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Toxicologic Pathology Jan 2018Particulate exposure has been implicated in the development of a number of neurological maladies such as multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's...
Particulate exposure has been implicated in the development of a number of neurological maladies such as multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's disease, and idiopathic Parkinson's disease. Only a few studies have focused on the olfactory pathway as a portal through which combustion-generated particles may enter the brain. The primary objective of this study was to define the deposition, uptake, and transport of inhaled ultrafine iron-soot particles in the nasal cavities of mice to determine whether combustion-generated nanoparticles reach the olfactory bulb via the olfactory epithelium and nerve fascicles. Adult female C57B6 mice were exposed to iron-soot combustion particles at a concentration of 200 μg/m, which included 40 μg/m of iron oxide nanoparticles. Mice were exposed for 6 hr/day, 5 days/week for 5 consecutive weeks (25 total exposure days). Our findings visually demonstrate that inhaled ultrafine iron-soot reached the brain via the olfactory nerves and was associated with indicators of neural inflammation.
Topics: Animals; Brain; Female; Ferric Compounds; Inhalation Exposure; Mice; Mice, Inbred C57BL; Mucociliary Clearance; Nanoparticles; Nasal Cavity; Olfactory Bulb; Olfactory Mucosa; Soot
PubMed: 28914166
DOI: 10.1177/0192623317729222 -
The Science of the Total Environment Sep 2022Increased solar and geomagnetic activity (SGA) may alter sympathetic nervous system activity, reduce antioxidant activity, and modulate physiochemical processes that...
BACKGROUND
Increased solar and geomagnetic activity (SGA) may alter sympathetic nervous system activity, reduce antioxidant activity, and modulate physiochemical processes that contribute to atmospheric aerosols, all which may reduce pulmonary function.
OBJECTIVES
Investigate associations between forced expiratory volume at 1 s (FEV) and forced vital capacity (FVC) with SGA, and assess whether SGA enhances adverse effects of particulate pollution, black carbon (BC) and particulate matter ≤2.5 μm in diameter (PM).
METHODS
We conducted a repeated measures analysis in 726 Normative Aging Study participants (Boston, Massachusetts, USA) between 2000 and 2017, using interplanetary magnetic field (IMF), planetary K index (Kp), and sunspot number (SSN) as SGA measures. Linear mixed effects models were used to assess exposure moving averages up to 28 days for both SGA and pollution.
RESULTS
Increases in IMF, Kp Index and SSN from the day of the pulmonary function test averaged through day 28 of were associated with a significant decrement in FEV and FVC, after adjusting for potential confounders. There were greater effects for longer moving averages and enhanced effects of PM and BC on FEV and FVC with increased SGA. For example, for each inter-quartile increase (4.55 μg/m3) in average PM 28 days before testing, low IMF (10th percentile: 3.2 nT) was associated with a -21.4 ml (95 % CI: -60.8, 18.1) and -7.1 ml (95 % CI: -37.7, 23·4) decrease in FVC and FEV, respectively; high IMF (90th percentile: 9.0 nT) was associated with a -120.7 ml (95 % CI:-166.5, -74.9) and -78.6 ml (95 % CI: -114.3, -42·8) decrease in FVC and FEV, respectively.
DISCUSSION
Increased periods of solar and geomagnetic activity may directly contribute to impaired pulmonary function and also enhance effects of PM and BC. Since exposure to solar activity is ubiquitous, stricter measures in reducing air pollution exposures are warranted, particularly in elderly populations.
Topics: Aged; Air Pollutants; Air Pollution; Dust; Environmental Exposure; Forced Expiratory Volume; Humans; Lung; Particulate Matter; Soot
PubMed: 35660608
DOI: 10.1016/j.scitotenv.2022.156434 -
Frontiers in Public Health 2022Inhaled particles that are poorly soluble or insoluble and of low toxicity ("poorly soluble low toxicity" or "PSLT" particles), can accumulate in the lung and at lung... (Review)
Review
Inhaled particles that are poorly soluble or insoluble and of low toxicity ("poorly soluble low toxicity" or "PSLT" particles), can accumulate in the lung and at lung overload levels induce lung cancers in rats. The question of whether PSLT particles increase lung cancer risk in humans is complicated by large differences between rats and humans and the relatively large particle doses administered in animal studies even when compared with heavy human occupational exposures. We review the findings of epidemiological studies on occupational exposure to each of three different PSLT particles (carbon black, talc and taconite). The epidemiological evidence indicates that at even very high occupational exposure levels at which non-malignant respiratory diseases including pneumoconiosis and even talcosis are observed, lung cancer risks appear not to be elevated. Although positive human cancer risks might be predicted based on extrapolation from overload doses in rats to relevant exposures in humans, the epidemiological "reality check" based on the three examples indicates that these PSLT particles are unlikely to increase lung cancer risk in humans even at high occupational levels of exposure. Therefore, we propose that careful evaluation of the epidemiological evidence can serve as a "reality check" for human risk assessment and help balance the risk evaluation process.
