and daily exposure frequency. However, in the worse-case scenario of 33 m3 small room with low air exchange rate, the consequent inhalation HQs are all greater than 1 for children and adults, except for lead, indicating significant non-cancer risks when exposed to humidifier particles under the worse-case scenario. The cancer risks for arsenic, cadmium, chromium, and lead metals reveal are greater than acceptable one case in a million population (1E-6) produced from inhalation of the humidifier emitted metal-containing particles only. The MPPD model results indicate inhaled metal-containing airborne particles deposit primarily in head and pulmonary regions, and a greater dose (unit in µg/kg body weight/day) deposits in children than adults. Inhalation of ultrasonic humidifier aerosolized metals results in additional, and potentially greater risks (indicated by HQinhalation >1, and greater deposited dose) than ingestion at the same aqueous metal concentration, especially for children. Room conditions (i.e. volume and ventilation) influence risks. Both inhalation and ingestion exposures require consideration for eliminating multiple metal exposures and health-based environmental policy making. Consumers should be aware that they may be degrading their indoor air quality by using ultrasonic humidifiers even when filling with acceptable water quality for drinking. / Doctor of Philosophy / The purpose of this work is to investigate the exposure from use of ultrasonic humidifiers filled with drinking water containing inorganic metals. Typical exposure pathway of drinking water metals is ingestion. However, inhalation of aerosolized metals can cause undesirable health effects towards metal exposure, when fill water of ultrasonic humidifiers is the same drinking water, and the inhalation of aerosolized metals exposure pathway can be overlooked. Emitted airborne particles are composed of soluble metals in drinking water, and are respirable with diameters between 100-200 nm. PM2.5 (particulate matter with aerodynamic under 2.5 µm) concentrations increase from approximately 2 µg/m3 to hundreds of µg/m3 in a common-sized room, exceeding the USEPA's regulatory level of 15 µg/m3 for ambient air PM2.5. The resulting air metal concentrations increase with increasing metals in the fill water, and/or lower ventilation rates in a household room. In addition, children receive greater average daily exposure doses than adults (i.e. average daily dose and deposited dose, in unit of µg/kg body weight/day), when assuming daily inhalation exposure of 8 hr/day and daily ingestion exposure. The ingestion doses from various metals are greater than inhalation doses, however, the inhalation risks may be greater for certain metals than ingestion. Even when using acceptable drinking water quality that meets regulations for metals, the indoor air quality is still degraded and can pose adverse health effects. In conclusion, the dissertation work presents a framework to estimate risks developed from multi-media and single or multi-metals exposure. The addition from inhalation of aerosolized metals in drinking water should be considered in an overall risk assessment, especially for the susceptible population of young children. Consumers should be aware that they may be degrading their indoor air quality by using ultrasonic humidifiers even when filling with acceptable water quality for drinking.

The purpose of the study was to examine home conditions, housing satisfactions, and allergen avoidance practices of people with allergic rhinitis, focusing on female patients who lived in an urban area in a hot, humid climate. The Morris and Winter theory of housing adjustment provides a theoretical base for this study. Nine hypotheses were tested to investigate interrelationships among home conditions, housing satisfaction in terms of health issues, allergen avoidance practices, and age. A sample of 41 female allergy patients aged 20 to 77 years completed a screening questionnaire and an in-depth survey questionnaire. The researcher visited their dwellings to conduct home observations and to take photos.Dust mite allergens were reported as the most common allergy triggers. Presence of cockroaches, presence of furry pets outdoors, molds in bathrooms, and molds in kitchens were the most common problematic home conditions. Open shelves, bookcases, drapes, horizontal blinds, and foam rubber pillows were the most common allergy related items found in respondents' bedrooms. Concerning health issues, the majority of the respondents were satisfied with their homes. Allergen avoidance practices were not followed regularly, particularly, using allergen-proof pillowcases and sheets, washing bedding in hot water, wearing a particle mask when vacuuming, using an exhaust fan, an air cleaner, a dehumidifier, and cockroach traps. The respondents who received suggestions from doctors were more likely to follow allergen avoidance practices than those who did not receive suggestions.The result shows a significant negative relationship between problematic home conditions and housing satisfaction in terms of health issues. A significant negative relationship between age and allergen avoidance practices was found. Older sufferers were less likely to use allergen-proof products. They also lived in older homes that were more likely to have allergy related conditions. The most common obstacles that prevented respondents from improving their homes in order to avoid allergens were cost of products, emotional attachment to pets, not having time to improve homes, and procrastination. Based on these findings, design recommendations, home maintenance recommendations, and lifestyle practice recommendations were developed. / Ph. D.

