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 31 毫秒
1.
Damla N  Cevik U  Karahan G  Kobya AI 《Chemosphere》2006,62(6):957-960
Gross alpha and gross beta activities were determined for 27 different tap water samples collected from Eastern Black Sea region of Turkey. The instrumentation used to count the gross alpha and gross beta activities was a alpha/beta counter of the low background multiple detector type with 10 sample detectors (Berthold LB770). The obtained results showed that natural activity concentrations of alpha- and beta-emitting radionuclides in tap water samples did not exceed WHO and ITS recommended levels. Concentrations ranging from 0.2 mBq/l to 15 mBq/l and from 25.2 mBq/l to 264.4 mBq/l were observed for the gross alpha and gross beta activities, respectively. For all samples the gross beta activities were higher than the corresponding gross alpha activities.  相似文献   

2.
Lei AP  Wong YS  Tam NF 《Chemosphere》2003,50(3):293-301
The glutathione-S-transferase (GST, EC 2.5.1.18) activities in different freshwater microalgal species, namely, Chlorella vulgaris, Scenedesmus quadricauda, Scenedesmus platydiscus and Selenastrum capricornutum under the control condition (without pyrene addition) and at different pyrene concentrations were compared. During 7-days incubation under the control condition (without pyrene addition), all microalgal species exhibited measurable GST activities but the activities varied significantly among species and the difference could be more than 100-fold. The addition of pyrene at concentrations ranged from 0.1 to 1.0 mg l(-1) to microalgal cultures led to changes in GST activities but the patterns of changes varied from species to species. Among the four species, remarkably decreases in GST activities were found in S. quadricauda, a species most sensitive to pyrene toxicity, at high pyrene concentrations. On the contrary, GST activities in S. platydiscus and Se. capricornutum increased significantly as pyrene concentrations increased. These two species were found to be more resistant to pyrene and had higher efficiencies in metabolising pyrene than other species. C. vulgaris did not show any significant change in their GST activities with the addition of pyrene, and pyrene was not metabolised by this species. These results suggest that pyrene-induced changes of GST activities in microalgae might be related to their resistance and their ability to metabolise pyrene. In general, the pyrene-induced changes of GST activities were higher at 4-days than at 1- and 7-days incubation in all microalgae.  相似文献   

3.
Total and holo-enzyme activities of tryptophan 2,3-dioxygenase were measured in vitro in the presence and absence of the organophosphorous insecticide, dimethoate. Addition of dimethoate to the reaction mixture decreased the activities of both total and holo-forms. Total and holo-enzyme activities were decreased by 34% and 26%, respectively, by 1 mM dimethoate. On the other hand, 5 mM dimethoate resulted in 56% and 34% inhibition to total and holo-enzyme activities, respectively. Lineweaver-Burk plot of the total-enzyme activity at different tryptophan concentration in the presence of 2 mM dimethoate gave uncompetitive type of inhibition.  相似文献   

4.
灯心草部分生理生化指标对土壤复合重金属胁迫的响应   总被引:1,自引:0,他引:1  
通过盆栽试验,以叶绿素含量和POD、SOD、CAT3种抗氧化酶活性作为观测指标,研究了Cu、Cd、Pb、Zn和As复合重金属胁迫下灯心草部分生理生化指标的变化趋势和机理.结果表明,灯心草的生理毒害效应呈明显的剂量-效应关系.表现为与对照相比,叶绿素含量减少,叶绿素a/b值降低,叶片失绿现象明显.随着复合重金属胁迫浓度的增加,灯心草3种酶活性均呈先升后降的变化趋势,但出现抗性酶活性高峰所对应的重金属浓度不同,表现出不同的特征变化趋势.总体来说,在接近土壤环境质量标准低浓度设计范围内,酶活性有逐渐被激活的趋势.但在高浓度水平下,酶活性普遍受到抑制.生长在铅锌尾矿和模拟矿毒水污染土壤中的灯心草叶绿素合成受到显著抑制(P<0.05),但POD和CAT两种酶活性均高于对照.  相似文献   

