The Indoor Air Quality Observatory (OQAI): a unique project to understand air pollution in our living spaces

Over the past 10 years, indoor air quality has become a major component of environmental health. In France, the Indoor Air Quality Observatory (OQAI) runs national campaigns to measure indoor air pollution in homes, schools, office spaces and health care or medical-social establishments. After presenting the pollutants concerned and their health effects, this article summarizes the main outcomes of the OQAI’s national campaigns in three types of environments: dwellings, classrooms and offices. It then focuses more specifically on the relationships between indoor air quality and energy performance, as making the building envelope more airtight to reduce energy loss can lead to reduced air exchange, resulting in a deterioration in indoor air quality. Although further research is necessary to improve our understanding of the airborne substances present in buildings and of their health effects, there are already good practices and tools that can be implemented to improve indoor air quality in our living spaces

Environnement intérieur : vers une prise de conscience française de l'enjeu sanitaire

National audienceLargement prise en compte depuis une vingtaine d'années aux Etats-Unis, au Canada et dans les pays nord-européens, la problématique de l'environnement intérieur semble émerger concrètement en France

Les composés organiques semi-volatils dans l'air des logements

National audienceLes composés organiques semivolatils peuvent être présents à la fois dans l’air et dans les poussières déposées au sol des environnements intérieurs. Les jeunes enfants, de par leurs comportements, sont ainsi exposés à ces poussières par ingestion et contact cutané, en plus de leur exposition par inhalation. D’où le projet de recherche "ECOS-PM", qui visait non seulement à mesurer les concentrations en composés organiques semivolatils dans l’air des logements, mais aussi à identifier leurs déterminants

Contamination des logements français en composés organiques semi-volatils en phase particulaire

Semi-volatile organic compounds (SVOCs) refer to a broad spectrum of molecules from different chemical families that have numerous properties. They can be used as pesticides, plasticizers, flame retardants, surfactants, lubricants, etc. Consequently, they are introduced in numerous applications in buildings or used daily by the entire population. Once emitted through evaporation or abrasion in the indoor environment or introduced from the outdoors, their chemical or biological degradation is limited, and they persist indoors. This persistence also explains why some SVOCs that were banned a few years ago are still detected in the air and dust inside buildings. In indoor environments, SVOCs are divided between the gas phase, airborne particles, and dust settled on floors and surfaces. SVOCs are of concern due to their established or suspected health effects and their widespread exposure through different environmental media and pathways. The objective of the thesis was to study the concentrations of 66 SVOCs on airborne particles (PM10) and 48 SVOCs in settled dust in two samples of dwellings randomly selected across France. PM10 were sampled during the nationwide housing survey carried out by the French Observatory of indoor air quality in 2003-2005. The dust samples were collected from vacuum cleaner bags during a nationwide survey carried out in French dwellings where at least one child aged 6 months to 6 years lived (2008-2009). The SVOCs to be analyzed had prior been selected using a ranking method based on their toxicity and indoor concentrations. The data analysis focused in particular on the identification of French specificities in terms of detected molecules and measured concentrations. It highlighted some determinants of exposure, e.g., influence of particle size, type of dust collected, dust bioaccessibility, which are not always considered and limit the comparability of results. The measured concentrations were also used to assess the health ranking implemented prior to this work and to confirm its relevance. The concentrations measured both in the air and in settled dust were compared to study the similarities in terms of concentrations and SVOC mixtures. Finally, the exposure doses to SVOCs were calculated for both a child and an adult to assess the respective contributions of inhalation and ingestion to these compounds in particulate phase in dwellings.Les composés organiques semi-volatils (COSV) font l’objet d’une attention croissante depuis une dizaine d’années. Utilisés dans de nombreux produits et matériaux du quotidien, ils sont émis dans les bâtiments par dispersion lors de l’usage, par évaporation ou abrasion. Du fait de leurs caractéristiques physico-chimiques, ces composés se répartissent à la fois dans l’air, en phases gazeuse et particulaire, et dans les poussières déposées au sol, sur le mobilier et les objets. Compte tenu du temps passé par la population dans les bâtiments, en particulier par les populations sensibles comme les enfants, les femmes enceintes et les personnes âgées, l’exposition à ces substances mérite d’être documentée, tenant compte des voies d’exposition en jeu : inhalation, ingestion et contact cutané. La thèse a porté sur les COSV présents en phase particulaire dans les logements. L’objectif de la thèse visait à exploiter les mesures de 66 COSV dans les particules en suspension de diamètre inférieur à 10 µm (PM10) et de 48 COSV dans les poussières au sol de taille inférieure à 100 µm considérées comme étant celles adhérant à la peau. Ces mesures ont été réalisées dans le cadre de deux campagnes nationales : la campagne « Logements » de l’Observatoire de la qualité de l’air intérieur conduite en 2003-2005 et l’enquête Plomb-Habitat dont les prélèvements ont eu lieu en 2008-2009. Une hiérarchisation des molécules jugées prioritaires au regard de leur impact sanitaire potentiel avait permis au préalable d’établir la liste des COSV à mesurer. L’exploitation de ces données de contamination a notamment porté sur l’identification d’éventuelles spécificités françaises au regard des molécules en présence et/ou des concentrations mesurées. Elle a permis de mettre en lumière un ensemble de facteurs déterminants de l’exposition (influence de la taille des particules, du type de poussières collectées, de leur bioaccessibilité), qui ne sont pas toujours considérés et qui limitent par ailleurs la comparabilité des résultats. Les concentrations mesurées ont aussi permis d’évaluer rétrospectivement la hiérarchisation sanitaire et d’en confirmer la pertinence. Les concentrations des COSV quantifiés à la fois dans l’air et au sol ont été mises en perspective afin d’examiner dans quelle mesure les particules en suspension et les poussières déposées sont similaires en termes de concentrations et de mélanges de COSV en présence. Enfin, l‘estimation des doses d’exposition aux COSV à partir d’équations simples, de variables humaines d’exposition et des données de contamination a permis une première évaluation des contributions respectives de l’inhalation et de l’ingestion aux expositions domestiques des enfants et adultes à ces composés en phase particulaire

