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Aryal A, Harmon AC, Varner KJ, Noël A, Cormier SA, Nde DB, Mottram P, Maxie J, Dugas TR. Inhalation of particulate matter containing environmentally persistent free radicals induces endothelial dysfunction mediated via AhR activation at the air-blood interface. Toxicol Sci 2024; 199:246-260. [PMID: 38310335 DOI: 10.1093/toxsci/kfae007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2024] Open
Abstract
Particulate matter (PM) containing environmentally persistent free radicals (EPFR) is formed by the incomplete combustion of organic wastes, resulting in the chemisorption of pollutants to the surface of PM containing redox-active transition metals. In prior studies in mice, EPFR inhalation impaired endothelium-dependent vasodilation. These findings were associated with aryl hydrocarbon receptor (AhR) activation in the alveolar type-II (AT-II) cells that form the air-blood interface in the lung. We thus hypothesized that AhR activation in AT-II cells promotes the systemic release of mediators that promote endothelium dysfunction peripheral to the lung. To test our hypothesis, we knocked down AhR in AT-II cells of male and female mice and exposed them to 280 µg/m3 EPFR lo (2.7e + 16 radicals/g) or EPFR (5.5e + 17 radicals/g) compared with filtered air for 4 h/day for 1 day or 5 days. AT-II-AhR activation-induced EPFR-mediated endothelial dysfunction, reducing endothelium-dependent vasorelaxation by 59%, and eNOS expression by 50%. It also increased endothelin-1 mRNA levels in the lungs and peptide levels in the plasma in a paracrine fashion, along with soluble vascular cell adhesion molecule-1 and iNOS mRNA expression, possibly via NF-kB activation. Finally, AhR-dependent increases in antioxidant response signaling, coupled to increased levels of 3-nitrotyrosine in the lungs of EPFR-exposed littermate control but not AT-II AhR KO mice suggested that ATII-specific AhR activation promotes oxidative and nitrative stress. Thus, AhR activation at the air-blood interface mediates endothelial dysfunction observed peripheral to the lung, potentially via release of systemic mediators.
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Affiliation(s)
- Ankit Aryal
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana 70803, USA
| | - Ashlyn C Harmon
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana 70803, USA
| | - Kurt J Varner
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, USA
| | - Alexandra Noël
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana 70803, USA
| | - Stephania A Cormier
- Department of Biological Sciences, Louisiana State University A&M College and Pennington Biomedical Research Institute, Baton Rouge, Louisiana 70803, USA
| | - Divine B Nde
- Department of Chemistry, Louisiana State University A&M College, Baton Rouge, Louisiana 70803, USA
| | - Peter Mottram
- Department of Pathobiological Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana 70803, USA
| | - Jemiah Maxie
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana 70803, USA
| | - Tammy R Dugas
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana 70803, USA
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Aryal A, Noël A, Khachatryan L, Cormier SA, Chowdhury PH, Penn A, Dugas TR, Harmon AC. Environmentally persistent free radicals: Methods for combustion generation, whole-body inhalation and assessing cardiopulmonary consequences. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 334:122183. [PMID: 37442324 PMCID: PMC10528481 DOI: 10.1016/j.envpol.2023.122183] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 07/04/2023] [Accepted: 07/10/2023] [Indexed: 07/15/2023]
Abstract
Particulate matter (PM) containing environmentally persistent free radicals (EPFRs) results from the incomplete combustion of organic wastes which chemisorb to transition metals. This process generates a particle-pollutant complex that continuously redox cycles to produce reactive oxygen species. EPFRs are well characterized, but their cardiopulmonary effects remain unknown. This publication provides a detailed approach to evaluating these effects and demonstrates the impact that EPFRs have on the lungs and vasculature. Combustion-derived EPFRs were generated (EPFR lo: 2.1e-16 radical/g, EPFR hi: 5.5e-17 radical/g), characterized, and verified as representative of those found in urban areas. Dry particle aerosolization and whole-body inhalation were established for rodent exposures. To verify that these particles and exposures recapitulate findings relevant to known PM-induced cardiopulmonary effects, male C57BL6 mice were exposed to filtered air, ∼280 μg/m3 EPFR lo or EPFR hi for 4 h/d for 5 consecutive days. Compared to filtered air, pulmonary resistance was increased in mice exposed to EPFR hi. Mice exposed to EPFR hi also exhibited increased plasma endothelin-1 (44.6 vs 30.6 pg/mL) and reduced nitric oxide (137 nM vs 236 nM), suggesting vascular dysfunction. Assessment of vascular response demonstrated an impairment in endothelium-dependent vasorelaxation, with maximum relaxation decreased from 80% to 62% in filtered air vs EPFR hi exposed mice. Gene expression analysis highlighted fold changes in aryl hydrocarbon receptor (AhR) and antioxidant response genes including increases in lung Cyp1a1 (8.7 fold), Cyp1b1 (9 fold), Aldh3a1 (1.7 fold) and Nqo1 (2.4 fold) and Gclc (1.3 fold), and in aortic Cyp1a1 (5.3 fold) in mice exposed to EPFR hi vs filtered air. We then determined that lung AT2 cells were the predominate locus for AhR activation. Together, these data suggest the lung and vasculature as particular targets for the health impacts of EPFRs and demonstrate the importance of additional studies investigating the cardiopulmonary effects of EPFRs.
