Search Results (198)

Volatile organic compounds (VOCs) are highly volatile chemicals in natural and anthropogenic environments, significantly affecting indoor air quality. Major sources of indoor VOCs include emissions from building materials, furnishings, and consumer products. Natural wood products release VOCs, including terpenes and aldehydes, which exert diverse health effects ranging from mild respiratory irritation to severe outcomes, such as formaldehyde-induced carcinogenicity. The temporal dynamics of VOC emissions were investigated, and the toxicological and physiological effects of the VOCs emitted by two types of natural wood, Korean Red Pine (Pinus densiflora) and Japanese Cypress (Chamaecyparis obtusa), were evaluated. Using female C57BL/6 mice as an animal model, the exposure setups included phytoncides, formaldehyde, and intact wood samples over short- and long-term durations. The exposure effects were assessed using oxidative stress markers, antioxidant enzyme activity, hepatic and renal biomarkers, and inflammatory cytokine profiles. Long-term exposure to Korean Red Pine and Japanese Cypress wood VOCs did not induce significant pathological changes. Japanese Cypress exhibited more distinct benefits, including enhanced oxidative stress mitigation, reduced systemic toxicity, and lower pro-inflammatory cytokine levels compared to the negative control group, attributable to its more favorable VOC emission profile. These findings highlight the potential health and environmental benefits of natural wood VOCs and offer valuable insights for optimizing timber use, improving indoor air quality, and informing public health policies. Full article

Renovating existing buildings is a key strategy for achieving the EU’s climate targets, as over 75% of the current building stock is energy inefficient. This study evaluates the environmental impacts of three façade renovation scenarios for an office building at the Technical University in Zvolen (Slovakia) using a life cycle assessment (LCA) approach. The aim is to quantify and compare these impacts based on material selection and its influence on sustainable construction. The analysis focuses on key environmental indicators, including global warming potential (GWP), abiotic depletion (ADE, ADF), ozone depletion (ODP), toxicity, acidification (AP), eutrophication potential (EP), and primary energy use (PERT, PENRT). The scenarios vary in the use of insulation materials (glass wool, wood fibre, mineral wool), façade finishes (cladding vs. render), and window types (aluminium vs. wood–aluminium). Uncertainty analysis identified GWP, AP, and ODP as robust decision-making categories, while toxicity-related results showed lower reliability. To support integrated and transparent comparison, a composite environmental index (CEI) was developed, aggregating characterisation, normalisation, and mass-based results into a single score. Scenario C–2, featuring an ETICS system with mineral wool insulation and wood–aluminium windows, achieved the lowest environmental impact across all categories. In contrast, scenarios with traditional cladding and aluminium windows showed significantly higher impacts, particularly in fossil fuel use and ecotoxicity. The findings underscore the decisive role of material selection in sustainable renovation and the need for a multi-criteria, context-sensitive approach aligned with architectural, functional, and regional priorities. Full article

The present work introduces a sustainable, low-carbon method to fabricate durable, non-toxic superhydrophobic surfaces using bamboo-derived cellulose. Uniform TEMPO-carboxylated cellulose particles (TOC-Ps), approximately 2 μm in diameter, were synthesized through thermal polymerization and spray drying. These particles, featuring a nano-scale convex structure formed by intertwined TOC nanofibers, were applied to substrates and modified with low-surface-energy materials to achieve superhydrophobicity. At an optimal TOC-P mass ratio of 6%, the surface displayed a water contact angle of 156.2° and a sliding angle of 7°. The coating maintained superhydrophobicity after extensive mechanical testing—120 cm of abrasion, 100 bending cycles, and continuous trampling—and exhibited robust chemical stability across harsh conditions, including subjection to high temperatures, UV irradiation, and corrosive solutions (pH 2–12). The hierarchical micro–nano structure was found to enhance both hydrophobicity and durability, offering an environmentally friendly alternative for self-cleaning surfaces, textiles, and building applications. Full article

