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Si L, Li Z. Atmospheric precipitation chemistry and environmental significance in major anthropogenic regions globally. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 926:171830. [PMID: 38513855 DOI: 10.1016/j.scitotenv.2024.171830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 02/11/2024] [Accepted: 03/18/2024] [Indexed: 03/23/2024]
Abstract
In order to investigate the spatiotemporal distribution and influencing factors of global precipitation chemistry, we conducted a comprehensive analysis using multiple data sources, revealing the impact of human activities on the natural environment. The results indicate a decreasing trend in global precipitation acidity over the past 20 years. The distribution of global precipitation is influenced by both natural and anthropogenic factors. Alkaline cation concentrations are higher in desert and arid regions, while high concentrations of SO42- and NO3- are primarily found in industrial areas, and agricultural areas exhibit higher NH4+ concentrations. Coastal regions have higher Na+ and Cl- concentrations compared to inland areas. However, the increased Na + and Cl- concentrations due to inland salinization should not be overlooked. Additionally, influenced by atmospheric circulation, transboundary pollution from South Asia leads to higher SO42- and NO3- concentrations in precipitation over the Tibetan Plateau. Meteorological factors have a weaker influence on precipitation chemistry compared to geographical and human activity factors, although ion concentrations in snowfall are higher than in rainfall.
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Affiliation(s)
- Lanping Si
- Observation and Research Station of Eco-Hydrology and National Park by Stable Isotope Tracing in Alpine region/Gansu Qilian Mountains Ecology Research Center/Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Zongxing Li
- Observation and Research Station of Eco-Hydrology and National Park by Stable Isotope Tracing in Alpine region/Gansu Qilian Mountains Ecology Research Center/Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, China.
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Attri P, Mani D, Satyanarayanan M, Reddy D, Kumar D, Sarkar S, Kumar S, Hegde P. Atmospheric aerosol chemistry and source apportionment of PM10 using stable carbon isotopes and PMF modelling during fireworks over Hyderabad, southern India. Heliyon 2024; 10:e26746. [PMID: 38495155 PMCID: PMC10943357 DOI: 10.1016/j.heliyon.2024.e26746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 02/11/2024] [Accepted: 02/19/2024] [Indexed: 03/19/2024] Open
Abstract
This study examined the influence of fireworks on atmospheric aerosols over the Southern Indian city of Hyderabad during festival of Diwali using mass closure, stable carbon isotopes and the EPA-PMF model. Identification of chemical species in day and night time aerosol samples for 2019 and 2020 Diwali weeks showed increased concentrations of NH4+, NO3-, SO42-, K+, organic carbon (OC), Ba, Pb and Li, which were considered as tracers for fireworks. PM10 source apportionment was done using inorganic (trace elements, major ions) and carbonaceous (organic and elemental carbon; OC & EC) constituents, along with stable isotopic compositions of TC and EC. K+/Na+ ∼1 and K+nss/OC > 0.5 indicated contribution from fireworks. High NO3-, NH4+, Na+, Cl- and SO42- suggested the presence of deliquescent salts NaCl, NH4NO3 and (NH4)2SO4. TAE/TCE >1 suggested H+ exclusion, indicating possible presence of H2SO4 and NH4HSO4 in the aerosols. Ba, Pb, Sb, Sr and Fe increased by 305 (87), 12 (11), 12 (3), 3 (2) and 3 (4) times on Diwali nights, compared to pre-Diwali of 2019 (2020), and are considered as metallic tracers of fireworks. δ13CTC and δ13CEC in aerosols closely resembled that of diesel and C3 plant burning emissions, with meagre contribution from firecrackers during Diwali period. The δ13CEC was relatively depleted than δ13CTC and δ13COC. For both years, δ13COC-EC (δ13COC - δ13CEC) were positive, suggesting photochemical aging of aerosols during long-range transport, while for pre-Diwali 2019 and post-Diwali 2020, δ13COC-EC were negative with high OC/EC ratio, implying secondary organic aerosols formation. High toluene during Diwali week contributed to fresh SOA formation, which reacted with precursor 12C, leading to 13C depletions. Eight-factored EPA-PMF source apportionment indicated highest contribution from residue/waste burning, followed by marine/dust soil and fireworks, while least was contributed from solid fuel/coal combustion.
