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Downey JP, Lakey PSJ, Shiraiwa M, Abbatt JPD. Ozone Loss on Painted Surfaces: Dependence on Relative Humidity, Aging, and Exposure to Reactive SVOCs. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:12073-12081. [PMID: 38923518 DOI: 10.1021/acs.est.4c02208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Abstract
Ozone and its oxidation products result in negative health effects when inhaled. Despite painted surfaces being the most abundant surface in indoor spaces, surface loss remains one of the largest uncertainties in the indoor ozone budget. Here, ozone uptake coefficients (γO3) on painted surfaces were measured in a flow-through reactor where 79% of the inner surfaces were removable painted glass sheets. Flat white paint initially had a high uptake coefficient (8.3 × 10-6) at 20% RH which plateaued to 1.1 × 10-6 as the paint aged in an indoor office over weeks. Increasing the RH from 0 to 75% increased γO3 by a factor of 3.0, and exposure to 134 ppb of α-terpineol for 1 h increased γO3 by a factor of 1.6 at 20% RH. RH also increases α-terpineol partitioning to paint, further increasing ozone loss, but the type of paint (flat, eggshell, satin, semigloss) had no significant effect. A kinetic multilayer model captures the dependence of γO3 on RH and the presence of α-terpineol, indicating the reacto-diffusive depth for O3 is 1 to 2 μm. Given the similarity of the kinetics on aged surfaces across many paint types and the sustained reactivity during aging, these results suggest a mechanism for catalytic loss.
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Affiliation(s)
- Jillian P Downey
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Pascale S J Lakey
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Manabu Shiraiwa
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Jonathan P D Abbatt
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
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2
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Link MF, Robertson RL, Shore A, Hamadani BH, Cecelski CE, Poppendieck DG. Ozone generation and chemistry from 222 nm germicidal ultraviolet light in a fragrant restroom. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2024; 26:1090-1106. [PMID: 38787731 DOI: 10.1039/d4em00144c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2024]
Abstract
Devices using 222 nm germicidal ultraviolet light (GUV222) have been marketed to reduce virus transmission indoors with low risk of occupant harm from direct UV exposure. GUV222 generates ozone, an indoor air pollutant and oxidant, under constrained laboratory conditions, but the chemistry byproducts of GUV222-generated ozone in real indoor spaces is uncharacterized. We deployed GUV222 in a public restroom, with an air change rate of 1 h-1 one weekend and 2 h-1 the next, to measure ozone formation and byproducts generated from ozone chemistry indoors. Ozone from GUV222 increased background concentrations by 5 ppb on average for both weekends and reacted rapidly (e.g., at rates of 3.7 h-1 for the first weekend and 2.0 h-1 for the second) with gas-phase precursors emitted by urinal screens and on surfaces. These ozone reactions generated volatile organic compound and aerosol byproducts (e.g., up to 2.6 μg m-3 of aerosol mass). We find that GUV222 is enhancing indoor chemistry by at least a factor of two for this restroom. The extent of this enhanced chemistry will likely be different for different indoor spaces and is dependent upon ventilation rates, species and concentrations of precursor VOCs, and surface reactivity. Informed by our measurements of ozone reactivity and background aerosol concentrations, we present a framework for predicting aerosol byproduct formation from GUV222 that can be extended to other indoor spaces. Further research is needed to understand how typical uses of GUV222 could impact air quality in chemically diverse indoor spaces and generate indoor air chemistry byproducts that can affect human health.
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Affiliation(s)
- Michael F Link
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
| | - Rileigh L Robertson
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
| | - Andrew Shore
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
| | - Behrang H Hamadani
- National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
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3
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Huang L, Frank ES, Shrestha M, Riahi S, Tobias DJ, Grassian VH. Heterogeneous Interactions of Prevalent Indoor Oxygenated Organic Compounds on Hydroxylated SiO 2 Surfaces. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:6623-6630. [PMID: 33945687 DOI: 10.1021/acs.est.1c00067] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Oxygenated organic compounds (OOCs) are widely found in indoor environments and come from either the direct emissions from indoor activities or the subsequent oxidation of nonoxygenated OCs. Adsorption and partitioning of OCs on surfaces are significant processes in indoor chemistry, yet these interactions specifically involving OOCs are still poorly understood. In this study, we investigate the interactions of three prevalent indoor OOCs (dihydromyrcenol, α-terpineol, and linalool) on an indoor surface proxy (hydroxylated SiO2) by combining vibrational spectroscopy with ab initio molecular dynamics simulations. The adsorption of these compounds on the SiO2 surface is driven by π hydrogen bonding and O-H hydrogen bonding interactions, with O-H hydrogen bonding interactions being stronger. The results of kinetic measurements suggest that indoor surfaces play a significant role in the removal of these OOCs, especially under moderate and low air exchange. Additionally, indoor surfaces can also serve as a reservoir of OOCs due to their much slower desorption kinetics when compared to other indoor relevant organic compounds such as limonene. Overall, the results gleaned by experiment and theoretical simulations provide a molecular representation of the interaction of OOCs on indoor relevant surfaces as well as implications of these interactions for indoor air chemistry.
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Affiliation(s)
- Liubin Huang
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, United States
| | - Elianna S Frank
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Mona Shrestha
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, United States
| | - Saleh Riahi
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Douglas J Tobias
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Vicki H Grassian
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, United States
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4
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Deming BL, Ziemann PJ. Quantification of alkenes on indoor surfaces and implications for chemical sources and sinks. INDOOR AIR 2020; 30:914-924. [PMID: 32115779 DOI: 10.1111/ina.12662] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 12/31/2019] [Accepted: 02/25/2020] [Indexed: 05/03/2023]
Abstract
Indoor surfaces are known to support organic films, but their thickness, composition, and variability between environments remain poorly characterized. Alkenes are expected to be a significant component of these films, with the reaction with O3 being a major sink for O3 and source of airborne chemicals. Here, we present a sensitive, microscale, nanospectrophotometric method for quantifying the alkene (C=C bond) content of surface films and demonstrate its applicability in five studies relevant to indoor air chemistry. Collection efficiencies determined for a filter wipe method were ~64%, and the overall detection limit for monoalkenes was ~10 nmol m-2 . On average, painted walls and glass windows sampled across the University of Colorado Boulder campus were coated by ~4 nm thick films containing ~20% alkenes, and a simple calculation indicates that the lifetime for these alkenes due to reaction with O3 is ~1 hour, indicating that the films are highly dynamic. Measurements of alkenes in films of skin oil, pan-fried cooking oils, a terpene-containing cleaner, and on various surfaces in a closed classroom overnight (where carboxyl groups were also measured) provided insight into the effects of chemical and physical processes on film and air composition.
