Smoke Particles Research Articles

PSIV-26 Development of a Controlled Exposure Particulate and Oxidative Radical Mask for Causality Experiments Investigating Smoke Exposure on Livestock Animals

Abstract Understanding and mapping the specific effects of smoke inhalation on cattle performance provides strategic insights for producers and policy makers to better prepare or adjust when faced with sporadic or even seasonal reductions in air quality. As of now, no current studies have attempted to investigate the effects of seasonal fires on performance and health adequately in livestock while addressing obvious confounding effects, controlling exposure, and examining fuel for differential oxidative radicals and particulate smoke. Herein, we propose the design of the first cost-effective controlled system for investigating smoke, particulate matter, and varied oxidative radicals through a pre-mixing chamber. The mask main body is constructed from 8” nominal diameter schedule 40 PVC pipe. The endcap was designed in an online CAD software to provide an interface for standard 2 ⅞” bulkhead fittings and was produced via additive manufacturing (3D printing). A silicone SCUBA neck seal was used to line the face orifice and is the component that directly contacts the animal’s nose and mouth. A neoprene rubber sheet and an insulation hose were used as padding under the silicone seal to help maintain an airtight connection and animal comfort when the mask is worn. Bulkhead fittings used provide 1 ½” female national pipe thread connection to allow for modular connection of inlet and outlet hoses, check valves for airflow isolation, filters, or any number of connections can be made via these gasket sealed fittings, making this platform extremely adaptable. In its shown configuration, 3D printed adapters were made to attach 4” suction hose to 2” socket union joints for quick connect/disconnect functionality. An inlet and outlet gas/smoke flow regulator are attached to a mixing chamber where particulate and chemical composition sensors are utilized to deliver the desired composition of smoke delivered to the animals. Negative pressure fans and pumps regulate the flow to the animals and are utilized for exposure of smoke in time-specific intervals. An additional fully 3D printed version enables the mask design to be lower in weight through regulation of the density of the internal matrix, and after an initial investment in the equipment also represents a cost-efficient approach to generating multiple masks. Understanding the effects of particulate and reactive oxidative molecules on livestock health and performance requires the study of a controlled exposure, the system presented herein represents a viable and cheap alternative for bettering a mechanistic model and understanding of the effects of smoke on animal health and performance. Ultimately, the proposed mask paired with currently available sensors permit for the controlled exposure of smoke particulate with different chemical compositions for accurate evaluation of prolonged exposure effects on livestock.

High-Efficiency Particulate Air Filters for Preventing Wildfire-related Asthma Complications: A Cost-Effectiveness Study.

Rationale: Air pollution caused by wildfire smoke is linked to adverse health outcomes, especially for people living with asthma. Objectives: To evaluate whether government rebates for high-efficiency particulate air (HEPA) filters, which reduce concentrations of smoke particles indoors, are cost effective in managing asthma and preventing exacerbations in British Columbia (BC), Canada. Methods: We used a Markov model to analyze health states for asthma control, exacerbation severity, and death over a retrospective time horizon of 5 years (2018-2022). Concentrations of wildfire smoke-derived particulate matter with an aerodynamic diameter ⩽2.5 μm (PM2.5) from the Canadian Optimized Statistical Smoke Exposure Model and relevant literature informed the model. The base-case analysis assumed continuous use of a HEPA filter. Costs and quality-adjusted life-years (QALYs) resulting from varying rebates were computed for each Health Service Delivery Area (HSDA). Measurements and Main Results: In the base-case analysis, HEPA filter use resulted in increased costs of $83.34 (SE, $1.03) and increased QALYs of 0.0011 (SE, 0.0001) per person. The average incremental cost-effectiveness ratio among BC HSDAs was $74,652/QALY (SE, $3,517), with incremental cost-effectiveness ratios ranging from $40,509 to $89,206 per QALY in HSDAs. Across the province, the intervention was projected to prevent 4,418 exacerbations requiring systemic corticosteroids, 643 emergency department visits, and 425 hospitalizations during the 5-year time horizon. A full rebate was cost effective in 1 of the 16 HSDAs across BC. The probability of cost-effectiveness ranged from 0.1% to 74.8% across HSDAs. A $100 rebate was cost effective in most HSDAs. Conclusions: The cost-effectiveness of HEPA filters in managing wildfire smoke-related asthma issues in BC varies by region. Government rebates up to two-thirds of the filter cost are generally cost effective, with a full rebate being cost effective only in Kootenay Boundary.