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Affiliation(s)
- Pradeep Attri
- Centre for Earth, Ocean and Atmospheric Sciences, University of Hyderabad, Telangana 500046, India
| | - Devleena Mani
- Centre for Earth, Ocean and Atmospheric Sciences, University of Hyderabad, Telangana 500046, India
| | - M. Satyanarayanan
- CSIR-National Geophysical Research Institute, Hyderabad, Telangana 500007, India
| | - D.V. Reddy
- CSIR-National Geophysical Research Institute, Hyderabad, Telangana 500007, India
| | - Devender Kumar
- CSIR-National Geophysical Research Institute, Hyderabad, Telangana 500007, India
| | | | - Sanjeev Kumar
- Physical Research Laboratory, Ahmedabad, Gujarat 380009, India
| | - Prashant Hegde
- Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram, Kerala 695021, India
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Xu Y, O'Sharkey K, Cabison J, Rosales M, Chavez T, Johnson M, Yang T, Cho SH, Chartier R, Grubbs B, Lurvey N, Lerner D, Lurmann F, Farzan S, Bastain TM, Breton C, Wilson JP, Habre R. Sources of personal PM 2.5 exposure during pregnancy in the MADRES cohort. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2024:10.1038/s41370-024-00648-z. [PMID: 38326532 DOI: 10.1038/s41370-024-00648-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 02/09/2024]
Abstract
BACKGROUND Personal exposure to fine particulate matter (PM2.5) is impacted by different sources each with different chemical composition. Determining these sources is important for reducing personal exposure and its health risks especially during pregnancy. OBJECTIVE Identify main sources and their contributions to the personal PM2.5 exposure in 213 women in the 3rd trimester of pregnancy in Los Angeles, CA. METHODS We measured 48-hr integrated personal PM2.5 exposure and analyzed filters for PM2.5 mass, elemental composition, and optical carbon fractions. We used the EPA Positive Matrix Factorization (PMF) model to resolve and quantify the major sources of personal PM2.5 exposure. We then investigated bivariate relationships between sources, time-activity patterns, and environmental exposures in activity spaces and residential neighborhoods to further understand sources. RESULTS Mean personal PM2.5 mass concentration was 22.3 (SD = 16.6) μg/m3. Twenty-five species and PM2.5 mass were used in PMF with a final R2 of 0.48. We identified six sources (with major species in profiles and % contribution to PM2.5 mass) as follows: secondhand smoking (SHS) (brown carbon, environmental tobacco smoke; 65.3%), fuel oil (nickel, vanadium; 11.7%), crustal (aluminum, calcium, silicon; 11.5%), fresh sea salt (sodium, chlorine; 4.7%), aged sea salt (sodium, magnesium, sulfur; 4.3%), and traffic (black carbon, zinc; 2.6%). SHS was significantly greater in apartments compared to houses. Crustal source was correlated with more occupants in the household. Aged sea salt increased with temperature and outdoor ozone, while fresh sea salt was highest on days with westerly winds from the Pacific Ocean. Traffic was positively correlated with ambient NO2 and traffic-related NOx at residence. Overall, 76.8% of personal PM2.5 mass came from indoor or personal compared to outdoor sources. IMPACT We conducted source apportionment of personal PM2.5 samples in pregnancy in Los Angeles, CA. Among identified sources, secondhand smoking contributed the most to the personal exposure. In addition, traffic, crustal, fuel oil, fresh and aged sea salt sources were also identified as main sources. Traffic sources contained markers of combustion and non-exhaust wear emissions. Crustal source was correlated with more occupants in the household. Aged sea salt source increased with temperature and outdoor ozone and fresh sea salt source was highest on days with westerly winds from the Pacific Ocean.
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Affiliation(s)
- Yan Xu
- Spatial Sciences Institute, University of Southern California, Los Angeles, CA, USA.
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, CA, USA.
