Cultured human-cell-based bioassay for environmental risk management

Among bioassays for evaluating various impacts of chemicalson humans and ecosystems, those based on culturedmammalian-cells can best predict acute lethal toxicity to humans. Weexpect them to be employed in the future in environmentalrisk management alongside mutagenicity tests and endocrine-disrupting activity tests. We recently developed adisposable bioassay device that immobilizes humanhepatocarcinoma cells in a small micropipette tip. Thisenables very quick (within 2 h) evaluation of acute lethaltoxicity to humans. For bioassay-based environmentalmanagement, 2 promising approaches have been demonstrated bythe US-EPA: toxicity identification evaluation (TIE) andtoxicity reduction evaluation (TRE). The Japanese Ministryof Environment has been supporting a multi-center validationproject, aimed at assembling a bioassay database. To makefull use of these resources, we present a numerical modelthat describes contribution of individual chemical toobserved toxicity. This will allow the selection of the mosteffective countermeasure to reduce the toxicity. Bioassay-based environmental risk management works retrospectively,whereas impact assessment using substance flow models andtoxicity databases works prospective. We expect that these 2approaches will exchange information, act complementarily,and work effectively in keeping our environment healthy inthe 21st century.     

CADMIUM ACCUMULATION AND TOXICITY IN SUBMERGED PLANT HYDRILLA VERTICILLATA (l.f.) ROYLE

Cadmium accumulation and its toxicity in relation tochlorophyll, protein, cysteine contents and in vivo nitrate reductaseactivity were studied under controlled conditions in Hydrillaverticillata, a submerged commonly occurring macrophyte. Plants weresubjected to six different concentrations of Cd ranging from 1.0 to 25.0 µM for 24, 48, 72 and 168 h. Tissue Cd concentration was maximum (13.71 µmoles/g dw) at 25 µM background concentration. At this concentration, a decrease of approximately 79 and 72% was found in chlorophyll and protein content. In vivo nitrate reductase activity was stimulated at 1.0 µM; however, the activity gradually declined beyond this concentration. Exposure to various cadmium concentrations resulted in an increase in cysteine content of the plant.     

Determination of Toxic Pollutants in Water Using A Marine Phytoplankton Dunaliella Bioculata and Doppler Laser Velocimetry

This paper reports an experimental study of the response of the unicellular flagellated algae Dunaliella bioculata to toxic pollutants in water using the 'Doppler laser velocimetry' method. the response to toxic pollutants was encouraging and indicates that Dunaliella bioculata is a good biological model for the detection of toxic pollutants in water.     

应用重组孕激素基因酵母测定饮用水中内分泌干扰物的方法

研究了用重组孕激素受体基因酵母测定饮用水中内分泌干扰物的方法,并利用该种方法检测了南方某水厂不同处理工艺过程水样对孕激素受体活性的抑制水平.结果表明,重组孕激素受体基因酵母能够与孕激素专一性的结合,诱导产生明显的剂量-效应关系,EC₅₀值为0.5 nmol/L,具有较高灵敏度;环境内分泌干扰物五氯酚和壬基酚具有孕激素受体抑制活性,其IC₅₀值分别为2.4μmol/L和3.7μmol/L;重组孕激素受体基因/报道基因的酵母技术是一种筛选和定量分析具有孕激素受体抑制活性的内分泌干扰物的快速、有效方法.结合固相萃取的前处理技术,重组孕激素受体基因酵母对水厂不同处理工艺水样检测出明显的孕激素受体抑制活性,抑制率均大于58%,表明重组孕激素受体基因酵母检测技术能够快速监测和鉴别水样中具有抑制孕激素受体活性的物质.     

The use of the tergal gland defensive secretion in male intrasexual aggression of the rove beetle,Aleochara curtula (Coleoptera: Staphylinidae), measured by closed-loop-stripping-analyses and tandem bioassay — mass fragmentography

Summary 2-methyl-1,4-benzoquinone as a target compound of the tergal gland secretion of the rove beetle,Aleochara curtula, was quantified from the reservoirs of individual beetles. Males store less secretion than females, and they evaporate more of the secretion as measured by adsorption from the air (closed-loop-stripping-analysis). The amount of emitted quinone is increased during aggressive interactions of rival males. The pulsed emission of the secretion during aggression is demonstrated by a novel technique combining observation of behavior with the on-line measurement of target fragment ions by mass-spectrometry (tandem bioassay — mass fragmentography). The emission of the secretion is used as a weapon in combats between males and may result in the repulsion of subordinate males from the mating site, but may also serve to mimic females chemically in order to avoid aggressive encounters.     

