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This study aimed to optimize the methods for sampling and analyzing methylmercury (MeHg) concentrated within diffusive gradients in thin films (DGT) and its application to different water bodies. We explored the elution solution for MeHg, comprised of 1.13 mM thiourea and 0.1M HCl, optimizing its volume to 50 mL. In addition, we found that it is necessary to analyze the entire extraction solution after adjusting its pH, to ensure completion of the ethylation reaction. The DGT samplers were deployed in two distinct aquatic environments (i.e., Okjeong Lake and Nakdong River) for up to 6 weeks, and this study demonstrated to predict the time-weighted average concentration with a diffusion coefficient of 7.65 × 10 -6 cm 2 s -1 for MeHg in the diffusive gel. To assess the diffusive boundary layer (DBL) effects, the DGT samplers with different agarose diffusive gel thickness were deployed. The mass of MeHg accumulated in the DGT resin at a given time decreased with increasing diffusive gel thickness, because of creating longer diffusion pathways within thicker gels. The labile MeHg concentration estimated by the DGT in Okjeong Lake and Nakdong River are found in the range of 61-111 and 55-105 pg L -1 , respectively, which were found to be similar to the grab sampling data. Additionally, this study evaluated depth-dependent MeHg in Okjeong Lake. The vertical profile results showed that the concentration of MeHg at the depth of 2.3 and 15.7 m are about 1.5 and 4.6 times of the DGT installed at 0.3 m of the surface layer, respectively, suggesting potential mercury methylation in deep waters. These findings have practical implications for predicting bioavailability, assessing risks, and formulating strategies for water body management and contamination remediation., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Objective: SimBox simulations allow for high-frequency open-access health care education, overcoming cost and resource barriers. Prehospital paramedics and emergency medical technician (EMT) care for children infrequently. In this study, prehospital providers evaluated pediatric SimBox simulations., Methods: This was a cross-sectional study of EMS professionals participating in a series of simulations conducted in a larger project assessing improvement of the quality of pediatric care in the prehospital setting. Participants were teams of two, which comprised a paramedic/paramedic, paramedic/EMT, or 2 EMTs. The simulations used facilitator resources, debriefing prompts, video depictions of patients and vital signs, and a low-fidelity manikin. Pediatric emergency care coordinators, EMS training officers, and/or emergency physicians facilitated simulations of seizure, sepsis with respiratory failure, and child abuse, followed by debriefings. Participants completed an online survey after the simulation and rated it in 4 domains: prebriefing, scenario content, debriefing, and overall. Ratings were trifold: "strongly agree," "somewhat agree," or "do not agree." Data were analyzed by case type, participant type, location, participant reaction to simulation elements, and the debriefing. Net Promoter Scores were calculated to assess participant endorsement of SimBox., Results: There were 121 participants: 103 (87%) were paramedics, and 18 (13%) were EMTs. Participant agreement of simulation benefit for clinical practice was high, for example, "I am more confident in my ability to prioritize care and interventions" (98.4% strongly or somewhat agree), and 99.2% of participants agreed the postsimulation debriefing with facilitators "provided opportunities to self-reflect on my performance during simulation." Overall, 97.5% strongly or somewhat agreed that the simulations "improved my comfort in pediatric acute care." Net Promoter Score showed 65.3% were promoters of and 24% were passive about SimBox., Conclusion: SimBox simulations are associated with improved self-efficacy of prehospital care providers for care of acutely ill or injured children. The majority promotes SimBox as a learning tool., Competing Interests: Disclosure: The authors declare no conflict of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

