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Purpose: The spread of airborne diseases, including coronaviruses, remains a widespread public health concern. Published studies outline the use of protective barriers to limit the spread of pathogenic particles and droplets resulting from coughing, sneezing, and talking. The findings suggest a role for these barriers during aerosol-generating procedures, such as flexible endoscopic evaluation of swallowing (FEES). However, the question remains of whether doffing a protective barrier will create a concentrated cloud of particles that will increase health professionals' exposure. Method: We simulated four clinical scenarios of coughing and sneezing, talking, eating and drinking, and delivering supplemental oxygen to test whether doffing the FEES Box protective barrier would result in a particle cloud. Result: For all scenarios simulated, doffing the FEES Box did not result in a significant increase in mean particle count. Further, the manner of FEES Box removal did not significantly influence mean particle counts on a consistent basis. Conclusion: These results suggest that doffing the FEES Box does not increase exposure to airborne particles. Although more research is needed to confirm these findings, FEES Box usage should be considered during aerosol-generating procedures, to protect and reassure healthcare professionals who work with patients with COVID-19 or other airborne diseases. [ABSTRACT FROM AUTHOR]

In this study, the nanostructure, surface functional groups, and oxidation activity of soot particulate along the exhaust after-treatment system of a heavy-duty diesel engine fueled with waste cooking oil (WCO) biodiesel blends are investigated by TEM, XPS, and TGA respectively. The main findings are as follows: Along the exhaust after-treatment system, fringe length of primary particles of soot particulate emitted from tested heavy-duty diesel engine fueled with B0, B10, B20, and B100, i.e., 0%, 10%, 20%, and 100% ratio of WCO biodiesel blended into petroleum diesel in volume respectively increases, while fringe tortuosity and separation distance of primary particles reduces. The fringe length of B10, B20, and B100 is smaller, but the fringe tortuosity and separation distance are larger than that of B0. The O/C ratio of soot particulate tends to increase firstly and then decrease as the exhaust passes through DOC+cDPF and SCR+ASC in sequence. The O/C ratio of B10, B20, and B100 are also higher than that of B0. Soot particulate at cDPF outlet contains carborundum and biuret is found at SCR+ASC outlet. The sp3/sp2 ratio decreases along the exhaust after-treatment system, and B10, B20, and B100 tend to get higher sp3/sp2 ratio than B0. The C–OH and C=O content of soot particulate from different WCO biodiesel blends show generally similar trends along the exhaust after-treatment system, while the activation energy of soot particulate keeps increasing along the exhaust after-treatment system, but decreases with the increasing of blend ratio. These findings can provide useful references for optimizing the after-treatment system for WCO biodiesel blends. [ABSTRACT FROM AUTHOR]

Abstract Background Particulate matter exposure (PM) is a cause of aerodigestive disease globally. The destruction of the World Trade Center (WTC) exposed first responders and inhabitants of New York City to WTC-PM and caused obstructive airways disease (OAD), gastroesophageal reflux disease (GERD) and Barrett’s Esophagus (BE). GERD not only diminishes health-related quality of life but also gives rise to complications that extend beyond the scope of BE. GERD can incite or exacerbate allergies, sinusitis, bronchitis, and asthma. Disease features of the aerodigestive axis can overlap, often necessitating more invasive diagnostic testing and treatment modalities. This presents a need to develop novel non-invasive biomarkers of GERD, BE, airway hyperreactivity (AHR), treatment efficacy, and severity of symptoms. Methods Our observational case-cohort study will leverage the longitudinally phenotyped Fire Department of New York (FDNY)-WTC exposed cohort to identify Biomarkers of Airway Disease, Barrett’s and Underdiagnosed Reflux Noninvasively (BAD-BURN). Our study population consists of n = 4,192 individuals from which we have randomly selected a sub-cohort control group (n = 837). We will then recruit subgroups of i. AHR only ii. GERD only iii. BE iv. GERD/BE and AHR overlap or v. No GERD or AHR, from the sub-cohort control group. We will then phenotype and examine non-invasive biomarkers of these subgroups to identify under-diagnosis and/or treatment efficacy. The findings may further contribute to the development of future biologically plausible therapies, ultimately enhance patient care and quality of life. Discussion Although many studies have suggested interdependence between airway and digestive diseases, the causative factors and specific mechanisms remain unclear. The detection of the disease is further complicated by the invasiveness of conventional GERD diagnosis procedures and the limited availability of disease-specific biomarkers. The management of reflux is important, as it directly increases risk of cancer and negatively impacts quality of life. Therefore, it is vital to develop novel noninvasive disease markers that can effectively phenotype, facilitate early diagnosis of premalignant disease and identify potential therapeutic targets to improve patient care. Trial registration Name of Primary Registry: “Biomarkers of Airway Disease, Barrett's and Underdiagnosed Reflux Noninvasively (BADBURN)”. Trial Identifying Number: NCT05216133 . Date of Registration: January 31, 2022.

The objective of this study was to identify the difference on pain intensity and disability between particulate and nonparticulate steroid injections in patients with lumbar radicular pain. Subgroup analysis by study design, type of particulate steroid, and follow-up duration were performed. We performed the literature search in the PubMed, Embase, and Cochrane Library up March, 2023. Studies, including randomized controlled trials (RCTs) and nonrandomized studies, that compared particulate steroid injection and nonparticulate steroid injection in patients with lumbar radicular pain were independently reviewed by 2 reviewers for eligibility for inclusion. Outcomes of interest were pain intensity and disability. Two reviewers independently assessed the quality of included studies using the revised Cochrane Risk of Bias (RoB2.0) tool for RCTs and the Risk of Bias in Nonrandomized Studies of Interventions Tool (ROBINS-I) for nonrandomized studies. Effect sizes were estimated using mean difference (MD) and standardized mean difference (SMD). A total of 10 studies were included in this meta-analysis. The results showed no significant difference in visual analog scale, disability score and the numbers of patients with 50% pain reduction between particulate and nonparticulate steroid injection groups (P >.05). Particulate steroid injections showed significant better effect in pain scale in RCTs (MD=0.62; 95% CI 0.08-1.16, P =.02). In subgroup analysis with steroid types, methylprednisolone showed better effect compared with dexamethasone, while dexamethasone showed better effect compared with betamethasone. This meta-analysis suggested no significant differences between the particulate and nonparticulate steroid groups in pain or disability score. Therefore, considering the safety profile of nonparticulate steroids, nonparticulate steroid injection may be helpful in patients with lumbar radicular pain. [ABSTRACT FROM AUTHOR]

