Presence Of Particulate Matter Research Articles

Inflammatory Cytokines and Chemokines Are Synergistically Induced in a ROS-Dependent Manner by a Co-Culture of Corneal Epithelial Cells and Neutrophil-like Cells in the Presence of Particulate Matter.

Ocular exposure to particulate matter (PM) causes local inflammation; however, the influence of neutrophils on PM-induced ocular inflammation is still not fully understood. In this study, we constructed a system to investigate the role of PM in ocular inflammation using a co-culture of human corneal epithelial cells (HCE-T) and differentiation-induced neutrophils (dHL-60). To investigate whether HCE-T directly endocytosed PM, we performed a holographic analysis, which showed the endocytosis of PM in HCE-T. The cytokines and chemokines produced by HCE-T were measured using an ELISA. HCE-T treated with PM produced IL-6 and IL-8, which were inhibited by N-Acetyl-L-cysteine (NAC), suggesting the involvement of ROS. Their co-culture with dHL-60 enhanced their production of IL-6, IL-8, and MCP-1. This suggests an inflammatory loop involving intraocular corneal epithelial cells and neutrophils. These cytokines and chemokines are mainly regulated by NF-κB. Therefore, this co-culture system was examined in the presence of an IKK inhibitor known to downregulate NF-κB activity. The IKK inhibitor dramatically suppressed the production of these factors in co-culture supernatants. The results suggest that the inflammatory loop observed in the co-culture is mediated through ROS and the transcription factor NF-κB. Thus, the co-culture system is considered a valuable tool for analyzing complex inflammations.

Assessment of elemental chemistry, spatial distribution, and potential risks of road-deposited dusts in Sharjah, United Arab Emirates

Road dust is a major source of pollution in the environment, carrying different pollutants, including heavy metals and metalloids, from one location to another. This study assesses the concentrations of eight heavy metals and one metalloid (Zn, Pb, Mn, Fe, Cr, Cu, Cd, Ni, and As) in dust samples collected from sixty-eight streets of Sharjah, United Arab Emirates using ICP-OES, as well as investigates their effects on both the environment and humans. Mean concentrations of the elements in μg/g across the sites were 392 ± 46 (Zn), 68.28 ± 11.3 (Pb), 1437 ± 67 (Mn), 39,481 ± 4611 (Fe), 460 ± 31 (Cr), 150 ± 44 (Cu), 1.25 ± 0.65 (Cd), 856 ± 72 (Ni), and 0.97 ± 0.28 (As). The Cdeg and ERI calculated from the study were 54.79 and 573, respectively, suggesting varying pollution levels. The highest contributions were from Ni, Cd, Zn, Cu, Cr, and Pb, especially in areas with heavy traffic. The non-carcinogenic risk assessments were generally low for the three routes of exposure, except HQoral that was slightly higher for children. Similarly, none of the elements exhibited any carcinogenic risk except chromium. Overall, the cancer risk is considered low. In view of the limited studies from UAE in relation to the metal content of road-deposited dusts, the current study serves as novel knowledge, especially in the context of geographical areas with a higher occurrence of sandstorms and the presence of particulate matter. The study also adds to the global understanding of the contribution of street dust to environmental pollution and its implications for human health.

