bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of p-amino acetanilide functionalized multi-walled carbon nanotubes as an effective carrier for lansoprazole release
Authors: Abniki Milad , Azizi Zahra , Poorebrahim Sepideh , Moniri Elham
Published: May 2023

Nowadays the nano-drug delivery system is an appropriate procedure for solving the problem of controlling drug performance in a traditional method. For this purpose, a new nano-adsorbent of modification multi-walled carbon nanotubes with cyanuric chloride and para-amino acetanilide was synthesized for the effective sorption and desorption of lansoprazole drugs. Physicochemical properties of the multi-walled carbon nanotubes with cyanuric chloride and para-amino acetanilide were then specified with energy dispersive spectroscopy, scanning electron microscope, infrared spectroscopy (IR), thermal gravimetric (TGA), and elemental analysis (CHN). The adsorption process followed by the drug release kinetics and isotherm models has indicated a good and acceptable kinetic adsorption and Langmuir isotherm model in conditions simulated. The maximum capacity value for the lansoprazole adsorption by nano-adsorbent was 48.781 mg g−1 at an optimal pH of 6. The result of the drug release mechanism was shown in the first 30 min in the stomach is as much as 30% of the drug is released into the environment by MT-CC/pA. The efficiency and adsorption capacity of the produced nano-adsorbent is extremely high for lansoprazole sorption.
Analysis of Al–Mg–Si alloy reinforced with optimal palm kernel shell ash particle and its impact on dynamic properties for sounding rocket application
Authors: Oyedeji Elijah Oyewusi , Dauda Mohammed , Yaro Shehu Aliyu , Abdulwahab Malik , Nathaniel Oyedeji Ayodeji
Published: May 2023

Due to heavy usage and rising populations, there is a growing need for local and naturally derived materials in the automotive and aerospace industries. Furthermore, due to their excellent mechanical qualities and high strength-to-weight ratio, composite materials are expected to perform better than traditional materials, particularly in automotive and aerospace applications. According to this perspective, this research aims to investigate the effects of optimal compositions of Al–Mg–Si alloy reinforced with palm kernel shell ash (PKSA) particles on dynamic mechanical characteristics of the composite produced via the powder metallurgy route. PKSA compositions of 0, 2, 4, 6, 8, 10 and 12 wt% as reinforcement on Al–Mg–Si powder were used to evaluate the static tensile strength of the produced composites. In this study, the damping factor, change in length, flexural, storage, and loss moduli were determined. In addition, the produced composites’ bulk density, hardness, creep, and dynamic mechanical thermal analysis were also investigated. According to the study’s morphology result, recrystallisation of the powdered composition during ball milling increased dislocation density and harder phases in the PKSA, contributing to the PKSA’s better characteristics. Furthermore, the optimum weight percentage of 6.0 wt% of PKSA (Sample C4) has significant properties compared to the unreinforced (control) sample and was also found to have improved storage modulus, loss modulus, and damping behaviour. These findings showed that the developed composite, particularly sample C4, may be used in various technical applications, including automotive and aerospace industries.
Thermally tunable vanadium-dioxide-based broadband metamaterial absorber with switchable functionality in the terahertz band
Authors: Xu Chongyang , Duan Guiyuan , Xu Wei , Wang Xingzhu , Huang Yang , Zhang Xiangyang , Zhu Huaxin , Wang Ben-Xin
Published: May 2023

In this paper, a thermally tunable broadband metamaterial absorber, with switchable functionality in the terahertz band, consisted of periodically arranged vanadium dioxide (VO2) and a gold film separated by a layer of polyimide is reported, which is capable of switching from absorber to reflector through the phase change property of VO2. When VO2 is in the metallic state, three near-perfect absorption peaks localized at 3.48 THz, 5.09 THz and 7.05 THz are obtained, and the combination of them gives rise to a broadband absorption, more than 90% of absolute absorption bandwidth reaches 4.35 THz (3.1–7.45 THz) with a relative absorption bandwidth of 82.46%. When VO2 is in the dielectric state, it can switch from near-perfect broadband absorption to near-perfect reflection with the maximum intensity modulation of 92.4%. The broadband absorption is insensitive to polarization of incident beam due to symmetrical structure design and exhibits excellent tolerance for large oblique incidence angle. In addition, size changes of patterned VO2 array structure provides a large impact on the absorption performance of the thermally tunable device, especially the absorption bandwidth. Our proposed device is expected to have outstanding prospects in terahertz thermal imaging, communications, and temperature-controlled metasurface.
Multi-criteria comparison tools to evaluate cost- and eco-efficiency of ultra-high-performance concrete
Authors: Tavares Cesario , Skillen Kinsey , Shi Xijun , Grasley Zachary
Published: May 2023

