Lithography Research Articles

Sustainable Lithography Paradigm Enabled by Mechanically Peelable Resists.

Lithography is critical in micro- and nanofabrication processes, enabling the development of integrated circuits, semiconductor devices, and various advanced electronic and photonic systems. However, there are challenges related to sustainability, efficiency, and yield, as well as compatibility with transient electronics. This work introduces a sustainable lithography paradigm employing mechanically peelable resists compatible with existing cleanroom processes. The resists exhibit near-zero adhesion to various substrates, facilitating efficient, cost-effective, environmentally friendly, and chemical-free mechanical stripping without observable particulate residues. The mechanical lift-off process enables scalable and 100%-yield pattern transfer using commercially available tape within seconds. Furthermore, the new paradigm supports distributed and in situ conformal manufacturing using the peelable resist as a "transferable stencil mask" to fabricate various functional devices on flexible and nonplanar surfaces, as well as ultra-thin biodegradable substrates. Overall, this work expands the potential for using lift-off as a standard process in the pan-semiconductor industry and opens new avenues for lithographic procedures aimed at the reliable mass production of transient electronics and integrated biodegradable devices, addressing growing sustainability issues caused by electronic waste.

A spatial transfer-based hybrid model for wind speed forecasting

Accurate wind speed forecasting is essential for optimizing energy dispatch and enhancing grid stability. This study presents a novel hybrid wind speed forecasting model (WSDTW-CLA), emphasizing the spatial transfer characteristics of wind speed while mitigating the inherent errors in existing models. The proposed method employs the Wind Speed Dynamic Time Warping (WSDTW) algorithm to align wind speed data from neighboring stations, effectively facilitating the capture of spatial transfer patterns during the preprocessing phase. This alignment generates a wind speed spatial matrix that incorporates future-relevant information, providing precise input for forecasting module. The model employs a hybrid neural network combining a convolutional neural network (CNN), a long short-term memory (LSTM) network, and an autoencoder (AE) to predict wind speeds by establishing feature connections from the preprocessed data. The performance of the WSDTW-CLA model is evaluated using seasonal datasets from March, June, September, and December in Yunnan Province, China. A multi-step comparative analysis involving seven established models and seven sub-models within the proposed framework demonstrates that the WSDTW-CLA model significantly outperforms other similar models, with all evaluation metrics showing improvements of over 30 %. This proposed method enhances the utilization of wind energy resources, thereby promoting the advancement of the wind power industry.

Poly acrylic acid patterning by electron beam lithography

Poly acrylic acid (PAA) is a polymer and a derivative of acrylic acid that is a superabsorbent, being able to absorb and retain water, and swell many times beyond its original volume. This property classifies it into a group of polymers called hydrogels. Hydrogels are being investigated in emerging applications such as drug delivery, biosensors, tissue engineering, wound healing bandages, and more. The ability to lithographically pattern hydrogel materials to specific dimensions at the micro and nanoscales can be very useful in devices and sensors. Limited work has been done on characterizing PAA for lithographic purposes, and so, this work investigates the ability to pattern PAA by electron beam lithography (EBL). PAA is interesting in that its carrier solvent, developer, and remover are all water alone, which may make it attractive for processes or materials that cannot tolerate solvents, acids, and bases used with other common EBL resists. PAA behaves as a negative tone resist with a relatively low base dose of 75 μC/cm2 at 100 kV acceleration voltage. The resolution is limited to 1.8 μm due to a low contrast of 1.29. However, PAA may still have many uses at that resolution where the positioning and dimension control of a hydrogel could be useful. Furthermore, PAA can successfully be used for pattern transfer with either a metal liftoff process or a silicon plasma etch.