A pilot randomized clinical trial of γ-tocopherol supplementation on wood smoke-induced neutrophilic and eosinophilic airway inflammation.

Air pollutants, including particulates from wood smoke, are a significant cause of exacerbation of lung disease. γ-Tocopherol is an anti-inflammatory isoform of vitamin E that has been shown to reduce allergen-, ozone-, and endotoxin-induced inflammation. The objective of this study was to determine whether γ-tocopherol would prevent experimental wood smoke-induced airway inflammation in humans. This was a randomized, placebo-controlled clinical trial testing the effect of a short course of γ-tocopherol-enriched supplementation on airway inflammation following a controlled exposure to wood smoke particulates. Short-course γ-tocopherol intervention did not reduce wood smoke-induced neutrophilic airway inflammation, but it did prevent wood smoke-induced eosinophilic airway inflammation. γ-Tocopherol is a potential intervention for exacerbation of allergic airway inflammation, but further study examining longer dosing periods is required.

The effect of relative humidity on the polarization Mueller matrix under the oil smoke environment

For the variation of the polarized Mueller matrix of oil smoke particles under different relative humidity levels, the polarized single scattering characteristics of oil smoke particles are studied by using the Mie scattering theory, and the multiple scattering simulation is implemented with the Monte Carlo method. Variation in relative humidity is achieved by changing in mixing of the oil smoke and the water fog particles during the same dry particle filling time. Using the 36 sets of polarized Mueller matrices method, the Mueller matrix patterns of oil smoke were calculated for four conditions of 0%, 10%, 40%, and 95% relative humidity, respectively. We can verify the simulation’s correctness from the simulation and the experimental results. Specifically, as the relative humidity increases, the size of the Mueller matrix pattern increases, and the patterns of m22, m33, and m44 related to the depolarization characteristic change significantly. Furthermore, the scattering depolarization coefficients of the Mueller matrix polar decomposition increase with the increasing relative humidity, with the ability of depolarization being continuously enhanced. This method determines differences in relative humidity using intuitive measurements of stabilized scattering patterns, which can present a theoretical basis for the impact of environmental variation on polarization detection.

Annual cycle of aerosol properties over the central Arctic during MOSAiC 2019–2020 – light-extinction, CCN, and INP levels from the boundary layer to the tropopause