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Affiliation(s)
- Benjamin L Deming
- Department of Chemistry and Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
| | - Paul J Ziemann
- Department of Chemistry and Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
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5
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Blanchard EL, Lawrence JD, Noble JA, Xu M, Joo T, Ng NL, Schmidt BE, Santangelo PJ, Finn M. Enveloped Virus Inactivation on Personal Protective Equipment by Exposure to Ozone. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2020:2020.05.23.20111435. [PMID: 32511511 PMCID: PMC7273279 DOI: 10.1101/2020.05.23.20111435] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Ozone is a highly oxidizing gas easily generated from atmospheric oxygen with inexpensive equipment and is commonly used for the disinfection of municipal water, foods, and surfaces. We report tests of the ability of ozone to inactivate enveloped respiratory viruses (influenza A virus and respiratory syncytial virus), chosen as more easily handled surrogates for SARS-CoV-2, on N95 respirators and other personal protective equipment (PPE) commonly used in hospitals. At 20 ppm, an ozone concentration easily achieved by standard commercial equipment, the viruses were inactivated with high efficiency as long as the relative humidity was above a threshold value of approximately 50%. In the absence of humidity control, disinfection is more variable and requires considerably longer exposure under relatively dry conditions. This report extends the observations of a previous publication (http://doi.org/10.1080/01919510902747969) to hospital-relevant materials and provides additional details about the relationship of humidity to the antiviral activity of ozone. Home CPAP disinfection devices using ozone can provide effective results for individuals. Ozone did not appear to degrade any of the materials tested except for elastic bands if strained during treatment (such as by the pressure exerted by stapled attachment to N95 respirators). The filtration efficiency of N95 respirator material was not compromised. Overall, we recommend exposures of at least 40 minutes to 20 ppm ozone and >70% relative humidity at ambient temperatures (21-24°C) for 4-log (99.99%) reduction of viral infectivity on a variety of PPE, including gowns, face shields, and respirators. Shorter exposure times are likely to be effective under these conditions, but at the risk of some variability for different materials. Higher ozone concentrations and higher humidity levels promoted faster inactivation of viruses. Our work suggests that ozone exposure can be a widely accessible method for disinfecting PPE, permitting safer re-use for healthcare workers and patients alike in times of shortage.
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Affiliation(s)
- Emmeline L. Blanchard
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Justin D. Lawrence
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Jeffery A. Noble
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA
| | - Minghao Xu
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, USA
| | - Taekyu Joo
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Nga Lee Ng
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Britney E. Schmidt
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Philip J. Santangelo
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - M.G. Finn
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, USA
- School of Biological Sciences; Georgia Institute of Technology, Atlanta, GA, USA
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6
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Angulo Milhem S, Verriele M, Nicolas M, Thevenet F. Does the ubiquitous use of essential oil-based products promote indoor air quality? A critical literature review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:14365-14411. [PMID: 32162221 DOI: 10.1007/s11356-020-08150-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 02/19/2020] [Indexed: 06/10/2023]
Abstract
Essential oils are frequently used as natural fragrances in housecleaning products and air fresheners marketed as green and healthy. However, these substances are volatile and reactive chemical species. This review focuses on the impact of essential oil-based household products on indoor air quality. First, housecleaning products containing essential oils are explored in terms of composition and existing regulations. Specific insight is provided regarding terpenes in fragranced housecleaning products, air fresheners, and pure essential oils. Second, experimental methodologies for terpene monitoring, from sampling to experimental chambers and analytical methods, are addressed, emphasizing the experimental issues in monitoring terpenes in indoor air. Third, the temporal dynamics of terpene emissions reported in the literature are discussed. Despite experimental discrepancies, essential oil-based products are significant sources of terpenes in indoor air, inducing a high exposure of occupants to terpenes. Finally, the fate of terpenes is explored from sorptive and reactive points of view. In addition to terpene deposition on surfaces, indoor oxidants may induce homogeneous and heterogeneous reactions, resulting in secondary pollutants, such as formaldehyde and secondary organic aerosols. Overall, essential oil-based products can negatively impact indoor air quality; therefore, standard protocols and real-scale approaches are needed to explore the indoor physics and chemistry of terpenes, from emissions to reactivity.
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Affiliation(s)
- Shadia Angulo Milhem
- IMT Lille Douai, SAGE, Université de Lille, 59000, Lille, France
- Centre Scientifique et Technique du Bâtiment (CSTB), 38000, Grenoble, France
| | - Marie Verriele
- IMT Lille Douai, SAGE, Université de Lille, 59000, Lille, France
| | - Melanie Nicolas
- Centre Scientifique et Technique du Bâtiment (CSTB), 38000, Grenoble, France
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7
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Abbatt JPD, Wang C. The atmospheric chemistry of indoor environments. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2020; 22:25-48. [PMID: 31712796 DOI: 10.1039/c9em00386j] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Through air inhalation, dust ingestion and dermal exposure, the indoor environment plays an important role in controlling human chemical exposure. Indoor emissions and chemistry can also have direct impacts on the quality of outdoor air. And so, it is important to have a strong fundamental knowledge of the chemical processes that occur in indoor environments. This review article summarizes our understanding of the indoor chemistry field. Using a molecular perspective, it addresses primarily the new advances that have occurred in the past decade or so and upon developments in our understanding of multiphase partitioning and reactions. A primary goal of the article is to contrast indoor chemistry to that which occurs outdoors, which we know to be a strongly gas-phase, oxidant-driven system in which substantial oxidative aging of gases and aerosol particles occurs. By contrast, indoor environments are dark, gas-phase oxidant concentrations are relatively low, and due to air exchange, only short times are available for reactive processing of gaseous and particle constituents. However, important gas-surface partitioning and reactive multiphase chemistry occur in the large surface reservoirs that prevail in all indoor environments. These interactions not only play a crucial role in controlling the composition of indoor surfaces but also the surrounding gases and aerosol particles, thus affecting human chemical exposure. There are rich research opportunities available if the advanced measurement and modeling tools of the outdoor atmospheric chemistry community continue to be brought indoors.
