Toward the Development and Application of an Environmental Risk Assessment Framework for Microplastic.

Emissions of plastic waste to the environment and the subsequent degradation into microplastic particles that have the potential to interact with biological organisms represent a concern for global society. Current understanding of the potential impacts on aquatic and terrestrial population stability and ecosystem structure and function associated with emissions of microplastic particles is limited and insufficient to fully assess environmental risks. Multistakeholder discussions can provide an important element in helping to identify and prioritize key knowledge gaps in assessing potential risks. In the present review, we summarize multistakeholder discussions from a 1-d International Council of Chemical Associations-sponsored symposium, which involved 39 scientists from 8 countries with representatives from academia, industry, and government. Participants were asked to consider the following: discuss the scientific merits and limitations of applying a proposed conceptual environmental risk assessment (ERA) framework for microplastic particles and identify and prioritize major research needs in applying ERA tools for microplastic particles. Multistakeholder consensus was obtained with respect to the interpretation of the current state of the science related to effects and exposure to microplastic particles, which implies that it is unlikely that the presence of microplastic in the environment currently represents a risk. However, the quality and quantity of existing data require substantial improvement before conclusions regarding the potential risks and impacts of microplastic particles can be fully assessed. Research that directly addresses the development and application of methods that strengthen the quality of data should thus be given the highest priority. Activities aimed at supporting the development of and access to standardized reference material were identified as a key research need. Environ Toxicol Chem 2019;38:2087-2100. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

Shifting headlines? Size trends of newsworthy fishes.

The shifting baseline syndrome describes a gradual lowering of human cognitive baselines, as each generation accepts a lower standard of resource abundance or size as the new norm. There is strong empirical evidence of declining trends of abundance and body sizes of marine fish species reported from docks and markets. We asked whether these widespread trends in shrinking marine fish are detectable in popular English-language media, or whether news writers, like many marine stakeholders, are captive to shifting baselines. We collected 266 English-language news articles, printed between 1869 and 2015, which featured headlines that used a superlative adjective, such as 'giant', 'huge', or 'monster', to describe an individual fish caught. We combined the reported sizes of the captured fish with information on maximum species-specific recorded sizes to reconstruct trends of relative size (reported size divided by maximum size) of newsworthy fishes over time. We found some evidence of a shifting baseline syndrome in news media over the last 140 years: overall, the relative length of the largest fish worthy of a headline has declined over time. This pattern held for charismatic fish species (e.g. basking sharks, whale sharks, giant mantas), which are now reported in the media at smaller relative lengths than they were near the turn of the 20th century, and for the largest species under high risk of extinction. In contrast, there was no similar trend for pelagic gamefish and oceanic sharks, or for species under lower risk of extinction. While landing any individual of the large-bodied 'megafish' may be newsworthy in part because of their large size relative to other fish species, the 'megafish' covered in our dataset were small relative to their own species-on average only 56% of the species-specific maximum length. The continued use in the English-language media of superlatives to describe fish that are now a fraction of the maximum size they could reach, or a fraction of the size they used to be, does reflect a shifting baseline for some species. Given that media outlets are a powerful tool for shaping public perception and awareness of environmental issues, there is a real concern that such stories might be interpreted as meaning that superlatively large fish still abound.

Advancements in Life Cycle Human Exposure and Toxicity Characterization.

BACKGROUND: The Life Cycle Initiative, hosted at the United Nations Environment Programme, selected human toxicity impacts from exposure to chemical substances as an impact category that requires global guidance to overcome current assessment challenges. The initiative leadership established the Human Toxicity Task Force to develop guidance on assessing human exposure and toxicity impacts. Based on input gathered at three workshops addressing the main current scientific challenges and questions, the task force built a roadmap for advancing human toxicity characterization, primarily for use in life cycle impact assessment (LCIA). OBJECTIVES: The present paper aims at reporting on the outcomes of the task force workshops along with interpretation of how these outcomes will impact the practice and reliability of toxicity characterization. The task force thereby focuses on two major issues that emerged from the workshops, namely considering near-field exposures and improving dose­response modeling. DISCUSSION: The task force recommended approaches to improve the assessment of human exposure, including capturing missing exposure settings and human receptor pathways by coupling additional fate and exposure processes in consumer and occupational environments (near field) with existing processes in outdoor environments (far field). To quantify overall aggregate exposure, the task force suggested that environments be coupled using a consistent set of quantified chemical mass fractions transferred among environmental compartments. With respect to dose­response, the task force was concerned about the way LCIA currently characterizes human toxicity effects, and discussed several potential solutions. A specific concern is the use of a (linear) dose­response extrapolation to zero. Another concern addresses the challenge of identifying a metric for human toxicity impacts that is aligned with the spatiotemporal resolution of present LCIA methodology, yet is adequate to indicate health impact potential. CONCLUSIONS: Further research efforts are required based on our proposed set of recommendations for improving the characterization of human exposure and toxicity impacts in LCIA and other comparative assessment frameworks. https://doi.org/10.1289/EHP3871.

