Search Results (10)

Significant numbers of aircrew and jet airline passengers are affected by post-flight symptoms of ill health, usually nowadays labelled “aerotoxic syndrome”. It could be inferred from a large passenger survey carried out in the Netherlands that up to 50% of flights may engender malaise to varying degrees, and up to 50% of the population might be susceptible to suffering from actual intoxication from the contaminants known to occur in aircraft cabin air. In-flight measurements of its composition have revealed the presence of known neurotoxins, notably tricresyl phosphate and carbon monoxide, both of which can enter the cabin air as it is bled off the main engines. This study reviews the quantitative aspects of this evidence and estimates the susceptibility of the population to neurological damage at the measured levels of contamination, its typical impacts on health, and the likelihood and timescales of post-exposure recovery. Airworthiness directives already mandate that crew and passenger compartment air must be free from harmful or hazardous vapours and gases, but uncertainty regarding the nature of these particular hazards has led to this important aspect of airworthiness having been hitherto unduly neglected. The continuing exponential growth of air passenger traffic means that cabin air contamination will eventually become a major public health hazard if effective action is not taken, some possible courses of which are discussed. Full article

The author reviewed and classified maintenance reports that cited smoke, odor, or fumes (SOFs) that US airlines sent to the FAA over four years between 2018 and 2023. The US fleet composition was also calculated to put the number of SOF reports on each aircraft type in perspective. “Fume events” (engine oil or hydraulic fluid) were the most common type of onboard SOFs reported by US airlines (43%), followed by electrical (20%), and fans (6.1%). During these years, A320fam aircraft made up 20% of the US fleet but 80% of the reported fume events. Conversely, B737fam aircraft made up 27% of the US fleet but only 3.0% of the reported fume events. Aircraft design features, airline reporting practices, and maintenance procedures that may contribute to these differences were reviewed. Pilots were most likely to document a fume event during descent (47%) and takeoff/climb (19%). The A320fam, MD80fam, A330, and ERJ140-145 aircraft were over-represented in other types of SOFs reports. Airline narratives show that the APU can be the primary source of oil/hydraulic fumes, even when it is not operating. Additionally, failure to find the source of fumes, rectify it, and clean any secondary sources of fumes can cause repeat events. Full article

Disassembly is a key step in remanufacturing, especially for end-of-life (EoL) products such as electric vehicle (EV) batteries, which are challenging to dismantle due to uncertainties in their condition and potential risks of fire, fumes, explosions, and electrical shock. To address these challenges, this paper presents a robotic teleoperation system that leverages augmented reality (AR) and digital twin (DT) technologies to enable a human operator to work away from the danger zone. By integrating AR and DTs, the system not only provides a real-time visual representation of the robot’s status but also enables remote control via gesture recognition. A bidirectional communication framework established within the system synchronises the virtual robot with its physical counterpart in an AR environment, which enhances the operator’s understanding of both the robot and task statuses. In the event of anomalies, the operator can interact with the virtual robot through intuitive gestures based on information displayed on the AR interface, thereby improving decision-making efficiency and operational safety. The application of this system is demonstrated through a case study involving the disassembly of a busbar from an EoL EV battery. Furthermore, the performance of the system in terms of task completion time and operator workload was evaluated and compared with that of AR-based control methods without informational cues and ‘smartpad’ controls. The findings indicate that the proposed system reduces operation time and enhances user experience, delivering its broad application potential in complex industrial settings. Full article

