Search Results (609)

Fine particulate matter (PM_2.5) is studied for the first time at ground level in different sites of Greater Rosario (GR), an urban and industrial area of central-eastern Argentina. Twelve sites were selected according to land use, and 87 samples were analyzed during winter 2021 and summer 2022. The spatial and temporal distribution of PM_2.5 was examined, comparing results among sites and with global data. Ground-based data were complemented with satellite-derived Aerosol Optical Depth (AOD) and nitrogen dioxide vertical column density (NO₂ VCD). During winter, the highest PM_2.5 was obtained at an industrial site in northern GR, while in summer, maximum values were observed in the center of Rosario. Summer rain events could contribute to the wet deposition of suspended particles, resulting in lower PM_2.5 concentrations. Satellite data indicate higher average AOD in summer (attributable to forest fires in NE Argentina) and higher NO₂ VCD in winter, coinciding with burning events in the Paraná Delta islands and reflected in some PM_2.5 peaks. This analysis represents the first approach to assessing the air quality of Rosario and its surroundings, with on-site data collected in association with land use. Full article

Microplastics are ubiquitous environmental particles with complex physical and chemical properties that enable them to interact with other contaminants. Recent evidence suggests that microplastics act as carriers for various chemical pollutants, altering their transport, deposition, and deposition dose. This conceptual review synthesizes current knowledge of radon progeny behavior and microplastic properties and suggests potential mechanisms for their interaction, although direct experimental validation of radon progeny specifically is currently lacking. It discusses attachment kinetics, transport pathways in air and water, and microplastic-mediated shifts in human lung deposition patterns and ecological exposure. Theoretical dosimetry reasoning suggests that, if attachment occurs, small respirable microplastics (1–10 μm) could increase inhalation doses by prolonging the airborne residence time of progeny indoors, whereas macro- and coarse microplastics would primarily affect localized environmental hotspots. These possibilities remain to be tested experimentally. Integrated experimental and modelling approaches, including radon chamber studies, aerosol and aquatic transport experiments, respiratory tract modelling, and ecological bioassays, are proposed to quantify these processes and inform risk assessment. Knowledge gaps remain in attachment efficiency, retention, co-contaminant interactions, and long-term exposure scenarios. Addressing these gaps is critical for refining human and ecological risk assessments and guiding regulatory frameworks in radon-microplastic-impacted environments. Full article

Breath aerosol analysis requires low-cost sensing substrates capable of capturing aerosolized biomolecular components while preserving chemically interpretable readouts. Here, methylcellulose–phenol red (MCPR) films are evaluated as multimodal sensing substrates using model bioaerosols consisting of sodium sulfate, bovine serum albumin (BSA), and polystyrene latex particles under acidic, neutral, and alkaline pH conditions. ATR-FTIR spectroscopy revealed inverse pH-dependent trends in sulfate (1000–1100 cm⁻¹) and protein amide (1500–1700 cm⁻¹) spectral regions. A sulfate-to-protein AUC ratio increased from 0.86 ± 0.01 at pH 4 to 3.56 ± 0.32 at pH 10, demonstrating ratiometric compositional discrimination of ionic and proteinaceous aerosol fractions. UV–Vis spectroscopy showed pH-dependent λmax shifts from 432 to 556 nm, confirming the preservation of phenol red optical responsiveness after aerosol exposure. FTIR-derived ratio metrics correlated linearly with optical responses, indicating coupled vibrational and optical sensing behavior. SEM-EDS analysis of methylcellulose capture films confirmed deposition of sulfate, proteinaceous, and particulate aerosol components, supporting the platform’s suitability for multimodal spectroscopic sensing. These findings establish MCPR films as integrated capture-and-sensing substrates capable of coupling optical pH responsiveness with label-free vibrational analysis, supporting future development of low-cost breath-relevant aerosol sensing platforms. Full article

