-
Environment International Sep 2012While exposures to urban fine particulate matter (PM(2.5)) and soot-black carbon (soot-BC) have been associated with asthma exacerbations, there is limited evidence on...
BACKGROUND
While exposures to urban fine particulate matter (PM(2.5)) and soot-black carbon (soot-BC) have been associated with asthma exacerbations, there is limited evidence on whether these pollutants are associated with the new development of asthma or allergy among young inner city children. We hypothesized that childhood exposure to PM(2.5) and the soot-BC component would be associated with the report of new wheeze and development of seroatopy in an inner city birth cohort.
METHODS
As part of the research being conducted by the Columbia Center of Children's Environmental Health (CCCEH) birth cohort study in New York City, two-week integrated residential monitoring of PM(2.5), soot-BC (based on a multi-wavelength integrating sphere method), and modified absorption coefficient (Abs*; based on the smoke stain reflectometer) was conducted between October 2005 and May 2011 for 408 children at ages 5-6 years old. Residential monitoring was repeated 6 months later (n=262) to capture seasonal variability. New wheeze was identified through the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaires during up to 3 years of follow-up and compared to a reference group that reported never wheeze, remitted wheeze, or persistent wheeze. Specific immunoglobulin (Ig) E against cockroach, mouse, cat, and dust mite and total IgE levels was measured in sera at ages 5 and 7 years.
RESULTS
PM(2.5), soot-BC, and Abs* measured at the first visit were correlated moderately with those at the second visit (Pearson r>0.44). Using logistic regression models, a positive association between PM(2.5) and new wheeze was found with adjusted odds ratio [95% confidence intervals] of 1.51 [1.05-2.16] per interquartile range (IQR). Positive but non-significant association was found between the development of new wheeze and soot-BC and (OR 1.40 [0.96-2.05]), and Abs* (OR 1.57 [0.91-2.68]); Significantly positive associations were found between air pollutant measurements and new wheeze when restricting to those participants with repeat home indoor measurements 6 months apart. Associations between pollutants and IgE levels were not detected.
CONCLUSIONS
Our findings suggest that childhood exposure to indoor air pollution, much of which penetrated readily from outdoor sources, may contribute to the development of wheeze symptoms among children ages 5 to 7 years.
Topics: Air Pollutants; Air Pollution, Indoor; Asthma; Child; Cohort Studies; Environmental Monitoring; Female; Humans; Hypersensitivity; Inhalation Exposure; Male; New York City; Particulate Matter; Prospective Studies; Respiratory Sounds; Soot
PubMed: 22572116
DOI: 10.1016/j.envint.2012.03.012 -
Environment International Sep 2023Exposure to fine particulate matter (PM) impairs cognition, while physical activity (PA) improves cognitive function. However, whether taking PA with PM exposure is...
BACKGROUND
Exposure to fine particulate matter (PM) impairs cognition, while physical activity (PA) improves cognitive function. However, whether taking PA with PM exposure is still beneficial to cognition remains unknown.
METHODS
We utilized national representative longitudinal data from the China Family Panel Study (CFPS), comprising a total sample of 108,099 from 2010 to 2018 in three waves. Cognitive performance and leisure-time PA were measured using the standard cognitive module and Godin-Shephard Leisure-Time Physical Activity Questionnaire. Gridded overall PM and major chemical components of PM were estimated using a two-stage machine learning model and matched to each participant based on their residential location. Mixed-effect models and difference-in-difference models were employed to investigate the individual and joint effects of total PM, PM components, and leisure-time PA on cognition.
RESULTS
Every 1 μg/m increase in PM was associated with a -0.035 (95% confidence interval [CI] = -0.052, -0.018) point change in cognitive score. All PM components exhibited negative associations with cognitive change, with black carbon (BC) contributing the most significant cognitive decline (β = -1.025, 95% CI = -1.367, -0.683). Every one-time (or one-hour) increase in leisure-time PA frequency (or PA time) per week was associated with an increase in cognitive score by 0.576 (0.270) points (PA frequency: 95% CI = 0.544, 0.608, PA time: 95% CI = 0.248, 0.293). PA frequency (β = -0.005, 95% CI = -0.006, -0.003) and PA time (β = -0.002, 95% CI = -0.003, -0.001) exhibited interactive effects with PM. Increased PA frequency and time were more beneficial to cognitive function in the low PM exposure group compared to those exposed to high PM levels. Moreover, relative to lower PM exposure, the cognitive benefits of physically active individuals with higher PM exposure were attenuated but still improved cognition when compared to those with no PA.