Ecological compensation based on multiscale ecosystem carbon sequestration service flow

Scientific assessments of the supply, demand and flow of ecosystem services and the formulation of ecological compensation policies are important for the promotion of sustainable regional development. Based on the supply–demand ratio model, breakpoint model, field strength model, geographic information system spatial analysis and statistical methods, we assessed the supply, demand and supply–demand relationships of carbon sequestration services on the Loess Plateau for 2000, 2010 and 2020. We also analyzed the interregional flow of carbon sequestration services at multiple scales and accounted for horizontal ecological compensation. The results revealed that from 2000 to 2020, both the supply and demand of carbon sequestration services increased, with a greater increase in demand. The high-supply areas were mostly in the central and northwestern parts of the Loess Plateau, and the high-demand areas were mostly in areas other than the central part. The supply–demand ratio for carbon sequestration services declined, with a large increase in the number of deficit counties and surplus counties, mostly in the central and western parts of the study area. The flow rates of carbon sequestration services within the Loess Plateau increased. The intercounty flow rates within the same city were the highest but decreased. Decreasing intercity flow rates appeared within the same province although they initially increased. Finally, interprovincial flow rates were the lowest, but they were increasing. The outflow of carbon sequestration services from the Loess Plateau to external regions was greater than the inflow from external regions, but the outflow decreased in 2020 compared with 2010, while the inflow from external regions increased. Most cities actually received or paid less ecological compensation than that accounted for based on the basis of flow rates after considering willingness to pay and ability to pay. Moreover, the number and total compensation of cities receiving ecological compensation were greater than the number and total compensation of payers in the 44 cities within the Loess Plateau. This study provides a theoretical basis for not only understanding the spatial transfer patterns of ecosystem services at multiple scales but also formulating ecological compensation policies, thereby promoting the realization of regional sustainable development.

Numerical study on flow pattern transition, liquid film and heat transfer for R1233zd/FC72 mixtures across tube bundles

The non-azeotropic mixtures phase-change flow across tube bundles is widely used in the refrigeration industry. A simulation model of R1233zd/FC72 mixtures is presented to study flow pattern transition and heat transfer across tube bundles. Volume of Fluid (VOF) model is used to determine the flow pattern. An experiment is conducted to validate the simulation model with average deviation of 8.97%. The results showed that the flow pattern transition appears for various conditions. In addition, the liquid film thickness and heat transfer are analyzed, focusing particularly on the impact of various mixture components. With increasing vapor quality, the flow pattern transfers from sheet flow to semi-annular flow and then to droplet flow. Sheet to semi-annular flow transition occurs for a vapor quality of 0.4–0.6, and semi-annular flow transfers to droplet flow for a vapor quality of 0.7–0.8. For sheet flow, the local heat transfer coefficient on the tube surface is the highest at 90° (circumferential angle) from the summit point of the cross-sectional tube circle due to the thinnest liquid film. The liquid film turns thinner with increasing mass fraction of R1233zd and vapor quality. Increasing the mass fraction of R1233zd and vapor quality promotes heat transfer. However, the flow pattern transfers from sheet flow to the other ones, the heat transfer coefficient starts to decrease. The heat transfer coefficient is the highest for a vapor quality of around 0.4–0.5 and a mass fraction of R1233zd of around 0.7–0.9.

Heat Transfer Enhancement in Pulsating Flows: A Bayesian Approach to Experimental Correlations

Abstract This research focuses on improving the modeling of heat transfer effects in pulsating exhaust flows. We address the challenges of understanding oscillating flow by employing the Metropolis–Hastings Markov Chain Monte Carlo sampling method for parameter estimation, accounting for measurement uncertainties. The knowledge can be applied to waste heat from reciprocating devices, pulsating turbocharger performance, and flow fields with significant cyclic variations. We demonstrate the feasibility of characterizing heat transfer capacity in pulsating flows using Bayesian inference and polynomial regression for experimental data correlation. This methodology is furthermore applied to identify heat transfer patterns in cold gas flow through a heated pipe across a range of mass flowrates and pulsating frequencies. To achieve this, the thermal performance variations across the length of the pipe through temperature and pressure changes are quantified. The model developed exhibits robust performance and high data efficiency (R2∈[0.83,0.89]) and notable extrapolation capacity in predicting mean heat transfer behavior based on boundary measurements. The results address the lack of experimental insights into pulsating flows encountered in heavy-duty transport applications and can be extended for heat recovery in systems such as exhaust manifolds and organic Rankine cycle gas turbines.