| | - Karl O'Sharkey
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, CA, USA
| | - Jane Cabison
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, CA, USA
| | - Marisela Rosales
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, CA, USA
| | - Thomas Chavez
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, CA, USA
| | - Mark Johnson
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, CA, USA
| | - Tingyu Yang
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, CA, USA
| | | | | | - Brendan Grubbs
- Department of Obstetrics and Gynecology, University of Southern California, Los Angeles, CA, USA
| | | | | | | | - Shohreh Farzan
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, CA, USA
| | - Theresa M Bastain
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, CA, USA
| | - Carrie Breton
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, CA, USA
| | - John P Wilson
- Spatial Sciences Institute, University of Southern California, Los Angeles, CA, USA
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, CA, USA
- Department of Civil & Environmental Engineering, Computer Science, and Sociology, University of Southern California, Los Angeles, CA, USA
| | - Rima Habre
- Spatial Sciences Institute, University of Southern California, Los Angeles, CA, USA
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, CA, USA
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Burdette TC, Bramblett RL, Zimmermann K, Frossard AA. Influence of Air Mass Source Regions on Signatures of Surface-Active Organic Molecules in Size Resolved Atmospheric Aerosol Particles. ACS EARTH & SPACE CHEMISTRY 2023; 7:1578-1591. [PMID: 37609122 PMCID: PMC10441572 DOI: 10.1021/acsearthspacechem.3c00161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 07/21/2023] [Accepted: 07/21/2023] [Indexed: 08/24/2023]
Abstract
The physical and chemical properties of atmospheric aerosol particles depend on their sources and lifetime in the atmosphere. In coastal regions, sources may include influences from marine, continental, anthropogenic, and natural emissions. In this study, particles in ten diameter-size ranges were collected, and particle number size distributions were measured, at Skidaway Island, GA in May and June 2018. Based on air mass back trajectories and concentrations of major ions in the particles, the air mass source regions were identified as Marine Influenced, Mixed, and Continental Influenced. Organic molecules were extracted from the particles using solid-phase extraction and characterized using tensiometry and high-resolution mass spectrometry. The presence of surfactants was confirmed in the extracts through the observation of significant surface tension depressions. The organic formulas contained high hydrogen-to-carbon (H/C) and low oxygen-to-carbon (O/C) ratios, similar to surfactants and lipid-like molecules. In the Marine Influenced particles, the fraction of formulas identified as surfactant-like was negatively correlated with minimum surface tensions; as the surfactant fraction increased, the surface tension decreased. Analyses of fatty acid compounds demonstrated that organic compounds extracted from the Marine Influenced particles had the highest carbon numbers (18), compared to those of the Mixed (15) and Continental Influenced (9) particles. This suggests that the fatty acids in the Continental Influenced particles may have been more aged in the atmosphere and undergone fragmentation. This is one of the first studies to measure the chemical and physical properties of surfactants in size-resolved particles from different air mass source regions.
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Affiliation(s)
- Tret C. Burdette
- Department
of Chemistry, University of Georgia, Athens, Georgia 30606, United States
| | - Rachel L. Bramblett
- Department
of Chemistry, University of Georgia, Athens, Georgia 30606, United States
| | - Kathryn Zimmermann
- Department
of Chemistry, Georgia Gwinnett College, Lawrenceville, Georgia 30043, United States
| | - Amanda A. Frossard
- Department
of Chemistry, University of Georgia, Athens, Georgia 30606, United States
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Scerri MM, Weinbruch S, Delmaire G, Mercieca N, Nolle M, Prati P, Massabò D. Exhaust and non-exhaust contributions from road transport to PM 10 at a Southern European traffic site. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 316:120569. [PMID: 36347413 DOI: 10.1016/j.envpol.2022.120569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 10/27/2022] [Accepted: 10/30/2022] [Indexed: 06/16/2023]
Abstract
It is a well - established fact that road traffic is one of the main contributors to ambient levels of airborne particulate matter (APM). This study was carried out at a traffic site in which the PM10 levels are monitored all year round. A trend analysis of these levels revealed that over a decade there was no discernible trend, with the PM10 concentrations normally hovering around the EU limit values. In 2018, one of these limit values was exceeded. The contribution of traffic at the site was therefore investigated through a chemical speciation of 209 PM10 samples collected throughout this year. The speciation data were used in a source apportionment exercise in which the output of the PMF model was further refined using the lesser-known, constraint weighted non - negative matrix factorization (CW - NMF) model. This technique enabled the isolation of two factors clearly related to traffic, which were labelled as "exhaust contribution" (responsible for 3.4% of the PM10), "tire/brake wear contribution" (contributing 17% of the PM10). Additionally, a factor including both traffic resuspended dust and crustal material was also isolated and labelled "road dust/crustal" factor. The two contributors to the factor jointly contribute 18% to the PM10 and the contribution of the traffic resuspended dust was estimated at 7.3%. The traffic resuspended component of this factor together with the "tire/brake wear contribution" jointly make up the non-exhaust contribution of traffic - derived dust. Consonant with what has been known for quite some time, the exhaust fraction is the minor component of traffic PM10. It is therefore, clear that policies aimed at controlling traffic derived PM10 pollution at the receptor will have a minimal effect unless the non - exhaust emissions are adequately controlled.
