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Science Advances Nov 2022Chronic exposure to airborne carbon black ultrafine (nCB) particles generated from incomplete combustion of organic matter drives IL-17A-dependent emphysema. However,...
Chronic exposure to airborne carbon black ultrafine (nCB) particles generated from incomplete combustion of organic matter drives IL-17A-dependent emphysema. However, whether and how they alter the immune responses to lung cancer remains unknown. Here, we show that exposure to nCB particles increased PD-L1 PD-L2 CD206 antigen-presenting cells (APCs), exhausted T cells, and T cells. Lung macrophages that harbored nCB particles showed selective mitochondrial structure damage and decreased oxidative respiration. Lung macrophages sustained the HIF1α axis that increased glycolysis and lactate production, culminating in an immunosuppressive microenvironment in multiple mouse models of non-small cell lung cancers. Adoptive transfer of lung APCs from nCB-exposed wild type to susceptible mice increased tumor incidence and caused early metastasis. Our findings show that nCB exposure metabolically rewires lung macrophages to promote immunosuppression and accelerates the development of lung cancer.
Topics: Mice; Animals; Soot; Particulate Matter; Lung Neoplasms; Macrophages; Lung; Carbon; Tumor Microenvironment
PubMed: 36383649
DOI: 10.1126/sciadv.abq0615 -
The European Respiratory Journal Jul 2023https://bit.ly/43d9A75
https://bit.ly/43d9A75
Topics: Humans; COVID-19; Soot; Air Pollution; SARS-CoV-2
PubMed: 37343979
DOI: 10.1183/13993003.00818-2023 -
Current Environmental Health Reports Mar 2020The evidence on the role of air pollution on skin aging has increased in recent years. The accumulating evidence is based on both, epidemiological and mechanistic... (Review)
Review
PURPOSE OF THE REVIEW
The evidence on the role of air pollution on skin aging has increased in recent years. The accumulating evidence is based on both, epidemiological and mechanistic studies. The purpose of this review is to evaluate the recent evidence on the impacts of air pollution on skin aging as well as identify knowledge gaps for future research.
RECENT FINDINGS
Traffic-related air pollution exposure (particulate matter (PM), soot and nitrogen dioxide (NO)) has been associated with premature skin aging in several independent cohorts. In real life, human skin is additionally exposed to UV radiation, which is known for its effects on premature skin aging. More recent epidemiological findings suggest that (1) associations of PM can be altered by UV radiation with stronger PM associations at lower levels of UV, and (2) there is an association of tropospheric ozone with wrinkle formation, independent of NO, PM, and UV. The association between traffic-related air pollution and skin aging has been well-established. More recent epidemiological studies focused on the associations with ozone as well as interactions with of ambient air pollution with UV radiation, a research area that is becoming more important with the increase of global warming.
Topics: Air Pollutants; Environmental Exposure; Female; Humans; Male; Nitrogen Dioxide; Ozone; Particulate Matter; Skin Aging; Soot
PubMed: 31927691
DOI: 10.1007/s40572-020-00262-9 -
Biodegradation Aug 2022To probe the bioavailability of soot released into the atmosphere is pivotal to understanding their environmental impacts. Soot aerosol absorbs organic matter, creating...
To probe the bioavailability of soot released into the atmosphere is pivotal to understanding their environmental impacts. Soot aerosol absorbs organic matter, creating a hot spot for biogeochemical transformation and the global carbon cycle. Soot primarily contains condensed aromatics chemically recalcitrant; however, oligotrophic microorganisms might use it as a nutritional source. This study investigated the influence of psychrotolerant bacterial consortia on soot. Significant increase in the bacterial biomass, reduction in water-insoluble organic carbon (OC) and elemental carbon (EC) in soot residues and increase in water-soluble OC in the filtrate signifies the use of soot as a carbon and nutritional source. The influence on morphology and composition of soot was reported using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy, and Energy Dispersive X-Ray analysis (EDX). The FTIR analysis showed significant variations in the pattern of soot spectra, suggesting degradation. Elemental analysis and EDX showed a reduction in carbon percentage. Besides, the reduction of optical density with incubation time signifies the OC and EC consumption. This study shows that soot can be a substrate and pivotal factor in the microbial food web. Nowadays, soot emission to the environment is growing; therefore, soot involvement in microbe-mediated processes should be closely focused.
Topics: Aerosols; Air Pollutants; Biodegradation, Environmental; Carbon; Environmental Monitoring; Soot; Water
PubMed: 35666328
DOI: 10.1007/s10532-022-09990-1 -
Environment International Jul 2023Ultrafine particles, including black carbon (BC), can reach the systemic circulation and therefore may distribute to distant organs upon inhalation. The kidneys may be...
