Laboratory Exposure Research Articles

Minimizing formaldehyde exposure in a hospital pathology laboratory.

The safety and health of healthcare workers employed in pathology laboratories and exposed to formaldehyde (FA) is a matter of concern worldwide, as several health effects have been observed in workers resulting from exposure to FA, both short and long-term. The study was aimed to describe the strategy implemented in a hospital pathology laboratory to minimize workers' exposure to FA through interventions to working environment and workforce. The NIOSH 2016 method for detecting gaseous FA was adopted to perform personal and area active sampling of FA. The samples were subsequently analyzed by High Performance Liquid Chromatography. The exposure to FA was measured before and after improvement interventions. The pre-intervention step showed FA levels exceeding the threshold limit values (TLV) established by ACGIH, both the time-weighted average (TLV-TWA) and short term exposure limit (TLV-STEL); after the improvement interventions, the median concentrations of personal and area FA sampling were respectively of 0.025 ppm (Range = 0.023-0.027) and 0.023 ppm (Range = 0.022-0.028) and significantly lower than pre-intervention step (p < 0.05) and below the TLV-TWA and TLV-STEL established by ACGIH. In our study the workers' involvement in the risk management of FA exposure together with engineering improvements revealed a strategic way to minimize the FA pollution in the studied laboratory. Healthcare companies should consider the need to ensure the workers' participation in the management of occupational hazards, including FA, to reach the goal of healthy workplaces.

Human Health Exposure Analysis Resource (HHEAR): A model for incorporating the exposome into health studies.

Characterizing the complexity of environmental exposures in relation to human health is critical to advancing our understanding of health and disease throughout the life span. Extant cohort studies open the door for such investigations more rapidly and inexpensively than launching new cohort studies and the Human Health Exposure Analysis Resource (HHEAR) provides a resource for implementing life-stage exposure studies within existing study populations. Primary challenges to incorporation of environmental exposure assessment in health studies include: (1) lack of widespread knowledge of biospecimen and environmental sampling and storage requirements for environmental exposure assessment among investigators; (2) lack of availability of and access to laboratories capable of analyzing multiple environmental exposures throughout the life-course; and (3) studies lacking sufficient power to assess associations across life-stages. HHEAR includes a consortium of researchers with expertise in laboratory analyses, statistics and logistics to overcome these limitations and enable inclusion of exposomics in human health studies. This manuscript describes the structure and strengths of implementing the harmonized HHEAR resource model, and our approaches to addressing challenges. We describe how HHEAR incorporates analyses of biospecimens and environmental samples and human health studies across the life span - serving as a model for incorporating environmental exposures into national and international research. We also present program successes to date. HHEAR provides a full-service laboratory and data analysis exposure assessment resource, linking scientific, life span, and toxicological consultation with both laboratory and data analysis expertise. HHEAR services are provided without cost but require NIH, NCI, NHLBI, or ECHO funding of the original cohort; internal HHEAR scientific review and approval of a brief application; and adherence to data sharing and publication policies. We describe the benefits of HHEAR's structure, collaborative framework and coordination across project investigators, analytical laboratories, biostatisticians and bioinformatics specialists; quality assurance/quality control (QA/QC) including integrated sample management; and tools that have been developed to support the research (exposure information pages, ontology, new analytical methods, common QA/QC approach across laboratories, etc.). This foundation supports HHEAR's inclusion of new laboratory and statistical analysis methods and studies that are enhanced by including targeted analysis of specific exposures and untargeted analysis of chemicals associated with phenotypic endpoints in biological and environmental samples. HHEAR is an interdisciplinary team of toxicologists, epidemiologists, laboratory scientists, and data scientists across multiple institutions to address broad and complex questions that benefit from integrated laboratory and data analyses. HHEAR's processes, features, and tools include all life stages and analysis of biospecimens and environmental samples. They are available to the wider scientific community to augment studies by adding state of the art environmental analyses to be linked to human health outcomes.