Topics: Animals; Humans; Lung Neoplasms; Occupational Exposure; Rats; Risk Assessment; Soot; Talc
PubMed: 35903380
DOI: 10.3389/fpubh.2022.920032 -
Wiley Interdisciplinary Reviews.... 2014Increasing evidence link nanomaterials with adverse biological outcomes and due to the variety of applications and potential human exposures to nanoparticles, it is thus... (Review)
Review
Increasing evidence link nanomaterials with adverse biological outcomes and due to the variety of applications and potential human exposures to nanoparticles, it is thus important to evaluate their toxicity for the risk assessment of workers and consumers. It is crucial to understand the underlying mechanisms of their toxicity as observation of similar effects after different nanomaterial exposures does not reflect similar intracellular processing and organelle interactions. A thorough understanding of mechanisms is needed not only for accurate prediction of potential toxicological impacts but also for the development of safer nanoapplications by modulating the physicochemical characteristics. Furthermore biomedical applications may also take advantage of an in depth knowledge about the mode of action of nanotoxicity to design new nanoparticle-derived drugs. In the present manuscript we discuss the similarities and differences in molecular pathways of toxicity after carbon black (CB) and titanium dioxide (TiO₂) nanoparticle exposures and identify the main toxicity mechanisms induced by these two nanoparticles which may also be indicative for the mode of action of other insoluble nanomaterials. We address the translocation, cell death induction, genotoxicity, and inflammation induced by TiO₂ and CB nanoparticles which depend on their internalization, reactive oxygen species (ROS) production capacities and/or protein interactions. We summarize their distinct cellular mechanisms of toxicity and the crucial steps which may be targeted to avoid adverse effects or to induce them for nanomedical purposes. Several physicochemical characteristics could influence these general toxicity pathways depicted here and the identification of common toxicity pathways could support the grouping of nanomaterials in terms of toxicity.
Topics: Animals; Cell Death; Humans; Mice; Nanoparticles; Reactive Oxygen Species; Soot; Titanium; Toxicity Tests
PubMed: 25266826
DOI: 10.1002/wnan.1302 -
Biomedical Research (Tokyo, Japan) 2022Air pollution is associated with increased morbidity and mortality and with cell death at a cellular level. However, the exact mechanism of particulate matter-induced...
Air pollution is associated with increased morbidity and mortality and with cell death at a cellular level. However, the exact mechanism of particulate matter-induced cell death remains to be elucidated. The aim of the present in vitro study using human alveolar epithelial cells (A549) was to determine the cell death pathway(s) induced by black carbon (BC) and ozone oxidized-black carbon (O-BC). BC and O-BC induced A549 cell death and the cytotoxic effect was dose-dependent. Cell death was significantly abrogated by inhibitor of receptor protein interacting kinase 1 (RIPK1) but only mildly inhibited by apoptosis inhibitor and RIPK3. BC- and O-BC-treated cells showed RIPK1 and RIPK3 protein overexpression and high phosphorylated levels of these proteins, as well as detectable levels of caspase-8 active form. BC- and O-BC-triggered cell death was also fully rescued in A549 cells that under-expressed RIPK1 with RIPK1 siRNA. Our results indicated that BC and O-BC could induce cell death through a multitude of pathways including apoptotic and necroptotic pathways and that RIPK1 is the upstream signal protein of these cell death pathways, with an important role in the regulation of BC-induced cell death.
Topics: A549 Cells; Apoptosis; Cell Death; Humans; Receptor-Interacting Protein Serine-Threonine Kinases; Soot
PubMed: 35173113
DOI: 10.2220/biomedres.43.23 -
Proceedings of the National Academy of... Jul 2016Many oxygenated hydrocarbon species formed during combustion, such as furans, are highly toxic and detrimental to human health and the environment. These species may...
