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To monitor health risks associated with vaping, we introduce a multi-spectral optical sensor powered by machine learning for real-time characterization of electronic cigarette aerosols. The sensor can accurately measure the mass of particulate matter (PM) in specific particle size channels, providing essential information for estimating lung deposition of vaping aerosols. For the sensor's input, wavelength-specific optical attenuation signals are acquired for three separate wavelengths in the ultraviolet, red, and near-infrared range, and the inhalation pressure is collected from a pressure sensor. The sensor's outputs are PM mass in three size bins, specified as 100–300 nm, 300–600 nm, and 600–1000 nm. Reference measurements of electronic cigarette aerosols, obtained using a custom vaping machine and a scanning mobility particle sizer, provided the ground truth for size-binned PM mass. A lightweight two-layer feedforward neural network was trained using datasets acquired from a wide range of puffing conditions. The performance of the neural network was tested using unseen data collected using new combinations of puffing conditions. The model-predicted values matched closely with the ground truth, and the accuracy reached 81–87% for PM mass in three size bins. Given the sensor's straightforward optical configuration and the direct collection of signals from undiluted vaping aerosols, the achieved accuracy is notably significant and sufficiently reliable for point-of-interest sensing of vaping aerosols. To the best of our knowledge, this work represents the first instance where machine learning has been applied to directly characterize high-concentration undiluted electronic cigarette aerosols. Our sensor holds great promise in tracking electronic cigarette users' puff topography with quantification of size-binned PM mass, to support long-term personalized health and wellness. [ABSTRACT FROM AUTHOR]

A combination of magnetic polarity and rock magnetic analysis on the well‐documented section of the Um Sohryngkew River (USR) in the south Shillong Plateau, NE India, produced a sharp reversal marking the C29r‐C29n geomagnetic polarity transition at approximately 65.688 Ma. The rock magnetic studies indicate ferrimagnetic dominant mineralogy with abundance of SSD grains, with an anomalous peak in susceptibility coinciding with Ir‐rich limonitic layer. The magnetic reversal occurs precisely 61 m above the Ir‐rich distinct in situ limonitic layer, indicating that the C29r‐C29n geomagnetic reversal post‐dates the widely accepted Ir‐anomaly based K‐Pg boundary by approximately 355 Ka. Furthermore, the rock magnetic studies indicate its frequency dependence coinciding with the Ir‐rich limonitic layer suggesting a possible dust/aerosol source, while akaganéite is reported from the interval approximately 1 m below peak susceptibility, indicating signature of Deccan volcanism. This study infers the completeness of the USR section with a high rate of sedimentation of approximately 17 cm/ka among the marine K‐Pg boundary sections in the world. [ABSTRACT FROM AUTHOR]

Serious concerns exist that the increasing frequency of fires may delay the recovery of ozone given increasing temperatures due to climate change. Australian bushfires from September 2019 to February 2020 were catastrophic. A random forest spatial-temporal (RF sp) analysis using satellite data to detect an association between Australian bushfires and stratosphere ozone on the local depletion of ozone in the vicinity of fires in three regions of Australia (Pacific Ocean, Victoria, NSW) has shown a significant reduction in ozone attributable to aerosols from fires. By intervention analysis, increases in aerosols in all three regions were shown to have a significant and ongoing impact 1–5 days later on reducing ozone (p < 0.0001). Intervention analysis also gave similar periods of aerosol exceedance to those found by Hidden Markov models (HMMs). HMMs established a significant and quantifiable decline in ozone due to bushfire-induced aerosols, with significant lags of 10–25 days between times of aerosol exceedance and subsequent ozone level decline in all three regions. [ABSTRACT FROM AUTHOR]

Atmospheric Aerosols are highly abundant in windblown dust events originating in arid and semiarid areas. Aerosols are dangerous to human health when the emission rate is presumably high. Harmattan dust is considered to be amongst the most harmful of all air pollutants due to the toxic effect of the dust constituents. Respiratory infections make up more than 20% of the causes of human mortality and morbidity. This study was carried out to assess the correlation between aerosol loading and respiratory diseases at Zaria, Kaduna State in North-Central Nigeria. The aerosol data were accessed from the National Aeronautics and Space Administration (NASA) Moderate Resolution Imaging Spectra-radiometer (MODIS) platform, while data on respiratory diseases were obtained from Ahmadu Bello University (A.B.U) Teaching Hospital Shika, Zaria, Nigeria from Jan 2009 - Dec 2018. Within that period, 2022 patients were diagnosed with different ranges of respiratory diseases. Out of 2022 516 (25.52%) were adult male, 455 (22.5%) were female, while teenagers were constituted 290 (14.34%), children were 385 (19.04%), and infants were 376 (18.6%). The correlation between aerosol optical depth and the number of cases of respiratory ailments was evaluated. A correlation coefficient of 0.65 was evaluated in the dry season, while in the rainy season the correlation coefficient was -0.55, overall correlation for an inter-annual variation is 0.27 while for the seasonal variation is 0.49. These results suggest that there is a positive correlation between aerosol loading and respiratory cases at Zaria. It also shows that the correlation between the dry seasons is high compared to the rainy season. [ABSTRACT FROM AUTHOR]

Earth's Northern and Southern Hemispheres reflect essentially equal amounts of sunlight. How—and whether—this hemispheric albedo symmetry is maintained remains a mystery. We decompose Earth's hemispheric albedo symmetry into components associated with the surface, clear‐sky atmosphere, and different cloud types as defined by cloud effective pressure and optical thickness. Climatologically, greater reflection by the surface, aerosols, and high clouds in the Northern Hemisphere is balanced by greater low and mid‐level cloudiness in the Southern Hemisphere. Both hemispheres have darkened at similar rates over the past two decades; whether the darkening from more rapidly declining aerosol in the Northern Hemisphere is causing a departure from all‐sky symmetry remains uncertain. Natural experiments including long‐term trends, sea ice loss, and volcanic eruptions provide strong evidence against the hypothesis that extratropical low clouds compensate changing clear‐sky asymmetries on annual‐to‐decadal timescales but some evidence that tropical high cloud shifts may do so. Plain Language Summary: Mysteriously, the Northern and Southern Hemispheres reflect the same amount of sunlight as each other, but scientists are not yet sure why, how, or even whether this phenomenon is sustained by the Earth system. The Northern Hemisphere is brighter in clear skies because it contains more pollution particles in the atmosphere and has more land area, whereas the Southern Hemisphere is cloudier. We break down this cloudiness contrast into components related to different cloud types defined by their height and thickness. Tropical high‐altitude clouds increase reflection preferentially in the Northern Hemisphere but are overcompensated by low‐ and mid‐level clouds in the Southern Hemisphere, especially in the subtropics and midlatitudes. Both hemispheres have darkened over the past two decades, but whether the Northern Hemisphere is darkening faster than the Southern Hemisphere due to decreasing particulate pollution or if they are darkening at the exact same rate remains uncertain. Based on long‐term trends and "natural experiments" like sea ice loss and volcanic eruptions, we can rule out the hypothesis that low‐level clouds in the Southern Ocean act to balance out clear‐sky asymmetries at yearly‐to‐decadal timescales, but we cannot rule out the hypothesis that high‐altitude tropical clouds do so. Key Points: Greater reflection from Northern Hemisphere clear‐skies and high clouds is balanced by Southern Hemisphere low and mid‐level cloudsEvidence points against extratropical low cloud adjustments compensating for clear‐sky albedo changes on decadal timescalesLimited and conflicting evidence for whether shifts in tropical high clouds compensate clear‐sky changes at annual to decadal timescales [ABSTRACT FROM AUTHOR]

The Asian Summer Monsoon (ASM) convection transports aerosols and their precursors from the boundary layer to the upper troposphere and lower stratosphere (UTLS). This process forms an annually recurring aerosol layer near the tropopause. Recent observations have revealed a distinct property of the aerosol layer over the ASM region, it is nitrate‐rich. We present a newly implemented aerosol formation algorithm that enhances the representation of nitrate aerosol in the Community Aerosol and Radiation Model for Atmospheres (CARMA) coupled with the Community Earth System Model (CESM). The simulated aerosol chemical composition, as well as vertical distributions of aerosol size and mass, are evaluated using in situ and remote sensing observations. The simulated concentrations (ammonium, nitrate, and sulfate) and size distributions are generally within the error bars of data. We find nitrate, organics, and sulfate contribute significantly to the UTLS aerosol concentration between 15°–45°N and 0°–160°E. The two key formation mechanisms of nitrate‐containing aerosols in the ATAL are ammonium neutralization to form ammonium nitrate in regions where convection is active, and condensation of nitric acid in regions of cold temperature. Furthermore, including nitrate formation in the model doubles the surface area density in the tropical tropopause region between 15°–45°N and 0°–160°E, which alters the chlorine partitioning and subsequently impacts the rate of ozone depletion. Plain Language Summary: The Asian Summer Monsoon can efficiently transport pollutants into the upper troposphere and form a layer of aerosols called the Asian Tropopause Aerosol Layer (ATAL). This research investigates the two key formation mechanisms for nitrate aerosol in the ATAL: one is due to cold temperature, and one is due to ammonium neutralization. The simulations are validated against in situ measurements. It also found that O3 chemistry inside ATAL is influenced by nitrate aerosol. Key Points: A new nitrate aerosol formation algorithm is implemented for the community model CARMA to represent the Asian Tropopause Aerosol LayerThe simulated aerosol size distributions and compositions are within error bars of observationsIncluding the new nitrate formation scheme doubles the simulated surface area, changing the chlorine partitioning and ozone depletion [ABSTRACT FROM AUTHOR]

