RESUMEN

Microplastic (MP) research faces challenges due to costly, time-consuming, and error-prone analysis techniques. Additionally, the variability in data quality across studies limits their comparability. This study addresses the critical need for reliable and cost-effective MP analysis methods through validation of a semi-automated workflow, where environmentally relevant MP were spiked into and recovered from marine fish gastrointestinal tracts (GITs) and blue mussel tissue, using Nile red staining and machine learning automated analysis of different polymers. Parameters validated include trueness, precision, uncertainty, limit of quantification, specificity, sensitivity, selectivity, and method robustness. For fish GITs a 95 ± 9 % recovery rate was achieved, and 87 ± 11 % for mussels. Polymer identification accuracies were 76 ± 8 % for fish GITs and 80 ± 13 % for mussels. Polyethylene terephthalate fragments showed more variability with lower accuracies. The proposed validation parameters offer a step towards quality management guidelines, as such aiding future researchers and fostering cross-study comparability.

Asunto(s)

RESUMEN

Traditionally, for indoor radon testing, predominantly passive measurements have been used, typically applying the solid-state alpha track-etch method for long-term and the charcoal method for short-term measurements. However, increasingly, affordable consumer-grade active monitors have become available in the last few years, which can generate a concentration time series of an almost arbitrary duration. Firstly, we argue that consumer-grade monitors can well be used for quality-assured indoor radon assessment and consequent reliable decisions. Secondly, we discuss the requirements of quality assurance, which actually allow for reliable decision-making. In particular, as part of a rational strategy, we discuss how to interpret measurement results from low-cost active monitors with high and low sensitivity with respect to deciding on conformity with reference levels that are the annual average concentration of indoor radon. Rigorous analysis shows that temporal variations in radon are a major component of the uncertainty in decision-making, the reliability of which is practically independent of monitor sensitivity. Manufacturers of low-cost radon monitors already provide sufficient reliability and quality of calibration for their devices, which can be used by both professional inspectors and the general public. Therefore, within the suggested measurement strategy and metrologically assured criteria, we only propose to clarify the set and values of the key metrological characteristics of radon monitors as well as to upgrade user-friendly online tools. By implementing clear metrological requirements as well as the rational measurement strategy for the reliable conformity assessment of a room (building) with radon safety requirements, we anticipate significant reductions in testing costs, increased accessibility, and enhanced quality assurance and control (QA/QC) in indoor radon measurements.

RESUMEN

In recent years, plastic pollution in the environment has also increased due to the increasing production and consumption of plastics worldwide. The presence of microplastics (MPs) in the environment from different sources is observed almost everywhere, especially in aquatic environments. A standard method for sampling, identification, and quantification of MPs in wastewater has not yet been established. In this study, it was aimed to determine the MPs and their characteristics in the effluent of an advanced biological domestic wastewater treatment plant. The seasonal changes of MPs in a year were revealed. Pre-treatments suitable for the studied wastewater were developed for visual determination of MPs. Fibers are the dominant type of MPs, with numbers ranging between 32.0 and 95.5 particle/L. MPs in five different polymer structures were determined by FTIR analysis. These are Polyethylene, Polypropylene, Polyester, Polyurethane and Polyethylene terephthalate. The results were evaluated according to QA/QC and determined to meet the standards.

Asunto(s)

