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High Altitude Pulmonary Edema (HAPE) seriously threatens the health of people at high altitudes. There are drug treatments for HAPE, and dry powder formulations (DPFs) represent a rapid and accessible delivery vehicle for these drugs. However, there are presently no reports on the inhalability of DPFs in low-pressure environments. Given the reduced atmospheric pressure typical at high altitudes, conventional DPFs might not be suitable for inhalation. Therefore, it is necessary to elucidate the deposition behaviors of dry powder in the respiratory tract at low pressure, as well as to improve their pulmonary deposition efficiency via adjustments to their formulation and design. The effect of air pressure, inspiratory velocity, and particle properties (such as size, density, and aerodynamic diameter) on pulmonary deposition of DPFs was calculated by a computational fluid dynamics (CFD)-coupled discrete phase model. DPFs of various aerodynamic diameters were prepared by spray drying, and the inhalability of these DPFs in a low-pressure environment was evaluated in mice. Finally, a mouse model of HAPE was established, and the treatment of HAPE by nifedipine-loaded DPFs with small aerodynamic diameter was validated. CFD results showed that low pressure decreased the deposition of DPFs in the lungs. At 0.5 standard atmosphere, DPFs with aerodynamic diameter of ∼2.0 μm could not enter the lower respiratory tract; however, a decrease in the physical diameter, density, and, consequently, the aerodynamic diameter of the DPFs was able to enhance pulmonary deposition of these powders. To validate the CFD results, three kinds of dry powder with aerodynamic diameters of 0.66, 0.98, and 2.00 μm were prepared by spray drying. Powders with smaller aerodynamic diameter could be inhaled into the lungs of mice more effectively, and, consequently could ameliorate the progression of HAPE more effectively than conventional powders. These results were consistent with the CFD results. Low atmospheric pressure can prevent the pulmonary deposition of DPFs at high altitudes. Compared with conventional DPFs, powders with smaller aerodynamic diameter can be effectively inhaled at these pressures and thus might be more suitable for the treatment the HAPE. [ABSTRACT FROM AUTHOR]

An Assessment of PM2.5 at Oluku dumpsite and selected residential buildings was investigated in Ovia North East local government in Benin City, Edo state Nigeria using a portable hand-held digital anemometer (BTMETER 100) and air quality monitor (L529K). Data obtained gives the mean values of PM2.5 range of 36.20-45.50 μg/m³ and 58.17-393.82 μg/m³ for wet and dry season respectively, which shows significant difference in spatial and seasonal distribution of PM2.5 (p< 0.05) in the study area and control stations. Further findings revealed that concentration PM2.5 in both seasons and sampling locations exceeded the WHO and USEPA Limits of 25 μg/m³and 35 μg/m³ respectively with the exception of the control (GAQC) location during wet season. [ABSTRACT FROM AUTHOR]

An Assessment of PM2.5 at Oluku dumpsite and selected residential buildings was investigated in Ovia North East local government in Benin City, Edo state Nigeria using a portable hand-held digital anemometer (BTMETER 100) and air quality monitor (L529K). Data obtained gives the mean values of PM2.5 range of 36.20-45.50 µg/m3and 58.17–393.82 µg/m3 for wet and dry season respectively, which shows significant difference in spatial and seasonal distribution of PM2.5 (p ) in the study area and control stations. Further findings revealed that concentration PM2.5 in both seasons and sampling locations exceeded the WHO and USEPA Limits of 25 µg/m3and 35 µg/m3 respectively with the exception of the control (GAQC) location during wet season.

To regulate the safety protocols in nuclear facilities, radioactive aerosols have been extensively researched to understand their health impacts. However, most measured particle-size distributions remain at low resolutions, with the particle sizes ranging from nanometer to micrometer. This study combines the high-resolution detection of 500 size classes, ranging from 6 nm to 10 μm, for aerodynamic diameter distributions, with a regional lung deposition calculation. We applied the new approach to characterize particle-size distributions of aerosols generated during the plasma arc cutting of simulated non-radioactive steel alloy wastes. The high-resolution measured data were used to calculate the deposition ratios of the aerosols in different lung regions. The deposition ratios in the alveolar sacs contained the dominant particle sizes ranging from 0.01 to 0.1 μm. We determined the distribution of various metals using different vapor pressures of the alloying components and analyzed the uncertainties of lung deposition calculations using the low-resolution aerodynamic diameter data simultaneously. In high-resolution data, the changes in aerosols that can penetrate the blood system were better captured, correcting their potential risks by a maximum of 42%. The combined calculations can aid the enhancement of high-resolution measuring equipment to effectively manage radiation safety in nuclear facilities.

