1
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Yuan S, Chen M, Qin X, Chen X, Zhang J, Zhang C. Effects of surface fluoride modification on TiO 2 for the photocatalytic oxidation of toluene. J Environ Sci (China) 2025; 147:561-570. [PMID: 39003071 DOI: 10.1016/j.jes.2023.04.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/25/2023] [Accepted: 04/26/2023] [Indexed: 07/15/2024]
Abstract
In the present study, we investigated the influence of surface fluorine (F) on TiO2 for the photocatalytic oxidation (PCO) of toluene. TiO2 modified with different F content was prepared and tested. It was found that with the increasing of F content, the toluene conversion rate first increased and then decreased. However, CO2 mineralization efficiency showed the opposite trend. Based on the characterizations, we revealed that F substitutes the surface hydroxyl of TiO2 to form the structure of Ti-F. The presence of the appropriate amount of surface Ti-F on TiO2 greatly enhanced the separation of photogenerated carriers, which facilitated the generation of ·OH and promoted the activity for the PCO of toluene. It was further revealed that the increase of only ·OH promoted the conversion of toluene to ring-containing intermediates, causing the accumulation of intermediates and then conversely inhibited the ·OH generation, which led to the decrease of the CO2 mineralization efficiency. The above results could provide guidance for the rational design of photocatalysts for toluene oxidation.
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Affiliation(s)
- Shaoyu Yuan
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Min Chen
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Xiaoxiao Qin
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Xueyan Chen
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jianghao Zhang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Changbin Zhang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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2
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Fu Z, Guo S, Xie HB, Zhou P, Boy M, Yao M, Hu M. A Near-Explicit Reaction Mechanism of Chlorine-Initiated Limonene: Implications for Health Risks Associated with the Concurrent Use of Cleaning Agents and Disinfectants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 39231115 DOI: 10.1021/acs.est.4c04388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/06/2024]
Abstract
Limonene, a key volatile chemical product (VCP) commonly found in personal care and cleaning agents, is emerging as a major indoor air pollutant. Recently, elevated levels of reactive chlorine species during bleach cleaning and disinfection have been reported to increase indoor oxidative capacity. However, incomplete knowledge of the indoor transformation of limonene, especially the missing chlorine chemistry, poses a barrier to evaluating the environmental implications associated with the concurrent use of cleaning agents and disinfectants. Here, we investigated the reaction mechanisms of chlorinated limonene peroxy radicals (Cl-lim-RO2•), key intermediates in determining the chlorine chemistry of limonene, and toxicity of transformation products (TPs) using quantum chemical calculations and toxicology modeling. The results indicate that Cl-lim-RO2• undergoes a concerted autoxidation process modulated by RO2• and alkoxy radicals (RO•), particularly emphasizing the importance of RO• isomerization. Following this generalized autoxidation mechanism, Cl-lim-RO2• can produce low-volatility precursors of secondary organic aerosols. Toxicological findings further indicate that the majority of TPs exhibit increased respiratory toxicity, mutagenicity, and eye/skin irritation compared to limonene, presenting an occupational hazard for indoor occupants. The proposed near-explicit reaction mechanism of chlorine-initiated limonene significantly enhances our current understanding of both RO2• and RO• chemistry while also highlighting the health risks associated with the concurrent use of cleaning agents and disinfectants.
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Affiliation(s)
- Zihao Fu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, International Joint Laboratory for Regional Pollution Control, Ministry of Education (IJRC), College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Song Guo
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, International Joint Laboratory for Regional Pollution Control, Ministry of Education (IJRC), College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Hong-Bin Xie
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Putian Zhou
- Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, P.O. Box 64, Helsinki FIN-00014, Finland
| | - Michael Boy
- Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, P.O. Box 64, Helsinki FIN-00014, Finland
| | - Maosheng Yao
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, International Joint Laboratory for Regional Pollution Control, Ministry of Education (IJRC), College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Min Hu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, International Joint Laboratory for Regional Pollution Control, Ministry of Education (IJRC), College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
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3
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Zhang W, Xu L, Zhang H. Recent advances in mass spectrometry techniques for atmospheric chemistry research on molecular-level. MASS SPECTROMETRY REVIEWS 2024; 43:1091-1134. [PMID: 37439762 DOI: 10.1002/mas.21857] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 06/06/2023] [Accepted: 06/21/2023] [Indexed: 07/14/2023]
Abstract
The Earth's atmosphere is composed of an enormous variety of chemical species associated with trace gases and aerosol particles whose composition and chemistry have critical impacts on the Earth's climate, air quality, and human health. Mass spectrometry analysis as a powerful and popular analytical technique has been widely developed and applied in atmospheric chemistry for decades. Mass spectrometry allows for effective detection, identification, and quantification of a broad range of organic and inorganic chemical species with high sensitivity and resolution. In this review, we summarize recently developed mass spectrometry techniques, methods, and applications in atmospheric chemistry research in the past several years on molecular-level. Specifically, new developments of ion-molecule reactors, various soft ionization methods, and unique coupling with separation techniques are highlighted. The new mass spectrometry applications in laboratory studies and field measurements focused on improving the detection limits for traditional and emerging volatile organic compounds, characterizing multiphase highly oxygenated molecules, and monitoring particle bulk and surface compositions.
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Affiliation(s)
- Wen Zhang
- Department of Chemistry, University of California, Riverside, California, USA
| | - Lu Xu
- NOAA Chemical Sciences Laboratory, Boulder, Colorado, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado, USA
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, Missouri, USA
| | - Haofei Zhang
- Department of Chemistry, University of California, Riverside, California, USA
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4
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Fu Z, Guo S, Yu Y, Xie HB, Li S, Lv D, Zhou P, Song K, Chen Z, Tan R, Hu K, Shen R, Yao M, Hu M. Oxidation Mechanism and Toxicity Evolution of Linalool, a Typical Indoor Volatile Chemical Product. ENVIRONMENT & HEALTH (WASHINGTON, D.C.) 2024; 2:486-498. [PMID: 39049896 PMCID: PMC11264274 DOI: 10.1021/envhealth.4c00033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 03/21/2024] [Accepted: 03/21/2024] [Indexed: 07/27/2024]
Abstract
Linalool, a high-reactivity volatile chemical product (VCP) commonly found in cleaning products and disinfectants, is increasingly recognized as an emerging contaminant, especially in indoor air. Understanding the gas-phase oxidation mechanism of linalool is crucial for assessing its impact on atmospheric chemistry and human health. Using quantum chemical calculations and computational toxicology simulations, we investigated the atmospheric transformation and toxicity evolution of linalool under low and high NO/HO2· levels, representing indoor and outdoor environments. Our findings reveal that linalool can undergo the novel mechanisms involving concerted peroxy (RO2·) and alkoxy radical (RO·) modulated autoxidation, particularly emphasizing the importance of cyclization reactions indoors. This expands the widely known RO2·-dominated H-shift-driven autoxidation and proposes a generalized autoxidation mechanism that leads to the formation of low-volatility secondary organic aerosol (SOA) precursors. Toxicological analysis shows that over half of transformation products (TPs) exhibited higher carcinogenicity and respiratory toxicity compared to linalool. We also propose time-dependent toxic effects of TPs to assess their long-term toxicity. Our results indicate that the strong indoor emission coupled with slow consumption rates lead to significant health risks under an indoor environment. The results highlight complex indoor air chemistry and health concerns regarding persistent toxic products during indoor cleaning, which involves the use of linalool or other VCPs.
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Affiliation(s)
- Zihao Fu
- State
Key Joint Laboratory of Environmental Simulation and Pollution Control,
International Joint Laboratory for Regional Pollution Control, Ministry
of Education (IJRC), College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Song Guo
- State
Key Joint Laboratory of Environmental Simulation and Pollution Control,
International Joint Laboratory for Regional Pollution Control, Ministry
of Education (IJRC), College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
- Collaborative
Innovation Center of Atmospheric Environment and Equipment Technology, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Ying Yu
- State
Key Joint Laboratory of Environmental Simulation and Pollution Control,
International Joint Laboratory for Regional Pollution Control, Ministry
of Education (IJRC), College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Hong-Bin Xie
- Key
Laboratory of Industrial Ecology and Environmental Engineering (Ministry
of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Shiyu Li
- State
Key Joint Laboratory of Environmental Simulation and Pollution Control,
International Joint Laboratory for Regional Pollution Control, Ministry
of Education (IJRC), College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Daqi Lv
- State
Key Joint Laboratory of Environmental Simulation and Pollution Control,
International Joint Laboratory for Regional Pollution Control, Ministry
of Education (IJRC), College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Putian Zhou
- Institute
for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, P.O. Box 64, FIN-00014 Helsinki, Finland
| | - Kai Song
- State
Key Joint Laboratory of Environmental Simulation and Pollution Control,
International Joint Laboratory for Regional Pollution Control, Ministry
of Education (IJRC), College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Zheng Chen
- State
Key Joint Laboratory of Environmental Simulation and Pollution Control,
International Joint Laboratory for Regional Pollution Control, Ministry
of Education (IJRC), College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Rui Tan
- State
Key Joint Laboratory of Environmental Simulation and Pollution Control,
International Joint Laboratory for Regional Pollution Control, Ministry
of Education (IJRC), College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Kun Hu
- State
Key Joint Laboratory of Environmental Simulation and Pollution Control,
International Joint Laboratory for Regional Pollution Control, Ministry
of Education (IJRC), College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Ruizhe Shen
- State
Key Joint Laboratory of Environmental Simulation and Pollution Control,
International Joint Laboratory for Regional Pollution Control, Ministry
of Education (IJRC), College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Maosheng Yao
- State
Key Joint Laboratory of Environmental Simulation and Pollution Control,
International Joint Laboratory for Regional Pollution Control, Ministry
of Education (IJRC), College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Min Hu
- State
Key Joint Laboratory of Environmental Simulation and Pollution Control,
International Joint Laboratory for Regional Pollution Control, Ministry
of Education (IJRC), College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
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5
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Fahy WD, Wania F, Abbatt JPD. When Does Multiphase Chemistry Influence Indoor Chemical Fate? ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:4257-4267. [PMID: 38380897 DOI: 10.1021/acs.est.3c08751] [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: 02/22/2024]
Abstract
Human chemical exposure often occurs indoors, where large variability in contaminant concentrations and indoor chemical dynamics make assessments of these exposures challenging. A major source of uncertainty lies in the rates of chemical transformations which, due to high surface-to-volume ratios and rapid air change rates relative to rates of gas-phase reactions indoors, are largely gas-surface multiphase processes. It remains unclear how important such chemistry is in controlling indoor chemical lifetimes and, therefore, human exposure to both parent compounds and transformation products. We present a multimedia steady-state fugacity-based model to assess the importance of multiphase chemistry relative to cleaning and mass transfer losses, examine how the physicochemical properties of compounds and features of the indoor environment affect these processes, and investigate uncertainties pertaining to indoor multiphase chemistry and chemical lifetimes. We find that multiphase reactions can play an important role in chemical fate indoors for reactive compounds with low volatility, i.e., octanol-air equilibrium partitioning ratios (Koa) above 108, with the impact of this chemistry dependent on chemical identity, oxidant type and concentration, and other parameters. This work highlights the need for further research into indoor chemical dynamics and multiphase chemistry to constrain human exposure to chemicals in the built environment.