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Affiliation(s)
- Ankit Aryal
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana, 70803, USA
| | - Alexandra Noël
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana, 70803, USA
| | - Lavrent Khachatryan
- Department of Chemistry, Louisiana State University A&M College, Baton Rouge, Louisiana, 70803, USA
| | - Stephania A Cormier
- Department of Biological Sciences, Louisiana State University A&M College and the Pennington Biomedical Research Institute, Baton Rouge, Louisiana, 70803, USA
| | - Pratiti H Chowdhury
- Department of Biological Sciences, Louisiana State University A&M College and the Pennington Biomedical Research Institute, Baton Rouge, Louisiana, 70803, USA
| | - Arthur Penn
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana, 70803, USA
| | - Tammy R Dugas
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana, 70803, USA
| | - Ashlyn C Harmon
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana, 70803, USA.
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Jia SM, Wang DQ, Liu LY, Zhang ZF, Ma WL. Size-resolved environmentally persistent free radicals in cold region atmosphere: Implications for inhalation exposure risk. JOURNAL OF HAZARDOUS MATERIALS 2023; 443:130263. [PMID: 36332281 DOI: 10.1016/j.jhazmat.2022.130263] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 10/17/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
Environmental persistent free radicals (EPFRs) have attracted more attentions recently due to their potential adverse effects to human. EPFRs in full-size range particles were comprehensively investigated in this study. The average EPFRs concentration during heating season was 3.01 × 1014 spins/m3, which was much higher than that in non-heating season (4.30 × 1013 spins/m3). The highest concentration of EPFRs presented in 0.56-1.0 µm particles during heating season, while it shifted to 5.6-10 µm particles during non-heating season. Besides, the contributions of EPFRs on PM>10 to the total concentration of EPFRs cannot be neglected, especially in the non-heating season. The International Commission on Radiological Protection model and the specific factors of the Chinese population were applied to evaluate the inhalation exposure risk of EPFRs. The results indicated that the exposure levels of EPFRs to the upper respiratory tract were much higher. The daily exposure dose of EPFRs suggested the inhalation exposure risk of 3-4 years old was higher than other age groups. In summary, these finding provided new insights for the full range particle size distribution and the inhalation exposure risk of EPFRs, which improved our understanding on the environmental fate and the health risk of EPFRs in atmosphere.
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Affiliation(s)
- Shi-Ming Jia
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; Heilongjiang Provincial Key Laboratory of Polar Environment and Ecosystem (HPKL-PEE), Harbin 150090, China
| | - De-Qi Wang
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; Heilongjiang Provincial Key Laboratory of Polar Environment and Ecosystem (HPKL-PEE), Harbin 150090, China
| | - Li-Yan Liu
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; Heilongjiang Provincial Key Laboratory of Polar Environment and Ecosystem (HPKL-PEE), Harbin 150090, China
| | - Zi-Feng Zhang
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; Heilongjiang Provincial Key Laboratory of Polar Environment and Ecosystem (HPKL-PEE), Harbin 150090, China
| | - Wan-Li Ma
- International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; Heilongjiang Provincial Key Laboratory of Polar Environment and Ecosystem (HPKL-PEE), Harbin 150090, China.
