scholarly journals Predominance of Secondary Organic Aerosol to Particle-bound Reactive Oxygen Species Activity in Fine Ambient Aerosol

2019 ◽  
Author(s):  
Jun Zhou ◽  
Miriam Elser ◽  
Ru-Jin Huang ◽  
Manuel Krapf ◽  
Roman Fröhlich ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Health Effects ◽  
Secondary Organic Aerosol ◽  
Reactive Oxygen ◽  
Organic Aerosol ◽  
Epidemiological Studies ◽  
Anthropogenic Sources ◽  
Emission Sources ◽  
Oxygen Species ◽  
Concentration Variance

Abstract. Reactive oxygen species (ROS) are believed to contribute to the adverse health effects of aerosols. This may happen by inhaled particle-bound (exogenic) ROS (PB-ROS) or by ROS formed within the respiratory tract by certain aerosol components (endogenic ROS). We investigated the chemical composition of aerosols and their exogenic ROS content at the two contrasting locations Beijing (China) and Bern (Switzerland). We apportioned the ambient organic aerosol to different sources and attributed the observed PB-ROS to them. The oxygenated organic aerosol (OOA, a proxy for secondary organic aerosol, SOA) explained the highest fraction of the exogenic ROS concentration variance at both locations. We also characterized primary and secondary aerosol emissions generated from different biogenic and anthropogenic sources in smog chamber experiments. The exogenic PB-ROS content in the OOA from these emission sources was comparable to that in the ambient measurements. Our results imply that SOA from gaseous precursors of different anthropogenic emission sources is a crucial source of PB-ROS and should be additionally considered in toxicological and epidemiological studies in an adequate way besides primary emissions. The importance of PB-ROS may be connected to the seasonal trends in health effects of PM reported by epidemiological studies, with elevated incidences of adverse effects in warmer seasons, which are accompanied by more intense atmospheric oxidation processes.

scholarly journals Predominance of secondary organic aerosol to particle-bound reactive oxygen species activity in fine ambient aerosol

2019 ◽  
Vol 19 (23) ◽  
pp. 14703-14720 ◽  
Author(s):  
Jun Zhou ◽  
Miriam Elser ◽  
Ru-Jin Huang ◽  
Manuel Krapf ◽  
Roman Fröhlich ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Health Effects ◽  
Secondary Organic Aerosol ◽  
Reactive Oxygen ◽  
Organic Aerosol ◽  
Epidemiological Studies ◽  
Water Soluble ◽  
Anthropogenic Sources ◽  
Emission Sources ◽  
Oxygen Species

Abstract. Reactive oxygen species (ROS) are believed to contribute to the adverse health effects of aerosols. This may happen by inhaled particle-bound (exogenic) ROS (PB-ROS) or by ROS formed within the respiratory tract by certain aerosol components (endogenic ROS). We investigated the chemical composition of aerosols and their exogenic ROS content at the two contrasting locations Beijing (China) and Bern (Switzerland). We apportioned the ambient organic aerosol to different sources and attributed the observed water-soluble PB-ROS to them. The oxygenated organic aerosol (OOA, a proxy for secondary organic aerosol, SOA) explained the highest fraction of the exogenic ROS concentration variance at both locations. We also characterized primary and secondary aerosol emissions generated from different biogenic and anthropogenic sources in smog chamber experiments. The exogenic PB-ROS content in the OOA from these emission sources was comparable to that in the ambient measurements. Our results imply that SOA from gaseous precursors of different anthropogenic emission sources is a crucial source of water-soluble PB-ROS and should be additionally considered in toxicological and epidemiological studies in an adequate way besides primary emissions. The importance of PB-ROS may be connected to the seasonal trends in health effects of PM reported by epidemiological studies, with elevated incidences of adverse effects in warmer seasons, which are accompanied by more-intense atmospheric oxidation processes.

scholarly journals Particle-bound reactive oxygen species (PB-ROS) emissions and formation pathways in residential wood smoke under different combustion and aging conditions

2018 ◽  
Vol 18 (10) ◽  
pp. 6985-7000 ◽  
Author(s):  
Jun Zhou ◽  
Peter Zotter ◽  
Emily A. Bruns ◽  
Giulia Stefenelli ◽  
Deepika Bhattu ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Regression Model ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Oxygen Species ◽  
Wood Combustion ◽  
Aerosol Mass ◽  
Combustion Emissions ◽  
Aging Conditions ◽  
Combustion Regimes