A 38‐year aerosol optical thickness (AOT) satellite product from the Advanced Very High‐Resolution Radiometer (AVHRR) is used to investigate the aerosol variabilities in the North Indian Ocean (NIO). A dipolar mode with a notable meridional contrast between the equatorial and northern NIO is revealed by the second mode of Empirical Orthogonal Function (EOF) analysis with a sharp rise over the Arabian Sea (AS) and Bay of Bengal (BoB) since 2002. Our results show that the aerosol dipolar variation is primarily modulated by an El Niño–Southern Oscillation (ENSO) during 1983–2001 (ID1) and by a warm phase of Atlantic Multi‐decadal Oscillation (AMO) during 2002–2020 (ID2), leading to a dry‐and‐warming condition spanning the coasts of East Africa, the Arabian Peninsula (AP), and South Asia (SA) that favors increasing aerosol emission and a longer life cycle in the upstream regions. A warm phase of the AMO tends to excite an anomalous cyclone in western Siberia and reinforces anticyclonic circulation in the Tibetan Plateau. Correlation analyses between the second EOF mode time series and other parameters in ID1 and ID2 show that an interannual dry‐and‐warming condition over the AP–SA is associated with a noticeable north‐south contrast of convection between the equatorial NIO and AP–SA in ID1. But in ID2, a zonal contrast of anomalous convective activities between the AP–SA and the BoB‐South China Sea is dominant, partially due to the warming AMO, which aids the development of anticyclonic cells over the TP and the strengthened subtropical westerly jet streams. Plain Language Summary: Using satellite aerosol observations during 1983–2020 and a multivariate statistical technique for temporal‐spatial analysis, we explored the aerosol long‐term and year‐by‐year variations in the North Indian Ocean (NIO). Our results show a significant rise in springtime aerosol over the Arabian Sea and Bay of Bengal since the early 2000s, which is attributed to intensification of a dry‐and‐warming condition in the coasts of East Africa, the Arabian Peninsula, and South Asia. A relatively low aerosol concentration before the early 2000s is mainly modulated by the anomalies of sea surface temperature (SST) in both the West and East Pacific associated with an El Niño or La Niña event, but an increasing aerosol concentration after the early 2000s is linked to warmer SST associated with a phenomenon called Atlantic Multi‐decadal Oscillation (AMO). A warm phase of the AMO may aid the development of the remote teleconnection pattern in the midlatitude regions of the Northern Hemisphere, and thus reinforce the anomalies of atmospheric circulation in the subtropical regions. Key Points: A notable springtime aerosol rise over the Arabian Sea and Bay of Bengal (ASBoB) since the early 2000s is revealed by using satellite dataThe El Niño events may cause a relatively low aerosol loading over the ASBoB during 1983–2001A warm‐phase Atlantic Multi‐decadal Oscillation may favor a notable high aerosol loading over the ASBoB during 2002–2020 [ABSTRACT FROM AUTHOR]

AbstractConcrete structures have high massive building materials than steel structures and possess very low thermal conductivity and high specific heat capacity. However, an efficient approach to reducing high production cost and structural weight of concrete elements without impacting their strength evolve as a growing necessity that leads to innovation in the Light weight concrete (LWC) fields such as aerated concrete and foamed concrete. Those large bubbles seem highly likely to get a break, move upwards through buoyancy and may get lost, while concrete has been mixed, transported, placed and vibrated. Hence to prevent increased bubble spacing, and air loss and to increase concrete durability, a sort of micron-sized air-cells could be generated in aerosol form, by passing out compressed air to dense form generating surfactants. Therefore to circumvent certain drawbacks of conventional LWC, the study delineated to bring out an innovative air-cell impregnated concrete (AIC) material, with homogenous mixing of cement, sand, water and uniformly distributed micron-sized air-cells wherein course-aggregates were replaced with air-cells. This uniform air-cell distribution creates durable concrete with unique feature characteristics since the micron-sized air-cells will be stable and does not collapse. The suitable surfactant towards contributing the strength and durability of proposed AIC structure are assessed, based on results. [ABSTRACT FROM AUTHOR]

Palytoxins are a group of highly potent and structurally complex marine toxins that rank among some of the most toxic substances known to science. Palytoxins are naturally synthesized by a variety of marine organisms, including Palythoa zoanthids, Ostreopsis dinoflagellates, and Trichodesmium cyanobacteria, and are widely distributed in tropical and temperate regions where they can bioaccumulate in marine life. The evolution of research on palytoxins has been an intricate exchange between interdisciplinary fields, drawing insights from chemistry, biology, medicine, and environmental science in efforts to better understand and mitigate the health risks associated with this family of toxins. In this review, we begin with a brief history covering the discovery of this group of toxins and the events that led to its isolation. We then focus on the chemical structure of these compounds and their proposed mechanism of action. Finally, we review in vitro, ex vivo, and in vivo studies related to their toxicity, with the aim to provide a broad overview of the current knowledge on palytoxin toxinology. [ABSTRACT FROM AUTHOR]

Background: The use of probiotic bacteria to improve lung health has been gaining interest. Although the oral delivery of probiotics and their effects are well documented, there is currently limited knowledge on the respiratory delivery of probiotics. Objectives: This study aimed to investigate whether nebulisation is suitable for delivering Lacticaseibacillus rhamnosus GG (LGG) into the lungs for the potential treatment of bacterial pulmonary infections. Methods: It compared the dose output and aerosol performance of a vibrating-mesh nebuliser (VMN) and a jet nebuliser (JN) in nebulising LGG suspended in de Man Rogosa Sharpe (MRS) broth, phosphate-buffered saline (PBS), or normal saline (0.9% w/v sodium chloride in water). Results: The VMN consistently produced a higher output than the JN for all liquid media, indicating that VMN was more efficient. The fine-particle fractions of both nebulisers were comparable for a given medium. The highest fine-particle fraction was achieved with LGG suspended in MRS broth for both nebulisers (20.5 ± 2.8% for VMN; 18.7 ± 3.4% for JN). This suggests that the aerosol performance of nebulised probiotics may depend on the medium in which the probiotic bacteria were suspended. Conclusions: Therefore, this study demonstrated that the nebulisation efficiency of LGG depended on the nebuliser type and liquid medium of the probiotic suspension. [ABSTRACT FROM AUTHOR]

Droplets of electrolyte solutions in an insulating medium are ubiquitous in nature. The net charges of these droplets are normally nonzero, and they fluctuate. However, a theory on the probability distribution function for the net charge of droplets is lacking, so far. Thus, a statistical‐mechanical theory of a charged droplet is developed including the effect of the electrostatic energy of charging as well as the random distribution of ions. Then, the probability distribution function for the net charge of an electrolyte droplet is calculated assuming that it is generated from a macroscopic solution with the different cation and anion concentrations. Using the Gaussian approximation and Stirling's formula, the analytic results for the average and variance of the net charge of a droplet are obtained. [ABSTRACT FROM AUTHOR]

In Europe, respiratory protective devices must be certified before they can be marketed. Among the parameters of interest, inward leakage (IL) characterizes the tightness between the face seal and the face, to verify that the device is well-designed. European standard EN 13274-1 (2001) and International Organization for Standardization (ISO) standard ISO 16900-1 (2019) specify that IL should be measured using sodium chloride (NaCl) aerosol or sulfur hexafluoride (SF6) gas. For reusable masks made of nonporous materials, both test agents are considered equally acceptable. However, the few studies that have compared IL values measured with various aerosols and gases have come to divergent conclusions. This work then aimed to measure IL with the test agents recommended by the standards to determine whether they are really equivalent. Since krypton (Kr) is an interesting candidate for replacing SF6 in standard tests, IL was assessed with SF6 and Kr simultaneously, and with NaCl aerosol using various calculation methods. Tests were carried out on 5 models of full-face masks donned on a headform connected to a breathing machine simulating 3 sinusoidal breathing rates of various intensities. The respirator fit on the headform was evaluated using a controlled negative pressure method to determine a manikin fit factor. Four scenarios were then tested to represent very poor, bad, good, and excellent fit. Gas concentration was measured using a mass spectrometer, and IL was calculated for SF6 and Kr. A combination of 3 devices allowed the determination of the number-based concentration of particles with diameters between 20 nm and 2 µm, and IL was calculated for each of the 33 channels, as well as using a cumulative number concentration. In addition, to comply with standards, a conversion was carried out to calculate IL using a cumulative mass concentration. The results of this work evidenced that the IL values measured with NaCl were systematically lower than those determined with gases. IL was also shown to vary with particle size, with a maximum value exceeding that calculated with cumulative concentrations (in number or mass). As part of the revision of the standards, protocols for measuring inward leakage should be redefined. On the one hand, acceptability thresholds should be re-evaluated according to the nature of the test agent (gas or aerosol), as it is clear that the 2 options do not give the same results for a given configuration. On the other hand, the aerosol leakage measurement protocol needs to be reworked to enable the measurement of a well-defined, robust, and reproducible inward leakage value. [ABSTRACT FROM AUTHOR]