Particle size measurement of aerosolized particles from orally inhaled and nasal drug products (OINDPs) can be used to assess the likely deposition distribution in the human respiratory tract (HRT). Size is normally expressed in terms of aerodynamic diameter, since this scale directly relates to the mechanics of particle transport from inhaler to deposition locations. The multistage cascade impactor (CI) is the principal apparatus used to size fractionate aerosols in terms of their aerodynamic particle size distributions (APSDs). Clinically meaningful metrics, such as fine and coarse particle mass fractions, can be determined from the cumulative mass-weighted APSD. In effective data analysis (EDA), CI data are reduced to small and large particle mass. The sum and ratio of these metrics are used to characterize impactor-sized mass, without the need for stage groupings or other APSD interpretation. Aerosol characterization by full-resolution CI is complex, and so, an abbreviated impactor measurement has recently come to prominence. Here, multiple stages of the CI are reduced to just one or two size fractionating stages so that measures of fine (and extrafine) particle mass from a two-stage system can be directly determined without the need to group the mass of active pharmaceutical ingredient (API) on adjacent stages. Time-of-flight-based methods determine APSD more rapidly but require refinements such as single-particle mass spectroscopy to relate size measurements to API content. Alternatives for size characterizing OINDP aerosols are few; laser diffractometry is by far the most important, especially for nasal sprays and solution-based orally inhaled formulations in which there is no confounding of data from suspended excipient(s). Laser-phase Doppler anemometry (L-PDA) has also been shown to be useful for nasal sprays. If aerodynamic size-related information is not a priority, optical microscopy combined with Raman chemical imaging offers prospects for separate determination of API components in combination product-generated aerosols. [ABSTRACT FROM AUTHOR]

Introduction: Air quality in industrial workshops is affected by various harmful chemical agents. Purpose of this study was to compare work environment air quality in a number of industrial workshops based on the mass concentration and number of suspended particles in air and application of Kriging geostatistical method in industries. Materials and Methods: This observational study was carried out in four workshops including cuprous waste separation works, rolling and cutting, casting and copper smelting, manufacturing aluminum products and double-glazed glass production. Using particle mass counter sampler of Tes 5200 model, mass concentration and number concentration of suspended particles in row of different diameters were measured. The spatial distribution map of PM2.5 and PM10 in each of workshops was prepared using Kriging geostatistic method in GIS environment Version 10.5. Results: The highest mass concentration (8.42 mg/m3) and number concentration (445058 Particle/lit in differential mode and 885446 Particle/lit in cumulative mode) were measured in the manufacturing aluminum products workshop. The highest mass concentration and number concentration of suspended particles were obtained for row diameters of 10 µm and 0.5 µm, respectively. Interpretation of Kriging maps showed that various areas of the industries such as radiation furnace, scrap press, aluminum smelter, sieve, diamond machine, glass furnace and ingot molds had the highest frequency of PM2.5 and PM10. Conclusion: Engineering control actions such as installation of ventilation systems in halls and design and installation of a local hood in the entrance sections of the aluminum smelting furnace and sieve in manufacture of aluminum products workshop and copper ingot molds in casting and smelting workshop is essential for improved air quality.

Aerodynamic diameter is an important determinant of the physical processes that act upon airborne fungi. Processes include gravitational settling, respiratory deposition, penetration into buildings, resuspension from surfaces into air, and long-range transport. This study combined next-generation DNA sequencing (NGS) with quantitative PCR (qPCR) to evaluate diverse, taxon-specific, fungal aerodynamic diameters from bioaerosol samples. The accuracy of the method was demonstrated by comparing geometric mean aerodynamic diameters of selected taxa produced by the NGS-based method to the diameters produced by taxon-specific qPCR (r=0.996). Geometric means (dg) and geometric standard deviations (σg) of aerodynamic diameters were characterized for more than 50 fungal taxa, spanning 55 genera, 9 classes, and 2 phyla. The results reported in this study demonstrate the robust nature of this method, provide novel insights into aerodynamic properties of diverse airborne fungal species, and potentially enable a better accounting of taxon-specific fungal fate and exposure both in indoor air and in the atmosphere.

Aerodynamic diameter is an important determinant of the physical processes that act upon airborne fungi. Processes include gravitational settling, respiratory deposition, penetration into buildings, resuspension from surfaces into air, and long-range transport. This study combined next-generation DNA sequencing (NGS) with quantitative PCR (qPCR) to evaluate diverse, taxon-specific, fungal aerodynamic diameters from bioaerosol samples. The accuracy of the method was demonstrated by comparing geometric mean aerodynamic diameters of selected taxa produced by the NGS-based method to the diameters produced by taxon-specific qPCR (r=0.996). Geometric means (dg) and geometric standard deviations (σg) of aerodynamic diameters were characterized for more than 50 fungal taxa, spanning 55 genera, 9 classes, and 2 phyla. The results reported in this study demonstrate the robust nature of this method, provide novel insights into aerodynamic properties of diverse airborne fungal species, and potentially enable a better accounting of taxon-specific fungal fate and exposure both in indoor air and in the atmosphere.

