Environmental risk and liability management and its influence on profitability

Managing environmental risk and liability for corporations and consultants requires a prudent combination of insurance techniques, company risk control plans, pollution prevention, and the proper allocation of retention funds. This article presents a review of current risk management techniques used to shield profits from limited and catastrophic loss scenarios. We recommend that corporations and consulting firms integrate insurance and risk management planning to mitigate environmental liabilities, navigate business risks, and safeguard corporate performance..© 1999 John Wiley & Sons, Inc.     

Exploring metapopulation-scale suppression alternatives for a global invader in a river network experiencing climate change

Invasive species can dramatically alter ecosystems, but eradication is difficult, and suppression is expensive once they are established. Uncertainties in the potential for expansion and impacts by an invader can lead to delayed and inadequate suppression, allowing for establishment. Metapopulation viability models can aid in planning strategies to improve responses to invaders and lessen invasive species’ impacts, which may be particularly important under climate change. We used a spatially explicit metapopulation viability model to explore suppression strategies for ecologically damaging invasive brown trout (Salmo trutta), established in the Colorado River and a tributary in Grand Canyon National Park. Our goals were to estimate the effectiveness of strategies targeting different life stages and subpopulations within a metapopulation; quantify the effectiveness of a rapid response to a new invasion relative to delaying action until establishment; and estimate whether future hydrology and temperature regimes related to climate change and reservoir management affect metapopulation viability and alter the optimal management response. Our models included scenarios targeting different life stages with spatially varying intensities of electrofishing, redd destruction, incentivized angler harvest, piscicides, and a weir. Quasi-extinction (QE) was obtainable only with metapopulation-wide suppression targeting multiple life stages. Brown trout population growth rates were most sensitive to changes in age 0 and large adult mortality. The duration of suppression needed to reach QE for a large established subpopulation was 12 years compared with 4 with a rapid response to a new invasion. Isolated subpopulations were vulnerable to suppression; however, connected tributary subpopulations enhanced metapopulation persistence by serving as climate refuges. Water shortages driving changes in reservoir storage and subsequent warming would cause brown trout declines, but metapopulation QE was achieved only through refocusing and increasing suppression. Our modeling approach improves understanding of invasive brown trout metapopulation dynamics, which could lead to more focused and effective invasive species suppression strategies and, ultimately, maintenance of populations of endemic fishes.     

湖泊和水库中甲基汞行为的多介质模型研究

以QWASI模型为例 ,简介了多介质环境数学模型 ,并运用模型对氯化甲基汞的行为进行了研究。计算结果表明 ,在环境条件满足一定要求的情况下 ,空气是水体中污染物的主要来源相 ,与文献报道一致。证实了多介质环境模型在湖泊和水库体系汞行为模拟中的适用性。通过对多个模型输入参数进行敏感度分析 ,发现污染物在空气中的背景浓度、水体流域面积、水中溶解度、年降雨量等较为重要。针对现有QWASI模型研究水体中汞行为的局限 ,探讨了改进模型的思路和方法     

Diversion from landfill: quality products from valuable plastics

Mechanical recycling of 100% post-consumer plastic waste into high-quality products has been performed. The chemical and physical properties of these recycled materials have been compared with similar products manufactured from virgin resins. The properties of a blow-moulded bottle prepared from 100% post-consumer high-density polyethylene (HDPE) showed that this recycled polymer exceeded the materials specifications for virgin plastic designs. Similarly, a sample of thermoplastic polyolefin (TPO, 100% polypropylene), obtained entirely from shredder residue (SR) displayed sufficient material strength for future separation and reprocessing.     

Allocation of supplementary aeration stations in the Chicago waterway system for dissolved oxygen improvement

The Chicago Waterway System (CWS), used mainly for commercial and recreational navigation and for urban drainage, is a 122.8 km branching network of navigable waterways controlled by hydraulic structures. The CWS receives pollutant loads from 3 of the largest wastewater treatment plants in the world, nearly 240 gravity Combined Sewer Overflows (CSO), 3 CSO pumping stations, direct diversions from Lake Michigan, and eleven tributary streams or drainage areas. Even though treatment plant effluent concentrations meet the applicable standards and most reaches of the CWS meet the applicable water quality standards, Dissolved Oxygen (DO) standards are not met in the CWS during some periods. A Use Attainability Analysis was initiated to evaluate what water quality standards can be achieved in the CWS. The UAA team identified several DO improvement alternatives including new supplementary aeration stations. Because of the dynamic nature of the CWS, the DUFLOW model that is capable of simulating hydraulics and water quality processes under unsteady-flow conditions was used to evaluate the effectiveness of new supplementary aeration stations. This paper details the use of the DUFLOW model to size and locate supplementary aeration stations. In order to determine the size and location of supplemental aeration stations, 90% compliance with a 5 mg/l DO standard was used as a planning target. The simulations showed that a total of four new supplementary aeration stations with oxygen supply capacities ranging from 30 to 80 g/s would be sufficient to meet the proposed target DO concentration for the North Branch and South Branch of the Chicago River. There are several aeration technologies, two of which are already being used in the CWS, available and the UAA team determined that the total capital costs of the alternatives range from $35.5 to $89.9 million with annual operations and maintenance costs ranging from $554,000 to $2.14 million. Supplemental aeration stations have been shown to be a potentially effective means to improve DO concentrations in the CWS and will be included in developing an integrated strategy for improving water quality in the CWS.     

