Utility of a modified o-DGT passive sampler for measurement of bisphenol analogues in freshwater and coastal waters.

Bisphenol analogues (BPs) are commonly found in riverine and coastal waters. However, the lack of a reliable and robust passive sampling method has hindered our ability to monitor these compounds in aquatic systems. The study developed a novel organic-diffusive gradients in thin film (o-DGT) sampler based on stainless steel mesh membrane, polyacrylamide diffusive gel, and hydrophilic-lipophilic balance (HLB) binding gel. This innovative design tackled issues of filter membrane sorption in traditional o-DGT devices and potential gel damage in membrane-less o-DGT devices, showing promising application prospects. The mass accumulation of 15 target BPs was linear over 10 days in both freshwater (r2 ≥ 0.92) and seawater (r2 ≥ 0.94), with no saturation observed. The diffusion coefficients (D) through polyacrylamide diffusive gels ranged from 4.04 × 10-6 to 5.77 × 10-6 cm2 s-1 in freshwater and from 1.74 × 10-6 to 4.69 × 10-6 cm2 s-1 in seawater for the target BPs (except for bisphenol PH) at 22 °C. The D values of the target BPs in seawater were lower than those in freshwater due to the high salinity in seawater (35 ‰). The o-DGT samplers demonstrated good integrity in field applications. The total concentrations of the eight detected BPs ranged from 9.2 to 323 ng L-1, which was consistent with the measurements obtained by grab sampling. Among all BPs, bisphenol S, bisphenol F, and bisphenol A were consistently detected at all sites using both sampling methods. The concentrations of some novel BPs in coastal water measured by grab sampling were comparable to those measured in rivers, suggesting the need to strengthen pollution control of BPs in coastal areas. These results indicate that the o-DGT passive sampling method developed in the present study can be effectively used for monitoring BPs in freshwater and coastal environments.

Development of an accreditation process for analytical methods to measure microplastics in drinking water for regulatory monitoring.

Development of a laboratory accreditation program to ensure competency of laboratories performing analytical measurements is a key step in adopting new analytical measurement methods for regulatory decision-making. Here, we describe California's three-part accreditation process for spectroscopically measuring microplastics in drinking water, and show how data from a multi-laboratory method comparison study informed development of accreditation programs for the resulting methods, which can inform analogous future work for other analytes. The first part is periodic performance evaluation (PE) samples, in which laboratories are provided blind samples of known composition to quantify within acceptable performance limits. The second is inspection, or audit, assessing whether the laboratory has the proper equipment to conduct the work and whether it is correctly employing proper procedures. The third is implementation of a quality management system providing documentation that protocols demonstrated during inspection are continuously maintained. These fell into three broad categories: instrument maintenance; laboratory cleanliness, especially important for microplastics and one that must be accompanied by a blanks measurement and correction process; and training so samples are being processed by qualified analysts. An intercomparison exercise among 22 laboratories was necessary to determine what parameter permutations were important for PE samples, and expected accuracy from competent laboratories. The recommended PE sample composition was two size categories (20-50um and 500um-1mm), two polymer types, and two morphologies (fibers and non-fibers). Discussions among intercomparison exercise participants were key in determining the factors that most contributed to laboratory variability, and the focus for both on-site inspections and quality management systems.

Development and validation of an acid/alkaline digestion method for efficient microplastic extraction from wastewater treatment plant effluents: Sulfuric acid concentration and contact time do matter.

Accurate analysis of microplastic particles (MPs) in environmental samples requires removal of interferences during sample preparation. Wastewater samples are interference-rich and thus particularly challenging, with concentrated sulfuric acid currently deemed impractical as a reagent. Therefore, this study aimed to establish a straightforward, effective, and safe method employing concentrated sulfuric acid and potassium hydroxide to eliminate interferents from effluent samples obtained from wastewater treatment plants (WWTPs). We found that 80 % sulfuric acid at room temperature with a brief contact time of 5 min was viable through a qualitative spot test involving 37 plastics categorized into three types (I, II, and III) based on their polymer structure's oxygen position. A quantitative assessment revealed that treatments involving H2SO4 and KOH (20 %, 24 h, 48 °C), either separately or in combination, had no discernible physical impact on the overall plastics, except for a subtle one for Type III plastics (e.g., nylon and PMMA) known to be labile under harsh pH conditions. This acid/alkaline digestion (AAD) method, incorporating such conditions for H2SO4 and KOH treatments, yielded a high mass removal efficacy (97.8 ± 2.4 %, n = 13) for eliminating natural particle interferents for primary, secondary, and tertiary effluent samples. Furthermore, the AAD method allowed for the determination of MPs in effluents with high surrogate particle recoveries (e.g., 95.1 % for larger than 500 µm size fraction). This method is readily adaptable to create appropriate protocols for different types of environmental matrices.