The influence of lymphatic vessels on nanoparticle distribution and heat transfer within tissue

AbstractThis study analytically investigates the dynamics of nanoparticle transport within a three‐dimensional porous cylinder simulating a lymphatic vessel, without external heat sources. The governing equations and boundary conditions are transformed to yield a system of ordinary differential equations, which are solved numerically using MATLAB built‐in function, bvp4c. Key parameters are visually examined and physically interpreted in relation to temperature, velocity, concentration, and Nusselt number profiles. The study reveals that the distribution of temperature and Nusselt number are maximized by increasing the heat transfer coefficient, whereas NP concentration is increased by decreasing it. Furthermore, the Brownian motion parameter enhances both heat transmission and NP concentration. It is also observed that simpler extravasation into lymphatics decreases tissue nanoparticle levels and heat conduction. Ultimately, optimal intra‐lymphatic nanoparticle distribution pathways are achieved by specifically varying heat transfer and interstitial mass flux patterns. By simulating biological barriers and lymphatic drainage, this model enhances our understanding of the underlying transport mechanisms controlling nanoparticle mobilization.

Potential conflict diagnosis, simulation optimization and coordination of production-living-ecological space in gully areas of the Loess Plateau, China

The gully areas on the Loess Plateau have always been ecologically fragile agricultural areas. These areas often face the common problem of intensified conflicts in production-living-ecological space during economic development, and there is an urgent need for systematic spatial governance. This study innovatively developed a full process technical framework of “identification diagnosis - simulation optimization - coordinated governance” for potential conflicts in the production-living-ecological space, and used Huachi County in the gully area of the Loess Plateau as an example for empirical research. Under this framework, we analyzed the transfer patterns of production, living, and ecological space in the research area; Improved the spatial suitability evaluation index system of “multi-dimensional + multi-objective”; The conflict determination matrix was used to identify the scope, scale, type, and intensity of potential spatial conflicts; We conducted spatial optimization simulations under two scenarios: prioritizing ecological protection and prioritizing social and livelihood development, and designed an overall spatial optimization plan; Propose spatial collaborative governance strategies based on the theory of public space governance. Research shows that this framework has good applicability for the research area and is more direct for guiding subsequent spatial planning and policy practice. The potential conflict between production space and ecological space in Huachi County is the most common, the potential conflict intensity between living space and production space is the largest, and the potential conflict risk between living space and ecological space is rising. To coordinate potential conflicts in space, it is necessary to establish a vertical allocation type of spatial function coordination chain of “goal + collaboration + adjustment”, as well as a horizontal negotiation type of spatial configuration coordination chain of “allocation + cooperation + balance”, forming a “double vertical and double horizontal” spatial coordination framework.

In-situ fabricated hexagonal PDMS microsphere arrays for substrate-mode light extraction in blue fluorescent organic light emitting diodes

To inhibit the total reflection in the substrate-mode light loss of organic light-emitting diodes (OLEDs) and fully take advantage of the excellent light converging and out-coupling effect of the hexagonal array of microsphere, we in-situ fabricated the hexagonal array of polydimethylsiloxane (PDMS) microsphere onto the substrate of OLEDs via the porous template for substrate-mode light extraction. Firstly, regular honeycomb porous polystyrene (PS) template was prepared via a self-assembly “breath figure” process. The PS molecular weight, solvent, and humidity play an important role on the uniformity of pore distribution and pore diameter according to Young-Laplace equation. Based on the optimized porous PS template, the PDMS microsphere array was fabricated by pattern transferring, which indicates more prominent light diffraction than the flat PDMS film. Finite-difference time-domain (FDTD) simulation denotes that higher duty ratio of the PDMS microsphere array contributes to higher light out-coupling efficiency. Therefore, a PDMS microsphere array with larger duty ratio of 84.0 % was applied in the extraction of external light for the blue fluorescent OLED device. The maximum luminance, current efficiency, and power efficiency are all improved, and the external quantum efficiency (EQE) is increased by 18.81 % with spectral stability.

