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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 -
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 -
Frontiers in Public Health 2022Various synthetic powders with primary particle sizes at the nanoscale and a high commercial impact have been studied using Wistar rats. The test materials were metal... (Review)
Review
Various synthetic powders with primary particle sizes at the nanoscale and a high commercial impact have been studied using Wistar rats. The test materials were metal oxides, i.e., TiO, ZnO and amorphous silica, and carbon black (technical soot). Dosing schemes were in the regular ranges typically used in subacute rat studies to simulate occupational exposure scenarios (mg range). Nanoscaled particle agglomerates have the potential to disintegrate and translocate as individual nanoparticles to remote locations following deposition in the lungs. The toxicokinetic fate of metal oxides post-inhalation in lungs/organs was investigated (i) by chemical analysis of the retained particulate/dissolved matter and (ii) by visualization of particles in various remote organs using transmission electron microscopy (TEM). The three titanium dioxides (NM-103, NM-104, NM-105; JRC coding) showed a very slow dissolution in lung fluids. In contrast, the coated ZnO (NM-111) dissolved quickly and was eliminated from the body within approximately 1 day. The precipitated amorphous silica (NM-200) showed a partial dissolution. Chemical analysis in lungs (particulate and soluble TiO) and in remote organs (liver and brain) showed a small solubility effect under physiological conditions. The translocation to remote organs was negligible. This confirms that for poorly soluble TiO particles there was no considerable translocation to the liver and brain. The chemical analysis of zinc demonstrated a very rapid dissolution of ZnO particles after deposition in the lungs. Statistically significant increases in Zn levels in the lungs were detectable only on day 1 post-exposure (NM-111). Overall, no relevant amounts of increased NM-111 in the ionic or particulate matter were detected in any body compartment. Amorphous silica (NM-200) particles were found in the cytoplasm of intraalveolar macrophages in the lung and the cytoplasm of macrophages in the lung associated lymph node. Interestingly, these particles were found in a few animals of all treatment groups (1, 2.5, and 5 mg/m NM-200) even after 91 days post-exposure. In all other organs of the NM-200 treated animals such as the nasal epithelium, trachea, larynx, liver, spleen, kidney, and mesenteric lymph node no particles were found at any time point investigated. Carbon black was tagged internally ("intrinsically") with a γ tracer (beryllium; half-time: 53.3 days). Due to limited amounts, the test item (0.3 mg per rat lung) was intratracheally instilled into the lungs. This dose avoided a particle overload effect, meaning that the toxicokinetic fate of carbon black could be followed under the approximated physiological conditions of lung clearance. Analysis of the γ labeled carbon black confirmed conclusively that there was no evidence for the translocation of carbon black beyond the lung into the blood or other body compartments. Very small amounts were only detected in lung-associated lymph nodes (LALN). On day 20 post-treatment, upon necropsy, both carbon black samples were practically exclusively found in lungs (75.1% and 91.0%, respectively) and in very small amounts in the lung-associated lymph nodes (LALN), i.e., ~0.5%. In the other organs/tissues, the test item was not significantly detectable. Separation of leukocytes and cell-free supernatant of a bronchoalveolar lavagate by centrifugation revealed that carbon black was completely located in the cell sediment, indicating total engulfment by alveolar macrophages. In conclusion, in occupational settings the nanomaterials titanium dioxide, zinc oxide, amorphous silica, and carbon black acted as microscaled agglomerates, not as individual nanoparticles. They displayed no potential to translocate beyond the lung into the blood compartment. Besides lungs, very small particulate amounts were detected only in LALN. This finding is consistent with the behavior of microscaled poorly soluble particles. Overall, there was no evidence of translocation of the nanomaterials following pulmonary exposures.