Withstanding extreme events is increasingly a significant challenge for the construction industry. Where civil infrastructures remain using traditional concrete, which has low tensile strength, poor durability, and weak crack resistance, in this regard, ultra-high-performance concrete (UHPC), with its outstanding mechanical properties and high strength, offers the prospect of wide application. This advanced technology allows for the fabrication of thin and light-dimensional structures to accelerate construction while increasing corrosion resistance to minimize maintenance intervention and extend the service life of the infrastructures. Despite this, UHPC is less eco-friendly due to consuming more cement than the usual material, which requires replacement materials, such as silica fume (SF) and rice husk ash (RHA), which are readily available from other local material production. This study proposes an experimental approach to assess the influence of SF and RHA content on the properties of UHPC. Different SF and RHA compositions will be adjusted to analyze their effects on slump flow, compressive strength, flexural strength, tensile strength, and the stress–strain relationship in UHPC tension testing. Based on the results, the most effective ratio is RHA replacing 50% of the SF in the UHPC mixture. Specialized tensile experiments reveal enhanced tensile strength with judicious RHA incorporation at 5-day and 28-day stages, particularly in initial crack and damage conditions. Stress–strain curves for 5% to 15% RHA samples show increased ductility, indicating that optimal RHA-SF ratios enhance UHPC cracking characteristics. Based on the results, a discussion on the appropriate proportions for utilizing most local materials will be derived, especially for regions of Vietnam. It is evaluated as a feasible and promising solution to reduce greenhouse gas emissions threatening global climate change. Full article

Aerotoxic syndrome is a rarely recognized and poorly defined illness resulting from exposure to products of oil combustion in commercial aircraft bleed air systems. The pathophysiology of this syndrome is not well understood. A 42-year-old male pilot developed duty-limiting symptoms consistent with aerotoxic syndrome following exposure to airline cabin fumes and recurrence of symptoms following re-exposure despite apparent full recovery from the initial exposure event. Given his persistent symptoms and concern for immediate debilitation/incapacitation if re-exposed, the pilot was deemed medically unqualified for return to commercial piloting duties and a disability determination was made. Consideration of aerotoxic syndrome in aircrew members with unusual or episodic symptoms of neuro/cognitive dysfunction is essential for further characterizing this occupational illness, guiding medical management, and understanding its impact on aviation workforce health. Full article

Zinc is one of the more mobile metals in the soil and thus involves the risk of entering the food chain. Zinc compounds are used in the galvanization process, which is assumed to be safe for the environment. However, random events or failures such as unsealing bathtubs with liquid zinc or hydrochloric acid, as well as violent fires in industrial halls, may pose a real threat to the environment, including human health. Therefore, this research was carried out to determine the content of zinc and selected potentially toxic metals in arable soils after a failure in a galvanizing plant located in the village of Dębska Wola (southeastern Poland). In addition, the potential risk associated with excessive accumulation of identified pollutants in the environment was assessed. In order to determine the level of contamination, soil samples were taken, and basic physical and chemical properties were analysed. The concentrations of Zn, Pb, and Cd in the soil were determined using the atomic emission spectrometry technique with inductively coupled plasma (ICP-OES), and pH measurements were performed using the potentiometric method after prior wet mineralisation of the research samples. The analysed samples had a varied pH of the organic–mineral horizon from pH_H2O 4.66 to pH_H2O 5.33 and from pH_KCl 3.89 to pH_KCl 5.06. As a result of a failure, toxic metal fumes were released into the atmosphere, causing concentrations of Zn in the soil samples from 0–5 cm in the range of 1201–2007 mg∙kg⁻¹, as well as Pb (109–509 mg∙kg⁻¹) and Cd (4.6–17 mg∙kg⁻¹). High contents of zinc and lead found in several soil samples are of anthropogenic nature and require detailed monitoring in order to eliminate the risk associated with their accumulation. The study area should be re-analysed to determine the rate of reclamation of degraded soils. Full article

Fire events remain a severe hazard despite significant progress in the construction industry. The high-temperature resistance of concrete structures highly depends on the properties of their ingredients. The present study provides an analytical review of the available experimental studies investigating the influence of high temperatures on the residual mechanical characteristics of concrete, namely compressive and tensile strength, as well as the modulus of elasticity. This paper primarily focuses on the influences of supplementary cementing materials, including silica fume (SF), fly ash (FA), and ground granulated blast furnace slag (GGBFS), as well as different aggregate types. The literature findings show that the mechanical characteristics of concrete are degraded dramatically due to heat-caused changes in concrete. In addition, the mechanical properties of concrete are highly influenced by the types of aggregate and the amount of supplementary cementing materials at both high temperatures and room temperature. The inclusion of FA and GGBFS improves the high-temperature resistance of concrete. However, high contents of FA and GGBFS result in adverse effects on the properties of concrete. This review will provide a basis for future studies and enhance the knowledge of the behaviour of reinforced concrete structures subjected to high temperatures. Full article

