Journal of Aerosol Science最新文献

{"title":"Ammonium nitrate nanoparticle emissions from ammonia-fueled internal combustion engines","authors":"Tejashri S. Patil,&nbsp;Alex R. Voris,&nbsp;Seamus P. Kane,&nbsp;William F. Northrop","doi":"10.1016/j.jaerosci.2025.106614","DOIUrl":"10.1016/j.jaerosci.2025.106614","url":null,"abstract":"<div><div>When synthesized from renewable energy, anhydrous ammonia (NH₃) is a zero-carbon fuel; therefore, by definition, its combustion produces no carbonaceous soot particles. However, this study reveals that ammonium nitrate ultrafine particles are emitted in significant quantities from ammonia combustion in engines. In the experimental work, a retrofitted single-cylinder Cummins ISB6.7 engine was operated at 1200 RPM and 1800 RPM at 50 % load. Gaseous emissions were measured using a Fourier transform infrared (FTIR) emissions bench, while particle size distribution was assessed using a scanning mobility particle sizer. Size-separated particles were collected using a MOUDI impactor and characterized to identify the chemical composition using attenuated total reflectance-FTIR, Raman spectroscopy, and X-ray photoelectron spectroscopy techniques. Additionally, particle morphology was studied using transmission electron microscopy, while energy-dispersive X-ray spectroscopy mapping was performed to confirm elemental composition. The particle size distribution indicated a monomodal lognormal distribution with diameters ranging from 6.15 nm to 224.7 nm. The geometric mean diameter was 30.6 nm at 1200 RPM and 28.9 nm at 1800 RPM. The corresponding total concentrations were 2.5 × 10⁶ and 3.4 × 10⁶ particles/cm³, respectively. Characterization results indicate that the measured particle emissions primarily consist of ammonium nitrate, potentially synthesized in combustion through the reaction of unburned ammonia with nitrogen dioxide. Elemental maps show nitrogen and oxygen, indicating the presence of nitrates, along with sulfur, magnesium, potassium, and calcium, likely originating from lubricant oil additives. One formation mechanism is believed to involve heterogeneous nucleation, during which particles are adsorbed onto existing ash particles containing inorganic metals originating from the entrainment and combustion of lubricant oil.</div></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"188 ","pages":"Article 106614"},"PeriodicalIF":3.9,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144116241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of methods for aerosolising polystyrene latex nanoparticles and assessment of their toxicity","authors":"Hugo Öhrneman ,&nbsp;Sarah McCarrick ,&nbsp;Anda Gliga ,&nbsp;Per Wollmer ,&nbsp;Karin Broberg ,&nbsp;Jakob Löndahl","doi":"10.1016/j.jaerosci.2025.106607","DOIUrl":"10.1016/j.jaerosci.2025.106607","url":null,"abstract":"<div><div>Aerosolised Polystyrene Latex (PSL) nanoparticles are, due to their well-defined size, spherical shape, and inert surface, useful in many experimental applications, including studies of particle deposition in the human lung. Aerosolising nanoparticles entails added challenges, and nanoparticles can potentially be more hazardous than otherwise equivalent microparticles. The objective of this work was to evaluate methods for aerosolising PSL nanoparticles and assess their toxicity.</div><div>We investigated a Collison-type generator, a TSI Electrospray, and the recent Kanomax NanoAerosol Generator (NAG). We also examined the cyto- and genotoxicity of nano-PSL to human bronchial epithelial cells (BEAS-2B) in serum-free conditions and to monocyte-derived macrophages (THP-1) in both serum-free and serum-enriched conditions.</div><div>When comparing the generators, we found that the NAG produced an aerosol with greater separation between the PSL and residual particles than the Collison and was the most stable generator tested. The electrospray generated an aerosol without any overlap between the residual and the PSL modes but was also the most unpredictable, making it less suited for areas where ease of use and high repeatability are needed. We found that the Collison is generally unsuitable to generate nano-sized aerosol. The lowest observed effect level for cytotoxicity in BEAS-2B was 25, 50 and 50 μg/mL for 30, 50 and 100 nm PSL, respectively. For serum-free THP-1 macrophages, it was 50 μg/mL for 30 nm PSL and 150 μg/mL for 50 and 100 nm PSL. THP-1 macrophages displayed no cytotoxicity in serum-enriched culture. None of the tested particles were genotoxic in the alkaline comet assay.</div><div>Overall, the NAG exceeded the Collison and electrospray in stability but produced a more polydisperse aerosol than the electrospray. PSL particles induced dose- and size-dependent cytotoxicity in BEAS-2B and in THP-1 cells with the smallest particles (30 nm) being the most toxic. However, the concentration is several orders of magnitude higher than typical concentrations for experimental applications.