The Prohibition of Forestation on Cultivated Land in China: A Difference-in-Differences Model Analysis of the Effects of Cutting Down Trees on Farmland Transfer

The implementation of China’s stringent farmland protection policy has resulted in the compulsory removal of trees from farmland, which has significantly impacted farmers’ willingness to transfer their land. To explain the impact of cutting trees on farmers’ land transfer, this study conducted a two-way fixed-effect difference-in-differences (DID) model based on a survey of 163 households in Daxiapo Village in China during 2020–2023. The results show that cutting trees significantly promotes farmland transfer among farmers. Moreover, the promotion effect of cutting trees is more pronounced when transferring land in than it is when transferring land out. For land plots with poor accessibility and fertility, the effects of transferring land out are more significant than for plots that are fertile and conveniently located. As a result, the prohibition of forestation on farmland has increased the contiguity of some land plots and improved the spatial configuration of farmland, but land fragmentation is still prominent on land owned by large-scale farmers. Therefore, this paper proposes two optimization scenarios to address the issue of farmland fragmentation and compares the feasibility of these plans in the short and long term. This paper suggests that short-term policies prohibiting forestation can trigger abrupt changes in farmland transfer patterns and drive further changes in the spatial configuration of farmland. Though some large-scale farming households were established through land transfer, the problem of plot fragmentation must be solved. This article presents several possible scenarios to aid in the design of more systematic policy systems to balance the protection of cultivated land, farmers’ willingness, and the spatial contiguity of cultivated land.

Genomic evolution and patterns of horizontal gene transfer in Papilio

The Papilio genus, known for its ecological and phenotypic diversity, is a valuable model for evolutionary studies. This study conducted a comparative genomic analysis of 11 Papilio species, revealing species-specific gene family expansions, including the UDP-glucosyltransferase 2 gene associated with insect detoxification, particularly expanding in Papilio polyxenes. Our analysis also revealed 199 horizontal gene transfer (HGT) acquired genes from 76 microbial species, with Pseudomonadota and Bacillota as common HGT donors across these genomes. Furthermore, we examined the evolutionary patterns of nine ABC transporter subfamilies, uncovering potential links between gene family evolution and environmental adaptation. This study provides new insights into evolutionary relationships and genomic adaptations within the Papilio genus, contributing to broader butterfly evolutionary research.

Travel Distances for Interhospital Transfers of Critically Ill Children: A Geospatial Analysis.

The U.S. pediatric acute care system has become more centralized, placing increasing importance on interhospital transfers. We conducted a geospatial analysis of critically ill children undergoing interfacility transfer with a specific focus on understanding travel distances between the patient's residence and the hospitals in which they receive care. Retrospective geospatial analysis using five U.S. state-level administrative databases; four states observed from 2016 to 2019 and one state from 2018 to 2019. Participants included 10,665 children who experienced 11,713 episodes of critical illness involving transfer between two hospitals. Travel distances and the incidence of "potentially suboptimal triage," in which patients were transferred to a second hospital less than five miles further from their residence than the first hospital. Patients typically present to hospitals near their residence (median distance from residence to first hospital, 4.2 miles; interquartile range [IQR], 1.8-9.6 miles). Transfer distances are relatively large (median distance between hospitals, 28.9 miles; IQR, 11.2-53.2 miles), taking patients relatively far away from their residences (median distance from residence to second hospital, 30.1 miles; IQR, 12.2-54.9 miles). Potentially suboptimal triage was frequent: 24.2 percent of patients were transferred to a hospital less than five miles further away from their residence than the first hospital. Potentially suboptimal triage was most common in children living in urban counties, and became less common with increasing medical complexity. The current pediatric critical care system is organized in a hub-and-spoke model, which requires large travel distances for some patients. Some transfers might be prevented by more efficient prehospital triage. Current transfer patterns suggest the choice of initial hospital is influenced by geography as well as by attempts to match hospital resources with perceived patient needs.

Grayscale Lithography and a Brief Introduction to Other Widely Used Lithographic Methods: A State-of-the-Art Review.

