A CONFIRMATION OF MOUNT'S AUTOPSY TECHNIQUE FOR ZINC-CAUSED FISH MORTALITY1

ABSTRACT. A total of 203 bluegill sunfish (Lepornis macrochirus, Rafinesque) which had been used in several acute zinc experiments carried out under varied environmental conditions were autopsied according to Mount's procedure for determining fish mortality due to zinc poisoning. Three classes of fish were used: those exposed to but not killed by zinc; those killed by zinc; and those not exposed to zinc. Two statistical tests were used to analyze these data and both tests gave results indicating significant differences (a = .05) between all three classes of fish. This indicates that the Mount autopsy technique is very probably a valid generalization. The possibilities of using Mount's technique as a predictive tool are discussed.     

EFFECTS OF TREATED BLEACHED KRAFT MILL EFFLUENT ON EGGS AND PROLARVAE OF STRIPED BASS (MORONE SAXATILIS)1

ABSTRACT: Striped bass (Morone saxatilis) eggs and prolarvae were exposed to a range of treated bleached kraft mill effluent (BKME) concentrations from 0 to 20 percent effluent by volume (v/v) under continuous flow test conditions. The treated BKME used in the study before dilution had a BOD₅ of 18 to 25 mg/l, TSS of 60 to 185 mg/l and true color of 1750 to 1755 mg/l. No mortality attributable to BKME was found in three separate egg studies. No delayed hatching of the eggs occurred in any of the BKME treatments relative to the control treatment. No significant morphological abnormalities (pugheadness, truncation, or scoliosis) were found in prolarvae exposed to BKME from the egg stage through six days post/hatch. Tests with prolarvae revealed that BKME at concentrations from 2 to 20 percent v/v did not cause mortality during exposures up to 60 hours. However, BKME concentrations ranging between 8 to 12 percent up to 20 percent v/v caused increased mortality after 72 hours of exposure.     

二恶英类物质的生物检测方法

我国的食品卫生、环境安全和公共健康正受到二恶英污染的威胁。国内虽已建成或在建少数HRGC-HRMS二恶英检测实验室,但其检测能力十分有限。笔者介绍二恶英类化合物生物检测方法,对各分析方法的原理和应用进行了对比分析;重点探讨CALUX法,与HRGC-HRMS及其他生物法相比,认为CALUX法更适于对大批量样品二恶英含量的快速定量筛选,对于二恶英污染调查有广阔的应用前景;同时对我国开展二恶英类分析检测提出了建议和展望,为完善二恶英类物质检测分析体系提供了依据。     

高内涵筛选技术的原理及其在生态毒理学的应用

大量存在于环境中的有毒污染物仍然缺乏足够的毒理学数据来对其进行有效的监管,为了满足海量化合物毒性评价的需要,基于离体生物测试的高通量毒性筛选方法在近些年得到了迅猛的发展。高内涵筛选技术是新型的高通量化合物毒性筛选方法,该方法最显著的特点是能够在保持细胞结构和功能完整的基础上同时获取多种毒性指标。因此在简介高内涵筛选技术原理的基础上,综述了其在生态毒理学领域已有的应用,并针对性地对高内涵筛选技术的发展和挑战进行了展望。     

Leaf surface compounds of the potato (<Emphasis Type="Italic">Solanum tuberosum</Emphasis>) and their influence on Colorado potato beetle (<Emphasis Type="Italic">Leptinotarsa decemlineata</Emphasis>) feeding

Summary.  The sampling behavior of the Colorado potato beetle Leptinotarsa decemlineata Say (CPB) involves examination of the surface of potato leaves. It has been suggested that leaf surface compounds (volatiles and cuticular waxes) may be involved in host-plant recognition, acceptance or discrimination. Here we report on the effect of leaf surface extracts of six Polish commercial potato varieties on CPB feeding. We tested the influence of potato leaf surface extracts on CPB adult and larval feeding, then separated the extracts with HPLC, and finally tested the effect of the HPLC-separated fractions on CPB feeding. The bioassays were performed using potato leaf discs deprived of their original surface compounds. Applied to test discs at concentrations ten times higher than natural (10 leaf area equivalent), the extracts deterred CPB adults and larvae from feeding. HPLC-separated fractions composed of alkanes, sesquiterpene hydrocarbons, wax esters, benzoic acid esters, fatty acid methyl, ethyl, isopropyl and phenylethyl esters, aldehydes, ketones, methyl ketones, fatty acids, primary alcohols, β-amyrin and sterols did not affect adult CPB feeding. Similarly, alkanes, sesquiterpene hydrocarbons, wax esters, methyl ketones, sesquiterpene alcohols and secondary alcohols had no effect on larval CPB feeding. The sterol fraction (cholesterol, β-sitosterol and stigmasterol) acted as a phagostimulant to CPB larvae. We isolated a fraction demonstrating a phagodeterrent effect on CPB adults and larvae. The qualitative composition of the deterrent fraction was quite similar in all potato extracts, but there were quantitative differences between the varieties. Much further work is needed to identify the compounds that can produce the deterrent effect.     

