西流湖水体藻类污染现状和产毒蓝藻的全细胞PCR检测

目的了解西流湖水体浮游藻类尤其是产毒蓝藻的污染现状,并建立全细胞PCR检测产毒蓝藻的方法。方法从2004年3月开始,采集西流湖水体表层水样,用血细胞计数板法计数藻细胞;设计特异引物,采用全细胞PCR方法检测水样中藻青蛋白基因中间序列(PC-IGS)和微囊藻毒素多肽合成酶基因mcyB,并对mcyB扩增产物克隆测序。结果西流湖水体藻类主要是蓝藻、绿藻、硅藻和裸藻,夏秋季蓝藻为优势藻门;2004年7月7日~9月27日水样PC-IGS序列PCR检测阳性,7月29日~9月27日水样mcyB基因PCR检测阳性,扩增片断mcyB测序结果与Genbank报道的铜绿微囊藻mcyB同源性大于97%,氨基酸序列同源性大于94%。结论西流湖夏秋季有产毒蓝藻出现,全细胞PCR法可以检测水体中产毒蓝藻。     

微囊藻 毒素的污染现状，毒性机理和检测方法

1　引言藻类植物在自然界中分布广泛 ,生态习性多种多样。蓝藻(亦称蓝绿藻 )是一种普遍存在于自然水体中的一类有色素、营自养生活的浮游藻类。近年来由于人类生产、生活过程中大量工业废水、生活污水排放 ,使得水体急剧富营养化 ,每年夏秋季节在一些淡水湖泊、河流中常可见到大规模的水华现象 ,水质感观性状恶化 ,严重影响居民生活和经济发展。蓝藻是目前已知产生毒素最多、对人类健康造成的危害最大的藻类。微囊藻毒素 (ｍｉｃｒｏｃｙｓｔｉｎｓ ,ＭＣｓ)就是由蓝藻门中铜绿微囊藻、水华鱼腥藻、颤藻、念珠藻、束丝藻等产生的一类肝脏毒…     

黄河花园口某调蓄池产毒微囊藻和微囊藻毒素污染监测

目的了解黄河花园口某调蓄池浮游藻类、蓝藻、产毒微囊藻和微囊藻毒素污染情况。方法从2005年3月～2006年1月,用2.5L有机玻璃采水器在该调蓄池共采样15次。采用血细胞计数板法计数浮游藻类细胞密度,用全细胞PCR检测产毒微囊藻的藻青蛋白基因中间序列和微囊藻毒素合成酶基因,用ELISA法检测水体微囊藻毒素浓度,并对全细胞PCR和ELISA阳性结果进行比较。结果该调蓄池浮游藻类主要是硅藻、绿藻、蓝藻和裸藻,其他藻类较少;优势藻门有随季节变化逐渐演替的规律,总藻细胞密度和蓝藻细胞密度夏秋季较高。藻青蛋白基因中间序列和微囊藻毒素合成酶基因从2005年7月至11月PCR检测结果阳性;微囊藻毒素从6月份开始检出,其变化范围在0～0.251μg/L之间,夏季最高;全细胞PCR与ELISA的阳性结果没有差异。结论黄河花园口某调蓄池有产毒微囊藻和微囊藻毒素污染,全细胞PCR可以用于自然水体中产毒微囊藻的快速检测。     

高效液相色谱法/液相色谱-质谱法在微囊藻毒素检测中的应用进展

生活及工农业生产中含有大量氮、磷的废污水进入水体后,藻类大量繁殖,其中微囊藻属、鱼腥藻属、颤藻属、念珠藻属等代谢产生的微囊藻毒素(Microcystin,MC)是淡水水体藻毒素污染中范围最广、危害最严重的藻毒素[1]。近20年来,我国湖泊水库富营养化发展迅速,滇池、太湖、武汉东湖、云南     