5.
Ismert M  Oster T  Bagrel D 《Chemosphere》2002,46(2):273-280
Polycyclic aromatic hydrocarbons are xenobiotics whose elevated toxicity for living organisms requires to efficiently monitor air pollution, either by evaluating their levels in the environment, or by assessing their biological impacts on sentinel organisms. We investigated the effects of naphthalene exposure on some xenobiotic-metabolising enzyme activities in three organs of Helix aspersa. Particular activities depending on cytochrome P450 (ethoxyresorufin O-deethylase, EROD; ethoxycoumarin O-deethylase, ECOD; pentoxyresorufin O-dealkylase, PROD) and associated with glutathione (glutathione S-transferase, GST; glutathione peroxidase, GPX; glutathione reductase, GR) were assessed. In control animals, the P450-dependent specific activities were distributed according to the range kidney > digestive gland > mantle cavity forming tissues (MCFT). Neither ECOD nor PROD activities could be detected in MCFT. In the two other organs, the major phase I activities were due to ECOD, the level of PROD being very low or null. The glutathione-associated activities showed comparable levels in the three organs, except GPX activity that was higher in the digestive gland. Naphthalene (NAP) exposure did not affect any activity in MCFT, but it significantly decreased EROD and ECOD activities in the kidney as opposed to their increase in the digestive gland, whereas PROD activities were not influenced by the treatment. Glutathione-dependent activities were not significantly affected by NAP exposure, except for GPX which activity diminished in the digestive gland. This study demonstrates that complex detoxification pathways should exist in Helix aspersa as in mammals and that they could be used as potential biomarkers of NAP exposure.  相似文献   

6.
Li G  Sang N  Guo D 《Chemosphere》2006,65(6):1058-1063
The effects of the Xingou landfill leachate on levels of thiobarbituric acid reactive substances (TBARS) and the activities of Cu, Zn-superoxide dismutase (Cu, Zn-SOD), Se-dependent glutathione peroxidase (Se-dependent GPx) and catalase (CAT) were investigated in hearts, kidneys and spleens of Kunming albino mice of both sexes. Exposure to leachate caused significant increases of TBARS levels in the organs tested from mice of both sexes. For hearts, Cu, Zn-SOD, Se-dependent GPx and CAT activities were significantly increased at high concentrations for male mice, but the activities of these antioxidant enzymes were significantly increased at low concentration and decreased at high concentrations for female mice. For kidneys, Cu, Zn-SOD and Se-dependent GPx activities were significantly increased at high concentrations for male mice, but the activities were significantly increased at low concentrations and the ratio of increase was reduced with the increasing of concentration for female mice; CAT activities remained unchanged for male mice and were significantly increased at all concentrations tested for female mice. For spleens, Cu, Zn-SOD and Se-dependent GPx activities were significantly increased at high concentrations for male mice, but the activities were significantly increased at low concentrations and decreased at high concentrations for female mice; CAT activities remained unchanged for male mice and were significantly increased at high concentrations for female mice. The results suggest that leachate exposure can cause oxidative damage on hearts, kidneys and spleens of mice, and there were sex difference and organ difference in the response of antioxidant status.  相似文献   

7.
From 2010 to 2012, the Yangtze River and Hanjiang River (Wuhan section) were monitored for estrogenic activities during various water level periods. Using a recombinant yeast estrogen screen (YES) assay, 54 water samples were evaluated over the course of nine sampling campaigns. The mean 17β-estradiol equivalent (EEQ) value of raw water from the Yangtze River was 0–5.20 ng/L; and the EEQ level from the Hanjiang River was 0–3.22 ng/L. In Wuhan, drinking water treatment plants (DWTPs) using conventional treatments reduced estrogenic activities by more than 89 %. In general, water samples collected during the level period showed weaker estrogenic activities compared to those collected during the dry period. The samples collected in 2010 showed the strongest estrogenic activities of the 3-year period. The lack of correlations between estrogenic activities and selected common water quality parameters showed that estrogenic activity cannot be tied to common water quality parameters.  相似文献   