Abstract. Wood combustion emissions can induce oxidative stress in the human respiratory tract by reactive oxygen species (ROS) in the aerosol particles, which are emitted either directly or formed through oxidation in the atmosphere. To improve our understanding of the particle-bound ROS (PB-ROS) generation potential of wood combustion emissions, a suite of smog chamber (SC) and potential aerosol mass (PAM) chamber experiments were conducted under well-determined conditions for different combustion devices and technologies, different fuel types, operation methods, combustion regimes, combustion phases, and aging conditions. The PB-ROS content and the chemical properties of the aerosols were quantified by a novel ROS analyzer using the DCFH (2′,7′-dichlorofluorescin) assay and a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). For all eight combustion devices tested, primary PB-ROS concentrations substantially increased upon aging. The level of primary and aged PB-ROS emission factors (EFROS) were dominated by the combustion device (within different combustion technologies) and to a greater extent by the combustion regimes: the variability within one device was much higher than the variability of EFROS from different devices. Aged EFROS under bad combustion conditions were ∼ 2–80 times higher than under optimum combustion conditions. EFROS from automatically operated combustion devices were on average 1 order of magnitude lower than those from manually operated devices, which indicates that automatic combustion devices operated at optimum conditions to achieve near-complete combustion should be employed to minimize PB-ROS emissions. The use of an electrostatic precipitator decreased the primary and aged ROS emissions by a factor of ∼ 1.5 which is however still within the burn-to-burn variability. The parameters controlling the PB-ROS formation in secondary organic aerosol were investigated by employing a regression model, including the fractions of the mass-to-charge ratios m∕z 44 and 43 in secondary organic aerosol (SOA; f44−SOA and f43−SOA), the OH exposure, and the total organic aerosol mass. The regression model results of the SC and PAM chamber aging experiments indicate that the PB-ROS content in SOA seems to increase with the SOA oxidation state, which initially increases with OH exposure and decreases with the additional partitioning of semi-volatile components with lower PB-ROS content at higher OA concentrations, while further aging seems to result in a decay of PB-ROS. The results and the special data analysis methods deployed in this study could provide a model for PB-ROS analysis of further wood or other combustion studies investigating different combustion conditions and aging methods.

scholarly journals Pleiotropic Effects of Biguanides on Mitochondrial Reactive Oxygen Species Production

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Alena Pecinova ◽  
Zdenek Drahota ◽  
Jana Kovalcikova ◽  
Nikola Kovarova ◽  
Petr Pecina ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Respiratory Chain ◽  
Reactive Oxygen Species Production ◽  
Reactive Oxygen ◽  
Epidemiological Studies ◽  
The Body ◽  
Oxygen Species ◽  
Brown Adipose ◽  
First Choice ◽  
Species Production

Metformin is widely prescribed as a first-choice antihyperglycemic drug for treatment of type 2 diabetes mellitus, and recent epidemiological studies showed its utility also in cancer therapy. Although it is in use since the 1970s, its molecular target, either for antihyperglycemic or antineoplastic action, remains elusive. However, the body of the research on metformin effect oscillates around mitochondrial metabolism, including the function of oxidative phosphorylation (OXPHOS) apparatus. In this study, we focused on direct inhibitory mechanism of biguanides (metformin and phenformin) on OXPHOS complexes and its functional impact, using the model of isolated brown adipose tissue mitochondria. We demonstrate that biguanides nonspecifically target the activities of all respiratory chain dehydrogenases (mitochondrial NADH, succinate, and glycerophosphate dehydrogenases), but only at very high concentrations (10−2–10−1 M) that highly exceed cellular concentrations observed during the treatment. In addition, these concentrations of biguanides also trigger burst of reactive oxygen species production which, in combination with pleiotropic OXPHOS inhibition, can be toxic for the organism. We conclude that the beneficial effect of biguanides should probably be associated with subtler mechanism, different from the generalized inhibition of the respiratory chain.

scholarly journals Application of a Fluorescent Probe for the Online Measurement of PM-Bound Reactive Oxygen Species in Chamber and Ambient Studies

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4564 ◽  
Author(s):  
Reece Brown ◽  
Svetlana Stevanovic ◽  
Zachary Brown ◽  
Mingfu Cai ◽  
Shengzhen Zhou ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cigarette Smoke ◽  
High Efficiency ◽  
Reactive Oxygen ◽  
Organic Aerosol ◽  
Oxygen Species ◽  
Side Stream ◽  
Chamber Study ◽  
Phase Corrections ◽  
Flow Through