Cellulose-based aerogel is an environmentally friendly multifunctional material that is renewable, biodegradable, and easily surface-modified. However, due to its flammability, cellulose serves as an ignition source in fire incidents, leading to the combustion of building materials and resulting in significant economic losses and safety risks. Consequently, it is essential to develop cellulose-based building materials with flame-retardant properties. Initially, a porous cellulose-based flame-retardant aerogel was successfully synthesized through freeze-drying, utilizing lignocellulose as the raw material. Subsequently, phosphorylation of cellulose was coupled with Ca²⁺ cross-linking via self-assembly and surface deposition effects to enhance its flame-retardant properties. Finally, the synthesized materials were characterized using infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, mechanical compression testing, and scanning electron microscopy. The aerogel of the phosphorylated cellulose nanofibrils cross-linked via 1.5% CaCl₂ exhibited the most effective flame-retardant properties and the best mechanical characteristics, achieving a UL-94 test rating of V-0 and a maximum flame-retardant rate of 90.6%. Additionally, its compressive strength and elastic modulus were recorded at 0.39 and 0.98 MPa, respectively. The preparation process is environmentally friendly, yielding products that demonstrate significant flame-retardant effects and are non-toxic. This product is anticipated to replace polymer-based commercial aerogel materials, representing a sustainable solution to the issue of “white pollution”. Full article

Carbon dioxide (CO₂) clathrate hydrate is gaining attention as a promising material for cold thermal energy storage (CTES) due to its high energy storage capacity and low environmental footprint. It shows strong potential in building applications, where space cooling accounts for nearly 40% of total energy use and over 85% of electricity demand in developed countries. CO₂ hydrates are also being explored for use in refrigeration, cold chain logistics, supercomputing, biomedical cooling, and defense systems. With the growing number of applications in mind, this review focuses on the thermal behavior of CO₂ hydrates and their environmental impact. It highlights recent efforts to reduce formation pressure and temperature using chemical promoters and surfactants. This paper also reviews key experimental techniques used to study hydrate properties, including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), high-pressure differential scanning calorimetry (HP-DSC), and the T-history method. In lifecycle comparisons, CO₂ hydrate systems show better energy efficiency and lower carbon emissions than traditional ice or other phase-change materials (PCMs). This review also discusses current commercialization challenges such as high energy input during formation and promoter toxicity. Finally, practical strategies to move CO₂ hydrate-based CTES from lab-scale studies to real-world cooling and temperature control applications are discussed. Full article

Purpose: Pulsed low dose rate radiotherapy (PLDR) is a radiotherapy approach expected to reduce normal tissue toxicity while maintaining equivalent tumor control as conventional radiotherapy (CRT). This preliminary study evaluates the effectiveness of PLDR in reducing normal tissue toxicity in vivo. Materials and Methods: In the initial phase, C57BL/6 mice underwent histological examination following single-fraction, total-body irradiation. Observations were conducted at 3 and 5 days post-treatment. Mice were divided into control, PLDR, and CRT groups, receiving varying doses ranging from 4 to 12 Gy. Building upon the histological findings, the second phase centered on whole-abdominal irradiation (WAI) and determining the lethal dose for WAI using CRT. Subsequently, this dose was applied in PLDR settings to compare survival rates and changes in body weight. The experiment was replicated to collect histology samples at 1-, 3-, 5-, 7-, and 9-day endpoints, enabling the assessment and comparison of tissue toxicity. Finally, exploration into PLDR’s lethal WAI dose was conducted. Results: Histology results showed the abdominal region as the main site of difference between PLDR and CRT, with both methods causing a dose-dependent increase in atrophy and hyperplasia. However, CRT led to higher tissue toxicity compared to PLDR. In the survival study, the fatal dose for WAI treatment was 18 Gy, with mice in the CRT group experiencing substantial weight loss and dying within 9–12 days post-treatment. In contrast, mice in the PLDR group, despite an initial weight loss, recovered their weight and survived. Histology results also showed that the PLDR group had less tissue toxicity. Furthermore, the fatal dose of WAI for PLDR was revealed to be 29 Gy, which is over 60% higher than the dose required for CRT, indicating a substantial difference in tolerance and potential safety margin provided by PLDR treatment. Conclusions: PLDR demonstrated a reduced normal toxicity compared to CRT, potentially beneficial in re-treatment scenarios or for tumors where CRT-induced toxicity limits tumor control, such as in liver cases. Full article

