It is a dilemma problem to achieve both these two goals: a) to maintain a best indoor air quality and b) to use a most efficient energy for a house at the same time. One of the outstanding components involving these goals is a smart ventilation system in the house. Smart ventilation strategies, including demand-controlled ventilation (DCV), have been of great interests and some studies believe that DCV strategies have the potential for energy reductions for all ventilation systems. This research aims to improve smart ventilation system, in aspects of energy consumption, indoor CO2 concentrations and living comfortness, by analyzing long-term sensor data. Based on a case study on an experimental house -- Dalarnas Villa, this research investigates how the current two ventilations modes work in the house and improves its ventilation system by developing customized ventilation schedules. A variety of data analysis methods were used in this research. Clustering analysis is used to identify the CO2 patterns and hence determine the residents living patterns; correlation analysis and regression analysis are used to quantify a model to estimate fan energy consumption; a mathematical model is built to simulation the CO2 decreasing when the house is under 0 occupancy. And finally, two customized schedules are created for a typical workday and holiday, respectively, which show advantages in all aspects of energy consumption, CO2 concentrations and living comfortness, compared with the current ventilation modes.

Firewood is a dominant household fuel type used in many developing countries. Even in countries where there is improved access to electricity, most households still rely on firewood for their energy needs. Harvesting of some wood is illegal, however the high poverty rate, absence of alternative fuels and lack of law enforcement means even the protected wood species will continue to be used, with consequent pressure on the forests. Furthermore, the combustion of firewood for domestic use takes place in poorly ventilated homes emitting hazardous pollutants, which causes indoor air pollution and affect human health. The use of firewood as a household fuel can be superimposed nearly perfectly on that of socioeconomic development. Additionally, the use of household firewood is invariably associated with poverty in countries, in communities within a country and in households within a community. Indoor air pollution studies on human health should then consider socio-economic factors which seem to be one of the determinants of both firewood use and ill health, a determinant which is often neglected in most indoor air pollution studies. Domestic inhalation of firewood smoke is one of the mechanisms linking socio-economic (poverty) to disease. The current study sought to determine a baseline of wood usage and health risks caused by volatile organic compounds in Senwabarwana villages. This study integrated observations, ethnobotanical meta-analysis and experimental into one comprehensive integrated environmental health risk assessment framework to assess the risks associated with exposure to volatile organic compounds from firewood combustion. Basic information about firewood usage, socio-economic dynamics and perceived health problems related to volatile organic compounds was collected using a structured questionnaire. The Vac-U-Chamber was used to sample the air. The results show that firewood is extensively used in poorly ventilated kitchens for cooking and home heating in Senwabarwana villages. Ten priority firewood plant species are frequently used in the study area, namely Mohweleri (Combretum apiculatum), Moretshe (Dichrostachys cinera), Motswiri (Combretum imberbe), Mokgwa (Acacia burkei), Mushu (Acacia tortilis), Motshe (Cussonia paniculate), Mokata (Combretum hereroense), Mphata (Lonchocarpus capassa), Mokgalo (Ziziphus mucronate) and Mogwana (Grewia monticola), in their order of preference. The results also indicated thirteen common reasons or factors that influence the hoice of firewood plant species by households, the main four being: (i) the embers formed during combustion, (ii) heat value, (iii) low ash content and (iv) availability of the firewood plant species. Further analysis revealed several uses and ranking thereof, including reviewing the national status and legal profile of each identified plant species. The study found that most of the firewood species used in Senwabarwana Village were indigenous. Major drivers of firewood use are household income, educational status of breadwinners, family sizes, and place of residence, fuel affordability and accessibility, among others. Concentrations of benzene, toluene, ethylbenzene and xylene per plant species were studied to assess the risk exposed to the Senwabarwana community. Literature indicates that these pollutants have several health effects associated with acute exposure such as eye, nose and throat irritation, headaches, dizziness, nausea and vomiting. Both hazard quotient and hazard index were found to be less than one indicating no risk exists with the use of plant species used for firewood in Senwabarwana even to sensitive individuals. The risk of developing health effects due to the presence of the studied volatile organic compounds can be assessed as negligible. Since firewood is a more convenient source of energy, it is recommended that the size of the windows be extended for ventilation. Agroforesty should also be implemented as a conservation method. The wood that emits less concentration of pollutants be used for firemaking. / Environmental Sciences