Particles influence on the direct absorption spectroscopy of TDLAS

Tunable Diode Laser Absorption Spectroscopy (TDLAS) technology is widely used for monitoring the gas pollutants. But in actual measurement environments, there are usually particles, which will affect the TDLAS direct absorption spectroscopy. In this paper, the influence of particles on the direct absorption spectroscopy of TDLAS was analyzed by using TDLAS-DAS technology combined with particle extinction method. According to analysis, it was found that the presence of particles does not affect the gas characteristic absorption spectral line strength and the gas absorption spectroscopy broadening, but it does affect the output laser intensity and absorbance received by the detector. The transmittance of particles can be obtained through the slope of the output laser intensity, which can be used to correct the absorbance to achieve accurate measurement of gas concentration. This paper analyzed the effects of particle size, incident wavelength, and composition on particle extinction coefficient and obtained the extinction coefficient of soot. If the laser wavelength is 1.53 μm and the particle size of soot is 45 μm, the extinction coefficient of soot is 2.1016. The magnitude of laser intensity attenuation at different particle concentrations can be obtained based on the extinction coefficient of particulate matter. When the concentration of soot is greater than 26290 mg/m3 and the optical path is 100 cm, the transmittance is less than 0.1 and the laser intensity attenuation reach over 90 %, which may affect the detection of gas absorption spectroscopy information and the accuracy of measurement. On this basis, this paper established the relationship between gas concentration and corrected absorbance to invert the gas concentration in the presence of particulate matter when the concentration of soot is less than 26290 mg/m3. The inversion gas concentration error obtained by the absorbance peak calibration method is within 3 %, and the inversion gas concentration error obtained by the absorbance integration method is within 1 %. From the inversion results, it can be seen that the accurate measurement of gas concentration in the presence of particulate matter can be achieved by extracting the slope of the output laser intensity to correct absorbance.

Molecular composition of fresh and aged aerosols from residential wood combustion and gasoline car with modern emission mitigation technology.

Emissions from road traffic and residential heating contribute to urban air pollution. Advances in emission reduction technologies may alter the composition of emissions and affect their fate during atmospheric processing. Here, emissions of a gasoline car and a wood stove, both equipped with modern emission mitigation technology, were photochemically aged in an oxidation flow reactor to the equivalent of one to five days of photochemical aging. Fresh and aged exhausts were analyzed by ultrahigh resolution mass spectrometry. The gasoline car equipped with a three-way catalyst and a gasoline particle filter emitted minor primary fine particulate matter (PM2.5), but aging led to formation of particulate low-volatile, oxygenated and highly nitrogen-containing compounds, formed from volatile organic compounds (VOCs) and gases incl. NOx, SO2, and NH3. Reduction of the particle concentration was also observed for the application of an electrostatic precipitator with residential wood combustion but with no significant effect on the chemical composition of PM2.5. Comparing the effect of short and medium photochemical exposures on PM2.5 of both emission sources indicates a similar trend for formation of new organic compounds with increased carbon oxidation state and nitrogen content. The overall bulk compositions of the studied emission exhausts became more similar by aging, with many newly formed elemental compositions being shared. However, the presence of particulate matter in wood combustion results in differences in the molecular properties of secondary particles, as some compounds were preserved during aging.

Is there a downside to plant ecological services in the city? Influences of particulate matter on the two-spotted spider mite (Tetranychus urticae) foraging on the small-leaved lime in urban conditions

The aim of this research was to examine how particulate matter (PM) pollution affects the life history of the two-spotted spider mite (TSSM), Tetranychus urticae (Trombidiformes: Tetranychidae), in modelled urban conditions. For this purpose, experimental populations of TSSM were cultured on the foliage of small-leaved lime (Tilia cordata) contaminated with PM at intensities corresponding to differing city zones such as a park, a busy road and an industrial area. The control samples in the study were washed, unpolluted leaves. The spider mite was selected as a model organism due to its cosmopolitan distribution, broad host spectrum, resistance to a variety of pesticides and food-intake mode involving cell-content sucking, while T. cordata is widely planted in cities and has demonstrated a considerable capability for PM capture. Data on the longevity and mortality of particular instars and on female fecundity at different pollution levels were collected and statistically evaluated. Concentrations of PM typical for roads and industrial city zones significantly reduced total female fecundity (avg. 53.9 and 55.9 eggs/female, respectively, vs 79.2 in control), which entailed a slower population increase, while the survival rate of particular developmental instars (P = 0.52) and fertility curves (P = 0.19) remained unchanged. The presence of PM caused physiological effects in the mites, despite the lack of direct consumption of the pollutant by adult and juvenile instars. Considering the incomparable resilience of TSSM to unfavourable environmental factors, it is predicted that the detrimental influence of PM on other representatives of urban arthropods may be even more severe. The results suggest that there is a need for further investigations into the ecological ramifications of air purification provided by urban green spaces.