Treatment-level impacts of microplastic exposure may be confounded by variation in individual-level responses in juvenile fish

Microplastic (MP) pollution is a key global environmental issue and laboratory exposure studies on aquatic biota are proliferating at an exponential rate. However, most research is limited to treatment-level effects, ignoring that there may be substantial within-population variation in responses to anthropogenic stressors. MP exposure experiments often reveal considerable, yet largely overlooked, inter-individual variation in particle uptake within concentration treatments. Here, we investigated to what degree treatment-level responses to MP exposure may be affected by variation in MP ingestion rates in the early life stages of a marine fish, the Gilt-head seabream, Sparus aurata. First, we tested whether MP ingestion variation is repeatable. Second, we assessed to what degree this variation may determine individual-level effects of MP exposure on fitness-related behavioural performance (i.e., escape response). We found that consistent inter-individual variation in MP ingestion was prevalent and led to differential impacts within exposure treatments. Individuals with high MP ingestion rates exhibited markedly inferior escape responses, a result that was partially concealed in treatment-level analyses. Our findings show that the measured response of populations to environmental perturbations could be confounded by variation in individual-level responses and that the explicit integration of MP ingestion variation can reveal cryptic patterns during exposure experiments.

Detection of spatial and spatio-temporal Salmonella Heidelberg and Salmonella Typhimurium human case clusters focused around licensed abattoirs in Ontario in 2015, and their potential relation to known outbreaks.

Salmonellosis is one of several zoonotic diseases for which individuals with occupational animal contact, including abattoir workers, are at an increased risk. If meat is contaminated during slaughter, this can increase the risk of enteric illness for consumers. In this study, we investigated whether reported cases of Salmonella Heidelberg and Typhimurium were clustered around abattoirs in Ontario in 2015 and whether there was any evidence (laboratory/exposure) to suggest an abattoir at the centre of a cluster might be the source of exposure. Data for each reported case of S.Heidelberg and S.Typhimurium in Ontario in 2015 were collected. Multi-focused and non-focused spatial and space-time cluster detection tests were performed for each serotype, with and without cases linked to known outbreaks, using Poisson and space-time permutation models. Focused tests included the location of abattoirs operational in all or part of 2015. Laboratory data and exposure information were used to explore the relatedness of cases within identified clusters. Focused spatial tests identified clusters of S.Heidelberg and S.Typhimurium around abattoirs. Focused space-time permutation tests identified 2 significant space-time clusters of S.Heidelberg; one cluster (n=11 cases) included 8 of 9 cases associated with a known outbreak and the other cluster (n=18 cases) was not part of a previously identified outbreak. Review of laboratory and risk factor information suggested that cases within each cluster shared a common exposure. Cases were not asked about goat or sheep meat consumption. The focused cluster test, particularly with the space-time permutation model, could assist in identifying outbreaks associated with a particular physical location, such as an abattoir. Improvements to the current case investigation process, such as consistent collection and reporting of high-risk occupation information and more detailed food consumption history, could assist in outbreak identification when coupled with this statistic.

Structural silicone sealants after exposure to laboratory test for durability assessment

AbstractDuring the service life of structural sealant glazing (SSG) facades, the load‐bearing capacity of the silicone bonds needs to be guaranteed. Laboratory tests can assess the durability of SSG‐systems based on mechanical characteristics of the bond after simultaneous exposure to both climatic and mechanical loads. This article studies how the material characteristics of two common structural sealants are affected by laboratory and field exposure. Dynamic mechanical analysis (DMA) confirms a reduction in the dynamic modulus of exposed silicone samples. Results from thermogravimetric analysis, Fourier‐transform infrared spectroscopy, differential scanning calorimetry, and small‐angle X‐ray scattering/wide‐angle X‐ray scattering show differences between the two sealants and indicate no/minor changes in the composition and morphology of the laboratory and field exposed sealants. Mechanical characterization methods, such as DMA, and tensile and shear testing of the structural bond, are shown to be sensitive toward the combined climatic and mechanical loadings, and are hence suitable for studying degradation mechanisms of structural sealants.

