Burning Smoke Research Articles

Observing super-coarse carbonaceous aerosol particles containing chloride in a tropical savanna climate at an agro-forest site in Thailand.

Coarse aerosol particles containing chloride in tropical forests are significant for understanding biogeochemical cycles and atmospheric processes, with implications for environmental health and climate change mitigation. This study explored the sources of super-coarse carbonaceous aerosol particles containing chloride in a tropical savanna climate. Aerosol samples were collected from an agro-forest site in Thailand during the dry season and analyzed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and Fourier-transform infrared (FTIR) spectroscopy. By examining the morphology and elemental compositions of individual aerosol particles, along with employing Positive Matrix Factorization (PMF) and backward trajectory analysis, potential sources were identified. The findings revealed two primary sources for the super-coarse aerosol particles: a mixture of biomass burning smoke and inorganic salts (likely from saline soil and sea salt), as well as halophilic fungal spores. FTIR analysis indicated the presence of compounds linked to biomass burning and clay minerals, influenced by prevailing northeast and southeast winds. Recommendations for future research include continued monitoring, correlation with meteorological parameters, and the application of transmission electron microscopy (TEM) for more detailed visualization and confirmation of aerosol sources.

Dispersal of microbes from grassland fire smoke to soils.

Wildland fire is increasingly recognized as a driver of bioaerosol emissions, but the effects that smoke-emitted microbes have on the diversity and community assembly patterns of the habitats where they are deposited remain unknown. In this study, we examined whether microbes aerosolized by biomass burning smoke detectably impact the composition and function of soil sinks using lab-based mesocosm experiments. Soils either containing the native microbial community or presterilized by γ-irradiation were inundated with various doses of smoke from native tallgrass prairie grasses. Smoke-inundated, γ-irradiated soils exhibited significantly higher respiration rates than both smoke-inundated, native soils and γ-irradiated soils exposed to ambient air only. Microbial communities in γ-irradiated soils were significantly different between smoke-treated and control soils, which supports the hypothesis that wildland fire smoke can act as a dispersal agent. Community compositions differed based on smoke dose, incubation time, and soil type. Concentrations of phosphate and microbial biomass carbon and nitrogen together with pH were significant predictors of community composition. Source tracking analysis attributed smoke as contributing nearly 30% of the taxa found in smoke-inundated, γ-irradiated soils, suggesting smoke may play a role in the recovery of microbial communities in similar damaged soils. Our findings demonstrate that short-distance microbial dispersal by biomass burning smoke can influence the assembly processes of microbial communities in soils and has implications for a broad range of fields including agriculture, restoration, plant disease, and biodiversity.

Characteristics and toxicity of burning smoke released from non-metallic materials of ships in a closed environment

Characteristics and toxicity of burning smoke released from non-metallic materials of ships in a closed environment

Vaping and Orthopedic Surgery: Perioperative Management

The growing use of electronic cigarettes (ECs) as a perceived safer alternative to traditional combustible smoking has significant implications for orthopedic surgery patients. Surgeons need to recognize the harms and risks associated with ECs beyond their nicotine content. EC aerosols contain cytotoxic elements, including harmful chemicals, carcinogens, heavy metals, and flavoring agents. They can induce oxidative stress, resulting from an imbalance between cell antioxidant defense and reactive oxygen species (ROS). These effects can compromise bone repair, particularly with skeletal system disorders. Furthermore, ECs’ impact on wound healing and surgical site infection (SSI) have been well-documented. Smoking can reduce the inflammatory healing response, impair oxidative bacterial killing mechanisms, delay the proliferation healing response, and alter collagen metabolism. Some surgical practices remain unchanged despite physicians’ efforts to inquire about EC use. Most orthopedic surgeons do not delay surgery due to nicotine consumption, and urine tests for nicotine are rarely used. However, preoperative smoking cessation interventions offer a unique opportunity to help patients stop consuming nicotine. Therefore, it is crucial for orthopedic surgeons to understand the harms of ECs and communicate the associated risks to patients.