Prevalence and Characteristics of Invasive Staphylococcus argenteus among Patients with Bacteremia in Hong Kong.

Staphylococcus argenteus is a novel Staphylococcus species derived from Staphylococcus aureus. Information on the prevalence and genetic characteristics of invasive S. argenteus in Asia is limited. In this study, 275 invasive S. aureus complex strains were retrieved from blood culture specimens in Hong Kong and re-analyzed using MALDI-TOF mass spectrometry and an in-house multiplex real-time PCR for S. argenteus. The prevalence of invasive S. argenteus in Hong Kong was found to be 4.0% (11/275). These strains were primarily susceptible to commonly used antibiotics, except penicillin. Whole-genome sequencing revealed the circulation of three S. argenteus genotypes (ST-2250, ST-1223, and ST-2854) in Hong Kong, with ST-2250 and ST-1223 being the predominant genotypes. The local ST-2250 and ST-1223 strains showed close phylogenetic relationships with isolates from mainland China. Antimicrobial-resistant genes (fosB, tet-38, mepA, blaI, blaZ) could be found in nearly all local S. argenteus strains. The ST-1223 and ST-2250 genotypes carried multiple staphylococcal enterotoxin genes that could cause food poisoning and toxic shock syndrome. The CRISPR/Cas locus was observed only in the ST-2250 strains. This study provides the first report on the molecular epidemiology of invasive S. argenteus in Hong Kong, and further analysis is needed to understand its transmission reservoir.

A rare presentation of Legionella pneumophila and Mycobacterium intracellulare co-infection masquerading as metastatic lung cancer in a patient with positive anti-interferon gamma antibody.

Adult-onset immunodeficiency (AOID) syndrome due to the presence of anti-interferon gamma antibody (AIGA) is characterized by multiple opportunistic infections. We report a case of a 65-year old healthy woman who suffered from Legionella pneumophila and Mycobacterium intracellulare co-infection with clinical presentation mimicking metastatic lung cancer. She presented with chronic cough and weight loss. Her positron emission tomography scan showed a right upper lobe mass, mediastinal lymphadenopathy and multiple bone lesions. Acid fast bacilli culture of the lung mass and mediastinal lymph node revealed Mycobacterium intracellulare and she improved with prolonged antibiotic. Relapse of disseminated Mycobacterium intracellulare infection occurred 15 months post-treatment and AIGA was positive with functional neutralizing activity on downstream immune pathway. AOID syndrome secondary to AIGA was diagnosed. This case illustrated the importance of high index of suspicion of AOID syndrome and the difficulty of early diagnosis. Further studies on its predictive factors and AIGA-targeted treatment modalities are urgently needed.

Passive-Sampler-Derived PCB and OCP Concentrations in the Waters of the World─First Results from the AQUA-GAPS/MONET Network.

Persistent organic pollutants (POPs) are recognized as pollutants of global concern, but so far, information on the trends of legacy POPs in the waters of the world has been missing due to logistical, analytical, and financial reasons. Passive samplers have emerged as an attractive alternative to active water sampling methods as they accumulate POPs, represent time-weighted average concentrations, and can easily be shipped and deployed. As part of the AQUA-GAPS/MONET, passive samplers were deployed at 40 globally distributed sites between 2016 and 2020, for a total of 21 freshwater and 40 marine deployments. Results from silicone passive samplers showed α-hexachlorocyclohexane (HCH) and γ-HCH displaying the greatest concentrations in the northern latitudes/Arctic Ocean, in stark contrast to the more persistent penta (PeCB)- and hexachlorobenzene (HCB), which approached equilibrium across sampling sites. Geospatial patterns of polychlorinated biphenyl (PCB) aqueous concentrations closely matched original estimates of production and use, implying limited global transport. Positive correlations between log-transformed concentrations of Σ7PCB, ΣDDTs, Σendosulfan, and Σchlordane, but not ΣHCH, and the log of population density (p < 0.05) within 5 and 10 km of the sampling sites also supported limited transport from used sites. These results help to understand the extent of global distribution, and eventually time-trends, of organic pollutants in aquatic systems, such as across freshwaters and oceans. Future deployments will aim to establish time-trends at selected sites while adding to the geographical coverage.