Dans le but d’évaluer la contamination des atmosphères intérieures et extérieures induite par les usages non agricoles de pesticides, deux approches complémentaires ont été mises en oeuvre : l’utilisation de capteurs passifs de type Tenax TA pour réaliser des prélèvements d’air, et l’utilisation de cheveux employés comme biomarqueurs d’exposition. Des campagnes de mesures ont été menées sur plusieurs sites à la suite de traitements de désherbage ou de désinsectisation ainsi quedans des logements. Les échantillons d’air et de cheveux ont été extraits respectivement par thermodésorption et par extraction solide-liquide, avant d’être analysés en chromatographie gazeuse couplée à la spectrométrie de masse (GC-MS). Une augmentation du niveau de contamination de l’air extérieur et intérieur et l’existence de transferts entre ces deux milieux ont pu être observées après l’application de pesticides. Dans les logements, des pesticides actuellement employés mais aussi des pesticides interdits et persistants ont été détectés. Plusieurs pesticides ont également été détectés dans les cheveux, mais l’exposition humaine à ces derniers n’a pas pu toujours être corrélée à une contamination de l’air. / In order to evaluate indoor and outdoor air contamination resulting from non-agricultural uses of pesticides, two complementary approaches were applied: passive samplers based on Tenax TA used for air sampling and hair used as biomarkers of exposure. Sampling campaigns were conducted on several sites after weeding and pest control treatments as well as in accommodations. Air samples and hair samples were respectively extracted by thermal desorption and solid-liquid extraction prior to their analysis by gas chromatography combined with mass spectrometry (GC-MS). An increase of the indoor and outdoor air contamination levels and the existence of transfers between these two environments could be observed after pesticides applications. In accommodations, pesticides currently used and banned but persistent ones were detected. Several pesticides were also detected in hair samples but human exposure to these pesticides cannot be correlated with air contamination in all cases.

La pollution de l’air intérieur est aujourd’hui reconnue comme un enjeu de santé publique. La règlementation impose depuis 2012 un étiquetage des matériaux de construction et d’ameublement en matière d’émission de polluants volatils. Bien que les méthodes de mesure d’émission de polluants soient nombreuses, il n’existe aucun matériau-standard émissif de référence pour les polluants de l’air intérieur qui permettrait la comparaison et la validation des mesures d’émission. L’objectif de ce travail est de produire des matériaux émissifs de référence en utilisant des matériaux à porosité contrôlée avec des tailles de pores adaptées à celle du polluant-cible pour un relargage contrôlé en concentration en fonction du temps. Les matériaux étudiés sont des polymères inorganiques ou hybrides organique-inorganiques synthétisés par voie sol-gel sous forme de blocs monolithiques ou déposés sur des substrats solides (verre ou textile). Différents matériaux microporeux ou/et mésoporeux ont été dopés au toluène et au naphtalène par exposition à leur vapeur saturante pendant des durées variables (2h à plusieurs jours). Ceci permet d’étudier l’influence de la taille des pores du matériau sur la vitesse de relargage du polluant. Le suivi cinétique du relargage spontané des polluants est réalisé selon un 1er mode statique avec une mesure optique du spectre d’absorption du polluant gazeux dans l’UV en fonction du temps. Dans le 2ème mode, le relargage dynamique sous balayage d’air du matériau dopé disposé dans une cellule FLEC normalisée est réalisé avec une mesure en continu de la concentration du polluant par chromatographie en phase gazeuse. Nous avons montré qu’il est possible de produire des matériaux à porosité contrôlée avec des gammes de distributions de tailles de pores allant de 0,8 à 12 nm. En choisissant judicieusement la matrice poreuse et la durée de dopage et en contrôlant les conditions de mise en œuvre (température, humidité), nous pouvons imposer la vitesse de relargage du polluant. Les gammes de vitesses d’émission vont de 30 µg.m-3.h-1 (classe A+) à 8.104 µg.m-3.h-1 (classe C) pour le toluène et de 2,6.103 à 2,6.104 µg.m-3.h-1 pour le naphtalène. Ces résultats montrent que ces matériaux pourront être utilisés pour une large gamme de polluants. / Indoor air pollution is now recognized as a public health issue. Since 2012, the regulations have required the labelling of construction and furnishing materials with regard to the emission of volatile pollutants. Although there are many methods for measuring pollutant emissions, there is no standard reference emissive material for indoor air pollutants that would allow for comparison and validation of emission measurements. The objective of this work is to produce reference emissive materials by using porous materials with pore sizes tailored to the doped target pollutant with controlled release in pollutant concentration over time. The materials studied are inorganic or hybrid organic-inorganic polymers synthesized by sol-gel in the form of monolithic blocks or deposited on solid substrates (glass or textile). Various microporous and/or mesoporous materials have been doped with toluene and naphthalene pollutants by exposure to the latters’ saturated vapour for varying periods of time (2 hours to several days). The influence of the size of the pores of the material on the release of the pollutant has been studied. The kinetic monitoring of the spontaneous release of pollutants is carried out in two independent modes. A 1st static mode involves an optical measurement of the absorption spectrum of the gaseous pollutant in the UV as a function of time. In the 2nd mode, the dynamic air-sweeping release of the doped material placed in a standard FLEC cell is carried out with continuous measurement of the pollutant concentration by gas chromatography. We have shown that it is possible to produce materials with controlled porosity with narrow pore size distributions over the 0.8 to 12 nm domain. Further, by choosing judiciously the porous matrix and doping time and controlling the experimental conditions of release (temperature, humidity), we can impose the rate of release of the pollutant. The emission velocity ranges from 30 µg.m-3.h-1 (class A+) to 8.104 µg.m-3.h-1 (class C) for toluene and from 2.6.103 to 2.6.104 µg.m-3.h-1 for naphthalene. These results indicate that these materials can be used for a wide range of pollutants.