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4
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Pang L, Huang Z, Yang H, Pang R, Wu M, Jin B. A scalable field study using leaves as a novel passive air sampler to evaluate the potential source of organophosphate esters in street dust. CHEMOSPHERE 2023; 312:137248. [PMID: 36400197 DOI: 10.1016/j.chemosphere.2022.137248] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/07/2022] [Accepted: 11/12/2022] [Indexed: 06/16/2023]
Abstract
Organophosphate esters (OPEs) are widely used as flame retardants and plasticizers in industrial and commercial products. It is generally believed that OPEs in street dust mainly originate from road traffic and anthropogenic activities. The influence of atmospheric deposition is still unknown. In this study, leaves were employed as a novel passive air sampler to collect particle matters (PM) in 12 cities in the central province of Henan, China. Similar compositional profiles of OPEs were found in street dust and PM samples. The concentrations of individual OPEs in PM were 1-4 times higher than in street dust. Chlorinated OPEs concentration in PM shows a moderate correlation (r2 = 0.538, p < 0.01) with that in street dust. The concentration of alkyl OPEs in PM has a high correlation (r2 = 0.843, p < 0.01) with that in street dust. No significant correlation (r2 = 0.133, p = 0.132) was found on the aryl OPEs concentrations between street dust and PM. Spearman correlation reveals that the emission sources of tricresyl phosphate (TCrP) and triethyl phosphate (TEP) may be different from other OPEs in dust and PM samples. Principle component analysis (PCA) provides an appropriate explanation that tris (2-chloroethyl) phosphate (TCEP), triphenyl phosphate (TPhP), tris (chloropropyl) phosphate (TCPP), tributyl phosphate (TnBP), and TEP in street dust and PM may be emitted from the same sources, suggesting that PM has a significant influence on the occurrence of OPEs in street dust. The estimated dry deposition fluxes of particle-bound OPEs show a significant correlation (R2 = 0.969, p < 0.01) with OPEs concentrations in street dust, revealing that the input of atmospheric deposition could be a major source of OPEs in street dust.
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Affiliation(s)
- Long Pang
- Department of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou, 450001, China.
| | - Ziling Huang
- Department of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou, 450001, China
| | - Huiqiang Yang
- Department of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou, 450001, China
| | - Rong Pang
- Department of Medicine, Huanghe Science and Technology College, Zhengzhou, Henan, 450001, China
| | - Mingkai Wu
- Department of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou, 450001, China
| | - Baodan Jin
- Department of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou, 450001, China
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5
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Guo C, Richmond-Bryant J. A critical review of environmentally persistent free radical (EPFR) solvent extraction methodology and retrieval efficiency. CHEMOSPHERE 2021; 284:131353. [PMID: 34225117 PMCID: PMC8487994 DOI: 10.1016/j.chemosphere.2021.131353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 06/14/2021] [Accepted: 06/26/2021] [Indexed: 05/16/2023]
Abstract
Long-lived environmentally persistent free radical (EPFR) exposures have been shown in toxicology studies to lead to respiratory and cardiovascular effects, which were thought to be due to the persistence of EPFR and their ability to produce reactive oxygen species. To characterize EPFR exposure and resulting health impacts, it is necessary to identify and systematize analysis protocols. Both direct measurement and solvent extraction methods have been applied to analyze environmental samples containing EPFR. The use of different protocols and solvents in EPFR analyses makes it difficult to compare results among studies. In this work, we reviewed EPFR studies that involved solvent extraction and carefully reported the details of the extraction methodology and retrieval recovery. EPFR recovery depends on the structure of the radical species and the solvent. For the limited number of studies available for review, the polar solvents had superior recovery in more studies. Radicals appeared to be more oxygen-centered following extraction for fly ash and particulate matter (PM) samples. Different solvent extraction methods to retrieve EPFR may produce molecular products during the extraction, thus potentially changing the sample toxicity. The number of studies reporting detailed methodologies is limited, and data in these studies were not consistently reported. Thus, inference about the solvent and protocol that leads to the highest EPFR extraction efficiency for certain types of radicals is not currently possible. Based on our review, we proposed reporting criteria to be included for future EPFR studies.
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Affiliation(s)
- Chuqi Guo
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, 27695, USA.