Patterns of microparticles in blank samples: A study to inform best practices for microplastic analysis.

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.

The influence of complex matrices on method performance in extracting and monitoring for microplastics.

Previous studies have evaluated method performance for quantifying and characterizing microplastics in clean water, but little is known about the efficacy of procedures used to extract microplastics from complex matrices. Here we provided 15 laboratories with samples representing four matrices (i.e., drinking water, fish tissue, sediment, and surface water) each spiked with a known number of microplastic particles spanning a variety of polymers, morphologies, colors, and sizes. Percent recovery (i.e., accuracy) in complex matrices was particle size dependent, with ∼60-70% recovery for particles >212 µm, but as little as 2% recovery for particles <20 µm. Extraction from sediment was most problematic, with recoveries reduced by at least one-third relative to drinking water. Though accuracy was low, the extraction procedures had no observed effect on precision or chemical identification using spectroscopy. Extraction procedures greatly increased sample processing times for all matrices with the extraction of sediment, tissue, and surface water taking approximately 16, 9, and 4 times longer than drinking water, respectively. Overall, our findings indicate that increasing accuracy and reducing sample processing times present the greatest opportunities for method improvement rather than particle identification and characterization.

Current status of machine learning in thyroid cytopathology.

The implementation of Digital Pathology has allowed the development of computational Pathology. Digital image-based applications that have received FDA Breakthrough Device Designation have been primarily focused on tissue specimens. The development of Artificial Intelligence-assisted algorithms using Cytology digital images has been much more limited due to technical challenges and a lack of optimized scanners for Cytology specimens. Despite the challenges in scanning whole slide images of cytology specimens, there have been many studies evaluating CP to create decision-support tools in Cytopathology. Among different Cytology specimens, thyroid fine needle aspiration biopsy (FNAB) specimens have one of the greatest potentials to benefit from machine learning algorithms (MLA) derived from digital images. Several authors have evaluated different machine learning algorithms focused on thyroid cytology in the past few years. The results are promising. The algorithms have mostly shown increased accuracy in the diagnosis and classification of thyroid cytology specimens. They have brought new insights and demonstrated the potential for improving future cytopathology workflow efficiency and accuracy. However, many issues still need to be addressed to further build on and improve current MLA models and their applications. To optimally train and validate MLA for thyroid cytology specimens, larger datasets obtained from multiple institutions are needed. MLAs hold great potential in improving thyroid cancer diagnostic speed and accuracy that will lead to improvements in patient management.

How to establish detection limits for environmental microplastics analysis.

Establishing analytical detection limits is crucial. Common methods to do so are suitable only for variables with continuous distributions. Because count data for microplastic particles is a discrete variable following the Poisson distribution, currently-used approaches for estimating the detection limit in microplastics analysis are inadequate. Here we evaluate detection limits with techniques for low-level discrete observations to develop proper approaches for estimating the minimum detectable amount (MDA) in microplastic particle analysis, using blank sample data from an interlaboratory calibration exercise for clean water (representing drinking water), dirty water (ambient water), sediment (porous media) and fish tissue (biotic tissues). Two MDAs are applicable: MDAA to evaluate analytical methods, estimated with replicate blank data; and MDAB for individual sample batches, calculated with a single blank count. For illustrative purposes, this dataset's overall MDAA values were 164 counts (clean water), 88 (dirty water), 192 (sediment), and 379 (tissue). MDA values should be reported on a laboratory-specific basis and for individual size fractions, as this provides more useful information about capabilities of individual laboratories. This is due to wide variation in blank levels, as noted by MDAB values (i.e., among different laboratories) from 14 to 158 (clean water), 9 to 86 (dirty water, 9 to 186 (sediment), and 9 to 247 (tissue). MDA values for fibers were considerably greater than for non-fibers, suggesting that separate MDA values should be reported. This study provides a guideline for estimation and application of microplastics MDA for more robust data to support research activities and environmental management decisions.