In Situ and Rapid Toxicity Assessment of Air Pollution by Self-Assembly Passive Colonization Hydrogel.

Air pollution is a leading environmental health risk factor, and in situ toxicity assessment is urgently needed. Bacteria-based bioassays offer cost-effective and rapid toxicity assessments. However, the application of these bioassays for air toxicity assessment has been challenging, due to the instability of bacterial survival and functionality when directly exposed to air pollutants. Here, we developed an approach employing self-assembly passive colonization hydrogel (SAPCH) for in situ air toxicity assessment. The SAPCH features a core-shell structure, enabling the quantitatively immobilization of bacteria on its shell while continuously provides nutrients from its core. An antimicrobial polyelectrolyte layer between the core and shell confines bacteria to the air-liquid interface, synchronizing bacterial survival with exposure to air pollutants. The SAPCH immobilized a battery of natural and recombinant luminescent bacteria, enabling simultaneous detection of various toxicological endpoints (cytotoxicity, genotoxicity and oxidative stress) of air pollutants within 2 h. Its sensitivity was 3-5 orders of magnitude greater than that of traditional liquid-phase toxicity testing, and successfully evaluating the toxicity of volatile organic compounds and combustion smoke. This study presents a method for in situ, rapid, and economical toxicity assessment of air pollution, making a significant contribution to future air quality monitoring and control.

Halogen-free epoxy flame retardant & promoter with diimidazole skeleton improves overall properties of epoxy resins

In order to solve the widespread problem in the field of flame retardancy epoxy(FREP), for the deterioration of the overall properties, we designed a novel structural flame retardant & promoter DOPO-CDI and synthesized it using a simple nucleophilic addition one-step method, which exhibits remarkable flame retardant and curing promotion, the flame retardant and promote mechanism of DOPO-CDI on neat EP is illustrated in Fig 0a, which obtained excellent overall properties shown in Fig 0b. Compared with neat epoxy, it has high flame retardancy, low additives results in an limiting oxygen index(LOI) of up to 37.5 % and a V-0 rating of UL-94, a lower curing exothermic peak temperature, a shorter curing time. And in terms of mechanical properties, the excellent strength of epoxy has been further enhanced, flexural strength and tensile strength are increased by 13.3 % and 21.6 % respectively. Moreover, the toughness of epoxy, which is generally lacking, has been greatly improved, in particular, compared with neat epoxy, the impact strength of epoxy with 3 wt% DOPO-CDI increased by 103.6 %. Unlike most FREP, glass transition temperature(Tg) of the epoxy with the introduction of DOPO-CDI raises to 165.6 °C, which is a significant improvement compared to that of the neat epoxy, in terms of combustion behavior, DOPO-CDI has a considerable inhibitory effect on the combustion exotherm and smoke emission. This work explores a way to balance processing, mechanical and thermal properties when preparing FREP, which has great potential for application.

Study on Synergistic Flame-Retardancy of Surface Modified Zinc Stannate and Ammonium Polyphosphate on Polypropylene Nanocomposites

The effect of zinc stannate and synergy between zinc stannate with ammonium polyphosphate in polypropylene matrix is studied. The zinc stannate nanoparticles were synthesized by surfactant assisted low temperature precipitation method, and further surface modified with tetraethyl-orthosilicate at room temperature. Zinc stannate (ZS) and ammonium polyphosphate (APP) were incorporated in polypropylene matrix (1, 5 and 10 % by wt.). PP nanocomposites were analysed for flexural strength, tensile strength, linear burning rate, smoke density and LOI test. Morphology of nano particles and composites were analysed by FESEM. Mechanical analysis of PP nanocomposites demonstrates that, the modified ZS-TEOS performed better than unmodified ZS. Smoke density profiles suggest that the APP could slightly generate more smoke in PP with ZS and ZS-TEOS. Linear burning rate test results indicates that the APP with ZS and ZS-TEOS provide stability to PP for resisting flame spread.