| | - Jennifer Richmond-Bryant
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, 27695, USA
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Harmon AC, Noël A, Subramanian B, Perveen Z, Jennings MH, Chen YF, Penn AL, Legendre K, Paulsen DB, Varner KJ, Dugas TR. Inhalation of particulate matter containing free radicals leads to decreased vascular responsiveness associated with an altered pulmonary function. Am J Physiol Heart Circ Physiol 2021; 321:H667-H683. [PMID: 34415187 PMCID: PMC8794232 DOI: 10.1152/ajpheart.00725.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 08/16/2021] [Accepted: 08/16/2021] [Indexed: 12/31/2022]
Abstract
Airborne particulate matter (PM) is associated with an increased risk for cardiovascular diseases. Although the goal of thermal remediation is to eliminate organic wastes through combustion, when incomplete combustion occurs, organics chemisorb to transition metals to generate PM-containing environmentally persistent free radicals (EPFRs). Similar EPFR species have been detected in PM found in diesel and gasoline exhaust, woodsmoke, and urban air. Prior in vivo studies demonstrated that EPFRs reduce cardiac function secondary to elevations in pulmonary arterial pressures. In vitro studies showed that EPFRs increase ROS and cytokines in pulmonary epithelial cells. We thus hypothesized that EPFR inhalation would promote lung inflammation and oxidative stress, leading to systemic inflammation, vascular endothelial injury, and a decline in vascular function. Mice were exposed to EPFRs for either 4 h or for 4 h/day for 10 days and lung and vascular function were assessed. After a 4-h exposure, plasma nitric oxide (NO) was reduced while endothelin-1 (ET-1) was increased, however lung function was not altered. After 10 day, plasma NO and ET-1 levels were again altered and lung tidal volume was reduced. These time course studies suggested the vasculature may be an early target of injury. To test this hypothesis, an intermediate time point of 3 days was selected. Though the mice exhibited no marked inflammation in either the lung or the blood, we did note significantly reduced endothelial function concurrent with a reduction in lung tidal volume and an elevation in annexin V protein levels in the lung. Although vascular dysfunction was not dependent upon inflammation, it may be associated with an injury at the air-blood interface. Gene expression analysis suggested roles for oxidative stress and aryl hydrocarbon receptor (Ahr) signaling. Studies probing the relationship between pulmonary oxidative stress and AhR signaling at the air-blood interface with vascular dysfunction seem warranted.NEW & NOTEWORTHY Particulate matter (PM) resulting from the combustion of organic matter is known to contribute to cardiopulmonary disease. Despite hypotheses that cardiovascular dysfunction occurring after PM exposures is secondary to lung or systemic inflammation, these studies investigating exposures to PM-containing environmentally persistent free radicals (EPFRs) demonstrate that cardiovascular dysfunction precedes pulmonary inflammation. The cardiopulmonary health consequences of EPFRs have yet to be thoroughly evaluated, especially in healthy, adult mice. Our data suggest the vasculature as a direct target of PM exposure, and our studies aimed to elucidate the mechanisms contributing to EPFR-induced vascular dysfunction.
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Affiliation(s)
- Ashlyn C Harmon
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana
| | - Alexandra Noël
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana
| | | | - Zakia Perveen
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana
| | - Merilyn H Jennings
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana
| | - Yi-Fan Chen
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana
| | - Arthur L Penn
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana
| | - Kelsey Legendre
- Department of Pathobiological Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana
| | - Daniel B Paulsen
- Department of Pathobiological Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana
| | - Kurt J Varner
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, Louisiana
| | - Tammy R Dugas
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana
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Guo C, Hasan F, Lay D, Dela Cruz ALN, Ghimire A, Lomnicki SM. Phytosampling-a supplementary tool for particulate matter (PM) speciation characterization. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:39310-39321. [PMID: 33755885 PMCID: PMC8713460 DOI: 10.1007/s11356-021-13292-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
Ambient air particulate matter (PM) and PM-associated environmentally persistent free radicals (EPFRs) have been documented to contribute to pollution-related health effects. Studies of ambient air PM potentially bear artifacts stemming from the collection methods. We have investigated the applicability of PM phytosampling (PHS) as a supplementary tool to a classic PM sampler in respect of achieving better PM chemical composition assessment (primarily organic fraction). Phytosampling is a static PM collection method relying on the particle entrapment by the plant's leaf through electrostatic forces and surface trichomes. We have investigated the differences in the EPFR and polycyclic aromatic hydrocarbon (PAH) speciation and concentration on ambient air PM for PHS and high-volume PM sampler (HVS). The advantages of PHS are easy particle recovery from the matrix, collection under natural environmental conditions, and the ability to apply a dense collection network to accurately represent spatial pollutant distribution. The experimental results show that the PHS can provide valuable speciation information, sometimes different from that observed for HVS. For PM collected by PHS, we detected the larger contribution of oxygen-centered EPFRs, different decay behavior, and more consistent PAH distribution between different PM sizes compared to the PM from HVS. These results indicate that the isolation of samples from the ambient during HVS sampling and exposure to high-volume airflow may alter the chemical composition of the samples, while the PHS method could provide details on the original speciation and concentration and be more representative of the PM surface. However, PHS cannot evaluate an absolute air concentration of PM, so it serves as an excellent supplementary tool to work in conjunction with the standard PM collection method.