Background: Particulate matter exposure (PM) is a cause of aerodigestive disease globally. The destruction of the World Trade Center (WTC) exposed first responders and inhabitants of New York City to WTC-PM and caused obstructive airways disease (OAD), gastroesophageal reflux disease (GERD) and Barrett's Esophagus (BE). GERD not only diminishes health-related quality of life but also gives rise to complications that extend beyond the scope of BE. GERD can incite or exacerbate allergies, sinusitis, bronchitis, and asthma. Disease features of the aerodigestive axis can overlap, often necessitating more invasive diagnostic testing and treatment modalities. This presents a need to develop novel non-invasive biomarkers of GERD, BE, airway hyperreactivity (AHR), treatment efficacy, and severity of symptoms. Methods: Our observational case-cohort study will leverage the longitudinally phenotyped Fire Department of New York (FDNY)-WTC exposed cohort to identify Biomarkers of Airway Disease, Barrett's and Underdiagnosed Reflux Noninvasively (BAD-BURN). Our study population consists of n = 4,192 individuals from which we have randomly selected a sub-cohort control group (n = 837). We will then recruit subgroups of i. AHR only ii. GERD only iii. BE iv. GERD/BE and AHR overlap or v. No GERD or AHR, from the sub-cohort control group. We will then phenotype and examine non-invasive biomarkers of these subgroups to identify under-diagnosis and/or treatment efficacy. The findings may further contribute to the development of future biologically plausible therapies, ultimately enhance patient care and quality of life. Discussion: Although many studies have suggested interdependence between airway and digestive diseases, the causative factors and specific mechanisms remain unclear. The detection of the disease is further complicated by the invasiveness of conventional GERD diagnosis procedures and the limited availability of disease-specific biomarkers. The management of reflux is important, as it directly increases risk of cancer and negatively impacts quality of life. Therefore, it is vital to develop novel noninvasive disease markers that can effectively phenotype, facilitate early diagnosis of premalignant disease and identify potential therapeutic targets to improve patient care. Trial registration: Name of Primary Registry: "Biomarkers of Airway Disease, Barrett's and Underdiagnosed Reflux Noninvasively (BADBURN)". Trial Identifying Number: NCT05216133. Date of Registration: January 31, 2022. [ABSTRACT FROM AUTHOR]

Highlights: Microplastics (MPs) and microrubbers (MRs) determined in lichens and mosses around Shiraz. In lichens, MPs mainly thin fibres up to 1 MP g−1; MRs were < 0.1 MP g−1. In mosses, abundances were similar but with a greater fraction of larger, non-fibrous particles. Larger MPs and MRs decreased in abundance with distance and elevation from Shiraz. Around Shiraz, the common moss, Grimmia critina, would be the most suitable biomonitor. Lichens and mosses have been employed as biomonitors of atmospheric particulate pollutants, like metals and industrial solids, for many decades. Here, we evaluated the potential of nine species of crustose and foliose lichens and a widely distributed moss (Grimmia critina) to act as biomonitors of airborne microplastics (MPs) and microrubbers (MRs). About 200 lichens and 40 mosses were sampled across different altitudinal transects in the vicinity of Shiraz City, southwest Iran, and MPs and MRs were quantified and characterised after sample peroxidation. In most species of lichen, MP and MR abundance overall was < 1 g−1 and < 0.1 g−1, respectively, and the majority of plastics were fibres of < 10 µm in diameter and < 1000 µm in length. Respective weight normalised abundances of MPs and MRs were similar in G. critina, but there were greater proportions of both larger (> 1000 µm) and non-fibrous particles among the MPs. In both lichens and moss, there was a greater number of larger MPs and MRs at locations closest to and at the same elevation as Shiraz than at more distant and elevated locations, suggesting an inverse relationship between particle size and distance travelled. Among the lichens, members of the genus Acarospora, with their areolated form, appeared to act as the most suitable biomonitors for MPs and MRs. Overall, however, the wide distribution of the moss, G. crinita, and its ability to intercept and accumulate a broader range of sizes and shapes of MPs and MRs make this species a better choice, at least in the type of environment studied. [ABSTRACT FROM AUTHOR]

Objective: Surgical plume has known potential occupational health hazards. This study compares nanoparticle concentrations in surgical plumes generated between different pediatric tonsillectomy surgical techniques and assesses the efficacy of mitigation measures. Methods: This is a cross‐sectional study performed at a tertiary care academic center. Extracapsular or intracapsular tonsillectomy was performed in 60 patients using four techniques and in 10 additional patients using mitigation measures. Two nanoparticle counters were used to measure particulate concentrations: CPC™ and DiSCmini™. Tonsillectomy techniques included: (1) microdebrider (MD), (2) Bovie with manual suctioning by an assistant (B), (3) Bovie with built‐in smoke evacuation system (BS), and (4) Coblator™ (CB). An additional Yankauer suction was used in the mitigation groups (BSY) and (CBY). Comparative analysis was performed using one‐way ANOVA on ranks and pairwise comparisons between the groups. Results: The mean concentrations (particles/cm3) and coefficient of variants for the DiSCmini particulate counter were MD: 5140 (1.6), B: 30700 (1.5), BS: 25001 (0.8), CB: 54814 (1.7), CBY: 2395 (1.3) and BSY: 11552 (1.0). Mean concentrations for the CPC particulate counter were MD: 1223 (1.4), B: 3405 (0.7), BS: 5002 (0.9), CB: 13273 (1.0), CBY: 1048 (1.2) and BSY: 3046 (0.6). The lowest mean concentrations were noted in cases using MD and the highest in cases using CB. However, after mitigation, CBY had the lowest overall levels. Conclusion: Tonsillectomy technique does impact the levels of nanoparticles emitted within the surgical plume, which may present an occupational hazard for operating room personnel. Level of Evidence: 3 Laryngoscope, 134:2444–2448, 2024 [ABSTRACT FROM AUTHOR]

Occupational exposure to airborne dust is responsible for numerous respiratory and cardiovascular diseases. Because of these hazards, air samples are regularly collected on filters and sent for laboratory analysis to ensure compliance with regulations. Unfortunately, this approach often takes weeks to provide a result, which makes it impossible to identify dust sources or protect workers in real time. To address these challenges, we developed a system that characterizes airborne dust by its spectro-chemical profile. In this device, a micro-cyclone concentrates particles from the air and introduces them into a hollow waveguide where an infrared signature is obtained. An algorithm is then used to quantitate the composition of respirable particles by incorporating the infrared features of the most relevant chemical groups and compensating for Mie scattering. With this approach, the system can successfully differentiate mixtures of inorganic materials associated with construction sites in near-real time. The use of a free-space optic assembly improves the light throughput significantly, which enables detection limits of approximately 10 µg/m3 with a 10 minute sampling time. While respirable crystalline silica was the focus of this work, it is hoped that the flexibility of the platform will enable different aerosols to be detected in other occupational settings. [ABSTRACT FROM AUTHOR]

Water quality, trace gas (SO2, CO2, and NO2), particulate matter (PM 10 as well as PM2.5), and effluent emissions were quantified near cement and oil factories and nearby suburban areas within Delta Nigeria. Results display that ambient air particulate matter PM2.5 varies between 2.1 to 7.9 μg/m3 and VOC (0.013−8.53 μg/m3), while CO and CO2 were 100% and 30% respectively not within regulatory limits, consequently leading to asthma, coughing, and difficulty breathing. Four out of nine sites investigated for noise effects were above WHO stipulated limits. While some parameters such as BOD and COD display critical levels for effluent scrutiny and conductivity, calcium, TDS, total hardness, DO (Dissolved oxygen) and total alkalinity were also above clean water specifications. Wastewater consists of spills and other water effects which produce pollutants such as soluble organic chemicals that deplete dissolved oxygen, anions, volatile materials, and other heavy metals. Based on age, the greatest impact (52%) was seen in ages varying from 0 to 16 while that of the age set 16 to 60 was 45%. Curbing of oil and cement particulate pollutants and requesting a buffer region between the cement and oil depots and neighborhoods, complemented with regulatory enforcement and persistent monitoring, should be a top precedence to the regulatory authority.