The management of asbestos-containing waste (ACW) presents a significant environmental challenge due to the material’s widespread historical use and persistent toxicity. While landfilling remains the primary disposal method, it poses long-term environmental risks and conflicts with circular economy principles. Across Europe, large quantities of asbestos remain in building stock, including approximately 15 million tons in Poland, 4.5 million tons in Lithuania, and 1 million tons in Latvia. This study examines Latvia’s ACW management challenges and opportunities, combining theoretical analysis with empirical research. A large-scale survey (n = 2005) revealed significant gaps in public knowledge, with 28% of respondents willing to reuse asbestos-containing roofing despite recognizing its hazards, highlighting a critical disconnect between awareness and behavior. The study also assessed Latvia’s pilot Asbestos Removal Program, demonstrating high public demand but limited funding capacity. Thermal treatment, particularly plasma vitrification, was identified as the most mature alternative to landfilling, though implementation barriers include high capital costs and specialized expertise requirements. Findings emphasize the need for sustainable financing mechanisms, such as a differentiated landfill tax, to ensure the long-term viability of asbestos removal initiatives. Latvia’s experience provides valuable insights for other nations seeking to mitigate ACW-related health and environmental risks through improved policy frameworks and practical management solutions. Full article

This study aims to enhance the sustainable utilization of electrolytic manganese residue (EMR), an industrial solid waste rich in sulfates and pollutants, by modifying it with appropriate proportions of granulated blast furnace slag (GBFS) and carbide slag (CS) and evaluating its potential as a cement retarder. The influence of both the GBFS/CS ratio and the dosage of modified EMR on the performance of cement mortar was systematically investigated, focusing on workability, mechanical properties, hydration behavior, leaching toxicity, and carbon emissions. Results showed that GBFS and CS significantly reduced pollutant concentrations in EMR while improving gypsum crystallinity. Modified EMR exhibited retarding properties, extending the initial and final setting times of cement mortar from 98 min and 226 min to 169 min and 298 min. With an 8 wt.% dosage, the 28-day compressive strength reached 58.76 MPa, a 1.3-fold increase compared to cement mortar (45.21 MPa). The content of reactive SiO₂, Al₂O₃, Ca(OH)₂, and CaSO₄·2H₂O promoted secondary hydration of cement and generated significant ettringite (AFt) and calcium silicate hydrate (C-S-H) gels, forming a dense microstructure. Pollutants in the modified EMR-cement mortar were reduced through precipitation, substitution, and encapsulation, meeting leaching toxicity standards. This study highlights the feasibility and environmental benefits of employing modified EMR as a cement retarder, demonstrating its potential in sustainable building materials. Full article

The Life Cycle Assessment (LCA) evaluates the environmental impacts of a product or service throughout its life cycle, from material extraction to end-of-life, considering factors such as global warming, acidification, and toxicity. However, despite its significant health effects, noise has not yet been incorporated into the LCA. This study integrates noise impact into the LCA to assess and compare alternative structural designs for Australian high-rise residential and commercial buildings. Three scenarios were analysed: (1) reinforced concrete frames, (2) hybrid timber designs using engineered wood (e.g., cross-laminated timber and Glulam), and (3) steel-frame structures. The system boundary spans cradle to grave, with a 100-year lifespan. Material quantities were extracted from BIM software 2024 (Revit Architecture) for accuracy. The ReCiPe 2016 method converted inventory data into impact indicators, while noise impact was assessed using Highly Annoyed People (HAP) and Highly Sleep-Deprived People (HSDP). The results show that commercial buildings have more significant environmental impacts than residential structures due to their higher material usage. Steel frames generally exhibit the highest environmental impact, while concrete structures contribute most to noise effects. The total noise-integrated impact ranks as steel > concrete > timber. Additionally, noise accounts for up to 33% of the total impact on densely populated areas but remains negligible in low-population regions. These findings highlight the importance of incorporating noise into the LCA for a more holistic assessment of sustainable building designs. Full article