RESUMEN

This trend article provides an overview of recent advancements in Non-Target Screening (NTS) for water quality assessment, focusing on new methods in data evaluation, qualification, quantification, and quality assurance (QA/QC). It highlights the evolution in NTS data processing, where open-source platforms address challenges in result comparability and data complexity. Advanced chemometrics and machine learning (ML) are pivotal for trend identification and correlation analysis, with a growing emphasis on automated workflows and robust classification models. The article also discusses the rigorous QA/QC measures essential in NTS, such as internal standards, batch effect monitoring, and matrix effect assessment. It examines the progress in quantitative NTS (qNTS), noting advancements in ionization efficiency-based quantification and predictive modeling despite challenges in sample variability and analytical standards. Selected studies illustrate NTS's role in water analysis, combining high-resolution mass spectrometry with chromatographic techniques for enhanced chemical exposure assessment. The article addresses chemical identification and prioritization challenges, highlighting the integration of database searches and computational tools for efficiency. Finally, the article outlines the future research needs in NTS, including establishing comprehensive guidelines, improving QA/QC measures, and reporting results. It underscores the potential to integrate multivariate chemometrics, AI/ML tools, and multi-way methods into NTS workflows and combine various data sources to understand ecosystem health and protection comprehensively.

RESUMEN

Indoor radon measurements have been conducted in many countries worldwide for several decades. However, to date, there is a lack of a globally harmonized measurement standard. Furthermore, measurement protocols in the US (short-term tests for 2-7 days) and European Union countries (long-term tests for at least 2 months) differ significantly, and their metrological support is underdeveloped, as clear mathematical algorithms (criteria) and QA/QC procedures considering fundamental ISO/IEC concepts such as "measurement uncertainty" and "conformity assessment" are still absent. In this context, for many years, the authors have been advancing and refining the theory of metrological support for standardizing indoor radon measurements based on a rational criterion for conformity assessment within the ISO/IEC concepts. The rational criterion takes into account the main uncertainties arising from temporal variations in indoor radon and instrumental errors, enabling the utilization of both short- and long-term measurements while ensuring specified reliability in decision making (typically no less than 95%). The paper presents improved mathematical algorithms for determining both temporal and instrumental uncertainties. Additionally, within the framework of the rational criterion, unified metrological requirements are formulated for various methods and devices employed in indoor radon measurements.

RESUMEN

Microplastic and nanoplastic research has proliferated in recent years in response to the escalating plastic pollution crisis. However, a lack of optimised methods for sampling and sample processing has potential implications for contaminating samples resulting in an overestimation of the quantity of microplastics and nanoplastics present in environmental samples. In response, a series of recommendations have been made, but most have not been quantified or validated sources of contamination. In the present study, we investigated sources of plastic contamination in common laboratory procedures including water sources (e.g., Milli-Q), consumables (e.g., unburnt glassware), airflow (e.g., fume hood) and dust. Using flow cytometry, we identified water, air flow and dust as sources of significant contamination. Milli-Q and reverse osmosis were the least contaminated sources when compared with tap water. Interestingly, current recommendations are to use glass consumables in replacement of plastic consumables, however, we have identified glassware and glass consumables as a significant source of contamination. Current best practice is to cover the glass tube with aluminium foil to reduce airborne contamination, but we found fresh aluminium foil to be a significant source of contamination, bringing light to the limitations foil has as a contamination control measure. Lastly, we identified significant quantities of microplastics and nanoplastics present in dust collected within the laboratory, suggesting this is a widespread and underestimated source of contamination. We have provided validated sources of contamination for both consumables and common laboratory procedures and provided mitigation strategies based on these. Additional recommendations include the appropriate design of experimental controls to quantify levels of introduced contamination based on methods and the detection techniques utilised. The application of these mitigation strategies and appropriate experimental design will allow for more accurate estimations on the level of microplastic and nanoplastic contamination within environmental samples.