Inhalation of diesel exhaust (DE) has been shown to be an occupational hazard in the transportation, mining, and gas and oil industries. DE also contributes to air pollution, and therefore, is a health hazard to the general public. Because of its effects on human health, changes have been made to diesel engines to reduce both the amounts of particulate matter and volatile fumes they generate. The goal of the current study was to examine the effects of inhalation of diesel exhaust. The study presented here specifically examines the effects of exposure to 0.2 and 1.0 mg/m3 DE or filtered air (6h/d for 4 d) on measures of peripheral and cardio-vascular function, and biomarkers of heart and kidney dysfunction in male rats. A Tier 2 engine used in oil and gas fracking operations was used to generate the diesel exhaust. Exposure to 0.2 mg/m3 DE resulted in an increase in blood pressure 1d following the last exposure, and increases in dobutamine-induced cardiac output and stroke volume 1 and 27d after exposure. Changes in peripheral vascular responses to norepinephrine and acetylcholine were minimal as were changes in transcript expression in the heart and kidney. Exposure to 1.0 mg/m3 DE did not result in major changes in blood pressure, measures of cardiac function, peripheral vascular function or transcript expression. Based on the results of this study, we suggest that exposure to DE generated by a Tier 2 compliant diesel engine generates acute effects on biomarkers indicative of cardiovascular dysfunction. Recovery occurs quickly with most measures of vascular/cardiovascular function returning to baseline levels by 7d following exposure. [ABSTRACT FROM AUTHOR]

Nickel isotope fractionation during continental weathering is not well constrained due to the limited research on Ni isotopes during weathering of mafic rocks such as basalt. This study investigated two weathering profiles (strongly and extremely weathered) derived on basalts in tropical China. The strongly weathered profile was dominated by kaolinite and divided into three layers with depth (soil, saprolite and rock). The extremely weathered profile was mainly composed of Fe- and Al-(oxyhydr)oxides and kaolinite, and included a special ferricrust layer, iron-rich duricrust with ferruginous nodules, between the soil and saprolite. We analysed the Ni speciation (e.g. Fe-oxide phases and residual phase) and isotopic composition of soil, ferricrust, saprolite, rock and water samples in the weathering profiles. Pore water and groundwater were collected underlying the extremely weathered profile, and the size-distribution of particulate Ni (1 kDa–450 nm) in water samples was analysed. Nickel in both profiles was mainly hosted in the residual phase (>71% of total Ni) which included primarily secondary silicates and Al-(oxyhydr)oxides. Weathering intensity controlled the mineral compositions and physico-chemical properties of the weathering profiles as well as Ni isotopic variations. Nickel redistribution (∼30%) and isotope fractionation (Δ60Ni regolith-rock = −0.08‰ to 0.07‰) were slight in the strongly weathered profile due to the dominance of secondary silicates in Ni speciation. For the extremely weathered profile, significant Ni depletion (∼67%) and isotope fractionation (Δ60Ni regolith-rock = −0.25‰ to 0.32‰) were related to the transformation of secondary silicates into Fe- and Al-(oxyhydr)oxides during lateritic weathering. The positive correlation of δ60Ni and Ni concentrations indicated that Ni isotope fractionation was controlled by Ni adsorption and incorporation of secondary minerals. In the lower saprolite, the calculated isotope fractionation between Ni remaining in the profile and leaching to the solution (Δ60Ni solid-solution = −0.47‰) indicated that Ni isotope fractionation was mainly controlled by the preferential adsorption of isotopically light Ni on Fe- and Al-(oxyhydr)oxides. However, in the soil and ferricrust, acidic pH (∼5.0) might reduce Δ60Ni solid-solution to −0.28‰ by releasing the isotopically light adsorbed Ni, leading to the predominance of incorporated Ni in Fe- and Al-(oxyhydr)oxides. Specifically, the highest δ60Ni value (0.27 ± 0.05‰) and Ni concentration in the upper saprolite indicated that the isotopically heavy Ni leached from the soil and ferricrust was scavenged by precipitating secondary silicates. Finally, the estimated isotopic composition of Ni leached from the extremely weathered profile (δ60Ni output = 0.02 ± 0.15‰) was close to that of pore water (0.06 ± 0.01‰) where Ni was mainly present in the particulate phase. Compared with groundwater (δ60Ni = 0.33 ± 0.04‰) dominated by dissolved Ni, Ni output from the profile likely consisted of isotopically heavy dissolved Ni and light particulate Ni. Overall, this study provides a comprehensive understanding of Ni redistribution and speciation in basalt weathering profiles, highlighting the significance of weathering intensity in controlling Ni isotope fractionation and its implications for Ni outputs from continental weathering. [ABSTRACT FROM AUTHOR]

OBJECTIVES: This study assessed the short-term associations between in-vehicle ultrafine particles (UFP) and black carbon (BC) concentrations and irritation symptoms and lung parameters of taxi drivers, pre- and post-lockdown. METHODS: As part of PUF-TAXI project, 33 taxi drivers were followed up during two typical working days. In-vehicle UFP and BC were continuously measured by monitoring instruments. Irritation symptoms during the working day were reported via an auto-questionnaire and lung function was assessed by a portable spirometer, pre- and post- work shift. Generalized estimating equations, adjusted for potential confounders, were used to study the association between air pollutants and health outcomes. Effect modification by measurement period (pre- and post-lockdown) was investigated. RESULTS: UFP and BC concentrations inside taxi vehicles decreased significantly post- compared to pre-lockdown. Incidence of nose irritation was positively associated with in-vehicle UFP and BC levels pre-lockdown, when pollutant levels were higher, whereas no significant association was found post-lockdown. The decrease in the FEF_25–75% (forced expiratory flow at 25–75% of the forced vital capacity) during the working day was significantly associated with in-taxi UFP levels before but not after lockdown. No association was found with BC. By contrast, incidence of eye irritation was significantly inversely associated with in-vehicle humidity, regardless of pollutant concentrations and the measurement period. CONCLUSIONS: Our findings indicate that an upgrade in in-vehicle air quality could improve respiratory health. This study showed that the magnitude of the incidence of nasal irritation and decrease in lung function depends on UFP concentrations the commuters are exposed to.

Epidural steroid injections (ESIs) play an important role in the multifaceted management of neck and back pain. Corticosteroid preparations used in ESIs may be considered "particulate" or "non-particulate" based on whether they form a crystalline suspension or a soluble clear solution, respectively. In the past two decades, there have been reports of rare but severe and permanent neurological complications as a result of ESI. These complications have principally occurred with particulate corticosteroid preparations when using a transforaminal injection technique at cervical or thoracic levels, and only rarely in the lumbosacral spine. As a result, some published clinical guidelines and recommendations have advised against the use of particulate corticosteroids for transforaminal ESI, and the FDA introduced a warning label for injectable corticosteroids regarding the risk of serious neurological adverse events. There is growing evidence that the efficacy of non-particulate corticosteroids for pain relief and functional improvement after ESI is non-inferior to particulate agents, and that non-particulate injections almost never result in permanent neurological injury. Despite this, particulate corticosteroids continue to be routinely used for transforaminal epidural injections. More consistent clinical guidelines and societal recommendations are required alongside increased awareness of the comparative efficacy of non-particulate agents among specialists who perform ESIs. The current role for particulate corticosteroids in ESIs should be limited to caudal and interlaminar approaches, or transforaminal injections in the lumbar spine only if initial non-particulate ESI resulted in a significant but short-lived improvement. [ABSTRACT FROM AUTHOR]

