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Yang S, Müller T, Wang N, Bekö G, Zhang M, Merizak M, Wargocki P, Williams J, Licina D. Influence of Ventilation on Formation and Growth of 1-20 nm Particles via Ozone-Human Chemistry. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:4704-4715. [PMID: 38326946 PMCID: PMC10938884 DOI: 10.1021/acs.est.3c08466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 01/26/2024] [Accepted: 01/29/2024] [Indexed: 02/09/2024]
Abstract
Ozone reaction with human surfaces is an important source of ultrafine particles indoors. However, 1-20 nm particles generated from ozone-human chemistry, which mark the first step of particle formation and growth, remain understudied. Ventilation and indoor air movement could have important implications for these processes. Therefore, in a controlled-climate chamber, we measured ultrafine particles initiated from ozone-human chemistry and their dependence on the air change rate (ACR, 0.5, 1.5, and 3 h-1) and operation of mixing fans (on and off). Concurrently, we measured volatile organic compounds (VOCs) and explored the correlation between particles and gas-phase products. At 25-30 ppb ozone levels, humans generated 0.2-7.7 × 1012 of 1-3 nm, 0-7.2 × 1012 of 3-10 nm, and 0-1.3 × 1012 of 10-20 nm particles per person per hour depending on the ACR and mixing fan operation. Size-dependent particle growth and formation rates increased with higher ACR. The operation of mixing fans suppressed the particle formation and growth, owing to enhanced surface deposition of the newly formed particles and their precursors. Correlation analyses revealed complex interactions between the particles and VOCs initiated by ozone-human chemistry. The results imply that ventilation and indoor air movement may have a more significant influence on particle dynamics and fate relative to indoor chemistry.
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Affiliation(s)
- Shen Yang
- Human-Oriented
Built Environment Lab, School of Architecture, Civil and Environmental
Engineering, École Polytechnique
Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Tatjana Müller
- Max
Planck Institute for Chemistry, Hahn-Meitner Weg 1, 55128 Mainz, Germany
| | - Nijing Wang
- Max
Planck Institute for Chemistry, Hahn-Meitner Weg 1, 55128 Mainz, Germany
| | - Gabriel Bekö
- International
Centre for Indoor Environment and Energy, Department of Environmental
and Resource Engineering, Technical University
of Denmark, 2800 Kongens Lyngby, Denmark
| | - Meixia Zhang
- Human-Oriented
Built Environment Lab, School of Architecture, Civil and Environmental
Engineering, École Polytechnique
Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
- School
of Mechanical Engineering, Beijing Institute
of Technology, 100081 Beijing, China
| | - Marouane Merizak
- Human-Oriented
Built Environment Lab, School of Architecture, Civil and Environmental
Engineering, École Polytechnique
Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Pawel Wargocki
- International
Centre for Indoor Environment and Energy, Department of Environmental
and Resource Engineering, Technical University
of Denmark, 2800 Kongens Lyngby, Denmark
| | - Jonathan Williams
- Max
Planck Institute for Chemistry, Hahn-Meitner Weg 1, 55128 Mainz, Germany
- Energy,
Environment and Water Research Center, The
Cyprus Institute, 2121 Nicosia, Cyprus
| | - Dusan Licina
- Human-Oriented
Built Environment Lab, School of Architecture, Civil and Environmental
Engineering, École Polytechnique
Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
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Chen C, Yao M, Luo X, Zhu Y, Liu Z, Zhuo H, Zhao B. Outdoor-to-indoor transport of ultrafine particles: Measurement and model development of infiltration factor. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 267:115402. [PMID: 32858436 DOI: 10.1016/j.envpol.2020.115402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/01/2020] [Accepted: 08/07/2020] [Indexed: 05/05/2023]
Abstract
Ambient ultrafine particles (UFPs: particles of diameter less than 100 nm) cause significant adverse health effects. As people spend most time indoors, the outdoor-to-indoor transport of UFPs plays a critical role in the accuracy of personal exposure assessments. Herein, a strategy was proposed to measure and analyze the infiltration factor (Finf) of UFPs, an important parameter quantifying the fraction of ambient air pollutants that travel inside and remain suspended indoors. Ninety-three measurements were conducted in 11 residential rooms in all seasons in Beijing, China, to investigate Finf of UFPs and its associated influencing factors. A multilevel regression model incorporating eight possible factors that influence infiltration was developed to predict Finf and FinfSOA (defined as the ratio of indoor to outdoor UFP concentrations without indoor sources, but with indoor secondary organic aerosol (SOA) formation). It was found that the air change rate was the most important factor and coagulation was considerable, while the influence of SOA formation was much smaller than that of other factors. Our regression model accurately predicted daily-average Finf. The annually-averaged Finf of UFPs was 0.66 ± 0.10, which is higher than that of PM2.5 and PM10, demonstrating the importance of controlling indoor UFPs of outdoor origin.
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Affiliation(s)
- Chen Chen
- Department of Building Science, School of Architecture, Tsinghua University, Beijing, 100084, China
| | - Mingyao Yao
- Department of Building Science, School of Architecture, Tsinghua University, Beijing, 100084, China
| | - Xu Luo
- Department of Building Science, School of Architecture, Tsinghua University, Beijing, 100084, China
| | - Yulin Zhu
- Department of Building Science, School of Architecture, Tsinghua University, Beijing, 100084, China
| | - Zhaoyang Liu
- Center for Statistical Science, Tsinghua University, Beijing, 100084, China; Department of Industrial Engineering, Tsinghua University, Beijing, 100084, China
| | - Hanchen Zhuo
- Department of Building Science, School of Architecture, Tsinghua University, Beijing, 100084, China
| | - Bin Zhao
- Department of Building Science, School of Architecture, Tsinghua University, Beijing, 100084, China; Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Tsinghua University, Beijing, 100084, China.
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