Forty-three (43) schools in the City of Richmond were used for this study. The rooms in these schools that were selected for testing were those rooms in which complaints about air quality were made by school staff. Tests were done to find out the counts of the different mold species present in these schools. Air-O-Cell (AOC) samples were taken in all schools, swab samples were taken in a few and in the rest biotapes were used. Samples that were taken were analyzed and interpreted at AmeriSci Laboratories, an accredited industrial hygiene laboratory. Documentation was done for the sampling methods. Statistical analysis was run on the data received. Tables of results were made, discussions done and conclusions drawn from the laboratory results.The null hypothesis for this study is that "Total inside mold counts are not elevated above the total outside mold counts in Richmond Public Schools" and the alternative hypothesis is that "Total inside mold counts are elevated above the total outside mold counts in Richmond Public Schools". Biodiversity of molds in the indoor environment should be equal to biodiversity of molds in the outdoor environment for each of the classrooms sampled. Also, Total indoor mold counts exceeding 1000 counts/m3 means that particular school could be faced with a mold problem. In conclusion, it was found out that 58% of the schools sampled could be faced with mold problems, thereby rejecting the null hypothesis, and 42% had no mold problems at all, supporting the null hypothesis. Cladosporium was the most dominant mold genus in the schools and the school with the highest total count of molds in the rooms sampled was Maggie Walker School. Recommendations were then made to reduce the abundance of molds in Richmond Public Schools.

Hospitals and healthcare facilities are very specific times of microenvironments, which requiring monitoring air quality. People who use healthcare facilities are due to a weakened immune system very sensitive to air quality. Acceptable indoor air quality in healthcare facilities may have adverse effects on job performance at the personnel and their errors may have very serious consequences. The aim of this paper is to evaluate the main components of the inner microclimate (temperature and relative air humidity) and concentrations of carbon dioxide in the environment of selected healthcare facilities in the Czech Republic and to compare the results with the related legislation. The measurements were carried out in two hospitals and nine private medical offices from December 2011 to March 2013. The results showed that the values of microclimate factors and the concentration of carbon dioxide in the environment of patient rooms were different in cold and warm part of the year. In the patient rooms the levels of relative humidity diverged from the legal requirements mostly in winter - while those of temperature in summer. The concentration of carbon dioxide was affected by the occupancy rate and the size of the rooms. Air quality in the operating theater was primarily characterized by very low relative...