This work was motivated by the increasing need for proper metrics and tools to demonstrate the effect of mechanical performance, as a function of concrete mix composition, in dictating the dimensions of structural elements and associated costs and embodied carbon dioxide (CO2) emissions. Mixture compositions associated with different concrete technologies were compared using multi-criteria comparison indices derived using structural design considerations and calculated using information on compressive strength, volumetric embodied CO2 and unit costs. In addition, predicted compressive strengths obtained with machine learning (ML) models are used to calculate these indices for a domain of mix proportions associated with ultra-high-performance concrete materials to generate multi-objective density diagrams (MODDs). The makeup of this tool facilitates the evaluation of rather complicated trends associated with mix proportions and multi-objective outcomes, allowing ML-based tools to be of easy interpretation by industry personnel with no expertise in artificial intelligence. MODDs could be used as aids in the decision-making process during mix design stages and serve as proof of mixture optimization that could be introduced in environmental product declarations. Results show that, in contrast to conventional wisdom, high-binder content and ultra-high strength concrete technologies are not necessarily detrimental to cost and/or eco efficiencies. For the applications evaluated herein, optimum solutions were mostly obtained with these types of concrete, suggesting that industry trends toward requiring minimization of embodied carbon footprint on a per volume of concrete basis are misguided and should not be used as a standalone metric to minimize the total carbon footprint of concrete structures.
Erratum to “Tame topology of arithmetic quotients and algebraicity of Hodge loci”
Authors: Bakker B. , Klingler B. , Tsimerman J.
Published: May 2023

We correct an error in the functoriality of the

R

a
l
g

\mathbb {R}_\mathrm {alg}

-definable structures on arithmetic quotients

Γ
∖
G

/

M

\Gamma \backslash G/M

constructed in [B. Bakker, B. Klingler, and J. Tsimerman, Tame topology of arithmetic quotients and algebraicity of Hodge loci, J. Amer. Math. Soc. 33 (2020), no. 4, 917-939]. The statements for Hodge manifolds and period maps are unaffected.
Long-term beneficial impact of the randomised trial ‘Train the Brain’, a motor/cognitive intervention in mild cognitive impairment people: effects at the 14-month follow-up
Authors: Sale Alessandro , Noale Marianna , Cintoli Simona , Tognoni Gloria , Braschi Chiara , Berardi Nicoletta , Maggi Stefania , Maffei Lamberto ,   the Train the Brain Consortium, Maffei L , Picano E , Andreassi M G , Angelucci A , Baldacci F , Baroncelli L , Begenisic T , Bellinvia P F , Berardi N , Biagi L , Bonaccorsi J , Bonanni E , Bonuccelli U , Borghini A , Braschi C , Broccardi M , Bruno R M , Caleo M , Carlesi C , Carnicelli L , Cartoni G , Cecchetti L , Cenni M C , Ceravolo R , Chico L , Cintoli S , Cioni G , Coscia M , Costa M , D’Angelo G , D’Ascanio P , De Nes M , Del Turco S , Di Coscio E , Di Galante M , di Lascio N , Faita F , Falorni I , Faraguna U , Fenu A , Fortunato L , Franco R , Gargani L , Gargiulo R , Ghiadoni L , Giorgi F S , Iannarella R , Iofrida C , Kusmic C , Limongi F , Maestri M , Maffei M , Maggi S , Mainardi M , Mammana L , Marabotti A , Mariotti V , Melissari E , Mercuri A , Micera S , Molinaro S , Narducci R , Navarra T , Noale M , Pagni C , Palumbo S , Pasquariello R , Pellegrini S , Pietrini P , Pizzorusso T , Poli A , Pratali L , Retico A , Ricciardi E , Rota G , Sale A , Sbrana S , Scabia G , Scali M , Scelfo D , Sicari R , Siciliano G , Stea F , Taddei S , Tognoni G , Tonacci A , Tosetti M , Turchi S , Volpi L
Published: May 2023

No treatment options are currently available to counteract cognitive deficits and/or delay progression towards dementia in older people with mild cognitive impairment (MCI). The ‘Train the Brain’ programme is a combined motor and cognitive intervention previously shown to markedly improve cognitive functions in MCI individuals compared to non-trained MCI controls, as assessed at the end of the 7-month intervention. Here, we extended the previous analyses to include the long-term effects of the intervention and performed a data disaggregation by gender, education and age of the enrolled participants. We report that the beneficial impact on cognitive functions was preserved at the 14-month follow-up, with greater effects in low-educated compared to high-educated individuals, and in women than in men.
Development and validation of a standardized blood culture contamination definition and metric dashboard for a large health care system
Authors: Hancock Jill A , Campbell Sheldon , Jones Makoto M , Wang-Rodriguez Jessica ,   VHA Microbiology SME Workgroup, Klutts Stacey , Campbell Sheldon , Weber Theresa , Greene Bonnie , Espinosa Ruben Benitez , Orth Cari , Anderson Lyndi , Vigliotti Chasity , Frank Amy , Baraceros-Pineda Rosella , Donkle Jeanna , Cummings Tammy , Behrends Laura , Young Jennifer , Krajcir Shannon , Scholten Rachel , Klutts J Stacey
Published: May 2023

Objectives

Blood culture contamination is a major problem in health care, with significant impacts on both patient safety and cost. Initiatives to reduce blood culture contamination require a reliable, consistent metric to track the success of interventions. The objective of our project was to establish a standardized definition of blood culture contamination suitable for use in a Veterans Health Administration (VHA) national data query, then to validate this definition and query. A secondary objective was to construct a national VHA data dashboard to display the data from this query that could be used in VHA quality improvement projects aimed at reducing blood culture contamination.

