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Keffer JL, Zhou N, Rushworth DD, Yu Y, Chan CS. Microbial magnetite oxidation via MtoAB porin-multiheme cytochrome complex in Sideroxydans lithotrophicus ES-1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.20.614158. [PMID: 39345469 PMCID: PMC11429942 DOI: 10.1101/2024.09.20.614158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 10/01/2024]
Abstract
Most of Earth's iron is mineral-bound, but it is unclear how and to what extent iron-oxidizing microbes can use solid minerals as electron donors. A prime candidate for studying mineral-oxidizing growth and pathways is Sideroxydans lithotrophicus ES-1, a robust, facultative iron oxidizer with multiple possible iron oxidation mechanisms. These include Cyc2 and Mto pathways plus other multiheme cytochromes and cupredoxins, and so we posit that the mechanisms may correspond to different Fe(II) sources. Here, S. lithotrophicus ES-1 was grown on dissolved Fe(II)-citrate and magnetite. S. lithotrophicus ES-1 oxidized all dissolved Fe 2+ released from magnetite, and continued to build biomass when only solid Fe(II) remained, suggesting it can utilize magnetite as a solid electron donor. Quantitative proteomic analyses of S. lithotrophicus ES-1 grown on these substrates revealed global proteome remodeling in response to electron donor and growth state and uncovered potential proteins and metabolic pathways involved in the oxidation of solid magnetite. While the Cyc2 iron oxidases were highly expressed on both dissolved and solid substrates, MtoA was only detected during growth on solid magnetite, suggesting this protein helps catalyze oxidation of solid minerals in S. lithotrophicus ES-1. A set of cupredoxin domain-containing proteins were also specifically expressed during solid iron oxidation. This work demonstrated the iron oxidizer S. lithotrophicus ES-1 utilized additional extracellular electron transfer pathways when growing on solid mineral electron donors compared to dissolved Fe(II). Importance Mineral-bound iron could be a vast source of energy to iron-oxidizing bacteria, but there is limited evidence of this metabolism, and it has been unknown whether the mechanisms of solid and dissolved Fe(II) oxidation are distinct. In iron-reducing bacteria, multiheme cytochromes can facilitate iron mineral reduction, and here, we link a multiheme cytochrome-based pathway to mineral oxidation, broadening the known functionality of multiheme cytochromes. Given the growing recognition of microbial oxidation of minerals and cathodes, increasing our understanding of these mechanisms will allow us to recognize and trace the activities of mineral-oxidizing microbes. This work shows how solid iron minerals can promote microbial growth, which if widespread, could be a major agent of geologic weathering and mineral-fueled nutrient cycling in sediments, aquifers, and rock-hosted environments.
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Li A, Wu S, Li Q, Wang Q, Chen Y. Elucidating the Molecular Pathways and Therapeutic Interventions of Gaseous Mediators in the Context of Fibrosis. Antioxidants (Basel) 2024; 13:515. [PMID: 38790620 PMCID: PMC11117599 DOI: 10.3390/antiox13050515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 04/13/2024] [Accepted: 04/22/2024] [Indexed: 05/26/2024] Open
Abstract
Fibrosis, a pathological alteration of the repair response, involves continuous organ damage, scar formation, and eventual functional failure in various chronic inflammatory disorders. Unfortunately, clinical practice offers limited treatment strategies, leading to high mortality rates in chronic diseases. As part of investigations into gaseous mediators, or gasotransmitters, including nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S), numerous studies have confirmed their beneficial roles in attenuating fibrosis. Their therapeutic mechanisms, which involve inhibiting oxidative stress, inflammation, apoptosis, and proliferation, have been increasingly elucidated. Additionally, novel gasotransmitters like hydrogen (H2) and sulfur dioxide (SO2) have emerged as promising options for fibrosis treatment. In this review, we primarily demonstrate and summarize the protective and therapeutic effects of gaseous mediators in the process of fibrosis, with a focus on elucidating the underlying molecular mechanisms involved in combating fibrosis.
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Affiliation(s)
- Aohan Li
- Chronic Disease Research Center, Medical College, Dalian University, Dalian 116622, China; (A.L.); (S.W.); (Q.L.)
| | - Siyuan Wu
- Chronic Disease Research Center, Medical College, Dalian University, Dalian 116622, China; (A.L.); (S.W.); (Q.L.)
| | - Qian Li
- Chronic Disease Research Center, Medical College, Dalian University, Dalian 116622, China; (A.L.); (S.W.); (Q.L.)
| | - Qianqian Wang
- Chronic Disease Research Center, Medical College, Dalian University, Dalian 116622, China; (A.L.); (S.W.); (Q.L.)