Phase distribution and probabilistic risk assessment of polycyclic aromatic hydrocarbons in indoor air of coffee shops at Zahedan, Iran

Polycyclic aromatic hydrocarbons (PAHs) are a class of hydrocarbons, some of which are established human carcinogens. Human exposure to these chemicals is complex and originates from both indoor and outdoor sources. This study measured the concentration of PAHs in the gaseous and particulate phases during the cold months of 2022 using XAD-2 sorbent tubes and Polytetrafluoroethylene (PTFE) filters in the indoor air of coffee shops in Zahedan, Iran (n = 23). The average concentrations of particulate-bound PAHs and gaseous PAHs were 13,411.86 ± 6517.24 ng/m³ and 6432.76 ± 4311.72 ng/m³, respectively. Source apportionment analyses indicated that the primary sources of PAHs in coffee shops were fossil fuel combustion and environmental tobacco smoke (ETS), commonly referred to as second and third-hand smoke. The lifetime cancer risk (LTCR) of inhaled PAHs was calculated using the Monte Carlo simulation method. The mean LTCR for adults and children from inhaling these substances were 9.43 × 10-6 ± 5.06 × 10-6 and 5.34 × 10-6 ± 2.87 × 10-6, respectively. The hazard quotient (HQ) of PAHs exceeded 1. These findings highlight the need to reduce PAHs exposure in public spaces through proper health warning labels and regulated indoor smoking policies.

Physiological adaptations of the placenta in response to exposure to pm2.5 from wood combustion smoke: Increase in vitamin c transporter Glut-1 and SVTC-2

Physiological adaptations of the placenta in response to exposure to pm2.5 from wood combustion smoke: Increase in vitamin c transporter Glut-1 and SVTC-2

Optimizing calliandra (Calliandra calothyrsus) biomass pellets: Impact of particle size and bark composition

Calliandra biomass pellets offer a promising alternative energy source to replace fossil fuels. Typically, these pellets are produced by directly processing the stem and bark of the calliandra (Calliandra calothyrsus) plant without separation, aiming for manufacturing efficiency. This study investigated the quality differences between calliandra biomass pellets with and without bark and varying particle sizes. Particle sizes used were 20 mesh, 40 mesh, and 60 mesh. The pellets were made using a 12 mm diameter biomass pellet mold and a manual hydraulic press with a pressure of 3 tons. Characterization involved assessing proximate analysis, calorific value, physical and mechanical properties, and Fourier Transform Infrared analysis. The test results were compared with biomass pellet standards from Indonesia, Japan, Korea, and Germany. Results indicate that bark affects several properties, with higher ash content observed in pellets with bark due to the higher mineral content in bark. Volatile matter decreases with finer particle size, influencing combustion rate. Moisture content is higher in pellets with bark, impacting combustion efficiency and smoke production. Fixed carbon values are influenced by moisture and volatile matter content. Calorific values are generally higher in pellets without bark and smaller particle sizes. Density and compressive strength increase with decreasing particle size. FTIR analysis reveals differences in functional groups between pellets with and without bark, indicating variations in chemical composition. Overall, this research provides insight into the potential of calliandra biomass pellets with bark and without bark along with particle size as a renewable energy source.

Secondhand smoke exposure and asthma status among adolescents: Findings from the 2019–2020 California Student Tobacco Survey