Objectives To recycle the wasted activated carbon from water purifiers and reuse stormwater runoff, this study evaluated water quality of stormwater runoff with regeneration using granular activated carbon containing commercial activated carbon for water treatment and wasted activated carbon from household water purifiers. Methods The removal of total coliforms, chloride, BOD, T-N, T-P, turbidity, and pH in stormwater runoff were analyzed by down-flow column test using granular activated carbon with varied mixing ratios. In addition, chemical modification with ferrous sulfate and ultrasonic treatment were conducted to improve the removal efficiency of total coliforms, and turbidity. Results and Discussion The optimal mixing ratio of granular activated carbon was 7:3 (GAC:WGAC), which showed high removal efficiency of 88.2% for total coliforms, 70.8% for chloride, 72.6% for BOD, 88.4% for T-N, 50.7% for T-P, and 85.9% for turbidity. The granular activated carbon with surface modification using a 0.2 M FeSO4 solution with ultrasonic treatment demonstrated the highest removal efficiency, with a reduction of 11.8% in total coliforms, 29.2% in chloride, 12.1% in BOD, 20.3% in T-P, and 13.2% in turbidity, while T-N showed a decrease of 19.4% in removal efficiency. Conclusion The granular activated carbon with a 7:3 mixing ratio showed highest removal efficiencies for all water quality parameters, while the total coliforms and turbidity did not meet the water quality standards for reclaimed water. This indicated that further physicochemical surface modification with FeSO4 and ultrasonic treatment was needed to improve the removal performance and meet the water quality standards for reclaimed water. This approach explored in this study using wasted activated carbon should be continued in the area of resource and water circulation to properly utilize resources of wastes.

Occupational exposure to airborne dust is responsible for numerous respiratory and cardiovascular diseases. Because of these hazards, air samples are regularly collected on filters and sent for laboratory analysis to ensure compliance with regulations. Unfortunately, this approach often takes weeks to provide a result, which makes it impossible to identify dust sources or protect workers in real time. To address these challenges, we developed a system that characterizes airborne dust by its spectro-chemical profile. In this device, a micro-cyclone concentrates particles from the air and introduces them into a hollow waveguide where an infrared signature is obtained. An algorithm is then used to quantitate the composition of respirable particles by incorporating the infrared features of the most relevant chemical groups and compensating for Mie scattering. With this approach, the system can successfully differentiate mixtures of inorganic materials associated with construction sites in near-real time. The use of a free-space optic assembly improves the light throughput significantly, which enables detection limits of approximately 10 µg/m3 with a 10 minute sampling time. While respirable crystalline silica was the focus of this work, it is hoped that the flexibility of the platform will enable different aerosols to be detected in other occupational settings.

Annual deaths caused by exposure to outdoor-indoor particulate matter air pollution are a problem currently faced by the World Health Organization. This study assessed outdoor and indoor exposure to PM10 particulate matter in the city of Riohacha (Colombia) from March 17 to April 17, 2018, in three representative sites of the urban area. A low-volume gravimetric sampler, more specifically a MiniVol Portable Air Sampler operating at 5 L/min, was used at three sampling stations. Elemental analysis was performed on a microwave plasma atomic emission spectrometer (MP-AES). In total, 14 inorganic elements (Zn, Fe, Cd, V, Ca, Ni, Cu, As, Co, Pb, K, Mn, Mg, and Na) were quantified in the PM10 mass. The indoor and outdoor concentrations of PM10 ranged from 3.81 to 19.07 μg/m3 and from 17.86 to 51.35 μg/m3, respectively. The indoor/outdoor ratio of PM10 concentrations ranged from 0.213 ± 0.01 at the station with the lowest levels of PM10 to 0.360 ± 0.02 at the station with the highest levels of PM10. Chemical elements with the highest levels in PM10 were crustal elements (Ca, Na, K, Fe, Mg, As, and Co), and those with the lowest levels in PM10 were anthropogenic tracers emitted from transportation (Cd, V, Cu, Mn, Ni, Pb, and Zn). Source contributions were estimated by principal component analysis. Three factors were detected inside and three outside the stations. The emissions from motor vehicles, resuspension of road dust and marine aerosol were the major sources contributing to overall PM10 mass in Riohacha City.

The coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), broke out in December 2019 in Wuhan city, in the Hubei province of China. Since then, it has spread practically all over the world, disrupting many human activities. In temperate climates overwhelming evidence indicates that its incidence increases significantly during the cold season. Italy was one of the first nations, in which COVID-19 reached epidemic proportions, already at the beginning of 2020. There is therefore enough data to perform a systematic investigation of the correlation between the spread of the virus and the environmental conditions. The objective of this study is the investigation of the relationship between the virus diffusion and the weather, including temperature, wind, humidity and air quality, before the rollout of any vaccine and including rapid variation of the pollutants (not only their long term effects as reported in the literature). Regarding them methodology, given the complexity of the problem and the sparse data, robust statistical tools based on ranking (Spearman and Kendall correlation coefficients) and innovative dynamical system analysis techniques (recurrence plots) have been deployed to disentangle the different influences. In terms of results, the evidence indicates that, even if temperature plays a fundamental role, the morbidity of COVID-19 depends also on other factors. At the aggregate level of major cities, air pollution and the environmental quantities affecting it, particularly the wind intensity, have no negligible effect. This evidence should motivate a rethinking of the public policies related to the containment of this type of airborne infectious diseases, particularly information gathering and traffic management.

Sensors and sensor systems for monitoring fine particles with aerodynamic diameters smaller than 2.5 µm can provide real-time feedback on indoor air quality and thus can help guide actions to manage indoor air pollutant concentrations. Standardized verification of the performance and accuracy of sensors and sensor systems is crucial for predicting the efficacy of such monitoring. A new ASTM International standard test method (ASTM D8405) was created for this need and is the most exacting laboratory protocol published to date for evaluating indoor air quality sensors and sensor systems measuring particles smaller than 2.5 µm in diameter. ASTM D8405 subjects sensors and sensor systems to five test phases: (1) an initial particle concentration ramp; (2) exposure to various temperature and humidity conditions; (3) exposure to interfering particles; (4) temperature cycling; and (5) a final particle concentration ramp to assess drift. This paper discusses the development of the standard test method, key aspects of the testing process, example evaluation results, and a comparison of this standard test method against peer evaluation protocols. [ABSTRACT FROM AUTHOR]

Hole EDM process parameters are extensively addressed, but electrode design variables have not been optimized to boost output objectives. This investigation optimizes electrode parameters, including the tool rotational speed (S), water pressure (P), electrode length (L), and internal diameter (ID) to enhance the machined gap (MG), hole conicity (HC), noise emission (NE), particulate pollution (PP), and power factor coefficient (PFC) of the Ti6Al4V. The method based on the removal effects of criteria and multi-attributive border approximation area comparison is utilized to select weights and optimality. A novel model of the process sustainable index (PSI) is comprehensively proposed to evaluate the deployment of the EDM operation. The radial basis function interpolation models were proposed and applied to forecast the response outcomes. The findings presented that the optimal S, P, L, and ID were 200 rpm, 80 kg/cm2, 340 mm, and 0.6 mm, respectively. The enhancements in the MG, HC, NE, PP, and PFC were 58.2%, 44.1%, 24.2%, 12.0%, and 10.7%, respectively. Quality indicators were primarily affected by the electrode length and internal diameter, while ecological indices significantly were influenced by the tool rotational speed and water pressure, respectively. The optimality could be applied in the practical hole EDM for saving costs and efforts. [ABSTRACT FROM AUTHOR]