The anatomy course during the time of COVID‐19 ‐ students’ initiation of reflections on life's passing in dissection and non‐dissection anatomy courses

BackgroundDuring the COVID‐19 pandemic, in‐person cadaveric dissection to teach anatomy was often omitted. While knowledge‐based assessment can be evaluated via remote exams, soft skills (e.g., reflections on the topic of death) can often be overlooked. This study aims to quantitatively investigate how different anatomy course formats play a role in initiating students’ reflections on life's passing, during the COVID‐19 pandemic.MethodIn the fall semester of 2020, 216 medical, dental, premedical undergraduate, and health sciences students from 14 international universities discussed (in small groups) differences in their anatomy courses as part of an online exchange program. Formats of anatomy education delivery in the 14 universities ranged from dissection, hybrid dissection‐prosection, and prosection only, to no laboratory exposure during the pandemic. Students’ responses to the question, “Did/does your Anatomy course initiate your thinking on life's passing?” were collected utilizing a multiple‐choice question and a short essay. Statistical analysis was performed using Chi‐square analysis.Results105 students dissected (group 1), 21 had a hybrid dissection‐prosection class (group 2), and 79 had no dissection (group 3). 11 students did not have an anatomy course. Within the 3 groups, 149 students had exposure to human anatomical specimens and 52 students did not. A majority of students in groups 1 and 2 reported that the anatomy course helped them to initiate reflections on the topic of death, compared to those in group 3 (75% and 71% respectively, versus 36%, p<0.05). The majority of students who had exposure to human anatomical specimens thought that the course did initiate thoughts about life's passing, compared to students who did not have this exposure (p<0.05). Students who did not dissect during the time of the pandemic felt that talking with their peers who did dissect during this period (i.e., at schools that did offer dissection) resulted in initiating thoughts about the topic of death.DiscussionAnatomy dissection courses and exposure to human anatomical specimens help initiate reflection on the topic of life's passing. During the COVID‐19 pandemic interactions between students who do not dissect and their peers who do dissect help initiate thoughts about the topic of death in the non‐dissecting students, as reflected by their essays. Without exposure to human bodies there is less chance that students will think about this subject.ConclusionAnatomy dissection courses are important for the initiation of students’ feelings about the topic of death. During the COVID‐19 pandemic, dissecting students can help non‐dissecting students with initiating reflections about life's passing by discussing this subject with each other.

Long-term exposure of marine mussels to paracetamol: is time a healer or a killer?

Pharmaceuticals pose a major threat to the marine environment, and several studies have recently described their negative effects on marine organisms. Pharmaceutical compounds are constantly being released into aquatic ecosystems, and chronic exposure, even at low concentrations, may have a major impact on marine organisms. The purpose of the present study is to evaluate the biological changes induced by one of the most widely used pharmaceuticals—paracetamol—in the blue mussel Mytilus edulis, after a long-term exposure at environmentally relevant concentrations. We present our data alongside and in comparison with results from a previous short-term exposure, to demonstrate the significance of exposure period on the effects of paracetamol in adult blue mussels. After 24 days of laboratory exposure, seven potential target genes were selected to examine toxicological effects in mussels’ gonads and possible disruptive effects on reproductive processes. The results show the modulation of some important reproduction-related genes: estrogen receptor-2 (ER2), vitelline envelope zona pellucida domain-9 (V9), and vitellogenin (VTG). Variations in mRNA expression of four other genes involved in apoptosis (HSP70, CASP8, BCL2, and FAS) are also highlighted. Histopathological alterations caused by paracetamol, together with neutral red retention time response in mussels’ hemocytes, are presented herein. Overall, this study highlights the exacerbated effects of low concentration of paracetamol after chronic exposure, similar to the damage induced by higher concentrations in a short exposure scenario, thus emphasizing the importance of length of exposure period when studying the effects of this substance. Additionally, this study also discusses the potential of paracetamol to inflict several major changes in the reproductive system of mussels and thus possibly affect the survival of populations.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11356-021-14136-6.

Virulence and Infectivity of UC, MD, and L Strains of Infectious Hematopoietic Necrosis Virus (IHNV) in Four Populations of Columbia River Basin Chinook Salmon