8.
镉对鲫鱼组织转氨酶和过氧化氢酶活性的影响   总被引:23,自引:0,他引:23  
当水中镉离子浓度为32mg/L,64mg/L时,肝胰脏,肾脏和鳃的谷丙转氨酶和谷草转氨酶活性显著降低,而过氧化氢酶活性则显著升高,对鲫鱼心脏3种酶活性的影响不明显,体外试验表明,镉能直接抑制GPT、GOT的活性,而对Catalase活性不产生直接影响。  相似文献   

9.
以古运河镇江段为研究对象,研究了表层沉积物中碱性磷酸酶活性、硝酸还原酶活性和亚硝酸还原酶活性的时空变化以及3种酶活性与河流表层沉积物中氮磷阴离子浓度及上覆水水质的相关性。结果表明,镇江古运河表层沉积物中碱性磷酸酶活性、硝酸还原酶活性和亚硝酸还原酶活性具有显著的时间和区域性差异,枯水期(12月)各酶活性较高,分别介于0.29~0.32 mg/(g·24 h)、0.13~0.19 mg/(g·24 h)、3.05~5.21 mg/(g·24 h);丰水期(5月)各酶活性较低,变化范围分别为0.18~0.29 mg/(g·24 h)、0.08~0.14 mg/(g·24 h)、2.95~3.64 mg/(g·24 h)。冗余分析结果显示,古运河表层沉积物酶活性在枯水期差异较大,丰水期差异较小,各酶活性与其相关离子浓度呈显著正相关(P0.05),硝酸还原酶和亚硝酸还原酶与上覆水的水质呈正相关。3种酶活性可被作为判断古运河镇江段沉积物富营养化负荷的参考性指标,硝酸还原酶和亚硝酸还原酶还可作为评价古运河镇江段水质的参考性指标。  相似文献   

10.
外源Cd对不同利用方式红壤脲酶活性的影响   总被引:2,自引:0,他引:2  
采用室内培养实验,通过将外源Cd添加到同一母质、全镉含量相近的不同利用方式的红壤中(林地、水稻土和菜园土),研究了外源Cd污染对不同利用方式红壤脲酶活性的影响。结果表明:整个培养过程中,Cd污染对3种红壤脲酶活性都有抑制作用,且随重金属浓度的增强而增强。同剂量Cd污染对3种红壤脲酶活性的抑制效应不同,大小为林地>水稻土>菜园土。实验设定的Cd处理水平下,对林地、水稻土和菜园土脲酶活性产生显著抑制作用(p<0.05)的Cd浓度分别为5、30和50 mg/kg土。  相似文献   

11.
The common sole, Solea solea (Linneus, 1758), and the Senegalese sole, Solea senegalensis (Kaup, 1858), are two important commercial species that coexist in the NW Mediterranean. In order to assess the species' ability to respond to chemical insults, a comparison of activities on enzymes involved in xenobiotic metabolism was carried out. Juveniles of both species were sampled in winter 2011 from the Ebro Delta region, and activities of selected enzymes such as acetylcholinesterase (AChE), carboxylesterase (CbE), ethoxyresorufin O-deethylase (EROD) and glutathione S-transferase (GST) were determined in several tissues. Lipid peroxidation (LP) levels in plasma were measured as a sign of oxidative stress. In vitro exposures to selected pesticides were contrasted, analysing AChE and CbE activities in several tissue homogenates. Overall, enzymatic activities were higher in S. solea except for gill GST and CbE and kidney GST, while plasmatic LP levels were similar. In vitro contrasts revealed lower IC50 values for CbE activities in S. solea, suggesting a greater buffer capacity of this enzyme to potentially reduce pesticide toxicity over AChE.  相似文献   

12.
Abstract

The assessment of personnel exposure to volatile solvent vapors is an important aspect in any comprehensive health and safety program. This is particularly true at Treatment, Storage, and Disposal Facilities (TSDFs) and for industries dealing with volatile solvents. This paper presents organic vapor monitoring data from seven TSDFs and from several routine small business and household activities. It shows that proper controls at TSDFs effectively reduce personnel vapor exposure. Through an examination of data from a specialized business such as a TSDF, along with data from more routine activities, a different perspective arises regarding potential hazards associated with hazardous waste disposal activities.  相似文献   

13.