The Exponential model is introduced to predict the modulus of particulate or short‐fiber reinforced composites. The model allows the prediction of Young's modulus, bending modulus, shear modulus, and bulk modulus in a series of composites from a single experimental point. Subsequently, a modification of the widely used Chamis model is introduced, also allowing the prediction of particulate composite moduli from a single experimental point. The predictions of each model are compared with original experimental data derived from tension tests on sustainable and bio‐based composites, covering common cases of thermosets and thermoplastics, as well as different chemical treatments and sizes of the reinforcing materials, and are plotted against the predictions of the rule of mixtures, the inverse rule of mixtures and the Chamis model. Two different matrices (PLA and Ecopoxy) and six different reinforcements (chemically treated and untreated Luffa cylindrica short fibers, acetylated and untreated cotton flocks, and olive pits of 1–5 μm or 50–150 μm diameter) are used. The comparisons show that both the proposed models are capable of achieving much higher prediction accuracy (2.28–59.51 times less root mean square error) than the three models already in use, and easily adapting to the matrix and/or reinforcement changes. [ABSTRACT FROM AUTHOR]

Anaerobic ammonium oxidation (anammox) plays an important role in nitrogen removal in coastal seas, and ladderanes, as specific biomarkers of anammox bacteria, can be used to indicate the anammox activity. However, the origins of ladderanes and their controlling factors in the coastal seas influenced by anthropogenic activities are still not well constrained. To address this, we reported ladderanes, long-chain n-alkanols (terrestrial biomarker) and sterols (marine biomarker) in suspended particulates from the estuaries and inner area of Laizhou Bay in North China, to study ladderane sources and its distribution patterns. This study proposed a novel index, Rlad, using ladderane ratio of ladderane III to ladderane IV, and by correlating this index with other biomarker distributions to evaluate the source of ladderanes. High Rlad values (> 0.9) indicated biosynthesis by terrestrial anammox bacteria Ca. Brocadia and Ca. Kuenenia, while low Rlad values (< 0.9) indicated biosynthesis by marine anammox bacteria Ca. Scalindua. High Rlad values and high ladderane concentrations in particulates from the estuaries and nearshore area of Laizhou Bay revealed sources from the terrestrial input via riverine inflow as well as in situ production in oxygen-depleted estuaries, supported by high concentrations of terrestrial biomarkers; Low Rlad values and low ladderane concentrations in particulates from offshore area indicated sources from marine environment via the cold hypoxia water input by the Bohai circulation. Comparison of ladderane concentrations of our study with previously published results from a wide range of environments with human influences from Chinese coastal area revealed that high ladderane concentrations synthesized by terrestrial anammox bacteria could contribute significantly to coastal seas, and the anammox process in river-estuary-bay system might be underestimated. This study provides new understandings about the evaluation of the source and distribution of ladderanes under anthropogenic influences in coastal seas.

We conducted a systematic review and meta-analysis of global epidemiological studies of air pollution and angina pectoris, aiming to explore the deleterious air pollutant(s) and vulnerable sub-populations. PubMed and Web of Science databases were searched for eligible articles published between database inception and October 2021. Meta-analysis weighted by inverse-variance was utilized to pool effect estimates based on the type of air pollutant, including particulate matters (PM2.5 and PM10: particulate matter with an aerodynamic diameter ≤ 2.5 µm and ≤ 10 µm), gaseous pollutants (NO2: nitrogen dioxide; CO: carbon monoxide; SO2: sulfur dioxide, and O3: ozone). Study-specific effect estimates were standardized and calculated with percentage change of angina pectoris for each 10 µg/m3 increase in air pollutant concentration. Twelve studies involving 663,276 angina events from Asia, America, Oceania, and Europe were finally included. Meta-analysis showed that each 10 µg/m3 increase in PM2.5 and PM10 concentration was associated with an increase of 0.66% (95%CI: 0.58%, 0.73%; p < 0.001) and 0.57% (95%CI: 0.20%, 0.94%; p = 0.003) in the risk of angina pectoris on the second day of exposure. Adverse effects were also observed for NO2 (0.67%, 95%CI: 0.33%, 1.02%; p < v0.001) on the second day, CO (0.010%, 95%CI: 0.006%, 0.014%; p < 0.001). The elderly and patients with coronary artery disease (CAD) appeared to be at higher risk of angina pectoris. Our findings suggest that short-term exposure to PM2.5, PM10, NO2, and CO was associated with an increased risk of angina pectoris, which may have implications for cardiologists and patients to prevent negative cardiovascular outcomes. [ABSTRACT FROM AUTHOR]

Abstract Background Uncontrolled wildfires in Australian temperate Eucalyptus forests produce significant smoke emissions, particularly carbon dioxide (CO2) and particulates. Emissions from fires in these ecosystems, however, have received less research attention than the fires in North American conifer forests or frequently burned Australian tropical savannas. Here, we use the 2013 Forcett–Dunalley fire that caused the first recorded pyrocumulonimbus event in Tasmania, to understand CO2 and particulate matter (PM2.5) emissions from a severe Eucalyptus forest fire. We investigate the spatial patterns of the two emissions using a fine scale mapping of vegetation and fire severity (50 m resolution), and utilising available emission factors suitable for Australian vegetation types. We compare the results with coarse-scale (28 km resolution) emissions estimates from Global Fire Emissions Database (GFED) to determine the reliability of the global model in emissions estimation. Results The fine scale inventory yielded total CO2 emission of 1.125 ± 0.232 Tg and PM2.5 emission of 0.022 ± 0.006 Tg, representing a loss of 56 t CO2 ha−1 and 1 t PM2.5 ha−1. The CO2 emissions were comparable to GFED estimates, but GFED PM2.5 estimates were lower by a factor of three. This study highlights the reliability of GFED for CO2 but not PM2.5 for estimating emissions from Eucalyptus forest fires. Our fine scale and GFED estimates showed that the Forcett–Dunalley fire produced 30% of 2013 fire carbon emissions in Tasmania, and 26–36% of mean annual fire emissions for the State, representing a significant single source of emissions. Conclusions Our analyses highlight the need for improved PM2.5 emission factors specific to Australian vegetation, and better characterisation of fuel loads, particularly coarse fuel loads, to quantify wildfire particulate and greenhouse gas emissions more accurately. Current Australian carbon accountancy approach of excluding large wildfires from final GHG accounts likely exaggerates Tasmania’s claim to carbon neutrality; we therefore recommend that planned and unplanned emissions are included in the final national and state greenhouse gas accounting to international conventions. Advancing these issues is important given the trajectory of more frequent large fires driven by anthropogenic climate change.