Abstract. The MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) expedition was the largest Arctic field campaign ever conducted. MOSAiC offered the unique opportunity to monitor and characterize aerosols and clouds with high vertical resolution up to 30 km height at latitudes from 80 to 90∘ N over an entire year (October 2019 to September 2020). Without a clear knowledge of the complex aerosol layering, vertical structures, and dominant aerosol types and their impact on cloud formation, a full understanding of the meteorological processes in the Arctic, and thus advanced climate change research, is impossible. Widespread ground-based in situ observations in the Arctic are insufficient to provide these required aerosol and cloud data. In this article, a summary of our MOSAiC observations of tropospheric aerosol profiles with a state-of-the-art multiwavelength polarization Raman lidar aboard the icebreaker Polarstern is presented. Particle optical properties, i.e., light-extinction profiles and aerosol optical thickness (AOT), and estimates of cloud-relevant aerosol properties such as the number concentration of cloud condensation nuclei (CCN) and ice-nucleating particles (INPs) are discussed, separately for the lowest part of the troposphere (atmospheric boundary layer, ABL), within the lower free troposphere (around 2000 m height), and at the cirrus level close to the tropopause. In situ observations of the particle number concentration and INPs aboard Polarstern are included in the study. A strong decrease in the aerosol amount with height in winter and moderate vertical variations in summer were observed in terms of the particle extinction coefficient. The 532 nm light-extinction values dropped from >50 Mm−1 close to the surface to <5 Mm−1 at 4–6 km height in the winter months. Lofted, aged wildfire smoke layers caused a re-increase in the aerosol concentration towards the tropopause. In summer (June to August 2020), much lower particle extinction coefficients, frequently as low as 1–5 Mm−1, were observed in the ABL. Aerosol removal, controlled by in-cloud and below-cloud scavenging processes (widely suppressed in winter and very efficient in summer) in the lowermost 1–2 km of the atmosphere, seems to be the main reason for the strong differences between winter and summer aerosol conditions. A complete annual cycle of the AOT in the central Arctic could be measured. This is a valuable addition to the summertime observations with the sun photometers of the Arctic Aerosol Robotic Network (AERONET). In line with the pronounced annual cycle in the aerosol optical properties, typical CCN number concentrations (0.2 % supersaturation level) ranged from 50–500 cm−3 in winter to 10–100 cm−3 in summer in the ABL. In the lower free troposphere (at 2000 m), however, the CCN level was roughly constant throughout the year, with values mostly from 30 to 100 cm−3. A strong contrast between winter and summer was also given in terms of ABL INPs which control ice production in low-level clouds. While soil dust (from surrounding continents) is probably the main INP type during the autumn, winter, and spring months, local sea spray aerosol (with a biogenic aerosol component) seems to dominate the ice nucleation in the ABL during the summer months (June–August). The strong winter vs. summer contrast in the INP number concentration by roughly 2–3 orders of magnitude in the lower troposphere is, however, mainly caused by the strong cloud temperature contrast. A unique event of the MOSAiC expedition was the occurrence of a long-lasting wildfire smoke layer in the upper troposphere and lower stratosphere. Our observations suggest that the smoke particles frequently triggered cirrus formation close to the tropopause from October 2019 to May 2020.

Gas–particle partitioning of semivolatile organic compounds when wildfire smoke comes to town

Abstract. Wildfires have become an increasingly important source of organic gases and particulate matter in the western USA. A large fraction of organic particulate matter emitted in wildfires is semivolatile, and the oxidation of organic gases in smoke can form lower-volatility products that then condense on smoke particulates. In this research, we measured the gas- and particle-phase concentrations of semivolatile organic compounds (SVOCs) during the 2017 northern California wildfires in a downwind urban area, using semivolatile thermal desorption aerosol gas chromatography (SV-TAG), and measured SVOCs in a rural site affected by biomass burning using cTAG (comprehensive thermal desorption aerosol gas chromatography mass spectrometry) in Idaho in 2018. Commonly used biomass burning markers such as levoglucosan, mannosan, and nitrocatechols were found to stay predominantly in the particle phase, even when the ambient organic aerosol (OA) was relatively low. The phase partitioning of SVOCs is observed to be dependent on their saturation vapor pressure, while the equilibrium absorption model underpredicts the particle-phase fraction of most of the compounds measured. Wildfire organic aerosol enhanced the condensation of polar compounds into the particle phase but not some nonpolar compounds, such as polycyclic aromatic hydrocarbons.

Escape of surgical smoke particles, comparing conventional and valveless trocar systems

