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1.
Studies are performed on the toxicity for 24, 48, 72 and 96 hours in the static test with dilutions of 10 … 32 vol.% of wastewaters from the pulp and paper production as well as of the mixed wastewater. The pulp waste shows the highest toxic effect, the LC50 of the three types of wastewater being between 15 and 27% in dependence on the test conditions. A general increase of the toxic effect is caused by a rise in temperature from 26 °C to 36 °C and an increase of the pH value from 7.5 to 8.2. The increase of the oxygen concentration from 5.2 to 7.2 mg/1 results in a reduction of the toxicity of the pulp and mixed wastes, the size of fishes having a significant effect only for the pulp waste. Concentrations of wastes of 6 … 9% may be regarded to be harmless for long periods of time. 相似文献
2.
Effects of acute cadmium poisoning on survival, its residual values and histopathology in certain organs of a freshwater airbreathing fish, Channa punctatus (BLOCH ) were investigated. The threshold concentration, MATC and LC50 values obtained from 96 h static bioassay, revealed that Channa is more susceptible to cadmium ions at higher temperature. The atomic absorption spectrophotometric determination of cadmium residues differed significantly in organs of specimens having survived and died after 96 h of exposure. The gill accumulate the highest amount of cadmium, the liver accumulated a slightly smaller amount than the gill, while the kidney accumulated the least. The histopathological lesions subjected to sublethal (5.2 mg/l Cd) and lethal (8.4 mg/l Cd) concentrations of cadmium were: detachment and rupture of lamellar epithelium, collapse of pillar cells and hypertrophy in mucus producing gland cells in the gill; vacuolization and coagulative necrosis in hepatic cells of the liver; and expansion, necrosis and accumulation of cellular debris in renal tubules of the kidney. The probable causes for death of fish due to cadmium ions have been discussed. 相似文献
3.
The effects of exposure to LC50 (10.5 mg/l) for 96 h and to a sublethal concentration (1.05 mg/l) of Sevin for 120 days have been observed on some haematological, biochemical and enzymatic parameters of Channa punctatus. The fish were hyperglycemic and hyperlactemic and the glycogen content of the liver and muscles decreased, but the lactic acid content of two tissues increased. The activity of hexokinase increased in the kidney, intestine, liver and muscles but decreased in the gills and brain. The activity of lactate dehydrogenase decreased in the kidney and intestine, and increased in the liver, muscles, brain and gills. The pyruvate dehydrogenase activity decreased in all the six tissues. Both the exposures produced a decrease in the succinate dehydrogenase activity of the liver. The enzyme activity decreased in the brain, gills and muscles after chronic exposure, whereas the kidney and intestine showed an elevation in enzyme activity. 相似文献
4.
Histopathological changes in various cellular constituents of gill, liver and kidney were studied in Heteropneustes fossilis (Bloch) after treatment with cadmium. The changes included fusion, vacuolization, necrosis, hypertrophy and formation of cellular debris in the gill; swellings in nuclei, vacuolization, necrosis and coagulation of cytoplasm in the liver; expansion of renal tubules and formation of cellular debris in the kidney. The changes in the tissue architecture have been discussed in reference to fish mortality. 相似文献
5.
In the present investigation the effect of water-borne copper on the gill architecture of a freshwater teleost, Heteropneustes fossilis (BLOCH ) was studied through scanning electron microscopy. The changes produced on the gill surface in a sublethal measured copper concentration (8.17 mg/1) in static bioassay after 96 h of exposure were fusion of secondary lamellae, rupture of various cellular components and deposition of excessive mucus and blood on the gill surface. The epithelial surface of treated gill thus lost the organized structures like microvilli, arborizing ridges and channels. The cause of fish mortality due to action of copper has been discussed in reference to reduced relative diffusing capacity along with other wide ranging effects on the metabolism of fish. 相似文献
6.
Des W. Connell 《Marine pollution bulletin》1995,31(4-12)
It is now well established that the octanol/water partition coefficient (K0W) can be used to estimate bioconcentration of persistent organic compounds, such as the chlorohydrocarbons as well as PAHs and other hydrophobic substances. However, while these relationships are well established in the laboratory, use in the field often poses a number of problems. In recent studies of contaminants in fish from Australia, bioconcentration has been described using additional information on specimen size, lipid content and fish movement patterns.The use of internal biotic concentration provides an additional new and different perspective on toxicant behaviour as compared to the conventional ambient aqueous concentration-based toxicity measures. The internal lethal concentration for persistent organic compounds approaches a constant value for many compounds, and at these concentrations lethal effects are observed. This constant internal lethal concentration provides a basis for predicting toxicity and its relationship to exposure period. In addition, sublethal effects can be successfully related to the internal biotic concentration. 相似文献
7.
