单甲脒在水生生物中的积累和释放

本文朱生环境中对单甲脒在鱼和藻类中的积累释放及鱼体中的ＢＣＦ值进行了研究，结果表明，鱼体在３，５，６ｄ的ＢＣＦ值分别为３．５３，４．７３及５．２９，鱼体中单米积累为内脏〉锶〉肌肉，饲养７ｄ达积累最高量；藻类在６ｈ后达积累最高量；单甲脒在水藻和鱼（内脏）的富集比分别为１：３及１：１２。     

多效唑在大型溞体内富集与释放行为

本文探讨了大型在含藻（系统Ａ）和不含藻（系统Ｂ）水体内，对￣３Ｈ多效唑的生物富集以及释放行为。用药物动力学模型分析了多效唑在大型－水体之间的转移。结果表明：在实验初期，由于大型对小球藻的摄食作用，大型在系统Ａ的生物富集系数显著大于系统Ｂ，存在生物放大作用。而在实验后期，两个系统中大型对多效唑的生物富集系数趋于相近。多效唑在大型体内的释放行为符合一级动力学过程，半衰期为６ｈ．实验结束后，多效唑在大型体内的残留量占总量的２０％。     

重金属Cu,Pb,Zn,Cr,Cd在水稻植株中的富集和分布

研究了外源可溶性重金属进入水稻土环境后，在水稻植株中的迁移、在水稻植株不同部位的分布及其分布随时间的变化。在水稻生长季节，重金属在水稻植株中迁移能力的大小依次为：Cd,Cr＞Zn,Cu＞Pb。重金属在水稻植株不同部位的积累分布是：根部＞根基茎＞主茎＞穗＞籽实＞叶部。水稻分蘖期重金属在根部、茎干部和叶片的积累量达到最大，随着时间的延长，在根部积累的重金属愈来愈少；在茎干部积累的重金属在拔节期降至最小，随后含量又稍微上升；叶片上的重金属含量在拔节期迅速下降，随后趋于稳定。     

多效唑对水生生物的急性毒性评价研究

本文以斜生栅藻、大型水蚤和草鱼为试验生物,研究植物生长调节剂多效唑对水生生物的急性毒性效应。多效唑对斜生栅藻EC_(50)-96h为20.62mg/l;对大型水蚤LC_(50)-48h为21.86mg/h;对草鱼苗静态生物检测结果为LC_(50)—120h 16.33mg/l,流水生物检测结果为LC_(50)-96h 14.36mg/l,LC_(50)-120h 9.13mg/l。经多效唑处理后,藻的细胞形态也发生明显改变。根据农药的实验室毒性评价划分标准,多效唑对三种生物的毒性均属低毒;田间安全性预评价的结果也表明其毒性为低毒,故认为多效唑是一种对水生生物危害较小的农药。但其慢性毒性及长期积累效应,尚有待进一步研究。     

多效唑在番茄和土壤中的残留与降解动态研究

研究了多效唑（paclobutrazol）在番茄（Lycopersicon eseulentum）和土壤中的残留分析方法及残留动态。建立番茄和土壤样品中多效唑残留的固相萃取-高效液相色谱（SPE-HPLC）检测方法,样品用乙腈提取,再用φ（甲醇-二氯甲烷）=5∶95混合溶剂经LC-NH2固相萃取柱净化,以φ（乙腈-水）=55∶45作流动相,Shiseido C18色谱柱（4.6 mm×250 mm,5μm）于222 nm波长检测,外标法定量。在0.1~5.0 mg·L-1范围内,多效唑峰面积与其质量浓度之间呈良好线性关系,相关系数为0.9995。采用田间试验方法,在番茄幼苗期施用不同多效唑质量分数50、100、200、600 mg·kg-1,研究在不同处理时间1、6 h,1、2、3、7、14、21、30、45、60 d,多效唑在番茄以及土壤中的残留动态变化。添加质量分数水平为0.05、0.1、0.5 mg·kg-1时,多效唑在果实、植株和土壤中的添加回收率分别为92.45%~103.70%、94.52%~98.85%和94.30%~102.10%,变异系数分别为3.69%~5.00%、1.58%~4.53%和1.28%~3.35%。结果表明：多效唑在番茄植株和土壤中的降解规律均符合一级动力学方程C=Coe-kt。当施用质量分数为600 mg·kg-1时,其在番茄植株中的残留半衰期为1.66 d,在土壤中的半衰期为2.78 d;在植株中的降解速率大于在土壤中的降解速率。按照推荐使用的施用浓度,采收时多效唑在番茄和土壤中无残留,证明推荐施用浓度是合理的。     

