Search Results (301)

Background: “Third-hand” exposure produced by “second-hand” environmental vaping aerosol (EVA) has been reported as a parallel analogue of “third-hand smoke” (THS) produced by residues of environmental tobacco smoke (ETS). Methods: To assess the plausibility and scope of “third-hand” vaping exposure, we examine the available evidence on THS phenomenology and the physicochemical properties of EVA. We also evaluate daily intake doses from direct dermal exposure to nicotine under simplified but minimally realistic scenarios for vaping and smoking. Results: The only THS phenomenology fully reproduced in EVA is the adsorption of nicotine and its byproducts on indoor surfaces. Unlike significant, measurable THS exposures in normal environments (homes, hospitality venues, cars), third-hand exposures from vaping have only been found under special conditions: laboratory-generated aerosols or in vape shops where excessively abnormal and intense vaping activity takes place. Conclusions: The physicochemical properties of EVA are incompatible with an aging process leading to a THS analogue under the environmental conditions in which vaping normally takes place. However, objectively and rigorously evaluating the risks of dermal exposure from smoking and vaping remains an open issue. Full article

Heated tobacco products (HTPs) generate an inhalable aerosol by heating tobacco instead of burning it as conventional cigarettes do. Although several harmful and potentially harmful constituents (HPHCs) are generally reduced compared with conventional cigarette smoke, the World Health Organization’s list of nine priority toxicants (WHO 9) may not fully reflect the chemical complexity of HTP aerosols. The main goal of this review is to evaluate the occurrence, quantitative levels, and toxicological relevance of HPHCs identified in IQOS aerosols and to propose an expanded toxicant panel for aerosol characterization. The review was conducted according to PRISMA 2020 recommendations using literature retrieved from the Web of Science Core Collection database. The studies included in the present review consistently report lower levels of many combustion-related toxicants in IQOS aerosols, compared with conventional cigarette smoke, particularly for carbon monoxide, volatile organic compounds, and polycyclic aromatic hydrocarbons. However, several toxicologically relevant compounds, including carbonyls, tobacco-specific nitrosamines, phenolics, and trace metals, remained detectable in several studies. An expanded panel of twenty priority toxicants was proposed, based on toxicological relevance, frequency of detection, regulatory significance, and analytical feasibility. The proposed panel extends beyond the WHO 9 framework while preserving regulatory applicability and analytical practicality. The findings support the need for harmonized methodologies and broader toxicant monitoring strategies for the comparative assessment of heated tobacco products. Full article

This study compared the temporal effects of traditional cigarettes and e-cigarettes on lung health in male Rattus norvegicus over 8- and 12-week periods. Thirty rats were evaluated for tracheal/alveolar histopathology and systemic markers (IL-6, TNF-α, SOD-3, MDA). Chronic cigarette exposure (12 weeks) and nicotine aerosol (8 weeks) significantly suppressed weight gain, while ascorbic acid aerosol caused less growth inhibition. At 8 weeks, cigarette exposure (K3) induced adaptive tracheal mucosal thickening (66.88 ± 17.92 µm vs. 52.40 ± 2.63 µm in control K1), increased goblet cells (4.2 ± 2.44 N/mm), elevated SOD-3 (12.75 ± 1.10 pg/mL), and initiated emphysematous alveolar expansion (469.77 ± 91.31 µm vs. 202.03 ± 29.38 µm in K1 in K1). Conversely, 12-week cigarette smoke (K4) triggered epithelial exhaustion, significantly thinning the tracheal mucosa (34.65 ± 6.55 µm) and elevating systemic IL-6 (11.45 ± 1.17 pg/mL vs. 8.43 ± 0.88 pg/mL in control K2). Notably, chronic electronic ascorbic acid aerosolization (K6) preserved localized alveolar structural layouts and limited septal thickening compared with nicotine groups. However, it failed to suppress systemic inflammation, as evidenced by elevated IL-6 levels. In conclusion, while ascorbic acid aerosols moderate localized parenchymal destruction compared to nicotine, chronic aerosol exposure accelerates systemic immune activation. 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