A quasi-consensus has steadily formed in the scientific literature on the fact that the prevention measures implemented by most countries to curb the 2020 COVID-19 pandemic have led to significant reductions in pollution levels around the world, especially in urban environments. Fewer studies have looked at how these reductions at the ground level translate into variations in the whole atmosphere. In this study, we examine the columnar values of aerosols at 51 mainland European stations of the Aerosol Robotic Network (AERONET). We show that when considered in the context of the long-term trend over the last decade, the columnar aerosol levels for 2020, at the regional level, do not appear exceptional. Both the yearly means and the number of episodes with extreme values for this period are within one standard deviation of the long-term trends. We conclude that the spatially and temporally localized reductions do not add up to statistically significant reductions at the global levels of aerosols. Furthermore, considering that pandemic lockdowns can be thought of as a simulation of a climate change mitigation scenario, we conclude that such lifestyle-based changes present a very low potential as a global climate change mitigation strategy. [ABSTRACT FROM AUTHOR]

The Atlantic Meridional Overturning Circulation (AMOC) is a crucial system influencing regional and even global climate changes, with the Subpolar North Atlantic (SPNA) being a key region affecting this system. In the context of global climate change, the impact and mechanisms of aerosols on the AMOC remain unclear. This study, based on state-of-the-art ensemble model simulations paired with latest observations, reveals that aerosols in the SPNA region significantly influence sea surface temperature anomalies by affecting cloud cover, which in turn affects ocean stratification, thus impacting the strength of the AMOC. Based on this, we present the trends and spatiotemporal characteristics of future AMOC under different forcings. Our research contributes to a deeper understanding and prediction of the AMOC. [ABSTRACT FROM AUTHOR]

We report a large outbreak of severe acute respiratory syndrome coronavirus 2 in a residential living facility. Measurements of carbon dioxide levels, aerosol particle clearance, and airflow were used to identify and remediate areas with suboptimal ventilation. A simple intervention involving continuous operation of bathroom fans was effective in significantly improving ventilation in resident rooms. ● Areas with suboptimal ventilation pose a risk for SARS-CoV-2 transmission. ● An outbreak of COVID-19 occurred in a hospital-affiliated residential living facility. ● Carbon dioxide monitoring and aerosol clearance were used to assess ventilation. ● Testing demonstrated that double-occupancy resident rooms were poorly ventilated. ● Operation of bathroom fans significantly improved ventilation in resident rooms. [ABSTRACT FROM AUTHOR]

Evapotranspiration (ET) is crucial for the global water balance, plant growth, and freshwater availability. It connects the surface water balance with surface energy fluxes, making its accurate representation vital for climate projections. However, global climate models (GCMs) struggle with ET representation due to resolution limitations and simplified depictions of soil, plant, and atmosphere interactions. Simulated future changes in ET are uncertain, and the role of driving processes remain unclear. Here, we explore the utility of a simple and interpretable method to disentangle these varying drivers. We investigate the sensitivity of JJA ET to different atmospheric variables through simple linear models predicting ET from atmospheric variables only. The model consistently yields good results across GCMs or forcing scenarios. We find that GCMs have shown strong decreases and subsequent increases in ET over the historical period, related to changes in net surface radiation. For future climate projections, decreases in water availability compete with higher available surface radiation, making future projections uncertain. Single forcing GCM realizations show that historical ET trends in densely populated regions have been more influenced by aerosol emissions than greenhouse gases. Finally, we investigate which atmospheric variables explain most short‐term (year‐to‐year) and long‐term (decadal) changes. While water availability may be the most important driver of short‐term variability, for certain regions, radiation trends dominate long‐term forcing. This paper leverages a simple approach to provide a comprehensive and understandable view into recent and future changes in ET, reconciling the evidence provided by more complex case studies. Plain Language Summary: Evapotranspiration (ET) is essential for the global water cycle, plant growth, and the availability of freshwater. It links the surface water balance with surface energy exchanges, making its accurate representation important for predicting climate change. However, climate models have difficulty accurately representing ET due to their coarse resolution and simplified interactions between soil, plants, and the atmosphere. This leads to uncertainty in predicted future changes in ET and the underlying processes driving these changes. We use a simple method to analyze the various factors influencing ET. We focus on the sensitivity of boreal summer (June, July, August) ET to different atmospheric variables. Our findings indicate that climate models show significant fluctuations in ET over the historical period, influenced by changes in radiation. For future projections, reduced water availability competes with increased radiation, creating uncertainty. Additionally, climate model experiments reveal that historical ET trends in populated areas have been more affected by aerosol emissions than by greenhouse gases. We also explore which atmospheric variables are most influential for short‐term (year‐to‐year) and long‐term (decadal) changes. Water availability seems to be the main driver of short‐term variability, while radiation trends are more important for long‐term changes in certain regions. Key Points: Historical boreal summer evapotranspiration (ET) trends over populated regions have been influenced more by anthropogenic aerosol emissions than greenhouse gasesThe sensitivity of long‐term ET changes to energy limitation is not as apparent when considering short‐term variabilityWhile radiation drives recent historical change, future changes appear equally influenced by water limitation as well [ABSTRACT FROM AUTHOR]

As the world's largest carbon emitter, China has been confronting the dual challenge of climate change and air pollution. China's quest for reducing carbon emissions will promisingly benefit the air quality, yet its impact on carbon sinks remains unclear. Here, we assess the effect of China's clean air actions and carbon neutrality policy on air quality and its associated co‐benefits for terrestrial carbon sinks by integrating multiple observations and numerical modeling. We find a quadratic response of plant photosynthesis to aerosol loading due to trade‐offs between diffuse fertilization effect and light limitations. The estimations show that China's air pollution suppresses terrestrial carbon uptake through aerosol‐induced light limitations, leading to a 7.3% decrease in plant productivity in the 2010s. In the context of carbon neutrality pledge, the associated aerosol reductions tend to alleviate the suppression and produce an additional CO2 removal of 0.39 GtCO2 year−1. Our results uncover the enhanced terrestrial carbon sinks by aerosol mitigation, highlighting the synergy between carbon neutrality and clean air. Plain Language Summary: As the world's largest carbon emitter, China has pledged to peak its carbon emissions before 2030 and achieve carbon neutrality before 2060 as an active response to climate change. China's climate strategies and efforts to reduce carbon emissions will promisingly benefit the air quality through reducing particulate matter air pollution. However, the impact of particulate pollution reductions on vegetation photosynthesis at regional and national scales remains uncertain. Here, we assess the impact of China's climate actions on climate factors and the associated ecological impacts with multiple observations and computational modeling. We find that plant photosynthesis increases under moderate particulate pollution and decreases under heavily polluted conditions. Results from models indicate that the severe air pollution at 2015 level suppresses China's ecosystem productivity, while the air quality improvements under carbon neutrality pledge significantly enhance vegetation photosynthesis and carbon absorption. Our results highlight the overlooked climate mitigation potential of reducing air pollution to enhance ecosystem productivity under China's carbon neutrality pathways. Key Points: Both observation and simulation show a quadratic response of photosynthetic productivity to aerosol loading in the eastern China regionAerosol loading in China attenuates the incident shortwave radiation, which weakens plant photosynthesis and terrestrial carbon uptakeAerosol mitigation under China's carbon neutrality pursuit can enhance ecosystem productivity and promote terrestrial carbon sink [ABSTRACT FROM AUTHOR]

This study aimed to establish a feasible dissolution method for inhalation aerosols. A method of collecting fine particles was investigated to capture aerosol particles less than 4 μm in diameter for dissolution tests. This dose collection method enabled the aerosol particles to be uniformly distributed on the glass fiber filter, thus considerably reducing particle agglomeration. Budesonide was used as a model drug. The aerodynamic particle size distribution (APSD) of the meter-dose inhaler (MDI) was compared by replacing actuators with different orifice sizes. Dissolution tests were conducted on fine particle doses collected using various actuators, and the dissolution profiles were modeled. The fine particle dose decreased with an increasing orifice size of the actuator. Actuators with different orifice sizes would affect the dissolution behavior of inhaled drugs. This finding was supported by similarity factor f2 analysis, suggesting the dissolution method has a discriminative capacity. The results of various model fits showed that the dissolution profiles produced by the different actuators could be fitted well using the Weibull mathematical model. The method employed in this study could offer a potential avenue for exploring the relationship between the orifice size of the actuator and the dissolution behavior of inhaled corticosteroids. This dissolution method was simple, reproducible, and suitable for determining the dissolution of inhalation aerosols. [ABSTRACT FROM AUTHOR]