The household sector is a major driver of energy consumption and greenhouse gas (GHG) emissions. However, most existing studies have only estimated households’ carbon footprint from their expenditures. Households’ daily activity time, a scarce resource that limits and determines their consumption behavior, has rarely been integrated into the estimation. Incorporating the daily time-use patterns should thus provide a more practical perspective for mitigation policies aiming at promoting sustainable household lifestyles. In this study, by linking household time-use data and expenditure data of Japan, the carbon footprint and the GHG intensity of time of 85 daily household activities constituting the 24 hours in a day are estimated. Compared to the maximal 20-activity disaggregation in existing studies, our detailed 85-category disaggregation of daily time enables unprecedented details on the discrepancies between the carbon footprint from daily activities, many of which have previous been treated as one activity. Results indicate significant carbon mitigation potential in activities with a high GHG intensity of time, such as cooking, bathing, and mobility-related and activities. Average daily GHG emissions were also found to be higher on weekends as time-use patterns shift from paid work to free-time activities, highlighting the need for mitigation strategies on a weekly scale.

  相似文献   

14.
In this study we aimed to assess the dioxin- and estrogen-like activities of contaminants extracted from twenty species of freshwater and seawater fishes, using luciferase reporter assays. Transfected MCF7 cells were treated with sample extracts and luciferase activities were then measured at 24-h of post-treatment. The mean values of the detected dioxin- and estrogen-like activities in the freshwater fishes were 25.3 pg TEQ/g ww and 102.3 pM EEQ/g ww whereas in the seawater fishes, the values were 46.2 pg TEQ/g ww and 118.8 pM EEQ/g ww. Using sample-relevant dosage of estrogen, inductions of cell proliferation markers (i.e. retinoblastoma, cyclin D) and stimulations of cell growth were revealed by Western blotting, colony formation and BrdU uptake assays. A cotreatment with TCDD significantly reduced these effects. Using the sample extracts with different dioxin- and estrogen-like activities, similar observation was revealed. The data highlighted the mixture effect of food contaminants on human health.  相似文献   

15.
The effect of a chronic exposure to sublethal concentration of mercuric chloride (0.3 mg/l) on the activities of some enzymes in the digestive system of the teleost fish Channa punctatus was examined after 15 and 30 days of treatment. Glucose-6-phosphatase was significantly inhibited in the intestine and pyloric caeca. No marked alterations were observed in the activities of maltase and lactase except for elevation in maltase activity and inhibition in lactase activity in the intestine and pyloric caeca after 15 days of treatment. Three peptidases (aminotripeptidase, glycylglycine dipeptidase and glycyl-1-leucine dipeptidase) showed decreased activities in all parts of the digestive system. A decrease was also observed in the activity of lipase except for the stomach where inhibition after 15 days was insignificant. The results indicate that the activities of all the enzymes examined are inhibited in intestine and pyloric caeca and digestion of proteins and lipids may be more affected by mercury than the digestion of some carbohydrates.  相似文献   

16.
Changes in photosynthetic and antioxidant activities in maize (Zea mays L.) leaves of cultivars 3223 and 31G98 exposed to excess copper (Cu) were investigated. Cu treatment reduced the shoot and root length of both cultivars. No significant difference of Cu accumulation in the roots of both cultivars was observed while the cultivar 3223 accumulated significantly higher Cu in leaves than 31G98. The observed decreases in effective quantum efficiency of PSII, ETR and qP indicate an over excitation of photochemical system in 3223 compared to 31G98. The leaf chlorophyll and carotenoid contents of both cultivars decreased with increasing Cu concentration. A far higher production of anthocyanins in 31G98 has been observed than that of 3223. At 1.5 mM Cu concentration, all antioxidant enzyme activities increased in leaves of the cultivar 31G98 while there were no significant changes in SOD and GR activities in 3223 compared to the control except increased APX and POD activities. The lower Cu accumulation in leaves and higher antioxidant enzyme activities in 31G98 suggested an enhanced tolerance capacity of this cultivar to protect the plant from oxidative damage.  相似文献   

17.