Background and objectivesSecondhand tobacco smoke is associated with worsening asthma symptoms among children. However, the relationship between secondhand marijuana smoke and asthma symptoms among youth has not been examined. This study compares the prevalence of secondhand tobacco and marijuana smoke exposure, overall and by asthma status, among middle and high school students. MethodsThe study assessed participants of the 2019–2020 California Student Tobacco Survey: a large, cross-sectional random sample of 8th, 10th, and 12th graders (N = 158,937). Descriptive analyses examined exposure to combustible tobacco and marijuana secondhand smoke by students’ asthma status and sociodemographic characteristics. ResultsMore students with asthma were exposed to combustible tobacco secondhand smoke (13.4 %) and marijuana secondhand smoke (12.0 %) than students without asthma (10.9 % and 9.3 %, respectively). The prevalence of secondhand marijuana smoke exposure was higher among 12th grade students (12.2 %) while the prevalence of secondhand tobacco smoke exposure was higher among 8th grade students (13.4 %) and those who lived in rural locations (15.4 %). ConclusionsCalifornia students are exposed to marijuana secondhand smoke at similar proportions to combustible tobacco secondhand smoke and more students with asthma are exposed to marijuana secondhand smoke. These results expand the public health issue of secondhand smoke exposure among children with asthma by highlighting the need to examine marijuana secondhand smoke. Given the rapid shift in marijuana laws across the US, exposure to secondhand marijuana smoke is likely to increase. Therefore, vulnerable populations, such as children with asthma, should be prioritized for interventions that aim to alleviate secondhand marijuana exposure.

Pathophysiology of vessel wall damage from cigarettes—differential relevance of combustion smoke and nicotine

Pathophysiology of vessel wall damage from cigarettes—differential relevance of combustion smoke and nicotine

Incense-burning smoke ingredient Auramine enhances lincRNA-p21 expression for chemosensitization in p53-mutated non-small cell lung cancer

Incense-burning smoke is a deleterious air pollutant that initiates cytotoxic effects by inducing apoptosis in lung epithelial cells and also acts as a risk factor for lung cancers. Auramine, an ingredient of incense smoke, has been implicated in tumor progression and cellular sensitivity in non-small cell lung cancer (NSCLC) towards anti-cancer agents through unclear mechanisms. Tumor protein p53 (TP53)-activated long intergenic non-coding RNA-p21 (lincRNA-p21) undertakes a pivotal role in regulating cell apoptosis and chemosensitivity. TP53 mutations prevalent in 50% of NSCLC, contribute to diminished therapeutic efficacy. However, the influence of auramine on chemotherapy-induced lincRNA-p21 expression and apoptosis in NSCLC with different TP53 genetic statuses remains unexplored. This study disclosed that both wild-type p53 (wtp53) and mutant p53 (mutp53) mediate lincRNA-p21 expression, albeit through distinct promoter enhancers, p53-response element (p53RE) and non-B DNA structure G-quadruplex (GQ), respectively. Intriguingly, auramine functions as an effective stabilizer of the GQ structure, augmenting mutp53-mediated lincRNA-p21 expression and enhancing apoptosis and cellular sensitivity to chemotherapy in mutp53-expressing NSCLC cells. These findings suggest a mechanism by which mutp53, in the presence of auramine, is endowed with tumor-suppressing function akin to wtp53, thereby aiding in combating chemoresistance in NSCLC cells harboring TP53 mutations.

Rural Combustion Smoke Purification and Carbon Smoke Collection Device

Rural Combustion Smoke Purification and Carbon Smoke Collection Device

Synthesis of P-decorated polysiloxane for good flame retardancy and toughness of epoxy thermosets

Polysiloxanes are modifiers that can enhance the fire safety and toughness of epoxy thermosets. However, the design of high-efficiency polysiloxane modifiers remains a formidable challenge, due to their indefinite structures as well as the complexity and high costs of the preparation process. A phosphorous-containing epoxy-functionalized polydimethylsiloxane (PDMS-DGE) has been prepared by a three-step process using octamethylcyclotetrasiloxane (D4), 2,4,6,8-tetramethylcyclotetrasiloxane (D4H), 1,1,3,3-tetramethyldisiloxane (TMDS), allyl glycidyl ether (AGE), and 9,10-dihydro-9-oxo-10-phosphaphenanthrene (DOPO). Incorporation of 15 wt% PDMS-DGE strongly improved the flame retardancy of epoxy thermosets. There was 38.2 % increase in limiting oxygen index value (LOI), 54.4 % decline in total heat release (THR), and 27.2 % decrease in total smoke production (TSP) as compared to the same values for combustion of unmodified epoxy thermoset. This could be ascribed to the generation of phosphorus/silicon-containing char layers, which effectively reduced the formation of combustible gases, smoke, and heat during burning. Compared to neat EP thermoset, the flexural strength and impact strength of the 15 wt% PDMS-DGE modified epoxy thermoset was increased by 51.1 % and 107.8 %, respectively. This is due to the existence of epoxy groups, rigid phosphaphenanthrene structures, and flexible polydimethylsiloxane chains in PDMS-DGE. Further, the presence of PDMS-DGE provides epoxy thermosets with good moisture resistance. A facile strategy to develop polysiloxanes for epoxy thermosets with both flame retardant properties and toughness, which has vast potential for industrial applications has been proposed.