CONCLUSION
Engaging in leisure-time PA provides cognitive benefits even under PM exposure, although PM exposure attenuates these benefits. Among all PM components, BC demonstrated the most significant cognitive hazard and interaction with leisure-time PA. Promoting PA as a preventive measure may offer a cost-effective and convenient strategy to mitigate the negative impact of PM exposure on cognition. There is no excuse to avoid PA under PM exposure, as its cognitive benefits persist even in polluted environments.
Topics: Humans; Longitudinal Studies; Exercise; Cognition; Particulate Matter; Soot; Leisure Activities
PubMed: 37598596
DOI: 10.1016/j.envint.2023.108143 -
Journal of Exposure Science &... May 2023Little is known about sources of residential exposure to carbonaceous aerosols, which include black carbon (BC), the elemental carbon core of combustion particles, and...
BACKGROUND
Little is known about sources of residential exposure to carbonaceous aerosols, which include black carbon (BC), the elemental carbon core of combustion particles, and organic compounds from biomass combustion (delta carbon).
OBJECTIVE
Assess the impact of residential characteristics on indoor BC and delta carbon when known sources of combustion (e.g., smoking) are minimized.
METHODS
Between November 2012-December 2014, 125 subjects (129 homes) in Northeast USA were recruited and completed a residential characteristics questionnaire. Every 3 months, participants received an automated sampler to measure fine particulate matter (PM) in their home during a weeklong period (N = 371 indoor air samples) and were also questioned about indoor exposures. The samples were analyzed using a transmissometer at 880 nm (reflecting BC) and at 370 nm. The difference between the two wavelengths estimates delta carbon. Outdoor BC and delta carbon were measured using a central site aethalometer.
RESULTS
Geometric mean indoor concentrations of BC and delta carbon (0.65 µg/m³ and 0.19 µg/m³, respectively), were greater than central site concentrations (0.53 µg/m³ and 0.02 µg/m³, respectively). Multivariable analysis showed that greater indoor concentrations of BC were associated with infrequent candle use, multi-family homes, winter season, lack of air conditioning, and central site BC. For delta carbon, greater indoor concentrations were associated with apartments, spring season, and central site concentrations.
SIGNIFICANCE
In addition to outdoor central site concentrations, factors related to the type of housing, season, and home exposures are associated with indoor exposure to carbonaceous aerosols. Recognition of these characteristics should enable greater understanding of indoor exposures and their sources.
Topics: Humans; Air Pollutants; Air Pollution, Indoor; Environmental Monitoring; Particulate Matter; New England; Surveys and Questionnaires; Aerosols; Carbon; Soot
PubMed: 35079108
DOI: 10.1038/s41370-021-00405-6 -
Environmental Research Sep 2022Black carbon (BC) is a product of incomplete combustion, present in urban aerosols and sourcing mainly from road traffic. Epidemiological evidence reports positive...
