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Zhang Z, Cheng Y, Liang L, Liu J. The Measurement of Atmospheric Black Carbon: A Review. TOXICS 2023; 11:975. [PMID: 38133376 PMCID: PMC10748019 DOI: 10.3390/toxics11120975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/16/2023] [Accepted: 11/28/2023] [Indexed: 12/23/2023]
Abstract
Black Carbon (BC), the second-largest contributor to global warming, has detrimental effects on human health and the environment. However, the accurate quantification of BC poses a significant challenge, impeding the comprehensive assessment of its impacts. Therefore, this paper aims to critically review three quantitative methods for measuring BC: Thermal Optical Analysis (TOA), the Optical Method, and Laser-Induced Incandescence (LII). The determination principles, available commercial instruments, sources of deviation, and correction approaches associated with these techniques are systematically discussed. By synthesizing and comparing the quantitative results reported in previous studies, this paper aims to elucidate the underlying relationships and fundamental disparities among Elemental Carbon (EC), Equivalent Black Carbon (eBC), and Refractory Black Carbon (rBC). Finally, based on the current advancements in BC quantification, recommendations are proposed to guide future research directions.
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Affiliation(s)
- Zhiqing Zhang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China; (Z.Z.); (Y.C.)
| | - Yuan Cheng
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China; (Z.Z.); (Y.C.)
| | - Linlin Liang
- State Key Laboratory of Severe Weather & Key Laboratory for Atmospheric Chemistry, Chinese Academy of Meteorological Sciences, Beijing 100081, China
| | - Jiumeng Liu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China; (Z.Z.); (Y.C.)
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Wei W, Wang M, Yuan Q, Zhang Z, Li X, Han S, Duan Y, Fu Q, Lee SC. Comprehensive Assessment of Pollution Sources and Health Impacts in Suburban Area of Shanghai. TOXICS 2023; 11:552. [PMID: 37505518 PMCID: PMC10383545 DOI: 10.3390/toxics11070552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/15/2023] [Accepted: 06/21/2023] [Indexed: 07/29/2023]
Abstract
Shanghai, one of China's largest metropolises, faces significant environmental pollution challenges due to rapid economic development. Suburban areas of Shanghai are affected by both long-distance transport and local sources of pollutants. This study conducted an integrated analysis that links health-risk assessment of heavy metals and source apportionment of atmospheric constituents to distinguish the contributions of emission sources and the major sources of health risks. Source-apportionment analysis revealed that secondary sources had the greatest contribution to the local pollutants, indicating the significant influence of peripheral and long-distance transport. Health-risk assessment of Cr, Ni, As, and Cd revealed that local residents were exposed to respiratory health risks, in which Cr is the major contributor. This health risk was primarily associated with emissions from nearby industry-related sources. Our study highlights the significant effects of both long-distance transport and local source emissions on atmospheric composition and human health in large urban agglomerations. The findings can inform future efforts to develop more precise emission-reduction strategies and policy improvements to mitigate environmental pollution and protect public health.
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Affiliation(s)
- Wan Wei
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - Meng Wang
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - Qi Yuan
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - Zhuozhi Zhang
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - Xinwei Li
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - Shuwen Han
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - Yusen Duan
- Shanghai Environmental Monitoring Center, Shanghai 200030, China
| | - Qingyan Fu
- Shanghai Environmental Monitoring Center, Shanghai 200030, China
| | - Shun-Cheng Lee
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
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Chow JC, Watson JG, Wang X, Abbasi B, Reed WR, Parks D. Review of Filters for Air Sampling and Chemical Analysis in Mining Workplaces. MINERALS (BASEL, SWITZERLAND) 2022; 12:10.3390/min12101314. [PMID: 37180428 PMCID: PMC10174218 DOI: 10.3390/min12101314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
This review considers the use of filters to sample air in mining workplace environments for dust concentration measurement and subsequent analysis of hazardous contaminants, especially respirable crystalline silica (RCS) on filters compatible with wearable personal dust monitors (PDM). The review summarizes filter vendors, sizes, costs, chemical and physical properties, and information available on filter modeling, laboratory testing, and field performance. Filter media testing and selection should consider the characteristics required for mass by gravimetry in addition to RCS quantification by Fourier-transform infrared (FTIR) or Raman spectroscopic analysis. For mass determination, the filters need to have high filtration efficiency (≥99% for the most penetrable particle sizes) and a reasonable pressure drop (up to 16.7 kPa) to accommodate high dust loading. Additional requirements include: negligible uptake of water vapor and gaseous volatile compounds; adequate particle adhesion as a function of particle loading; sufficient particle loading capacity to form a stable particle deposit layer during sampling in wet and dusty environments; mechanical strength to withstand vibrations and pressure drops across the filter; and appropriate filter mass compatible with the tapered element oscillating microbalance. FTIR and Raman measurements require filters to be free of spectral interference. Furthermore, because the irradiated area does not completely cover the sample deposit, particles should be uniformly deposited on the filter.
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Affiliation(s)
- Judith C. Chow
- Division of Atmospheric Sciences, Desert Research Institute, Reno, NV 89511, USA
- Correspondence:
| | - John G. Watson
- Division of Atmospheric Sciences, Desert Research Institute, Reno, NV 89511, USA
| | - Xiaoliang Wang
- Division of Atmospheric Sciences, Desert Research Institute, Reno, NV 89511, USA
| | - Behrooz Abbasi
- Department of Mining and Metallurgical Engineering, University of Nevada, Reno, NV 89557, USA
| | - Wm. Randolph Reed
- Office of the Director, National Institute for Occupational Safety and Health, Pittsburgh, PA 15236, USA
| | - David Parks
- Spokane Mining Research Division, National Institute for Occupational Safety and Health, Spokane, WA 99207, USA
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Bhardwaj A, Sunder Raman R. Evaluation of organic aerosol filter sampling artefacts and implications to gravimetric PM 2.5 mass at a COALESCE network site - Bhopal, India. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 319:115749. [PMID: 35982559 DOI: 10.1016/j.jenvman.2022.115749] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 06/14/2022] [Accepted: 07/10/2022] [Indexed: 06/15/2023]
Abstract
Filter based PM2.5 samples are typically used to measure its chemical constituents. Such measurements are made in dense sampling networks to assess regulatory compliance and for source apportionment. Thus, quantifying sampling artefacts is crucial. In this study, 24-h integrated PM2.5 samples collected over Bhopal, India a COALESCE (CarbOnaceous AerosoL Emissions, Source apportionment and ClimatE impacts) site during 2019 and 2020, were used to estimate particulate organic carbon (OC) artefacts. Total OC and its thermal fractions (OC1, OC2, OC3, and OC4) measured on 349 bare quartz (Q) and QbQ filters each, were used to determine OC positive artefacts on quartz filters. 50 QbT (Quartz behind Teflon) filters in conjunction with the simultaneous QbQ samples (a subset of the total QbQ) were used to estimate OC volatilization from Teflon filters. On average, adsorbed gaseous OC contributed 17% and 11% to the measured total OC during 2019 and 2020, respectively. Further, the volatilization loss of organics from Teflon filter (used to quantify PM2.5 mass) ranged between 7% and 9%, and 5% and 6% of the PM2.5 mass during 2019 and 2020, respectively. The results of this study provide the first systematic long-term evaluation of thermal carbon fraction-wise sampling artefacts, estimates of organic volatilization losses from Teflon filters and their implications to PM2.5 mass closure, over a regionally representative location in India.
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Affiliation(s)
- Ankur Bhardwaj
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal By-pass Road, Bhauri, Bhopal, 462066, Madhya Pradesh, India
| | - Ramya Sunder Raman
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal By-pass Road, Bhauri, Bhopal, 462066, Madhya Pradesh, India.
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Wang M, Wang Q, Ho SSH, Li H, Zhang R, Ran W, Qu L, Lee SC, Cao J. Chemical characteristics and sources of nitrogen-containing organic compounds at a regional site in the North China Plain during the transition period of autumn and winter. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 812:151451. [PMID: 34780830 DOI: 10.1016/j.scitotenv.2021.151451] [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] [Received: 06/06/2021] [Revised: 10/31/2021] [Accepted: 11/01/2021] [Indexed: 06/13/2023]
Abstract
Organic nitrogen constitutes a significant fraction of the nitrogen budget in particulate matter (PM). However, the composition and sources of nitrogen-containing organic compounds (NOCs) in PM remain unclear currently in North China Plain (NCP), China. Rare local or regional studies on NOCs were conducted. In this study, ambient fine particles (PM2.5) were collected in Xianghe, a regional background site in NCP, from 26 October to 26 December 2017. The insights from this study include NOC molecule identification, concentration level, and NOC sources and origins. Specifically, we have identified and quantified >90 NOC species, with urea being the most abundant, accounting for 39.7 ± 4.7% of the total NOC followed by free amino acids (FAAs; 21.9 ± 1.5%), cyclic NOCs (15.3 ± 4.5%), amines (14.8 ± 1.5%), alkyl amides (5.8 ± 0.5%), isocyanates (1.7 ± 0.2%), and nitriles (1.1 ± 0.2%). The time series of FAAs was well correlated (r = 0.51-0.68, p < 0.01) with the organic marker of levoglucosan and was moderately correlated with Ox (r = 0.29-0.41, p < 0.01), suggesting biomass burning and secondary formation were important FAAs sources. We also show that amines can be oxidized and/or reacted by aqueous-phase processing to form secondary aerosols, which are further enhanced by the involvement of iron in the catalytic process. Using the receptor model of positive matrix factorization (PMF), six factors were identified including coal combustion, crustal sources, biomass burning, industry-related sources, traffic emissions, and secondary aerosols. Source apportionment of NOC shows biomass burning was the dominant factor, accounting for 31.8% of the total NOCs. This study provides a unique dataset of NOCs at this regional background site in the NCP, with the insights of NOC chemical composition and sources gained in this study being important for future NOC modeling as well as NOC health effects studies.
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Affiliation(s)
- Meng Wang
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China
| | - Qiyuan Wang
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an 710061, China.
| | - Steven Sai Hang Ho
- Division of Atmospheric Sciences, Desert Research Institute, Reno, NV 89512, United States; Hong Kong Premium Services and Research Laboratory, Kowloon, Hong Kong SAR, China
| | - Huan Li
- Xi'an Institute for Innovative Earth Environment Research, Xi'an 710061, China
| | - Renjian Zhang
- Key Laboratory of Middle Atmosphere and Global Environment Observation, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; Xianghe Observatory of Whole Atmosphere, Institute of Atmospheric Physics, Chinese Academy of Sciences, Xianghe 065400, China
| | - Weikang Ran
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China
| | - Linli Qu
- Hong Kong Premium Services and Research Laboratory, Kowloon, Hong Kong SAR, China
| | - Shun-Cheng Lee
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China.
| | - Junji Cao
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China; CAS Center for Excellence in Quaternary Science and Global Change, Xi'an 710061, China.