Background/Objectives: Methods of smoking have evolved over the years, including heated tobacco products. The impact of exposure to traditional tobacco smoke and heated/electronic tobacco products (IQOS) on biofilm formation has not been previously compared in vitro. Aims and objectives: The present study aimed to evaluate the impact of tobacco and electronic smoking on microbial biofilm formation on dental hard tissues. Materials and Methods: Thirty premolars were randomly assigned to six groups (n = 10 per group) according to tissue type and smoking exposure: Six experimental groups were defined: Group 1, non-exposed enamel; Group 2, enamel subjected to conventional cigarette smoke (CS); Group 3, enamel subjected to heated tobacco (HT); Group 4, non-exposed cementum; Group 5, cementum subjected to conventional cigarette smoke; and Group 6, cementum exposed to heated tobacco. Enamel and root discs were then immersed in 2 mL of an adjusted, standardized bacterial suspension of Streptococcus mutans (S. mutans) to allow bacterial biofilm adhesion after incubation for 48 h at 37 °C. The mean colony-forming unit (CFU) count was calculated, and the surface topography and roughness were assessed using scanning electron microscopy and ImageJ software with the SurfCharJ plugin, respectively. Results: Conventional cigarette smoking showed significantly higher S. mutans adhesion on the enamel and root discs compared with IQOS and control groups. Both IQOS and cigarette smoking increased roughness on enamel and root versus the control group, and cigarette smoking produced significantly higher roughness on the enamel surface when compared to IQOS; however, there were no significant differences in the roughness between the two smoking methods on the root surface. SEM analysis showed the most extensive enamel and root microtopography change in IQOS smoking. Conclusions: Aerosols from heated tobacco products (IQOS) alter the surface topography and roughness of enamel and root, while traditional cigarette smoking significantly increases bacterial colonization. Further in vivo studies are warranted to simulate the dynamic nature of the oral cavity. 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

Biomass burning is a major source of atmospheric pollution. However, rapid and quantitative assessment of particulate matter in smoke plumes remains challenging, owing to the physical uncertainties, limited coverage, and labor-intensive quality control of conventional monitoring approaches. Existing image-based deep learning methods typically address either smoke detection or air quality assessment separately. To address this gap, we develop a Unified Smoke Detection and Aerosol Estimation Framework (SDAF), a three-stage deep learning approach evaluated using a smoke-rich airborne dataset. The framework integrates smoke localization with PM₁ estimation by combining a YOLOv11-based detector with an optimized convolutional neural network. The model achieves high accuracy under in-plume conditions (R² of 0.985). However, its performance degrades under out-of-plume conditions due to substantial differences in visual features between the two domains. Consequently, direct across-domain transfer performs poorly, whereas region of interest (ROI)-level fine-tuning substantially improves performance for out-of-plume images (R² of 0.621). Despite these promising results, fundamental limitations remain. Image-based PM₁ estimation is intrinsically ill-posed due to the non-unique mapping between visual observations and particle mass. Overall, the framework enables an integrated workflow from smoke localization to quantitative PM₁ estimation using image data alone, offering a scalable solution for biomass burning monitoring and air quality assessment while highlighting the fundamentally indirect nature of image-based PM₁ inference relative to spatially resolved retrievals. Full article

