Search Results (103)

A one-year observation campaign from December 2020 to December 2021 was carried out in Jinan, a city that previously suffered from severe fine particulate matter (PM_2.5) pollution. The meteorological parameters and ambient concentrations of the air pollutants were recorded, and PM_2.5 samples were collected during the campaign. The inorganic chemical compositions of the PM_2.5 samples were measured, identifying 8 water-soluble ions (WSIs) and 15 trace metals. Pollution events, including 7 dust events (DEs) and 19 secondary inorganic events (SIEs), were identified and classified. The inorganic chemical compositions of the pollution events were characterized, summarized, and concluded. The low ratio of WSIs to PM_2.5, high concentrations of Ca²⁺ and Mg²⁺, and significant increases in trace metals were the dominant characteristics of PM_2.5 during DEs. The high concentrations of SO₄²⁻, NO₃⁻, and NH₄⁺; the high ratio of secondary ions to WSIs; and the high ratio of WSIs to PM_2.5 were the dominant characteristics of PM_2.5 during SIEs. Even though, recently, the PM_2.5 pollution in Jinan has not been as severe as pollution from a dozen years ago, it still exists, just at lower frequencies and pollution levels. This investigation provides the characteristics of PM_2.5 pollution under dramatically improved conditions and various ideas for the management and control of PM_2.5 pollution. Full article

The impact of PM_2.5 on the environment and human health has garnered significant attention. While research on PM_2.5 composition is increasing, fewer studies have focused on how dusty conditions in a special region affect the PM_2.5 composition. This region’s unique environmental conditions, characterized by frequent dust events, complicate air quality management. The study investigates the seasonal distribution of inorganic elements in the PM_2.5 under both dusty and non-dusty conditions through systematic sampling. Selective screening methods identified key pollutant elements, and a respiratory system model was developed to examine their diffusion and deposition patterns in the upper respiratory tract. Key findings reveal that inorganic element concentrations in the PM_2.5 follow consistent seasonal trends, with significantly higher levels during dust events compared to non-dusty periods. Crustal elements are dominated in the PM_2.5, but non-metallic elements (Cl, S) and metallic/quasi-metallic elements (Mn, Cd, Cr, As, Hg) are also prevalent, likely influenced by anthropogenic activities and industrial emissions. By PCA with human health assessments, six characteristic pollutants were identified: As, Co, Cd, Cr, V, and Mn. Simulations using COMSOL Multiphysics 6.2 software demonstrated distinct behaviors: As tends to concentrate in the posterior regions of the respiratory tract, while Co and Cd exhibit relatively uniform distributions, primarily affecting areas where airflow slows upstream. Cr, V, and Mn show dispersed and uniform patterns. Notably, even during dusty conditions, the concentration of the six pollutants remains relatively low in the different parts of the upper respiratory tract, suggesting minimal immediate health impacts. Our study provides valuable insights into the behavior of inorganic elements in the PM_2.5 and their potential health implications, highlighting the need for further research on the effects of dusty conditions on air quality and public health. Full article

Zinc sulphide is a widely used inorganic powder, and its production has reached quantities greater than 1000 t/year. Therefore, in accordance with OECD guideline 436, an acute inhalation test was implemented to provide more accurate data. This study is crucial for ensuring the safety of workers exposed to zinc sulphide dust and complying with regulatory requirements for REACH. Due to particle-specific properties, the maximum attainable concentration of zinc sulphide for an inhalation study was not certain. Two dry dispersion systems were used to aerosolize the zinc sulphide powder, and the generated aerosol was supplied to a nose-only inhalation exposure system. The results showed a maximum attainable concentration of 0.82 mg/L at an MMAD of 1.5 µm over a 4 h exposure. In the inhalation study, all six rats showed no specific symptoms and good health status and survived a post-exposure observation period of up to 14 days. From the results observed, the status of Not classified was derived according to CLP. Based on the experimental results, an LC50 was not determined but is considered to be higher than 0.82 mg/L (the maximum achievable aerosol concentration). These findings highlight the importance of documenting efforts to achieve aerosol conditions when concentrations required by OECD test guidelines cannot be reached. Full article

