Classification of dwellings into profiles regarding indoor air quality, and identification of indoor air pollution determinant factors

International audienceThis study aims to identify the most relevant variables, among outdoor measures, building characteristics and socioeconomic situation, for predicting indoor air chemical pollution in dwellings. To achieve this, we propose a two-step plan: first, group the dwellings into classes according to the indoor measured concentrations, then use regression tools to express a dwelling's class as a function of the aforementioned variables. In the first step, we use modelbased clustering algorithms in a multivariate Gaussian mixture context; in the second step, we use binary decision trees in a discrimination context. This approach does not handle the pollutants individually, but considers them together as a multidimensional variable that must be summarized by a categorical variable (the dwelling's class)

Applicability and relevance of six indoor air quality indexes

International audienceThe evaluation of indoor air quality (IAQ) in buildings is complex because IAQ involves a broad spectrum of substances and agents that vary over time and space. To address this complexity, IAQ indexes are used to describe, classify and improve IAQ by providing easy-to-understand and comprehensive rankings of IAQ levels in buildings. Although many IAQ indexes have been proposed all over the world, their relevancy regarding the evaluation of IAQ levels has not been fully studied in a large number of dwellings. In this study, six measurement-based IAQ indexes proposed for use in the USA, France, Taiwan, and Hong Kong were evaluated. The calculation of IAQ levels was based on nine indoor parameters measured in 567 French dwellings, i.e., indoor air temperature, relative humidity, and concentrations of formaldehyde, total volatile organic compounds, radon, carbon monoxide, carbon dioxide, PM2.5, and PM10. A factorial analysis using the multiple correspondence analysis and the hierarchical cluster analysis methods was performed to determine whether the calculated IAQ levels of different indexes in the studied dwellings were repeatable across all indexes. The results showed that three of the indexes tended to provide only positive IAQ ratings, while the other three indexes were more discriminating. Three classes of IAQ levels in dwellings, along with indoor parameters associated with each class, were identified. All of the indoor parameters were associated with the classification of IAQ 2 levels, while the formaldehyde concentration and relative humidity were the key parameters to identify the dwellings with the best IAQ

Base de référence nationale sur la qualité de l'air intérieur et le confort des occupants de bâtiments performants en énergie : deuxième état descriptif de la qualité de l'air intérieur et du confort de bâtiments d'habitation performants en énergie

Ce travail, réalisé dans le cadre de la convention 2014-2015 du programme "Bâtiments Performants en Énergie" de l'OQAI, fournit un deuxième état descriptif des données de qualité de l'environnement intérieur de bâtiments d'habitation performants en énergie. Il porte sur les données d'enquête relatives à 72 logements répartis dans 43 bâtiments. Le rapport, structuré en trois parties, présente : 1 /les caractéristiques des bâtiments, des logements et de leurs occupants ; 2 /les résultats des mesures de concentration du CO2, des indicateurs de qualité d'air intérieur, des paramètres de confort thermique et des débits/pressions aux bouches des systèmes de ventilation mécanique ainsi que la mise en perspective de ces résultats avec la population nationale de logements et les réglementations en vigueur non spécifiques à l'habitat ; 3/ les résultats d'une étude exploratoire sur l'influence de trois variables d'intérêt liées au bâtiment (pièce de mesure, type d'habitat et catégorie de logement) sur la qualité de l'environnement intérieur. Cette deuxième exploitation des données de la base nationale OQAI-BPE confirme les premières tendances observées lors de la première étude, à savoir une qualité de l'air intérieur globalement comparable dans les logements performants en énergie étudiés par rapport à la population nationale de logements, avec néanmoins quelques différences mises en évidence. Ainsi, dans les logements performants en énergie, on observe un indice de contamination fongique plus élevé en proportion, des concentrations en hexaldéhyde, alpha-pinène et limonène plus élevées, et des températures intérieures plus élevées. La suite de l'exploitation de la base OQAI-BPE vise à l'analyse approfondie des données de mesures en fonction des caractéristiques des bâtiments et de leurs occupants

Observatoire de la qualité de l’air intérieur. Bases méthodologiques, expérimentales et métrologiques

Note portant sur l’auteur Note portant sur l’auteur Le travail présenté dans le cadre de cette action de recherche avait pour objectif d’établir les bases méthodologiques, expérimentales et métrologiques nécessaires à la mise en place d’un réseau d’observation de la qualité de l’air dans l’environnement intérieur. Officiellement lancé le 10 juillet 2001, l’Observatoire de la qualité de l’air intérieur est conduit de manière concertée par l’ensemble des ministères concernés : Logement, Santé, ..