RESUMEN

Poor positioning decreases mammography sensitivity and is arguably the single most important contributor to image quality (IQ). Inadequate IQ may subject patients to technical repeat views during the examination or return for technical recalls. Artificial intelligence (AI) software can objectively evaluate breast positioning and compression metrics for all images and technologists. This study assessed whether implementation of AI software across the authors' institution improved IQ and reduced rates of technical repeats and recalls (TR). From April 2019 to March 2022, TR was retrospectively evaluated for 40 technologists (198 054 images; Centricity electronic medical record system, GE HealthCare), and AI IQ metrics were available for 42 technologists (211 821 images; Analytics, Volpara Health Technologies). Diagnostic and digital breast tomosynthesis images and implant cases were excluded. Kolmogorov-Smirnov, χ2, and paired t tests were used to evaluate whether AI IQ metrics and TR rates improved between the initial and most recent 12-month periods following AI software implementation (ie, baseline [April 2019 to March 2020] vs current [April 2021 to March 2022]). Comparing baseline with current periods, TR significantly reduced from 0.77% (788 of 102 953 images) to 0.17% (160 of 95 101 images), respectively (P < .001), and overall mean quality score improved by 6% ([2.42 - 2.28]/2.28; P = .001), demonstrating the potential of AI software to improve IQ and reduce patient TR. Keywords: Mammography, Breast, Oncology, QA/QC, Screening, Technology Assessment © RSNA, 2023.

RESUMEN

For the detection of microplastics (MPs) in aquatic biota using Fourier transform infrared spectroscopy (FTIR), the ability to remove organic matter (OM) in pretreatment steps is essential to increase the time efficiency of MPs measurement and method uniformity. In principle, decreasing OM can be achieved by increasing the number of pretreatment steps. However, MPs are lost in proportion to the number of transfers between each step. Therefore, we have created a "Cylindrical MPs Fractionator" composed of commercially available materials. This container allows for a six-step pretreatment process that is designed to increase the removal capacity of OM with only one transfer to prevent the loss of MPs.•Biological or sediment samples are placed in the extractor and subjected to chemical treatment and density separation.•Residues containing MPs are obtained on filters by vacuum filtration.•After additional chemical treatment of the obtained residue, the components of the residue are identified by microscopic FTIR.This method removed 99.3% of OM and recovered 88.5% of MPs. The presenting method confirmed that this can be used with the same process for 11 organisms and sediments from estuarine ecosystem in Japan as models.

RESUMEN

Quality assurance and quality control (QA/QC) techniques are critical to analytical chemistry, and thus the analysis of microplastics. Procedural blanks are a key component of QA/QC for quantifying and characterizing background contamination. Although procedural blanks are becoming increasingly common in microplastics research, how researchers acquire a blank and report and/or use blank contamination data varies. Here, we use the results of laboratory procedural blanks from a method evaluation study to inform QA/QC procedures for microplastics quantification and characterization. Suspected microplastic contamination in the procedural blanks, collected by 12 participating laboratories, had between 7 and 511 particles, with a mean of 80 particles per sample (±SD 134). The most common color and morphology reported were black fibers, and the most common size fraction reported was 20-212 µm. The lack of even smaller particles is likely due to limits of detection versus lack of contamination, as very few labs reported particles <20 µm. Participating labs used a range of QA/QC techniques, including air filtration, filtered water, and working in contained/'enclosed' environments. Our analyses showed that these procedures did not significantly affect blank contamination. To inform blank subtraction, several subtraction methods were tested. No clear pattern based on total recovery was observed. Despite our results, we recommend commonly accepted procedures such as thorough training and cleaning procedures, air filtration, filtered water (e.g., MilliQ, deionized or reverse osmosis), non-synthetic clothing policies and 'enclosed' air flow systems (e.g., clean cabinet). We also recommend blank subtracting by a combination of particle characteristics (color, morphology and size fraction), as it likely provides final microplastic particle characteristics that are most representative of the sample. Further work should be done to assess other QA/QC parameters, such as the use of other types of blanks (e.g., field blanks, matrix blanks) and limits of detection and quantification.