- Engineering Technology Research Center for The Utilization of Functional Components of Organic Natural Products, Dalian University, Dalian 116622, China
| | - Yingqing Chen
- Chronic Disease Research Center, Medical College, Dalian University, Dalian 116622, China; (A.L.); (S.W.); (Q.L.)
- Engineering Technology Research Center for The Utilization of Functional Components of Organic Natural Products, Dalian University, Dalian 116622, China
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Liu Y, Guan Y, Shi J, Gao H, Yao X, Zhang D. Phosphorus and its solubility in aerosols from continental and marine sources in the sea areas near China: Results from a 40-day cruise mission in late spring. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 875:162655. [PMID: 36894079 DOI: 10.1016/j.scitotenv.2023.162655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/04/2023] [Accepted: 03/01/2023] [Indexed: 06/18/2023]
Abstract
Accurate assessments of soluble phosphorus (P) in aerosol particles are essential to understand the atmospheric nutrients supply to the marine ecosystem. We quantified total P (TP) and dissolved P (DP) in the aerosol particles collected in the sea areas near China in a cruise mission from May 1 to June 11, 2016. The overall concentrations of TP and DP were 3.5-99.9 ng m-3 and 2.5-27.0 ng m-3, respectively. When the air originating from the desert areas, TP and DP were 28.7-99.9 ng m-3 and 10.8-27.0 ng m-3, respectively, and P solubility was 24.1-54.6 %. When the air influenced mainly by anthropogenic emissions from eastern China, TP and DP were 11.7-12.3 ng m-3 and 5.7-6.3 ng m-3, respectively, and P solubility was 46.0-53.7 %. More than half of the TP and more than 70 % of the DP were from pyrogenic particles, with a considerable DP converted via aerosol acidification after the particles met humid marine air. On average, aerosol acidification promoted the fractional solubility of dissolved inorganic P (DIP) to TP from 22 % to 43 %. When the air originating from the marine areas, TP and DP were 3.5-22.0 ng m-3 and 2.5-8.4 ng m-3, respectively, and P solubility was 34.6-93.6 %. About one-third of the DP was from biological emissions in organic forms (DOP), leading to higher solubility than in the particles from continental sources. These results reveal the dominance of inorganic P in TP and DP from the desert and anthropogenic mineral dust and the significant contribution of organic P from marine sources. The results also indicate the necessity to treat aerosol P carefully according to different sources of the aerosol particles and atmospheric processes the particles experience in assessing aerosol P input to seawater.
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Affiliation(s)
- Yatong Liu
- Key Laboratory of Marine Environmental Science and Ecology, Ocean University of China, Ministry of Education of China, Qingdao 266100, China
| | - Yang Guan
- Key Laboratory of Marine Environmental Science and Ecology, Ocean University of China, Ministry of Education of China, Qingdao 266100, China
| | - Jinhui Shi
- Key Laboratory of Marine Environmental Science and Ecology, Ocean University of China, Ministry of Education of China, Qingdao 266100, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China.
| | - Huiwang Gao
- Key Laboratory of Marine Environmental Science and Ecology, Ocean University of China, Ministry of Education of China, Qingdao 266100, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Xiaohong Yao
- Key Laboratory of Marine Environmental Science and Ecology, Ocean University of China, Ministry of Education of China, Qingdao 266100, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Daizhou Zhang
- Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, Kumamoto 862-8502, Japan
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Shi J, Guan Y, Gao H, Yao X, Wang R, Zhang D. Aerosol Iron Solubility Specification in the Global Marine Atmosphere with Machine Learning. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:16453-16461. [PMID: 36316194 DOI: 10.1021/acs.est.2c05266] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Aerosol iron (Fe) solubility is a key factor for the assessment of atmospheric nutrients input to the ocean but poorly specified in models because the mechanism of determining the solubility is unclear. We develop a deep learning model to project the solubility based on the data that we observed in a coastal city of China. The model has five variables: the size range of particles, relative humidity, and the ratios of sulfate, nitrate and oxalate to total Fe (TFe) contents in aerosol particles. Results show excellent statistical agreements with the solubility in the literature over most worldwide seas and margin areas with the Pearson correlation coefficients (r) as large as 0.73-0.97. The exception is the Atlantic Ocean, where good agreement is obtained with the model trained using local data (r: 0.34-0.66). The model further uncovers that the ratio of oxalate/TFe is the most important variable influencing the solubility. These results indicate the feasibility of treating the solubility as a function of the six factors in deep learning models with careful training and validation. Our model and projected solubility provide innovative options for better quantification of air-to-sea input of aerosol soluble Fe in observational and model studies in the global marine atmosphere.
