Estimates of 1973–1982 Annual Sulfur Oxide Emissions from Electric Utilities

Estimates of 1973–1982 annual SO₂ emissions from electric utility plants are presented in this paper. Results are based on analyses of plant level data collected by the U.S. Department of Energy on consumption and quality of fuels burned. Emissions are estimated from known information about fuel consumption, sulfur content, ash content, and control equipment. Results show that electric utility emissions decreased 16% from 1973 to 1982 and that these reductions were due to the use of lower sulfur coals and to the operation of flue gas desulfurization equipment.     

Mathematical problem definition for ecological restoration planning

Ecological restoration is an increasingly important tool for managing and improving highly degraded or altered environments. Faced with a large number of sites or ecosystems to restore, and a diverse array of restoration approaches, investments in ecological restoration must be prioritized. Nevertheless, there are relatively few examples of the systematic prioritization of restoration actions. The development of a general theory for ecological restoration that is sufficiently sophisticated and robust to account for the inherent complexity of restoration planning, and yet is flexible and adaptable to ensure applicability to a diverse array of restoration problems is needed. In this paper we draw on principles from systematic conservation planning to explicitly formulate the ‘restoration prioritization problem’. We develop a generalized theory for static and dynamic restoration planning problems, and illustrate how the basic problem formulation can be expanded to allow for many factors characteristic of restoration problems, including spatial dependencies, the possibility of restoration failure, and the choice of multiple restoration techniques. We illustrate the applicability of our generic problem definition by applying it to a case study - restoration prioritization on The Irvine Ranch Natural Landmark in Southern California. Through this case study we illustrate how the definition of the general restoration problem can be extended to account for the specific constraints and considerations of an on-the-ground restoration problem.     

Evaluating institutional fit for the conservation of threatened species

Recovery and conservation of threatened species require adequate institutional responses. We tested an approach to systematically identify and measure how an institutional framework acknowledges threats and required responses for the recovery of endangered species. We measured institutional functional fit with a drivers-pressure-state-impacts-response (DPSIR) model integrated with a quantitative text mining method and qualitative analysis of statutory instruments to examine regulatory responses that support the recovery of 2 endangered species native to Australia, the bridled nailtail wallaby (Onychogalea fraenata) and the Eastern Bristlebird (Dasyornis brachypterus). The key components of the DPSIR model were present in the institutional framework at statutory and operational levels, but some institutional gaps remained in the protection and recovery of the Eastern Bristlebird, including feral predator control, weed control, and grazing management in some locations. However, regulatory frameworks varied in their geographic scope and the application and implementation of many instruments remained optional. Quantitative text mining can be used to quickly navigate a large volume of regulatory documents, but challenges remain in selection of terms, queries of co-occurrence, and interpretation of word frequency counts. To inform policy, we recommend that quantitative assessments of institutional fit be complemented with qualitative analysis and interpreted in light of the sociopolitical and institutional context.     

Chitosan for direct bioflocculation of wastewater

Environmental Chemistry Letters - Coagulation/flocculation is a major phenomenon occurring during industrial and municipal water treatment to remove suspended particles. Common coagulants are metal...     

Collaborative assessment of California spiny lobster population and fishery responses to a marine reserve network

Assessments of the conservation and fisheries effects of marine reserves typically focus on single reserves where sampling occurs over narrow spatiotemporal scales. A strategy for broadening the collection and interpretation of data is collaborative fisheries research (CFR). Here we report results of a CFR program formed in part to test whether reserves at the Santa Barbara Channel Islands, USA, influenced lobster size and trap yield, and whether abundance changes in reserves led to spillover that influenced trap yield and effort distribution near reserve borders. Industry training of scientists allowed us to sample reserves with fishery relevant metrics that we compared with pre-reserve fishing records, a concurrent port sampling program, fishery effort patterns, the local ecological knowledge (LEK) of fishermen, and fishery-independent visual surveys of lobster abundance. After six years of reserve protection, there was a four- to eightfold increase in trap yield, a 5-10% increase in the mean size (carapace length) of legal sized lobsters, and larger size structure of lobsters trapped inside vs. outside of three replicate reserves. Patterns in trap data were corroborated by visual scuba surveys that indicated a four- to sixfold increase in lobster density inside reserves. Population increases within reserves did not lead to increased trap yields or effort concentrations (fishing the line) immediately outside reserve borders. The absence of these catch and effort trends, which are indicative of spillover, may be due to moderate total mortality (Z = 0.59 for legal sized lobsters outside reserves), which was estimated from analysis of growth and length frequency data collected as part of our CFR program. Spillover at the Channel Islands reserves may be occurring but at levels that are insufficient to influence the fishery dynamics that we measured. Future increases in fishing effort (outside reserves) and lobster biomass (inside reserves) are likely and may lead to increased spillover, and CFR provides an ideal platform for continued assessment of fishery-reserve interactions.     