Bochdalek hernia masquerading as pleural effusion in a young adult.

Bochdalek hernia (BH) is a congenital diaphragmatic hernia which rarely presents in adulthood. We report on a 25-year-old man admitted with 3-year recurrent and self-limiting abdominal pain and vomiting. Chest radiograph showed left pleural opacity which shifted position in the decubitus film suggesting pleural effusion. Before attempting drainage, point-of-care (POC) thoracic ultrasound (TUS) demonstrated features of intrathoracic gastrointestinal content above the left hemi-diaphragm. Computed tomography of the thorax confirmed a large left BH. Acute recurrent symptoms 3 months post-discharge was associated with BH enlargement and early bowel ischemia, which was successfully managed by emergency surgery. This case illustrates the importance of pre-procedural imaging with POC-TUS before pleural procedures in all cases of suspected or apparent pleural effusion, and of prompt surgical treatment of symptomatic BH despite clinical stabilization.

Comparison of two procedures for microplastics analysis in sediments based on an interlaboratory exercise.

Microplastics (MP) are distributed throughout ecosystems and settle into sediments where they may threaten benthic communities; however, methods for quantifying MP in sediments have not been standardized. This study compares two methods for analyzing MP in sediments, including extraction and identification, and provides recommendations for improvement. Two laboratories processed sediment samples using two methods, referred to as "core" and "augmentation", and identified particles with visual microscopy and spectroscopy. Using visual microscopy, the augmentation method yielded mean recoveries (78%) significantly greater than the core (47%) (p = 0.03), likely due to the use of separatory funnels in the former. Spectroscopic recovery of particles was lower at 42 and 54% for the core and augmentation methods, respectively. We suspect the visual identification recoveries are overestimations from erroneous identification of non-plastic materials persisting post-extraction, indicating visual identification alone is not an accurate method to identify MP, particularly in complex matrices like sediment. However, both Raman and FTIR proved highly accurate at identifying recovered MP, with 96.7% and 99.8% accuracy, respectively. Low spectroscopic recovery of spiked particles indicates that MP recovery from sediments is lower than previously assumed, and MP may be more abundant in sediments than current analyses suggest. To our knowledge, likely due to the excessive time/labor-intensity associated with MP analyses, this is the first interlaboratory study to quantify complete method performance (extraction, identification) for sediments, with regards to capabilities and limitations. This is essential as regulatory bodies move toward long-term environmental MP monitoring.

Quantitative assessment of visual microscopy as a tool for microplastic research: Recommendations for improving methods and reporting.

Microscopy is often the first step in microplastic analysis and is generally followed by spectroscopy to confirm material type. The value of microscopy lies in its ability to provide count, size, color, and morphological information to inform toxicity and source apportionment. To assess the accuracy and precision of microscopy, we conducted a method evaluation study. Twenty-two laboratories from six countries were provided three blind spiked clean water samples and asked to follow a standard operating procedure. The samples contained a known number of microplastics with different morphologies (fiber, fragment, sphere), colors (clear, white, green, blue, red, and orange), polymer types (PE, PS, PVC, and PET), and sizes (ranging from roughly 3-2000 µm), and natural materials (natural hair, fibers, and shells; 100-7000 µm) that could be mistaken for microplastics (i.e., false positives). Particle recovery was poor for the smallest size fraction (3-20 µm). Average recovery (±StDev) for all reported particles >50 µm was 94.5 ± 56.3%. After quality checks, recovery for >50 µm spiked particles was 51.3 ± 21.7%. Recovery varied based on morphology and color, with poorest recovery for fibers and the largest deviations for clear and white particles. Experience mattered; less experienced laboratories tended to report higher concentration and had a higher variance among replicates. Participants identified opportunity for increased accuracy and precision through training, improved color and morphology keys, and method alterations relevant to size fractionation. The resulting data informs future work, constraining and highlighting the value of microscopy for microplastics.

Monitoring microplastics in drinking water: An interlaboratory study to inform effective methods for quantifying and characterizing microplastics.