Depuis 2001 et la création d'un observatoire de la qualité de l'air intérieur (OQAI), la qualité de l'air intérieur est devenue un enjeu majeur de santé publique et fait l'objet d'un cadre réglementaire qui continue d'évoluer au cours des dernières années. Deux décrets récents, en France, prévoient la mise en œuvre de l'étiquetage des matériaux de construction en fonction de leurs émissions de composés organiques volatils (COV) (décret n° 2011-321, 23/03/2011) et le contrôle de la concentration des polluants (benzène et formaldéhyde) avec un guide des valeurs pour les bâtiments ouverts au public (n ° 2011-1728, 12/02/2012). De nos jours, la méthode analytique utilisée pour mesurer la concentration en formaldéhyde dans l'air consiste en un prélèvement sur cartouche de 2,4-dinitrophénylhydrazine (DNPH), qui est analysée par chromatographie en phase liquide après extraction. Cette méthode nécessite un équipement lourd et une étape en laboratoire est nécessaire. La société Ethera développe et commercialise des capteurs spécifiques pour la détection et la mesure du formaldéhyde avec des échantillonneurs passifs ou actifs. Ce capteur est basé sur des matrices nanoporeuses contenant du Fluoral-P (4-amino-3-pentène-2-one), qui réagit sélectivement avec le formaldéhyde pour produire un composé coloré de la 3,5-diacétyl-1,4-dihydrolutidine (DDL). La DDL est détectée à 420nm par lecture optique et la différence de densité optique mesurée avant et après l'exposition du capteur est directement proportionnelle à la concentration en formaldéhyde dans l'air intérieur. Le but de cette thèse est d'améliorer les performances des échantillonneurs passifs. Les différentes phases du développement des échantillonneurs passifs sont étudiées (conception, évaluation en chambre d’exposition) avec différentes approches et méthodologies. Deux axes d'étude sont considérés: une approche théorique et des essais en laboratoire. Une approche théorique a été mise en œuvre pour optimiser un échantillonneur passif ou dimensionner un nouveau préleveur. Les tests de laboratoire ont permis d'évaluer les paramètres métrologiques des échantillonneurs passifs (limite de détection, sensibilité, répétabilité, linéarité ...) et les effets des facteurs d'exposition (température, humidité relative, concentration). / Since 2001 and the creation of a French Indoor Air Quality Observatory (OQAI), indoor air quality has become a major public health issue. It is the subject of a regulatory framework that continues to evolve in recent years. Two recent decrees, in France, foresee the implementation of the labeling of building materials according to their emissions of volatile organic compounds (VOCs) (decree n°2011-321, 23/03/2011) and the survey of air concentration of two pollutants (benzene and formaldehyde) with guide values in public buildings (n°2011-1728, 2/12/2012). Today, the analytical method used to measure formaldehyde concentration in air consists in a 2,4-dinitrophenylhydrazine (DNPH) sampling cartridge which is analyzed by liquid chromatography after solvent extraction. This method is time consuming, expensive and complicated to perform. The company Ethera develops and markets specific, sensitive sensors for detection and measurement of formaldehyde with passive or active samplers. This sensor is based on a nanoporous matrix containing Fluoral-P (4-amino-3-penten-2-one), which selectively reacts with formaldehyde to produce a colored compound the 3,5-diacetyl-1,4-dihydrolutidine (DDL). DDL is detected at 420nm by optical reading and the difference of the optical density measured before and after exposition of the sensor is directly proportional to the concentration of formaldehyde in air. The purpose of this thesis is to improve the performance of passive samplers. The different phases of the development of passive samplers are studied (design, evaluation in environmental chamber) with different approaches and methodologies. In fact, two axis of study are considered: a theoretical approach and laboratory tests. Theoretical approach will be implemented to optimize a passive sampler or for sizing a new one based on the study of theoretical sampling rates. Laboratory tests will allow to assess metrological parameters of passive samplers (detection limit, sensitivity, repeatability, linearity…) and to estimate effects of exposure factors (temperature, relative humidity, concentration levels …).