Topics: Animals; Lung; Nanoparticles; Occupational Exposure; Oxides; Particulate Matter; Rats; Rats, Wistar; Silicon Dioxide; Soot; Toxicokinetics; Zinc Oxide
PubMed: 35801236
DOI: 10.3389/fpubh.2022.909247 -
Environmental Science and Pollution... Aug 2022With the awakening of environmental awareness, the importance of air quality to human health and the proper functioning of social mechanisms is becoming increasingly... (Review)
Review
With the awakening of environmental awareness, the importance of air quality to human health and the proper functioning of social mechanisms is becoming increasingly prominent. The low cost and high efficiency of catalytic technique makes it a natural choice for achieving deep air purification. Stainless steel alloys have demonstrated their full potential for application in a variety of catalytic fields. The diversity of 3D networks or fibrous structures increases the turbulence within the heterogeneous catalysis, balance the temperature distribution in the reaction bed and, in combination with a highly thermally conductive skeleton, avoid agglomeration and deactivation of the active components; corrosion resistance and thermal stability are adapted to highly endothermic/exothermic or corrosive reaction environments; oxide layers formed by bulk transition metals activated by thermal treatment or etching can significantly alter the physico-chemical properties between the substrate and active species, further improving the stability of stainless steel catalysts; suitable electronic conductivity can be applied to the electrothermal catalysis, which is expected to provide guidance for the reduction of intermittent emission exhausts and the storage of renewable energy. The current applications of stainless steel as catalyst or support in the air purification have covered soot particle capture and combustion, catalytic oxidation of VOCs, SCR, and air sterilization. This paper summarizes several preparation methods and presents the relationships between the preparation process and the activity, and reviews its application and the current status of research in atmospheric environmental management, proposing the advantages and challenges of the stainless steel-based catalysts.
Topics: Air Pollution; Catalysis; Corrosion; Humans; Soot; Stainless Steel
PubMed: 35672638
DOI: 10.1007/s11356-022-21079-z -
The Lancet. Planetary Health Oct 2022Maternal exposure to particulate air pollution during pregnancy has been linked to multiple adverse birth outcomes causing burden of disease later in the child's life.... (Observational Study)
Observational Study
Maternal exposure to ambient black carbon particles and their presence in maternal and fetal circulation and organs: an analysis of two independent population-based observational studies.
BACKGROUND
Maternal exposure to particulate air pollution during pregnancy has been linked to multiple adverse birth outcomes causing burden of disease later in the child's life. To date, there is a paucity of data on whether or not ambient particles can both reach and cross the human placenta to exert direct effects on fetal organ systems during gestation.
METHODS
In this analysis, we used maternal-perinatal and fetal samples collected within the framework of two independent studies: the ENVIRONAGE (Environmental Influences on Ageing in Early Life) birth cohort of mothers giving birth at the East-Limburg Hospital in Genk, Belgium, and the SAFeR (Scottish Advanced Fetal Research) cohort of terminated, normally progressing pregnancies among women aged 16 years and older in Aberdeen and the Grampian region, UK. From the ENVIRONAGE study, we included 60 randomly selected mother-neonate pairs, excluding all mothers who reported that they ever smoked. From the SAFeR study, we included 36 fetuses of gestational age 7-20 weeks with cotinine concentrations indicative of non-smoking status. We used white light generation under femtosecond pulsed illumination to detect black carbon particles in samples collected at the maternal-fetal interface. We did appropriate validation experiments of all samples to confirm the carbonaceous nature of the identified particles.
FINDINGS
We found evidence of the presence of black carbon particles in cord blood, confirming the ability of these particles to cross the placenta and enter the fetal circulation system. We also found a strong correlation (r ≥0·50; p<0·0001) between the maternal-perinatal particle load (in maternal blood [n=60], term placenta [n=60], and cord blood [n=60]) and residential ambient black carbon exposure during pregnancy. Additionally, we found the presence of black carbon particles in first and second trimester tissues (fetal liver [n=36], lung [n=36], and brain [n=14]) of electively terminated and normally progressing pregnancies from an independent study.
INTERPRETATION
We found that maternally inhaled carbonaceous air pollution particles can cross the placenta and then translocate into human fetal organs during gestation. These findings are especially concerning because this window of exposure is key to organ development. Further studies are needed to elucidate the mechanisms of particle translocation.
FUNDING
European Research Council, Flemish Scientific Research Foundation, Kom op Tegen Kanker, UK Medical Research Council, and EU Horizon 2020.
Topics: Air Pollution; Carbon; Child; Cotinine; Female; Humans; Infant, Newborn; Maternal Exposure; Pregnancy; Soot
PubMed: 36208643
DOI: 10.1016/S2542-5196(22)00200-5 -
Environmental Health Perspectives Dec 2018Particulate matter (PM) air pollution has been associated with decreased pulmonary function, but the exposure–response relationship in chronic obstructive pulmonary...
BACKGROUND
Particulate matter (PM) air pollution has been associated with decreased pulmonary function, but the exposure–response relationship in chronic obstructive pulmonary disease (COPD) patients is uncertain, and most studies have only focused on exposures to ambient pollution.
