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71.
There is inadequate morphological nomenclature and definition of organ pathology when using wild fish in biomonitoring of environmental pollution. The aim of this investigation was to provide a guide that assesses histology of Shorthorn (Myoxocephalus scorpius) and Fourhorn (Myoxocephalus quadricornis) sculpins obtained from a study using these two fish species as bioindicator organisms to evaluate environmental impact attributed to a dumpsite located in East Greenland. Specific histopathological lesions were quantified on the basis of Bernet et al. and all lesions were photomicrographed, evaluated, and placed into specific categories of five reaction patterns. These were circulatory disturbances, regressive changes, progressive alterations, inflammation, and tumors based on anatomical location, type, and severity. This method is postulated to enable an objective assessment of the histological integrity of fish gills and liver; thus, making it possible to compare sculpin pathology and reaction patterns at different locations. Data suggest that this updated histological guide might be used for identification and quantification of histological lesions when applying sculpins in biomonitoring programs in Greenland and other Arctic regions.  相似文献   
72.
Abstract

For many years, the sculpin has been utilized as a sentinel monitoring species for anthropogenic impacts on the marine environment. To further develop its potential as a screening model body burden of several trace elements, including cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb) and selenium (Se), were investigated. In addition, histopathology in shorthorn sculpins (Myoxocephalus scorpius; n?=?20) and fourhorn sculpins (Myoxocephalus quadricornis; n?=?10) were examined at three sites around the Scoresby Sound settlement in Central East Greenland. Fourhorn sculpins caught at the most distant site from the settlement, contained significantly higher hepatic Cu and Cd concentrations as well as significantly elevated gill Pb levels compared to the shorthorn sculpins collected at two other sites closer to the settlement. Histological examinations showed that fish with significantly higher concentrations of hepatic Cd and Se exhibited greater nuclear alterations, interstitial hyperplasia/hypertrophy, interstitial mononuclear infiltrations and granulomas. Further, fish with higher Cd and Cu gill tissue levels displayed a significantly higher number of cytoplasmic alterations and lamellar epithelium lifting, hypertrophic and hyperplastic epithelium along with mucus cell hyperplasia. While the presence of liver lesions were not species or sex-specific, the presence of gill lesions decreased in the order female fourhorn sculpins?>?female shorthorn sculpins?>?male fourhorn sculpins?>?male shorthorn sculpins. Hepatic Hg concentrations exceeded known lowest observable effect doses (LOED) for fish (0.1–0.5?μg g?1 ww) in 27% of fish, while liver Cd residues in 80% exceeded LOED (0.42–1.8?μg g?1 ww). Based upon these results, data suggest that using the sculpin as a valuable sentinel fish species histopathology may serve as a reliable tool for assessing marine ecosystem exposure to trace metals. However, confounding physiological and ecological factors also need to be considered.  相似文献   
73.
Removal of radionuclides at a waterworks   总被引:1,自引:0,他引:1  
A waterworks with an average production rate of 1.3 m3 s(-1), providing several large cities in the province of Scania with drinking water has been studied regarding its capacity to remove several natural and anthropogenic radionuclides. The raw water is surface water from lake Bolmen which is transported through an 80 km long tunnel in the bedrock before it enters the waterworks. The method used for purification is a combination of coagulation-flocculation and filtration in sand filters. Two different purification lines are currently in use, one using Al2(SO4)3 as a coagulant and one using FeCl3. After coagulation and flocculation the precipitate is removed and the water is passed through two different sand filters (rapid filtration and slow filtration). Water samples were collected at the lake, the inlet to the waterworks, after each of the flocculation basins (Al2(SO4)3 and FeCl3), after rapid filtration and from the municipal distribution network. The samples were analysed with respect to their content of uranium, thorium, polonium, radium, plutonium and caesium. The results show a high removal capacity for uranium (about 85%), thorium (>90%), plutonium (>95%) and polonium (>90% in the coagulation-flocculation process) while caesium, strontium and radium pass through the purification process with almost unchanged activity concentrations. During transportation of the water in the tunnel it was also observed that infiltration of groundwater leads to a change in isotopic ratios and/or activity concentrations for the naturally occurring radionuclides and plutonium.  相似文献   
74.
Discharges of the nuclides 129I, 137Cs and 99Tc from the nuclear reprocessing facilities at Sellafield (UK) and La Hague (France) are very useful as oceanic tracers. On the basis of 129I/127I, 137Cs and 99Tc measurements in archived seaweeds, the ratios of 129I/127I, 129I/137Cs and 129I/99Tc have been estimated in seawater at two locations (Utsira and Kiberg) in the Norwegian Coastal Current from 1980 to 1998. These ratios, which vary up to two orders of magnitude over this period, are potentially very interesting for determining "transit times" in the Arctic and North Atlantic oceans. While the long-term trends in these ratios are quite clear, measurements in monthly and bimonthly samples show considerable structure. Further studies are required to determine the exact origin of this structure, which may be a limiting factor in the time resolution that can be obtained with these parameters.  相似文献   
75.