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Affiliation(s)
- Jinhui Shi
- Key Laboratory of Marine Environmental Science and Ecology, Ocean University of China, Ministry of Education of China, Qingdao266100, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao266237, China
| | - Yang Guan
- Key Laboratory of Marine Environmental Science and Ecology, Ocean University of China, Ministry of Education of China, Qingdao266100, China
| | - Huiwang Gao
- Key Laboratory of Marine Environmental Science and Ecology, Ocean University of China, Ministry of Education of China, Qingdao266100, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao266237, China
| | - Xiaohong Yao
- Key Laboratory of Marine Environmental Science and Ecology, Ocean University of China, Ministry of Education of China, Qingdao266100, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao266237, China
| | - Renzheng Wang
- Key Laboratory of Marine Environmental Science and Ecology, Ocean University of China, Ministry of Education of China, Qingdao266100, China
| | - Daizhou Zhang
- Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, Kumamoto862-8502, Japan
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Hettiarachchi E, Ivanov S, Kieft T, Goldstein HL, Moskowitz BM, Reynolds RL, Rubasinghege G. Atmospheric Processing of Iron-Bearing Mineral Dust Aerosol and Its Effect on Growth of a Marine Diatom, Cyclotella meneghiniana. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:871-881. [PMID: 33382945 DOI: 10.1021/acs.est.0c06995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Iron (Fe) is a growth-limiting micronutrient for phytoplankton in major areas of oceans and deposited wind-blown desert dust is a primary Fe source to these regions. Simulated atmospheric processing of four mineral dust proxies and two natural dust samples followed by subsequent growth studies of the marine planktic diatom Cyclotella meneghiniana in artificial sea-water (ASW) demonstrated higher growth response to ilmenite (FeTiO3) and hematite (α-Fe2O3) mixed with TiO2 than hematite alone. The processed dust treatment enhanced diatom growth owing to dissolved Fe (DFe) content. The fresh dust-treated cultures demonstrated growth enhancements without adding such dissolved Fe. These significant growth enhancements and dissolved Fe measurements indicated that diatoms acquire Fe from solid particles. When diatoms were physically separated from mineral dust particles, the growth responses become smaller. The post-mineralogy analysis of mineral dust proxies added to ASW showed a diatom-induced increased formation of goethite, where the amount of goethite formed correlated with observed enhanced growth. The current work suggests that ocean primary productivity may not only depend on dissolved Fe but also on suspended solid Fe particles and their mineralogy. Further, the diatom C. meneghiniana benefits more from mineral dust particles in direct contact with cells than from physically impeded particles, suggesting the possibility for alternate Fe-acquisition mechanism/s.
