Article
Chemistry, Analytical
Lance Wallace, Wayne Ott
Summary: Low-cost monitors now enable long-term measurements of indoor exposure to fine particles, which come from both outdoor infiltration and indoor activities. An infiltration factor is needed to calculate the relative contribution of each source. This study presents a method to identify periods of varying infiltration factor and finds periods of relative constancy. The usefulness of the approach is demonstrated using examples from the PurpleAir network, with an improved algorithm offering better accuracy and detection limit than the manufacturer's algorithms.
Article
Construction & Building Technology
Inga Garbariene, Julija Pauraite, Daria Pashneva, Agne Minderyte, Karolis Sarka, Vadimas Dudoitis, Lina Davulien, Mindaugas Gaspariunas, Vitalij Kovalevskij, Danielis Lingis, Laurynas Bucinskas, Justina Sapolaite, Z. ilvinas Ezerinskis, Gedi Mainelis, Jurgita Ovadnevaite, Simonas Kecorius, Kristina Plauskaite-Sukiene, Steigvile Bycenkiene
Summary: This study evaluated the impact of outdoor particulate pollution on indoor air quality by investigating the chemical composition and sources of submicron aerosol particles (PM1) indoors and outdoors. The results showed differences in the chemical composition and sources of PM1 between indoor and outdoor environments, with biomass burning and road dust resuspension being the primary sources. The three-stage building filter system was found to provide effective protection against indoor particle pollution.
BUILDING AND ENVIRONMENT
(2022)
Article
Environmental Sciences
Qiaorong Xie, Yuqing Dai, Xianlei Zhu, Fan Hui, Xianqiang Fu, Qiangbin Zhang
Summary: This study assessed the personal exposure and inhaled dose of indoor-active university students in Beijing during hazy and non-hazy days. The results showed significantly higher daily personal exposure and inhaled dose on hazy days, indicating a significant influence from the ambient air quality. The study also found a strong correlation between indoor and outdoor PM2.5 concentrations, with outdoor-origin air contributing to a large proportion of indoor PM2.5. These findings highlight the importance of both improving ambient air quality and constructing environmentally friendly buildings for public health protection.
ENVIRONMENTAL RESEARCH
(2022)
Article
Green & Sustainable Science & Technology
Bo Ram Park, Ye Seul Eom, Dong Hee Choi, Dong Hwa Kang
Summary: The study aimed to evaluate outdoor PM2.5 infiltration into multifamily homes by analyzing field test results and building characteristics using regression models. Results showed that building airtightness was significantly correlated with PM2.5 infiltration, and outdoor-origin PM2.5 concentration in leaky units could be up to 1.59 times higher than in airtight units.
Article
Multidisciplinary Sciences
Fatemeh Zahed, Alireza Pardakhti, Majid Shafiepour Motlagh, Behrouz Mohammad Kari, Azadeh Tavakoli
Summary: The contradiction between indoor air quality and energy conservation through airtightness is studied in this research. The impact of different levels of airtightness on the concentration of PM2.5 and formaldehyde in indoor environments is investigated using a multizone model. The results show that increasing airtightness reduces PM2.5 but increases formaldehyde, and achieving acceptable indoor air quality requires specific solutions under severe outdoor air pollution.
Article
Engineering, Environmental
Michael F. Link, Jienan Li, Jenna C. Ditto, Han Huynh, Jie Yu, Stephen M. Zimmerman, Katelyn L. Rediger, Andrew Shore, Jonathan P. D. Abbatt, Lauren A. Garofalo, Delphine K. Farmer, Dustin Poppendieck
Summary: Energy-efficient residential building standards require mechanical ventilation systems, but outdoor pollution can enter indoor spaces and impact indoor air chemistry. The study found that NO pollutants can neutralize ozone and inhibit the production of NO3, which affects the oxidation of volatile organic compounds (VOCs).
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Construction & Building Technology
Pat E. Rasmussen, Christine Levesque, Owen Butler, Marc Chenier, H. David Gardner
Summary: This study investigated trends in the elemental composition of PM2.5 collected from indoor, outdoor, and personal microenvironments using two different metrics. Positive correlations using one metric often turned negative when the other metric was applied. The findings suggest that elemental associations in PM2.5 may be influenced by Fe-Mn oxyhydroxide sorption processes, with evidence of varying correlations between S and PM2.5 in different seasons and environments.
Article
Construction & Building Technology
Luca Tofful, Silvia Canepari, Tiziana Sargolini, Cinzia Perrino
Summary: This study explored the impact of outdoor and indoor sources on the chemical composition of particulate matter (PM) in a domestic environment. It found that outdoor sources contributed significantly to PM mass concentrations, with organic and secondary inorganic species being important contributors. Indoors, PM concentrations were influenced by inhabitant activities, smoking, and the use of electric appliances.
BUILDING AND ENVIRONMENT
(2021)
Article
Environmental Sciences
Samuel Stamp, Esfand Burman, Lia Chatzidiakou, Elizabeth Cooper, Yan Wang, Dejan Mumovic
Summary: This study evaluates the long-term and continuous monitoring of indoor and outdoor pollutants in various settings in the UK. The findings suggest that indoor-outdoor ratios of particulate matter and nitrogen dioxide exhibit dynamic behaviors influenced by occupant activity and window opening behavior. The traditional approach, which simplifies these ratios into static values, fails to capture the variability and key information. Therefore, a dynamic evaluation of the ratios can provide valuable insights into ventilation strategies and the impact of occupant behavior and indoor sources.
ATMOSPHERIC ENVIRONMENT
(2022)
Article
Construction & Building Technology
Nan Ma, Max Hakkarainen, Miaomiao Hou, Dorit Aviv, William W. Braham
Summary: This study focuses on human ozone exposures in residential houses in urban environments in the U.S., and explores the impact of building characteristics and design variables on outdoor ozone penetration. The results show that indoor ozone concentration is higher with windows open compared to windows closed, and indoor ozone concentration tends to increase when outdoor ozone concentration is high.
