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First-ever measurements of particulate matter (PM2.5, PM10, and TSP) along with gaseous pollutants (CO, NO2, and SO2) were performed from June 2019 to April 2020 in Faisalabad, Metropolitan, Pakistan, to assess their seasonal variations; Summer 2019, Autumn 2019, Winter 2019-2020, and Spring 2020. Pollutant measurements were carried out at 30 locations with a 3-km grid distance from the Sitara Chemical Industry in District Faisalabad to Bhianwala, Sargodha Road, Tehsil Lalian, District Chiniot. ArcGIS 10.8 was used to interpolate pollutant concentrations using the inverse distance weightage method. PM2.5, PM10, and TSP concentrations were highest in summer, and lowest in autumn or winter. CO, NO2, and SO2 concentrations were highest in summer or spring and lowest in winter. Seasonal average NO2 and SO2 concentrations exceeded WHO annual air quality guide values. For all 4 seasons, some sites had better air quality than others. Even in these cleaner sites air quality index (AQI) was unhealthy for sensitive groups and the less good sites showed Very critical AQI (> 500). Dust-bound carbon and sulfur contents were higher in spring (64 mg g-1) and summer (1.17 mg g-1) and lower in autumn (55 mg g-1) and winter (1.08 mg g-1). Venous blood analysis of 20 individuals showed cadmium and lead concentrations higher than WHO permissible limits. Those individuals exposed to direct roadside pollution for longer periods because of their occupation tended to show higher Pb and Cd blood concentrations. It is concluded that air quality along the roadside is extremely poor and potentially damaging to the health of exposed workers.

Purpose: Astaxanthin (AX), commonly used for dermal applications, exhibits anti-inflammatory and antioxidant activities; however, it has poor water solubility. In this study, we investigated the physicochemical properties of AX-containing particulates formulated using the amphiphilic graft copolymer Soluplus (polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer: Sol) and polyethylene glycol-2000 (PEG 2000); in addition, the stability and skin applications of AX particulates were investigated. Methods: AX, Sol, and PEG were mixed by weight to prepare AX particles using the hydration method. The prepared particles were subjected to stability evaluations including particle size distribution, zeta potential estimation, and fluorescence spectroscopy as well as physical evaluations including 1H-1H NOESY NMR spectral measurement, powder X-ray diffraction, and differential scanning calorimetry. Functional evaluations included singlet oxygen scavenging, skin permeation test, and fluorescence microscopy. Results: Relatively stable particles of Sol/AX and Sol/PEG 2000/AX, approximately 100 nm and 125 nm in size, respectively, were formed at a mixed weight ratio (9/1) of 0.1 M Ascorbic Acid solution (0.1 M ASC) and a mixed weight ratio (8/1/1) of 0.1 M ASC, respectively, at 25 °C after storage for 14 days under light-shielded condition. Stability evaluations revealed a decrease in fluorescence intensity and color fading for Sol/AX = 9/1 and Sol/PEG 2000/AX = 8/1/1 (dispersion medium: distilled water); however, no change in fluorescence intensity of AX was observed immediately after preparation in Sol/AX = 9/1 and Sol/PEG 2000/AX = 8/1/1 (dispersion medium: 0.1 M ASC). The fluorescence intensity of AX did not fluctuate significantly immediately after adjustment, and the particles remained stable, showing a bright orange color with time. NMR spectra of Sol/AX = 9/1 and Sol/PEG 2000/AX (dispersion medium: 0.1 M ASC) showed the interactions between the CH3 group e from Sol (1.8 ~ 2.0 ppm) and the CH groups H-15,11 from AX (6.7 ~ 6.8 ppm), 8',12' (6.4 ~ 6.5 ppm), H-10,14 (6.4 ~ 6.5 ppm), and 7,7' (6.2 ~ 6.3 ppm), indicating the disappearance of cross peaks. Furthermore, new cross peaks were identified for the CH3 group e of Sol (1.8 ~ 2.0 ppm), the 7-membered ring z of Sol (1.5 ~ 1.8 ppm), the 5-membered ring S of ASC (3.5 ~ 3.6 ppm), the CH group T (3.8 ~ 3.9 ppm), and the CH group U (4.7 ppm). Fluorescence microscopy observations of microparticles formulated with Sol/PEG 2000/AX showed a slight improvement in skin penetration. Conclusion: New AX particulates were formed using Sol/PEG 2000/AX = 8/1/1, suggesting that Sol/PEG 2000/AX maintained the stability and improved the skin penetration of AX. [ABSTRACT FROM AUTHOR]

The ubiquitous existence of microplastics and nanoplastics raises concerns about their potential impact on the human reproductive system. Limited data exists on microplastics within the human reproductive system and their potential consequences on sperm quality. Our objectives were to quantify and characterize the prevalence and composition of microplastics within both canine and human testes and investigate potential associations with the sperm count, and weights of testis and epididymis. Using advanced sensitive pyrolysis-gas chromatography/mass spectrometry, we quantified 12 types of microplastics within 47 canine and 23 human testes. Data on reproductive organ weights, and sperm count in dogs were collected. Statistical analyses, including descriptive analysis, correlational analysis, and multivariate linear regression analyses were applied to investigate the association of microplastics with reproductive functions. Our study revealed the presence of microplastics in all canine and human testes, with significant inter-individual variability. Mean total microplastic levels were 122.63 µg/g in dogs and 328.44 µg/g in humans. Both humans and canines exhibit relatively similar proportions of the major polymer types, with PE being dominant. Furthermore, a negative correlation between specific polymers such as PVC and PET and the normalized weight of the testis was observed. These findings highlight the pervasive presence of microplastics in the male reproductive system in both canine and human testes, with potential consequences on male fertility. [ABSTRACT FROM AUTHOR]

California must operate and maintain an effective and efficient transportation infrastructure while ensuring that the health of communities and the planet are not compromised. By assessing transportation projects using a life-cycle perspective, all relevant emission sources and activities from the construction, operation, maintenance, and end-of-life phases can be analyzed and mitigated. This report presents a framework to assess the life-cycle human health and climate change impacts from six types of transportation projects: (1) Roadways; (2) Marine ports; (3) Logistical distribution centers; (4) Railyards; (5) Bridges and overpasses; and (6) Airports. The framework was applied using an integrated model to assess fine particulate matter (PM2.5) and greenhouse gas (GHG) emissions, noise impacts, and monetized damages (Value of Statistical Life, Social Cost of Carbon) from two case studies: routine resurfacing and vehicle operations on road segments within the San Francisco Bay Area using 2019 data, and annual marine, cargo, rail, trucking, and infrastructure maintenance operations at the Port of Oakland in 2020. The results suggest that emission sources in a project’s supply chain and construction (material production and deliveries, construction activities, fuel refining) can significantly contribute to the full scope of impacts from transportation systems. Equitable mitigation policies (e.g., electrification, pollution control technologies) need to be tailored to address the sources that impact communities the most.