水环境中微囊藻毒素检测技术研究进展

微囊藻毒素主要是由蓝绿藻产生的一类毒素,是淡水水体污染范围最广的一类藻毒素。随着水体受藻类毒素污染频度的增加,微囊藻毒素受关注的程度亦日渐加大,对自然水体中微囊藻毒素的检测和控制也变得越来越重要,而检测更是控制的基础。选择一种快速、经济、敏感的检测水环境中微囊藻毒素的方法已必不可少。笔者较详细地综述了目前国内外微囊藻毒素的各种检测方法及其成果,指出了其优缺点,并在此基础上,展望了自然水体中微囊藻毒素检测方法的发展方向。     

蓝藻毒素健康危害研究进展

由于生活性及工业性污染日趋加重,使许多水体富营养化而导致发生藻类水华现已成为全球性环境问题〔1〕,藻类毒素对健康的损害越来越受到关注。本文就蓝藻毒素健康危害研究进展作一综述。1　概述藻类是一群具有色素、营自养生活的低等植物,蓝藻是其中一门,且是已知产生毒素最多门类。微囊藻毒素(ｍｉｃｒｏｃｙｓｔｉｎ下简称ＭＣ)是一组由水体中蓝绿藻如微囊藻、鱼腥藻、颤藻及念珠藻产生的具有亲肝特性的环状多肽毒素〔2〕,目前已发现有50多种异构体。该毒素耐热,自来水的凝聚沉淀、过滤加氯都不能破坏,另外在水生生物中可富集。在ＭＣ中均…     

武汉市农村地区饮用水藻类污染状况调查

目的了解武汉市农村地区饮用水藻类污染状况。方法以武汉市郊黄陂、蔡甸两个区的饮用水为样本,鉴定种类,藻类计数和测定微囊藻毒素,并与同期汉江水厂,长江水厂及东湖水水样做对比分析。结果武汉市农村地区饮用水中的藻类分布以绿藻和硅藻为主,蓝藻次之,但有微囊藻、颤藻等可能产毒的种类检出,藻类数量远高于长江水和汉江水,此次调查微囊藻毒素均未超过现有标准规定的1.0μg/L。结论农村的水质状况较差,应积极开展农村饮用水藻类污染监测。     

淡水产品中微囊藻毒素富集及其危害

随着社会工业化进程的加快,人类在工农业生产及日常生活中,向水体排入大量的含氮、磷污染物,使水体富营养化,进而导致蓝藻水华大面积频繁爆发。淡水中蓝绿藻属分泌产生的蓝藻毒素是目前已经发现的污染范围最广、研究最多的一类藻毒素。其中的微囊藻毒素(microcystins,MCs)作为蓝藻最主要的次生代谢产物,分布广泛、毒性较大且危害最为严重〔1〕。由于MCs的稳定性,使其可富集于鱼类或贝类并     

上海淀山湖、黄浦江水系浮游藻类及藻类毒素的动态研究

通过对淀山湖、黄浦江水系浮游藻类的种群构成和蓝藻毒素的季节变化进行周年监测，发现淀山湖藻类及其毒素的污染具有明显的季节性，７～９月份蓝藻大量繁殖，形成了一年中污染的高峰。优势种群已由隐藻被毒性较高的蓝藻所取代，而蓝藻中占优势的铜绿微囊藻、水华鱼腥藻等能产生一种具有强烈肝毒性的短肽，称为微囊藻毒素。应用ＥＬＩＳＡ方法对淀山湖水中的微囊藻毒素进行测定，结果表明水体中微囊藻毒素与蓝藻的变化规律呈正相关，夏、秋季水中毒素出现高峰，最高值达５５．４ｎｇ／ｍｌ，说明淀山湖藻类毒素的污染较为严重。通过对水体总磷、总氮、叶绿素ａ、ｐＨ值等因素的分析，讨论了影响该水系营养水平和藻类生长的主要因素。     