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Affiliation(s)
- Jonathan P D Abbatt
- Department of Chemistry, University of Toronto, 80 St. George St., Toronto, ON M5S 3H6, Canada.
| | - Chen Wang
- Department of Chemistry, University of Toronto, 80 St. George St., Toronto, ON M5S 3H6, Canada.
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8
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Haines SR, Adams RI, Boor BE, Bruton TA, Downey J, Ferro AR, Gall E, Green BJ, Hegarty B, Horner E, Jacobs DE, Lemieux P, Misztal PK, Morrison G, Perzanowski M, Reponen T, Rush RE, Virgo T, Alkhayri C, Bope A, Cochran S, Cox J, Donohue A, May AA, Nastasi N, Nishioka M, Renninger N, Tian Y, Uebel-Niemeier C, Wilkinson D, Wu T, Zambrana J, Dannemiller KC. Ten questions concerning the implications of carpet on indoor chemistry and microbiology. BUILDING AND ENVIRONMENT 2019; 170:1-16. [PMID: 32055099 PMCID: PMC7017391 DOI: 10.1016/j.buildenv.2019.106589] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Carpet and rugs currently represent about half of the United States flooring market and offer many benefits as a flooring type. How carpets influence our exposure to both microorganisms and chemicals in indoor environments has important health implications but is not well understood. The goal of this manuscript is to consolidate what is known about how carpet impacts indoor chemistry and microbiology, as well as to identify the important research gaps that remain. After describing the current use of carpet indoors, questions focus on five specific areas: 1) indoor chemistry, 2) indoor microbiology, 3) resuspension and exposure, 4) current practices and future needs, and 5) sustainability. Overall, it is clear that carpet can influence our exposures to particles and volatile compounds in the indoor environment by acting as a direct source, as a reservoir of environmental contaminants, and as a surface supporting chemical and biological transformations. However, the health implications of these processes are not well known, nor how cleaning practices could be optimized to minimize potential negative impacts. Current standards and recommendations focus largely on carpets as a primary source of chemicals and on limiting moisture that would support microbial growth. Future research should consider enhancing knowledge related to the impact of carpet in the indoor environment and how we might improve the design and maintenance of this common material to reduce our exposure to harmful contaminants while retaining the benefits to consumers.
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Affiliation(s)
- Sarah R. Haines
- Department of Civil, Environmental & Geodetic Engineering, College of Engineering, Environmental Health Sciences, College of Public Health, and Environmental Sciences Graduate Program, The Ohio State University, Columbus, OH, 43210, USA
| | - Rachel I. Adams
- Plant & Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Brandon E. Boor
- Lyles School of Civil Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | | | - John Downey
- Cleaning Industry Research Institute, Granville, OH, 43023, USA
| | - Andrea R. Ferro
- Department of Civil and Environmental Engineering, Clarkson University, Potsdam, NY, 13699, USA
| | - Elliott Gall
- Department of Mechanical and Materials Engineering, Portland State University, Portland, OR, 97201, USA
| | - Brett J. Green
- Allergy and Clinical Immunology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, 26505, USA
| | - Bridget Hegarty
- Civil and Environmental Engineering, College of Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Elliott Horner
- UL Environment and Sustainability, Marietta, GA, 30067, USA
| | - David E. Jacobs
- National Center for Healthy Housing, Columbia, MD, 21044, USA
| | - Paul Lemieux
- Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, 27711, USA
| | - Pawel K. Misztal
- Department of Civil, Architectural and Environmental Engineering, University of Texas at Austin, Austin, TX, 78712, USA
| | - Glenn Morrison
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Matthew Perzanowski
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, 10032, USA
| | - Tiina Reponen
- Division of Environmental and Industrial Hygiene, Department of Environmental Health, College of Medicine, University of Cincinnati, Cincinnati, OH, 45220, USA
| | - Rachael E. Rush
- Allergy and Clinical Immunology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, 26505, USA
- Department of Microbiology, Immunology, and Cell Biology, West Virginia University, Morgantown, WV, 26506, USA
| | - Troy Virgo
- Shaw Industries, Inc., Dalton, GA, 30722-2128, USA
| | - Celine Alkhayri
- Department of Civil, Environmental & Geodetic Engineering, College of Engineering, The Ohio State University, Columbus, OH, 43210, USA
| | - Ashleigh Bope
- Department of Civil, Environmental & Geodetic Engineering, College of Engineering, Environmental Health Sciences, College of Public Health, and Environmental Sciences Graduate Program, The Ohio State University, Columbus, OH, 43210, USA
| | - Samuel Cochran
- Department of Civil, Environmental & Geodetic Engineering, College of Engineering, Environmental Health Sciences, College of Public Health, and Environmental Sciences Graduate Program, The Ohio State University, Columbus, OH, 43210, USA
| | - Jennie Cox
- Division of Environmental and Industrial Hygiene, Department of Environmental Health, College of Medicine, University of Cincinnati, Cincinnati, OH, 45220, USA
| | - Allie Donohue
- Department of Civil, Environmental & Geodetic Engineering, College of Engineering, The Ohio State University, Columbus, OH, 43210, USA
| | - Andrew A. May
- Department of Civil, Environmental & Geodetic Engineering, College of Engineering, The Ohio State University, Columbus, OH, 43210, USA
| | - Nicholas Nastasi
- Department of Civil, Environmental & Geodetic Engineering, College of Engineering, Environmental Health Sciences, College of Public Health, and Environmental Sciences Graduate Program, The Ohio State University, Columbus, OH, 43210, USA
| | - Marcia Nishioka
- Department of Civil, Environmental & Geodetic Engineering, College of Engineering, The Ohio State University, Columbus, OH, 43210, USA
| | - Nicole Renninger
- Department of Civil, Environmental & Geodetic Engineering, College of Engineering, The Ohio State University, Columbus, OH, 43210, USA
| | - Yilin Tian
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, 94720, USA
| | - Christina Uebel-Niemeier
- Division of Environmental and Industrial Hygiene, Department of Environmental Health, College of Medicine, University of Cincinnati, Cincinnati, OH, 45220, USA
| | | | - Tianren Wu