Abstract Purpose Astaxanthin (AX), commonly used for dermal applications, exhibits anti-inflammatory and antioxidant activities; however, it has poor water solubility. In this study, we investigated the physicochemical properties of AX-containing particulates formulated using the amphiphilic graft copolymer Soluplus (polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer: Sol) and polyethylene glycol-2000 (PEG 2000); in addition, the stability and skin applications of AX particulates were investigated. Methods AX, Sol, and PEG were mixed by weight to prepare AX particles using the hydration method. The prepared particles were subjected to stability evaluations including particle size distribution, zeta potential estimation, and fluorescence spectroscopy as well as physical evaluations including 1H-1H NOESY NMR spectral measurement, powder X-ray diffraction, and differential scanning calorimetry. Functional evaluations included singlet oxygen scavenging, skin permeation test, and fluorescence microscopy. Results Relatively stable particles of Sol/AX and Sol/PEG 2000/AX, approximately 100 nm and 125 nm in size, respectively, were formed at a mixed weight ratio (9/1) of 0.1 M Ascorbic Acid solution (0.1 M ASC) and a mixed weight ratio (8/1/1) of 0.1 M ASC, respectively, at 25 °C after storage for 14 days under light-shielded condition. Stability evaluations revealed a decrease in fluorescence intensity and color fading for Sol/AX = 9/1 and Sol/PEG 2000/AX = 8/1/1 (dispersion medium: distilled water); however, no change in fluorescence intensity of AX was observed immediately after preparation in Sol/AX = 9/1 and Sol/PEG 2000/AX = 8/1/1 (dispersion medium: 0.1 M ASC). The fluorescence intensity of AX did not fluctuate significantly immediately after adjustment, and the particles remained stable, showing a bright orange color with time. NMR spectra of Sol/AX = 9/1 and Sol/PEG 2000/AX (dispersion medium: 0.1 M ASC) showed the interactions between the CH3 group e from Sol (1.8 ~ 2.0 ppm) and the CH groups H-15,11 from AX (6.7 ~ 6.8 ppm), 8’,12’ (6.4 ~ 6.5 ppm), H-10,14 (6.4 ~ 6.5 ppm), and 7,7’ (6.2 ~ 6.3 ppm), indicating the disappearance of cross peaks. Furthermore, new cross peaks were identified for the CH3 group e of Sol (1.8 ~ 2.0 ppm), the 7-membered ring z of Sol (1.5 ~ 1.8 ppm), the 5-membered ring S of ASC (3.5 ~ 3.6 ppm), the CH group T (3.8 ~ 3.9 ppm), and the CH group U (4.7 ppm). Fluorescence microscopy observations of microparticles formulated with Sol/PEG 2000/AX showed a slight improvement in skin penetration. Conclusion New AX particulates were formed using Sol/PEG 2000/AX = 8/1/1, suggesting that Sol/PEG 2000/AX maintained the stability and improved the skin penetration of AX.

Previous studies involving workers at brick kilns in the Kathmandu Valley of Nepal have investigated chronic exposure to hazardous levels of fine particulate matter (PM2.5) common in ambient and occupational environments. Such exposures are known to cause and/or exacerbate chronic respiratory diseases, including chronic obstructive pulmonary disease (COPD) and asthma. However, there is a paucity of data regarding the status of systemic inflammation observed in exposed workers at brick manufacturing facilities within the country. In the current study, we sought to elucidate systemic inflammatory responses by quantifying the molecular cytokine/chemokine profiles in serum from the study participants. A sample of participants were screened from a kiln in Bhaktapur, Nepal (n = 32; 53% female; mean ± standard deviation: 28.42 ± 11.47 years old) and grouped according to job category. Blood was procured from participants on-site, allowed to clot at room temperature, and centrifuged to obtain total serum. A human cytokine antibody array was used to screen the inflammatory mediators in serum samples from each of the participants. For the current study, four job categories were evaluated with n = 8 for each. Comparisons were generated between a control group of administration workers vs. fire master workers, administration workers vs. green brick hand molders, and administration workers vs. top loaders. We discovered significantly increased concentrations of eotaxin-1, eotaxin-2, GCSF, GM-CSF, IFN-γ, IL-1α, IL-1β, IL-6, IL-8, TGF-β1, TNF-α, and TIMP-2 in serum samples from fire master workers vs. administration workers (p < 0.05). Each of these molecules was also significantly elevated in serum from green brick hand molders compared to administration workers (p < 0.05). Further, each molecule in the inflammatory screening with the exception of TIMP-2 was significantly elevated in serum from top loaders compared to administration workers (p < 0.05). With few exceptions, the fire master workers expressed significantly more systemic inflammatory molecular abundance when compared to all other job categories. These results reveal an association between pulmonary exposure to PM2.5 and systemic inflammatory responses likely mediated by cytokine/chemokine elaboration. The additional characterization of a broader array of inflammatory molecules may provide valuable insight into the susceptibility to lung diseases among this population. [ABSTRACT FROM AUTHOR]

Atmospheric aerosols affect human health and influence atmospheric and biological processes. Dust can be transported long distances in the atmosphere, and the mechanisms that influence dust transport are not fully understood. To improve the database for numerical models that simulate dust transport, measurements are needed that cover both the vertical distribution of the dust and its size distribution. In addition to measurements with crewed aircraft, uncrewed aircraft systems (UASs) provide a particularly suitable platform for this purpose. In this paper, we present a payload for the small fixed-wing UAS of the type Multiple-Purpose Airborne Sensor Carrier 3 (MASC-3) for aerosol particle measurements that is based on the optical particle counter (OPC) OPC-N3 (Alphasense, United Kingdom), modified by the addition of a dryer and a passive aspiration system (OPC-Pod). Based on field tests with a reference instrument in Mannheim, Germany, wind tunnel tests, and a comparison measurement with the UAS-mounted aerosol particle measurement Universal Cloud and Aerosol Sounding System (UCASS) during a dust event over Cyprus, we show that the OPC-Pod can measure particle number concentrations in the range of 0.66–31 μm as well as particle size distributions. The agreement of the OPC-Pod with UCASS is good. Both instruments resolve a vertical profile of the Saharan dust event, with a prominent dust layer between 1500 and 2800 m MSL, with particle number concentrations up to 35 cm−3 for particles between 0.66 and 31 μm. [ABSTRACT FROM AUTHOR]