Lithography serves as a fundamental process in the realms of microfabrication and nanotechnology, facilitating the transfer of intricate patterns onto a substrate, typically in the form of a wafer or a flat surface. Grayscale lithography (GSL) is highly valued in precision manufacturing and research endeavors because of its unique capacity to create intricate and customizable patterns with varying depths and intensities. Unlike traditional binary lithography, which produces discrete on/off features, GSL offers a spectrum of exposure levels. This enables the production of complex microstructures, diffractive optical elements, 3D micro-optics, and other nanoscale designs with smooth gradients and intricate surface profiles. GSL plays a crucial role in sectors such as microelectronics, micro-optics, MEMS/NEMS manufacturing, and photonics, where precise control over feature depth, shape, and intensity is critical for achieving advanced functionality. Its versatility and capacity to generate tailored structures make GSL an indispensable tool in various cutting-edge applications. This review will delve into several lithographic techniques, with a particular emphasis on masked and maskless GSL methods. As these technologies continue to evolve, the future of 3D micro- and nanostructure manufacturing will undoubtedly assume even greater significance in various applications.

Ecological effects of land use and land cover change in the typical ecological functional zones of Egypt

Evaluation the value of ecosystem services can provide crucial reference for formulating ecological protection plans and making informed management decision. This study utilized Landsat remote sensing images as the data source and employed land-use transfer chains and land use transfer matrix methods to compare the ecological effects of land use and land cover change(LUCC) in the two typical ecological functional zones of Egypt, one area isthe northern region of Egypt with the Priority function of Economic Development, another area is the Nasser Reservoir area with the priority function of water conservation. The key findings are as follows: (1)The northern region of Egypt and the Nasser Reservoir exhibited different trends across the ecological functional zones.From 1985 to 2020, the northern region of Egypt is characterized by an increase in arable land and impervious surface,the Nasser Reservoir area is distinguished by the expansion of water and a reduction in sand.(2) Key land transfer patterns vary significantly between the ecological functional zones of the northern region of Egypt and the Nasser Reservoir. From 1985 to 2020, the Egypt’s northern region experienced significant shifts between arable land, sand, and impervious surfaces. The conversion of arable land to impervious surfaces represented 2.41% of the total arable land transfer area, while sand converted to impervious surfaces accounted for 11.68% of the total sand transfer area. In the Nasser Reservoir region, significant conversions occurred between water, grasslands, and sand. Sand converted to water made up 3.83% of the total sand transfer area, while grassland converted to water compriseed 5.38% of the total grassland transfer area. (3) The ecological benefits of the northern region of Egypt and the Nasser Reservoir have increased significantly. In northern region of Egypt, the primary drivers of this increase in ecological service value are the conversion of arable land and grasslands, along with the ecological development and utilization of sand. In the Nasser Reservoir area,the inflow of water and the continued outflow of sands are the main factors contributing to the rise in ecosystem service value. (4) Differentiated LUCC management should be implemented for different ecological functional zones. In northern region of Egypt, the focus should be on balancing ecological security with human development, while the Nasser Reservoir area should prioritize water resource protection and sustainable development. The research findings are not only significant for optimizing LUCC but also for enhancing ecosystem service functions in Egypt.

Scalable fabrication approach and fill factor optimization for single pixel microlens arrays

Microlenses are a suitable approach to improve the performance of optical systems. An important optical efficiency determining parameter is the fill factor, which describes the relation of the lens area to the total optical active area. In this work, an optimization of the fill factor by optimizing the fabrication process steps is presented. The approach here is the use of i-line waferstepper lithography in combination with thermal reflow of photoresist and subsequent 1:1 pattern transfer in the lens material by reactive ion etching. For this method, the fill factor is determined by the minimum lens gap and, thus, the optical efficiency is strongly limited by the resolution limit of the i-line waferstepper lithography (350 nm). The goal of this investigation is to achieve the lowest possible lens gap even below the stepper-based resolution limit by optimizing each single process step without developing a new approach. The final result of the optimization was a fill factor improvement of 15%.