The present paper deals with the inhibition of the specific activity of the acid and alkaline phosphatases in the kidney tissue of mudskipper Boleophthalmus dentatus, exposed to different sublethal concentrations of mercuric chloride. There was a more or less linear inhibition of the specific activity of both the enzymes with increasing concentration of mercuric chloride as well as exposure time. The inhibition of acid phosphatase could be due to the rupture of lysosomal membrane in the presence of mercury compound, which acts as a labilizing agent. The inhibition of alkaline phosphatase probably caused a breakdown of the membrane transport system. 相似文献
8.
Chou CL 《Marine pollution bulletin》2007,54(6):720-725
The study was undertaken to investigate the uptake of mercury in salmon throughout the entire farming period at the net cage. Mercury concentrations in muscle, liver, kidney, and gill and responses to the various dietary mercury concentrations were determined. The accumulation of mercury is in the order of kidney>gill=liver>muscle. The highest mercury peak concentrations were observed for both kidney and gill at the parr-smolt period, while liver and muscle mercury peaked one month later after caging at the grow-out site. High dietary sodium and calcium fed to the salmon contributed to the elevation of mercury in kidney and gill during the smolting process. The mercury burden over the grow-out period increased sharply with a linear relationship of mercury uptake. The tissue mercury burden per gram of growth was calculated using the slope of mercury burden and the slope of growth over the period of each stage. The results showed dietary mercury loadings on marketable salmon were within tolerance limits of FDA and US EPA. Rapid growth of salmon and low dietary mercury progressively reduces the uptake of mercury in salmon. The time series of mercury monitoring showed that mercury concentrations in salmon were greater at the parr stage in freshwater than at the grow-out stage in salt water. 相似文献
9.
Seasonal changes of the gill epithelia of Arctic char (Salvelinus alpinus) from a high mountain lake
Rudolf Hofer Michael Kühnl Roland Psenner 《Aquatic Sciences - Research Across Boundaries》2000,62(4):297-307
The gill structure of Arctic char from a low ionic (1-2 7mol Cl-) high mountain lake (2344 m above sea level) showed distinct seasonal changes. From spring to early winter chloride cells (responsible for ion uptake) were numerous, and during summer gill epithelia were highly hypertrophic resulting in a thick blood-to-water barrier. This gill morphology is typical for fish from soft water habitats and reflects osmoregulatory responses. In mid-winter, however, both chloride cell numbers and epithelia thickness were reduced and comparable to the situation in freshwater with high ionic contents. This pattern correlated with seasonal fluctuations of water chemistry. The most significant correlation was found with CO2 which accumulated under the ice cover, reaching a tenfold oversatturation. The concentration of Ca, Na, and Cl varied only by a factor of two or less and the correlation with the epithelial thickness was much weaker. 相似文献
10.
The effects of chronic exposures to sublethal concentration of two pesticides Carbaryl and Endosulfan on alkaline and acid phosphatase activities in the intestine of a fresh water teleost Channa striatus have been observed by exposing the fish for a period of two to thirty days to 10 ppm and 20 ppm of Carbaryl and 0.00075 and 0.001 ppm of Endosulfan. The inhibition of alkaline phosphatase activity has been dependent on the duration of exposure, concentration and the type of pesticide used. The acid phosphatase activity increased with the duration of exposure in higher concentration of Carbaryl and both the concentrations of Endosulfan. Endosulfan produced more pronounced effects than Carbaryl. 相似文献
11.
The activity concentration of Cesium-137 ((137)Cs) and naturally-occurring Polonium-210 ((210)Po) were measured in the muscle tissue, kidney and liver of Pacific walrus (Odobenus rosmarus divergens) and bearded seal (Erignathus barbatus) collected by native hunters from the Bering Sea during May 1996. The mean (137)Cs concentrations in muscle, liver and kidney of Pacific walrus were 0.07, 0.09 and 0.07 Bq kg(-1) (n=5, wet weight), respectively, and 0.17, 0.10, and 0.17 Bq kg(-1) (n=2, wet weight), respectively, in bearded seal. In general, (137)Cs tissue concentrations are significantly lower than those previously reported for mammals from other regions. By comparison, (210)Po activity concentrations are more variable and appear to be higher level compared with mammal data from other regions. The mean (210)Po concentration in the muscle tissue, liver and kidney of Pacific walrus (n=5, wet weight) were 28.7, 189, and 174 Bq kg(-1), respectively. This compares with (210)Po concentration values (n=2, wet weight) of 27, 207 and 68 Bq kg(-1) measured in the muscle tissue, liver and kidney, of bearded seal, respectively. Estimated concentration factors--as defined by the radionuclide concentration ratio between the target tissue to that in sea water--were two to three orders of magnitude higher for (210)Po that those of (137)Cs. We conclude from radiological dose estimates that ingestion of (137)Cs in foods derived from walrus and seal will pose no threat to human health. This work has important implications for assessment of risks of Alaskan coastal communities concerned about the dumping of nuclear waste in the Russia Arctic. 相似文献
12.