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Affiliation(s)
- William D Fahy
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Frank Wania
- Department of Physical and Environmental Sciences, University of Toronto at Scarborough, Toronto, Ontario M1C 1A4, Canada
| | - Jonathan P D Abbatt
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
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6
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Qu Y, Xie D, Liu Y. Emissions of Volatile Organic Compounds from Human Occupants in a Student Office: Dependence on Ozone Concentration. ACS ENVIRONMENTAL AU 2024; 4:3-11. [PMID: 38250339 PMCID: PMC10797682 DOI: 10.1021/acsenvironau.3c00043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 10/07/2023] [Accepted: 10/24/2023] [Indexed: 01/23/2024]
Abstract
Human occupants themselves constitute an important source of volatile organic compounds (VOCs) in indoor environments through breath and dermal emissions. In order to quantify VOC emissions from occupants under real-world settings, previous indoor observational studies often determined emission factors (i.e., average emission rates per person). However, the values obtained across these studies exhibited large variability, and the causes of this variability still need to be understood. Herein we report 10-day real-time VOC measurements in a university student office, using a proton transfer reaction-quadrupole interface-time-of-flight mass spectrometer. A method was developed to identify VOCs of primary human origin and to quantify the corresponding emission factors, accounting for the dynamically changing occupancy level and ventilation rate in the assessed office. We found that the emission factors of many dermally emitted VOCs strongly increased as the ozone concentration increased from <3 to 10-15 ppb. These VOCs include geranyl acetone, 6-methyl-5-hepten-2-one (6-MHO), and C10-C12 saturated aldehydes, which align with characteristic first-generation ozonolysis products of skin oil. The strongest increase occurred for 6-MHO, from 113 to 337 μg/h/p. In comparison, acetone and isoprene, which are primarily emitted from human breath, varied little with the ozone level. In light of this finding, we conducted an integrated analysis of emission factors reported in the literature for two frequently reported species, namely, 6-MHO and decanal. Ozone concentration alone can explain 94-97% of the variation in their emission factors across previous studies, and the best-estimated ozone dependence obtained using the literature data is consistent with those obtained in the current study. These results suggest that the ozone concentration is a key factor regulating emission factors of many dermally emitted VOCs in real indoor environments, which has to be considered when reporting or using the emission factors.
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Affiliation(s)
- Yuekun Qu
- Key
Joint Laboratory of Environmental Simulation and Pollution Control,
College of Environmental Science and Engineering, Peking University, Beijing 100871, PR China
| | - Di Xie
- Key
Joint Laboratory of Environmental Simulation and Pollution Control,
College of Environmental Science and Engineering, Peking University, Beijing 100871, PR China
| | - Yingjun Liu
- Key
Joint Laboratory of Environmental Simulation and Pollution Control,
College of Environmental Science and Engineering, Peking University, Beijing 100871, PR China
- Center
for Environment and Health, Peking University, Beijing 100871, PR China
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7
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Vergelli L, Frasca F, Bertolin C, Favero G, Siani AM. A review on inorganic gaseous pollutants in conservation spaces: monitoring instrumentation and indoor concentrations. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 196:85. [PMID: 38147197 DOI: 10.1007/s10661-023-12216-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 11/30/2023] [Indexed: 12/27/2023]
Abstract
This contribution presents the results of a review of scientific literature on gaseous inorganic pollutants monitored in confined indoor spaces housing cultural heritage. A survey on standards suggesting concentration thresholds together with European projects on the topic was provided. Sixty-six scientific articles were systematically selected based on the PRISMA flow diagram over the period 1984-2021 for a total number of 80 case studies mainly located in Europe (64%). Monitoring was mainly performed in museums and galleries (61%), specifically in exhibition rooms (79%). Active devices were rarely employed, whereas passive samplers, exposed in situ and then laboratory-analysed, were mostly used for nitrogen dioxide and sulphur dioxide monitoring. Direct-reading continuous devices were widely used for ozone monitoring. It was found that average concentrations of ozone were below 5 ppb in only 50% of cases, nitrogen dioxide below 10 ppb in more than 60% of cases, nitric oxide below 5 ppb in 30% of cases, nitric and nitrous acid below 1 ppb in less than 50% of cases, sulphur dioxide below 2 ppb in more than 60% of cases, and hydrogen sulphide below 0.1 ppb in only 25% of cases. Comparisons were performed following the thresholds suggested in the literature. The lowest concentration values were usually associated to the use of mechanical ventilation systems equipped with air filters and to non-urban case studies. The low number of case studies can be due to the difficulties to perform monitoring in conservation spaces with current instruments. Further research should be conducted to uniform standards that suggest instruments' requirements and pollutant thresholds to limit degradation on cultural materials.
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Affiliation(s)
- Lisa Vergelli
- Department of Earth Sciences, Sapienza University of Rome, P.Le Aldo Moro 5, Rome, Italy
| | - Francesca Frasca
- Department of Physics, Sapienza University of Rome, P.Le Aldo Moro 5, Rome, Italy
- Research Center for Applied Sciences to the Safeguard of Environment and Cultural Heritage (CIABC), Sapienza University of Rome, P.Le Aldo Moro, 00185, Rome, Italy
| | - Chiara Bertolin
- Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology, Richard Birkelands Vei 2B, Gløshaugen, 7491, Trondheim, Norway
| | - Gabriele Favero
- Research Center for Applied Sciences to the Safeguard of Environment and Cultural Heritage (CIABC), Sapienza University of Rome, P.Le Aldo Moro, 00185, Rome, Italy
- Department of Environmental Biology, Sapienza University, P.Le Aldo Moro 5, Rome, Italy
| | - Anna Maria Siani
- Department of Physics, Sapienza University of Rome, P.Le Aldo Moro 5, Rome, Italy.
- Research Center for Applied Sciences to the Safeguard of Environment and Cultural Heritage (CIABC), Sapienza University of Rome, P.Le Aldo Moro, 00185, Rome, Italy.
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8
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Jiang J, Ding X, Patra SS, Cross JN, Huang C, Kumar V, Price P, Reidy EK, Tasoglou A, Huber H, Stevens PS, Boor BE, Jung N. Siloxane Emissions and Exposures during the Use of Hair Care Products in Buildings. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:19999-20009. [PMID: 37971371 DOI: 10.1021/acs.est.3c05156] [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: 11/19/2023]
Abstract
Cyclic volatile methyl siloxanes (cVMS) are ubiquitous in hair care products (HCPs). cVMS emissions from HCPs are of concern, given the potential adverse impact of siloxanes on the environment and human health. To characterize cVMS emissions and exposures during the use of HCPs, realistic hair care experiments were conducted in a residential building. Siloxane-based HCPs were tested using common hair styling techniques, including straightening, curling, waving, and oiling. VOC concentrations were measured via proton-transfer-reaction time-of-flight mass spectrometry. HCP use drove rapid changes in the chemical composition of the indoor atmosphere. cVMS dominated VOC emissions from HCP use, and decamethylcyclopentasiloxane (D5) contributed the most to cVMS emissions. cVMS emission factors (EFs) during hair care routines ranged from 110-1500 mg/person and were influenced by HCP type, styling tools, operation temperatures, and hair length. The high temperature of styling tools and the high surface area of hair enhanced VOC emissions. Increasing the hair straightener temperature from room temperature to 210 °C increased cVMS EFs by 50-310%. Elevated indoor cVMS concentrations can result in substantial indoor-to-outdoor transport of cVMS via ventilation (0.4-6 tons D5/year in the U.S.); thus, hair care routines may augment the abundance of cVMS in the outdoor atmosphere.
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Affiliation(s)
- Jinglin Jiang
- Lyles School of Civil Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Xiaosu Ding
- Lyles School of Civil Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Satya S Patra
- Lyles School of Civil Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Jordan N Cross
- Lyles School of Civil Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Chunxu Huang
- Lyles School of Civil Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Vinay Kumar
- O'Neill School of Public and Environmental Affairs, Indiana University, Bloomington, Indiana 47405, United States
| | - Paige Price
- O'Neill School of Public and Environmental Affairs, Indiana University, Bloomington, Indiana 47405, United States
| | - Emily K Reidy
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | | | - Heinz Huber
- Edelweiss Technology Solutions, LLC, Novelty, Ohio 44072, United States
| | - Philip S Stevens
- O'Neill School of Public and Environmental Affairs, Indiana University, Bloomington, Indiana 47405, United States
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Brandon E Boor
- Lyles School of Civil Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Nusrat Jung
- Lyles School of Civil Engineering, Purdue University, West Lafayette, Indiana 47907, United States
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9
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Zhang R, He X, Liu J, Xiong J. VOC transport in an occupied residence: Measurements and predictions via deep learning. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 892:164559. [PMID: 37263430 DOI: 10.1016/j.scitotenv.2023.164559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/22/2023] [Accepted: 05/28/2023] [Indexed: 06/03/2023]
Abstract
Monitoring and prediction of volatile organic compounds (VOCs) in realistic indoor settings are essential for source characterization, apportionment, and exposure assessment, while it has seldom been examined previously. In this study, we conducted a field campaign on ten typical VOCs in an occupied residence, and obtained the time-resolved VOC dynamics. Feature importance analysis illustrated that air change rate (ACR) has the greatest impact on the VOC concentration levels. We applied three multi-feature (temperature, relative humidity, ACR) deep learning models to predict the VOC concentrations over ten days in the residence, indicating that the long short-term memory (LSTM) model owns the best performance, with predictions the closest to the observed data, compared with the other two models, i.e., recurrent neural network (RNN) model and gated recurrent unit (GRU) model. We also found that human activities could significantly affect VOC emissions in some observed erupted peaks. Our study provides a promising pathway of estimating long-term transport characteristics and exposures of VOCs under varied conditions in realistic indoor environments via deep learning.
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Affiliation(s)
- Rui Zhang
- School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Xinglei He
- School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Jialong Liu
- School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Jianyin Xiong
- School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China; Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720, United States; State Key Laboratory of Green Building in Western China, Xi'an University of Architecture and Technology, Xi'an 710055, China.
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10
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Qu Y, Zou Z, Weschler CJ, Liu Y, Yang X. Quantifying Ozone-Dependent Emissions of Volatile Organic Compounds from the Human Body. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:13104-13113. [PMID: 37610659 DOI: 10.1021/acs.est.3c02340] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Ozone reactions on human body surfaces produce volatile organic compounds (VOCs) that influence indoor air quality. However, the dependence of VOC emissions on the ozone concentration has received limited attention. In this study, we conducted 36 sets of single-person chamber experiments with three volunteers exposed to ozone concentrations ranging from 0 to 32 ppb. Emission fluxes from human body surfaces were measured for 11 targeted skin-oil oxidation products. For the majority of these products, the emission fluxes linearly correlated with ozone concentration, indicating a constant surface yield (moles of VOC emitted per mole of ozone deposited). However, for the second-generation oxidation product 4-oxopentanal, a higher surface yield was observed at higher ozone concentrations. Furthermore, many VOCs have substantial emissions in the absence of ozone. Overall, these results suggest that the complex surface reactions and mass transfer processes involved in ozone-dependent VOC emissions from the human body can be represented using a simplified parametrization based on surface yield and baseline emission flux. Values of these two parameters were quantified for targeted products and estimated for other semiquantified VOC signals, facilitating the inclusion of ozone/skin oil chemistry in indoor air quality models and providing new insights on skin oil chemistry.
