Comparison of Three Pebble Count Protocols (EMAP,PIBO, and SFT) in Two Mountain Gravel‐Bed Streams1

Abstract: Although the term ``pebble count'' is in widespread use, there is no standardized methodology used for the field application of this procedure. Each pebble count analysis is the product of several methodological choices, any of which are capable of influencing the final result. Because there are virtually countless variations on pebble count protocols, the question of how their results differ when applied to the same study reach is becoming increasingly important. This study compared three pebble count protocols: the reach‐averaged Environmental Monitoring and Assessment Program (EMAP) protocol named after the EMAP developed by the Environmental Protection Agency, the habitat‐unit specific U.S. Forest Service’s PACFISH/INFISH Biological Opinion (PIBO) Effectiveness Monitoring Program protocol, and a data‐intensive method developed by the authors named Sampling Frame and Template (SFT). When applied to the same study reaches, particle‐size distributions varied among the three pebble count protocols because of differences in sample locations within a stream reach and along a transect, in particle selection, and particle‐size determination. The EMAP protocol yielded considerably finer, and the PIBO protocol considerably coarser distributions than the SFT protocol in the pool‐riffle study streams, suggesting that the data cannot be used interchangeably. Approximately half of the difference was due to sampling at different areas within the study reach (i.e., wetted width, riffles, and bankfull width) and at different locations within a transect. The other half was attributed to using different methods for particle selection from the bed, particle‐size determination, and the use of wide, nonstandard size classes. Most of the differences in sampling outcomes could be eliminated by using simple field tools, by collecting a larger sample size, and by systematically sampling the entire bankfull channel and all geomorphic units within the reach.     

Characterisation of occupational exposure to air contaminants in a nitrate fertiliser production plant

The aim of this study was to characterise personal exposures to dust, acid vapours, and gases among workers in a Norwegian nitrate fertiliser production plant, as part of an ongoing epidemiological study. In total, 178 inhalable and 179 thoracic aerosol mass fraction samples were collected from randomly chosen workers (N = 141) from three compound fertiliser departments (A, B and C), a calcium nitrate fertiliser production department, nitric acid- and ammonia-production departments, and a shipping department. The overall median inhalable and thoracic aerosol mass concentrations were generally low (1.1 mg m(-3) (min-max: <0.93-45) and 0.21 mg m(-3) (min-max: <0.085-11), respectively). Workers at the compound fertiliser departments B and C had significantly higher inhalable aerosol mass air concentrations compared to the other departments (p < 0.05), except for compound fertiliser department A; however, the difference between the compound fertiliser department C and calcium nitrate department was slightly above the significant level. Workers at the compound fertiliser department A had significantly higher thoracic aerosol mass air concentrations compared to the other departments (p < 0.05), except for compound fertiliser departments B and C. The results indicate that the extrathoracic aerosol fraction of the aerosol compared to the thoracic fraction dominated in most departments. Measurement of the main constituents Ca, K, Mg, and P in the water-soluble and water-insoluble aerosol mass fractions showed that the air concentrations of these elements were low. There is, however, a shift towards more water-soluble species as the production goes from raw material with phosphate rock towards the final product of fertilisers. Overall, the arithmetic mean of water-soluble Ca in the thoracic mass fraction was 51% (min-max: 1-100). A total of 169 personal samples were analysed for HNO(3) vapour and HF. The highest median concentration of HNO(3) (0.63 mg m(-3)) was in the compound fertiliser departments B, and all measurements but four of the HF concentrations were below the LOD of 190 μg m(-3). Exposures to NH(3), CO and NO(2) were measured using direct-reading electrochemical sensors and the time weighted overall averages were all below the LODs of the respective sensors, NH(3) 2 ppm; CO 2 ppm; and NO(2) 0.2 ppm, but some short-term peaks were detected. Even though our results indicate that the workers may experience peak exposure episodes when performing job tasks such as cleaning or maintenance work, the overall air concentrations are well below what is considered to cause known health risks.     

评估可离子化有机化合物的生物累积潜力：当前的认知和研究的重点

本研究的目的是回顾目前关于可离子化有机化合物(IOCs)的生物累积潜力的认知,重点讨论鱼类经验数据的有效性。IOCs在鱼体内的生物积累潜力可以很好地表征为：依赖pH的鳃摄取和排泄,肠道吸收和磷脂吸附(膜-水分区)。关键的挑战包括缺乏关于IOCs生物转化和血浆结合的经验数据。鱼拥有多种蛋白质,可以在细胞膜上传输IOCs。然而,除了少数情况下,这种传输对环境污染物的吸收和积累的意义是未知的。本文提出了2个研究案例。第一个描述了pH值和生物转化对有机酸和碱的生物富集的建模作用,而第二个则采用了一个更新的模型来研究导致全氟烷基酸积累的因素。全氟化烷基酸个案研究是值得关注的,因为它说明了膜转运蛋白在肾脏中可能具有的重要性,并强调了交叉比对方法(read-across approaches)的潜在价值。认识到当前需要对IOCs进行生物累积危害评估和生态风险评估,作者提供了一个分层策略,从保守的假设(模型和相关数据)到需要化学特定信息的更复杂的模型。
精选自Armitage, J. M., Erickson, R. J., Luckenbach, T., Ng, C. A., Prosser, R. S., Arnot, J. A., Schirmer, K. and Nichols, J. W. (2017), Assessing the bioaccumulation potential of ionizable organic compounds: Current knowledge and research priorities. Environmental Toxicology and Chemistry, 36: 882–897. doi: 10.1002/etc.3680
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3680/full
     