Progress in herbicide determination with the thylakoid bioassay

Chloroplast thylakoids are used as biological units to determine herbicides in different kinds of water samples as well as in aqueous extracts of compost, soil or food samples. The thylakoid bioassy shows clearly inhibition of fluorescence yield in the presence of photosystem II specific herbicides. Due to this method the ecotoxicological effect of samples with unknown pollutants can be tested fast and cost effective. It has been proven that all photosynthetic active compounds are recorded at the same time because only additive interactions occur. Therefore, the contamination level can be expressed as cumulative parameter for photosystem II active substances. Application was improved clearly by the addition of the radical scavenger sodium ascorbate to the isolation media and by a higher concentration of the measuring medium. A new data evaluation method is described yielding in a lower detection limit of 0.4 μg diuron/1. The guidelines for the quality of water for human consumption with an allowable concentration of pesticides in groups is 0,5 μg/1 [1,2] and can be controlled with the thylakoid bioassay without performing any preconcentration steps.     

发光细菌毒性测试条件的优化与毒性参照物的应用

针对传统发光细菌毒性测试方法中存在的结果重现性不高、使用剧毒物质氯化汞作为毒性参照物容易造成环境污染等问题,通过一系列实验优化了发光细菌生物毒性测试的条件:适宜pH值为5 0～9 0,最佳暴露时间为20min。同时筛选出了Zn2+作为毒性参照物代替传统方法中的剧毒物质HgCl2。Zn2+具有毒性中等、结果稳定、价格便宜等诸多优点。而且Zn2+与HgCl2的毒性之间存在一定相关性:Zn2+毒性为HgCl2毒性的1 12 5。采用Zn2+作为参照物不仅可以方便地表征不同化学物质的毒性,而且可以直观地表征复杂环境样品的毒性,是一种简便可行的方法。      

Lichen microalgae are sensitive to environmental concentrations of atrazine

The identification of new organisms for environmental toxicology bioassays is currently a priority, since these tools are strongly limited by the ecological relevance of taxa used to study global change. Lichens are sensitive bioindicators of air quality and their microalgae are an untapped source for new low-cost miniaturized bioassays with ecological importance. In order to increase the availability of a wider range of taxa for bioassays, the sensitivity of two symbiotic lichen microalgae, Asterochloris erici and Trebouxia sp. TR9, to atrazine was evaluated. To achieve this goal, axenic cultures of these phycobionts in suspension were exposed to a range of environmental concentrations of the herbicide atrazine, a common water pollutant. Optical density and chlorophyll autofluorescence were used as endpoints of ecotoxicity and ecophysiology on cell suspensions. Results show that lichen microalgae show high sensitivity to very low doses of atrazine, being higher in Asterochloris erici than in Trebouxia sp. TR9. We conclude that environmental concentrations of atrazine could modify population dynamics probably through a shift in reproduction strategies of these organisms. This seminal work is a breakthrough in the use of lichen microalgae in the assessment of micropollution effects on biodiversity.     

Ecotoxicological Classification of the Berlin River System Using Bioassays in Respect to the European Water Framework Directive

Bioassays as well as biochemical responses (biomarkers) in ecosystems due to environmental stress provide us with signals (environmentally signalling) of potential damage in the environment. If these responses are perceived in this early stage in ecosystems, the eventual damage can be prevented. Once ecosystem damage has occurred, the remedial action processes for recovery could be expensive and pose certain logistical problems. Ideally, “early warning signals” in ecosystems using sensing systems of biochemical responses (biomarkers) would not only tell us the initial levels of damage, but these signals will also provide us with answers by the development of control strategies and precautionary measures in respect to the European Water Framework Directive (WFD). Clear technical guidelines or technical specifications on monitoring are necessary to establish and characterise reference conditions for use in an ecological status classification system for surface water bodies. For the Ecotoxicological Risk Assessment (ERA) of endocrine effects we used an approach of the exposure – dose – response concept. Based on the “Ecototoxicological Classification System of Sediments” that uses pT-values to classify effects in different river systems, we transferred the bio-monitoring data to the five-level ecological system of the WFD. To understand the complexity of the structure of populations and processes behind the health of populations, communities and ecosystems an ERA should establish links between natural factors, chemicals, and biological responses so as to assess causality. So, our ecological monitoring assessment has incorporated exposure & effects data.     

利用化学分析和生物测试方法比较研究污染土壤中芳烃受体效应物质的积累

长期使用污水或再生水灌溉的潜在生态风险已经引起普遍关注,但是少有研究持久性有机有毒物质在土壤中积累所产生的慢性毒性.采用7-乙氧基-异吩唑酮-脱乙基酶(EROD)方法测试了北京郊区某再生水灌溉土壤中的芳烃受体效应物质,并用2,3,7,8-TCDD标定出相应的二英毒性当量(TEQ_bio).同时利用化学分析得到的土壤中16种多环芳烃(PAHs)的含量,根据文献报道毒性当量因子(TEF)换算成二英的毒性当量(TEQ_PAHs).分析生物测试的结果,发现灌溉土壤中芳烃受体