Basalt rock dust (RD) is a rock quarry byproduct that may improve soil health in organic farming systems. RD was applied at two contrasting organic farms (the no-till VT-Farm in Thetford, Vermont, and the tilled MA-Farm in Barre, Massachusetts) and in soil batch reactors to investigate the impacts of basalt RD applications (6.7 tons ha⁻¹) on physical and chemical soil health properties. Triplicate soil pits at two fields (RD and no RD) at each farm were sampled down between 80 to 110 cm depths in 2020. Median coarse (>2 mm) and very coarse aggregates (>50 mm) increased by 15% to 25%, and soil organic carbon concentrations increased by 69% to 135% for RD added, compared to no RD, in the top 20 cm of the soil profile at both farms. Plant-available Ca, Mg, and K increased between 62% and 252% in the top 30 cm for both farms. Plant-available micronutrients (B, Mn, Cu, and Zn) showed limited increases from the RD addition at the two farms. The laboratory batch reactor results confirm the increased Ca and Mg release rates tested across soils, but K, P, and the micronutrient batch reactor results did not increase from the RD addition. One contrary finding was (−41% at the VT-Farm) the lower plant-available P and soluble P (−5 to −29%) under the RD addition, suggesting that further studies on the interactions with Fe and pH from the RD addition are warranted. Full article

Sand media filters are especially recommended to prevent emitter clogging with loaded irrigation waters, but their performances rely on backwashing. Despite backwashing being a basic procedure needed to restore the initial filtration capacity, there is a lack of information about the solid removal efficiency along the media bed depth. An experimental filter with a 200 mm silica sand bed height was used to assess the effect of two operation velocities (30/45 and 60/75 (filtration/backwashing) m h⁻¹) and two clogging particles (inorganic sand dust and organic from a reclaimed effluent) on the efficiency of backwashing for removing the total suspended solids retained in different media bed slices. The average solid removal backwashing efficiency was greater with organic particles (78%) than with inorganic ones (64%), reaching its maximum at a 5–15 mm bed depth. A higher operation velocity increased the solid removal efficiency by 16%, using organic particles, but no significant differences were observed with inorganic particles. The removal efficiencies across the media bed were more uniform with organic particles (63–89%) than with inorganic (40–85%), which makes it not advisable to reduce the media height when reclaimed effluents are used. This study may contribute to future improvements in sand media filter design and management. Full article

Despite extensive research on particulate matter (PM) pollution in India’s Indo-Gangetic Plain (IGP), source apportionment remains challenging. This study investigates the effect of particulate matter (PM₁₀)-associated water soluble inorganic ions (WSIIs) on ambient air concentration across the middle IGP from January to December 2018. Moreover, the seasonal fluctuation and chemical characterization of PM₁₀ were assessed for the year 2018. The results revealed a high concentration of PM₁₀ (156 µg/m³), exceeding the WHO and National Ambient Air Quality Standard (NAAQS) limits. The highest PM₁₀ levels were observed during autumn, winter, summer, and the rainy season. The study identified SO₄²⁻ and NH₄⁺ as the most common WSIIs, constituting 46% and 23% of the total WSIIs. Source apportionment analysis indicated that street dust, biomass burning, and vehicle and industrial emissions together with secondary formation significantly contributed to IGP’s PM pollution. Additionally, the investigation of air mass back trajectory suggests that air quality in IGP is largely influenced by eastern and western Maritime air masses originated from the Arabian Sea, the Bay of Bengal, Gujarat, Afghanistan, Pakistan, and Bangladesh. Full article