Exploring Patterns of Seafood Provision Revealed in the Global Ocean Health Index

Sustainable provision of seafood from wild-capture fisheries and mariculture is a fundamental component of healthy marine ecosystems and a major component of the Ocean Health Index. Here we critically review the food provision model of the Ocean Health Index, and explore the implications of knowledge gaps, scale of analysis, choice of reference points, measures of sustainability, and quality of input data. Global patterns for fisheries are positively related to human development and latitude, whereas patterns for mariculture are most closely associated with economic importance of seafood. Sensitivity analyses show that scores are robust to several model assumptions, but highly sensitive to choice of reference points and, for fisheries, extent of time series available to estimate landings. We show how results for sustainable seafood may be interpreted and used, and we evaluate which modifications show the greatest potential for improvements.     

Re-cycling of remediated soil - Evaluation of leaching tests as tools for characterization

In Sweden, leaching tests with deionized water (D.W.) are utilized in risk assessment of materials entering landfills, but implementation of these results to evaluate the risk of spreading of pollutants in the environment is difficult. One problem is that most leaching procedures only consider heavy metals release, whereas organic pollutants are left out. The aim of the present study was to assess the possible pollutant mitigation in four remediated soils, three with heavy metals and one with polycyclic aromatic hydrocarbons (PAH) contamination. The mitigation was evaluated by standardized batch and column leaching tests utilizing three different leaching solutions: D.W., a weak ionic solution (0.001 M CaCl₂) and an artificially made soil water (ASW). In general, batch leaching tests implied larger contaminant removal than column leaching test, possibly due to the more rough treatment of the soil particles, and guidelines would at times be exceeded by the batch leaching test but not by column leaching tests. Utilization of CaCl₂ was found to release less heavy metal than D.W., whereas the metals mobilized by ASW were removed from solution by the filtration of soil leachates. Low molecular weight PAH was most efficiently mobilized by CaCl₂, while D.W. worked better for high molecular weight PAH. Despite very low initial PAH-concentrations, tap- and groundwater criteria were exceeded by all leaching solutions.     

Knowledge coproduction on the impact of decisions for waterbird habitat in a changing climate

Scientists, resource managers, and decision makers increasingly use knowledge coproduction to guide the stewardship of future landscapes under climate change. This process was applied in the California Central Valley (USA) to solve complex conservation problems, where managed wetlands and croplands are flooded between fall and spring to support some of the largest concentrations of shorebirds and waterfowl in the world. We coproduced scenario narratives, spatially explicit flooded waterbird habitat models, data products, and new knowledge about climate adaptation potential. We documented our coproduction process, and using the coproduced models, we determined when and where management actions make a difference and when climate overrides these actions. The outcomes of this process provide lessons learned on how to cocreate usable information and how to increase climate adaptive capacity in a highly managed landscape. Actions to restore wetlands and prioritize their water supply created habitat outcomes resilient to climate change impacts particularly in March, when habitat was most limited; land protection combined with management can increase the ecosystem's resilience to climate change; and uptake and use of this information was influenced by the roles of different stakeholders, rapidly changing water policies, discrepancies in decision-making time frames, and immediate crises of extreme drought. Although a broad stakeholder group contributed knowledge to scenario narratives and model development, to coproduce usable information, data products were tailored to a small set of decision contexts, leading to fewer stakeholder participants over time. A boundary organization convened stakeholders across a large landscape, and early adopters helped build legitimacy. Yet, broadscale use of climate adaptation knowledge depends on state and local policies, engagement with decision makers that have legislative and budgetary authority, and the capacity to fit data products to specific decision needs.     

Medical investigation after a motorcoach strikes the rear of a tractor semitrailer parked on the highway; 13 fatal

Abstract

Objective: The objective of this study was to examine the medical conditions of 2 commercial drivers and the effects of physical barriers to occupant egress in a crash involving a tractor trailer and a motorcoach in order to assess and identify the factors that caused the crash and had a significant effect on occupant extrication.

Methods: Physical evidence from the scene, video evidence, commercial driver information, phone records, toxicology findings, autopsy results, and personal medical information were reviewed.