S-impregnation of biochar through elemental S streaming is known to increase its sorption performance against Hg and methyl mercury (MeHg). However, the effects of %S-loading on biochar's mechanism and sorption capacities for MeHg, and its consequent impact when used as an amendment material for Hg-contaminated sediments, are poorly understood, and thus, were investigated in this work. Our results showed that a minimum sulfur loading of 1% was the most effective in reducing MeHg levels in sediments. At higher %S-loading (3-20%), the reduction in surface area, pore blockage due to unreacted sulfur particles, and presence of poorly bound sulfur species resulted in lowered effectiveness for MeHg control. Increasing S-functionalization during impregnation shifted the sorption process of MeHg from Hg-O to Hg-S in S-impregnated biochar (BCS). Our 60-day slurry experiment showed a significant reduction in pore water THg (40-70%) and MeHg (30-55%), as well as sediment MeHg (50-60%) in biochar-amended sediments. The reduction in the bioavailable Hg resulted in lowered Hg methylation, as supported by the suppression of both the Fe- and SO 4 2- -reduction activities in the amended sediments. The microbial community structure in BCS-amended sediments showed a shift towards sulfur-consuming, iron-reducing, thiosulfate-oxidizing, and sulfate-reducing bacterial populations. At the genus level, the overall relative abundance of principal Hg methylators was also lower in the BCS treatment than in the unamended sediments. This study highlights the application of BCS as a promising strategy for remediation of Hg-contaminated sediments., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Activated carbon (AC) amendment is considered as one of the alternatives for managing and remediating mercury (Hg) contaminated sediments because of its high sorptive capacity and potential to immobilize the contaminant. For this study, the underlying mechanisms that control the reduction of Hg bioavailability in AC-amended estuarine sediments were investigated in box microcosm set-ups with 28-day Asian clam bioassay experiments. The application of diffusive gradients in thin film technique (DGT) revealed that the total mercury and methylmercury levels in sediment pore water decreased by 60%-75% in 1%-3% AC-amended sediments. This decrease subsequently led to a linear reduction in the Hg body burden in Asian clams, even at 1% sorbent mixing. These observations implied that AC amendment reduced the net flux of Hg into the pore water and overlying water, resulting in reduced Hg bioaccumulation in benthic organisms. The addition of AC to sediment also led to reduced dissolved organic carbon and several biogeochemical indicators (HS - , Mn, and Fe) in the pore water. Furthermore, the 16 S rRNA gene amplicon sequencing analysis revealed noticeable alterations in the microbial communities after AC amendment. The predominant phylum was Firmicutes in control sediment, Bacteroidetes in 1% AC-amended sediment, and Proteobacteria in both 2% and 3% AC-amended sediment samples. The genera-level analysis showed that the relative abundance of the Hg-methylators decreased as the level of AC amendment increased. These observations suggested that AC amendment decreased Hg bioavailability not only by physicochemical sorption but also by changing geochemical species and shifting the microbial community composition., (Copyright © 2021. Published by Elsevier Ltd.)

Background: Though family satisfaction with prehospital care is a surrogate for quality and patient outcomes, there are no tools available to measure family satisfaction., Objective: To develop the EMS Family Assessment of Medical Interventions & Liaisons with the Young (FAMILY) instrument., Methods: Components of family experiences with pediatric prehospital care were identified with a modified Delphi method. The expert panel included Emergency Medical Technicians, paramedics, family representatives, and EMS leaders from Colorado, Connecticut, and Rhode Island. An online survey was used to assess proposed questions from each of five candidate domains from national guidelines, including Safety, Communication, Family Presence, Cultural Awareness, Children with Special Healthcare Needs and Overall Satisfaction. Round-1 items were scored on a five-point Likert scale. Inclusion in the final instrument required 70% agreement ranking items as " include " or " definitely include ." In Round-2, participants assessed proposed refinements. This resulted in FAMILY Version-1, with sections for family members and EMS care providers. EMSC Family Action Network (FAN) representatives evaluated the FAMILY, leading to Version-2. Suggestions from the national FAN about content, clarity, and whether the instrument captured their experiences with pediatric EMS care led to the final FAMILY version. Bilingual speakers translated the instrument into Spanish, while assessing the content for semantic, idiomatic, experiential, and conceptual equivalence between the English and Spanish versions., Results: There were 22 experts in Round-1, and 20 continued into Round-2 .The Delphi process yielded 12 questions in six domains with 14 recommended modifications. Two questions were excluded. Five domains reached 70% agreement in Round-1. Cultural Awareness reached 75% agreement after Round-2. Six FAN representatives evaluated Version-1, leading to changes for clarity, content and cultural sensitivity. Seventeen FAN representatives evaluated Version-2 leading to additional refinement. The assessment of the equivalence between the English and Spanish survey versions resulted in changes in the Spanish language content for equivalent meaning., Conclusion: A panel of EMS and family stakeholders successfully developed an instrument to assess family satisfaction with pediatric EMS care. Further validation is required in a large respondent population. Assessing family satisfaction with pediatric EMS encounters is an important step toward improving prehospital care.