BackgroundDuring minimal access surgery, surgical smoke is produced which can potentially be inhaled by the surgical team, leading to several health risks. This smoke can escape from the abdominal cavity into the operating room due to trocar leakage. The trocars and insufflator that are used during surgery influence gas leakage. Therefore, this study compares particle escape from a valveless (Conmed AirSeal iFS), and a conventional (Karl Storz Endoflator) system.Materials and methodsUsing an in vitro model, a conventional and a valveless trocar system were compared. A protocol that simulated various surgical phases was defined to assess the surgical conditions and particle leakage. Insufflation pressures and instrument diameters were varied as these are known to affect gas leakage.ResultsThe conventional trocar leaked during two distinct phases. Removal of the obturator caused a sudden release of particles. During instrument insertion, an average of 211 (IQR 111) particles per second escaped when using the 5 mm diameter instrument. With the 10 mm instrument, 50 (IQR 13) particles per second were measured. With the conventional trocar, a higher abdominal pressure increased particle leakage. The valveless trocar demonstrated a continuously high particle release during all phases. After the obturator was removed, particle escape increased sharply. Particle escape decreased to 1276 (IQR 580) particles per second for the 5 mm instrument insertion, and 1084 (IQR 630) particles per second for 10 mm instrument insertion. With the valveless trocar system, a higher insufflation pressure lowered particle escape.ConclusionsThis study shows that a valveless trocar system releases more particles into the operating room environment than a conventional trocar. During instrument insertion, the leakage through the valveless system is 6 to 20 times higher than the conventional system. With a valveless trocar, leakage decreases with increasing pressure. With both trocar types leakage depends on instrument diameter.

Study on the fast elimination of smoke particle based on electro-acoustic coupling agglomeration technology

Fire smoke, which consists large amounts of fine particles, is considered as the fatal factor in fires. In this study, a fast smoke particle elimination method based on electro-acoustic coupling agglomeration technology is proposed. First, the experimental results show that the electro-acoustic coupling agglomeration has higher smoke elimination efficiency compared to single-field. The smoke transmission is much less than 80% after 30 s of single acoustic or electric field action, while the coupled field reaches 90%. Then, the effects of acoustic frequency, sound pressure level and voltage on the smoke elimination characteristics are discussed. It is found that the optimal acoustic frequency is 1.5 kHz. While as the sound pressure level and voltage increase, the elimination efficiency first increases and then tends to stabilize, the critical values of the sound pressure level and voltage are 135 dB and 7 kV. This indicates that there is an optimal combination of the three variables. Finally, through the theoretical analysis of particle movement and the micro-morphology of agglomerates, the particle agglomeration mechanism under the electro-acoustic coupling is analyzed. This study provides a new idea for the fast elimination of fire smoke particle.

Investigating the invisible threat: An exploration of air exchange rates and ultrafine particle dynamics in hospital operating rooms

The air exchange rate (AER), defined as the number of times the air is fully replaced per hour in an indoor space, is an important parameter affecting indoor air quality (IAQ). Hospital operation rooms (ORs), one of the indoor environments with relatively high health risks, should maintain high AERs to quickly remove surgical smoke during surgery. This study aimed to investigate the characteristics and transmission of pollutants in ORs through on-site measurements and numerical simulations. To determine actual AER (AERactual), both exponential decay and concentration variations, resulting in a more precise representation of indoor air pollutant residence time, were considered. Our results revealed that gaseous pollutants exhibited lower AERactual values compared to particulate pollutants due to their higher diffusibility. Notably, the AERactual of total volatile organic compounds (TVOC) was found to be greater than that of carbon dioxide (CO2) due to the higher reactivity of TVOC. Furthermore, this study also investigated the characteristics of surgical smoke particles and observed variations in emission factors (EF) depending on the surgical procedure, ranging from approximately 1010 to 1011 particles per minute. Moreover, coarse particles (>2.5 μm) were primarily influenced by drag forces, resulting in lower AERactual values. Additionally, the AERactual of ultrafine particles (UFPs) was examined, revealing that smaller particles exhibited lower AERactual values, potentially due to stronger Brownian motion. By combining measurement and simulation analysis, the spatial distribution of lung deposited surface area (LDSA) concentrations could be evaluated, providing accurate exposure concentrations for health risk assessments.

Phase Behavior and Viscosity in Biomass Burning Organic Aerosol and Climatic Impacts.