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Nayak G, Kumar A, Bikkina S, Tiwari S, Sheteye SS, Sudheer AK. Carbonaceous aerosols and their light absorption properties over the Bay of Bengal during continental outflow. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2022; 24:72-88. [PMID: 34897330 DOI: 10.1039/d1em00347j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The marine atmosphere of the Bay of Bengal (BoB) is prone to get impacted by anthropogenic aerosols from the Indo-Gangetic Plain (IGP) and Southeast Asia (SEA), particularly during the northeast monsoon (NEM). In this study, we quantify and characterize carbonaceous aerosols and their absorption properties collected in two cruise campaigns onboard ORV Sindhu Sadhana during the continental outflow period over the BoB. Aerosol samples were classified based on the air mass back trajectory analyses, wherein samples were impacted by the continental air parcel (CAP), marine air parcel (MAP), and mix of both (CAP + MAP). Significant variability in the PM10 mass concentration (in μg m-3) is found with a maximum value for MAP samples (75.5 ± 36.4) followed by CAP + MAP (58.5 ± 27.3) and CAP (58.5 ± 27.3). The OC/EC ratio (>2) and diagnostic tracers i.e. nss-K+/EC (0.2-0.96) and nss-K+/OC (0.11-1.32) along with the absorption angstrom exponent (AAE: 4.31-6.02) and MODIS (Moderate Resolution Imaging Spectroradiometer) derived fire counts suggest the dominance of biomass burning emission sources. A positive correlation between OC and EC (i.e. r = 0.86, 0.70, and 0.42 for CAP, MAP, and CAP + MAP, respectively) further confirmed the similar emission sources of carbonaceous species. Similarly, a significant correlation between estimated secondary organic carbon (SOC) and water-soluble organic carbon (WSOC; r = 0.99, 0.96, and 0.97 for CAP, MAP, and CAP + MAP, respectively) indicate their similar chemical nature as well as dominant contribution of SOC to WSOC. The absorption coefficient (babs-365) and mass absorption efficiency (MAEBrC-365) of the soluble fraction were estimated at 365 nm wherein, babs-365 showed a linear relationship with WSOC and nss-K+, signifying the contribution of water soluble brown carbon from biomass burning emissions. The estimated MAEBrC-365 (0.30-0.93 m2 g-1), during this study, was consistent with the earlier observations over the BoB, particularly during the continental outflow season.
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Affiliation(s)
- Gourav Nayak
- Geological Oceanography Division, CSIR-National Institute of Oceanography, Dona Paula, Goa-403 004, India.
| | - Ashwini Kumar
- Geological Oceanography Division, CSIR-National Institute of Oceanography, Dona Paula, Goa-403 004, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Srinivas Bikkina
- Geological Oceanography Division, CSIR-National Institute of Oceanography, Dona Paula, Goa-403 004, India.
| | - Shani Tiwari
- Geological Oceanography Division, CSIR-National Institute of Oceanography, Dona Paula, Goa-403 004, India.
| | - Suhas S Sheteye
- Geological Oceanography Division, CSIR-National Institute of Oceanography, Dona Paula, Goa-403 004, India.
| | - A K Sudheer
- Physical Research Laboratory, Department of Space, Ahmedabad, India
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Veld MI', Alastuey A, Pandolfi M, Amato F, Pérez N, Reche C, Via M, Minguillón MC, Escudero M, Querol X. Compositional changes of PM 2.5 in NE Spain during 2009-2018: A trend analysis of the chemical composition and source apportionment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 795:148728. [PMID: 34328931 DOI: 10.1016/j.scitotenv.2021.148728] [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] [Received: 04/15/2021] [Revised: 06/11/2021] [Accepted: 06/24/2021] [Indexed: 06/13/2023]
Abstract
In this work, time-series analyses of the chemical composition and source contributions of PM2.5 from an urban background station in Barcelona (BCN) and a rural background station in Montseny (MSY) in northeastern Spain from 2009 to 2018 were investigated and compared. A multisite positive matrix factorization analysis was used to compare the source contributions between the two stations, while the trends for both the chemical species and source contributions were studied using the Theil-Sen trend estimator. Between 2009 and 2018, both stations showed a statistically significant decrease in PM2.5 concentrations, which was driven by the downward trends of levels of chemical species and anthropogenic source contributions, mainly from heavy oil combustion, mixed combustion, industry, and secondary sulfate. These source contributions showed a continuous decrease over the study period, signifying the continuing success of mitigation strategies, although the trends of heavy oil combustion and secondary sulfate have flattened since 2016. Secondary nitrate also followed a significant decreasing trend in BCN, while secondary organic aerosols (SOA) very slightly decreased in MSY. The observed decreasing trends, in combination with the absence of a trend for the organic aerosols (OA) at both stations, resulted in an increase in the relative proportion of OA in PM2.5 by 12% in BCN and 9% in MSY, mostly from SOA, which increased by 7% in BCN and 4% in MSY. Thus, at the end of the study period, OA accounted for 40% and 50% of the annual mean PM2.5 at BCN and MSY, respectively. This might have relevant implications for air quality policies aiming at abating PM2.5 in the study region and for possible changes in toxicity of PM2.5 due to marked changes in composition and source apportionment.
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Affiliation(s)
- Marten In 't Veld
- Institute of Environmental Assessment and Water Research, IDAEA-CSIC, Barcelona 08034, Spain; Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya, Barcelona 08034, Spain.
| | - Andres Alastuey
- Institute of Environmental Assessment and Water Research, IDAEA-CSIC, Barcelona 08034, Spain
| | - Marco Pandolfi
- Institute of Environmental Assessment and Water Research, IDAEA-CSIC, Barcelona 08034, Spain
| | - Fulvio Amato
- Institute of Environmental Assessment and Water Research, IDAEA-CSIC, Barcelona 08034, Spain
| | - Noemi Pérez
- Institute of Environmental Assessment and Water Research, IDAEA-CSIC, Barcelona 08034, Spain
| | - Cristina Reche
- Institute of Environmental Assessment and Water Research, IDAEA-CSIC, Barcelona 08034, Spain
| | - Marta Via
- Institute of Environmental Assessment and Water Research, IDAEA-CSIC, Barcelona 08034, Spain; Department of Applied Physics, University of Barcelona, Barcelona 08028, Spain
| | - María Cruz Minguillón
- Institute of Environmental Assessment and Water Research, IDAEA-CSIC, Barcelona 08034, Spain
| | - Miguel Escudero
- Centro Universitario de la Defensa, Academia General Militar, Zaragoza 50090, Spain
| | - Xavier Querol
- Institute of Environmental Assessment and Water Research, IDAEA-CSIC, Barcelona 08034, Spain
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Li T, Dai Q, Bi X, Wu J, Zhang Y, Feng Y. Size distribution and chemical characteristics of particles from crop residue open burning in North China. J Environ Sci (China) 2021; 109:66-76. [PMID: 34607675 DOI: 10.1016/j.jes.2021.02.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 01/06/2021] [Accepted: 02/14/2021] [Indexed: 06/13/2023]
Abstract
Crop residue open burning is an important emission source of ambient particles in China. This study analyzed the particle emission characteristics of crop residue open burning through combustion experiments with a novel open combustion simulation device using three typical crop straws in north China (corn, wheat, and rice). Particle samples size ranging from 0.006-9.890 µm were collected by an Electrical Low Pressure Impactor plus, a high size-resolution instrument capable of dividing particles into 14 size stages. The size distributions of organic carbon (OC), elemental carbon (EC), water-soluble ions, and elements were analyzed, and source chemical profiles were constructed for PM0.1, PM1, PM2.5, and PM10. The number concentration of particles was concentrated in the Aiken nuclei mode (0.006-0.054 µm), accounting for 75% of the total number, whereas the mass concentration was concentrated in the accumulation mode (0.054-0.949 µm), accounting for 85.43% of the mass loading. OC, EC, Cl-, and K(include total K and water-soluble K) were the major chemical components of the particles, whose mass percentage distributions differed from those of other components. These five main components exhibited a bell-shaped size distribution in the 0.006-9.890 µm range, whereas the other components exhibited a U-shaped distribution. Among the chemical profiles for PM0.1-PM10, OC was the most important component at 10-30%, followed by EC at 2%-8%. The proportions of K+, Cl-, and K varied substantially in different experimental groups, ranging from 0-15%, and K+ and Cl- were significantly correlated (r = 0.878, α = 0.000).
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Affiliation(s)
- Tingkun Li
- State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China
| | - Qili Dai
- State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China
| | - Xiaohui Bi
- State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China
| | - Jianhui Wu
- State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China
| | - Yufen Zhang
- State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China
| | - Yinchang Feng
- State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China..
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Oh SH, Song M, Schauer JJ, Shon ZH, Bae MS. Assessment of long-range oriented source and oxidative potential on the South-west shoreline, Korea: Molecular marker receptor models during shipborne measurements. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 281:116979. [PMID: 33813190 DOI: 10.1016/j.envpol.2021.116979] [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: 06/12/2020] [Revised: 03/07/2021] [Accepted: 03/15/2021] [Indexed: 06/12/2023]
Abstract
In order to determine the quantitative contributions of PM2.5 on the South-west shoreline of Korea, filter based samplings were conducted in the summertime of 2017 and 2018 (total 32 days) via shipborne measurements using both a high volume and middle volume air sampler. Water-soluble organic carbon, water-soluble ions, organic carbon and elemental carbon, elemental species, and organic molecular markers by Liquid Chromatography-tandem Mass Spectrometry were utilized to characterize the collected substrates. The current study investigates the (1) chemical characteristics of PM2.5, (2) source apportionment using positive matrix factorization (PMF), and (3) relationship between sources and the dithiothreitol (DTT) assay during the two sampling periods. A mean PM2.5 concentration of 19.3 μg/m3 was observed along the entire sampling route. The ratio of water-soluble to organic carbon implies that secondary aerosol formation is dominant. The result of methanesulfonic acid (MSA) suggests the contribution of a marine-oriented biogenic source of PM2.5. The PMF source apportionment model showed six source categories with reasonably stable profiles: 1) sulfate-rich, 2) MSA-rich, 3) nitrate-rich, 4) secondary organic, 5) continental, and 6) biomass burning sources. The PMF showed three strong events (i.e., long-range transport, mixed (ocean and long-range stay), and domestic origin events) in the contributions of sources, as well as a dependence on wind transport. Higher associations with DTT oxidative potential normalized to PM2.5 mass concentration (DTT-OPm) related to long-range transport, hence, confirming the impacts of the highest intrinsic oxidative potential.
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Affiliation(s)
- Sea-Ho Oh
- Department of Environmental Engineering, Mokpo National University, Muan, 58554, Republic of Korea
| | - Myoungki Song
- Department of Environmental Engineering, Mokpo National University, Muan, 58554, Republic of Korea
| | - James J Schauer
- Department of Civil & Environmental Engineering, University of Wisconsin-Madison, Madison, 53705, USA
| | - Zang-Ho Shon
- Department of Environmental Engineering, Dong-Eui University, Busan, 47340, Republic of Korea
| | - Min-Suk Bae
- Department of Environmental Engineering, Mokpo National University, Muan, 58554, Republic of Korea.