Asunto(s)

RESUMEN

The European Human Biomonitoring Initiative (HBM4EU) ran from 2017 to 2022 with the aim of advancing and harmonizing human biomonitoring in Europe. More than 40,000 analyses were performed on human samples in different human biomonitoring studies in HBM4EU, addressing the chemical exposure of the general population, temporal developments, occupational exposure and a public health intervention on mercury in populations with high fish consumption. The analyses covered 15 priority groups of organic chemicals and metals and were carried out by a network of laboratories meeting the requirements of a comprehensive quality assurance and control system. The coordination of the chemical analyses included establishing contacts between sample owners and qualified laboratories and monitoring the progress of the chemical analyses during the analytical phase, also addressing status and consequences of Covid-19 measures. Other challenges were related to the novelty and complexity of HBM4EU, including administrative and financial matters and implementation of standardized procedures. Many individual contacts were necessary in the initial phase of HBM4EU. However, there is a potential to develop more streamlined and standardized communication and coordination in the analytical phase of a consolidated European HBM programme.

Asunto(s)

Asunto(s)

RESUMEN

Prostate-specific membrane antigen (PSMA) is a cell surface protein highly expressed in nearly all prostate cancers, with restricted expression in some normal tissues. The differential expression of PSMA from tumor to non-tumor tissue has resulted in the investigation of numerous targeting strategies for therapy of patients with metastatic prostate cancer. In March of 2022, the FDA granted approval for the use of lutetium-177 PSMA-617 (Lu-177-PSMA-617) for patients with PSMA-positive metastatic castration-resistant prostate cancer (mCRPC) who have been treated with androgen receptor pathway inhibition and taxane-based chemotherapy. Therefore, the use of Lu-177-PSMA-617 is expected to increase and become more widespread. Herein, we describe logistical, technical, and radiation safety considerations for implementing a radiopharmaceutical therapy program, with particular focus on the development of operating procedures for therapeutic administrations. Major steps for a center in the U.S. to implement a new radiopharmaceutical therapy (RPT) program are listed below, and then demonstrated in greater detail via examples for Lu-177-PSMA-617 therapy.

Asunto(s)

RESUMEN

Although significant headway has been achieved regarding method harmonisation for the analysis of microplastics, analysis and interpretation of control data has largely been overlooked. There is currently no consensus on the best method to utilise data generated from controls, and consequently many methods are arbitrarily employed. This study identified 6 commonly implemented strategies: a) No correction; b) Subtraction; c) Mean Subtraction; d) Spectral Similarity; e) Limits of detection/ limits of quantification (LOD/LOQ) or f) Statistical analysis, of which many variations are possible. Here, the 6 core methods and 45 variant methods (n = 51) thereof were used to correct a dummy dataset using control data. Most of the methods tested were too inflexible to account for the inherent variation present in microplastic data. Only 7 of the 51 methods tested (six LOD/LOQ methods and one statistical method) showed promise, removing between 96.3 % and 100 % of the contamination data from the dummy set. The remaining 44 methods resulted in deficient corrections for background contamination due to the heterogeneity of microplastics. These methods should be avoided in the future to avoid skewed results, especially in low abundance samples. Overall, LOD/LOQ methods or statistical analysis comparing means are recommended for future use in microplastic studies.

Asunto(s)

RESUMEN

PURPOSE: This overview of the current landscape of quantitative magnetic resonance imaging biomarkers (qMR IBs) aims to support the standardisation of academic IBs to assist their translation to clinical practice. METHODS: We used three complementary approaches to investigate qMR IB use and quality management practices within the UK: 1) a literature search of qMR and quality management terms during 2011-2015 and 2016-2020; 2) a database search for clinical research studies using qMR IBs during 2016-2020; and 3) a survey to ascertain the current availability and quality management practices for clinical MRI scanners and associated equipment at research institutions across the UK. RESULTS: The analysis showed increased use of all qMR methods between the periods 2011-2015 and 2016-2020 and diffusion-tensor MRI and volumetry to be popular methods. However, the "translation ratio" of journal articles to clinical research studies was higher for qMR methods that have evidence of clinical translation via a commercial route, such as fat fraction and T2 mapping. The number of journal articles citing quality management terms doubled between the periods 2011-2015 and 2016-2020; although, its proportion relative to all journal articles only increased by 3.0%. The survey suggested that quality assurance (QA) and quality control (QC) of data acquisition procedures are under-reported in the literature and that QA/QC of acquired data/data analysis are under-developed and lack consistency between institutions. CONCLUSIONS: We summarise current attempts to standardise and translate qMR IBs, and conclude by outlining the ideal quality management practices and providing a gap analysis between current practice and a metrological standard.

