首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 343 毫秒
1.
Acute (24 h) and sublethal (35 days) effects of cadmium chloride (CdCl2) were examined in Cirrhinus mrigala using various endpoints (accumulation pattern, thyroid hormones (THs), and antioxidants). The mean concentrations of CdCl2 for 24 and 96 h were found to be 35.974 and 22.387 mg L?l, respectively. LC50 concentration of CdCl2 for 24 h (35.97 mg L?l) was used for the acute study. For the sublethal studies, fish were exposed to 3.59 mg L?1 (Treatment I) and 7.19 mg L?1 (Treatment II) corresponding to 1/10th and 1/5th of 24 h LC50 of the CdCl2. During acute exposure, higher accumulation of CdCl2 was noticed in the gill, liver, and kidney of C. mrigala, which is found in the order gill > liver > kidney tissues. Similarly, in sublethal treatments (Treatment I and II), a concentration and time-dependent increase of CdCl2 accumulation was noticed in the order of gill > liver > kidney. GSH, GST, and GPx activities were found to be relatively lower from the treated groups in both acute and sublethal treatments. However, LPO activity was significantly increased in CdCl2-treated fish C. mrigala. Further, plasma T3 reduction was more pronounced than T4 in acute study. During sublethal treatments, both T4 and T3 levels showed a continuous decrease as the exposure period extended. All the values in this study were statically significant (P < 0.01 and P < 0.05).  相似文献   

2.
Applying an integrated approach using the Comet, micronucleus (MN), and random amplified polymorphic DNA (RAPD) assays, occurrence of erythrocytic nuclear abnormalities (ENAs) and the liver activity of antioxidants enzymes (catalase and glutathione-S-transferase (GST)) was carried out to evaluate the effects of acute (6, 24, and 96 h) and subchronic (15 days) exposures to aluminum on fish Prochilodus lineatus. The Comet assay showed that fish erythrocytes exhibited significantly higher DNA damage after 6 and 96 h of Al exposure. MN frequencies were very low and did not increase significantly after Al exposures, while ENAs frequency increased significantly after all exposure periods. RAPD profiles obtained with DNA from fish fins collected before the toxicity tests were compared to the profiles with DNA from gills and liver of the same fish sampled after Al exposures. Alterations in RAPD profiles, including appearance and disappearance of bands, after 6 h, 24 h, and 15 days of Al exposure were detected. Fish exposed to Al for 6 and 24 h also showed significant increases in GST and catalase activities. These results indicated that Al exposure was genotoxic to P. lineatus, inducing DNA damage in peripheral erythrocytes. The induction of antioxidant enzymes might be an indication that Al causes oxidative damage to DNA, while the very low frequency of MN suggests that Al does not produce clastogenic or aneugenic effects. Genotoxic effects after 15 days of Al exposure was revealed only by RAPD, showing that this assay represents a sensitive method to detect genotoxic damage, occasionally not detected by other genotoxic tests used in toxicological genetics studies.  相似文献   

3.
Blood from Tilapia zillii exposed to three sublethal concentrations of Cd (10.62, 17.70 and 24.78 mg L?1) for 24, 48, 72 and 96 hr was analyzed to identify and evaluate changes in erythrocyte count (RBC), hematocrit (Ht), hemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), erythrocyte sedimentation rate (ESR), leucocyte count (WBC), differential leucocyte counts, total protein, glucose and lactic acid. Hematological and physiological changes attributable to Cd poisoning were observed. Fish showed obvious signs of stress at 17.70 and 24.78 mg L?1 Cd. Clear time related effects of Cd on the biochemical factors were recorded. The severe stress conditions caused by Cd may be responsible for the hematological and physiological changes in blood.  相似文献   

4.
Endosulfan, an organochlorine pesticide, has been applied ubiquitously worldwide. However, endosulfan has been identified as a type of persistent organic pollutants (POPs), and its ecotoxicity has drawn attentions from scientists. The present study was implemented to examine the effects of endosulfan on the diversity and structure of soil microorganism communities. A control treatment and three concentrations (0.1, 1.0, and 10.0 mg/kg) were set up in laboratory experiments and sampled on days 7, 14, 21, and 28. The results revealed that the populations of bacteria and actinomycetes decreased significantly after 1.0 and 10.0 mg/kg treatments and that the soil microbial biomass carbon (MBC) was increased by endosulfan compared with the control. Terminal restriction fragment length polymorphism (T-RFLP) results revealed that the soil bacterial diversity was decreased by endosulfan and that the soil microbial community structure became unstable after endosulfan application. Moreover, the results of a 16S rRNA clone library revealed that the phyla Proteobacteria, Actinobacteria, Bacteroidetes, Spirochaetes, and Firmicutes showed an obvious advantage and closely relative. In conclusion, the results of the present study indicated that 0.1–10.0 mg/kg endosulfan showed obvious influences on the diversity and structure of the soil microbial community.  相似文献   

