O balanceamento de uma rede de distribuição de ar consiste em estabelecer as vazões corretas nos elementos terminais conforme previsto no projeto. A revisão bibliográfica apontou que o balanceamento aplicado à distribuição de ar passou a ser considerado no final dos anos de 1960. A aplicação de modelos matemáticos com a simulação do escoamento do ar nos dutos das redes tem início no final dos anos 80. No presente trabalho o objetivo foi estudar metodologia para simulação e balanceamento de redes de distribuição de ar, implementando-a em um programa de computador. Foram estudados diferentes métodos para realizar o balanceamento: método proporcional, método T e o método direto. Foi adotado o direto, em que as vazões são impostas e as diferenças de pressão determinadas para escoamentos em caminhos em paralelo. Mediante o uso de conceitos que fazem analogia entre a fluido-dinâmica e a eletricidade, foi desenvolvido um algoritmo e elaborado um programa de computador. O aplicativo desenvolvido possui 6 etapas principais: caracterização da rede, perda distribuída, perda localizada, perda total, simulação do escoamento e comparação de caminhos. A partir de um estudo de caso, o programa foi testado simulando uma rede de distribuição. Esta mesma rede teve seu balanceamento avaliado por cálculos em planilha eletrônica. Os resultados do estudo de caso com os valores de pressão para todos os trechos da rede, assim como as diferenças de pressão que definem a magnitude do balanceamento foram comparados e estão coincidentes dentro da margem esperada. / The balancing of a net air distribution consists in establishment the correct flowrate in the terminals elements according the design. The bibliographic review show that the balancing applied in air distribution are consider at the 60`s. In the end of the 80\\2019s the mathematics models beginning applied to air flow simulation in ducts. In the present work the objective is studies the methodology to simulation and balancing air distribution nets using software. Different methods are studies to apply in balance: proportional method, T method and direct method. The direct method is adopted, which the flowrate is fixed and the pressure difference is obtained for the parallel paths. Using fluid-dynamics and electrical analogy concepts an algorithm was developed and a software was prepared. The applicatory developed was divided in 6 main stages: net characterization, continuous losses, local losses, total losses, flow simulation and path comparing. Using a case study the software was tested and the distribution net was simulating. This same net was balancing evaluated by a computational spreadsheet. The case study results present the values of pressure for the sections of the net, and the pressure differences to obtained the balancing. This values was consider coincident with the expected.

A disseminação de agentes infecciosos em ambientes interiores é um assunto de interesse da sociedade em geral e uma questão de saúde pública, tendo em vista os surtos recentes do vírus SARS, gripe suína, gripe aviária, etc. Em particular, o sistema com suprimento de ar individualizado têm se mostrado eficaz, atuando como barreira contra contaminação cruzada entre ocupantes. Diversas metodologias têm sido aplicadas nesses estudos, tal como gás traçador, geradores de partículas e simulação CFD, muitas vezes sem muito critério, ou com equipamentos e simulações excessivamente complexas. Neste contexto, o objetivo do presente trabalho é desenvolver um processo robusto e com menor complexidade do que os utilizados atualmente para avaliar a dispersão de contaminantes aéreos em ambientes interiores. O processo desenvolvido é aplicado em um estudo de caso onde a influência de um sistema de ventilação personalizado de cabine de aeronave é avaliado sobre a ótica da infecção cruzada. O trabalho contempla a realização de atividades de simulação computacional (CFD) e medições experimentais no ambiente interno de uma cabine de avião (mock-up), onde os campos de velocidade do ar são medidos com Velocimetria por Imagem de Partículas (PIV), partículas entre 2 e 10m são geradas com um gerador de aerossol e contadas com contadores ópticos portáteis. Obteve-se boa correlação entre os resultados numéricos e experimentais para o campo de velocidades e boa concordância qualitativa entre as contagens de partículas no experimento e nas simulações CFD Lagrangeanas. Observou-se, dentre outros aspectos, que a válvula gasper, tal como ensaiada no presente trabalho, contribui para a qualidade do ar na zona de respiração dos ocupantes sentados, promovendo um aumento nas taxas de deposição de partículas nas superfícies internas do mock-up. / The indoor dispersion of infections agents still concern the society, and has become a matter of public health, taken into account the outbreak of SARS in 2003, and the recent cases of influenza strains (H1N1, avian flu, SARS, etc). The use of personalized ventilation has improved the occupants\' air quality on recent evaluations, working as a contaminant spread barrier. Different kinds of methodologies are usually applied for those studies, such as tracer gas, particle generators and CFD simulations, sometimes without adequate criteria, or applying quite complex equipment and simulation methodologies such as transient analysis. Therefore, the main objective of the present work is to develop a robust method, and if possible less complicated than the current ones, to evaluate the dispersion of indoor airborne contaminants. Moreover, one\'s intend to apply the proposed method in a case study to evaluate the influence of a personalized ventilation system to the spread of indoor air contaminants. The study is composed by CFD simulations and experimental measurements inside an aircraft cabin mock-up, where the velocity and temperature field, as well as particle concentration are measured. Particle Image Velocimetry technique is used to analyse air flow velocities. Particles from 2 to 10µm are produced with aerosol generator and injected into the cabine. Finally, particle distributions are measured with hand held optical counters to evaluate air quality at the breathing zone. Good correlation between numerical and experimental results was obtained for velocity field, and adequate qualitative agreement was obtained for concentration field. One\'s conclude the investigated personalized ventilation system has improved the air quality around occupants breathing zone, mainly by increasing the deposition rates at the internal cabin surfaces.