Asunto(s)

RESUMEN

The first magnetic resonance (MR)-guided radiotherapy system in Japan was installed in May 2017. Implementation of online MR-guided adaptive radiotherapy (MRgART) began in February 2018. Online MRgART offers greater treatment accuracy owing to the high soft-tissue contrast in MR-images (MRI), compared to that in X-ray imaging. The Japanese Society for Magnetic Resonance in Medicine (JSMRM), Japan Society of Medical Physics (JSMP), Japan Radiological Society (JRS), Japanese Society of Radiological Technology (JSRT), and Japanese Society for Radiation Oncology (JASTRO) jointly established the comprehensive practical guidelines for online MRgART. These guidelines propose the essential requirements for clinical implementation of online MRgART with respect to equipment, personnel, institutional environment, practice guidance, and quality assurance/quality control (QA/QC). The minimum requirements for related equipment and QA/QC tools, recommendations for safe operation of MRI system, and the implementation system are described. The accuracy of monitor chamber and detector in dose measurements should be confirmed because of the presence of magnetic field. The ionization chamber should be MR-compatible. Non-MR-compatible devices should be used in an area that is not affected by the static magnetic field (outside the five Gauss line), and their operation should be checked to ensure that they do not affect the MR image quality. Dose verification should be performed using an independent dose verification system that has been confirmed to be reliable through commissioning. This guideline proposes the checklists to ensure the safety of online MRgART. Successful clinical implementation of online MRgART requires close collaboration between physician, radiological technologist, nurse, and medical physicist.

Asunto(s)

RESUMEN

A quality assurance/quality control program was implemented in the framework of the EU project HBM4EU to assess and improve the comparability of biomarker analysis and to build a network of competent laboratories. Four rounds of proficiency tests were organized for 15 phthalate and two DINCH urinary biomarkers (0.2-138 ng/mL) over a period of 18 months, with the involvement of 28 laboratories. A substantial improvement in performance was observed after the first round in particular, and by the end of the program, an average satisfactory performance rate of 90% was achieved. The interlaboratory reproducibility as derived from the participants' results varied for the various biomarkers and rounds, with an average of 24% for the biomarkers of eight single-isomer phthalates (e.g., DnBP and DEHP) and 43% for the more challenging biomarkers of the mixed-isomer phthalates (DiNP, DiDP) and DINCH. When the reproducibility was based only on the laboratories that consistently achieved a satisfactory performance, this improved to 17% and 26%, respectively, clearly demonstrating the success of the QA/QC efforts. The program thus aided in building capacity and the establishment of a network of competent laboratories able to generate comparable and accurate HBM data for phthalate and DINCH biomarkers in 14 EU countries. In addition, global comparability was ensured by including external expert laboratories.

RESUMEN

To date, no standardized methods have been proposed for conducting microplastic analyses in treated drinking waters, resulting in challenges associated with direct comparisons among studies. This study compares known methods for collecting and extracting microplastics from drinking waters: an in-laboratory (in-lab) filtration method and an in-line filtration method (i.e., water filtered on-site without an intermediate storage and/or transportation step). In-lab methods have been the predominant method for sample collection in drinking water matrices, and in-line methods are emerging due to the potential to sample large volumes of water on site and minimize contamination from airborne particles, but the two methods have yet to be directly compared using real samples. In response, this study evaluates both methods in terms of recovering spiked reference microplastics, collecting microplastics from tap water samples using the same water volume, and quantifying the removal of microplastics through a full-scale ultrafiltration system. In-line filtration was shown to have higher recoveries for all the reference microplastics examined (+37 % for PVC fragments, +23 % for PET fragments, +22 % for nylon fibers and +7 % for PET fibers) and a greater potential to reduce microplastic contamination. It also resulted in lower standard deviations for total microplastic counts in the tap water and UF influent and effluent samples. The filtration capacity of the proposed in-line filtration method could exceed 350 L of treated water, but this is highly dependent on the water quality. This study therefore supports the use of in-line filtration methods towards the standardization of microplastic collection procedures in drinking water.