This study aims to determine the presence of norovirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and bocavirus in air samples from a tertiary care hospital in Bangkok, Thailand. Air samples were collected in water using the BioSampler and concentrated using speedVac centrifugation. Based on RT-qPCR, norovirus RNA and SARS-CoV-2 RNA were detected in 13/60 (21.7%) and 3/60 (5.0%) of samples, respectively. One air sample had a weak positivity for both norovirus and SARS-CoV-2 RNAs. Detection rate of norovirus genogroup (G) II (13.3%) was higher than norovirus GI (6.7%). One air sample (1.7%) tested positive for GI and GII. The norovirus GI RNA concentration was 6.0 × 102 genome copies/m3. The norovirus GII RNA concentrations ranged from 3.4 × 101 to 5.0 × 103 genome copies/m3. Based on RT-nested PCR, norovirus GII was detected in two (3.3%) samples. All samples tested negative for GI RNA and bocavirus DNA. By phylogenetic analysis, GII.17, which is closely related to the outbreak Kawasaki308/JPN/2015 strain, was found in the RT-nested PCR-positive samples. This study highlights the potential of aerosols for norovirus and SARS-CoV-2 transmission and probably cause gastrointestinal and respiratory illnesses, respectively. [ABSTRACT FROM AUTHOR]

Light‐absorbing carbonaceous aerosols that dominate atmospheric aerosol warming over India remain poorly characterized. Here, we delve into UV‐visible‐IR spectral aerosol absorption properties at nine PAN‐India COALESCE network sites (Venkataraman et al., 2020, https://doi.org/10.1175/bams‐d‐19‐0030.1). Absorption properties were estimated from aerosol‐laden polytetrafluoroethylene filters using a well‐constrained technique incorporating filter‐to‐particle correction factors. The measurements revealed spatiotemporal heterogeneity in spectral intrinsic and extrinsic absorption properties. Absorption analysis at near‐UV wavelengths from carbonaceous aerosols at these regional sites revealed large near‐ultraviolet brown carbon absorption contributions from 21% to 68%—emphasizing the need to include these particles in climate models. Further, satellite‐retrieved column‐integrated absorption was dominated by surface absorption, which opens possibilities of using satellite measurements to model surface‐layer optical properties (limited to specific sites) at a higher spatial resolution. Both the satellite‐modeled and direct in‐situ absorption measurements can aid in validating and constraining climate modeling efforts that suffer from absorption underestimations and high uncertainties in radiative forcing estimates. Plain Language Summary: Particulate pollution in the atmosphere scatter and absorb incoming solar energy, thus cooling or warming Earth's atmosphere. In developing countries and especially in India, one of the most polluted regions of the world, the extent to which particles can absorb solar energy and warm the atmosphere is not well understood. Here, for the first time, we measure particle absorption simultaneously at nine ground sites across India, in diverse geographical regions with different levels and types of particulate pollution. We find that organic carbon particles exert large absorption at near‐ultraviolet wavelengths, which contain significant solar energy. These light absorbing organic carbon particles, called brown carbon, are emitted in large quantities from biomass burning (e.g., burning crop residue and cooking on wood‐fired stoves). Comparing ground measurements of absorption with satellite‐retrieved measurements that are representative of the entire atmospheric column, we find that near‐surface atmospheric particles can exert significant warming. This study highlights the need to improve climate model simulations of particulate pollution's impact on the climate by incorporating spatiotemporal surface‐level absorption measurements, including absorption by brown carbon particles. Key Points: Measurements at nine regional PAN‐India sites reveal several regions with large aerosol absorption strengthBrown carbon contributes significantly (21%–68%) to near‐ultraviolet absorption, indicating its importance in shortwave light absorptionStrong correlations observed between satellite data and surface absorption indicate future potential in modeling surface absorption [ABSTRACT FROM AUTHOR]

Aims Methods Results Conclusion Intubated patients with methicillin‐resistant Staphylococcus aureus pneumonia, fail optimized treatment with intravenous (IV) vancomycin (serum trough 15–20 μg/mL) in 38–79% of cases. Airway blood flow is diminished compared to alveoli and we hypothesized that vancomycin concentrations achieved in airway secretions are suboptimal and nonbactericidal. Targeted therapy by inhalation may overcome this deficit.Airway pharmacokinetics of optimized IV and inhaled vancomycin in infected clinically stable prolonged mechanically ventilated patients were measured. First, IV vancomycin was given until optimized concentrations were achieved (15–20 μg/mL), and, at the same time point, sputum vancomycin concentrations were measured. Then, sputum concentrations were re‐assessed after 4 treatments of inhaled vancomycin (120 mg/2 mL) via a previously characterized nebulizing system that deposited 18 ± 2 mg in the lungs. Vancomycin post‐distribution phase serum peak and trough concentrations were also obtained. Serum albumin was measured to assess binding to vancomycin.Mean serum trough concentration was 18.4 ± 6.5 μg/mL. Sputum concentrations were affected by serum albumin. Only patients with severe hypoalbuminaemia had penetration of drug leading to therapeutic (15.7–17 μg/mL) sputum concentrations. Following inhaled vancomycin, sputum concentrations increased significantly to 199 ± 37.0 μg/mL (P = .002) exceeding minimum inhibitory concentration by 2 orders of magnitude.Despite optimized serum concentrations, patients with albumin near normal had suboptimal concentrations of vancomycin in their sputum. Inhaled therapy may be clinically important for successful treatment of ventilator‐associated methicillin‐resistant Staphylococcus aureus infection. Further studies of inhaled therapy are needed to define their role as adjunctive therapy in ventilator‐associated pneumonia and as single therapy in tracheobronchitis. [ABSTRACT FROM AUTHOR]

This study investigated the impact of sweeteners on the release of heavy metals during the heating and atomization processes in electronic cigarettes. Based on a PG/VG base e-liquid with the addition of 2% and 5% neotame or sucralose, we quantitatively analyzed the impact of sweetener content on the levels of heavy metals such as Ni, Cr, and Fe in the e-liquid and aerosol after heating and atomization. Additionally, the heated e-liquid samples were used to culture SH-SY-5Y and Beas-2B cells, and their cytotoxic effects were assessed using the CCK-8 assay. The results indicated that the e-liquid with 5% sucralose had the highest average levels of heavy metals after heating and atomization, particularly nickel (13.36 ± 2.50 mg/kg in the e-liquid and 12,109 ± 3,229 ng/200 puffs in the aerosol), whereas the e-liquid with neotame had significantly lower average heavy metal content in comparison. Additionally, it was measured that the chloride ion concentration in the e-liquid with 5% sucralose reached 191 mg/kg after heating at 200°C for 1 h, indicating that heating sucralose generated chloride ions, Which might corrode metal parts components leading to heavy metal release. Cytotoxicity tests revealed that the base e-liquid without sweeteners exhibited the highest average cell viability after heating, at 64.80% ± 2.84% in SH-SY-5Y cells and 63.24% ± 0.86% in Beas-2B cells. Conversely, the e-liquid variant with 5% sucralose showed a significant reduction in average cell viability, reducing it to 50.74% ± 0.88% in SH-SY-5Y cells and 53.03% ± 0.76% in Beas-2B cells, highlighting its more pronounced cytotoxic effects compared to other tested e-liquids. In conclusion, sucralose in e-liquids should be limited preferably less than 2%, or replaced with neotame, a safer alternative, to minimize health risks. [ABSTRACT FROM AUTHOR]

The role that aquatic aerosols might play in inter-ecosystem exchanges in freshwater riparian environments has largely been understudied. In these environments, where freshwater streams are used both as drinking water and for treated waste disposal, water features like waterfalls, downed trees, and increased streamflow can serve as bioaerosol producers. Such water features could have an important role in the bacterial colonization of surrounding surfaces, including the riparian phyllosphere. In this study, we explore the influence of a freshwater stream's bacterial community composition and micropollution on riparian maple leaves exposed to bioaerosols produced from that stream. Using culture-based and non-culture-based techniques, we compared phylloplane microbial communities in riparian zones, adjacent non-riparian forested zones, and the surface waters of the stream. In this system, riparian zone maple leaf surfaces had higher bacterial counts than non-riparian zone trees. Using metagenomic profiling of the 16S rRNA gene, we found that, while microbial communities on leaves in both the riparian zone and forested sites were diverse, riparian zone bacterial communities were significantly more diverse. In addition, we found that riparian leaf bacterial communities shared more amplicon sequence variants (ASVs) with stream bacterial communities than forest leaves, indicating that the riparian zone phyllosphere is likely influenced by bioaerosols produced from water surfaces. [ABSTRACT FROM AUTHOR]