No description available.

<p>This study is focused on the design, production, and operation of a controlled environmental olfaction chamber to evaluate human physiological and emotional response to volatile chemical emissions (VCPs) from scented household products in addition to careful characterization of the volatile organic compounds (VOCs) present in these product emissions. Utilizing proton transfer reaction time-of-flight mass spectrometry, the chamber can collect VCP emissions and identify VOCs present to complete an accurate chemical profile of household and common product emissions not previously known. This instrument is one of the first of its kind and will serve as a key element in understanding the relationship between human physical and cognitive health and the built environment.</p>

In this thesis the oxidation of monoterpenes by O3 and NO2 and factors that influenced the oxidation were studied. In the environment both ozone (O3) and nitrogen dioxide (NO2) are present as oxidising gases, which causes sampling artefacts when using Tenax TA as an adsorbent to sample organic compounds in the air. A scrubber was developed to remove O3 and NO2 prior to the sampling tube, and artefacts during sampling were minimised when using the scrubber. The main organic compounds sampled in this thesis were two monoterpenes, alfa-pinene and delta-3-carene, due to their presence in both indoor and outdoor air. The recovery of the monoterpenes through the scrubber varied between 75-97% at relative humidities of 15-75%. The reactions of alfa-pinene and delta-3-carene with O 3, NO2 and nitric oxide (NO) at different relative humidities (RHs) and reaction times were studied in a dark reaction chamber. The experiments were planned and performed according to an experimental design were the factors influencing the reaction (O3, NO2, NO, RH and reaction times) were varied between high and low levels. In the experiments up to 13% of the monoterpenes reacted when O3, NO2, and reaction time were at high levels, and NO, and RH were at low levels. In the evaluation eight and seven factors (including both single and interaction factors) were found to influence the amount of alfa-pinene and delta-3-carene reacted, respectively. The three most influencing factors for both of the monoterpenes were the O 3 level, the reaction time, and the RH. Increased O3 level and reaction time increased the amount of monoterpene reacted, and increased RH decreased the amount reacted. A theoretical model of the reactions occurring in the reaction chamber was created. The amount of monoterpene reacted at different initial settings of O3, NO2, and NO were calculated, as well as the influence of different reaction pathways, and the concentrations of O3 and NO2, and NO at specific reaction times. The results of the theoretical model were that the reactivity of the gas mixture towards alfa-pinene and delta-3-carene was underestimated. But, the calculated concentrations of O3, NO2, and NO in the theoretical model were found to correspond to a high degree with experimental results performed under similar conditions. The possible associations between organic compounds in indoor air, building variables and the presence of sick building syndrome were studied using principal component analysis. The most complex model was able to separate 71% of the “sick” buildings from the “healthy” buildings. The most important variables that separated the “sick” buildings from the “healthy” buildings were a more frequent occurrence or a higher concentration of compounds with shorter retention times in the “sick” buildings. The outcome of this thesis could be summarised as follows; - - - -

