三种剂型鱼藤酮对土鲮鱼和蚯蚓的毒性效应以及环境安全性评价

发布时间：2018-09-18 09:54

【摘要】：农药对非靶标生物的安全性大小是评价农药对生态环境影响的重要指标。不同剂型的农药在生物过程中可能存在差异,使之表现出不同的行为和环境毒力。本文选取了环境中土壤、水体、鱼、蚯蚓和浮萍等主要的影响因子,简要对乳油(EC)、微乳剂(ME)和悬浮剂(SC)等三种剂型鱼藤酮对土鲮鱼和蚯蚓的毒性差异以及在其各组织器官中的动态分布等进行了研究,同时探索了三种剂型(EC、ME和SC)鱼藤酮在其生物体内的富集行为,最后也对三种剂型鱼藤酮在浮萍、土壤、水体等环境载体中的富集行为做了研究。选用土鲮鱼和蚯蚓测定了三种剂型鱼藤酮对它的毒性。从毒性结果上来看,三种剂型间都显示出了一定的差异,鱼和蚯蚓的结果一致显示EC和ME表现出更高的毒性。三种剂型对鱼的LC_(50)均小于0.16 mg/L,但是对水中蚯蚓的LC_(50)却高达2.31~3.48mg/L,这说明鱼藤酮对不同生物种类毒性差异显著;比较三种剂型鱼藤酮对水中和土壤中蚯蚓的毒力可以看出,水环境中三种剂型鱼藤酮都表现出比在土壤中更高的毒杀活性,由此可以得知,环境的差异性也能显著影响鱼藤酮的效果。利用高效液相色谱分别检测了死亡过程和恢复过程中三种剂型鱼藤在鱼体内及在各组织器官中的含量变化。在0.05 mg/L的不同剂型鱼藤酮溶液处理后,24 h时,EC、ME和SC在全鱼中的富集量为0.78 mg/kg、0.49 mg/kg和0.32 mg/kg,EC在鱼体内的富集倍数高达15倍;鱼鳃、鱼鳞、肌肉、眼睛、头和中肠中三种剂型鱼藤酮的富集含量也做了检测,结果显示在各个组织当中EC的富集量都高于微ME和SC。从鱼藤酮在各个组织分布上来看,在肌肉组织储蓄鱼藤酮最多,三种剂型在肌肉中最高储蓄量达到2.66μg,三种剂型鱼藤酮在肌肉中的比例均超过70%。利用石蜡切片H.E.染色法观察了三种剂型处理后对鱼肌肉、眼睛、鳃和中肠道的影响,结果显示三种剂型都对各个组织器官产生损伤。另外,试验中发现,当将翻白的中毒鱼(还未死亡)立即放入大量清水中,随着时间的延长,鱼将慢慢恢复正常,利用这一特性,检测了0.1 mg/L三种剂型鱼藤酮处理后,在恢复过程中鱼藤酮在土鲮鱼各个组织器官中含量的变化。鱼的恢复过程主要在15 min之内完成,15 min后EC、ME和SC在鱼体内的恢复率分别为73.01%、88.95%和93.20%,各个检测组织器官中鱼藤酮的含量也快速下降。从水、土壤、浮萍以及鱼饲料等四种环境因子出发,探索了三种剂型在环境中的富集行为。结果显示,24 h内三种剂型在水、土壤、浮萍、鱼饲料中都产生不同程度的富集,EC的富集含量高于ME和SC。另外,三种剂型鱼藤酮在清水中的半衰期为23.70~25.32 h,但在放入浮萍和鱼的模拟生态环境中,三种剂型鱼藤酮的半衰期降到2.84~8.28 h,差异显著。结果说明:水生生物如鱼、蚯蚓等的存在能显著加快鱼藤酮的消解。利用蚯蚓探索了水、土壤两种环境下三种剂型的毒力差异,结果显示水中鱼藤酮的毒性远远高于土壤中,相同时间内,鱼藤酮在水中蚯蚓体内的富集量也远远高于土壤中的。另外,同时利用土壤法测试了蚯蚓对三种剂型鱼藤酮的降解能力差异,三种剂型在无蚯蚓土壤中的半衰期为1.85 d、2.79 d和2.01 d,在加入蚯蚓的土壤中半衰期分别为0.81 d、1.10 d及1.29 d。光学显微镜下观察并比较了不同剂型鱼藤酮处理后蚯蚓表皮组织的形态变化,结果显示三种剂型鱼藤酮都会对蚯蚓外表皮造成伤害,ME和EC损伤更严重。本文的研究结果证明不同剂型鱼藤酮对蚯蚓和土鲮鱼的毒性有差异,鱼藤酮对鱼高毒的原因之一推测是鱼藤酮可以通过鳃大量进入体内并且鱼藤酮可以穿透鱼的肌肉组织,最后在鱼体内产生富集,同时,将中毒鱼放入大量清水中,鱼也可以通过鳃呼吸等将鱼藤酮排入外部环境中以此完成对体内鱼藤酮的消除作用;另外一方面,不同剂型会影响鱼藤酮在土壤中的降解,蚯蚓的存在可显著加快鱼藤酮的降解,但是鱼藤酮也可以对蚯蚓产生危害,鱼藤酮在水环境中对蚯蚓的危害高于土壤中。本试验为鱼藤酮EC、ME和SC三种剂型的合理使用提供了理论指导和科学建议。
[Abstract]:The safety of pesticides to non-target organisms is an important index to evaluate the impact of pesticides on the ecological environment. Different formulations of pesticides may show different behaviors and environmental toxicity in the biological process. The toxicity difference and dynamic distribution of rotenone in different tissues and organs were studied. The enrichment behavior of rotenone in organisms of three dosage forms (EC, ME and SC) was also explored. Finally, rotenone in duckweed, soil and water was also studied. The enrichment behavior in environmental carriers was studied. The toxicity of rotenone was determined by using mud carp and earthworm. The toxicity results showed that there were some differences among the three dosage forms. The results of fish and earthworm showed that EC and ME showed higher toxicity. The LC_ (50) of the three dosage forms to fish was less than 0.16 mg/L, but the toxicity of rotenone to fish was lower than 0.16 mg/L. The L C_ (50) of earthworms in water was as high as 2.31-3.48 mg/L, which indicated that rotenone had significant toxicity to different organisms. Comparing the toxicity of rotenone to earthworms in water and soil, we can see that rotenone in water environment showed higher toxicity than rotenone in soil, so we can know the environmental difference. The contents of three dosage forms of rotenone in the body and in the tissues and organs of the fish during the process of