- Lyles School of Civil Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Jordan Zambrana
- Indoor Environments Division, Office of Air and Radiation, U.S. Environmental Protection Agency, Washington, DC, 20460, USA
| | - Karen C. Dannemiller
- Department of Civil, Environmental & Geodetic Engineering, College of Engineering, and Environmental Health Sciences, College of Public Health, The Ohio State University, Columbus, OH, 43210, USA
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9
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Morrison G, Lakey PSJ, Abbatt J, Shiraiwa M. Indoor boundary layer chemistry modeling. INDOOR AIR 2019; 29:956-967. [PMID: 31461792 DOI: 10.1111/ina.12601] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 07/29/2019] [Accepted: 08/25/2019] [Indexed: 06/10/2023]
Abstract
Ozone (O3 ) chemistry is thought to dominate the oxidation of indoor surfaces. We consider the hypothesis that reactions taking place within indoor boundary layers result in greater than anticipated hydroxyl radical (OH) deposition rates. We develop models that account for boundary layer mass-transfer phenomena, O3 -terpene chemistry and OH formation, removal, and deposition; we solve these analytically and by applying numerical methods. For an O3 -limonene system, we find that OH flux to a surface with an O3 reaction probability of 10-8 is 4.3 × 10-5 molec/(cm2 s) which is about 10 times greater than predicted by a traditional boundary layer theory. At very low air exchange rates the OH surface flux can be as much as 10% of that for O3 . This effect becomes less pronounced for more O3 -reactive surfaces. Turbulence intensity does not strongly influence the OH concentration gradient except for surfaces with an O3 reaction probability >10-4 . Although the O3 flux dominates OH flux under most conditions, OH flux can be responsible for as much as 10% of total oxidant uptake to otherwise low-reactivity surfaces. Further, OH chemistry differs from that for ozone; therefore, its deposition is important in understanding the chemical evolution of some indoor surfaces and surface films.
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Affiliation(s)
- Glenn Morrison
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC, USA
| | | | - Jonathan Abbatt
- Department of Chemistry, University of Toronto, Toronto, ON, Canada
| | - Manabu Shiraiwa
- Department of Chemistry, University of California, Irvine, CA, USA
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10
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Klein F, Baltensperger U, Prévôt ASH, El Haddad I. Quantification of the impact of cooking processes on indoor concentrations of volatile organic species and primary and secondary organic aerosols. INDOOR AIR 2019; 29:926-942. [PMID: 31449696 PMCID: PMC6856830 DOI: 10.1111/ina.12597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 08/08/2019] [Accepted: 08/15/2019] [Indexed: 05/06/2023]
Abstract
Cooking is recognized as an important source of particulate pollution in indoor and outdoor environments. We conducted more than 100 individual experiments to characterize the particulate and non-methane organic gas emissions from various cooking processes, their reaction rates, and their secondary organic aerosol yields. We used this emission data to develop a box model, for simulating the cooking emission concentrations in a typical European home and the indoor gas-phase reactions leading to secondary organic aerosol production. Our results suggest that about half of the indoor primary organic aerosol emission rates can be explained by cooking. Emission rates of larger and unsaturated aldehydes likely are dominated by cooking while the emission rates of terpenes are negligible. We found that cooking dominates the particulate and gas-phase air pollution in non-smoking European households exceeding 1000 μg m-3 . While frying processes are the main driver of aldehyde emissions, terpenes are mostly emitted due to the use of condiments. The secondary aerosol production is negligible with around 2 μg m-3 . Our results further show that ambient cooking organic aerosol concentrations can only be explained by super-polluters like restaurants. The model offers a comprehensive framework for identifying the main parameters controlling indoor gas- and particle-phase concentrations.
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Affiliation(s)
- Felix Klein
- Laboratory of Atmospheric ChemistryPaul Scherrer InstituteVilligenSwitzerland
- Present address:
Meteorologisches Observatorium HohenpeissenbergDeutscher Wetterdienst (DWD)HohenpeissenbergGermany
| | - Urs Baltensperger
- Laboratory of Atmospheric ChemistryPaul Scherrer InstituteVilligenSwitzerland
| | - André S. H. Prévôt
- Laboratory of Atmospheric ChemistryPaul Scherrer InstituteVilligenSwitzerland
| | - Imad El Haddad
- Laboratory of Atmospheric ChemistryPaul Scherrer InstituteVilligenSwitzerland
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11
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Qiu J, Ishizuka S, Tonokura K, Sato K, Inomata S, Enami S. Effects of pH on Interfacial Ozonolysis of α-Terpineol. J Phys Chem A 2019; 123:7148-7155. [PMID: 31329444 DOI: 10.1021/acs.jpca.9b05434] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Acidity changes the physical properties of atmospheric aerosol particles and the mechanisms of reactions that occur therein and on the surface. Here, we used surface-sensitive pneumatic ionization mass spectrometry to investigate the effects of pH on the heterogeneous reactions of aqueous α-terpineol (C10H17OH), a representative monoterpene alcohol, with gaseous ozone. Rapid (≤10 μs) ozonolysis of α-terpineol produced Criegee intermediates (CIs, zwitterionic/diradical carbonyl oxides) on the surface of water microjets. We studied the effects of microjet bulk pH (1-11) on the formation of functionalized carboxylate and α-hydroxy-hydroperoxide chloride adduct (HH-Cl-) products generated by isomerization and hydration of α-terpineol CIs, respectively. Compared with the signal at pH ≈ 6, the mass spectral signal of HH-Cl- was less intense under both basic and more acidic conditions, whereas the intensity of the functionalized carboxylate signal increased with increasing pH up to 4 and then remained constant. The decrease of HH-Cl- signals at bulk pH values of >6 is attributable to the accumulation of OH- at the air-water interface that suppresses the relative abundance of hydrophilic HH and Cl-. The present study suggests that α-terpineol in ambient aqueous organic aerosols will be converted into much lower volatile and potentially toxic organic hydroperoxides during the heterogeneous ozonolysis.