郑州市主要生活饮用水源微囊藻细胞毒素特征分析

目的分析郑州市主要生活饮用水源微囊藻细胞毒素特征。方法以西流湖和黄河花园口段某调蓄池作为调查现场,采用96孔板结和极限稀释法对采集藻细胞进行分离纯化;应用全细胞PCR方法检测所分离微囊藻细胞株藻青蛋白基因中间序列(PC-IGS)和微囊藻毒素多肽合成酶基因B(mcyB),并对提取毒素应用固相萃取(SPE)高效液相色谱(HPLC)法进行检测。结果自西流湖分离的XLH细胞株和黄河花园口调蓄池分离的2株微囊藻细胞BM1、BM2,PC-IGS、mcyB基因扩增均为阳性;mcyB基因序列测定结果与Genbank中报道的mcy基因同源性达99%;HPLC检测3株藻细胞所含毒素异构体主要为MC-LR,占毒素总量的质量百分比分别为97.9%、98.6%和99.3%。结论自郑州市主要生活饮用水源分离的3株微囊藻细胞均为产毒株,产生毒素异构体主要为毒性较大的MC-LR。     

螺旋藻类保健食品生产原料及产品中微囊藻毒素污染现状调查

为了观察微囊藻毒素对螺旋藻类保健食品的污染状况 ,于 2 0 0 2年 7～ 8月份对江苏、云南、福建和广东我国主要螺旋藻生产基地的 33份水源水、1 60份养殖用水、86份螺旋藻浆、70份螺旋藻原料粉进行了微囊藻毒素的测定 ,同时随机采集了上述四省的 1 9种 71份市售螺旋藻产品 ,用ELISA法对样品的微囊藻毒素进行测定。结果提示 :水源水中的 1 2份自来水样中均未检测出微囊藻毒素 ,9份地下水样中有 6份、1 2份地表水样中有 8份检测出不同污染水平的微囊藻毒素 ;1 60份螺旋藻养殖场池水和 86份螺旋藻浆中的微囊藻毒素平均污染水平分别是 2 0 7 9pg ml和 31 9ng g ,两者相差 1 53倍 ;70份螺旋藻原料粉中的微囊藻毒素平均污染水平是 2 0 6 4ng g;1 9种 71份市售螺旋藻产品中总微囊藻毒素污染水平平均为 31 7 2ng g,其中主要剂型是片剂和胶囊 ,片剂和胶囊中的微囊藻毒素污染平均水平分别为 1 4 2 7ng g和 2 2 2 6ng g。提示螺旋藻生产过程和市售产品中均有不同程度的微囊藻毒素污染 ,通过服用螺旋藻而摄入的微囊藻毒素对人类健康的影响不可忽视 ,有必要进行深入研究 ,制定符合我国特点的藻类保健食品中微囊藻毒素限量标准     

Cyanobakterientoxine bei der Uferfiltration

Cyanobacterial toxins are substances produced by cyanobacteria or blue-green algae. They can occur in surface waters worldwide and have to be reliably removed when using affected surface waters as a drinking water source. Bank filtration has been used for 150 years for drinking water (pre-)treatment. It utilizes natural elimination processes like sorption and degradation in the sub-surface. Retention of cells on the sediment surface is the most prominent process for eliminating these primarily cell-bound toxins. Middle to coarse grained sands eliminated more than 99.9 % of intracellular toxins within the first 10 cm of flow path. Elimination of extracellular microcystin during underground passage is mainly due to biodegradation. Reversible adsorption processes do not reduce the total load but lead to longer contact times for extended biodegradation. Laboratory experiments showed that the sediment structure, i.e. high clay/silt and organic content, is crucial for maximum adsorption. However, redox conditions play an important role for degradation rates: under aerobic conditions half-lives of less than one day occurred frequently, whereas anoxic conditions resulted in lag phases of one day and more, as well as in half lives of more than 25 days. Field experiments showed that temperature is crucial for degradation velocity under natural conditions.Under optimal conditions 10 d residence time are sufficient to reduce microcystin concentrations to values below the WHO guidelines value for drinking water (1 microg/L). Under sub-optimal conditions a residence time of up to 90 days may be necessary.     