Maternal gastrointestinal microbiome shapes gut microbial function and resistome of newborns in a cow-to-calf model

BackgroundThe maternal gut microbiome is the direct and important source of early colonization and development of the neonatal gut microbiome. However, differences in unique and shared features between mothers with different physiological phenotypes and their newborns still lack exhaustive investigation. Here, using a cow-to-calf model, a comprehensive investigation was conducted to elucidate the pattern and characterization of microbial transfer from the maternal source to the offspring.ResultsThe microbiota in the rumen and feces of dairy cows were divided into two clusters via enterotype analysis. The cows from the enterotype distinguished by Prevotella in the rumen had better production performance, whereas no difference was observed in the cows classified by feces enterotype. Furthermore, through a pairwise combination of fecal and ruminal enterotypes, we screened a group of dairy cows with excellent phenotypes. The gastrointestinal microbiomes of cows with different phenotypes and their offspring differed significantly. The rumen was a more important microbial source for meconium than feces. Transmission of beneficial bacteria from mother to offspring was observed. Additionally, the meconium inherits advantageous metabolic functions of the rumen. The resistome features of the rumen, feces, and meconium were consistent, and resistome abundance from cows to calves showed an expanding trend. The interaction between antibiotic-resistance genes and mobile genetic elements from the rumen to meconium was the most remarkable. The diversity of core metabolites from cows to calves was stable and not affected by differences in phenotypes. However, the abundance of specific metabolites varied greatly.ConclusionsOur study demonstrates the microbial taxa, metabolic function, and resistome characteristics of maternal and neonatal microbiomes, and reveals the potential vertical transmission of the microbiome from a cow-to-calf model. These findings provide new insights into the transgenerational transmission pattern of the microbiome.2cueHjjtpyRzwmAWUdZ5oAVideo

Practice Patterns Vary Widely in the Care of Pediatric and Adolescent Pelvic and Acetabular Fractures: A CORTICES Survey.

Pediatric pelvic and acetabular fractures are rare but potentially devastating injuries and significant management variation exists across the United States. This study sought to elucidate treatment decision-making trends, involvement of adult trauma fellowship-trained surgeons in pediatric care, and pre- and postoperative transfer patterns. Pediatric orthopaedic surgeons who serve as trauma liaisons at 20 PTCs were surveyed regarding training, practice volume, and factors contributing to institutional management of pelvic and acetabular injuries. Five clinical scenarios of pelvic ring and acetabular fractures that varied by injury pattern, age, and sex were presented. Descriptive statistics were used to summarize the results. Eighteen institutions responded to the survey (90% response rate, 16 Level, 1 PTC). All surgeons were pediatric fellowship-trained (77.7% in practice >5y). The four most common factors affecting whether surgeons independently managed both pelvic ring and acetabular fractures were patient age, fracture characteristics, displacement and need for surgery. The majority reported managing <10 acetabular (72.2%) but >10 pelvic ring (77.8%) injuries per year. In the clinical scenarios, patients <10 were more likely to have treatment decisions made by a pediatric orthopaedic surgeon. Older patients were more likely to be transferred to another institution for surgery but were often transferred back to the PTC postoperatively. In all clinical scenarios other than posterior hip dislocation, a trauma fellowship-trained surgeon was more likely to be the operative surgeon, even when the patient was not transferred. There is substantial variation in the management of pediatric and adolescent pelvic and acetabular fractures. Even at tertiary care PTCs, volumes are low, and trauma fellowship-trained surgeons are often involved in decision-making and operative management. Age and injury pattern seem to play a large role in variation, and patient transfers between facilities are common. V.

Magnetic Liquid Gating Valve Terminal for Patterned Droplet Generation and Transportation of Highly Viscous Bioactive Fluids.

