title: Chemical kinetics of multiphase reactions between ozone and human skin lipids: Implications for indoor air quality and health effects.
abstract: Ozone reacts with skin lipids such as squalene, generating an array of organic compounds, some of which can act as respiratory or skin irritants. Thus, it is important to quantify and predict the formation of these products under different conditions in indoor environments. We developed the kinetic multilayer model that explicitly resolves mass transport and chemical reactions at the skin and in the gas phase (KM-SUB-Skin). It can reproduce the concentrations of ozone and organic compounds in previous measurements and new experiments. This enabled the spatial and temporal concentration profiles in the skin oil and underlying skin layers to be resolved. Upon exposure to ~30 ppb ozone, the concentrations of squalene ozonolysis products in the gas phase and in the skin reach up to several ppb and on the order of ~10 mmol m-3. Depending on various factors including the number of people, room size, and air exchange rates, concentrations of ozone can decrease substantially due to reactions with skin lipids. Ozone and dicarbonyls quickly react away in the upper layers of the skin, preventing them from penetrating deeply into the skin and hence reaching the blood.
authors.affiliation: Multiphase Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany.
authors.forename: P S J
authors.initials: PSJ
authors.lastname: Lakey
authors.affiliation: Department of Chemistry, University of Oslo, Oslo, Norway.
authors.forename: A
authors.initials: A
authors.lastname: Wisthaler
authors.affiliation: Multiphase Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Berkemeier
authors.affiliation: Department of Chemistry, University of Oslo, Oslo, Norway.
authors.forename: T
authors.initials: T
authors.lastname: Mikoviny
authors.affiliation: Multiphase Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Pöschl
authors.affiliation: Multiphase Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany.|Department of Chemistry, University of California, Irvine, CA, USA.
authors.forename: M
authors.initials: M
authors.lastname: Shiraiwa
mesh_terms: D000393:Air Pollutants; D016902:Air Pollution, Indoor / Q000032:analysis; D004784:Environmental Monitoring; D006801:Humans; D007700:Kinetics; D008055:Lipids / Q000737:chemistry*; D013058:Mass Spectrometry; D008954:Models, Biological; D009930:Organic Chemicals / Q000737:chemistry; D010126:Ozone / Q000032:analysis* / Q000737:chemistry; D012867:Skin / Q000378:metabolism*
chemical_list: D000393:Air Pollutants; D008055:Lipids; D009930:Organic Chemicals; D010126:Ozone
keywords: dicarbonyls; kinetic modeling; ozone; respiratory irritants; skin irritants; squalene