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Affiliation(s)
- Yuekun Qu
- Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, People's Republic of China
| | - Ziwei Zou
- Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Department of Building Science, Tsinghua University, Beijing 100084, People's Republic of China
| | - Charles J Weschler
- Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, New Jersey 08854, United States
- International Centre for Indoor Environment and Energy, Technical University of Denmark, Lyngby 2800, Denmark
| | - Yingjun Liu
- Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, People's Republic of China
- Center for Environment and Health, Peking University, Beijing 100871, People's Republic of China
| | - Xudong Yang
- Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Department of Building Science, Tsinghua University, Beijing 100084, People's Republic of China
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11
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Salthammer T, Hohm U, Stahn M, Grimme S. Proton-transfer rate constants for the determination of organic indoor air pollutants by online mass spectrometry. RSC Adv 2023; 13:17856-17868. [PMID: 37323443 PMCID: PMC10262294 DOI: 10.1039/d3ra01705b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 06/06/2023] [Indexed: 06/17/2023] Open
Abstract
Proton transfer reaction mass spectrometry (PTR-MS) has become an indispensable analytical tool for indoor related sciences. With high-resolution techniques not only is the online monitoring of the selected ions in the gas phase possible, but also, with some limitations, the identification of substance mixtures without chromatographic separation. The quantification is carried out with the help of kinetic laws, which require knowledge of the conditions in the reaction chamber, the reduced ion moblilities and the reaction rate constant kPT under these conditions. Ion-dipole collision theory can be used to calculate kPT. One approach is an extension of Langevin's equation and is known as average dipole orientation (ADO). In a further development, the analytical solution of ADO was replaced by trajectory analysis, which resulted in capture theory. The calculations according to ADO and capture theory require precise knowledge of the dipole moment and the polarizability of the respective target molecule. However, for many relevant indoor related substances, these data are insufficiently known or not known at all. Consequently, the dipole moment μD and polarizability α of 114 organic compounds that are frequently found in indoor air had to be determined using advanced quantum mechanical methods. This required the development of an automated workflow that performs conformer analysis before computing μD and α using density functional theory (DFT). Then the reaction rate constants with the H3O+ ion are calculated according to the ADO theory (kADO), capture theory (kcap) and advanced capture theory for different conditions in the reaction chamber. The kinetic parameters are evaluated with regard to their plausibility and critically discussed for their applicability in PTR-MS measurements.
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Affiliation(s)
- Tunga Salthammer
- Fraunhofer WKI, Department of Material Analysis and Indoor Chemistry 38108 Braunschweig Germany
| | - Uwe Hohm
- Institute of Physical and Theoretical Chemistry, University of Braunschweig - Institute of Technology 38106 Braunschweig Germany
| | - Marcel Stahn
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn 53115 Bonn Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn 53115 Bonn Germany
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12
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Deal AM, Vaida V. Oxygen Effect on the Ultraviolet-C Photochemistry of Lactic Acid. J Phys Chem A 2023; 127:2936-2945. [PMID: 36962071 DOI: 10.1021/acs.jpca.3c00992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2023]
Abstract
Lactic acid, a small α-hydroxyacid, is ubiquitous in both indoor and outdoor environments. Recently, the photochemistry of lactic acid has garnered interest among the abiotic organic chemistry community as it would have been present in abiotic settings and photoactive with the high-energy solar radiation that would have been available in the low oxygen early Earth environment. Additionally, we propose that the photochemistry of lactic acid is relevant to modern Earth during indoor ultraviolet-C (UVC) sterilization procedures as lactic acid is emitted by humans and is thus prevalent in indoor environments where UVC sterilization is increasingly being used. Here, we study the oxygen effect on the gas phase photolysis of lactic acid using Fourier-transform infrared (FTIR) spectroscopy and isotopically labeled oxygen (18O2). We find that the major products of gas phase lactic acid photolysis are CO2, CO, acetaldehyde, and acetic acid. Furthermore, these products are the same with or without added oxygen, but the partial pressures of produced CO2, CO, and acetaldehyde increase with the amount of added oxygen. Notably, the added oxygen is primarily incorporated into produced CO2 and CO, while little or none is incorporated into acetaldehyde. We combine the results presented here with those in the literature to propose a mechanism for the gas phase photolysis of lactic acid and the role of oxygen in this mechanism. Finally, we compare the output of a krypton-chloride excimer lamp (λ = 222 nm), one of the lamps proposed for UVC sterilization procedures, to the absorption of lactic acid. We show that lactic acid would be photoactive during UVC sterilization procedures, and we use the gas phase results presented here and aqueous lactic acid photolysis results previously published to assess potential byproducts from lactic acid reactions during UVC sterilization procedures.
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Affiliation(s)
- Alexandra M Deal
- Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Veronica Vaida
- Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States
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13
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Arathala P, Musah RA. Theoretical Study of the Atmospheric Chemistry of Methane Sulfonamide Initiated by OH Radicals and the CH 3S(O) 2N •H + 3O 2 Reaction. J Phys Chem A 2022; 126:9447-9460. [DOI: 10.1021/acs.jpca.2c06432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Parandaman Arathala
- Department of Chemistry, University at Albany─State University of New York, 1400 Washington Avenue, Albany, New York12222, United States
| | - Rabi A. Musah
- Department of Chemistry, University at Albany─State University of New York, 1400 Washington Avenue, Albany, New York12222, United States
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14
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You B, Zhou W, Li J, Li Z, Sun Y. A review of indoor Gaseous organic compounds and human chemical Exposure: Insights from Real-time measurements. ENVIRONMENT INTERNATIONAL 2022; 170:107611. [PMID: 36335895 DOI: 10.1016/j.envint.2022.107611] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 10/29/2022] [Accepted: 10/31/2022] [Indexed: 06/16/2023]
Abstract
Gaseous organic compounds, mainly volatile organic compounds (VOCs), have become a wide concern in various indoor environments where we spend the majority of our daily time. The sources, compositions, variations, and sinks of indoor VOCs are extremely complex, and their potential impacts on human health are less understood. Owing to the deployment of the state-of-the-art real-time mass spectrometry during the last two decades, our understanding of the sources, dynamic changes and chemical transformations of VOCs indoors has been significantly improved. This review aims to summarize the key findings from mass spectrometry measurements in recent indoor studies including residence, classroom, office, sports center, etc. The sources and sinks, compositions and distributions of indoor VOCs, and the factors (e.g., human activities, air exchange rate, temperature and humidity) driving the changes in indoor VOCs are discussed. The physical and chemical processes of gas-particle partitioning and secondary oxidation processes of VOCs, and their impacts on human health are summarized. Finally, the recommendations for future research directions on indoor VOCs measurements and indoor chemistry are proposed.
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Affiliation(s)
- Bo You
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei Zhou
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Junyao Li
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhijie Li
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yele Sun
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
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15
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Tănăsescu EC, Lite MC. Harmful health effects of pesticides used on museum textile artifacts - overview. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 247:114240. [PMID: 36323153 DOI: 10.1016/j.ecoenv.2022.114240] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 10/04/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
The paper discusses the types of fibers contained in the museum textile artifacts and the types of pests and pesticides. Also, the main health problems associated with pesticide exposure are presented. Textile fibers represent an excellent source of food for microbes and insects. The key to the long-term preservation of textiles is by implementing an integrated management program for pest and environmental conditions control. The main types of pesticides are insecticides, herbicides, fungicides, rodenticides, acaricides, and fumigants and a way for classification can be made according to the LD50 (lethal dose) value which evaluates the toxicity of a pesticide. Depending on the LD50 values, pesticides can be very toxic, moderately toxic, slightly toxic, and relatively non-toxic. Exposure to pesticides can occur through 4 four routes: oral, dermal, respiratory, and eye exposure. The main diseases that can be associated with exposure to pesticides are discussed in the paper. In the end, a basic set of precautionary recommendations when handling museum objects that may contain hazardous materials was presented.
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Affiliation(s)
- Elena-Cornelia Tănăsescu
- National Research and Development Institute for Textiles and Leather - INCDTP, Lucretiu Patrascanu, 16, 030508 Bucharest, Romania; Politehnica University of Bucharest, 1-7 Gheorghe Polizu Street, 011061 Bucharest, Romania.
| | - Mihaela-Cristina Lite
- National Research and Development Institute for Textiles and Leather - INCDTP, Lucretiu Patrascanu, 16, 030508 Bucharest, Romania; Politehnica University of Bucharest, 1-7 Gheorghe Polizu Street, 011061 Bucharest, Romania
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16
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Moravek A, VandenBoer TC, Finewax Z, Pagonis D, Nault BA, Brown WL, Day DA, Handschy AV, Stark H, Ziemann P, Jimenez JL, de Gouw JA, Young CJ. Reactive Chlorine Emissions from Cleaning and Reactive Nitrogen Chemistry in an Indoor Athletic Facility. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:15408-15416. [PMID: 36326040 DOI: 10.1021/acs.est.2c04622] [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: 06/16/2023]
Abstract
Indoor gas-phase radical sources are poorly understood but expected to be much different from outdoors. Several potential radical sources were measured in a windowless, light-emitting diode (LED)-lit room in a college athletic facility over a 2 week period. Alternating measurements between the room air and the supply air of the heating, ventilation, and air-conditioning system allowed an assessment of sources. Use of a chlorine-based cleaner was a source of several photolabile reactive chlorine compounds, including ClNO2 and Cl2. During cleaning events, photolysis rates for these two compounds were up to 0.0023 pptv min-1, acting as a source of chlorine atoms even in this low-light indoor environment. Unrelated to cleaning events, elevated ClNO2 was often observed during daytime and lost to ventilation. The nitrate radical (NO3), which is rapidly photolyzed outdoors during daytime, may persist in low-light indoor environments. With negligible photolysis, loss rates of NO3 indoors were dominated by bimolecular reactions. At times with high NO2 and O3 ventilated from outdoors, N2O5 was observed. Elevated ClNO2 measured concurrently suggests the formation through heterogeneous reactions, acting as an additional source of reactive chlorine within the athletic facility and outdoors.
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Affiliation(s)
- Alexander Moravek
- Department of Chemistry, York University, Toronto, OntarioM3J 1P3, Canada
| | | | - Zachary Finewax
- Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, Colorado80309, United States
- Department of Chemistry, University of Colorado, Boulder, Colorado80309, United States
| | - Demetrios Pagonis
- Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, Colorado80309, United States
- Department of Chemistry, University of Colorado, Boulder, Colorado80309, United States
| | - Benjamin A Nault
- Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, Colorado80309, United States
- Department of Chemistry, University of Colorado, Boulder, Colorado80309, United States
| | - Wyatt L Brown
- Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, Colorado80309, United States
- Department of Chemistry, University of Colorado, Boulder, Colorado80309, United States
| | - Douglas A Day
- Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, Colorado80309, United States
- Department of Chemistry, University of Colorado, Boulder, Colorado80309, United States
| | - Anne V Handschy
- Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, Colorado80309, United States
- Department of Chemistry, University of Colorado, Boulder, Colorado80309, United States
| | - Harald Stark
- Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, Colorado80309, United States
- Aerodyne Research, Inc., Billerica, Massachusetts01821, United States
| | - Paul Ziemann
- Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, Colorado80309, United States
- Department of Chemistry, University of Colorado, Boulder, Colorado80309, United States
| | - Jose L Jimenez
- Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, Colorado80309, United States
- Department of Chemistry, University of Colorado, Boulder, Colorado80309, United States
| | - Joost A de Gouw
- Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, Colorado80309, United States
- Department of Chemistry, University of Colorado, Boulder, Colorado80309, United States
| | - Cora J Young
- Department of Chemistry, York University, Toronto, OntarioM3J 1P3, Canada
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17
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Ding L, Wang L, Nian L, Tang M, Yuan R, Shi A, Shi M, Han Y, Liu M, Zhang Y, Xu Y. Non-targeted screening of volatile organic compounds in a museum in China Using GC-Orbitrap mass spectrometry. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 835:155277. [PMID: 35447177 DOI: 10.1016/j.scitotenv.2022.155277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 04/08/2022] [Accepted: 04/10/2022] [Indexed: 06/14/2023]
Abstract
Non-targeted analysis (NTA) was used in identifying volatile organic compounds (VOCs) in a museum in China with the gas chromatograph (GC)-Orbitrap-mass spectrometer (MS). Approximately 230 VOCs were detected, of which 117 were observed at 100% frequency across all sampling sites. Although some were common in indoor environments, most of the detected VOCs were rarely reported in previous studies on museum environments. Some of the detected VOCs were found to be associated with the materials used in furnishings and the chemicals applied in conservation treatment. Spearman's correlation analysis showed that several classes of VOCs were well correlated, suggesting their common sources. Compared with compounds in outdoor air, indoor VOCs had a lower level of unsaturation and more portions of chemically reduced compounds. Hierarchical cluster analysis (HCA) were performed. The results suggested that the sampling adsorbents chosen may have a large impact and that a single type of adsorbent may not be sufficient to cover a wide range of compounds in NTA studies. The MonoTrap adsorbent containing octadecylsilane (ODS) and activated carbon (AC) is suitable for aliphatic polar compounds that contain low levels of oxygen, whereas the MonoTrap ODS and silica gel are good at sampling aliphatic and aromatic hydrocarbons with limited polarity. Principle component analysis (PCA) showed that the indoor VOCs changed significantly at different times in the museum; this may have been caused by the removal of artifacts and refurbishment of the gallery between sampling events. A comparison with compounds identified by chamber emission tests showed that decorative materials may have been one of the main sources of indoor VOCs in the museum. The VOCs identified in the present study are likely to be present in other similar museums; therefore, further examination may be warranted of their potential impacts on cultural heritage artifacts, museum personnel, and visitors.