Semi-empirical equation for determining the pressure drop of nanofibers

Air pollution, particularly the presence of particulate matter, has been linked to increased mortality rates. Air filtration is a widely used method to reduce exposure to airborne particles and protect public health. Nanofiber filter media has gained attention due to its ability to efficiently remove nanosized particles while minimizing pressure drop. However, accurately predicting the pressure drop in nanofiber media, which is influenced by the slip flow effect, remains a challenge. In this study, a simple semi-empirical equation was developed to calculate the pressure drop across nanofiber filter media. The model considers various filter parameters such as diameter, thickness, and solidity. Existing theoretical and empirical models were compared with experimental data, revealing limitations in accurately predicting pressure drop in nanofibers. To address this, a new empirical model, proposed by Bian, was examined. However, the Bian model demonstrated limited applicability due to its specific range of solidities. Numerical simulations were conducted to obtain additional pressure drop data, and a total of 107 cases were tested across various filter parameters. The simulations were performed using the Stokes equation to account for the low Reynolds numbers associated with nanofibers. The developed semi-empirical model provides a practical tool for analyzing the effect of filter parameters on nanofiber filter media's pressure drop, aiding in the design of efficient air filtration systems.

Overlooked Impacts of Urban Environments on the Air Quality in Naturally Ventilated Schools Amid the COVID-19 Pandemic

The density, form, and dimensions of urban morphology are important for healthy living conditions in cities, especially if they are related to the climate and air pollution. Morphology and environmental conditions determine the relationship between open and built space, the width of street spaces, the aerodynamic characteristics of wind currents, albedo, and the retention of pollutants, as well as determining the radiative exchange with the atmosphere. Studies on the COVID-19 pandemic have focused on the assumption of a possible relationship between the spread of the SARS-CoV-2 virus and the presence and concentration of airborne particulate matter (PM10 and PM2.5). This paper focuses on the research of indoor air quality (IAQ) in two schools with naturally ventilated classrooms in Ljubljana, Slovenia. The presence of particulate matter (PM2.5 and PM10) and the concentration of CO2 were studied, along with other microclimatic conditions, e.g., ambient temperature, relative humidity, air pressure, and wind conditions. These were compared and assessed via analysis of variance (ANOVA) and Duncan’s post hoc test. The main concern was to see how effective different ventilation strategies are, as well as how the openings in the classroom impact the concentrations of CO2 relative to the concentrations of PM2.5 and PM10 particles as a side effect of these ventilation strategies. The inconsistent application of recommended COVID-19 ventilation strategies suggests that IAQ in naturally ventilated classrooms is highly determined by individual perceptions of indoor air quality. The results also suggest that the IAQ is significantly affected by the schools’ urban environment; however, this is not considered within the national COVID-19 ventilation recommendations. Future ventilation guidelines for pandemics should also include the urban environment as a risk factor for inadequate IAQ, instead of focusing solely on pathogen characteristics.

Micro-flow imaging and flow virometry as preferred methods to monitor particulate matter for a human cytomegalovirus vaccine candidate.

The presence of particulate matter in vaccine samples is of concern as aggregates have the potential to reduce product efficacy, impact immunogenicity, or block capillaries upon injection. As a result, regulatory agencies routinely request particulate matter tests for particles in the micron size range for release. Particles may come in a variety of forms and can be intrinsic (e.g., from proteinaceous aggregates) or extrinsic (e.g., silicone oil from tubing or contamination from the manufacturing process). They may span the size range of sub-visible to visible particle sizes. In recent years, there has been a rise in requests from regulatory agencies for methods to detect and monitor aggregated particles as well as a desire to evaluate particle size and concentration of sub-micron sized particles. Typically utilized techniques include biophysical analytical methodologies that leverage light scattering or imaging. In this study, Dynamic Light Scattering (DLS), Micro-Flow Imaging (MFI) and Flow Virometry are evaluated as methods to detect and monitor sub-micron to micron sized particles, to support assessments of stability and processability, for drug substance (DS) and drug product (DP) samples of a Human Cytomegalovirus (HCMV) vaccine candidate. For this attenuated live virus vaccine candidate, MFI and flow virometry proved to be the most sensitive methods to monitor particulate matter.