A stepping scheme-based modeling and calculating methodology for predicting the elastic properties of composite materials that contain arbitrarily shaped particles is presented. This study involved different disciplinary approaches and proved it by mathematical. A multiple parameter microstructure model is constructed using inverse Fourier transforms and constraint conditions. A stepping scheme is used to calculate elastic properties and relationships between the microstructure and effective performance are constructed. Finally, this stepping scheme calculation methodology is used to predict the effective elastic moduli of CuCr alloys. [ABSTRACT FROM AUTHOR]

Additive manufacturing of dense pastes, those with greater than 50 vol% particles, via material extrusion direct ink write is a promising method to produce customized structures for high-performance materials, such as energetic materials and pharmaceuticals, as well as to enable the use of waste or other locally available particles. However, the high volume fraction and the large sizes of the particles for these applications lead to significant challenges in developing inks and processing methods to prepare quality parts. In this prospective, we analyze challenges in managing particle characteristics, stabilizing the suspensions, mixing the particles and binder, and 3D printing the pastes. [ABSTRACT FROM AUTHOR]

At highly populated areas, such as the Greater Athens Area in Greece, the air quality differs significantly from one municipality to another, being highly affected by the local anthropogenic sources (traffic, residential heating, navigation) and consequent emissions. Thus, the existence of a dense network of low-cost air quality sensors provides evidence of seasonal patterns on particulate concentrations within the urban zone. In the present study, hourly PM2.5 concentrations recorded using low-cost sensors at six municipalities in the Greater Athens Area (Vrilissia, Psychiko, Peristeri, Rentis, Agia Varvara, Palaio Faliro) with different characteristics (population density, pollutant sources, surrounding land use) were collected for the year 2022. The highest mean seasonal values were recorded in the western and southern suburbs (Peristeri, Rentis and Palaio Faliro) during the cold period (winter of the year 2022). Mean concentrations decreased significantly in spring; the mean concentrations were 31.3 μg/m3 and 18.5 μg/m3 in Vrilissia in winter and spring, respectively (year: 2022).

A network of low-cost sensors operates at six islands in the Aegean Sea (Lemnos, Lesvos, Chios, Samos, Syros and Rhodes) providing real-time PM2.5 concentrations to the public. In the present study, the effect of the prevailing meteorological conditions on the local air quality was examined. For this reason, data about wind direction, dry and wet temperature, wind speed and sunlight were provided by the Hellenic National Meteorological Service for the period from January to September 2022. The analysis of the hourly PM2.5 concentrations revealed different air quality patterns on each island, as well as seasonal changes for the same islands (e.g., higher concentrations in Samos during the cold period). Temperature was found to contribute significantly to the PM2.5 measurements since it affects the anthropogenic activities related to emissions. For instance, higher temperatures in winter result in limited residential heating needs.

The objective of this work was to evaluate the relationship between the fuel quality and the gaseous and particulate pollutant emissions generated from a hot-water boiler during the combustion of different types of innovative processed fuels: smokeless coal, smokeless briquettes 1–3, smokeless pellets and unprocessed hard coal. The aim of our research was to prove the presumption that smokeless processed coals produce less gaseous and particulate emissions. By using modern fuels in already used and manufactured older boilers, there is a possibility to significantly reduce emissions of organic gaseous compounds (OGC) and polycyclic aromatic hydrocarbons (PAHs). The emission situation in the heating season can be significantly improved even without costly production, and thus consumption of natural resources and energy, and installation of modern boilers. Physical and chemical characterization of solid-fuel samples, including determination of moisture content, ash, volatile organic content, calorific value and elemental composition analysis, were performed. Fuels were burned in one type of hot-water boiler class 1 according to EN 303-5 to determine the impact of applied fuel types on pollutant emissions. The pollutant emissions were characterized by the contents of gaseous components: nitrogen oxides NOx, sulfur dioxide SO2, carbon monoxide CO, carbon dioxide CO2, organic gaseous compounds OGC and particle components: total suspended particles TSP, particulate matter less than 2.5 µm and 10 µm (PM2.5 and PM10, respectively) and polycyclic aromatic hydrocarbons PAHs in both phases. The emission factors from six types of fuel were compared with applicable European standards. The lowest NOx content was observed for smokeless briquette 1, while the lowest SO2 content was observed for smokeless pellets. The emission of CO was at a similarly low level of 200 g/kg for smokeless briquette 1, smokeless briquette 2 and hard coal. Gaseous and pollutant emissions described by PM2.5 and TSP were observed to be the lowest for smokeless coal, smokeless briquette 1 and smokeless briquette 2. [ABSTRACT FROM AUTHOR]

Herein, high strength Al-Zn(-Mg) alloy designated as AA7068 based composites containing twin unlike dispersoids of ZrO2p and Grp were synthesized through an enhanced stir-squeeze caster. The density of the casted materials accompanying porosity was investigated through the liquid displacement technique following the Archimedes principle. Mechanical behavior, such as hardness, impact toughness, tensile strength, and ductility was examined under the as-casted, artificially aged (T6), and retrogressed and reaged (RRA) conditions. Microstructural analysis and determination of intermetallic compounds were carried out using FESEM-EDX and XRD techniques. The fractured surface under tensile loading was also examined through FESEM to recognize the governing mode of failure. Hardness, 0.2% proof stress, and UTS of the composite containing 4 wt.% of ZrO2p were improved over monolithic alloy up to 29.8, 68.2, and 37.5% at the as-casted condition and 43.5, 86.3, and 85% at artificially aged condition, respectively. However, the addition of Grp decreased the properties mentioned above. On the contrary, the addition of both the particulates of ZrO2 and Gr (added separately or concurrently) decreased the ductility and impact strength irrespective of the material condition. FESE micrographs reveal the uniform distribution of dispersoids in the matrix phase. Furthermore, fractography depicts that the monolithic AA7068 matrix fractured in a ductile manner, while interfacial decohesion and particle cracking were the prime causes of failure in the composites. [ABSTRACT FROM AUTHOR]

Background: Uncontrolled wildfires in Australian temperate Eucalyptus forests produce significant smoke emissions, particularly carbon dioxide (CO2) and particulates. Emissions from fires in these ecosystems, however, have received less research attention than the fires in North American conifer forests or frequently burned Australian tropical savannas. Here, we use the 2013 Forcett–Dunalley fire that caused the first recorded pyrocumulonimbus event in Tasmania, to understand CO2 and particulate matter (PM2.5) emissions from a severe Eucalyptus forest fire. We investigate the spatial patterns of the two emissions using a fine scale mapping of vegetation and fire severity (50 m resolution), and utilising available emission factors suitable for Australian vegetation types. We compare the results with coarse-scale (28 km resolution) emissions estimates from Global Fire Emissions Database (GFED) to determine the reliability of the global model in emissions estimation. Results: The fine scale inventory yielded total CO2 emission of 1.125 ± 0.232 Tg and PM2.5 emission of 0.022 ± 0.006 Tg, representing a loss of 56 t CO2 ha−1 and 1 t PM2.5 ha−1. The CO2 emissions were comparable to GFED estimates, but GFED PM2.5 estimates were lower by a factor of three. This study highlights the reliability of GFED for CO2 but not PM2.5 for estimating emissions from Eucalyptus forest fires. Our fine scale and GFED estimates showed that the Forcett–Dunalley fire produced 30% of 2013 fire carbon emissions in Tasmania, and 26–36% of mean annual fire emissions for the State, representing a significant single source of emissions. Conclusions: Our analyses highlight the need for improved PM2.5 emission factors specific to Australian vegetation, and better characterisation of fuel loads, particularly coarse fuel loads, to quantify wildfire particulate and greenhouse gas emissions more accurately. Current Australian carbon accountancy approach of excluding large wildfires from final GHG accounts likely exaggerates Tasmania's claim to carbon neutrality; we therefore recommend that planned and unplanned emissions are included in the final national and state greenhouse gas accounting to international conventions. Advancing these issues is important given the trajectory of more frequent large fires driven by anthropogenic climate change. [ABSTRACT FROM AUTHOR]