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Affiliation(s)
- Li Ding
- National Museum of China, Beijing, China
| | - Luyang Wang
- Department of Building Science, Tsinghua University, Beijing, China; Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Beijing, China
| | - Luying Nian
- Department of Building Science, Tsinghua University, Beijing, China; Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Beijing, China
| | - Ming Tang
- National Museum of China, Beijing, China
| | - Rui Yuan
- Department of Building Science, Tsinghua University, Beijing, China; Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Beijing, China
| | - Anmei Shi
- National Museum of China, Beijing, China
| | - Meng Shi
- Department of Building Science, Tsinghua University, Beijing, China; Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Beijing, China
| | - Ying Han
- National Museum of China, Beijing, China
| | - Min Liu
- National Museum of China, Beijing, China
| | - Yinping Zhang
- Department of Building Science, Tsinghua University, Beijing, China; Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Beijing, China
| | - Ying Xu
- Department of Building Science, Tsinghua University, Beijing, China; Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Beijing, China; Department of Civil, Architectural and Environmental Engineering, The University of Texas at Austin, TX, USA.
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18
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Coffaro B, Weisel CP. Reactions and Products of Squalene and Ozone: A Review. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:7396-7411. [PMID: 35648815 PMCID: PMC9231367 DOI: 10.1021/acs.est.1c07611] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 05/13/2022] [Accepted: 05/13/2022] [Indexed: 05/15/2023]
Abstract
This critical review describes the squalene-ozone (SqOz) reaction, or squalene ozonolysis. Ambient ozone penetrates indoors and drives indoor air chemistry. Squalene, a component of human skin oil, contains six carbon-carbon double bonds and is very reactive with ozone. Bioeffluents from people contribute to indoor air chemistry and affect the indoor air quality, resulting in exposures because people spend the majority of their time indoors. The SqOz reaction proceeds through various formation pathways and produces compounds that include aldehydes, ketones, carboxylic acids, and dicarbonyl species, which have a range of volatilities. In this critical review of SqOz chemistry, information on the mechanism of reaction, reaction probability, rate constants, and reaction kinetics are compiled. Characterizations of SqOz reaction products have been done in laboratory experiments and real-world settings. The effect of multiple environmental parameters (ozone concentration, air exchange rate (AER), temperature, and relative humidity (RH)) in indoor settings are summarized. This critical review concludes by identifying the paucity of available exposure, health, and toxicological data for known reaction products. Key knowledge gaps about SqOz reactions leading to indoor exposures and adverse health outcomes are provided as well as an outlook on where the field is headed.
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Affiliation(s)
- Breann Coffaro
- Environmental
and Health Sciences Institute and Graduate Program in Exposure Science, Rutgers, The State University of New Jersey, Piscataway Township, New
Jersey 08854, United
States
| | - Clifford P. Weisel
- Environmental
and Health Sciences Institute and School of Public Health, Rutgers, The State University of New Jersey, Piscataway Township, New
Jersey 08854, United
States
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19
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Fu Z, Xie HB, Elm J, Liu Y, Fu Z, Chen J. Atmospheric Autoxidation of Organophosphate Esters. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:6944-6955. [PMID: 34793133 DOI: 10.1021/acs.est.1c04817] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Organophosphate esters (OPEs), widely used as flame retardants and plasticizers, have frequently been identified in the atmosphere. However, their atmospheric fate and toxicity associated with atmospheric transformations are unclear. Here, we performed quantum chemical calculations and computational toxicology to investigate the reaction mechanism of peroxy radicals of OPEs (OPEs-RO2•), key intermediates in determining the atmospheric chemistry of OPEs, and the toxicity of the reaction products. TMP-RO2• (R1) and TCPP-RO2• (R2) derived from trimethyl phosphate and tris(2-chloroisopropyl) phosphate, respectively, are selected as model systems. The results indicate that R1 and R2 can follow an H-shift-driven autoxidation mechanism under low NO concentration ([NO]) conditions, clarifying that RO2• from esters can follow an autoxidation mechanism. The unexpected autoxidation mechanism can be attributed to the distinct role of the ─(O)3P(═O) phosphate-ester group in facilitating the H-shift of OPEs-RO2• from commonly encountered ─OC(═O)─ and ─ONO2 ester groups in the atmosphere. Under high [NO] conditions, NO can mediate the autoxidation mechanism to form organonitrates and alkoxy radical-related products. The products from the autoxidation mechanism have low volatility and aquatic toxicity compared to their corresponding parent compounds. The proposed autoxidation mechanism advances our current understanding of the atmospheric RO2• chemistry and the environmental risk of OPEs.
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Affiliation(s)
- Zihao Fu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Hong-Bin Xie
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Jonas Elm
- Department of Chemistry and iClimate, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark
| | - Yang Liu
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
| | - Zhiqiang Fu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Jingwen Chen
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
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20
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Wang N, Ernle L, Bekö G, Wargocki P, Williams J. Emission Rates of Volatile Organic Compounds from Humans. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:4838-4848. [PMID: 35389619 PMCID: PMC9022422 DOI: 10.1021/acs.est.1c08764] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 03/25/2022] [Accepted: 03/28/2022] [Indexed: 05/30/2023]
Abstract
Human-emitted volatile organic compounds (VOCs) are mainly from breath and the skin. In this study, we continuously measured VOCs in a stainless-steel environmentally controlled climate chamber (22.5 m3, air change rate at 3.2 h-1) occupied by four seated human volunteers using proton transfer reaction time-of-flight mass spectrometry and gas chromatography mass spectrometry. Experiments with human whole body, breath-only, and dermal-only emissions were performed under ozone-free and ozone-present conditions. In addition, the effect of temperature, relative humidity, clothing type, and age was investigated for whole-body emissions. Without ozone, the whole-body total emission rate (ER) was 2180 ± 620 μg h-1 per person (p-1), dominated by exhaled chemicals. The ERs of oxygenated VOCs were positively correlated with the enthalpy of the air. Under ozone-present conditions (∼37 ppb), the whole-body total ER doubled, with the increase mainly driven by VOCs resulting from skin surface lipids/ozone reactions, which increased with relative humidity. Long clothing (more covered skin) was found to reduce the total ERs but enhanced certain chemicals related to the clothing. The ERs of VOCs derived from this study provide a valuable data set of human emissions under various conditions and can be used in models to better predict indoor air quality, especially for highly occupied environments.
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Affiliation(s)
- Nijing Wang
- Atmospheric
Chemistry Department, Max Planck Institute
for Chemistry, Hahn-Meitner-Weg 1, 55128 Mainz, Germany
| | - Lisa Ernle
- Atmospheric
Chemistry Department, 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, Nils Koppels Alle 402, 2800 Lyngby, Denmark
| | - Pawel Wargocki
- International
Centre for Indoor Environment and Energy, Department of Environmental
and Resource Engineering, Technical University
of Denmark, Nils Koppels Alle 402, 2800 Lyngby, Denmark
| | - Jonathan Williams
- Atmospheric
Chemistry Department, Max Planck Institute
for Chemistry, Hahn-Meitner-Weg 1, 55128 Mainz, Germany
- Climate
& Atmosphere Research Centre, The Cyprus
Institute, 1645 Nicosia, Cyprus
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21
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Stinson B, Laguerre A, Gall ET. Per-Person and Whole-Building VOC Emission Factors in an Occupied School with Gas-Phase Air Cleaning. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:3354-3364. [PMID: 35130699 DOI: 10.1021/acs.est.1c06767] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Using real-time measurements of CO2 and volatile organic compounds (VOCs) in the air handler of an occupied middle school, we quantified source strengths for 249 VOCs and apportioned the source to the building, occupants and their activities, outdoor air, or recirculation air. For VOCs quantified in this study, there is a source to the outdoors of 8.6 ± 1.8 g/h in building exhaust air, of which 5.9 ± 1.7 g/h can be attributed to indoor sources (the building and occupants and their activities). The corresponding whole-building area emission factor from indoor sources is 1020 ± 300 μg/(m2 h), including reactive VOCs like isoprene and monoterpenes (33 ± 5.1 and 29 ± 5.7 μg/(m2 h), respectively). Per-person emission factors are calculated for compounds associated with occupants and their activities, e.g., monoterpenes are emitted at a rate of 280 ± 80 μg/(person h). The air handler included carbon scrubbing, reducing supply air concentrations of 125 compounds by 38 ± 19% (mean ± std. dev.) with a net removal of 2.4 ± 0.4 g/h of organic compounds from the building. This carbon scrubber reduces steady-state indoor concentrations of organics by 65 μg/m3 and the contribution of indoor sources of VOCs to the outdoor environment by ∼40%. These data inform the design and operation of buildings to reduce human exposure to VOCs inside buildings. These data indicate the potential for gas-phase air cleaning to improve both indoor air quality and reduce VOC emissions from buildings to the outdoor environment.