Association of Electronic Cigarette Usage with the Subsequent Initiation of Combustible Cigarette Smoking among Dental Students in Riyadh, Saudi Arabia: A Longitudinal Study.

The use of electronic cigarettes, or "e-cigarettes", among youths has sparked worries about the possibility of nicotine dependence as a serious public health issue. Dental practitioners play a critical role in helping their patients quit smoking. Dental schools across the globe have policies encouraging their students to help patients quit smoking. Current research, however, indicates that a significant portion of dental students smoke combustible cigarettes and use e-cigarettes. According to studies, using e-cigarettes has resulted in the subsequent initiation of combustible cigarette smoking among its users. The aim of this study was to determine the association between the use of electronic cigarettes and the subsequent initiation of combustible cigarette smoking among dental students who were not attitudinally susceptible to smoking combustible cigarettes. A longitudinal cohort study was conducted among 121 study participants who were never combustible cigarette users and were attitudinally non-susceptible to smoking at baseline. At baseline, 66 (54.6%) study participants were categorized as e-cigarette users who were attitudinally non-susceptible to combustible cigarette smoking, and 55 (45.4%) study participants were categorized as non-users who were attitudinally non-susceptible to combustible cigarette smoking. The initiation of combustible cigarette smoking was assessed at 6- and 12-month intervals. Binomial regression analysis of the outcome at the end of one-year follow-up, when analyzed with independent variables, revealed a significant influence of e-cigarette use on taking up combustible cigarette smoking [Relative Risk: 9.395; 95% CI: 3.03-29.04]. Chi-squared analysis of independent variables revealed e-cigarette use to be significantly associated with fathers' education level (p = 0.00), parental cigarette smoking status (p = 0.00), cigarette smoking among friends (p = 0.00), and family income (p = 0.00). E-cigarette users are more likely to believe it to be healthier (p = 0.00) than combustible smoking. In the present study, e-cigarette usage demonstrated a significant influence on taking up combustible cigarette smoking among its users. Educational institutions should implement stringent policies and regulations to prevent health professionals from using these products.

Prevalence of Cigarette Smoking, E-cigarette Use, and Dual Use Among Urban and Rural Women During the Peripartum Period, PRAMS 2015-2020.

Evidence has emerged on the health dangers of electronic cigarette (e-cigarette) use among pregnant women and neonates. We examined whether rural residence is a risk factor for smoking and e-cigarette use among women during the peripartum period in the United States. This study was based on pooled cross-sectional 2015-2020 data from the Pregnancy Risk Assessment Monitoring System. The outcome was exclusive smoking, exclusive e-cigarette use, and use of both products (ie, dual use) versus use of neither tobacco product by women with live infants aged 2 to 6 months. We examined rural-urban differences in outcome by using univariate and multivariable multinomial logistic regressions with post hoc contrasts and marginal analyses, adjusting for complex survey design and nonresponse. During the peripartum period, 5.0% of women were smoking combustible cigarettes, 5.0% were using e-cigarettes, and 1.9% were using both tobacco products. The crude prevalence of e-cigarette use was 1.1 percentage point higher, and the adjusted prevalence was 0.8 percentage points lower for rural versus urban women (P < .001 for both). Among rural women, 6.7% (95% CI, 6.3%-7.1%) smoked combustible cigarettes exclusively and 2.6% (95% CI, 2.3%-2.8%) used both products, as compared with 4.5% (95% CI, 4.4%-4.8%) and 1.7% (95% CI, 1.6%-1.8%) of urban women, respectively, adjusting for sociodemographic and health-related characteristics. Maternal sociodemographic and health-related characteristics differed by combustible smoking versus e-cigarette use during the peripartum period. The effect of residence on e-cigarette use was significantly confounded by sociodemographic and health-related characteristics, resulting in clinically comparable prevalence of e-cigarette use in rural and urban mothers with live infants aged 2 to 6 months.