Coxiella burnetii is an intracellular bacterium responsible for an anthropozoonosis that can be asymptomatic or manifest as acute or chronic Q fever. This extensive series of 588 patients represents one of the largest single-center studies on sporadic acute Q fever, highlighting the Canary Islands as a high-incidence region in Spain. Epidemiologically, the domestic cycle is the primary driver of infection, with caprine livestock serving as the main reservoir, showing a local prevalence of 60.4%. Transmission is predominantly airborne via aerosols; the environmental resilience of C. burnetii facilitates its transport into urban areas, where the majority of patients reside despite lacking direct animal contact. While fever, headache, and diaphoresis are hallmark symptoms, over 90% of patients exhibit transient urinalysis abnormalities, a finding that often leads to misdiagnosis and inappropriate antimicrobial use. Clinically, the non-specific (45.7%) and hepatic (44.1%) forms are most prevalent, whereas the pulmonary form (7.8%) is strongly associated with smoking and alcohol consumption. Although localized forms affecting the nervous system or skin (such as panniculitis) were observed, the overall prognosis remains excellent with no progression to chronic Q fever in this series. In summary, the extensive series described characterizes acute Q fever patients in the Autonomous Community of the Canary Islands, with features that are similar in some cases but also show notable differences compared to other national and international series. Furthermore, depending on the patients’ age, the time elapsed between the onset of clinical manifestations and hospital evaluation, and the clinical form, acute Q fever displays significant differences. Full article

This study investigates long-term wildfire emissions and smoke-plume geospatial characteristics in Greece by analyzing a multi-pollutant dataset spanning January 2003 to August 2025. Details of emissions of carbon monoxide (CO), carbon dioxide (CO₂), methane (CH₄), particulate matter (PM_2.5), organic carbon (OC), and black carbon (BC) were derived from the Global Fire Assimilation System (GFAS), which converts MODIS fire radiative power into trace gas and aerosol fluxes at 0.1° resolution, and also accounts for the land type. Burned-area statistics from the European Forest Fire Information System (EFFIS) were used for cross-validation. Data were processed into daily, monthly, annual, and cumulative time series, with spatial mapping at the municipality scale and information regarding long-term trends. The analysis shows that while there are several sizeable wildfire events in the country every year, the bulk of the total of Greek wildfire emissions for the last 23 years is attributable to a few extreme fire seasons (2007, 2021, and 2023) that produced abrupt emission surges and accounted for a disproportionate share of national totals. Analysis of spatial data identifies the areas of Evia, East Attica, Messinia, and Evros as persistent emission hotspots. Although wildfire CO₂ emissions are generally a minor fraction of Greece’s anthropogenic totals (<5%), they reached 15–17% during peak fire years. Plume-injection height analysis reveals that most smoke remains below ~1 km but can reach 3–6 km during extreme events, facilitating long-range transport. Overall, the dataset demonstrates a shift toward more intense and concentrated wildfire events in recent years, highlighting both their growing climatic relevance and their acute impacts on regional air quality. Full article

Adolescent vaping has become a persistent health and behavioural challenge in schools, yet many institutions lack reliable tools to detect and respond to concealed e-cigarette use. This study addresses this problem by evaluating the real-world performance of a low-cost “Internet of Things” (IoT) vape detection system deployed across 37 high-risk restroom and change-room locations at a large Australian Independent school. The aim was to determine whether an IoT-based environmental monitoring platform could accurately identify vaping events, support timely staff intervention, and provide actionable insights into student behaviour patterns. A longitudinal case study design was used, collecting continuous particulate matter (PM_2.5 and PM₁₀) data at one-minute intervals over an 18-month period, where PM_2.5 and PM₁₀ refer to particulate matter with aerodynamic diameters ≤ 2.5 µm and ≤10 µm, respectively, reported in micrograms per cubic metre (µg/m³. Threshold-based alerting, cloud-based data processing, and school-led Closed-circuit television (CCTV) verification were combined to assess detection accuracy, temporal trends, and operational responses. The system recorded more than 300 vaping-related incidents, with clusters aligned to predictable times of day and higher prevalence among senior students. Operational detection performance was high, with alert events characterised by rapid, concurrent PM_2.5 and PM₁₀ excursions consistent with vaping-related aerosol profiles, although staff responsiveness declined over time due to alert fatigue and competing priorities. A major environmental smoke event demonstrated the need for context-aware logic to reduce false positives. The findings demonstrate that real-time aerosol monitoring is not only technically reliable but also highly effective in detecting vaping within school environments. These perspectives help explain why user engagement, alert fatigue, and institutional follow-through are as critical as sensor accuracy itself. Ultimately, the effectiveness of vape detection relies on strong organisational commitment, well-defined response workflows, and alignment with broader wellbeing and policy strategies. When these elements are in place, such systems can evolve from simple detection tools into intelligent, integrated components of school health governance. Full article