Materiais de construção como: adesivos, selantes, aglomerados, compensados, carpetes, revestimentos de parede, isolamentos, forros acústicos etc., emitem compostos orgânicos volateis (COVs) em ambientes internos (Niu e Burnett, 2001). No caso da tinta no Brasil, Salasar (2006) indica que \"as tintas à base de solventes emitem 520 vezes mais COVs em relação às tintas à base de água\". Consequentemente aumentos significativos na concentração de poluentes químicos e biológicos do ar em ambientes internos são provocados pelas baixas taxas de troca de ar em conjunto com a emissão de COVs originados pelos materiais de construção dos ambientes internos (Gioda & Neto, 2003). O objetivo nesta pesquisa é identificar compostos orgânicos volateis nas emissões de tintas imobiliárias usadas em ambientes internos na cidade de São Carlos. O laboratório foi realizado com o equipamento de cromatografia gasosa acoplado a espectrometria de massas, com siglas GC/MS, junto com o aparelho para extração da amostra chamado de micro extração de fase sólida (SPME), para duas amostras de cada tinta sendo uma fresca (úmida) e outra seca. O laboratório GC/MS quando é utilizado com micro extração de fase sólida (SPME) é o método mais aproximado do ideal, já que permite qualificar os COVs contidos nas amostras de tinta com maior eficiência que qualquer outro método (Koziel & Pawliszym, 2001). A escolha das tintas, esmaltes e o verniz foram determinadas como aquelas de maior uso e venda entre os pintores e lojas de tintas, respectivamente, na cidade de São Carlos. Os resultados mostraram que as tintas podem chegar a emitir juntas mais de 61 compostos orgânicos voláteis, a maior parte deles causa irritação respiratória e cinco desses compostos são suspeitos de desenvolver câncer, a concentração de cada composto não foi determinada. Uma suposição é que a saúde dos pintores pode estar sendo afetada, pois eles têm contato constante com as emissões das tintas, neste sentido é preocupante que esses trabalhadores da construção civil sejam informais, pois nesta condição o risco à sua saúde pode ser agravado devido à falta de capacitação necessária sobre a utilização do material que estão manipulando. Parte do resultado da pesquisa mostra também por meio de um questionário, as marcas de tintas imobiliárias comumente usadas na cidade de São Carlos, assim como uma noção sobre as doenças que as tintas produzem. O questionário foi elaborado para 40 pessoas entre pintores e vendedores de lojas de tinta na cidade de São Carlos. As fichas de segurança de produtos químicos FISPQ correspondentes para cada tinta omitem informações sobre alguns ingredientes considerados de risco encontrados nas amostras de tintas, como por exemplo, compostos suspeitos de desenvolver câncer. É importante para o Brasil a criação com urgência de um selo ambiental confiável que garanta a baixa concentração de emissão de COVs nas tintas como produto, mediante valores quantificáveis. Se similar ao selo \"Green Seal\", o mesmo daria não só uma forma de controle sobre a emissão de COVs nos prédios senão confiabilidade e garantia. O selo será um parâmetro de exigência nas certificações ambientais para confirmar as baixas emissões de COVs nos materiais das edificações sustentáveis, que até agora são inexistentes. / Building materials such as: Adhesives, sealants, plywood, carpeting, wall coverings, insulation, acoustic ceilings etc., emit volatiles organic compounds (VOCs) in indoor environments (Niu e Burnett, 2001). In the case of the paint in Brazil, Salasar (2006) indicates that \"solvent-based paints emit VOCs 520 times as compared to water-based paint.\". Consequently significant concentration of chemical and biological pollutants from indoor air, are caused by low rates of air exchange in conjunction with the emission of VOCs originating from the construction of the indoor materials (Gioda & Neto, 2003). The objective of this research is to identify volatile organic compounds (VOC) emissions from architectural coatings used indoors in São Carlos. The laboratory was performed with gas chromatography equipment coupled to mass spectrometry with acronyms GC/MS, with the instrument for sample extraction called solid phase micro extraction (SPME) for two samples of each paint: a fresh (wet) and a dry. The GC/MS laboratory when used with solid phase micro extraction (SPME) is the closest to the ideal method, allows to qualify the VOCs contained in the paint samples more efficiently than any other method (Pawliszym & Koziel, 2001). The choice of paints, enamels and varnish were determined as those of greater use and sale among painters and paint stores, respectively, in the city of São Carlos. The results showed that the paint can issue more than 61 volatile organic compounds, most of them cause respiratory irritation and five of these compounds are suspected of developing cancer, the concentration of each compound was not determined. One of the hypotheses is that the health of painters may be being affected, as they have constant contact with emissions from paints,in this respect it is wrong that these workers of the construction are informal, because in this condition the risk to your health can be aggravated due to lack of necessary training on the use of the material. Part of the search result also shows by means of a questionnaire , the marks of paints commonly used in the city of São Carlos, as well as a notion about the diseases that produce the paints. The questionnaire was designed in 40 people between painters and sellers of paint shops in the city of São Carlos. Safety data sheets for chemicals corresponding MSDS for each paint omit some information about ingredients considered risk in samples of paints, such as examples, compounds suspected of developing cancer. It is important for Brazil to urgently create a reliable environmental seal that ensures low emission concentration of VOCs in paints and product through quantifiable values . If the seal is similar to the seal \"Green Seal\", it would not only a form of control over the emission of VOCs in buildings too reliability and warranty The stamp will be a requirement parameter in environmental certifications to confirm low emissions of VOCs in materials of sustainable buildings , which until now are nonexistent.

As modern life develops, humans spend most of their time inside buildings. Understanding the effects of different building materials that exist indoors on indoor air quality is crucial to ensure comfort, health, and productivity of building occupants. Indoor air quality (IAQ) is an important field of building science that focuses on studying the existence of different compounds indoors. These compounds include: airborne particles such as dust, volatile organic compounds (VOCs) such as carbonyls, reactive gases such as radon, ozone and others. Ozone is a strong oxidant gas that has adverse effects on human health, and is highly reactive with building materials that exist indoors. This reaction may reduce its concentration indoors, but may produce other by-products that could be more harmful for human health than ozone itself. In this dissertation, ozone reaction with different building materials is investigated in four studies. The first includes studying the effect of indoor carpet fiber type on ozone removal and carbonyl emissions. This study provides valuable data and knowledge about the importance of selecting carpet type and its effect on indoor environment. In the second study, different indoor plants were tested to evaluate their ability to remove ozone. The results from this study show wide variation between plants tested on ozone removal. Also, the ability of plants as ozone removal agent changes as light levels change. The third part studies ozone removal efficiency of HVAC filters previously installed in air handling units located on green and white membrane roofs of a commercial building. Detailed filter surface analysis using scanning electron microscope (SEM) was performed to understand the nature of deposits on these filters. The reason for differences in ozone removal efficiency of two filters in comparison with new filter is also discussed. The fourth study investigated ozone removal and carbonyl emissions from three different VOC content indoor latex paints. The outcomes from this research show that zero VOC latex paint has the most ozone effective removal capacity and this paint is the least carbonyl emitter. The research presented in this dissertation adds new data, valuable knowledge, and expands the understanding of the importance of selecting indoor materials to raise indoor air quality and make the buildings' indoor environment healthier and safer.