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Affiliation(s)
- Junting Qiu
- Graduate School of Frontier Sciences , The University of Tokyo , 5-1-5 Kashiwanoha , Kashiwa 277-8563 , Japan
| | - Shinnosuke Ishizuka
- National Institute for Environmental Studies , 16-2 Onogawa , Tsukuba 305-8506 , Japan
| | - Kenichi Tonokura
- Graduate School of Frontier Sciences , The University of Tokyo , 5-1-5 Kashiwanoha , Kashiwa 277-8563 , Japan
| | - Kei Sato
- National Institute for Environmental Studies , 16-2 Onogawa , Tsukuba 305-8506 , Japan
| | - Satoshi Inomata
- National Institute for Environmental Studies , 16-2 Onogawa , Tsukuba 305-8506 , Japan
| | - Shinichi Enami
- National Institute for Environmental Studies , 16-2 Onogawa , Tsukuba 305-8506 , Japan
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12
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Yao J, Guo J, Yang Z, Li H, Qiu B. Degradation of α-terpineol in aqueous solution by UV/H 2O 2: kinetics, transformation products and pathways. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2019; 79:2195-2202. [PMID: 31318357 DOI: 10.2166/wst.2019.221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The monoterpene alcohol α-terpineol is extensively used as the foaming agent in mineral processing and can be released to environment along with the wastewater. This study evaluated the feasibility of eliminating α-terpineol in water by ultraviolet irradiation (UV) in combination with hydrogen peroxide (H2O2). Within an H2O2 dose of 10 mg/L and an UV fluence of 64.8 J/cm2, more than 95% of the α-terpineol can be removed. The reactions fitted well to pseudo-first-order kinetics, and the apparent rate constant was 0.0678 min-1. The effects of matrix species including various anions and humic acid (HA), were evaluated. The degradation rate decreased significantly with the addition of bicarbonate and HA. Further verification was carried out with three types of real water samples. In the ground water and the surface water, the degradation rate decreased likely due to the presence of natural organic matter. Finally, possible degradation pathways were proposed based on the identification of transformation products, and the occurrence of two main transformation products were monitored. This study demonstrated that the UV/H2O2 is an effective technology for the degradation of α-terpineol in water.
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Affiliation(s)
- Jie Yao
- Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China E-mail:
| | - Jinglin Guo
- Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China E-mail:
| | - Zhaoguang Yang
- Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China E-mail: ; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Changsha 410083, China
| | - Haipu Li
- Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China E-mail: ; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Changsha 410083, China
| | - Bo Qiu
- Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China E-mail: ; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Changsha 410083, China
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13
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Abstract
This review aims to encapsulate the importance, ubiquity, and complexity of indoor chemistry. We discuss the many sources of indoor air pollutants and summarize their chemical reactions in the air and on surfaces. We also summarize some of the known impacts of human occupants, who act as sources and sinks of indoor chemicals, and whose activities (e.g., cooking, cleaning, smoking) can lead to extremely high pollutant concentrations. As we begin to use increasingly sensitive and selective instrumentation indoors, we are learning more about chemistry in this relatively understudied environment.
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Affiliation(s)
- Charles J Weschler
- Environmental and Occupational Health Sciences Institute , Rutgers University , Piscataway , New Jersey 08854 , United States
- International Centre for Indoor Environment and Energy, Department of Civil Engineering , Technical University of Denmark , Lyngby , Denmark
| | - Nicola Carslaw
- Environment Department , University of York , York , North Yorkshire YO10 5NG , U.K
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14
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Yang Y, Waring MS. Secondary organic aerosol formation initiated by α-terpineol ozonolysis in indoor air. INDOOR AIR 2016; 26:939-952. [PMID: 26609907 DOI: 10.1111/ina.12271] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 11/18/2015] [Indexed: 06/05/2023]
Abstract
Secondary organic aerosol (SOA) owing to reactive organic gas (ROG) ozonolysis can be an important indoor particle source. However, SOA formation owing to ozonolysis of α-terpineol, which is emitted by consumer product usage and reacts strongly with ozone, has not been systematically quantified. Therefore, we conducted 21 experiments to investigate the SOA formation initiated by α-terpineol ozonolysis for high (0.84 h-1 ), moderate (0.61 h-1 ), and low (0.36 h-1 ) air exchange rates (AER), which is the frequency with which indoor is replaced by outdoor air. α-Terpineol concentrations of 6.39 to 226 ppb were combined with high ozone (~25 ppm) to ensure rapid and complete ozonolysis. No reactants were replenished, so SOA peaked quickly and then decreased due to AER and surface losses, and peak SOA ranged from 2.03 to 281 μg/m3 at unit density. SOA mass formation was parameterized with the aerosol mass fraction (AMF), a.k.a. the SOA yield, and AMFs ranged from 0.056 to 0.24. The AMFs strongly and positively correlated with reacted α-terpineol, whereas they weakly and negatively correlated with higher AERs. One-product, two-product, and volatility basis set (VBS) models were fit to the AMF data. Predictive modeling demonstrated that α-terpineol ozonolysis could meaningfully form SOA in indoor air.