In order to model the propagation of light through a sand cloud, it is critical to have accurate data for the optical constants of the sand particles that comprise it. The same holds true for modeling propagation through particles of any type suspended in a medium. Few methods exist, however, to measure these quantities with high accuracy. In this paper, a characterization method based on spectroscopic ellipsometry (SE) that can be applied to a particulate material is presented. In this method, a polished disc of an adhesive compound is prepared, and its optical constants are measured. Next, a mixture of the adhesive and a sand sample is prepared and processed into a polished disc, and SE is performed. By treating the mixture as a Bruggeman effective medium, the optical constants of the particulate material are extracted. For verification of the proposed method, it is first applied to pure silica powder, demonstrating good agreement between measured optical constants and literature values. It is then applied to Arizona road dust, a standard reference material, as well as real desert sand samples. The resulting optical constant data is input into a rigorous scattering model to predict extinction coefficients for various types of sand. Modeling results are compared to spectroscopic measurements on static sand samples, demonstrating good agreement between predicted and measured spectral properties including the presence of a Christiansen feature near a wavelength of 8 µm. [ABSTRACT FROM AUTHOR]

Various activities in chemical stores such as production, packaging, repackaging, offloading, and storing of chemicals can emit toxic chemicals into the ambient air which may be detrimental to health. This research work aimed to determine whether or not there is hepatoxicity and nephrotoxicity in chemical storekeepers. A total of twenty male adult storekeepers of four chemical stores were used as subjects. Four male storekeepers of a garment store 1km from the chemical stores of the same market were used as control subjects. Heavy metals in the indoor air of the shops and the blood samples of the subjects were determined using an atomic absorption spectrophotometer while an aerocet analyzer was used for the measurement of particulate matter. Kidney and liver function tests were carried out on the serum of subjects using standard analytical test kits. Concentrations of all the assayed heavy metals in the ambient air of the chemical stores and the blood samples of chemical storekeepers were significantly higher (p<0.05) than in the controls. Particulate matter concentrations in all the chemical stores increased significantly (p<0.05). Serum urea, creatinine, sodium ion, potassium ion, chloride, and bicarbonate were significantly elevated (p<0.05) in the chemical storekeepers compared to control subjects. Concentrations of serum bilirubin and liver enzymes were significantly elevated (p<0.05) while total protein and albumin concentrations were significantly decreased (p<0.05) in the majority of the chemical storekeepers compared to the control subjects. There were strong indications of renal and hepato-toxicities in the chemical storekeepers at Ariaria International Market. [ABSTRACT FROM AUTHOR]

Extreme heat events stress the body and can result in fatalities, especially for those with underlying health problems. Air pollution is another threat to health and is an important confounder of extreme heat risks. However, previous empirical studies that have addressed the joint health impacts of air pollution and heat rarely considered the endogeneity and spillover effects of air pollution. To fill this research gap, this article investigates the interconnected impacts of extreme heat and fine particulate matter (PM2.5) on all-cause and cause-specific mortality. We correct the endogeneity of PM2.5 by applying the control function approach and explore transboundary externalities of all-source PM2.5 and wildfire-caused PM2.5. We use a county-year balanced panel dataset covering 2992 U.S. counties from 2001 through 2011. Results show that extreme heat and air pollution exacerbate each other and jointly increase mortality. Specifically, a 1-standard-deviation (SD) increase in the heat index results in 0.60% (95% confidence interval: 0.26%–0.97%), 2.14% (1.34%–2.94%), and 0.86% (0.41%–1.34%) more all-cause fatalities, fatalities from respiratory system diseases, and fatalities from circulatory system diseases, respectively. A 1-SD increase in PM2.5 results in 5.75% (3.61%–7.90%), 6.99% (3.01%–11.15%), and 2.93% (0.66%–5.28%) additional fatalities, respectively. Failure to consider the endogeneity of PM2.5 leads to a substantial underestimation of PM2.5 risk. In addition, our instrumental variable strategy offers evidence of spillover effects from PM2.5 and wildfires. Significance Statement: This study illustrates how extreme heat events combined with air pollutants threaten health. This article investigates the interconnected impact of extreme heat and air pollution using data from 2992 United States counties over the 2001–11 period. Results indicate that extreme heat and air pollution jointly increase mortality. Results also show that wind-driven pollution from other counties and wildfires increase mortality. [ABSTRACT FROM AUTHOR]

The quantification and prediction of particulate matter (PM) concentrations in the air are essential due to their negative impacts on human health and the environment. This study quantified PM concentrations and associated health effects at four natural gas-based power plants in Bangladesh. The measurement of PM2.5 and PM10 using the respirable dust samplers APS-113NL and APS-113BL, respectively from the year of 2015 to 2021 revealed that the concentration of both types of particles fluctuated over the years. The highest recorded levels of particles were in 2019, with PM2.5 at 126 µg/m3 and PM10 at 283 µg/m3 and the lowest recorded levels of particles were in 2017, with PM2.5 at 76.3 µg/m3 and PM10 at 203.3 µg/m3. In 2021, PM2.5 and PM10 concentrations were 88.5 and 225 µg/m3, respectively, lower than in the past two years. Statistical modeling assessed atmospheric contaminants analyzed time series data, and projected air quality. ARIMA, ETS, and ANN modeling methods have been used to predict the monthly average of PM2.5 and PM10 concentrations. RMSE, MAPE, MASE, and MAE have been utilized for model orders, time series analysis, and forecasting validation. There is a significant variation between the forecasting models and forecasts for average PM2.5 and PM10 concentrations in natural gas-fired power plants from 2022 to 2024. This study also conducted a face-to-face interview with over 100 employees using a structured questionnaire to assess the health effects they are facing due to poor air quality in the power generation complex and found that 2 and 13 % of employees had respiratory and skin issues, respectively. Nonetheless, regular health checks, air filtration, and renewable energy consumption may benefit residents and the environment.

Economic incentives have been introduced at PAO Koks to reduce environmental pollution. The best available technologies have been introduced. As a result, particulate emissions have been reduced by 1.56 kg per t of coke. [ABSTRACT FROM AUTHOR]

Air quality in a cancer facility is integral to the success of patient treatment. The organization must be committed to providing a patient care environment free of physical and biological hazards that result from construction and demolition activities. This project intended to safely demolish a derelict building in Texas while minimizing air quality risks and impacts to nearby hospitals and a proximal cancer hospital. Two of the neighboring facilities were less than 18 feet (5.5 m) away from the demolition location. Adjacent facilities included inpatient and outpatient cancer treatment clinics, a large data center, a pediatric hospital complex, and a heart institute. Plans to minimize infection risks and dust for respective facilities were designed before implosion and remained in place until total debris removal. Risk assessments of nearby buildings were completed to determine the appropriate precautions and physical barriers needed. Culturable and non-culturable fungal air samples were collected during implosion to verify the management of outside contaminants. Additionally, continuous particulate and routine sampling for culturable and non-culturable fungi were performed for approximately 7 months after the project demolition. Air sampling results from 32 internal areas indicated that most areas remained at pre-implosion background levels. Areas that experienced elevated particle counts were cleaned and resampled, and baseline values returned to pre-implosion levels within 12 hr. Fungal air sampling results were acceptable based on predetermined infection control guidelines. The building was successfully demolished via implosion with no injuries and minimal damage to nearby facilities. The team learned that an integrated approach to project management that includes all stakeholders is essential to success. Contingency planning should account for all variables; no assumptions should be made. Staffing plans should be reviewed to ensure the sampling strategy developed can be implemented appropriately. [ABSTRACT FROM AUTHOR]