Pour répondre aux aspects essentiels du développement durable, les nouvelles constructions doivent réduire leur consommation énergétique. Cela se traduit par une meilleure isolation des bâtiments mais aussi par une maitrise et un control du renouvellement de l'air par ventilation mécanique contrôlée. De telles actions participent à l’augmentation des concentrations de polluants en intérieur pouvant avoir des conséquences sanitaires importantes. La technique de dépollution passive de l’air reposant sur des processus photocatalytiques est une solution intéressante pour répondre à cette problématique. L’objectif de cette étude est d’optimiser une peinture pour application intérieure contenant des nanoparticules de dioxyde de titane (TiO2) afin de réduire les concentrations de polluants gazeux comme de dioxyde d’azote (NO2) tout en limitant la formation de contaminants tel que l’acide nitreux (HONO). Dans cette optique, durant cette thèse, différents jeux de peintures (photocatalytiques et de référence) ont été étudiés dans des conditions simulées de laboratoire et dans un environnement réel. Les expériences en laboratoire ont montré une efficacité d’élimination du NO2 jusqu’à 4 fois plus importante sur une peinture photocatalytique que sur une peinture standard. Cette étude met également en évidence la formation hétérogène d’acide nitreux pendant la réaction photocatalysée du NO2. Les rendements de formation de HONO sont compris entre 4 et 20 % du NO2 consommé. Lors d’une étude à échelle 1, dans une pièce modèle, des concentrations significatives de HONO ont été mesurées. Ces observations mettent à jour des mécanismes encore non élucidés de formation de cette espèce en air / In order to improve building energy consumption, new constructions reduce air exchange rate by including better insulation and adding controlled ventilation. However, this energetic advantage participates in increasing the concentration of indoor pollutants and can be the cause of adverse effects on the occupants’ health. A possible solution to this issue is to use the photocatalysis principle/theory as an innovating technique for air remediation. The aim of this study is to optimize photocatalytic materials containing titanium dioxide (TiO2) in order to reduce the concentrations of indoor air pollutants such as nitrogen dioxide (NO2) without the generation of emerging contaminants such as nitrous acid HONO. Over the course of this Ph.D., effects of different photocatalytic paints, tested under simulated and real conditions were studied. Laboratory experiments showed an effective elimination of nitrogen dioxide (NO2) up to 4 times higher with a photocatalytic paint than with a standard paint, the most important parameters influencing NO2 elimination being nanoTiO2 quantity built-in the paint, light intensity, and temperature. This study also highlights the heterogeneous formation of nitrous acid (HONO) during the photocatalysis of NO2, reactivity yields range from 4 % to 20 % of used NO2. During a scale one study in a model room, a significant concentration of HONO was measured. Those observations reveal yet not fully elucidated mechanisms for the indoor formation of this compound

La qualité de l'air intérieur est devenue une préoccupation de santé publique du fait notamment de l'augmentation du temps passé dans les environnements intérieurs et les espaces clos. L'objectif de ce travail est de développer des procédés mettant en œuvre la décharge couronne afin de traiter les polluants gazeux chimiques et particulaires dans l'air intérieur. Le premier volet du travail concerne la dégradation des polluants gazeux chimiques présents en très faibles concentrations dans l’air intérieur. Le couplage d’une décharge couronne et d’un catalyseur est mis en œuvre pour dégrader du toluène dans des conditions représentatives de l’air intérieur. Cette étude démontre la très bonne efficacité de la décharge couronne vis-à-vis du toluène avec de faibles densités d’énergie. Elle identifie les conditions opératoires optimales et propose des mécanismes réactionnels suite à l’identification des principaux produits de réaction. Cependant, le plasma génère des espèces indésirables comme l'ozone et les oxydes d'azote qui doivent impérativement être détruits. Nous avons choisi d'adjoindre à la décharge couronne un catalyseur à base d'oxydes de métaux de transition (MnOx/Al2O3). Différents catalyseurs sont synthétisés puis modifiés par greffage d’agents modifiants. Leur efficacité vis-à-vis de l’ozone et des NOx est quantifiée en présence de différentes teneurs en vapeur d’eau. Le deuxième volet concerne la collecte des particules par filtration électrostatique. Trois procédés sont étudiés ; ils associent un étage d’ionisation et un étage de collecte. L’ionisation est assurée soit par un électrofiltre fil-plaque soit par des aiguilles portées à un potentiel de quelques kilovolts. L’efficacité de collecte est mesurée dans la gamme de 10 nm à 20 µm en fonction de différents paramètres opératoires (tension, polarité, vitesse, paramètres géométriques, concentration en particules, humidité, etc.). Les aiguilles ont une efficacité légèrement inférieure à celle de l’électrofiltre mais présentent une très faible production de l'ozone et une consommation énergétique moindre. L’étude paramétrique permet de dimensionner, d'optimiser la géométrie du procédé et de définir les meilleures conditions de fonctionnement / Indoor air quality has become a public health issue because of the increased time spent in indoor environments and confined spaces. The goal of this work is to develop processes using corona discharge to treat chemical gaseous and particulate pollutants in indoor air. The first part of the work concerns the degradation