Small- and medium-sized enterprises (SMEs) play an important role in China’s sustainable development. With the increasing green awareness among SMEs, they have become more environmentally conscious, and many of them are considering the utilization of green materials as an effective method to reduce environmental impact. At the same time, Chinese SMEs must also ensure product quality when deciding to utilize green materials. Based on quality management theory, we developed a model to empirically explore the impact of quality training and quality standards on the utilization of green materials by SMEs. Firstly, we conducted an exploratory case study with four Chinese SMEs to identify important and common attributes and levels associated with SMEs’ utilization of green materials. Secondly, building on these case studies, we designed a discrete choice experiment (DCE). We conducted a survey involving 313 Chinese SMEs to collect data, which we analyzed using a random parameter logit model. The results show that quality training promotes SMEs’ green material utilization, while quality standards hinder it. In addition, both quality training and quality standards enhance the positive effects of heavy metal toxicity reduction and recycling rates on utilization, while weakening the positive effect of sewage reduction on utilization. Full article

Fire has been proven to threaten human lives and buildings significantly. Extensive research is being conducted globally to reduce fire risks, particularly in high-rise buildings that incorporate steel for structural support, timber for decorative elements, and cladding for insulation. Traditional passive fireproofing materials, such as concrete coverings, gypsum boards, and cementitious coatings, often lack aesthetic appeal. Intumescent coatings offer a promising solution to this issue. These coatings require a thin layer on the substrate to protect from fire, and the thin layer expands up to many times its original thickness when exposed to fire, forming an insulating char that acts as a barrier between fire and the substrate. This barrier prevents the steel from reaching critical temperature and helps maintain its integrity during a fire incident. Hence, intumescent coatings are a great choice for passive fire protection of load-bearing steel, wooden structures, timber, and cementitious buildings. Although some research articles discuss intumescent coating types, application methods, fabrication processes, cost-effectiveness, bonding performance, toxicity, and various uses, a comprehensive study encompassing all these topics still needs to be conducted. This review paper explores different types of intumescent coatings, their formulation and manufacturing methods, their application processes, and their use on various substrates. It also covers the key intumescent coating materials and their interactions during fire. Challenges and issues, such as fire protection time, char-forming temperature, and toxicity, are discussed. Full article

Electronic waste (e-waste) is the fastest-growing waste stream on the planet, yet it remains critically under-addressed in global waste management and recycling efforts. The rapid pace of technological advancement has led to increased consumption of electronic devices, many of which are challenging and costly to recycle efficiently. Insufficient infrastructure for e-waste recycling has resulted in large quantities being exported to countries with minimal waste management capabilities. In these regions, waste is often processed manually, exposing workers to hazardous materials and toxic elements commonly found in electronic components, leading to serious health risks. E-waste consists primarily of fibrous composite materials and plastics mixed with valuable metals and reusable components. While metals are often recovered, the remaining materials are typically discarded, contributing to significant environmental harm. Addressing e-waste challenges requires more than just technological solutions. In the United States, limited policies promote large-scale reuse and recycling practices, particularly among corporations. To build a sustainable approach, a combination of next-generation, cost-effective chemical recycling technologies and forward-thinking policy reforms will be essential for the effective management and reduction of e-waste. This paper explores the global generation and composition of e-waste, highlighting its environmental and health impacts due to improper handling and disposal. It reviews current and emerging recycling technologies while examining the challenges and opportunities in e-waste management. Finally, it discusses sustainable solutions and future directions for improving e-waste recycling through innovative technologies and policy reforms, concluding with recommendations for a circular economy approach. Full article