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Watson JG, Cao J, Wang X, Chow JC. PM 2.5 pollution in China's Guanzhong Basin and the USA's San Joaquin Valley mega-regions. Faraday Discuss 2021; 226:255-289. [PMID: 33877224 DOI: 10.1039/d0fd00094a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The Guanzhong Basin (GZB) of northwest China is examined as a mega-region containing the mega-city of Xi'an. The concept of a "mega-region" is more accurate than that of a "mega-city" for air quality management as there is an interaction between urban and non-urban emissions. Parallels are drawn between the GZB and the San Joaquin Valley (SJV) mega-region of central California for excessive wintertime PM2.5 concentrations. Long-term chemical composition measurements show the usual high levels of organic and elemental carbon, minerals, sulfate, nitrate, and ammonium. Wintertime provides prolonged high pressure systems in both areas punctuated by unstable precipitation events. Sluggish nighttime winds allow pollutants such as ammonia from distant agricultural operations, to mix with urban pollutants, sometimes serving as a reactor to create secondary sulfates and nitrates, and possibly some secondary organic compounds. A shallow surface layer forms at night in the SJV and GZB that couples to an upper level inversion after sunrise, allowing pollutants accumulated aloft to mix to the surface. Although current air quality management strategies have focused on urban emissions, and PM2.5 levels are on a downward trend, future management efforts must consider reducing emissions from a variety of sources in the larger region of these basins. Agricultural emissions are important in the SJV, but are just being addressed in the GZB. Tactics developed for the SJV would probably be effective in other areas of the world with similar emissions, topography, and meteorology. Experiments related to agricultural NOx emissions, emission inventory enhancements, source apportionment, and estimates of precursor limitations for ammonium nitrate formation, have been conducted in the SJV that can be tested in the GZB.
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Affiliation(s)
- John G Watson
- Division of Atmospheric Sciences, Desert Research Institute, Reno, Nevada, USA.
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Xie M, Zhao Z, Holder AL, Hays MD, Chen X, Shen G, Jetter JJ, Champion WM, Wang Q. Chemical composition, structures, and light absorption of N-containing aromatic compounds emitted from burning wood and charcoal in household cookstoves. ATMOSPHERIC CHEMISTRY AND PHYSICS 2020; 20:14077-14090. [PMID: 33552150 PMCID: PMC7863623 DOI: 10.5194/acp-20-14077-2020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
N-containing aromatic compounds (NACs) are an important group of light-absorbing molecules in the atmosphere. They are often observed in combustion emissions, but their chemical formulas and structural characteristics remain uncertain. In this study, red oak wood and charcoal fuels were burned in cookstoves using the standard water boiling test (WBT) procedure. Submicron aerosol particles in the cookstove emissions were collected using quartz (Q f ) and polytetrafluoroethylene (PTFE) filter membranes positioned in parallel. A back-up quartz filter (Q b ) was also installed downstream of the PTFE filter to evaluate the effect of sampling artifact on NACs measurements. Liquid chromatography-mass spectroscopy (LC-MS) techniques identified seventeen NAC chemical formulas in the cookstove emissions. The average concentrations of total NACs in Q b samples (0.37 ± 0.31 - 1.79 ± 0.77 μg m-3) were greater than 50% of those observed in the Q f samples (0.51 ± 0.43 - 3.91 ± 2.06 μg m-3), and the Q b to Q f mass ratios of individual NACs had a range of 0.02 - 2.71, indicating that the identified NACs might have substantial fractions remaining in the gas-phase. In comparison to other sources, cookstove emissions from red oak or charcoal fuels did not exhibit unique NAC structural features, but had distinct NACs composition. However, before identifying NACs sources by combining their structural and compositional information, the gas-particle partitioning behaviors of NACs should be further investigated. The average contributions of total NACs to the light absorption of organic matter at λ = 365 nm (1.10 - 2.57%) in Q f and Q b samples (10.7 - 21.0%) are up to 10 times larger than their mass contributions (Q f 0.31 - 1.01%, Q b 1.08 - 3.31%), so the identified NACs are mostly strong light absorbers. To explain more sample extracts absorption, future research is needed to understand the chemical and optical properties of high molecular weight (e.g., MW > 500 Da) entities in particulate matter.
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Affiliation(s)
- Mingjie Xie
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, 219 Ningliu Road, Nanjing 210044, China
| | - Zhenzhen Zhao
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, 219 Ningliu Road, Nanjing 210044, China
| | - Amara L. Holder
- Office of Research and Development, U.S. Environmental Protection Agency, 109 T.W. Alexander Drive, Research Triangle Park, NC 27711, USA
| | - Michael D. Hays
- Office of Research and Development, U.S. Environmental Protection Agency, 109 T.W. Alexander Drive, Research Triangle Park, NC 27711, USA
| | - Xi Chen
- Office of Research and Development, U.S. Environmental Protection Agency, 109 T.W. Alexander Drive, Research Triangle Park, NC 27711, USA
| | - Guofeng Shen
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - James J. Jetter
- Office of Research and Development, U.S. Environmental Protection Agency, 109 T.W. Alexander Drive, Research Triangle Park, NC 27711, USA
| | - Wyatt M. Champion
- Oak Ridge Institute for Science and Education (ORISE) Postdoctoral Fellow at U.S. Environmental Protection Agency, Office of Research and Development, Air Methods and Characterization Division, 109 T.W. Alexander Drive, Research Triangle Park, NC 27711, USA
| | - Qin’geng Wang
- State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing 210023, China
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Fujitani Y, Sato K, Tanabe K, Takahashi K, Hoshi J, Wang X, Chow JC, Watson JG. Volatility Distribution of Organic Compounds in Sewage Incineration Emissions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:14235-14245. [PMID: 33108869 DOI: 10.1021/acs.est.0c04534] [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: 06/11/2023]
Abstract
Intermediate volatility and semivolatile organic compounds (IVOC/SVOC) are important precursors of secondary organic aerosol (SOA) while SVOC is an important contributor to primary organic aerosol (POA). However, combustion emissions data for volatility classes are limited. This study reports the gas and particle emissions that were sampled with various dilution factors from a sewage sludge incinerator burning fuel oil. Volatility distributions were determined using measurements from online mass spectrometry and offline organic compound analyses. In the low volatility organic compound (LVOC) to IVOC range, volatility bins with organic saturation concentrations of 10-100 μg m-3 were most abundant, which was due to organic acids generated from sludge burning. Organic aerosol (OA) emission factors (EFOA) increased 1.4 times after cooling to ambient temperatures in comparison to those of the samples from the hot stack. Upon further isothermal dilution at 25 °C, the EFOA decreased while organic gas phase EFs increased with increasing dilution. Phase partitioning in volatility bins with saturation concentrations of 10-100 μg m-3 was sensitive to isothermal dilution that influenced the EFs. Therefore, gas- and particle-phase measurements alone cannot constrain EFs for these volatility classes. Low dilution factors may overestimate the particle phase and underestimate the gas phase EFs compared with real-world emission conditions.
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Affiliation(s)
- Yuji Fujitani
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan
| | - Kei Sato
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan
| | - Kiyoshi Tanabe
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan
| | | | - Junya Hoshi
- Tokyo Metropolitan Research Institute for Environmental Protection, Tokyo 136-0075, Japan
| | - Xiaoliang Wang
- Division of Atmospheric Sciences, Desert Research Institute, Reno, Nevada 89512, United States
| | - Judith C Chow
- Division of Atmospheric Sciences, Desert Research Institute, Reno, Nevada 89512, United States
| | - John G Watson
- Division of Atmospheric Sciences, Desert Research Institute, Reno, Nevada 89512, United States
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Pervez S, Verma M, Tiwari S, Chakrabarty RK, Watson JG, Chow JC, Panicker AS, Deb MK, Siddiqui MN, Pervez YF. Household solid fuel burning emission characterization and activity levels in India. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 654:493-504. [PMID: 30447588 DOI: 10.1016/j.scitotenv.2018.11.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 10/26/2018] [Accepted: 11/02/2018] [Indexed: 06/09/2023]
Abstract
Emission factors (EFs) of PM2.5, carbon fractions, major ionic (K+, Ca2+, NH4+, SO42-, NO3- and Cl-) and elemental (Al, Cr, Cu and Fe) species from combustion of commonly used household solid fuel were determined in 10 different states in India during cooking practices. The study involved sampling during actual household cooking involving use of a variety of fuels including coal balls (CB), fuel wood (FW), dung cakes (DC), crop residues (CR), mixed fuels (MF: dung cakes + fuel woods). Species-wise highest EFs (g·kg-1) were: 34.16 ± 10.1 for PM2.5 (CB), 14.18 ± 5.8 for OC (CB), 2.33 ± 1.4 for EC (DC), 1.03 ± 0.2 for K+ (CR), 2.21 ± 0.6 NH4+ (DC), 0.61 ± 0.2 for NO3- (CB), 0.59 ± 0.1 for SO42- (CB), 0.69 ± 0.1 for Cl- (CR) among the fuels. Higher OC EFs for CB could be attributed to higher moisture content (>13%) in coal-powder that is used to handmade coal balls. It is observed that, in general, OC3 and EC1 were the dominant thermally evolved carbon mass fractions. The study averaged MCE values were in the range 0.93-0.98, which could be attributed to higher variability in flaming and smoldering episodes during the combustion of selected fuels. Sum of ionic EFs for emissions from DC, CR and MF were found to be higher than those observed for FW and CB. The K+/EC and Cl-/EC (~1) ratios could be better indicators of CR fuels to differentiate it from FW, whereas NH4+/EC (~1) is suitable to indicate DC. Average annual emission estimates of PM2.5 (2.00 ± 0.53 Tg·yr-1), OC (0.86 ± 0.23 Tg·yr-1) and EC (0.11 ± 0.02 Tg·yr-1) for tested fuels are evaluated to be contributing 27, 15 and 4% of total PM2.5, OC and EC, respectively, toward annual emission budget from different anthropogenic activities in India.