5.
The roles of verapamil (VRP), a calcium channel blocker, on cadmium-induced physiological stress in freshwater teleost Oncorhynchus mykiss were investigated in this study. Forty-eight juvenile rainbow trout were divided randomly into four groups, i.e., control group, VRP group (100 μg/L VRP), Cd group (50 μg/L Cd2+), and VRP?+?Cd group (100 μg/L VRP?+?50 μg/L Cd2+). After 1-week exposure, oxidative stress indices (lipid peroxidation and carbonyl protein) and antioxidant parameters (superoxide dismutase, glutathione reductase, glutathione peroxidase, and reduced glutathione) were measured in gill and liver of all tested fish. Additionally, the behavioral changes were recorded during the experimental period. Compared with the control, cadmium-induced stress was apparent as reflected by a serious oxidative stress in gill and liver tissues, inhibited branchial antioxidant parameters, and induced hepatic antioxidant responses, as well as abnormal behaviors observed. In the VRP?+?Cd group, the antioxidant defense system of fish returned to the control level, and the fish behavioral abnormalism markedly decreased. The present results suggested that VRP could reduce the cadmium-induced physiological stress in rainbow trout and provided further evidence that Cd2+ uptake through Ca2+ transport pathways in freshwater teleost.  相似文献   

6.
The effects of ammonium chloride on survival and feeding energetics of the freshwater fish Oreochromis mossambicus were studied. At a concentration of 600 mg L-1 ammonium chloride, 100% mortality was observed within 24 h; no mortality occurred at 400 mg L-1 within 96 h; Concentration of 450 mg L-1 ammonium chloride was found as median lethal concentration at 96 h exposure. Rearing the fish in increasing sublethal concentrations of ammonium chloride, it was found that the feeding rate decreased from 20.309 ± 0.506 mg g live fish-1 day-1 (mg g-1 d-1 (control) to 11.594 ± 0.479 mg g-1 d-1 at the highest sublethal concentration (100 mg L-1. Growth rate was drastically reduced.  相似文献   

7.
The concentrations of mercury, lead, cadmium, and arsenic were evaluated in 96 samples, 12 by each one of the following eight fish species: snook (Centropomus undecimalis), crevalle jack (Caranx hippos), Serra Spanish mackerel (Scomberomorus brasiliensis), southern red snapper (Lutjanus purpureus), blue runner (Caranx crysos), Atlantic tarpon (Megalops atlanticus), ladyfish (Elops saurus), and Atlantic goliath grouper (Epinephelus itajara), which were collected during 1 year in the Atrato River Delta in the Gulf of Urabá, Colombian Caribbean. Three fish were caught from each of the following sites the community usually uses to catch them (known as fishing grounds): Bahía Candelaria, Bahía Marirrío, Bocas del Roto, and Bocas del Atrato. The quantification of metals was performed by microwave-induced plasma-optical emission spectrometry. The Pb concentration fluctuated from 0.672 to 3.110 mg kg?1, surpassing the maximum permissible limit (MPL?=?0.3 mg kg?1) for human consumption for all species. The Hg concentration ranged between < Limit of detection and 6.303 mg kg?1, and in the crevalle jack and Atlantic tarpon, concentrations exceeded the MPL (0.5 mg kg?1). The levels of Cd and As were not significant in the studied species and did not exceed the MPL (0.05 mg kg?1).  相似文献   

8.
The physiological effects of sublethal concentrations (0.3 of 96-hr TL.) of two different pollutants (endrin and toluene) on the levels of cholesterol, glucose and protein in serum and glycogen in liver and muscle of a freshwater fish, Clarias lazera, at time intervals from 24 to 96 hr have been compared. These results indicated that the two pollutants at sublethal concentrations influenced the metabolism of cholesterol, glucose in serum and glycogen in liver and muscle in Clarias lazera. The changes induced by endrin were more striking than those induced by toluene.  相似文献   

