Preliminary Study On Toxicological Effects Of Water-Borne DAMS And TPP Under Single And Combined Exposure On Cyprinus Carpio

In natural environment,there are many kinds of pollutants,which usually have combined toxicological effects on the organism.As a new type of anionic surfactant,dodecylbenzenesulfonic acid monoisopropylamine salt?DAMS?is gradually used in industrial production,daily life and other areas due to its good detergency and emulsification.It is easy to interact with other pollutants after entering the environment,thus affecting its behavior in the environment.Triphenyl phosphate?TPP?is a kind of organophosphate flame retardant,which is widely used in industry,construction,textile industry and other fields.Because of the increasing needs and production of DAMS and TPP,they widely exist in air,land and water environment.Therefore,it is necessary to study the toxicological effects of DAMS and TPP to provide scientific evidence for ecological environment risk assessment.In this paper,Cyprinus carpio was chosen as the study object.DAMS and TPP were used as the experimental poisons.Under the condition of water temperature?25±1??,acute exposure and subacute exposure were carried out respectively.Experiment 1:Cyprinus carpio was exposed to17.00,19.00,21.00,23.00,25.00 mg/L DAMS and blank control group respectively;with dimethyl sulfoxide?DMSO?was used as a solution,Cyprinus carpio was exposed to 0.5,1,2,4,6 mg/L,blank control group and solvent control group respectively?volume ratio:0.05%?DMSO);The 96h half-lethal concentrations?96 h LC50?of DAMS and TPP were respectively determined in water-bone.Experiment 2:firstly,according to 96 h LC50of DAMS and TPP,single exposure experiment was carried out on Cyprinus carpio,and DAMS water-bone exposure concentration was set as 0.5,1,2,4,8 mg/L and blank control group according to equal proportion method;TPP water exposure concentration was set as 0.05,0.1,0.2,0.4 mg/L,blank control group and solvent control group?volume ratio:0.05%DMSO?.Secondly,according to the factorial design method,the lowest and highest concentrations of single exposure group of DAMS and TPP were selected for combined exposure experiment;there were four combined exposure groups,blank control group and solvent control group?volume ratio:0.05%DMSO?.After 28 days of single or combined exposure to two poisons of different concentrations,the effects of DAMS and TPP on oxidation and antioxidant system,brain cholinesterase?AChE?activity,serum sex hormone level and organ histology structure of Cyprinus carpio were studied.The overall experiment results of this study are as follows:Experiment one:with the increase of DAMS and TPP concentration in water-bone,the mortality of Cyprinus carpio increased gradually,and there was a significant linear positive correlation between mortality and water toxicant concentration.By using linear interpolation method,the 96 h LC50of single exposure to DAMS and TPP of Cyprinus carpio was 20.5 mg/L and 2.54 mg/L respectively.Experiment two:1.Effects of single and combined exposure of DAMS and TPP on liver oxidation and antioxidant system of Cyprinus carpioAfter 28 days of water-bone exposure with different concentrations of DAMS,except 0.5mg/L group,other concentration groups the activity of SOD was significantly lower than that in the blank control group?p<0.05?.After 28 days of TPP exposure,except 0.2 mg/L group,other concentration groups the activity of SOD in the liver were significantly different from that of the blank control group and the solvent control group.After 28 days of combined poisons exposure,SOD activity in the liver of each combined exposure group was significantly different from that of the blank control group and the solvent control group.After 28 days of DAMS exposure,MDA content in the Cyprinus carpio liver of the 4 mg/L and 8 mg/L groups increased sharply,significantly higher than that of the blank control group?p<0.05?.After 28 days of TPP exposure,MDA content in the liver of each concentration group was significantly higher than that of the blank control group and solvent control group?p<0.05?.The liver MDA content of the combination of?0.05 mg/L TPP+8 mg/L DAMS?and the combination of?0.4 mg/L TPP+8 mg/L DAMS?in the combined exposure group was significantly higher than that of the blank control group and the solvent control group?p<0.05?.The liver MDA content of the combination of?0.05 mg/L TPP+0.5 mg/L DAMS?and the combination of?0.4mg/L TPP+0.5 mg/L DAMS?were not significantly different from that of the blank control group and the solvent control group.After 28 days of exposure to DAMS,the T-AOC of the liver of Cyprinus carpio was significantly different from that in the blank control group?p<0.05?.After 28 days of TPP exposure,the level of T-AOC in the liver of each concentration group was significantly lower than blank control group and solvent control group.After 28 days of four combined way exposure to DAMS and TPP of Cyprinus carpio,the level of T-AOC in liver was significantly different from that in blank control group and solvent control group?p<0.05?2.The effects of single and combined exposure to DAMS and TPP on the oxidation and antioxidant system of gill tissue of Cyprinus carpioAfter 28 days of exposure to DAMS,except 0.5 mg/L group,the other concentrations were significantly lower than blank control group?p<0.05?.After 