California Senate Bill 1422 requires the development of State-approved standardized methods for quantifying and characterizing microplastics in drinking water. Accordingly, we led an interlaboratory microplastic method evaluation study, with 22 participating laboratories from six countries, to evaluate the performance of widely used methods: sample extraction via filtering/sieving, optical microscopy, FTIR spectroscopy, and Raman spectroscopy. Three spiked samples of simulated clean water and a laboratory blank were sent to each laboratory with a prescribed standard operating procedure for particle extraction, quantification, and characterization. The samples contained known amounts of microparticles within four size fractions (1-20 µm, 20-212 µm, 212-500 µm, >500 µm), four polymer types (PE, PS, PVC, and PET), and six colors (clear, white, green, blue, red, and orange). They also included false positives (natural hair, fibers, and shells) that may be mistaken for microplastics. Among laboratories, mean particle recovery using stereomicroscopy was 76% ± 10% (SE). For particles in the three largest size fractions, mean recovery was 92% ± 12% SD. On average, laboratory contamination from blank samples was 91 particles (± 141 SD). FTIR and Raman spectroscopy accurately identified microplastics by polymer type for 95% and 91% of particles analyzed, respectively. Per particle, FTIR spectroscopy required the longest time for analysis (12 min ± 9 SD). Participants demonstrated excellent recovery and chemical identification for particles greater than 50 µm in size, with opportunity for increased accuracy and precision through training and further method refinement. This work has informed methods and QA/QC for microplastics monitoring in drinking water in the State of California.

The emergency department incidence of incidental intracranial aneurysm on computed tomography angiography (EPIC-ACT) study.

BACKGROUND: Subarachnoid hemorrhage has been traditionally ruled-out in the emergency department (ED) through computed tomography (CT) followed by lumbar puncture if indicated. Mounting evidence suggests that non-contrast CT with CT angiography (CTA) can safely rule-out subarachnoid hemorrhage and obviate the need for lumbar puncture, but adoption of this approach is hindered by concerns of identifying incidental aneurysms. This study aims to estimate the incidence of incidental aneurysms identified on CTA head and neck in an ED population. METHODS: This was a health records review of all patients ≥ 18 years who underwent CTA head and neck for any indication at four large urban tertiary care EDs over a 3 month period. Patients were excluded if they underwent CT venogram only, had previously documented intracranial aneurysms, or had intracranial hemorrhage with or without aneurysm. Imaging reports were reviewed by two independent physicians before extracting relevant demographic (age, sex), clinical (CTAS level, CEDIS primary complaint) and radiographic (number, size, and location of aneurysms) information. The incidence rate of incidental aneurysms was calculated. RESULTS: A total of 1089 CTA studies were reviewed with a 3.3% (95% CI 2.3-4.6) incidence of incidental intracranial aneurysms. The median size of incidental aneurysms was 4 mm (0.7-11) and 10 (27.7%) patients had multiple aneurysms. Patients with incidental aneurysms did not differ based on mean age, sex, and CTAS levels. CONCLUSIONS: The "risk" of discovering an incidental aneurysm is 3.3%. Clinicians should not be deterred from using CTA in the appropriate clinical settings. These estimates can inform shared decision-making conversations with patients when comparing subarachnoid hemorrhage rule-out options.