9.
Acute toxicity of Pb to the water flea; (Daphnia sp) and Copepod, (Cyclop sp) both important component of zooplankton diet of fish was determined by static assay. A positive relationship between percentage mortality and exposure concentration was found in all tests. Mean 24-h LC50, 48-h LC50 and 96-h LC50 values were 2.51?±?0.0.04 mg l?1, 1.88?±?0.06 mg l?1 and 1.65?±?0.19 mg l?1 for Daphnia spp and 3.11?±?0.03 mg l?1, 2.97?±?0.05 mg l?1 and 2.61?±?0.09 mg l?1 for Cyclop spp, respectively. For all tested species did the LC50 values decrease with time; the decrease was more marked for Daphnia spp. Observed symptoms include spiral movement followed by change of body colour to white and rapid disintegration of the skin. The Daphnia spp. appear to be more sensitive to Pb poison than Cyclop spp. The results showed that concentrations of Lead (Pb) in excess of 0.19 mg l?1 and 0.30 mg l?1 can be potentially harmful to Daphnia magna and Cyclop spp respectively.  相似文献   

10.
Persistent organic pollutants (POPs) immobilization in farm land is an important issue to solve the residue in crop, and char has been considered for the remediation. In here, three commercially available chars like powdered oak char (POC), granulated oak char (GOC), and rice husk char (RHC) including powdered activated carbon (PAC) were investigated for their potential to adsorb and immobilize endosulfan in the soil. The maximum adsorption capacities (mg g?1) of the applied chars as POC, GOC, and RHC were 714.8, 322.6, and 181.8, respectively, and the capacity of POC was similar with PAC (713.8). In addition, the pore volume (0.138 cm3 g?1) and the surface area (270.3 m2 g?1) of POC were over 3-fold higher than GOC and RHC. The bioconcentration factor (BCF) reducing effect of α-, β-endosulfan, and endosulfan sulfate in oriental radish (Raphanus sativus var. sativus) was investigated by amendment of three commercially available chars to the contaminated soils. The BCF of total endosulfan was 0.025 in the radish root. POC treatments effectively suppressed the endosulfan uptake (BCF 0.002). However, GOC and RHC showed little BCF reducing effect of endosulfan in radish.  相似文献   

11.
The present investigation was undertaken to evaluate the effect of sublethal concentrations (0.088 and 0.044 mg 1?1, i.e., 1/5th and 1/10th fraction of 96 h LC50) of mercuric chloride on Ca, inorganic phosphate, water content, ash, glycogen, Fe, total protein, lipid contents and vitamin A, C, D, and E of liver, muscles and ovary of the freshwater fish Notopterus notopterus exposed for 30 days. The results obtained indicate that Ca, inorganic phosphate, water, ash, glycogen, Fe, total protein contents and vitamin D decreased significantly or insignificantly in these tissues of the Hg exposed fishes. However, lipid content increased in liver and muscles, but decreased in the ovaries. Vitamin A and D increased in the liver but decreased in the muscles and ovaries. Moreover, vitamin E increased in all the tissues of the fish exposed to 0.088 mg 1?1 and decreased in the fish exposed to 0.044 mg 1?1 of Hg concentrations.  相似文献   

12.
《Applied soil ecology》2001,16(3):263-273
The insecticide endosulfan is extensively used in the Australian cotton growing industry. Irrigation tailwater contaminated with endosulfan is released onto floodplains to avoid direct entry into river systems where endosulfan is highly toxic to fish. We examined the short-term effects of endosulfan, at levels likely to be present in tailwaters, on soil arthropods on such a floodplain near Moree, NSW. The study consisted of four treatments: a dry control (replicates untreated), wet control (replicates flooded with water only), 1 μg/l endosulfan and 10 μg/l endosulfan. Treatments were applied in the middle of summer and soil invertebrate samples were taken 1 week, 1 month and 2 months following treatment. Invertebrates were sorted to order level and oribatid mites to species. Endosulfan sulphate was detected in all treatments, including the two controls, most likely the result of spray drift. The focus of the experiment was therefore to explore the short-term impacts of endosulfan contaminated tailwater on communities that had been previously exposed to endosulfan. More than 7700 arthropods were collected from a total sample area of 0.336 m2. The dominant groups were the prostigmatid and oribatid mites (35 species), collembolans and hemipterans. Our analyses did not detect any short-term effect of the endosulfan treatments on the number of individuals, spatial aggregations or community structure of the soil fauna. There were clear responses to changes in soil moisture related to treatment applications. The study, therefore, made two important findings: (1) a diverse and abundant soil fauna persists on floodplains exposed to endosulfan contaminated tailwater, and (2) this diverse and abundant soil fauna were unaffected by the addition of endosulfan at concentrations common to tailwater run-off from cotton fields. There is clearly a need to determine whether these findings can be extended to soil arthropod biodiversity in areas previously unexposed to endosulfan.  相似文献   