Reversible fouling by particulate matter from natural seawater reduces RED performance while limiting biofouling

Reverse Electrodialysis (RED) has shown to be a promising technology for electricity production but membrane fouling can influence the energy yield, thus, it is crucial to gain knowledge on the impact and prevention of fouling. We used a sequence of pre-treatments (dual-media filter, microfilter and activated carbon filter) to fractionate foulants in seawater based on size and investigated its effect on RED. Fouling reversibility was studied by applying a cleaning procedure with reversal and increased flow and air sparging at the end of the experiment. After 63 days of operation, when using only the dual-media filter as pre-treatment, the pressure drop increased by 520 mbar in the seawater compartments without affecting the electrochemical measurements. The application of the cleaning procedure allowed to recover 90 % of the pumping power losses. A membrane autopsy showed the development of a biofilm layer on the membrane of the stacks receiving the most treated water while it was not detected when only the dual-media filter was used, which showed that the presence of particulate matter could help limit biofouling development. Together with the performance recovery, we concluded that the application of the dual media filtration system is a suitable and cost effective pre-treatment for RED.

Multi Kernel Support Vector Machine for Particulate Matter Estimation

The presence of particulate matter, in the atmospheric environment, affects the health of living creatures as well as the ecosystem. Estimation of particulate matter has become one of the most challenging study for researchers. There are numerous computer techniques for the estimation of these particles. In this study, a multi kernel support vector machine (M-SVM) approach is introduced for the categorisation of particulate matter captured as digital images. Images from the archive of many outdoor scene (AMOS) have been taken for implementation purpose. The model is trained to predict the level of particulate matter captured as a digital image. An experimental model with M-SVM classification predicts the particulate matter captured as image among three levels, i.e., whether an image has a normal level, critical level or highly critical level. Simulated results were found to analyse the particulate matter with 98% of accuracy, which ensures efficient recognition of our experimental method.

Visual compatibility and particle counter evaluations of syringes of intramuscular psychotropic coadministered solutions

BackgroundPatients in the acute phase of agitation can require the administration of multiple drugs by intramuscular injection in order to temporarily stabilise their condition. Administration of multiple psychotropic medications in...

ZIF-8 Modified Nanofiber Composite Window Screen for Efficient Indoor PM2.5 and Formaldehyde Removal

Because people spend a lot of time indoors every day, the presence of particulate matter with a diameter less than 2.5 µm (PM2.5) and volatile organic molecular substances in indoor air adversely affect public health. These toxic compounds can be removed from the air using high-efficiency air-filter materials with adsorption capacity. Metal-organic frameworks (MOFs) are among the most suitable materials for air purification as they are synthetic porous materials with excellent adsorption ability. In this study, the zeolitic imidazolate framework-8 (ZIF-8) is uniformly grown on the surface of polyacrylonitrile (PAN) nanofibers using an in situ growth method to prepare ZIF-8@PAN nanofiber composite membranes. The nanofiber composite membrane effectively removes PM2.5 and formaldehyde from the air. After loading the optimal amount of ZIF-8, the filtration efficiency of the nanofiber membrane for salt aerosol with a diameter of 0.3 µm increases from 90.3 % to 96.9 %, and the removal rate of formaldehyde becomes 98 % within 20 min in the enclosed space of the laboratory. Moreover, after five repeated tests, the formaldehyde adsorption rate remains above 80 %. In addition, ZIF-8@PAN nanofiber membranes are used to fabricate anti-haze window screens, which have great potential to improve indoor air quality and mitigate related health risks.