Many oxygenated hydrocarbon species formed during combustion, such as furans, are highly toxic and detrimental to human health and the environment. These species may also increase the hygroscopicity of soot and strongly influence the effects of soot on regional and global climate. However, large furans and associated oxygenated species have not previously been observed in flames, and their formation mechanism and interplay with polycyclic aromatic hydrocarbons (PAHs) are poorly understood. We report on a synergistic computational and experimental effort that elucidates the formation of oxygen-embedded compounds, such as furans and other oxygenated hydrocarbons, during the combustion of hydrocarbon fuels. We used ab initio and probabilistic computational techniques to identify low-barrier reaction mechanisms for the formation of large furans and other oxygenated hydrocarbons. We used vacuum-UV photoionization aerosol mass spectrometry and X-ray photoelectron spectroscopy to confirm these predictions. We show that furans are produced in the high-temperature regions of hydrocarbon flames, where they remarkably survive and become the main functional group of oxygenates that incorporate into incipient soot. In controlled flame studies, we discovered ∼100 oxygenated species previously unaccounted for. We found that large alcohols and enols act as precursors to furans, leading to incorporation of oxygen into the carbon skeletons of PAHs. Our results depart dramatically from the crude chemistry of carbon- and oxygen-containing molecules previously considered in hydrocarbon formation and oxidation models and spearhead the emerging understanding of the oxidation chemistry that is critical, for example, to control emissions of toxic and carcinogenic combustion by-products, which also greatly affect global warming.
Topics: Aerosols; Air Pollutants; Carbon; Computational Biology; Fires; Furans; Hydrocarbons; Mass Spectrometry; Molecular Structure; Oxygen; Photoelectron Spectroscopy; Polycyclic Aromatic Hydrocarbons; Smoke; Soot
PubMed: 27410045
DOI: 10.1073/pnas.1604772113 -
Nature Communications Feb 2022Black carbon (BC) from fossil fuel and biomass combustion darkens the snow and makes it melt sooner. The BC footprint of research activities and tourism in Antarctica...
Black carbon (BC) from fossil fuel and biomass combustion darkens the snow and makes it melt sooner. The BC footprint of research activities and tourism in Antarctica has likely increased as human presence in the continent has surged in recent decades. Here, we report on measurements of the BC concentration in snow samples from 28 sites across a transect of about 2,000 km from the northern tip of Antarctica (62°S) to the southern Ellsworth Mountains (79°S). Our surveys show that BC content in snow surrounding research facilities and popular shore tourist-landing sites is considerably above background levels measured elsewhere in the continent. The resulting radiative forcing is accelerating snow melting and shrinking the snowpack on BC-impacted areas on the Antarctic Peninsula and associated archipelagos by up to 23 mm water equivalent (w.e.) every summer.
Topics: Antarctic Regions; Carbon; Carbon Footprint; Environmental Monitoring; Humans; Snow; Soot
PubMed: 35194040
DOI: 10.1038/s41467-022-28560-w -
Environmental Pollution (Barking, Essex... Apr 2023Abandoned brownfields represent a challenge for their recovery. To apply sustainable remediation technologies, such as bioremediation or phytoremediation, indigenous...
Abandoned brownfields represent a challenge for their recovery. To apply sustainable remediation technologies, such as bioremediation or phytoremediation, indigenous microorganisms are essential agents since they are adapted to the ecology of the soil. Better understanding of microbial communities inhabiting those soils, identification of microorganisms that drive detoxification process and recognising their needs and interactions will significantly improve the outcome of the remediation. With this in mind we have carried out a detailed metagenomic analysis to explore the taxonomic and functional diversity of the prokaryotic and eukaryotic microbial communities in soils, several mineralogically distinct types of pyrometallurgic waste, and groundwater sediments of a former mercury mining and metallurgy site which harbour very high levels of arsenic and mercury pollution. Prokaryotic and eukaryotic communities were identified, which turned out to be more diverse in the surrounding contaminated soils compared to the pyrometallurgic waste. The highest diversity loss was observed in two environments most contaminated with mercury and arsenic (stupp, a solid mercury condenser residue and arsenic-rich soot from arsenic condensers). Interestingly, microbial communities in the stupp were dominated by an overwhelming majority of archaea of the phylum Crenarchaeota, while Ascomycota and Basidiomycota fungi comprised the fungal communities of both stump and soot, results that show the impressive ability of these previously unreported microorganisms to colonize these extreme brownfield environments. Functional predictions for mercury and arsenic resistance/detoxification genes show their increase in environments with higher levels of pollution. Our work establishes the bases to design sustainable remediation methods and, equally important, to study in depth the genetic and functional mechanisms that enable the subsistence of microbial populations in these extremely selective environments.
Topics: Mercury; Arsenic; Soot; Microbiota; Eukaryota; Soil; Soil Microbiology; Soil Pollutants; Ascomycota
PubMed: 36804142
DOI: 10.1016/j.envpol.2023.121305 -
Particle and Fibre Toxicology Jan 2014Certain multi-walled carbon nanotubes (MWCNTs) have been shown to elicit asbestos-like toxicological effects. To reduce needs for risk assessment it has been suggested...