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Affiliation(s)
- Chuqi Guo
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Farhana Hasan
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Dean Lay
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Albert Leo N Dela Cruz
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Ajit Ghimire
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Slawo M Lomnicki
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
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Men C, Liu R, Wang Q, Miao Y, Wang Y, Jiao L, Li L, Cao L, Shen Z, Li Y, Crawford-Brown D. Spatial-temporal characteristics, source-specific variation and uncertainty analysis of health risks associated with heavy metals in road dust in Beijing, China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 278:116866. [PMID: 33740604 DOI: 10.1016/j.envpol.2021.116866] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 02/24/2021] [Accepted: 02/27/2021] [Indexed: 06/12/2023]
Abstract
Based on the concentrations of ten heavy metals (As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Zn, Fe) in 144 road dust samples collected from 36 sites across 4 seasons from 2016 to 2017 in Beijing, this study systematically analyzed the levels and main sources of health risks in terms of their temporal and spatial variations. A combination of receptor models (positive matrix factorization and multilinear engine-2), human health risk assessment models, and Monte Carlo simulations were used to apportion the seasonal variation of the health risks associated with these heavy metals. While non-carcinogenic risks were generally acceptable, Cr and Ni induced cautionary carcinogenic risks (CR) to children (confidence levels was approximately 80% and 95%, respectively).. Additionally, fuel combustion posed cautionary CR to children in all seasons, while the level of CR from other sources varied, depending on the seasons. Heavy metal concentrations were the most influential variables for uncertainties, followed by ingestion rate and skin adherence factor. The values and spatial patterns of health risks were influenced by the spatial pattern of risks from each source.
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Affiliation(s)
- Cong Men
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing, 100875, China
| | - Ruimin Liu
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing, 100875, China.
| | - Qingrui Wang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing, 100875, China
| | - Yuexi Miao
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing, 100875, China
| | - Yifan Wang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing, 100875, China
| | - Lijun Jiao
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing, 100875, China
| | - Lin Li
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing, 100875, China
| | - Leiping Cao
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing, 100875, China
| | - Zhenyao Shen
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing, 100875, China
| | - Ying Li
- Department of Environmental Health, College of Public Health, East Tennessee State University, Johnson City, TN, 37614, USA
| | - Douglas Crawford-Brown
- Department of Land Economy, Cambridge Centre for Climate Change Mitigation Research (4CMR), University of Cambridge, Cambridge, CB3 9EP, UK
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9
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Wang C, Huang Y, Zhang Z, Cai Z. Levels, spatial distribution, and source identification of airborne environmentally persistent free radicals from tree leaves. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 257:113353. [PMID: 31662268 DOI: 10.1016/j.envpol.2019.113353] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 10/04/2019] [Accepted: 10/04/2019] [Indexed: 05/16/2023]
Abstract
Environmentally persistent free radicals (EPFRs) are receiving increasing concern due to their toxicity and ubiquity in the environment. To avoid restrictions imposed when using a high-volume active sampler, this study uses tree leaves to act as passive samplers to investigate the spatial distribution characteristics and sources of airborne EPFRs. Tree leaf samples were collected from 120 sites in five areas around China (each approximately 4 km × 4 km). EPFR concentrations in particles (<2 μm) on the surface of 110 leaf samples were detected, ranging from 7.5 × 1016 to 4.5 × 1019 spins/g. For the 10 N.D. samples, they were all collected from areas inaccessible by vehicles. The g-values of EPFRs on 68% leaf samples were larger than 2.004, suggesting the electron localized on the oxygen atom, and they were consistent with the road dust sample (g-value: 2.0042). Significant positive correlation was found between concentrations of elemental carbon (tracer of vehicle emissions) and EPFRs. Spatial distribution mapping showed that EPFR levels in various land uses differed noticeably. Although previous work has linked atmospheric EPFRs to waste incineration, the evidence in this study suggests that vehicle emissions, especially from heavy-duty vehicles, are the main sources. While waste incinerators with low emissions or effective dust-control devices might not be an important EPFR contributor. According to our estimation, over 90% of the EPFRs deposited on tree leaves might be attributed to automotive exhaust emissions, as a synergistic effect of primary exhausts and degradation of aromatic compounds in road dust. With adding the trapping agent into the particle samples (<2 μm), signals of hydroxyl radicals were observed. This indicates that EPFRs collected from this phytosampling method can lead to the release of reactive oxygen species (ROS) once they are inhaled by human beings. Thus, this study helps highlight EPFR "hotspots" for potential health risk identification.