Atmospheric aerosols influence the terrestrial carbon cycle through diverse radiative and biogeochemical effects, yet their net impact on vegetation productivity remains contentious and region-specific. To address this, we analyzed the spatiotemporal coupling between aerosol optical depth (AOD) and net primary productivity (NPP) over three African biomes (2013–2023), using multi-source datasets (MODIS, CERES, ERA5, CRU TS). We explicitly distinguished statistically significant relationships (p < 0.05) from non-significant ones when interpreting correlation patterns. Because AOD is an optical measure and does not provide aerosol composition, interpretations involving dust versus smoke are treated as qualitative and indirect. Through structural equation modeling (SEM), we identified two contrasting mechanistic pathways: in the humid Congo Basin rainforest, aerosols were associated with lower NPP via a cooling-mediated pathway (increased cloud albedo leading to reduced temperature and light availability), whereas in the arid savanna, they were associated with more substantial limitations on NPP via a warming-aggravated pathway (increased temperature and potentially coupled water stress). SEM fit was poor for the semi-arid South African plateau, underscoring the dominant role of water availability in strongly water-limited systems. This framework reconciles the paradox of dual aerosol effects by demonstrating that the net impact is dictated by regional climate context. Overall, our conclusions emphasize context-dependent associations rather than direct causal attribution from correlations alone. Our findings provide a process-based understanding that is critical for improving carbon cycle models and for formulating targeted climate adaptation strategies in Africa. Full article

Extracellular vesicles (EVs) are lipid-enclosed particles secreted from a wide variety of cells, with the ability to transfer biologically active content from parent to recipient cells. Lung epithelial-derived EVs (LE-EVs) play an important role in the progression of pulmonary disease, but there is limited evidence regarding the impact of cigarette smoke (CS) and electronic cigarette aerosol (ECA) on epithelial-derived EVs. The aim of this systematic review was to evaluate the current published literature on the impact of cigarette smoke and electronic cigarette aerosol on LE-EVs. Original research studies and clinical data were included, but research involving microparticles or non-epithelial-derived EVs was excluded. A total of 29 articles were identified from three databases (EMBASE, Web of Science and PubMed), of which nine demonstrated that CS exposure leads to molecular changes in epithelial-derived EVs, whereas 21 reported that CS-induced LE-EVs can deliver their cargo to neighbouring cells. The results highlighted that LE-EVs secreted in response to cigarette or e-cigarette exposure presented altered EV cargo, associated with increased cellular damage, inflammation and disease development. The current literature suggests that conventional and electronic cigarettes can influence the secretion of EVs from lung epithelial cells, with these EVs potentially playing a role in the development of lung inflammation. Nonetheless, there is limited research studying the impact of ECA on LE-EVS. Further research examining the impact of electronic cigarettes on lung epithelial-derived EVs, using robust human in vitro models coupled with clinical studies, is required. Full article