BACKGROUND
Certain multi-walled carbon nanotubes (MWCNTs) have been shown to elicit asbestos-like toxicological effects. To reduce needs for risk assessment it has been suggested that the physicochemical characteristics or reactivity of nanomaterials could be used to predict their hazard. Fibre-shape and ability to generate reactive oxygen species (ROS) are important indicators of high hazard materials. Asbestos is a known ROS generator, while MWCNTs may either produce or scavenge ROS. However, certain biomolecules, such as albumin - used as dispersants in nanomaterial preparation for toxicological testing in vivo and in vitro - may reduce the surface reactivity of nanomaterials.
METHODS
Here, we investigated the effect of bovine serum albumin (BSA) and cell culture medium with and without BEAS 2B cells on radical formation/scavenging by five MWCNTs, Printex 90 carbon black, crocidolite asbestos, and glass wool, using electron spin resonance (ESR) spectroscopy and linked this to cytotoxic effects measured by trypan blue exclusion assay. In addition, the materials were characterized in the exposure medium (e.g. for hydrodynamic size-distribution and sedimentation rate).
RESULTS
The test materials induced highly variable cytotoxic effects which could generally be related to the abundance and characteristics of agglomerates/aggregates and to the rate of sedimentation. All carbon nanomaterials were found to scavenge hydroxyl radicals (•OH) in at least one of the solutions tested. The effect of BSA was different among the materials. Two types of long, needle-like MWCNTs (average diameter >74 and 64.2 nm, average length 5.7 and 4.0 μm, respectively) induced, in addition to a scavenging effect, a dose-dependent formation of a unique, yet unidentified radical in both absence and presence of cells, which also coincided with cytotoxicity.
CONCLUSIONS
Culture medium and BSA affects scavenging/production of •OH by MWCNTs, Printex 90 carbon black, asbestos and glass-wool. An unidentified radical is generated by two long, needle-like MWCNTs and these two CNTs were more cytotoxic than the other CNTs tested, suggesting that this radical could be related to the adverse effects of MWCNTs.
Topics: Asbestos, Crocidolite; Bronchi; Cell Survival; Cell-Free System; Culture Media; Dose-Response Relationship, Drug; Electron Spin Resonance Spectroscopy; Epithelial Cells; Free Radical Scavengers; Free Radicals; Glass; Humans; Light; Microscopy, Electron, Transmission; Nanotubes, Carbon; Particle Size; Scattering, Radiation; Serum Albumin, Bovine; Soot
PubMed: 24438343
DOI: 10.1186/1743-8977-11-4 -
Environmental Health : a Global Access... Mar 2022Recent studies showed that air pollution might play a role in the etiology of mental disorders. In this study we evaluated the association between air pollution and...
BACKGROUND
Recent studies showed that air pollution might play a role in the etiology of mental disorders. In this study we evaluated the association between air pollution and mental and self-rated health and the possible mediating effect of physical activity in this association.
METHODS
In 2008, 2013 and 2018 the Belgian Health Interview Survey (BHIS) enrolled 16,455 participants who completed following mental health dimensions: psychological distress, suboptimal vitality, suicidal ideation, and depressive and generalized anxiety disorder and self-rated health. Annual exposure to nitrogen dioxide (NO), particulate matter ≤ 2.5 µm (PM) and black carbon (BC) were estimated at the participants' residence by a high resolution spatiotemporal model. Multivariate logistic regressions were carried out taking into account a priori selected covariates.
RESULTS
Long-term exposure to PM, BC and NO averaged 14.5, 1.4, and 21.8 µg/m, respectively. An interquartile range (IQR) increment in PM exposure was associated with higher odds of suboptimal vitality (OR = 1.27; 95% CI: 1.13, 1.42), poor self-rated health (OR = 1.20; 95% CI: 1.09, 1.32) and depressive disorder (OR = 1.19; 95% CI: 1.00, 1.41). Secondly, an association was found between BC exposure and higher odds of poor self-rated health and depressive and generalized anxiety disorder and between NO exposure and higher odds of psychological distress, suboptimal vitality and poor self-rated health. No association was found between long-term ambient air pollution and suicidal ideation or severe psychological distress. The mediation analysis suggested that between 15.2% (PM-generalized anxiety disorder) and 40.1% (NO-poor self-rated health) of the association may be mediated by a difference in physical activity.
CONCLUSIONS
Long-term exposure to PM, BC or NO was adversely associated with multiple mental health dimensions and self-rated health and part of the association was mediated by physical activity. Our results suggest that policies aiming to reduce air pollution levels could also reduce the burden of mental health disorders in Belgium.
Topics: Air Pollutants; Air Pollution; Environmental Exposure; Exercise; Humans; Nitrogen Dioxide; Particulate Matter; Soot
PubMed: 35255905
DOI: 10.1186/s12940-022-00839-x