Estuarine fish health assessment: evidence of wastewater impacts based on nitrogen isotopes and histopathology 总被引：2，自引：1，他引：1
Sewage effluent is a powerful agent of ecological change in estuaries. While the effects of sewage pollution on water quality are usually well documented, biological responses of exposed organisms are not. We quantified health impacts in the form of pathological tissue changes across multiple organs in estuarine fish exposed to elevated levels of treated wastewater. Structural pathologies were compared in wild populations of four fish species from two subtropical estuaries on the east coast of Australia that differ substantially in the amount of direct wastewater loadings. Uptake of sewage-derived nitrogen by fish was traced with stable nitrogen isotopes. Pathologies were common in the liver, spleen, gill, kidney and muscle tissues, and included granulomas, melanomacrophage aggregates, and multiple deformities of the gill epithelia. Tissue deformities were more frequent in fish exposed directly to wastewater discharges. Mullet (Valamugil georgii) were most affected, with only a single specimen free of pathologies in the sewage-impacted estuary. Similarly, in those fish that had structural abnormalities, more deformities were generally found in individuals from sites receiving sewage. These spatial contrasts in impaired fish health correspond to significantly enriched delta15N values in fish muscle as a consequence of fish assimilating sewage-N. Overall, the pattern of lower health and enriched delta15N values in fish from sewage-impacted areas suggests that organism health is lowered by sewage inputs to estuaries. Measurements of organism health are required to understand the effects of sewage on estuarine ecosystems, and histopathology of fishes is a powerful tool to achieve this. 相似文献
13.
A zone of contaminated ground water has been identified in an unconfined sand aquifer adjacent to a pit into which spent pulp liquor was intermittently discharged from 1970 to 1979. A network of multilevel sampling, bundle-type piezometers was installed. Up to seven depthspecific sampling points were incorporated into each piezometer providing a cost-effective means for three-dimensional mapping of hydraulic head and water quality in the unconfined sand aquifer. Ground-water samples retrieved from this network showed an area of contamination 900 m long, 400 m wide, and more than 25 m deep. This plume is dispersed about the ground-water flow lines passing beneath the waste disposal pit, and it terminates at a vigorous ground-water discharge area located 800 m from the pit. The contaminated ground water is characterized by elevated concentrations of sodium (3,000 mg/1), chloride (590 mg/1), alkalinity (2,700 mg/1), total organic carbon (2,000 mg/1), chemical oxygen demand (10,800 mg/1), biological oxygen demand (2,000 mg/1), tannin and lignin (780 mg/1), and lower sulphate (1 mg/1) compared to background ground waters in the area. The apparent rate of sodium migration is more than 50 m/yr and is close to the average linear ground-water velocity. Removal of some organic matter by biological transformation has produced the increased alkalinity in the contaminated ground water and somewhat reduced pH. Tannin and lignin are relatively inert compared to other organic compounds found in the waste liquor. Extremely low sulphate levels occurring in the highly contaminated ground waters indicate the existence of conditions favorable for microbially-mediated sulphate reduction. 相似文献
14.
The effect of different concentrations, viz. 0.01, 0.001 and 0.0001 ppm of methyl mercuric chloride on survival, growth behaviour and chlorophyll content of Chlorella vulgaris has been studied under various environmental conditions. Methyl mercury at 0.01 ppm is 100% toxic to the test alga. At a sublethal (0.001 ppm) dose of CH3HgCl, Chlorophyll a was more inhibited than Chlorophyll b. Toxicity was found to be very much under the influence of pH as at acid pH growth is highly reduced by a sublethal concentration, whereas the same concentration does not have an inhibitory influence in the alkaline range of pH. Eutrophic waters seem to reduce the heavy metal toxicity in general. 相似文献
15.