Methods

A VHA microbiology expert work group was formed to generate a standardized definition and oversee the validation studies. The standardized definition was used to generate data for calendar year 2021 using a Structured Query Language data query. Twelve VHA hospital microbiology laboratories compared the data from the query against their own locally derived contamination data and recorded those data in a data collection worksheet that all sites used. Data were collated and presented to the work group.

Results

More than 50,000 blood culture accessions were in the validation data set, with more than 1,200 contamination events. The overall blood culture contamination rate for the 12 facilities participating was 2.56% with local definitions and data and 2.43% with the standardized definitions and data query. The main differences noted between the 2 data sets were deemed to be issues in local definitions. The query and definition were then converted into a national data dashboard that all VHA facilities can now access.

Conclusions

A standardized definition for blood culture contamination and a national data query were validated for enterprise-wide VHA use. To our knowledge, this represents the first reported standardized, validated, and automated approach for calculating and tracking blood culture contamination. This tool will be key in quality initiatives aimed at reducing contamination events in VHA.
And Where that Language Does Not Yet Exist
Authors: Stallings L H
Published: May 2023

This essay-review is centered on two recently published contemporary works about language, literature, embodiment, and ritual: Ana-Maurine Lara’s Queer Freedom: Black Sovereignty (2020) and Mecca Jamila Sullivan’s The Poetics of Difference: Queer Feminist Poetics in the African Diaspora (2021). Exploring creative and critical praxis as method and object of study, both authors provide innovative studies of queerness and queer worldmaking in the work of African diasporic spiritual and artistic communities.Lara’s and Sullivan’s arguments seem most relevant and timely for what twenty-first–century Black theorizing must do: refuse US exceptionalism, solidify transnational solidarities/relations across the African Diaspora, . . . better prepare for the abolition of gender.
Whites Aren’t Alright
Authors: Mitchell Jon
Published: May 2023

This essay evaluates how the three writers under review contribute to a persistent discussion about American identity and the many debates that still circulate around it—what it is and isn’t, and who it includes, fails to include, or shouldn’t include. Individually, each author tries to add nuance and contemporary problematics to the debates. Collectively, moreover, they remind the reader that, despite the work of identity politics in its many forms throughout the twentieth century and since; despite the increased secularization of the nation, or at least its culture; and despite even the election of a Black president or the presidential candidacy of a woman, these debates about race, gender, sexuality, and the place of religion in American life are just as significant now as they have ever been. Instead of seeing racism, sexism, homophobia, and religious fervor as remnants of the past or as legacies of beliefs that have been surpassed through progress, each book works to show how the fights over national identity are very much ongoing.“Despite how weathered this material has become . . . battles for equality are still pitched over the same ideas of a national sovereignty embedded in a frontier mentality that . . . sees the very work of inclusion and representation itself as the failure of the nation.”
146 Keynote: Jim Vincent and Inhalable Dust
Authors: Cherrie John
Published: May 2023

Jim Vincent was truly a modern-day Renaissance man. An accomplished jazz and classical pianist and composer, who performed with some of Europe's top improvisers, making appearances at major jazz festivals and in BBC broadcast concerts. However, his legacy lies elsewhere. He graduated in physics at the University of Durham with first-class honours in 1962, proceeding to a PhD in 1966. After jobs in academia and industry, in 1979 he became Head of Physics at the Institute of Occupational Medicine (IOM) in Edinburgh. He took over a research team that had been working on sampling of dusts for studies of the risks of lung disease in coal miners and other workers. Jim’s team defined the sampling criteria for the aerosol that can be inhaled into the nose or mouth, in collaboration with other European scientists and, in 1986, published the description and experimental characterisation of the IOM Inhalable Dust sampler. This sampler has been recommended for measuring dust exposure in workplaces around the world. Its design, which the IOM patented, has remained essentially unchanged for almost 40 years. Jim’s academic and professional achievements spanned an enormous breadth, but his legacy is his contribution to the way we sample hazardous aerosols.
91 Isocyanates Aerosols Sampling for Occupational Exposures Assessment
Authors: Guillemot Marianne , Ravera Christel , Melin Sandrine , Simon Xavier , Langlois Eddy
Published: May 2023

Isocyanate compounds are potent sensitizers, in particular through the development of skin dermatitis and allergies. They are one of the main causes of occupational asthma. None no-adverse-effect level has been establishes for isocyanates, therefore, it is important to measure isocyanates level at workplaces. Most of the time, isocyanates are present in workplaces atmosphere both in gas and particle phase, which makes their quantitative sampling difficult. Actual sampling methods do not fit with individual sampling over 8 hours. The aim of this work was first to characterize the particles size distribution in workplaces, depending on the isocyanate and the process used. Then, we studied the effectiveness of CIP 10-I as a sampling device for four isocyanates, compared to impinger and impregnated filter. Particles size distribution was determined thank to different cascade impactors such as Andersen, DLPI+ and MiniMOUDI-8. The Mass Median Aerodynamic Diameter (MMAD) of 4,4’-MDI (4,4’-diphenylmethane diisocyanate) particles in polyurethane foam projection process was found to be higher than 4 µm. In paint spray process, HDI (hexamethylene diisocyanate) particles MMAD was between 1 and 2 µm. The aerosol generation system was designed to obtain particles sizes closed to those observed in workplaces. The CIP 10-I collection foam was impregnated with the same derivative agent as filters. HDI, 2,4-TDI and 2,6-TDI (Toluene diisocyanate) aerosols were generating at concentrations between 10 and 250 µg/m3 in dry air. Whatever the concentration, CIP 10-I collection efficiency is higher than that of filters. Further investigation are currently performed to investigate CIP 10-I performance for MDI sampling.
108 Can Low-Cost Sensor Networks Help Occupational Hygiene?
Authors: Kangas Anneli , Winkler Nicholas P , Poikkimäki Mikko , Neumann Patrick P , Säämänen Arto
Published: May 2023