Contaminated sediments and bioassay responses of three macroinvertebrates, the midge larva Chironomus riparius, the water louse Asellus aquaticus and the mayfly nymph Ephoron virgo

Bioassays are widely used to estimate ecological risks of contaminated sediments. We compared the results of three whole sediment bioassays, using the midge larva Chironomus riparius, the water louse Asellus aquaticus, and the mayfly nymph Ephoron virgo. We used sediments from sixteen locations in the Dutch Rhine-Meuse Delta that differed in level of contamination. Previously developed protocols for each bioassay were followed, which differed in sediment pretreatment, replication, and food availability. The Chironomus bioassay was conducted in situ, whereas the other two were conducted in the laboratory. The measured endpoints, survival and growth, were related to contaminant levels in the sediment and to food quantity in water and sediment.

Only the response of A. aquaticus in the bioassay was correlated with sediment contamination. Food availability in overlying water was much more important for C. riparius and E. virgo, thereby masking potential sediment contaminant effects. We conclude that growth of A. aquaticus was depressed by sediment contamination, whereas growth of E. virgo and C. riparius was stimulated by seston food quantity. We discuss that the trophic state of the ecosystem largely affects the ecological risks of contaminated sediments.     

城市污水石灰法深度处理工艺中有毒物质的变化规律

分别采用7-乙氧基异酚恶唑酮．脱乙基酶（EROD）活性测定法，重组人激素受体基因的酵母测试和Q67发光菌试验方法，对北京市某生活污水处理厂的进水、二沉出水以及经过石灰法深度处理后的出水中的类二恶英物质、类雌激素物质和急性毒性物质进行了分析。进水中的三类生物毒性效应物质中的急性毒性物质，可通过活性污泥法基本去除，而对类雌激素物质和类二恶英物质的去除率分别为76％和52％。经过石灰沉淀法的深度处理后，可使上述两类物质的总去除率达到95％和68％。出水中的雌激素当量水平与欧洲国家污水处理厂出水水平相当，而类二恶英物质的总浓度低于美国EPA饮用水中二恶英的最大允许浓度。展示了生物毒性测试方法在排水生态风险和工艺评价方面的应用潜力。     

利用EROD生物测试法快速筛选二噁类化合物

环境样品采集于湖北省鸭儿湖地区。每一样品分作两份,一份用于高分辨色质联用多离子检测法测定,另一份样品的提取液经多层色谱净化后再用7－乙氧基－异吩　唑酮－脱乙基酶（EROD）活力诱导法进行生物测试。PCDDs/PCDF＿s和PCB＿s总的TCDD毒性等价指数（TEQ＿s）最高,分别为1090ng/kg和996ng/kg。说明湖中二　　类化合物来源于附近化工厂有机氯生产排放的污水。同时,周围农田中发现的二　　类化合物数量少得多。这些化合物可能是来自于污水灌溉或大气尘降。在本研究中,EROD生物测试法具有良好的剂量效应关系,适合于对环境样品中的二　　类化合物进行快速定量筛选,而HRGC/HRMS－MID对生物测试所获得的数据作了进一步确认。     

水中五氯酚钠对发光细菌毒性测定的影响因素

应用发光细菌检测法,考察了不同的影响因素对水体中典型的有机污染物五氯酚钠的生物毒性测定结果的影响.结果表明,五氯酚钠对发光细菌的EC₅₀值随着pH值和硬度的增加而增加;五氯酚钠的15 min EC₅₀和20 min EC₅₀基本相符;与水体中相同浓度的常规有机污染物相比,五氯酚钠表现出更强的毒性,实验中常规有机污染物的存在对五氯酚钠毒性测定的结果影响较小.原水毒性检测实验显示一定毒性(相对发光率降低14%),原水水质对测定结果影响程度与去离子水相似.     

Occupational exposures,delivered doses and exposure limits for chromium and nickel†

The interaction of HCH (50 mg/kg) and dietary protein levels on microsomal drug metabolizing enzymes system and liver lipids were studied in the rats for 90 days. The results indicated that rats fed a lower protein diet and HCH has a higher rate of mortality, lower rate of growth and an increased liver weight. A significant induction in the hepatic microsomal aminopyrine‐N‐demethylase, p‐nitroanisole‐O‐dealkylase, benzo(a)pyrene hydroxylase and glutathione‐S‐transferase activity was observed in pesticide treated animals as compared to control animals. The pathological changes observed in liver of HCH treated animals consisted mainly of necrosis and fatty degeneration of hepatocytes. HCH also induced the significant accumulation of cholesterol, triglycerides, phospholipid and total lipid in liver in low protein diet animals. Protein accelerates the metabolism of HCH, resulting in a decrease of HCH concentration with the increase of dietary protein level. A close correlation existed between lipid accumulation, induction of drug metabolizing enzyme system and deposition of HCH in liver.