</div></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"188 ","pages":"Article 106607"},"PeriodicalIF":3.9,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144089392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The statistical overloading framework for accurate evaluation of pollutant dispersal with rigorous uncertainty estimation","authors":"K.A. Krishnaprasad ,&nbsp;R. Patel ,&nbsp;C. El Khoury ,&nbsp;A.J. Banko ,&nbsp;N. Zgheib ,&nbsp;S. Balachandar","doi":"10.1016/j.jaerosci.2025.106590","DOIUrl":"10.1016/j.jaerosci.2025.106590","url":null,"abstract":"<div><div>Accurate characterization of turbulent dispersal of aerosols and pollutants is a topic of interest involving turbulent flows in a variety of indoor and outdoor settings. For the case of a ventilated indoor space, the stochastic nature of the dispersal process results in variations due to factors such as turbulent transport and spatial inhomogeneity. Statistical overloading is a novel technique wherein the computational domain is overloaded with an abundance of pollutant particles that are randomly seeded over space and time. This would allow us to capture quantities of interest, such as mean and variation of pollutant concentration, to any desired accuracy for all possible pollutant release and sensing locations, using just one master simulation. In this study, the statistical overloading framework is employed for the case of turbulent dispersal in ventilated indoor spaces using Euler–Lagrange LES simulations in a canonical room of dimensions <span><math><mrow><mn>10</mn><mo>×</mo><mn>10</mn><mo>×</mo><mn>3</mn><mo>.</mo><mn>2</mn><mspace></mspace><msup><mrow><mtext>m</mtext></mrow><mrow><mn>3</mn></mrow></msup></mrow></math></span>. We establish clear guidelines for selecting computational parameters involved in designing turbulent dispersal simulations, with potential applications to other challenges involving aerosol, particulate, or pollutant dispersal. These parameters include, but are not limited to, the minimum number of particles to be tracked during the simulation and the minimum number of turbulent/spatial realizations required to achieve converged statistics to any specified level of accuracy. We leverage the extensive Lagrangian statistics obtained from Euler–Lagrange simulations, combined with well-established statistical theory, to derive the aforementioned guidelines and requirements.</div></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"188 ","pages":"Article 106590"},"PeriodicalIF":3.9,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143899729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of enthalpy of vaporization for particulate matter through molecular dynamics using OPLS force field","authors":"Seung Weon Jeong ,&nbsp;Yeonseo Kim ,&nbsp;Hyung-Kyu Lim ,&nbsp;Min Chan Kim ,&nbsp;Chul Han Song ,&nbsp;Sangheon Lee","doi":"10.1016/j.jaerosci.2025.106595","DOIUrl":"10.1016/j.jaerosci.2025.106595","url":null,"abstract":"<div><div>Chemical pollutant molecules dispersed in the atmosphere in the form of particulate matter are harmful to humans. Accurate data sets on the volatility of particulate matter components are required to address the ongoing issues of air pollution, as volatility determines the distribution of particulate components between gas and particle phases. Herein, we estimate the volatility for representative components of particulate matter by calculating the enthalpy of vaporization using molecular dynamics simulations. Compared with conventional static prediction methods such as Hansen solubility parameter and conductor-like screening model methods, the molecular dynamics method proves to effectively and accurately predict enthalpies of vaporization for a wide range of particulate matter components without additional parameter optimization. Using the molecular dynamics approach, we calculate enthalpies of vaporization for 71 representative organic species that could be primary particulate matter sources. The predicted enthalpy of vaporization values can be used as a fundamental data set for future air quality modeling and scientific understanding of the formation of particulate matter. Given the limitations in experimentally characterizing the volatility of various components in particulate matter, we envisage that our dynamical method based on the evaluation of intermolecular interactions can also be used to study the dynamics associated with the formation of particulate matter in addition to providing thermodynamic data.