Abstract Particle‐based pulmonary delivery has great potential for delivering inhalable therapeutics for local or systemic applications. The design of particles with enhanced aerodynamic properties can improve lung distribution and deposition, and hence the efficacy of encapsulated inhaled drugs. This study describes the nanoengineering and nebulization of metal–phenolic capsules as pulmonary carriers of small molecule drugs and macromolecular drugs in lung cell lines, a human lung model, and mice. Tuning the aerodynamic diameter by increasing the capsule shell thickness (from ≈100 to 200 nm in increments of ≈50 nm) through repeated film deposition on a sacrificial template allows precise control of capsule deposition in a human lung model, corresponding to a shift from the alveolar region to the bronchi as aerodynamic diameter increases. The capsules are biocompatible and biodegradable, as assessed following intratracheal administration in mice, showing >85% of the capsules in the lung after 20 h, but 90% of capsules remaining nonassociated with cells. The amenability to nebulization, capacity for loading, tunable aerodynamic properties, high biocompatibility, and biodegradability make these capsules attractive for controlled pulmonary delivery.

Particle‐based pulmonary delivery has great potential for delivering inhalable therapeutics for local or systemic applications. The design of particles with enhanced aerodynamic properties can improve lung distribution and deposition, and hence the efficacy of encapsulated inhaled drugs. This study describes the nanoengineering and nebulization of metal–phenolic capsules as pulmonary carriers of small molecule drugs and macromolecular drugs in lung cell lines, a human lung model, and mice. Tuning the aerodynamic diameter by increasing the capsule shell thickness (from ≈100 to 200 nm in increments of ≈50 nm) through repeated film deposition on a sacrificial template allows precise control of capsule deposition in a human lung model, corresponding to a shift from the alveolar region to the bronchi as aerodynamic diameter increases. The capsules are biocompatible and biodegradable, as assessed following intratracheal administration in mice, showing >85% of the capsules in the lung after 20 h, but <4% remaining after 30 days without causing lung inflammation or toxicity. Single‐cell analysis from lung digests using mass cytometry shows association primarily with alveolar macrophages, with >90% of capsules remaining nonassociated with cells. The amenability to nebulization, capacity for loading, tunable aerodynamic properties, high biocompatibility, and biodegradability make these capsules attractive for controlled pulmonary delivery. [ABSTRACT FROM AUTHOR]

Highlights • Radioactive aerosols from activated metal cutting determine internal dose. • Cutting methods are the most critical factor to influence aerosols distributions. • Choosing cutting methods can reduce aerosols by a factor of 500. • Choosing cutting environments can reduce aerosols by a factor of 100. • Worker's internal exposure of cobalt-60 can be underestimated by a factor of 4. Abstract Radioactive aerosols from nuclear power plant decommissioning have not been actively studied compared to those from severe accidents. However, it will be more critical issues in the future. The radioactive aerosols will deposit on the surfaces of matter and disperse in the working space. Hence, the workers in nuclear power plant decommissioning may inhale some of the aerosols during the normal operation or accident. The health effects of aerosols depend not only on the particle size but also on the aerodynamic and thermodynamic characteristics. Therefore, it is crucial to understand the distribution of radioactive aerosols regarding their aerodynamic diameters, radioactive isotopes, and chemical forms to ascertain the respirable fraction. We analyze the effect of the cutting method, cutting material, and cutting conditions on the mass and radioactivity distributions of radioactive aerosols and identify the dominant factor for the safety of workers in the nuclear power plant decommissioning process. We confirm that the chemical composition and radioactive contamination in cutting material affect the aerodynamic diameter distribution and the amount of aerosol. Finally, we suggest the underwater plasma arc cutting process that could minimize the internal dose of workers at the nuclear power plant decommissioning sites. [ABSTRACT FROM AUTHOR]

