Identification of species and sources of atmospheric chromophores by fluorescence excitation-emission matrix with parallel factor analysis

The Science of The Total Environment, Год журнала: 2020, Номер 718, С. 137322 - 137322

Опубликована: Фев. 14, 2020

Язык: Английский

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Enhanced cytotoxicity of photoaged phenol-formaldehyde resins microplastics: Combined effects of environmentally persistent free radicals, reactive oxygen species, and conjugated carbonyls

Environment International, Год журнала: 2020, Номер 145, С. 106137 - 106137

Опубликована: Сен. 19, 2020

Phenol-formaldehyde resin microplastic (PF-MP) is one of the major inhalable microplastics in environments released from manufacture, processing and usage PF materials. The associated toxicities PF-MP might be affected by photoaging. In this study, dynamic evolutions oxidative potential (OP) redox-active species, including environmentally persistent free radicals (EPFRs), reactive oxygen species (ROS), peroxides conjugated carbonyls, as well cytotoxicity were systematically investigated a result simulated sunlight irradiation. As photoaging time extended, OP increased. contents produced ROS PF-bound EPFRs due to light irradiation increased well, displayed significant correlations with (Spearman r > 0.6, p < 0.05). photoaged distinctly cellular reduced cell viability human lung epithelial adenocarcinoma cells (A549). showed similar trend level PF-MP, suggesting that active induced vitro toxicities. results not only highlight adverse health effects but also provide new perspectives for environmental risks airborne MPs.

Язык: Английский

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Study on the oxidation potential of the water-soluble components of ambient PM2.5 over Xi’an, China: Pollution levels, source apportionment and transport pathways

Environment International, Год журнала: 2020, Номер 136, С. 105515 - 105515

Опубликована: Янв. 29, 2020

Reactive oxygen species (ROS) are a class of substances that general concern in terms human health and used to represent the oxidation potential (OP) atmosphere. In this study, ROS levels 116 daily fine particulate matter (PM2.5) samples taken over Xi'an 2017 were measured with dithiothreitol (DTT) method. The sources DTTv (volume-based DTT consumption) PM2.5 as well their contributions identified by both positive matrix factorization (PMF) multiple linear regression (MLR) based on chemical (PM). results showed yearly average was 0.53 nmol/min/m3 (0.19-1.10 nmol/min/m3). highest level occurred winter, followed spring, summer autumn. most strongly correlated water-soluble organic carbon (WSOC; r = 0.85), but effects WSOC very limited. SO2, NO2, CO, elemental (EC) K+ (r > 0.64) had moderate correlations moderately related environmentally persistent free radicals (EPFRs) 0.56). mixed-effects model pollutants originating from incomplete combustion greater than those complete combustion. Source apportionment PMF motor vehicle emissions (27.4%), secondary sulfates (21.6%) coal (18.8%) more important contributors dust (8.4%), metal processing (4.9%), industrial (11.3%) nitrates (7.5%). for consistent MLR results, which verified feasible methods source specific such EPFRs. Backward trajectory clusters dominant cluster groups local regional transport, while OP affected long-range transport transport. As stated above, improvement atmospheric require not only efforts also large-scale joint cooperation. Furthermore, study PM information provides guidance effect research.

Язык: Английский

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Light-absorbing and fluorescent properties of atmospheric brown carbon: A case study in Nanjing, China

Chemosphere, Год журнала: 2020, Номер 251, С. 126350 - 126350

Опубликована: Фев. 29, 2020

Язык: Английский

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Characterization and comparison of PM_2.5 oxidative potential assessed by two acellular assays

Atmospheric chemistry and physics, Год журнала: 2020, Номер 20(9), С. 5197 - 5210