Smoke particles generated by burning biomass consist mainly of organic aerosol termed biomass burning organic aerosol (BBOA). BBOA influences the climate by scattering and absorbing solar radiation or acting as nuclei for cloud formation. The viscosity and the phase behavior (i.e., the number and type of phases present in a particle) are properties of BBOA that are expected to impact several climate-relevant processes but remain highly uncertain. We studied the phase behavior of BBOA using fluorescence microscopy and showed that BBOA particles comprise two organic phases (a hydrophobic and a hydrophilic phase) across a wide range of atmospheric relative humidity (RH). We determined the viscosity of the two phases at room temperature using a photobleaching method and showed that the two phases possess different RH-dependent viscosities. The viscosity of the hydrophobic phase is largely independent of the RH from 0 to 95%. We use the Vogel-Fulcher-Tamman equation to extrapolate our results to colder and warmer temperatures, and based on the extrapolation, the hydrophobic phase is predicted to be glassy (viscosity >1012 Pa s) for temperatures less than 230 K and RHs below 95%, with possible implications for heterogeneous reaction kinetics and cloud formation in the atmosphere. Using a kinetic multilayer model (KM-GAP), we investigated the effect of two phases on the atmospheric lifetime of brown carbon within BBOA, which is a climate-warming agent. We showed that the presence of two phases can increase the lifetime of brown carbon in the planetary boundary layer and polar regions compared to previous modeling studies. Hence, the presence of two phases can lead to an increase in the predicted warming effect of BBOA on the climate.

SO3 removal rate and emission test of the limestone-gypsum wet desulfurization system for coal-fired power plants

This paper studies the SO3 removal ability of dual tower wet desulfurization (in series) and adopts a combination of on-site flue gas sampling and laboratory condensation control. A dual tower (series) supported boiler is used. The SO3 content in the original and clean flue gas of the dual cycle wet desulfurization device was measured, and the removal rate of SO3 of the device was measured. Desulfurization is calculated on the basis of the influence of unit electrical load, coal sulfur content, and desulfurization (raw material flue gas) inlet particle concentration on removal rate. This paper discusses and analyzes the SO3 and SO3 emission concentrations for SO3 removal rules in desulfurization systems. The results indicate that the total sulfur content of coal is relatively high, and the concentration of SO3 is relatively high. The traditional flue gas and net flue gas content in the dual tower wet desulfurization system (series) is relatively high. When burning sulfur-containing coal, there may be “blue smoke” in the flue gas. When the unit load changes between 182 MW and 350 MW, the SO3 removal rate of dual tower wet desulfurization (in series) is between 46.7% and 65.3%, with a net flue gas SO3 concentration of 16.0 mg/m3∼20.5 mg/m3. Due to equipment layout and other reasons, the SO3 removal rate of the primary tower is lower than that of the secondary tower. The removal rate of SO3 is also affected by the concentration of original smoke particles. Due to the condensation of SO3 on the particles and the dust removal of the adsorption tower, the higher the concentration of raw flue gas particles is, the higher the removal rate is. SO3 will be higher. The study also suggests the SO3 removal ability of double tower (series) and double ring wet desulfurization, which is better adapted to changes in load and coal. The next step is to explore the SO3 removal capacity of the dual tower system by optimizing its operating parameters. In addition, due to the arrangement of a desulfurization system after dust removal, it is impossible to control the SO3 source. Subsequent research can control the production of existing SO3 through coal distribution and combustion control.

Effect of peat biomass smoke exposure on oxidative stress in Wistar rats

Background: Indonesia ranks third in the world regarding air pollution due to forest and land fires; most of the land burned is a peatland. Particulate matter (PM) 2.5 is the largest component of the total smoke particles. Short-term and long-term exposure to PM2.5 remains a hazard to human health.Objective: This study aims to examine the effect of exposure to peat biomass smoke on serum malondialdehyde (MDA) levels and body weight of Wistar rats.Methods: Experimental animals were randomly divided into three groups: Control group (C) is not given treatment, and treatment groups (X1 and X2) are exposed to smoke from peat biomass of 100 g and 150 g of biomass for 60 seconds per day for 14 days. The body weight was examined before and after treatment, while Serum MDA levels were examined after treatment.Results: The results showed significant differences (p < 0.05) in serum MDA levels between groups. The highest serum MDA levels were found in group X2 (3.03 ± 0.185 nmol/ml), followed by group X1 (2.67 ± 0.212 nmol/ml) compared to the control group (2.24 ± 0.476 nmol/ml). In contrast, increasing body weight between groups did not show a significant difference.Conclusion: Exposure to PM 2.5 from peat biomass smoke increases oxidative stress in experimental animals.