</div></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"188 ","pages":"Article 106595"},"PeriodicalIF":3.9,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143895362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantification of the spatiotemporal heterogenous infection risk associated with respiratory virus-laden aerosols in an aircraft cabin in the context of airborne contagious diseases","authors":"Abu Raihan Ibna Ali ,&nbsp;R.L.F. Liang ,&nbsp;F.M. Mohee ,&nbsp;M. Freire-Gormaly","doi":"10.1016/j.jaerosci.2025.106594","DOIUrl":"10.1016/j.jaerosci.2025.106594","url":null,"abstract":"<div><div>A single-aisle aircraft cabin was investigated to quantify the infection risk by utilizing a spatiotemporal model for MV, DV, and DV with extra outlets. The ventilation effectiveness was also assessed. The HRE of the DV system was 68.9 % higher compared to the MV system. PD for MV configuration was lower compared to DV with a range of 0.34 %–6.75 %. On average, the DR for MV was found to be about 3.98 %, while for DV configuration, it was found to be approximately 2.59 %. The position of the index passenger impacts the dispersion of aerosols in the cabin, leading to varied infection risk levels throughout the cabin. The seat nearest to the index person in the same row possesses the highest risk of infection both from near-wall and near-aisle coughing in the MV configuration, as well as near-wall coughing in the DV configuration. However, the seat closest to the aisle in the same row had the highest risk of exposure to risk from near-aisle coughing in a DV configuration. Highly infectious zones were located in the same row seated with the index person and the back from the index person for MV near-wall and near-aisle injections. For the near-aisle coughing in the DV system, the risk was negligible for the first two columns containing the index passenger. Lower infection risk with higher HRE and dissatisfaction was found with DV configuration for the susceptible passengers. Wearing a highly efficient mask, such as an N95, significantly reduces the risk of infection in all cases.</div></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"189 ","pages":"Article 106594"},"PeriodicalIF":3.9,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144297190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atomization characteristics of soft mist inhaler (SMI) devices: aerosolized particle delivery through the respiratory tract—an innovative numerical and experimental study","authors":"Mona Mohammadkhani,&nbsp;Janusz Kozinski,&nbsp;Leila Pakzad","doi":"10.1016/j.jaerosci.2025.106593","DOIUrl":"10.1016/j.jaerosci.2025.106593","url":null,"abstract":"<div><div>Soft mist inhalers (SMIs) stand out for their innovative design and high efficiency, making them promising candidates for advanced research in inhalation therapy. This study presents both experimental and numerical methods to differentiate multiphase flow fields within the device mouthpiece and the realistic VCU (Virginia Commonwealth University) medium-sized mouth-throat (MT) airway.</div><div>Using a numerical approach, the volume of fluid (VOF) method was coupled with the discrete phase model (DPM), incorporating an adaptive mesh refinement technique to thoroughly analyze the liquid jet breakup mechanisms for SMI's two nozzles. Furthermore, we introduced a novel particle data transmission method (PDTM) to track atomized particles in the realistic MT airway. To validate the plume generated by the VOF-DPM model, a high-speed camera along with image analysis techniques were employed. Experimental results from a next-generation impactor (NGI) further confirmed the accuracy of the numerical model in simulating airway particle deposition.</div><div>We compared our results from the proposed VOF-DPM-PDTM model to the traditional DPM-stochastic collision model. Our findings indicate that integrating the VOF-DPM model with the novel PDTM improved the prediction of drug deposition in the SMI mouthpiece by up to 90 %. According to the VOF-DPM model, approximately 28 % of the drug is deposited in the mouthpiece area, which aligns closely with the experimental outcome of 30 %. Analysis of the particles revealed that about 65 % undergo bag and multimode breakup, resulting in a mass median diameter of approximately 4.9 μm, with distinct secondary peaks in both fine and coarse particle size ranges. Image analysis further showed that drug aerosols disperse at an angle of approximately 36.5° and travel about 0.80 mm from the SMI nozzle exit at a speed of 25.53 m/s. This contributes to increased drug loss within the device's mouthpiece. We also introduced a more refined particle injection data model for the DPM framework, offering greater detail and improved accuracy compared to the existing predefined version.