万家寨引黄工程水源地水质调查分析

利用气相色谱法分别在黄河沙汾河水库水中检出296和241个色谱峰；利用色质联用技术分别在黄河水和汾河水库水中检出74个和95个质谱峰，并定性56种和78种化合物。采用化学物质的潜在危害指数法，筛选出10种毒性较大的化合物，用气相以谱外标法给予了准确定量。结果表明，邻苯二甲酸酯类、苯系物和多环芳烃是黄河水和汾河水库水中主要的有机污染物，其浓度大小的排列顺序为：邻苯二甲酸酯类＞苯系物＞多环芳烃。     

多效唑对蔓性千斤拔种子产量和农艺性状影响

为明确多效唑对蔓性千斤拔种子产量和农艺性状的调节效应,对4种不同浓度多效唑处理(CK:喷清水、T_1:50 mg/L、T_2:100 mg/L、T_3:150 mg/L)的蔓性千斤拔种子产量构成因子、主要农艺性状及相关性进行了比较研究.结果表明,低浓度的多效唑对种子产量有显著的正效应,总体表现为T_1T_2CKT_3;不同浓度多效唑对主茎节数无显著影响,但对分枝数有明显促进作用;相关分析显示,株高、分枝数和结荚高度与单株种子产量均表现为显著或极显著正相关,其相关系数分别为0.619 3、0.613 0和0.804 1;通径分析表明,各农艺性状对单株种子产量直接作用大小表现为:分枝数结荚高度株高第一结荚节位主茎节数,其中分枝数和结荚高度均表现为正效应,对种子产量的贡献率分别为0.369 1和0.272 2.     

内蒙阿拉善地区植物与土壤元素背景值特征及其相互关系

内蒙阿拉善地区植物、土壤的元素背景特征及其相互关系的研究结果表明：５３种植物的９种元素（Ｚｎ、Ｃｕ、Ｎｉ、Ｐｂ、Ｃｄ、Ｃｏ、Ｃｒ、Ｖ、Ｍｎ）背景含量有很大差异．不同生活型植物背景值也各异，总的规律为：Ｍｎ＞Ｚｎ＞Ｖ＞Ｃｕ＞Ｎｉ＞Ｃｒ＞Ｐｂ＞Ｃｏ＞Ｃｄ；同种植物的元素含量在不同群落中有明显差别，但都在同一个数量级．土壤９种元素的背景含量均以Ｍｎ含量最高，其次为Ｚｎ和Ｖ，Ｃｄ的含量最低；不同上类各剖面各种元素的垂直分布规律为底层或表层的元素含量高于中间各层．土壤元素背景值都高于植物背景值，前者一般为后者的２～２０倍．植物对元素的吸收系数以Ｃｄ最大，Ｃｒ最小．土壤元素含量与有机质含量的相关性因土类不同而异：沙土的有机质含量最低，只有Ｚｎ含量与有机质相关性显著；而盐土的有机质含量最高，有Ｃｏ、Ｃｄ、Ｍｎ、Ｎｉ、Ｃｒ、Ｚｎ６种元素含量与之显著相关．     

多效唑在土壤中降解,吸附和淋溶作用

本文研究了植物生长调节剂多效唑（ＭＥＴ）在土壤中的环境引物，ＭＥＴ在土壤中降解较缓慢并随土壤环境条件而异，淹水厌氧条件比旱地好氧条件降解更缓慢，灭菌土壤中未见明显降解。微生物培养试验表明，ＭＥＴ对真菌有明显抑止作用，以ＭＥＴ为唯一营养源的培养基上能生长出几种放线菌。在三种供试土壤中，ＭＥＴ在高有机质含量的黑土中吸附常数远大于黄棕壤和潮土；ＭＥＴ的淋浴则在砂粒含量较高和有机质含量较低的潮土中最快，黑     

4种唑类杀菌剂对蛋白核小球藻的急性毒性及其致毒机理

唑类杀菌剂因其广谱性和稳定性会残留在水环境中,从而危害人类及其他生物的健康.目前对唑类杀菌剂的毒性研究大多集中在急性毒性,对其致毒机理知之甚少.本研究将三唑醇、三唑酮、克霉唑和氯咪巴唑4种常见的唑类杀菌剂作为目标污染物,以蛋白核小球藻作为指示生物,研究4种唑类杀菌剂暴露96 h后对蛋白核小球藻生长和生理变化的抑制作用.结果表明,4种目标污染物浓度越高对蛋白核小球藻的生长抑制程度越强,在50％效应下,96 h时毒性大小为:氯咪巴唑>克霉唑>三唑醇>三唑酮.其毒性机制可能与活性氧(ROS)的持续积累有关,随着污染物浓度升高,ROS含量不断增加,其中刺激作用最明显的是克霉唑,ROS的增加促进丙二醛(MDA)的大量产生,从而使绿藻产生氧化损伤,激发了不同水平的超氧化物歧化酶(SOD)和过氧化氢酶(CAT)的活性;同时,它们对叶绿素和蛋白质的合成也存在明显的抑制,破坏了绿藻的光合机制,最终造成藻细胞凋亡.研究结果为评估唑类杀菌剂对水生生物的毒性提供重要的理论支持.     