Indoor Air Quality Requirements in Green Building Certifications

International audienceGreen building certifications aim to achieve sustainable buildings that are healthy, energy-saving, and environmentally friendly. To construct healthy built environments for occupants, a high indoor environment quality (IEQ) has to be maintained. The goal of this paper is to analyze how and to what extent indoor air quality (IAQ), as a subset of IEQ, is taken into account in green building certifications worldwide. Thus, IAQ requirements were reviewed in 31 green building certifications from 30 countries worldwide. These certification programs include 13 countries in Asia, 9 in Europe, 5 in Americas, 2 in Oceania, and 1 in Africa. Fifty-five green building schemes were selected from among the 31 certifications. Rating systems are commonly used in green building schemes to evaluate the capability and level of a building to achieve life-cycle sustainability. The average contribution of IAQ to green building schemes worldwide is 2 7.5%. Volatile organic compounds (VOCs), formaldehyde, and carbon dioxide (CO2) are the indoor air pollutants most frequently considered. Ozone (O3) and semi-volatile organic compounds (SVOCs) are mentioned in less than 6.7% of the certifications worldwide. Emission source control, ventilation, and indoor air measurement are the three main pathways used in green building schemes for IAQ management. All of the certifications include ventilation as a way to manage IAQ. Emission source control is included in 77% of the certifications and is mainly targeted at building material emissions. Indoor air measurement is included in 65% of the certifications but may be optional

A long-term dynamic model for predicting the concentration of semivolatile organic compounds in indoor environments: application to phthalates

International audienceSemivolatile organic compounds (SVOCs) in indoor environments can partition into the gas phase, airborne particles, and settled dust and onto available surfaces. A long-term dynamic model was developed to predict the hourly concentrations of SVOCs over a year in the gas phase, airborne particles, and settled dust and on each sink surface. The model takes into account mass transfer mechanisms, the reactivity of SVOCs with oxidants indoors, and the influence of four indoor environmental factors (the air temperature, relative humidity, concentration of indoor airborne particles, and air exchange rate) on the mass transfer parameters. The model was validated for DEHP (di-2-ethylhexyl phthalate) and BBzP (butyl benzyl phthalate) by comparing the predicted concentrations in all the phases with the measured concentrations obtained in an environmental chamber and a test house. The model was then used to predict the hourly averaged concentration of BBzP in all the phases under real environmental conditions over a year. More than 52% of the variance in the BBzP concentration was found to be associated with the covariance of the environmental factors. The air exchange rate contributed to 16% of the variance in the concentration. In addition, the indoor air temperature and relative humidity contributed 9% of the variance in the gas-phase concentration of BBzP and 7% of the variance in the settled dust concentration of BBzP. The variance in the concentration of the total suspended particles contributed 10% of the variance in the BBzP concentration on the walls and windows

VOCs and formaldehyde emissions from cleaning products and air fresheners

International audienceHuman indoor exposure to Volatile Organic Compounds (VOCs) may be associated with the use of household products. However little is known about their emissions and to what extent they contribute to indoor air pollution. The French Agency for Environmental and Occupational Health Safety (Afsset) conducted tests in order to characterize VOCs emissions from 32 consumer products: air fresheners, glass cleaners, furniture polishes, toilet products, carpet and floor cleaning products. All experiments were conducted by the Scientific and Technical Centre for Building (CSTB) in realistic conditions of use (in emission test chamber or in an experimental house). Results show that the use of consumer products can lead to high indoor VOCs concentrations. Some of them are toxic airborne contaminants. The link between formaldehyde emissions and product compositions is discussed. Finally, formaldehyde concentrations are compared to the indoor air quality guideline value proposed by Afsse

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

Cumulative indoor exposures to Semi-Volatile Organic Compounds (SVOCs) in France: the ECOS project.

International audienceSemivolatile organic compounds (SVOCs) are widely used indoor as plasticizers, flame retardants, or pesticides. They are present in indoor environments both in air (as gas and suspended particles) and settled dust. Thus exposition to possibly harmful agents: (phthalates, polybromodiphenylethers, organophosphorous compounds...) occurs (Mitchell et al. 2007;Wu et al. 2007). Here is presented the framework of the ECOS project, which objective is to assess domestic cumulative exposure to these substances and associated health risks