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Affiliation(s)
- Brett Stinson
- Department of Mechanical and Materials Engineering, Portland State University, 1930 Southwest 4th Avenue, Suite 400, Portland, Oregon 97201, United States
| | - Aurélie Laguerre
- Department of Mechanical and Materials Engineering, Portland State University, 1930 Southwest 4th Avenue, Suite 400, Portland, Oregon 97201, United States
| | - Elliott T Gall
- Department of Mechanical and Materials Engineering, Portland State University, 1930 Southwest 4th Avenue, Suite 400, Portland, Oregon 97201, United States
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22
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Piletic IR, Kleindienst TE. Rates and Yields of Unimolecular Reactions Producing Highly Oxidized Peroxy Radicals in the OH-Induced Autoxidation of α-Pinene, β-Pinene, and Limonene. J Phys Chem A 2022; 126:88-100. [PMID: 34979075 PMCID: PMC8895440 DOI: 10.1021/acs.jpca.1c07961] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Recent ambient atmospheric measurements have detected highly oxygenated organic molecules (HOMs) at many sites and are a consequence of autoxidation processes occurring at ambient temperatures. Monoterpenes in particular have a propensity to autoxidize although they exhibit a wide range of HOM yields, which may be due to a variety of reasons including reactions with different oxidants like OH and O3, differing hydrogen (H) atom transfer or peroxy radical cyclization rates, numbers of available reaction pathways, and/or energy loss processes for activated HO-monoterpene or O3-monoterpene adducts. In this work, the autoxidation mechanisms of (+)-α-pinene, (+)-β-pinene, and (+)-limonene following initial OH oxidation and three successive O2 additions are examined using density functional theory (DFT) to understand what accounts for the disparity. Rates of different potential autoxidation pathways initiated by OH addition or abstraction reactions are quantified using transition-state theory (TST) and master equation approaches using the lowest-energy conformers. OH abstraction reactions do not appreciably influence HOM production in the pinenes and limit autoxidation for limonene because the subsequent autoxidation reactions are slow while OH addition reactions are found to be the main route to HOMs for all three monoterpenes. Generally, faster autoxidation rates are computed in later unimolecular reactions that produce RO7 radicals after OH addition (∼10 s-1 or greater) than rates for RO5 peroxy radical production (0.2-7 s-1). Mechanistic pathways that form RO7 peroxy radicals are similar for all three monoterpenes with a particular bicyclo RO7 radical involving a five-membered peroxide ring being favored for all three monoterpenes. The molar yields of RO7 radicals are 4.6% (+10.0/-2.4), 3.8% (+9.1/-2.6), and 7.6% (+13.1/-4.9) for α-pinene, β-pinene, and limonene, respectively, at 298 K and 1 ppb of NO and only significantly decline at NO concentrations exceeding 10 ppb. The higher yield for limonene relative to the pinenes is predominantly a consequence of the initial oxidation step: OH adducts of the bicyclic pinenes have to use the excess energy after OH addition to break one of the rings and make the molecule more flexible for autoxidation although this process is inefficient, while one of the prominent OH adducts for monocyclic limonene does not have to do this and may add O2 immediately before autoxidizing further. These insights may be used to guide a better representation of these processes in atmospheric models because they affect particulate matter (PM), NOx, and ozone concentrations via enhanced production of low-volatility species, less early-generation NOx cycling, and altered organic nitrate production.
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Affiliation(s)
- Ivan R. Piletic
- Center for Environmental Measurement & Modeling, U.S. Environmental Protection Agency, Research Triangle Park, NC, 27711
| | - Tadeusz E. Kleindienst
- Center for Environmental Measurement & Modeling, U.S. Environmental Protection Agency, Research Triangle Park, NC, 27711
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23
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Deal AM, Frandsen BN, Vaida V. Lactic acid photochemistry following excitation of S
0
to S
1
at 220 to 250 nm. J PHYS ORG CHEM 2022. [DOI: 10.1002/poc.4316] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Alexandra M. Deal
- Department of Chemistry and Cooperative Institute for Research in Environmental Sciences University of Colorado Boulder Boulder CO USA
| | - Benjamin N. Frandsen
- Department of Chemistry and Cooperative Institute for Research in Environmental Sciences University of Colorado Boulder Boulder CO USA
| | - Veronica Vaida
- Department of Chemistry and Cooperative Institute for Research in Environmental Sciences University of Colorado Boulder Boulder CO USA
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24
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Wu T, Tasoglou A, Huber H, Stevens PS, Boor BE. Influence of Mechanical Ventilation Systems and Human Occupancy on Time-Resolved Source Rates of Volatile Skin Oil Ozonolysis Products in a LEED-Certified Office Building. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:16477-16488. [PMID: 34851619 DOI: 10.1021/acs.est.1c03112] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Building mechanical ventilation systems are a major driver of indoor air chemistry as their design and operation influences indoor ozone (O3) concentrations, the dilution and transport of indoor-generated volatile organic compounds (VOCs), and indoor environmental conditions. Real-time VOC and O3 measurements were integrated with a building sensing platform to evaluate the influence of mechanical ventilation modes and human occupancy on the dynamics of skin oil ozonolysis products (SOOPs) in an office in a LEED-certified building during the winter. The ventilation system operated under variable recirculation ratios (RRs) from RR = 0 (100% outdoor air) to RR = 1 (100% recirculation air). Time-resolved source rates for 6-methyl-5-hepten-2-one (6-MHO), 4-oxopentanal (4-OPA), and decanal were highly dynamic and changed throughout the day with RR and occupancy. Total SOOP source rates during high-occupancy periods (10:00-18:00) varied from 2500-3000 μg h-1 when RR = 0.1 to 6300-6700 μg h-1 when RR = 1. Source rates for gas-phase reactions, outdoor air, and occupant-associated emissions generally decreased with increasing RR. The recirculation air source rate increased with RR and typically became the dominant source for RR > 0.5. SOOP emissions from surface reservoirs were also a prominent source, contributing 10-50% to total source rates. Elevated per person SOOP emission factors were observed, potentially due to multiple layers of soiled clothing worn during winter.
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Affiliation(s)
- Tianren Wu
- Lyles School of Civil Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Ray W. Herrick Laboratories, Center for High Performance Buildings, Purdue University, West Lafayette, Indiana 47907, United States
| | - Antonios Tasoglou
- RJ Lee Group Incorporated, Monroeville, Pennsylvania 15146, United States
| | - Heinz Huber
- Edelweiss Technology Solutions, Limited Liability Company, Novelty, Ohio 44072, United States
| | - Philip S Stevens
- O'Neill School of Public and Environmental Affairs, Indiana University, Bloomington, Indiana 47405, United States
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Brandon E Boor
- Lyles School of Civil Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Ray W. Herrick Laboratories, Center for High Performance Buildings, Purdue University, West Lafayette, Indiana 47907, United States
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25
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Tao S, Shen G, Cheng H, Ma J. Toward Clean Residential Energy: Challenges and Priorities in Research. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:13602-13613. [PMID: 34597039 DOI: 10.1021/acs.est.1c02283] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Solid fuels used for cooking, heating, and lighting are major emission sources of many air pollutants, specifically PM2.5 and black carbon, resulting in adverse environmental and health impacts. At the same time, the transition from using residential solid fuels toward using cleaner energy sources can result in significant health benefits. Here, we briefly review recent research progress on the emissions of air pollutants from the residential sector and the impacts of emissions on ambient and indoor air quality, population exposure, and health consequences. The major challenges and future research priorities are identified and discussed.
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Affiliation(s)
- Shu Tao
- College of Environmental Science and Technology, Southern University of Science and Technology, Shenzhen 518055, China
- College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Guofeng Shen
- College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Hefa Cheng
- College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Jianmin Ma
- College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
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26
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Finewax Z, Pagonis D, Claflin MS, Handschy AV, Brown WL, Jenks O, Nault BA, Day DA, Lerner BM, Jimenez JL, Ziemann PJ, de Gouw JA. Quantification and source characterization of volatile organic compounds from exercising and application of chlorine-based cleaning products in a university athletic center. INDOOR AIR 2021; 31:1323-1339. [PMID: 33337567 DOI: 10.1111/ina.12781] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 11/30/2020] [Indexed: 05/15/2023]
Abstract
Humans spend approximately 90% of their time indoors, impacting their own air quality through occupancy and activities. Human VOC emissions indoors from exercise are still relatively uncertain, and questions remain about emissions from chlorine-based cleaners. To investigate these and other issues, the ATHLETic center study of Indoor Chemistry (ATHLETIC) campaign was conducted in the weight room of the Dal Ward Athletic Center at the University of Colorado Boulder. Using a Vocus Proton-Transfer-Reaction Time-of-Flight Mass Spectrometer (Vocus PTR-TOF), an Aerodyne Gas Chromatograph (GC), an Iodide-Chemical Ionization Time-of-Flight Mass Spectrometer (I-CIMS), and Picarro cavity ringdown spectrometers, we alternated measurements between the weight room and supply air, allowing for determination of VOC, NH3 , H2 O, and CO2 emission rates per person (emission factors). Human-derived emission factors were higher than previous studies of measuring indoor air quality in rooms with individuals at rest and correlated with increased CO2 emission factors. Emission factors from personal care products (PCPs) were consistent with previous studies and typically decreased throughout the day. In addition, N-chloraldimines were observed in the gas phase after the exercise equipment was cleaned with a dichlor solution. The chloraldimines likely originated from reactions of free amino acids with HOCl on gym surfaces.
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Affiliation(s)
- Zachary Finewax
- Cooperative Institute for Research in Environmental Sciences (CIRES, University of Colorado, Boulder, CO, USA
- Department of Chemistry, University of Colorado, Boulder, CO, USA
| | - Demetrios Pagonis
- Cooperative Institute for Research in Environmental Sciences (CIRES, University of Colorado, Boulder, CO, USA
- Department of Chemistry, University of Colorado, Boulder, CO, USA
| | | | - Anne V Handschy
- Cooperative Institute for Research in Environmental Sciences (CIRES, University of Colorado, Boulder, CO, USA
- Department of Chemistry, University of Colorado, Boulder, CO, USA
| | - Wyatt L Brown
- Cooperative Institute for Research in Environmental Sciences (CIRES, University of Colorado, Boulder, CO, USA
- Department of Chemistry, University of Colorado, Boulder, CO, USA
| | - Olivia Jenks
- Cooperative Institute for Research in Environmental Sciences (CIRES, University of Colorado, Boulder, CO, USA
- Department of Chemistry, University of Colorado, Boulder, CO, USA
| | - Benjamin A Nault
- Cooperative Institute for Research in Environmental Sciences (CIRES, University of Colorado, Boulder, CO, USA
- Department of Chemistry, University of Colorado, Boulder, CO, USA
| | - Douglas A Day
- Cooperative Institute for Research in Environmental Sciences (CIRES, University of Colorado, Boulder, CO, USA
- Department of Chemistry, University of Colorado, Boulder, CO, USA
| | | | - Jose L Jimenez
- Cooperative Institute for Research in Environmental Sciences (CIRES, University of Colorado, Boulder, CO, USA
- Department of Chemistry, University of Colorado, Boulder, CO, USA
| | - Paul J Ziemann
- Cooperative Institute for Research in Environmental Sciences (CIRES, University of Colorado, Boulder, CO, USA
- Department of Chemistry, University of Colorado, Boulder, CO, USA
| | - Joost A de Gouw
- Cooperative Institute for Research in Environmental Sciences (CIRES, University of Colorado, Boulder, CO, USA
- Department of Chemistry, University of Colorado, Boulder, CO, USA
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27
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Sheu R, Fortenberry CF, Walker MJ, Eftekhari A, Stönner C, Bakker A, Peccia J, Williams J, Morrison GC, Williams BJ, Gentner DR. Evaluating Indoor Air Chemical Diversity, Indoor-to-Outdoor Emissions, and Surface Reservoirs Using High-Resolution Mass Spectrometry. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:10255-10267. [PMID: 34270218 PMCID: PMC8461992 DOI: 10.1021/acs.est.1c01337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Detailed offline speciation of gas- and particle-phase organic compounds was conducted using gas/liquid chromatography with traditional and high-resolution mass spectrometers in a hybrid targeted/nontargeted analysis. Observations were focused on an unoccupied home and were compared to two other indoor sites. Observed gas-phase organic compounds span the volatile to semivolatile range, while functionalized organic aerosols extend from intermediate volatility to ultra-low volatility, including a mix of oxygen, nitrogen, and sulfur-containing species. Total gas-phase abundances of hydrocarbon and oxygenated gas-phase complex mixtures were elevated indoors and strongly correlated in the unoccupied home. While gas-phase concentrations of individual compounds generally decreased slightly with greater ventilation, their elevated ratios relative to controlled emissions of tracer species suggest that the dilution of gas-phase concentrations increases off-gassing from surfaces and other indoor reservoirs, with volatility-dependent responses to dynamically changing environmental factors. Indoor-outdoor emissions of gas-phase intermediate-volatility/semivolatile organic hydrocarbons from the unoccupied home averaged 6-11 mg h-1, doubling with ventilation. While the largest single-compound emissions observed were furfural (61-275 mg h-1) and acetic acid, observations spanned a wide range of individual volatile chemical products (e.g., terpenoids, glycol ethers, phthalates, other oxygenates), highlighting the abundance of long-lived reservoirs resulting from prior indoor use or materials, and their gradual transport outdoors.