Infectious Hematopoietic Necrosis Virus (IHNV) infects juvenile salmonid fish in conservation hatcheries and aquaculture facilities, and in some cases, causes lethal disease. This study assesses intra-specific variation in the IHNV susceptibility of Chinook salmon (Oncorhynchus tshawytscha) in the Columbia River Basin (CRB), in the northwestern United States. The virulence and infectivity of IHNV strains from three divergent virus genogroups are measured in four Chinook salmon populations, including spring-run and fall-run fish from the lower or upper regions of the CRB. Following controlled laboratory exposures, our results show that the positive control L strain had significantly higher virulence, and the UC and MD strains that predominate in the CRB had equivalently low virulence, consistent with field observations. By several experimental measures, there was little variation in host susceptibility to infection or disease. However, a small number of exceptions suggested that the lower CRB spring-run Chinook salmon population may be less susceptible than other populations tested. The UC and MD viruses did not differ in infectivity, indicating that the observed asymmetric field prevalence in which IHNV detected in CRB Chinook salmon is 83% UC and 17% MD is not due to the UC virus being more infectious. Overall, we report little intra-species variation in CRB Chinook salmon susceptibility to UC or MD IHNV infection or disease, and suggest that other factors may instead influence the ecology of IHNV in the CRB.

Behavioral Parameters of Planarians (Girardia tigrina) as Fast Screening, Integrative and Cumulative Biomarkers of Environmental Contamination: Preliminary Results

The present study aims to use behavioral responses of the freshwater planarian Girardia tigrina to assess the impact of anthropogenic activities on the aquatic ecosystem of the watershed Araguaia-Tocantins (Tocantins, Brazil). Behavioral responses are integrative and cumulative tools that reflect changes in energy allocation in organisms. Thus, feeding rate and locomotion velocity (pLMV) were determined to assess the effects induced by the laboratory exposure of adult planarians to water samples collected in the region of Tocantins-Araguaia, identifying the sampling points affected by contaminants. Furthermore, physicochemical and microbiological parameters, as well as the presence of inorganic compounds (dissolved aluminum, total barium, total chloride, dissolved iron, total fluoride, total manganese, nitrates, nitric nitrogen, total sulfate, total zinc) and surfactants, were determined on each specific sampling point. The behavioral biomarkers (feeding rate and pLMV) of the freshwater planarians were significantly decreased when organisms were exposed to water samples from four municipalities (Formoso do Araguaia, Lagoa da Confusão, Gurupi and Porto Nacional), sites of the Tocantins-Araguaia hydrographic region—TAHR. Both behavioral biomarkers decreased up to ~37–39% compared to organisms in ASTM medium only. Our results showed that these behavioral biomarkers can be used for fast screening monitoring of environmental samples of freshwater ecosystems, since a decrease in feeding rate and locomotor activity was observed in sites impacted by anthropogenic activities. However, the absence of effects observed in some sampling points does not represent the absence of contamination, since several other classes of contaminants were not determined. In these negative results, the absence of deleterious effects on behavioral biomarkers might only be indicative that the potential presence of contaminants on such sites does not significantly affect the performance of planarians. This fast screening approach seems to be useful to determine contaminated sites in freshwater ecosystems for biomonitoring purposes. This knowledge will help to develop biomonitoring programs and to decide appropriate sampling sites and analysis.

Biological effects of multimetal (Ni, Cd, Pb, Cu, Cr, Zn) mixture in rainbow trout Oncorhynchus mykiss: Laboratory exposure and recovery study

The present study tested the biological consequences of exposure to a multimetal mixture as a multiple chemical stressor on Oncorhynchus mykiss at molecular, cellular, physiological and whole-organism levels and on biomarker responses of this fish during the depuration period. To represent environmentally relevant multiple chemical stressors, in our study, we used the mixture of Zn, Cu, Ni, Cr, Pb and Cd at the concentrations corresponding to Maximum-Permissible-Concentrations (MPCs) acceptable for the EU inland waters. This study was undertaken with a view to elucidate if changes in the MPC of the test mixture components (Ni, Pb, Cd) could cause significantly different biomarker responses in O. mykiss from those previously determined in the carnivorous and omnivorous fishes exposed to the mixture of the same metals but at different MPCs of Ni, Pb and Cd. This study has revealed that exposure to mixtures of metals at MPC produces genotoxic effects in fish blood erythrocytes and a lethargic effect on O. mykiss behaviour, and, also, significantly increases the levels of Cd, Cr and Ni accumulated in the gills tissue. O. mykiss successfully depurated Cr and Ni in less than 28 days, however, the level of Cd decreased by only approximately 40% over the same period. A significant capacity of O. mykiss to restore its DNA integrity (Comet assay) after exposure to metal mixtures was revealed. However, the 28-day recovery period proved to be insufficiently long for erythrocytes with nuclear abnormalities to recover to the unexposed level. In conclusion, changes in the MPCs of Ni, Pb and Cd in the test mixture produce biological effects similar to those previously determined in S. salar, R. rutilus and P. fluviatilis exposed to the mixture of the same metals but at lower MPCs of Ni and Pb and at higher MPC of Cd.

