Toxicity Of Tris (2-chloropropyl) Phosphate And Cadmium On Earthworms

Tris(2-chloroisopropyl)phosphate(TCPP)is a kind of organophosphorus flame retardants(OPFRs),which has the advantages of low price and good fire retardant effects.As an emerging flame retardant,its market potential is huge,and its production and consumption are increasing year by year,but it is difficult to degrade in the environment.At present,it has been detected in all kinds of environmental media,and also in living organisms including human body,indicating that it can be enriched through the food chain and harm human life and health.Cadmium(Cd)is the heavy metal with the highest rate of over-standard currently,which has the characteristics of high toxicity and strong mobility.Cd is one of the most polluted heavy metals,TCPP is one of the organophosphorus flame retardants with the highest detection rate,both of which are abundant in the environment.Therefore,it is important to study the combination of the two representative pollutants.In this paper,Eisenia fetida was used as the test organism.The experiment was carried out in artificial soil.The TCPP single test set concentration was 0,5,10,20,40 mg/kg,choose 5mg/kg respectively with the Cd concentration TCPP composite experiment,infected after respectively at 7,14,21,28 days sampling determination of relevant indicators,measurement indicators include: Reactive oxygen species(ROS)content,superoxide dismutase(SOD)activity,activity of peroxidase(POD)and catalase(CAT)activity and glutathione s transferase(GST)activity and malondialdehyde(MDA)content and earthworm body cavity cell DNA damage,the TCPP single and TCPP with Cd to evaluate the toxicity of compound pollution,for TCPP single and-organic compound pollution of heavy metals in soil provide theoretical basis for the ecological risk assessment.The main conclusions of this research are as follows:(1)The effects of TCPP on the enzyme activities in earthworms in single exposure: the antioxidant enzymes(SOD,CAT,POD)and GST activities showed a trend of first promotion and then inhibition.The ROS content of the experimental group was always higher than that of the blank group,MDA content increased at the later stage.It indicates that under TCPP stress,the ROS content increases,and the antioxidant enzymes and GST are stimulated and activated to clear excess ROS,but long-term exposure will damage the antioxidant enzymes and GST production system and reduce their activity,Lipid peroxidation occurred in the earthworm body.(2)DNA damage of earthworm under single TCPP exposure: TCPP treatment groups of all concentration series can cause different degrees of damage to earthworm cell DNA,and the degree of DNA damage increased with the increase of exposure concentration and time.(3)The effects of TCPP and Cd compounds on the enzyme activity in earthworms: The activity change trend of the antioxidant enzymes(SOD,CAT,POD)is similar to that of the single poison,but the CAT activity recovers to the control group in the later stage.At the same level,GST activity was inhibited from the second week.In the late stage of exposure,the increase in both ROS and MDA compared with the blank control group was higher than the sum of the increase in the single treatment group.On the whole,the combined performance of the two A certain degree of synergy.(4)DNA damage of earthworm under complex of TCPP and Cd compounds exposure:The changes of DNA damage in earthworms is similar to that of single infection,and the damage is always significantly higher than that of the single treatment group.TCPP and Cd show a certain degree synergy.