This study presents an improved wet scavenging process for particles in air quality modeling, focusing on the Korean Peninsula. New equations were incorporated into the air quality chemical transport model (CTM) to enhance the simulation of particulate matter (PM) concentrations. The modified air quality CTM module, utilizing size-dependent scavenging formulas, was applied to simulate air quality for April 2018, a month characterized by significant precipitation. Results showed that the modified model produced more accurate predictions of PM10 and PM2.5 concentrations compared to the original air quality CTM model. The maximum monthly average differences were 5.46 µg/m3 for PM10 and 2.87 µg/m3 for PM2.5, with pronounced improvements in high-concentration regions. Time-series analyses for Seoul and Busan demonstrated better agreement between modeled and observed values. Spatial distribution comparisons revealed enhanced accuracy, particularly in metropolitan areas. This study highlights the importance of incorporating region-specific, size-dependent wet scavenging processes in air quality models. The improved model shows promise for more accurate air quality predictions, potentially benefiting environmental management and policy-making in the region. Future research should focus on integrating more empirical data to further refine the wet scavenging process in air quality modeling. [ABSTRACT FROM AUTHOR]

Heated tobacco products (HTPs) are newly developed nicotine delivery systems via the inhalation of mainstream aerosols generated during the heating of tobacco leaf materials. Previous studies have shown that the amount of chemicals generated is much lower than that generated by conventional combustible cigarettes. However, little attention has been paid to formate, a conjugated base of formic acid with potentially toxic effects on human health. This study aims to understand the actual emission levels and behaviour of formate in mainstream aerosols produced by commercially available HTP devices in Japan. Aerosols were generated from four types of devices with regular and menthol-type flavours using a vaping machine following the CRM 81 puffing protocol. Formate was tapped in 5 mM sodium carbonate solution and subsequently analysed using ion chromatography. The results showed that the total emission amount of formate ranged from 0.0027 ± 0.0031 to 0.27 ± 0.055 mg L−1, varying with heating temperature and flavour type. Moreover, the majority of formate existed in a particulate form due to the weak-basic property of the aerosol, and the formate emission level was much greater than the workplace exposure limit for the direct inhalation of mainstream aerosols. The formate in the mainstream aerosol can be considered a health concern, when using "high-temperature type" HTPs over a long period. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) are employed in a range of devices due to their high energy and power density. However, the increased power density of LIBs raises concerns regarding their safety when subjected to external abuse. The thermal behavior is influenced by a number of factors, i.e., the state of charge (SoC), the cell chemistry and the abuse conditions. In this study, three distinct cylindrical Li-ion cells, i.e., lithium nickel cobalt aluminum oxide (NCA), lithium titanate oxide (LTO), and lithium iron phosphate (LFP), were subjected to thermal abuse (heating rate of 5 °C/min) in an air flow reactor, with 100% SoC. Venting and thermal runaway (TR) were recorded in terms of temperature and pressure, while the emitted products (gas, solid, and liquid) were subjected to analysis by FT-IR and ICP-OES. The concentrations of the toxic gases (HF, CO) are significantly in excess of the Immediate Danger to Life or Health Limit (IDLH). Furthermore, it is observed that the solid particles are the result of electrode degradation (metallic nature), whereas the liquid aerosol is derived from the electrolyte solvent. It is therefore evident that in the event of a LIB fire, in order to enhance the safety of the emergency responders, it is necessary to use appropriate personal protective equipment (PPE) in order to minimize exposure to toxic substances, i.e., particles and aerosol. [ABSTRACT FROM AUTHOR]

This study investigates the impacts of summer monsoon activity on aerosols over the Indian region. We analyze the variability of aerosols during active and break monsoon phases, as well as strong and weak monsoon years, using data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). Our findings show a clear distinction in aerosol distribution between active and break phases. During active phases, the Aerosol Optical Depth (AOD) and aerosol extinction are lower across the Indian region, while break phases are associated with higher AOD and extinction. Furthermore, we observed a significant increase in AOD over Central India during strong monsoon years, compared to weak monsoon years. Utilizing the vertical feature mask (VFM) data from CALIPSO, we identified polluted dust and dusty marine aerosols as the dominant types during both active/break phases and strong/weak monsoon years. Notably, the contributions of these pollutants are significantly higher during break phases compared to during active phases. Our analysis also reveals a shift in the origin of these aerosol masses. During active phases, the majority originate from the Arabian Sea; in contrast, break phases are associated with a higher contribution from the African region. [ABSTRACT FROM AUTHOR]

Sea spray particles play a key role in transferring momentum, heat, and gas across the atmosphere–ocean interface at high wind speeds and represent an important source of cloud condensation nuclei which affect the genesis, chemistry, and radiative properties of marine clouds. Here, we present direct measurements of sea spray particle fluxes obtained using an eddy covariance technique through the use of a newly developed high temporal resolution optical particle counter. With this instrumentation measurements were made over the coastal ocean during a 5-week field campaign conducted at an observation pier from November to December 2021. Our optical particle counter was capable of measuring size spectra at a rate of 10 Hz in 8 channels covering a range of mean radii between 0.3 and 15. The power spectra of particle number density followed the Kolmogorov −2/3 power law. The shape of the cospectrum of the particle number density flux was basically similar to that of the cospectra of the heat and gas fluxes. The measured sea spray particle fluxes at mean wind speeds of up to 21 m s−1 were dominated by an upward flux, which likely represents aerosol production caused by the bursting of bubbles at the ocean surface. [ABSTRACT FROM AUTHOR]

In a nuclear emergency, consequence assessment based on the plant conditions using a simple method is important for a prompt response. Response Technical Manual (RTM-96) is a manual calculation method for prompt dose projection at arbitrary distances by converting pre-calculated doses with the conversion factor based on distance and weather. However, the 'conversion factor' in RTM-96 does not consider accident scenarios with filtered containment venting system (FCVS). Therefore, in this study, we defined the ratio of effective dose between 1 km and an arbitrary distance as the 'Distance Conversion Factor (DCF)' and aimed to clarify the difference between DCFs by accident scenarios, focusing on the presence or absence of FCVS. The results showed that the differences in DCFs for different accident scenarios were minor in the case of no rainfall. In contrast, in the case of rainfall, DCF differed significantly with scenarios with FCVS and those with containment failure. Therefore, the authors propose that DCFs with rainfall should be calculated separately for several representative accident scenarios rather than uniformly for all accident scenarios, as in the conventional method. The results can contribute to developing a new prompt consequence assessment method, such as RTM-96, which considers FCVS. [ABSTRACT FROM AUTHOR]

The fractionation of airborne particles based on multiple characteristics is becoming increasingly significant in various industrial and research sectors, including mining and recycling. Recent developments aim to characterize and fractionate particles based on multiple properties simultaneously. This study investigates the fractionation of a technical aerosol composed of a mixture of micron-sized copper and silicon particles by size and material composition using a classifying aerodynamic lens (CAL) setup. Particle size distribution and material composition are analyzed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) for samples collected from the feed stream (upstream of CAL) and product stream (downstream of CAL) at varying operational pressures. The experimental findings generally agree with the predictions of an analytical fractionation model but also point to the importance of particle shape as a third fractionation property. Moreover, the results suggest that material-based fractionation is efficient at low operational pressures, even when the aerodynamic properties of the particle species are similar. This finding could have significant implications for industries where precise particle fractionation is crucial. [ABSTRACT FROM AUTHOR]

The presence of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) in wastewater and its potential as an airborne transmission source require extensive investigation, particularly in wastewater treatment plants (WWTPs), where few studies have been conducted. The aim of this study was to investigate the presence of SARS‐CoV‐2 and norovirus (NoV) RNA in wastewater and air samples collected from a municipal WWTP. In addition, the study assessed the potential risk of viral exposure among WWTP employees. In both the summer and winter campaigns of this study, SARS‐CoV‐2 and NoV RNA were quantified in wastewater/sludge samples other than effluent. Viral RNA was not detected in any of the air samples collected. The exposure risk assessment with the SARS‐CoV‐2 RNA concentrations in the influent pumping station of this study shows a lower risk than the calculation with the historical data provided by AquaVall, but both show a low‐to‐medium exposure risk for the WWTP workers. The sensitivity analysis shows that the result of the model is strongly influenced by the SARS‐CoV‐2 RNA quantification in the wastewater. This study underscores the need for extensive investigations into the presence and viability of SARS‐CoV‐2 in wastewater, especially as a potential airborne transmission source within WWTPs. [ABSTRACT FROM AUTHOR]

Electronic cigarettes (ECs) are battery-powered gadgets that heat liquid to produce an aerosol. Nicotine is a primary ingredient in some e-liquids; however, due to a lack of quality control regulations, the nicotine may become tainted, or the measured and labelled values may not correspond. To avoid such issues, it is essential to identify the components that contribute to erroneous nicotine quantification. Herein, the differences between free-base nicotine and nicotine salts are discussed, highlighting the lower volatility of nicotine salts and their longer persistence in the body. Discrepancies were noted in the concentration of nicotine salts in some e-liquid samples, with labelled and measured values of 48 and 68.8 mg/mL, respectively, in one sample, and 24 and 33.1 mg/mL, respectively, in another. Inconsistencies were also observed in e-liquids labelled as nicotine-free: one sample had a nicotine concentration of 21.80 mg/cartridge, while another had a concentration of 23.91 mg/mL. The review also covers differences in the potency, flavour, and storage of nicotine under various conditions. Additionally, the literature suggests that the components in ECs are separated into the liquid and vapour phases; thus, phase selection should be considered to ensure optimal experimental outcomes. For instance, the vapour phase comprises the greatest quantities of volatile organic compounds, even though nicotine has been detected in all phases. Finally, the role of ECs in smoking cessation is discussed. The reviewed findings underscore the need for further research on e-liquids, particularly regarding their long-term clinical effects. [ABSTRACT FROM AUTHOR]