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Affiliation(s)
- Chen Wang
- School of Environmental Science and Engineering and Key Laboratory of Municipal Solid Waste Recycling Technology and Management of Shenzhen City, Southern University of Science and Technology, Shenzhen, 518055, PR China; State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, PR China
| | - Yanpeng Huang
- School of Environmental Science and Engineering and Key Laboratory of Municipal Solid Waste Recycling Technology and Management of Shenzhen City, Southern University of Science and Technology, Shenzhen, 518055, PR China
| | - Zuotai Zhang
- School of Environmental Science and Engineering and Key Laboratory of Municipal Solid Waste Recycling Technology and Management of Shenzhen City, Southern University of Science and Technology, Shenzhen, 518055, PR China.
| | - Zongwei Cai
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, PR China
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Xu M, Wu T, Tang YT, Chen T, Khachatryan L, Iyer PR, Guo D, Chen A, Lyu M, Li J, Liu J, Li D, Zuo Y, Zhang S, Wang Y, Meng Y, Qi F. Environmentally persistent free radicals in PM 2.5: a review. ACTA ACUST UNITED AC 2019; 1:177-197. [PMID: 34308260 DOI: 10.1007/s42768-019-00021-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Environmentally persistent free radicals (EPFRs) are a new class of pollutants that are long-lived in fine particles (PM2.5), i.e., their 1/e lifetime ranges from days to months (or even infinite). They are capable of producing harmful reactive oxygen species such as hydroxyl radicals. The redox cycling of EPFRs is considered as an important pathway for PM2.5 to induce oxidative stress inside the humans, causing adverse health effects such as respiratory and cardiovascular diseases. Consequently, research regarding their toxicity, formation and environmental occurrences in PM2.5 has attracted increasing attentions globally during the past two decades. However, literature data in this field remain quite limited and discrete. Hence, an extensive review is urgently needed to summarize the current understanding of this topic. In this work, we systematically reviewed the analytical methods and environmental occurrences, e.g., types, concentrations, and decay behaviors, as well as possible sources of EPFRs in PM2.5. The types of pretreatment methods, g-values of common EPFRs and categories of decay processes were discussed in detail. Moreover, great efforts were made to revisit the original data of the published works of EPFRs in airborne particulate matter and provided additional useful information for comparison where possible, e.g., their mean and standard deviation of g-values, line widths (ΔH p-p), and concentrations. Finally, possible research opportunities were highlighted to further advance our knowledge of this emerging issue.
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Affiliation(s)
- Mengxia Xu
- Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo 315100, China.,New Materials Institute, University of Nottingham Ningbo China, Ningbo 315100, China
| | - Tao Wu
- Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo 315100, China.,New Materials Institute, University of Nottingham Ningbo China, Ningbo 315100, China
| | - Yu-Ting Tang
- School of Geographical Sciences, University of Nottingham Ningbo China, Ningbo 315100, China
| | - Tong Chen
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China
| | - Lavrent Khachatryan
- Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Poornima Ramesh Iyer
- Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo 315100, China
| | - Dengting Guo
- Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo 315100, China
| | - Anran Chen
- Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo 315100, China
| | - Miao Lyu
- Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo 315100, China
| | - Jinhu Li
- Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo 315100, China
| | - Jiaqi Liu
- Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo 315100, China
| | - Dan Li
- Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo 315100, China
| | - Yuxin Zuo
- Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo 315100, China
| | - Shihan Zhang
- Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo 315100, China
| | - Yiran Wang
- Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo 315100, China
| | - Yining Meng
- Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo 315100, China
| | - Fei Qi
- Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo 315100, China
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11
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Wang Y, Li S, Wang M, Sun H, Mu Z, Zhang L, Li Y, Chen Q. Source apportionment of environmentally persistent free radicals (EPFRs) in PM 2.5 over Xi'an, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 689:193-202. [PMID: 31271986 DOI: 10.1016/j.scitotenv.2019.06.424] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 06/23/2019] [Accepted: 06/25/2019] [Indexed: 06/09/2023]
Abstract
Environmentally persistent free radicals (EPFRs) have recently attracted considerable attention as a new type of environmental risk substance due to their potential health effects. However, the sources and contributions of EPFRs in PM2.5 are not yet clear. Therefore, this study reports the sources of EPFRs in PM2.5 based on chemical analysis and positive matrix factorization (PMF). Daily PM2.5 samples (116) were collected in Xi'an city from April 4 to December 29, 2017, and were quantitatively analyzed for EPFRs and other chemical constituents. The PMF model revealed contributions from five main sources of EPFRs in PM2.5 (dust sources, coal combustion, secondary nitrates, industrial emissions and motor vehicle emissions). Coal combustion, motor vehicle emissions and dust sources are the top three contributors to EPFRs (76.12% in total). Coal combustion is highly important for PM2.5 (35.10%) and EPFRs (16.75%). A high dust source contribution to EPFRs in spring may be due to dust storm events. Motor vehicle emissions are the top contributor to EPFRs, with a mean percentage of 32.13%. Secondary nitrates barely contributes to EPFRs (3.42%), indicating an EPFR origin from primary emissions rather than secondary inorganic reactions. Industrial emissions contribute less to PM2.5 (4.31%) than to EPFRs (11.71%), which implies that fossil fuels contains many high-molecular-weight organics that could emit EPFRs. Integrating the PMF results with meteorological data revealed that atmospheric pollutants emitted in Xi'an city center could be transported to the sampling site by southern winds. These results suggest the need for further studies on the public health effects of EPFRs and can be used to help formulate source control measures to reduce the potential health risks posed by EPFRs in PM2.5.