Elevated particulate matter (PM) concentrations pose severe health risks, necessitating green infrastructure mitigation. While deposition is well documented, wind-induced remobilization remains insufficiently quantified. This study establishes a size-fractionated (PM_1–2.5 and PM_2.5–10) wind-induced resuspension and net removal values for six Central European shrub and climbing species (Parthenocissus quinquefolia, Hedera helix, Viburnum opulus, Viburnum lantana, Ligustrum ovalifolium, and Cornus mas) under controlled laboratory conditions. Following standardized aerosol chamber loading, leaves were subjected to constant, laminar airflow velocity of 3 m/s. Numerical quantification of particle counts per unit area (cm²) was performed via scanning electron microscopy with backscattered electron signal processing. Results demonstrate significant interspecific variations. Parthenocissus quinquefolia was most efficient, retaining the highest particle counts (121.6 × 10³ particles/cm² for PM_2.5–10) and achieving net removal rates of 46.3% and 60.5% for PM_1–2.5 and PM_2.5–10, respectively, relative to initial deposition. Cornus mas exhibited the lowest net removal efficiency for coarse particles (21.2% for PM_2.5–10), while Hedera helix showed the highest fractional resuspension rates (k = 1.93 × 10⁻⁴ ∙ s⁻¹ and 2.01 × 10⁻⁴ ∙ s⁻¹, respectively). These species-specific traits are vital for optimizing urban green infrastructure. Ultimately, these findings provide actionable recommendations for targeted plant selection to maximize urban air purification. Full article

High-frequency FY-4B aerosol optical depth (AOD) observations provide useful spatiotemporal constraints for dust nowcasting, but their application over bright deserts is limited by retrieval gaps and high-AOD uncertainty. This study develops a physics-informed spatiotemporal learning framework for 15–60 min FY-4B AOD nowcasting over the Taklimakan Desert. Historical FY-4B AOD, valid masks, ERA5 dynamic fields, model-level diagnostics, and surface constraints are organized on a unified 48 × 64 grid. An LSTM–TCN–Transformer temporal backbone is combined with spatial-context encoding, mask-aware observation encoding, and structured source–transport prediction heads to represent both temporal evolution and spatial plume structures. A physics encoder represents boundary-layer mixing, vertical wind shear, source-region emission, upwind transport, and deposition loss. Mask-aware encoding and structured prediction heads are used to handle missing retrievals, source and transport increments, high-AOD tails, and low-confidence regions. Results show that FY-4B AOD constrains the main dust-belt position and spatial extent within 1 h, with skill decreasing from 15 to 60 min. High-coverage samples show more stable spatial structures, whereas low-coverage and extreme high-AOD cases have larger peak underestimation and boundary errors. The proposed framework improves high-AOD event detection and spatial-structure preservation compared with persistence, advective persistence, ConvLSTM, and ST-UNet baselines. An additional case-based comparison with MODIS MAIAC AOD and MERRA-2 dust optical depth shows partial spatial colocation between predicted high-value footprints and independent aerosol-enhancement references; however, the reported skill scores should still be interpreted mainly as spatiotemporal consistency with the FY-4B AOD product field rather than direct validation of true atmospheric dust loading. Full article

Organic memristive devices are promising components for neuromorphic systems. Although based on solution-processable materials, their fabrication often involves complex, resource-intensive processes. Here, we report the fabrication of organic memristive devices using aerosol jet printing to deposit both the active channel based on proprietary polyaniline-based bioink and PEDOT:PSS electrodes. Polymers printing has been carried out both on rigid and flexible substrates, the latter with the aim of demonstrating a flexible device not subjected to films delamination upon bending. By optimizing printing parameters, we achieved devices exhibiting high ON/OFF current ratios exceeding 100 and rapid switching dynamics, with performance comparable on glass and Kapton supports. Morphological and electrical characterizations revealed that channel thickness and uniformity critically influence resistive switching behavior. These findings demonstrate that aerosol jet printing enables scalable, low-material-consumption production of flexible organic memristive devices suitable for neuromorphic applications, potentially facilitating their integration into complex, energy-efficient bio-inspired circuits. Full article