Abstract This study demonstrates an our newly designed novel in-line real impactor, which is operated at the inlet flow rate of 1.0 L/min and has vertical annular nozzle to separate particles larger than 20.5 µm in the aerodynamic diameter. The Stk 50 for an impactor with a rectangular nozzle was selected as the design parameters of the impactor. The influences of both existences of an orifice and distance between orifice and impaction plate are investigated numerically and experimentally. In numerical simulations, Stk 50 of an impactor without an orifice is found to be 20.5% and 17.0% larger than that of an impactor with an orifice when the distance between an orifice and the impaction plate is 1.2 mm and 1.8 mm, respectively. For the impactor with an orifice, the Stk 50 is predicted to decrease from 0.74 to 0.43 when the distance between orifice and impaction plate was decreased from 1.8 mm to 1.2 mm with an orifice. It is found that the pressure drop of the impactor with an orifice is at most 2.35% larger than that of the impactor without an orifice. Thus, the presence of an orifice can increase the pressure drop slightly but increase collection efficiency significantly. For our newly developed impactor, the collection efficiency of is primarily influenced by the distance between an orifice and the impaction plate. In experiments, the Stk 50 was decreased from 0.50 to 0.25 when the distance between orifice and impaction plate was decreased from 1.8 mm to 1.2 mm. The Stk 50 obtained from experimental data shows the same tendency as numerical predictions Highlights • Novel in-line real impactor with a vertical annular nozzle was devised. • Design parameters of the impactor were optimized using the Stk 50 of the rectangular nozzle. • Collection efficiencies significantly increased but pressure drop slightly changed. [ABSTRACT FROM AUTHOR]

Fungal species composition and site of deposition within the airways affects whether diseases develop and where they may arise. The aim of this study is to obtain knowledge regarding the potential deposition of airborne culturable, viable, and non-viable fungi in the airways of pig farm workers, and how this composition changes over multiple sampling days. Airborne fungi were sampled using impactors and subsequently analyzed using amplicon sequencing and matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) fingerprinting. The geometric mean aerodynamic diameter (Dg) of airborne particles with culturable airborne fungi were not affected by sampling days and ranged in size between 3.7 and 4.6 µm. Amplicon sequencing of the internal transcribed spacer region of the rRNA gene operon, in combination with DNA interchelating agents, revealed a large presence of non-viable fungi, but several pathogenic and toxic fungal species were detected in the viable portion. The diversity was found to be significantly associated with the sampling day but did not change significantly over multiple sampling rounds during the same day. The non-viable fraction contained genera typically associated with the pig gastrointestinal tract, such as Kazachstania and Vishniacozyma. In conclusion, the Dg of culturable fungi was between 3.7 and 4.6 µm, and the Dg of the viable and total fungi was 1.5 and 2.1 µm, respectively. The species composition changed over the multiple sampling days.

With the increase in depth of mines, the movement and dispersion of particulate matter (PM) are very difficult to predict due to improper ventilation. Insufficient open pit ventilation remains the principal driver for the lack of dispersion and evacuation from mines and ultimately increases the time and amount of exposure to miners. Studies suggest that there is a direct and dependent relationship between the composition and exposure time to PM in mining operations. Furthermore, this paper helps the reader appreciate the need of carrying out studies to understand the nature of the dispersion of PM inside the mines. [ABSTRACT FROM AUTHOR]

Aim: Chitosan-coated polylactic-co-glycolic acid nanoparticles of voriconazole (VChNP) were developed to increase residence time and provide sustained drug release locally to treat recurrent lung-fungal infection. Materials & methods: VChNP has been developed using a simple, unique technique and characterized. Pharmacokinetics, lung deposition with time and gamma imaging were conducted with optimized formulations. Results: The deposition of fluorescein isothiocyanate-labeled VChNP in lung was confirmed by confocal microscopy. Gamma-scintigraphic images showed that Tc-99m-labeled VChNP had better pulmonary retention for longer period than that of noncoated formulation. Drastic improvement in pharmacokinetic profile of VChNP than noncoated formulation was observed. Conclusion: Thus, VChNP may be useful for effective pulmonary delivery with improved bioavailability. Such chitosan-coated nanoparticles may open up a new avenue for efficacious treatment of lung-fungal infection. [ABSTRACT FROM AUTHOR]

The purpose of this study was to reveal the effects of the conformation of poly (DL-lactide- co -glycolide) (PLGA) molecules in the feed solution on the aerodynamic diameter of PLGA microparticles prepared by using spray drying method. We investigated the conformation of PLGA molecules in the feed solution using viscometry. The data provide information about the polymer coil radius ( R coil ), the overlap concentration ( c *). Then, we prepared various rifampicin-loaded PLGA microparticles by changing the mixing ratio of dichloromethane and methanol. We used a cascade impactor and mice to measure the aerodynamic diameter of the microparticles in vitro and in vivo , respectively. The viscosity measurement showed that an increased molar ratio of methanol in the solvent compositions resulted in the decreased R coil and increased c *. Then, we found that the increased molar ratio of methanol in the solvent compositions resulted in the increased fine particle fraction value in vitro and delivery ratio to lung in vivo . The conformation of PLGA molecules in the feed solutions influences PLGA network in the microparticles, which would affect the aerodynamic diameter of the microparticles. In conclusion, the finding of our study suggests that solvent selection and connectivity of PLGA molecules of microparticles are associated with the aerodynamic diameter. [ABSTRACT FROM AUTHOR]