InterCriteria Analysis Applied on Air Pollution Influence on Morbidity

Human health is reflected in all spheres of life and the economy. One of the main causes of morbidity and early mortality is polluted air. Ambient air pollution is a serious source of disease and mortality across the world. Cities are notorious for their high levels of air pollution and sickness. However, the precise degree of the health impacts of air pollution at the municipal level are still largely unclear. One of the main reasons for increased morbidity is the presence of particulate matter. The aim of our study is to show the relationship between elevated levels of particulate matter in the air and certain diseases. In this paper, we apply InterCriteria Analysis (ICrA) to find the correlation between the level of air pollution and the number of people seeking medical help. This is a new approach for the problem. The results show the affect of air pollution on certain diseases with a short exposure on polluted air and when the exposure is prolonged. We observed that some diseases are exacerbated by brief exposure to polluted air, while in others, exacerbation occurs after prolonged exposure.

Extended stability study of an extemporaneously analgesic solution of clonidine, ropivacaine and fentanyl

The aim of this work was to perform an extended stability study for the analgesic containing fentanyl, clonidine and ropivacaine in physiological saline solution 0.9% at different infusion sites, such as infusion bags, epidural infusion sets and syringes. The extended stability was assessed by an HPLC system equipped with a photodiode array detector set at 210 nm. The separation was conducted on a C18 column maintained at 40˚C and using an isocratic mobile phase consisted of buffer solution-methanol-acetonitrile (45:45:10, v/v/v). The presence of particulate matter and the pH of each solution were also investigated. Twenty-four hours after the preparation, the formation of one suspected product was observed and for all drugs, in 24 hours it was observed the concentration decrease in different sets (PVC infusion bags, syringes and epidural infusion administration sets). The pH values of each solution varied no more than 5% during the study and no particle was observed. Conclusion: The extended stability study was applied to the analgesic solution and promoted the detection of an unexpected peak in 24 hours. Based on it, further stability studies are necessary to determine the extended stability data.

X-ray imaging: A potential enabler of automated particulate detection and cake-structure analysis in lyophilized products?

The presence of particulate matter in parenteral products is a major concern since it affects the patients' safety and is one of the main reasons for product recalls. Conventional quality control is based on a visual inspection, which is a labour-intensive task. Limited to clear solutions and the surface of lyophilised products, it cannot be applied to opaque containers. This study assesses the application of X-ray imaging for detecting the particulate matter in a pharmaceutical lyophilized product. The most common types of particulates (i.e., steel, glass, lyo stopper, polymers and organics in different size classes) were intentionally spiked in vials. After optimizing all relevant parameters of the X-ray set-up, all classes of particulates were detected. At the same time, due to contrast enhancement, the inherent structures of lyophilized cake became obvious. This work addresses the potential and limits of X-ray technology in that regard, paving the way for automated image-based particulate matter detection. Moreover, this paper discusses using this approach to predict critical quality attributes (CQAs) of the drug product based on the cake structure attributes.

Generation and photogeneration of hydroxyl radicals and singlet oxygen by particulate matter and its inorganic components

Polluted air containing particulate matter (PM) is a huge environmental problem in the city of Kraków, Poland. PM causes numerous negative health effects including infection of the respiration system and cardiovascular disorders. The development of autoimmune disorders can be facilitated by redox active transition metals due to the generation of reactive oxygen species (ROS) and induction of oxidative stress, which results in lipid peroxidation, protein oxidation and severe oxidative modification of DNA. Our goal was to study ROS generation (in particular, HO• and 1O2) in the presence of PM collected via different procedures at different locations in Kraków. Scanning electron microscopy analysis confirmed that in all collected samples, aggregates of small grains could be observed. Cold plasma treatment was used to remove parts of the organic matter and to uncover inorganic compounds which become more relevant following plasma treatment. All samples were photoactive and showed hydroxyl radical generation. Singlet oxygen production studies indicated that during plasma treatment, unsaturated organic species are produced that intensify the generation of 1O2. Generation of hydroxyl radicals and singlet oxygen in vitro was confirmed using human epithelial cell line A549.