Bald eagle mortality and chlorinated hydrocarbon contaminants in livers from British Columbia, Canada, 1989-1994

Between 1989 and 1994, we obtained 278 carcasses of bald eagles (Haliaeetus leucocephalus) found dead or dying in British Columbia, Canada. All specimens were necropsied and the cause of death determined wherever possible. Livers from a subset of 75 birds were analyzed for polychlorinated biphenyl (PCB) and organochlorine (OC) pesticide residues. A further subset of 19 eagles found dead around the Strait of Georgia, an area of known pulp mill pollution, in summer, and therefore presumably resident birds, were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) and non-ortho PCBs. Liver concentrations ranged from less than 1 to 190 mg/kg for DDE, and up to 72 mg/kg for total PCBs. Concentrations of other OCs were generally less than 1 mg/kg, with the exception of chlordane-related compounds which were occasionally over 2 mg/kg. All birds analyzed for PCDDs and PCDFs contained detectable concentrations of the major 2,3,7,8-substituted isomers. Some birds were very contaminated; one eagle found near a kraft pulp mill site in 1990 contained: 400 ng/kg 2,3,7,8-TCDD, 1400 ng/kg 1,2,3,7,8-PnCDD and 4400 ng/kg 1,2,3,6,7,8-HxCDD. Birds with higher PCB and dichlorodiphenyldichloroethane (DDE) concentrations appeared to weigh less, and there was a significant negative relationship between both PCBs and DDE and numeric scoring of body condition, reflecting the well known process of starvation-induced mobilization of body lipids and contaminants. Birds with higher 2,3,7,8-TCDD concentrations tended to have unusually low concentrations of 2,3,7,8-TCDF, interpreted to indicate hepatic cytochrome P4501A-type induction by TCDD and subsequent metabolism of TCDF.     

The impact of technology characteristics and job control on worker mental health

Recent research suggests that the occurrence of operational problems in advanced manufacturing technology (AMT) places stressful demands on operators. Applying Karasek's demand–control model, we predict that two properties of operational problems, namely technological uncertainty and abstractness, interact with timing and method control to predict operator strain. The results failed to confirm ordinal effects for timing or method control, but showed a dis-ordinal (crossover) interaction for timing control. While these findings provide little support for the demand–control model, they suggest that two new processes, namely ‘traction–distraction’ and ‘passivity–challenge’, are critical to understanding the nature of the relationship between operational problems and operator strain in AMT systems. We describe these processes and examine the implications for future research. © 1997 John Wiley & Sons, Ltd.     

Chemical and mineralogical forms of Cu and Ni in contaminated soils from the Sudbury mining and smelting region, Canada

Available information on soil contamination by trace elements in the Sudbury Cu/Ni mining and smelting region consists largely of total elemental concentration data. Little is known about the mode of occurrence and behaviour of Cu and Ni (the main metallic contaminants) in the soils of the region. In this study, sequential extraction and Scanning Electron Microscopy and Energy Dispersive X-ray Analysis (SEM/EDX) observations were complementarily used to define Cu and Ni forms in the Sudbury soils, so as to assess metal mobility. Most Cu (on average 75%) was associated with 'non-residual' soil forms, whereas Ni was mainly (on average 60%) associated with inorganic 'residual' forms of a sulphide and oxide nature. Therefore, Cu occurs in the soils in more mobile forms than Ni. Consequently, Cu should be removed from these soils at a faster rate than Ni. This is an unusual finding, because generally Ni is known to be more mobile in soils than Cu. SEM/EDX analysis confirmed the greater Cu mobility by showing that the metal was strongly associated with organic matter and was homogeneously distributed on the clay fraction surfaces. Nickel occurred alone or was associated with Fe oxides in various size fractions. Both elements were found as sulphides but Ni was often included in the silicate matrices of spherical particles in associations with Fe. SEM/EDX observations have shown that Cu and Ni are associated with soil forms which would not have been predicted by the sequential extraction alone, such as carbonaceous material, silicate spheres and carbonate particles, supporting complementary use of the two techniques.