According to the Environmental Protection Agency’s National Emissions Inventory Report, hundreds of thousands of tons of particulate matter (PM2.5) are released by diesel combustion per year. The toxic PM2.5 air pollution causes serious public health problems and is responsible for millions of worldwide deaths each year. This study investigates the electrochemical energy storage capability of annealed soot PM originating from diesel exhaust. Soot composite electrodes were utilized as anode electrodes and cycled against Li counter electrodes. X-ray diffraction and Raman spectroscopy showed the graphitized carbon structure of the annealed soot particles. The cycle life and rate-capability of the electrodes were investigated via galvanostatic cycling tests. The electrodes exhibited excellent rate performance with discharge capacities of 235, 195, 150, 120, and 80 mAh/g when cycled at rates of 1C, 2C, 5C, 10C, and 20C, respectively. The electrode demonstrated an initial discharge capacity of 154 mAh/g at 4C rate with a capacity retention of almost 77% after 500 cycles. Raman analysis confirms the retention of structural ordering in the soot carbon after 500 cycles. Kinetic analysis, obtained through cyclic voltammetry at different scan rates, indicates pseudocapacitive charging behavior in the soot composite electrode. The study provides a viable pathway towards a sustainable energy-environment by converting an abundant toxic pollutant into a valuable electrode material for Li-ion batteries.View the NCST Project Webpage

This report documents the successful capture and reuse of diesel exhaust soot particles as a conductive additive in lithium manganese oxide (LMO) and lithium iron phosphate (LFP) cathodes in Li-ion batteries. This approach enables an abundant toxic pollutant to be converted into a valuable material for energy storage devices. This study consists of an initial characterization of the diesel soot particles, a high-temperature annealing step to remove residual organics and unburned hydrocarbons, and characterization of the electrical performance in a Li-ion battery configuration. Here, composite electrodes are fabricated by mixing active materials (LFP or LMO) with conductive carbon and binders. The performance of the diesel soot particles as conductive additives is compared with that of commercially available activated carbon (i.e., Super P®). The current evolution of the composite electrode made with diesel soot particles demonstrates comparable performance to the electrodes containing the Super P® carbon. Based on high-resolution transmission electron microscope (HRTEM) images and scanning mobility particle sizer (SMPS) spectra, it is found that these diesel soot nanoparticles follow a narrow log-normal distribution centered around 100 nm in diameter and consist of highly porous amorphous carbon, which provide a large surface-to-volume ratio, making them ideal candidates for electrode materials in Li ion batteries.View the NCST Project Webpage

The use of biodiesel is still experiencing problems due to large amount of water content which produce from the transesterification process, making it has unstable oxidizing properties. The large amount of water content in biodiesel causes the emergence of microorganisms which becoming sludge in the engine room, and can clog the fuel filter. In this study, we propose the application of oxygenate bio-additives to minimize water and particulate content by using turpentine essential oils, clove terpenes, rhodinol, camphor oil, and synthetic additive 2EHN. Based on the study's results, the water content of biodiesel B35 with the AC bio-additive mixture experienced the highest decrease in water content, which was 18% or 287.2 ppm and performs well in reducing particulate levels of 4, 6, and 14 microns. The completely randomized design (CRD) test results for non-factorial moisture content on days 0, 3, 5, 7, and 14 and particulate matter 4, 6, and 14 microns showed no significant difference because each P value was obtained greater than α (0.05).

Thermal spray coating is a process in which molten metal is sprayed onto a surface. Little is known about the health effects associated with these aerosols. Sprague-Dawley rats were exposed to aerosols (25 mg/m3 × 4 hr/d × 4 d) generated during thermal spray coating using different consumables [i.e. stainless-steel wire (PMET731), Ni-based wire (PMET885), Zn-based wire (PMET540)]. Control animals received air. Bronchoalveolar lavage was performed at 4 and 30 d post-exposure to assess lung toxicity. The particles were chain-like agglomerates and similar in size (310–378 nm). Inhalation of PMET885 aerosol caused a significant increase in lung injury and inflammation at both time points. Inhalation of PMET540 aerosol caused a slight but significant increase in lung toxicity at 4 but not 30 d. Exposure to PMET731 aerosol had no effect on lung toxicity. Overall, the lung responses were in the order: PMET885≫PMET540 >PMT731. Following a shorter exposure (25 mg/m3 × 4 h/d × 1d), lung burdens of metals from the different aerosols were determined by ICP-AES at 0, 1, 4 and 30 d post-exposure. Zn was cleared from the lungs at the fastest rate with complete clearance by 4 d post-exposure. Ni, Cr, and Mn had similar rates of clearance as nearly half of the deposited metal was cleared by 4 d. A small but significant percentage of each of these metals persisted in the lungs at 30 d. The pulmonary clearance of Fe was difficult to assess because of inherently high levels of Fe in control lungs. [ABSTRACT FROM AUTHOR]

There has not been a satisfying numerical validation of the theory of effective waves in random particulate materials. Validation has been challenging because the theoretical methods for effective waves have been limited to random particulate media in infinite slabs or half-spaces, which require a very large number of particles to perform accurate numerical simulations. This paper offers a solution by providing, from first principles, a method to calculate effective waves for a sphere filled with particles for a spherically symmetric incident wave. We show that this case can excite exactly the same effective wavenumbers, which are the most important feature to validate for effective waves. To check correctness, we also deduce an integral equation method which does not assume the effective wave solution. Our methods are, in principal, valid for any frequency, particle volume fraction and disordered pair-correlation. With the methods we provide, it is now possible to validate, with a heavier Monte Carlo simulation, the predictions from effective wave theory. [ABSTRACT FROM AUTHOR]

Key Takeaways: Regular monitoring of particle concentration in conjunction with turbidity analysis provides supplementary data that can provide important water quality information. Particle analysis using flow imaging microscopy (FIM) can help operators better understand various treatment processes and algae growth in source waters. Specific size ranges can be monitored using FIM for target pathogens such as Cryptosporidium and Giardia. [ABSTRACT FROM AUTHOR]

