Study On Ecotoxicological Effects Of Perfluorooctane Sulphonate On Erathworm(Eisenia Foetida) And Enchytraeid(Fridericia Bulbosa) In Soil

Perfluorooctane sulfonates (PFOS) is hydrophobic and oleophobic, and widely used in the aera of textile, leather, pesticides, paint and other industries. As a new kind of persistent organic pollutants (POPs), PFOS is biodegradable as well as bioaccumulation characteristics caused by pollution has gradually become a global environmental problem. Recently, the ecological toxicity studies at home and abroad for PFOS were focused in the water environment, but not in the soil environment.In this study Eisenia foetida and Fridericia bulbosa were uesed as experimental animals, and the artificial soil test was uesed to study the acute toxic effects of PFOS to Eisenia foetida and Fridericia bulbosa. According to acute toxicological test result, an sdditional test with lower concentration is tried out to study the effects of PFOS on the vermis body catalase(CAT), superoxide dismutase(SOD),glutathione peroxidase(GSH-PX) activity of three antioxidant enzymes and cytochrome P450(CYP450) content and lysosomal membrane damage of Eisenia foetida and Fridericia bulbosa. The results are showed as follow:1. The acute toxicity of PFOS to Eisenia foetida and Fridericia bulbosa was studied by the method of artificial soil test. The results showed:when the test organisms was Eisenia foetida,the7d-LC50and14d-LC50were962.35mg/kg and856.82mg/kg respectively, the toxicity of PFOS to Eisenia foetida was the medium level; when the test organisms was Fridericia bulbosa,the7d-LC50and14d-LC50were109.28mg/kg and95.25mg/kg respectively, its14-LC50is lower compared with the result of Eisenia foetida. The toxicities of PFOS to Eisenia foetida and Fridericia bulbosa have accumulation characteristics, the mortalities of Eisenia foetida and Fridericia bulbosa were gradually increased with the increasing of exposure time and concentration of PFOS, the LC50was reduced with the extension of PFOS exposure time.2. Enzymatic activities are regarded as fast and prognostic indices of individual reaction to the environmental stress and should allow prediction of the consequences of pollution at population and ecosystem levels. From the organizational level, use the artificial soil method to investigate whether their CAT,SOD, GSH-PX and CYP450were influenced by PFOS at different concentrations and exposure times. The results showed that:The pollution of PFOS can cause Eisenia foetida related indicators of antioxidant enzymes in the body system disorder appears the effects of oxidative stress increase while its detoxifying enzymes in the body. Each treatment group and the control group of enzymes of PFOS response, but the response to varying degrees of CYP450content was significantly higher in response to the most sensitive; SOD insensitive; the sensitivities of four enzymes were CYP450> CAT> GSH-P X＞SOD. The initial low concentrations of PFOS significantly increased the activities of CAT and CYP450; the results were indicated that CYP450or CYP450and other3kinds of antioxidant enzymes can be used as an important indecatoer to characterize the PFOS exposure.The toxicities of PFOS to antioxidant enzymes and cytochrome P450in Fridericia bulbosa was different; and in each treatment groups, the tendency of individual enzyme was also different; the activity of GSH-PX was more sensitivity than CAT, SOD, GYP450. Throughout the whole experiment, the activity of GSH-PX gradually reduced and trended to smooth change, SOD activity and CYP450content decreased in the early stage, later gradually increased. CAT activity is constantly changing, the sensitivities of four enzymes were GSH-PX＞CYP450＞SOD＞CAT.3. According to acute toxicological test result, the toxicity at the subcellular level caused by PFOS was investigated, the results as follows:The Eisenia foetida coelomocytes NRRT decreased with the increase in the concentration of PFOS exposure concentration and exposure time, the membrane stability was damaged by a certain toxicity of PFOS. There was a certain dose-effect relationship between NRRT and the exposure concentration or the exposure time of PFOS. Therefore, NRRT can be used a biomarker to influence the PFOS contamination.4. Fridericia bulbosa and Eisenia foetida were compered in the individual characteristics, the rearing environment, the produces of method and the test organisms. The results idicated that the mortality can be quantitative characterization of PFOS pollution, the acute toxicity of Fridericia bulbosa was more sensitive, can be used prior as a biomakerto influence the PFOS contamination, and Eisenia foetida is more suitable for the solution of stability of enzyme.