The potential of diffusive gradient in thin film (DGT) as a long-term monitoring tool to assess trace level mercury (Hg) in surface waters was evaluated. A piston type DGT sampler and a plate-type device that could hold 15 DGTs were designed. The device contained piston type DGT samplers with varying diffusive gel thicknesses, that is, 0.5, 0.75, and 1.0 mm, respectively. Three DGT devices were deployed in a lake for 5 weeks, and two were deployed in a stream for 3 weeks. In the lake, the total Hg (THg) mass accumulated in the DGT varied between 0.05 and 0.15 ng, which increased with an increase in deployment time and decreased with an increase in agarose diffusion gel thickness. The DGT concentration in the lake water for a 2 week period was estimated to be about 0.8-1.0 ng/L, which was close to the measured value of 1.1 (± 0.13) ng/L, using the grab sampling technique. However, the DGT estimated at 4 and 6 weeks showed a concentration of about 0.5-0.7 ng/L, which is about twice as small as that measured by grab sampling. This underestimation of the THg levels in water appear to be caused by additional thicknesses of the physical diffusive boundary layer (0.15, 0.5, 1.29 mm) and biofilm, outside the DGT filter. The predicted DGT concentration in the upper stream of the Nakdong River was estimated to be about 0.8-1.4 ng/L, which is similar to the value of 1.22 (± 0.29) ng/L measured in the field by grab sampling. The concentration of THg was estimated to be about 1.0-1.2 ng/L, which is similar to the values measured by grab sampling. The additional diffusion thickness formed outside the DGT filter was 0.018 mm and 0.093 mm at 1 and 3 weeks, respectively, which is not larger than the diffusion gel thickness (0.5-1.0 mm). This was because DGT was installed in a region where the flow velocity is high, and the thickness of the diffusion boundary layer outside the filter is negligible.

Heavy metal contamination in aquatic systems is a big problem in many areas around the world. In 2016, high mercury concentrations were reported in bivalves (Corbicula leana) and sediments near the confluence of the Hyeongsan River and Chilseong Creek located in Pohang, a steel industrial city in the south-east coast of the Korean peninsula. Given that both the Chilseong and Gumu creeks run through the Pohang industrial complex and ultimately flow to the Hyeongsan River, it is imperative to determine if the industrial effluents have any impact on the mercury contamination in these two streams and the Hyeongsan River. In this work, we investigated the concentration levels of different heavy metals using cold vapor atomic fluorescence spectroscopy and inductively coupled plasma-mass spectroscopy. The metal concentration in the water samples from the Hyeongsan River, Gumu Creek, and Chilseong Creek did not exceed the limits for drinking water quality set by the US EPA and World Health Organization. However, the sediment samples were found to be heavily contaminated by Hg with levels exceeding the toxic effect threshold. Gumu Creek was found to be heavily contaminated. The concentrations of the different heavy metals increased downstream, and the samples collected from the sites in the Hyeongsan River near the Gumu Creek, an open channel for wastewater discharge of companies in the Pohang Industrial Complex, showed higher contamination levels, indicating that the effluents from the industrial complex are a possible source of contamination in the river.

Objective: Paramedics and emergency medical technicians (EMTs) triage pediatric disaster victims infrequently. The objective of this study was to measure the effect of a multiple-patient, multiple-simulation curriculum on accuracy of pediatric disaster triage (PDT)., Methods: Paramedics, paramedic students, and EMTs from three sites were enrolled. Triage accuracy was measured three times (Time 0, Time 1 [two weeks later], and Time 2 [6 months later]) during a disaster simulation, in which high and low fidelity manikins and actors portrayed 10 victims. Accuracy was determined by participant triage decision concordance with predetermined expected triage level (RED [Immediate], YELLOW [Delayed], GREEN [Ambulatory], BLACK [Deceased]) for each victim. Between Time 0 and Time 1, participants completed an interactive online module, and after each simulation there was an individual debriefing. Associations between participant level of training, years of experience, and enrollment site were determined, as were instances of the most dangerous mistriage, when RED and YELLOW victims were triaged BLACK., Results: The study enrolled 331 participants, and the analysis included 261 (78.9%) participants who completed the study, 123 from the Connecticut site, 83 from Rhode Island, and 55 from Massachusetts. Triage accuracy improved significantly from Time 0 to Time 1, after the educational interventions (first simulation with debriefing, and an interactive online module), with a median 10% overall improvement (p < 0.001). Subgroup analyses showed between Time 0 and Time 1, paramedics and paramedic students improved more than EMTs (p = 0.002). Analysis of triage accuracy showed greatest improvement in overall accuracy for YELLOW triage patients (Time 0 50% accurate, Time1 100%), followed by RED patients (Time 0 80%, Time 1 100%). There was no significant difference in accuracy between Time 1 and Time 2 (p = 0.073)., Conclusion: This study shows that the multiple-victim, multiple-simulation curriculum yields a durable 10% improvement in simulated triage accuracy. Future iterations of the curriculum can target greater improvements in EMT triage accuracy.