of chemical gaseous pollutants present in very low concentrations in indoor air. The coupling of a corona discharge and a catalyst is implemented to degrade toluene under conditions representative of the indoor air. Tests were carried out under a range of operating and environmental conditions. This study demonstrates the very good efficiency of the corona discharge for toluene with very low specific density. Optimal operating conditions are identified and reaction mechanisms are proposed following the identification of the main reaction products. However, the generations of by-products, ozone and NOx, which can be hazardous compounds, have to be taken into account. The combination of corona discharge with catalysis seems as a promising way to ensure the suitability and the safety of non-thermal plasma as an indoor air cleaner. Different catalysts based on transition metal oxides (MnOx/Al2O3) are synthesized and then modified by grafting modifying agents. Their efficiency for ozone and NOx elimination is quantified in the presence of different water vapor contents. The second part concerns the particle collection by electrostatic precipitation. Three processes are studied; they combine an ionization stage and a collection stage. The ionization is ensured either by a wire-plate electrostatic precipitator (ESP) or by needles brought to a potential of a few kilovolts. The collection efficiency is measured in the range of 10 nm to 20 μm according to different operating parameters (voltage, polarity, velocity, geometrical parameters, particle concentration, humidity, etc.). The needles have a slightly lower efficiency than the ESP but present a very low production of ozone and a lower energy consumption. The parametric study makes it possible to dimension, to optimize the geometry of the process and to define the best operating conditions

Cette thèse développe les connaissances scientifiques sur l’origine et le comportement des polluants intérieurs en phases gazeuse et particulaire. Une description complète des processus physiques contrôlant les concentrations de polluants en air intérieur dans une pièce inoccupée et non meublée a été réalisée. En utilisant des paramètres bien quantifiés (taux de renouvellement d’air, facteur de pénétration et vitesse de dépôt), nous avons pu appliquer un modèle de bilan massique aux particules. Les résultats ont montré que, en l’absence significative de sources intérieures, une caractérisation fine des paramètres ci-dessus permettait de décrire de manière satisfaisante les concentrations intérieures en PM2.5 et PM10 à partir des données extérieures, tandis que les PM1 montrent une variabilité significativement plus marquée due aux transformations physicochimiques. Par la suite, les composés organiques volatils (COV) et la composition chimique des particules submicroniques ont été mesurés en temps réel lors d’une campagne intensive. Un enrichissement important des concentrations en COV a été observé lorsque l’air ambiant pénètre à l’intérieur du bâtiment, en particulier pour les COV oxygénés qui présentent une dépendance significative avec l’humidité relative, tandis que pour les particules les changements observés dépendent de leur composition chimique et de leur diamètre, montrant une diminution de 20% pour les PM1 à 86% pour les plus grosses particules (>5 μm). L’excès d’ammonium observé dans les deux environnements a permis de déconvoluer les nitrates organiques des inorganiques, ceux-ci présentant une dépendance plus forte avec la température, révélant une décomposition thermique plus importante en air intérieur. En résumé, l’environnement intérieur agit principalement comme une source d’émissions continues de COV, alors qu’une tendance inverse est observé pour les particules, du fait de transformations possibles pouvant se produire même dans les conditions les plus simples, sans occupant ni mobilier. / This thesis improves the scientific knowledge on the origin, behavior and fate of gas and particle-phase pollutants indoors under unoccupied unfurnished conditions. A first campaign provided a complete description of the physical processes controlling the indoor concentrations. Using well quantified parameters (air exchange rate, penetration factor and deposition rate), a mass balance model provided insights for the particle budget closure. The results showed that when indoor sources are not significant, a careful characterization of the abovementioned parameters allows to estimate PM2.5 and PM10 in a satisfying manner from outdoor data. However the PM1 fraction shows a significantly higher variability due to physicochemical transformations. Subsequently, a second intensive campaign was performed to investigate volatile organic compounds (VOC) and PM1 chemical composition in real time. A strong increase in VOC concentrations was observed when outdoor air penetrates indoors, especially oxygenated VOC which exhibited a significant dependence on relative humidity, while the changes observed for particles once indoors depend on their chemical composition and diameter, showing a decrease from 20% for submicron particles up to, 86% for large ones (>5. µm). The investigation of ammonium neutralization revealed an excess of ammonium indoors and outdoors, which is attributed to organic- in addition to inorganic-bonded ammonium nitrate. The latter showed a stronger dependency on temperature gradient from outdoors to indoors, revealing stronger thermal decomposition once indoors. In summary, the indoor environment acts mainly as a continuous emission source of VOCs, while the opposite trend is observed the particles due to possible transformations that can occur even under the simplest conditions, with no occupants and no furnishing.