Negative health effects in rats fed on sardine fishes

An adequate human diet should satisfy the requirements for energy and nutritive components including essential polyunsaturated fatty acids, essential amino acids, mineral components, vitamins, and fat. The benefits of the fish consumption are, however, often counteracted by toxic metals such as lead present in fish meat. Adverse effects of toxic metals on the aquatic environment and human health have aroused increasing interest in recent years. The achievement of an appropriate balance between the risks and benefits associated with fish consumption has therefore become a key health issue in current research. Therefore, we studied health impacts associated with the consumption of sardine fish, one of the most commonly consumed fish species throughout the world. Hepatic damages associated with the consumption of white or red muscle of sardine fish were explored and evaluated using a rat model. Rats were fed for 60 days with white or red sardine meat. Findings revealed (1) an elevated level of uric acid in the blood, (2) an accumulation of lead in the liver, (3) an atrophy of the liver, (4) an increase in plasma aspartate aminotransferase and alanine aminotransferase activities, and (5) an oxidative stress in the liver, including increased levels of lipid peroxidation and enhanced activities of superoxide dismutase, catalase, and glutathione peroxidase. Several abnormalities were also observed in liver histology. The alterations observed in the animals can be attributed to both the accumulation of lead and the high levels of purine in the sardine meat. The findings show that special attention should be given to the health effects associated with high intakes of sardine meat, particularly dark-meat sardine.     

Quantitative alterations in the structure of the digestive cell of Littorina littorea on exposure to cadmium

The effects of sublethal concentrations of cadmium (Cd) on the morphology of the digestive gland of the periwinkle Littorina littorea have been investigated using a planimetric procedure. Five planimetric parameters were recorded (mean epithelial thickness: MET; mean diverticular radius: MDR; mean luminal radius: MLR; MLR/MET and MET/MDR) and tested by diverse statistical methods. The results indicate that MET is depressed after long exposures at high Cd concentrations whilst MLR increases. Variations in MDR have been attributed to different conditions in the tissues surrounding digestive tubules, and are not-significant in relation to the treatment. However, certain increases might be significant due to the presence of parasites or hemocyte proliferation. The ratios MLR/MET and MET/MDR are highly sensitive, and can be expressed as statistical functions of metal concentration and exposure time. Combination of these five planimetric parameters is reliably indicative of the structural changes occurring in the digestive gland of molluscs under conditions of environmental stress.     

珠江流域野生淡水鱼中有机紫外线吸收剂的组织分布、生长稀释和物种特异性生物蓄积

以华南珠江流域9种野生淡水鱼为材料,本文研究了12种有机紫外线吸收剂（UVA）的组织分布、个体体型依赖性和物种特异性生物蓄积。鱼组织样品中12种UVA的浓度为109～2320 ng/g脂质重量（lw）。在超过一半的鱼组织样本中检测到2-羟基-4-甲氧基二苯甲酮（BP-3）、八甲基丙烯（OCR）、UV531和5种苯并三唑类紫外线稳定剂（UVP、UV329、UV234、UV328和UV327）。UV531在野生淡水鱼体内具有明显的生物蓄积潜力,其生物蓄积因子（Log BAF）和生物沉积物蓄积因子（BSAF）分别为4.54±0.55和4.88±6.78。一般来说,肝脏（989±464 ng/g lw）的UVA含量最高,其次是腹部脂肪（599±318 ng/g lw）、膀胱（494±282 ng/g lw）、背肌（470±240 ng/g lw）和卵（442±238 ng/g lw）。淡水野生鱼体内UVA的生物积累表现出物种特异性和化合物依赖性。摄食杂食性鱼类的底栖食碎屑者含有明显较高的UVA浓度,表明摄食碎屑/沉积物是野生淡水鱼暴露于UVA的重要途径。UV531和BP-3表现出生长稀释的潜力。代谢可能在消除鱼组织中的UVA方面发挥重要作用,其中肝脏的代谢率最高。在珠江流域的淡水生态系统中,UVA没有显示出明显的营养级放大作用。有必要进行更多的研究来阐明UVA在生物体内的母体转移。     