RéSUMé: CONTEXTE: L'hémorragie sous-arachnoïdienne (HSA) a été traditionnellement exclue au service des urgences (SU) par tomodensitométrie cérébrale (TDM) suivie d'une ponction lombaire si indiquée. Des preuves de plus en plus nombreuses suggèrent que la tomographie sans contraste avec l'angiographie par tomodensitométrie (l'angio-TDM) permet d'exclure en toute sécurité les HSA et d'éviter la ponction lombaire, mais l'adoption de cette approche est entravée par les craintes d'identifier des anévrismes accidentels. Cette étude vise à estimer l'incidence des anévrismes accidentels identifiés par l'angiographie de la tête et du cou dans une population d'urgences. MéTHODES: Il s'agissait d'une étude des dossiers médicaux de tous les patients âgés de ≥ 18 ans qui ont subi une angioplastie de la tête et du cou, quelle qu'en soit l'indication, dans quatre grands services d'urgence urbains de soins tertiaires sur une période de trois mois. Les patients étaient exclus s'ils n'avaient subi qu'une phlébographie par tomodensitométrie, s'ils avaient déjà eu des anévrismes intracrâniens documentés ou s'ils avaient eu une hémorragie intracrânienne avec ou sans anévrisme. Les rapports d'imagerie ont été examinés par deux médecins indépendants avant d'extraire les informations démographiques pertinentes (âge, sexe), cliniques (niveau CTAS, plainte primaire CEDIS) et radiographiques (nombre, taille et emplacement des anévrismes). Le taux d'incidence des anévrismes accidentels a été calculé. RéSULTATS: Un total de 1089 études angio-TDM ont été examinées avec une incidence de 3,3 % (IC à 95 % : 2,3-4,6) d'anévrismes intracrâniens accidentels. La taille médiane des anévrismes fortuits était de 4 mm (plage : 0,7-11) et 10 (27,7 %) patients présentaient des anévrismes multiples. Les patients présentant des anévrismes accidentels ne différaient pas en fonction de l'âge moyen, du sexe et des niveaux CTAS. CONCLUSIONS: Le « risque ¼ de découvrir un anévrisme fortuit est de 3,3 %. Les cliniciens ne doivent pas être dissuadés d'utiliser l'angio-TDM dans les contextes cliniques appropriés. Ces estimations peuvent éclairer les conversations de prise de décision partagée avec les patients lors de la comparaison des options d'exclusion de l'HSA.

Effects of biofouling on the uptake of perfluorinated alkyl acids by organic-diffusive gradients in thin films passive samplers.

While organic-diffusive gradients in thin films (o-DGT) passive samplers have been used to assess organic contaminants in water, the effects of biofouling on accurate analyte quantification by o-DGT are poorly understood. We evaluated the effects of biofouling on the uptake of six common perfluoroalkyl substances (PFAS) using a previously developed polyacrylamide-WAX (weak anion exchange) o-DGT without a filter membrane. Linear uptake (R2 > 0.91) over 21 days was observed in fouled samplers. The measured sampling rates (Rs) and accumulated masses of PFAS in pre-fouled o-DGT were significantly lower (p < 0.05, 20-39% relative error) than in control-fouled samplers. However, compared to clean o-DGT (no biofouling), the Rs of most PFAS in control-fouled samplers (i.e., those with clean diffusive and binding gels initially) were not affected by biofouling. Under flowing (∼5.8 cm s-1) and static conditions, the measured diffusive boundary layer (DBL) thicknesses for clean o-DGT were 0.016 and 0.082 cm, respectively, whereas the effective in situ biofilm thicknesses for fouled o-DGT were 0.018 and 0.14 cm, respectively. These results suggest that biofilm growth does not have significant effects on target PFAS sampling by o-DGT under typical flowing conditions (≥2 cm s-1). However, rapid surface growth of biofilm on o-DGT deployed in quiescent waters over long periods of time may exacerbate the adverse effects of biofilms, necessitating the estimation of biofilm thickness in situ. This study provides new insights for evaluating the capability of o-DGT samplers when biofilm growth can be significant.

Scrutinizing surficial sediment along a 600-km-long urban coastal zone: Occurrence and risk assessment of fipronil and its three degradates.

Contamination in the coastal zone is closely linked to urbanization and has become a global issue. The coastal aquatic environment is the terminal sink for many chemicals; however, little is known about the occurrence and variation among habitats as well as integrative toxicity for pesticides, i.e., fipronil, and its three major degradates (-desulfinyl, -sulfide, and -sulfone, fiproles hereafter) in sediments in urban coastlines. In the present study, we report results of a random stratified survey for fiproles in surficial sediments in five embayment habitats (strata) along the Southern California Bight (SCB), USA coastline. Fiproles were present in a small areal extent (6.8%) of the SCB embayment, and detected in 14 out of 174 stations with a total concentration of the four analytes ranging from 0.50 to 17.5 µg/kg dry weight. The area-weighted mean concentrations were 3.16 ± 3.37, 0.584 ± 0.558, 0.071 ± 0.103, and 0.005 ± 0.009 µg/kg in brackish estuaries, estuaries, bays, and marinas, respectively, with the results below the detection limits in ports. Fipronil sulfone had the greatest detection frequency (8.05%) and highest mean concentration (3.24 ± 3.36 µg/kg) among the four compounds. A screening-level deterministic risk assessment for invertebrates found that, region-wide, fiproles generally posed an insignificant to low acute risk to the amphipod Eohaustorius estuarius in 7.36% of the SCB embayment area. In addition, high risk to the midge Chironomus dilutus was found in 77.5% of the fiproles-detectable area in the brackish estuary stratum that is a part of the Los Angeles River. Fipronil sulfone was identified as the major contributor of these effects. The results of this study establish a baseline of occurrence and toxicity potential for fiproles in coastal sediments of southern California.