Stubble burning is a practice of removing paddy crop residues by burning it in order prepare the filed for next crop. Farmers used this practice for the preparation of land for next cultivation. This practice now considered as one of the vital activities that degrade or affects the ambient air quality which in how responsible for air pollution. It involves the removal of a large portion of the organic matter, nitrogen, phosphorus and great loss of biodiversity. It causes damage to the microorganisms present in the upper fertile layer of the soil which further affects the organic quality of soil. Last few decades it has also been observed that this practice has increased due to excessive use of combine harvester that leaves the stalk behind. Nowadays many researchers, Environmentalist are using remote sensing and GIS technique to estimate the stubble burn area. Thus in this review an attempt is made to study the impact of stubble burning on environment and agriculture. [ABSTRACT FROM AUTHOR]

The present investigation examined the impact of highways on the global dispersion patterns of metallic elements present in dust and snow. A total of 18 mixed snow samples were collected from both sides of the Moscow-Tambo-Astrakhan Caspian Highway by the end of the winter season. The analysis of the samples indicated the presence of 35 distinct chemical elements, where Al, Ba, Ca, Fe, K, Mg, Na, and Zn were identified as the primary contaminants. The primary area of pollution on the windward side originating from the road spans a distance of 20-40 meters, while on the leeward side, it extends to 10 meters. The data presented suggests that the metals found in highways exhibited variability in terms of their solubility in water and concentration. Our findings demonstrate that the predominant wind directions affect the dispersion of pollutants. Furthermore, it was observed that the region with a higher concentration of metal on the side of the road facing the wind had a thickness that was 2-3 times less than that of the opposite side. It is advisable to conduct a subsequent inquiry within the ensuing five years to obtain dependable data regarding the extent of metal pollution. [ABSTRACT FROM AUTHOR]

Previous studies involving workers at brick kilns in the Kathmandu Valley of Nepal have investigated chronic exposure to hazardous levels of fine particulate matter (PM2.5) common in ambient and occupational environments. Such exposures are known to cause and/or exacerbate chronic respiratory diseases, including chronic obstructive pulmonary disease (COPD) and asthma. However, there is a paucity of data regarding the status of systemic inflammation observed in exposed workers at brick manufacturing facilities within the country. In the current study, we sought to elucidate systemic inflammatory responses by quantifying the molecular cytokine/chemokine profiles in serum from the study participants. A sample of participants were screened from a kiln in Bhaktapur, Nepal (n = 32; 53% female; mean ± standard deviation: 28.42 ± 11.47 years old) and grouped according to job category. Blood was procured from participants on-site, allowed to clot at room temperature, and centrifuged to obtain total serum. A human cytokine antibody array was used to screen the inflammatory mediators in serum samples from each of the participants. For the current study, four job categories were evaluated with n = 8 for each. Comparisons were generated between a control group of administration workers vs. fire master workers, administration workers vs. green brick hand molders, and administration workers vs. top loaders. We discovered significantly increased concentrations of eotaxin-1, eotaxin-2, GCSF, GM-CSF, IFN-γ, IL-1α, IL-1β, IL-6, IL-8, TGF-β1, TNF-α, and TIMP-2 in serum samples from fire master workers vs. administration workers (p < 0.05). Each of these molecules was also significantly elevated in serum from green brick hand molders compared to administration workers (p < 0.05). Further, each molecule in the inflammatory screening with the exception of TIMP-2 was significantly elevated in serum from top loaders compared to administration workers (p < 0.05). With few exceptions, the fire master workers expressed significantly more systemic inflammatory molecular abundance when compared to all other job categories. These results reveal an association between pulmonary exposure to PM2.5 and systemic inflammatory responses likely mediated by cytokine/chemokine elaboration. The additional characterization of a broader array of inflammatory molecules may provide valuable insight into the susceptibility to lung diseases among this population.

Background: Humans are constantly exposed to various industrial, environmental, and endogenous particulates that result in inflammatory diseases. After being engulfed by immune cells, viz. Macrophages, such particulates lead to phagolysosomal dysfunction, eventually inducing pyroptosis, a form of cell death accompanied by the release of inflammatory mediators, including members of the interleukin (IL)-1 family. Phagolysosomal dysfunction results in the activation of the nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, an immune complex that induces pyroptosis upon exposure to various external stimuli. However, several particulates induce pyroptosis even if the NLRP3 inflammasome is inhibited; this indicates that such inhibition is not always effective in treating diseases induced by particulates. Therefore, discovery of drugs suppressing particulate-induced NLRP3-independent pyroptosis is warranted. Methods: We screened compounds that inhibit silica particle (SP)-induced cell death and release of IL-1α using RAW264.7 cells, which are incapable of NLRP3 inflammasome formation. The candidates were tested for their ability to suppress particulate-induced pyroptosis and phagolysosomal dysfunction using mouse primary macrophages and alleviate SP-induced NLRP3-independent lung inflammation. Results: Several Src family kinase inhibitors, including dasatinib, effectively suppressed SP-induced cell death and IL-1α release. Furthermore, dasatinib suppressed pyroptosis induced by other particulates but did not suppress that induced by non-particulates, such as adenosine triphosphate. Dasatinib reduced SP-induced phagolysosomal dysfunction without affecting phagocytosis of SPs. Moreover, dasatinib treatment strongly suppressed the increase in IL-1α levels and neutrophil counts in the lungs after intratracheal SP administration. Conclusion: Dasatinib suppresses particulate-induced pyroptosis and can be used to treat relevant inflammatory diseases. [ABSTRACT FROM AUTHOR]

It is of great significance to understand the particle distribution characteristics at different heights to effectively control particle pollution. Based on fractal theory, the fractal dimension of outdoor particles in a high-rise building in Xi'an and its relationship with the concentration of particles with different particle sizes are discussed and analyzed in this paper. The results indicate that the atmosphere in Xi'an is mainly composed of fine particles and that the average proportion of particles ranging from 0 to 1.0 µm is approximately 99.885% of the total particulates. The fractal dimension of particles in the atmosphere at different heights ranges from 5.014 to 5.764, with an average fractal dimension of 5.456. In summer, the fractal dimension of the outdoor particles on the 17th floor was the largest, at 5.764. The fractal dimension in summer is relatively high, being 0.158 higher than that in winter on average. The larger the fractal dimension, the higher the proportion of fine particles. In addition, the fractal dimension can characterize the adsorption of toxic and harmful gases by particles well. It provides parameter support for understanding particle distribution and the effective control of atmospheric particles at different heights and application values. [ABSTRACT FROM AUTHOR]