Опубликована: Май 4, 2020

Abstract. The capability of ambient particles to generate in vivo reactive oxygen species (ROS), called oxidative potential (OP), is a metric for evaluating the health effects particulate matter (PM) and supported by several recent epidemiological investigations. Studies using various types OP assays differ their sensitivities varying PM chemical components. In this study, we systematically compared two health-relevant acellular that track depletion antioxidants or reductant surrogates: (i) synthetic respiratory-tract lining fluid (RTLF) assay tracks ascorbic acid (AA) glutathione (GSH) (ii) dithiothreitol (DTT) DTT. Yearlong daily samples were collected at an urban site Atlanta, GA (Jefferson Street), during 2017, both DTT RTLF performed measure water-soluble PM2.5 mass major components, including metals, ions, organic elemental carbon also analyzed. Correlation analysis found as measured AA (OPDTT OPAA, respectively) correlated with organics some metal species, whereas from GSH (OPGSH) was exclusively sensitive Cu. These moderately each other due common contribution ions. OPDTT OPAA Pearson's r=0.55 0.56, respectively, OPGSH exhibited lower correlation (r=0.24). There little seasonal variation levels all weak seasonality OP-associated species. Multivariate linear regression models developed predict measures particle composition data. Variability not only attributed concentrations ions (mainly Fe Cu) compounds but antagonistic metal–organic metal–metal interactions. change Cu brown (BrC), proxy humic-like substances.

Язык: Английский

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The evolutionary behavior of chromophoric brown carbon during ozone aging of fine particles from biomass burning

Atmospheric chemistry and physics, Год журнала: 2020, Номер 20(8), С. 4593 - 4605

Опубликована: Апрель 21, 2020

Abstract. Biomass burning (BB) emits large amounts of brown carbon (BrC); however, the evolutionary behavior BrC in BB emissions (BB BrC) resulting from complex atmospheric processes is poorly understood. In this study, transformation contents and chromophoric characteristics smoke particles emitted by rice straw (RS), corn (CS), pinewood (PW) under O3 aging are investigated. The induced reduction light absorption fluorescence for BrC, suggesting decomposition chromophores fluorophores. These changes were accompanied a decrease aromaticity, average molecular weight, capacity chromophores, as well an increase humification excitation emission matrix combined with parallel factor analysis revealed that protein-like components (C3) predominantly decomposed aging, while relative distribution humic-like component highly oxygenated (C4) gradually increased. general, substances (C1 + C2 C4) transformed to be most abundant fluorophores all samples, which accounted 84 %–87 % total final O3-aged BrC. Two-dimensional correlation spectroscopy (2D-COS) was performed on synchronous fluorescence, suggested RS CS exhibits same susceptible upon aging. It showed firstly reacted fractions (263–289 nm) then fulvic-like (333–340 nm). comparison, changing sequence PW order shorter wavelengths (309 nm), (276 longer (358 2D-FTIR-COS (2D-COS FTIR) conjugated C=O aromatic C=C groups functional Moreover, it also consistent sequential change, OH; C=O; COO−; finally lignin-derived C–C, C–H, C–O groups. Our results provide new insights into fluorescent properties during great significance better understanding heterogeneous oxidation pathways BB-derived environment.

Язык: Английский

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Airborne Aerosols and Human Health: Leapfrogging from Mass Concentration to Oxidative Potential

Atmosphere, Год журнала: 2020, Номер 11(9), С. 917 - 917

Опубликована: Авг. 28, 2020

The mass concentration of atmospheric particulate matter (PM) has been systematically used in epidemiological studies as an indicator exposure to air pollutants, connecting PM concentrations with a wide variety human health effects. However, these effects can be hardly explained by using one single parameter, especially because is formed complex mixture chemicals. Current research shown that many adverse derived from the oxidative stress caused deposition lungs. potential (OP) PM, related presence transition metals and organic compounds induce production reactive oxygen nitrogen species (ROS/RNS), could parameter evaluate Therefore, estimating OP would allow us integrate toxic into unique which emission sources, size distribution and/or chemical composition. association between particle-induced toxicity still largely unknown. In this commentary article, we analyze how new paradigm help deal some unanswered questions impact over health.