Functional responses of a cosmopolitan invader demonstrate intraspecific variability in consumer-resource dynamics.

BACKGROUND: Variability in the ecological impacts of invasive species across their geographical ranges may decrease the accuracy of risk assessments. Comparative functional response analysis can be used to estimate invasive consumer-resource dynamics, explain impact variability, and thus potentially inform impact predictions. The European green crab (Carcinus maenas) has been introduced on multiple continents beyond its native range, although its ecological impacts appear to vary among populations and regions. Our aim was to test whether consumer-resource dynamics under standardized conditions are similarly variable across the current geographic distribution of green crab, and to identify correlated morphological features. METHODS: Crabs were collected from multiple populations within both native (Northern Ireland) and invasive regions (South Africa and Canada). Their functional responses to local mussels (Mytilus spp.) were tested. Attack rates and handling times were compared among green crab populations within each region, and among regions (Pacific Canada, Atlantic Canada, South Africa, and Northern Ireland). The effect of predator and prey morphology on prey consumption was investigated. RESULTS: Across regions, green crabs consumed prey according to a Type II (hyperbolic) functional response curve. Attack rates (i.e., the rate at which a predator finds and attacks prey), handling times and maximum feeding rates differed among regions. There was a trend toward higher attack rates in invasive than in native populations. Green crabs from Canada had lower handling times and thus higher maximum feeding rates than those from South Africa and Northern Ireland. Canadian and Northern Ireland crabs had significantly larger claws than South African crabs. Claw size was a more important predictor of the proportion of mussels killed than prey shell strength. DISCUSSION: The differences in functional response between regions reflect observed impacts of green crabs in the wild. This suggests that an understanding of consumer-resource dynamics (e.g., the per capita measure of predation), derived from simple, standardized experiments, might yield useful predictions of invader impacts across geographical ranges.

The Impact of Hemodynamic Transesophageal Echocardiography on the Use of Continuous Renal Replacement Therapy in Trauma.

Post-traumatic fluid management is a widely debated topic. No best-practice consensus exists. Adverse outcomes such as acute kidney injury or volume overload are common. Continuous renal replacement therapy (CRRT) is an adjunct therapy for severe acute renal failure and volume overload, but is costly and not without risk. Hemodynamic transesophageal echocardiography (hTEE) is widely accepted as a reliable way to monitor volume status of intensive care unit (ICU) patients. Although data exist evaluating hTEE and CRRT independently, there is a lack of research mutually inclusive of the two. We hypothesized that the use of hTEE is associated with less need for CRRT. Retrospective review of a level I trauma center from 2009 to 2015 identified patients that required CRRT. In 2013, we implemented a protocol using hTEE in trauma patients with significant resuscitation needs. We compared CRRT use before and after implementation of the protocol (pre- and post-hTEE). Multivariate analysis using two sample t tests and χ2 test of the odds ratio (O.R.) was completed on variables such as injury severity score (ISS), acute kidney injury network (AKIN), days of CRRT, ICU length of stay (LOS), and hospital LOS. A total of 5037 and 6699 trauma patients were evaluated in the pre- and post-hTEE groups, respectively. Mean ISS was 22 and 28 for pre- and post-hTEE, respectively (P value 0.19). Mean AKIN was 2.7 for both groups. Mean days on CRRT was eight before hTEE and seven after hTEE (P value 0.7); 23 patients required CRRT pre-hTEE, and 15 required CRRT post-hTEE (P value 0.01 O.R. 2.4). Given, the odds of CRRT pre-hTEE are more than twice that of CRRT post-hTEE; we conclude that the use of hTEE is associated with a reduction of CRRT.

The Trauma Time-Out: Evaluating the Effectiveness of Protocol-Based Information Dissemination in the Traumatically Injured Patient.

Procedural time-outs are widely accepted safety standards that are protocolized in nearly all hospital systems. The trauma time-out, however, has been largely unstudied in the existing literature and does not have a standard protocol outlined by any of the major trauma surgery organizations. The goal of this study was to evaluate our institution's use of the trauma time-out and assess how trauma team members viewed its effectiveness. A multiple-answer survey was sent to trauma team members at a Level I trauma center. Questions included items directed at background, experience, opinions, and write-in responses. Most responders were experienced trauma team members who regularly participated in trauma codes. All respondents noted the total time required to complete the time-out was less than 5 min, with the majority saying it took less than 1 min. Seventy-five percent agreed that trauma time-outs should continue, with 92% noting that it improved understanding of patient presentation and prehospital evaluation. Seventy-seven percent said it improved understanding of other team member's roles, and 75% stated it improved patient care. Subgroups of physicians and nurses were statistically similar; yet, physicians did note that it improved their understanding of the team member's function more frequently than nurses. The trauma time-out can be an excellent tool to improve patient care and team understanding of the incoming trauma patient. Although used widely at multiple levels of trauma institutions, development of a documented protocol can be the next step in creating a unified safety standard.