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Affiliation(s)
- Yuqin Wang
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China; Department of Earth and Atmospheric Sciences, Saint Louis University, St. Louis, MO 63108, USA
| | - Shengping Li
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Mamin Wang
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Haoyao Sun
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Zhen Mu
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Lixin Zhang
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Yanguang Li
- Key Laboratory for the Study of Focused Magmatism and Giant Ore Deposits, MLR, Xi'an 710054, China; Xi'an Center of Geological Survey, China Geological Survey, Xi'an 710054, China
| | - Qingcai Chen
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
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12
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Chen Q, Sun H, Mu Z, Wang Y, Li Y, Zhang L, Wang M, Zhang Z. Characteristics of environmentally persistent free radicals in PM 2.5: Concentrations, species and sources in Xi'an, Northwestern China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 247:18-26. [PMID: 30650344 DOI: 10.1016/j.envpol.2019.01.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 01/03/2019] [Accepted: 01/04/2019] [Indexed: 05/07/2023]
Abstract
Environmentally persistent free radicals (EPFRs) are a new class of environmental risk substances that can stably exist in atmospheric particles and pose a potential threat to human health. In this study, electron paramagnetic resonance (EPR) spectroscopy was used to study the concentration levels, species characteristics, and sources of EPFRs in PM2.5 in Xi'an in 2017. The results showed that the concentrations of EPFRs in PM2.5 in Xi'an in 2017 ranged from 9.8 × 1011 to 6.9 × 1014 spins/m3. The highest concentration of EPFRs occurred in winter when the average concentration was 2.1 × 1014 spins/m3. The lowest concentration of EPFRs occurred in autumn when the average concentration was 7.0 × 1013 spins/m3. According to the annual average atmospheric concentration of EPFRs, the amount of EPFRs inhaled by people in Xi'an is equivalent to approximately 5 cigarettes per person per day and approximately 23 cigarettes per person per day in winter when haze occurs. The results of the study on the EPFR characteristics show that the EPFRs in PM2.5 in Xi'an are mainly C-center organic radicals that are primarily non-decaying types, accounting for approximately 75% and 85% of total concentration of EPFRs in autumn and winter, respectively. Finally, a correlation analysis was used to explore the origins of EPFRs in PM2.5. Significant positive correlations were found between EPFRs and SO2, NO2 and the thermally derived OC3 and OC4 carbonaceous components. The results suggested that coal-fired and traffic may be important sources of EPFRs in PM2.5 in Xi'an. In addition, EPFRs are significantly positively correlated with O3 in summer, suggesting that some EPFRs may also originate from secondary processes. This study provides important basic data and evidence for further assessments of the potential health risks of EPFRs in PM2.5 and the development of effective air pollution control measures.
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Affiliation(s)
- Qingcai Chen
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China.