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Affiliation(s)
- Y Yang
- Department of Civil, Architectural and Environmental Engineering, Drexel University, Philadelphia, PA, USA
| | - M S Waring
- Department of Civil, Architectural and Environmental Engineering, Drexel University, Philadelphia, PA, USA
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15
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Leviss DH, Van Ry DA, Hinrichs RZ. Multiphase Ozonolysis of Aqueous α-Terpineol. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:11698-11705. [PMID: 27680201 DOI: 10.1021/acs.est.6b03612] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Multiphase ozonolysis of aqueous organics presents a potential pathway for the formation of aqueous secondary organic aerosol (aqSOA). We investigated the multiphase ozonolysis of α-terpineol, an oxygenated derivative of limonene, and found that the reaction products and kinetics differ from the gas-phase ozonolysis of α-terpineol. One- and two-dimensional NMR spectroscopies along with GC-MS identified the aqueous ozonolysis reaction products as trans- and cis-lactols [4-(5-hydroxy-2,2-dimethyltetrahydrofuran-3-yl)butan-2-one] and a lactone [4-hydroxy-4-methyl-3-(3-oxobutyl)-valeric acid gamma-lactone], which accounted for 46%, 27%, and 20% of the observed products, respectively. Hydrogen peroxide was also formed in 10% yield consistent with a mechanism involving decomposition of hydroxyl hydroperoxide intermediates followed by hemiacetal ring closure. Multiphase reaction kinetics at gaseous ozone concentrations of 131, 480, and 965 parts-per-billion were analyzed using a resistance model of net ozone uptake and found the second-order rate coefficient for the aqueous reaction of α-terpineol + O3 to be 9.9(±3.3) × 106 M-1 s-1. Multiphase ozonolysis will therefore be competitive with multiphase oxidation by hydroxyl radicals (OH) and ozonolysis of gaseous α-terpineol. We also measured product yields for the heterogeneous ozonolysis of α-terpineol adsorbed on glass, NaCl, and kaolinite, and identified the same three major products but with an increasing lactone yield of 33, 49, and 55% on these substrates, respectively.
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Affiliation(s)
- Dani H Leviss
- Department of Chemistry, Drew University , Madison, New Jersey 07940, United States
| | - Daryl A Van Ry
- Department of Chemistry, Drew University , Madison, New Jersey 07940, United States
| | - Ryan Z Hinrichs
- Department of Chemistry, Drew University , Madison, New Jersey 07940, United States
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16
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Xiang J, Weschler CJ, Mo J, Day D, Zhang J, Zhang Y. Ozone, Electrostatic Precipitators, and Particle Number Concentrations: Correlations Observed in a Real Office during Working Hours. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:10236-10244. [PMID: 27571436 DOI: 10.1021/acs.est.6b03069] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This study investigates the impacts of outdoor and indoor ozone concentrations, ESP operation and occupancy on particle number concentrations within a modern office in Changsha, China. The office's one-pass air handling system contains a mini-bag filter (MERV 12) followed by an electrostatic precipitator (ESP) and high efficiency particulate air (HEPA) filter. Over a five-week period the system was operated either without the ESP (Stage 1, first-third week) or with the ESP (Stage 2, fourth and fifth week). Ozone and particle number concentrations were measured on working days. During both stages, indoor ozone and particle number concentrations tracked the outdoor ozone concentration. When operating, the ESP produced approximately 29 mg h(-1) of ozone, increasing supply air ozone by 15 ppb and steady-state indoor ozone by about 3 ppb. Occupancy tended to decrease indoor ozone and increase particle levels. During occupancy, indoor particle levels were low (∼2600 particle/cm(3)) when the supply air ozone level was less than 18 ppb. Above this threshold, the supply air ozone concentration and indoor particle number concentration were linearly related, and ESP operation increased the average indoor particle level by about 22 000 particles/cm(3). The implications for worker exposure to both ozone and particles are discussed.
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Affiliation(s)
- Jianbang Xiang
- Department of Building Science, Tsinghua University , Beijing 100084, China
- Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Beijing 100084, China
| | - Charles J Weschler
- Department of Building Science, Tsinghua University , Beijing 100084, China
- Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Beijing 100084, China
- Environmental and Occupational Health Sciences Institute, Rutgers University , Piscataway, New Jersey 08854, United States
| | - Jinhan Mo
- Department of Building Science, Tsinghua University , Beijing 100084, China
- Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Beijing 100084, China
| | - Drew Day
- Global Health Institute and the Nicholas School of Environment, Duke University , Durham, North Carolina 27708, United States
| | - Junfeng Zhang
- Global Health Institute and the Nicholas School of Environment, Duke University , Durham, North Carolina 27708, United States
- Duke Kunshan University , Kunshan, Jiangsu 215316, China
| | - Yinping Zhang
- Department of Building Science, Tsinghua University , Beijing 100084, China
- Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Beijing 100084, China
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17
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Zhao H, Stephens B. A method to measure the ozone penetration factor in residences under infiltration conditions: application in a multifamily apartment unit. INDOOR AIR 2016; 26:571-581. [PMID: 26114258 DOI: 10.1111/ina.12228] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 06/20/2015] [Indexed: 06/04/2023]
Abstract
Recent experiments have demonstrated that outdoor ozone reacts with materials inside residential building enclosures, potentially reducing indoor exposures to ozone or altering ozone reaction byproducts. However, test methods to measure ozone penetration factors in residences (P) remain limited. We developed a method to measure ozone penetration factors in residences under infiltration conditions and applied it in an unoccupied apartment unit. Twenty-four repeated measurements were made, and results were explored to (i) evaluate the accuracy and repeatability of the new procedure using multiple solution methods, (ii) compare results from 'interference-free' and conventional UV absorbance ozone monitors, and (iii) compare results against those from a previously published test method requiring artificial depressurization. The mean (±s.d.) estimate of P was 0.54 ± 0.10 across a wide range of conditions using the new method with an interference-free monitor; the conventional monitor was unable to yield meaningful results due to relatively high limits of detection. Estimates of P were not clearly influenced by any indoor or outdoor environmental conditions or changes in indoor decay rate constants. This work represents the first known measurements of ozone penetration factors in a residential building operating under natural infiltration conditions and provides a new method for widespread application in buildings.