</div></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"188 ","pages":"Article 106593"},"PeriodicalIF":3.9,"publicationDate":"2025-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143899728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of alveoli-distributed lung geometries for humans and rats to predict localized particle deposition in the respiratory tract","authors":"Asgharian ,&nbsp;O.T. Price ,&nbsp;T. Schroeder ,&nbsp;D. Irwin ,&nbsp;P. Buehler ,&nbsp;L. Zai ,&nbsp;J. Schroeter ,&nbsp;R.W. Matheny","doi":"10.1016/j.jaerosci.2025.106591","DOIUrl":"10.1016/j.jaerosci.2025.106591","url":null,"abstract":"<div><div>Inhalation drug delivery has gained considerable attention due to its rapid onset and the potential for optimized delivery, minimizing or eliminating adverse side effects. The delivery targets can be local (such as the respiratory tract) or systemic. Extensive research has been conducted on the deposition of inhaled particles in the lungs, with available models relying on simplifying assumptions. However, these models require improvements to more accurately predict site-specific deposition patterns. In this study, we combined morphometric data for the conducting airways in humans and Sprague Dawley rats with additional data on the distribution and number of respiratory units in both species. This enabled us to create a new generation of 2-path and lobar-specific, 2-path lung geometries. Unlike previous models, which separated the conducting and respiratory airways at a preassigned generation number, our proposed geometries integrated these pathways, assigning alveolar units to the conducting airways where data supported it. A particle deposition model based on these updated geometries was developed to predict both local and regional deposition. While the regional deposition results were consistent with previous studies, the local (site-specific) deposition predictions differed significantly, offering more realistic predictions due to the conducting-alveolar airway structure that mimics geometric realism. These new geometries are recommended for applications that require accurate assessment of local deposition, such as targeted drug delivery.</div></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"188 ","pages":"Article 106591"},"PeriodicalIF":3.9,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143868869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the morphology and composition of aerosols from plant burning","authors":"Bruno Martinent ,&nbsp;Paul-Antoine Santoni ,&nbsp;Alexis Coppalle ,&nbsp;Yann Quilichini ,&nbsp;Toussaint Barboni","doi":"10.1016/j.jaerosci.2025.106589","DOIUrl":"10.1016/j.jaerosci.2025.106589","url":null,"abstract":"<div><div>Wildfires have significantly increased in frequency and intensity worldwide, driven by climate change, with urban expansion amplifying their impact on populations and structures near the wildland-urban interface. Combustion of biomass during vegetation fires produces complex aerosols that pose potential health risks through inhalation, ingestion, and dermal exposure. However, the understanding of aerosol morphology, composition, and behaviour remains incomplete. This study investigates the aerosols emitted during the combustion of <em>Cistus monspeliensis</em>, a Mediterranean shrub, under controlled laboratory conditions simulating wildfire scenarios. A full-scale combustion of a 1-m-high shrub was performed, enabling the capture of realistic emissions using an Electrical Low-Pressure Impactor +.</div><div>Aerosols were collected across different aerodynamic size fractions and analysed using scanning electron microscopy and energy dispersive X-ray spectroscopy. Particles were classified into four main types: soot aggregates, coarse fly ash (CFA), partially burnt particles, and condensed particles, with their morphology and elemental composition extensively characterized. Notably, potassium chloride condensates dominated smaller aerodynamic stages, while CFA exhibited high calcium and magnesium content in larger stages. Aerosol size and volume distributions revealed dynamic variations during combustion, with nanoparticles (43 nm aerodynamic diameter) prevailing before the heat release rate (HRR) peak and larger particles (69 nm aerodynamic diameter) dominating after the peak HRR.</div><div>The study also links particle physical characteristics to their aerodynamic behaviour, emphasizing the role of shape and density in discrepancies between measured and aerodynamic diameters. Deposition modelling using the Multiple-Path Particle Dosimetry model highlights potential health risks, particularly in the alveolar and tracheobronchial regions.</div><div>By integrating morphology, elemental composition, and size distribution, this research provides crucial insights into the characteristics of wildfire aerosols at their source, enhancing the understanding of their potential health implications. These findings contribute to the broader effort to model wildfire emissions and inform public health strategies, emphasizing the importance of studying aerosols under realistic combustion conditions.