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Affiliation(s)
- Eshani Hettiarachchi
- Department of Chemistry, New Mexico Institute of Mining and Technology, Socorro, New Mexico 87801, United States
| | - Sergei Ivanov
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Thomas Kieft
- Department of Biology, New Mexico Institute of Mining and Technology, Socorro, New Mexico 87801, United States
| | - Harland L Goldstein
- Geosciences and Environmental Change Science Center, U.S. Geological Survey, Denver, Colorado 80225, United States
| | - Bruce M Moskowitz
- Institute for Rock Magnetism, Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Richard L Reynolds
- Geosciences and Environmental Change Science Center, U.S. Geological Survey, Denver, Colorado 80225, United States
- Institute for Rock Magnetism, Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Gayan Rubasinghege
- Department of Chemistry, New Mexico Institute of Mining and Technology, Socorro, New Mexico 87801, United States
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Mineral Dust and Iron Solubility: Effects of Composition, Particle Size, and Surface Area. ATMOSPHERE 2020. [DOI: 10.3390/atmos11050533] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
There is significant iron deposition in the oceans, approximately 14–16 Tg annually from mineral dust aerosols, but only a small percentage (approx. 3%) of it is soluble and, thus, bioavailable. In this work, we examine the effect of mineralogy, particle size, and surface area on iron solubility in pure mineral phases to simulate atmospheric processing of mineral dust aerosols during transport. Pure iron-bearing minerals common to Saharan dust were partitioned into four size fractions (10–2.5, 2.5–1, 1–0.5, and 0.5–0.25 µm) and extracted into moderately acidic (pH 4.3) and acidic (pH 1.7) leaching media to simulate mineral processing during atmospheric transport. Results show that, in general, pure iron-bearing clay materials present an iron solubility (% dissolved Fe/total Fe in the mineral) an order of magnitude higher than pure iron oxide minerals. The relative solubility of iron in clay particles does not depend on particle size for the ranges examined (0.25–10 μm), while iron in hematite and magnetite shows a trend of increasing solubility with decreasing particle size in the acidic leaching medium. Our results indicate that while mineralogy and aerosol pH have an effect on the solubilization of iron from simulated mineral dust particles, surface processes of the aerosol might also have a role in iron solubilization during transport. The surface area of clay minerals does not change significantly as a function of particle size (10–0.25 µm), while the surface area of iron oxides is strongly size dependent. Overall, these results show how mineralogy and particle size can influence iron solubility in atmospheric dust.
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Li R, Jia X, Wang F, Ren Y, Wang X, Zhang H, Li G, Wang X, Tang M. Heterogeneous reaction of NO 2 with hematite, goethite and magnetite: Implications for nitrate formation and iron solubility enhancement. CHEMOSPHERE 2020; 242:125273. [PMID: 31896195 DOI: 10.1016/j.chemosphere.2019.125273] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 10/06/2019] [Accepted: 10/29/2019] [Indexed: 06/10/2023]
Abstract
Atmospheric processing may significantly increase solubility of iron in mineral dust, but the effects of heterogeneous reactions on iron solubility have been poorly understood. In this work, we investigated heterogeneous reaction of NO2 (15 ± 1 and 2.5 ± 0.1 ppmv, equal to ∼3.7 × 1014 and ∼6.2 × 1013 molecule cm-3) with hematite, magnetite and goethite at different relative humidities (RH, 0-90%), and changes in particulate nitrate and soluble iron due to heterogeneous reaction with NO2 were quantified as a function of time (up to 24 h). After reaction with 2.5 ± 0.1 ppmv NO2 for 24 h (or less time), hematite and magnetite were fully saturated, while goethite was only partly deactivated. Nitrate yield was largest for goethite, and the mass ratio of formed nitrate to unreacted mineral only reached ∼1% or less after 24 h reaction. All the three minerals showed low reactivities towards NO2, and the average reactive uptake coefficients of NO2 in the first 3 h were found to be < 5 × 10-8. In addition, the increase in iron solubility was found to be small and in some cases even insignificant for the three minerals after heterogeneous reaction with NO2 for 24 h. Overall, the impacts of heterogeneous reaction of NO2 with hematite, magnetite and goethite on nitrate aerosol formation and iron solubility could be very limited.
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Affiliation(s)
- Rui Li
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaohong Jia
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fu Wang
- Longhua Center for Disease Control and Prevention of Shenzhen, Shenzhen 518109, China
| | - Yan Ren
- Longhua Center for Disease Control and Prevention of Shenzhen, Shenzhen 518109, China
| | - Xiao Wang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huanhuan Zhang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guanghui Li
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 511443, China
| | - Xinming Wang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Mingjin Tang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
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Wu M, Liang G, Duan H, Yang X, Qin G, Sang N. Synergistic effects of sulfur dioxide and polycyclic aromatic hydrocarbons on pulmonary pro-fibrosis via mir-30c-1-3p/ transforming growth factor β type II receptor axis. CHEMOSPHERE 2019; 219:268-276. [PMID: 30543962 DOI: 10.1016/j.chemosphere.2018.12.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 11/23/2018] [Accepted: 12/02/2018] [Indexed: 06/09/2023]
Abstract
SO2 and PAHs are well-known pollutants of coal burning and significant contributors to haze episodes. The purpose of the study is to determine whether the combined effects of SO2 and BaP are synergetic and to investigate the pro-fibrotic influences and possible mechanism from the aspect of microRNAs. In the present study cellular metabolic activity of BEAS-2B was assessed using MTT probe. C57BL/6 mice were exposed to BaP (40 mg/kg b.w.) for 5 days or SO2 (7 mg/m3) inhalation for 4 weeks alone or together. Lung tissues were processed for histology to assess pulmonary fibrosis. The protein level of pulmonary pro-fibrotic genes (Col1a1, Col3a1, alpha-SMA, fibronectin) and TGFβR2 were analyzed by Western blot and immunofluorescence in vivo and in vitro. Furthermore, we clarified that the microRNA expression of mir-30c-1-3p by real-time RT-PCR. The luciferase reporter assay was used to determine the binding sites of mir-30c-1-3p in the 3'-UTR of TGFβR2. It was confirmed that SO2 and BaP acted together to produce synergistic effects in cellular metabolic activity. Coexisting of SO2 and BaP increased the protein expression of pro-fibrotic genes and TGFβR2 and decreased mir-30c-1-3p in vivo and in vitro. Dual-luciferase reporter gene assays showed that TGFβR2 was a validated target of mir-30c-1-3p. All above results demonstrated that mir-30c-1-3p was involved in the synergistic pro-fibrotic effects of SO2 and BaP in lung via targeting TGFβR2. This work implies the potential risk of pulmonary fibrosis from the co-existence of SO2 and PAHs and provides new insights into the molecular markers for relevant diseases.
