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591.
Heavy metal bioaccumulation in different tissues of two fish species with regards to their feeding habits and trophic levels 总被引:1,自引:0,他引:1
N. Pourang 《Environmental monitoring and assessment》1995,35(3):207-219
Heavy metals residues (i.e. Cu, Zn, Mn, and Pb) were determined in seven chosen tissues of two fish species (Esox lucius and Carassius auratus) from Anzali wetland. The impact of feeding habit on metal accumulations in different tissues as well as the respective contribution of water and food to matel uptake by fishes were considered. No tendency for bioamplification was observed for the metals along the wetland trophic levels. Generally, there was no statistically significant relationship between the metal content of the tissues and the fish length for both species. In all cases, except for lead, the mean amounts of the metals in the flesh of the species were higher than those in commercially important fishes from the Caspian sea. However, they were below the recommended levels for human consumption. 相似文献
592.
Michael O. Angelidis Panagiotis G. Markantonatos Nikiforos Ch. Bacalis 《Environmental monitoring and assessment》1995,35(2):137-153
The impact of point (domestic and industrial effluents) and non-point (agricultural land runoff) pollution sources on the quality of the receiving waters of the Evrotas River (Laconia, Greece) was investigated during a monitoring study from August 1991 to August 1992. The part of the river which was located near the city of Sparta was seasonally influenced by the discharge of effluents from orange juice plants (operating during winter) and by the discharge of septage for the emptying of cesspools which are serving part of the city. The low dilution of incoming pollutants (septage) during the low water flow in summer lead to the decreasing self-purification capacity of the river and the development of septicity conditions in some of its parts. In the vicinity of intensively cultivated areas, the high concentrations of nitrogen and phosphorus which were detected in the river water during winter and spring may be partly attributed to the leaching of the applied fertilizers because of nirogen mobilization and soil erosion, following the season's precipitations. The protection of the Evrotas River water Quality must therefore include adequate treatment of the septage produced in the area, as well as the construction of wastewater treatment plants for the major industries of the area. The non-point pollution could be controlled by the restoration of the Evrotas riparian vegetation, together with a more rational use of fertilizers in the area. 相似文献
593.
Indicators of ecosystem health at the species level and the example of selenium effects on fish 总被引:1,自引:0,他引:1
Peter V. Hodson 《Environmental monitoring and assessment》1990,15(3):241-254
Chemical monitoring of aquatic ecosystems describes the chemical exposures of aquatic biota and measures the success of pollution control. However, meeting water quality criteria cannot assure that aquatic biota are protected from the effects of unexpected chemicals, mixtures and interactions between toxicity and environmental stressors.Biological monitoring is an obvious solution since aquatic biota integrate spatial and temporal variations in exposure to many simultaneous stressors. Top predators, typical of specific ecosystems (e.g. lake trout in cold water oligotrophic lakes) indicate whether environmental criteria have been met. The presence of naturally reproducing, self-sustaining and productive stocks of edible fish demonstrates a high quality environment. If these conditions are not met, there is a clear sign of environmental degradation. Specific changes in population structure and performance may also diagnose which life stage is affected and the nature of the stressor.Unfortunately, environmental managers cannot rely solely on populations, communities or ecosystems to indicate chmical effects. The lag between identifying a problem and finding a cause may destroy the resource that we wish to protect, particularly where chemicals are persistent.A solution to this dilemma is the measurement of primary or secondary responses of individual organisms to chemical exposure. Since toxicity at any level of organization must start with a reaction between a chemical and a biological substrate, these responses are the most sensitive and earliest sign of chemical exposure and effect.Application of this idea requires research on molecular mechanisms of chemical toxicity in aquatic biota and adaptation of existing mammalian diagnostic tools. Since relevance of biochemical responses to populations and ecosystems is not obvious, there is a need to study the links between chemical exposure and responses of individuals, populations and ecosystems.The recognition of chemical problems and cause-effect relationships requires the integration of chemical and biological monitoring, using the principles of epidemiology to test the strength of relationships and to identify specific research needs. The contamination of a reservoir with selenium and impacts on fish populations provide an excellent example of this approach. 相似文献
594.
