Study On The Toxicity Of Phthalates To Mytilus Coruscus In Marine Environment

Phthalic Acid Esters(PAEs)are widely used in the fields of packaging and building materials.As a kind of environmental hormone organic compounds,PAEs are easy to migrate into water bodies,sediments and marine organisms,but they are not easy to degrade.They can be enriched in organisms through ingestion,inhalation,skin contact,etc.,and interfere with the endocrine system and affect tissue development and immune response,causing oxidative damage.Long-term human exposure can cause adverse effects such as deformities,mutations,and cancer.In recent years,with the increase of terrestrial pollution and the use of plastic,the content of PAEs in the marine environment has increased sharply.It has been detected in most environmental samples in China and even in the global oceans,and has become a widespread pollutant in the world.It is necessary to deeply explore its toxic effects on marine organisms and their toxic mechanisms to provide technical support for related toxicological and ecological impact studies.Dibutyl Phthalate(DBP),as a relatively large amount of phthalate plasticizer,has attracted widespread attention due to its impact on marine organisms.China has listed it as one of the priority controlled pollutants.In order to study the impact of PAEs on the anti-oxidant and epidemic prevention system of marine shellfish,this study took DBP,which is currently used in large quantities and is on the black list of pollutants,as the research object,and Mytilus coruscus as the test organism.The stress of different concentrations of DBP(0,100 mg/L,200 mg/L,280 mg/L,360 mg/L)on the 3rd,7th,11 d,15d,and the release of clear water on its gills,visceral mass,mantle and gonads were studied on the 3d(S3),7d(S7),and 15d(S15).Changes in the antioxidant system-related indicators of membranes and gonads including superoxide dismutase(SOD),catalase(CAT)activity,and malondialdehyde(MDA)content.It is hoped to provide certain data support for the toxic mechanism of shellfish by DBP.The specific research results are as follows:(1)During DBP stress,SOD,CAT activity,and MDA content of the mantle,gills,gonads,and visceral mass of Mytilus coruscus showed different changes,but the overall concentration-time effect was more obvious.The regularity is similar.(2)When different DBP concentrations were applied for the same period of time,SOD activity changes in the four tissues of Mytilus coruscus basically showed the state of being induced first,but due to the different physiological functions of different tissues,their performances were different.The longer the stress time,the SOD activity of gonads,gills,visceral masses and other tissues will also appear to be inhibited.The CAT activity of different tissues initially differed greatly.The mantle and gonads were mainly induced on the third day of DBP stress.The gills and visceral masses behaved in the opposite way,and were in a state of inhibition,but the overall performance of the four tissues was still mainly induced;While the MDA content also had a similar law,mainly elevated;The same DBP concentration,different stress time,the law was similar to the above,with obvious concentration-time effect.(3)When Mytilus coruscus stressed by different DBP concentrations were transferred to clear water for the same time,the SOD activity,CAT activity,and MDA content in the anti-oxidation and epidemic prevention systems of the four tissues of Mytilus coruscus showed similar results.Among them,SOD activity in gills,gonads,and visceral masses showed a tendency of first inhibition and then induction,while SOD activity in the outer membrane showed the opposite trend;CAT activity in four tissues of Mytilus coruscus was basically induced,and only the visceral mass showed a trend of inhibition;The MDA content appears to increase during the initial release,but at high concentrations,the gonads and visceral masses showed a certain downward trend;The DBP concentration was the same,the stress time was different,the law was similar to the above,and it had obvious concentration-time effect.(4)Based on the analysis of SOD activity,CAT activity,and MDA content,the effect of DBP on the antioxidative and epidemic prevention of Mytilus coruscus was found,and it was found that the changes of the three substances in the mantle,gills,gonads,and visceral mass would change with DBP concentration and time change.The mantle was the tissue that the Mytilus coruscus first contact,and the degree of induction or inhibition was relatively obvious in the early stage of stress.Compared with the other three tissues,the gills are the filter food tissues,and the influence was second.Mantle,while the effect of DBP on gonads and visceral masses is relatively slow,and the degree of influence was again the gonads and finally the visceral masses.In short,under the action of different concentrations of DBP,with time,SOD,CAT activity,and MDA content in the four tissues of Mytilus coruscus(mantle,gills,gonads,and visceral masses)showed inconsistent changes.But basically all changes had a certain concentration-time effect.Studies had shown that under DBP stress,the tissue of Mytilus coruscus had oxidative damage,which can induce the body to produce lipid peroxidation,and 15 days of water release was not enough to fully restore it to normal levels.The results of this experiment were from the perspective of oxidative damage.The impact of DBP on mussels with Mytilus coruscus was evaluated,which can provide data and theoretical support for the impact of PAEs on marine shellfish.However,the change of antioxidant enzyme activity in marine organisms may be affected by various factors such as concentration,individual organisms,and the environment.Therefore,its response mechanism needs to be considered comprehensively,and its mechanism needs further study.