Results: On October 23, 2016, at 5:16 a.m., a motorcoach carrying a driver and 42 passengers struck the rear of a stopped semitrailer occupied by its driver in the center-right lane of Interstate 10 at highway speed outside Palm Springs, California. The motorcoach driver and 12 passengers died; 11 passengers were seriously injured.

All traffic had been stopped on I-10 early that morning to allow electrical lines to be strung over the highway. Security camera footage showed that the truck arrived at the end of a traffic queue 2?min before traffic flow resumed. Physical evidence indicated that the truck’s parking brake was still engaged at the time of the collision about 2?min later. The truck driver had a body mass index (BMI) between 45.6 and 50?kg/m², which placed him at very high risk of moderate to severe obstructive sleep apnea; he also inaccurately recalled that he had been stopped for 20–25?min and had placed the vehicle in gear just before the collision.

The motorcoach driver was on the return leg of an overnight trip to a casino. Based on his phone records, known driving time, and security camera footage, at the time of the collision he had had 4?h of sleep opportunity in the preceding 35?h. There was no evidence that the motorcoach driver attempted any evasive action before the collision. In addition, postmortem testing revealed a hemoglobin A1C of 11.4%, indicating poorly controlled diabetes; this was apparently undiagnosed prior to the crash.

The motorcoach was equipped with a single loading door at the front of the vehicle; it was rendered inoperable by the collision. Emergency egress was initially carried out through the emergency exit windows, but they repeatedly swung shut, impeding passengers’ efforts to exit. Emergency responders eventually cut open the bus wall to create a larger means of egress. Overall, it took almost 3?h to extricate the occupants from the vehicle.

Conclusions: The National Transportation Safety Board (NTSB) determined that the probable cause of the accident was the truck driver’s falling asleep, most likely due to undiagnosed moderate-to-severe obstructive sleep apnea, and the motorcoach driver’s failure to identify the stopped truck as a hazard requiring evasive action, most likely as the result of fatigue. Additional easy-to-use emergency exits would have decreased the time to extricate the occupants.     

Using Nonprofit Narratives and News Media Framing to Depict Air Pollution in Delhi,India

How is the air pollution issue in Delhi framed by the news media and narrated by nonprofit organizations? To study news media framing, we employed an inductive approach based on automated text coding of news coverage of the issue. To study nonprofit organization narrations, a deductive approach guided by the Narrative Policy Framework was used to focus on the stories told via online documents as found on nonprofit websites. The findings confirm existing theory and empirical research regarding the leading causes and effects of air pollution; however, perceptions are mixed regarding the government’s ability to implement policy. The combined deductive and inductive approaches provide a systematic and multi-method research study for understanding perceptions of air pollution in one of the largest cities in the world. The result is a depiction of the priorities that influence public opinions, political decisions, and eventually public policies.     

Accumulation of perfluorooctane sulfonate (PFOS) in the food chain of the Western Scheldt estuary: Comparing field measurements with kinetic modeling

The environmentally persistent perfluorooctane sulfonate (PFOS) is a perfluoroalkylated acid (PFA), which has been found to accumulate and biomagnify through food webs all over the world. In the present investigation, the accumulation kinetics of PFOS was explored using the bioaccumulation model OMEGA. As accumulation behavior of PFOS may show similarities to fatty acids as well as to neutral organic compounds, different modeling approaches were used. Accumulation kinetics of PFOS was modeled similar to (1) moderately and (2) highly hydrophobic compounds, (3) metals and (4) as a combination of hydrophobic compounds and metals. Modeled elimination and uptake rate constants were compared to empirical rate constants from literature. Subsequently, model predictions were compared to field-based biota-suspended solids accumulation ratios (BSAF) in the estuarine food chain of the Western Scheldt, The Netherlands. Results show that uptake of PFOS is comparable to moderately hydrophobic compounds and elimination is best described by elimination kinetics of metals. These observations indicate that the accumulation behavior of PFOS is comparable to that of short and medium chained fatty acids.     

Expanding the range of halogenated 1'-methyl-1,2'-bipyrroles (MBPs) using GC/ECNI-MS and GCxGC/TOF-MS

Halogenated 1'methyl-1,2'-bipyrroles (MBPs) have been identified worldwide in marine mammals. Here we present the tentative identification of previously undetected MBP congeners in Delpinus delphis blubber using gas chromatography/electron capture negative ion mass spectrometry (GC/ECNI-MS) and comprehensive two-dimensional gas chromatography/time of flight mass spectrometry (GCxGC/TOF-MS). This is the first report of 26 congeners. The presence of numerous partially halogenated congeners suggests that they are either biosynthesized concomitantly with their perhalogenated counterparts or that their dehalogenation products can also bioaccumulate. The newly found compounds fit the geographic trend that has been previously noted. That is, samples from the Atlantic Ocean are dominated by the more brominated congeners while those from the Pacific are dominated by the more chlorinated congeners.