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Affiliation(s)
- Shamsh Pervez
- School of Studies in Chemistry, Pandit Ravishankar Shukla University, Raipur, Chhattisgarh 492010, India.
| | - Madhuri Verma
- School of Studies in Chemistry, Pandit Ravishankar Shukla University, Raipur, Chhattisgarh 492010, India
| | - Suresh Tiwari
- Indian Institute of Tropical Meteorology, Pune, Maharashtra 411008, India
| | - Rajan K Chakrabarty
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - John G Watson
- Division of Atmospheric Sciences, Desert Research Institute, Reno, NV 89512, USA; Institute of Earth and Environment, Chinese Academy of Science, Xian, China
| | - Judith C Chow
- Division of Atmospheric Sciences, Desert Research Institute, Reno, NV 89512, USA; Institute of Earth and Environment, Chinese Academy of Science, Xian, China
| | | | - Manas Kanti Deb
- School of Studies in Chemistry, Pandit Ravishankar Shukla University, Raipur, Chhattisgarh 492010, India
| | - Mohammad Nahid Siddiqui
- Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia
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Zimmerman N, Rais K, Jeong CH, Pant P, Delgado-Saborit JM, Wallace JS, Evans GJ, Brook JR, Godri Pollitt KJ. Carbonaceous aerosol sampling of gasoline direct injection engine exhaust with an integrated organic gas and particle sampler. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 652:1261-1269. [PMID: 30586812 DOI: 10.1016/j.scitotenv.2018.10.332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 10/07/2018] [Accepted: 10/24/2018] [Indexed: 06/09/2023]
Abstract
Positive and negative artifacts of particle-phase organic carbon (p-OC) and the polycyclic aromatic hydrocarbons (PAHs) in gasoline direct injection (GDI) engine exhaust particulate matter (PM) were assessed using an integrated organic gas and particle sampler (IOGAPS). Three configurations (denuder + sorbent impregnated filters (SIFs), upstream Zefluor filter + denuder + SIFs, and standard filter pack + SIFs) were used to collect GDI exhaust samples at cold start and highway cruise operating conditions with no aftertreatment. Approximately 35% of the measured GDI p-OC was attributed to positive artifacts; negative artifacts were not detectable due to low overall SVOC concentrations. GDI engine exhaust PAH concentrations were approximately 10 times higher during cold start than highway cruise. At highway cruise, pyrene and fluoranthene were the dominant PAHs in the undenuded filter pack; downstream of the denuder benzo(a)anthracene was the dominant PAH. From a comparison of our findings to published PAH emission factors we estimate that three-way catalyst conversion efficiencies of PAHs were approximately 80% for 3 of the 15 PAHs measured during highway cruise operation. These conversion efficiencies may be considerably lower during cold start operation when the three-way catalyst has not reached its operating temperature. Our previous work showed that adverse biological responses to GDI engine exhaust exposure may be dominated by the particle phase when measured downstream of a Teflon filter. Understanding the partitioning characteristics of PAHs may help elucidate specific PAHs contributing to this effect.
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Affiliation(s)
- Naomi Zimmerman
- Southern Ontario Centre for Atmospheric Aerosol Research, University of Toronto, Toronto, Ontario, Canada; Engine Research and Development Laboratory, University of Toronto, Toronto, Ontario, Canada.
| | - Khaled Rais
- Engine Research and Development Laboratory, University of Toronto, Toronto, Ontario, Canada
| | - Cheol-Heon Jeong
- Southern Ontario Centre for Atmospheric Aerosol Research, University of Toronto, Toronto, Ontario, Canada
| | - Pallavi Pant
- Department of Environmental Health Sciences, School of Public Health and Health Sciences, University of Massachusetts Amherst, Amherst, MA, United States; School of Geography, Earth & Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Juana Mari Delgado-Saborit
- School of Geography, Earth & Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - James S Wallace
- Southern Ontario Centre for Atmospheric Aerosol Research, University of Toronto, Toronto, Ontario, Canada; Engine Research and Development Laboratory, University of Toronto, Toronto, Ontario, Canada
| | - Greg J Evans
- Southern Ontario Centre for Atmospheric Aerosol Research, University of Toronto, Toronto, Ontario, Canada
| | - Jeffrey R Brook
- Southern Ontario Centre for Atmospheric Aerosol Research, University of Toronto, Toronto, Ontario, Canada; Air Quality Research Division, Environment Canada, Toronto, Ontario, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
| | - Krystal J Godri Pollitt
- Department of Environmental Health Sciences, School of Public Health, Yale University, New Haven, CT, United States
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Gantt B, Beaver M, Timin B, Lorang P. Recommended metric for tracking visibility progress in the Regional Haze Rule. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2018; 68:438-445. [PMID: 29309260 PMCID: PMC6161829 DOI: 10.1080/10962247.2018.1424058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 12/22/2017] [Accepted: 12/22/2017] [Indexed: 05/21/2023]
Abstract
UNLABELLED For many national parks and wilderness areas with special air quality protections (Class I areas) in the western United States (U.S.), wildfire smoke and dust events can have a large impact on visibility. The U.S. Environmental Protection Agency's (EPA) 1999 Regional Haze Rule used the 20% haziest days to track visibility changes over time even if they are dominated by smoke or dust. Visibility on the 20% haziest days has remained constant or degraded over the last 16 yr at some Class I areas despite widespread emission reductions from anthropogenic sources. To better track visibility changes specifically associated with anthropogenic pollution sources rather than natural sources, the EPA has revised the Regional Haze Rule to track visibility on the 20% most anthropogenically impaired (hereafter, most impaired) days rather than the haziest days. To support the implementation of this revised requirement, the EPA has proposed (but not finalized) a recommended metric for characterizing the anthropogenic and natural portions of the daily extinction budget at each site. This metric selects the 20% most impaired days based on these portions using a "delta deciview" approach to quantify the deciview scale impact of anthropogenic light extinction. Using this metric, sulfate and nitrate make up the majority of the anthropogenic extinction in 2015 on these days, with natural extinction largely made up of organic carbon mass in the eastern U.S. and a combination of organic carbon mass, dust components, and sea salt in the western U.S. For sites in the western U.S., the seasonality of days selected as the 20% most impaired is different than the seasonality of the 20% haziest days, with many more winter and spring days selected. Applying this new metric to the 2000-2015 period across sites representing Class I areas results in substantial changes in the calculated visibility trend for the northern Rockies and southwest U.S., but little change for the eastern U.S. IMPLICATIONS Changing the approach for tracking visibility in the Regional Haze Rule allows the EPA, states, and the public to track visibility on days when reductions in anthropogenic emissions have the greatest potential to improve the view. The calculations involved with the recommended metric can be incorporated into the routine IMPROVE (Interagency Monitoring of Protected Visual Environments) data processing, enabling rapid analysis of current and future visibility trends. Natural visibility conditions are important in the calculations for the recommended metric, necessitating the need for additional analysis and potential refinement of their values.
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Affiliation(s)
- Brett Gantt
- a Office of Air Quality Planning and Standards , U.S. Environmental Protection Agency , Research Triangle Park , NC , USA
| | - Melinda Beaver
- a Office of Air Quality Planning and Standards , U.S. Environmental Protection Agency , Research Triangle Park , NC , USA
| | - Brian Timin
- a Office of Air Quality Planning and Standards , U.S. Environmental Protection Agency , Research Triangle Park , NC , USA
| | - Phil Lorang
- a Office of Air Quality Planning and Standards , U.S. Environmental Protection Agency , Research Triangle Park , NC , USA
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16
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Chow JC, Watson JG, Green MC, Wang X, Chen LWA, Trimble DL, Cropper PM, Kohl SD, Gronstal SB. Separation of brown carbon from black carbon for IMPROVE and Chemical Speciation Network PM 2.5 samples. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2018; 68:494-510. [PMID: 29341854 DOI: 10.1080/10962247.2018.1426653] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 11/10/2017] [Accepted: 12/11/2017] [Indexed: 06/07/2023]
Abstract
UNLABELLED The replacement of the Desert Research Institute (DRI) model 2001 with model 2015 thermal/optical analyzers (TOAs) results in continuity of the long-term organic carbon (OC) and elemental carbon (EC) database, and it adds optical information with no additional carbon analysis effort. The value of multiwavelength light attenuation is that light absorption due to black carbon (BC) can be separated from that of brown carbon (BrC), with subsequent attribution to known sources such as biomass burning and secondary organic aerosols. There is evidence of filter loading effects for the 25% of all samples with the highest EC concentrations based on the ratio of light attenuation to EC. Loading corrections similar to those used for the seven-wavelength aethalometer need to be investigated. On average, nonurban Interagency Monitoring of PROtected Visual Environments (IMPROVE) samples show higher BrC fractions of short-wavelength absorption than urban Chemical Speciation Network (CSN) samples, owing to greater influence from biomass burning and aged aerosols, as well as to higher primary BC contributions from engine exhaust at urban sites. Sequential samples taken during an Everglades National Park wildfire demonstrate the evolution from flaming to smoldering combustion, with the BrC fraction increasing as smoldering begins to dominate the fire event. IMPLICATIONS The inclusion of seven wavelengths in thermal/optical carbon analysis of speciated PM2.5 (particulate matter with an aerodynamic diameter ≤2.5 μm) samples allows contributions from biomass burning and secondary organic aerosols to be estimated. This separation is useful for evaluating control strategy effectiveness, identifying exceptional events, and determining natural visibility conditions.
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Affiliation(s)
- Judith C Chow
- a Division of Atmospheric Sciences , Desert Research Institute , Reno , NV , USA
- b State Key Laboratory of Loess and Quaternary Geology (SKLLQG) , Institute of Earth Environment, Chinese Academy of Sciences , Xi'an, Shaanxi Province, People's Republic of China
| | - John G Watson
- a Division of Atmospheric Sciences , Desert Research Institute , Reno , NV , USA
- b State Key Laboratory of Loess and Quaternary Geology (SKLLQG) , Institute of Earth Environment, Chinese Academy of Sciences , Xi'an, Shaanxi Province, People's Republic of China
| | - Mark C Green
- a Division of Atmospheric Sciences , Desert Research Institute , Reno , NV , USA
| | - Xiaoliang Wang
- a Division of Atmospheric Sciences , Desert Research Institute , Reno , NV , USA
| | - L-W Antony Chen
- c Department of Environmental and Occupational Health , University of Nevada , Las Vegas , NV , USA
| | - Dana L Trimble
- a Division of Atmospheric Sciences , Desert Research Institute , Reno , NV , USA
| | - Paul M Cropper
- a Division of Atmospheric Sciences , Desert Research Institute , Reno , NV , USA
| | - Steven D Kohl
- a Division of Atmospheric Sciences , Desert Research Institute , Reno , NV , USA
| | - Steven B Gronstal
- a Division of Atmospheric Sciences , Desert Research Institute , Reno , NV , USA
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17
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Emami F, Masiol M, Hopke PK. Air pollution at Rochester, NY: Long-term trends and multivariate analysis of upwind SO 2 source impacts. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 612:1506-1515. [PMID: 28915545 DOI: 10.1016/j.scitotenv.2017.09.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Revised: 08/23/2017] [Accepted: 09/04/2017] [Indexed: 05/25/2023]
Abstract
There have been many changes in the air pollutant sources in the northeastern United States since 2001. To assess the effect of these changes, trend analyses of the monthly average values were performed on PM2.5 and its components including major ions, elemental carbon (EC), organic carbon (OC), and gaseous pollutant concentrations measured between 2001 (in some cases 1999) and 2015 at the NYS Department of Environmental Conservation sites in Rochester, NY. Mann-Kendall regression with Sen's slope was applied to estimate the trends and seasonality. Using piecewise regression, significant reductions in the air pollution of Rochester area were observed between 2008 and 2010 when a 260MW coal-fired power plant was decommissioned, new heavy-duty diesel trucks had to be equipped with catalytic regenerator traps, and the economic recession that began in 2008 reduced traffic and other activities. The monthly average PM2.5 mass showed a downward trend (-5μg/m3; -41%) in Rochester between 2001 and 2015. This change is largely due to reductions in particulate sulfate that showed a 65% decrease. The sulfate concentrations were compared to changes in SO2 emissions in seventeen upwind source domains, and other systematic changes by multivariate linear regression. Selectivity ratio obtained from target projection discriminated the most important source domains that are SO2 emissions from Georgia for winter, North Carolina for transition (spring and fall) and Ohio along with other influences for summer. North Carolina and Michigan were identified as the main sources for entire period. These observations suggest that any further reductions in the specified regional SO2 emissions would result in a proportional decrease in sulfate in Rochester.