This study aims at achieving a better picture of the spatial and temporal distribution of industrial pollutants in the working environment. We explore the utilization of this information in occupational hygiene practice by developing and building a low-cost sensor network in multiple real working environments. Sensor networks were installed in different scenarios: in- and outdoors of a steel factory and on a cruise ship’s car deck. The stationary sensor networks are composed of multiple custom sensing nodes. Each node is equipped with various low-cost sensors to assess gaseous components, dust particles, temperature, and humidity. Additionally, measurements using validated traditional occupational hygiene methods and high end portable direct-reading instruments (DRIs) are performed stationary and mobile. Mobile devices carried by the workers in the breathing zone complement the measurements by the stationary sensor network. The results consist of evaluations carried out through combining the sensor data, contextual information and the results obtained with traditional occupational methods. Can this data fusion be used to assess exposure, and target risk management measures? In this work, we discuss the feasibility of the available sensors for industrial measurements and further explore the suitability of pollutant concentration maps for exposure assessment and for planning control measures.
129 A Novel Controlled Test Atmosphere Generation System for the Exposure Assessment Method Setup and Validation
Authors: Langlois Eddy , Schultz Benoit , Ravera Christel , Lily Jean Baptiste
Published: May 2023

Active sampling and analytical methods for the exposure assessment to chemical compounds have to be validated prior to be used on field. Requirements for the evaluation of these measuring procedures are specified in the ISO 22065 standard and include experiments to be done with a dynamic system for generating known concentration of gas and vapour in air under controlled conditions. Unfortunately, laboratories are rarely equipped with this kind of system and they have to carry out manual spiking of samples with a liquid micro-syringe, which is time consuming and source of uncertainty. In order to meet the requirements for accurate methods, we have designed and developed a fully automated generation system -called COMET generation system- that allows producing simultaneously four distinct concentration levels of gaseous pollutants and to perform automated multiple samples in each concentration branch according to the ISO 22065 standard compliance. The system is based on innovative pollutant generation, temperature and humidity control and multiple sampling technologies to be contained under a fume hood. The design of the system allows performing all the required sampling within a week whereas manual spiking need several weeks and excluding some important experiments where the temperature and the moisture have to be controlled. An online gas chromatograph or an Infrared photoacoustic analyzer determine the actual concentration in each concentration level branch. Two different methods were validated with both manual spiking and with the COMET system and the results were similar. Repeatability and overall uncertainty are significantly lower with the COMET system.
16 Advanced Solutions for Comprehensive Ambient Air Monitoring
Authors: Widdowson Caroline , Calder Hannah
Published: May 2023

Growing concerns over harmful exposure to low levels of hazardous air pollutants has led to increasingly demanding volatile organic compound (VOC) monitoring programs. Regulations are evolving to increase monitoring frequency, expand the list of target compounds and set lower detection limits in ambient air. Alongside this ambient and indoor air research continues to identify new, challenging compounds. There have long been specific standard methods and regulations for subsets of compounds, each using different instrumentation. For example method TO-15 for air toxics requires TD-GC-MS, ozone precursors monitoring uses TD-GC-FID and aldehydes are sampled with DNPH cartridges, analyzed by HPLC. Each compound set has its own challenges. Even so there is a drive to combine all three analyses into a single analytical run with the possibility of monitoring in online and offline. Additional considerations are high levels of humidity and large sample volumes, required to meet lower reporting limits. These require sophisticated trapping and water management techniques. As such removal of water from canister and on-line samples without loss of polar species is paramount for successful analysis of the Ozone Precursors, Air Toxics and oxygenated VOCs. This presentation will address the challenges associated with this complex compound list and show how confident identification and quantitation, with maximum sensitivity, can be achieved using state of the art pre-concentration technology. The cryogen-free methodology allows remote, on-line analysis or off-line canister sampling, all with a sample-to-sample cycle time of <60 minutes, significantly reducing equipment overhead and analysis times whilst enhancing insight into air quality.
22 Evaluation of Occupational Exposure to Respirable Crystalline Silica in Processing of Artificial Stone
Authors: Salamon Fabiola , Martinelli Andrea , Gottardo Ottorino , Carrieri Mariella
Published: May 2023

Introduction

Clusters of silicosis cases related to the fabrication of quartz conglomerate products and accessories for the furnishing of kitchens and bathrooms are recently reported. The aim of this study was to evaluate the exposure to airborne respirable dust and crystalline silica (RCS) in a company specialized in the production of quartz conglomerates countertops and to investigate the effectiveness of introduced preventive measures (wet finishing, increasing of exhaust ventilation, closing in cabins some of the sanding and finishing operations).

