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991.
IntroductionWiththeincreasingvarietiesandquantitiesofdyesenteringintotheenvironment,dyes,asanimportanttypeofpollutants,haveanadverseeffectonwater soil plantsystems ,accordingtosomeexperimentalresults(Cheng ,inpress) .IntheeasternChina ,industrialwastewaterf…  相似文献   
992.
实验室培养的端足类日本大螯蜚F1代对Cd的急性毒性响应   总被引:1,自引:0,他引:1  
通过将实验室20℃恒温培养端足类日本大螯蜚(Grandidierella japonica)F1代个体暴露于重金属Cd加标海水中的方法,获取日本大螯蜚1周、2周、3周及4周发育阶段的24 h、48 h、72 h、96 h和10 d的死亡率,并求其各时间的半致死浓度(LC50).实验表明,端足类日本大螯蜚F1代个体对Cd的毒理敏感性较好,但略差于野生自然个体,不同发育阶段半致死浓度不存在很大的差异,2周龄个体最适宜用于毒性检验试验.  相似文献   
993.
6种含氮杂环化合物对发光细菌的毒性研究   总被引:15,自引:0,他引:15  
研究了吲哚,吡啶,喹啉,异喹啉、2-甲基喹啉和8-羟基喹啉6种含氮杂环化合物对发光细菌的急性毒性作用及上述物质两两混合对发光细菌的联合毒性作用。结果表明,上述物质对发光细菌的EC50分别为11.75、591.50、24.30、8.24、52.26和0.88mg/L,毒性由强至弱依次为8-羟基喹啉、异喹啉、吲哚、喹啉、2-甲基喹、吡啶。所有物质两两混合的联合毒性作用均表现为相加作用。  相似文献   
994.
麻痹性贝毒素的毒理效应及检测技术   总被引:8,自引:0,他引:8  
近年来世界各地,特别是我国浙江、广东等沿海地区赤潮发生过度频繁,许多赤潮生物分泌的毒素不但使其他海洋生物中毒,更会对人类健康造成潜在的危害。因此对赤潮毒素的研究已成为海洋环境科学研究的重要内容。麻痹性贝毒素是其中重要的一类赤潮藻毒素。它们毒性大,作用强,在全球的分布越来越广泛,并且已经在世界范围内造成了严重的危害,引起了国内外科学家的高度重视。本文详细综述了近年来国外在麻痹性贝毒素检测技术方面最新的研究进展,重点介绍了麻痹性贝毒素的化学结构、前处理技术和分析检测新技术及其毒性作用机理。  相似文献   
995.
Whether the multi-biological toxicity from lead exposure could be transferred to progeny has not been clarified.In the present study,we explored the Caenorhabditis elegans to analyze the multiple toxicities from lead exposure and their possibly transferable properties.The lead exposure could cause series of severe multi-biological defects with a concentration-dependent manner by affecting the endpoints of life span,development,reproduction and locomotion behaviors in nematodes.Moreover,most of these toxicities could be transferred to progeny from lead exposed animals and some of the defects in progeny appeared even more severe than in their parents,such as the body sizes and mean life spans.We summarized the defects caused by lead exposure into three groups according to their transferable properties or rescue patterns.That is,the defects caused by lead exposure could be largely,or partially,or became even more severe in progeny animals.Therefore,our results suggest that lead exposure can cause severely multi-biological defects,and most of these multiple toxicities can be considered as transferable for exposed animals in C.elegans.  相似文献   
996.
四种藻类植物对镍的耐受性及其中毒的变化   总被引:3,自引:0,他引:3  
四种纯种培养的藻类植物对镍离子的耐受性不同。衣藻属(Chlamydomonas sp.)可耐受10ppm的镍;栅列藻属(Scenedesmus sp.)5ppm;颤藻属(Oscillatoria sp.)1ppm;聚球藻属(Synechococcus sp.)0.02ppm。受试的两种绿藻比蓝纯菌(蓝藻类,Cyanobacteria)对镍离子毒性的抗性大得多。本文还报道了影响这些藻类对镍的敏感性和抗性的某些环境因素,并阐明了一些抗性的机制。  相似文献   
997.