纳米ZnO和纳米CuO在斑马鱼体内的富集与清除

为探讨工程纳米材料的生物毒性,采用半静态暴露方式(更换试液周期为1 d),在4 mg·L-1和10 mg·L-1浓度条件下,进行了斑马鱼(Danio rerio)对2种金属氧化物纳米材料——nano-Zn O和nano-Cu O的富集和清除实验。整个实验为期52 d,其中暴露阶段28 d,清除阶段24 d。通过测定不同时间节点纳米材料在鱼体内的浓度,研究了斑马鱼对nano-Zn O和nano-Cu O的富集与清除规律;并计算暴露阶段的最大富集系数(BAFmax)以及清除阶段的排出速率常数和总量清除率,比较分析了斑马鱼对这2种纳米材料的富集与清除能力。结果表明:在暴露阶段,nano-Zn O和nano-Cu O在斑马鱼体内的BAFmax分别为169.5和493.4(4 mg·L-1处理组)及168.4和298.6(10 mg·L-1处理组),二者在斑马鱼体内均不具有生物蓄积性;在清除阶段,nano-Cu O可以被斑马鱼有效地排出,其总量清除率(99.5%)和排出速率常数均高于nano-Zn O,而直到清除24 d时,斑马鱼对nano-Zn O的清除仍不完全(清除率91%)。本实验结果为金属氧化物纳米材料对水生生物的慢性毒理学研究提供了基础数据。     

Is frequent consumption of tuna fish safe? Evidence of liver damages in rats fed on red or white meat from tuna fish caught in the Gulf of Gab��s (Tunisian coast)

In recent years, a number of studies have clearly pointed out the nutritional benefits of fish consumption. However, some concerns about potential health risks derived from contaminants found in fish have also been raised. Therefore, balancing adequately the risks and benefits of fish consumption is currently a health key issue. As tuna fish represents a large part of the traditional food in some countries, the possible impact of tuna fish consumption on public health was investigated. Hepatic damages following consumption of tuna fish white (ordinary) or red (dark) muscle were evaluated in rat. Under our experimental conditions, feeding the animals for 60?days with white or, more markedly, red tuna meat resulted in 1) an elevated uric acid level in blood, 2) an accumulation of lead in liver, 3) an atrophy of liver, 4) an increase in plasma aspartate aminotransferase and alanine aminotransferase activities, and 5) an oxidative stress in liver including an increased level of lipids peroxidation and enhanced activities of superoxide dismutase, catalase and glutathione peroxidase. In addition, liver histology revealed several abnormalities. These alterations could be attributed to both lead accumulation and high purine levels in tuna meat. We conclude that attention should be paid to a possible health impact of frequent and important consumption of tuna fish meat, especially the dark one.     

Transfer pathways and accumulation of vanadium in the crab Carcinus maenas

The transfer pathways of vanadium in Carcinus meanas (L.) were investigated from February to April 1978 in order to determine the role of the food and environmental medium in the accumulation of this metal. The carbs, purchased from a fish market in Nice, France, in February 1978, were contaminated by food (the polychaete Nereis divesicolor), by environmental medium, and by food plus medium. In the early stages (15 d) of contamination, the accumulation of vanadium was greatest in crabs exposed to the contaminated medium. In later stages (30 d) crabs exposed to contaminated food plus medium exhibited the highest accumulation. Very little accumulation was observed in crabs contaminated by food alone.     

Elemental distribution in relation to skin necroses of marine flatfishes from the english channel

It has been suggested that industrial waste discharges are associated with the occurrence of fin damage and skin lesions. A mixed population of diseased and healthy blatfish consisting ofLimanda limanda, Pleuronectes platessa, Platichthys flesus andSolea solea were collected from an industrialised area (Calais, France) and were compared with diseased and healthyl. limanda caught in a non-industrialised area (Brixham, England). Analysis of skin samples from necrosed and healthy fish by X-ray microanalysis and atomic absorption spectroscopy has shown that no elemental accumulation occurs either in necrosed fish, or fish from an industrialised area. The fish from Calais were heavily infested with the ectoparasitic copepodLepeophtheirus pectoralis (O.F. Müller) and, although few were found on fish from Brixham, it is unlikely that this infestation was related to the discharge of industrial effluents.     

A model of mercury contamination in a woodland stream

A model for the accumulation of mercury in four compartments of woodland stream has been set up. The four components considered are sediments, detritus, invertebrates and fish. The model inputs are concentrations of dissolved monomethyl mercury and dissolved inorganic mercury (Hg²⁺) in the water. The model predicts that some reevaluation of current safe mercury concentrations in water may be needed in order to keep mercury concentrations in fish below current actions levels.     

Effect of selenium on mercury methylation in facultative lake sediments

The effect of selenium (Na₂SeO₃) on the methylation of mercury (HgCl₂) in facultative sediment was studied. The results showed that small amount of selenium (0.25 μg/g) added to the sediment could significantly reduce the net methylation rate of mercury. The more the selenium was added, the higher the inhibition effect was. These results made the addition of selenium to the aquatic systems more practical and safe as a way to alleviate mercury accumulation in fish. Additionally, higher temperature was favorable to the net methylation of mercury, and high concentration of methylmercury emerged earlier.