Epigenetic alterations are a driving force of the carcinogenesis process. MicroRNAs play a role in silencing mutated oncogenes, thus defending the cell against the adverse consequences of genotoxic damages induced by environmental pollutants. These processes have been well investigated in lungs; however, although skin is directly exposed to a great variety of environmental pollutants, more research is needed to better understand the effect on cutaneous tissue. Therefore, we investigated microRNA alteration in human skin biopsies exposed to diesel fumes, ozone, and UV light for over 24 h of exposure. UV and ozone-induced microRNA alteration right after exposure, while the peak of their deregulations induced by diesel fumes was reached only at the end of the 24 h. Diesel fumes mainly altered microRNAs involved in the carcinogenesis process, ozone in apoptosis, and UV in DNA repair. Accordingly, each tested pollutant induced a specific pattern of microRNA alteration in skin related to the intrinsic mechanisms activated by the specific pollutant. These alterations, over a short time basis, reflect adaptive events aimed at defending the tissue against damages. Conversely, whenever environmental exposure lasts for a long time, the irreversible alteration of the microRNA machinery results in epigenetic damage contributing to the pathogenesis of inflammation, dysplasia, and cancer induced by environmental pollutants. Full article

This paper describes the relative frequency of reports of oil and hydraulic fluid fumes in the ventilation supply air (“fume events”) compared to other types of fumes and smoke reported by U.S. airlines over 10 years. The author reviewed and categorized 12,417 fume/smoke reports submitted to the aviation regulator to comply with the primary maintenance reporting regulation (14 CFR § 121.703) from 2002–2011. The most commonly documented category of onboard fumes/smoke was electrical (37%). Combining the categories of “bleed-sourced”, “oil”, and “hydraulic fluid” created the second most prevalent category (26%). The remaining sources of onboard fumes/smoke are also reported. To put the data in context, the fume event reporting regulations are described, along with examples of ways in which certain events are underreported. These data were reported by U.S. airlines, but aviation regulations are harmonized globally, so the data likely also reflect onboard sources of fumes and smoke reported in other countries with equivalent aviation systems. The data provide insight into the relative frequency of the types of reported fumes and smoke on aircraft, which should drive design, operational, and maintenance actions to mitigate onboard exposure. The data also provide insight into how to improve current fume event reporting rules. Full article

Introduction: Organizing pneumonia (OP) is a rare syndrome that has been associated with a variety of underlying factors including infections, collagen vascular diseases, toxic fumes, cancer, drugs and radiotherapy. A cryptogenic form is also observed. OP is a curable disease in the most cases. Steroids are the standard therapy, but other treatment regimens have been used as well. Material and methods: In the period from 1999 to 2005, 9 women and 3 men (age range 44–71 years) with OP were selected for the study. There were 9 non-smokers, 2 smokers and 1 ex-smoker. Open lung biopsy was performed in 5 patients, and in 7 patients diagnosis was established on the basis of transbronchial lung biopsy. Results: Dyspnoea (100%), cough (100%), weakness (100%), fever (83%), loss of weight (83%), sweats (33%) and chest pain (8%) were the most frequently noticed symptoms. Radiographically, all patients had bilateral consolidations with areas of ground glass attenuations. A migratory pattern of these lesions was observed in 9 (75%) patients. In all patients clarithromycin (CLA) in a dose 0.5 g b.i.d was administered. Nine (75%) patients were successfully treated. Complete clinical and radiological remission was obtained after 3 months of CLA therapy in 7 and a partial response in an additional 2 patients, in whom treatment was prolonged to 4 months. During the first month of CLA treatment 3 patients did not respond to the therapy, and prednisone was introduced. The observation period ranged from 30 to 90 months (mean 42 months). Adverse reaction to CLA and relapse did not occur. Conclusions: OP can be treated with clarithromycin. It may be an alternative treatment, particularly for patients in good clinical status and in whom the probability of adverse events in the course of corticotherapy is high. Full article