Identification of the major HOxradical pathways in an indoor air environment.
OH and HO2profiles measured in a real environment have been compared to the results of the INCA-Indoor model to improve our understanding of indoor chemistry. Significant levels of both radicals have been measured and their profiles display similar diurnal behavior, reaching peak concentrations during direct sunlight (up to 1.6×106and 4.0×107cm-3for OH and HO2, respectively). Concentrations of O3, NOx, volatile organic compounds (VOCs), HONO, and photolysis frequencies were constrained to the observed values. The HOxprofiles are well simulated in terms of variation for both species (Pearson's coefficients: pOH=0.55, pHO2=0.76) and concentration for OH (mean normalized bias error: MNBEOH=-30%), HO2concentration being always underestimated (MNBEHO2=-62%). Production and loss pathways analysis confirmed HONO photolysis role as an OH precursor (here up to 50% of the production rate). HO2formation is linked to OH-initiated VOC oxidation. A sensitivity analysis was conducted by varying HONO, VOCs, and NO concentrations. OH, HO2, and formaldehyde concentrations increase with HONO concentrations; OH and formaldehyde concentrations are weakly dependent on NO, whereas HO2concentrations are strongly reduced with increasing NO. Increasing VOC concentrations decreases OH by consumption and enhances HO2and formaldehyde.
Laboratoire Image Ville Environnement, LIVE UMR 7362 CNRS, Université de Strasbourg, Strasbourg, France.|Laboratoire des Sciences de l'Ingénieur pour l'Environnement, LaSIE UMR 7356 CNRS, Université de La Rochelle, La Rochelle, France.
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0000-0003-2970-7600
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Mendez
PhysicoChimie des Processus de Combustion de l'Atmosphère, PC2A UMR 8522 CNRS, Université Lille 1, Villeneuve d'Ascq, France.
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Amedro
Laboratoire Image Ville Environnement, LIVE UMR 7362 CNRS, Université de Strasbourg, Strasbourg, France.
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Blond
Laboratoire Image Ville Environnement, LIVE UMR 7362 CNRS, Université de Strasbourg, Strasbourg, France.|Laboratoire des Sciences du Climat et de l'Environnement, LSCE UMR 8212, Gif sur Yvette, France.
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Hauglustaine
Laboratoire des Sciences de l'Ingénieur pour l'Environnement, LaSIE UMR 7356 CNRS, Université de La Rochelle, La Rochelle, France.
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Blondeau
Emissions, Measurements, and Modeling of the Atmosphere (EMMA) Laboratory, Unité Environnement, Génomique Fonctionnelle et Études Mathématiques, Centre d'Analyses et de Recherche, Faculty of Sciences, Saint Joseph University, Beirut, Lebanon.|Laboratoire Interuniversitaire des Systèmes Atmosphériques, LISA UMR 7583 CNRS, Université Paris-Est Créteil (UPEC), Université Paris Diderot (UPD), Créteil, France.
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Afif
PhysicoChimie des Processus de Combustion de l'Atmosphère, PC2A UMR 8522 CNRS, Université Lille 1, Villeneuve d'Ascq, France.
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Fittschen
PhysicoChimie des Processus de Combustion de l'Atmosphère, PC2A UMR 8522 CNRS, Université Lille 1, Villeneuve d'Ascq, France.
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Schoemaecker
D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry; D016902:Air Pollution, Indoor / Q000032:analysis*; D004784:Environmental Monitoring; D005557:Formaldehyde / Q000032:analysis; D017665:Hydroxyl Radical / Q000032:analysis* / Q000737:chemistry; D010084:Oxidation-Reduction; D055549:Volatile Organic Compounds / Q000032:analysis*
D000393:Air Pollutants; D055549:Volatile Organic Compounds; D005557:Formaldehyde; D017665:Hydroxyl Radical
HOx chemistry; HOx measurements; field campaign; indoor air chemistry; nitrous acid; photolysis