Effectiveness of a covered oil-free cooking process on the abatement of air pollutants from cooking meats

Cooking events can generate household air pollutants that deteriorate indoor air quality (IAQ), which poses a threat to human health and well-being. In this study, the emission characteristics and emission factors (EFs) of air pollutants of different meats (beef, lamb, chicken, pork, and fish) cooked by a novel oil-free process and common with-oil processes were investigated. Oil-free cooking tends to emit lower total volatile organic compound (TVOC) levels and fewer submicron smoke particles and can reduce the intake of fat and calories. However, TVOC emissions during oil-free cooking were significantly different, and the lamb EFs were nearly 8 times higher than those during with-oil cooking. The particle-bound polycyclic aromatic hydrocarbon (ƩPPAH) and benzo(a)pyrene-equivalent (ƩBaPeq) EFs during with-oil cooking ranged from 76.1 to 140.5 ng/g and 7.7–12.4 ng/g, respectively, while those during oil-free cooking ranged from 41.0 to 176.6 ng/g and 5.4–47.6 ng/g, respectively. The ƩPPAH EFs of chicken, pork, and fish were lower during oil-free cooking than during cooking with oil. Furthermore, the ƩBaPeq EFs of beef, chicken, pork, and fish were lower during oil-free cooking than during cooking with oil. Therefore, it is recommended to use the oil-free method to cook chicken, pork, and fish to reduce ƩPPAH and ƩBaPeq emissions, but not recommended to cook lamb due to the increase of ƩBaPeq emissions. The with-oil uncovered cooking EFs of aldehydes ranged from 3.77 to 22.09 μg/g, and those of oil-free cooking ranged from 4.88 to 19.96 μg/g. The aldehyde EFs were lower during oil-free covered cooking than with-oil uncovered cooking for beef, chicken, and fish. This study provides a better realizing of new cooking approaches for the reduction of cooking-induced emission, but further research on the effects of food composition (moisture and fat) and characteristics is needed.

Estimation of intelligent-based quality of service in terrestrial FSO links: A case of South Africa propagation paths

Free Space Optical (FSO) communication is one of the popular technologies’ dominants in the optical communication domain. Despite all the advantages, FSO links are grossly affected by severe atmospheric conditions such as fog, rain, snow, smoke, and dust or aerosol particles suspended in the air. Fog is one of the major challenges for free-space optics to achieve carrier-class availability and causes extreme attenuation. A 10-year (2010––2019) visibility data were obtained from the South African Weather Services (SAWS) with a special focus on Cape Town (–33.925° S, 18.424° E). This extracted and processed Cape Town data was used to estimate the needed fog-induced attenuation. The intelligent algorithm is rooted in the theory of Artificial Neural Networks (ANN) systems which intelligently control the sub-tropical climate conditions of the chosen region. The adopted network-based technique is capable to interact with ever-changing weather by generating appropriate improvements to the free space optical communication link quality of service for efficient services to the customers. In this study, an Intelligent Algorithm (IA) based on an Artificial Neural Network (ANN) has been utilized to improve the reliability of QoS that can satisfy customer SLAs and improve received signal over FSO communications. The results obtained by implementing the IA system indicates that the power transmitted range from 8 to 100 dB and the adjusted Signal to Noise Ratio (SNR) between 390–––420 dB at 650 nm optical wavelength, whereas the same trend could be observed when the optical wavelength of 1550 nm was applied. Subsequently, the model effectively estimated the automatic transmit power control for enhancement in SNR and resulting in better QoS at the receiving end, regardless of the related weather changes along with the transmission link.