Depuis quatre décennies, la prévalence des affections respiratoires chroniques de l'enfant a considérablement augmenté dans les pays développés. Les conditions de survenue de ces affections sont complexes, mais de nombreux travaux suggèrent la contribution importante de l'exposition par inhalation aux polluants de l'air intérieur. Dans ce contexte, cette thèse vise à évaluer l’exposition cumulée à une gamme de polluants chimiques et biologiques de l’air intérieur dans un échantillon donné de logements. Il a également pour objectif de créer une typologie des logements en fonction de leur multi-contamination, et vise à construire des modèles explicatifs des concentrations des polluants en fonction des caractéristiques de l’habitat et des habitudes de vie des occupants.Une enquête environnementale a été menée dans 150 logements issus de la cohorte Pélagie, suivie en Bretagne depuis 2002. Des prélèvements ont permis de mesurer la concentration de 8 aldéhydes, 4 THM, 22 autres COV, 9 COSV et 4 genres de moisissures dans l’air de ces logements. Celles-ci, ainsi que 4 allergènes ont également été dosés dans des échantillons de poussières. Les paramètres d’ambiance (température, humidité relative et dioxyde de carbone) ont été mesurés. Un questionnaire renseigné par les familles a permis de collecter des informations sur les logements et leurs occupants : structure et historique du bâtiment, revêtements, ménage, chauffage, aération, utilisation de certains produits ou réalisation d’activités particulières. Ces données ont été analysées par des approches statistiques multivariées, et des modèles de régression linéaire et logistique ont été mis en oeuvre pour relier les concentrations des contaminants aux caractéristiques des logements. Ces mesures ont mis en évidence une contamination importante et systématique des logements par une grande part des contaminants chimiques et biologiques, à des niveaux parfois élevés au regard d’études comparables et des valeurs guides lorsqu’elles existent. Des analyses en composantes principales ont permis de mettre en évidence des sous-groupes de composés qui ont pu être interprétés en termes de sources, et de sélectionner un certain nombre de composés traceurs représentatifs de chaque sous-groupe. Une analyse factorielle multiple a permis de répartir les logements en 7 classes, chacune présentant un profil de multi-contamination particulier. Enfin, les modèles de régression linéaire et logistique construits pour les composés traceurs permettent d’expliquer entre 5 et 60% de la variabilité des concentrations, et mettent en évidence la multiplicité des sources, l’importance de la description précise des environnements intérieurs, et l’impact des paramètres d’ambiance sur ces concentrations. Ce travail décrit donc une contribution importante à l’évaluation des expositions aux contaminants de l’air intérieur et fournit un certain nombre d’éléments quant à la prédiction des expositions dans les environnements intérieurs. / For the last four decades, the prevalence of chronic respiratory affections in children has increased dramatically in developed countries. Occurring conditions of these affections are complex, but many studies suggest the important contribution of inhalation exposure to indoor air pollutants. In this context, this thesis aims to assess the cumulative exposure to a range of chemical and biological pollutants in indoor air in a given sample of dwellings. It also aims to create a typology of these dwellings based on their multi-contamination, and to build explanatory models for concentrations of pollutants based on characteristics of the dwellings and lifestyle of the occupants. An environmental survey was conducted in 150 dwellings from the Pelagie cohort, followed in Brittany since 2002. We measured the concentration of 8 aldehydes, 4 THMs, 22 other VOCs, 9 SVOCs and 4 mold genera in the air of these dwellings. Molds as well as four allergens were also measured in dust samples. Ambient parameters (temperature, relative humidity and carbon dioxide) were also measured. A questionnaire completed by families allowed collecting information on dwellings and their occupants: structure and history of the building, wall and floor coatings, cleaning, heating and ventilation habits, use of certain products or performing specific activities. These data were analyzed by multivariate statistical approaches, and linear and logistic regression models were used to link the concentrations of the contaminants with the housing characteristics. These measures showed an important and systematic contamination of the dwellings by a large amount of both chemical and biological contaminants, sometimes at relatively high levels regarding comparable studies and guideline values when they exist. Principal components analysis allowed to identify subgroups of compounds that could be interpreted in terms of sources, and to select representative compounds of each subgroup. A multiple factor analysis was used to classify the dwellings into 7 categories, each with a special multi-contamination profile. Finally, linear and logistic regression models built for the representative compounds explained between 5 and 60% of the variability of the concentrations, and highlighted the multiplicity of sources, the importance of a precise description of indoor environments, and the impact of the ambient parameters on these concentrations. This work thus describes an important contribution to the exposure assessment to indoor air contaminants and provides elements for prediction of exposures in indoor environments.