Strontium-90 (90SR) released to the ground near the N Reactor at the U.S. Department of Energy's Hanford Site enters the Columbia River through shoreline seeps. The 90Sr is then potentially available for uptake by plants and animals. The life history and foraging behavior of nesting Canada geese is such that female geese could ingest 90Sr while foraging on shoreline plants. Radichemical analyses showed that goose eggshells taken from an island, downstream from the N Reactor, contained more 90Sr than did eggshells collected from other downstream islands. Reed canary grass samples taken from shoreline areas immediately downstream from the N Reactor contained higher concentrations of 90Sr than samples from other downstream areas. All goose eggshells did not contain enhanced levels of 90Sr, and all reed canary grass samples did not contain enhanced levels of 90Sr, but a relationship exists between the releases of 90Sr to the Columbia River and the enhanced levels of 90Sr in some of the environmental samples analyzed.Pacific Northwest Laboratory is operated by Battelle Memorial Institute for the U.S. Department of Energy under contract DE-ACO6-76RLO 1830. 相似文献
595.
Nitrogen leaching is a world-wide concern for the quality of ground- and surfacewater. Measures to abate this is still limited by a lack of understanding mechanisms behind all factors describing the leaching process, time lags between countermeasures and improvement in waterquality and spatial distribution of nitrogen leaching. The purpose of this study was to do an initial test of the SOILNDB model system which is built on the existing mechanistic SOIL and SOILN models and an automatic parameterization procedure for use of simplified input data. The test was done by simulating nitrogen leaching from each of the 150 fields in a small catchment during a three-year study period. The simulated mean root-zone nitrogen leaching rate from all the fields in the catchment was compared to measurements of nitrogen flow in the stream draining the catchment and showed good agreement in between-year dynamics. 相似文献
596.
Sun HF Takata A Hata N Kasahara I Taguchi S 《Journal of environmental monitoring : JEM》2003,5(6):891-895
The degradation, sorption, transportation and material balance of cationic surfactants discharged from domestic waste into river water was studied. Ion-pair solid-phase extraction behavior showed that the sorption of cationic surfactants as an ion-pair with anionic surfactant onto river sediment was so strong that little cationic surfactant was found in the bulk water. Cationic surfactant was found in river sediment at more than 500 times higher concentration than that in the bulk water. The degradation of the cationic surfactant was very slow in river water and much slower in the sediment. A material balance of cationic surfactant was estimated for a river running through Toyama City by measuring the flow rate and the concentration of cationic surfactant in the water at several points. It was found that more than 30% of cationic surfactant introduced to the river was lost during the river running through ca. 3 km in 3 h. This reduction probably comes from a quick transfer of the cationic surfactant from river water to sediment and water weed by means of adsorption or precipitation with suspending solids. 相似文献
597.
Peter A. Beedlow Don S. Daly Michael E. Thiede 《Environmental monitoring and assessment》1986,6(3):277-282
An electrical device capable of continuously measuring micronsized changes in stem diameter of woody and herbaceous plants is described. Fumigation of sunflowers with automotive exhaust was used to test the ability of the device to detect short-term plant responses. 相似文献
598.
Eolian (wind blown) sand constitutes a very serious problem to development in sandy desert lands and causes equally serious problems in lands that are undergoing desertification. In this paper, eolian sand movement due to bulk movement such as sand dune and ripple movement, sand drift by saltation, and sand storms by strong winds are discussed. Associated problems such as eolian sand encroachment on highways, farms, communities and industrial complexes are also discussed and workable solutions are offered. Solutions include chemical stabilization of the surface grains, fences to trap the blown sand and vegetation to prevent soil deflation. Vegetation is emphasized and recommended as the ultimate viable solution to combat desertification and eolian sand problems. 相似文献
599.
CO concentrations were measured in five kindergartens, one children's hospital and two homes for aged, practically without indoor sources, all situated in the city centre, for ten random days in winter and ten in summer. The indoor CO concentrations were the result of the distance from and the traffic density in the nearest street, of general pollution level, seasonal differences, day-to-day variations and daily cycle of air pollution, the vicinity of traffic having a dominant influence. Therefore location of institutions for sensitive population groups in old city centres within a block of houses seems to be a suitable solution as far as exposure to CO is concerned.Revised version of a paper presented as poster at the VIth World Congress on Air Quality, Paris 1983. 相似文献
600.
Distribution of heavy metals in water and sediments of selected sites of Yamuna river (India) 总被引:2,自引:0,他引:2
Mohammad Ajmal Mujahid A. Khan Azhar A. Nomani 《Environmental monitoring and assessment》1985,5(2):205-214
The concentration of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn metals in water and sediments of Yamuna river were determined by atomic absorption spectrophotometry in the year 1981. The data showed that there was considerable variation in the concentration of elements from one sampling station to the other which may be due to the variation in the quality of industrial and sewage wasters being added to the river at different sampling stations. The sediment samples collected from different sampling stations were also analysed for calcium carbonate, organic matter, potassium, and phosphorus. 相似文献