Near Real-Time Monitoring of Formaldehyde in a Low-Energy School Building

International audienceThe emergence of new super-insulated buildings to reduce energy consumption places the quality of indoor air at the center of the debate. Among the indoor air pollutants, aldehydes are often present, and formaldehyde is of major interest regarding its multiple sources and its health impact. Therefore, French regulations expect to reduce formaldehyde concentrations below 10 μg m −3 in public buildings by 2023. Formaldehyde and other aldehydes were measured for two weeks during an intensive field campaign conducted in a school recently built and equipped with programmable dual-flow ventilation. Aldehydes were monitored with the ISO 16000-3 reference method based on sampling with 2,4-dinitrophenylhydrazine (DNPH) tubes while formaldehyde concentration was continuously measured by using a sensitive near real-time formaldehyde microanalyzer with a detection limit of 1 μg m −3. Formaldehyde was the major aldehyde. Its concentrations varied in the range of 2-25 μg m −3 and decreased by half when mechanical ventilation was ON, while the other ones were always below 5 μg m −3. In addition, an excellent agreement was observed between the different analytical techniques deployed to quantify formaldehyde levels. The microanalyzer was able to measure fast variations of formaldehyde concentration in the studied room, according to the building's ventilation periods

Collection of substantial amount of fine and ultrafine particles during the combustion of miscanthus and forest residues in small and medium scale boilers for morphological and chemical characterizations

Renewable energies are destined to play a very important role in the future world energy balance. Among these energies, biomass production and utilization is growing considerably since it offers the possibility to provide partial substitution of fossil fuels. If health impacts of fine particles (PM2.5) from diesel combustion are well documented (Gangwar et al., 2012), those from biomass combustion need substantial information and improvements. Size fractionations of PM2.5 have to be performed in order to both determine morphological and chemical characteristics, these properties being essential for biological effects. Particulate matter was sampled during combustion of miscanthus and forest residues in medium and small scale biomass boilers (400 kW from Köb Pyrot and 40 kW from REKA). Fly ashes from medium scale boiler were sampled with a cyclone device and their granulometry was studied with both optical microscope and Malvern laser granulometer. PM2.5 (sized in the range of 0.4 μm to 2.07 μm) from low scale boiler were sampled using a DEKATI DGI impactor modified for substantial PM collection. A quick overview of setup modifications for manual impactor will be developed. Particles were observed using fluorescence microscopy. A semi-quantitative method to compare fly ashes fluorescence was developped using ImageJ (Schneider et al., 2012). Speciation of organic compounds Polycyclic Aromatic Hydrocarbon (PAH) and Humic Like Substances (HULIS) was determined on PM2.5 and fly ashes. A correlation between observed fluorescence and concentration was attempted

Development of rapid air sampling methods followed by analyses in laboratory : determination of temporal variations of volatile organic compounds and semi-volatile organic compounds concentrations to highlight indoor physico-chemical processes

Cette thèse se consacre à la mise au point de techniques d’échantillonnage suivies d’analyses réalisées au laboratoire pour mettre en évidence les espèces majoritaires en air intérieur et caractériser leurs variations temporelles. Le développement analytique a été effectué pour 52 COVs et pour 16 HAPs associés à la phase particulaire de l’air. Les prélèvements des COVs ont été réalisés au moyen d’un préleveur automatique permettant d’échantillonner l’air sur des tubes extraits par désorption thermique et analysés par chromatographie gazeuse couplée à la détection FID. Pour la quantification des HAPs, le prélèvement des particules est effectué par un impacteur à cascade à trois étages permettant de fractionner l’aérosol en fonction de leur diamètre aérodynamique. Les HAPs sont quantifiés par chromatographie liquide haute performance couplée à la détection par fluorescence. Ces deux techniques ont été mises en application dans le cadre de la 1ère campagne intensive du projet MERMAID.This work aims at developing rapid and simple air sampling techniques followed by laboratory analyses to highlight the occurrence of the main species in indoor air and to describe their temporal variations. The analytical development was focused on 52 VOCs belonging to a wide variety of chemical families to determine their concentrations. The sampling step was performed using an automatic sampler allowing the sampling of air on adsorbent tubes. These tubes were then thermally desorbed and analyzed by gas chromatography coupled to FID. Another analytical development was conducted to determine the particle bound PAHs concentrations. The sampling of particles was realized by the mean of a 3-stages cascade impactor allowing an aerosol fractionation depending on their aerodynamic diameter. Finally, quantification of PAHs was realized by liquid chromatography coupled to fluorescence detection. These two techniques were applied in a field campaign in the frame of the MERMAID program

Développement de méthodes d'échantillonnage rapides et d'analyses différées au laboratoire : détermination de l'évolution temporelle des concentrations des COVs et COSVs et compréhension des processus physico-chimiques en air intérieur