Régulation du métabolisme du glucose par les proteines alimentaires chez la truite arc-en-ciel (Oncorhynchus mykiss)

Le but de ce travail était de déterminer si les forts taux de proteines alimentaires pouvaient causer une production persistante de glucose hépatique chez la truite arc-en-ciel, quels que soient les apports de glucides alimentaires. des variations qualitatives ou quantitatives des acides aminés influencent l'expression des enzymes clés de ce métabolisme : les interactions entre les protéines alimentaires et le métabolisme du glucose semblent fortes mais n'expliquent pas sa faible utilsation par la truite.The ain of this study was to determine if high levels of dietary protein coukd cause an increased hepatic glucose production in rainbow trout, irrespective of the dietary carbohydrate supply. Qualitative and quantitative variations of amino acid supply modulate key gluconeogenic enzymes expression : a strong relationship between dietary protein and glucose metabolism seems to exist but does not explain its poor metabolic use by rainbow trout.BORDEAUX1-BU Sciences-Talence (335222101) / SudocSudocFranceF

Qualité de l'air dans les écoles, ventilation et santé

National audienc

Size distribution measurement of fine and ultrafine particle emission from cooking activities

International audienceWe present here a comparison of particles emission rate (diameter in the range 5 nm to 1 mm) on 8 different cooking activities (cooking with electric stove or oven). All the necessary staff for the activities was purchased from common chain stores and the test procedure is most of possible representative of the usual way

Setting of French indoor air quality guidelines for chronic exposure to benzene

International audienceIndoor air quality guidelines (IAQGs) provide safe levels of indoor pollutant concentrations below which adverse health effects are not expected to occur in the general population, including susceptible groups. The development of French IAQGs has been on-going since 2005 in the framework of the National Environment and Health Action Plan (NEHAP, 2004-2008). According to toxicological and epidemiological data, benzene inhalation leads to acute and chronic effects. For long-term exposure, haematological effects and leukaemia have been observed in the Pliofilm cohort. Benzene is classified as carcinogenic for humans and its genotoxic effects have been demonstrated. Considering non carcinogenic effects and available toxicological reference values for benzene, the IAQG of 10 micro g.m-3 is proposed to protect the general population for long-term exposure. To protect from carcinogenic effects, the proposed IAQGs are based on WHO's potency slope factor: 2 and 0.2 micro g.m-3 respectively associated with an excess lifetime risk of 10-5 and 10-6

Fine and ultrafine particles in 20 French dwellings related to time-activity diaries

International audienceFine particles (FP ; > 0,3 μm diameter) were measured continuously over a week in the living room of 20 French occupied dwellings with an optical particle counter (OPC) in the frame of the French national survey 2003-2005 conducted by the Observatory of Indoor Air Quality (OQAI). In a subset of 10 dwellings, ultrafine particles (UFP ; > 0,01 μm) were also measured with a condensation particle counter (CPC) during one evening. Particles 1-hour median levels vary between 4.3×103 and 6×104 part/cm3 for UFP and from 23 to 323 part/cm3 for FP > 3 μm. Max/min ratios vary between dwellings from 10 to 257 for FP and up to 15 for UFP. The maximum concentration for either FP or UFP occurred between 7 and 9 pm corresponding systematically with the maximum occupation rate of the living room. Reported activities and carbon monoxide (CO) monitoring allow to determine the specific sources of particles indoors, i.e. specific activity (tobacco smoke, air freshener, cooking, etc.), occupation without activity (particle resuspension), combustion (high CO), and outdoors (windows opening). RELEVANCE: Particles are a major pollutant in the indoor environment with contributions from both outdoor and indoor sources. Crossing measurements with time-activity diaries allowed to determine the major occurrence of particle pollution in dwellings within a typical week and to identify the major sources of particles. Occupation appears clearly to be a key factor as it implies the activation of direct or indirect sources (resuspension) of particles (both UFP and FP). It is thus important to adapt any strategy to reduce indoor particle exposure to the active occupation profile. UNCERTAINTY: Outdoor concentration of particles was not assessed during the experiment. It contributes to the background particle concentration especially when the windows are opened. Two OPCs and two CPCs were used in the study. Inter-instrument variations were below the measurement uncertainty (20% for CPC and 10% for OPC). The mean completion rate of time-activity diaries was 67% (23% standard deviation)

Granulométrie des particules émises par différentes activités domestiques

International audienceDans le cadre du PRIMEQUAL2, une étude sur la caractérisation des particules émises par différentes activités domestiques (cuissons sur plaque électrique ou au four, bougies, encens, utilisation de spray, utilisation d'imprimante, chauffage) a été entreprise. La présente communication est axée sur les données granulométriques observées