Industry is one of the main activities in the city and in many cities of the world, and the dominant industrial zones are the most significant morphological forms of concentration of industrial facilities in the city and are concentrated industrial and business activity. Industrial parks combine activities related to energy and resource consumption, emissions, waste generation, economic benefits, and regional development. The focus of this work is the path of transformation between the present and the vision of a sustainable city in the future. The problem and the subject of research related to two related objects of research: the city and sustainable development. In this paper, the co-author’s industrial symbiosis parks, modern tendencies of the spatial distribution of productive activities, circular economy, to attract leading corporations and open the way for new ventures while preserving the living environment in an urban area.

  相似文献   

18.
The aim of the experiment was to study the influence of acrylamide (ACR) on major antioxidants in the lungs of Swiss mice. The experiment was conducted on male mice that were 8 weeks old. The mice were exposed to ACR at a single dose of 26 µg per animal, which was administered orally. Mice were anesthetized 3, 24, and 48 h after the ACR gavage. Next, histopathological and biochemical analyses of GSH concentration and the activities of SOD, GPx, and CAT were performed in the lungs. Animals exposed to ACR showed demonstrated symptoms of inflammation in lungs, hypertrophy of bronchiolar epithelium, and hyperplasia of alveolar epithelium. GSH concentration was significantly decreased 3 h after ACR gavage, which was followed by a significant increase 48 h after ACR gavage. Similarly, SOD and GPx demonstrated decreased activities 3 h after exposure to ACR, followed by increased activities 48 h after exposure to ACR. CAT activity was significantly increased 24 and 48 h after exposure to ACR. We conclude that oral exposure of mice to ACR results in alterations of lung microstructure, accompanied by the symptoms of redox imbalance.  相似文献   

19.
Hepatic MFO components (cytochrome P-450, cytochrome b(5), and ethoxyresorufin O-deethylase, EROD) were measured in brown bullheads (Ictalurus nebulosus) inhabiting a creek receiving a complex mixture of organics and trace metals. The activities of these same enzymes were also measured in bullheads from an uncontaminated reference site to assess the relative ability of MFO parameters to serve as a biomarker of aquatic pollution. Bullheads analyzed from the polluted site had lower hepatic microsomal P-450 (p < 0.01) concentrations and similar EROD activities per mg protein as compared to bullheads from the reference site. However, analysis of enzyme turnover ratios revealed greater EROD activity per mg cytochrome P-450 (p < 0.05) in the fish from the polluted site. No difference in cytochrome b(5) activities were observed between the two groups. As compared to the reference site, bullheads collected from the polluted creek had an increased occurrence of lip and lower jaw lesions and liver damage, including elevated liver/body weight ratios. Accordingly, the monooxygenase activities measured in this study were not reliable indicators of chemical pollution or contaminant stress in bullheads in the polluted creek. Further research is needed concerning contaminant interactions, particularly among organic pollutants and metals and their effects on monooxygenase activities.  相似文献   

20.
The extent of pollution of the environment as a result of mining activities in Kabwe, the provincial capital of Central province in Zambia has not yet been evaluated. Mining of lead and zinc were the core activities of Kabwe mine while cadmium and silver were produced as by-products. The smelting processes produced a significant amount of copper. The spatial distribution of four heavy metals in soils in the northern, eastern, southern and western directions of the mine was analyzed using atomic absorption spectrometry (AAS). Samples were collected up to 20 km in each direction from the mine. Results were consistent with the wind flow patterns in the town. Results ranged between 0.08 and 28 mg kg(-1) (Cd); 0.20 and 0.61 mg kg(-1) (Cu); 0.10 and 758 mg kg(-1) (Pb) and 0.40 and 234 mg kg(-1) (Zn) suggesting high precipitation of metals from the core mining activities. These concentrations were for only the fractions of metals extractable by 0.5M nitric acid and that could be available for plant uptake in the environment. The distribution of metals indicated a decrease of metal concentrations with distance from the mine, which confirmed that precipitation due to mining activities was the main cause of soil contamination.  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