【作者】 马茹飞；

【导师】 黄长江；

【作者基本信息】 汕头大学 ， 环境科学， 2005， 硕士

【摘要】 壬基酚（Nonylphenol,NP）是一种非离子表面活性剂,广泛应用于造纸、纺织、橡胶塑料、洗衣粉和洗涤剂等中,与人们的日常生活关系十分密切。然而,壬基酚又是一种内分泌干扰物,会对机体产生负面影响。因此,正确了解壬基酚的负面生态效应对生态保护和维护人类自身的健康等均具有重要的现实意义。本研究以奥尼罗非鱼（OreochromisNiloticus×O.Aureus）为研究材料,进行NP的急性和慢性毒理试验,并对慢性试验中的NP组织残留量进行检测。 急性试验采用半静态方式进行,周期为96h,5个NP试验浓度分别为150.0、225.0、337.5、506.3、759.4 μg/L,同时设空白对照和乙醇溶剂对照。各试验浓度及对照组均设2个平行,每个平行的受试鱼苗为10尾。在试验结束后或每组最后3尾死亡后立即进行外周血和鳃、肾脏、脾、肝脏4种器官组织的采样,以进行微核率和核异常率的计数及组织病理学的检查。慢性试验也是采用半静态方式进行,周期为20 w,根据急性试验所得的半致死浓度设置的5个NP浓度分别为0.265、0.529、2.646、5.292、26.46μg/L,同时设空白对照和乙醇溶剂对照。各试验浓度及对照组均设3个平行,每个平行的受试鱼苗为20尾。于4、8、12、16和20w进行外周血和鳃、肾脏、脾、肝脏4种器官组织的取样,以进行外周血细胞微核率和核异常率的计数及组织病理学的检查。在第20w慢性试验结束后,从每组的三个平行中随机取出试验鱼共3尾,进行体内NP残留的测定。NP残留量检测过程中的全鱼组织中NP的分离、提取及NP检测的色谱条件均事先经过优化。 急性试验结果表明,不同壬基酚浓度下试验鱼的存活率表现出随着壬基酚浓度升高而显著降低的趋势。用寇氏法求得的NP对罗非鱼的24、48、72、96h的LC₅0分别为413.4、351.5、3l1.2、264.6μg/L,属于剧毒物质。试验鱼血红细胞核的异常形态有小核、核质缢裂、核质外凸、核质内凹和双核。试验鱼暴露于不同浓度的壬基酚下,其外周血红细胞的微核率和核异常率与对照组相比均有不同程度的增加。病理组织学检查结果表明其鳃、肾脏、脾、肝脏均发生不同程度的病理变化。鱼中毒后,鳃小片上皮细胞增生,填满鳃小片间的空隙,导致鳃小片发生融合,甚至数条鳃丝融合在一起。肾小球的毛细血管萎缩,部更多还原

【Abstract】 Nonylphenol (NP) is a nonionic surfactant, which is widely used in the industries of paper-making, rubber, plastics and cleanser, being intimate to our daily life. However, nonylphenol is a kind of endocrine disrupting chemicals, which can cause adverse effects to organisms. Therefore, understanding of its negative ecological effects has important realistic meanings to ecology protection and health maintenance of human beings. This study was designed to evaluate acute and chronic toxicities of NP to hybrid tilapia {Oreochromis Niloticus x O. Aureus) and determine NP accumulation in the fish tissues after chronic exposure.Acute test used semi-static method with an experimental period of 96 h. In the experiment, groups of 10 randomly selected fish were exposed to the different treatments including NP concentrations at 150.0, 225.0, 337.5, 506.3, and 759.4μg/L, and blank and ethanol controls. There were two parallels in each treatment. Immediately at the end of the experiment or immediately after death of the last three fish, three fish from each treatment were randomly collected for counting of micronucleus and abnormal nuclei, and evaluating of histological lesions. Chronic test also used semi-static method with an experimental period of 20 w. In chronic test, groups of 20 randomly selected fish were were exposed to the different treatments including NP concentrations at 0.265, 0.529, 2.646, 5.292, and 26.46μg/L determined by LC50 from acute test, and blank and ethanol controls. There were three parallels for each treatment. In 4w, 8w, 12w, 16w and 20w, three fish were randomly collected from each treatment for counting of micronucleus and abnormal nuclei, and evaluating of histological lesions. Also immediately after chronic test in 20 w, three fish from three parallels of each treatment were randomly collected for detecting of NP in the tissue. The extraction method of NP from fish tissues and chromatographic detection method of NP were all optimized before the formal detection of NP in the experimental fish.The results from the acute test showed that mortality of experimental fish increased with the increasing of NP concentrations. LC50 of experimental fish exposed for 24, 48, 72, and 96h, were 413.4, 351.5, 311.2 and 264.6μg/L, respectively. Therefore, NP is a virulent poison to the hybridtilapia. The kinds of abnormal nuclei in the blood cells of experimental fish included small nucleus, cleavage of nucleolus, concave nucleolus and double nuclei. Micronucleus and abnormal nuclei rates in the blood cells were significantly higher from the fish exposed to NP than those from the controls. Histological observation also showed that there were great pathological changes in the tissues of gill, kidney, spleen, and liver from the fish exposed to NP. By NP treatment, the tilapias showed a proliferation of epithelial cells in the gillbrachial leaflets, a connection of gillbrachial leaflets, or a connection of gill filaments. The kidney lesions included an atrophy of capillary blood vessels in glomerulus and hydropic degeneration with epithelial cells of renal tubules and haemorrhage in the tissue. In the spleen, amyloidosis and fibrosis degeneration and massive eosinophilic materials were observed. Liver lesions were characterized by hydropic and fatty degeneration, accompanied by haemorrhages in the central veins.The results from the chronic test showed that micronucleus and abnormal nuclei rates of blood red cells were also significantly higher from the fish treated by NP than those from the controls. Moreover, micronucleus rate significantly increased with extending of exposure time and increasing of NP concentration, indicating a significant time and dosage dependent. Although abnormal nuclei rate showed a significant time-effect, it did not increase but decrease in some cases with high NP concentration and long exposure time. In the chronic test, NP exposure also exhibited a great pathological damage to the gill, kidney, spleen and liver of tilapia. Compared to the results in acute test, however, lesion in chronic test was much slighter in the gill, but more serious observed in the kidney and spleen and liver, where massive necrotic areas were all found except for the symptoms observed in acute test.In 20 w of chronic test, NP was found in the fish tissues from every NP treatment with an average bio-concentration factor of 2961.6. This finding indicated that the hybrid tilapia could accumulate NP at a high rate. Moreover, a significant positive correlation was found between the NP concentration in the fish tissue and those in the experimental treatments. The concentrations of NP in the chronic test ranged from 0.265 |ig/L to 26.46 ug/L, equal to the NP concentrations in the natural rivers with intensive pollution. Because NP concentration as low as 0.265 ug/Lshowed genetic toxicology and pathological damage to tilapia in the present study, NP level in some intensive rivers would be enough to cause serious effects to their aquatic organisms. If the pollution transfer to human begins by food chain, it would be very harmful to human health.更多还原