The Role of Physical Parameterizations on the Numerical Weather Prediction: Impact of Different Cumulus Schemes on Weather Forecasting on Complex Orographic Areas

Numerical weather predictions (NWP) play a fundamental role in air quality management. The transport and deposition of all the pollutants (natural and/or anthropogenic) present in the atmosphere are strongly influenced by meteorological conditions such as, for example, precipitation and winds. Furthermore, the presence of particulate matter in the atmosphere favors the physical processes of nucleation of the hydrometeors, thus increasing the risk of even extreme weather events. In this framework of reference, the present work aimed to improve the quality of weather forecasts related to extreme events through the optimization of the weather research and forecasting (WRF) model. For this purpose, the simulation results obtained using the WRF model, where physical parametrizations of the cumulus scheme can be optimized, are reported. As a case study, we considered the extreme meteorological event recorded on 25 November 2016, which affected the whole territory of Sicily and, in particular, the area of Sciacca (Agrigento). In order, to evaluate the performance of the proposed approach, we compared the WRF model outputs with data obtained by a network of radar and weather stations. The comparison was performed through statistical methods on the basis of a “contingency table”, which allowed for ascertaining the best suited physical parametrizations able to reproduce this event.

Optimal Design of High-Frequency Induction Heating Apparatus for Wafer Cleaning Equipment Using Superheated Steam

In this study, wafer cleaning equipment was designed and fabricated using the induction heating (IH) method and a short-time superheated steam (SHS) generation process. To prevent problems arising from the presence of particulate matter in the fluid flow region, pure grade 2 titanium (Ti) R50400 was used in the wafer cleaning equipment for heating objects via induction. The Ti load was designed and manufactured with a specific shape, along with the resonant network, to efficiently generate high-temperature steam by increasing the residence time of the fluid in the heating object. The IH performance of various shapes of heating objects made of Ti was analyzed and the results were compared. In addition, the heat capacity required to generate SHS was mathematically calculated and analyzed. The SHS heating performance was verified by conducting experiments using the designed 2.2 kW wafer cleaning equipment. The performance of the proposed pure Ti-based SHS generation system was found to be satisfactory, and SHS with a temperature higher than 200 °C was generated within 10 s using this system.

Strongly and Loosely Bound Water in Ambient Particulate Matter—Qualitative and Quantitative Determination by Karl Fischer Coulometric Method

Simple physical characterization of water evaporation can provide detailed information regarding its component distribution in particulate matter (PM) samples. The water presence in PM can greatly influence its polarity and subsequent reaction activity, for example, in secondary inorganic and organic matter formation. In this study, the presence of PM-bound water is detected using the Karl Fischer titration method in a temperature gradient with an aim to quantitatively assess different types of water occurrence. The analyses were initiated by testing two reference materials, namely urban particulate matter 1648a and urban dust 1649b (NIST). Four different types of water were found in both NIST materials, which helped to optimize the temperature ramp program and its adjustment for real PM samples. It was found that water contents in total suspended particles (TSP) are similar to those typically occurring in urban background stations—approximately 7.12–45.13% of the TSP mass, differentiated into the following water mass contributions: 48.5% of the total water found was loosely bound water; 23.3% was attributed to the absorption water; while the missing 20% could be probably attributed to crystal water removed only above 180 °C and artifacts connected with the drift correction problem. By comparing water release curves for single PM-compounds like pure SiO2; Al2O3; NH4NO3; (NH4)2SO4 and NH4Cl with water spectra obtained for real PM samples, it was found that water in particulate matter mainly comes from the dehydration of TSP-bound crystalline like Al2O3, SiO2 and to a lesser extent from salts like NH4NO3; (NH4)2SO4 and NH4Cl. A newly used thermal ramp method was able to assess water contents from Teflon–polypropylene baked filters characterized by low melting points and therefore filter degradation even under temperatures oscillating around 200 °C. The advantage of this new work is the separation of different types of TSP-bound water contributions, facilitating and promoting further research on the origin of PM-bound water and its role in atmospheric chemistry, secondary aerosol formation and visibility.

Towards Green Cements: The Metakaolin Route

One of the main challenges to be faced by the industry in this 21st century is the drastic reduction of its gaseous emissions, whether with the presence of particulate matter or substances that are aggressive to the environment. Both are problems found in the cement industry, which is responsible for up to 7% of carbon dioxide emissions produced by industrial human activity, which leads to the greenhouse effect [1].