In the last few years, an increasing interest has developed regarding the application of different techniques for the identification of pollutants inside the tissues deriving from patients affected by benign or neoplastic diseases. Particular attention was paid to neoplasia linked to particular exposures, e.g., heavy metals, carbon dusts, silica, asbestos. As regards the last pollutant, a wide body of scientific literature has been collected, considering the severe effects caused by mineral fibers on human health. Optical and electronic microscopies were widely applied to identify the fibers in respiratory and extra-respiratory organs to detect the minerals and to link their presence to an exposure source and to understand their role in cancer development. The main advantage of electron microscopy lies in the possibility of coupling the microscopes with energy dispersive spectrometers and also collecting data on the elemental composition of various inorganic phases. In term of sample preparation and time of analysis, the most utilized microscope technique is Scanning Electron Microscopy with an annexed energy dispersive spectrometer (SEM/EDS), allowing for the morphological and chemical characterization of the observed particles/fibers. Moreover, this technique is envisaged by Italian Law for asbestos identification in air and bulk samples. On the other hand, this technique does not allow a reliable identification of the mineral phase in the case of polymorphs with the same chemical formula but different crystal structures. In this work, the coupling of a spectroscopical technique—micro-Raman spectroscopy—to SEM/EDS is proposed for a sure phase identification of particles, showing EDS spectra with ambiguous phase identification, observed in samples of tissues from patients affected by colorectal cancer and living in an asbestos-polluted area. In these tissues, different particles with EDS spectra that do not allow a sure identification of the phase—in particular calcium-rich particles and titanium oxides—were successively analyzed by micro-Raman spectroscopy. Thanks to this last technique, it was possible to ascribe the mineral phases associated to these particles to “aragonite” (a calcium carbonate polymorph) and to “anatase” (a Ti dioxide polymorph). Full article

Ventilation may lead to a deterioration in indoor air quality in urban environments located close to roads. Understanding the differences in the chemical compositions of size-resolved particulate matter (PM) in indoor air and outdoor air could aid in assessing the health impacts of air in these settings and establishing relevant regulation policies. In this study, indoor and outdoor size-resolved PM was collected from an office in Beijing in summer (between 5 and 25 July 2020) and winter (between 5 and 31 January 2021). Its chemical components, including sulfate, nitrate, ammonium, chlorine, organic matter (OM), elemental carbon (EC), crustal materials (CM), and heavy metals (HM), were analyzed. The mean levels of indoor and outdoor PM_2.1 and PM₉ were found to be much higher than those in the guidelines for PM_2.5 and PM₁₀ outlined by the National Ambient Air Quality Standard. Moreover, the levels of PM_2.1 and PM_2.1–9 mass were higher outdoors than they were indoors. The size distributions of mass concentrations were shown to be bimodal, peaking at 0.43–0.65 μm and 4.7–5.8 μm, respectively. The most abundant chemicals were OM, nitrate, and sulfate for PM_2.1 and OM, CM, and nitrate for PM_2.1–9. We found higher percentages of sulfate, nitrate, ammonium, EC, and HM in smaller-size fractions of PM. Additionally, positive matrix factorization showed that biomass burning, secondary inorganic aerosol, coal combustion, dust, traffic, and industrial pollution were the main sources of PM during the study period. The greatest non-carcinogenic and carcinogenic hazards were found at 0.43–0.65 μm in summer and 2.1–3.3 μm in winter. Our results indicate that size-resolved PM of ambient origin may infiltrate buildings near roads to varying degrees, resulting in negative health effects. Full article