The relationship between air quality and the spread of Covid-19 has been proven to be sometimes positive and sometimes negative in previous studies. A research gap was seen in Iran regarding the impact of air quality on the spread of Covid-19. Thus, this study examined the relationship between the reproductive number of Covid-19 with the air quality index and meteorological factors. The reproductive number is an index to explain the spread of a viral disease. The air quality index related to each of the pollutants NO2, O3, CO, PM2.5, PM10, and the criterion pollutant were utilized in this study. Meteorological factors, including temperature, relative humidity, precipitation, air pressure, and wind speed were used. The data were obtained weekly and at Tehran province. The dependence of variables was determined using Pearson and Spearman correlation coefficients. The examined relationships were then estimated by regression. Each independent variable was tested in a distinct regression because of the limitations of the study. The linear and curvature regressions were performed according to the dispersion of variables and statistical assumptions. The best model was fitted based on statistical significance and regression coefficient of determination. The results of correlation tests showed the dependence of reproductive number with PM10, PM2.5, SO2 and relative humidity. Regression tests also confirmed the relationship between the reproductive number (dependent variable) and each of the independent variables PM10 (coefficient of determination 0.274), PM2.5 (coefficient of determination 0.358), SO2 (coefficient of determination 0.359), and relative humidity (determination coefficient 0.213). The results indicated that an increase in PM10, PM2.5, SO2 and decrease in relative humidity was associated with an increase in spread of Covid-19. [ABSTRACT FROM AUTHOR]

Particulates from compression ignition (CI) engines have received serious attention in the last two decades. CI engines emit higher particulate matter (PM) and nitrogen oxides (NOx) than spark ignition (SI) engines. Both these species are harmful to human health and the environment. Compared to NOx emissions, PM constitutes many more chemical species in solid and liquid phases. This review paper focuses on soot morphology and chemical characterization of PM emissions from CI engines. Effects of different fuels, lubricating oil, and engine operating conditions on particulate characteristics are analyzed exhaustively. The first part of this paper focuses on the effects of particulates on living organisms, the consequences of exposure to diesel particulates, and the composition of diesel particulates. In recent decades, micro and nano-scale characteristics of PM have been exhaustively investigated to understand its structure, formation, and chemical functionalities. Typically, particulates comprise of elemental carbon (EC), organic carbon (OC), polycyclic aromatic hydrocarbons (PAHs), the soluble organic fraction (SOF), and trace metals. This paper summarizes most aspects of diesel particulate emissions for the benefit of active researchers in the field and underlines the importance of particulate emission reduction from the CI engines. Diesel combustion generates particles with enormous long-chain aggregates of smaller sizes and immature soot particles. Low-temperature combustion (LTC) modes and oxygenated fuels reduce the soot emissions and generate compact/clustered aggregates. Oxygenated fuels in CI engines produce more nucleation mode particles (NMPs) and high-reactivity soot aggregates. Higher trace metal concentrations were observed in diesel origin particulates than biofuel origin particulates. Biodiesel origin particulates possess higher mutagenicity and carcinogenicity because of nitro-PAHs. Transient engine operations cause higher particulates than steady-state engine operations. [ABSTRACT FROM AUTHOR]

A recent study conducted at the Point Loma wastewater outfall in San Diego used a novel sampling technique, the Pelagic Laser Tomographer (PLT), in combination with traditional water column profiling instruments to analyze suspended particulate distributions and effluent plume dynamics. Coastal wastewater discharges create buoyant plumes that interact with the surrounding water, and the tracking and mapping of the resulting diluted effluent is essential for monitoring outfall system performance. The results from the PLT sampling highlight the utility of high spatial and temporal resolution estimates of suspended particulate size spectra to help capture the dynamics of the plume interactions with the coastal current flow field. In addition, new tools like the PLT can help marine scientists estimate natural and anthropogenic particulate size distributions that are essential to our understanding sediment and pollutant transport, nutrient cycling, and ecosystem energy dynamics.

During operation, all components of a gas-turbine unit (GTU), including the blading of the axial compressor, are affected by the flow in the GTU flowpath, which results in the development of defects and deterioration of the main performance characteristics (efficiency, effective power, etc.). One of the most serious defects is erosive wear since it can cause destruction of one blade or all the blades in the compressor. This can lead to preliminary removal of a GTU from operation. Therefore, the erosion resistance of compressor blades is one of the main parameters controlling the service life of a gas-turbine unit. That is why studies of the erosive wear of axial compressors during operation of GTUs are urgent. This paper provides a review of the available publications on the erosive wear of blades and vanes in an axial compressor of gas-turbine units. The major erosion mechanisms classified by the type of particulates acting on blade material are examined. The geometric parameters of the compressor blading are found whose change due to erosive wear can disturb the flow aerodynamics and deteriorate the performance of individual elements and the overall GTU. The main three lines of erosive wear studies may be listed as follows: prediction of erosive wear, assessment and prediction of erosion consequences, and development of protective measures to control erosion during operation of a gas-turbine unit. The most frequently examined and promising subjects of erosion studies are outlined as applicable to gas turbine and compressor machine building. The state-of-the-art of studies in this field is analyzed. [ABSTRACT FROM AUTHOR]

Windblown dust events, including dust storms and smaller blowing dust events, pose severe risks to public health and transportation safety. In the United States, the statistics of fatalities caused by dust events remains elusive. We developed a new dataset by merging dust fatality data from NOAA Storm Events Database and the Department of Transportation Fatality Analysis Reporting System (FARS). There was a total of 232 deaths from windblown dust events from 2007 to 2017. This number is much larger than that reported by the NOAA Natural Hazard Statistics, which assigns some dust fatalities to high winds and thunderstorms (∼45%) and does not include many events in FARS. Dust fatalities are most frequent over the Southwest, consistent with the spatial distribution of dust storm occurrences. Other high-risk regions include the Colorado Plateau, Columbia Plateau in Washington and Oregon, the High Plains where the disastrous "Dust Bowl" occurred, and the Corn Belt where blowing dust from croplands presents a driving hazard. All six most deadly dust wrecks (three deaths or more) involved semi trucks and five of them were caused by dust storms along Interstate 10. There exist two "hotspots" for dust fatalities: 1) the "Deadliest 10 Miles" between Phoenix and Tucson, Arizona, and 2) Lordsburg Playa in New Mexico, where active dust mitigation projects have been managed by state transportation agencies. In most years, dust events caused comparable life losses to that from other weather hazards such as hurricanes, thunderstorms, lightning, and wildfires. This work presents new evidence that dust is an underappreciated weather hazard. [ABSTRACT FROM AUTHOR]

Daily atmospheric concentrations of the pollutants PM10 and O3 vary according to weather types. This study aims to identify the weather patterns associated with PM10 and O3 pollution episodes from 2009 to 2020. Episodes characterized by exceedance of World Health Organization standards were identified, and their duration and persistence were studied. The results show that air pollution days are associated with three atmospheric patterns for PM10 and four for O3. The dominant weather pattern corresponds to an anticyclonic situation in central and Eastern Europe with a ridge of high pressure over France at the surface and 500-hPa geopotential height. For PM10, the persistent high-concentration sequences were found to be associated with a thermal inversion constraining the vertical dispersion of pollutants. For O3, the four weather types responsible for ozone pollution all have a higher occurrence in summer. The highest percentage (46% of days) is associated with the presence of a ground-level barometric marsh (an area of the atmosphere between two weather systems where the pressure varies slightly but is slightly low) and a ridge at 500 hPa (weather type T1). Similarly, thermal inversions and thermal winds cause pollution to persist beyond 8 consecutive days. Significance Statement: Air quality is not only influenced by ground-level emissions, but also by complex meteorological processes that can contribute to pollutant accumulations. The importance of this research is that the prediction of these processes helps to prevent the development of extreme concentrations near the surface. The results of this study provide a better understanding of how characteristic weather patterns in the Cergy-Pontoise conurbation impact PM10 and O3 pollutant levels. These impacts are expressed by the intensity and frequency of pollution episodes. [ABSTRACT FROM AUTHOR]