This manuscript details the application of a profluorescent nitroxide (PFN) for the online quantification of radical concentrations on particulate matter (PM) using an improved Particle Into Nitroxide Quencher (PINQ). A miniature flow-through fluorimeter developed specifically for use with the 9,10-bis(phenylethynyl)anthracene-nitroxide (BPEAnit) probe was integrated into the PINQ, along with automated gas phase corrections through periodic high efficiency particle arrestor (HEPA) filtering. The resulting instrument is capable of unattended sampling and was operated with a minimum time resolution of 2.5 min. Details of the fluorimeter design and examples of data processing are provided, and results from a chamber study of side-stream cigarette smoke and ambient monitoring campaign in Guangzhou, China are presented. Primary cigarette smoke was shown to have both short-lived (t1/2 = 27 min) and long-lived (t1/2 = indefinite) PM-bound reactive oxygen species (ROS) components which had previously only been observed in secondary organic aerosol (SOA).

scholarly journals Comparative Reactive Oxygen Species (ROS) Content among Various Flavored Disposable Vape Bars, including Cool (Iced) Flavored Bars

Toxics ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 235
Author(s):  
Shaiesh Yogeswaran ◽  
Thivanka Muthumalage ◽  
Irfan Rahman
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Health Effects ◽  
Reactive Oxygen ◽  
Ros Production ◽  
Oxygen Species ◽  
Aerosol Generator ◽  
Pulmonary Cells ◽  
Single Puff ◽  
Insight Into

Studies have shown that aerosols generated from flavored e-cigarettes contain Reactive Oxygen Species (ROS), promoting oxidative stress-induced damage within pulmonary cells. Our lab investigated the ROS content of e-cigarette vapor generated from disposable flavored e-cigarettes (vape bars) with and without nicotine. Specifically, we analyzed vape bars belonging to multiple flavor categories (Tobacco, Minty Fruit, Fruity, Minty/Cool (Iced), Desserts, and Drinks/Beverages) manufactured by various vendors and of different nicotine concentrations (0–6.8%). Aerosols from these vape bars were generated via a single puff aerosol generator; these aerosols were then individually bubbled through a fluorogenic solution to semi-quantify ROS generated by these bars in H2O2 equivalents. We compared the ROS levels generated by each vape bar as an indirect determinant of their potential to induce oxidative stress. Our results showed that ROS concentration (μM) within aerosols produced from these vape bars varied significantly among different flavored vape bars and identically flavored vape bars with varying nicotine concentrations. Furthermore, our results suggest that flavoring chemicals and nicotine play a differential role in generating ROS production in vape bar aerosols. Our study provides insight into the differential health effects of flavored vape bars, in particular cool (iced) flavors, and the need for their regulation.

scholarly journals Reactive oxygen species associated with water-soluble PM2.5 in the southeastern United States: spatiotemporal trends and source apportionment

2014 ◽  
Vol 14 (13) ◽  
pp. 19625-19672 ◽  
Author(s):  
V. Verma ◽  
T. Fang ◽  
H. Guo ◽  
L. King ◽  
J. T. Bates ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Particulate Matter ◽  
Source Apportionment ◽  
Biomass Burning ◽  
Reactive Oxygen ◽  
Water Soluble ◽  
Ros Generation ◽  
Emission Sources ◽  
Vehicular Emissions ◽  
Oxygen Species

Abstract. We assess the potential of the water-soluble fraction of atmospheric fine aerosols in the southeastern US to generate reactive oxygen species (ROS) and identify major ROS-associated emission sources. ROS-generation potential of particles was quantified by the dithiothreitol (DTT) assay and involved analysis of fine particulate matter (PM) extracted from high-volume quartz filters (23 h integrated samples) collected at various sites in different environmental settings in the southeast, including three urban Atlanta sites, in addition to a rural site. Paired sampling was conducted with one fixed site in Atlanta (Jefferson Street), representative of the urban environment, with the others rotating among different sites, for ~250 days between June 2012 and September 2013 (N = 483). A simple linear regression between the DTT activity and aerosol chemical components revealed strong associations between PM ROS generation potential and secondary organic aerosol (WSOC) in summer, and biomass burning markers in winter. Redox-active metals were also correlated with the DTT activity, but mostly at urban and roadside sites. Positive matrix factorization (PMF) was applied to apportion the relative contribution of various sources to the ROS generation potential of water-soluble PM2.5 in urban Atlanta. PMF showed that vehicular emissions contribute uniformly throughout the year (12 to 25%), while secondary oxidation processes dominated the DTT activity in summer (46%) and biomass burning in winter (47%). Mineral dust was significant only during drier periods (~12% in summer and fall). Source apportionment by chemical mass balance (CMB) was reasonably consistent with PMF, but with higher contribution from vehicular emissions (32%). Given the spatially large data set of PM sampled over an extended period, the study reconciles the results from previous work that showed only region- or season-specific aerosol components or sources contributing to PM ROS activity, possibly due to smaller sample sizes. Our results indicate that the ability to generate ROS is a generic property of fine PM to which almost all major emission sources contribute to variable extents. The ubiquitous nature of the ROS generation property of ambient particulate matter suggests widespread population exposures to aerosol components that have the ability to catalyze the production of oxidants in vivo.