Since 2016, the Ministry of Ecology and Environment and the Beijing Municipal Government have adjusted the minimum concentration limit for ambient air dustfall several times, indicating that they attach great importance to dustfall. To grasp the pollution characteristics and sources of dustfall, in this work, the filtration method was used to determine the insoluble dustfall and water-soluble dustfall in the urban area of Beijing. From our analysis, the influence of the meteorological parameters on dustfall was found, and the chemical components of dustfall were determined. The positive matrix factorization (PMF) model was also utilized to analyze the sources of dustfall. The results indicated that the average amount of dustfall in 2021–2022 was 4.4 t·(km²·30 d)⁻¹, and the proportion of insoluble dustfall deposition was 82.4%. Dustfall was positively correlated with the average wind speed and temperature and negatively correlated with the relative humidity and rain precipitation. The impact of the meteorological parameters on insoluble dustfall and water-soluble dustfall was the opposite. The average proportions of crustal material, ions, organic matter, element carbon, trace elements, and unknown components were 48%, 16%, 14%, 1.4%, 0.20%, and 20%, respectively. The proportions of the crustal material and ions were the highest in spring (57%) and summer (37%). The contribution rates of fugitive dust source, secondary inorganic source, mobile source, coal combustion source, snow melting agent source, and other sources were 42.4%, 19.3%, 8.3%, 3.0%, 2.7%, and 24.3%, respectively. This study supported dustfall pollution control by analysing the pollutant characteristics and sources of dustfall from the standpoint of total chemical components. In order to better control dustfall pollution, control measures and evaluation standards for fugitive dust pollution should be formulated. Full article

Raman spectroscopy is a non-destructive analytical technique for characterizing organic and inorganic materials with spatial resolution in the micrometer range. This makes it a method of choice for space-mission sample characterization, whether on return or in situ. To enhance its sensitivity, we use signal amplification via interaction with plasmonic silver-based colloids, which corresponds to surface-enhanced Raman scattering (SERS). In this study, we focus on the analysis of biomolecules of prebiotic interest on extraterrestrial dust trapped in silica aerogel, jointly with the Japanese Tanpopo mission. The aim is twofold: to prepare samples as close as possible to the real ones, and to optimize analysis by SERS for this specific context. Serpentinite was chosen as the inorganic matrix and adenine as the target biomolecule. The dust was projected at high velocity into the trapping aerogel and then mechanically extracted. A quantitative study shows effective detection even for adenine doping from a 5·10⁻⁹mol/L solution. After the dust has been expelled from the aerogel using a solvent, SERS mapping enables unambiguous adenine detection over the entire dust surface. This study shows the potential of SERS as a key technique not only for return samples, but also for upcoming new explorations. Full article

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. Full article

The Mediterranean Basin is involved in a recurring phenomenon wherein air masses laden with dust from North Africa impact the southern regions of the European continent. Saharan dust has been associated with increased mortality and respiratory symptoms. Palermo is a large coastal city, and in addition to the impact of desert dust particles, it has a mixture of anthropogenic sources of pollutants. In this study, we collected Saharan dust samples during August 2022 and October 2023, following a high-intensity Saharan dust event, and measured concentrations of 33 major and trace elements as well as Rare Earth Elements (REE). The mineralogical characterization of the deposition dust collected during Saharan events revealed calcite, dolomite, quartz, and clay minerals. The presence of palygorskite is indicative of Saharan events. Seven elements (Ca, Mg, Al, Ti, Fe, K, and Na) account for 98% of the total analyzed inorganic burden. Elemental ratios are valuable tools in atmospheric sciences for estimating sources of air masses. The results highlight that the city of Palermo is mainly affected by dust from the north-western Sahara. Full article

Photovoltaic (PV) power generation is a clean energy source, and the accumulation of ash on the surface of PV panels can lead to power loss. For polycrystalline PV panels, self-cleaning film is an economical and excellent solution. However, the main reasons why self-cleaning coatings are currently difficult to use on a large scale are poor durability and low transparency. It is a challenge to improve the durability and transparency of self-cleaning thin films for PV panel surface against ash accumulation. Therefore, in this paper, a resin composite film containing modified silica components was designed and synthesized, mainly by the organic/inorganic composite method. A transparent hydrophobic coating with nano-micro planar structures was constructed, which primarily relies on the hydrophobic properties of the compound itself to build the hydrophobic oleophobic coating. The layer has a micrometer-scale smooth surface structure and high transparency, with a 0.69% increase in light transmittance compared with uncoated glass, and the durability is good. It is mainly applied to the surface of photovoltaic devices, which can alleviate the dust accumulation problem of photovoltaic panels in arid, high-temperature, and dusty areas and reduce the maintenance cost of them. Full article