28 days of TPP exposure,SOD activity in gill tissue of Cyprinus carpio increased and then decreased with the increase of exposure concentration,which was significantly higher in each exposure group than in the blank control group and solvent control group?p<0.05?.After 28 days of combined toxic exposure,there was a significant difference in SOD activity between the four combined exposure concentration groups and the solvent control group?p<0.05?.After 28 days of DAMS exposure,there was a significant difference in MDA content in gill tissue between the exposed groups and blank control group?p<0.05?,and there was no significant difference in MDA content in gill tissue between the 4 and 8 mg/Lgroups.After 28 days of TPP exposure,MDA content in gill tissue of Cyprinus carpio in each concentration group was significantly higher than that in the blank control group and solvent control group?p<0.05?.The MDA content of gill tissue in the combined exposure group?0.05 mg/L TPP+0.5 mg/L DAMS?was significantly higher than that in the blank control group and solvent group,?0.4 mg/L TPP+0.5 mg/L DAMS?and?0.4 mg/L TPP+8 mg/L DAMS?the combined exposure group was significantly lower than that 8 mg/L DAMS?0.05mg/L TPP?0.4mg/L TPP in the single concentration group?p<0.05?.After 28 days of exposure DAMS,except 0.5 mg/L group,other concentration groups was significantly lower than that in the blank control group?p<0.05?.After exposed to TPP of 0.05,0.1,0.2 and 0.4 mg/L for 28 days,the T-AOC level of gill tissue was significantly lower than that of the blank control group and solvent control group.The level of T-AOC in gill tissue of the four combined exposure groups was significantly lower than that of the blank control group and solvent control group?p<0.05?.3.The effect of single and combined exposure of DAMS and TPP on the histology of Cyprinus carpioAfter 28 days of single exposure to DAMS and TPP,with the increase of toxic exposure concentration,the damage of Cyprinus carpio hepatocytes gradually aggravated,and there were cavitation of hepatocytes,nuclear migration,nuclear dissolution,expansion and congestion of hepatic blood sinuses and other phenomena.Liver and gill tissue in the four combined exposure groups indicated different situations of damage,less serious than those in the single exposure group of DAMS and TPP.4.The effect of single and combined exposure of DAMS and TPP on AChE activity in brain tissue of Cyprinus carpioand and serum sex hormone content of male Cyprinus carpioAfter 28 days of single and combined exposure of DAMS and TPP,the ACh E activity of Cyprinus carpio brain in each concentration group was significantly lower than that in the blank control group?p<0.05?.After 28 days of single exposure to DAMS,the serum estradiol?E₂?and testosterone?T?of male Cyprinus carpio were not significantly affected.There was no significant difference in the serum E₂ and T between the groups.After 28 days of TPP single exposure,except 0.05 mg/L group,the other concentration groups were significantly lower than the blank control group.There were significant differences in E₂ and T content between the combined exposure group and the single exposure group?p<0.05?.The main conclusions of this paper are as follows:1.DAMS and TPP is highly toxic to Cyprinus carpio,and the toxicity of TPP was higher than that of DAMS.With the equal toxic exposure method,DAMS and TPP were used to evaluate different toxic effects.The experiment results indicated various types of effects,that is,the marking additive index method indicated synergistic effect,and the toxic unit method indicated antagonistic effect.2.Both DAMS and TPP could increase the level of ROS in the liver and gill of Cyprinus carpio and inhibit the activity of SOD.In the condition of combined exposure,they could result in the oxidative stress injury of Cyprinus carpio,while indicating antagonistic effect.3.DAMS and TPP lead to tissue damage of Cyprinus carpio liver and gill.With the increase of exposure concentration,the damage is more serious.Compared with the condition of TPP exposure,there was no obvious difference in the damage when the carp is in the combined exposure condition.,but the damage to the liver and gill tissue was less severe than the DAMS'single exposure.4.The brain AChE activity decreased with the increase of the exposure concentration of DAMS and TPP.The results of factorial design indicated that the brain ACh E activity of the combined exposure group was significantly lower than that of the blank control group and solvent control group,and the two groups were mainly cooperative.5.TPP exposure affected the content of E2 and T in the blood of carp,while DAMS exposure had no significant effect.The results of factorial design indicated that there was a synergistic or independent effect on the changes of serum sex hormones.To sum up,this paper takes Cyprinus carpio as the test organism,with the relevant experimental methods and variety of biomarkers,to explore the oxidative stress injury of liver and gill,the toxic effect of nervous and sex hormone of single and combined pollution of DAMS and TPP on Cyprinus carpio,to detect and evaluate the risk of long-term combined exposure of DAMS and TPP on aquatic organism and water environment,thus to provide scientific basis for the prevention and control of environmental pollution and ecological security.