Aerosol-generating procedures (AGPs) expose healthcare personnel to airborne pathogens and require portable engineering controls that can be integrated into routine clinical workflows. We developed a portable, foldable negative-pressure aerosol-containment system (FNPACS) combining adaptive fan control, an H14 high-efficiency particulate air (HEPA) filter, and a disposable metal-oxide prefilter in a mobile filtration module. Bench performance was evaluated using pressure-flow testing in accordance with National Environmental Balancing Bureau (NEBB) procedures and International Organization for Standardization (ISO) 14644-3, polyalphaolefin aerosol challenge testing, and smoke visualization, while an exploratory clinical study assessed environmental contamination via real-time reverse-transcription PCR (rRT-PCR) in 11 patients (31 assay analyses). Bench testing demonstrated HEPA filtration efficiencies of 99.994–99.997%, stable negative-pressure generation across fan duty cycles, no detectable downstream breakthrough beyond the HEPA filter under the tested conditions, and effective inward airflow on smoke testing. A Lagrangian discrete phase model (DPM) particle-tracking simulation further characterized size-dependent aerosol-surrogate transport. Under HEPA-ON active-extraction conditions, 73.0–86.1% of simulated 0.3–10 µm water-equivalent particles were transported to the HEPA suction pathway, while 13.9–27.0% were deposited on internal wall surfaces. In the clinical evaluation, SARS-CoV-2 RNA detection on environmental swabs was limited and predominantly low level. The clearest reproducible signal occurred on the top interior surface under HEPA-OFF conditions, whereas HEPA-ON detections were isolated or presumptive high-Ct signals without reproducible confirmation. These findings provide preliminary engineering and usability support for FNPACS as a feasible near-source aerosol-control platform for AGPs. The patient swab component should be interpreted as an exploratory, proof-of-concept assessment rather than confirmatory evidence of clinical containment efficiency because several clinical cases had non-supportive patient-related controls and were therefore not used in the primary containment interpretation. Full article

The search for extraterrestrial life has traditionally focused on environments where liquid H₂O is stable over long timescales, such as subsurface aquifers, hydrothermal systems, or ice-rich deposits. However, many planetary bodies are characterized by active cycles of particulate transport involving either mineral dust or atmospheric aerosols. In planetary science, these are commonly distinguished as refractory particles (non-volatile mineral dust) and volatile or mixed aerosol particles, including condensates such as ices, organics, or acidic droplets. Here, we propose the concept of planetary aerobiomes, defined as distributed particle-associated microbial persistence and dispersal systems in extraterrestrial environments. In this framework, refractory mineral particles may act as mobile particle-associated microenvironments that could support microbial survival and dispersal, while in some cases also providing partial physical shielding from environmental stressors. Drawing on observations from terrestrial dust-associated microbiomes and mineral–microbe interactions, particle-associated systems may represent previously overlooked ecological substrates in planetary environments. Rather than replacing models centred on environments with persistent liquid H₂O, this perspective expands them by considering particle-associated microenvironments as transient but potentially relevant biosignature-preservation niches in arid, dust-dominated worlds such as Mars, as well as in aerosol-rich environments including Titan, Venus, and icy moons. We further discuss the implications for life-detection strategies, highlighting atmospheric particles as potential reservoirs of biosignatures, and consider their relevance for applied microbiology, including in situ resource utilization (ISRU) and bioregenerative life-support systems (BLSS). Beyond astrobiological implications, understanding microbial persistence within particle-associated extreme environments may provide useful models for applied microbiology, including stress-resilient microbial engineering, biomining, contamination control, and bioregenerative technologies for space exploration. Full article

Iron (Fe) is an essential micronutrient that constrains primary productivity across approximately 50% of the global ocean, thereby regulating ocean–atmosphere carbon exchange and climate. Atmospheric deposition dominates the external supply of Fe to the open ocean, directly impacting marine biogeochemical cycles. This review systematically synthesizes current knowledge on the sources of total and soluble aerosol Fe and on the key factors and mechanisms governing Fe solubility, including proton- and ligand-promoted dissolution, photoreduction, cloud processing, and their spatiotemporal variability. We critically evaluate the methodologies used to measure Fe solubility across studies, highlighting persistent uncertainties that arise from inconsistent extraction solutions, filter pore sizes, and leaching protocols. By identifying these challenges and integrating field observations, laboratory experiments, and model results, we aim to clarify the controls on atmospheric Fe solubility and provide a more robust assessment of its contribution to marine primary productivity and biogeochemistry. Full article