Asunto(s)

RESUMEN

Active carbon-based sorbents are well known and are used in analytical chemistry. Activated carbon fibers (ACFs) are mainly used as abatement systems in industrial emission pollution control. The objective of this study was to extend the use of ACFs in analytical chemistry for the analysis of polychlorodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs), dioxin-like polychlorobiphenyls (PCBs), and chlorobenzenes (CBs). For this purpose, the extraction efficiency was evaluated based on the QA/QC criteria defined by EPA/ISO reference methods on 13C-standards recovery rates. The procedures tested were ultrasonic assisted extraction (UAE), Soxhlet extraction (SE), accelerated solvent extraction (ASE), and microwave-assisted extraction (MAE). Each experiment was performed in triplicate to ensure the repeatability of the results, and a second extraction assessed the complete extraction. The comparison of the results of each set of experiments with the minimum requirements of the reference methods for each class of compounds led to SE being chosen as the best technique. SE with toluene resulted in a reduction of time and costs and with respect to the other investigated techniques. The present work demonstrated that ACFs can be used in environmental fields means of both prevention and control (exploiting the adsorbent characteristics) and for analytical purposes (exploiting the desorption) for the described chlorinated classes of pollutants.

RESUMEN

Methods for sampling, analysis and interpretation of fresh and saltwater microplastics and anthropogenic microfibers have improved since 2004, but techniques for reducing and monitoring procedural contamination are still limited. Quantifying the amount of procedural contamination introduced to samples improves the robustness of counts of microplastics and anthropogenic microfibers in the environment. This pilot study investigates procedural contamination introduced into water samples when rigorous QA/QC anti-contamination protocols are used and removed. Procedural contamination accounted for 33.8% of the total microfibers and microplastics found in samples when protocols were used (n = 81), but 70.7% when they were not (n = 8). With the use of extensive control sampling and full characterization of samples (morphological, optical and chemical) it was possible to identify the predominant sources of contamination (crew clothing) and make recommendations for anti-contamination and procedural contamination identification/reduction protocols for shoreline and small/medium sized vessel sampling for microplastics and anthropogenic microfibers.

Asunto(s)

RESUMEN

Omics methodologies are widely used in toxicological research to understand modes and mechanisms of toxicity. Increasingly, these methodologies are being applied to questions of regulatory interest such as molecular point-of-departure derivation and chemical grouping/read-across. Despite its value, widespread regulatory acceptance of omics data has not yet occurred. Barriers to the routine application of omics data in regulatory decision making have been: 1) lack of transparency for data processing methods used to convert raw data into an interpretable list of observations; and 2) lack of standardization in reporting to ensure that omics data, associated metadata and the methodologies used to generate results are available for review by stakeholders, including regulators. Thus, in 2017, the Organisation for Economic Co-operation and Development (OECD) Extended Advisory Group on Molecular Screening and Toxicogenomics (EAGMST) launched a project to develop guidance for the reporting of omics data aimed at fostering further regulatory use. Here, we report on the ongoing development of the first formal reporting framework describing the processing and analysis of both transcriptomic and metabolomic data for regulatory toxicology. We introduce the modular structure, content, harmonization and strategy for trialling this reporting framework prior to its publication by the OECD.

Asunto(s)