A quantitative screening-level approach to incorporate chemical exposure and risk into alternative assessment evaluations.

As the general public and retailers ask for disclosure of chemical ingredients in the marketplace, a number of hazard screening tools were developed to evaluate the so-called "greenness" of individual chemical ingredients and/or formulations. The majority of these tools focus only on hazard, often using chemical lists, ignoring the other part of the risk equation: exposure. Using a hazard-only focus can result in regrettable substitutions, changing 1 chemical ingredient for another that turns out to be more hazardous or shifts the toxicity burden to others. To minimize the incidents of regrettable substitutions, BizNGO describes "Common Principles" to frame a process for informed substitution. Two of these 6 principles are: "reduce hazard" and "minimize exposure." A number of frameworks have emerged to evaluate and assess alternatives. One framework developed by leading experts under the auspices of the US National Academy of Sciences recommended that hazard and exposure be specifically addressed in the same step when assessing candidate alternatives. For the alternative assessment community, this article serves as an informational resource for considering exposure in an alternatives assessment using elements of problem formulation; product identity, use, and composition; hazard analysis; exposure analysis; and risk characterization. These conceptual elements build on practices from government, academia, and industry and are exemplified through 2 hypothetical case studies demonstrating the questions asked and decisions faced in new product development. These 2 case studies-inhalation exposure to a generic paint product and environmental exposure to a shampoo rinsed down the drain-demonstrate the criteria, considerations, and methods required to combine exposure models addressing human health and environmental impacts to provide a screening level hazard and exposure (risk) analysis. This article informs practices for these elements within a comparative risk context to improve alternatives assessment evaluation and decision making. Integr Environ Assess Manag 2017;13:1007-1022. © 2017 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Superficial x-ray in the treatment of basal and squamous cell carcinomas: a viable option in select patients.

BACKGROUND: Effective nonsurgical modalities are limited in the treatment of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). OBJECTIVE: We sought to evaluate the efficacy and viability of superficial x-ray therapy in the treatment of BCC and SCC in an outpatient setting. METHODS: A retrospective analysis was performed on 1715 histologically confirmed primary cutaneous BCC and SCC treated with superficial x-ray therapy at Dermatology Associates of Tallahassee in Florida between 2000 and 2010. RESULTS: Of the 1715 tumors reviewed during this period, 712 were histologically proven BCC (631 nodular and 81 superficial), 994 were SCC (861 SCC in situ and 133 invasive SCC), and 9 displayed distinct features of both BCC and SCC in the same biopsy specimen. Kaplan-Meier estimates (with 95% confidence intervals) of cumulative recurrence rates of all tumors at 2 and 5 years were 1.9% (1%-2.7%) and 5.0% (3.2%-6.7%), respectively; of BCC at 2 and 5 years were 2% (0.8%-3.3%) and 4.2% (1.9%-6.4%), respectively; and of all SCC at 2 and 5 years were 1.8% (0.8%-2.8%) and 5.8% (2.9%-8.7%), respectively. Tumors on male patients and those with a diameter greater than 2 cm were associated with a statistically significant increase in recurrence likelihood. LIMITATIONS: This study represents only patients treated in 1 dermatology office in North Florida and may not be representative of the general patient population. CONCLUSIONS: Superficial x-ray therapy remains a viable nonsurgical option for the treatment of primary BCC and SCC in patients where surgical intervention is declined, unadvisable, or potentially associated with significant cosmetic or functional limitations.

Silylene transfer to alpha-keto esters and application to the synthesis of gamma-lactones.

Disubstituted alpha-hydroxy acids have been synthesized by metal-catalyzed silylene transfer to alpha-keto esters. A range of substituents are tolerated in the transformation with the exception of branched groups at the vinylic position. The alpha-hydroxy acid products can be converted into gamma-lactones using a variety of lactonization conditions.

Synthesis of tertiary alpha-hydroxy acids by silylene transfer to alpha-keto esters.

Alpha-keto esters can be converted into alpha-hydroxy acids in a single flask involving metal-catalyzed silylene transfer, 6pi-electrocyclization, Ireland-Claisen rearrangement, and hydrolysis. This reaction sequence is stereoselective and tolerates alkyl- and aryl-substituted alpha-keto ester substrates as well as an alpha-imino ester.

Exploring biochemistry and cellular biology with protein libraries.

Polypeptide libraries cast a broad net for defining enzyme and binding protein specificities. In addition to uncovering rules for molecular recognition, the binding preferences and functional group tolerances from such libraries can reveal mechanisms underlying biochemical and cellular processes. Ligands obtained from protein libraries can also provide pharmaceutical lead compounds and even reagents to further explore cell biology. Here, we review selected recent examples of protein libraries demonstrating these principles. In particular, we focus on combinatorial libraries composed of randomized peptides or variations of a single protein. The characteristics of various techniques for library constructions and screening are also briefly surveyed.