<p>In this thesis the oxidation of monoterpenes by O3 and NO2 and factors that influenced the oxidation were studied. In the environment both ozone (O3) and nitrogen dioxide (NO2) are present as oxidising gases, which causes sampling artefacts when using Tenax TA as an adsorbent to sample organic compounds in the air. A scrubber was developed to remove O3 and NO2 prior to the sampling tube, and artefacts during sampling were minimised when using the scrubber. The main organic compounds sampled in this thesis were two monoterpenes, alfa-pinene and delta-3-carene, due to their presence in both indoor and outdoor air. The recovery of the monoterpenes through the scrubber varied between 75-97% at relative humidities of 15-75%.</p><p>The reactions of alfa-pinene and delta-3-carene with O 3, NO2 and nitric oxide (NO) at different relative humidities (RHs) and reaction times were studied in a dark reaction chamber. The experiments were planned and performed according to an experimental design were the factors influencing the reaction (O3, NO2, NO, RH and reaction times) were varied between high and low levels. In the experiments up to 13% of the monoterpenes reacted when O3, NO2, and reaction time were at high levels, and NO, and RH were at low levels. In the evaluation eight and seven factors (including both single and interaction factors) were found to influence the amount of alfa-pinene and delta-3-carene reacted, respectively. The three most influencing factors for both of the monoterpenes were the O 3 level, the reaction time, and the RH. Increased O3 level and reaction time increased the amount of monoterpene reacted, and increased RH decreased the amount reacted.</p><p>A theoretical model of the reactions occurring in the reaction chamber was created. The amount of monoterpene reacted at different initial settings of O3, NO2, and NO were calculated, as well as the influence of different reaction pathways, and the concentrations of O3 and NO2, and NO at specific reaction times. The results of the theoretical model were that the reactivity of the gas mixture towards alfa-pinene and delta-3-carene was underestimated. But, the calculated concentrations of O3, NO2, and NO in the theoretical model were found to correspond to a high degree with experimental results performed under similar conditions. The possible associations between organic compounds in indoor air, building variables and the presence of sick building syndrome were studied using principal component analysis. The most complex model was able to separate 71% of the “sick” buildings from the “healthy” buildings. The most important variables that separated the “sick” buildings from the “healthy” buildings were a more frequent occurrence or a higher concentration of compounds with shorter retention times in the “sick” buildings.</p><p>The outcome of this thesis could be summarised as follows;</p><p>-</p><p>-</p><p>-</p><p>-</p>

<p>The principal aim was to study selected aspects of indoor environment in dwellings and their association with symptoms compatible with the sick building syndrome (SBS). A validated questionnaire was developed specifically for residential indoor investigations, using sociological principles and test procedures. The questionnaire was mailed to 14,243 multi-family dwellings in Stockholm, selected by stratified random sampling. Females, subjects with a history of atopy, those above 65 y, and those in new buildings reported more symptoms. Subjects owning their own dwelling had less symptoms. A multiple regression model was developed, to identify residential buildings with a higher than expected occurrence of SBS. In total, 28.5% reported at least one sign of building dampness in their home (condensation on windows, humidity in the bathroom, mouldy odour, water leakage). All indicators of dampness were related to symptoms, even when adjusting for demographic data, and other building characteristics (OR=2.9-6.0). Associations between symptoms and other building data was evaluated in older houses, built before 1961. Subjects in older buildings with a mechanical ventilation system had fewer symptoms. Heating by electric radiators, and wood heating was associated with an increase of most types of symptoms (OR=1.2-5.0). Multiple sealing measures (OR=1.3), and major reconstruction (OR=1.1-1.9), was associated with an increase of symptoms. The effect of seasonal adapted ventilation (SAV) was studied in a small experimental study. A 20% reduction of ventilation flow from 0.5-0.8 ac/h to 0.4-0.5 ACH during the heating season increased the perception of poor indoor air quality in the dwelling in general, and in the bedroom. In conclusion, low building age, and building dampness in the dwelling are associated with SBS. In older houses, mechanical ventilation is beneficial. The thesis did not support the view that energy saving measures in general is an important risk factor for SBS, but major reconstruction and multiple sealing measures can be risk factor for symptoms. Reducing the outdoor ventilation flow below the current Swedish ventilation standard (0.5 ACH) may increase the perception of impaired air quality. </p>