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Affiliation(s)
- H Zhao
- Department of Civil, Architectural and Environmental Engineering, Illinois Institute of Technology, Chicago, IL, USA
| | - B Stephens
- Department of Civil, Architectural and Environmental Engineering, Illinois Institute of Technology, Chicago, IL, USA
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18
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19
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Fung CCD, Shu S, Zhu Y. Ultrafine particles generated from coloring with scented markers in the presence of ozone. INDOOR AIR 2014; 24:503-510. [PMID: 24547888 DOI: 10.1111/ina.12103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 02/13/2014] [Indexed: 05/29/2023]
Abstract
High concentrations of ultrafine particles (UFPs) have been previously reported during school art activities. This is possibly due to secondary organic aerosols (SOAs) formed from reactions between ozone and volatile organic compounds emitted from art products. Four brands of markers, three scented and one unscented, were tested inside a stainless steel chamber at eight different ozone concentrations between 0 and 300 ppb. Out of the 32 tested markers, only the lemon- and orange-scented markers from one brand reacted with ozone to form UFPs. Limonene, pinene, and several other terpenes were identified as ingredients of ink in SOA-forming markers. Coloring with one lemon-scented marker for 1 min without ozone generated on average approximately 26 ± 4 ppb of limonene inside the chamber. At 150 ppb ozone, using one lemon marker for 1 min formed on average 7.7 × 10(10) particles. The particle size distribution indicated an initial mode of 15 nm which grew to 40 nm. At 50 ppb ozone and below, no significant SOA formation occurred. The number of particles formed is moderately correlated with the mass of ink used (R(2) = 0.68). Based on these data, scented markers are not likely a strong source of SOA under normal indoor ozone levels.
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Affiliation(s)
- C-C D Fung
- Department of Environmental Health Sciences, Jonathan and Karin Fielding School of Public Health, University of California Los Angeles, Los Angeles, CA, USA
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20
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Liu J, Fung D, Jiang J, Zhu Y. Ultrafine particle emissions from essential-oil-based mosquito repellent products. INDOOR AIR 2014; 24:327-335. [PMID: 24245647 DOI: 10.1111/ina.12080] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 11/14/2013] [Indexed: 05/29/2023]
Abstract
UNLABELLED Ultrafine particle (UFP) emissions from three essential-oil-based mosquito repellent products (lemon eucalyptus (LE), natural insects (NI), and bite shield (BS)) were tested in a 386 l chamber at a high air exchange rate of 24/h with filtered laboratory air. Total particle number concentration and size distribution were monitored by a condensation particle counter and a scanning mobility particle sizer, respectively. UFPs were emitted from all three products under indoor relevant ozone concentrations (~ 17 ppb). LE showed a nucleation burst followed by a relatively stable and continuous emission while the other two products (NI and BS) showed episodic emissions. The estimated maximum particle emission rate varied from 5.4 × 10(9) to 1.2 × 10(12) particles/min and was directly related to the dose of mosquito repellent used. These rates are comparable to those due to other indoor activities such as cooking and printing. The emission duration for LE lasted for 8-78 min depending on the dose applied while the emission duration for NI and BS lasted for 2-3 h. PRACTICAL IMPLICATIONS Certain essential-oil-based mosquito repellents can produce high concentrations of UFPs when applied, even at low ozone levels. Household and personal care products that contain essential oil may need to be tested at indoor relevant ozone levels to determine their potential to increase personal UFP exposures.
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Affiliation(s)
- J Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing, China
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21
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Fu D, Leng C, Kelley J, Zeng G, Zhang Y, Liu Y. ATR-IR study of ozone initiated heterogeneous oxidation of squalene in an indoor environment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:10611-10618. [PMID: 23957297 DOI: 10.1021/es4019018] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
There has been a surge of interest in interfacial ozone chemistry for its application in indoor air quality and public health. Squalene, one of the most abundant ozone reactive constituents in an indoor environment, has received increasing attention lately, and a number of studies have been devoted to its heterogeneous interaction with ozone in actual and simulated settings. At present, there is still a large discrepancy in the measurement of the reactive uptake coefficient of ozone onto a squalene surface, and knowledge about this system remains incomplete. In this work, we investigated the ozone initiated heterogeneous oxidation of squalene using attenuated total reflection infrared spectroscopy (ATR-IR). We measured pseudo-first-order rate constants and uptake coefficients based on time dependent absorbance changes in C═C (1668 cm(-1)) and C═O (1730 cm(-1)) vibration bands. The uptake coefficients are (1.7 ± 0.2) × 10(-4) from the C═C band and (5.1 ± 0.7) × 10(-4) from the C═O band. The latter is likely an upper limit of reaction probability for ozone uptake onto squalene. Studies of temperature (5-32 °C) and relative humidity (0 and 80% RH) dependence revealed that indoor temperatures and RHs did not affect reaction kinetics. The insignificant RH effect is probably due to the weak interaction between water and squalene molecules. We quantitatively characterized the hydrophilicity and redox activity of squalene before and after exposure to ozone for the first time, and observed considerable enhancements in both hydrophilicity and redox activity during reaction. This may imply that ozone initiated heterogeneous oxidation could pose a higher public health risk in an indoor environment, and it may help explain some of the adverse health effects associated with elevated indoor pollutants.
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Affiliation(s)
- Dong Fu
- Department of Chemistry, University of Colorado Denver , Denver, Colorado 80217, United States
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22
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Waring MS, Siegel JA. Indoor secondary organic aerosol formation initiated from reactions between ozone and surface-sorbed D-limonene. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:6341-6348. [PMID: 23724989 DOI: 10.1021/es400846d] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Reactions between ozone and terpenoids produce numerous products, some of which may form secondary organic aerosol (SOA). This work investigated the contribution to gas-phase SOA formation of ozone reactions with surface-sorbed D-limonene, which is common indoors. A model framework was developed to predict SOA mass formation because of ozone/terpenoid surface reactions, and it was used with steady state experiments in a 283 L chamber to determine the aerosol mass fraction of SOA resulting from surface reactions, ξs (the ratio of mass of SOA formed and mass of ozone consumed by ozone/terpenoid surface reactions), for ozone/D-limonene reactions on stainless steel. The ξs = 0.70-0.91, with lower relative humidity leading to both higher mass and number formation. Also, surface reactions promoted nucleation more than gas-phase reactions, and number formation due to surface reactions and gas-phase reactions were 126-339 and 51.1-60.2 no./cm(3) per μg/m(3) of formed SOA, respectively. We also used the model framework to predict that indoor spaces in which ozone/D-limonene surface reactions would likely lead to meaningful gas-phase SOA formation are those with surfaces that have low original reactivity with ozone, such as glass, sealed materials, or smooth metals.