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Affiliation(s)
- Roger Sheu
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, United States
| | - Claire F Fortenberry
- Department of Energy, Environmental, & Chemical Engineering and Center for Aerosol Science and Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Michael J Walker
- Department of Energy, Environmental, & Chemical Engineering and Center for Aerosol Science and Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Azin Eftekhari
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27515, United States
| | - Christof Stönner
- Department of Atmospheric Chemistry, Max Planck Institute for Chemistry, Mainz 55128, Germany
| | - Alexa Bakker
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, United States
| | - Jordan Peccia
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, United States
| | - Jonathan Williams
- Department of Atmospheric Chemistry, Max Planck Institute for Chemistry, Mainz 55128, Germany
| | - Glenn C Morrison
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27515, United States
| | - Brent J Williams
- Department of Energy, Environmental, & Chemical Engineering and Center for Aerosol Science and Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Drew R Gentner
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, United States
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28
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Hallar AG, Brown SS, Crosman E, Barsanti K, Cappa CD, Faloona I, Fast J, Holmes HA, Horel J, Lin J, Middlebrook A, Mitchell L, Murphy J, Womack CC, Aneja V, Baasandorj M, Bahreini R, Banta R, Bray C, Brewer A, Caulton D, de Gouw J, De Wekker SF, Farmer DK, Gaston CJ, Hoch S, Hopkins F, Karle NN, Kelly JT, Kelly K, Lareau N, Lu K, Mauldin RL, Mallia DV, Martin R, Mendoza D, Oldroyd HJ, Pichugina Y, Pratt KA, Saide P, Silva PJ, Simpson W, Stephens BB, Stutz J, Sullivan A. Coupled Air Quality and Boundary-Layer Meteorology in Western U.S. Basins during Winter: Design and Rationale for a Comprehensive Study. BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY 2021; 0:1-94. [PMID: 34446943 PMCID: PMC8384125 DOI: 10.1175/bams-d-20-0017.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Wintertime episodes of high aerosol concentrations occur frequently in urban and agricultural basins and valleys worldwide. These episodes often arise following development of persistent cold-air pools (PCAPs) that limit mixing and modify chemistry. While field campaigns targeting either basin meteorology or wintertime pollution chemistry have been conducted, coupling between interconnected chemical and meteorological processes remains an insufficiently studied research area. Gaps in understanding the coupled chemical-meteorological interactions that drive high pollution events make identification of the most effective air-basin specific emission control strategies challenging. To address this, a September 2019 workshop occurred with the goal of planning a future research campaign to investigate air quality in Western U.S. basins. Approximately 120 people participated, representing 50 institutions and 5 countries. Workshop participants outlined the rationale and design for a comprehensive wintertime study that would couple atmospheric chemistry and boundary-layer and complex-terrain meteorology within western U.S. basins. Participants concluded the study should focus on two regions with contrasting aerosol chemistry: three populated valleys within Utah (Salt Lake, Utah, and Cache Valleys) and the San Joaquin Valley in California. This paper describes the scientific rationale for a campaign that will acquire chemical and meteorological datasets using airborne platforms with extensive range, coupled to surface-based measurements focusing on sampling within the near-surface boundary layer, and transport and mixing processes within this layer, with high vertical resolution at a number of representative sites. No prior wintertime basin-focused campaign has provided the breadth of observations necessary to characterize the meteorological-chemical linkages outlined here, nor to validate complex processes within coupled atmosphere-chemistry models.
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Affiliation(s)
| | | | - Erik Crosman
- Department of Life, Earth, and Environmental Sciences, West Texas A&M University
| | - Kelley Barsanti
- Department of Chemical and Environmental Engineering, Center for Environmental Research and Technology, University of California, Riverside
| | - Christopher D. Cappa
- Department of Civil and Environmental Engineering, University of California, Davis 95616 USA
| | - Ian Faloona
- Department of Land, Air and Water Resources, University of California, Davis
| | - Jerome Fast
- Atmospheric Science and Global Change Division, Pacific Northwest, National Laboratory, Richland, Washington, USA
| | - Heather A. Holmes
- Department of Chemical Engineering, University of Utah, Salt Lake City, UT
| | - John Horel
- Department of Atmospheric Sciences, University of Utah, Salt Lake City, UT
| | - John Lin
- Department of Atmospheric Sciences, University of Utah, Salt Lake City, UT
| | | | - Logan Mitchell
- Department of Atmospheric Sciences, University of Utah, Salt Lake City, UT
| | - Jennifer Murphy
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Caroline C. Womack
- Cooperative Institute for Research in Environmental Sciences, University of Colorado/ NOAA Chemical Sciences Laboratory, Boulder, CO
| | - Viney Aneja
- Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University
| | | | - Roya Bahreini
- Environmental Sciences, University of California, Riverside, CA
| | | | - Casey Bray
- Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University
| | - Alan Brewer
- NOAA Chemical Sciences Laboratory, Boulder, CO
| | - Dana Caulton
- Department of Atmospheric Science, University of Wyoming
| | - Joost de Gouw
- Cooperative Institute for Research in Environmental Sciences & Department of Chemistry, University of Colorado, Boulder, CO
| | | | | | - Cassandra J. Gaston
- Department of Atmospheric Science - Rosenstiel School of Marine and Atmospheric Science, University of Miami
| | - Sebastian Hoch
- Department of Atmospheric Sciences, University of Utah, Salt Lake City, UT
| | | | - Nakul N. Karle
- Environmental Science and Engineering, The University of Texas at El Paso, TX
| | - James T. Kelly
- Office of Air Quality Planning and Standards, US Environmental Protection Agency, Research Triangle Park, NC
| | - Kerry Kelly
- Chemical Engineering, University of Utah, Salt Lake City, UT
| | - Neil Lareau
- Atmospheric Sciences and Environmental Sciences and Health, University of Nevada, Reno, NV
| | - Keding Lu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Science and Engineering, Peking University, Beijing, China, 100871
| | - Roy L. Mauldin
- National Center for Atmospheric Research, Boulder, CO 80307, USA
| | - Derek V. Mallia
- Department of Atmospheric Sciences, University of Utah, Salt Lake City, UT
| | - Randal Martin
- Civil and Environmental Engineering, Utah State University, Utah Water Research Laboratory, Logan, UT
| | - Daniel Mendoza
- Department of Atmospheric Sciences, University of Utah, Salt Lake City, UT
| | - Holly J. Oldroyd
- Department of Civil and Environmental Engineering, University of California, Davis
| | | | | | - Pablo Saide
- Department of Atmospheric and Oceanic Sciences, and Institute of the Environment and Sustainability, University of California, Los Angeles
| | - Phillip J. Silva
- Food Animal Environmental Systems Research Unit, USDA-ARS, Bowling Green, KY
| | - William Simpson
- Department of Chemistry, Biochemistry, and Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK 99775-6160
| | - Britton B. Stephens
- Earth Observing Laboratory, National Center for Atmospheric Research, Boulder, CO
| | - Jochen Stutz
- Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles
| | - Amy Sullivan
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO
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29
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Liquid crystal display screens as a source for indoor volatile organic compounds. Proc Natl Acad Sci U S A 2021; 118:2105067118. [PMID: 34074793 DOI: 10.1073/pnas.2105067118] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Liquid crystal displays (LCDs) have profoundly shaped the lifestyle of humans. However, despite extensive use, their impacts on indoor air quality are unknown. Here, we perform flow cell experiments on three different LCDs, including a new computer monitor, a used laptop, and a new television, to investigate whether their screens can emit air constituents. We found that more than 30 volatile organic compounds (VOCs) were emitted from LCD screens, with a total screen area-normalized emission rate of up to (8.25 ± 0.90) × 109 molecules ⋅ s-1 ⋅ cm-2 In addition to VOCs, 10 liquid crystal monomers (LCMs), a commercial chemical widely used in LCDs, were also observed to be released from those LCD screens. The structural identification of VOCs is based on a "building block" hypothesis (i.e., the screen-emitted VOCs originate from the "building block chemicals" used in the manufacturing of liquid crystals), which are the key components of LCD screens. The identification of LCMs is based upon the detailed information of 362 currently produced LCMs. The emission rates of VOCs and LCMs increased by up to a factor of 9, with an increase of indoor air humidity from 23 to 58% due to water-organic interactions likely facilitating the diffusion rates of organics. These findings indicate that LCD screens are a potentially important source for indoor VOCs that has not been considered previously.
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30
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Gall ET, Mishra AK, Li J, Schiavon S, Laguerre A. Impact of Cognitive Tasks on CO 2 and Isoprene Emissions from Humans. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:139-148. [PMID: 33301299 DOI: 10.1021/acs.est.0c03850] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The human body emits a wide range of chemicals, including CO2 and isoprene. To examine the impact of cognitive tasks on human emission rates of CO2 and isoprene, we conducted an across-subject, counterbalanced study in a controlled chamber involving 16 adults. The chamber replicated an office environment. In groups of four, participants engaged in 30 min each of cognitive tasks (stressed activity) and watching nature documentaries (relaxed activity). Measured biomarkers indicated higher stress levels were achieved during the stressed activity. Per-person CO2 emission rates were greater for stressed than relaxed activity (30.3 ± 2.1 vs 27.0 ± 1.7 g/h/p, p = 0.0044, mean ± standard deviation). Isoprene emission rates were also elevated under stressed versus relaxed activity (154 ± 25 μg/h/p vs 116 ± 20 μg/h/p, p = 0.041). The chamber temperature was held constant at 26.2 ± 0.49 °C; incidental variation in temperature did not explain the variance in emission rates. Isoprene emission rates increased linearly with salivary α-amylase levels (r2 = 0.6, p = 0.02). These results imply the possibility of considering cognitive tasks when determining building ventilation rates. They also present the possibility of monitoring indicators of cognitive tasks of occupants through measurement of air quality.