Chemical compositions and radiative properties of dust and anthropogenic air masses study in Taipei Basin, Taiwan, during spring of 2004

Asia is one of the major sources of not only mineral dust but also anthropogenic aerosols. Continental air masses associated with the East Asian winter monsoon always contain high contents of mineral dust and anthropogenic species and transported southeastward to Taiwan, which have significant influences on global atmospheric radiation transfer directly by scattering and absorbing solar radiation in each spring. However, few measurements for the long-range transported aerosol and its optical properties were announced in this area, between the Western Pacific and the southeastern coast of Mainland China. The overall objective of this work is to quantify the optical characteristics of different aerosol types in the Eastern Asian. In order to achieve this objective, meteorological parameters, concentrations of PM₁₀ and its soluble species, and optical property of atmospheric scattering coefficients were measured continuously with 1 h time-resolved from 11 February to 7 April 2004 in Taipei Basin (25°00′N, 121°32′E). In this work, the dramatic changes of meteorological parameters such as temperature and winds were used to determine the influenced period of each air mass. Continental, strong continental, marine, and stagnant air masses defined by the back-trajectory analysis and local meteorology were further characterized as long-range transport pollution, dust, clean marine, and local pollution aerosols, respectively, according to the diagnostic ratios. The aerosol mass scattering efficiency of continental pollution, dust, clean marine, and local pollution aerosols were ranged from 1.3 to 1.6, 0.7 to 1.0, 1.4 and 1.4 to 2.3 m² g⁻¹, respectively. Overall, there are two distinct populations of aerosol mass scattering efficiencies, one for an aerosol chemical composition dominated by dust (<1.0 m² g⁻¹) and the other for an aerosol chemical composition dominated by anthropogenic pollutants (1.3–2.3 m² g⁻¹), which were similar to the previous measurements with high degree of temporal resolution.     

The prenatal determination of glucose-6-phosphatase activity by fetal liver biopsy

Two fetuses at risk for glucose-6-phosphatase deficiency had in utero liver biopsies. Analysis of each showed this enzyme activity to be in the normal range and the pregnancies continued. Neither child has any clinical or metabolic evidence of glucose-6-phosphatase deficiency.     

Saltcedar control and water salvage on the Pecos river, Texas, 1999-2003

A large scale ecosystem restoration program was initiated in 1997 on the Pecos River in Western Texas. Saltcedar (Tamarix spp.), a non-native invasive tree, had created a near monoculture along the banks of the river by replacing most native vegetation. Local irrigation districts, private landowners, federal and state agencies, and private industry worked together to formulate and implement a restoration plan, with a goal of reducing the effects of saltcedar and restoring the native ecosystem of the river. An initial management phase utilizing state-of-the-art aerial application of herbicide began in 1999 and continued through 2003. Initial mortality of saltcedar averaged about 85-90%. Monitoring efforts were initiated at the onset of the project to include evaluating the effects of saltcedar control on salinity of the river water, efficiency of water delivery down the river as an irrigation water source, and estimates of water salvage. To date, no effect on salinity can be measured and irrigation delivery was suspended in 2002-2003 due to drought conditions. Water salvage estimates show a significant reduction in system water loss after saltcedar treatment. However, a flow increase in the river is not yet evident. Monitoring efforts will continue in subsequent years.     

Stream Phosphorus Transport in the Lake Tahoe Basin, 1989–1996

Lake Tahoe is undergoing the initial stages of culturaleutrophication due to human alteration of the airshed andwatershed. The lake's switch from nitrogen (N) to phosphorus (P)limitation has been attributed primarily to atmospheric Nloading. This places an increased importance on controllingwatershed movement of P to the lake. A stream water qualitymonitoring data set consisting of nine streams in the Lake Tahoebasin has been analyzed to characterize the spatiotemporalvariation of P delivery to the lake. This data is from the LakeTahoe Interagency Monitoring Program (LTIMP), which providesscientific data for planning and regulatory agencies to addressenvironmental problems in the Lake Tahoe basin. Results indicatethat P delivery (concentrations, loads) varies greatly atinterannual, seasonal, and spatial scales. Annual and seasonaltotal P (TP) concentrations can vary up to three orders ofmagnitude in a given stream and are strongly associated withsuspended sediment. Particulate P is the major form of Ptransported by Tahoe streams and was strongly correlated withpercent surficial geologic deposits, which are primarily locatednear streams. Tahoe streams with the highest annualP concentrations often had the lowest annual P loads, and visaversa. P loading is greatest during the spring snowmelt (75% ofannual average). Potential watershed parameters influencing Pdelivery to Lake Tahoe have been identified as precipitation,basin area, basin steepness, and road and human developmentcoverage. Results also suggest that human development impacts onstream P loads are most prevalent during high precipitationyears. Identification and quantification of stream sediment andP sources such as streambanks and impervious surface isnecessary to aid in watershed restoration efforts.     

Self-leadership and performance outcomes: the mediating influence of self-efficacy

A key foundation of empowering organizations is employee self-leadership. This study examines the effects of self-leadership skills and self-efficacy perceptions on performance. Structural equations modeling determined whether the influence of self-leadership on performance is mediated by self-efficacy perceptions. Results for the sample of 151 respondents indicated self-leadership strategies had a significant effect on self-efficacy evaluations, and self-efficacy directly affected performance. Further, self-efficacy perceptions were found to fully mediate the self-leadership/performance relationship. Theoretical and practical implications are discussed. © 1998 John Wiley & Sons, Ltd.