death and recovery were determined by high performance liquid chromatography. And 0.32 mg/kg, EC in fish body enrichment multiple as high as 15 times; gill, fish scales, muscle, eyes, head and midgut in three dosage forms of rotenone enrichment content were also detected, the results showed that in each tissue of the EC enrichment was higher than micro-ME and SC. The highest savings of the three dosage forms were 2.66 UG and rotenone was more than 70% in the muscle. The effects of the three dosage forms on the muscle, eyes, gills and midgut of fish were observed by H.E. staining with paraffin section. The results showed that all the three dosage forms were harmful to the tissues and organs. When the poisoned fish (not yet dead) was put into a large amount of water immediately, the fish would gradually return to normal with the extension of time. Using this characteristic, the changes of rotenone content in tissues and organs of mud carp during the recovery process after treatment with rotenone of 0.1 mg/L were detected. The recovery rates of EC, ME and SC in fish were 73.01%, 88.95% and 93.20% respectively after 15 minutes, and the contents of rotenone in tissues and organs were also rapidly decreased. The concentration of EC in duckweed and fish feed was higher than that in ME and SC. In addition, the half-lives of rotenone in clear water were 23.70-25.32 h, but in the simulated ecological environment of duckweed and fish, the half-lives of rotenone in three dosages decreased to 2.84-8.28 h, the difference was significant. The toxicity of rotenone in water and soil was studied. The results showed that rotenone toxicity in water was much higher than that in soil. At the same time, rotenone concentration in water was much higher than that in soil. The half-lives of rotenone in earthworm-free soil were 1.85 d, 2.79 D and 2.01 D. The half-lives of rotenone in earthworm-free soil were 0.81 d, 1.10 D and 1.29 d, respectively. The morphological changes of earthworm epidermis were observed and compared under optical microscope. The results showed that rotenone of three dosage forms could damage the outer epidermis of earthworms, ME and EC were more serious. The results of this study showed that rotenone of different dosage forms had different toxicity to earthworms and mud carp. One of the reasons for rotenone's high toxicity to fish was that rotenone could enter the body in large quantities through gill and rotenone could penetrate fish. At the same time, when poisoned fish are put into a large amount of clean water, fish can also discharge rotenone into the external environment through gill respiration to eliminate rotenone in vivo; on the other hand, different dosage forms will affect rotenone degradation in the soil, the presence of earthworms can significantly accelerate the fish. Degradation of rotenone, but rotenone can also cause harm to earthworms. Rotenone is more harmful to earthworms in aquatic environment than in soil. This experiment provides theoretical guidance and scientific suggestions for rational use of rotenone EC, ME and SC.
【学位授予单位】：华南农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X171.5;X592

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