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Affiliation(s)
- Michael S Waring
- Department of Civil, Architectural and Environmental Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania 19104, United States.
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23
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Waring MS, Siegel JA. Indoor secondary organic aerosol formation initiated from reactions between ozone and surface-sorbed D-limonene. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:6341-6348. [PMID: 23724989 DOI: 10.1016/j.atmosenv.2013.11.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Reactions between ozone and terpenoids produce numerous products, some of which may form secondary organic aerosol (SOA). This work investigated the contribution to gas-phase SOA formation of ozone reactions with surface-sorbed D-limonene, which is common indoors. A model framework was developed to predict SOA mass formation because of ozone/terpenoid surface reactions, and it was used with steady state experiments in a 283 L chamber to determine the aerosol mass fraction of SOA resulting from surface reactions, ξs (the ratio of mass of SOA formed and mass of ozone consumed by ozone/terpenoid surface reactions), for ozone/D-limonene reactions on stainless steel. The ξs = 0.70-0.91, with lower relative humidity leading to both higher mass and number formation. Also, surface reactions promoted nucleation more than gas-phase reactions, and number formation due to surface reactions and gas-phase reactions were 126-339 and 51.1-60.2 no./cm(3) per μg/m(3) of formed SOA, respectively. We also used the model framework to predict that indoor spaces in which ozone/D-limonene surface reactions would likely lead to meaningful gas-phase SOA formation are those with surfaces that have low original reactivity with ozone, such as glass, sealed materials, or smooth metals.
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Affiliation(s)
- Michael S Waring
- Department of Civil, Architectural and Environmental Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania 19104, United States.
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24
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Pathak RK, Salo K, Emanuelsson EU, Cai C, Lutz A, Hallquist AM, Hallquist M. Influence of ozone and radical chemistry on limonene organic aerosol production and thermal characteristics. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:11660-11669. [PMID: 22985264 DOI: 10.1021/es301750r] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Limonene has a strong tendency to form secondary organic aerosol (SOA) in the atmosphere and in indoor environments. Initial oxidation occurs mainly via ozone or OH radical chemistry. We studied the effect of O(3) concentrations with or without a OH radical scavenger (2-butanol) on the SOA mass and thermal characteristics using the Gothenburg Flow Reactor for Oxidation Studies at Low Temperatures and a volatility tandem differential mobility analyzer. The SOA mass using 15 ppb limonene was strongly dependent on O(3) concentrations and the presence of a scavenger. The SOA volatility in the presence of a scavenger decreased with increasing levels of O(3), whereas without a scavenger, there was no significant change. A chemical kinetic model was developed to simulate the observations using vapor pressure estimates for compounds that potentially contributed to SOA. The model showed that the product distribution was affected by changes in both OH and ozone concentrations, which partly explained the observed changes in volatility, but was strongly dependent on accurate vapor pressure estimation methods. The model-experiment comparison indicated a need to consider organic peroxides as important SOA constituents. The experimental findings could be explained by secondary condensed-phase ozone chemistry, which competes with OH radicals for the oxidation of primary unsaturated products.
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Affiliation(s)
- Ravi K Pathak
- Atmospheric Science, Department of Chemistry and Molecular Biology, University of Gothenburg, S-412 96 Gothenburg, Sweden
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25
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Flemmer MM, Ham JE. Cavity ring-down spectroscopy with an automated control feedback system for investigating nitrate radical surface chemistry reactions. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:085103. [PMID: 22938328 PMCID: PMC4643663 DOI: 10.1063/1.4739768] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Nitrate radical (NO(3)(●)) surface chemistry of indoor environments has not been well studied due to the difficulty in generating and maintaining NO(3)(●) at low concentrations for long term exposures. This article presents the Surface Chemistry Reactant Air Delivery and Experiment System (SCRADES), a novel feedback controlled system developed to deliver nitrate radicals at specified concentrations (50-500 ppt, ±30 ppt) and flow rates (500-2000 ml min(-1)) to a variety of indoor surfaces to initiate reaction chemistry for periods of up to 72 h. The system uses a cavity ring-down spectrometer (CRDS), with a detection limit of 1.7 ppt, to measure the concentration of NO(3)(●) supplied to a 24 l experiment chamber. Nitrate radicals are introduced via thermal decomposition of N(2)O(5) and diluted with clean dry air until the desired concentration is achieved. Additionally, this article addresses details concerning NO(3)(●) loss through the system, consistency of the NO(3)(●) concentration delivered, and stability of the CRDS cavity over long exposure durations (72 h).
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Affiliation(s)
- Michael M. Flemmer
- Exposure Assessment Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, West Virginia 26505, USA
| | - Jason E. Ham
- Exposure Assessment Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, West Virginia 26505, USA
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26
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Stephens B, Gall ET, Siegel JA. Measuring the penetration of ambient ozone into residential buildings. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:929-936. [PMID: 22146069 DOI: 10.1021/es2028795] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Much of human exposure to ambient ozone and ozone reaction byproducts occurs inside buildings. However, there are currently no experimental data on the ability of ozone to penetrate through building envelopes and into residences. This paper presents a method to determine the penetration factor for ozone in buildings, and applies it in an unoccupied test house and seven single-family residences. The mean (±SD) ozone penetration factor was measured as 0.79 ± 0.13 in the eight homes using this method, ranging from 0.62 ± 0.09 to 1.02 ± 0.15. An analysis of tests across the homes revealed that ozone penetration was significantly higher in homes with more painted wood envelope materials, homes with larger air leakage exponents from fan pressurization tests, and older homes. The test method utilizes a large calibrated fan to elevate air exchange rates and steady-state indoor ozone concentrations to levels that can be accurately measured, so there is a potential for overpredicting ozone penetration factors. However, evidence suggests that this bias is likely small in most of the homes, and, even if a bias exists, the measured ozone penetration factors were lower than the usual assumption of unity in seven of the eight tested homes.
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Affiliation(s)
- Brent Stephens
- Department of Civil, Architectural and Environmental Engineering, The University of Texas at Austin, Austin, Texas, United States.
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