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Affiliation(s)
- Meiqiong Wu
- College of Environmental Science and Resources, Research Center of Environment and Health, Shanxi University, Taiyuan, Shanxi, 030006, China
| | - Gang Liang
- College of Environmental Science and Resources, Research Center of Environment and Health, Shanxi University, Taiyuan, Shanxi, 030006, China
| | - Huiling Duan
- College of Environmental Science and Resources, Research Center of Environment and Health, Shanxi University, Taiyuan, Shanxi, 030006, China
| | - Xiaofeng Yang
- College of Environmental Science and Resources, Research Center of Environment and Health, Shanxi University, Taiyuan, Shanxi, 030006, China
| | - Guohua Qin
- College of Environmental Science and Resources, Research Center of Environment and Health, Shanxi University, Taiyuan, Shanxi, 030006, China.
| | - Nan Sang
- College of Environmental Science and Resources, Research Center of Environment and Health, Shanxi University, Taiyuan, Shanxi, 030006, China.
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Longo AF, Feng Y, Lai B, Landing WM, Shelley RU, Nenes A, Mihalopoulos N, Violaki K, Ingall ED. Influence of Atmospheric Processes on the Solubility and Composition of Iron in Saharan Dust. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:6912-6920. [PMID: 27286140 DOI: 10.1021/acs.est.6b02605] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Aerosol iron was examined in Saharan dust plumes using a combination of iron near-edge X-ray absorption spectroscopy and wet-chemical techniques. Aerosol samples were collected at three sites located in the Mediterranean, the Atlantic, and Bermuda to characterize iron at different atmospheric transport lengths and time scales. Iron(III) oxides were a component of aerosols at all sampling sites and dominated the aerosol iron in Mediterranean samples. In Atlantic samples, iron(II and III) sulfate, iron(III) phosphate, and iron(II) silicates were also contributors to aerosol composition. With increased atmospheric transport time, iron(II) sulfates are found to become more abundant, aerosol iron oxidation state became more reduced, and aerosol acidity increased. Atmospheric processing including acidic reactions and photoreduction likely influence the form of iron minerals and oxidation state in Saharan dust aerosols and contribute to increases in aerosol-iron solubility.
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Affiliation(s)
| | | | | | - William M Landing
- Department of Earth, Ocean and Atmospheric Science, Florida State University , Tallahassee, Florida 32306, United States
| | - Rachel U Shelley
- Department of Earth, Ocean and Atmospheric Science, Florida State University , Tallahassee, Florida 32306, United States
| | - Athanasios Nenes
- Foundation for Research and Technology, Hellas , Patras 70013, Greece
- National Observatory of Athens , Penteli GR-15236, Greece
| | - Nikolaos Mihalopoulos
- National Observatory of Athens , Penteli GR-15236, Greece
- Department of Chemistry, University of Crete , Iraklion 71003, Greece
| | - Kalliopi Violaki
- Department of Chemistry, University of Crete , Iraklion 71003, Greece
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Effect of Pollution Controls on Atmospheric PM2.5 Composition during Universiade in Shenzhen, China. ATMOSPHERE 2016. [DOI: 10.3390/atmos7040057] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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