</div></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"187 ","pages":"Article 106589"},"PeriodicalIF":3.9,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143828724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"“SARS-CoV-2 airborne detection within different departments of a COVID-19 hospital building and evaluation of air cleaners in air viral load reduction”","authors":"Ilias S. Frydas ,&nbsp;Marianthi Kermenidou ,&nbsp;Maria Karypidou ,&nbsp;Spyros Karakitsios ,&nbsp;Dimosthenis A. Sarigiannis","doi":"10.1016/j.jaerosci.2025.106587","DOIUrl":"10.1016/j.jaerosci.2025.106587","url":null,"abstract":"<div><div>The pandemic of COVID-19 has brought in light the necessity for the development of novel detection methods for airborne transmitted pathogens, and the importance of effective clean air measures in hospital departments. In this study, airborne SARS-CoV-2 and particle matter (PM1, PM2.5) detection was performed in different areas of the COVID-19 building at the Ippokrateio University Hospital in Thessaloniki, Greece. More specifically, Sioutas cascade impactors were placed in the ICU (Intensive Care Unit) and HDU (High-Dependency Unit) on the first floor, and at the corridor and rooms at the COVID-19 clinic on the second floor. Furthermore, TECORA air pumps were placed at the building entrance to measure for PM1 and PM2.5. Afterwards, in a COVID room with confirmed air viral load an air cleaner was placed to examine the effect on viral load reduction. Results showed that no viral copies were detected in the air of ICU and HDU departments, in which negative pressure air filtration with HEPA filters is applied. On the contrary, viral load was effectively detected in rooms and corridors of the COVID floor and ranged from 25,9 to 1123,7 copies/m³. PM1 filters showed 77.8 % viral positivity, and PM2.5 filters were 38.5 % virus positive. Moreover, air viral load in the COVID room with an air cleaner showed a reduction of up to 98.1 %. In conclusion, SARS-CoV-2 was effectively detected in the air of different areas in the COVID building after continuous sampling ranging between 24 h and 7 days, and it was shown how important and effective air cleaners are as first-line measures against pathogen airborne transmission in hospital environments.</div></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"187 ","pages":"Article 106587"},"PeriodicalIF":3.9,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clearance of Particles from Regular-flavored Little Cigar Smoke Across Lung Lobes in Female Sprague-Dawley Rats","authors":"Kaisen Lin ,&nbsp;Christopher Wallis ,&nbsp;Patricia Edwards ,&nbsp;Austin Cole ,&nbsp;Laura Van Winkle ,&nbsp;Anthony S. Wexler","doi":"10.1016/j.jaerosci.2025.106588","DOIUrl":"10.1016/j.jaerosci.2025.106588","url":null,"abstract":"<div><div>Quantifying the clearance and retention of inhaled particles in the respiratory tract is critical for understanding their toxicity and overall health impacts. While previous studies have focused on the clearance of monodisperse nanoparticles in animal models, limited research exists on the clearance kinetics of tobacco smoke particles. Even fewer studies provide lobe-specific clearance data, which hampers our understanding of smoke particle accumulation following long-term exposure. This gap highlights the need for further research, particularly involving little cigars given their popularity among youth. In this study, we investigated the lobar clearance of smoke particles in rat lungs following exposure to combusted Swisher Sweets regular-flavored little cigars. Twelve-week-old female Sprague-Dawley rats were exposed to smoke particles at a concentration of 80 mg/m³ for 4 hours. Lung lobes were collected and analyzed for particle retention on Days 0, 1, 7, and 21 post-exposure. Inductively Coupled Plasma Mass Spectrometry was used to quantify chromium concentrations in each lobe, serving as a tracer for smoke particles. Our results revealed a two-phase clearance of little cigar smoke particles across all lung lobes, with an overall half-life of 5.7 days for the fast phase and 25.0 days for the slow phase. While no statistically significant differences in particle retention among lobes were observed after 21 days, the majority of retained particles were found in the left lobe and right caudal lobe. When comparing the half-life of smoke particles in this study to previously reported data for nanoparticles, we found the results to be comparable. Our findings demonstrate that the clearance of smoke particles follows a similar pattern across different lung lobes in rats, with a two-phase clearance mechanism indicating that the chromium in the smoke particles likely exists in the Cr (III) oxidation state. These insights provide valuable information for estimating the clearance and retention of little cigar smoke particles, contributing to toxicity research in the context of long-term exposure.</div></div>","PeriodicalId":14880,"journal":{"name":"Journal of Aerosol Science","volume":"187 ","pages":"Article 106588"},"PeriodicalIF":3.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143828725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}