Polyurethane foam (PF) is a versatile polymer widely used in various applications. By changing the composition of polyol and isocyanate, these foams can be classified into rigid polyurethane foams (PUFRs) and flexible polyurethane foams (PUFFs). The flexible polyurethane foam (PUFFs) is well known for its sound absorption capacities; nevertheless, its flammability poses significant safety hazards. The purpose of this study is to look into how flexible polyurethane foam reacts to fire, specifically its combustion properties, and the risks that come with them. The study aims to find out the rates of horizontal and vertical burning, the make-up of the reaction products, and the temperatures that build up inside the polyurethane foam mass when a support pole is placed in front of the stage and sound-absorbing material is added to stop stage sounds from reverberating. There were performed experiments to determine the fire behavior of the samples in contact with an ignition source in the form of a small flame and experiments to determine the ignition temperature of the sound-absorbing sponge, where it was found that vertical position accelerates combustion, and in practical applications, this aspect must be considered for fire prevention. To determine the combustion gases, several methods were used, namely spectrophotometric, ion chromatography, and gas-chromatographic methods. Analysis of the gases resulting from the combustion of the sound-absorbing sponge indicates the presence of dangerous toxic compounds (hydrogen cyanide, carbon monoxide, and hydrochloric acid), which can endanger human health in the event of a fire. Full article

Challenges in the traditional cast-and-cure manufacturing of composite solid propellants, such as the use of mandrels and the toxicity of curing agents, are being addressed through new propellant formulations and additive manufacturing techniques. Within this framework, this study aimed to investigate the properties of UV-curable composite solid rocket propellants, focusing on their compatibility with advanced 3D printing technologies. Polybutadiene-based propellants incorporating a specific photoinitiator were examined. Key rheological properties, including the pseudoplasticity and pot-life, were assessed to evaluate the material’s behavior during the printing process. Furthermore, photopolymerization tests were performed using a customized delta illuminator to evaluate the conversion efficiency under UVA and UVC light sources. Concurrently, a modular Cartesian 3D printer was developed and preliminary tests were performed. Rheological tests also revealed a flow index n of 0.32 at 60 °C and 0.46 at 80 °C, indicating significant pseudoplastic behavior. The pot-life tests showed that the viscosity of the propellant reached the upper limit of ${10}^6$ cP more quickly at higher temperatures, indicating a shorter time range of printability. UVA irradiation resulted in a polymerization conversion rate of about 90%, while UVC exposure did not significantly enhance the conversion rate beyond this value. Finally, the 3D printing tests confirmed the feasibility of producing solid propellant, though challenges related to material segregation and the extrusion consistency were observed. Material separation resulted in a significant impact on the printability, causing underextrusion and nozzle clogging, particularly with smaller nozzle diameters and higher extrusion pressures. Overall, this research represents a significant step forward in the development of UV-curable propellants for additive manufacturing, building on previous advancements by the research group. It demonstrates tangible progress in addressing key challenges such as the printability, material performance, and curing efficiency, while also highlighting areas requiring further refinement. These findings underscore the continuous evolution of this technology toward higher readiness levels, paving the way for its broader application in composite solid propellant manufacturing. Full article

The addition of carbon nanotubes (CNTs) to cement matrix brings multiple beneficial effects ranging from improving mechanical and physical properties to the creation of smart materials. When subjected to an erosive environment or as end-of-life waste, mortars with CNT addition might get released into the environment and come in contact with surface waters. The assessment of the environmental impact of mortars reinforced with carbon nanotubes is an important factor concerning their sustainability, as it has not yet been addressed in the literature. The presented paper aims to assess the water toxicity of cement mortars with various dosages of 0.05 wt.%, 0.1 wt.%, and 0.2 wt.% of carbon nanotube. The effect of the quality of water dispersion of CNTs was also considered through two sonication times of the suspension: 20 min and 60 min. Tests using indicator organisms, Aliivibrio fischeri, Daphnia magna, and Lemna minor, were conducted on shredded and non-shredded mortars. The results reveal no to low toxicity for all tested mortars under the assumed framework of toxicity assessment. The toxicity results for samples containing CNTs were comparable to those without CNTs, indicating that the toxicity of mortars incorporating CNTs is not greater than that of conventional cement-based materials. The water toxicity of the cement mortars is rather connected with the washing away of the hydration products more than with the presence of carbon nanotubes. Full article