Ensuring the effective removal of airborne particles is essential for maintaining indoor air quality, particularly in environments with limited ventilation. This study examines how ion polarity regime, voltage, and relative humidity influence aerosol particle removal in a controlled, room-sized chamber (35.8 m³) using a custom-built air ionizer. Experiments were conducted under stagnant and ventilated conditions (0.5 h⁻¹) while varying ionizer polarity (positive, negative, bipolar, alternating), voltage (6 kV, 10 kV), humidity (40%, 70%), and aerosol type (incense smoke, nebulized KCl). Positive and negative unipolar ionization achieved over 90% removal within 60 min, with decay rates of 0.04–0.05 min⁻¹, half-lives of 13–17 min, and clean air delivery rates (CADR) of 60–90 m³ h⁻¹. Bipolar ionization was less efficient due to ion-ion recombination, yielding CADR values below 25 m³ h⁻¹, while alternating polarity improved deposition (40–70 m³ h⁻¹) by reducing recombination losses. Relative humidity had a minimal influence on unipolar performance but moderated efficiency in bipolar and alternating modes. Under low ventilation, unipolar negative ionization sustained high removal (96.7%), while ozone remained below the detection limits of the methods used. These findings indicate that ion polarity control and field strength strongly influence particle removal and that unipolar or alternating-polarity operation can provide effective particle removal under controlled chamber conditions, including a low-ventilation case of 0.5 h⁻¹. Full article

The organic complexation of Cu²⁺ in aquatic systems dominates its chemical speciation, affecting its reactivity and bioavailability. Using voltammetry, we investigated Cu²⁺ organic complexing capacity (CuCC) in atmospheric samples, including water-soluble aerosol fraction, rainwater (wet-only deposition), and bulk deposition (wet and dry deposition), collected in a coastal marine area (National Park Brijuni, Adriatic Sea). The focus was on minimizing analytical interferences from surface-active substances (SAS) that accounted for up to 56% of dissolved organic carbon. Method optimization was performed using model SAS (humic-like substances, fulvic acid, and pollen-derived organic material), resulting in an optimal desorption potential of −1.4 V and the addition of 1 mg/L Triton X-100. Under these conditions, CuCC parameters of average ligand concentration and conditional stability constant of (209.8 ± 6.7) nM and log K = (10.2 ± 0.6) in water-soluble aerosol fraction, (117.1 ± 5.0) nM and log K = (9.6 ± 0.2) in rainwater, and (142.9 ± 4.1) nM and log K = (10.2 ± 0.2) in bulk deposition were determined. Atmospheric inputs represented a source of weak Cu-binding ligands for marine areas. In conclusion, short-term monitoring provided insight into the variability of different atmospheric inputs and offered a methodological basis for future long-term, more comprehensive studies. Full article

This work evaluates a potassium ion-selective electrode (K-ISE) fabricated using Aerosol Jet Printing (AJP) and compares its performance with that of a commercial K⁺-selective electrode (KION). Both sensors exhibit near-Nernstian behavior, with average sensitivities of 57.91 ± 5.07 mV/dec for the AJP device and 57.28 ± 5.07 mV/dec for the commercial electrode, confirming a near-Nernstian K⁺ response over the tested concentration range. Single-interferent response tests demonstrate that AJP-printed electrodes provide a more stable and less sensitive response to sodium interference (24.37 ± 1.39 mV/dec) compared to KION (33.95 ± 8.95 mV/dec), while showing comparable NH₄⁺ response and a slightly higher response toward urea than KION. Morphological analysis (OM and SEM) reveals that AJP enables smoother, more homogeneous films and improved control over the transducer/membrane interface. Unlike previous studies, this work presents a direct experimental comparison between AJP-fabricated and commercial ISEs under controlled interference conditions relevant to agricultural and environmental matrices. Although the AJP sensors exhibited near-Nernstian behavior and fast response times, their reproducibility was lower than that of the commercial electrodes (RSD = 30.12% vs. 18.45%), indicating that further optimization of the printing and membrane deposition processes is required. Full article