This work aims at developing rapid and simple air sampling techniques followed by laboratory analyses to highlight the occurrence of the main species in indoor air and to describe their temporal variations. The analytical development was focused on 52 VOCs belonging to a wide variety of chemical families to determine their concentrations. The sampling step was performed using an automatic sampler allowing the sampling of air on adsorbent tubes. These tubes were then thermally desorbed and analyzed by gas chromatography coupled to FID. Another analytical development was conducted to determine the particle bound PAHs concentrations. The sampling of particles was realized by the mean of a 3-stages cascade impactor allowing an aerosol fractionation depending on their aerodynamic diameter. Finally, quantification of PAHs was realized by liquid chromatography coupled to fluorescence detection. These two techniques were applied in a field campaign in the frame of the MERMAID program.Cette thèse se consacre à la mise au point de techniques d’échantillonnage suivies d’analyses réalisées au laboratoire pour mettre en évidence les espèces majoritaires en air intérieur et caractériser leurs variations temporelles. Le développement analytique a été effectué pour 52 COVs et pour 16 HAPs associés à la phase particulaire de l’air. Les prélèvements des COVs ont été réalisés au moyen d’un préleveur automatique permettant d’échantillonner l’air sur des tubes extraits par désorption thermique et analysés par chromatographie gazeuse couplée à la détection FID. Pour la quantification des HAPs, le prélèvement des particules est effectué par un impacteur à cascade à trois étages permettant de fractionner l’aérosol en fonction de leur diamètre aérodynamique. Les HAPs sont quantifiés par chromatographie liquide haute performance couplée à la détection par fluorescence. Ces deux techniques ont été mises en application dans le cadre de la 1ère campagne intensive du projet MERMAID

An analytical method coupling accelerated solvent extraction and HPLC-fluorescence for the quantification of particle-bound PAHs in indoor air sampled with a 3-stages cascade impactor

International audienc

Simultaneous Monitoring of Particle-Bound PAHs Inside a Low-Energy School Building and Outdoors over Two Weeks in France

International audienceThe emergence of new super-insulated buildings to reduce energy consumption can leadto a degradation of the indoor air quality. While some studies were carried out to assess the airquality in these super-insulated buildings, they were usually focused on the measurement of gasphase pollutants such as carbon dioxide and volatile organic compounds. This work reports the firstmeasurements of Polycyclic Aromatic Hydrocarbons (PAHs) associated with particles as a functionof time and particle size in a low-energy building. The airborne particles were collected indoorsand outdoors over three to four days of sampling using two three-stage cascade impactors allowingto sample simultaneously particles with aerodynamic diameter Dae > 10 µm, 2.5 µm < Dae < 10 µm,1 µm< Dae < 2.5 µm, and Dae < 1 µm. The 16 US-EPA priority PAHswere then extracted and quantifiedby high-performance liquid chromatography (HPLC) coupled to fluorescence detection. The resultingtotal particle concentrations were low, in the ranges 3.73 to 9.66 and 0.60 to 8.83 µg m-3 for indoorsand outdoors, respectively. Thirteen PAHs were always detected in all the samples. The total PAHconcentrations varied between 290 and 415 pg m-3 depending on the particle size, the environment(indoors or outdoors) and the sampling period considered. More interestingly, the temporal variationsof individual PAHs highlighted that high molecular weight PAHs were mainly associated to the finestparticles and some of them exhibited similar temporal behaviors, suggesting a common emission source.The indoor-to-outdoor concentration ratios of individual PAH were usually found close to or less than 1,except during the event combining rainy conditions and limited indoor ventilation rate

Particle-bound PAHs quantification using a 3-stages cascade impactor in French indoor environments

International audienc

An Assessment of Indoor Air Quality in the Arrivals Hall of Beirut–Rafic Hariri International Airport: Monitoring of VOCs and NO2

In Beirut–Rafic Hariri International Airport (RHIA), airport employees stay at least 12 h inside the airport’s buildings and suffer from respiratory symptoms. Additionally, direct openings exist between the apron and the arrivals hall providing a pathway for contaminated air to enter the buildings. Hence, we study the impact of Beirut–RHIA’s activities on the indoor air of the arrivals hall (impact on employees and passengers) during June, November, and October 2014. Due to their impacts on air quality and human health, assessing of the concentrations of nitrogen dioxide (NO2) and Volatile Organic Compounds (VOCs) was the target of our study by using gas chromatographic techniques (GC-MS and GC-FID) for VOCs and calorimetric methods for NO2 concentrations. NO2 levels indicated a probable hazard to the health of passengers and employees, while measured VOC levels did not present any risks except for acrolein. This is the first study to assess the speciation of a large number of VOCs (46 VOCs) for airport indoor air while revealing a very interesting correlation between aircraft number and the concentrations of VOC groups (namely heavy alkanes, aldehydes and ketones, and monoaromatics). Moreover, this is the first study in Lebanon to assess the speciation of a large number of VOCs in indoor air

An assessment of indoor air quality in the maintenance room at Beirut-Rafic Hariri International Airport

International audienc

Temporal Variations of Atmospheric PAHs in an Urban Area (Strasbourg, France) by Using Long-Duration High-Volume Sampling

International audienc