Materials and Methods

The study was carried out on 51 workers involved in cutting and finishing operations in four facilities. Exposure to respirable dust was evaluated using GS3 cyclones positioned at the breathing zone level for the entire duration of the work shift. RCS content was measured by X-ray diffractometric analysis.

Results and Discussion

Respirable dust levels were in the range 0.046-1.154 mg/m3 (mean 0.160 mg/m3) with RCS levels within the range <0.003-0.098 mg/m3 (mean 0.022 mg/m3). All RCS levels were lower than the Italian OEL of 0.100 mg/m3 and the 22% above the more restrictive ACGIH-TLV of 0.025 mg/m3. Statistically higher levels were found in correspondence with finishing operations than in cut operations (p<0.05) and during dry operations than in wet (p=0.02). RCS levels were lower than those found in the past before the introduction of preventive technical measures where RCS levels were up to 0.744 mg/m3. Although there was a decisive reduction in exposure levels compared to what was observed in the past, the data still showed a risk condition for some activities. Board of the Italian Association of Industrial Hygienists (AIDII). Her scientific activity is documented by over 80 printed publications both as articles in Journals and contributions to National Congresses.
68 Urinary Biomarkers of Benzene Exposure and Oxidative Damage in Residents of the Oil Extraction Area of Muanda, Dr Congo
Authors: Radu - Corneliu Duca
Published: May 2023

The territory of Muanda, on the Atlantic coastline of the DR Congo, is an area of off-shore and on-shore oil extraction. Following concerns of the local population about the possible environmental and health consequences of these activities, a pilot study was performed in December 2015 to assess, among other issues, the exposure of residents of various relevant locations to oil-derived chemicals. We measured metabolites of benzene (t,t-Muconic Acid, MA, and S-Phenylmercapturic acid, S-PMA) by LC-MS and 8-hydroxy-2’-deoxyguanosine (8-OHdG, as an indicator of DNA damage) by ELISA, in urine spot samples of 53 volunteers (34 adults, 19 children, recruited by convenience sampling) living within areas of oil extraction with flaring (n=27), in an area where petroleum products were handled (n=14), and in a control area in the Mangroves National Park (n=12). Concentrations of both MA and S-PMA were increased among residents of the oil extraction areas (0.23±0.05 mg/L, 1.04±0.30 µg/L, respectively) and petroleum products area (0.32±0.08 mg/L, 1.74±0.63 µg/L, respectively) compared with controls (0.06±0.01 mg/L, 0.40±0.13 µg/L, respectively). Concentrations of of MA and S-PMA correlated with levels of 8-OHdG (RSpearman = 0.37, p<0.01). Our biomonitoring study revealed a low degree of benzene exposure among residents living in the oil extraction and petroleum handling areas compared to a control area. Although the levels of benzene metabolites were low, the positive correlation with 8-OHdG possibly indicates that pollution by hydrocarbons induced oxidative damage in this study population.
70 Evaluation of High Efficiency Nebulisers to Increase the Sensitivity of the ICP-AES Technique Promulgated in ISO 15202
Authors: Butler Owen , Musgrove Darren
Published: May 2023

International Standard (ISO) 15202 describes methods for the determination of metals and metalloids in workplace air. Its development involved harnessing selected sample digestion procedures, promulgated in existing national standards, with additional method validation work carried out by HSE. In summary, requirements for air sampling (part 1); acid digestion procedures for dissolving air filter samples (part 2) and procedures for the analysis of digests (part 3) by inductively coupled plasma-atomic emission spectrometry (ICP-AES) are described. Exposure limit values for many metals/metalloids are now reducing and consequently more sensitive analytical techniques such as ICP-MS (promulgated in ISO 30011) may well be required in occupational hygiene laboratories. Boosting the sensitivity of the ICP-AES technique through the use of high efficiency sample introduction systems (nebulisers) is however possible as described in this presentation.
90 Bioaerosol Exposure in Automated and Traditional Waste Sorting Plants
Authors: Eriksen Elke , Afanou Anani Komlavi , Straumfors Anne , Graff Pål , Madsen Anne Mette
Published: May 2023

The waste management sector takes a central part in the transition towards circular economy and is subject to technological progress and the implementation of new work operations. Traditional waste collection and processing systems are characterized by numerous tasks that favour waste workers’ exposure to bioaerosols, whereas exposure in modern automated waste sorting plants remains elusive. Moreover, there is still a lack of health-risk based exposure limits for most components contained in bioaerosols. We investigated occupational exposure to bioaerosols in traditional and automated waste sorting plants. The results revealed significant differences in various exposure levels, such as total dust (GM automated: 0.34 mg/m3, GM manual: 0.66 mg/m3), endotoxins (GM automated: 51 EU/m3, GM manual: 32 EU/m3) and microorganisms between and within type of plant. An assessment of the composition of air-borne fungal particles (FESEM based immunodetection method) showed significantly increased levels of fungal spores at automated waste sorting plants (GM automated: 1.2 × 105 spores/m3, GM manual: 2.1 × 104 spores/m3). Elevated total dust levels and concentrations of submicronic fungal fragments were significantly correlated to the occurrence of symptoms of the extrathoracic region, such as congested nose, in exposed workers. The results of this study showed high variation in exposure levels between and within type of waste sorting plant, as well as seasonal variation for some parameters, such as total dust and endotoxins. This indicates that Norwegian waste workers are potentially exposed to high levels of dust and microorganisms that may cause adverse health effects in receptible individuals.
94 Reducing Exposure to Respirable Crystalline Silica in the Construction and Minerals Industry by Using Wearable Real Time Respirable Dust Monitors
Authors: Averdieck William , Furnell Linda
Published: May 2023