Aerosols continuously transport trace elements (TEs) across long distances to the ocean, fueling marine primary production and affecting global carbon cycles. Given the multiple sources and complex transport mechanisms, field investigations of aerosol TEs on a global scale are significant for understanding their role in marine biogeochemical cycles. Here, aerosol samples were collected along a 50,000‐km route covering subtropical Northwest Pacific (NWP) marginal seas, Indian Ocean, Southern Ocean, Drake Passage, and South Pacific. Samples were analyzed for the concentrations of Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Tl, and Pb. Aerosol TEs were distributed heterogeneously, with significantly lower concentrations over remote oceans compared to coastal seas. Meanwhile, TE concentrations were generally high in the Indian Ocean, moderate in the Southern Ocean, and low in the South Pacific. Cr, Ni, Cu, Zn, Cd, As, and Pb were widely enriched, primarily originating from anthropogenic sources, while Al, Ti, V, Mn, Fe, and Co were mainly from crustal sources in remote oceans. Moreover, specific sources of TEs were clarified, for example, Cr and Ni were mainly from vehicle emissions. The estimated bulk TE deposition fluxes also varied spatially. For instance, the greatest deposition of Fe occurs in the NWP marginal sea, followed by the Drake Passage, Indian Ocean Sector of Southern Ocean, Pacific Sector of Southern Ocean, and South Pacific. This study contributes to a deeper understanding of the complex dynamics of aerosol TEs in the global ocean, providing valuable information for future studies and policy making regarding climate change. Plain Language Summary: Trace Elements serving as essential micronutrients (e.g., Fe and Mn), harmful pollutants (e.g., As and Pb), or reliable tracers (e.g., Ti and Al) are crucial for understanding marine biogeochemical processes. Aerosols continuously transport TEs over long‐distances to the ocean, providing a significant source to the surface layer. Their complex sources and transport mechanisms cause substantial spatial variability in distribution and deposition. Limited observations and challenges of uncontaminated sampling further constrain our understanding of the role of aerosol TEs in the ocean. During a 180‐day cruise, aerosol TEs were observed across a large spatial scale, providing an opportunity to better explore differences in aerosol TEs across multiple ocean basins due to consistent sampling and analysis. Results showed that TE concentrations were generally high in the Indian Ocean, moderate in the Southern Ocean, and low in the South Pacific. We identified TEs from crustal and anthropogenic sources, and further elucidated the specific origins of the anthropogenic elements. Furthermore, the bulk deposition fluxes of 14 TEs and dust as well as the contributions of dry and wet deposition. These findings help elucidate the aerosol TE depositions and their influence on marine TE cycles. Key Points: Field observations of aerosol trace elements are conducted in the NW Pacific marginal sea, Indian Ocean, Southern Ocean, and South PacificThe degree of enrichment and the specific sources of trace elements are presentedBulk fluxes of dust and trace element as well as contribution ratios of dry and wet deposition are estimated across multiple basins [ABSTRACT FROM AUTHOR]

Human norovirus is transmitted mainly via the faecal-oral route, but norovirus disease outbreaks have been reported in which airborne transmission has been suggested as the only explanation. We used murine norovirus (MNV) as a surrogate for human norovirus to determine the aerosolization of infectious norovirus in an experimental setup. A 3-l air chamber system was used for aerosolization of MNV. Virus in solution (6 log10 TCID50/ml) was introduced into the nebulizer for generating aerosols and a RAW 264.7 cell dish without a lid was placed in the air chamber. Cell culture medium samples were taken from the dishes after the aerosol exposure time of 30 or 90 min, and the dishes were placed in a 37 °C, 5% CO2 incubator and inspected with a light microscope for viral cytopathic effects (CPEs). We determined both the infectious MNV TCID50 titre and used an RT-qPCR assay. During the experiments, virus infectivity remained stable for 30 and 90 min in the MNV solution in the nebulizer. Infectious MNV TCID50 values/ml of 2.89 ± 0.29 and 3.20 ± 0.49 log10 were measured in the chamber in RAW 264.7 cell dish media after the 30-min and 90-min exposure, respectively. The MNV RNA loads were 6.20 ± 0.24 and 6.93 ± 1.02 log10 genome copies/ml, respectively. Later, a typical MNV CPE appeared in the aerosol-exposed RAW cell dishes. We demonstrated that MNV was aerosolized and that it remained infectious in the experimental setup used. Further studies required for understanding the behaviour of MNV in aerosols can thus be performed. [ABSTRACT FROM AUTHOR]

Q fever, also known as query fever, is a zoonotic illness brought on by the Coxiella burnetii bacteria. This disease was first discovered in 1935 in Queensland, Australia. Worldwide, Q fever is a disease that requires notification, and certain nations classify it as a national health concern. A feature of C. burnetii is known as cell wall phase fluctuation. Serological testing is the main method used to diagnose Q fever illnesses. Inhalation is the primary method of C. burnetii transmission in both people and animals, with smaller amounts occurring through milk and milk product ingestion. The bacterial strain that is causing the infection determines how severe it is. Q fever is a significant zoonosis that can be dangerous for personnel working in veterinary laboratories, livestock breeding operations, and slaughterhouses due to its high human contagiousness. C. burnetii is a biological weapon that can be sprayed on food, water, or even mail. It can also be employed as an aerosol. Antibiotics work well against this disease's acute form, but as the infection develops into a chronic form, treatment becomes more difficult and the illness frequently returns, which can result in a high death rate. Vaccination has been demonstrated to lower the incidence of animal infections, C. burnetii shedding, and abortion. Several hygienic precautions should be put in place during an outbreak to lessen the spread of disease to animals. [Open Vet J 2024; 14(10.000): 2509-2524]

Background137Cs in atmospheric aerosol is the product of past nuclear weapon tests and nuclear accidents. When 137Cs is released into the atmosphere, it will deposit in dry land and marine environment, causing pollution of soil surface, water, agricultural products, and animal byproducts, and affecting public health.ObjectiveTo identify the variation pattern of 137Cs activity concentration in aerosol and its correlation with dust concentration in Beijing area from 2017 to 2020.Methods A total of 958 aerosol samples were collected from November 1, 2017 to June 30, 2020 in Beijing with a high volume air sampler at a sampling flow rate about 600 m3·h−1 and a collection time for each sample about 24 h. The activity concentration of 137Cs in the aerosol samples was determined with a low-background high-purity germanium γ spectrometer. The dust concentration was calculated using the difference in the mass of the aerosol filter before and after sampling. The detection rate of 137Cs and dust concentration in different seasons were compared. Spearman rank correlation test was used to analyze the correlation between 137Cs activity concentration and dust concentration.Results From 2017 to 2020, the 137Cs activity concentrations of 33 from 958 aerosol samples in Beijing were above the minimum detectable activityconcentration, the overall detection rate of 137Cs was 3.4%, and the activity concentration ranged from 1.86 to 45.53 μBq·m−3, with a median value of 4.85 μBq·m−3. The detection rate of 137Cs was highest in spring, followed by autumn, and lowest in winter and summer (8.4%, 3.0%, 1.1%, and 0.5%, respectively). The dust concentration ranged from 0.03 to 1.55 mg·m−3, with an average value of 0.18 mg·m−3. There was a statistically significant difference in the dust concentrations in spring, summer, autumn, and winter (F=45.51, P

Abstract This study aims to determine the presence of norovirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and bocavirus in air samples from a tertiary care hospital in Bangkok, Thailand. Air samples were collected in water using the BioSampler and concentrated using speedVac centrifugation. Based on RT-qPCR, norovirus RNA and SARS-CoV-2 RNA were detected in 13/60 (21.7%) and 3/60 (5.0%) of samples, respectively. One air sample had a weak positivity for both norovirus and SARS-CoV-2 RNAs. Detection rate of norovirus genogroup (G) II (13.3%) was higher than norovirus GI (6.7%). One air sample (1.7%) tested positive for GI and GII. The norovirus GI RNA concentration was 6.0 × 102 genome copies/m3. The norovirus GII RNA concentrations ranged from 3.4 × 101 to 5.0 × 103 genome copies/m3. Based on RT-nested PCR, norovirus GII was detected in two (3.3%) samples. All samples tested negative for GI RNA and bocavirus DNA. By phylogenetic analysis, GII.17, which is closely related to the outbreak Kawasaki308/JPN/2015 strain, was found in the RT-nested PCR-positive samples. This study highlights the potential of aerosols for norovirus and SARS-CoV-2 transmission and probably cause gastrointestinal and respiratory illnesses, respectively.

