The number fraction of iron-containing particles affects OH, HO<sub>2</sub> and H<sub>2</sub>O<sub>2</sub> budgets in the atmospheric aqueous phase DOI Creative Commons

Amina Khaled,

Minghui Zhang, Barbara Ervens

et al.

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(3), P. 1989 - 2009

Published: Feb. 11, 2022

Abstract. Reactive oxygen species (ROS), such as OH, HO2 and H2O2, affect the oxidation capacity of atmosphere cause adverse health effects particulate matter. The role transition metal ions (TMIs) in impacting ROS concentrations conversions atmospheric aqueous phase has been recognized for a long time. Model studies usually assume that total TMI mass measured bulk aerosol or cloud water samples is distributed equally across all particles droplets. This assumption contrary to single-particle measurements have shown only small number fraction contain iron other TMIs (FN,Fe<100 %), which implies also not droplets TMIs. In current study, we apply box model with an explicit multiphase chemical mechanism simulate formation cycling simulations are performed range 1 % ≤ FN,Fe 100 constant pH values 3, 4.5 6 concentration (10 50 ng per cubic meter air). results compared two sets FN,Fe<100 (FeN<100) (FeBulk). We find largest differences between OH / O2- at = 6. Under these conditions, subsaturated because its high effective Henry's law fast loss reactions radical anion. As main reduction process Fe(III) reaction O2-, show subsaturation leads Fe(II) Fe(total) ratios lower by factor 2 approaches. trend largely independent concentration, both source sink rates scale concentration. compare model-derived reactive uptake parameters γOH γHO2 full FN,Fe. While affected distribution, calculated from 0.0004 0.03 %, respectively. Implications findings discussed application lab-derived models present on aerosols. conclude distribution (FN,Fe) should be taken into account estimate potential matter might overestimated sampling Our study suggests iron-containing may more important than determining budgets water.

Language: Английский

Plastic Burning Particulate Matter as a Source of Environmentally Persistent Free Radicals and Reactive Oxygen and Chlorine Species DOI
Rizana Salim, Sukriti Kapur, Meredith Schervish

et al.

Published: Feb. 26, 2025

Abstract Burning plastic waste releases massive amounts of atmospheric particulate matter (PM), but its chemical composition and health-related properties are largely unelucidated. Here we characterize PM generated from burning common types plastics quantify reactive oxygen/chlorine species oxidative potential (OP). We find that contains high levels environmentally persistent free radicals (EPFRs), transition metals, polycyclic aromatic hydrocarbons. In the aqueous phase, generates hydrogen peroxide, •OH radicals, carbon-centered organic exhibiting OP as characterized by DTT OH assays. Remarkably, is associated with concentrations hypochlorous acid. Kinetic model simulations demonstrate respiratory deposition leads to formation via complex redox reactions among constituents antioxidants in lung lining fluid. Our study highlights significant health implications for unregulated burning, particularly many areas developing countries.

Language: Английский

Citations

0
Isoprene Epoxydiol-Derived Sulfated and Nonsulfated Oligomers Suppress Particulate Mass Loss during Oxidative Aging of Secondary Organic Aerosol DOI

N. Cazimir Armstrong,

Yuzhi Chen, Tianqu Cui

et al.

Environmental Science & Technology, Journal Year: 2022, Volume and Issue: 56(23), P. 16611 - 16620

Published: Nov. 15, 2022

Acid-driven multiphase chemistry of isoprene epoxydiols (IEPOX) with inorganic sulfate aerosols contributes substantially to secondary organic aerosol (SOA) formation, which constitutes a large mass fraction atmospheric fine particulate matter (PM2.5). However, the chemical sinks freshly generated IEPOX-SOA particles remain unclear. We examined role heterogeneous oxidation by gas-phase hydroxyl radical (•OH) under dark conditions as one potential sink. After 4 h •OH exposure (∼3 × 108 molecules cm–3), changes in smog chamber-generated were assessed hydrophilic interaction liquid chromatography coupled electrospray ionization high-resolution quadrupole time-of-flight spectrometry (HILIC/ESI-HR-QTOFMS). A comparison molecular-level compositional during aging or without revealed that decomposition oligomers acts sink for and maintains reservoir low-volatility compounds, including monomeric esters oligomer fragments. propose tentative structures formation mechanisms previously uncharacterized SOA constituents PM2.5. Our results suggest this •OH-driven renewal products may extend lifetimes particle-phase slowing production low-molecular weight, high-volatility fragments likely quantities 2-methyltetrols methyltetrol sulfates reported