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Affiliation(s)
- Mark M Scerri
- Institute of Earth Systems, University of Malta, Tal-Qroqq, Msida, MSD2080, Malta.
| | - Stephan Weinbruch
- Institute of Applied Geosciences, Technical University Darmstadt, Schnittspahnstraße 9, 64287, Darmstadt, Germany
| | - Gilles Delmaire
- Laboratoire d'Informatique Signal et Image de la Côte d'Opale (LISIC), Université du Littoral Côte d'Opale, F62228, Calais, France
| | - Nadine Mercieca
- Environment and Resources Authority, Hexagon House, Spencer Hill, Marsa, MRS1441, Malta
| | - Michael Nolle
- Environment and Resources Authority, Hexagon House, Spencer Hill, Marsa, MRS1441, Malta
| | - Paolo Prati
- Physics Department & INFN, Università degli studi di Genova, Via Dodecaneso 33, 16146, Genova, Italy
| | - Dario Massabò
- Physics Department & INFN, Università degli studi di Genova, Via Dodecaneso 33, 16146, Genova, Italy
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Mardi AH, Dadashazar H, Painemal D, Shingler T, Seaman ST, Fenn MA, Hostetler CA, Sorooshian A. Biomass Burning Over the United States East Coast and Western North Atlantic Ocean: Implications for Clouds and Air Quality. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2021; 126:e2021JD034916. [PMID: 34777928 PMCID: PMC8587641 DOI: 10.1029/2021jd034916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 10/05/2021] [Indexed: 06/13/2023]
Abstract
Biomass burning (BB) aerosol events were characterized over the U.S. East Coast and Bermuda over the western North Atlantic Ocean (WNAO) between 2005 and 2018 using a combination of ground-based observations, satellite data, and model outputs. Days with BB influence in an atmospheric column (BB days) were identified using criteria biased toward larger fire events based on anomalously high AERONET aerosol optical depth (AOD) and MERRA-2 black carbon (BC) column density. BB days are present year-round with more in June-August (JJA) over the northern part of the East Coast, in contrast to more frequent events in March-May (MAM) over the southeast U.S. and Bermuda. BB source regions in MAM are southern Mexico and by the Yucatan, Central America, and the southeast U.S. JJA source regions are western parts of North America. Less than half of the BB days coincide with anomalously high PM2.5 levels in the surface layer, according to data from 14 IMPROVE sites over the East Coast. Profiles of aerosol extinction suggest that BB particles can be found in the boundary layer and into the upper troposphere with the potential to interact with clouds. Higher cloud drop number concentration and lower drop effective radius are observed during BB days. In addition, lower liquid water path is found during these days, especially when BB particles are present in the boundary layer. While patterns are suggestive of cloud-BB aerosol interactions over the East Coast and the WNAO, additional studies are needed for confirmation.
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Affiliation(s)
- Ali Hossein Mardi
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
| | - Hossein Dadashazar
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
| | - David Painemal
- Science Systems and Applications, Inc., Hampton, VA, USA
- NASA Langley Research Center, Hampton, VA, USA
| | | | | | - Marta A Fenn
- Science Systems and Applications, Inc., Hampton, VA, USA
- NASA Langley Research Center, Hampton, VA, USA
| | | | - Armin Sorooshian
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
- Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
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Extreme Aerosol Events at Mesa Verde, Colorado: Implications for Air Quality Management. ATMOSPHERE 2021. [DOI: 10.3390/atmos12091140] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A significant concern for public health and visibility is airborne particulate matter, especially during extreme events. Of most relevance for health, air quality, and climate is the role of fine aerosol particles, specifically particulate matter with aerodynamic diameters less than or equal to 2.5 micrometers (PM2.5). The purpose of this study was to examine PM2.5 extreme events between 1989 and 2018 at Mesa Verde, Colorado using Interagency Monitoring of Protected Visual Environments (IMPROVE) monitoring data. Extreme events were identified as those with PM2.5 on a given day exceeding the 90th percentile value for that given month. We examine the weekly, monthly, and interannual trends in the number of extreme events at Mesa Verde, in addition to identifying the sources of the extreme events with the aid of the Navy Aerosol Analysis and Prediction (NAAPS) aerosol model. Four sources were used in the classification scheme: Asian dust, non-Asian dust, smoke, and “other”. Our results show that extreme PM2.5 events in the spring are driven mostly by the dust categories, whereas summertime events are influenced largely by smoke. The colder winter months have more influence from “other” sources that are thought to be largely anthropogenic in nature. No weekly cycle was observed for the number of events due to each source; however, interannual analysis shows that the relative amount of dust and smoke events compared to “other” events have increased in the last decade, especially smoke since 2008. The results of this work indicate that, to minimize and mitigate the effects of extreme PM2.5 events in the southwestern Colorado area, it is important to focus mainly on smoke and dust forecasting in the spring and summer months. Wintertime extreme events may be easier to regulate as they derive more from anthropogenic pollutants accumulating in shallow boundary layers in stagnant conditions.