Indoor air quality has become a challenge together with the global aim &lsquo / decreasing energy consumption&rsquo / . Increasing insulation levels of building envelopes but implementing inaccurate building system details has caused excessive heat, accumulation of pollutants, etc. in spaces. In terms of educational spaces, the increase in complaints and illnesses due to unfavorable indoor air conditions leads to a decrease in concentration and so academic performance of students and staff. In the context, the aim of the study was indicating the poor indoor air quality conditions caused by inadequate fresh air supply in crowded educational spaces and making recommendations for the improvement. In the study, a classroom and a design studio in the METU Faculty of Architecture building were investigated. In order to examine the existing situation, at two locations of each room the temperature, relative humidity and CO2 were continuously recorded between 13 September 2011 and 24 February 2012 and air speed for ten-day periods between 26 November 2011 and 5 January 2012. The evaluation of the collected data indicated that both of the rooms had temperature, so relative humidity and CO2 accumulation problems mainly due to insufficient fresh air supply in the winter period. In order to eliminate the poor conditions in the rooms, the needed outdoor air can be provided through the inlet openings coupled with fan coils, which are in existence but not in use.

No description available.

The work started with the clinical observations in patients working in buildings with indoor air problems. Signs of seborrhoeic dermatitis, erythematous facial skin conditions and itching conditions on the trunk were noted. Another point of departure was the attribution of facial skin symptoms to VDT work by patients. A questionnaire-based prevalence study of symptoms compatible with the Sick Building Syndrome (SBS) and facial skin symptoms in 4,943 office workers formed the basis for two case referent studies, one focusing on SBS, the other on facial skin symptoms in VDT workers. The prevalence of SBS was three times higher in women than men. The prevalence was higher in young persons and in atopies. Facial skin symptoms showed the same pattern. Psychosocial work load, paper and VDT work were also risk indicators for SBS and for skin symptoms. The symptom excess in women was analyzed with reference to differences in biological or acquired risks and different illness and reporting behaviour. In spite of inequalities in social conditions at home and at work and differences in physical working conditions, these differences could only explain a small part of the gender difference. The odds ratio for SBS in women was lowered from 3.4 in the crude analysis to 3.0 in the multivariate analysis. Effect modification was in most cases stronger in men and the clinical validation of the questionnaire refuted the hypothesis that women over-report symptoms. The results indicate that the gender difference in symptom prevalence is part of a general pattem common to psychosomatic illnesses. In the case referent study of SBS, atopy, psychosocial work load, buildings built or renovated after 1977, the presence of photocopiers and a low outdoor air flow rate were risk indicators. The association between air quality and the occurrence of SBS symptoms was demonstrated by a flow-response relation between the outdoor air flow rate and SBS symptoms. In the case referent study of skin symptoms in VDT work, psychosocial work load, electric background fields, the presence of fluorescent lights with plastic shields and low cleaning frequency were risk indicators. The clinical findings in the two case groups and their referents supported the applied relevance of the studies. Compared with the referents, the SBS cases had more work- related facial erythema, seborriioeic dermatitis and general pruritus, while skin symptom cases, had more work-related facial erythema than their referents. The results show that SBS symptoms and facial skin symptoms have a multifactorial background with constitutional, psychosocial and physical risk indicators. As the indoor air quality is a determinant of SBS symptoms, and the building itself is but one source of indoor air pollution, it is suggested that the name Sick Building Syndrome (SBS) be replaced by Indoor Air Syndrome (IAS). / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1994, härtill 5 uppsatser.</p> / digitalisering@umu