Till now, the effect of different embolic materials (particulate vs coil) on pre-embolization of carotid body tumors remains poorly understood. The aim of this study was to explore the comparative results between particulate and coil embolization for carotid body tumors. Thirty-seven patients with carotid body tumors who underwent embolization before surgical resection were reviewed and analyzed in this retrospective study between 2008 and 2020. Twenty-one patients were included in the particulate group, while 16 patients were included in the coil group. All procedure-related details, complications and 5-year follow-up data were collected in the study. The preoperative embolization time was obviously longer in the particulate group than in the coil group (42.6 ± 12.3 min vs. 33.7 ± 10.1 min, P =.02), and the fluo time of the procedure (864.5 ± 240.9 s vs. 729.6 ± 251.5 s) and cumulative air kerma (634.6 ± 188.4 mGy vs. 486.7 ± 164.7 mGy) value were higher in the particulate group (P =.01). The incidences of total adverse events in both groups were not significantly different (28.6% vs. 25.0%, P >.05); however, two cases of ectopic embolization only occurred in the particulate group. Interestingly, medical expenditure was higher in the particulate group than in the coil group (P =.02). For the 3-year follow-up evaluation, recurrence and all-cause mortality were similar in both groups (P >.05). Preoperative embolization with coils could be relatively safe, have a lower radiation dosage and be cost-effective for the treatment of carotid body tumors. [ABSTRACT FROM AUTHOR]

Till now, the effect of different embolic materials (particulate vs coil) on pre-embolization of carotid body tumors remains poorly understood. The aim of this study was to explore the comparative results between particulate and coil embolization for carotid body tumors. Thirty-seven patients with carotid body tumors who underwent embolization before surgical resection were reviewed and analyzed in this retrospective study between 2008 and 2020. Twenty-one patients were included in the particulate group, while 16 patients were included in the coil group. All procedure-related details, complications and 5-year follow-up data were collected in the study. The preoperative embolization time was obviously longer in the particulate group than in the coil group (42.6 ± 12.3 min vs. 33.7 ± 10.1 min, P =.02), and the fluo time of the procedure (864.5 ± 240.9 s vs. 729.6 ± 251.5 s) and cumulative air kerma (634.6 ± 188.4 mGy vs. 486.7 ± 164.7 mGy) value were higher in the particulate group (P =.01). The incidences of total adverse events in both groups were not significantly different (28.6% vs. 25.0%, P >.05); however, two cases of ectopic embolization only occurred in the particulate group. Interestingly, medical expenditure was higher in the particulate group than in the coil group (P =.02). For the 3-year follow-up evaluation, recurrence and all-cause mortality were similar in both groups (P >.05). Preoperative embolization with coils could be relatively safe, have a lower radiation dosage and be cost-effective for the treatment of carotid body tumors.

Tracking mass through harsh environments requires surrogate particles that withstand the event and endure until sampling. Silica-covered quantum dots have been shown to withstand a range of environmental pHs from months to years; in this work they are shown to endure in anticipated local environments. Two methods of particle synthesis were employed to produce luminescent silica with particle diameters 0.1–4 μm. These tracer particles scale for mass production, tolerate harsh environments, and endure in debris. They could be deployed in places such as chemical explosions, industrial processes, geologic test beds, oil and gas fields, nuclear reactors, and geothermal plants to track mass under harsh conditions. [ABSTRACT FROM AUTHOR]

We report the characterization of anthropogenic magnetic particulate matter (MPM) collected on leaves from roadside Callistemon (bottlebrush) trees from Lahore, Pakistan, and on known sources of traffic‐related particulates to assess the potential of first‐order reversal curve (FORC) diagrams to discriminate between different sources of anthropogenic magnetic particles. Magnetic measurements on leaves indicate the presence of surface‐oxidized magnetite spanning the superparamagnetic (<30 nm) to single domain (∼30–70 nm) to vortex size range (∼70–700 nm). Fe‐bearing particles are present both as discrete particles on the surface of larger mineral dust or carbonaceous particles and embedded within them, such that their aerodynamic sizes may be decoupled from their magnetic grain sizes. FORC diagrams of brake‐pad residue specimens show a distinct combination of narrow central ridge, extending from 0 to 200 mT, and a low‐coercivity, vertically spread signal, attributed to vortex and multi‐vortex behavior of metallic Fe. This is in agreement with scanning electron microscopy results that show the presence of metallic as well as oxidized Fe. Exhaust‐pipe residue samples display a more conventional "magnetite‐like" signal comprising a lower coercivity central ridge (0–80 mT) and a tri‐lobate signal attributed to vortex state and/or magnetostatic interactions. The FORC signatures of leaf samples combine aspects of both exhaust residue and brake‐pad endmembers, suggesting that FORC fingerprints have the potential to identify and quantify the relative contributions from exhaust and non‐exhaust (brake‐wear) emissions. Such measurements may provide a cost‐effective way to monitor the changing contribution; of future particulate emissions as the vehicle fleet is electrified over the coming years. Key Points: Microscopy and magnetic measurements of tree leaves indicate different sources of anthropogenic particulate air pollutionFirst‐order reversal curves can potentially be used as a proxy to identify particulate sourcesHigh concentrations of Fe‐bearing ultrafine particles found in brake‐pad and exhaust‐pipe residue specimens [ABSTRACT FROM AUTHOR]

Fire investigators may be occupationally exposed to many of the same compounds as the more widely studied fire suppression members of the fire service but are often tasked with working in a given exposure for longer periods ranging from hours to multiple days and may do so with limited personal protective equipment. In this study, we characterize the area air concentrations of contaminants during post-fire investigation of controlled residential fires with furnishings common to current bedroom, kitchen and living room fires in the United States. Area air sampling was conducted during different investigation phases including when investigations might be conducted immediately after fire suppression and extended out to 5 days after the fire. Airborne particulate over a wide range of dimensions, including sub-micron particles, were elevated to potentially unhealthy levels (based on air quality index) when averaged over a 60 min investigation period shortly after fire suppression with median PM2.5 levels over 100 µg/m3 (range 16–498 µg/m3) and median peak transient concentrations of 1,090 µg/m3 (range 200–23,700 µg/m3) during drywall removal or shoveling activities. Additionally, airborne aldehyde concentrations were elevated compared to volatile organic compounds with peak values of formaldehyde exceeding NIOSH ceiling limits during the earliest investigation periods (median 356 µg/m3, range: 140–775 µg/m3) and occasionally 1 day post-fire when the structure was boarded up before subsequent investigation activities. These results highlight the need to protect investigators' airways from particulates when fire investigation activities are conducted as well as during post-fire reconstruction activities. Additionally, vapor protection from formaldehyde should be strongly considered at least through investigations occurring 3 days after the fire and personal formaldehyde air monitoring is recommended during investigations. [ABSTRACT FROM AUTHOR]