INDOOR AND BUILT ENVIRONMENT
(2022)
Article
Construction & Building Technology
Nuodi Fu, Moon Keun Kim, Bing Chen, Stephen Sharples
Summary: This study investigated the impact of outdoor air pollutants on indoor air quality in a high-rise building, considering factors related to the seasons and air infiltration. The results showed that the influence of outdoor air pollutants on indoor air quality was highest in winter, with multiple factors affecting indoor air quality. A high-efficiency filter and double-filter system are recommended to maintain healthy indoor air quality, especially in heavily polluted outdoor air in winter.
INDOOR AND BUILT ENVIRONMENT
(2022)
Article
Environmental Sciences
Jiayang He, Ching-Hsuan Huang, Nanhsun Yuan, Elena Austin, Edmund Seto, Igor Novosselov
Summary: The increased frequency of wildfires in the Western United States has raised concerns about the impact of wildfire smoke on air quality and human health. This study demonstrates the use of low-cost sensors to gather high-resolution indoor and outdoor PM2.5 data during a wildfire event in Seattle. The findings suggest that locations with air filtration systems have lower PM2.5 levels and personal exposure varies in different microenvironments.
ATMOSPHERIC ENVIRONMENT
(2022)
Article
Construction & Building Technology
Zhitong Wang, Cong Liu, Qian Hua, Xiaohong Zheng, Wenjing Ji, Xiaosong Zhang
Summary: This study examines the effect of particulate iron on tracking indoor PM2.5 of outdoor origin at temporal and spatial scales. The results show that iron tracks PM2.5 well on average during outdoor-to-indoor transport, with variations in tracking performance over time and geographic regions. Sulphate appears to have a less stable tracking effect compared to iron.
INDOOR AND BUILT ENVIRONMENT
(2021)
Article
Environmental Sciences
Francesca Marcovecchio, Cinzia Perrino
Summary: The atmospheric concentration of bioparticles was determined in outdoor and indoor sites using a commercial low-volume sampler and a detection method based on particle collection on polycarbonate filters. Higher concentrations of PBAPs were recorded during the warm period, with differences in shape and mass distribution. Indoor PBAPs concentrations were much higher compared to outdoors, with wide polyhedral-shaped particles identifiable as skin flakes.
Article
Construction & Building Technology
Lance A. Wallace, Tongke Zhao, Neil E. Klepeis
Summary: Low-cost monitors have enabled the measurement of indoor PM2.5 concentrations over extended periods for the first time. The study found that indoor-generated particles contribute, on average, 46%-52% of total indoor PM2.5 concentrations, with significant variation across different sites. These findings provide valuable insights for epidemiological studies to better understand long-term exposure to indoor-generated particles.
Article
Construction & Building Technology
H. Zhao, B. Stephens
Article
Construction & Building Technology
S. A. Kunkel, P. Azimi, H. Zhao, B. C. Stark, B. Stephens
Article
Construction & Building Technology
Parham Azimi, Haoran Zhao, Torkan Fazli, Dan Zhao, Afshin Faramarzi, Luke Leung, Brent Stephens
BUILDING AND ENVIRONMENT
(2018)
Article
Engineering, Environmental
Haoran Zhao, Elliott T. Gall, Brent Stephens
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2019)
Article
Construction & Building Technology
Haoran Zhao, Wanyu R. Chan, Sebastian Cohn, William W. Delp, Iain S. Walker, Brett C. Singer
Summary: This study investigated pollutant concentrations and performance of mechanical ventilation equipment in 23 low-income apartments, finding that some apartments did not meet ventilation requirements, resulting in higher indoor pollutant concentrations.
Article
Environmental Sciences
Haoran Zhao, Wanyu R. Chan, William W. Delp, Hao Tang, Iain S. Walker, Brett C. Singer
INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH
(2020)
Article
Environmental Sciences
Yicheng Zeng, Haoran Yu, Haoran Zhao, Brent Stephens, Vishal Verma
Summary: The study investigated the intrinsic toxicity of PM in an unoccupied apartment in Chicago, finding that indoor PM2.5 had higher intrinsic oxidative potential than outdoor PM2.5, influenced by differences in indoor and outdoor temperature and relative humidity. Further research is needed to confirm the hypotheses regarding the transformation processes and factors affecting the chemical composition.
ATMOSPHERIC ENVIRONMENT
(2021)
Article
Construction & Building Technology
Brett C. Singer, Haoran Zhao, Chelsea Preble, William W. Delp, Jovan Pantelic, Michael D. Sohn, Thomas W. Kirchstetter
Summary: Tracer gas experiments were conducted to study the dispersion of contaminants from simulated speaking in physically distanced meeting and classroom configurations. Results showed that chilled or neutral supply air provided good mixing, while thermal stratification during heating led to higher exposure variations. Operating two within-zone air cleaners together vertically in the room helped mitigate elevated exposure variations.
Article
Environmental Sciences
Haoran Zhao, Iain S. Walker, Michael D. Sohn, Brennan Less
Summary: Recent studies have successfully linked emissions of various volatile organic compounds to material mass diffusion transfer using empirical characteristics. This study develops a new approach to estimate aggregated emission rates based on field measurements. By using a regression model and considering formaldehyde concentrations, air exchange rates, and indoor environmental parameters, the study predicts formaldehyde emission rates for single-family houses.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH
(2022)
Article
Environmental Sciences
Jiayao Xu, Han Jiang, Haoran Zhao, Brent Stephens
AEROSOL AND AIR QUALITY RESEARCH
(2017)