Real time monitoring of respirable dust (as a surrogate for RCS) opens the opportunity to warn workers when entering work areas with increased dust levels to provide them the information to fit RPE properly or exit the area. However in the past, the adoption of such monitoring approaches has been limited due to the bulkiness and price of devices. This paper reflects on how the miniaturisation of Optical Particle Counters has enabled light weight (<150g) wearable devices to be developed which are convenient for workers in the construction and minerals industry to wear on all working days. It provides an overview of the Optical particle counter. its performance in measuring respirable dust and how it has been integrated into a battery powered ' DustCanary; wearable device. Due to its size and convenience the DustCanary provides protection to both those at first line risk due to the areas they work (eg stone cutters, plant operatives) who by wearing such can devices can help identify changes in performance of Local Exhaust Ventilation (LEV). or controls so that remedial action can be taken secondary risk on a plant who are not necessarily wearing RPE (such as delivery drivers) who can be warned when they enter an area where there are elevated respirable dust levels Case study data and examples will be shared.
101 PAH Exposure During Construction of Railroad Swithes with Creosote Impregnated Ties
Authors: Graff Pål , Westberg Håkan , Strandberg Bo , Lindh Christian , Bryngelsson Ing-Liss , Hagberg Jessika
Published: May 2023

Coal tar creosote, or creosote, is a by-product of the carbonization of coal to produce coke and has been used as a wood preservative since the late 19th century. Creosote is a mixture of many different compounds such as polycyclic aromatic hydrocarbons (PAH)s, phenols and cresols. Even though several PAHs are carcinogenic to humans, creosote is still used in impregnation of railway ties and electricity and telephone poles. Occupational exposure can occure from inhalation of creosote vapour or through skin contact. Dermal uptake is considered to be the most important route of exposure to PAHs. Even though the ratio between different PAHs may vary, measurements of 1-hydroxy-pyrene (1-HP) in urine is the common method for biological monitoring of occupational exposure to PAH. This study was conducted indoors in a facility where railroad switches are assembled with concrete or creosote impregnated wood ties. The aim of the study was to assess the workers´exposure to PAHs by (i) measuring PAH 16 in the breathing zone from whole shift samples, (ii) examining the dermal exposure of pyrene using a tape stripping technique, (iii) assessing the workers´ internal exposure by measuring 1-OHP in urine samples. The study show that during construction of railroad switches made from creosote impregnated ties workers get urinary levels of 1-OPH above the Biological Guidance Value during the work week. Dermal uptake seems to be the main route of exposure and preventive measures should be focused upon reducing the dermal exposure.

Speaker Biography

Pål Graff works as a Professor at the Norwegian National Institute of Occupational Health and Norwegian University of Life Sciences. His main research interests are exposure assessment and epidemiology.
136 Occupational Exposure to Asbestos
Authors: Ervik Torunn , Hammer Stine Eriksen , Skaugset Nils Petter , Graff Pål
Published: May 2023

Asbestos containing materials (ACMs) are still found in many buildings even though the use of asbestos in building materials has been prohibited in Norway since 1985. Employees that may be at risk of exposure to airborne fibers are workers within the construction industry. However, firefighters and workers investigating fires may also encounter asbestos fibers in their work. The aim of this study was to investigate the airborne fiber concentration during abatement of various ACMs. A comparison of counting results from scanning electron microscope (SEM) and phase-contrast microscope (PCM) were performed for these measurements. A separate part of the study focused on thermal transformation of fibers during fires. Parallel personal air samples were collected during asbestos abatement of different building materials and analyzed with SEM and PCM, respectively. Material samples from abatement sites and from fire scenes were investigated in SEM. The highest fiber concentrations were measured during interior wall removal (1.5-4.5 fibers/cm3 (f/cm3)). Thin fibers (<0.2 µm in width) constituted up to 50% of the total fiber concentration for some ACMs. Asbestos fibers observed in ACMs after fire may show a thermal transformation, however, in many cases the fibers are unchanged. For ACMs investigated in this study, there seem to be a good correlation between samples analyzed by SEM and PCM if the only dominant fiber type present is asbestos fibers. Thin fibers may constitute a large fraction of the total fiber concentration released and counting these fibers are therefore important for an adequate risk and exposure assessments.
142 Gas Phase Polycyclic Aromatic Hydrocarbon Exposure in Kenyan Households
Authors: Forbes Patricia , Osano Aloys , Maghanga Justin
Published: May 2023