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Affiliation(s)
- Fereshteh Emami
- Center for Air Resources Engineering and Science, Clarkson University, Potsdam, NY 13699, United States
| | - Mauro Masiol
- Center for Air Resources Engineering and Science, Clarkson University, Potsdam, NY 13699, United States; Department of Public Health Sciences, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, United States
| | - Philip K Hopke
- Center for Air Resources Engineering and Science, Clarkson University, Potsdam, NY 13699, United States; Department of Public Health Sciences, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, United States.
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18
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Raman A, Arellano AF. Spatial and Temporal Variations in Characteristic Ratios of Elemental Carbon to Carbon Monoxide and Nitrogen Oxides across the United States. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:6829-6838. [PMID: 28547992 DOI: 10.1021/acs.est.7b00161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A ratio-based method is used to characterize anthropogenic elemental carbon (ECa) using in situ measurements and emissions of carbon monoxide (CO) and nitrogen oxides (NOx). We use long-term records of ground-based measurements from the U.S. Environmental Protection Agency (EPA) Air Quality System and Interagency Monitoring of Protected Visual Environments to assess the patterns in anthropogenic combustion ratios (ΔECa/ΔCO and ΔECa/ΔNOx) across the U.S. Petroleum Administration for Defense Districts (PADD) regions for the years 2000-2015. We investigate the change in these ratios between the periods 2000-2007 and 2008-2015. Overall, ΔECa/ΔCO ratios increase by 0.7-82% and ΔECa/ΔNOx by 6.8-104% across the East and West PADD regions. The urban West showed the largest increase relative to other regions. This is mainly attributed to a 13-23% increase in ΔECa during the winter and fall seasons and significant reductions in urban ΔNOx (except in winter). We also find that emission ratios derived from the EPA's National Emission Inventory (NEI) overestimate (underestimate) the increase in the observed enhancement ratios in the East (West). Analyses of changes in NEI emissions in the West reveal (a) smaller reductions in NEI emissions for NOx from the off-road sector and (b) an increase in PM2.5 (particulate matter 2.5 μm or less in diameter) emissions from commercial/residential combustion and smaller reductions in nonroad emissions.
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Affiliation(s)
- Aishwarya Raman
- Department of Hydrology and Atmospheric Sciences, University of Arizona , Tucson, Arizona 85721, United States
| | - Avelino F Arellano
- Department of Hydrology and Atmospheric Sciences, University of Arizona , Tucson, Arizona 85721, United States
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19
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Hidy GM, Mueller PK, Altshuler SL, Chow JC, Watson JG. Air quality measurements-From rubber bands to tapping the rainbow. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2017; 67:637-668. [PMID: 28333580 DOI: 10.1080/10962247.2017.1308890] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
UNLABELLED It is axiomatic that good measurements are integral to good public policy for environmental protection. The generalized term for "measurements" includes sampling and quantitation, data integrity, documentation, network design, sponsorship, operations, archiving, and accessing for applications. Each of these components has evolved and advanced over the last 200 years as knowledge of atmospheric chemistry and physics has matured. Air quality was first detected by what people could see and smell in contaminated air. Gaseous pollutants were found to react with certain materials or chemicals, changing the color of dissolved reagents such that their light absorption at selected wavelengths could be related to both the pollutant chemistry and its concentration. Airborne particles have challenged the development of a variety of sensory devices and laboratory assays for characterization of their enormous range of physical and chemical properties. Advanced electronics made possible the sampling, concentration, and detection of gases and particles, both in situ and in laboratory analysis of collected samples. Accurate and precise measurements by these methods have made possible advanced air quality management practices that led to decreasing concentrations over time. New technologies are leading to smaller and cheaper measurement systems that can further expand and enhance current air pollution monitoring networks. IMPLICATIONS Ambient air quality measurement systems have a large influence on air quality management by determining compliance, tracking trends, elucidating pollutant transport and transformation, and relating concentrations to adverse effects. These systems consist of more than just instrumentation, and involve extensive support efforts for siting, maintenance, calibration, auditing, data validation, data management and access, and data interpretation. These requirements have largely been attained for criteria pollutants regulated by National Ambient Air Quality Standards, but they are rarely attained for nonroutine measurements and research studies.
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Affiliation(s)
| | | | | | - Judith C Chow
- d Desert Research Institute , Reno , Nevada , USA
- e State Key Laboratory of Loess and Quaternary Geology (SKLLQG) , Institute of Earth Environment, Chinese Academy of Sciences , Xi'an , People's Republic of China
| | - John G Watson
- d Desert Research Institute , Reno , Nevada , USA
- e State Key Laboratory of Loess and Quaternary Geology (SKLLQG) , Institute of Earth Environment, Chinese Academy of Sciences , Xi'an , People's Republic of China
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20
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Hsu YM, Wang X, Chow JC, Watson JG, Percy KE. Collocated comparisons of continuous and filter-based PM2.5 measurements at Fort McMurray, Alberta, Canada. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2016; 66:329-39. [PMID: 26727574 PMCID: PMC4784491 DOI: 10.1080/10962247.2015.1136362] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 12/21/2015] [Accepted: 12/22/2015] [Indexed: 05/03/2023]
Abstract
UNLABELLED Collocated comparisons for three PM(2.5) monitors were conducted from June 2011 to May 2013 at an air monitoring station in the residential area of Fort McMurray, Alberta, Canada, a city located in the Athabasca Oil Sands Region. Extremely cold winters (down to approximately -40°C) coupled with low PM(2.5) concentrations present a challenge for continuous measurements. Both the tapered element oscillating microbalance (TEOM), operated at 40°C (i.e., TEOM(40)), and Synchronized Hybrid Ambient Real-time Particulate (SHARP, a Federal Equivalent Method [FEM]), were compared with a Partisol PM(2.5) U.S. Federal Reference Method (FRM) sampler. While hourly TEOM(40) PM(2.5) were consistently ~20-50% lower than that of SHARP, no statistically significant differences were found between the 24-hr averages for FRM and SHARP. Orthogonal regression (OR) equations derived from FRM and TEOM(40) were used to adjust the TEOM(40) (i.e., TEOM(adj)) and improve its agreement with FRM, particularly for the cold season. The 12-year-long hourly TEOM(adj) measurements from 1999 to 2011 based on the OR equations between SHARP and TEOM(40) were derived from the 2-year (2011-2013) collocated measurements. The trend analysis combining both TEOM(adj) and SHARP measurements showed a statistically significant decrease in PM(2.5) concentrations with a seasonal slope of -0.15 μg m(-3) yr(-1) from 1999 to 2014. IMPLICATIONS Consistency in PM(2.5) measurements are needed for trend analysis. Collocated comparison among the three PM(2.5) monitors demonstrated the difference between FRM and TEOM, as well as between SHARP and TEOM. The orthogonal regressions equations can be applied to correct historical TEOM data to examine long-term trends within the network.
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Affiliation(s)
- Yu-Mei Hsu
- Wood Buffalo Environmental Association, Fort McMurray, Alberta, Canada
| | | | | | | | - Kevin E. Percy
- Wood Buffalo Environmental Association, Fort McMurray, Alberta, Canada
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Watson JG, Chow JC, Lowenthal DH, Antony Chen LW, Shaw S, Edgerton ES, Blanchard CL. PM2.5 source apportionment with organic markers in the Southeastern Aerosol Research and Characterization (SEARCH) study. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2015; 65:1104-1118. [PMID: 26102211 DOI: 10.1080/10962247.2015.1063551] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
UNLABELLED Positive matrix factorization (PMF) and effective variance (EV) solutions to the chemical mass balance (CMB) were applied to PM(2.5) (particulate matter with an aerodynamic diameter <2.5 μm) mass and chemically speciated measurements for samples taken from 2008 to 2010 at the Atlanta, Georgia, and Birmingham, Alabama, sites. Commonly measured PM(2.5) mass, elemental, ionic, and thermal carbon fraction concentrations were supplemented with detailed nonpolar organic speciation by thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS). Source contribution estimates were calculated for motor vehicle exhaust, biomass burning, cooking, coal-fired power plants, road dust, vegetative detritus, and secondary sulfates and nitrates for Atlanta. Similar sources were found for Birmingham, with the addition of an industrial source and the separation of biomass burning into open burning and residential wood combustion. EV-CMB results based on conventional species were qualitatively similar to those estimated by PMF-CMB. Secondary ammonium sulfate was the largest contributor, accounting for 27-38% of PM(2.5), followed by biomass burning (21-24%) and motor vehicle exhaust (9-24%) at both sites, with 4-6% of PM(2.5) attributed to coal-fired power plants by EV-CMB. Including organic compounds in the EV-CMB reduced the motor vehicle exhaust and biomass burning contributions at both sites, with a 13-23% deficit for PM(2.5) mass. The PMF-CMB solution showed mixing of sources within the derived factors, both with and without the addition of speciated organics, as is often the case with complex source mixtures such as those at these urban-scale sites. The nonpolar TD-GC/MS compounds can be obtained from existing filter samples and are a useful complement to the elements, ions, and carbon fractions. However, they should be supplemented with other methods, such as TD-GC/MS on derivitized samples, to obtain a wider range of polar compounds such as sterols, sugars, and organic acids. The PMF and EV solutions to the CMB equations are complementary to, rather than replacements for, each other, as comparisons of their results reveal uncertainties that are not otherwise evident. IMPLICATIONS Organic markers can be measured on currently acquired PM(2.5) filter samples by thermal methods. These markers can complement element, ion, and carbon fraction measurements from long-term speciation networks. Applying the positive matrix factorization and effective variance solutions for the chemical mass balance equations provides useful information on the accuracy of the source contribution estimates. Nonpolar compounds need to be complemented with polar compounds to better apportion cooking and secondary organic aerosol contributors.
