Advancing effects analysis for integrated, large-scale wildfire risk assessment

In this article, we describe the design and development of a quantitative, geospatial risk assessment tool intended to facilitate monitoring trends in wildfire risk over time and to provide information useful in prioritizing fuels treatments and mitigation measures. The research effort is designed to develop, from a strategic view, a first approximation of how both fire likelihood and intensity influence risk to social, economic, and ecological values at regional and national scales. Three main components are required to generate wildfire risk outputs: (1) burn probability maps generated from wildfire simulations, (2) spatially identified highly valued resources (HVRs), and (3) response functions that describe the effects of fire (beneficial or detrimental) on the HVR. Analyzing fire effects has to date presented a major challenge to integrated risk assessments, due to a limited understanding of the type and magnitude of changes wrought by wildfire to ecological and other nonmarket values. This work advances wildfire effects analysis, recognizing knowledge uncertainty and appropriately managing it through the use of an expert systems approach. Specifically, this work entailed consultation with 10 fire and fuels program management officials from federal agencies with fire management responsibilities in order to define quantitative resource response relationships as a function of fire intensity. Here, we demonstrate a proof-of-concept application of the wildland fire risk assessment tool, using the state of Oregon as a case study.     

Aluminium in UK rivers: a need for integrated research related to kinetic factors, colloidal transport, carbon and habitat

Dissolved aluminium concentrations ([Al]) in the <0.45 μm filtered fraction are described for 54 UK river sites covering rural, acidic/acid sensitive, agricultural and urban typologies, and wide pH range (4 to 11). High [Al] occurred under acidic conditions and for acid runoff neutralised by bicarbonate rich groundwater. Thermodynamic analysis indicates Al hydroxide/hydroxy-silicate oversaturation at circumneutral pH across the rivers, but undersaturation at lower/higher pH. The oversaturation reflects in part the presence of Al bearing colloids as indicated by (1) [Al] being correlated with components associated with both lithogenic (Fe, Ti and lanthanides) colloids and organic carbon, (2) baseflow studies using cross-flow ultrafiltration and (3) comparison of our data with Acid Waters Monitoring Network (AWMN) information on labile and non-labile Al. Tree harvesting and emission reductions of SO(x) in acidic and acid sensitive catchments in mid-Wales led to acidification reversal, lower [Al] and changing [H(+)] - [Al] relationships. The [Al] decline was confined to acidic conditions while [Al] increased during the later part of the monitoring period with a peak around 2002 for moorland and forested systems. Colloidal production across the flow range was indicated late in the record by comparison of our data with information collected by the AWMN for a site in mid-Wales. This production seems interlinked with organic carbon and with dissolved CO(2) changes. In order for further understanding of Al hydrogeochemistry in river systems there is a need to integrate research that moves from equilibrium to kinetic and colloidal consideration including the critical issues of organic and inorganic controls within the context of bioavailability and aquatic stress. The colloidal Al may well be of low environmental concern to fish and other factors such as habitat may well be critical.     

Analysis of per- and polyfluoroalkyl substances in Houston Ship Channel and Galveston Bay following a large-scale industrial fire using ion-mobility-spectrometry-mass spectrometry

Per- and polyfluoroalkyl substances (PFAS) are persistent organic pollutants of concern because of their ubiquitous presence in surface and ground water; analytical methods that can be used for rapid comprehensive exposure assessment and fingerprinting of PFAS are needed. Following the fires at the Intercontinental Terminals Company (ITC) in Deer Park, TX in 2019, large quantities of PFAS-containing firefighting foams were deployed. The release of these substances into the Houston Ship Channel/Galveston Bay (HSC/GB) prompted concerns over the extent and level of PFAS contamination. A targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based study of temporal and spatial patterns of PFAS associated with this incident revealed presence of 7 species; their levels gradually decreased over a 6-month period. Because the targeted LC-MS/MS analysis was focused on about 30 PFAS molecules, it may have missed other PFAS compounds present in firefighting foams. Therefore, we utilized untargeted LC-ion mobility spectrometry-mass spectrometry (LC-IMS-MS)-based analytical approach for a more comprehensive characterization of PFAS in these water samples. We analyzed 31 samples from 9 sites in the HSC/GB that were collected over 5 months after the incident. Our data showed that additional 19 PFAS were detected in surface water of HSC/GB, most of them decreased gradually after the incident. PFAS features detected by LC-MS/MS correlated well in abundance with LC-IMS-MS data; however, LC-IMS-MS identified a number of additional PFAS, many known to be components of firefighting foams. These findings therefore illustrate that untargeted LC-IMS-MS improved our understanding of PFAS presence in complex environmental samples.     