Effects of Real-Time Dosimetry on Staff Radiation Exposure in the Cardiac Catheterization Laboratory.

Radiation protection is essential for staff of cardiac catheterization laboratories in order to prevent long-term radiation- associated injury and disease. Instant feedback about the actual received dose may help operators to optimize the use of existing shielding devices. Therefore, the current study was designed to investigate whether routine use of real-time dosimetry may be able to reduce staff radiation exposure. Over a period of 72 days, operators and assisting nurses were equipped with RaySafe i3 real-time dosimeters (Unfors RaySafe AB), but had no access to the dosimetry results during the first half of the study. This was followed by a second period that allowed operators to modify their behavior according to the dosimetry results. Compared with the first phase, the knowledge of real-time dosimetry results led to a uniform reduction in radiation exposure of all team members by approximately 60%, independent of the chosen vascular access. There were no significant changes in fluoroscopy time, dose-area product, or patient characteristics. Real-time dosimetry effectively reduced staff radiation exposure in the cardiac catheterization laboratory. This change was caused by optimized use of existing shielding equipment since no modifications of the general procedural approach or patient characteristics had occurred.

Strengthening Medical Laboratory Systems in Kenya: An Innovative Biosafety Training Model.

Background: With increased rates of laboratory-acquired infections from clinical and research laboratories globally, efforts have been made to improve awareness of modern practices and pursue innovations in biosafety to manage risks and laboratory exposures arising from infectious agents and other hazards. Objectives: This article demonstrates a sustainable biosafety training model developed to enhance laboratory quality and support accreditation in health facilities in Kenya. Methods: A biosafety technical working group was formed, and sensitization meetings held with health managers. Trainings were then conducted for training of trainers (TOTs) who then cascaded trainings in health facilities. This was followed by mentorships and monitoring for implementation. Results: Five sensitization meetings were carried out for 264 health managers. TOTs was done for 48 trained trainers and 1044 laboratory workers in 216 facilities covering 44 counties. Site visits were done in 51 facilities, with biosafety achievements measured in 21 (41%), respectively. Achievements in 21 facilities included the following: improvised eye wash stations in 16 facilities (76%), biological spill kits in 17 (81%), buckets of sand in 15 (71%), fire extinguishers in 12 (57%), hepatitis B vaccination in 14 (66%), establishment of phlebotomy areas in 18 facilities (85%), material safety data sheets in 18 (85%), documentation of incidents and exposures in 16 (76%), and proper waste segregation in 17 (81%). Conclusion: This model ensured rapid scale-up to multiple counties and enabled learners to understand biosafety principles. Due to management buy-in, resources were availed to implement interventions, and this was demonstrated by remarkable achievements across all assessed facilities.

Clinical Propedeutics Students’ Skills in a Simulation Laboratory

During medical education, one of the basic subjects taught to students is clinical propedeutics. That said, technological innovation has vastly improved the quality of medical formation. One of the most recent tools is clinical simulation, which through simulation, incites the development of medical abilities. To demonstrate the medical skills acquired by clinical propedeutics’ students in a simulation laboratory. A quasi-experimental study was performed in undergraduate medical school students enrolled in a clinical propedeutics course. A convenience sample was used, involving a group of students with prior clinical simulation training, and a group without it. A thoracic simulation was performed, to be then evaluated by an instructor committee using the Mini – CEX evaluation. The Research Committee and the Research Ethics Committee of the academic institution granted study approval. Eighteen students without previous simulation laboratory exposure, and 17 with prior simulation training were included. The results of the semiquantitative evaluations exhibited higher scores in the group with prior clinical simulation experience, obtaining significance in all aspects of Mini – CEX, except for physical exploration (8 [4, 5] vs. 5 [4, 5], p<.005). The examiners most notably commented positively in regards to clinical reasoning and communication abilities in the group with previous exposure. The overall examiners’ satisfaction was greater with the simulation group (8 [7.5–8] vs 7 [6, 7], p=.003). The clinical skills enhanced in simulation laboratory training were anamnesis, professionalism, clinical reasoning, communication skills, and organization/efficiency.