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Affiliation(s)
- John G Watson
- a Division of Atmospheric Sciences , Desert Research Institute, Nevada System of Higher Education , Reno , NV , USA
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Chow JC, Lowenthal DH, Chen LWA, Wang X, Watson JG. Mass reconstruction methods for PM 2.5: a review. AIR QUALITY, ATMOSPHERE, & HEALTH 2015; 8:243-263. [PMID: 26052367 PMCID: PMC4449935 DOI: 10.1007/s11869-015-0338-3] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 03/17/2015] [Indexed: 05/19/2023]
Abstract
Major components of suspended particulate matter (PM) are inorganic ions, organic matter (OM), elemental carbon (EC), geological minerals, salt, non-mineral elements, and water. Since oxygen (O) and hydrogen (H) are not directly measured in chemical speciation networks, more than ten weighting equations have been applied to account for their presence, thereby approximating gravimetric mass. Assumptions for these weights are not the same under all circumstances. OM is estimated from an organic carbon (OC) multiplier (f) that ranges from 1.4 to 1.8 in most studies, but f can be larger for highly polar compounds from biomass burning and secondary organic aerosols. The mineral content of fugitive dust is estimated from elemental markers, while the water-soluble content is accounted for as inorganic ions or salt. Part of the discrepancy between measured and reconstructed PM mass is due to the measurement process, including: (1) organic vapors adsorbed on quartz-fiber filters; (2) evaporation of volatile ammonium nitrate and OM between the weighed Teflon-membrane filter and the nylon-membrane and/or quartz-fiber filters on which ions and carbon are measured; and (3) liquid water retained on soluble constituents during filter weighing. The widely used IMPROVE equations were developed to characterize particle light extinction in U.S. national parks, and variants of this approach have been tested in a large variety of environments. Important factors for improving agreement between measured and reconstructed PM mass are the f multiplier for converting OC to OM and accounting for OC sampling artifacts.
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Affiliation(s)
- Judith C. Chow
- Division of Atmospheric Sciences, Desert Research Institute, Reno, NV 89512 USA
- The State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an, Shaanxi 710075 China
- Graduate Faculty, University of Nevada, Reno, NV 89503 USA
| | - Douglas H. Lowenthal
- Division of Atmospheric Sciences, Desert Research Institute, Reno, NV 89512 USA
- Graduate Faculty, University of Nevada, Reno, NV 89503 USA
| | - L.-W. Antony Chen
- Division of Atmospheric Sciences, Desert Research Institute, Reno, NV 89512 USA
- Department of Environmental and Occupational Health, University of Nevada, Las Vegas, NV 89154 USA
| | - Xiaoliang Wang
- Division of Atmospheric Sciences, Desert Research Institute, Reno, NV 89512 USA
- Graduate Faculty, University of Nevada, Reno, NV 89503 USA
| | - John G. Watson
- Division of Atmospheric Sciences, Desert Research Institute, Reno, NV 89512 USA
- The State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an, Shaanxi 710075 China
- Graduate Faculty, University of Nevada, Reno, NV 89503 USA
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Solomon PA, Crumpler D, Flanagan JB, Jayanty RKM, Rickman EE, McDade CE. U.S. national PM2.5 Chemical Speciation Monitoring Networks-CSN and IMPROVE: description of networks. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2014; 64:1410-38. [PMID: 25562937 DOI: 10.1080/10962247.2014.956904] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The US. EnvironmentalProtection Agency (EPA) initiated the national PM2.5 Chemical Speciation Monitoring Network (CSN) in 2000 to support evaluation of long-term trends and to better quantify the impact of sources on particulate matter (PM) concentrations in the size range below 2.5 μm aerodynamic diameter (PM2.5; fine particles). The network peaked at more than 260 sites in 2005. In response to the 1999 Regional Haze Rule and the need to better understand the regional transport of PM, EPA also augmented the long-existing Interagency Monitoring of Protected Visual Environments (IMPROVE) visibility monitoring network in 2000, adding nearly 100 additional IMPROVE sites in rural Class 1 Areas across the country. Both networks measure the major chemical components of PM2.5 using historically accepted filter-based methods. Components measured by both networks include major anions, carbonaceous material, and a series of trace elements. CSN also measures ammonium and other cations directly, whereas IMPROVE estimates ammonium assuming complete neutralization of the measured sulfate and nitrate. IMPROVE also measures chloride and nitrite. In general, the field and laboratory approaches used in the two networks are similar; however, there are numerous, often subtle differences in sampling and chemical analysis methods, shipping, and quality control practices. These could potentially affect merging the two data sets when used to understand better the impact of sources on PM concentrations and the regional nature and long-range transport of PM2zs. This paper describes, for the first time in the peer-reviewed literature, these networks as they have existed since 2000, outlines differences infield and laboratory approaches, provides a summary of the analytical parameters that address data uncertainty, and summarizes major network changes since the inception of CSN. Implications: Two long-term chemical speciation particle monitoring networks have operated simultaneously in the United States since 2001, when the EPA began regular operations of its PM2.5 Chemical Speciation Monitoring Network (IMPROVE began in 1988). These networks use similar field sampling and analytical methods, but there are numerous, often subtle differences in equipment and methodologies that can affect the results. This paper describes these networks since 20000 (inception of CSN) and their differences, and summarizes the analytical parameters that address data uncertainty, providing researches and policymakers with background information they may need (e.g., for 2018 PM2.5 designation and State Implementation Plan process; McCarthy, 2013) to assess results from each network and decide how these data sets can be mutually employed for enhanced analyses. Changes in CSN and IMPROVE that have occurred over the years also are described.
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Affiliation(s)
- Paul A Solomon
- U.S. Environmental Protection Agency, Las Vegas, NV, USA.
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Wagstrom KM, Baker KR, Leinbach AE, Hunt SW. Synthesizing scientific progress: outcomes from U.S. EPA's carbonaceous aerosols and source apportionment STAR grants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:10561-10570. [PMID: 25111572 DOI: 10.1021/es500782k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In response to recommendations by the National Research Council in the late 1990 s and early 2000s for critical research into understanding sources and formation mechanisms of PM2.5, EPA created multiple funding opportunities through the Science to Achieve Results (STAR) program: "Measurement, Modeling, and Analysis Methods for Airborne Carbonaceous Fine Particulate Matter" (2003) and "Source Apportionment of Particulate Matter" (2004). The carbonaceous fine PM solicitation resulted in 16 different projects focusing on the measurement methods, source identification, and exploration of the chemical and physical processes important for PM2.5 carbon in the atmosphere. The source apportionment funding opportunity led to 11 projects improving tools and characterization of source-receptor relationships of PM2.5. Many funding mechanisms include a final synopsis of funded research and published manuscripts. Here, this evaluation is extended to include citations of research published as part of these solicitations. These solicitations resulted in 275 publications that included more than 850 unique authors in 37 different journals with a weighted average 2011 impact factor of 4.21. At the time of this assessment, these publications have been cited by 13,612 peer review journal articles with 31 (11%) of the manuscripts being cited over 100 times.
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Affiliation(s)
- Kristina M Wagstrom
- Chemical and Biomolecular Engineering, University of Connecticut , Storrs, Connecticut 06269, United States
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25
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Fruin S, Urman R, Lurmann F, McConnell R, Gauderman J, Rappaport E, Franklin M, Gilliland FD, Shafer M, Gorski P, Avol E. Spatial Variation in Particulate Matter Components over a Large Urban Area. ATMOSPHERIC ENVIRONMENT (OXFORD, ENGLAND : 1994) 2014; 83:211-219. [PMID: 24578605 PMCID: PMC3932493 DOI: 10.1016/j.atmosenv.2013.10.063] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
To characterize exposures to particulate matter (PM) and its components, we performed a large sampling study of small-scale spatial variation in size-resolved particle mass and composition. PM was collected in size ranges of < 0.2, 0.2-to-2.5, and 2.5-to-10 μm on a scale of 100s to 1000s of meters to capture local sources. Within each of eight Southern California communities, up to 29 locations were sampled for rotating, month-long integrated periods at two different times of the year, six months apart, from Nov 2008 through Dec 2009. Additional sampling was conducted at each community's regional monitoring station to provide temporal coverage over the sampling campaign duration. Residential sampling locations were selected based on a novel design stratified by high- and low-predicted traffic emissions and locations over- and under-predicted from previous dispersion model and sampling comparisons. Primary vehicle emissions constituents, such as elemental carbon (EC), showed much stronger patterns of association with traffic than pollutants with significant secondary formation, such as PM2.5 or water soluble organic carbon. Associations were also stronger during cooler times of the year (Oct through Mar). Primary pollutants also showed greater within-community spatial variation compared to pollutants with secondary formation contributions. For example, the average cool-season community mean and standard deviation (SD) for EC were 1.1 and 0.17 μg/m3, respectively, giving a coefficient of variation (CV) of 18%. For PM2.5, average mean and SD were 14 and 1.3 μg/m3, respectively, with a CV of 9%. We conclude that within-community spatial differences are important for accurate exposure assessment of traffic-related pollutants.
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Affiliation(s)
- Scott Fruin
- Keck School of Medicine, Division of Environmental Health, University of Southern California, Los Angeles, CA 90089, USA
- Corresponding author. Present address: Department of Preventive Medicine, Divisions of Environmental Health, University of Southern California, 2001 North Soto Street, Los Angeles, CA 90089-9237, USA. Tel.: +1 323 442 2870; fax: +1 323 442 3272.
| | - Robert Urman
- Keck School of Medicine, Division of Environmental Health, University of Southern California, Los Angeles, CA 90089, USA
| | - Fred Lurmann
- Sonoma Technology Inc., #C, Petaluma, CA 94954, USA
| | - Rob McConnell
- Keck School of Medicine, Division of Environmental Health, University of Southern California, Los Angeles, CA 90089, USA
| | - James Gauderman
- Keck School of Medicine, Division of Environmental Health, University of Southern California, Los Angeles, CA 90089, USA
| | - Ed Rappaport
- Keck School of Medicine, Division of Environmental Health, University of Southern California, Los Angeles, CA 90089, USA
| | - Meredith Franklin
- Keck School of Medicine, Division of Environmental Health, University of Southern California, Los Angeles, CA 90089, USA
| | - Frank D. Gilliland
- Keck School of Medicine, Division of Environmental Health, University of Southern California, Los Angeles, CA 90089, USA
| | - Martin Shafer
- Wisconsin State Laboratory of Hygiene, Environmental Health Division, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Patrick Gorski
- Wisconsin State Laboratory of Hygiene, Environmental Health Division, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Ed Avol
- Keck School of Medicine, Division of Environmental Health, University of Southern California, Los Angeles, CA 90089, USA
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Zhu CS, Cao JJ, Tsai CJ, Shen ZX, Han YM, Liu SX, Zhao ZZ. Comparison and implications of PM₂.₅ carbon fractions in different environments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 466-467:203-209. [PMID: 23895783 DOI: 10.1016/j.scitotenv.2013.07.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 06/01/2013] [Accepted: 07/08/2013] [Indexed: 05/27/2023]
Abstract
The concentrations of PM₂.₅ carbon fractions in rural, urban, tunnel and remote environments were measured using the IMPROVE thermal optical reflectance (TOR) method. The highest OC1 and EC1 concentrations were found for tunnel samples, while the highest OC2, OC3, and OC4 concentrations were observed for urban winter samples, respectively. The lowest levels of most carbon fractions were found for remote samples. The percentage contributions of carbon fractions to total carbon (TC) were characterized by one peak (at rural and remote sites) and two peaks (at urban and tunnel sites) with different carbon fractions, respectively. The abundance of char in tunnel and urban environments was observed, which might partly be due to traffic-related tire-wear. Various percentages of optically scattering OC and absorbing EC fractions to TC were found in the four different environments. In addition, the contribution of heating carbon fractions (char and soot) indicated various warming effects per unit mass of TC. The ratios of OC/EC and char/soot at the sites were shown to be source indicators. The investigation of carbon fractions at different sites may provide some information for improving model parameters in estimating their radiative effects.