| | - Haoyao Sun
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China
| | - Zhen Mu
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China
| | - Yuqin Wang
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China
| | - Yanguang Li
- Key Laboratory for the Study of Focused Magmatism and Giant Ore Deposits, MLR, Xi'an, 710054, China; Xi'an Center of Geological Survey, China Geological Survey, Xi'an, 710054, China
| | - Lixin Zhang
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China
| | - Mamin Wang
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China
| | - Zimeng Zhang
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China
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13
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Particulate matter containing environmentally persistent free radicals induces AhR-dependent cytokine and reactive oxygen species production in human bronchial epithelial cells. PLoS One 2018; 13:e0205412. [PMID: 30308017 PMCID: PMC6181347 DOI: 10.1371/journal.pone.0205412] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 09/25/2018] [Indexed: 12/13/2022] Open
Abstract
Particulate matter (PM) is emitted during the combustion of fuels and wastes. PM exposure exacerbates pulmonary diseases, and the mechanism may involve oxidative stress. At lower combustion temperatures such as occurs in the cool zone of a flame, aromatic compounds chemisorb to the surface of metal-oxide-containing PM, resulting in the formation of surface-stabilized environmentally persistent free radicals (EPFR). Prior studies showed that PM-containing EPFR redox cycle to produce reactive oxygen species (ROS), and after inhalation, EPFR induce pulmonary inflammation and oxidative stress. Our objective was to elucidate mechanisms linking EPFR-induced oxidant injury with increased cytokine production by pulmonary epithelial cells. We thus treated human bronchial epithelial cells with EPFR at sub-toxic doses and measured ROS and cytokine production. To assess aryl hydrocarbon receptor (AhR) activity, cells were transfected with a luciferase reporter for xenobiotic response element activation. To test whether cytokine production was dependent upon AhR activation or oxidative stress, some cells were co-treated with an antioxidant or an AhR antagonist. EPFR increased IL-6 release in an ROS and AhR- and oxidant-dependent manner. Moreover, EPFR induced an AhR activation that was dependent upon oxidant production, since antioxidant co-treatment blocked AhR activation. On the other hand, EPFR treatment increased a cellular ROS production that was at least partially attenuated by AhR knockdown using siRNA. While AhR activation was correlated with an increased expression of oxidant-producing enzymes like cytochrome P450 CYP1A1, it is possible that AhR activation is both a cause and effect of EPFR-induced ROS. Finally, lipid oxidation products also induced AhR activation. ROS-dependent AhR activation may be a mechanism for altered epithelial cell responses after EPFR exposure, potentially via formation of bioactive lipid or protein oxidation products.
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14
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Chen Q, Sun H, Wang M, Mu Z, Wang Y, Li Y, Wang Y, Zhang L, Zhang Z. Dominant Fraction of EPFRs from Nonsolvent-Extractable Organic Matter in Fine Particulates over Xi'an, China. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:9646-9655. [PMID: 30071162 DOI: 10.1021/acs.est.8b01980] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
To understand the nature and possible sources of environmentally persistent free radicals (EPFRs) in atmospheric aerosols, the present study used a solvent extraction method to fractionate aerosol components with different polarities and solvent resistance in fine particulate matter (PM2.5) from Xi'an, China. The characteristics of EPFRs, that is., their concentration, type and lifetime, were obtained based on their electron paramagnetic resonance spectra. The results showed that the EPFRs in the PM2.5 samples were carbon-centered with a nearby heteroatom ( g = 2.0031) and had a long half-life of more than 3 years. Nearly all of the extractable EPFRs were detected in the water-insoluble organic fraction and showed characteristics indicating that may contain oxygen-centered radical ( g = 2.0038). Most of the total EPFRs in the PM2.5 were derived from solvent-resistant organic matter (88%), which likely consisted of graphene oxide analogues. The results suggest that previous studies may have missed the major proportion of EPFRs in atmospheric particulates if they only focused on solvent-extractable or metallic oxide-formed EPFRs. Our results showed that the EPFR concentration was significantly and positively correlated with the elemental carbon and NO2 concentrations, suggesting that traffic emissions may be an important source of EPFRs in PM2.5 over Xi'an.
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Affiliation(s)
- Qingcai Chen
- School of Environmental Science and Engineering , Shaanxi University of Science and Technology , Xi'an 710021 , China
- Graduate School of Environmental Studies , Nagoya University , Nagoya 464-8601 , Japan
| | - Haoyao Sun
- School of Environmental Science and Engineering , Shaanxi University of Science and Technology , Xi'an 710021 , China
| | - Mamin Wang
- School of Environmental Science and Engineering , Shaanxi University of Science and Technology , Xi'an 710021 , China
| | - Zhen Mu
- School of Environmental Science and Engineering , Shaanxi University of Science and Technology , Xi'an 710021 , China
| | - Yuqin Wang
- School of Environmental Science and Engineering , Shaanxi University of Science and Technology , Xi'an 710021 , China
- Department of Earth and Atmospheric Sciences , Saint Louis University , St. Louis , Missouri 63108 , United States
| | - Yanguang Li
- Key Laboratory for the Study of Focused Magmatism and Giant Ore Deposits , MLR , Xi'an 710054 , China
- Xi'an Center of Geological Survey , China Geological Survey , Xi'an 710054 , China
| | - Yansong Wang
- College of Chemistry and Chemical Engineering , Shaanxi University of Science and Technology , Xi'an 710021 , China
| | - Lixin Zhang
- School of Environmental Science and Engineering , Shaanxi University of Science and Technology , Xi'an 710021 , China
| | - Zimeng Zhang
- School of Environmental Science and Engineering , Shaanxi University of Science and Technology , Xi'an 710021 , China
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