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Affiliation(s)
- Elliott T Gall
- Department of Mechanical and Materials Engineering, Portland State University, Portland, Oregon 97201, United States
| | - Asit Kumar Mishra
- Berkeley Education Alliance for Research in Singapore, Singapore 138602
| | - Jiayu Li
- Berkeley Education Alliance for Research in Singapore, Singapore 138602
| | - Stefano Schiavon
- Center for the Built Environment, University of California, Berkeley, California 94720-2284, United States
| | - Aurélie Laguerre
- Department of Mechanical and Materials Engineering, Portland State University, Portland, Oregon 97201, United States
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31
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Wang N, Zannoni N, Ernle L, Bekö G, Wargocki P, Li M, Weschler CJ, Williams J. Total OH Reactivity of Emissions from Humans: In Situ Measurement and Budget Analysis. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:149-159. [PMID: 33295177 PMCID: PMC7788569 DOI: 10.1021/acs.est.0c04206] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Humans are a potent, mobile source of various volatile organic compounds (VOCs) in indoor environments. Such direct anthropogenic emissions are gaining importance, as those from furnishings and building materials have become better regulated and energy efficient homes may reduce ventilation. While previous studies have characterized human emissions in indoor environments, the question remains whether VOCs remain unidentified by current measuring techniques. In this study conducted in a climate chamber occupied by four people, the total OH reactivity of air was quantified, together with multiple VOCs measured by proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) and fast gas chromatography-mass spectrometry (fast-GC-MS). Whole-body, breath, and dermal emissions were assessed. The comparison of directly measured OH reactivity and that of the summed reactivity of individually measured species revealed no significant shortfall. Ozone exposure (37 ppb) was found to have little influence on breath OH reactivity but enhanced dermal OH reactivity significantly. Without ozone, the whole-body OH reactivity was dominated by breath emissions, mostly isoprene (76%). With ozone present, OH reactivity nearly doubled, with the increase being mainly caused by dermal emissions of mostly carbonyl compounds (57%). No significant difference in total OH reactivity was observed for different age groups (teenagers/young adults/seniors) without ozone. With ozone present, the total OH reactivity decreased slightly with increasing age.
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Affiliation(s)
- Nijing Wang
- Max
Planck Institute for Chemistry, Mainz 55128, Germany
| | - Nora Zannoni
- Max
Planck Institute for Chemistry, Mainz 55128, Germany
| | - Lisa Ernle
- Max
Planck Institute for Chemistry, Mainz 55128, Germany
| | - Gabriel Bekö
- International
Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark, Lyngby 2800, Denmark
| | - Pawel Wargocki
- International
Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark, Lyngby 2800, Denmark
| | - Mengze Li
- Max
Planck Institute for Chemistry, Mainz 55128, Germany
| | - Charles J. Weschler
- International
Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark, Lyngby 2800, Denmark
- Environmental
and Occupational Health Sciences Institute, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Jonathan Williams
- Max
Planck Institute for Chemistry, Mainz 55128, Germany
- The
Cyprus Institute, Nicosia 2121, Cyprus
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32
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Mahilang M, Deb MK, Pervez S. Biogenic secondary organic aerosols: A review on formation mechanism, analytical challenges and environmental impacts. CHEMOSPHERE 2021; 262:127771. [PMID: 32799139 DOI: 10.1016/j.chemosphere.2020.127771] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 07/15/2020] [Accepted: 07/19/2020] [Indexed: 06/11/2023]
Abstract
The review initiates with current state of information on the atmospheric reaction mechanism of biogenic volatile organic compounds (BVOCs) and its fate in the atmosphere. The plants release BVOCs, i.e., isoprene, monoterpenes, and sesquiterpenes, which form secondary organic aerosols (SOA) upon oxidation. These oxidation reactions are primarily influenced by solar radiations along with other meteorological parameters viz.; temperature and relative humidity, therefore, the chemistry behind SOA formation is different during day than the night time. The review throws light upon the day and nighttime formation mechanism of SOA, recent advancements in the analytical techniques available for the measurements, and its impact on the environment. Studies have revealed that day time SOA formation is dominated by OH and O3, however, NOx initiated SOA production is dominated during night. The formation mechanism addresses that the gaseous products of VOCs are firstly formed and then partitioned over the pre-existing particles. New particle formation and biomass-derived aerosols are found to be responsible for enhanced SOA formation. 2-Dimensional gas chromatography-mass spectrometer (2D-GC/MS) is observed to be best for the analysis of organic aerosols. Radiative forcing (RF) SOA is observed to be a useful parameter to evaluate the environmental impacts of SOA and reviewed studies have shown mean RF in the ranges of -0.27 to +0.20 W m-2.
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Affiliation(s)
- Mithlesh Mahilang
- School of Studies in Chemistry, Pandit Ravishankar Shukla University, Raipur, Chhattisgarh, 492010, India
| | - Manas Kanti Deb
- School of Studies in Chemistry, Pandit Ravishankar Shukla University, Raipur, Chhattisgarh, 492010, India.
| | - Shamsh Pervez
- School of Studies in Chemistry, Pandit Ravishankar Shukla University, Raipur, Chhattisgarh, 492010, India
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Che W, Li ATY, Frey HC, Tang KTJ, Sun L, Wei P, Hossain MS, Hohenberger TL, Leung KW, Lau AKH. Factors affecting variability in gaseous and particle microenvironmental air pollutant concentrations in Hong Kong primary and secondary schools. INDOOR AIR 2021; 31:170-187. [PMID: 32731301 DOI: 10.1111/ina.12725] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 07/13/2020] [Accepted: 07/13/2020] [Indexed: 06/11/2023]
Abstract
School-age children are particularly susceptible to exposure to air pollutants. To quantify factors affecting children's exposure at school, indoor and outdoor microenvironmental air pollutant concentrations were measured at 32 selected primary and secondary schools in Hong Kong. Real-time PM10 , PM2.5 , NO2, and O3 concentrations were measured in 76 classrooms and 23 non-classrooms. Potential explanatory factors related to building characteristics, ventilation practice, and occupant activities were measured or recorded. Their relationship with indoor measured concentrations was examined using mixed linear regression models. Ten factors were significantly associated with indoor microenvironmental concentrations, together accounting for 74%, 61%, 46%, and 38% of variations observed for PM2.5 , PM10 , O3, and NO2 microenvironmental concentrations, respectively. Outdoor concentration is the single largest predictor for indoor concentrations. Infiltrated outdoor air pollution contributes to 90%, 70%, 75%, and 50% of PM2.5 , PM10 , O3, and NO2 microenvironmental concentrations, respectively, in classrooms during school hours. Interventions to reduce indoor microenvironmental concentrations can be prioritized in reducing ambient air pollution and infiltration of outdoor pollution. Infiltration factors derived from linear regression models provide useful information on outdoor infiltration and help address the gap in generalizable parameter values that can be used to predict school microenvironmental concentrations.
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Affiliation(s)
- Wenwei Che
- Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Alison T Y Li
- Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Henry Christopher Frey
- Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Hong Kong, China
- Department of Civil, Construction and Environmental Engineering, North Carolina State University, Raleigh, NC, USA
| | - Kimberly Tasha Jiayi Tang
- Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Li Sun
- Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Peng Wei
- Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Md Shakhaoat Hossain
- Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Tilman Leo Hohenberger
- Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Hong Kong, China
| | - King Wai Leung
- Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Alexis K H Lau
- Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Hong Kong, China
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
- Institute for the Environment, The Hong Kong University of Science & Technology, Hong Kong, China
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34
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Frandsen BN, Deal AM, Lane JR, Vaida V. Lactic Acid Spectroscopy: Intra- and Intermolecular Interactions. J Phys Chem A 2020; 125:218-229. [PMID: 33377780 DOI: 10.1021/acs.jpca.0c09341] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Lactic acid, a relevant molecule in biology and the environment, is an α-hydroxy acid with a high propensity to form hydrogen bonds, both internally and to other hydrogen-bond-accepting molecules. This work includes the novel recording of infrared spectra of gas-phase lactic acid using Fourier transform infrared spectroscopy, and the vibrational absorption features of lactic acid are assigned with the aid of computationally simulated vibrational spectra with anharmonic corrections. Theoretical chemistry methods are used to relate intramolecular hydrogen-bond strengths to the relative stability of lactic acid conformers. The formation of hydrogen-bonded lactic acid dimers and 1:1 water complexes is investigated by simulated vibrational spectra and calculated thermodynamic parameters for the lactic acid monomer and dimer and its water complex in the gas phase. The results of this study are discussed in the context of environmental chemistry with an emphasis on indoor environments.
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Affiliation(s)
- Benjamin N Frandsen
- Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States.,Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, UCB 216, Boulder, Colorado 80309, United States
| | - Alexandra M Deal
- Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States.,Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, UCB 216, Boulder, Colorado 80309, United States
| | - Joseph R Lane
- School of Science, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand
| | - Veronica Vaida
- Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States.,Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, UCB 216, Boulder, Colorado 80309, United States
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Shen G, Ainiwaer S, Zhu Y, Zheng S, Hou W, Shen H, Chen Y, Wang X, Cheng H, Tao S. Quantifying source contributions for indoor CO 2 and gas pollutants based on the highly resolved sensor data. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 267:115493. [PMID: 33254594 DOI: 10.1016/j.envpol.2020.115493] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 08/16/2020] [Accepted: 08/20/2020] [Indexed: 05/21/2023]
Abstract
Household air pollution is the dominant contributor to population air pollutant exposure, but it is often of less concern compared with ambient air pollution. One of the major knowledge gaps in this field are detailed quantitative source contributions of indoor pollutants, especially for gaseous compounds. In this study, temporally, spatially, and vertically resolved monitoring for typical indoor gases including CO2, CO, formaldehyde, methane, and the total volatile organic compounds (VOCs) was conducted to address pollution dynamics and major sources in an urban apartment. The indoor concentrations were significantly higher than the simultaneously measured outdoor concentrations. A new statistic approach was proposed to quantitatively estimate contributions of different sources. It was estimated that outdoor CO2 contributed largely to the indoor CO2, while main indoor sources were human metabolism and cooking. Outdoor infiltration and cooking contributed almost equally to the indoor CO. The contribution of outdoor infiltration to methane was much higher than that to formaldehyde. Cooking contributed to 24%, 19%, and 25% of indoor formaldehyde, methane, and VOCs, whereas the other unresolved indoor sources contributed 61%, 19%, and 35% of these pollutants, respectively. Vertical measurements showed that the uplifting of hot air masses led to relatively high concentrations of the pollutants in the upper layer of the kitchen and in the other rooms to a lesser extent.
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Affiliation(s)
- Guofeng Shen
- College of Urban and Environmental Sciences, Laboratory for Earth Surface Processes, Sino-French Institute for Earth System Science, Peking University, Beijing, 100871, China
| | - Subinuer Ainiwaer
- College of Urban and Environmental Sciences, Laboratory for Earth Surface Processes, Sino-French Institute for Earth System Science, Peking University, Beijing, 100871, China
| | - Yaqi Zhu
- College of Urban and Environmental Sciences, Laboratory for Earth Surface Processes, Sino-French Institute for Earth System Science, Peking University, Beijing, 100871, China
| | - Shuxiu Zheng
- College of Urban and Environmental Sciences, Laboratory for Earth Surface Processes, Sino-French Institute for Earth System Science, Peking University, Beijing, 100871, China
| | - Weiying Hou
- College of Urban and Environmental Sciences, Laboratory for Earth Surface Processes, Sino-French Institute for Earth System Science, Peking University, Beijing, 100871, China
| | - Huizhong Shen
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, 30332, USA
| | - Yilin Chen
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, 30332, USA
| | - Xilong Wang
- College of Urban and Environmental Sciences, Laboratory for Earth Surface Processes, Sino-French Institute for Earth System Science, Peking University, Beijing, 100871, China
| | - Hefa Cheng
- College of Urban and Environmental Sciences, Laboratory for Earth Surface Processes, Sino-French Institute for Earth System Science, Peking University, Beijing, 100871, China
| | - Shu Tao
- College of Urban and Environmental Sciences, Laboratory for Earth Surface Processes, Sino-French Institute for Earth System Science, Peking University, Beijing, 100871, China.