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Affiliation(s)
- Chong-Shu Zhu
- Key Lab of Aerosol Science & Technology, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China.
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Zhang J, Fan X, Graham L, Chan TW, Brook JR. Evaluation of an annular denuder system for carbonaceous aerosol sampling of diesel engine emissions. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2013; 63:87-99. [PMID: 23447867 DOI: 10.1080/10962247.2012.739582] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
UNLABELLED Sampling of particle-phase organic carbon (OC) from diesel engines is complicated by adsorption and evaporation of semivolatile organic carbon (SVOC), defined as positive and negative artifacts, respectively. In order to explore these artifacts, an integrated organic gas and particle sampler (IOGAPS) was applied, in which an XAD-coated multichannel annular denuder was placed upstream to remove the gas-phase SVOC and two downstream sorbent-impregnated filters (SIFs) were employed to capture the evaporated SVOC. Positive artifacts can be reduced by using a denuder but particle loss also occurs. This paper investigates the IOGAPS with respect to particle loss, denuder efficiency, and particle-phase OC artifacts by comparing OC, elemental carbon (EC), SVOC, and selected organic species, as well as particle size distributions. Compared to the filterpack methods typically used, the IOGAPS approach results in estimation of both positive and negative artifacts, especially the negative artifact. The positive and negative artifacts were 190 microg/m3 and 67 microg/m3, representing 122% and 43% of the total particle OC measured by the IOGAPS, respectively. However particle loss and denuder break-through were also found to exist. Monitoring particle mass loss by particle number or EC concentration yielded similar results ranging from 10% to 24% depending upon flow rate. Using the measurements of selected particle-phase organic species to infer particle loss resulted in larger estimates, on the order of 32%. The denuder collection efficiencyfor SVOCs at 74 L/min was found to be less than 100%, with an average of 84%. In addition to these uncertainties the IOGAPS method requires a considerable amount of extra effort to apply. These disadvantages must be weighed against the benefits of being able to estimate positive artifacts and correct, with some uncertainty, for the negative artifacts when selecting a method for sampling diesel emissions. IMPLICATIONS Measurements of diesel emissions are necessary to understand their adverse impacts. Much of the emissions is organic carbon covering a range ofvolatilities, complicating determination of the particle fraction because of sampling artifacts. In this paper an approach to quantify artifacts is evaluated for a diesel engine. This showed that 63% of the particle organic carbon typically measured could be the positive artifact while the negative artifact is about one-third of this value. However, this approach adds time and expense and leads to other uncertainties, implying that effort is needed to develop methods to accurately measure diesel emissions.
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Affiliation(s)
- Jie Zhang
- ERMS, Environment Canada, Ottawa, Ontario, Canada
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Hand JL, Schichtel BA, Pitchford M, Malm WC, Frank NH. Seasonal composition of remote and urban fine particulate matter in the United States. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jd017122] [Citation(s) in RCA: 177] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Cheng Y, Zou SC, Lee SC, Chow JC, Ho KF, Watson JG, Han YM, Zhang RJ, Zhang F, Yau PS, Huang Y, Bai Y, Wu WJ. Characteristics and source apportionment of PM1 emissions at a roadside station. JOURNAL OF HAZARDOUS MATERIALS 2011; 195:82-91. [PMID: 21907488 DOI: 10.1016/j.jhazmat.2011.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 08/04/2011] [Accepted: 08/04/2011] [Indexed: 05/31/2023]
Abstract
The mass concentrations of PM(1) (particles less than 1.0 μm in aerodynamic diameter), organic carbon (OC), elemental carbon (EC), water-soluble ions, and up to 25 elements were reported for 24h aerosol samples collected every sixth day at a roadside sampling station in Hong Kong from October 2004 to September 2005. Annual average PM(1) mass concentration was 44.5 ± 19.5 μg m(-3). EC, OM (organic matter, OC × 1.2), and SO(4)(=) were the dominant components, accounting for ∼ 36%, ∼ 26%, and ∼ 24% of PM(1), respectively. Other components, i.e., NO(3)(-), NH(4)(+), geological material, trace elements and unidentified material, comprised the remaining ∼ 14%. Annual average OC/EC ratio (0.6 ± 0.3) was low, indicating that primary vehicle exhaust was the major source of carbonaceous aerosols. The seasonal variations of pollutants were due to gas-particle partitioning processes or a change in air mass rather than secondary aerosol produced locally. Vehicle exhaust, secondary aerosols, and waste incinerator/biomass burning were dominant air pollution sources, accounting for ∼ 38%, ∼ 22% and ∼ 16% of PM(1), respectively. Pollution episodes during summer (May-August) which were frequently accompanied by tropical storms or typhoons were dominated by vehicle emissions. During winter (November-February) pollution episodes coincided with northeasterly monsoons were characterized by secondary aerosols and incinerator/biomass burning emissions.
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Affiliation(s)
- Y Cheng
- Department of Environmental Science and Technology, School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, No.28 Xianning West Road, Xi'an, Shaanxi, 710049, China.
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Chen LWA, Watson JG, Chow JC, DuBois DW, Herschberger L. PM 2.5 source apportionment: reconciling receptor models for U.S. nonurban and urban long-term networks. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2011; 61:1204-1217. [PMID: 22168104 DOI: 10.1080/10473289.2011.619082] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Chemical mass balance (CMB) and trajectory receptor models were applied to speciated particulate matter with aerodynamic diameter < or =2.5 microm (PM2.5) measurements from Speciation Trends Network (STN; part of the Chemical Speciation Network [CSN]) and Interagency Monitoring of Protected Visual Environments (IMPROVE) monitoring network across the state of Minnesota as part of the Minnesota PM2.5 Source Apportionment Study (MPSAS). CMB equations were solved by the Unmix, positive matrix factorization (PMF), and effective variance (EV) methods, giving collective source contribution and uncertainty estimates. Geological source profiles developed from local dust materials were either incorporated into the EV-CMB model or used to verify factors derived from Unmix and PMF. Common sources include soil dust, calcium (Ca)-rich dust, diesel and gasoline vehicle exhausts, biomass burning, secondary sulfate, and secondary nitrate. Secondary sulfate and nitrate aerosols dominate PM2.5 mass (50-69%). Mobile sources outweigh area sources at urban sites, and vice versa at rural sites due to traffic emissions. Gasoline and diesel contributions can be separated using data from the STN, despite significant uncertainties. Major differences between MPSAS and earlier studies on similar environments appear to be the type and magnitude of stationary sources, but these sources are generally minor (<7%) in this and other studies. Ensemble back-trajectory analysis shows that the lower Midwestern states are the predominant source region for secondary ammoniated sulfate in Minnesota. It also suggests substantial contributions of biomass burning and soil dust from out-of-state on occasions, although a quantitative separation of local and regional contributions was not achieved in the current study. Supplemental materials are available for this article. Go to the publisher's online edition of the Journal of the Air & Waste Management Association for a summary of input data, Unmix and PMF factor profiles, and additional maps.
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Affiliation(s)
- L W Antony Chen
- Division of Atmospheric Sciences, Desert Research Institute, Reno, Nevada 89512,USA.
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31
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Malm WC, Schichtel BA, Pitchford ML. Uncertainties in PM2.5 gravimetric and speciation measurements and what we can learn from them. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2011; 61:1131-49. [PMID: 22168097 DOI: 10.1080/10473289.2011.603998] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The U.S. Environmental Protection Agency (EPA) and the federal land management community (National Park Service, United States Fish and Wildlife Service, United States Forest Service, and Bureau of Land Management) operate extensive particle speciation monitoring networks that are similar in design but are operated for different objectives. Compliance (mass only) monitoring is also carried out using federal reference method (FRM) criteria at approximately 1000 sites. The Chemical Speciation Network (CSN) consists of approximately 50 long-term-trend sites, with about another 250 sites that have been or are currently operated by state and local agencies. The sites are located in urban or suburban settings. The Interagency Monitoring of Protected Visual Environments (IMPROVE) monitoring network consists of about 181 sites, approximately 170 of which are in nonurban areas. Each monitoring approach has its own inherent monitoring limitations and biases. Determination of gravimetric mass has both negative and positive artifacts. Ammonium nitrate and other semivolatiles are lost during sampling, whereas, on the other hand, measured mass includes particle-bound water. Furthermore, some species may react with atmospheric gases, further increasing the positive mass artifact. Estimating aerosol species concentrations requires assumptions concerning the chemical form of various molecular compounds, such as nitrates and sulfates, and organic material and soil composition. Comparing data collected in the various monitoring networks allows for assessing uncertainties and biases associated with both negative and positive artifacts of gravimetric mass determinations, assumptions of chemical composition, and biases between different sampler technologies. All these biases are shown to have systematic seasonal characteristics. Unaccounted-for particle-bound water tends to be higher in the summer, as does nitrate volatilization. The ratio of particle organic mass divided by organic carbon mass (Roc) is higher during summer and lower during the winter seasons in both CSN and IMPROVE networks, and Roc is lower in urban than non-urban environments.
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Affiliation(s)
- William C Malm
- Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, Colorado 80523-1375, USA.