Aluminium (Al) is a key element in critical loadcalculations for forest. Here, we argue for re-evaluating theimportance of Al. Effects of two levels of enhanced Alconcentrations and lowered Ca:Al ratios in the soil solutionin a field manipulation experiment in a mature spruce stand(1996–1999) on tree vitality parameters were tested. Inaddition, Al solubility controls were tested. Various loads ofAl were added to forest plots by means of an irrigationsystem. Potentially toxic Al concentrations and criticalratios of Ca to inorganic Al were established. The ratio of Cato total Al was not a suitable indicator for unfavourableconditions for plant growth. No significant effects on crowncondition, tree growth and fine root production were observedafter three years of treatment. In 1999, foliar Mg content inthe highest Al addition treatment had declined significantly.This agreed with the known response to Al stress of seedlingsin nutrient solution experiments. No support was found forusing the chemical criterion Ca:Al ratio in soil solution,foliar and root tissue as an indicator for forest damage dueto acidification. Al solubility was considerably lower thanimplied by the assumption of equilibrium with gibbsite,particularly in the root zone. The gibbsite equilibrium iscommonly used in critical load models. Substitution of thegibbsite equilibrium with an Al-organic matter complexationmodel to describe Al solubility in soil water may have largeconsequences for calculation of critical loads. The resultsindicate that critical load maps for forests should bereconsidered.  相似文献   
998.
The shallow Fairmont Lakes in southern Minnesota have been treated with copper sulfate for 58 years to reduce excessive algal growth. Copper sulfate was applied to five lakes at cumulative rates upo to 1647 kg/ha (1470 1b/acre), totaling 1.5 million kilograms. Data collected since treatment of the Fairmont Lakes began in 1921 provide alarming insights into lake responses to sustained chemical treatment with copper sulfate. Short-term and long-term effects have occurred. Short-term effects include: a) the intended temporary killing of algae, b) dissolved oxygen depletion by decomposition of dead algae, c) accelerated phosphorus recycling from the lake bed and recovery of the algal population within 7 to 21 days, and d) occasional fish kills due to oxygen depletion or copper toxicity or both. Long-term effects are shown to include: a) copper accumulation in the sediments, b) tolerance adjustments of certain species of algae to higher copper sulfate dosages, c) shift of species from green to blue-green algae and from game fish to rough fish, d) disappearance of macrophytes, and e) reductions in benthic macroinvertebrates. The conclusion is that while copper sulfate treatments enjoy great popularity because they kill and remove algae almost instantaneously, other immediate or cumulative side effects can be harmful to many other aquatic organisms.  相似文献   
999.
ABSTRACT: Current procedures for setting site-specific water quality criteria consider abiotic and biotic factors. Suspended solids were shown to be important in reducing zinc toxicity to water column organisms. At zinc concentrations of ~ 1 mg/L in solutions with < 100 mg/L of all suspended solids tested, zinc toxicity to D. magna was reduced. Sorption of zinc to suspended solids and/or changes in water chemistry due to the addition of suspended solids appear to have been the factors causing reductions in zinc toxicity to D. magna. Only suspended solids levels of 483–734 mg/L of a type that increased total alkalinity, total hardness, and total dissolved carbon clearly reduced the toxicity of ~ 20 mg/L zinc to P. promelas. The toxic form of zinc to these organisms appears to reside in the aqueous phase. Characteristics of suspended solids did not influence the partition coefficient of zinc in sorption experiments of 96 h. The slopes of dose-response curves proved to be useful for assessing the potential of an organism to respond to changes in aqueous phase zinc concentrations, and may be a useful biological parameter when considering site-specific water quality criteria for chemicals.  相似文献   
1000.
ABSTRACT Picric acid (2,4,6-trinitrophenol) and picramic acid (2-amino-4,6-dinitrophenol) are potential water pollutents due to a variety of industrial and munition uses. The possible impacts of picric and picramic acid to two recreationally and commercially important species, rainbow trout, Salmo gairdneri, and American oysters, Crassostrea virginica, were evaluated. Picramic acid was more toxic than picric acid to both species tested. The 96-h LC50s for picric and picramic acids for rainbow trout were 109.6 and 46.2 mg/1, respectively. The 144-h LC50s for picric and picramic acid for American oysters were 254.9 and 69.8 mg/1, respectively. Sublethal no growth EC50s and shell deposition EC50s for oysters showed that both compounds caused adverse effects at much lower concentrations than indicated by the LC50s. For example, the 144-h shell deposition EC50s were 27.9 mg/1 for picric acid and 5.6 mg/1 for picramic acid. Sediment adsorbtion studies in estuarine water indicated that both compounds are not readily adsorbed which suggests that sediment would not play a major role as a sink in contaminated systems. Oysters, which filter large quantities of particulate matter, would more likely be affected by picric and picramic acids in the water column than by exposure to contaminated sediment.  相似文献   
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