A comparison of SEM-EDS with ICP-AES for the quantitative elemental determination of estuarine particles

Suspended particulate matter (SPM) is a key component regulating the biogeochemistry of natural and contaminant moieties in estuaries. Individual particle analyses can complement conventional bulk analyses of SPM, but are rarely undertaken. This study used scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDS) of particles to quantify a range of elements in the reference estuarine sediment PACS-2. This approach was compared with a bulk SPM analysis based on inductively coupled plasma-atomic emission spectrometry (ICP-AES). The median concentrations of Al, Fe, Mg, and Ca for the two approaches were similar, and accuracy for both methods was good. SEM-EDS analysis was also satisfactory for K. Agreement was poorer for Mn and Ti, which were present at trace concentrations. Increasing the number of particles examined by SEM-EDS should improve the analysis. SEM-EDS analysis of SPM from the Tamar Estuary, UK, revealed marked geochemical differences between particle sub-populations.Selected article from 6th European Meeting on Environmental Chemistry, Belgrade, 2005, organised by Prof. Dr. Branimir Jovancicevic and the European Association of Chemistry and the Environment (ACE, www.research.plymouth.ac.uk/ace)     

Different phagostimulants in potato foliage for Manduca sexta and Leptinotarsa decemlineata

Summary. In the past decades, several studies have focused on the identification of feeding stimulants for specialists that feed on solanaceous plants, especially potato (Solanum tuberosum). In the 1950's, a phagostimulant was isolated from potato and tomato for Manduca sexta and characterised as a glycoside. It was suggested that the phagostimulant for M. sexta and Leptinotarsa decemlineata is identical. We tested whether these insects indeed share the same recognition factor. Previous bioassays for L. decemlineata larvae and adults were found to be unsatisfactory, so a new assay system was developed, using starch and wheat flour-based wafers as a neutral substrate. An aqueous extract of potato foliage that was highly active as a stimulant was fractionated by reverse phase medium pressure liquid chromatography (MPLC). Both insects were stimulated by a MPLC fraction that eluted with 25% methanol in water. Further separation of this and the following fraction (35% methanol, stimulatory for the beetle only) by semi-preparative high performance liquid chromatography (HPLC), using gradients of water and acetonitrile, resulted in the isolation of two distinct fractions that stimulated feeding by L. decemlineata. None of the HPLC fractions was active for M. sexta. However, fractions of the flash chromatography with less polarity (45–75% methanol) had a stimulatory effect only on M. sexta. Thus, the two insects do not use a common feeding stimulant, and for both at least two compounds of different polarity are active. Received 3 July 2000; accepted 24 October 2000     

Injecting remediation compounds—How you inject is equally as important as what you inject

The injection of remediation compounds has rapidly become a widely accepted approach for addressing contaminated sites. One of the most fundamental questions surrounding the use of in situ remediation has been “What compound are you injecting at your site?” With the advances in the industry's understanding and acceptance of the in situ remediation process remediation professionals are now asking a follow‐up question that has become equally important to the success of a project: “How are you injecting a compound at your site?” This article discusses advances in field applications for in situ remediation and injecting remediation compounds. © 2003 Wiley Periodicals, Inc.     

可持续的配送:改善汽车装载量的机会

本文论述了对公路汽车利用进行改进的机会,包括其潜在的经济和环境利益.能够通过增加对环境损害较小的货运比例、提高车辆的装载因子、改善能源效率和降低单位耗能的排放来降低公路运输对环境的影响.提高车辆的装载因子(所运载的货物重量与其所能够运输的最大重量之比)有助于减慢货运卡车数量的增长.