13.
Microcystin-LR (MC-LR) is a cyclic heptapeptide toxin produced by cyanobacteria in eutrophic water. It can be transferred into soil–crop systems via irrigation and cyanobacterial paste fertilization. No studies have examined the potential toxicity of MC-LR to soil animals. Therefore, in the present study, the toxicological effects of MC-LR on earthworm (Eisenia fetida), including survival, growth, reproduction, oxidative stress, and cell viability, were investigated. The LC50 of MC-LR was 0.149 μg cm?2 at 72 h based on a filter paper test and 0.460 mg kg?1 at 14 days based on an acute soil test. MC-LR seriously affected the reproduction of earthworms. Based on hatchability, the EC50 of MC-LR was 0.268 mg kg?1, similar to environmentally relevant concentrations of microcystins. The changes in activities of superoxide dismutase, guaiacol peroxidase, catalase, and glutathione peroxidase, together with the levels of glutathione and malondialdehyde, indicated that oxidative damage and lipid peroxidation played significant roles in MC-LR toxicity. In addition, the toxicity of MC-LR in earthworms increased despite degradation of MC-LR in soil over time, possibly due to the formation of toxic metabolites of MC-LR or the bioaccumulation of MC-LR in earthworms. A reduction in the neutral red retention time along with an increase in coelomocyte apoptosis with increasing MC-LR concentrations indicated a severe damage to viability. These results suggest that environmentally relevant MC-LR concentrations in agricultural soil may cause reproductive, biochemical, and cellular toxicity to Eisenia fetida. This information can be used in ecological risk assessments on MC-LR in soil.  相似文献   

14.
The effect of 96 h exposure tosublethal cadmium concentrations on oxygen consumptionrate (VO2 mg h-1) and oxygen extractionefficiency (OEE′ %) was determined in juvenile Ctenopharyngodon idella acclimated to 26, 29 and 32 °C for at least two weeks. The relationshipsamong the physiological rates (VO2 andOEE′, body weight and temperature, were fittedby second order polynomial models; the responsesurfaces generated allowed the evaluation of stressinduced by the interaction of those variables. BothVO2 and OEE′ invariably increased astemperature increased. In small animals kept in 0.5 mgCd L-1, the VO2 increase was compensated bya proportional increase in OEE′, whereas inlarger fishes (>1 g) no compensatory response wasobserved. Both small and large fishes were unable tocompensate for a higher VO2 when exposed tohigher cadmium concentration. It is concluded thatOEE′ in young fish is an early response of stressdue to sublethal cadmium exposure.  相似文献   

15.
Carp were exposed to different sublethal concentrations of sodium alkil-aril suphonate at 30 °C. The effect on the permeability of the fish gill membrane produced by detergent was measured as an increase in Na+ loss brought out by deionized water. Sodium loss was greater in control fish than in experimental ones. Sodium ion loss was inversely correlated with detergent concentrations, which reflects the occurrence of demineralization. This was proved by measuring plasmatic Na+ concentration in experimental and control fish. Sodium loss hyperbolic patterns may be indicative of carp hormonal control. Loss was probably influenced by the animals corporal weight.  相似文献   

16.
Variation of mercury (Hg) in sediments and biota from Coatzacoalcos estuary during the dry, rainy and windy seasons was estimated. In sediments, Hg concentrations ranged from 0.07 μg g?1 in site 13 (Ixhuatepec) located upstream, to 1.06 μg g?1 in site 3 (Coatzacoalcos river), located in the industrialized area. Highest enrichment factor (EF) and index of geoaccumulation (I geo) in surficial sediments were 53 and 5.1 respectively. From EF and I geo, it is considered that Coatzacoalcos estuary is from moderately contaminated to contaminated. In most fish species from Coatzacoalcos estuary, the sequence of Hg concentration was liver>muscle>gills. Average Hg concentrations in soft tissue of bivalves ranged from 0.09 μg g?1 in Corbicula fluminea to 0.18 μg g?1 in Polymesoda caroliniana. Biota-sediment accumulation factor (BSAF) ranged from 0.9 in P. caroliniana during the rainy season (site 4) to 3.8 in P. caroliniana from the same site during the windy season.  相似文献   