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Tang H, Hiemstra S, Thompson JE. Characterization of a novel particle into liquid sampler for analysis of single fluorescent aerosol particles through capillary electrophoresis. Anal Chim Acta 2011; 702:120-6. [DOI: 10.1016/j.aca.2011.06.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Revised: 06/07/2011] [Accepted: 06/11/2011] [Indexed: 01/16/2023]
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Thurston GD, Ito K, Lall R. A Source Apportionment of U.S. Fine Particulate Matter Air Pollution. ATMOSPHERIC ENVIRONMENT (OXFORD, ENGLAND : 1994) 2011; 45:3924-3936. [PMID: 24634604 PMCID: PMC3951912 DOI: 10.1016/j.atmosenv.2011.04.070] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Using daily fine particulate matter (PM2.5) composition data from the 2000-2005 U.S. EPA Chemical Speciation Network (CSN) for over 200 sites, we applied multivariate methods to identify and quantify the major fine particulate matter (PM2.5) source components in the U.S. Novel aspects of this work were: (1) the application of factor analysis (FA) to multi-city daily data, drawing upon both spatial and temporal variations of chemical species; and, (2) the exclusion of secondary components (sulfates, nitrates and organic carbon) from the source identification FA to more clearly discern and apportion the PM2.5 mass to primary emission source categories. For the quantification of source-related mass, we considered two approaches based upon the FA results: 1) using single key tracers for sources identified by FA in a mass regression; and, 2) applying Absolute Principal Component Analysis (APCA). In each case, we followed a two-stage mass regression approach, in which secondary components were first apportioned among the identified sources, and then mass was apportioned to the sources and to other secondary mass not explained by the individual sources. The major U.S. PM2.5 source categories identified via FA (and their key elements) were: Metals Industry (Pb, Zn); Crustal/Soil Particles (Ca, Si); Motor Vehicle Traffic (EC, NO2); Steel Industry (Fe, Mn); Coal Combustion (As, Se); Oil Combustion (V, Ni); Salt Particles (Na, Cl) and Biomass Burning (K). Nationwide spatial plots of the source-related PM2.5 impacts were confirmatory of the factor interpretations: ubiquitous sources, such as Traffic and Soil, were found to be spread across the nation, more unique sources (such as Steel and Metals Processing) being highest in select industrialized cities, Biomass Burning was highest in the U.S. Northwest, while Residual Oil combustion was highest in cities in the Northeastern U.S. and in cities with major seaports. The sum of these source contributions and the secondary PM2.5 components agreed well with the U.S. PM2.5 observed during the study period (mean=14.3 ug/m3; R2= 0.91). Apportionment regression analyses using single-element tracers for each source category gave results consistent with the APCA estimates. Comparisons of nearby sites indicated that the PM2.5 mass and the secondary aerosols were most homogenous spatially, while traffic PM2.5 and its tracer, EC, were among the most spatially representative of the source-related components. Comparison of apportionment results to a previous analysis of the 1979-1982 IP Network revealed similar and correlated major U.S. source category factors, albeit at lower levels than in the earlier period, suggesting a consistency in the U.S. spatial patterns of these source-related exposures over time, as well. These results indicate that applying source apportionment methods to the nationwide CSN can be an informative avenue for identifying and quantifying source components for the subsequent estimation of source-specific health effects, potentially contributing to more efficient regulation of PM2.5.
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Affiliation(s)
- George D. Thurston
- New York University, School of Medicine, Department of Environmental Medicine, 57 Old Forge Rd, Tuxedo, NY 10987
- Corresponding Author: Dr. George D. Thurston (), Address: 57 Old Forge Rd, Room 270, Tuxedo, New York, 10987, Phone: 845-731-3564, Fax: 845-351-5472
| | - Kazuhiko Ito
- New York University, School of Medicine, Department of Environmental Medicine, 57 Old Forge Rd, Tuxedo, NY 10987
| | - Ramona Lall
- New York University, School of Medicine, Department of Environmental Medicine, 57 Old Forge Rd, Tuxedo, NY 10987
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Wang X, Robbins C, Hoekman SK, Chow JC, Watson JG, Schuetzle D. Dilution sampling and analysis of particulate matter in biomass-derived syngas. ACTA ACUST UNITED AC 2011. [DOI: 10.1007/s11783-011-0347-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Chow JC, Watson JG, Robles J, Wang X, Chen LWA, Trimble DL, Kohl SD, Tropp RJ, Fung KK. Quality assurance and quality control for thermal/optical analysis of aerosol samples for organic and elemental carbon. Anal Bioanal Chem 2011; 401:3141-52. [DOI: 10.1007/s00216-011-5103-3] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 05/03/2011] [Accepted: 05/12/2011] [Indexed: 11/28/2022]
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Chow JC, Watson JG, Green MC, Frank NH. Filter light attenuation as a surrogate for elemental carbon. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2010; 60:1365-1375. [PMID: 21141430 DOI: 10.3155/1047-3289.60.11.1365] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Light attenuation (b(att)) measured from filter light transmission is compared with elemental carbon (EC) measurements for more than 180,000 collocated PM2.5 (particulate matter [PM] < or = 2.5 microm in aerodynamic diameter) and PM10 (PM < or = 10 microm in aerodynamic diameter) samples from nearly 200 U.S. locations during the past 2 decades. Although there are theoretical reasons for expecting highly variable relationships between b(att) and EC (such as the effects of "brown carbon" and iron oxides in PM2.5), reasonable correlations are found. These correlations are not a strong function of season or location (e.g., rural vs. urban). Median EC concentrations can be predicted from filter transmittance measurements to within +/- 15-30%. Although EC predicted from b(att) shows larger uncertainties (30-60%), especially at concentrations less than 0.3 microg/m3, the consistent mass absorption efficiency (sigm(att)) derived from the regression analysis demonstrates the feasibility of using b(att) as a surrogate for EC. This study demonstrates that a constant factor of 0.1 g/m2 (equivalent to the 10 m2/g sigma(att) used in the Interagency Monitoring of Protected Visual Environments chemical extinction formula) can be used to estimate EC concentrations from b(att) through a Teflon-membrane filter sample. Greater accuracy is achieved with site-specific sigma(att) derived from a period with collocated EC measurements.
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Affiliation(s)
- Judith C Chow
- Division of Atmospheric Sciences, Desert Research Institute, Reno, NV 89512, USA.
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Cahill TM. Size-resolved organic speciation of wintertime aerosols in California's Central Valley. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:2315-2321. [PMID: 20205457 DOI: 10.1021/es902936v] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Size-resolved aerosol samples, including the entire ultrafine fraction, were simultaneously collected along a transect in California's Central Valley during the winter of 2009. The samples were analyzed for PAHs, alkanes, organic acids, and sugars. The results showed that the organic constituents of aerosols did not follow the same pattern as PM(10), thus indicating that simple PM measurements are not good indicators of trace toxic organic chemicals. Levoglucosan, a tracer of wood smoke, was the most abundant organic chemical detected, thus demonstrating the predominance of wood smoke in the valley. The size profile of levoglucosan showed a maximum in the 0.34-0.56 microm size mode, which is larger than published emission profiles. This suggests that wood smoke aerosols increased in size as they aged in the environment. Some chemicals, such as benzo[a]pyrene, had similar aerosol size profiles as levoglucosan and likely arose from the same source. Other chemicals, such as coronene and sugars, had very different size profiles, indicating that they have different sources. One unexpected result was the relatively large fraction of certain chemicals present in the ultrafine fraction, which highlights the importance of collecting the entire ultrafine fraction.
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Affiliation(s)
- Thomas M Cahill
- Division of Mathematical and Natural Sciences, Arizona State University at the West Campus, Phoenix, Arizona 85069, USA.
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Bruns EA, Perraud V, Zelenyuk A, Ezell MJ, Johnson SN, Yu Y, Imre D, Finlayson-Pitts BJ, Alexander ML. Comparison of FTIR and particle mass spectrometry for the measurement of particulate organic nitrates. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:1056-61. [PMID: 20058917 DOI: 10.1021/es9029864] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
While multifunctional organic nitrates are formed during the atmospheric oxidation of volatile organic compounds, relatively little is known about their signatures in particle mass spectrometers. High resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS) and FTIR spectroscopy on particles impacted on ZnSe windows were applied to NH(4)NO(3), NaNO(3), and isosorbide 5-mononitrate (IMN) particles, and to secondary organic aerosol (SOA) from NO(3) radical reactions at 22 degrees C and 1 atm in air with alpha- and beta-pinene, 3-carene, limonene, and isoprene. For comparison, single particle laser ablation mass spectra (SPLAT II) were also obtained for IMN and SOA from the alpha-pinene reaction. The mass spectra of all particles exhibit significant intensity at m/z 30, and for the SOA, weak peaks corresponding to various organic fragments containing nitrogen [C(x)H(y)N(z)O(a)](+) were identified using HR-ToF-AMS. The NO(+)/NO(2)(+) ratios from HR-ToF-AMS were 10-15 for IMN and the SOA from the alpha- and beta-pinene, 3-carene, and limonene reactions, approximately 5 for the isoprene reaction, 2.4 for NH(4)NO(3) and 80 for NaNO(3). The N/H ratios from HR-ToF-AMS for the SOA were smaller by a factor of 2 to 4 than the -ONO(2)/C-H ratios measured using FTIR. FTIR has the advantage that it provides identification and quantification of functional groups. The NO(+)/NO(2)(+) ratio from HR-ToF-AMS can indicate organic nitrates if they are present at more than 15-60% of the inorganic nitrate, depending on whether the latter is NH(4)NO(3) or NaNO(3). However, unique identification of specific organic nitrates is not possible with either method.
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Affiliation(s)
- Emily A Bruns
- Department of Chemistry, University of California-Irvine, Irvine, CA 92697-2025, USA
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Nussbaum NJ, Zhu D, Kuhns HD, Mazzoleni C, Chang MCO, Moosmüller H, Watson JG. The In-Plume Emission Test Stand: an instrument platform for the real-time characterization of fuel-based combustion emissions. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2009; 59:1437-1445. [PMID: 20066909 DOI: 10.3155/1047-3289.59.12.1437] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The In-Plume Emission Test Stand (IPETS) characterizes gaseous and particulate matter (PM) emissions from combustion sources in real time. Carbon dioxide (CO2), carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO2), and other gases are quantified with a closed-path Fourier transform infrared spectrometer (FTIR). Particle concentrations, chemical composition, and other particle properties are characterized with an electrical low-pressure impactor (ELPI), a light-scattering particle detector, an optical particle counter, and filter samples amenable to different laboratory analysis. IPETS measurements of fuel-based emission factors for a diesel generator are compared with those from a Mobile Emissions Laboratory (MEL). IPETS emission factors ranged from 0.3 to 11.8, 0.2 to 3.7, and 22.2 to 32.8 g/kg fuel for CO, NO2, and NO, respectively. IPETS PM emission factors ranged from 0.4 to 1.4, 0.3 to 1.8, 0.3 to 2.2, and 1 to 3.4 g/kg fuel for filter, photoacoustic, nephelometer, and impactor measurements, respectively. Observed linear regression statistics for IPETS versus MEL concentrations were as follows: CO slope = 1.1, r2 = 0.99; NO slope = 1.1, r2 = 0.92; and NO2 slope = 0.8, r2 = 0.96. IPETS versus MEL PM regression statistics were: filter slope = 1.3, r2 = 0.80; ELPI slope = 1.7, r2 = 0.87; light-scattering slope = 2.7, r2 = 0.92; and photoacoustic slope = 2.1, r2 = 0.91. Lower temperatures in the dilution air (approximately 25 degrees C for IPETS vs. approximately 50 degrees C for MEL) may result in greater condensation of semi-volatile compounds on existing particles, thereby explaining the 30% difference for filters. The other PM measurement devices are highly correlated with the filter, but their factory-default PM calibration factors do not represent the size and optical properties of diesel exhaust. They must be normalized to a simultaneous filter measurement.
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