BACKGROUND
Ultrafine particles, including black carbon (BC), can reach the systemic circulation and therefore may distribute to distant organs upon inhalation. The kidneys may be particularly vulnerable to the adverse effects of BC exposure due to their filtration function.
OBJECTIVES
We hypothesized that BC particles reach the kidneys via the systemic circulation, where the particles may reside in structural components of kidney tissue and impair kidney function.
METHODS
In kidney biopsies from 25 transplant patients, we visualized BC particles using white light generation under femtosecond-pulsed illumination. The presence of urinary kidney injury molecule-1 (KIM-1) and cystatin c (CysC) were evaluated with ELISA. We assessed the association between internal and external exposure matrices and urinary biomarkers using Pearson correlation and linear regression models.
RESULTS
BC particles could be identified in all biopsy samples with a geometric mean (5th, 95th percentile) of 1.80 × 10 (3.65 × 10, 7.50 × 10) particles/mm kidney tissue, predominantly observed in the interstitium (100 %) and tubules (80 %), followed by the blood vessels and capillaries (40 %), and the glomerulus (24 %). Independent from covariates and potential confounders, we found that each 10 % higher tissue BC load resulted in 8.24 % (p = 0.03) higher urinary KIM-1. In addition, residential proximity to a major road was inversely associated with urinary CysC (+10 % distance: -4.68 %; p = 0.01) and KIM-1 (+10 % distance: -3.99 %; p < 0.01). Other urinary biomarkers, e.g., the estimated glomerular filtration rate or creatinine clearance showed no significant associations.
DISCUSSION AND CONCLUSION
Our findings that BC particles accumulate near different structural components of the kidney represent a potential mechanism explaining the detrimental effects of particle air pollution exposure on kidney function. Furthermore, urinary KIM-1 and CysC show potential as air pollution-induced kidney injury biomarkers for taking a first step in addressing the adverse effects BC might exert on kidney function.
Topics: Humans; Air Pollutants; Air Pollution; Biomarkers; Carbon; Kidney; Particulate Matter; Soot
PubMed: 37269720
DOI: 10.1016/j.envint.2023.107997 -
Chemosphere Oct 2023Multi-carbon air pollutants pose serious hazards to the environment and health, especially soot and volatile organic compounds (VOCs). Catalytic oxidation is one of the... (Review)
Review
Multi-carbon air pollutants pose serious hazards to the environment and health, especially soot and volatile organic compounds (VOCs). Catalytic oxidation is one of the most effective technologies for eliminating them. The oxidation of soot and most hydrocarbon VOCs begins with C-H (or edge-CH) activation, so this commonality can be targeted to design active sites. Rationally designed interface nanostructures optimize metal-support interactions (MSIs), providing suitable active sites for C-H activation. Meanwhile, the interfacial reactant spillover facilitates the further decomposition of activated intermediates. Thus, rationally exploiting interfacial effects is critical to enhancing catalytic activity. In this review, we analyzed recent advances in the following aspects: I. Understanding of the interface effects and design; II. Optimization of the catalyst-reactant contact, metal-support interface, and MSIs; III. Design of the interfacial composition and perimeter. Based on the analysis of the advances and current status, we provided challenges and opportunities for the rational design of interface nanostructures and interface-related stability. Meanwhile, a critical outlook was given on the interfacial sites of single-atom catalysts (SACs) for specific activation and catalytic selectivity.
Topics: Air Pollutants; Carbon; Soot; Oxidation-Reduction; Metals; Volatile Organic Compounds; Catalysis
PubMed: 37467856
DOI: 10.1016/j.chemosphere.2023.139547 -
Chemosphere Jul 2024Mn or Co supported CeO fiber catalysts were synthesized following a biotemplating route and evaluated in soot combustion and benzene total oxidation. The catalysts were...
Mn or Co supported CeO fiber catalysts were synthesized following a biotemplating route and evaluated in soot combustion and benzene total oxidation. The catalysts were characterized by SEM, EDX, N physisorption, FTIR-ATR, XRD, RAMAN and XPS. SEM results confirmed that the "twisted ribbon" morphology of the biotemplate was mostly maintained. XRD and Raman showed that Mn and Co cations partially insert into ceria lattice and also segregate at the surface of the fibers. XPS allowed to determine that both set of catalysts exhibit Ce and Ce species, in addition to adsorbed and lattice oxygen. Also, the average oxidation state (AOS) of surface Mn could be calculated. Compared to bare Fib Ce, the performances for both reactions were improved for the supported catalysts, except from the catalyst with lowest Mn content for soot combustion. The catalytic activity was discussed in terms of the physicochemical features of the supported catalysts.
Topics: Cerium; Oxidation-Reduction; Benzene; Catalysis; Manganese; Cobalt; Soot
PubMed: 38705410
DOI: 10.1016/j.chemosphere.2024.142247 -
Environmental Science & Technology Jul 2023Soot from jet fuel combustion in aircraft engines contributes to global warming through the formation of contrail cirrus clouds that make up to 56% of the total...