The sustainable development of products is of great interest to both industry and consumers due to various factors, such as anthropogenic climate change and the scarcity of resources and materials. In response to this, the simul⁺ Living Lab Sustainable Additive Manufacturing in Saxony (SAMSax) has been established as a physical experimental space aimed at improving the sustainability of products. This includes selecting resource-efficient manufacturing processes, using renewable materials, reducing energy consumption during use, and designing for recyclability. The innovative approach of the lab also integrates an open innovation process, involving present and potential stakeholders. Collaborating closely with stakeholders from industry, academia, and government fosters idea generation, provides solution approaches, and enhances acceptance and practical implementation. Methodologically, SAMSax focuses on upcycling organic and inorganic residues as well as by-products from industry and agriculture, reintegrating them as innovative components in industrial production using additive manufacturing (“3D printing”). The Living Lab provides a space for networking and active knowledge transfer through digital technologies, analyses, and collaborative developments, enabling the testing and evaluation of innovations in a real-world environment. Several potential waste materials suitable for additive manufacturing and new products have already been identified. In addition to industrial residues, materials, such as paper and wood dust; industrial by-products, such as sand; and agricultural residues, like harvest residues, are being analyzed, processed, and tested using additive manufacturing in the laboratory. In this way, SAMSax can contribute to an integrated and consistent circular economy. The research aims to demonstrate that the SAMSax Living Lab is a crucial driver of innovation in the field of additive manufacturing. Furthermore, this study contributes by presenting the Living Lab as an application-oriented research environment, focusing on innovative implementation in small- and medium-sized enterprises. Full article

Despite significant improvements in air quality during and after COVID-19 restrictions, haze continued to occur in Zhengzhou afterwards. This paper compares ionic compositions and sources of PM_2.5 before (2019), during (2020), and after (2021) the restrictions to explore the reasons for the haze. The average concentration of PM_2.5 decreased by 28.5% in 2020 and 27.9% in 2021, respectively, from 102.49 μg m⁻³ in 2019. The concentration of secondary inorganic aerosols (SIAs) was 51.87 μg m⁻³ in 2019, which decreased by 3.1% in 2020 and 12.8% in 2021. In contrast, the contributions of SIAs to PM_2.5 increased from 50.61% (2019) to 68.6% (2020) and 61.2% (2021). SIAs contributed significantly to PM_2.5 levels in 2020–2021. Despite a 22~62% decline in NO_x levels in 2020–2021, the increased O₃ caused a similar NO₃⁻ concentration (20.69~23.00 μg m⁻³) in 2020–2021 to that (22.93 μg m⁻³) in 2019, hindering PM_2.5 reduction in Zhengzhou. Six PM_2.5 sources, including secondary inorganic aerosols, industrial emissions, coal combustion, biomass burning, soil dust, and traffic emissions, were identified by the positive matrix factorization model in 2019–2021. Compared to 2019, the reduction in PM_2.5 from the secondary aerosol source in 2020 and 2021 was small, and the contribution of secondary aerosol to PM_2.5 increased by 13.32% in 2020 and 12.94% in 2021. In comparison, the primary emissions, including biomass burning, traffic, and dust, were reduced by 29.71% in 2020 and 27.7% in 2021. The results indicated that the secondary production did not significantly contribute to the PM_2.5 decrease during and after the COVID-19 restrictions. Therefore, it is essential to understand the formation of secondary aerosols under high O₃ and low precursor gases to mitigate air pollution in the future. Full article