无锡太湖水域藻类毒素污染与人群健康关系研究

[目的 ]　揭示无锡太湖水域藻类毒素污染现状 ,初步探讨微囊藻毒素 (Microcystin ,MC)对人群肝脏酶影响和与消化道恶性肿瘤死亡率的关系。　 [方法 ]　设暴露组和非暴露组 ,调查水样和鱼样MC含量及消化道肿瘤死亡率。　 [结果 ]　水样总的阳性率为 2 9.35 %,均值为 14 13.0 2pg/mL ,太湖水阳性率最高为 10 0 %,深井水最安全。 7种鱼类MC阳性率为 10 0 %,肝脏中MC均值高于肌肉 ,分别为 2 8.8ng/ g和 4.0ng/ g。肝脏酶指标GGT和AP暴露组高于非暴露组 ,差异有极显著性 (P <0 .0 1)。随着水中MC暴露等级的升高 ,男性各部位合计肿瘤标化死亡率也升高 ,而女性不明显。　 [结论 ]　无锡太湖水域MC污染严重 ,常规水处理不能将毒素完全去除 ,MC污染饮水—湖中生物—动物链状危险确已存在 ,对人群健康已构成一定威胁 ,必须引起重视。     

Microcystin-producing blooms--a serious global public health issue

The investigation on microcystin topics is increasing due to the related ecological and public health risks. Recent investigation confirms a gap in establishing global patterns relating a particular environment to the bloom occurrence of a species and the production of certain microcystin variants. All the results concerning the environmental effects on the microcystin synthesis of one species must be checked in the light of genome diversity. Thus, the poisoning risks of a bloom depend on the strain causing toxicity. To be more effective, specific water treatment methods are required for blooms of different microcystin producing species (such as colonial and filamentous cyanobacteria found in stratified and unstratified water bodies, respectively). With the increasing number of new microcystin variants discovered, the development of new rapid, inexpensive and sensitive enough monitoring methods to promptly screen simultaneously a great diversity of toxins and also check their toxic effects is becoming necessary.     

Effects of nonylphenol on the growth and microcystin production of Microcystis strains

Both organic pollution and eutrophication are prominent environmental issues concerning water pollution in the world. It is important to reveal the effects of organic pollutants on algal growth and toxin production for assessing ecological risk of organic pollution. Since nonylphenol (NP) is a kind of persistent organic pollutant with endocrine disruptive effect which exists ubiquitously in environments, NP was selected as test compound in our study to study the relationship between NP stress and Microcystis growth and microcystin production. Our study showed that responses of toxic and nontoxic Microcystis aeruginosa to NP stress were obviously different. The growth inhibition test with NP on M. aeruginosa yielded effect concentrations E(b)C(50) values within this range of 0.67-2.96 mg/L. The nontoxic M.aeruginosa strains were more resistant to NP than toxic strains at concentration above 1mg/L. Cell growth was enhanced by 0.02-0.2 mg/L NP for both toxic and nontoxic strains, suggesting a hormesis effect of NP on M. aeruginosa. Both toxic and nontoxic strains tended to be smaller with increasing NP. But with the increased duration of the experiment, both the cell size and the growth rate began to resume, suggesting a quick adaptation of M. aeruginosa to adverse stress. NP of 0.05-0.5 mg/L significantly promoted microcystin production of toxic strain PCC7820, suggesting that NP might affect microcystin production of some toxic M. aeruginosa in the field. Our study showed that microcystin excretion was species specific that up to 75% of microcystins in PCC7820 were released into solution, whereas >99% of microcystins in 562 remained in algal cells after 12 days' incubation. NP also significantly influenced microcystin release into cultural media. The fact that NP enhanced growth and toxin production of M. aeruginosa at low concentrations of 0.02-0.5 mg/L that might be possibly found in natural freshwaters implies that low concentration of NP may favor survival of M. aeruginosa in the field and may play a subtle role in affecting cyanobacterial blooms and microcystin production in natural waters.     