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36
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Chen Z, Peng Y, Chen J, Wang C, Yin H, Wang H, You C, Li J. Performance and Mechanism of Photocatalytic Toluene Degradation and Catalyst Regeneration by Thermal/UV Treatment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:14465-14473. [PMID: 33119280 DOI: 10.1021/acs.est.0c06048] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
This work presents a new strategy for industrial flue gas purification with TiO2-based photocatalysis technology, which could be achieved by a novel dual-stage circulating photocatalytic reactor. A lab-scale fixed bed reactor is utilized to investigate the performance of photocatalytic toluene degradation and inactive catalyst regeneration by thermal/UV treatment. The relationships between operational conditions and toluene oxidation are surveyed and discussed in detail. The results show that the intermediates could be further removed and decomposed by introducing UV radiation, compared with heat treatment alone. To reveal the photocatalytic mechanism and identify the accumulated intermediates over anatase TiO2, the adsorbed toluene and aromatic intermediates are identified by XPS, in situ DRIFTS, and on-line MS. The aromatic ring and other covalent bonds (C═O, C-O, and O-H) are detected during photocatalytic oxidation. The reaction pathway involving hydrogen abstraction is referred as the dominant pathway for toluene degradation, and ring opening via ·OH radicals is crucial to make aromatic intermediates change into CO2 and H2O. The results indicate that benzoic acid and benzaldehyde are the main accumulation because of their high reaction energy. A possible reaction mechanism is proposed for toluene oxidation, deactivation, and regeneration of catalysts, which has a significant value for guiding the practical applications.
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Affiliation(s)
- Zhen Chen
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
- Key Laboratory for Thermal Science and Power Engineering of the Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China
| | - Yue Peng
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jianjun Chen
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Chizhong Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Haibo Yin
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Haiming Wang
- Key Laboratory for Thermal Science and Power Engineering of the Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China
| | - Changfu You
- Key Laboratory for Thermal Science and Power Engineering of the Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China
| | - Junhua Li
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
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Laguerre A, George LA, Gall ET. High-Efficiency Air Cleaning Reduces Indoor Traffic-Related Air Pollution and Alters Indoor Air Chemistry in a Near-Roadway School. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:11798-11808. [PMID: 32841011 DOI: 10.1021/acs.est.0c02792] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Schools in proximity to roadways expose students to traffic-related air pollution (TRAP). We investigate impacts of air-cleaning on indoor TRAP levels and indoor chemistry in a renovated school adjacent an interstate highway. We monitor air pollutants pre- and post-renovation and quantify efficiency of particle (MERV8 and 16 filters) and gas (functionalized activated carbon) air-cleaning. Time-resolved measurements show air-cleaning systems are effective, with in situ particle removal efficiency >94% across 10 nm to 10 μm. Activated carbon removed BTEX and NO2 with variability in removal efficiency. Over eight months of monitoring, NO2 removal efficiency was 96% initially and decreased to 61%; and BTEX removal efficiency was >80% or increased to >80%. Air-cleaning reduced indoor TRAP to below or near urban background. Air-cleaning systems suppressed indoor chemistry by reducing indoor levels of oxidants (NO2, O3) and reactive organics of indoor origin. When the air cleaning system was inactive, our data show that indoor SOA formation within the school was elevated. Loss rates of NO2 and O3 through the air-cleaning system were ∼1.5-2.4 h-1 and ∼2.3 h-1, respectively. Air-cleaning was 83% and 69% efficient, respectively, in removing monoterpenes and isoprene. By suppressing precursors, scaling calculations show air-cleaning prevented ∼3.4 mg/h of indoor SOA formation due to indoor ozone-monoterpene chemistry. For comparison, we estimate that filtration removed ∼130 mg/h of PM0.01-0.3.
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Affiliation(s)
- Aurélie Laguerre
- Department of Mechanical and Materials Engineering, Portland State University, 1930 SW 4th Avenue, Suite 400, Portland, Oregon 97201, United States
| | - Linda A George
- Department of Environmental Science and Management, Portland State University, P.O. Box 751, Portland, Oregon 97201, United States
| | - Elliott T Gall
- Department of Mechanical and Materials Engineering, Portland State University, 1930 SW 4th Avenue, Suite 400, Portland, Oregon 97201, United States
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38
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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: 18] [Impact Index Per Article: 4.5] [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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39
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Algrim LB, Pagonis D, de Gouw JA, Jimenez JL, Ziemann PJ. Measurements and modeling of absorptive partitioning of volatile organic compounds to painted surfaces. INDOOR AIR 2020; 30:745-756. [PMID: 32077147 DOI: 10.1111/ina.12654] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 02/09/2020] [Accepted: 02/18/2020] [Indexed: 06/10/2023]
Abstract
Partitioning to surfaces is an important sink for volatile organic compounds (VOCs) indoors, but the mechanisms are not well understood or quantified. Here, a mass spectrometer was coupled to a portable surface reactor and a flow tube to measure partitioning of VOCs into paint films coated onto glass or wallboard, and their subsequent diffusion. A model was developed to extract values of the effective absorbing organic mass concentration of the film, Cw , which is a measure of absorption capacity, and VOC diffusion coefficients, Df , from VOC time profiles measured during film passivation and depassivation. Values of Cw agreed well with the value estimated from the paint film mass and flow tube air volume, and Df values (also measured using attenuated total reflectance-Fourier transform infrared spectroscopy) correlated well with VOC vapor saturation concentrations, C*, estimated using a group contribution method. The value of these relationships for estimating key parameters that control VOC partitioning into paint and the fate of VOCs indoors was demonstrated using a house model, which indicated that >50% of VOCs with C* ≤108 μg/m3 (C* of octane, hexanone, and propanol) that contacted a paint film of typical thickness fully permeated the film regardless of emission duration.
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Affiliation(s)
- Lucas B Algrim
- Department of Chemistry and Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
| | - Demetrios Pagonis
- Department of Chemistry and Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
| | - Joost A de Gouw
- Department of Chemistry and Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
| | - Jose L Jimenez
- 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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40
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Nazaroff WW, Weschler CJ. Indoor acids and bases. INDOOR AIR 2020; 30:559-644. [PMID: 32233033 DOI: 10.1111/ina.12670] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 03/18/2020] [Accepted: 03/19/2020] [Indexed: 05/15/2023]
Abstract
Numerous acids and bases influence indoor air quality. The most abundant of these species are CO2 (acidic) and NH3 (basic), both emitted by building occupants. Other prominent inorganic acids are HNO3 , HONO, SO2 , H2 SO4 , HCl, and HOCl. Prominent organic acids include formic, acetic, and lactic; nicotine is a noteworthy organic base. Sources of N-, S-, and Cl-containing acids can include ventilation from outdoors, indoor combustion, consumer product use, and chemical reactions. Organic acids are commonly more abundant indoors than outdoors, with indoor sources including occupants, wood, and cooking. Beyond NH3 and nicotine, other noteworthy bases include inorganic and organic amines. Acids and bases partition indoors among the gas-phase, airborne particles, bulk water, and surfaces; relevant thermodynamic parameters governing the partitioning are the acid-dissociation constant (Ka ), Henry's law constant (KH ), and the octanol-air partition coefficient (Koa ). Condensed-phase water strongly influences the fate of indoor acids and bases and is also a medium for chemical interactions. Indoor surfaces can be large reservoirs of acids and bases. This extensive review of the state of knowledge establishes a foundation for future inquiry to better understand how acids and bases influence the suitability of indoor environments for occupants, cultural artifacts, and sensitive equipment.
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Affiliation(s)
- William W Nazaroff
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, USA
| | - Charles J Weschler
- Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ, USA
- International Centre for Indoor Environment and Energy, Technical University of Denmark, Lyngby, Denmark
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Fu Z, Xie HB, Elm J, Guo X, Fu Z, Chen J. Formation of Low-Volatile Products and Unexpected High Formaldehyde Yield from the Atmospheric Oxidation of Methylsiloxanes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:7136-7145. [PMID: 32401014 DOI: 10.1021/acs.est.0c01090] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
With stricter regulation of atmospheric volatile organic compounds (VOCs) originating from fossil fuel-based vehicles and industries, the use of volatile chemical products (VCPs) and the transformation mechanism of VCPs have become increasingly important to quantify air quality. Volatile methylsiloxanes (VMS) are an important class of VCPs and high-production chemicals. Using quantum chemical calculations and kinetics modeling, we investigated the reaction mechanism of peroxy radicals of VMS, which are key intermediates in determining the atmospheric chemistry of VMS. L2-RSiCH2O2• and D3-RSiCH2O2• derived from hexamethyldisiloxane and hexamethylcyclotrisiloxane, respectively, were selected as representative model systems. The results indicated that L2-RSiCH2O2• and D3-RSiCH2O2• follow a novel Si-C-O rearrangement-driven autoxidation mechanism, leading to the formation of low volatile silanols and high yield of formaldehyde at low NO/HO2• conditions. At high NO/HO2• conditions, L2-RSiCH2O2• and D3-RSiCH2O2• react with NO/HO2• to form organic nitrate, hydroperoxide, and active alkoxy radicals. The alkoxy radicals further follow a Si-C-O rearrangement step to finally form formate esters. The novel Si-C-O rearrangement mechanism of both peroxy and alkoxy radicals are supported by available experimental studies on the oxidation of VMS. Notably, the high yield of formaldehyde is estimated to significantly contribute to formaldehyde pollution in the indoor environment, especially during indoor cleaning.
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Affiliation(s)
- Zihao Fu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Hong-Bin Xie
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Jonas Elm
- Department of Chemistry and iClimate, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark
| | - Xirui Guo
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Zhiqiang Fu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta T6G2R3, Canada
| | - Jingwen Chen
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
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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: 73] [Impact Index Per Article: 18.3] [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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Price DJ, Day DA, Pagonis D, Stark H, Algrim LB, Handschy AV, Liu S, Krechmer JE, Miller SL, Hunter JF, de Gouw JA, Ziemann PJ, Jimenez JL. Budgets of Organic Carbon Composition and Oxidation in Indoor Air. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:13053-13063. [PMID: 31652057 DOI: 10.1021/acs.est.9b04689] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The chemical composition of indoor air at the University of Colorado, Boulder art museum was measured by a suite of gas- and particle-phase instruments. Over 80% of the total observed organic carbon (TOOC) mass (100 μg m-3) consisted of reduced compounds (carbon oxidation state, OSC < -0.5) with high volatility (log10 C* > 7) and low carbon number (nC < 6). The museum TOOC was compared to other indoor and outdoor locations, which increased according to the following trend: remote < rural ≤ urban < indoor ≤ megacity. The museum TOOC was comparable to a university classroom and 3× less than residential environments. Trends in the total reactive flux were remote < indoor < rural < urban < megacity. High volatile organic compound (VOC) concentrations compensated low oxidant concentrations indoors to result in an appreciable reactive flux. Total hydroxyl radical (OH), ozone (O3), nitrate radical (NO3), and chlorine atom (Cl) reactivities for each location followed a similar trend to TOOC. High human occupancy events increased all oxidant reactivities in the museum by 65-125%. The lifetimes of O3, NO3, OH, and Cl reactivities were 13 h, 15 h, 23 days, and 189 days, respectively, corresponding to over 88% of indoor VOC oxidant reactivity being consumed outdoors after ventilation.
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Affiliation(s)
| | | | | | - Harald Stark
- Aerodyne Research Inc. , Billerica , Massachusetts 01821 , United States
| | | | | | | | - Jordan E Krechmer
- Aerodyne Research Inc. , Billerica , Massachusetts 01821 , United States
| | | | - James F Hunter
- Department of Civil and Environmental Engineering and Department of Materials Science and Engineering , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
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