Prevalence, Incidence, and Factors Associated With Non-Specific Chronic Low Back Pain in Community-Dwelling Older Adults Aged 60 Years and Older: A Systematic Review and Meta-Analysis.

Chronic low back pain (CLBP) is common among older adults. This systematic review aimed to summarize: (1) the prevalence and incidence of CLBP in older adults, and (2) demographic, psychological, and clinical factors positively/negatively associated with prevalence/incidence of CLBP among older adults. Four databases were searched to identify relevant publications. Ten studies (31,080 older adults) were included after being screened by 5 independent reviewers using predetermined criteria. The methodological quality of these studies was evaluated by standardized tools. The quality of evidence for all factors were appraised by modified GRADE for cohort studies. Twenty-eight and 1 factors were associated with a higher prevalence and a lower 5-year cumulative incidence of CLBP, respectively. No prognostic factor was identified. There was very limited to limited evidence that females, obesity, anxiety, depression, mental disorders, self-expectation of recovery, self-perceived health status, lifestyle (smoking, daily fluoride consumption), previous falls or lower body injury, retirement/disability due to ill health, family history of body pain, comorbidity (knee osteoarthritis, or chronic obstructive pulmonary disease with/without hypertension), weak abdominal muscles, leg pain, leg pain intensity, widespread pain, pain interference on functioning, use of pain medication, occupational exposure (driving for >20 years, or jobs involving bending/twisting for >10 years), disc space narrowing and severe facet osteoarthritis were significantly related to a higher prevalence of CLBP in older adults. However, very limited evidence suggested that intermediate level of leisure-time physical activity was associated with a lower prevalence of CLBP in older adults. Given the aging population and limited information regarding risk factors for CLBP in older adults, future high-quality prospective studies should identify relevant risk factors to help develop proper preventive and treatment strategies. PERSPECTIVE: Despite the high prevalence of non-specific chronic low back pain among older adults, there is only very limited to limited evidence regarding factors associated with a higher prevalence of chronic low back pain in this population. Given the aging population, high-quality prospective studies are warranted to address this gap.

Development and field evaluation of the organic-diffusive gradients in thin-films (o-DGT) passive water sampler for microcystins.

The presence of microcystins (MCs) in waterbodies requires a simple and reliable monitoring technique to characterize better their spatiotemporal distribution and ecological risks. An organic-diffusive gradients in thin films (o-DGT) passive sampler based on polyacrylamide diffusive gel and hydrophilic-lipophilic balance (HLB) binding gel was developed for MCs in water. The mass accumulation of three MCs (MC-LR, -RR, and -YR) was linear over 10 days (R2 ≥ 0.98). Sampling rates (2.68-3.22 mL d-1) and diffusion coefficients (0.90-1.08 × 10-6 cm2 s-1) of three MCs were obtained at 20 °C. Two different passive samplers, o-DGT and the Solid Phase Adsorption Toxin Tracking device (SPATT), were co-deployed to estimate MC levels at three lakes in California, USA. Measured total MC concentrations were up to 10.9 µg L-1, with MC-LR the primary variant at a measured maximum concentration of 2.74 µg L-1. Time-weighted average MC concentrations by o-DGT were lower than grab water samples, probably because grab sampling measures both dissolved and particulate phases (i.e., MCs in cyanobacteria). Passive water samplers by design can only measure dissolved-phase MCs, which are considerably less during the cyanobacteria-laden periods observed. Both o-DGT and grab samples gave comparable results for three MC variants at low levels of MCs, e.g., <0.1 µg L-1. o-DGT showed a higher correlation with grab sampling than SPATT did. This study demonstrates that o-DGT can be effectively used for monitoring and evaluation of dissolved MCs in waters.