A vast number of people in developing countries rely on solid fuels, including wood and charcoal, for domestic energy supply. We have studied the gaseous polycyclic aromatic hydrocarbon (PAH) concentrations in Kenyan homes in order to better understand the potential health risks associated with domestic combustion practices and to advise mitigation strategies. A comprehensive survey was conducted to elucidate the complex and multi-faceted factors governing fuel use in Kenyan coastal and inland regions. Results showed an almost equal distribution in fuel type usage between firewood, charcoal, kerosene and liquid petroleum gas (LPG). In rural areas, three-stone stoves were still predominant, whilst cleaner devices burning kerosene and LPG were used more widely in urban communities. Indoor air was subsequently sampled in a range of urban and rural households using portable polydimethylsiloxane sampling tubes. These were extracted using the plunger assisted solvent extraction (PASE) technique, followed by GC-MS analysis of the U.S. Environmental Protection Agency (EPA) priority PAHs. Total PAH concentrations in samples collected varied considerably (0.82 – 173.69 µg/m3), which could be attributed to differences in fuel type, combustion device, climate, and nature of the households. Higher [PAH] were found in rural homes, although ambient PAH concentrations were higher in urban environments, likely due to traffic contributions and population density. Toxicity equivalent quotient values varied widely between households and emphasised the importance of good combustion practices to minimise human exposure.
14 Carcinogenicity Risk Assessment of Various Carbon Nanotubes by Intra-Tracheal Intra-Pulmonary Spray (TIPS) Dosing Followed by 2-Year Observation
Authors: Tsuda Hiroyuki , Ahmed Omnia , Saleh Dina , Alexander William , Alexander David , Numano Takamasa , Takase Hiroshi , Naiki-Ito Aya , Hirose Akihiko , Kanno Jun , Yudasaka Masako , Yuge Ryota , Tomono Susumu , Wei Min , Hojo Motoki , Tsuruoka Shuji
Published: May 2023

Multi-walled carbon nanotubes (MWCNTs) are composed of multiple coaxially arranged graphene cylinders. MWCNTs range in diameter from 1 to over 100 nm depending on the number of constituting graphene cylinders. MWCNTs can be divided into two general subtypes, straight and tangled: increasing the number of constituent graphene cylinders increases the number of layers that compose the carbon nanotube wall, and as the number of wall layers increase, the wall thickness increases and the MWCNT becomes more rigid and straight. MWCNTs with a low number of wall layers are flexible and can assemble into tangled agglomerates. We initially showed MWCNT-N, a straight-type MWCNT with 30-40 walls, induced lung tumors and mesotheliomas after administration by intra-tracheal intra-pulmonary spraying (TIPS): rats were administered a total dose of 1mg/rat during the initial 2 weeks of the study, and animals were observed for 2 years without any further treatments. Using this short-term dosing and 2-year observation method we conducted carcinogenicity tests for other MWCNTs with different cylinder wall layers. We found that both straight type MWCNTs, MWCNT-7 (40 layers), MWCNT-A (150 layers), and tangled type MWCNTs, MWCNT-B (15 layers) and double-walled CNT (DWCNT) (2 layers) induced lung tumors and/or pleural mesotheliomas. In contrast to these results, we found carbon nanohorns, carbon nanostructures composed of single-walled carbon nanotubes (SWCNT), and carbon nanobrushes, a fibrous aggregate of carbon nanohorns, were not carcinogenic. Data on foreign body radical production, microarray and mutational signature analyses, and gene alterations will be presented.
17 Effects of Indoor Air Pollution on Both a Healthy and “an Inflamed” Model of the Alveolar Barrier in Vitro.
Authors: Meldrum Kirsty , Evans Stephen J , Burgum Michael J , Doak Shareen H , Clift Martin J D
Published: May 2023

Exposure to indoor air pollutants (IAP) has increased recently, with people spending more time indoors. Increased exposures of IAP on a healthy population are poorly understood, and those with allergic respiratory conditions less so. The objective of this study, therefore, was to implement a well-characterised in vitro model of the human alveolar epithelial barrier (A549+PMA differentiated THP-1 incubated with/without IL-13, IL-5 and IL-4) to determine the effects of a standardised indoor particulate (NIST2583) on both a healthy lung model and modelling a type-II inflammatory response. Using concentrations from the literature, and an environmentally appropriate exposure we investigated 232, 464 and 608ng/cm2 of NIST2583 respectively. Membrane integrity (blue dextran), viability (trypan blue), genotoxicity (micronucleus (Mn) assay) and (pro-) and (anti-)inflammatory effects (IL-6, IL-8, IL-33, and IL-10) were then assessed 24hours post exposure to both models. No changes in Mn frequency or membrane integrity in either model was noted when exposed to any concentration of NIST2583 tested. Though, a significant decrease (p<0.05) in viability at the highest concentration was observed in the healthy model. Whilst cell viability in the “inflamed” model significantly decreased (p<0.05) at the lower concentrations. A significant reduction (p<0.05) in IL-10 and increase in IL-33 was seen after exposure to NIST2583 in the “inflamed” model. Collectively, the results indicate the potential for IAP to cause the onset of an allergic response as well as exacerbating pre-existing allergic conditions. Furthermore, the data imposes the importance of considering unhealthy individuals when investigating the potential health effects of IAP.
20 An Approach Towards in Vitro-Based Human Toxicity Effect Factors for the Life Cycle Impact Assessment of Inhaled Low-Solubility Particles.
Authors: Romeo Daina , Hischier Roland , Nowack Bernd , Wick Peter
Published: May 2023