Importance of Internal Biotic Concentrations in Risk Evaluations with Aquatic Systems 总被引：4，自引：0，他引：4
Ecological risk evaluations are commonly performed using aqueous concentrations and aqueous toxicity measurements as a starting point. However risk evaluations could be carried out using internal biotic concentrations and the internal lethal or sublethal concentrations. This has several advantages. Firstly, the internal lethal and sublethal concentrations are relatively consistent in groups of chemicals having a similar mode of action. Thus in field situations the internal concentration, in fish and possibly other biota, can be used to evaluate possible biotic effects. Also other histopathological, biochemical, biomolecular and physiological effects can be assessed and used with this information to give an overall assessment. There are, however, several limitations with this approach including sensitivity, health, age and nutritional status of the biota as well as a lack of data on dose/response relationships with internal concentrations. 相似文献
16.
Median times to narcotization (ET50) of Cirolana borealis Lilljeborg by various levels of toluene in seawater were determined. Narcotization quickly became irreversible, and the ET50 values can be regarded as estimates of median lethal times. Respiratory rate, ATP concentration, and energy charge (E.C.) were not significantly affected by sublethal toluene levels which caused behavioural disturbance. At 12.5 ppm of toluene (nominal concentration; ET50:69 h) ATP dropped gradually to less than 1% and E.C. to about 50% of the control values during 8 days, after which time all the individuals were dead. At 125 ppm neither ATP concentration nor E.C. changed significantly during 24 h although the animals were inactive after about 1 h and died within 100 h. Due to the high degree of stabilization of adenine nucleotide levels and E.C. during environmental changes, these parameters do not appear useful as general indices of stress in environmental pollution studies. 相似文献
17.
18.
The exposure of catfish, Heteropneustes fossilis to different concentrations (200, 500, 700, 1000, 1500, 2000 ppm) of crude oil extract for a varying period (for up to 48 h in lethal extract and 360 h in sublethal one) resulted into a number of haematological changes. All the parameters taken here were found to have been increased except the haemoglobin level which fell down to 14.3 % in an acute lethal concentration (2000 ppm) after 48 h of exposure. The haematocrit value increased significantly (12 %) in 2000 ppm. The blood sugar level showed hyperglycemia in all the concentrations. The increase in ascorbic acid (28 %) was pronounced in higher concentrations. Changes occurring in different parameters seemed to be reversible as all the parameters returned to their normal levels after returning the fish to normal media, except the nuclear swelling which did not resume the normal functioning even after a prolonged treatment (1 month or more) in the recovery jar. The haematological effects shown by the crude oil resembled partly those kept in severe hypoxic conditions and partly to the fishes poisoned by heavy metals (Cu and Zn). On the basis of results obtained in this investigation, crude oil may be categorised as a complex toxic agent. 相似文献
19.
In this study, the DNA integrity of golden grey mullet (Liza aurata) collected in differently contaminated sites of a coastal lagoon, Ria de Aveiro (Portugal), was assessed, over the period of 1 year, using the DNA alkaline unwinding assay, in four different tissues (gill, kidney, liver and blood) and compared to a reference site. The four tissues displayed different DNA integrity basal levels, clearly affected by seasonal factors. Gill and kidney were, respectively, the most and least sensitive tissues. All sites demonstrated the capacity to interfere with DNA integrity. The sites displaying the highest and lowest DNA damage capability were, respectively, Barra (subject to naval traffic) and Vagos (contaminated with polycyclic aromatic hydrocarbons). In terms of seasonal variability, autumn seems to be the more critical season (more DNA damage) unlike summer when no DNA damage was found in any tissue. Data recommend the continued monitoring of this aquatic system. 相似文献
20.
Laboratory experiments were conducted to investigate the lethal and sublethal effects of suspended solids on the survival and physiological, behavourial and morphological changes of the green-lipped mussel Perna viridis collected from Tolo Harbour, Hong Kong. Results showed that P. viridis survived in all test conditions of suspended solids from 0 to 1200 mg/l over a period of 96 h. Physiological responses of the green-lipped mussel under 14-d exposure of suspended solids from 0 to 600 mg/l, followed by 14-d recovery in natural seawater, revealed no significant changes (p>0.05) in oxygen consumption and dry gonosomatic index for treatments in different concentrations of suspended solids and exposure time. Changes in clearance rate were only found to be significant (p<0.001) with exposure time. Responses in behavourial and morphological changes of the green-lipped mussel were also studied under similar experimental treatments and exposure time. Byssus production was significantly (p<0.001) related to exposure time. Gill damage, however, was significantly greater in treatments (p<0.001). Present findings suggested that P. viridis could tolerate a high level of suspended solids in the laboratory. There were dose-dependent effects of suspended solids on morphology of gill filaments. Implications of survival and responses of the green-lipped mussel to suspended solids in the marine environment are discussed. 相似文献