Background/Objectives: Heated tobacco products (HTPs) are a gateway to nicotine addiction for non-smokers, especially young people. The short- and long-term health effects of using heated tobacco products are not yet fully understood. The study aimed to assess the effect of heated tobacco use on blood pressure and heart rate in young, healthy individuals aged 18–30. The study also assessed exposure to tobacco smoke by measuring salivary cotinine concentration. Methods: The case–control study was conducted in 2022–2025 among 200 healthy individuals aged 18–30 years: 70 I-Quit-Ordinary-Smoking users (IQOS), 65 daily traditional cigarette smokers (DS), and 65 non-smokers (NS). The research tool was a questionnaire containing information on the use of tobacco products. The participants completed a questionnaire and then underwent blood pressure measurements, anthropometric measurements, and saliva collection for cotinine levels. Results: The average age of initiation of IQOS use was 18.5 years, and smoking had continued for an average of 2.3 years. The average age of initiation of smoking traditional cigarettes was 16.3 years, and smoking had continued for 4.4 years. There were no statistically significant differences in median values between systolic blood pressure (SBP) and diastolic blood pressure (DBP) between the IQOS, DS, and NS groups (p > 0.05). High SBP values ≥ 140 mm Hg were observed in 10% of the IQOS users, 18.5% of the daily smokers of conventional cigarettes, and 12.3% of the non-smokers. High DBP values ≥ 90 mm Hg were observed in 11.4% of IQOS, 7.7% of DS, and 7.7% of NS. The cigarette smokers demonstrated significantly higher median cotinine levels compared to the IQOS users and non-smokers: 153.7 vs. 64.3 vs. 0.5 ng/mL (p < 0.01). Salivary cotinine levels were positively correlated (ρ = 0.38; p < 0.01) with the daily number of heated tobacco sticks among IQOS users (weak correlation), as well as among DS (ρ = 0.42; p < 0.01) with a higher daily number of cigarettes (moderate correlation). Conclusions: Long-term studies are needed to determine the health effects of heated tobacco products among young people in Poland. Furthermore, the potential impact of HTP aerosols on passive smokers should be examined. Further studies should consider the use of salivary cotinine as a biomarker. Full article

Electronic cigarettes (ECs) are promoted as a safer alternative to traditional cigarettes, yet their impact on immune cells remains incompletely understood. This study investigates the activation of human primary adherent and non-adherent monocytes exposed ex vivo to aerosols from four flavored ECs (classic tobacco, menthol, watermelon, and strawberry) compared to cigarette smoke (CS) and nicotine alone. EC aerosols (ECEs) induced modest cytotoxicity, oxidative stress, and superoxide dismutase activity compared to CS, with high cell response heterogeneity indicating subpopulation-specific effects. Adherent monocytes showed elevated integrin expression (CD11a, CD11b), ICAM-1 (CD54), TNFα, and oxidative stress versus non-adherent cells, amplified by ECE. Dual fluorescence flow cytometry (green DCF for ROS and red for anti-TNFα Ab) revealed shifts toward pro-inflammatory/oxidative quadrants, particularly upper-right high-intensity relatively small subsets with macrophage M1-like CD68 expression in adherent cells. ECEs reduced phagocytosis in adherent monocytes, mimicking CS effects, probably driven by non-nicotine components. Strawberry flavor (ECE 4) elicited the strongest TNFα induction. These findings demonstrate EC-induced subclinical inflammation via selective monocyte activation, potentially contributing to chronic cardiopulmonary risks despite significantly lower overall toxicity than CS. Full article

We present an improved algorithm based on the POlarization LIdar PHOtometer Networking (POLIPHON) method to retrieve cloud condensation nuclei (CCN) concentration profiles from spaceborne lidar observations. Our previous paper, which was the first study to demonstrate the feasibility of using measurements from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) to retrieve CCN is revisited. Our results focus on the Evaluation of CALIPSO’s Aerosol Classification scheme over Eastern Mediterranean (ACEMED) research campaign that took place over Thessaloniki, Greece, in September 2011. We compare our results with our earlier retrievals, discussing the critical changes that have been made and the importance of using the proper conversions factors. We also demonstrate the use of conversion factors acquired based on CALIPSO aerosol typing for CCN retrievals. The analysis highlights the strong influence of smoke on CCN concentrations and shows that the assumed aging state of the smoke can significantly alter the retrieval outcome. Full article