Role of reactive oxygen species and antioxidants in periodontal disease

2021 ◽  
pp. 1-16
Author(s):  
Harish M. Saluja ◽  
Shivani Sachdeva ◽  
Amit Mani
Keyword(s):  
Reactive Oxygen Species ◽  
Periodontal Disease ◽  
Bacterial Species ◽  
Reactive Oxygen ◽  
Epidemiological Studies ◽  
Oxygen Species ◽  
Tissue Destruction ◽  
Tnf Α ◽  
Harmful Effects

Recent epidemiological studies reveal that more than two-third of the world’s population suffers from one of the chronic forms of periodontal disease. The primary etiological agent of this inflammatory disease is a polymicrobial complex, predominantly Gram negative anaerobic or facultative bacteria within the sub-gingival biofilm. These bacterial species initiate the production of various cytokines such as interleukin-8 and TNF-α, further causing an increase in number and activity of polymorphonucleocytes (PMN) along with these cytokines, PMNs also produce reactive oxygen species (ROS) superoxide via the respiratory burst mechanism as the part of the defence response to infection. ROS just like the interleukins have deleterious effects on tissue cells when produced in excess. To counter the harmful effects of ROS, human body has its own defence mechanisms to eliminate them as soon as they are formed. The aim of this review is to focus on the role of different free radicals, ROS, and antioxidants in the pathophysiology of periodontal tissue destruction.

scholarly journals Reactive oxygen species (ROS) emissions and formation pathways in residential wood smoke under different combustion and aging conditions

2017 ◽  
Author(s):  
Jun Zhou ◽  
Peter Zotter ◽  
Emily A. Bruns ◽  
Giulia Stefenelli ◽  
Deepika Bhattu ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Regression Model ◽  
Reactive Oxygen ◽  
Organic Aerosol ◽  
Oxygen Species ◽  
Wood Combustion ◽  
Aerosol Mass ◽  
Combustion Emissions ◽  
Aging Conditions ◽  
Combustion Regimes

Abstract. Wood combustion emissions can induce oxidative stress in the human respiratory tract caused by reactive oxygen species (ROS), either directly or after oxidation in the atmosphere. To improve our understanding of the ROS generation potential of wood combustion emissions, a suite of smog chamber (SC) and potential aerosol mass (PAM) chamber experiments were conducted under well determined conditions for different combustion devices and technologies, different fuel types, operation methods, combustion regimes, combustion phases and aging conditions. The ROS content as well as the chemical properties of the aerosols were quantified by a novel ROS analyzer and a high resolution time of flight aerosol mass spectrometer (HR-ToF-AMS). For all eight tested combustion devices, primary ROS concentrations substantially increased upon aging. The level of primary and aged ROS emission factors (EFROS) were dominated by the combustion device (within different combustion technologies) and to a greater extent by the combustion regimes: the variability within one device was much higher than the variability of EFROS from different devices. Aged EFROS under bad combustion conditions were ~ 2–80 times higher than under optimum combustion conditions. EFROS from automatically operated combustion devices were on average one order of magnitude lower than those from manually operated appliances, which indicates that automatic combustion devices operated at optimum conditions to achieve near-complete combustion should be employed to minimize ROS emissions. The parameters controlling the ROS formation in secondary organic aerosol were investigated by employing a regression model, including the fractions of the mass spectrometric signatures m/z 44 and 43 in SOA (f44-SOA and f43-SOA), the OH exposure, and the total organic aerosol mass. The regression model results of the SC and PAM chamber aging experiments indicate that the ROS content in SOA seems to increase with the SOA oxidation state, which initially increases with OH exposure and decreases with the additional partitioning of semi-volatile components with lower ROS content at higher OA concentrations, while further aging seems to result in a decay of ROS. The results and the special data analysis methods deployed in this study could provide a role model for ROS analysis of further wood or any other combustion studies investigating different combustion conditions and aging methods.

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