Black carbon (BC) is a product of incomplete combustion, present in urban aerosols and sourcing mainly from road traffic. Epidemiological evidence reports positive associations between BC and cardiovascular and respiratory disease. Despite this, BC is currently not regulated by the EU Air Quality Directive, and as a result BC data are not available in urban areas from reference air quality monitoring networks in many countries. To fill this gap, a machine learning approach is proposed to develop a BC proxy using air pollution datasets as an input. The proposed BC proxy is based on two machine learning models, support vector regression (SVR) and random forest (RF), using observations of particle mass and number concentrations (N), gaseous pollutants and meteorological variables as the input. Experimental data were collected from a reference station in Barcelona (Spain) over a 2-year period (2018-2019). Two months of additional data were available from a second urban site in Barcelona, for model validation. BC concentrations estimated by SVR showed a high degree of correlation with the measured BC concentrations (R = 0.828) with a relatively low error (RMSE = 0.48 μg/m). Model performance was dependent on seasonality and time of the day, due to the influence of new particle formation events. When validated at the second station, performance indicators decreased (R = 0.633; RMSE = 1.19 μg/m) due to the lack of N data and PM and the smaller size of the dataset (2 months). New particle formation events critically impacted model performance, suggesting that its application would be optimal in environments where traffic is the main source of ultrafine particles. Due to its flexibility, it is concluded that the model can act as a BC proxy, even based on EU-regulatory air quality parameters only, to complement experimental measurements for exposure assessment in urban areas.
Topics: Air Pollutants; Air Pollution; Carbon; Environmental Monitoring; Nonlinear Dynamics; Particulate Matter; Soot
PubMed: 35427594
DOI: 10.1016/j.envres.2022.113269 -
Journal of Synchrotron Radiation Nov 2022Skin reactions are well described complications of tattooing, usually provoked by red inks. Chemical characterizations of these inks are usually based on limited...
Skin reactions are well described complications of tattooing, usually provoked by red inks. Chemical characterizations of these inks are usually based on limited subjects and techniques. This study aimed to determine the organic and inorganic composition of inks using X-ray fluorescence spectroscopy (XRF), X-ray absorption spectroscopy (XANES) and Raman spectroscopy, in a cohort of patients with cutaneous hypersensitivity reactions to tattoo. A retrospective multicenter study was performed, including 15 patients diagnosed with skin reactions to tattoos. Almost half of these patients developed skin reactions on black inks. XRF identified known allergenic metals - titanium, chromium, manganese, nickel and copper - in almost all cases. XANES spectroscopy distinguished zinc and iron present in ink from these elements in endogenous biomolecules. Raman spectroscopy showed the presence of both reported (azo pigments, quinacridone) and unreported (carbon black, phtalocyanine) putative organic sensitizer compounds, and also defined the phase in which Ti was engaged. To the best of the authors' knowledge, this paper reports the largest cohort of skin hypersensitivity reactions analyzed by multiple complementary techniques. With almost half the patients presenting skin reaction on black tattoo, the study suggests that black modern inks should also be considered to provoke skin reactions, probably because of the common association of carbon black with potential allergenic metals within these inks. Analysis of more skin reactions to tattoos is needed to identify the relevant chemical compounds and help render tattoo ink composition safer.
Topics: Humans; Tattooing; Ink; Soot; Spectrum Analysis, Raman; Spectrometry, X-Ray Emission
PubMed: 36345752
DOI: 10.1107/S1600577522008165 -
Redox Biology Nov 2021Oxidation of engineered nanomaterials during application in various industrial sectors can alter their toxicity. Oxidized nanomaterials also have widespread industrial...
Oxidation of engineered nanomaterials during application in various industrial sectors can alter their toxicity. Oxidized nanomaterials also have widespread industrial and biomedical applications. In this study, we evaluated the cardiopulmonary hazard posed by these nanomaterials using oxidized carbon black (CB) nanoparticles (CB) as a model particle. Particle surface chemistry was characterized by X-ray photo electron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR). Colloidal characterization and in vitro dosimetry modeling (particle kinetics, fate and transport modeling) were performed. Lung inflammation was assessed following oropharyngeal aspiration of CB or oxidized CB particles (20 μg per mouse) in C57BL/6J mice. Toxicity and functional assays were also performed on murine macrophage (RAW 264.7) and endothelial cell lines (C166) with and without pharmacological inhibitors. Oxidant generation was assessed by electron paramagnetic resonance spectroscopy (EPR) and via flow cytometry. Endothelial toxicity was evaluated by quantifying pro-inflammatory mRNA expression, monolayer permeability, and wound closure. XPS and FTIR spectra indicated surface modifications, the appearance of new functionalities, and greater oxidative potential (both acellular and in vitro) of CB particles. Treatment with CB demonstrated greater in vivo inflammatory potentials (lavage neutrophil counts, secreted cytokine, and lung tissue mRNA expression) and air-blood barrier disruption (lavage proteins). Oxidant-dependent pro-inflammatory signaling in macrophages led to the production of CXCR3 ligands (CXCL9,10,11). Conditioned medium from CB-treated macrophages induced significant elevation in endothelial cell pro-inflammatory mRNA expression, enhanced monolayer permeability and impairment of scratch healing in CXCR3 dependent manner. In summary, this study mechanistically demonstrated an increased biological potency of CB particles and established the role of macrophage-released chemical mediators in endothelial damage.