In recent decades, there has been a significant increase in annual area burned in California's Sierra Nevada mountains. This rise in fire activity has prompted the need to understand how historical forest management practices affect fuel composition and emissions. Here we examined the total carbon (TC) concentration and radiocarbon abundance (Δ14C) of particulate matter (PM) emitted by the KNP Complex Fire, which occurred during California's 2021 wildfire season and affected several groves of giant sequoia trees in the southern Sierra Nevada. During a 26 h sampling period, we measured concentrations of fine airborne PM (PM2.5), as well as dry air mole fractions of carbon monoxide (CO) and methane (CH4), using a ground-based mobile laboratory. We also collected filter samples of PM2.5 for analysis of TC concentration and Δ14C. High correlation among PM2.5, CO, and CH4 time series confirmed that our PM2.5 measurements captured variability in wildfire emissions. Using a Keeling plot approach, we determined that the mean Δ14C of PM2.5 was 111.6 ± 7.7‰ (n = 12), which was considerably enriched relative to atmospheric carbon dioxide in the northern hemisphere in 2021 (-3.2 ± 1.4‰). Combining these Δ14C data with a steady-state one-box ecosystem model, we estimated that the mean age of fuels combusted in the KNP Complex Fire was 40 years, with a range of 29-57 years. These results provide evidence for emissions originating from woody biomass, larger-diameter fine fuels, and coarse woody debris that have accumulated over multiple decades. This is consistent with independent field observations that indicate high fire intensity contributed to widespread giant sequoia mortality. With the expanded use of prescribed fires planned over the next decade in California to mitigate wildfire impacts, our measurement approach has the potential to provide regionally-integrated estimates of the effectiveness of fuel treatment programs.

ABSTRACTThe Medium Resolution Spectral Image (MERSI) is a MODIS-like sensor aboard Fengyun-3 satellite. The first version of MERSI aerosol algorithm has been developed based on MODIS dark target (DT) algorithm, with modified models for estimating surface reflectance and an adjusted inland water masking method to release haze aerosols. This study applies MERSI DT algorithm to the global observations from the upgraded MERSI sensor (MERSI-II) on Fengyun-3D. And then, the Aerosol Optical Depth (AOD) results from the year of 2019–2020 are validated against the Aerosol Robotic Network (AERONET) data. In addition, analyses of the spatial distribution and error characteristics of MODIS and MERSI-II retrievals are presented. The overall validation demonstrates that MERSI-II retrievals perform well globally, with a correlation coefficient of 0.877 and 67.1% of matchups within the Expected Error envelope of ± (0.05 + 0.2τ), which are close to the statistic metrics of MODIS products. In addition, MERSI-II and MODIS AODs exhibit similar error trends and error dependence. Moreover, the similar global distribution characteristics of the two AODs are revealed in the retrieval performance at site and regional scales, as well as in the analysis of monthly averages. These findings indicate the success of the ported MERSI algorithm.

Abstract Exposure assessments to metalworking fluids (MWF) is difficult considering the complex nature of MWF. This study describes a comprehensive exposure assessment to straight and water-based MWFs among workers from 20 workshops. Metal and organic carbon (OC) content in new and used MWF were determined. Full-shift air samples of inhalable particulate and gaseous fraction were collected and analysed gravimetrically and for metals, OC, and aldehydes. Exposure determinants were ascertained through observations and interviews with workers. Determinants associated with personal inhalable particulate and gaseous fractions were systematically identified using mixed models. Similar inhalable particle exposure was observed for straight and water-based MWFs (64–386 µg/m3). The gaseous fraction was the most important contributor to the total mass fraction for both straight (322–2362 µg/m3) and water-based MWFs (101–699 µg/m3). The aerosolized particles exhibited low metal content irrespective of the MWF type; however, notable concentrations were observed in the sumps potentially reaching hazardous concentrations. Job activity clusters were important determinants for both exposure to particulate and gaseous fractions from straight MWF. Current machine enclosures remain an efficient determinant to reduce particulate MWF but were inefficient for the gaseous fraction. Properly managed water-based MWF meaning no recycling and no contamination from hydraulic fluids minimizes gaseous exposure. Workshop temperature also influenced the mass fractions. These findings suggest that exposures may be improved with control measures that reduce the gaseous fraction and proper management of MWF.

Abstract High pathogenicity avian influenza viruses (HPAIVs) have caused major epizootics in recent years, with devastating consequences for poultry and wildlife worldwide. Domestic and wild ducks can be highly susceptible to HPAIVs, and infection leads to efficient viral replication and massive shedding (i.e., high titres for an extended time), contributing to widespread viral dissemination. Importantly, ducks are known to shed high amounts of virus in the earliest phase of infection, but the dynamics and impact of environmental contamination on the epidemiology of HPAIV outbreaks are poorly understood. In this study, we monitored mule ducks experimentally infected with two H5N8 clade 2.3.4.4b goose/Guangdong HPAIVs sampled in France in 2016–2017 and 2020–2021 epizootics. We investigated viral shedding dynamics in the oropharynx, cloaca, conjunctiva, and feathers; bird-to-bird viral transmission; and the role of the environment in viral spread and as a source of samples for early detection and surveillance. Our findings showed that viral shedding started before the onset of clinical signs, i.e., as early as 1 day post-inoculation (dpi) or post-contact exposure, peaked at 4 dpi, and lasted for up to 14 dpi. The detection of viral RNA in aerosols, dust, and water samples mirrored viral shedding dynamics, and viral isolation from these environmental samples was successful throughout the experiment. Our results confirm that mule ducks can shed high HPAIV titres through the four excretion routes tested (oropharyngeal, cloacal, conjunctival, and feather) while being asymptomatic and that environmental sampling could be a non-invasive tool for early viral RNA detection in HPAIV-infected farms.

The fractionation of airborne particles based on multiple characteristics is becoming increasingly significant in various industrial and research sectors, including mining and recycling. Recent developments aim to characterize and fractionate particles based on multiple properties simultaneously. This study investigates the fractionation of a technical aerosol composed of a mixture of micron-sized copper and silicon particles by size and material composition using a classifying aerodynamic lens (CAL) setup. Particle size distribution and material composition are analyzed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) for samples collected from the feed stream (upstream of CAL) and product stream (downstream of CAL) at varying operational pressures. The experimental findings generally agree with the predictions of an analytical fractionation model but also point to the importance of particle shape as a third fractionation property. Moreover, the results suggest that material-based fractionation is efficient at low operational pressures, even when the aerodynamic properties of the particle species are similar. This finding could have significant implications for industries where precise particle fractionation is crucial.

In severe reactor accidents, the phenomenon of aerosols being captured and retained in the liquid as they follow the gas through the liquid phase often occurs during the discharge process of the suppression pool. It is one of the important thermal-hydraulic phenomena that affect the migration and release of radioactive source terms. Understanding the scrubbing characteristics of aerosols under this condition is of great significance for the radioactive assessment after severe accidents. The paper conducted experimental research on the scrubbing efficiency of aerosol under submerged jet conditions, exploring the influence of parameters such as aerosol diameter, liquid pool temperature, submergence, and injection pressure on the scrubbing efficiency of aerosol. When gas is injected into the liquid phase through a rupture or nozzle in the form of a jet, the entrained droplets generated by high-speed airflow shear will retain a large amount of aerosols in the liquid phase through the inertia effect. The experimental results indicate that an increase in injection pressure enhances the inertial effect, thereby improving the scrubbing efficiency. The increase in submergence also increases the residence time and probability of aerosols in contact with gas-liquid interfaces, ultimately leading to an improvement in scrubbing efficiency. Under steam jet conditions, the generation of thermophoresis and diffusiophoresis effects can improve the scrubbing efficiency of small-diameter aerosols. Under different submergence depths, there is a decreasing and then increasing relationship between scrubbing efficiency and aerosol diameter, with a turning point of around 0.3 μm. The change in liquid and gas temperature can alter the steam condensation rate and temperature gradient, thereby altering the scrubbing efficiency by affecting the thermophoresis and diffusiophoresis effects. After the temperature of the liquid pool decreases, the increase in temperature gradient and steam condensation rate will further improve the scrubbing efficiency. There is an approximate logarithmic relationship between the scrubbing efficiency and the gas-liquid phase temperature difference under the same injection pressure and submergence conditions. However, there are certain constraints on the proportion of thermal effects such as thermophoresis and diffusiophoresis, as well as the effects of inertia and submergence. By summarizing existing relevant experiments and fitting empirical formulas for predicting scrubbing efficiency under submerged jet conditions based on the dominant scrubbing mechanism, the predicted relative deviation range is －15%-25%, which can provide data and theoretical support for relevant experiments and models.