Soot from jet fuel combustion in aircraft engines contributes to global warming through the formation of contrail cirrus clouds that make up to 56% of the total radiative forcing from aviation. Here, the elimination of such emissions is explored through N injection (containing 0-25 vol % O) at the exhaust of enclosed spray combustion of jet fuel that nicely emulates aircraft soot emissions. It is shown that injecting N containing 5 vol % of O enhances the formation of polyaromatic hydrocarbons (PAHs) that adsorb on the surface of soot. This increases soot number density and volume fraction by 25 and 80%, respectively. However, further increasing the O concentration to 20 or 25 vol % enhances oxidation and nearly eliminates soot emissions from jet fuel spray combustion, reducing the soot number density and volume fraction by 87.3 or 95.4 and 98.3 or 99.6%, respectively. So, a judicious injection of air just after the aircraft engine exhaust can drastically reduce soot emissions and halve the radiative forcing due to aviation, as shown by soot mobility, X-ray diffraction, Raman spectroscopy, nitrogen adsorption, microscopy, and thermogravimetric analysis (for the organic to total carbon ratio) measurements.
Topics: Soot; Hydrocarbons; Aircraft; Aviation; Vehicle Emissions
PubMed: 37406187
DOI: 10.1021/acs.est.3c01048 -
Journal of Microscopy Oct 2022A pre-trained convolution neural network based on residual error functions (ResNet) was applied to the classification of soot and non-soot carbon nanoparticles in TEM...
A pre-trained convolution neural network based on residual error functions (ResNet) was applied to the classification of soot and non-soot carbon nanoparticles in TEM images. Two depths of ResNet, one 18 layers deep and the other 50 layers deep, were trained using training-validation sets of increasing size (containing 100, 400 and 1400 images) and were assessed using an independent test set of 200 images. Network training was optimised in terms of mini-batch size, learning rate and training length. In all tests, ResNet18 and ResNet50 had statistically similar performances, though ResNet18 required only 25-35% of the training time of ResNet50. Training using the 100-, 400- and 1400-image training-validation sets led to classification accuracies of 84%, 88% and 95%, respectively. ResNet18 and ResNet50 were also compared for their ability to categorise soot and non-soot nanoparticles via a fivefold cross-validation experiment using the entire set of 800 images of soot and 800 images of non-soot. Cross-validation was repeated 3 times with different training durations. For all cross-validation experiments, classification accuracy exceeded 91%, with no statistical differences between any of the network trainings. The most efficient network was ResNet18 trained for 5 epochs, which reached 91.2% classification after only 84 s of training on 1600 images. Use of ResNet for classification of 1000 images, the amount suggested for reliable characterisation of soot sample, requires <4 s, compared with >30 min for a skilled operator classifying images manually. Use of convolution neural networks for classification of soot and non-soot nanoparticles in TEM images is highly promising, particularly when manually classified data sets have already been established.
Topics: Carbon; Nanoparticles; Neural Networks, Computer; Soot
PubMed: 36065981
DOI: 10.1111/jmi.13140 -
Environmental Science & Technology Jun 2023Combustion-driven particulate black carbon (PBC) is a crucial slow-cycling pool in the organic carbon flux from rivers to oceans. Since the refractoriness of PBC stems...
Combustion-driven particulate black carbon (PBC) is a crucial slow-cycling pool in the organic carbon flux from rivers to oceans. Since the refractoriness of PBC stems from the association of non-homologous char and soot, the composition and source of char and soot must be considered when investigating riverine PBC. Samples along the Yangtze River continuum during different hydrological periods were collected in this study to investigate the association and asynchronous combustion drive of char and soot in PBC. The results revealed that PBC in the Yangtze River, with higher refractory nature, accounts for 13.73 ± 6.89% of particulate organic carbon, and soot occupies 37.53 ± 11.00% of PBC. The preponderant contribution of fossil fuel combustion to soot (92.57 ± 3.20%) compared to char (27.55 ± 5.92%), suggested that fossil fuel combustion is a crucial driver for PBC with high soot percentage. Redundancy analysis and structural equation modeling confirmed that the fossil fuel energy used by anthropogenic activities promoting soot is the crucial reason for high-refractory PBC. We estimated that the Yangtze River transported 0.15-0.23 Tg of soot and 0.15-0.25 Tg of char to the ocean annually, and the export of large higher refractory PBC to the ocean can form a long-term sink and prolong the residence time of terrigenous carbon.
Topics: Rivers; Soot; Anthropogenic Effects; Environmental Monitoring; Fossil Fuels; Dust; Carbon; China
PubMed: 37249317
DOI: 10.1021/acs.est.2c09827