Topics: Animals; Lung; Mice; Mice, Inbred C57BL; Nanoparticles; Receptors, Chemokine; Soot
PubMed: 34624601
DOI: 10.1016/j.redox.2021.102161 -
Artificial Organs Oct 2022The stimulation and recording performance of implanted neural interfaces are functions of the physical and electrical characteristics of the neural interface, its...
BACKGROUND
The stimulation and recording performance of implanted neural interfaces are functions of the physical and electrical characteristics of the neural interface, its electrode material and structure. Therefore, rapid optimization of such characteristics is becoming critical in most clinical and research studies. This paper describes the development of an upgraded 3D printed cuff electrode shell design containing a novel intrinsically conductive polymer (ICP) for stimulation and recording of peripheral nerve fibers.
METHODS
A 3D stereolithography (SLA) printer was used to print a scalable, custom designed, C-cuff electrode and I-beam closure for accurate, rapid implementation. A novel contact consisting of a percolated carbon graphite base electrodeposited with an intrinsically conductive polymer (ICP), poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) produced a PEDOT:PSS + carbon black (CB) matrix that was used to form the electrochemical interface on the structure. Prototype device performance was tested both in-vitro and in-vivo for electrical chemical capacity, electrochemical interfacial impedance, surgical handling, and implantability. The in-vivo work was performed on the sciatic nerve of 25 anesthetized Sprague Dawley rats to demonstrate recording and stimulating ability.
RESULTS
Prototypes of different spatial geometries and number of contacts (bipolar, tripolar, and tetrapolar) were designed. The design was successfully printed with inner diameters down to 500 μm. Standard bipolar and tripolar cuffs, with a 1.3 mm inner diameter (ID), 0.5 mm contact width, 1.0 mm pitch, and a 1.5 mm end distance were used for the functional tests. This geometry was appropriate for placement on the rat sciatic nerve and enabled in-vivo testing in anesthetized rats. The contacts on the standard bipolar electrode had an area of 2.1 × 10 cm . Cyclic voltammetry on ICP coated and uncoated graphite contacts showed that the ICP increased the average charge storage capacity (CSC) by a factor of 30. The corresponding impedance at 1 Hz was slightly above 1 kΩ, a 99.99% decrease from 100 kΩ in the uncoated state. The statistical comparison of the pre- versus post-stimulation impedance measurements were not significantly different (p-value > 0.05).
CONCLUSIONS
The new cuff electrode enables rapid development of cost-effective functional stimulation devices targeting nerve bundles less than 1.0 mm in diameter. This allows for recording and modulation of a low-frequency current targeted within the peripheral nervous system.
Topics: Animals; Bridged Bicyclo Compounds, Heterocyclic; Carbon; Electrodes; Electrodes, Implanted; Graphite; Polymers; Rats; Rats, Sprague-Dawley; Soot; Stereolithography
PubMed: 35971860
DOI: 10.1111/aor.14387 -
Scientific Reports Feb 2023Endoscopic tattooing with India ink is a popular method for identifying colonic lesions during minimally invasive surgery because it is highly challenging to localize...