Язык: Английский

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p-Phenylenediamine-Derived Quinones as New Contributors to the Oxidative Potential of Fine Particulate Matter

Environmental Science & Technology Letters, Год журнала: 2022, Номер 9(9), С. 712 - 717

Опубликована: Авг. 10, 2022

Atmospheric fine particulate matter (PM2.5) has been linked to multiple adverse outcomes, where redox-active species-induced oxidative stress is recognized as an important driver of its biotoxicity. Previous studies have proven that the potential (OP) a relevant metric for specific acute PM2.5 health effects and associated with various toxicants, especially organic quinones. However, discrepancies between OP induced by known components total levels caused remain. Here, we investigated values suite emerging contaminants, five p-phenylenediamine-derived quinones (PPD-quinones), in using acellular dithiothreitol (DTT) assay evaluated their contributions PM2.5-induced megacities China. N-(1,3-Dimethylbutyl)-N′-phenyl-p-phenylenediamine-quinone (6PPD-Q), highly toxic quinone responsible "urban runoff mortality syndrome", was found exhibit moderate DTT consumption rate 1.70 μM min–1 μM–1. Meanwhile, it noteworthy estimated contribution PPD-quinones 2.9 ± 2.7% OP. This first study reveals considerable urban PM2.5. The data improve our understanding toxicity both PPD-quinones, which illuminating further assessment environmental risk they pose.

Язык: Английский

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Chemical composition, optical properties, and oxidative potential of water- and methanol-soluble organic compounds emitted from the combustion of biomass materials and coal

Atmospheric chemistry and physics, Год журнала: 2021, Номер 21(17), С. 13187 - 13205

Опубликована: Сен. 6, 2021

Abstract. Biomass burning (BB) and coal combustion (CC) are important sources of brown carbon (BrC) in ambient aerosols. In this study, six biomass materials five types were combusted to generate fine smoke particles. The BrC fractions, including water-soluble organic (WSOC), humic-like substance (HULIS-C), methanol-soluble (MSOC), subsequently fractionated, their optical properties chemical structures then comprehensively investigated using UV–visible spectroscopy, proton nuclear magnetic resonance spectroscopy (1H NMR), fluorescence excitation–emission matrix (EEM) combined with parallel factor (PARAFAC) analysis. addition, the oxidative potential (OP) BB CC was measured dithiothreitol (DTT) method. results showed that WSOC, HULIS-C, MSOC accounted for 2.3 %–22 %, 0.5 %–10 6.4 %–73 % total mass combustion-derived PM2.5, respectively, extracting highest concentrations compounds. fractions had light absorption capacity (mass efficiency at 365 nm (MAE365): 1.0–2.7 m2/gC) both smoke, indicating contained more strong light-absorbing components. Therefore, may represent better than fractions. Some significant differences observed between emitted from higher MAE365 lower Ångström exponent values detected CC. EEM-PARAFAC identified four fluorophores: two protein-like, one humic-like, polyphenol-like fluorophores. protein-like substances dominant components WSOC (47 %–80 %), HULIS-C (44 %–87 (42 %–70 %). 1H-NMR suggested oxygenated aliphatic functional groups (H-C-O), whereas unsaturated (H-C-C= Ar−H). DTT assays indicated generally a stronger (DTTm, 2.6–85 pmol/min/µg) 0.4–11 pmol/min/µg), having OP HULIS-C. contributed half activity (63.1 ± 15.5 highlighting HULIS major contributor reactive oxygen species (ROS) production WSOC. Furthermore, principal component analysis Pearson correlation coefficients highly fluorophore C4 be active BrC.

Язык: Английский

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Pollution characteristics of environmental persistent free radicals (EPFRs) and their contribution to oxidation potential in road dust in a large city in northwest China

Journal of Hazardous Materials, Год журнала: 2022, Номер 442, С. 130087 - 130087

Опубликована: Сен. 29, 2022

Язык: Английский

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