Adsorption charring flame retardant effect of phosphaphenanthrene derivate intercalated micro-expanded graphite composite system in rigid polyurethane foams

Phosphaphenanthrene derivate molecule (DT) was synthesized by a simple method, and exploring the flame retardant effect of DT, micro-expanded graphite (MEG) with different combination modes compounded dimethyl methylphosphonate (DMMP) in polyurethane foam rigid polyurethane foams (RPUFs). The results showed that the properties of an intercalated DT-MEG system was better than a DT blended MEG system. Specific data of DT-MEG/DMMP were as follows: the LOI value of the 6DT-8MEG/16D sample reached 30.3%, the peak heat release rate (PHRR) value decreased by 70.4%, the total smoke release value decreased by 42.4%, the total heat release (THR) value was the lowest at only 14.9 MJ/m2, and the residue yields reached 31.6%. According to the test results, the flame retardant mechanism of the DT-MEG/DMMP compounded system was also explored. DMMP of DT-MEG/DMMP can exert flame retardant effects by releasing phosphorus free radicals in the gas phase to inhibit flame intensity at the beginning of combustion. Then, when the DT-MEG structure was heated, it expanded to form a caged char layer to exert adsorption charring flame retardant effects to filter and absorb the smoke particles. Meanwhile, the intercalated DT-MEG structure produced stronger adhesion with MEG during combustion, which generated more phosphoric acids to carbonize more RPUF matrix. Therefore, DT-MEG/DMMP compound flame retardant system can endow RPUFs with excellent synergistic flame retardant effects in both the gas and condensed phases. This exerts adsorption charring flame retardant effects in the DT-MEG microscopic form, and decreases the combustion intensity and obtains a compacted char layer.

Ambient Anthropogenic Carbons and Pediatric Respiratory Infections: A Case-Crossover Analysis in the Megacity Beijing.

Carbon loading in airway cells has shown to worsen function of antimicrobial peptides, permitting increased survival of pathogens in the respiratory tract; however, data on the impacts of carbon particles on childhood acute respiratory infection (ARI) is limited. We assembled daily health data on outpatient visits for ARI (bronchitis, pneumonia, and total upper respiratory infection [TURI]) in children aged 0-14years between 2015 and 2019 in Beijing, China. Anthropogenic carbons, including black carbon (BC) and its emission sources, and wood smoke particles (delta carbon, ultra-violet absorbing particulate matter, and brown carbon) were continuously monitored. Using a time-stratified case-crossover approach, conditional logistic regression was performed to derive risk estimates for each outcome. A total of 856,899 children were included, and a wide range of daily carbon particle concentrations was observed, with large variations for BC (0.36-20.44) and delta carbon (0.48-57.66μg/m3). Exposure to these particles were independently associated with ARI, with nearly linear exposure-response relationships. Interquartile range increases in concentrations of BC and delta carbon over prior 0-8days, we observed elevation of the odd ratio of bronchitis by 1.201 (95% confidence interval, 1.180, 1.221) and 1.048 (95% CI, 1.039, 1.057), respectively. Stronger association was observed for BC from traffic sources, which increased the odd ratio of bronchitis by 1.298 (95% CI, 1.273, 1.324). Carbon particles were also associated with elevated risks of pneumonia and TURI, and subgroup analyses indicated greater risks among children older than 6years. Our findings suggested that anthropogenic carbons in metropolitan areas may pose a significant threat to clinical manifestations of respiratory infections in vulnerable populations.

Clinical Issues - August 2023.

Respiratory protection against surgical smoke from liver tissue Key words: surgical N95 respirator, surgical smoke, liver tissue, fine and ultrafine particles, particulate matter concentrations. Local exhaust ventilation and surgical smoke safety Key words: local exhaust ventilation (LEV), surgical smoke evacuation, medical-surgical suction, hierarchy of controls, engineering control. Location of endoscopy storage cabinets Key words: endoscope; sterile storage; contamination; environmental conditions; heating, ventilation, and air-conditioning (HVAC) design parameters. Sterility of ultrasound transmission gel Key words: sterile gel, nonsterile gel, multidose container, ultrasound, outbreaks.