Controlled release of phosphorus-containing free radical from the porous channels of metal–organic frame to reduce the combustion heat and smoke releases of polystyrene

Controlled release of phosphorus-containing free radical from the porous channels of metal–organic frame to reduce the combustion heat and smoke releases of polystyrene

Full-scale experimental study on combustion characteristics and smoke temperature of double-source fires in different tunnels

Through a series of full-scale fire tests conducted in three different tunnels, the common characteristics of combustion and smoke temperature of double pool fires in actual operation tunnel environments are investigated. The evolution process of the coupling effects of shielding entrainment and thermal feedback enhancement is revealed. It is found that the ventilation state and the fire source spacing can alter the dominant relationship between the shielding entrainment effect and the thermal feedback enhancement effect, resulting in different evolution patterns of combustion characteristics and smoke flow patterns of double pool fires in tunnels. The heat release rate increases by 4 times when the double pool fire flames merge under the longitudinal ventilation compared with the double pool fire flames without fusion under the natural ventilation. The flame tilt angles of double pool fires were determined through the image processing method, and the prediction model of the flame inclination angle of downstream fire sources was established, considering fire source spacing. At the same time, the characteristic of temperature measured by Fiber Bragg Grating in double-source fire scenarios was investigated, developing a model to predict the longitudinal temperature rise distribution. It is found that the maximum temperature rise prediction model based on steady-state fire has poor applicability in the weak-plume fire scenario of full-scale tunnels. The analysis of the smoke flow patterns shows that the two-stage ventilation is more suitable for smoke control compared to full longitudinal ventilation in tunnel double-source fire accidents, especially for ensuring the safety of individuals trapped in the area between the two fire sources.

Exposure to fine particulate matter 2.5 from wood combustion smoke causes vascular changes in placenta and reduce fetal size

During gestation, maternal blood flow to the umbilical cord and placenta increases, facilitating efficient nutrient absorption, waste elimination, and effective gas exchange for the developing fetus. However, the effects of exposure to wood smoke during this period on these processes are unknown. We hypothesize that exposure to PM2.5, primarily sourced from wood combustion for home heating, affects placental vascular morphophysiology and fetal size. We used exposure chambers that received either filtered or unfiltered air. Female rats were exposed to PM2.5 during pre-gestational and/or gestational stages. Twenty-one days post-fertilization, placentas were collected via cesarean section. In these placentas, oxygen diffusion capacity was measured, and the expression of angiogenic factors was analyzed using qPCR and immunohistochemistry. In groups exposed to PM2.5 during pre-gestational and/or gestational stages, a decrease in fetal weight, crown-rump length, theoretical and specific diffusion capacity, and an increase in HIF-1α expression were observed. In groups exposed exclusively to PM2.5 during the pre-gestational stage, there was an increase in the expression of placental genes Flt-1, Kdr, and PIGF. Additionally, in the placental labyrinth region, the expression of angiogenic factors was elevated. Changes in angiogenesis and angiogenic factors reflect adaptations to hypoxia, impacting fetal growth and oxygen supply. In conclusion, this study demonstrates that exposure to PM2.5, emitted from wood smoke, in both pre-gestational and gestational stages, affects fetal development and placental health. This underscores the importance of addressing air pollution in areas with high levels of wood smoke, which poses a significant health risk to pregnant women and their fetuses.