Language: Английский

Citations

16
Targeting Mitochondrial Metabolism to Reverse Radioresistance: An Alternative to Glucose Metabolism DOI Creative Commons

Chenbin Bian,

Zhuangzhuang Zheng, Jing Su

et al.

Antioxidants, Journal Year: 2022, Volume and Issue: 11(11), P. 2202 - 2202

Published: Nov. 7, 2022

Radiotherapy failure and poor tumor prognosis are primarily attributed to radioresistance. Improving the curative effect of radiotherapy delaying cancer progression have become difficult problems for clinicians. Glucose metabolism has long been regarded as main metabolic process by which cells meet their bioenergetic anabolic needs, with complex interactions between mitochondria tumors being ignored. This misconception was not dispelled until early 2000s; however, cellular molecules signaling pathways involved in radioresistance remain incompletely defined. In addition a key site that regulates tumorigenesis, can influence radiation effects malignancies controlling redox reactions, participating oxidative phosphorylation, producing oncometabolites, triggering apoptosis. Therefore, promising targets development novel anticancer drugs. this review, we summarize internal relationship related mechanisms mitochondrial radioresistance, thus exploring possibility targeting reverse insensitivity. We suggest attention should be paid potential value prolonging survival patients.

Language: Английский

Citations

15
Recent advances of oxidative stress in thromboangiitis obliterans: biomolecular mechanisms, biomarkers, sources and clinical applications DOI
Qi Chen, Jing Chen, Jiahua Li

et al.

Thrombosis Research, Journal Year: 2023, Volume and Issue: 230, P. 64 - 73

Published: Aug. 25, 2023

Language: Английский

Citations

8
The number fraction of iron-containing particles affects OH, HO&lt;sub&gt;2&lt;/sub&gt; and H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; budgets in the atmospheric aqueous phase DOI Creative Commons

Amina Khaled,

Minghui Zhang, Barbara Ervens

et al.

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(3), P. 1989 - 2009

Published: Feb. 11, 2022

Abstract. Reactive oxygen species (ROS), such as OH, HO2 and H2O2, affect the oxidation capacity of atmosphere cause adverse health effects particulate matter. The role transition metal ions (TMIs) in impacting ROS concentrations conversions atmospheric aqueous phase has been recognized for a long time. Model studies usually assume that total TMI mass measured bulk aerosol or cloud water samples is distributed equally across all particles droplets. This assumption contrary to single-particle measurements have shown only small number fraction contain iron other TMIs (FN,Fe<100 %), which implies also not droplets TMIs. In current study, we apply box model with an explicit multiphase chemical mechanism simulate formation cycling simulations are performed range 1 % ≤ FN,Fe 100 constant pH values 3, 4.5 6 concentration (10 50 ng per cubic meter air). results compared two sets FN,Fe<100 (FeN<100) (FeBulk). We find largest differences between OH / O2- at = 6. Under these conditions, subsaturated because its high effective Henry's law fast loss reactions radical anion. As main reduction process Fe(III) reaction O2-, show subsaturation leads Fe(II) Fe(total) ratios lower by factor 2 approaches. trend largely independent concentration, both source sink rates scale concentration. compare model-derived reactive uptake parameters γOH γHO2 full FN,Fe. While affected distribution, calculated from 0.0004 0.03 %, respectively. Implications findings discussed application lab-derived models present on aerosols. conclude distribution (FN,Fe) should be taken into account estimate potential matter might overestimated sampling Our study suggests iron-containing may more important than determining budgets water.

Language: Английский

Citations

13