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Mineralogical and Chemical Tracing of Dust Variation in an Underground Historic Salt Mine. MINERALS 2021. [DOI: 10.3390/min11070686] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The aim of this study was to investigate the causes of the evolution of atmospheric dust composition in an open-to-public subterranean site (UNESCO-recognized historic mine) at increasing distances from the air intake. The role of the components imported with atmospheric air from the surface was compared with natural and anthropogenic sources of dust from inside the mine. Samples of deposited dust were directly collected from flat surfaces at 11 carefully selected sites. The morphological, mineralogical, and chemical characteristics were obtained using scanning electron microscopy (SEM), X-ray diffraction (XRD), and inductively coupled plasma spectroscopy (ICP). The study showed that the air in the underground salt mine was free of pollutants present in the ambient air on the surface. Most of the components sucked into the mine by the ventilation system from the surface (regular dust, particulate matter, gaseous pollutants, biogenic particles, etc.) underwent quick and instantaneous sedimentation in the close vicinity of the air inlet to the mine. The dust settled in the mine interior primarily consisted of natural geogenic particles, locally derived from the weathering of the host rock (halite, anhydrite, and aluminosilicates). This was confirmed by low values of enrichment factors (EF) calculated for minor and trace elements. Only one site, due to the tourist railroad and the associated local intensive tourist traffic, represented the anthropogenic sources of elevated concentrations of ferruginous particles and accompanied metals (P, Cr, Mn, Co, Ni, Cu, As, Mo, Cd, Sn, Sb, Pb, and W). The gravitational deposition of pollutants from these sources limits the effects of the emissions to the local range. The used methodology and the results are universal and might also apply to other mines, caves, or underground installations used for museums, tourists, or speleotherapeutic purposes.
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Cuevas-Robles A, Soltani N, Keshavarzi B, Youn JS, MacDonald AB, Sorooshian A. Hygroscopic and Chemical Properties of Aerosol Emissions at a Major Mining Facility in Iran: Implications for Respiratory Deposition. ATMOSPHERIC POLLUTION RESEARCH 2021; 12:292-301. [PMID: 33994823 PMCID: PMC8117051 DOI: 10.1016/j.apr.2020.12.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
This study characterizes the hygroscopic and chemical nature of aerosols originating from ten locations (4 outdoors and 6 indoors) around the Gol-E-Gohar (GEG) iron ore mine (Iran), including an assessment of how hygroscopic growth alters particulate deposition in the respiratory system. Aerosols collected on filters in three diameter (Dp) ranges (total suspended particulates [TSP], Dp ≤ 10 μm [PM10], and Dp ≤ 2.5 μm [PM2.5]) were analyzed for chemical and hygroscopic characteristics. The water-soluble aerosol composition is dominated by species associated with directly emitted crustal matter such as chloride, sodium, calcium, and sulfate. There was minimal contribution from organic acids and other secondarily formed species such as inorganic salts. Aerosol growth factors at 90% relative humidity varied between 1.39 and 1.72 and exceed values reported for copper mines in the United States where similar data are available. Values of the hygroscopicity parameter kappa (0.19 to 0.45) were best related to the mass fraction of chloride among all the studied species. Kappa values were generally similar when comparing the three types of samples (TSP, PM2.5, PM10) at each site and also when comparing each of the ten sampling sites. Accounting for hygroscopic growth yields an increase in the deposition fraction for aerosols with a dry Dp between 0.2 and 2 μm based on International Commission on Radiological Protection model calculations, with more variability when examining each of the three individual head airway regions.
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Affiliation(s)
- Alberto Cuevas-Robles
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
| | - Naghmeh Soltani
- Department of Earth Sciences, College of Science, Shiraz University, Shiraz, Iran
| | - Behnam Keshavarzi
- Department of Earth Sciences, College of Science, Shiraz University, Shiraz, Iran
| | - Jong-Sang Youn
- Department of Environmental Engineering, The Catholic University of Korea, Bucheon, Republic of Korea
| | - Alexander B MacDonald
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
| | - Armin Sorooshian
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
- Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
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