Abstract We report the characterization of anthropogenic magnetic particulate matter (MPM) collected on leaves from roadside Callistemon (bottlebrush) trees from Lahore, Pakistan, and on known sources of traffic‐related particulates to assess the potential of first‐order reversal curve (FORC) diagrams to discriminate between different sources of anthropogenic magnetic particles. Magnetic measurements on leaves indicate the presence of surface‐oxidized magnetite spanning the superparamagnetic (

Exhaust gas recirculation (EGR) is a type of mature technology used to reduce NOx emissions from diesel engines. However, the use of EGR causes diesel engines to produce more particulates. In this paper, the particulates of diesel, diesel/biodiesel blend (50% biodiesel) and biodiesel were collected and measured at different EGR rates. High-resolution transmission electron microscopy (TEM) and thermogravimetric (TG) analyses were used to study the effects of EGR on the microstructure, composition and oxidation characteristics of particulates. The results showed that with the increase of biodiesel content in the diesel/biodiesel blend, the accumulation of diesel/biodiesel particulates was denser, the particle size of particulates for the diesel/biodiesel blend was smaller, the soluble organic fractions (SOF) content in particulates was increased and the surface activation energy of the particulates was reduced. With the increase of the EGR rate, the boundary of multiple particulate overlap areas was difficult to distinguish, the particle size of the particulates increased, and the SOF content in the particulates increased, while the soot content decreased gradually. When the EGR rate was increased from 0% to 15% and 30%, the activation energy of particulates for biodiesel was decreased by 15.59% and 26.63%, respectively. [ABSTRACT FROM AUTHOR]

In 2019, New Zealand passed “The Climate Change Response (Zero Carbon) Amendment Act” which included establishing the Climate Change Commission, a Crown entity to provide independent advice to Government to help Aotearoa transition to a climate-resilient and low emissions future. The Climate Change Commission’s first draft advice was released in January 2021 and, amongst other things, highlighted the opportunity to transition away from fossil fuels for domestic space and water heating. Compared to natural gas or LPG the use of wood burners for domestic heating, while a carbon neutral heating option, has the disadvantage of contributing to the deterioration of local air quality. In order to improve winter air quality, Environment Canterbury (ECan) has introduced a pseudo real-life wood burner authorisation test method known as Canterbury Method One (CM1). Appliances passing the CM1 test method qualify as Ultra-low Emission Burners (ULEBs) and are the only wood burning appliances allowed to be installed into houses within clean air zones in Canterbury. This paper provides updated information on the numbers and design trends of ULEBs authorised to date, and comments on how manufacturers have achieved the ULEB performance limits. The ongoing improvement of ULEBs provides the opportunity to transition away from fossil fuels toward a carbon neutral fuel without generating adverse air pollution impacts. This paper provides a summary of the journey to-date. [ABSTRACT FROM AUTHOR]

• The Camp Fire wildfire occurred in 2018 during the peak of primate breeding season. • Local air quality, measured by ambient fine particulates, surpassed national safety standards. • The primates exposed to poor air quality during their pregnancies were analyzed. • Pregnant primates exposed to the wildfire smoke had an increase rate of pregnancy loss. The November 2018 Camp Fire, a devastating wildfire in Northern California, occurred during the peak of breeding season for field monkeys at the California National Primate Research Center (CNPRC). Effects of environmental stressors, such as wildfires, on birth outcomes in primates, and in humans, are poorly understood. Additionally, wildfires are of growing concern due to their increasing frequency and severity. The objective was to examine the impact of wildfire smoke on fertility, timing of birth, and pregnancy loss for field monkeys. A unique case-control study to investigate birth outcomes in rhesus macaques (Macaca mulatta) was conducted at the CNPRC. All females in the study were maintained in outdoor fields during a period of elevated ambient wildfire smoke from November 8–22, 2018. In addition to ambient air quality evaluations, the effects on fertility, timing to birth, and pregnancy loss were documented. Archival records of approximately 5,000 conceptions from the previous nine years served as control data. During the Camp Fire, ambient fine particulate (PM 2.5) levels exceeded the 24 -h National Ambient Air Quality Standard (35 μg/m 3) of the United States Environmental Protection Agency, reaching levels as high as 185 μg/m 3. A statistically significant association was observed between birth loss and the 2018–2019 CNPRC breeding season. As this wildfire event occurred during various stages of early pregnancy, an association can be inferred between early gestational exposure and increased risk of pregnancy loss. [ABSTRACT FROM AUTHOR]

Background: Despite increasing evidence that particulate air pollution has adverse effects on human semen quality, few studies examine the impact of air pollution on clinically relevant thresholds used to diagnose male fertility problems. Furthermore, exposure is often assessed using average air pollution levels in a geographic area rather than individualized estimates. Finally, physiologically-informed exposure windows are inconsistent. Objectives: We sought to test the hypothesis that airborne particulate exposures during early-phase spermatogenesis will have a differential impact on spermatogenic formation compared to late-phase exposures, using an individualized model of exposure to particulate matter ≤ 2.5 µm and ≤ 10 µm (PM2.5 and PM10, respectively). Methods: From an original cohort of 183 couples, we conducted a retrospective analysis of 130 healthy males seeking to become parents, using spermatogenesis-relevant exposure windows of 77–34 days and 37–0 days prior to semen collection to encompass sperm development stages of mitosis/meiosis and spermiogenesis, respectively. Individualized residential exposure to PM2.5 and PM10 was estimated by selecting multiple air pollution sensors within the same geographic air basin as participants and employing inverse distance weighting to calculate mean daily exposure levels. We used multiple logistic regression to assess the association between pollution, temperature, and dichotomized World Health Organization semen parameters. Results: During the early phase of spermatogenesis, air pollution exposure is associated with 1.52 (95% CI: 1.04–2.32) times greater odds of

Pre and Post-Monsoon levels of ambient SO2, NO2, PM2.5 and the trace metals Fe, Cu, etc. were measured at industrial and residential regions of the Kochi urban area in South India for a period of two years. The mean PM2.5, SO2 and NO2 concentrations across all sites were 38.98 ± 1.38 µg/m3, 2.78 ± 0.85 µg/m3 and 11.90 ± 4.68 µg/m3 respectively, which is lower than many other Indian cities. There was little difference in any on the measured species between the seasons. A few sites exceeded the NAAQS (define acronym and state standard) and most of the sites exceeded WHO (define acronym and state standard) standard for PM2.5. The average trace metal concentrations (ng/m3) were found to be Fe (32.58) > Zn (31.93) > Ni (10.13) > Cr (5.48) > Pb (5.37) > Cu (3.24). The maximum concentration of trace metals except Pb were reported in industrial areas. The enrichment factor, of metals relative to crustal material, indicated anthropogenic dominance over natural sources for the trace metal concentration in Kochi's atmosphere. This work demonstrates the importance of air quality monitoring in this area. [ABSTRACT FROM AUTHOR]

Within the scope of the study, the effect of the argumentation-supported problem based learning method on the detection of the misconceptions of the students studying in the Department of Science Education about "Particulate, Space and Motion Nature of Matter" was examined. Based on this main purpose action research in practice-based was applied in the study, one of the qualitative research methods. The study group of the research consists of 22 pre-service science teachers. It was observed that pre-service science teachers structured non-scientific claims, could not provide sufficient grounds, and could not use their rebuttal skills adequately before the implications. After the implications, it was observed that the pre-service science teachers had the targeted arguments and were able to write grounds and rebuttal in the categories of completely/partially correct to their arguments. [ABSTRACT FROM AUTHOR]