Identifikasi Sebaran Asap Kebakaran Hutan di Wilayah Jambi dengan Menggunakan Radar C-BAND

Forest and land fires along with the distribution of smoke are one of the disasters threats in the Jambi region which has tropical forests. By knowing the lowest level of visibility from observations, this study was conducted on September 23, 2015. Weather and satellite radar have ability to detect particles and the distribution of smoke from forest and land fires with great spatial and temporal resolution, supported by HIMAWARI-8 satellite data as comparison. C-Band Doppler radar and default strategy scanning are used to identify smoke in Jambi. Wind layer analysis uses CAPPI V products to display smoke distribution and CMAX dBZ with palette changes to identify smoke particles, which then will be carried out vertical cross section to see smoke reflectivity values, identify smoke vertical profiles, and patterns of smoke distribution of forest and land fires. The smoke reflectivity index value can be seen from the dBZ value. The results of the identification show that the smoke material reaches a maximum reflectivity value of 30 dBZ at the centre of the fire point and the minimum value of very fine smoke particles reaches -24.4 dBZ which scattered with the dominant velocity distribution direction to the northwest.

Smoke Particle-Source Prediction Model Based on Multiple Optical Wavelengths Using Deep Learning

Recently, installing smoke detectors has become crucial owing to the risk of fatal human damage that may be caused by inhaling smoke during a fire. Smoke detectors have been reported as highly efficient in detecting smoke particles from fire; however, they may generate false alarms because of their limitation in distinguishing the fire smoke from the smoke generated by daily activities. Despite the frequent occurrence of these false alarms, research on predicting the types of sources through smoke particles remains insufficient. This study involved the development process of an intelligent smoke detector for false alarm reduction that aims to predict the occurrence and type of fire and the evaluation of its performance using the light-scattering characteristics for fire/non-fire sources. First, a previous experimental dataset of fire-related conditions was collected from three fire sources and three non-fire sources to train the model with the light-scattering characteristics of the smoke generated from each source. In addition, to reduce the computing power, data preprocessing was performed on the collected dataset using the median and RobustScaler. Finally, we evaluated the prediction performance of the three deep learning models using three networks: RNN, LSTM, and CNN-LSTM. As a result, we confirmed that the scattering intensity of smoke particles has unique characteristics for each source. When the data preprocessing and prediction models were applied, all three models achieved an accuracy of 0.90 or higher. However, some errors occurred that appeared at similar scattering intensities. The proposed method differs from existing methods in that it presents the possibility of predicting fire and non-fire sources and can be used as an alternative for improving false alarms in the future.

Wildfire smoke knows no borders: Differential vulnerability to smoke effects on cardio-respiratory health in the San Diego-Tijuana region.

Exposure to fine particles in wildfire smoke is deleterious for human health and can increase cases of cardio-respiratory illnesses and related hospitalizations. Neighborhood-level risk factors can increase susceptibility to environmental hazards, such as air pollution from smoke, and the same exposure can lead to different health effects across populations. While the San Diego-Tijuana border can be exposed to the same wildfire smoke event, socio-demographic differences may drive differential effects on population health. We used the October 2007 wildfires, one the most devastating wildfire events in Southern California that brought smoke to the entire region, as a natural experiment to understand the differential effect of wildfire smoke on both sides of the border. We applied synthetic control methods to evaluate the effects of wildfire smoke on cardio-respiratory hospitalizations in the Municipality of Tijuana and San Diego County separately. During the study period (October 11th- October 26th, 2007), 2009 hospital admissions for cardio-respiratory diseases occurred in San Diego County while 37 hospital admissions were reported in the Municipality of Tijuana. The number of cases in Tijuana was much lower than San Diego, and a precise effect of wildfire smoke was detected in San Diego but not in Tijuana. However, social drivers can increase susceptibility to environmental hazards; the poverty rate in Tijuana is more than three times that of San Diego. Socio-demographics are important in modulating the effects of wildfire smoke and can be potentially useful in developing a concerted regional effort to protect populations on both sides of the border from the adverse health effects of wildfire smoke.