As an open microfluidic technology with excellent anti-fouling and energy-saving properties, liquid gating technology can selectively separate or transfer multiphase fluids, which has shown great application value in the field of biomedical engineering. However, no study has demonstrated that liquid gating technology has the ability to transfer high-viscosity fluids and biologically active substances, and current liquid gating valves are unable to realize smart-responsive pulsed-patterned transfer, which severely limits their application scope. In this paper, liquid gating technology is combined with magnetically responsive materials to prepare a liquid-based magnetic porous membrane (LMPM) with excellent magnetostatic deformation capability and antifouling properties. On this basis, a magnetic liquid gating valve terminal (MLGVT) with patterning transfer capability is developed, and the feasibility of liquid gating technology for transferring high-viscosity fluids and hydrogel bioinks is explored. Meanwhile, a flexible MLGVT is prepared and realized for targeted drug delivery. This study expands the potential of liquid gating technology for drug delivery, cellular transport and smart patches.

Potentially hazardous elements in atmospheric precipitation during the warm season (May–September) of 2019 in Moscow

Atmospheric precipitation acts as a significant pathway for pollutants from the atmosphere to the Earth’s surface, and analyzing urban precipitation data on intensity, fallout regime, transfer patterns, and solid particle content helps identify pollution sources. For the first time in the Moscow megacity, the levels of soluble forms of potentially hazardous elements (PHEs) in atmospheric precipitation were studied during the whole summer season of May–September 2019. The concentrations of Al, As, B, Ba, Be, Bi, Cd, Ce, Co, Cu, Fe, La, Li, Mn, Ni, P, Pb, Rb, Sb, Sn, Sr, and Zn were determined using inductively coupled plasma mass spectrometry and atomic emission spectroscopy methods. The research underscores the crucial role of atmospheric precipitation in washing PHEs out of the atmosphere. In May and September, concentrations of PHEs surpass the warm-season average. Notable contamination in May stems from elevated traffic during vacations, extensive burning of plant debris and wood, and pollen transport. Summer months are characterized by reduced forest and agricultural fires, traffic, and increased vegetation, leading to lower PHE concentrations, especially in July, with typical amount of precipitation contributing to pollutant dispersion. Elevated PHE levels in September are observed due to increased traffic load, biomass burning, and the expansion of unvegetated soil areas. Rainwater is enriched with Sb, Pb, Cd, Zn, Cu, B, Bi, P, and Sr, sourced from vehicle emissions, soil particles, industry, construction dust, biomass burning, and forest fires. Moderate enrichment with Ba, Mn, Ni, Co, and Sn also occurs episodically. Regression analysis highlights solid particles’ role as a major PHE source in rainwater, with the longer antecedent dry periods and the higher acidity level of rain intensifying the accumulation of PHEs. Long-range transport plays a lesser role, with Southern and Northern Europe, Western Siberia, and the central part of European Russia contributing meaningfully.

An integrated approach for assessing the health risks of pesticide residues on apple: From field dynamics to human exposure

The apple (Malus domestica), a cultivated fruit extensively grown in temperate regions worldwide, is abundant in nutrients and phytochemicals that promote health. However, the application of pesticides in apple cultivation raises significant concern regarding their influence on food safety. This study investigated the dynamic behavior of five pesticides, including chlorpyrifos, imidacloprid, acetamiprid, carbendazim, prochloraz, in apple trees, utilizing both field experiments and predictive modeling to analyze their distribution, transfer, and degradation patterns. Results from the field experiment revealed that at harvest, the residue levels of the five pesticides on apple were below international and national maximum residue limits. The dynamiCROP modeling results, corresponding to the field trial findings, demonstrated that these pesticides exhibited comparable dissipation patterns across various environmental compartments. The primary sources of pesticides in apples were the air and the fruit surface up to 10 days after application, while the soil and leaf surface became the main sources over time. The transferred pesticides adhered to the apple fruits at varying rates and persist therein. Choosing pesticides with lower impact scores helped reduce the impacts on human health and the environment. The assessment of health risks associated with consuming apples containing pesticide residues suggested that the impact on human health is acceptable. These findings were crucial for apple producers, as they enable the optimization of pesticide application timing to ensure compliance with food safety standards and help improve pesticide management strategies in agriculture. This study is essential for minimizing the environmental impact of pesticides and enhancing sustainable agricultural practices.