Abstract Background Some evidences have shown the association between air pollution exposure and the development of interstitial lung diseases. However, the effect of air pollution on the progression of restrictive ventilatory impairment and diffusion capacity reduction is unknown. This study aimed to evaluate the effects of long-term exposure to ambient air pollution on the change rates of total lung capacity, residual volume, and diffusion capacity among the elderly. Methods From 2016 to 2018, single-breath helium dilution with the diffusion capacity of carbon monoxide was performed once per year on 543 elderly individuals. Monthly concentrations of ambient fine particulate matters (PM2.5) and nitric dioxide (NO2) at the individual residential address were estimated using a hybrid Kriging/Land-use regression model. Linear mixed models were used to evaluate the association between long-term (12 months) exposure to air pollution and lung function with adjustment for potential covariates, including basic characteristics, indoor air pollution (second-hand smoke, cooking fume, and incense burning), physician diagnosed diseases (asthma and chronic airway diseases), dusty job history, and short-term (lag one month) air pollution exposure. Results An interquartile range (5.37 ppb) increase in long-term exposure to NO2 was associated with an additional rate of decline in total lung volume (− 1.8% per year, 95% CI: − 2.8 to − 0.9%), residual volume (− 3.3% per year, 95% CI: − 5.0 to − 1.6%), ratio of residual volume to total lung volume (− 1.6% per year, 95% CI: − 2.6 to − 0.5%), and diffusion capacity (− 1.1% per year, 95% CI: − 2.0 to − 0.2%). There is no effect on the transfer factor (ratio of diffusion capacity to alveolar volume). The effect of NO2 remained robust after adjustment for PM2.5 exposure. Conclusions Long-term exposure to ambient NO2 is associated with an accelerated decline in static lung volume and diffusion capacity in the elderly. NO2 related air pollution may be a risk factor for restrictive lung disorders.

Exposure to outdoor air pollutants poses a risk for both non-carcinogenic and carcinogenic respiratory disease outcomes. A standardized health risk assessment (US EPA) utilizes air quality data, body mass and breathing rates to determine potential risk. This health risk assessment study assesses the hazard quotient (HQ) for total PM2.5 and trace elemental constituents (Br, Cl, K, Ni, S, Si, Ti and U) exposure in Pretoria, South Africa. The World Health Organization (WHO) air quality guideline (5 µg m−3) and the yearly South African National Ambient Air Quality Standard (NAAQS) (20 µg m−3) were the references dosages for total PM2.5. A total of 350 days was sampled in Pretoria, South Africa. The mean total PM2.5 concentration during the 34-month study period was 23.2 µg m−3 (0.7–139 µg m−3). The HQ for total PM2.5 was 1.17, 3.47 and 3.78 for adults, children and infants. Non-carcinogenic risks for trace elements K, Cl, S and Si were above 1 for adults. Seasonally, Si was the highest during autumn for adults (1.9) and during spring for S (5.5). The HQ values for K and Cl were highest during winter. The exposure to Ni posed a risk for cancer throughout the year and for As during winters. [ABSTRACT FROM AUTHOR]

This paper describes the formation of the natural repose angle of non-cohesive bulk materials. The repose angle of particulates α is the angle between the tangent plane to the surface of the slope and the solid base. The paper presents a thermodynamic theory for the formation of the most energy-efficient natural slope α ≈ 30 ∘ that can be found very often both in nature and industry. The theoretical foundation is based on Janssen theory of the statistical distribution of vertical and horizontal stress and adds its own consideration about dissipative work during the movement of material as a slope is being formed. The presented model is expanded to include an experimental part describing four methods of creation of a natural repose angle on three sand samples. The experiments performed demonstrated the validity of the submitted theory and the thermodynamic model with certain deviations derived from the essence of the experiments performed. These experiments explain a frequent occurrence of natural slopes with a repose angle of around 30 ∘ . [ABSTRACT FROM AUTHOR]

In the last decade, advanced combustion techniques of the low-temperature combustion (LTC) family have attracted researchers because of their excellent emission characteristics; however, combustion control remains the main issue for the LTC modes. The objective of this study was to explore premixed charge compression ignition (PCCI) combustion mode using a double pilot injection (DPI; pilot-pilot-main) strategy to achieve superior combustion control and to tackle the soot-oxides of nitrogen (NOx) trade-off. Experiments were carried out in a single-cylinder research engine fueled with 20% v/v biodiesel blended with mineral diesel (B20) and 40% v/v biodiesel blended with mineral diesel (B40) vis-à-vis baseline mineral diesel. Engine speed and rate of fuel-mass injected were maintained constant at 1500 rpm and 0.6 kg/h mineral diesel equivalent, respectively. Pilot injection timings (at 45° and 35° before top dead center (bTDC)) and fuel quantities were fixed, while three fuel injection pressures (FIPs) and four different start of the main injection (SoMI) timings were investigated in this study. Results showed that multiple pilot injections resulted in a stable PCCI combustion mode, making it suitable for higher engine loads. For all test fuels, advancing SoMI timings led to relatively lesser knocking; however, engine performance characteristics degraded at advanced SoMI timings. B40 exhibited relatively superior engine performance among different test fuels at lower FIP; however, the difference in engine performance was insignificant at higher FIPs. Fuel injection parameters showed a significant effect on emissions, especially on the NOx and particulates. Advancing SoMI timing resulted in 20%–50% lower particulates emissions with a slight NOx increase; however, the differences in emissions at different SoMI timings reduced at higher FIPs. Somewhat higher particulates from biodiesel blends were a critical observation of this study, which was more dominant at advanced SoMI timings. Qualitative correlation between NOx-total particulate mass (TPM) was another critical analysis, which exhibited the relative importance of different fuel injection parameters for other alternative fuels. Overall, B20 at 700 bar FIP and 20° SoMI timing emerged as the most promising proposition with some penalty in CO emission. [ABSTRACT FROM AUTHOR]