Life Cycle Assessment (LCA) calculations of products containing nanomaterials are limited in their comprehensiveness by the lack of characterization factors linking nanomaterial emissions to their impacts on human health. This is mainly due to the scarcity of animal toxicological data compared to the number of existing nanomaterials, a constraint that could be lifted if in vivo data could be substituted by in vitro data to calculate nanomaterials' effect factors (EF). To support a future animal-independent LCA methodology, we present a step-by-step procedure to calculate in vitro-to-in vivo extrapolation factors to estimate human Benchmark Doses and subsequently in vitro-based EFs for inhaled non-soluble nanomaterials. Titanium dioxide, amorphous silica, cerium oxide and crystalline silica are presented as case studies. Based on mouse data, the in vitro-based EF of TiO2 is between 2.76*10-4 and 1.10*10-3 cases/(m2/g *kg intake), depending on the aerodynamic size of the particle, which is in good agreement with in vivo-based EFs (1.51*10-4 - 5.6*10-2 cases/(m2/g *kg intake)). The EF for amorphous silica is in a similar range as for TiO2, but the result is less robust due to only few in vivo data available. The discrepancy between in vivo and animal in vitro data in terms of availability and quality limits the coverage of further nanomaterials. While the work focused on LCA, the procedure can be easily adapted for risk assessment as well, thus increasing the relevance of our findings.
25 Using Advanced in Vitro Approaches to Elucidate the Differential Toxicity of Nitrogen Dioxide and Particulate Matter in Ambient Air Pollution
Authors: Bateman Joshua , Robertson Sarah , Buckley Alison , Wright Matthew , Guo Chang , Leonard Martin O , Doak Shareen H , Smith Rachel , Clift Martin J D
Published: May 2023

Ambient nitrogen dioxide (NO2) and particulate matter (PM) concentrations are often found to be proportional, such that inhalation of one pollutant is expected to be accompanied by the inhalation of the other. Epidemiological evidence consistently demonstrates the health burdens associated with the inhalation of NO2 and PM, though has difficulty deciphering the inhalation hazard of either pollutant individually. Airway models can be exposed to NO2 and PM separately or as a co-exposure in vitro, allowing mechanisms of toxicity to be elucidated. Herein, NCI-H441 cells were exposed to either 780 ng/cm2 Printex 90 carbon black (CB) (a surrogate model of PM) using a VitroCell Cloud12, 5 ppm NO2 (within a modified Coy hypoxic cabinet) or a combination of NO2+CB over 24 hours. Cytotoxicity was not altered by NO2 or CB (trypan blue exclusion assay), however CB, and to a lesser extent CB+NO2 exposure resulted in a non-significant increase in membrane permeability (p>0.05). qPCR revealed no alterations in expression of superoxide dismutase 1 (SOD1) for any exposure condition. Both CB and NO2 exposures resulted in significantly increased IL6 and IL8 release (ELISA) (p<0.05), although co-exposure of the two pollutants did not augment the detected IL6 or IL8 levels. These data indicate NO2 and CB produce an inflammatory response in this model, though little evidence suggests that NO2 and CB act in an additive or synergistic manner via this pathway. Additional work remains ongoing to establish the mechanisms of toxicity utilising an anatomically relevant triple cell co-culture of the alveolar epithelial barrier.
35 2D-Hexagonal Boron Nitride and Lung Exposure: Exploring Long-Term Effects in Healthy Versus Asthmatic Human Lung in Vitro Model
Authors: Gupta Govind , Wick Peter , Buerki-Thurnherr Tina
Published: May 2023

Inhalation is one of the most pertinent routes of exposure to nanoscale materials in occupational settings. Hexagonal boron nitride (hBN) is an emerging 2D material attracting significant attention due to its superior electrical, chemical, and thermal properties. For a successful commercial application of 2D-hBN, it is of key importance to understand their safety in occupational settings. However, long-term toxicity profile of this material is largely unknown. Here, an investigation of how 2D-hBN (obtained from Graphene Flagship consortium) interacts with lung cells of healthy versus diseased individuals has been performed. We used air−liquid interface-based exposure models to investigate the potential long-term toxicity of 2D-hBN in human lung airway epithelial cells (Calu-3) and 3D reconstituted airway epithelia (MucilairTM) of healthy and asthmatic subjects. Our results revealed that 2D-hBN was taken up by cells but did not trigger cytotoxicity at occupationally relevant repeated dose exposure for five weeks. However, screening of an immuno-cytokine/chemokine panel indicated an enhanced release of certain cytokines after exposure to 2D-hBN. In addition, we observed a pronounced intracellular accumulation of lipids in lipid droplets after exposure to 2D-hBN. Since lipid intermediates can play important roles in immune-cell activation and the development of lung diseases, we are currently analysing whether 2D-hBN induces alterations in lipid composition in healthy and asthmatic cells by applying global lipidomic profiling. Overall, our data indicate a potential correlation of certain lipid accumulation with enhanced immune signaling, highlighting the need for further studies to understand if 2D-hBN can sensitize for or aggravate pulmonary diseases.