A cross-sectional investigation of chronic exposure to microcystin in relationship to childhood liver damage in the Three Gorges Reservoir Region, China

Background: Microcystin-producing Microcystis bloom is a severe water problem in the world. Some reports indicate that chronic exposure to microcystin may result in liver damage in adults, but information on effects in children is limited.Objective: We investigated the relationship between microcystin exposure and liver damage in children.Methods: We measured microcystin concentrations in drinking water and aquatic food (carp and duck) from two lakes and four wells. Participants were 1,322 children 7–15 years of age who obtained drinking water from one of the tested sources, completed questionnaires, and provided blood samples for serum liver enzymes [alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and γ-glutamyltransferase (GGT)] and serum microcystin analysis. Multivariable logistic regression was used to identify risk factors associated with liver damage (two or more abnormal serum enzyme levels in ALT, AST, ALP, or GGT).Results: Microcystin was detected in most samples of water and aquatic food from two lakes. Children who drank water from the lake with the highest microcystin concentrations had a total estimated daily microcystin intake of 2.03 μg, a value much higher than the tolerable daily intake (0.40 μg) proposed by the World Health Organization for children. Hepatitis B virus (HBV) infection, use of hepatotoxic medicines, and microcystin exposure were associated with liver damage. AST and ALP levels were significantly higher in high-microcystin-exposed children than in low-exposed children and unexposed children when participants who were HBV-positive or hepatotoxic medicine users were excluded from the analysis.Conclusion: These results suggest that chronic exposure to microcystin may be associated with liver damage in children in the Three Gorges Reservoir Region.     

太湖淡水螺体内微囊藻毒素污染动态研究

目的了解太湖淡水螺体内微囊藻毒素的污染状况及其富集规律。方法实验模拟环形螺生长环境,在养殖水中添加8μg/L的微囊藻毒素,实验为期50 d,每隔10 d进行取样。同时,2011年5月和7月,采集太湖梅梁湾两个监测点的水样和环形螺,采用液质联用方法测定水样和环形螺中可食组织、不可食组织中微囊藻毒素含量。结果养殖试验中各组织均有微囊藻毒素积累,可食组织中积累量缓慢持续上升,不可食组织中毒素积累呈波浪形上升;不可食组织(最大值为9.44μg/kg)对毒素的积累能力明显大于可食组织(最大值为1.6μg/kg)。两个监测点螺蛳的可食部分和不可食部分中均检微囊藻毒素,不可食部分微囊藻毒素含量是可食部分的5.4~11.7倍。结论太湖环形螺体内存在微囊藻毒素污染,且存在富集作用。     

Health effects from radon-222 in drinking water in Algiers.

As part of a national programme, 222Rn in public water supply systems, private wells and in natural mineral waters has been measured in some locations of Algiers City. Radon concentration was determined by means of a passive method based on the use of electret ion chambers (EIC). The determination of radon concentration in the water samples consisted of sealing a known volume of water in a jar and measuring the airborne radon using an E-PERM (electret-passive environmental radon monitor) device. The radon concentrations in natural mineral waters were found to be the highest of all other water samples. It is found that the mean radon concentration of water samples was lower than the value of 11000 Bq m(-3) (11 Bq l(-1)) reported by the US Environmental Protection Agency. These investigations enabled a first estimate of the corresponding annual effective dose to the stomach and the lungs. It was observed that the annual effective dose resulting from direct consumption of water is far greater than that due to inhalation of radon emanating from tap water. Moreover, it is also shown that the annual effective dose due to inhalation of radon emanating from tap water and flushing water is negligible compared to the total annual dose for indoor radon in Algiers.