Assessment of pesticides in water using time-weighted average calibration of passive sampling device manufactured with carbon nanomaterial coating on stainless steel wire.

The continued contamination of water sources by pesticides is a problem that involves the life of aquatic organisms and human health, especially in countries whose economy is based on agriculture. The need to know the quality of drinking water under these circumstances is a priority for the public health of any community. Passive sampling methods allow the determination of long-term environmental pollutants through a single sample collection, reducing time and cost of analyses. One advantage of passive sampling is that it is possible to calculate a time-weighted average (TWA) concentration value or an equilibrium concentration value, depending on the type of device used and the exposure time. Passive sampling techniques using carbon nanomaterials (CNMs) have a high potential for pesticide sampling in aquatic systems. A device for passive sampling manufactured with CNMs in a microextraction system and recyclable materials was calibrated in laboratory exposure conditions over 15days. The calibration results showed linear accumulation periods between 5 and 10days. Sampling rates were between 0.014 and 0.146mL day-1. The sampler was field-tested in the San Francisco river basin in the state of Minas Gerais in Brazil for 7days. This research allowed for the detection and calculation of TWA concentrations for organochlorine pesticides such as α-HCH, 4,4-DDE, and 4,4-DD in water sources. The manufactured device demonstrated greater sensitivity than the grab sampling processes for the detection of pesticides. The performed passive sampling system using gas chromatography/mass spectrometry (GC/MS) technique allowed for the collection, detection, identification, and quantification of 26 pesticides.

Cytogenotoxicity evaluation of a heavy metal mixture, detected in a polluted urban wetland: Micronucleus and comet induction in the Indian green frog (Euphlyctis hexadactylus) erythrocytes and the Allium cepa bioassay

Heavy metal contamination in wetland ecosystems is a serious environmental and health concern. This study evaluated the cytogenotoxicity of a previously evidenced heavy metal contamination (Cd, Cr, Cu, Pb and Zn ∼5 ppm each) in a polluted urban wetland, the Bellanwila-Attidiya sanctuary (BAS) in Sri Lanka, using a battery of cytogenotoxic assays. Micronucleus and comet assays evaluated the genotoxicity in erythrocytes of a common amphibian, the Indian green frog (Euphlyctis hexadactylus), under natural metal exposure in the wetland, and in vitro exposure, respectively.The Allium cepa bioassay assessed the cytogenotoxicity of the heavy metal mixture and of the individual metals, under laboratory exposure. Although in vivo natural exposure showed no significant induction of micronuclei in frog erythrocytes (P > 0.1), a significant and dose dependent elevation of comets was evident with in vitro exposure to the metal mixture (P < 0.001). Field controls did not show significant impacts in the A. cepa bioassay, whereas individual exposure to heavy metals reported lower effects than their combined exposure under laboratory conditions; Pb2+was the most toxic metal, with the highest mitotic inhibition (Pb2+>Cd2+>Zn2+>Cr6 >Cu2+), mutagenic potential as evaluated in the percentage incidence of chromosomal aberrations (Pb2+> Zn2+> Cu2+> Cr6+> Cd2+) and cytotoxicity evaluated by the incidence of cell apoptosis and necrosis (Pb2+>Cr6+>Cu2+>Cd2+>Zn2+). Thus, the test battery of micronucleus, comet and A. cepa assays that reveal differential aspects of cytogenotoxicity may serve as a valuable tool in environmental monitoring, primarily to screen for complex environmental mixtures of heavy metals that may impact ecological health.

Benthic fauna contribute to microplastic sequestration in coastal sediments

Microplastics are ubiquitous in the marine environment, however, the mechanisms governing their uptake by, and burial within, seabed habitats are poorly understood. In this study, microplastic burial and its impact on fauna-mediated sedimentary processes was quantified at three coastal sites, and the potential contribution of burrowing faunal communities to this process assessed via functional trait diversity analysis of field data. In addition, laboratory exposures were used to assess whether sediment-processing undertaken by the brittlestar Amphiura filiformis, a key species in the sampled area, could explain the burial of microplastic fibres. Field observations confirmed broad-scale burial of microplastics across the coastal seabed, consistent across sites and seasons, with microplastic sequestration linked to benthic-pelagic exchange pathways, driven by burrowing fauna. Brittlestars were observed to bury and line their burrow walls with microfibres during experiments, and their burial activity was also modified following exposure to nylon fibres, relative to controls. Collectively, these results indicate that biodiverse and functionally important seabed habitats act as microplastic sinks, with burrowing fauna contributing to this process via well-known benthic-pelagic pathways, the rates of which are modified by plastic exposure.