Endoscopic tattooing with India ink is a popular method for identifying colonic lesions during minimally invasive surgery because it is highly challenging to localize lesions during laparoscopy. However, there is a perceived unmet need for the injection of India ink and carbon particle suspension due to various complications and inconstant durability during the perioperative period. In this study, carbon black-containing self-healing adhesive alginate/polyvinyl alcohol composite hydrogels were synthesized as endoscopic tattooing inks. Alginate (Alg) conjugated with phenylboronic acid (PBA) groups in the backbone was crosslinked with polyvinyl alcohol (PVA) because of the dynamic bonds between the phenylboronic acid in alginate and the cis-diol groups of PVA. The carbon black-incorporated Alg-PBA/PVA hydrogels exhibited self-healing and re-shapable properties, indicating that improved intraoperative localization could be achieved. In addition, the adhesive tattooing hydrogels were stably immobilized on the target regions in the intraperitoneal spaces. These carbon black-containing self-healing adhesive hydrogels are expected to be useful in various surgical procedures, including endoscopic tattooing.
Topics: Polyvinyl Alcohol; Soot; Tattooing; Hydrogels; Carbon; Laparoscopy
PubMed: 36732365
DOI: 10.1038/s41598-023-28113-1 -
International Journal of Molecular... Nov 2022Soot molecules are hazardous compounds threatening human health. Computational chemistry provides efficient tools for studying them. However, accurate quantum chemistry...
Soot molecules are hazardous compounds threatening human health. Computational chemistry provides efficient tools for studying them. However, accurate quantum chemistry calculation is costly for the simulation of large-size soot molecules and high-throughput calculations. Semi-empirical (SE) quantum chemistry methods are optional choices for balancing computational costs. In this work, we validated the performances of several widely used SE methods in the description of soot formation. Our benchmark study focuses on, but is not limited to, the validation of the performances of SE methods on reactive and non-reactive MD trajectory calculations. We also examined the accuracy of SE methods of predicting soot precursor structures and energy profiles along intrinsic reaction coordinate(s) (IRC). Finally, we discussed the spin density predicted by SE methods. The SE methods validated include AM1, PM6, PM7, GFN2-xTB, DFTB2, with or without spin-polarization, and DFTB3. We found that the shape of MD trajectory profiles, the relative energy, and molecular structures predicted by SE methods are qualitatively correct. We suggest that SE methods can be used in massive reaction soot formation event sampling and primary reaction mechanism generation. Yet, they cannot be used to provide quantitatively accurate data, such as thermodynamic and reaction kinetics ones.
Topics: Humans; Soot; Quantum Theory; Thermodynamics; Computer Simulation; Molecular Structure
PubMed: 36362159
DOI: 10.3390/ijms232113371 -
Analytical Chemistry Oct 2022This manuscript details the first report of a complete additively manufactured rotating disk electrode setup, highlighting how high-performing equipment can be designed...
This manuscript details the first report of a complete additively manufactured rotating disk electrode setup, highlighting how high-performing equipment can be designed and produced rapidly using additive manufacturing without compromising on performance. The additively manufactured rotating disk electrode system was printed using a predominantly acrylonitrile butadiene styrene (ABS) based filament and used widely available, low-cost electronics, and simplified machined parts to create. The additively manufactured rotating disk electrode system costs less than 2% of a comparable commercial solution (£84.47 ($102.26) total). The rotating disk electrode is also additively manufactured using a carbon black/polylactic acid (CB/PLA) equivalent, developing a completely additively manufactured rotating disk electrode system. The electrochemical characterization of the additively manufactured rotating disk electrode setup was performed using hexaamineruthenium(III) chloride and compared favorably with a commercial glassy carbon electrode. Finally, this work shows how the additively manufactured rotating disk electrode experimental system and additive manufactured electrodes can be utilized for the electroanalytical determination of levodopa, a drug used in the treatment of Parkinson's disease, producing a limit of detection of 0.23 ± 0.03 μM. This work represents a step-change in how additive manufacturing can be used in research, allowing the production of high-end equipment for hugely reduced costs, without compromising on performance. Utilizing additive manufacturing in this way could greatly enhance the research possibilities for less well-funded research groups.
Topics: Acrylonitrile; Butadienes; Carbon; Chlorides; Electrodes; Levodopa; Polyesters; Soot; Styrenes
PubMed: 36129134
DOI: 10.1021/acs.analchem.2c02884