Background/Objectives: The development of dry powder formulations for pulmonary delivery of therapeutic antibodies requires careful stabilization strategies to preserve protein integrity during spray-drying and long-term storage. This study investigates the impact of various sugar-derivatives, a polyol (D-mannitol), a disaccharide (D-sucrose) and a polysaccharide (dextran 10 kDa), used individually or in combination, on the physical stability of bovine polyclonal immunoglobulin G (pAb) in dry powders for inhalation (DPIs). Methods: A design of experiments (DoE) approach was employed to evaluate the effects of these excipients on residual moisture (RM), low-order aggregates (LOA) and high-order aggregates (HOA), immediately after spray-drying (T0) and after 10 months of storage at room temperature in a desiccator (T10). Results: All DPIs exhibited a high amorphous content and a favorable glass transition temperature, with RM decreasing over time. The combination of D-mannitol and dextran 10 kDA (DPI-MD) demonstrated the most effective stabilization, minimizing LOA and HOA formation at T0 and T10. Although the ternary mixture, including D-sucrose (DPI-MSD) exhibited higher process stability, it was less stable over time in comparison to the binary mixture. The aerodynamic performance of these carrier-free DPIs, assessed via laser diffraction (% ˂ 5 µm), were between 51 ± 3 (DPI-MD) and 67 ± 4 (DPI MSD) and a Next Generation Impactor, confirmed that formulation produced aerosol with suitable size distribution and fine particle fractions (FPFn upt to 71 ± 5% for DPI-MSD), for deep pulmonary deposition. Conclusions: These findings highlight the importance of combining excipients with complementary physical properties to achieve robust protein stabilization. The DPI-MD emerged as the most promising candidate for pAb lung delivery, balancing protein integrity, powder stability, and aerodynamic efficiency. Full article

This study focuses on modelling the spatial dependence of airborne particle contamination using Response Surface Methodology (RSM), with consideration of its implications for technical cleanliness and employee health. The analysis is based on two measurement campaigns conducted in an industrial production hall, where particle concentrations were recorded across multiple size fractions using a TROTEC PC220 device. The results demonstrate that RSM effectively captures nonlinear relationships and spatial gradients, enabling the identification of local extrema and contamination hotspots. Statistical analysis confirmed a significant influence of spatial coordinates on particle concentration across all fractions, with finer particles exhibiting stronger spatial dependence, consistent with aerosol behaviour in indoor environments. Quadratic model terms revealed stable hotspot regions persisting even after corrective measures, indicating persistent contamination sources or structural factors. Residual analysis suggested additional unmodeled local sources or transport mechanisms. Based on the integration of RSM and multi-fraction analysis, a mechanistic contamination model (source–transport–receptor framework with deposition processes) is proposed, linking particle behaviour with surface contamination and potential human exposure. The approach enables data-driven, localised contamination control and supports optimisation of technical cleanliness and occupational health conditions. Full article

Background/Objectives: Cannabidiol (CBD) has emerged as a potential therapeutic agent for respiratory disorders, including asthma and chronic obstructive pulmonary disease. However, its clinical translation via pulmonary delivery is limited by poor aqueous solubility, chemical instability, and low local bioavailability. This study aimed to develop and optimize a sodium stearate (NaSt)-based spray-dried dry powder inhaler (DPI) formulation to enhance the aerosol performance, dissolution, and storage stability of CBD. Methods: CBD microparticles were prepared by spray drying using NaSt as the primary excipient. The feed preparation method, spray-drying parameters, and CBD:NaSt ratios were systematically optimized. The resulting powders were evaluated for aerodynamic properties using cascade impaction, dissolution behavior in simulated lung fluid, solid-state characteristics, and accelerated stability under stress conditions. Results: The optimized formulation, SD-4, a spray-dried CBD:NaSt formulation prepared at a 20:80 weight ratio using Process B, demonstrated excellent aerosolization performance, with a fine particle fraction (FPF) exceeding 50% and a mass median aerodynamic diameter (MMAD) of 5.08 ± 0.1 μm. Dissolution testing revealed more than a three-fold increase in drug release compared with raw CBD, attributed to amorphous dispersion within the NaSt matrix and surfactant-induced micellization. Accelerated stability studies confirmed improved retention of the amorphous state and drug content, while antioxidant incorporation further reduced oxidative degradation. Conclusions: The NaSt-based spray-dried formulation significantly improved aerosol deposition efficiency, dissolution rate, and physicochemical stability of CBD. This formulation strategy may provide a promising platform for pulmonary delivery of poorly water-soluble compounds. Full article