17.
A total of 65 surface (0–20 cm) soil samples were collected in an effort to estimate the arsenic background values in Kavala area, Northern Greece. Arsenic was extracted by HNO3 from the <200?µm grain size fraction, and its concentrations were determined in all samples by inductively coupled plasma–mass spectrometry. Arsenic concentrations were log-transformed, and log-normal probability plots (Q–Q plots) were generated. The geochemical background was calculated as the values that lie between g/d and g?×?d (g, geometric mean; d, geometric standard deviation), which are 3.5 and 25.8 mg kg?1, respectively. The baseline value (g) was 9.5 mg kg?1. With the aid of GIS software, arsenic geochemical maps of the study area were created. The majority of the arsenic elevated concentrations were found in the proximity of the industrialized zone of Kavala.  相似文献   

18.
Stress responses can be measured at various levels of biological organization, from sub-organism through to ecosystem level. This study aimed to investigate stress protein induction as a sub-organism level stress response in two South African freshwater aquatic macroinvertebrates exposed to detergent linear alkylbenzene sulfonate (LAS). Shrimp Caridina nilotica and limpet Burnupia stenochorias were exposed to a range of LAS concentrations (0, 1, 1.8, 3.2, 6.5 and 12.7 mg/L and 0, 0.6, 1.2, 1.6 and 3.2 mg/L respectively) for 96 h. Surviving organisms were prepared for sodium dodecyl sulphate-polyacrylamide gel electrophoresis and Western blot analysis. In C. nilotica there appeared to be induction of a putative ≈ 70 kDa protein at 12.7 mg/L LAS, and induction of putative ≈45 and ≈40 kDa proteins at concentrations of 6.5 mg/L LAS and above. However, only an Hsp70 protein was detected with anti-Hsp72/Hsc73 at 12.7 mg/L LAS. No protein induction was observed in exposed B. stenochorias, however an Hsp40 protein was detected with anti-Hsp40 in exposed and unexposed limpets.  相似文献   

19.
The effect of waterborne zinc on survival, growth, and feed intake of Indian major carp, Cirrhinus mrigala (Hamilton), advanced fry was studied under laboratory condition. Survival rates of C. mrigala advanced fry (2.71?±?0.49 g) after 30 days exposure to control (0.01), 0.03, 0.06, 0.10, and 0.15 mg/L zinc using the static renewal method in freshwater at pH 7.3?±?0.2, temperature 26?±?2°C, and total hardness 114?±?16 mg/L as CaCO3 were 100%. Growth of the fish exposed to 0.10 and 0.15 mg/L of zinc was significantly lower (P?<?0.05) than in control (0.01), 0.03, and 0.06 mg/L of zinc after 30 days of exposure. However, there were no significant differences (P?>?0.05) in fish growth between 0.03 and 0.06 mg/L zinc concentrations. Feed intake rates were significantly (P?<?0.05) reduced in the fish exposed to 0.10 mg/L and higher levels of zinc. The zinc accumulation in the whole body of the fish increased with increasing concentrations of the metal.  相似文献   

20.
Chemical inputs from agricultural activities represent a threat to aquatic biota and its biochemical systems. Among these systems, acid phosphatases are involved in autophagic digestive processes, decomposing organic phosphates, signaling pathways, and other metabolic routes. In vitro tests are helpful to generate hypotheses about pollutant mechanisms of action through comparison of the toxicity effects of these compounds. In this work, we investigated the inhibitory effects of four organic pesticides and three metals on the acid phosphatases extracted from the freshwater microcrustacean Daphnia similis and the fish Metynnis argenteus. Our results demonstrated that only the metals have considerable inhibitory effects (50% or higher) on the enzyme activities. The calculated median effect concentrations (IC50) for the enzyme inhibition were 0.139 mM Hg2+ (fish enzyme), 0.652 mM Cu2+ (fish enzyme), and 1.974 mM Al3+ (Daphnia enzyme). Due to the relatively low value of the inhibition parameter for Hg2+, its inhibitory property could be used as a tool for Hg2+ detection in environmental samples. The enzyme activities obtained in the presence of the inhibitors are potential data as in vivo biomarkers for metals in both aquatic species.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号