Sensitivity and uncertainty analysis serves as a tool for modeling physical phenomenon and evaluating the model validity. It finds applications in simulating the dynamical behavior of aerosols in different contexts. Hygroscopic growth of aerosol particles is one such domain where it can optimize the accuracy of model output greatly. Accurate prediction of hygroscopic growth characteristics depends on the intrinsic parameters and the size-dependent evolution of growth factors. In reactor accident scenarios, growth characteristics of fission/activation product aerosols play a significant role in determining the airborne or deposited fraction. Köhler theory is fundamentally used to predict the growth behavior of aerosols with a detailed physical explanation of critical size and supersaturation characteristics. Alternative approaches including modified Köhler theories and semi-empirical models rely on the linkage of physical and chemical composition-based parameters. The variation of involved parameters and the choice of working range influence the outcome of the theory greatly. This study is focused on sensitivity analysis of the modified Köhler theory given by Brechtel and Kreidenweis and the evaluation of sensitivity and associated uncertainty in the parameters. Monte Carlo approach has been employed, and sensitivity indices were obtained. Identified sensitive parameters were dry particle diameter, solute density, molecular weight, and chemical composition dependent factor (b0). These parameters require careful attention while designing experimental measurements and/or preprocessing model inputs. All sensitive parameters were subjected to uncertainty analysis and the overall output of the aerosol growth code thus obtained has been observed to follow log-normal law with median size at 335.2 nm with a geometric standard deviation of 1.54. This finds applications in the case of studies aiming to predict the growth of aerosols in the reactor component systems during accident conditions. In such conditions, there lies no choice of selection of input parameters and one cannot be sure about their variation range. This provides a conservative estimate for such a random scenario as uncertainty analysis performed in this study covers all the random combinations of input parameters and the overall most probable grown droplet size is estimated.

Cigarette smoking is a risk factor for several diseases such as cancer, cardiovascular disease (CVD), and chronic obstructive pulmonary diseases (COPD), however, the underlying mechanisms are not fully understood. Alternative nicotine products with reduced risk potential (RRPs) including tobacco heating products (THPs), and e-cigarettes have recently emerged as viable alternatives to cigarettes that may contribute to the overall strategy of tobacco harm reduction due to the significantly lower levels of toxicants in these products’ emissions as compared to cigarette smoke. Assessing the effects of RRPs on biological responses is important to demonstrate the potential value of RRPs towards tobacco harm reduction. Here, we evaluated the inflammatory and signaling responses of human lung epithelial cells to aqueous aerosol extracts (AqE) generated from the 1R6F reference cigarette, the glo™ THP, and the Vype ePen 3.0 e-cigarette using multiplex analysis of 37 inflammatory and phosphoprotein markers. Cellular exposure to the different RRPs and 1R6F AqEs resulted in distinct response profiles with 1R6F being the most biologically active followed by glo™ and ePen 3.0. 1R6F activated stress-related and pro-survival markers c-JUN, CREB1, p38 MAPK and MEK1 and led to the release of IL-1α. glo™ activated MEK1 and decreased IL-1β levels, whilst ePen 3.0 affected IL-1β levels but had no effect on the signaling activity compared to untreated cells. Our results demonstrated the reduced biological effect of RRPs and suggest that targeted analysis of inflammatory and cell signaling mediators is a valuable tool for the routine assessment of RRPs.

Recently, in China, during the period of transition between spring and summer, the combination of sandstorms and ozone (O3) pollution has posed a significant challenge to the strategy of coordinated control of fine particulate matters (PM2.5) and O3. On the one hand, the dust invasion brings many primary aerosols and causes a large range of transboundary transport. On the other hand, the high concentration of aerosol causes a severe disturbance to the distribution of O3. Traditionally, high-resolution assessments of the spatial distribution of aerosols and O3 can be carried out using LiDAR technology. However, the negligence of the influence of aerosols in the process of O3 retrieval in traditional differential absorption lidar (DIAL) leads to an error in the accuracy of ozone concentration. Especially when dust transit occurs, the errors become bigger. In this study, a self-customized four-wavelength differential-absorption LiDAR system was used to synchronously obtain the accurate vertical distributions of ozone and high-concentration aerosol. The wavelength index of concentrated aerosol was inverted and applied to the differential equation framework for O3 calculation. This novel approach to retrieving the vertical profile of O3 was proposed and verified by applying it to a dust pollution event that occurred from April to May 2021 in Anyang City Henan Province, which is located in Northern China. It was found that the extinction coefficient of aerosol reached 2.5 km−1 during the dust period, and O3 was mainly distributed between 500 m and 1500 m. The O3 error exceeded over 10% arising from the high-concentration aerosol below 1.5 km during the dust storm event. By employing the inversion algorithm while considering the aerosol effects, the ozone concentration error was improved by over 10% compared with the error recorded without considering the aerosol influence especially in dust events. Through this study, it was found that the algorithm could effectively realize the synchronous and accurate inversion of high-concentration aerosols and O3 and can provide key technical support for air pollution control in China in the future. [ABSTRACT FROM AUTHOR]

Exposure assessments to metalworking fluids (MWF) is difficult considering the complex nature of MWF. This study describes a comprehensive exposure assessment to straight and water-based MWFs among workers from 20 workshops. Metal and organic carbon (OC) content in new and used MWF were determined. Full-shift air samples of inhalable particulate and gaseous fraction were collected and analysed gravimetrically and for metals, OC, and aldehydes. Exposure determinants were ascertained through observations and interviews with workers. Determinants associated with personal inhalable particulate and gaseous fractions were systematically identified using mixed models. Similar inhalable particle exposure was observed for straight and water-based MWFs (64–386 µg/m3). The gaseous fraction was the most important contributor to the total mass fraction for both straight (322–2362 µg/m3) and water-based MWFs (101–699 µg/m3). The aerosolized particles exhibited low metal content irrespective of the MWF type; however, notable concentrations were observed in the sumps potentially reaching hazardous concentrations. Job activity clusters were important determinants for both exposure to particulate and gaseous fractions from straight MWF. Current machine enclosures remain an efficient determinant to reduce particulate MWF but were inefficient for the gaseous fraction. Properly managed water-based MWF meaning no recycling and no contamination from hydraulic fluids minimizes gaseous exposure. Workshop temperature also influenced the mass fractions. These findings suggest that exposures may be improved with control measures that reduce the gaseous fraction and proper management of MWF. [ABSTRACT FROM AUTHOR]

High pathogenicity avian influenza viruses (HPAIVs) have caused major epizootics in recent years, with devastating consequences for poultry and wildlife worldwide. Domestic and wild ducks can be highly susceptible to HPAIVs, and infection leads to efficient viral replication and massive shedding (i.e., high titres for an extended time), contributing to widespread viral dissemination. Importantly, ducks are known to shed high amounts of virus in the earliest phase of infection, but the dynamics and impact of environmental contamination on the epidemiology of HPAIV outbreaks are poorly understood. In this study, we monitored mule ducks experimentally infected with two H5N8 clade 2.3.4.4b goose/Guangdong HPAIVs sampled in France in 2016–2017 and 2020–2021 epizootics. We investigated viral shedding dynamics in the oropharynx, cloaca, conjunctiva, and feathers; bird-to-bird viral transmission; and the role of the environment in viral spread and as a source of samples for early detection and surveillance. Our findings showed that viral shedding started before the onset of clinical signs, i.e., as early as 1 day post-inoculation (dpi) or post-contact exposure, peaked at 4 dpi, and lasted for up to 14 dpi. The detection of viral RNA in aerosols, dust, and water samples mirrored viral shedding dynamics, and viral isolation from these environmental samples was successful throughout the experiment. Our results confirm that mule ducks can shed high HPAIV titres through the four excretion routes tested (oropharyngeal, cloacal, conjunctival, and feather) while being asymptomatic and that environmental sampling could be a non-invasive tool for early viral RNA detection in HPAIV-infected farms. [ABSTRACT FROM AUTHOR]

In this contribution, we report the study of nuclear resonance magnetic spectroscopy techniques (1H-NMR, 13C-NMR, and 2D-NMR) efficiency in the characterisation of the functional composition of water-soluble organic compounds (WSOC) from atmospheric aerosols. The chosen site was our scientific and technical center of research (CRAPC) situated in Algerian Bou-Ismail city. where the concentrations of PM10 were found to be between 15.66 and 142.19 µg.m−3. As results, 1H-NMR analysis showed the coexistence of biological material and emissions from urban and biomass burning. The dominant source was identified by quantitative integration of each 1H NMR spectral region. By using the HSQC technique, many peaks are revealed in biogenic samples including biomass burning. On the other hand, the identification of the source of various organic compounds and their functional composition is possible through specific NMR spectra, which can also be used to adjust the surrounding organic aerosol sources. [ABSTRACT FROM AUTHOR]

Aerosol–cloud interactions play a crucial role in shaping Earth's climate and hydrological cycle. Observing these interactions with high precision and accuracy is of the utmost importance for improving climate models and predicting Earth's climate. Over the past few decades, lidar techniques have emerged as powerful tools for investigating aerosol–cloud interactions due to their ability to provide detailed vertical profiles of aerosol particles and clouds with high spatial and temporal resolutions. This review paper provides an overview of recent advancements in the study of ACI using lidar techniques. The paper begins with a description of the different cloud microphysical processes that are affected by the presence of aerosol, and with an outline of lidar remote sensing application in characterizing aerosol particles and clouds. The subsequent sections delve into the key findings and insights gained from lidar-based studies of aerosol–cloud interactions. This includes investigations into the role of aerosol particles in cloud formation, evolution, and microphysical properties. Finally, the review concludes with an outlook on future research. By reporting the latest findings and methodologies, this review aims to provide valuable insights for researchers engaged in climate science and atmospheric research. [ABSTRACT FROM AUTHOR]