Nanomechanical and Fluorescence Characterizations of Weathered PV Module Encapsulation

Nanoindentation and fluorescence spectroscopy provide spatially resolved mechanical and chemical characterization for degradation of poly (ethylene-co-vinyl acetate) (EVA) encapsulants aged under accelerated weathering and in field deployed photovoltaic (PV) modules. For the accelerated weathering tests, two different EVA formulations in the glass/EVA/glass-laminated coupons were exposed to ultraviolet (UV) light for 180 days at three different temperatures (40, 60, and 80 °C) and UV intensities (0.4, 2.2, and 2.9 W/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /nm at 340 nm). The fluorescence spectra and moduli were uniform through the cross section of both EVA formulations at the lowest temperature and UV intensity; however, under the highest temperature and UV intensity, the UV irradiated sides showed lower moduli and higher fluorescence compared to the opposite sides. For EVA obtained from PV modules deployed 27 years in Sacramento, CA, USA, changes in fluorescence intensity across the thickness were relatively greater than changes in modulus. On the other hand, for EVA obtained from the same type of module stored in the shed for 27 years, no fluorescence was observed, and a uniform modulus was seen through the EVA layer, but with substantially higher values than those obtained from the field-deployed modules. The different extent of changes between laboratory and field exposures suggests the importance of considering effects of temperature and UV intensity for designing a reliable accelerated testing. This study uniquely demonstrates the capability of microscale characterization using nanoindentation and fluorescence microscopy to monitor mechanical and chemical degradation of EVA encapsulants in PV modules.

Staggered enforcement of infection control and prevention measures following four consecutive potential laboratory exposures to imported Brucella melitensis

SummaryFrom 2015 until 2020, Brucella melitensis was isolated four times in our microbiology laboratory. All patients had travelled in endemic-areas. Immediately after the first occurrence, all laboratory staff were risk-stratified and preventive and protective measures were applied according to CDC guidelines. Nineteen workers were exposed and needed chemoprophylaxis and follow-up. At each subsequent occurrence, risk analysis was performed, and additional measures were implemented accordingly, leading to a progressive reduction of exposed staff members to none the fourth time. We describe here the additional measures that permitted this important exposure reduction.

Chest Exposure to X-Rays of Female Interventional Electrophysiologist

Interventional Female Cardiologists (WIC) operating in high case mix laboratories are exposed to a significant chest X-Ray scattered dose from the patient. In this setting stochastic effect may be highly detrimental because of breast radiation sensitivity. Aim of this study is to measure and optimize WICs’ chest radiation exposure in a high case mix electrophysiology laboratory, in order to validate and implement the use of personal protective equipment and lead equivalent glass viewing window, and to evaluate chest X-Ray exposure behind the protective equipment.

Validation of passive samplers for monitoring of acetic and formic acid in museum environments

Acetic acid and formic acid are volatile pollutants leading to degradation of some heritage materials. They are usually determined in museum environments with various types of passive samplers. In this work, SKC UMEx 200 passive samplers, originally intended for sampling of hbox {NO}_{2} and hbox {SO}_{2}, have been validated for sampling of these organic acids. The sampling rates, extraction efficiency, loss through reverse diffusion or during storage, capacity, and detection limits were determined for both acids. For laboratory exposure, a known concentration of both acids was prepared in a flow-through reactor system at controlled temperature and humidity, the samplers were extracted, followed by analysis using ion chromatography. The sampling rates were determined to be 16.7 ml/min for acetic and 17.7 ml/min for formic acid and the detection limits for 7-day exposure were determined to be {2.1},{upmu }{rm g/m}^3 for acetic and {1.9},{upmu }hbox {g/m}^3 for formic acid. The validated method was finally used for sampling of air in two case studies at the National Museum of Slovenia, where the concentrations in the range of 2–{54},{upmu }hbox {g/m}^3 were determined.