Un des enjeux pour améliorer la qualité de l’air intérieur des bâtiments est d’adopter de bonnes pratiques, notamment en matière de sélection des matériaux lors des phases de conception. Pour cela, des outils d’aide à la décision/conception sont indispensables en support à ces bonnes pratiques pour atteindre une maîtrise globale de la qualité de l’air intérieur. Dans le domaine du bâtiment, il n’existe pas à ce jour d’outil opérationnel permettant d’estimer, en amont d’une construction, la qualité de l’air intérieur. Des travaux sont engagés sur ce thème mais ils se heurtent à un manque d’informations sur le comportement des matériaux lorsque ceux-ci sont associés et soumis à des conditions normales d’usage. Ces travaux de thèse avaient donc pour objectif d’évaluer le comportement de matériaux (source ou puits) vis-à-vis de la contamination aux composés organiques volatils (COV) et au formaldéhyde lorsqu’ils sont évalués seuls dans des conditions normalisées retenues pour l’étiquetage sanitaire, mais aussi lorsqu’ils sont mis en œuvre dans des projets de construction (impact du changement d’échelle et effet d'assemblage). La méthodologie développée a donc associé des essais à l’échelle du matériau et à l’échelle d’une pièce dans le but d’acquérir des données d’entrée à un modèle pour la prédiction des concentrations et l’évaluation des contributions respectives des différents processus (émissions primaires, échanges aux interfaces air/surfaces intérieures,…) à la contamination intérieure par les COV. Une première partie de ce travail a consisté à évaluer en laboratoire les échanges de COV et de formaldéhyde à l'interface matériau-air pour une sélection de matériaux de construction et de décoration. Les émissions primaires ont été déterminées selon la méthode normalisée ISO 16000-9 et par une méthode d’échantillonnage passif basée sur un couplage cellule d'émission/micro-extraction sur phase solide (SPME) (dispositif DOSEC-SPME) et l’effet de l’assemblage de matériaux et de composants sur la qualité de l’air intérieur a été étudié. Les constantes d’adsorption/désorption du formaldéhyde sur les matériaux sélectionnés ont ensuite été déterminées par une méthodologie innovante. Ces constantes, ainsi que les données d’émission, ont été rassemblées dans une base données pour servir de critères (ou indicateurs) pour la sélection de matériaux respectueux de la qualité de l’air intérieur (QAI). Dans une deuxième partie, les résultats obtenus en conditions de laboratoire ont été confrontés à ceux obtenus en conditions réelles à l’échelle d’une pièce dans le cadre d’une étude de plusieurs mois dans le but de mettre en évidence l’impact du changement d’échelle. La dernière partie de cette thèse a consisté à développer un modèle de prévision de la QAI intégrant les données d'adsorption/désorption préalablement déterminées. A terme, la base de données et le modèle ont vocation à constituer des outils de gestion pour orienter les choix en matière de matériaux, de configuration et d'usage d’un bâtiment dans l’optique d’une réduction à la source des émissions de COV dans l’air intérieur. / One of the challenges for improving the indoor air quality of buildings is to adopt good practices, especially in the selection of materials during design phases. To this end, decision-making / design tools are essential in support of these good practices to achieve global control of indoor air quality.In the building sector, there is currently no operational tool to estimate the indoor air quality in building. Work is underway on this theme, but they encounter a lack of information on the behavior of materials when they are associated and subject to normal conditions of use.The purpose of this thesis was therefore to evaluate the behavior of materials (source or sink) with respect to contamination with volatile organic compounds (VOCs) and formaldehyde when they are evaluated alone under standardized conditions selected for health labeling, but also when they are implemented in construction projects (impact of the change of scale and the effect of assembly). The developed methodology has therefore combined material-scale and room-scale testing to acquire input data to a model for concentration prediction and assessment of the respective contributions of different processes (primary emissions, exchanges at air / interior surfaces interfaces, ...) to internal contamination by VOCs.A first part of this work consisted of laboratory evaluation of VOC and formaldehyde exchanges at the material-air interface for a selection of construction and decoration materials. The primary emissions were determined according to the ISO 16000-9 standard method and a passive sampling method based on solid-phase emission / micro-extraction (SPME) (DOSEC-SPME device) and the effect of the assembly of materials and components on indoor air quality has been studied. The adsorption / desorption constants of formaldehyde on the selected materials were then determined by an innovative methodology. These constants, as well as emission data, have been collated into a database to serve as criteria (or indicators) for the selection of IAQ-compliant materials.In a second part, the results obtained under laboratory conditions were compared with those obtained under real-world conditions on a scale of a part in a study of several months in order to highlight the impact of the change of scale.The last part of this thesis consisted in developing an IAQ prediction model integrating previously determined adsorption / desorption data. Ultimately, the database and the model are intended to constitute management tools to guide the choice of materials, configuration and use of a building with a view to reducing emissions at the source VOC in the indoor air.