The present paper reports the investigation of surface morphology, elemental composition, phase changes and field emission properties of Si ion irradiated nickel (Ni) and titanium (Ti). The Ni and Ti targets have been irradiated with 500 keV Si ions generated by Pelletron accelerator at various fluences ranging from 6.9 × 1013 to 77.1 × 1013 ions/cm2. Stopping range of ions in matter analysis revealed higher values of electronic stopping and sputtering yield for Ni as compared with Ti. For both irradiated metals, electronic energy loss dominant over the nuclear stopping. The growth of induced surface structures have been analysed by using field emission scanning electron microscopy (FESEM) analysis. In case of Ni, as the ion fluence increases from 6.9 × 1013 to 65.8 × 1013 ions/cm2, the formation of spherical particulates, agglomers and sputtering is observed. Although in the case of Ti, with the increase of Si ion fluence from 11.6 × 1013 to 77.1 × 1013 ions/cm2, the formation of irregular‐shaped particulates along with crater and sputtered channels is observed. X‐ray diffraction (XRD) analysis shows that no new phase is identified. However, a significant increase in peak intensity is observed with increasing ion fluence. The variation in crystallite size and dislocation line density is also observed as a function of Si ion fluence. Fourier transform infrared spectroscopy analysis shows that no bands are formed after the Si ion irradiation. Field emission properties of ion‐structured Ni and Ti are well correlated with the growth of surface structures observed by SEM and dislocation line density evaluated by XRD analysis. [ABSTRACT FROM AUTHOR]

Meeting cold-start emissions standards for particulate emissions and the criteria air pollutants, NO, CO and unburned hydrocarbons (HC), is critical for gasoline direct-injection spark-ignition (DISI) engines, including DISI engines in hybrid-electric powertrains. This work surveys recent strategies to reduce particulate mass (PM), particulate number (PN), NO, CO, and HC emissions during cold-start conditions. Results of studies that demonstrate progress using engine operating strategies (such as timing of fuel injection, spark-ignition, and valve events) and engine and after-treatment hardware development to mitigate and reduce cold-start engine-out and vehicle emissions are highlighted. Several methods are promising in terms of meeting more stringent cold-start emissions requirements, in particular, fuel injector design and operation have significant potential to reduce particulate emissions and advances in manufacturing can help reduce limitations from nozzle tip-wetting. Fast-heating of three-way catalysts also shows clear benefits, in addition to gasoline particulate filters to reduce vehicle PM and PN emissions. A clear challenge (and opportunity) is the dramatically larger parametric space for engine design and operation and the coupled interaction with after-treatment that should be considered to address cold-start emissions. Advances in modelling and physical experiments that allow more rapid development of DISI powertrain and after treatment systems are critical to meet future cold-start emissions requirements. [ABSTRACT FROM AUTHOR]

The current generation of Zero Emission Vehicle (ZEV) policies are designed to accelerate the transition away from conventional internal combustion engine (ICE) petrol and diesel vehicle fleets. However, the current focus on zero exhaust emissions and the lack of more detailed guidance regarding Non-Exhaust Emissions (NEEs) may mean that some of the trade-offs in transitioning to, e.g., Battery Electric Vehicle (BEV) fleets may be missed by many in the commercial sector. Here, as part of early work on the scoping of the First Bus EURO VI Diesel Vehicle (E6DV) to BEV fleet upgrades, we estimate E6DV total particulate emissions to be ca. 62–85 and 164–213 mg.veh − 1 .km − 1 for P M 2.5 and P M 10 , respectively, and that the majority, typically 93–97%, are NEEs. We also discuss the complex interaction between E6DV/BEV properties and estimate potential changes resulting from the transition to BEVs as ranging from a decrease of ca. 2–12% to an increase of ca. 12–50% depending on a combination of weight difference, regenerative brake performance and journey type. Finally, we propose metrics that would allow fleet operators more insight into a wider range of emission outcomes at the scoping stage of a fleet upgrade. [ABSTRACT FROM AUTHOR]

Background: In wildland–urban interface (WUI) fires, particulates from the combustion of both natural vegetative fuels and engineered cellulosic fuels may have deleterious effects on the environment. Aims: The research was conducted to investigate the morphology of the particulate samples generated from the combustion of oriented strand board (OSB). Findings were compared to the particulate samples collected from the combustion of noble-fir branches. Methods: The exposure conditions were varied to induce either smouldering combustion or flaming combustion of the specimens. Particulate samples were collected using thermophoretic sampling. Scanning electron microscopy (SEM) and subsequent image analysis were used to characterise particle sizes. Key results: The morphology of the generated particulates was influenced by the state of combustion for OSB as well as noble-fir branches. Conclusions: The combustion state resulted in differences in the particulate morphology for both OSB and noble-fir branches. More than 85% of the analysed particle diameters were less than 1000 nm in size collected from OSB specimens during smouldering combustion. Implications: The findings are the first step to better quantifying the morphology of particulates generated during WUI fire outbreaks. The experimental protocols and analysis methods presented may shed light on a problem that impacts human health in the WUI. In wildland–urban interface fires, particulates from combustion of natural vegetative and human-made fuels may have deleterious effects on the environment. Particulate samples were taken during both flaming combustion and smouldering combustion states. The morphology of the generated particulates is greatly influenced by the state of combustion for both fuels. (This paper is part of a Special Issue that includes papers on research presented at the IX International Conference on Forest Fire Research, Coimbra, Portugal, November 2022.) [ABSTRACT FROM AUTHOR]

Thermal spray coating is an industrial process in which molten metal is sprayed at high velocity onto a surface as a protective coating. An automated electric arc wire thermal spray coating aerosol generator and inhalation exposure system was developed to simulate an occupational exposure and, using this system, male Sprague–Dawley rats were exposed to stainless steel PMET720 aerosols at 25 mg/m3 × 4 h/day × 9 day. Lung injury, inflammation, and cytokine alteration were determined. Resolution was assessed by evaluating these parameters at 1, 7, 14 and 28 d after exposure. The aerosols generated were also collected and characterized. Macrophages were exposed in vitro over a wide dose range (0–200 µg/ml) to determine cytotoxicity and to screen for known mechanisms of toxicity. Welding fumes were used as comparative particulate controls. In vivo lung damage, inflammation and alteration in cytokines were observed 1 day post exposure and this response resolved by day 7. Alveolar macrophages retained the particulates even after 28 day post-exposure. In line with the pulmonary toxicity findings, in vitro cytotoxicity and membrane damage in macrophages were observed only at the higher doses. Electron paramagnetic resonance showed in an acellular environment the particulate generated free radicals and a dose-dependent increase in intracellular oxidative stress and NF-kB/AP-1 activity was observed. PMET720 particles were internalized via clathrin and caveolar mediated endocytosis as well as actin-dependent pinocytosis/phagocytosis. The results suggest that compared to stainless steel welding fumes, the PMET 720 aerosols were not as overtly toxic, and the animals recovered from the acute pulmonary injury by 7 days. [ABSTRACT FROM AUTHOR]