New data on the levels and long-range transport of plutonium in the Arctic Ocean, recorded in the course of two expeditions to this zone in 1994 and 1996, are discussed in this paper. Specifically, approximately 100 plutonium measurements in surface and sub-surface water sampled at 58 separate stations throughout the Kara, Laptev and East Siberian Seas, as well as along latitudinal transects across the Lomonosov Ridge, are reported and interpreted in terms of the circulation pathways responsible for the transport of this element from the North Atlantic to the Arctic Shelf and into the Arctic interior. In addition, the behaviour of plutonium in its transit through the vast Arctic shelf seas to open waters under extreme environmental conditions is discussed in terms of the partitioning of plutonium between filtered (<0.45 microm) seawater and suspended particulate, and its association with colloidal matter. Finally, limited evidence of the presence of a colloidal plutonium component in Arctic waters subject to direct riverine input is adduced.  相似文献   
76.
The activity concentration of (99)Tc in brown seaweed (Fucus vesiculosus and Fucus serratus) and seawater were analysed in samples collected in 1991, 1995 and 2001 at several stations along the Swedish west coast. In addition to these locations, a well-defined site (S?rdal, 56.76 degrees N, 12.63 degrees E) was included with (99)Tc activity concentration data in seaweed from 1967 to 2000. Over the years, the major source of (99)Tc in the coastal waters of western Sweden has been the radioactive liquid discharge from the nuclear fuel reprocessing plant in Sellafield (UK) transported via ocean currents in the North Sea. The (99)Tc activity concentration in seaweed at the S?rdal site increased from approximately 30 Bq kg(-1) up to 230 Bq kg(-1) (dry weight) between 1997 and 2000 due to the Sellafield EARP (Enhanced Actinide Removal Plant) discharges in 1995-1996, yielding an approximate transport time of 4-5 years between the Irish Sea and the Kattegat. Due to the very sharp gradient in (99)Tc concentration between the Baltic Sea and the North Sea, (99)Tc is presently one of the best transit tracers for the recent ventilation events in the Baltic Sea.  相似文献   
77.
Summary In 1986, the Danish Environmental Protection Agency established a new regulatory system aimed at small-scale polluting activities. Contrary to the dominant regulatory system based on individual standards for each polluting activity, the new regulatory system established uniform and fixed environmental standards for all activities within a trade. The fixed standards concern location, design and daily operation. Thus far, the new regulatory system has been implemented in the trades of fur farms and auto-repair shops.This study shows that fixed environmental standards reduce the total administrative costs, intensify local monitoring and enforcement of the standards, and improve the environmental state. It is proposed that the following criteria should be considered if the regulatory system is to be implemented in other trades. The trade should consist of many units and be characterised by a moderate pace of technological development, it should posses well-defined and well-known environmental problems, and have a cooperative trade association. In Denmark several trades have been identified as obvious objects for future regulation by fixed environmental standards.Bente Kjærgård is a Research Associate in the Department of Environment, Technology and Social Studies at Roskilde University. Correspondence should be addressed to this author. The other authors are Associate Professors in the same Department. Each author possesses a research degree as follows: Per Homann Jespersen in Chemical Engineering, Henning Schroll in Biology, Jesper Holm in Technological Planning, and Bente Kjærgård in Environmental Planning.  相似文献   
78.
Five students of a rescue training school cycled at 50 W for 20 min at 20 degrees C before walking at 5 km/hr up to 30 min in a climatic chamber at 55 degrees C and 30% relative humidity. 4 different types of clothing ensembles differing in terms of thickness and thermal insulation value were tested on separate days. All subjects completed 28-30 min in light clothing, but quit after 20-27 min in 3 firefighter ensembles due to a rectal temperature of 39.0 degrees C or subjective fatigue. No difference in the evolution of mean skin or rectal temperature was seen for the 3 turnout ensembles. Sweat production amounted to about 1000 g in the turnout gears of which less than 20% evaporated. It was concluded that the small differences between the turnout gears in terms of design, thickness and insulation value had no effect on the resulting heat physiological strain for the given experimental conditions.  相似文献   
79.
Protection of the environment is developing rapidly at the national and international level, but there are still no internationally agreed recommendations as to how radiological protection of the environment should be carried out. The International Commission on Radiological Protection (ICRP) is currently reviewing its existing recommendations for human protection. It has set up a task group with the aim of developing a protection policy for, and suggesting a framework of, the protection of the environment that could feed into its recommendations at the start of the 21st century. The task group will propose a framework for the protection of the environment from harmful effects of radiation, harmonising with the principles for the protection of humans. Although the task group has not yet finalised on the objectives for the environment, these might be to safeguard the environment by preventing or reducing the frequency of effects likely to cause early mortality, reduced reproductive success, or the occurrence of scorable DNA damage in individual fauna and flora to a level where they would have a negligible impact on conservation of species, maintenance of biodiversity, or the health and status of natural habitats or communities. To achieve these objectives, a set of reference dose models, reference dose per unit intake and reference organisms will be required.  相似文献   
80.
Environmental Chemistry Letters - Pollution of waste and natural waters by antibiotics is a major health issue that induces the development of resistant pathogens. Pollutant may be removed by...  相似文献   
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