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391.
Bluegill (Lepotmis macrochirus), largemouth bass (Micropterus salmoides), white catfish (Ictalurus catus), and channel catfish (Ictalurus punctatus), collected from an electric power plant cooling reservoir and a municipal water supply reservoir near Roxboro, North Carolina, were analyzed for selenium concentrations in axial muscle, reproductive and liver tissues. Fishes from the municipal water reservoir had lower selenium concentrations (≤0.2-2.1 μg/g - wet weight) than found in the cooling reservoir fishes (1.6-70.0 μg/g - wet weight) but similar distributions of concentrations among the tissues was evident. Selenium was differentially accumulated, with higher concentrations in liver tissues (0.7-70.0 μg/g - wet weight), followed by female reproductive tissues (0.7-25.0 μg/g - wet weight), axial muscle tissues (≤0.2-23.0 μg/g - wet weight) and male reproductive tissues (0.2-7.2 μg/g - wet weight).  相似文献   
392.
Precipitation and runoff samples were collected for 13 storms in a nonindustrial urban area in Central Pennsylvania between July 1980 and June 1981. Runoff was collected from tree surfaces, a residential roof and street, a shopping mall parking lot, a downtown business district alley, and a heavily traveled street. Analysis of the water samples showed 10 to 25 percent of the nitrogen, 25 percent of the sulfate, and less than 5 percent of the phosphorus, potassium, and calcium in water below a tree was deposited by the precipitation. The residential roof caused insignificant changes in water chemistry. The results for the four paved areas showed that all the nitrogen, and from 16 to 40 percent of the sulfate and 13, 4, and 2 percent of the phosphorus, potassium, and calcium, respectively, in runoff was deposited by the precipitation. Precipitation can also be an important source of sulfate and phosphorus in runoff. All of the surfaces raised the pH of the runoff, with the largest increases, from a pH of 4 to about 7, occurring in runoff from the paved areas. Precipitation and runoff chemistry was not related to antecedent conditions such as the length of the preceding dry period.  相似文献   
393.
394.
This article details a case study of a voluntary, decentralized institutional arrangement for nonpint source water pollution control used in the Root River watershed in southeastern Wisconsin. This watershed was chosen because of its mix of urban, agricultural, and urbanizing land uses. The project objectives were to monitor and draw conclusions about the effectiveness of a voluntary, decentralized institutional system, to specify deficiencies of the approach and suggest means to correct them, and to use the conclusions to speculate about the need for regulations regarding nonpoint source pollution control or the appropriateness of financial incentives for nonpoint source control. Institutional factors considered include diversity of land uses in the watershed, educational needs, economic conditions, personality, water quality, number of agencies involved, definition of authority, and bureaucratic requirements  相似文献   
395.
The impact of urbanization on timber harvesting in the south central United States was investigated. Geo-referenced Census and Forest Inventory Analysis (FIA) data were combined using a geographic information system (GIS) in order to examine the effects of various demographic and biophysical forest inventory characteristics on timber harvesting. These effects were estimated for intermediate and final harvests using a multinomial logit model. The probability for both types of harvests decreased with increasing population density, decreasing forest size, and decreasing distance to urban areas; however, the reduction in intermediate harvests was greater for each variable. Harvesting rates decreased by as much as 19% as population densities increased or distance to urban areas decreased. The results indicated that active forest management is curtailed far beyond the urban boundary. In order to model the impact of urbanization adequately, timber supply projections must also account for its impact on harvesting frequencies in surrounding areas.  相似文献   
396.
Environmental risk assessment and the intrusion of bias   总被引:1,自引:0,他引:1  
The concept of managing the environment and any associated human health impacts by means of such science-based tools as toxicological evaluation, risk assessment, and economic appraisal has become widely accepted in professional circles. These increasingly complex methodologies have not won universal support, however, even among the technically minded, and the wider public has in many cases remained sceptical. The public's seeming lack of enthusiasm has frequently been assigned to ignorance of science, irrationality even, and some attempts have been made to ameliorate the situation by means of education, though with little evidence of success. However, this review advances an alternative explanation, namely, that the disenchantment has more to do with procedural than technical matters. Many issues, although treated with technical risk assessment appear to have forced themselves onto the agenda because of factors only passingly connected with risk, and which are more related to the intrusion of disputed values and other sources of bias. This paper also notes that the intervention of bias in decision making is rife, and is found as much in professional as in public approaches. This need not itself be a problem, providing it is recognised and openly expressed. However, there remains a need for much greater circumspection and frankness by professions about the status of their art, and a determined effort if the full social benefits of environmental risk assessment (ERA) are to be realised.  相似文献   
397.
Community involvement has been identified as an important factor in the successful redevelopment of contaminated land, and access to technical resources has been a barrier for some communities. This paper describes how the US Environmental Protection Agency funded Technical Outreach Services to Communities programme was used to support four communities involved in land revitalization. The four New England case studies were used to retrospectively draw lessons learned that could be useful to others interested in similar community work. We suggest that the broad lessons point to four factors for success, namely, where there is: (1) a common vision in the community; (2) a cohesive community; (3) an opportunity for co-learning; and (4) a commitment among the parties for long-term engagement. We conclude that technical support can serve as a useful framework for developing trustful and long-term relationships with communities.  相似文献   
398.
This article chronicles activities and approaches carried out in working with community partners and public and private stakeholders in advancing revitalization within Bridgeport, CT. The approach described utilizes brownfields redevelopment as a focal point for a stakeholder process whose goal is neighbourhood revitalization. Two neighbourhoods—the Went End and East End—are the focus for major stakeholder-driven brownfields redevelopment processes. The article defines key elements of the stakeholder process including: involvement at several levels from neighbours to the site to the Mayor's office and beyond, a risk communication process that incorporates the broad concerns of the stakeholders including crime and violence, and the need for ongoing oversight and management throughout the redevelopment process.  相似文献   
399.
As employees find themselves in geographically separated teams, the loss of face‐to‐face interaction has led to the development of new monitoring technologies that provide availability information for enhancing collaboration. Drawing on diverse literatures in electronic performance monitoring, computer supported cooperative work, privacy, and fairness, a comprehensive theoretical model of monitoring acceptance was developed to examine the effects of being monitored for availability. In the first study, over 600 employees from a large number of organizations responded to one of a variety of monitoring system characteristics. Although the model found strong support overall, results suggest that technical solutions, such as manipulating the characteristics of the awareness system, are not sufficient to ensure fairness and privacy. A second, focus group study, adds support for the theoretical model and provides an explanation for these quantitative results concerning system characteristics. Specifically, the qualitative evidence suggests that these systems can invade employees' psychological barriers ‐ and thus manipulating the technology will only have small effects on fairness and privacy because the technology has already crossed the line from benign to invasive. The paper concludes by presenting theoretical and practical implications for the consideration of psychological boundaries in the design and use of ubiquitous monitoring and communication technologies. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
400.
Settled dust has been collected inside the main foyers ofthree University buildings in Wolverhampton City Centre,U.K. Two of the three buildings are located in a streetcanyon used almost exclusively by heavy duty dieselvehicles. The dust was collected on adhesive carbonspectro-tabs to be in a form suitable for analysis byscanning electron microscope and energy dispersive X-rayanalysis. Using these analytical techniques, individualparticle analysis was undertaken for morphology andchemistry. Seasonal variations and variations due tolocation were observed in both the morphologicalmeasurements and chemical analysis. Many of the differencesappear attributable to the influence of road traffic, inparticular, the heavy duty diesel vehicles, travellingalong the street canyon.  相似文献   
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