OBJECTIVES
We aimed to assess associations between pulmonary function and indoor and ambient PM [Formula: see text] ([Formula: see text]) and black carbon (BC).
METHODS
Between November 2012 and December 2014, 125 patients with COPD (mean age, 73.4 y) who were not currently smoking and without known indoor BC sources were recruited. Indoor BC and [Formula: see text] were measured in each home for a week in each season, up to four times a year, followed by in-person spirometry pre- and post-bronchodilator. Ambient exposures were available from a central site monitor. Multivariable adjusted mixed effects regression models were used to assess associations scaled per interquartile range (IQR) of exposure.
RESULTS
There were 367 study visits; the median (IQR) indoor BC and [Formula: see text] were 0.19 (0.22) [Formula: see text] and 6.67 (5.80) [Formula: see text], respectively. Increasing indoor exposures to BC were associated with decreases in pre-bronchodilator forced expiratory volume in 1 s [Formula: see text] and forced vital capacity (FVC), and [Formula: see text]. For example, in multivariable adjusted models, each IQR increase in indoor BC from the weekly integrated filter was associated with a [Formula: see text] [95% confidence interval (CI): [Formula: see text], [Formula: see text]] decrease in pre-bronchodilator [Formula: see text]. Increases in indoor [Formula: see text] were associated with decreases in [Formula: see text] and FVC of smaller magnitude than those for indoor BC; however, the results were less precise. Ambient BC was not associated with pre-bronchodilator pulmonary function, ambient [Formula: see text] was only associated with decreases in FVC and increases in [Formula: see text], and neither indoor nor ambient BC or [Formula: see text] were associated with post-bronchodilator pulmonary function.
CONCLUSIONS
Low-level exposures to indoor BC and [Formula: see text], but not ambient exposures, were consistently associated with decreases in pre-bronchodilator pulmonary function. There was no association between exposures and post-bronchodilator pulmonary function. https://doi.org/10.1289/EHP3668.
Topics: Aged; Aged, 80 and over; Air Pollution; Air Pollution, Indoor; Bronchodilator Agents; Environmental Exposure; Female; Forced Expiratory Volume; Humans; Male; Massachusetts; Middle Aged; Particle Size; Particulate Matter; Pulmonary Disease, Chronic Obstructive; Soot; Vital Capacity
PubMed: 30570336
DOI: 10.1289/EHP3668 -
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 -
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 -
Particle and Fibre Toxicology Apr 2023Microbial dysbiosis is a potential mediator of air pollution-induced adverse outcomes. However, a systemic comparison of the lung and gut microbiome alterations and...
BACKGROUND
Microbial dysbiosis is a potential mediator of air pollution-induced adverse outcomes. However, a systemic comparison of the lung and gut microbiome alterations and lung-gut axis following air pollution exposure is scant. In this study, we exposed male C57BL/6J mice to inhaled air, CB (10 mg/m), O (2 ppm) or CB + O mixture for 3 h/day for either one day or four consecutive days and were euthanized 24 h post last exposure. The lung and gut microbiome were quantified by 16 s sequencing.
RESULTS
Multiple CB + O exposures induced an increase in the lung inflammatory cells (neutrophils, eosinophils and B lymphocytes), reduced absolute bacterial load in the lungs and increased load in the gut. CB + O exposure was more potent as it decreased lung microbiome alpha diversity just after a single exposure. CB + O co-exposure uniquely increased Clostridiaceae and Prevotellaceae in the lungs. Serum short chain fatty acids (SCFA) (acetate and propionate) were increased significantly only after CB + O co-exposure. A significant increase in SCFA producing bacterial families (Ruminococcaceae, Lachnospiraceae, and Eubacterium) were also observed in the gut after multiple exposures. Co-exposure induced significant alterations in the gut derived metabolite receptors/mediator (Gcg, Glp-1r, Cck) mRNA expression. Oxidative stress related mRNA expression in lungs, and oxidant levels in the BALF, serum and gut significantly increased after CB + O exposures.
CONCLUSION
Our study confirms distinct gut and lung microbiome alterations after CB + O inhalation co-exposure and indicate a potential homeostatic shift in the gut microbiome to counter deleterious impacts of environmental exposures on metabolic system.
Topics: Mice; Animals; Male; Ozone; Soot; Mice, Inbred C57BL; Lung; Microbiota; RNA, Messenger
PubMed: 37085867
DOI: 10.1186/s12989-023-00528-8